195
10766
Effect of Addition of Separan at Different Concentrations as a Flocculants on Quality of Sugar Cane Juice
Abstract: The study was designed to evaluate the use of low
concentrations of separan flocculent (Less than 3 ppm) on
physicochemical properties of sugar cane juice. Colour, pH, purity,
turbidity, pol, brix, reducing sugars tannins and polyphenols of
crushed cane (green and burned) juice, mixed juice and clarified
juice were studied. The results showed that pol, brix, reducing sugar
and turbidity are higher in crushed cane juice. Clarified burned juice
had low turbidity, reducing sugars, pol and brix but had significantly
lower pH, purity and colour when compared to crushed juice.
Polyphenols of the crushed juice (1.19%) decreased significantly in
the clarified juice to 0.006%. Addition of separan at a concentration
of 0.015 ppm reduced significantly colour, polyphenols and tannins
and reducing sugar compared to the control.
Digital Article Identifier (DOI):
194
1012
Aqueous Extract of Flacourtia indica Prevents Carbon Tetrachloride Induced Hepatotoxicity in Rat
Abstract: Carbon tetrachloride (CCl4) is a well-known
hepatotoxin and exposure to this chemical is known to induce
oxidative stress and causes liver injury by the formation of free
radicals. Flacourtia indica commonly known as 'Baichi' has been
reported as an effective remedy for the treatment of a variety of
diseases. The objective of this study was to investigate the
hepatoprotective activity of aqueous extract of leaves of Flacourtia
indica against CCl4 induced hepatotoxicity. Animals were pretreated
with the aqueous extract of Flacourtia indica (250 & 500 mg/kg
body weight) for one week and then challenged with CCl4 (1.5 ml/kg
bw) in olive oil (1:1, v/v) on 7th day. Serum marker enzymes (ALP,
AST, ALT, Total Protein & Total Bilirubin) and TBARS level
(Marker for oxidative stress) were estimated in all the study groups.
Alteration in the levels of biochemical markers of hepatic damage
like AST, ALT, ALP, Total Protein, Total Bilirubin and lipid
peroxides (TBARS) were tested in both CCl4 treated and extract
treated groups. CCl4 has enhanced the AST, ALT, ALP and the
Lipid peroxides (TBARS) in liver. Treatment of aqueous extract of
Flacourtia indica leaves (250 & 500 mg/kg) exhibited a significant
protective effect by altering the serum levels of AST, ALT, ALP,
Total Protein, Total Bilirubin and liver TBARS. These biochemical
observations were supported by histopathological study of liver
sections. From this preliminary study it has been concluded that the
aqueous extract of the leaves of Flacourtia indica protects liver
against oxidative damages and could be used as an effective protector
against CCl4 induced hepatic damage. Our findings suggested that
Flacourtia indica possessed good hepatoprotective activity
Digital Article Identifier (DOI):
193
1637
In Vitro Antibacterial and Antifungal Effects of a 30 kDa D-Galactoside-Specific Lectin from the Demosponge, Halichondria okadai
Abstract: The present study has been taken to explore the
screening of in vitro antimicrobial activities of D-galactose-binding
sponge lectin (HOL-30). HOL-30 was purified from the marine
demosponge Halichondria okadai by affinity chromatography. The
molecular mass of the lectin was determined to be 30 kDa with a
single polypeptide by SDS-PAGE under non-reducing and reducing
conditions. HOL-30 agglutinated trypsinized and glutaraldehydefixed
rabbit and human erythrocytes with preference for type O
erythrocytes. The lectin was subjected to evaluation for inhibition of
microbial growth by the disc diffusion method against eleven human
pathogenic gram-positive and gram-negative bacteria. The lectin
exhibited strong antibacterial activity against gram-positive bacteria,
such as Bacillus megaterium and Bacillus subtilis. However, it did
not affect against gram-negative bacteria such as Salmonella typhi
and Escherichia coli. The largest zone of inhibition was recorded of
Bacillus megaterium (12 in diameter) and Bacillus subtilis (10 mm in
diameter) at a concentration of the lectin (250 μg/disc). On the other
hand, the antifungal activity of the lectin was investigated against six
phytopathogenic fungi based on food poisoning technique. The lectin
has shown maximum inhibition (22.83%) of mycelial growth of
Botrydiplodia theobromae at a concentration of 100 μg/mL media.
These findings indicate that the lectin may be of importance to
clinical microbiology and have therapeutic applications.
Digital Article Identifier (DOI):
192
11992
Statistical Optimization of Enzymatic Hydrolysis of Potato (Solanum tuberosum) Starch by Immobilized α-amylase
Abstract: Enzymatic hydrolysis of starch from natural sources
finds potential application in commercial production of alcoholic
beverage and bioethanol. In this study the effect of starch
concentration, temperature, time and enzyme concentration were
studied and optimized for hydrolysis of Potato starch powder (of
mesh 80/120) into glucose syrup by immobilized (using Sodium
arginate) α-amylase using central composite design. The
experimental result on enzymatic hydrolysis of Potato starch was
subjected to multiple linear regression analysis using MINITAB 14
software. Positive linear effect of starch concentration, enzyme
concentration and time was observed on hydrolysis of Potato starch
by α-amylase. The statistical significance of the model was validated
by F-test for analysis of variance (p ≤ 0.01). The optimum value of
starch concentration, enzyme concentration, temperature, time and
were found to be 6% (w/v), 2% (w/v), 40°C and 80min respectively.
The maximum glucose yield at optimum condition was 2.34 mg/mL.
Digital Article Identifier (DOI):
191
325
Study on the Derivatization Process Using N-O-bis-(trimethylsilyl)-trifluoroacetamide, N-(tert-butyldimethylsilyl)-N-methyltrifluoroace tamide, Trimethylsilydiazomethane for the Determination of Fecal Sterols by Gas Chromatography-Mass Spectrometry
Abstract: Fecal sterol has been proposed as a chemical indicator
of human fecal pollution even when fecal coliform populations have
diminished due to water chlorination or toxic effects of industrial
effluents. This paper describes an improved derivatization procedure
for simultaneous determination of four fecal sterols including
coprostanol, epicholestanol, cholesterol and cholestanol using gas
chromatography-mass spectrometry (GC-MS), via optimization study
on silylation procedures using N-O-bis
(trimethylsilyl)-trifluoroacetamide (BSTFA), and
N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide
(MTBSTFA), which lead to the formation of trimethylsilyl (TMS) and
tert-butyldimethylsilyl (TBS) derivatives, respectively. Two
derivatization processes of injection-port derivatization and water bath
derivatization (60 oC, 1h) were inspected and compared. Furthermore,
the methylation procedure at 25 oC for 2h with
trimethylsilydiazomethane (TMSD) for fecal sterols analysis was also
studied. It was found that most of TMS derivatives demonstrated the
highest sensitivities, followed by methylated derivatives. For BSTFA
or MTBSTFA derivatization processes, the simple injection-port
derivatization process could achieve the same efficiency as that in the
tedious water bath derivatization procedure.
Digital Article Identifier (DOI):
190
9050
Geostatistical Analysis and Mapping of Groundlevel Ozone in a Medium Sized Urban Area
Abstract: Ground-level tropospheric ozone is one of the air
pollutants of most concern. It is mainly produced by photochemical
processes involving nitrogen oxides and volatile organic compounds
in the lower parts of the atmosphere. Ozone levels become
particularly high in regions close to high ozone precursor emissions
and during summer, when stagnant meteorological conditions with
high insolation and high temperatures are common.
In this work, some results of a study about urban ozone
distribution patterns in the city of Badajoz, which is the largest and
most industrialized city in Extremadura region (southwest Spain) are
shown. Fourteen sampling campaigns, at least one per month, were
carried out to measure ambient air ozone concentrations, during
periods that were selected according to favourable conditions to
ozone production, using an automatic portable analyzer.
Later, to evaluate the ozone distribution at the city, the measured
ozone data were analyzed using geostatistical techniques. Thus, first,
during the exploratory analysis of data, it was revealed that they were
distributed normally, which is a desirable property for the subsequent
stages of the geostatistical study. Secondly, during the structural
analysis of data, theoretical spherical models provided the best fit for
all monthly experimental variograms. The parameters of these
variograms (sill, range and nugget) revealed that the maximum
distance of spatial dependence is between 302-790 m and the
variable, air ozone concentration, is not evenly distributed in reduced
distances. Finally, predictive ozone maps were derived for all points
of the experimental study area, by use of geostatistical algorithms
(kriging). High prediction accuracy was obtained in all cases as
cross-validation showed. Useful information for hazard assessment
was also provided when probability maps, based on kriging
interpolation and kriging standard deviation, were produced.
Digital Article Identifier (DOI):
189
5794
The Performance Analysis of Error Saturation Nonlinearity LMS in Impulsive Noise based on Weighted-Energy Conservation
Abstract: This paper introduces a new approach for the performance
analysis of adaptive filter with error saturation nonlinearity in
the presence of impulsive noise. The performance analysis of adaptive
filters includes both transient analysis which shows that how fast
a filter learns and the steady-state analysis gives how well a filter
learns. The recursive expressions for mean-square deviation(MSD)
and excess mean-square error(EMSE) are derived based on weighted
energy conservation arguments which provide the transient behavior
of the adaptive algorithm. The steady-state analysis for co-related
input regressor data is analyzed, so this approach leads to a new
performance results without restricting the input regression data to
be white.
Digital Article Identifier (DOI):
188
14594
Floating-Point Scaling for BSS Gain Control
Abstract: In Blind Source Separation (BSS) processing, taking
advantage of scaling factor indetermination and based on the floatingpoint
representation, we propose a scaling technique applied to the
separation matrix, to avoid the saturation or the weakness in the
recovered source signals. This technique performs an Automatic Gain
Control (AGC) in an on-line BSS environment. We demonstrate
the effectiveness of this technique by using the implementation of
a division free BSS algorithm with two input, two output. This
technique is computationally cheaper and efficient for a hardware
implementation.
Digital Article Identifier (DOI):
187
4161
A Neighborhood Condition for Fractional k-deleted Graphs
Abstract: Abstract–Let k ≥ 3 be an integer, and let G be a graph of order n with n ≥ 9k +3- 42(k - 1)2 + 2. Then a spanning subgraph F of G is called a k-factor if dF (x) = k for each x ∈ V (G). A fractional k-factor is a way of assigning weights to the edges of a graph G (with all weights between 0 and 1) such that for each vertex the sum of the weights of the edges incident with that vertex is k. A graph G is a fractional k-deleted graph if there exists a fractional k-factor after deleting any edge of G. In this paper, it is proved that G is a fractional k-deleted graph if G satisfies δ(G) ≥ k + 1 and |NG(x) ∪ NG(y)| ≥ 1 2 (n + k - 2) for each pair of nonadjacent vertices x, y of G.
Digital Article Identifier (DOI):
186
6176
Analytical solution of Gas Flow Through a Micro-Nano Porous Media by Homotopy Perturbation method
Abstract: In this paper, we have applied the homotopy perturbation
method (HPM) for obtaining the analytical solution of unsteady
flow of gas through a porous medium and we have also compared the
findings of this research with some other analytical results. Results
showed a very good agreement between results of HPM and the
numerical solutions of the problem rather than other analytical solutions
which have previously been applied. The results of homotopy
perturbation method are of high accuracy and the method is very
effective and succinct.
Digital Article Identifier (DOI):
185
13163
Structure of Covering-based Rough Sets
Abstract: Rough set theory is a very effective tool to deal with granularity and vagueness in information systems. Covering-based rough set theory is an extension of classical rough set theory. In this paper, firstly we present the characteristics of the reducible element and the minimal description covering-based rough sets through downsets. Then we establish lattices and topological spaces in coveringbased rough sets through down-sets and up-sets. In this way, one can investigate covering-based rough sets from algebraic and topological points of view.
Digital Article Identifier (DOI):
184
10351
Oscillation Criteria for Nonlinear Second-order Damped Delay Dynamic Equations on Time Scales
Abstract: In this paper, we establish several oscillation criteria for the nonlinear second-order damped delay dynamic equation r(t)|xΔ(t)|β-1xΔ(t)Δ + p(t)|xΔσ(t)|β-1xΔσ(t) + q(t)f(x(τ (t))) = 0 on an arbitrary time scale T, where β > 0 is a constant. Our results generalize and improve some known results in which β > 0 is a quotient of odd positive integers. Some examples are given to illustrate our main results.
Digital Article Identifier (DOI):
183
15641
Numerical Investigation of Two-dimensional Boundary Layer Flow Over a Moving Surface
Abstract: In this chapter, we have studied Variation of velocity in incompressible fluid over a moving surface. The boundary layer equations are on a fixed or continuously moving flat plate in the same or opposite direction to the free stream with suction and injection. The boundary layer equations are transferred from partial differential equations to ordinary differential equations. Numerical solutions are obtained by using Runge-Kutta and Shooting methods. We have found numerical solution to velocity and skin friction coefficient.
Digital Article Identifier (DOI):
182
10029
Remarks on Some Properties of Decision Rules
Abstract: This paper shows that some properties of the decision
rules in the literature do not hold by presenting a counterexample. We
give sufficient and necessary conditions under which these properties
are valid. These results will be helpful when one tries to choose the
right decision rules in the research of rough set theory.
Digital Article Identifier (DOI):
181
12252
Services and Applications for Smart Office Environments - A Survey of State-of-the-Art Usage Scenarios
Abstract: This paper reports on a survey of state-of-the-art
application scenarios for smart office environments. Based on an
analysis of ongoing research activities and industry projects,
functionalities and services of future office systems are extracted. In
a second step, these results are used to identify the key characteristics
of emerging products.
Digital Article Identifier (DOI):
180
13904
A New Efficient Scalable BIST Full Adder using Polymorphic Gates
Abstract: Among various testing methodologies, Built-in Self-
Test (BIST) is recognized as a low cost, effective paradigm. Also,
full adders are one of the basic building blocks of most arithmetic
circuits in all processing units. In this paper, an optimized testable 2-
bit full adder as a test building block is proposed. Then, a BIST
procedure is introduced to scale up the building block and to generate
a self testable n-bit full adders. The target design can achieve 100%
fault coverage using insignificant amount of hardware redundancy.
Moreover, Overall test time is reduced by utilizing polymorphic
gates and also by testing full adder building blocks in parallel.
Digital Article Identifier (DOI):
179
5067
Context Generation with Image Based Sensors: An Interdisciplinary Enquiry on Technical and Social Issues and their Implications for System Design
Abstract: Image data holds a large amount of different context
information. However, as of today, these resources remain largely
untouched. It is thus the aim of this paper to present a basic technical
framework which allows for a quick and easy exploitation of context
information from image data especially by non-expert users.
Furthermore, the proposed framework is discussed in detail
concerning important social and ethical issues which demand special
requirements in system design. Finally, a first sensor prototype is
presented which meets the identified requirements. Additionally,
necessary implications for the software and hardware design of the
system are discussed, rendering a sensor system which could be
regarded as a good, acceptable and justifiable technical and thereby
enabling the extraction of context information from image data.
Digital Article Identifier (DOI):
178
1610
Statistical Models of Network Traffic
Abstract: Model-based approaches have been applied successfully
to a wide range of tasks such as specification, simulation, testing, and
diagnosis. But one bottleneck often prevents the introduction of these
ideas: Manual modeling is a non-trivial, time-consuming task.
Automatically deriving models by observing and analyzing running
systems is one possible way to amend this bottleneck. To
derive a model automatically, some a-priori knowledge about the
model structure–i.e. about the system–must exist. Such a model
formalism would be used as follows: (i) By observing the network
traffic, a model of the long-term system behavior could be generated
automatically, (ii) Test vectors can be generated from the model,
(iii) While the system is running, the model could be used to diagnose
non-normal system behavior.
The main contribution of this paper is the introduction of a model
formalism called 'probabilistic regression automaton' suitable for the
tasks mentioned above.
Digital Article Identifier (DOI):
177
7757
Technology Based Learning Environment and Student Achievement in English as a Foreign Language in Pakistan
Abstract: The fast growing accessibility and capability of emerging technologies have fashioned enormous possibilities of designing, developing and implementing innovative teaching methods in the classroom. The global technological scenario has paved the way to new pedagogies in teaching-learning process focusing on technology based learning environment and its impact on student achievement. The present experimental study was conducted to determine the effectiveness of technology based learning environment on student achievement in English as a foreign language. The sample of the study was 90 students of 10th grade of a public school located in Islamabad. A pretest- posttest equivalent group design was used to compare the achievement of the two groups. A Pretest and A posttest containing 50 items each from English textbook were developed and administered. The collected data were statistically analyzed. The results showed that there was a significant difference between the mean scores of Experimental group and the Control group. The performance of Experimental group was better on posttest scores that indicted that teaching through technology based learning environment enhanced the achievement level of the students. On the basis of the results, it was recommended that teaching and learning through information and communication technologies may be adopted to enhance the language learning capability of the students.
Digital Article Identifier (DOI):
176
2982
Fast Cosine Transform to Increase Speed-up and Efficiency of Karhunen-Loève Transform for Lossy Image Compression
Abstract: In this work, we present a comparison between two
techniques of image compression. In the first case, the image is
divided in blocks which are collected according to zig-zag scan. In
the second one, we apply the Fast Cosine Transform to the image,
and then the transformed image is divided in blocks which are
collected according to zig-zag scan too. Later, in both cases, the
Karhunen-Loève transform is applied to mentioned blocks. On the
other hand, we present three new metrics based on eigenvalues for a
better comparative evaluation of the techniques. Simulations show
that the combined version is the best, with minor Mean Absolute
Error (MAE) and Mean Squared Error (MSE), higher Peak Signal to
Noise Ratio (PSNR) and better image quality. Finally, new technique
was far superior to JPEG and JPEG2000.
Digital Article Identifier (DOI):
175
8519
Evaluation of Aerodynamic Noise Generation by a Generic Side Mirror
Abstract: The aerodynamic noise radiation from a side view mirror (SVM) in the high-speed airflow is calculated by the combination of unsteady incompressible fluid flow analysis and acoustic analysis. The transient flow past the generic SVM is simulated with variable turbulence model, namely DES Detached Eddy Simulation and LES (Large Eddy Simulation). Detailed velocity vectors and contour plots of the time-varying velocity and pressure fields are presented along cut planes in the flow-field. Mean and transient pressure are also monitored at several points in the flow field and compared to corresponding experimentally data published in literature. The acoustic predictions made using the Ffowcs-Williams-Hawkins acoustic analogy (FW-H) and the boundary element (BEM).
Digital Article Identifier (DOI):
174
7363
Improved Asymptotic Stability Criteria for Uncertain Neutral Systems with Time-varying Discrete Delays
Abstract: This paper investigates the robust stability of uncertain neutral system with time-varying delay. By using Lyapunov method and linear matrix inequality technology, new delay-dependent stability criteria are obtained and formulated in terms of linear matrix inequalities (LMIs), which can be easy to check the robust stability of the considered systems. Numerical examples are given to indicate significant improvements over some existing results.
Digital Article Identifier (DOI):
173
2503
Computing Fractal Dimension of Signals using Multiresolution Box-counting Method
Abstract: In this paper, we have developed a method to
compute fractal dimension (FD) of discrete time signals, in the
time domain, by modifying the box-counting method. The size
of the box is dependent on the sampling frequency of the
signal. The number of boxes required to completely cover the
signal are obtained at multiple time resolutions. The time
resolutions are made coarse by decimating the signal. The loglog
plot of total number of boxes required to cover the curve
versus size of the box used appears to be a straight line, whose
slope is taken as an estimate of FD of the signal. The results
are provided to demonstrate the performance of the proposed
method using parametric fractal signals. The estimation
accuracy of the method is compared with that of Katz, Sevcik,
and Higuchi methods. In addition, some properties of the FD
are discussed.
Digital Article Identifier (DOI):
172
13517
Existence and Globally Exponential Stability of Equilibrium for BAM Neural Networks with Mixed Delays and Impulses
Abstract: In this paper, a class of generalized bi-directional associative memory (BAM) neural networks with mixed delays is investigated. On the basis of Lyapunov stability theory and contraction mapping theorem, some new sufficient conditions are established for the existence and uniqueness and globally exponential stability of equilibrium, which generalize and improve the previously known results. One example is given to show the feasibility and effectiveness of our results.
Digital Article Identifier (DOI):
171
14709
Incremental Algorithm to Cluster the Categorical Data with Frequency Based Similarity Measure
Abstract: Clustering categorical data is more complicated than
the numerical clustering because of its special properties. Scalability
and memory constraint is the challenging problem in clustering large
data set. This paper presents an incremental algorithm to cluster the
categorical data. Frequencies of attribute values contribute much in
clustering similar categorical objects. In this paper we propose new
similarity measures based on the frequencies of attribute values and
its cardinalities. The proposed measures and the algorithm are
experimented with the data sets from UCI data repository. Results
prove that the proposed method generates better clusters than the
existing one.
Digital Article Identifier (DOI):
170
12941
Effect of Muscle Loss on Hip Muscular Effort during the Swing Phase of Transfemoral Amputee Gait: A Simulation Study
Abstract: The effect of muscle loss due to transfemoral
amputation, on energy expenditure of hip joint and individual
residual muscles was simulated. During swing phase of gait, with
each muscle as an ideal force generator, the lower extremity was
modeled as a two-degree of freedom linkage, for which hip and knee
were joints. According to results, muscle loss will not lead to higher
energy expenditure of hip joint, as long as other parameters of limb
remain unaffected. This finding maybe due to the role of biarticular
muscles in hip and knee joints motion. Moreover, if hip flexors are
removed from the residual limb, residual flexors, and if hip extensors
are removed, residual extensors will do more work. In line with the
common practice in transfemoral amputation, this result demonstrates
during transfemoral amputation, it is important to maintain the length
of residual limb as much as possible.
Digital Article Identifier (DOI):
169
2867
Energy Distribution of EEG Signals: EEG Signal Wavelet-Neural Network Classifier
Abstract: In this paper, a wavelet-based neural network (WNN) classifier for recognizing EEG signals is implemented and tested under three sets EEG signals (healthy subjects, patients with epilepsy and patients with epileptic syndrome during the seizure). First, the Discrete Wavelet Transform (DWT) with the Multi-Resolution Analysis (MRA) is applied to decompose EEG signal at resolution levels of the components of the EEG signal (δ, θ, α, β and γ) and the Parseval-s theorem are employed to extract the percentage distribution of energy features of the EEG signal at different resolution levels. Second, the neural network (NN) classifies these extracted features to identify the EEGs type according to the percentage distribution of energy features. The performance of the proposed algorithm has been evaluated using in total 300 EEG signals. The results showed that the proposed classifier has the ability of recognizing and classifying EEG signals efficiently.
Digital Article Identifier (DOI):
168
10578
A Short Form of the Taiwan Health Literacy Scale (THLS) for Chinese-Speaking Adults
Abstract: The Taiwan Health Literacy Scale (THLS) was developed to cope with the need of measuring heath literacy of Chinese-speaking adults in Taiwan. Although the scale was proven having good reliability and validity, it was not popularly adopted by the practitioners due to the length, and the time required completing. Based on the THLS, this research further invited healthcare professionals to review the original scale for a possible shorten work. Under the logic of THLS, the research adopted an analytic hierarchy process technique to consolidate the healthcare experts- assessments to shorten the original scale. There are fifteen items out of the original 66 items were identified having higher loadings. Confirmed by the experts and passed a pilot test with 40 undergraduate students, a short form of THLS is then introduced. This research then used 839 samples from the major cities of the Hua-lien county in the eastern part of Taiwan to test the reliability and validity of this new scale. The reliability of the scale is high and acceptable. The current scale is also highly correlated with the original, of which provide evidence for the validity of the scale.
Digital Article Identifier (DOI):
167
13773
Investigation of Anti-diabetic and Hypocholesterolemic Potential of Psyllium Husk Fiber (Plantago psyllium) in Diabetic and Hypercholesterolemic Albino Rats
Abstract: The present study was conducted to observe the effect
of Plantago psyllium on blood glucose and cholesterol levels in
normal and alloxan induced diabetic rats. To investigate the effect of
Plantago psyllium 40 rats were included in this study divided into
four groups of ten rats in each group. One group A was normal,
second group B was diabetic, third group C was non diabetic and
hypercholesterolemic and fourth group D was diabetic and
hypercholesterolemic. Two groups B and D were made diabetic by
intraperitonial injection of alloxan dissolved in 1mL distilled water at
a dose of 125mg/Kg of body weight. Two groups C and D were
made hypercholesterolemic by oral administration of powder
cholesterol (1g/Kg of body weight). The blood samples from all the
rats were collected from coccygial vein on 1st day, then on 21st and
42nd day respectively. All the samples were analyzed for blood
glucose and cholesterol level by using enzymatic kits. The blood
glucose and cholesterol levels of treated groups of rats showed
significant reduction after 7 weeks of treatment with Plantago
psyllium. By statistical analysis of results it was found that Plantago
psyllium has anti-diabetic and hypocholesterolemic activity in
diabetic and hypercholesterolemic albino rats.
Digital Article Identifier (DOI):
166
11891
On the Prediction of Transmembrane Helical Segments in Membrane Proteins Based on Wavelet Transform
Abstract: The prediction of transmembrane helical segments
(TMHs) in membrane proteins is an important field in the
bioinformatics research. In this paper, a new method based on discrete
wavelet transform (DWT) has been developed to predict the number
and location of TMHs in membrane proteins. PDB coded as 1KQG
was chosen as an example to describe the prediction of the number and
location of TMHs in membrane proteins by using this method. To
access the effect of the method, 80 proteins with known 3D-structure
from Mptopo database are chosen at random as the test objects
(including 325 TMHs), 308 of which can be predicted accurately, the
average predicted accuracy is 96.3%. In addition, the above 80
membrane proteins are divided into 13 groups according to their
function and type. In particular, the results of the prediction of TMHs
of the 13 groups are satisfying.
Digital Article Identifier (DOI):
165
3551
Histopathological and Morphological Defects in the Mice Prenatally Exposed to Low EMF
Abstract: This research was carried out to determine the
possible effects of low electromagnetic field (EMF) exposure to the
developing mice fetuses. Pregnant mice were exposed to EMF
exposure at 0mT (sham) and 1.2 mT for six hours per session, carried
out on gestation day 3, 6, 9, 12 and 15. Samples from the stillborn
offspring were observed for morphological defects. The heart didn-t
show progressive cellular damage, the lungs were congested and
emphysemics. The bones were in advance stage of hypertrophy.
Spectrums of morphological defects were observed over 70% of the
surviving offspring. These results indicate that even at lower
exposure to low EMF, is enough to induce morphological defects in
prenatal mice.
Digital Article Identifier (DOI):
164
1069
The Care Management Network as an Effective Intervention in Mitigating the Risks of Hypertension
Abstract: Hospitals in southern Hualien teamed with the
Hypertension Joint Care Network. Working with the network, the
team provided a special designed health education to the individual
who had been identified as a hypertension patient in the outpatient
department. Some metabolism improvements achieved. This is a
retrospective study by purposively taking 106 patients from a hospital
between 2008 and 2010. Records of before and after education
intervention of the objects was collected and analyzed to see the how
the intervention affected the patients- hypertension control via clinical
parameter monitoring. The results showed that the clinical indicators,
the LDL-C, the cholesterol and the systolic blood pressure were
significantly improved. The study provides evidence for the
effectiveness of the network in controlling hypertension.
Digital Article Identifier (DOI):
163
14480
Bioprocessing of Proximally Analyzed Wheat Straw for Enhanced Cellulase Production through Process Optimization with Trichodermaviride under SSF
Abstract: The purpose of the present work was to study the
production and process parameters optimization for the synthesis of
cellulase from Trichoderma viride in solid state fermentation (SSF)
using an agricultural wheat straw as substrates; as fungal conversion
of lignocellulosic biomass for cellulase production is one among the
major increasing demand for various biotechnological applications.
An optimization of process parameters is a necessary step to get
higher yield of product. Several kinetic parameters like pretreatment,
extraction solvent, substrate concentration, initial moisture content,
pH, incubation temperature and inoculum size were optimized for
enhanced production of third most demanded industrially important
cellulase. The maximum cellulase enzyme activity 398.10±2.43
μM/mL/min was achieved when proximally analyzed lignocellulosic
substrate wheat straw inocubated at 2% HCl as pretreatment tool
along with distilled water as extraction solvent, 3% substrate
concentration 40% moisture content with optimum pH 5.5 at 45°C
incubation temperature and 10% inoculum size.
Digital Article Identifier (DOI):
162
13713
Development of a Health Literacy Scale for Chinese-Speaking Adults in Taiwan
Abstract: Background, measuring an individual-s Health
Literacy is gaining attention, yet no appropriate instrument is available
in Taiwan. Measurement tools that were developed and used in
western countries may not be appropriate for use in Taiwan due to a
different language system. Purpose of this research was to develop a
Health Literacy measurement instrument specific for Taiwan adults.
Methods, several experts of clinic physicians; healthcare
administrators and scholars identified 125 common used health related
Chinese phrases from major medical knowledge sources that easy
accessible to the public. A five-point Likert scale is used to measure
the understanding level of the target population. Such measurement is
then used to compare with the correctness of their answers to a health
knowledge test for validation. Samples, samples under study were
purposefully taken from four groups of people in the northern
Pingtung, OPD patients, university students, community residents,
and casual visitors to the central park. A set of health knowledge index
with 10 questions is used to screen those false responses. A sample
size of 686 valid cases out of 776 was then included to construct this
scale. An independent t-test was used to examine each individual
phrase. The phrases with the highest significance are then identified
and retained to compose this scale. Result, a Taiwan Health Literacy
Scale (THLS) was finalized with 66 health-related phrases under nine
divisions. Cronbach-s alpha of each division is at a satisfactory level
of 89% and above. Conclusions, factors significantly differentiate the
levels of health literacy are education, female gender, age, family
members of stroke victims, experience with patient care, and
healthcare professionals in the initial application in this study..
Digital Article Identifier (DOI):
161
5009
Identification of Cardiac Arrhythmias using Natural Resonance Complex Frequencies
Abstract: An electrocardiogram (ECG) feature extraction system
based on the calculation of the complex resonance frequency
employing Prony-s method is developed. Prony-s method is applied
on five different classes of ECG signals- arrhythmia as a finite sum
of exponentials depending on the signal-s poles and the resonant
complex frequencies. Those poles and resonance frequencies of the
ECG signals- arrhythmia are evaluated for a large number of each
arrhythmia. The ECG signals of lead II (ML II) were taken from
MIT-BIH database for five different types. These are the ventricular
couplet (VC), ventricular tachycardia (VT), ventricular bigeminy
(VB), and ventricular fibrillation (VF) and the normal (NR). This
novel method can be extended to any number of arrhythmias.
Different classification techniques were tried using neural networks
(NN), K nearest neighbor (KNN), linear discriminant analysis (LDA)
and multi-class support vector machine (MC-SVM).
Digital Article Identifier (DOI):
160
219
Molecular Identification of ESBL Genesbla GES-1, blaVEB-1, blaCTX-M blaOXA-1, blaOXA-4,blaOXA-10 and blaPER-1 in Pseudomonas aeruginosa Strains Isolated from Burn Patientsby PCR, RFLP and Sequencing Techniques
Abstract: Fourty one strains of ESBL producing P.aeruginosa
which were previously isolated from burn patients in Kerman
University general hospital, Iran were subjected to PCR, RFLP and
sequencing in order to determine the type of extended spectrum β-
lactamases (ESBL), the restriction digestion pattern and possibility of
mutation among detected genes. DNA extraction was carried out by
phenol chloroform method. PCR for detection of bla genes was
performed using specific primer for each gene. Restriction Fragment
Length Polymorphism (RFLP) for ESBL genes was carried out using
EcoRI, NheI, PVUII, EcoRV, DdeI, and PstI restriction enzymes. The
PCR products were subjected to direct sequencing of both the strands
for identification of the ESBL genes.The blaCTX-M, blaVEB-1, blaPER-1,
blaGES-1, blaOXA-1, blaOXA-4 and blaOXA-10 genes were detected in the
(n=1) 2.43%, (n=41)100%, (n=28) 68.3%, (n=10) 24.4%, (n=29)
70.7%, (n=7)17.1% and (n=38) 92.7% of the ESBL producing isolates
respectively. The RFLP analysis showed that each ESBL gene has
identical pattern of digestion among the isolated strains. Sequencing
of the ESBL genes confirmed the genuinety of PCR products and
revealed no mutation in the restriction sites of the above genes. From
results of the present investigation it can be concluded that blaVEB-1
and blaCTX-M were the most and the least frequently isolated ESBL
genes among the P.aeruginosa strains isolated from burn patients. The
RFLP and sequencing analysis revealed that same clone of the bla
genes were indeed existed among the antibiotic resistant strains.
Digital Article Identifier (DOI):
159
3477
Biological Characterization of the New Invasive Brine Shrimp Artemia franciscana in Tunisia: Sabkhet Halk El-Menzel
Abstract: Endemic Artemia franciscana populations can be found throughout the American continent and also as an introduced specie in several country all over the world, such as in the Mediterranean region where Artemia franciscana was identified as an invasive specie replacing native Artemia parthenogenetica and Artemia salina. In the present study, the characterization of the new invasive Artemia franciscana reported from Sabkhet Halk El-Menzel (Tunisia) was done based on the cysts biometry, nauplii instar-I length, Adult sexual dimorphism and fatty acid profile. The mean value of the diameter of non-decapsulated and decapsulated cysts, chorion thickness and naupliar length is 235.8, 226.3, 4.75 and 426.8 μm, respectively. Sexual dimorphism for adults specimen showed that maximal distance between compound eyes, diameter for compound eyes, length of first antenna and the abdomen length compared to the total body length ratio, are the most important variables for males and females discrimination with a total contribution of 62.39 %. The analysis of fatty acid methyl esters profile of decapsulated cysts resulted in low levels of linolenic acid (LLA, C18:3n-3) and high levels of eicosapentaenoic acid (EPA, C20:5n-3) with 3.11 and 11.10 %, respectively. Low quantity of docosahexaenoic acid (DHA, 22:6n-3) was also observed with 0.17 mg.g-1 dry weight.
Digital Article Identifier (DOI):
158
3420
A New Rigid Fistulectomy Set for Minimally Invasive “Core-Out“ Excision of High Anal Fistulas
Abstract: In this article, we propose a new surgical device for
circumferentially excision of high anal fistulas in a minimally
invasive manner. The new apparatus works on the basis of axially
rotating and moving a tubular blade along a fistulous tract
straightened using a rigid straight guidewire. As the blade moves
along the tract, its sharp circular cutting edge circumferentially
separates approximately 2.25 mm thickness of tract encircling the
rigid guidewire. We used the new set to excise two anal fistulas in a
62-year-old male patient, an extrasphincteric type and a long tract
with no internal opening. With regard to the results of this test, the
new device can be considered as a sphincter preserving mechanism
for treatment of high anal fistulas. Consequently, a major reduction
in the risk of fecal incontinence, recurrence rate, convalescence
period and patient morbidity may be achieved using the new device
for treatment of fistula-in-ano.
Digital Article Identifier (DOI):
157
3270
A New Method for Rapid DNA Extraction from Artemia (Branchiopoda, Crustacea)
Abstract: Artemia is one of the most conspicuous invertebrates
associated with aquaculture. It can be considered as a model
organism, offering numerous advantages for comprehensive and
multidisciplinary studies using morphologic or molecular methods.
Since DNA extraction is an important step of any molecular
experiment, a new and a rapid method of DNA extraction from adult
Artemia was described in this study. Besides, the efficiency of this
technique was compared with two widely used alternative techniques,
namely Chelex® 100 resin and SDS-chloroform methods. Data
analysis revealed that the new method is the easiest and the most cost
effective method among the other methods which allows a quick and
efficient extraction of DNA from the adult animal.
Digital Article Identifier (DOI):
156
9995
Biometrical Comparison of Artemia urmiana Günther, 1899 (Crustacea: Anostraca) Cysts between Rainy and Drought Years (1994-2003/4) from Urmia Lake, Iran
Abstract: Nowadays, biometrical characterizations of Artemia
cysts are used as one of the most important factors in the study of
Artemia populations and intraspecific particularity; meanwhile these
characters can be used as economical indices. For example, typically
high hatching efficiency is possible due to the small diameter of
cysts (high number per gram); therefore small diameter of cysts
show someway high quality of cysts. This study was performed
during a ten year period, including two different ecological
conditions: rainy and drought. It is important from two different
aspects because it covers alteration of A. urmiana during ten years
also its variation in the best and worst environmental situations in
which salinity increased from 173.8 ppt in 1994 to 280.8 ppt in
2003/4. In this study the biometrical raw data of Artemia urmiana
cysts at seven stations from the Urmia Lake in 1994 and their seven
identical locations at 26 studied stations in 2003/4 were reanalyzed
again and compared together. Biometrical comparison of untreated
and decapsulated cysts in each of the seven similar stations showed a
highly significant variation between 1994 and 2003/4. Based on this
study, in whole stations the untreated and decapsulated cysts from
1994 were larger than cysts of 2003/4 without any exception. But
there was no logical relationship between salinity and chorion
thickness in the Urmia Lake. With regard to PCA analyses the
stations of two different studied years certainly have been separated
with factor 1 from each other. In conclusion, the interaction between
genetic and environmental factors can determine and explain
variation in the range of cysts diameter in Artemia.
Digital Article Identifier (DOI):
155
10696
Epidemiology of Waterborne Diarrhoeal Diseases among Children Aged 6-36 Months Old in Busia - Western Kenya
Abstract: The purpose of the present study was to evaluate the
epidemiology of waterborne diarrhoeal among children aged 6-36
months old in Busia town, western Kenya. The study was carried out
between Feb. 2008 and Feb. 2010. Cases of diarrhoea reported in 385
households were linked to household water handling practices. A
mother with a child of 6-36 months old was also included in the
study. Diarrhoea prevalence among children 6-36 months was 16.7%
in Busia town, Bwamani (19.6%) and Mayenje (10.6%) clustered in
Mayenje sub-location reported the highest and the lowest prevalence
of diarrhoea. There was a positive correlation between the prevalence
of diarrhoea in children and the level of the mother-s education,
29.9% (n= 100). Diarrhoea cases decreased in range from 35.5% (n
=102) to 4.8% (n= 16), corresponding to increase in age from 6-35
months on average. In conclusion, prevalence of diarrhoea in
children of 6-36 months old was 16.7% in Busia town. This was
higher in children whose mother-s age was below 18 years and with
low level of education, the rate decreased with increase in age of
children. Prevalence of diarrhoea in children aged 6-36months in
households was higher in children aged 6-17 and 36 months and
whose mothers were less educated and fell between the ages of 18-24
years. The Influence of human activities at the main source of
drinking water on the prevalence of diarrhoea in these children was
insignificant.
Digital Article Identifier (DOI):
154
4787
Cloning of a β-Glucosidase Gene (BGL1) from Traditional Starter Yeast Saccharomycopsis fibuligera BMQ 908 and Expression in Pichia pastoris
Abstract: β-Glucosidase is an important enzyme for production
of ethanol from lignocellulose. With hydrolytic activity on
cellooligosaccharides, especially cellobiose, β-glucosidase removes
product inhibitory effect on cellulases and forms fermentable sugars.
In this study, β-glucosidase encoding gene (BGL1) from traditional
starter yeast Saccharomycosis fibuligera BMQ908 was cloned and
expressed in Pichia pastoris. BGL1 of S. fibuligera BMQ 908 shared
98% nucleotide homology with the closest GenBank sequence
(M22475) but identity in amino-acid sequences of catalytic domains.
Recombinant plasmid pPICZαA/BGL1 containing the sequence
encoding BGL1 mature protein and α-factor secretion signal was
constructed and transformed into methylotrophic yeast P. pastoris by
electroporation. The recombinant strain produced single extracellular
protein with molecular weight of 120 kDa and cellobiase activity of
60 IU/ml. The optimum pH of the recombinant β-glucosidase was 5.0
and the optimum temperature was 50°C.
Digital Article Identifier (DOI):
153
5017
Biodiversity and Phytosociological Analysis of Plants around the Municipal Drains in Jaunpur
Abstract: The habitat where the present study has been carried
out is productive in relation to nutrient quality and they may perform
several useful functions, but are also threatened for their existence.
Hence, the proposed work, will add much new information about
biodiversity of macrophytes in drains and their embankment. All the
species were identified with their different stages of growth which
encountered on the three selected sites (I, II and III). The number of
species occurring at each site is grouped seasonally, i.e. summer,
rainy and winter season and the species were further recorded for the
study of phytosociology. Phytosociological characters such as
frequency, density and abundance were influenced by the climatic,
anthropogenic and biotic stresses prevailing at the three study sites.
All the species present at the study sites have shown maximum
values of frequency, density and abundance in rainy season in
comparison to that of summer and winter seasons.
Digital Article Identifier (DOI):
152
4068
Supercritical Fluid Extraction of Lutein Esters from Marigold Flowers and their Hydrolysis by Improved Saponification and Enzyme Biocatalysis
Abstract: Lutein is a dietary oxycarotenoid which is found
to reduce the risks of Age-related Macular Degeneration
(AMD). Supercritical fluid extraction of lutein esters from
marigold petals was carried out and was found to be much
effective than conventional solvent extraction. The
saponification of pre-concentrated lutein esters to produce free
lutein was studied which showed a composition of about 88%
total carotenoids (UV-VIS spectrophotometry) and 90.7%
lutein (HPLC). The lipase catalyzed hydrolysis of lutein esters
in conventional medium was investigated. The optimal
temperature, pH, enzyme concentration and water activity
were found to be 50°C, 7, 15% and 0.33 respectively and the
activity loss of lipase was about 25% after 8 times re-use in at
50°C for 12 days. However, the lipase catalyzed hydrolysis of
lutein esters in conventional media resulted in poor
conversions (16.4%).
Digital Article Identifier (DOI):
151
9817
Screening Wheat Parents of Mapping Population for Heat and Drought Tolerance, Detection of Wheat Genetic Variation
Abstract: To evaluate genetic variation of wheat (Triticum aestivum) affected by heat and drought stress on eight Australian wheat genotypes that are parents of Doubled Haploid (HD) mapping populations at the vegetative stage, the water stress experiment was conducted at 65% field capacity in growth room. Heat stress experiment was conducted in the research field under irrigation over summer. Result show that water stress decreased dry shoot weight and RWC but increased osmolarity and means of Fv/Fm values in all varieties except for Krichauff. Krichauff and Kukri had the maximum RWC under drought stress. Trident variety was shown maximum WUE, osmolarity (610 mM/Kg), dry mater, quantum yield and Fv/Fm 0.815 under water stress condition. However, the recovery of quantum yield was apparent between 4 to 7 days after stress in all varieties. Nevertheless, increase in water stress after that lead to strong decrease in quantum yield. There was a genetic variation for leaf pigments content among varieties under heat stress. Heat stress decreased significantly the total chlorophyll content that measured by SPAD. Krichauff had maximum value of Anthocyanin content (2.978 A/g FW), chlorophyll a+b (2.001 mg/g FW) and chlorophyll a (1.502 mg/g FW). Maximum value of chlorophyll b (0.515 mg/g FW) and Carotenoids (0.234 mg/g FW) content belonged to Kukri. The quantum yield of all varieties decreased significantly, when the weather temperature increased from 28 ÔùªC to 36 ÔùªC during the 6 days. However, the recovery of quantum yield was apparent after 8th day in all varieties. The maximum decrease and recovery in quantum yield was observed in Krichauff. Drought and heat tolerant and moderately tolerant wheat genotypes were included Trident, Krichauff, Kukri and RAC875. Molineux, Berkut and Excalibur were clustered into most sensitive and moderately sensitive genotypes. Finally, the results show that there was a significantly genetic variation among the eight varieties that were studied under heat and water stress.
Digital Article Identifier (DOI):
150
2345
Biological Effects of a Carbohydrate-Binding Protein from an Annelid, Perinereis nuntia Against Human and Phytopathogenic Microorganisms
Abstract: Lectins have a good scope in current clinical
microbiology research. In the present study evaluated the
antimicrobial activities of a D-galactose binding lectin (PnL) was
purified from the annelid, Perinereis nuntia (polychaeta) by affinity
chromatography. The molecular mass of the lectin was determined to
be 32 kDa as a single polypeptide by SDS-PAGE under both reducing
and non-reducing conditions. The hemagglutinating activity of the
PnL showed against trypsinized and glutaraldehyde-fixed human
erythrocytes was specifically inhibited by D-Gal, GalNAc,
Galβ1-4Glc and Galα1-6Glc. PnL was evaluated for in vitro
antibacterial screening studies against 11 gram-positive and
gram-negative microorganisms. From the screening results, it was
revealed that PnL exhibited significant antibacterial activity against
gram-positive bacteria. Bacillus megaterium showed the highest
growth inhibition by the lectin (250 μg/disc). However, PnL did not
inhibit the growth of gram-negative bacteria such as Vibrio cholerae
and Pseudomonas sp. PnL was also examined for in vitro antifungal
activity against six fungal phytopathogens. PnL (100 μg/mL) inhibited
the mycelial growth of Alternaria alternata (24.4%). These results
indicate that future findings of lectin applications obtained from
annelids may be of importance to life sciences.
Digital Article Identifier (DOI):
149
608
Development of All-male Fingerlings by Heat Treatment and the Genetic Mechanism of Heat Induced Sex Determination in Nile Tilapia(Oreochromis niloticus L.)
Abstract: Juvenile Nile tilapia subjected to heat treatment at
temperatures ranging from 260C to 370C showed positive correlation
(P
Digital Article Identifier (DOI):
148
613
Induction of Alternative Oxidase Activity in Candida albicans by Oxidising Conditions
Abstract: Candida albicans ATCC 10231 had low endogenous activity of the alternative oxidase compared with that of C. albicans ATCC 10261. In C. albicans ATCC 10231 the endogenous activity declined as the cultures aged. Alternative oxidase activity could be induced in C. albicans ATCC 10231 by treatment with cyanide, but the induction of this activity required the presence of oxygen which could be replaced, at least in part, with high concentrations of potassium ferricyanide. We infer from this that the expression of the gene encoding the alternative oxidase is under the control of a redoxsensitive transcription factor.
Digital Article Identifier (DOI):
147
4512
Biochemical Characteristics of Sorghum Flour Fermented and/or Supplemented with Chickpea Flour
Abstract: Sorghum flour was supplemented with 15 and 30%
chickpea flour. Sorghum flour and the supplement were fermented at
35 oC for 0, 8, 16, and 24 h. Changes in pH, titrable acidity, total
soluble solids, protein content, in vitro protein digestibility and
amino acid composition were investigated during fermentation and/or
after supplementation of sorghum flour with chickpea. The pH of the
fermenting material decreased sharply with a concomitant increase in
the titrable acidity. The total soluble solids remained unchanged with
progressive fermentation time. The protein content of sorghum
cultivar was found to be 9.27 and that of chickpea was 22.47%. The
protein content of sorghum cultivar after supplementation with15 and
30% chickpea was significantly (P ≤ 0.05) increased to 11.78 and
14.55%, respectively. The protein digestibility also increased after
fermentation from 13.35 to 30.59 and 40.56% for the supplements,
respectively. Further increment in protein content and digestibility
was observed when supplemented and unsupplemented samples were
fermented for different periods of time. Cooking of fermented
samples was found to increase the protein content slightly and
decreased digestibility for both supplements. Amino acid content of
fermented and fermented and cooked supplements was determined.
Supplementation was found to increase the lysine and therionine
content. Cooking following fermentation decreased lysine,
isoleucine, valine and sulfur containg amino acids.
Digital Article Identifier (DOI):
146
7191
Apoptosis Induced by Low-concentration Ethanol in Hepatocellular Carcinoma Cell Strains and Down-regulated AFP and Survivin Analysis by Proteomic Technology
Abstract: Ethanol is generally used as a therapeutic reagent against Hepatocellular carcinoma (HCC or hepatoma) worldwide, as it can induce Hepatocellular carcinoma cell apoptosis at low concentration through a multifactorial process regulated by several unknown proteins. This paper provides a simple and available proteomic strategy for exploring differentially expressed proteins in the apoptotic pathway. The appropriate concentrations of ethanol required to induce HepG2 cell apoptosis were first assessed by MTT assay, Gisma and fluorescence staining. Next, the central proteins involved in the apoptosis pathway processs were determined using 2D-PAGE, SDS-PAGE, and bio-software analysis. Finally the downregulation of two proteins, AFP and survivin, were determined by immunocytochemistry and reverse transcriptase PCR (RT-PCR) technology. The simple, useful method demonstrated here provides a new approach to proteomic analysis in key bio-regulating process including proliferation, differentiation, apoptosis, immunity and metastasis.
Digital Article Identifier (DOI):
145
14575
Effect of Transglutaminase Cross Linking on the Functional Properties as a Function of NaCl Concentration of Legumes Protein Isolate
Abstract: The effect of cross linking of the protein isolates of
three legumes with the microbial enzyme transglutaminase (EC
2.3.2.13) on the functional properties at different NaCl concentration
was studied. The reduction in the total free amino groups (OD340) of
the polymerized protein showed that TGase treatment cross-linking
the protein subunit of each legume. The solubility of the protein
polymer of each legume was greatly improved at high concentration
of NaCl. At 1.2 M NaCl the solubility of the native legumes protein
was significantly decreased but after polymerization slightly
improved. Cross linked proteins were less turbid on heating to higher
temperature as compared to native proteins and the temperature at
which the protein turns turbid also increased in the polymerized
proteins. The emulsifying and foaming properties of the protein
polymer were greatly improved at all concentrations of NaCl for all
legumes.
Digital Article Identifier (DOI):
144
12697
Inhibition of the Growth of Pathogenic Candida spp. by Salicylhydroxamic Acid
Abstract: Candida spp. are common and aggressive pathogens. Because of the growing resistance of Candida spp. to current antifungals, novel targets, found in Candida spp. but not in humans or other flora, have to be identified. The alternative oxidase (AOX) is one such possibility. This enzyme is insensitive to cyanide, but is sensitive to compounds such as salicylhydroxamic acid (SHAM), disulfiram and n-alkyl gallates. The growth each of six Candida spp. was inhibited significantly by ~13 mM SHAM or 2 mM cyanide, albeit to differing extents. In C. dubliniensis, C. krusei and C. tropicalis the rate of O2 uptake was inhibited by 18-36% by 25 mM SHAM, but this had little or no effect on C. glabrata, C. guilliermondii or C. parapsilosis. Although SHAM substantially inhibited the growth of Candida spp., it is unlikely that the inhibition of AOX was the cause. Salicylhydroxamic acid is used therapeutically in the treatment of urinary tract infections and urolithiasis, but it also has some potential in the treatment of Candida spp. infection.
Digital Article Identifier (DOI):
143
13195
Strategy for Optimal Configuration Design of Existing Structures by Topology and Shape Optimization Tools
Abstract: A strategy is implemented to find the improved configuration design of an existing aircraft structure by executing topology and shape optimizations. Structural analysis of the Initial Design Space is performed in ANSYS under the loads pertinent to operating and ground conditions. By using the FEA results and data, an initial optimized layout configuration is attained by exploiting nonparametric topology optimization in TOSCA software. Topological optimized surfaces are then smoothened and imported in ANSYS to develop the geometrical features. Nodes at the critical locations of resulting voids are selected for sketching rough profiles. Rough profiles are further refined and CAD feasible geometric features are generated. The modified model is then analyzed under the same loadings and constraints as defined for topology optimization. Shape at the peak stress concentration areas are further optimized by exploiting the shape optimization in TOSCA.shape module. The harmonized stressed model with the modified surfaces is then imported in CATIA to develop the final design.
Digital Article Identifier (DOI):
142
14892
Isobaric Vapor-Liquid Equilibrium Data for Binary Mixtures of n-Butylamine and Triethylamine with Cumene at 97.3 kPa
Abstract: Isobaric vapor-liquid equilibrium measurements are reported for the binary mixtures of n-Butylamine and Triethylamine with Cumene at 97.3 kPa. The measurements have been performed using a vapor recirculating type (modified Othmer's) equilibrium still. The binary mixture of n-Butylamine + Cumene shows positive deviation from ideality. Triethylamine + Cumene mixture shows negligible deviation from ideality. None of the systems form an azeotrope. The activity coefficients have been calculated taking into consideration the vapor phase nonideality. The data satisfy the thermodynamic consistency test of Herington. The activity coefficients have been satisfactorily correlated by means of the Margules, NRTL, and Black equations. The activity coefficient values obtained by the UNIFAC model are also reported.
Digital Article Identifier (DOI):
141
4320
CFD Simulation of Dense Gas Extraction through Polymeric Membranes
Abstract: In this study is presented a general methodology to
predict the performance of a continuous near-critical fluid extraction
process to remove compounds from aqueous solutions using hollow
fiber membrane contactors. A comprehensive 2D mathematical
model was developed to study Porocritical extraction process. The
system studied in this work is a membrane based extractor of ethanol
and acetone from aqueous solutions using near-critical CO2.
Predictions of extraction percentages obtained by simulations have
been compared to the experimental values reported by Bothun et al.
[5]. Simulations of extraction percentage of ethanol and acetone
show an average difference of 9.3% and 6.5% with the experimental
data, respectively. More accurate predictions of the extraction of
acetone could be explained by a better estimation of the transport
properties in the aqueous phase that controls the extraction of this
solute.
Digital Article Identifier (DOI):
140
9946
Optimization of Growth of Rhodobacter Sphaeroides Using Mixed Volatile Fatty Acidsby Response Surface Methodology
Abstract: A combination of photosynthetic bacteria along with
anaerobic acidogenic bacteria is an ideal option for efficient
hydrogen production. In the present study, the optimum
concentration of substrates for the growth of Rhodobacter
sphaeroides was found by response surface methodology. The
optimum combination of three individual fatty acids was determined
by Box Behnken design. Increase of volatile fatty acid concentration
decreased the growth. Combination of sodium acetate and sodium
propionate was most significant for the growth of the organism. The
results showed that a maximum biomass concentration of 0.916 g/l
was obtained when the concentrations of acetate, propionate and
butyrate were 0.73g/l,0.99g/l and 0.799g/l, respectively. The growth
was studied under an optimum concentration of volatile fatty acids
and at a light intensity of 3000 lux, initial pH of 7 and a temperature
of 35°C.The maximum biomass concentration of 0.92g/l was
obtained which verified the practicability of this optimization.
Digital Article Identifier (DOI):
139
8482
Kinetics Studies on Biological Treatment of Tannery Wastewater Using Mixed Culture
Abstract: In this study, aerobic digestion of tannery industry
wastewater was carried out using mixed culture obtained from
common effluent treatment plant treating tannery wastewater. The
effect of pH, temperature, inoculum concentration, agitation speed
and initial substrate concentration on the reduction of organic matters
were found. The optimum conditions for COD reduction was found
to be pH - 7 (60%), temperature - 30ÔùªC (61%), inoculum
concentration - 2% (61%), agitation speed - 150rpm (65%) and initial
substrate concentration - 1560 mg COD/L (74%). Kinetics studies
were carried by using Monod model, First order, Diffusional model
and Singh model. From the results it was found that the Monod
model suits well for the degradation of tannery wastewater using
mixed microbial consortium.
Digital Article Identifier (DOI):
138
13999
Application of Central Composite Design Based Response Surface Methodology in Parameter Optimization and on Cellulase Production Using Agricultural Waste
Abstract: Response Surface Methodology (RSM) is a powerful
and efficient mathematical approach widely applied in the
optimization of cultivation process. Cellulase enzyme production by
Trichoderma reesei RutC30 using agricultural waste rice straw and
banana fiber as carbon source were investigated. In this work,
sequential optimization strategy based statistical design was
employed to enhance the production of cellulase enzyme through
submerged cultivation. A fractional factorial design (26-2) was applied
to elucidate the process parameters that significantly affect cellulase
production. Temperature, Substrate concentration, Inducer
concentration, pH, inoculum age and agitation speed were identified
as important process parameters effecting cellulase enzyme synthesis.
The concentration of lignocelluloses and lactose (inducer) in the
cultivation medium were found to be most significant factors. The
steepest ascent method was used to locate the optimal domain and a
Central Composite Design (CCD) was used to estimate the quadratic
response surface from which the factor levels for maximum
production of cellulase were determined.
Digital Article Identifier (DOI):
137
4340
Solid Concentration in Circulating Fluidized Bed Reactor for the MTO Process
Abstract: Methanol-to-olefins (MTO) coupled with
transformation of coal or natural gas to methanol gives an interesting
and promising way to produce ethylene and propylene. To investigate
solid concentration in gas-solid fluidized bed for methanol-to-olefins
process catalyzed by SAPO-34, a cold model experiment system is
established in this paper. The system comprises a gas distributor in a
300mm internal diameter and 5000mm height acrylic column, the
fiber optic probe system and series of cyclones. The experiments are
carried out at ambient conditions and under different superficial gas
velocity ranging from 0.3930m/s to 0.7860m/s and different initial bed
height ranging from 600mm to 1200mm. The effects of radial
distance, axial distance, superficial gas velocity, initial bed height on
solid concentration in the bed are discussed. The effects of distributor
shape and porosity on solid concentration are also discussed. The
time-averaged solid concentration profiles under different conditions
are obtained.
Digital Article Identifier (DOI):
136
8431
Optimization of the Process of Osmo – Convective Drying of Edible Button Mushrooms using Response Surface Methodology (RSM)
Abstract: Simultaneous effects of temperature, immersion time, salt concentration, sucrose concentration, pressure and convective dryer temperature on the combined osmotic dehydration - convective drying of edible button mushrooms were investigated. Experiments were designed according to Central Composite Design with six factors each at five different levels. Response Surface Methodology (RSM) was used to determine the optimum processing conditions that yield maximum water loss and rehydration ratio and minimum solid gain and shrinkage in osmotic-convective drying of edible button mushrooms. Applying surfaces profiler and contour plots optimum operation conditions were found to be temperature of 39 °C, immersion time of 164 min, salt concentration of 14%, sucrose concentration of 53%, pressure of 600 mbar and drying temperature of 40 °C. At these optimum conditions, water loss, solid gain, rehydration ratio and shrinkage were found to be 63.38 (g/100 g initial sample), 3.17 (g/100 g initial sample), 2.26 and 7.15%, respectively.
Digital Article Identifier (DOI):
135
749
Kinetic and Optimization Studies on Ethanol Production from Corn Flour
Abstract: Studies on Simultaneous Saccharification and Fermentation (SSF) of corn flour, a major agricultural product as the substrate using starch digesting glucoamylase enzyme derived from Aspergillus niger and non starch digesting and sugar fermenting Saccharomyces cerevisiae in a batch fermentation. Experiments based on Central Composite Design (CCD) were conducted to study the effect of substrate concentration, pH, temperature, enzyme concentration on Ethanol Concentration and the above parameters were optimized using Response Surface Methodology (RSM). The optimum values of substrate concentration, pH, temperature and enzyme concentration were found to be 160 g/l, 5.5, 30°C and 50 IU respectively. The effect of inoculums age on ethanol concentration was also investigated. The corn flour solution equivalent to 16% initial starch concentration gave the highest ethanol concentration of 63.04 g/l after 48 h of fermentation at optimum conditions of pH and temperature. Monod model and Logistic model were used for growth kinetics and Leudeking – Piret model was used for product formation kinetics.
Digital Article Identifier (DOI):
134
8839
Simultaneous Saccharification and Fermentation(SSF) of Sugarcane Bagasse - Kinetics and Modeling
Abstract: Simultaneous Saccharification and Fermentation (SSF) of sugarcane bagasse by cellulase and Pachysolen tannophilus MTCC *1077 were investigated in the present study. Important process variables for ethanol production form pretreated bagasse were optimized using Response Surface Methodology (RSM) based on central composite design (CCD) experiments. A 23 five level CCD experiments with central and axial points was used to develop a statistical model for the optimization of process variables such as incubation temperature (25–45°) X1, pH (5.0–7.0) X2 and fermentation time (24–120 h) X3. Data obtained from RSM on ethanol production were subjected to the analysis of variance (ANOVA) and analyzed using a second order polynomial equation and contour plots were used to study the interactions among three relevant variables of the fermentation process. The fermentation experiments were carried out using an online monitored modular fermenter 2L capacity. The processing parameters setup for reaching a maximum response for ethanol production was obtained when applying the optimum values for temperature (32°C), pH (5.6) and fermentation time (110 h). Maximum ethanol concentration (3.36 g/l) was obtained from 50 g/l pretreated sugarcane bagasse at the optimized process conditions in aerobic batch fermentation. Kinetic models such as Monod, Modified Logistic model, Modified Logistic incorporated Leudeking – Piret model and Modified Logistic incorporated Modified Leudeking – Piret model have been evaluated and the constants were predicted.
Digital Article Identifier (DOI):
133
15701
Synthesis and Characterization of Gallosilicate Sodalite Containing NO2- Ions
Abstract: Pure phase gallosilicate nitrite sodalite has been synthesized in a single step by low temperature (373 oK) hydrothermal technique. The product obtained was characterized using a combination of techniques including X-ray powder diffraction, IR, Raman spectroscopy, SEM, MAS NMR spectroscopy as well as thermogravimetry. Sodalite with an ideal composition was obtained after synthesis at 3730K and seven days duration using alkaline medium. The structural features of the Na8[GaSiO4]6(NO2)2 sodalite were investigated by IR, MAS NMR spectroscopy of 29Si and 23Na nuclei and by Reitveld refinement of X-ray powder diffraction data. The crystal structure of this sodalite has been refined in the space group P 4 3n; with a cell parameter 8.98386Å, V= 726.9 Å, (Rwp= 0.077 and Rp=0.0537) and Si-O-Ga angle is found to be 132.920 . MAS NMR study confirms complete ordering of Si and Ga in the gallosilicate framework. The surface area of single entity with stoichiometry Na8[GaSiO4]6(NO2)2 was found to be 8.083 x10-15 cm2/g.
Digital Article Identifier (DOI):
132
2747
Microstructural and In-Vitro Characterization of Glass-Reinforced Hydroxyapatite Composites
Abstract: Commercial hydroxyapatite (HA) was reinforced by
adding 2, 5, and 10 wt % of 28.5%CaO-28.5%P2O5-38%Na2 O-
5%CaF2 based glass and then sintered. Although HA shows good
biocompatibility with the human body, its applications are limited to
non load-bearing areas and coatings due to its poor mechanical
properties. These mechanical properties can be improved
substantially with addition of glass ceramics by sintering. In this
study, the effects of sintering hydroxyapatite with above specified
phosphate glass additions are quantified. Each composition was
sintered over a range of temperatures. Scanning electron microscopy
and x-ray diffraction were used to characterize the microstructure and
phases of the composites. The density, microhardness, and
compressive strength were measured using Archimedes Principle,
Vickers Microhardness Tester (at 0.98 N), and Instron Universal
Testing Machine (cross speed of 0.5 mm/min) respectively. These
results were used to indicate which composition provided suitable
material for use in hard tissue replacement. Composites containing 10
wt % glass additions formed dense HA/TCP (tricalcium phosphate)
composite materials possessing good compressive strength and
hardness than HA. In-vitro bioactivity was assessed by evaluating
changes in pH and Ca2+ ion concentration of SBF-simulated body
fluid on immersion of these composites in it for two weeks.
Digital Article Identifier (DOI):
131
10298
The Kinetic of Biogas Production Rate from Cattle Manure in Batch Mode
Abstract: In this study, the kinetic of biogas production was studied by performing a series laboratory experiment using rumen fluid of animal ruminant as inoculums. Cattle manure as substrate was inoculated by rumen fluid to the anaerobic biodigester. Laboratory experiments using 400 ml biodigester were performed in batch operation mode. Given 100 grams of fresh cattle manure was fed to each biodigester and mixed with rumen fluid by manure : rumen weight ratio of 1:1 (MR11). The operating temperatures were varied at room temperature and 38.5 oC. The cumulative volume of biogas produced was used to measure the biodigester performance. The research showed that the rumen fluid inoculated to biodigester gave significant effect to biogas production (P<0.05). Rumen fluid inoculums caused biogas production rate and efficiency increase two to three times in compare to manure substrate without rumen fluid. With the rumen fluid inoculums, gave the kinetic parameters of biogas production i.e biogas production rate constants (U), maximum biogas production (A), and minimum time to produce biogas (λ) are 3.89 ml/(gVS.day); 172.51 (ml/gVS); dan 7.25 days, respectively. While the substrate without rumen fluid gave the kinetic parameters U, A, and λ are 1.74 ml/(gVS.day); 73.81 (ml/gVS); dan 14.75 days, respectively. The future work will be carried out to study the dynamics of biogas production if both the rumen inoculums and manure are fed in the continuous system.
Digital Article Identifier (DOI):
130
7575
The Heat and Mass Transfer Phenomena in Vacuum Membrane Distillation for Desalination
Abstract: Vacuum membrane distillation (VMD) process can be
used for water purification or the desalination of salt water. The
process simply consists of a flat sheet hydrophobic micro porous
PTFE membrane and diaphragm vacuum pump without a condenser
for the water recovery or trap. The feed was used aqueous NaCl
solution. The VMD experiments were performed to evaluate the heat
and mass transfer coefficient of the boundary layer in a membrane
module. The only operating parameters are feed inlet temperature,
and feed flow rate were investigated. The permeate flux was strongly
affected by the feed inlet temperature, feed flow rate, and boundary
layer heat transfer coefficient. Since lowering the temperature
polarization coefficient is essential enhance the process performance
considerable and maximizing the heat transfer coefficient for
maximizes the mass flux of distillate water. In this paper, the results
of VMD experiments are used to measure the boundary layer heat
transfer coefficient, and the experimental results are used to reevaluate
the empirical constants in the Dittus- Boelter equation.
Digital Article Identifier (DOI):
129
9153
Process Parameter Optimization for the Production of Gentamicin using Micromonouspora Echiniospora
Abstract: The process parameters, temperature, pH and
substrate concentration, were optimized for the production of
gentamicin using Micromonouspora echinospora. Experiments were
carried out according to central composite design in response surface
method. The optimum conditions for the maximum production of
gentamicin were found to be: temperature – 31.7oC, pH – 6.8 and
substrate concentration – 3%. At these optimized conditions the
production of gentamicin was found to be – 1040 mg/L. The R2 value
of 0.9465 indicates a good fitness of the model.
Digital Article Identifier (DOI):
128
2720
Preparation and Bioactivity Evaluation of Bone like Hydroxyapatite - Bioglass Composite
Abstract: In this study, hydroxyapatite (HA) composites are
prepared on addition of 30%CaO-30%P2O5-40%Na2 O based glass to
pure HA, in proportion of 2, 5, and 10 wt %. Each composition was
sintered over a range of temperatures. The quantitative phase
analysis was carried out using XRD and the microstructures were
studied using SEM. The density, microhardness, and compressive
strength have shown increase with the increasing amount of glass
addition. The resulting composites have chemical compositions that
are similar to the inorganic constituent of the mineral part of bone,
and constitutes trace elements like Na. X-ray diffraction showed no
decomposition of HA to secondary phases, however, the glass
reinforced-HA composites contained a HA phase and variable
amounts of tricalcium phosphate phase, depending on the amount of
bioglass added. The HA-composite material exhibited higher
compressive strength compared to sintered HA. The HA composite
reinforced with 10 wt % bioglass showed highest bioactivity level.
Digital Article Identifier (DOI):
127
5014
Analysing Environmental Risks and Perceptions of Risks to Assess Health and Well-being in Poor Areas of Abidjan
Abstract: This study analyzed environmental health risks and
people-s perceptions of risks related to waste management in poor
settlements of Abidjan, to develop integrated solutions for health and
well-being improvement. The trans-disciplinary approach used relied
on remote sensing, a geographic information system (GIS),
qualitative and quantitative methods such as interviews and a
household survey (n=1800). Mitigating strategies were then
developed using an integrated participatory stakeholder workshop.
Waste management deficiencies resulting in lack of drainage and
uncontrolled solid and liquid waste disposal in the poor settlements
lead to severe environmental health risks. Health problems were
caused by direct handling of waste, as well as through broader
exposure of the population. People in poor settlements had little
awareness of health risks related to waste management in their
community and a general lack of knowledge pertaining to sanitation
systems. This unfortunate combination was the key determinant
affecting the health and vulnerability. For example, an increased
prevalence of malaria (47.1%) and diarrhoea (19.2%) was observed
in the rainy season when compared to the dry season (32.3% and
14.3%). Concerted and adapted solutions that suited all the
stakeholders concerned were developed in a participatory workshop
to allow for improvement of health and well-being.
Digital Article Identifier (DOI):
126
1397
Removal of Malachite Green from Aqueous Solution using Hydrilla verticillata -Optimization, Equilibrium and Kinetic Studies
Abstract: In this study, the sorption of Malachite green (MG) on Hydrilla verticillata biomass, a submerged aquatic plant, was investigated in a batch system. The effects of operating parameters such as temperature, adsorbent dosage, contact time, adsorbent size, and agitation speed on the sorption of Malachite green were analyzed using response surface methodology (RSM). The proposed quadratic model for central composite design (CCD) fitted very well to the experimental data that it could be used to navigate the design space according to ANOVA results. The optimum sorption conditions were determined as temperature - 43.5oC, adsorbent dosage - 0.26g, contact time - 200min, adsorbent size - 0.205mm (65mesh), and agitation speed - 230rpm. The Langmuir and Freundlich isotherm models were applied to the equilibrium data. The maximum monolayer coverage capacity of Hydrilla verticillata biomass for MG was found to be 91.97 mg/g at an initial pH 8.0 indicating that the optimum sorption initial pH. The external and intra particle diffusion models were also applied to sorption data of Hydrilla verticillata biomass with MG, and it was found that both the external diffusion as well as intra particle diffusion contributes to the actual sorption process. The pseudo-second order kinetic model described the MG sorption process with a good fitting.
Digital Article Identifier (DOI):
125
6156
Investigation into Heterotrophic Activities and Algal Biomass in Surface Flow Stormwater Wetlands
Abstract: Stormwater wetlands have been mainly designed in an
empirical approach for water quality improvement, with little
quantitative understanding of the internal microbial processes. This
study investigated into heterotrophic bacterial production rate,
heterotrophic bacterial mineralization percentage, and algal biomass
in hypertrophic and eutrophic surface flow stormwater wetlands.
Compared to a nearby wood leachate treatment wetland, the
stormwater wetlands had much higher chlorophyll-a concentrations.
The eutrophic stormwater wetland had improved water quality,
whereas the hypertrophic stormwater wetland had degraded water
quality. Heterotrophic bacterial activities in water were limited in the
stormwater wetlands due to competition of algal growth for nutrients.
The relative contribution of biofilms to the overall heterotrophic
activities was higher in the stormwater wetlands than that in the wood
leachate treatment wetland.
Digital Article Identifier (DOI):
124
14989
Development of a Catchment Water Quality Model for Continuous Simulations of Pollutants Build-up and Wash-off
Abstract: Estimation of runoff water quality parameters is required to determine appropriate water quality management options. Various models are used to estimate runoff water quality parameters. However, most models provide event-based estimates of water quality parameters for specific sites. The work presented in this paper describes the development of a model that continuously simulates the accumulation and wash-off of water quality pollutants in a catchment. The model allows estimation of pollutants build-up during dry periods and pollutants wash-off during storm events. The model was developed by integrating two individual models; rainfall-runoff model, and catchment water quality model. The rainfall-runoff model is based on the time-area runoff estimation method. The model allows users to estimate the time of concentration using a range of established methods. The model also allows estimation of the continuing runoff losses using any of the available estimation methods (i.e., constant, linearly varying or exponentially varying). Pollutants build-up in a catchment was represented by one of three pre-defined functions; power, exponential, or saturation. Similarly, pollutants wash-off was represented by one of three different functions; power, rating-curve, or exponential. The developed runoff water quality model was set-up to simulate the build-up and wash-off of total suspended solids (TSS), total phosphorus (TP) and total nitrogen (TN). The application of the model was demonstrated using available runoff and TSS field data from road and roof surfaces in the Gold Coast, Australia. The model provided excellent representation of the field data demonstrating the simplicity yet effectiveness of the proposed model.
Digital Article Identifier (DOI):
123
7435
Decolourization of Melanoidin Containing Wastewater Using South African Coal Fly Ash
Abstract: Batch adsorption of recalcitrant melanoidin using the abundantly available coal fly ash was carried out. It had low specific surface area (SBET) of 1.7287 m2/g and pore volume of 0.002245 cm3/g while qualitative evaluation of the predominant phases in it was done by XRD analysis. Colour removal efficiency was found to be dependent on various factors studied. Maximum colour removal was achieved around pH 6, whereas increasing sorbent mass from 10g/L to 200 g/L enhanced colour reduction from 25% to 86% at 298 K. Spontaneity of the process was suggested by negative Gibbs free energy while positive values for enthalpy change showed endothermic nature of the process. Non-linear optimization of error functions resulted in Freundlich and Redlich-Peterson isotherms describing sorption equilibrium data best. The coal fly ash had maximum sorption capacity of 53 mg/g and could thus be used as a low cost adsorbent in melanoidin removal.
Digital Article Identifier (DOI):
122
6420
Efficiency of Compact Organic Rankine Cycle System with Rotary-Vane-Type Expander for Low-Temperature Waste Heat Recovery
Abstract: This paper describes the experimental efficiency of a
compact organic Rankine cycle (ORC) system with a compact
rotary-vane-type expander. The compact ORC system can be used for
power generation from low-temperature heat sources such as waste
heat from various small-scale heat engines, fuel cells, electric devices,
and solar thermal energy. The purpose of this study is to develop an
ORC system with a low power output of less than 1 kW with a hot
temperature source ranging from 60°C to 100°C and a cold
temperature source ranging from 10°C to 30°C. The power output of
the system is rather less due to limited heat efficiency. Therefore, the
system should have an economically optimal efficiency. In order to
realize such a system, an efficient and low-cost expander is
indispensable. An experimental ORC system was developed using the
rotary-vane-type expander which is one of possible candidates of the
expander. The experimental results revealed the expander
performance for various rotation speeds, expander efficiencies, and
thermal efficiencies. Approximately 30 W of expander power output
with 48% expander efficiency and 4% thermal efficiency with a
temperature difference between the hot and cold sources of 80°C was
achieved.
Digital Article Identifier (DOI):
121
2617
Modeling Converters during the Warm-up Period for Hydrocarbon Oxidation
Abstract: Catalytic converters are used for minimizing the release of pollutants to the atmosphere. It is during the warm-up period that hydrocarbons are seen to be released in appreciable quantities from these converters. In this paper the conversion of a fast oxidizing hydrocarbon propylene is analysed using two numerical methods. The quasi steady state method assumes the accumulation terms to be negligible in the gas phase mass and energy balance equations, however this term is present in the solid phase energy balance. The unsteady state model accounts for the accumulation term to be present in the gas phase mass and energy balance and in the solid phase energy balance. The results derived from the two models for gas concentration, gas temperature and solid temperature are compared.
Digital Article Identifier (DOI):
120
537
Design and Economical Performance of Gray Water Treatment Plant in Rural Region
Abstract: In India, the quarrel between the budding human
populace and the planet-s unchanging supply of freshwater and
falling water tables has strained attention the reuse of gray water as
an alternative water resource in rural development. This paper
present the finest design of laboratory scale gray water treatment
plant, which is a combination of natural and physical operations such
as primary settling with cascaded water flow, aeration, agitation and
filtration, hence called as hybrid treatment process. The economical
performance of the plant for treatment of bathrooms, basins and
laundries gray water showed in terms of deduction competency of
water pollutants such as COD (83%), TDS (70%), TSS (83%), total
hardness (50%), oil and grease (97%), anions (46%) and cations
(49%). Hence, this technology could be a good alternative to treat
gray water in residential rural area.
Digital Article Identifier (DOI):
119
11749
A Normalization-based Robust Image Watermarking Scheme Using SVD and DCT
Abstract: Digital watermarking is one of the techniques for
copyright protection. In this paper, a normalization-based robust
image watermarking scheme which encompasses singular value
decomposition (SVD) and discrete cosine transform (DCT)
techniques is proposed. For the proposed scheme, the host image is
first normalized to a standard form and divided into non-overlapping
image blocks. SVD is applied to each block. By concatenating the
first singular values (SV) of adjacent blocks of the normalized image,
a SV block is obtained. DCT is then carried out on the SV blocks to
produce SVD-DCT blocks. A watermark bit is embedded in the highfrequency
band of a SVD-DCT block by imposing a particular
relationship between two pseudo-randomly selected DCT
coefficients. An adaptive frequency mask is used to adjust local
watermark embedding strength. Watermark extraction involves
mainly the inverse process. The watermark extracting method is blind
and efficient. Experimental results show that the quality degradation
of watermarked image caused by the embedded watermark is visually
transparent. Results also show that the proposed scheme is robust
against various image processing operations and geometric attacks.
Digital Article Identifier (DOI):
118
4393
Cognitive Radio Networks (CRN): Resource Allocation Techniques Based On DNA-inspired Computing
Abstract: Spectrum is a scarce commodity, and considering the spectrum scarcity faced by the wireless-based service providers led to high congestion levels. Technical inefficiencies from pooled, since all networks share a common pool of channels, exhausting the available channels will force networks to block the services. Researchers found that cognitive radio (CR) technology may resolve the spectrum scarcity. A CR is a self-configuring entity in a wireless networking that senses its environment, tracks changes, and frequently exchanges information with their networks. However, CRN facing challenges and condition become worst while tracks changes i.e. reallocation of another under-utilized channels while primary network user arrives. In this paper, channels or resource reallocation technique based on DNA-inspired computing algorithm for CRN has been proposed.
Digital Article Identifier (DOI):
117
15687
Impact of the Decoder Connection Schemes on Iterative Decoding of GPCB Codes
Abstract: In this paper we present a study of the impact of connection schemes on the performance of iterative decoding of Generalized Parallel Concatenated block (GPCB) constructed from one step majority logic decodable (OSMLD) codes and we propose a new connection scheme for decoding them. All iterative decoding connection schemes use a soft-input soft-output threshold decoding algorithm as a component decoder. Numerical result for GPCB codes transmitted over Additive White Gaussian Noise (AWGN) channel are provided. It will show that the proposed scheme is better than Hagenauer-s scheme and Lucas-s scheme [1] and slightly better than the Pyndiah-s scheme.
Digital Article Identifier (DOI):
116
2029
Fairness and Quality of Service Issues and Analysis of IEEE 802.11e Wireless LAN
Abstract: The IEEE 802.11e which is an enhanced version of the 802.11 WLAN standards incorporates the Quality of Service (QoS) which makes it a better choice for multimedia and real time applications. In this paper we study various aspects concerned with 802.11e standard. Further, the analysis results for this standard are compared with the legacy 802.11 standard. Simulation results show that IEEE 802.11e out performs legacy IEEE 802.11 in terms of quality of service due to its flow differentiated channel allocation and better queue management architecture. We also propose a method to improve the unfair allocation of bandwidth for downlink and uplink channels by varying the medium access priority level.
Digital Article Identifier (DOI):
115
14021
Noise Performance Optimization of a Fast Wavelength Calibration Algorithm for OSAs
Abstract: A new fast correlation algorithm for calibrating the
wavelength of Optical Spectrum Analyzers (OSAs) was introduced
in [1]. The minima of acetylene gas spectra were measured and
correlated with saved theoretical data [2]. So it is possible to find the
correct wavelength calibration data using a noisy reference spectrum.
First tests showed good algorithmic performance for gas line spectra
with high noise. In this article extensive performance tests were made
to validate the noise resistance of this algorithm. The filter and
correlation parameters of the algorithm were optimized for improved
noise performance. With these parameters the performance of this
wavelength calibration was simulated to predict the resulting
wavelength error in real OSA systems. Long term simulations were
made to evaluate the performance of the algorithm over the lifetime
of a real OSA.
Digital Article Identifier (DOI):
114
6010
Distributed Relay Selection and Channel Choice in Cognitive Radio Network
Abstract: In this paper, we study the cooperative communications where multiple cognitive radio (CR) transmit-receive pairs competitive maximize their own throughputs. In CR networks, the influences of primary users and the spectrum availability are usually different among CR users. Due to the existence of multiple relay nodes and the different spectrum availability, each CR transmit-receive pair should not only select the relay node but also choose the appropriate channel. For this distributed problem, we propose a game theoretic framework to formulate this problem and we apply a regret-matching learning algorithm which is leading to correlated equilibrium. We further formulate a modified regret-matching learning algorithm which is fully distributed and only use the local information of each CR transmit-receive pair. This modified algorithm is more practical and suitable for the cooperative communications in CR network. Simulation results show the algorithm convergence and the modified learning algorithm can achieve comparable performance to the original regretmatching learning algorithm.
Digital Article Identifier (DOI):
113
2090
Localizing and Recognizing Integral Pitches of Cheque Document Images
Abstract: Automatic reading of handwritten cheque is a computationally
complex process and it plays an important role in financial
risk management. Machine vision and learning provide a viable
solution to this problem. Research effort has mostly been focused
on recognizing diverse pitches of cheques and demand drafts with an
identical outline. However most of these methods employ templatematching
to localize the pitches and such schemes could potentially
fail when applied to different types of outline maintained by the
bank. In this paper, the so-called outline problem is resolved by
a cheque information tree (CIT), which generalizes the localizing
method to extract active-region-of-entities. In addition, the weight
based density plot (WBDP) is performed to isolate text entities and
read complete pitches. Recognition is based on texture features using
neural classifiers. Legal amount is subsequently recognized by both
texture and perceptual features. A post-processing phase is invoked
to detect the incorrect readings by Type-2 grammar using the Turing
machine. The performance of the proposed system was evaluated
using cheque and demand drafts of 22 different banks. The test data
consists of a collection of 1540 leafs obtained from 10 different
account holders from each bank. Results show that this approach
can easily be deployed without significant design amendments.
Digital Article Identifier (DOI):
112
9207
Static Single Point Positioning Using The Extended Kalman Filter
Abstract: Global Positioning System (GPS) technology is widely used today in the areas of geodesy and topography as well as in aeronautics mainly for military purposes. Due to the military usage of GPS, full access and use of this technology is being denied to the civilian user who must then work with a less accurate version. In this paper we focus on the estimation of the receiver coordinates ( X, Y, Z ) and its clock bias ( δtr ) of a fixed point based on pseudorange measurements of a single GPS receiver. Utilizing the instantaneous coordinates of just 4 satellites and their clock offsets, by taking into account the atmospheric delays, we are able to derive a set of pseudorange equations. The estimation of the four unknowns ( X, Y, Z , δtr ) is achieved by introducing an extended Kalman filter that processes, off-line, all the data collected from the receiver. Higher performance of position accuracy is attained by appropriate tuning of the filter noise parameters and by including other forms of biases.
Digital Article Identifier (DOI):
111
14145
An Adaptive Model for Blind Image Restoration using Bayesian Approach
Abstract: Image restoration involves elimination of noise. Filtering techniques were adopted so far to restore images since last five decades. In this paper, we consider the problem of image restoration degraded by a blur function and corrupted by random noise. A method for reducing additive noise in images by explicit analysis of local image statistics is introduced and compared to other noise reduction methods. The proposed method, which makes use of an a priori noise model, has been evaluated on various types of images. Bayesian based algorithms and technique of image processing have been described and substantiated with experimentation using MATLAB.
Digital Article Identifier (DOI):
110
2816
An Efficient Technique for EMI Mitigation in Fluorescent Lamps using Frequency Modulation and Evolutionary Programming
Abstract: Electromagnetic interference (EMI) is one of the
serious problems in most electrical and electronic appliances
including fluorescent lamps. The electronic ballast used to regulate
the power flow through the lamp is the major cause for EMI. The
interference is because of the high frequency switching operation of
the ballast. Formerly, some EMI mitigation techniques were in
practice, but they were not satisfactory because of the hardware
complexity in the circuit design, increased parasitic components and
power consumption and so on. The majority of the researchers have
their spotlight only on EMI mitigation without considering the other
constraints such as cost, effective operation of the equipment etc. In
this paper, we propose a technique for EMI mitigation in fluorescent
lamps by integrating Frequency Modulation and Evolutionary
Programming. By the Frequency Modulation technique, the
switching at a single central frequency is extended to a range of
frequencies, and so, the power is distributed throughout the range of
frequencies leading to EMI mitigation. But in order to meet the
operating frequency of the ballast and the operating power of the
fluorescent lamps, an optimal modulation index is necessary for
Frequency Modulation. The optimal modulation index is determined
using Evolutionary Programming. Thereby, the proposed technique
mitigates the EMI to a satisfactory level without disturbing the
operation of the fluorescent lamp.
Digital Article Identifier (DOI):
109
520
Supporting QoS-aware Multicasting in Differentiated Service Networks
Abstract: A scalable QoS aware multicast deployment in
DiffServ networks has become an important research dimension in
recent years. Although multicasting and differentiated services are
two complementary technologies, the integration of the two
technologies is a non-trivial task due to architectural conflicts
between them. A popular solution proposed is to extend the
functionality of the DiffServ components to support multicasting. In
this paper, we propose an algorithm to construct an efficient QoSdriven
multicast tree, taking into account the available bandwidth per
service class. We also present an efficient way to provision the
limited available bandwidth for supporting heterogeneous users. The
proposed mechanism is evaluated using simulated tests. The
simulated result reveals that our algorithm can effectively minimize
the bandwidth use and transmission cost
Digital Article Identifier (DOI):
108
11580
Fault Localization and Alarm Correlation in Optical WDM Networks
Abstract: For several high speed networks, providing resilience against failures is an essential requirement. The main feature for designing next generation optical networks is protecting and restoring high capacity WDM networks from the failures. Quick detection, identification and restoration make networks more strong and consistent even though the failures cannot be avoided. Hence, it is necessary to develop fast, efficient and dependable fault localization or detection mechanisms. In this paper we propose a new fault localization algorithm for WDM networks which can identify the location of a failure on a failed lightpath. Our algorithm detects the failed connection and then attempts to reroute data stream through an alternate path. In addition to this, we develop an algorithm to analyze the information of the alarms generated by the components of an optical network, in the presence of a fault. It uses the alarm correlation in order to reduce the list of suspected components shown to the network operators. By our simulation results, we show that our proposed algorithms achieve less blocking probability and delay while getting higher throughput.
Digital Article Identifier (DOI):
107
8079
Watermarking Scheme for Color Images using Wavelet Transform based Texture Properties and Secret Sharing
Abstract: In this paper, a new secure watermarking scheme for
color image is proposed. It splits the watermark into two shares using
(2, 2)- threshold Visual Cryptography Scheme (V CS) with Adaptive
Order Dithering technique and embeds one share into high textured
subband of Luminance channel of the color image. The other share
is used as the key and is available only with the super-user or the
author of the image. In this scheme only the super-user can reveal
the original watermark. The proposed scheme is dynamic in the sense
that to maintain the perceptual similarity between the original and the
watermarked image the selected subband coefficients are modified
by varying the watermark scaling factor. The experimental results
demonstrate the effectiveness of the proposed scheme. Further, the
proposed scheme is able to resist all common attacks even with strong
amplitude.
Digital Article Identifier (DOI):
106
14949
Presenting a Combinatorial Feature to Estimate Depth of Anesthesia
Abstract: Determining depth of anesthesia is a challenging problem
in the context of biomedical signal processing. Various methods
have been suggested to determine a quantitative index as depth of
anesthesia, but most of these methods suffer from high sensitivity
during the surgery. A novel method based on energy scattering of
samples in the wavelet domain is suggested to represent the basic
content of electroencephalogram (EEG) signal. In this method, first
EEG signal is decomposed into different sub-bands, then samples
are squared and energy of samples sequence is constructed through
each scale and time, which is normalized and finally entropy of the
resulted sequences is suggested as a reliable index. Empirical Results
showed that applying the proposed method to the EEG signals can
classify the awake, moderate and deep anesthesia states similar to
BIS.
Digital Article Identifier (DOI):
105
8329
Persian Printed Numeral Characters Recognition Using Geometrical Central Moments and Fuzzy Min-Max Neural Network
Abstract: In this paper, a new proposed system for Persian
printed numeral characters recognition with emphasis on
representation and recognition stages is introduced. For the first time,
in Persian optical character recognition, geometrical central moments
as character image descriptor and fuzzy min-max neural network for
Persian numeral character recognition has been used. Set of different
experiments on binary images of regular, translated, rotated and
scaled Persian numeral characters has been done and variety of
results has been presented. The best result was 99.16% correct
recognition demonstrating geometrical central moments and fuzzy
min-max neural network are adequate for Persian printed numeral
character recognition.
Digital Article Identifier (DOI):
104
27
Quadrature Formula for Sampled Functions
Abstract: This paper deals with efficient quadrature formulas involving functions that are observed only at fixed sampling points. The approach that we develop is derived from efficient continuous quadrature formulas, such as Gauss-Legendre or Clenshaw-Curtis quadrature. We select nodes at sampling positions that are as close as possible to those of the associated classical quadrature and we update quadrature weights accordingly. We supply the theoretical quadrature error formula for this new approach. We show on examples the potential gain of this approach.
Digital Article Identifier (DOI):
103
14677
Overloading Scheme for Cellular DS-CDMA using Quasi-Orthogonal Sequences and Iterative Interference Cancellation Receiver
Abstract: Overloading is a technique to accommodate more
number of users than the spreading factor N. This is a bandwidth
efficient scheme to increase the number users in a fixed bandwidth.
One of the efficient schemes to overload a CDMA system is to use
two sets of orthogonal signal waveforms (O/O). The first set is
assigned to the N users and the second set is assigned to the
additional M users. An iterative interference cancellation technique is
used to cancel interference between the two sets of users. In this
paper, the performance of an overloading scheme in which the first N
users are assigned Walsh-Hadamard orthogonal codes and extra users
are assigned the same WH codes but overlaid by a fixed (quasi) bent
sequence [11] is evaluated. This particular scheme is called Quasi-
Orthogonal Sequence (QOS) O/O scheme, which is a part of
cdma2000 standard [12] to provide overloading in the downlink
using single user detector. QOS scheme are balance O/O scheme,
where the correlation between any set-1 and set-2 users are
equalized. The allowable overload of this scheme is investigated in
the uplink on an AWGN and Rayleigh fading channels, so that the
uncoded performance with iterative multistage interference
cancellation detector remains close to the single user bound. It is
shown that this scheme provides 19% and 11% overloading with
SDIC technique for N= 16 and 64 respectively, with an SNR
degradation of less than 0.35 dB as compared to single user bound at
a BER of 0.00001. But on a Rayleigh fading channel, the channel
overloading is 45% (29 extra users) at a BER of 0.0005, with an SNR
degradation of about 1 dB as compared to single user performance
for N=64. This is a significant amount of channel overloading on a
Rayleigh fading channel.
Digital Article Identifier (DOI):
102
1135
Edge Segmentation of Satellite Image using Phase Congruency Model
Abstract: In this paper, we present a method for edge
segmentation of satellite images based on 2-D Phase Congruency
(PC) model. The proposed approach is composed by two steps: The
contextual non linear smoothing algorithm (CNLS) is used to smooth
the input images. Then, the 2D stretched Gabor filter (S-G filter)
based on proposed angular variation is developed in order to avoid
the multiple responses in the previous work. An assessment of our
proposed method performance is provided in terms of accuracy of
satellite image edge segmentation. The proposed method is compared
with others known approaches.
Digital Article Identifier (DOI):
101
2291
Online Signature Verification Using Angular Transformation for e-Commerce Services
Abstract: The rapid growth of e-Commerce services is
significantly observed in the past decade. However, the method to
verify the authenticated users still widely depends on numeric
approaches. A new search on other verification methods suitable for
online e-Commerce is an interesting issue. In this paper, a new online
signature-verification method using angular transformation is
presented. Delay shifts existing in online signatures are estimated by
the estimation method relying on angle representation. In the
proposed signature-verification algorithm, all components of input
signature are extracted by considering the discontinuous break points
on the stream of angular values. Then the estimated delay shift is
captured by comparing with the selected reference signature and the
error matching can be computed as a main feature used for verifying
process. The threshold offsets are calculated by two types of error
characteristics of the signature verification problem, False Rejection
Rate (FRR) and False Acceptance Rate (FAR). The level of these two
error rates depends on the decision threshold chosen whose value is
such as to realize the Equal Error Rate (EER; FAR = FRR). The
experimental results show that through the simple programming,
employed on Internet for demonstrating e-Commerce services, the
proposed method can provide 95.39% correct verifications and 7%
better than DP matching based signature-verification method. In
addition, the signature verification with extracting components
provides more reliable results than using a whole decision making.
Digital Article Identifier (DOI):
100
7706
Color Image Segmentation using Adaptive Spatial Gaussian Mixture Model
Abstract: An adaptive spatial Gaussian mixture model is proposed for clustering based color image segmentation. A new clustering objective function which incorporates the spatial information is introduced in the Bayesian framework. The weighting parameter for controlling the importance of spatial information is made adaptive to the image content to augment the smoothness towards piecewisehomogeneous region and diminish the edge-blurring effect and hence the name adaptive spatial finite mixture model. The proposed approach is compared with the spatially variant finite mixture model for pixel labeling. The experimental results with synthetic and Berkeley dataset demonstrate that the proposed method is effective in improving the segmentation and it can be employed in different practical image content understanding applications.
Digital Article Identifier (DOI):
99
10231
Input Textural Feature Selection By Mutual Information For Multispectral Image Classification
Abstract: Texture information plays increasingly an important
role in remotely sensed imagery classification and many pattern
recognition applications. However, the selection of relevant textural
features to improve this classification accuracy is not a straightforward
task. This work investigates the effectiveness of two Mutual
Information Feature Selector (MIFS) algorithms to select salient
textural features that contain highly discriminatory information for
multispectral imagery classification. The input candidate features are
extracted from a SPOT High Resolution Visible(HRV) image using
Wavelet Transform (WT) at levels (l = 1,2).
The experimental results show that the selected textural features
according to MIFS algorithms make the largest contribution to
improve the classification accuracy than classical approaches such
as Principal Components Analysis (PCA) and Linear Discriminant
Analysis (LDA).
Digital Article Identifier (DOI):
98
3764
Speaker Identification Using Admissible Wavelet Packet Based Decomposition
Abstract: Mel Frequency Cepstral Coefficient (MFCC) features
are widely used as acoustic features for speech recognition as well
as speaker recognition. In MFCC feature representation, the Mel frequency
scale is used to get a high resolution in low frequency region,
and a low resolution in high frequency region. This kind of processing
is good for obtaining stable phonetic information, but not suitable
for speaker features that are located in high frequency regions. The
speaker individual information, which is non-uniformly distributed
in the high frequencies, is equally important for speaker recognition.
Based on this fact we proposed an admissible wavelet packet based
filter structure for speaker identification. Multiresolution capabilities
of wavelet packet transform are used to derive the new features.
The proposed scheme differs from previous wavelet based works,
mainly in designing the filter structure. Unlike others, the proposed
filter structure does not follow Mel scale. The closed-set speaker
identification experiments performed on the TIMIT database shows
improved identification performance compared to other commonly
used Mel scale based filter structures using wavelets.
Digital Article Identifier (DOI):
97
7489
Design of Stable IIR Digital Filters with Specified Group Delay Errors
Abstract: The design problem of Infinite Impulse Response (IIR)
digital filters is usually expressed as the minimization problem of
the complex magnitude error that includes both the magnitude and
phase information. However, the group delay of the filter obtained
by solving such design problem may be far from the desired group
delay. In this paper, we propose a design method of stable IIR digital
filters with prespecified maximum group delay errors. In the proposed
method, the approximation problems of the magnitude-phase and
group delay are separately defined, and these two approximation
problems are alternately solved using successive projections. As a
result, the proposed method can design the IIR filters that satisfy the
prespecified allowable errors for not only the complex magnitude but
also the group delay by alternately executing the coefficient update
for the magnitude-phase and the group delay approximation. The
usefulness of the proposed method is verified through some examples.
Digital Article Identifier (DOI):
96
11327
Fast Wavelength Calibration Algorithm for Optical Spectrum Analyzers
Abstract: In this paper an algorithm for fast wavelength calibration of Optical Spectrum Analyzers (OSAs) using low power reference gas spectra is proposed. In existing OSAs a reference spectrum with low noise for precise detection of the reference extreme values is needed. To generate this spectrum costly hardware with high optical power is necessary. With this new wavelength calibration algorithm it is possible to use a noisy reference spectrum and therefore hardware costs can be cut. With this algorithm the reference spectrum is filtered and the key information is extracted by segmenting and finding the local minima and maxima. Afterwards slope and offset of a linear correction function for best matching the measured and theoretical spectra are found by correlating the measured with the stored minima. With this algorithm a reliable wavelength referencing of an OSA can be implemented on a microcontroller with a calculation time of less than one second.
Digital Article Identifier (DOI):
95
721
Relationship between Level of Physical Activity and Exercise Imagery among Klang Valley Citizens
Abstract: This study investigated the relationship between
exercise imagery use and level of physical activity within a wide
range of exercisers in Klang valley, Malaysia. One hundred and
twenty four respondents (Mage = 28.92, SD = 9.34) completed two
sets of questionnaires (Exercise Imagery Inventory and Leisure-Time
Exercise Questionnaire) that measure the use of imagery and exercise
frequency of participants. From the result obtained, exercise imagery
is found to be significantly correlated to level of physical activity.
Besides that, variables such as gender, age and ethnicity that may
affect the use of imagery and exercise frequency were also being
assessed in this study. Among all variables, only ethnicity showed
significant difference in level of physical activity (p < 0.05). Findings
in this study suggest that further investigation should be done on
other variables such as socioeconomic, educational level, and selfefficacy
that may affect the imagery use and frequency of physical
activity among exercisers.
Digital Article Identifier (DOI):
94
3683
Fast Forecasting of Stock Market Prices by using New High Speed Time Delay Neural Networks
Abstract: Fast forecasting of stock market prices is very important for
strategic planning. In this paper, a new approach for fast forecasting of
stock market prices is presented. Such algorithm uses new high speed
time delay neural networks (HSTDNNs). The operation of these
networks relies on performing cross correlation in the frequency
domain between the input data and the input weights of neural
networks. It is proved mathematically and practically that the number
of computation steps required for the presented HSTDNNs is less
than that needed by traditional time delay neural networks
(TTDNNs). Simulation results using MATLAB confirm the
theoretical computations.
Digital Article Identifier (DOI):
93
1426
Heterogeneity-Aware Load Balancing for Multimedia Access over Wireless LAN Hotspots
Abstract: Wireless LAN (WLAN) access in public hotspot areas
becomes popular in the recent years. Since more and more multimedia
information is available in the Internet, there is an increasing demand
for accessing multimedia information through WLAN hotspots.
Currently, the bandwidth offered by an IEEE 802.11 WLAN cannot
afford many simultaneous real-time video accesses. A possible way to
increase the offered bandwidth in a hotspot is the use of multiple access
points (APs). However, a mobile station is usually connected to the
WLAN AP with the strongest received signal strength indicator (RSSI).
The total consumed bandwidth cannot be fairly allocated among those
APs. In this paper, we will propose an effective load-balancing scheme
via the support of the IAPP and SNMP in APs. The proposed scheme is
an open solution and doesn-t need any changes in both wireless stations
and APs. This makes load balancing possible in WLAN hotspots,
where a variety of heterogeneous mobile devices are employed.
Digital Article Identifier (DOI):
92
6650
An Adaptive Mammographic Image Enhancement in Orthogonal Polynomials Domain
Abstract: X-ray mammography is the most effective method for
the early detection of breast diseases. However, the typical diagnostic
signs such as microcalcifications and masses are difficult to detect
because mammograms are of low-contrast and noisy. In this paper, a
new algorithm for image denoising and enhancement in Orthogonal
Polynomials Transformation (OPT) is proposed for radiologists to
screen mammograms. In this method, a set of OPT edge coefficients
are scaled to a new set by a scale factor called OPT scale factor. The
new set of coefficients is then inverse transformed resulting in
contrast improved image. Applications of the proposed method to
mammograms with subtle lesions are shown. To validate the
effectiveness of the proposed method, we compare the results to
those obtained by the Histogram Equalization (HE) and the Unsharp
Masking (UM) methods. Our preliminary results strongly suggest
that the proposed method offers considerably improved enhancement
capability over the HE and UM methods.
Digital Article Identifier (DOI):
91
10916
Audio Watermarking Based on Compression-expansion Technique
Abstract: A novel robust audio watermarking scheme is
proposed in this paper. In the proposed scheme, the host audio signals
are segmented into frames. Two consecutive frames are assessed if
they are suitable to represent a watermark bit. If so, frequency
transform is performed on these two frames. The compressionexpansion
technique is adopted to generate distortion over the two
frames. The distortion is used to represent one watermark bit.
Psychoacoustic model is applied to calculate local auditory mask to
ensure that the distortion is not audible. The watermarking schemes
using mono and stereo audio signals are designed differently. The
correlation-based detection method is used to detect the distortion
and extract embedded watermark bits. The experimental results show
that the quality degradation caused by the embedded watermarks is
perceptually transparent and the proposed schemes are very robust
against different types of attacks.
Digital Article Identifier (DOI):
90
1245
Dynamic Attribute Dependencies in Relational Attribute Grammars
Abstract: Considering the theory of attribute grammars, we use
logical formulas instead of traditional functional semantic rules.
Following the decoration of a derivation tree, a suitable algorithm
should maintain the consistency of the formulas together with the
evaluation of the attributes. This may be a Prolog-like resolution, but
this paper examines a somewhat different strategy, based on
production specialization, local consistency and propagation: given a
derivation tree, it is interactively decorated, i.e. incrementally
checked and evaluated. The non-directed dependencies are
dynamically directed during attribute evaluation.
Digital Article Identifier (DOI):
89
3811
Analysis of Classifications of Unsolicited Bulk Emails
Abstract: In recent times, the problem of Unsolicited Bulk
Email (UBE) or commonly known as Spam Email, has increased at a
tremendous growth rate. We present an analysis of survey based on
classifications of UBE in various research works. There are many
research instances for classification between spam and non-spam
emails but very few research instances are available for classification
of spam emails, per se. This paper does not intend to assert some
UBE classification to be better than the others nor does it propose
any new classification but it bemoans the lack of harmony on number
and definition of categories proposed by different researchers. The
paper also elaborates on factors like intent of spammer, content of
UBE and ambiguity in different categories as proposed in related
research works of classifications of UBE.
Digital Article Identifier (DOI):
88
2432
A Delay-Tolerant Distributed Query Processing Architecture for Mobile Environment
Abstract: The intermittent connectivity modifies the “always
on" network assumption made by all the distributed query processing
systems. In modern- day systems, the absence of network
connectivity is considered as a fault. Since the last upload, it might
not be feasible to transmit all the data accumulated right away over
the available connection. It is possible that vital information may be
delayed excessively when the less important information takes place
of the vital information. Owing to the restricted and uneven
bandwidth, it is vital that the mobile nodes make the most
advantageous use of the connectivity when it arrives. Hence, in order
to select the data that needs to be transmitted first, some sort of data
prioritization is essential. A continuous query processing system for
intermittently connected mobile networks that comprises of a delaytolerant
continuous query processor distributed across the mobile
hosts has been proposed in this paper. In addition, a mechanism for
prioritizing query results has been designed that guarantees enhanced
accuracy and reduced delay. It is illustrated that our architecture
reduces the client power consumption, increases query efficiency by
the extensive simulation results.
Digital Article Identifier (DOI):
87
6469
Multiobjective Optimization Solution for Shortest Path Routing Problem
Abstract: The shortest path routing problem is a multiobjective
nonlinear optimization problem with constraints. This problem has
been addressed by considering Quality of service parameters, delay
and cost objectives separately or as a weighted sum of both
objectives. Multiobjective evolutionary algorithms can find multiple
pareto-optimal solutions in one single run and this ability makes them
attractive for solving problems with multiple and conflicting
objectives. This paper uses an elitist multiobjective evolutionary
algorithm based on the Non-dominated Sorting Genetic Algorithm
(NSGA), for solving the dynamic shortest path routing problem in
computer networks. A priority-based encoding scheme is proposed
for population initialization. Elitism ensures that the best solution
does not deteriorate in the next generations. Results for a sample test
network have been presented to demonstrate the capabilities of the
proposed approach to generate well-distributed pareto-optimal
solutions of dynamic routing problem in one single run. The results
obtained by NSGA are compared with single objective weighting
factor method for which Genetic Algorithm (GA) was applied.
Digital Article Identifier (DOI):
86
15825
Controller Design of Discrete Systems by Order Reduction Technique Employing Differential Evolution Optimization Algorithm
Abstract: One of the main objectives of order reduction is to
design a controller of lower order which can effectively control the
original high order system so that the overall system is of lower
order and easy to understand. In this paper, a simple method is
presented for controller design of a higher order discrete system.
First the original higher order discrete system in reduced to a lower
order model. Then a Proportional Integral Derivative (PID)
controller is designed for lower order model. An error minimization
technique is employed for both order reduction and controller
design. For the error minimization purpose, Differential Evolution
(DE) optimization algorithm has been employed. DE method is
based on the minimization of the Integral Squared Error (ISE)
between the desired response and actual response pertaining to a
unit step input. Finally the designed PID controller is connected to
the original higher order discrete system to get the desired
specification. The validity of the proposed method is illustrated
through a numerical example.
Digital Article Identifier (DOI):
85
11021
A Degraded Practical MIMOME Channel: Issues Insecret Data Communications
Abstract: In this paper, a Gaussian multiple input multiple output multiple eavesdropper (MIMOME) channel is considered where a transmitter communicates to a receiver in the presence of an eavesdropper. We present a technique for determining the secrecy capacity of the multiple input multiple output (MIMO) channel under Gaussian noise. We transform the degraded MIMOME channel into multiple single input multiple output (SIMO) Gaussian wire-tap channels and then use scalar approach to convert it into two equivalent multiple input single output (MISO) channels. The secrecy capacity model is then developed for the condition where the channel state information (CSI) for main channel only is known to the transmitter. The results show that the secret communication is possible when the eavesdropper channel noise is greater than a cutoff noise level. The outage probability is also analyzed of secrecy capacity is also analyzed. The effect of fading and outage probability is also analyzed.
Digital Article Identifier (DOI):
84
2608
Error Correction Codes in Wireless Sensor Network: An Energy Aware Approach
Abstract: Link reliability and transmitted power are two important design constraints in wireless network design. Error control coding (ECC) is a classic approach used to increase link reliability and to lower the required transmitted power. It provides coding gain, resulting in transmitter energy savings at the cost of added decoder power consumption. But the choice of ECC is very critical in the case of wireless sensor network (WSN). Since the WSNs are energy constraint in nature, both the BER and power consumption has to be taken into count. This paper develops a step by step approach in finding suitable error control codes for WSNs. Several simulations are taken considering different error control codes and the result shows that the RS(31,21) fits both in BER and power consumption criteria.
Digital Article Identifier (DOI):
83
5510
A Purpose Based Usage Access Control Model
Abstract: As privacy becomes a major concern for consumers
and enterprises, many research have been focused on the privacy
protecting technology in recent years. In this paper, we present a
comprehensive approach for usage access control based on the notion
purpose. In our model, purpose information associated with a given
data element specifies the intended use of the subjects and objects in
the usage access control model. A key feature of our model is that it
allows when an access is required, the access purpose is checked
against the intended purposes for the data item. We propose an
approach to represent purpose information to support access control
based on purpose information. Our proposed solution relies on usage
access control (UAC) models as well as the components which based
on the notions of the purpose information used in subjects and
objects. Finally, comparisons with related works are analyzed.
Digital Article Identifier (DOI):
82
5655
A Hamiltonian Decomposition of 5-star
Abstract: Star graphs are Cayley graphs of symmetric groups of permutations, with transpositions as the generating sets. A star graph is a preferred interconnection network topology to a hypercube for its ability to connect a greater number of nodes with lower degree. However, an attractive property of the hypercube is that it has a Hamiltonian decomposition, i.e. its edges can be partitioned into disjoint Hamiltonian cycles, and therefore a simple routing can be found in the case of an edge failure. The existence of Hamiltonian cycles in Cayley graphs has been known for some time. So far, there are no published results on the much stronger condition of the existence of Hamiltonian decompositions. In this paper, we give a construction of a Hamiltonian decomposition of the star graph 5-star of degree 4, by defining an automorphism for 5-star and a Hamiltonian cycle which is edge-disjoint with its image under the automorphism.
Digital Article Identifier (DOI):
81
10894
A Hybrid Data Mining Method for the Medical Classification of Chest Pain
Abstract: Data mining techniques have been used in medical
research for many years and have been known to be effective. In order
to solve such problems as long-waiting time, congestion, and delayed
patient care, faced by emergency departments, this study concentrates
on building a hybrid methodology, combining data mining techniques
such as association rules and classification trees. The methodology is
applied to real-world emergency data collected from a hospital and is
evaluated by comparing with other techniques. The methodology is
expected to help physicians to make a faster and more accurate
classification of chest pain diseases.
Digital Article Identifier (DOI):
80
5944
Power Efficient OFDM Signals with Reduced Symbol's Aperiodic Autocorrelation
Abstract: Three new algorithms based on minimization of autocorrelation of transmitted symbols and the SLM approach which are computationally less demanding have been proposed. In the first algorithm, autocorrelation of complex data sequence is minimized to a value of 1 that results in reduction of PAPR. Second algorithm generates multiple random sequences from the sequence generated in the first algorithm with same value of autocorrelation i.e. 1. Out of these, the sequence with minimum PAPR is transmitted. Third algorithm is an extension of the second algorithm and requires minimum side information to be transmitted. Multiple sequences are generated by modifying a fixed number of complex numbers in an OFDM data sequence using only one factor. The multiple sequences represent the same data sequence and the one giving minimum PAPR is transmitted. Simulation results for a 256 subcarrier OFDM system show that significant reduction in PAPR is achieved using the proposed algorithms.
Digital Article Identifier (DOI):
79
14876
Autonomous Virtual Agent Navigation in Virtual Environments
Abstract: This paper presents a solution for the behavioural
animation of autonomous virtual agent navigation in virtual environments.
We focus on using Dempster-Shafer-s Theory of Evidence
in developing visual sensor for virtual agent. The role of the visual
sensor is to capture the information about the virtual environment
or identifie which part of an obstacle can be seen from the position
of the virtual agent. This information is require for vitual agent to
coordinate navigation in virtual environment. The virual agent uses
fuzzy controller as a navigation system and Fuzzy α - level for
the action selection method. The result clearly demonstrates the path
produced is reasonably smooth even though there is some sharp turn
and also still not diverted too far from the potential shortest path.
This had indicated the benefit of our method, where more reliable
and accurate paths produced during navigation task.
Digital Article Identifier (DOI):
78
8891
Methods for Case Maintenance in Case-Based Reasoning
Abstract: Case-Based Reasoning (CBR) is one of machine
learning algorithms for problem solving and learning that caught a lot
of attention over the last few years. In general, CBR is composed of
four main phases: retrieve the most similar case or cases, reuse the
case to solve the problem, revise or adapt the proposed solution, and
retain the learned cases before returning them to the case base for
learning purpose. Unfortunately, in many cases, this retain process
causes the uncontrolled case base growth. The problem affects
competence and performance of CBR systems. This paper proposes
competence-based maintenance method based on deletion policy
strategy for CBR. There are three main steps in this method. Step 1,
formulate problems. Step 2, determine coverage and reachability set
based on coverage value. Step 3, reduce case base size. The results
obtained show that this proposed method performs better than the
existing methods currently discussed in literature.
Digital Article Identifier (DOI):
77
986
Multiscale Analysis and Change Detection Based on a Contrario Approach
Abstract: Automatic methods of detecting changes through
satellite imaging are the object of growing interest, especially
beca²use of numerous applications linked to analysis of the Earth’s
surface or the environment (monitoring vegetation, updating maps,
risk management, etc...). This work implemented spatial analysis
techniques by using images with different spatial and spectral
resolutions on different dates. The work was based on the principle
of control charts in order to set the upper and lower limits beyond
which a change would be noted. Later, the a contrario approach was
used. This was done by testing different thresholds for which the
difference calculated between two pixels was significant. Finally,
labeled images were considered, giving a particularly low difference
which meant that the number of “false changes” could be estimated
according to a given limit.
Digital Article Identifier (DOI):
76
177
Optimal Path Planning under Priori Information in Stochastic, Time-varying Networks
Abstract: A novel path planning approach is presented to solve
optimal path in stochastic, time-varying networks under priori traffic
information. Most existing studies make use of dynamic programming
to find optimal path. However, those methods are proved to
be unable to obtain global optimal value, moreover, how to design
efficient algorithms is also another challenge.
This paper employs a decision theoretic framework for defining
optimal path: for a given source S and destination D in urban transit
network, we seek an S - D path of lowest expected travel time
where its link travel times are discrete random variables. To solve
deficiency caused by the methods of dynamic programming, such as
curse of dimensionality and violation of optimal principle, an integer
programming model is built to realize assignment of discrete travel
time variables to arcs. Simultaneously, pruning techniques are also
applied to reduce computation complexity in the algorithm. The final
experiments show the feasibility of the novel approach.
Digital Article Identifier (DOI):
75
10461
A Note on the Minimum Cardinality of Critical Sets of Inertias for Irreducible Zero-nonzero Patterns of Order 4
Abstract: If there exists a nonempty, proper subset S of the set of all (n+1)(n+2)/2 inertias such that S Ôèå i(A) is sufficient for any n×n zero-nonzero pattern A to be inertially arbitrary, then S is called a critical set of inertias for zero-nonzero patterns of order n. If no proper subset of S is a critical set, then S is called a minimal critical set of inertias. In [Kim, Olesky and Driessche, Critical sets of inertias for matrix patterns, Linear and Multilinear Algebra, 57 (3) (2009) 293-306], identifying all minimal critical sets of inertias for n×n zero-nonzero patterns with n ≥ 3 and the minimum cardinality of such a set are posed as two open questions by Kim, Olesky and Driessche. In this note, the minimum cardinality of all critical sets of inertias for 4 × 4 irreducible zero-nonzero patterns is identified.
Digital Article Identifier (DOI):
74
7389
Analysis for a Food Chain Model with Crowley–Martin Functional Response and Time Delay
Abstract: This paper is concerned with a nonautonomous three species food chain model with Crowley–Martin type functional response and time delay. Using the Mawhin-s continuation theorem in theory of degree, sufficient conditions for existence of periodic solutions are obtained.
Digital Article Identifier (DOI):
73
7989
An Iterative Method for the Least-squares Symmetric Solution of AXB+CYD=F and its Application
Abstract: Based on the classical algorithm LSQR for solving (unconstrained) LS problem, an iterative method is proposed for the least-squares like-minimum-norm symmetric solution of AXB+CYD=E. As the application of this algorithm, an iterative method for the least-squares like-minimum-norm biymmetric solution of AXB=E is also obtained. Numerical results are reported that show the efficiency of the proposed methods.
Digital Article Identifier (DOI):
72
12464
On the Prediction of Transmembrane Helical Segments in Membrane Proteins
Abstract: The prediction of transmembrane helical segments
(TMHs) in membrane proteins is an important field in the
bioinformatics research. In this paper, a method based on discrete
wavelet transform (DWT) has been developed to predict the number
and location of TMHs in membrane proteins. PDB coded as 1F88 was
chosen as an example to describe the prediction of the number and
location of TMHs in membrane proteins by using this method. One
group of test data sets that contain total 19 protein sequences was
utilized to access the effect of this method. Compared with the
prediction results of DAS, PRED-TMR2, SOSUI, HMMTOP2.0 and
TMHMM2.0, the obtained results indicate that the presented method
has higher prediction accuracy.
Digital Article Identifier (DOI):
71
11586
Minimal Critical Sets of Inertias for Irreducible Zero-nonzero Patterns of Order 3
Abstract: If there exists a nonempty, proper subset S of the set of all (n + 1)(n + 2)/2 inertias such that S Ôèå i(A) is sufficient for any n × n zero-nonzero pattern A to be inertially arbitrary, then S is called a critical set of inertias for zero-nonzero patterns of order n. If no proper subset of S is a critical set, then S is called a minimal critical set of inertias. In [3], Kim, Olesky and Driessche identified all minimal critical sets of inertias for 2 × 2 zero-nonzero patterns. Identifying all minimal critical sets of inertias for n × n zero-nonzero patterns with n ≥ 3 is posed as an open question in [3]. In this paper, all minimal critical sets of inertias for 3 × 3 zero-nonzero patterns are identified. It is shown that the sets {(0, 0, 3), (3, 0, 0)}, {(0, 0, 3), (0, 3, 0)}, {(0, 0, 3), (0, 1, 2)}, {(0, 0, 3), (1, 0, 2)}, {(0, 0, 3), (2, 0, 1)} and {(0, 0, 3), (0, 2, 1)} are the only minimal critical sets of inertias for 3 × 3 irreducible zerononzero patterns.
Digital Article Identifier (DOI):
70
15326
Global Exponential Stability of Impulsive BAM Fuzzy Cellular Neural Networks with Time Delays in the Leakage Terms
Abstract: In this paper, a class of impulsive BAM fuzzy cellular neural networks with time delays in the leakage terms is formulated and investigated. By establishing a delay differential inequality and M-matrix theory, some sufficient conditions ensuring the existence, uniqueness and global exponential stability of equilibrium point for impulsive BAM fuzzy cellular neural networks with time delays in the leakage terms are obtained. In particular, a precise estimate of the exponential convergence rate is also provided, which depends on system parameters and impulsive perturbation intention. It is believed that these results are significant and useful for the design and applications of BAM fuzzy cellular neural networks. An example is given to show the effectiveness of the results obtained here.
Digital Article Identifier (DOI):
69
4376
On Positive Definite Solutions of Quaternionic Matrix Equations
Abstract: The real representation of the quaternionic matrix is
definited and studied. The relations between the positive (semi)define
quaternionic matrix and its real representation matrix are presented.
By means of the real representation, the relation between the positive
(semi)definite solutions of quaternionic matrix equations and those of
corresponding real matrix equations is established.
Digital Article Identifier (DOI):
68
1081
Heuristic Method for Judging the Computational Stability of the Difference Schemes of the Biharmonic Equation
Abstract: In this paper, we research the standard 13-point difference schemes for solving the biharmonic equation. Heuristic method is applied to judging the stability of multi-level difference schemes of the biharmonic equation. It is showed that the standard 13-point difference schemes are stable.
Digital Article Identifier (DOI):
67
13
Induced Acyclic Path Decomposition in Graphs
Abstract: A decomposition of a graph G is a collection ψ of
graphs H1,H2, . . . , Hr of G such that every edge of G belongs
to exactly one Hi. If each Hi is either an induced path in G,
then ψ is called an induced acyclic path decomposition of G and
if each Hi is a (induced) cycle in G then ψ is called a (induced)
cycle decomposition of G. The minimum cardinality of an induced
acyclic path decomposition of G is called the induced acyclic path
decomposition number of G and is denoted by ¤Çia(G). Similarly
the cyclic decomposition number ¤Çc(G) is defined. In this paper we
begin an investigation of these parameters.
Digital Article Identifier (DOI):
66
14295
Existence and Stability of Anti-periodic Solutions for an Impulsive Cohen-Grossberg SICNNs on Time Scales
Abstract: By using the method of coincidence degree and constructing suitable Lyapunov functional, some sufficient conditions are established for the existence and global exponential stability of antiperiodic solutions for a kind of impulsive Cohen-Grossberg shunting inhibitory cellular neural networks (CGSICNNs) on time scales. An example is given to illustrate our results.
Digital Article Identifier (DOI):
65
15407
Bifurcation Analysis in a Two-neuron System with Different Time Delays
Abstract: In this paper, we consider a two-neuron system with time-delayed connections between neurons. By analyzing the associated characteristic transcendental equation, its linear stability is investigated and Hopf bifurcation is demonstrated. Some explicit formulae for determining the stability and the direction of the Hopf bifurcation periodic solutions bifurcating from Hopf bifurcations are obtained by using the normal form theory and center manifold theory. Some numerical simulation results are given to support the theoretical predictions. Finally, main conclusions are given.
Digital Article Identifier (DOI):
64
13986
New Application of EHTA for the Generalized(2+1)-Dimensional Nonlinear Evolution Equations
Abstract: In this paper, the generalized (2+1)-dimensional Calogero-Bogoyavlenskii-Schiff (shortly CBS) equations are investigated. We employ the Hirota-s bilinear method to obtain the bilinear form of CBS equations. Then by the idea of extended homoclinic test approach (shortly EHTA), some exact soliton solutions including breather type solutions are presented.
Digital Article Identifier (DOI):
63
8654
Exact Three-wave Solutions for High Nonlinear Form of Benjamin-Bona-Mahony-Burgers Equations
Abstract: By means of the idea of three-wave method, we obtain some analytic solutions for high nonlinear form of Benjamin-Bona- Mahony-Burgers (shortly BBMB) equations in its bilinear form.
Digital Article Identifier (DOI):
62
4717
Stability Analysis of Impulsive Stochastic Fuzzy Cellular Neural Networks with Time-varying Delays and Reaction-diffusion Terms
Abstract: In this paper, the problem of stability analysis for a class of impulsive stochastic fuzzy neural networks with timevarying delays and reaction-diffusion is considered. By utilizing suitable Lyapunov-Krasovskii funcational, the inequality technique and stochastic analysis technique, some sufficient conditions ensuring global exponential stability of equilibrium point for impulsive stochastic fuzzy cellular neural networks with time-varying delays and diffusion are obtained. In particular, the estimate of the exponential convergence rate is also provided, which depends on system parameters, diffusion effect and impulsive disturbed intention. It is believed that these results are significant and useful for the design and applications of fuzzy neural networks. An example is given to show the effectiveness of the obtained results.
Digital Article Identifier (DOI):
61
5844
The Projection Methods for Computing the Pseudospectra of Large Scale Matrices
Abstract: The projection methods, usually viewed as the methods
for computing eigenvalues, can also be used to estimate pseudospectra.
This paper proposes a kind of projection methods for computing
the pseudospectra of large scale matrices, including orthogonalization
projection method and oblique projection method respectively. This
possibility may be of practical importance in applications involving
large scale highly nonnormal matrices. Numerical algorithms are
given and some numerical experiments illustrate the efficiency of
the new algorithms.
Digital Article Identifier (DOI):
60
5346
The More Organized Proof For Acyclic Coloring Of Graphs With Δ = 5 with 8 Colors
Abstract: An acyclic coloring of a graph G is a coloring of its
vertices such that:(i) no two neighbors in G are assigned the same
color and (ii) no bicolored cycle can exist in G. The acyclic chromatic
number of G is the least number of colors necessary to acyclically
color G. Recently it has been proved that any graph of maximum
degree 5 has an acyclic chromatic number at most 8. In this paper
we present another proof for this result.
Digital Article Identifier (DOI):
59
4944
Applications of Trigonometic Measures of Fuzzy Entropy to Geometry
Abstract: In the literature of fuzzy measures, there exist many
well known parametric and non-parametric measures, each with its
own merits and limitations. But our main emphasis is on
applications of these measures to a variety of disciplines. To extend
the scope of applications of these fuzzy measures to geometry, we
need some special fuzzy measures. In this communication, we have
introduced two new fuzzy measures involving trigonometric
functions and simultaneously provided their applications to obtain
the basic results already existing in the literature of geometry.
Digital Article Identifier (DOI):
58
8412
Finite Element Modeling of Rotating Mixing of Toothpaste
Abstract: The objective of this research is to examine the shear thinning behaviour of mixing flow of non-Newtonian fluid like toothpaste in the dissolution container with rotating stirrer. The problem under investigation is related to the chemical industry. Mixing of fluid is performed in a cylindrical container with rotating stirrer, where stirrer is eccentrically placed on the lid of the container. For the simulation purpose the associated motion of the fluid is considered as revolving of the container, with stick stirrer. For numerical prediction, a time-stepping finite element algorithm in a cylindrical polar coordinate system is adopted based on semi-implicit Taylor-Galerkin/pressure-correction scheme. Numerical solutions are obtained for non-Newtonian fluids employing power law model. Variations with power law index have been analysed, with respect to the flow structure and pressure drop.
Digital Article Identifier (DOI):
57
12274
Multiple Positive Periodic Solutions of a Competitor-Competitor-Mutualist Lotka-Volterra System with Harvesting Terms
Abstract: In this paper, by using Mawhin-s continuation theorem of coincidence degree theory, we establish the existence of multiple positive periodic solutions of a competitor-competitor-mutualist Lotka-Volterra system with harvesting terms. Finally, an example is given to illustrate our results.
Digital Article Identifier (DOI):
56
8127
Performance Evaluation of Popular Hash Functions
Abstract: This paper describes the results of an extensive study
and comparison of popular hash functions SHA-1, SHA-256,
RIPEMD-160 and RIPEMD-320 with JERIM-320, a 320-bit hash
function. The compression functions of hash functions like SHA-1
and SHA-256 are designed using serial successive iteration whereas
those like RIPEMD-160 and RIPEMD-320 are designed using two
parallel lines of message processing. JERIM-320 uses four parallel
lines of message processing resulting in higher level of security than
other hash functions at comparable speed and memory requirement.
The performance evaluation of these methods has been done by using
practical implementation and also by using step computation
methods. JERIM-320 proves to be secure and ensures the integrity of
messages at a higher degree. The focus of this work is to establish
JERIM-320 as an alternative of the present day hash functions for the
fast growing internet applications.
Digital Article Identifier (DOI):
55
5103
Analyzing the Factors Effecting the Passenger Car Breakdowns using Com-Poisson GLM
Abstract: Number of breakdowns experienced by a machinery is a highly under-dispersed count random variable and its value can be attributed to the factors related to the mechanical input and output of that machinery. Analyzing such under-dispersed count observations as a function of the explanatory factors has been a challenging problem. In this paper, we aim at estimating the effects of various factors on the number of breakdowns experienced by a passenger car based on a study performed in Mauritius over a year. We remark that the number of passenger car breakdowns is highly under-dispersed. These data are therefore modelled and analyzed using Com-Poisson regression model. We use quasi-likelihood estimation approach to estimate the parameters of the model. Under-dispersion parameter is estimated to be 2.14 justifying the appropriateness of Com-Poisson distribution in modelling under-dispersed count responses recorded in this study.
Digital Article Identifier (DOI):
54
14450
Theoretical Modeling and Experimental Study of Combustion and Performance Characteristics of Biodiesel in Turbocharged Low Heat Rejection D.I Diesel Engine
Abstract: An effort has been taken to simulate the combustion
and performance characteristics of biodiesel fuel in direct injection
(D.I) low heat rejection (LHR) diesel engine. Comprehensive
analyses on combustion characteristics such as cylinder pressure,
peak cylinder pressure, heat release and performance characteristics
such as specific fuel consumption and brake thermal efficiency are
carried out. Compression ignition (C.I) engine cycle simulation was
developed and modified in to LHR engine for both diesel and
biodiesel fuel. On the basis of first law of thermodynamics the
properties at each degree crank angle was calculated. Preparation and
reaction rate model was used to calculate the instantaneous heat
release rate. A gas-wall heat transfer calculations are based on the
ANNAND-s combined heat transfer model with instantaneous wall
temperature to analyze the effect of coating on heat transfer. The
simulated results are validated by conducting the experiments on the
test engine under identical operating condition on a turbocharged D.I
diesel engine. In this analysis 20% of biodiesel (derived from
Jatropha oil) blended with diesel and used in both conventional and
LHR engine. The simulated combustion and performance
characteristics results are found satisfactory with the experimental
value.
Digital Article Identifier (DOI):
53
3659
Optimal Controllers with Actuator Saturation for Nonlinear Structures
Abstract: Since the actuator capacity is limited, in the real
application of active control systems under sever earthquakes it is
conceivable that the actuators saturate, hence the actuator saturation
should be considered as a constraint in design of optimal controllers.
In this paper optimal design of active controllers for nonlinear
structures by considering actuator saturation, has been studied. The
proposed method for designing optimal controllers is based on
defining an optimization problem which the objective has been to
minimize the maximum displacement of structure when a limited
capacity for actuator has been used. To this end a single degree of
freedom (SDF) structure with a bilinear hysteretic behavior has been
simulated under a white noise ground acceleration of different
amplitudes. Active tendon control mechanism, comprised of prestressed
tendons and an actuator, and extended nonlinear Newmark
method based instantaneous optimal control algorithm have been
used. To achieve the best results, the weights corresponding to
displacement, velocity, acceleration and control force in the
performance index have been optimized by the Distributed Genetic
Algorithm (DGA). Results show the effectiveness of the proposed
method in considering actuator saturation. Also based on the
numerical simulations it can be concluded that the actuator capacity
and the average value of required control force are two important
factors in designing nonlinear controllers which consider the actuator
saturation.
Digital Article Identifier (DOI):
52
14376
The Effect of Response Feedback on Performance of Active Controlled Nonlinear Frames
Abstract: The effect of different combinations of response
feedback on the performance of active control system on nonlinear
frames has been studied in this paper. To this end different feedback
combinations including displacement, velocity, acceleration and full
response feedback have been utilized in controlling the response of
an eight story bilinear hysteretic frame which has been subjected to a
white noise excitation and controlled by eight actuators which could
fully control the frame. For active control of nonlinear frame
Newmark nonlinear instantaneous optimal control algorithm has been
used which a diagonal matrix has been selected for weighting
matrices in performance index. For optimal design of active control
system while the objective has been to reduce the maximum drift to
below the yielding level, Distributed Genetic Algorithm (DGA) has
been used to determine the proper set of weighting matrices. The
criteria to assess the effect of each combination of response feedback
have been the minimum required control force to reduce the
maximum drift to below the yielding drift. The results of numerical
simulation show that the performance of active control system is
dependent on the type of response feedback where the velocity
feedback is more effective in designing optimal control system in
comparison with displacement and acceleration feedback. Also using
full feedback of response in controller design leads to minimum
control force amongst other combinations. Also the distributed
genetic algorithm shows acceptable convergence speed in solving the
optimization problem of designing active control systems.
Digital Article Identifier (DOI):
51
13644
Optimal Combination for Modal Pushover Analysis by Using Genetic Algorithm
Abstract: In order to consider the effects of the higher modes in
the pushover analysis, during the recent years several multi-modal
pushover procedures have been presented. In these methods the
response of the considered modes are combined by the square-rootof-
sum-of-squares (SRSS) rule while application of the elastic modal
combination rules in the inelastic phases is no longer valid. In this
research the feasibility of defining an efficient alternative
combination method is investigated. Two steel moment-frame
buildings denoted SAC-9 and SAC-20 under ten earthquake records
are considered. The nonlinear responses of the structures are
estimated by the directed algebraic combination of the weighted
responses of the separate modes. The weight of the each mode is
defined so that the resulted response of the combination has a
minimum error to the nonlinear time history analysis. The genetic
algorithm (GA) is used to minimize the error and optimize the weight
factors. The obtained optimal factors for each mode in different cases
are compared together to find unique appropriate weight factors for
each mode in all cases.
Digital Article Identifier (DOI):
50
8081
Improvement of Overall Equipment Effectiveness through Total Productive Maintenance
Abstract: Frequent machine breakdowns, low plant availability and increased overtime are a great threat to a manufacturing plant as they increase operating costs of an industry. The main aim of this study was to improve Overall Equipment Effectiveness (OEE) at a manufacturing company through the implementation of innovative maintenance strategies. A case study approach was used. The paper focuses on improving the maintenance in a manufacturing set up using an innovative maintenance regime mix to improve overall equipment effectiveness. Interviews, reviewing documentation and historical records, direct and participatory observation were used as data collection methods during the research. Usually production is based on the total kilowatt of motors produced per day. The target kilowatt at 91% availability is 75 Kilowatts a day. Reduced demand and lack of raw materials particularly imported items are adversely affecting the manufacturing operations. The company had to reset its targets from the usual figure of 250 Kilowatt per day to mere 75 per day due to lower availability of machines as result of breakdowns as well as lack of raw materials. The price reductions and uncertainties as well as general machine breakdowns further lowered production. Some recommendations were given. For instance, employee empowerment in the company will enhance responsibility and authority to improve and totally eliminate the six big losses. If the maintenance department is to realise its proper function in a progressive, innovative industrial society, then its personnel must be continuously trained to meet current needs as well as future requirements. To make the maintenance planning system effective, it is essential to keep track of all the corrective maintenance jobs and preventive maintenance inspections. For large processing plants these cannot be handled manually. It was therefore recommended that the company implement (Computerised Maintenance Management System) CMMS.
Digital Article Identifier (DOI):
49
3970
Stochastic Scheduling to Minimize Expected Lateness in Multiple Identical Machines
Abstract: There are many real world problems in which
parameters like the arrival time of new jobs, failure of resources, and
completion time of jobs change continuously. This paper tackles the
problem of scheduling jobs with random due dates on multiple
identical machines in a stochastic environment. First to assign jobs to
different machine centers LPT scheduling methods have been used,
after that the particular sequence of jobs to be processed on the
machine have been found using simple stochastic techniques. The
performance parameter under consideration has been the maximum
lateness concerning the stochastic due dates which are independent
and exponentially distributed. At the end a relevant problem has been
solved using the techniques in the paper..
Digital Article Identifier (DOI):
48
15905
EBSD Investigation of Friction Stir Welded Duplex Stainless Steel
Abstract: Electron back-scattered diffraction was used to follow the evolution of microstructure from the base metal to the stir zone (SZ) in a duplex stainless steel subjected to friction stir welding. In the stir zone (SZ), a continuous dynamic recrystallization (CDRX) was evidenced for ferrite, while it was suggested that a static recrystallization together with CDRX may occur for austenite. It was found that ferrite and austenite grains in the SZ take a typical shear texture of bcc and fcc materials respectively.
Digital Article Identifier (DOI):
47
10206
Research on Simulation Model of Collision Force between Floating Ice and Pier
Abstract: Adopting the measured constitutive relationship of
stress-strain of river ice, the finite element analysis model of
percussive force of river ice and pier is established, by the explicit
dynamical analysis software package LS-DYNA. Effects of element
types, contact method and arithmetic of ice and pier, coupled modes
between different elements, mesh density of pier, and ice sheet in
contact area on the collision force are studied. Some of measures for
the collision force analysis of river ice and pier are proposed as
follows: bridge girder can adopt beam161 element with 3-node; pier
below the line of 1.30m above ice surface and ice sheet use solid164
element with 8-node; in order to accomplish the connection of
different elements, the rigid body with 0.01-0.05m thickness is defined
between solid164 and beam161; the contact type of ice and pier adopts
AUTOMATIC_SURFACE_TO_SURFACE, using symmetrical
penalty function algorithms; meshing size of pier below the line of
1.30m above ice surface should not less than 0.25×0.25×0.5m3. The
simulation results have the advantage of high precision by making a
comparison between measured and computed data. The research
results can be referred for collision force study between river ice and
pier.
Digital Article Identifier (DOI):
46
12305
Improved Asymptotic Stability Analysis for Lure Systems with Neutral Type and Time-varying Delays
Abstract: This paper investigates the problem of absolute stability and robust stability of a class of Lur-e systems with neutral type and time-varying delays. By using Lyapunov direct method and linear matrix inequality technique, new delay-dependent stability criteria are obtained and formulated in terms of linear matrix inequalities (LMIs) which are easy to check the stability of the considered systems. To obtain less conservative stability conditions, an operator is defined to construct the Lyapunov functional. Also, the free weighting matrices approach combining a matrix inequality technique is used to reduce the entailed conservativeness. Numerical examples are given to indicate significant improvements over some existing results.
Digital Article Identifier (DOI):
45
6083
Wavelet and K-L Seperability Based Feature Extraction Method for Functional Data Classification
Abstract: This paper proposes a novel feature extraction method,
based on Discrete Wavelet Transform (DWT) and K-L Seperability
(KLS), for the classification of Functional Data (FD). This method
combines the decorrelation and reduction property of DWT and the
additive independence property of KLS, which is helpful to extraction
classification features of FD. It is an advanced approach of the
popular wavelet based shrinkage method for functional data reduction
and classification. A theory analysis is given in the paper to prove the
consistent convergence property, and a simulation study is also done
to compare the proposed method with the former shrinkage ones. The
experiment results show that this method has advantages in improving
classification efficiency, precision and robustness.
Digital Article Identifier (DOI):
44
3682
A Study of Dynamic Clustering Method to Extend the Lifetime of Wireless Sensor Network
Abstract: In recent years, the research in wireless sensor
network has increased steadily, and many studies were focusing on
reducing energy consumption of sensor nodes to extend their lifetimes.
In this paper, the issue of energy consumption is investigated and two
adaptive mechanisms are proposed to extend the network lifetime.
This study uses high-energy-first scheme to determine cluster heads
for data transmission. Thus, energy consumption in each cluster is
balanced and network lifetime can be extended. In addition, this study
uses cluster merging and dynamic routing mechanisms to further
reduce energy consumption during data transmission. The simulation
results show that the proposed method can effectively extend the
lifetime of wireless sensor network, and it is suitable for different base
station locations.
Digital Article Identifier (DOI):
43
4768
The Design and Analysis of Learning Effects for a Game-based Learning System
Abstract: The major purpose of this study is to use network and multimedia technologies to build a game-based learning system for junior high school students to apply in learning “World Geography" through the “role-playing" game approaches. This study first investigated the motivation and habits of junior high school students to use the Internet and online games, and then designed a game-based learning system according to situated and game-based learning theories. A teaching experiment was conducted to analyze the learning effectiveness of students on the game-based learning system and the major factors affecting their learning. A questionnaire survey was used to understand the students- attitudes towards game-based learning. The results showed that the game-based learning system can enhance students- learning, but the gender of students and their habits in using the Internet have no significant impact on learning. Game experience has a significant impact on students- learning, and the higher the experience value the better the effectiveness of their learning. The results of questionnaire survey also revealed that the system can increase students- motivation and interest in learning "World Geography".
Digital Article Identifier (DOI):
42
13261
Forward Kinematics Analysis of a 3-PRS Parallel Manipulator
Abstract: In this article the homotopy continuation method (HCM) to solve the forward kinematic problem of the 3-PRS parallel manipulator is used. Since there are many difficulties in solving the system of nonlinear equations in kinematics of manipulators, the numerical solutions like Newton-Raphson are inevitably used. When dealing with any numerical solution, there are two troublesome problems. One is that good initial guesses are not easy to detect and another is related to whether the used method will converge to useful solutions. Results of this paper reveal that the homotopy continuation method can alleviate the drawbacks of traditional numerical techniques.
Digital Article Identifier (DOI):
41
13303
Communication and Quality in Distributed Agile Development: An Empirical Case Study
Abstract: Through inward perceptions, we intuitively expect
distributed software development to increase the risks associated with
achieving cost, schedule, and quality goals. To compound this
problem, agile software development (ASD) insists one of the main
ingredients of its success is cohesive communication attributed to
collocation of the development team. The following study identified
the degree of communication richness needed to achieve comparable
software quality (reduce pre-release defects) between distributed and
collocated teams. This paper explores the relevancy of
communication richness in various development phases and its
impact on quality. Through examination of a large distributed agile
development project, this investigation seeks to understand the levels
of communication required within each ASD phase to produce
comparable quality results achieved by collocated teams. Obviously,
a multitude of factors affects the outcome of software projects.
However, within distributed agile software development teams, the
mode of communication is one of the critical components required to
achieve team cohesiveness and effectiveness. As such, this study
constructs a distributed agile communication model (DAC-M) for
potential application to similar distributed agile development efforts
using the measurement of the suitable level of communication. The
results of the study show that less rich communication methods, in
the appropriate phase, might be satisfactory to achieve equivalent
quality in distributed ASD efforts.
Digital Article Identifier (DOI):
40
15740
Time-Cost-Quality Trade-off Software by using Simplified Genetic Algorithm for Typical Repetitive Construction Projects
Abstract: Time-Cost Optimization "TCO" is one of the greatest challenges in construction project planning and control, since the optimization of either time or cost, would usually be at the expense of the other. Since there is a hidden trade-off relationship between project and cost, it might be difficult to predict whether the total cost would increase or decrease as a result of the schedule compression. Recently third dimension in trade-off analysis is taken into consideration that is quality of the projects. Few of the existing algorithms are applied in a case of construction project with threedimensional trade-off analysis, Time-Cost-Quality relationships. The objective of this paper is to presents the development of a practical software system; that named Automatic Multi-objective Typical Construction Resource Optimization System "AMTCROS". This system incorporates the basic concepts of Line Of Balance "LOB" and Critical Path Method "CPM" in a multi-objective Genetic Algorithms "GAs" model. The main objective of this system is to provide a practical support for typical construction planners who need to optimize resource utilization in order to minimize project cost and duration while maximizing its quality simultaneously. The application of these research developments in planning the typical construction projects holds a strong promise to: 1) Increase the efficiency of resource use in typical construction projects; 2) Reduce construction duration period; 3) Minimize construction cost (direct cost plus indirect cost); and 4) Improve the quality of newly construction projects. A general description of the proposed software for the Time-Cost-Quality Trade-Off "TCQTO" is presented. The main inputs and outputs of the proposed software are outlined. The main subroutines and the inference engine of this software are detailed. The complexity analysis of the software is discussed. In addition, the verification, and complexity of the proposed software are proved and tested using a real case study.
Digital Article Identifier (DOI):
39
6733
Simulation of Effect of Current Stressing on Reliability of Solder Joints with Cu-Pillar Bumps
Abstract: The mechanism behind the electromigration and
thermomigration failure in flip-chip solder joints with Cu-pillar bumps
was investigated in this paper through using finite element method.
Hot spot and the current crowding occurrs in the upper corner of
copper column instead of solders of the common solder ball. The
simulation results show that the change in thermal gradient is
noticeable, which might greatly affect the reliability of solder joints
with Cu-pillar bumps under current stressing. When the average
applied current density is increased from 1×104 A/cm2 to 3×104 A/cm2
in solders, the thermal gradient would increase from 74 K/cm to 901
K/cm at an ambient temperature of 25°C. The force from thermal
gradient of 901 K/cm can nearly induce thermomigration by itself.
With the increase in applied current, the thermal gradient is growing. It
is proposed that thermomigration likely causes a serious reliability
issue for Cu column based interconnects.
Digital Article Identifier (DOI):
38
13167
Optimization of Double Wishbone Suspension System with Variable Camber Angle by Hydraulic Mechanism
Abstract: Simulation accuracy by recent dynamic vehicle
simulation multidimensional expression significantly has progressed
and acceptable results not only for passive vehicles but also for
active vehicles normally equipped with advanced electronic
components is also provided. Recently, one of the subjects that has it
been considered, is increasing the safety car in design. Therefore,
many efforts have been done to increase vehicle stability especially
in the turn. One of the most important efforts is adjusting the camber
angle in the car suspension system. Optimum control camber angle in
addition to the vehicle stability is effective in the wheel adhesion on
road, reducing rubber abrasion and acceleration and braking. Since
the increase or decrease in the camber angle impacts on the stability
of vehicles, in this paper, a car suspension system mechanism is
introduced that could be adjust camber angle and the mechanism is
application and also inexpensive. In order to reach this purpose, in
this paper, a passive double wishbone suspension system with
variable camber angle is introduced and then variable camber
mechanism designed and analyzed for study the designed system
performance, this mechanism is modeled in Visual Nastran software
and kinematic analysis is revealed.
Digital Article Identifier (DOI):
37
15934
Structural Sustainability Techniques for RC High Rise Buildings
Abstract: Over the early years of the 21st century, cities
throughout the Middle East, particularly in the Gulf region have
expanded more rapidly than ever before. Given the presence of a
large volume of high-rise buildings allover the region, the local
authority aims to set a new standard for sustainable development;
with an integrated approach to maintain a balance between economy,
quality, environmental protection and safety of life. In the very near
future, as mandatory requirements, sustainability will be the criteria
that should be included in all building projects. It is well known in
the building sustainability topics that structural design engineers do
not have a key role in this matter. In addition, the LEED (Leadership
in Energy and Environmental Design) has looked almost exclusively
on the environmental components and materials specifications. The
objective of this paper is to focus and establish groundwork for
sustainability techniques and applications related to the RC high-rise
buildings design, from the structural point of view. A set of
recommendations related to local conditions, structural modeling and
analysis is given, and some helpful suggestions for structural design
team work are addressed. This paper attempts to help structural
engineers in identifying the building sustainability design, in order to
meet local needs and achieve alternative solutions at an early stage of
project design.
Digital Article Identifier (DOI):
36
15647
Migration of a Drop in Simple Shear Flow at Finite Reynolds Numbers: Size and Viscosity Ratio Effects
Abstract: The migration of a deformable drop in simple shear
flow at finite Reynolds numbers is investigated numerically by
solving the full Navier-Stokes equations using a finite
difference/front tracking method. The objectives of this study are to
examine the effectiveness of the present approach to predict the
migration of a drop in a shear flow and to investigate the behavior of
the drop migration with different drop sizes and non-unity viscosity
ratios. It is shown that the drop deformation depends strongly on the
capillary number, so that; the proper non-dimensional number for the
interfacial tension is the capillary number. The rate of migration
increased with increasing the drop radius. In other words, the
required time for drop migration to the centreline decreases. As the
viscosity ratio increases, the drop rotates more slowly and the
lubrication force becomes stronger. The increased lubrication force
makes it easier for the drop to migrate to the centre of the channel.
The migration velocity of the drop vanishes as the drop reaches the
centreline under viscosity ratio of one and non-unity viscosity ratios.
To validate the present calculations, some typical results are
compared with available experimental and theoretical data.
Digital Article Identifier (DOI):
35
8421
Feature Extraction of Dorsal Hand Vein Pattern Using a Fast Modified PCA Algorithm Based On Cholesky Decomposition and Lanczos Technique
Abstract: Dorsal hand vein pattern is an emerging biometric which is attracting the attention of researchers, of late. Research is being carried out on existing techniques in the hope of improving them or finding more efficient ones. In this work, Principle Component Analysis (PCA) , which is a successful method, originally applied on face biometric is being modified using Cholesky decomposition and Lanczos algorithm to extract the dorsal hand vein features. This modified technique decreases the number of computation and hence decreases the processing time. The eigenveins were successfully computed and projected onto the vein space. The system was tested on a database of 200 images and using a threshold value of 0.9 to obtain the False Acceptance Rate (FAR) and False Rejection Rate (FRR). This modified algorithm is desirable when developing biometric security system since it significantly decreases the matching time.
Digital Article Identifier (DOI):
34
6955
A Comparison of Marginal and Joint Generalized Quasi-likelihood Estimating Equations Based On the Com-Poisson GLM: Application to Car Breakdowns Data
Abstract: In this paper, we apply and compare two generalized estimating equation approaches to the analysis of car breakdowns data in Mauritius. Number of breakdowns experienced by a machinery is a highly under-dispersed count random variable and its value can be attributed to the factors related to the mechanical input and output of that machinery. Analyzing such under-dispersed count observation as a function of the explanatory factors has been a challenging problem. In this paper, we aim at estimating the effects of various factors on the number of breakdowns experienced by a passenger car based on a study performed in Mauritius over a year. We remark that the number of passenger car breakdowns is highly under-dispersed. These data are therefore modelled and analyzed using Com-Poisson regression model. We use the two types of quasi-likelihood estimation approaches to estimate the parameters of the model: marginal and joint generalized quasi-likelihood estimating equation approaches. Under-dispersion parameter is estimated to be around 2.14 justifying the appropriateness of Com-Poisson distribution in modelling underdispersed count responses recorded in this study.
Digital Article Identifier (DOI):
33
8433
Nonlinear Dynamic Modeling and Active Vibration Control of a System with Fuel Sloshing
Abstract: Attitude control of aerospace system with liquid containers may face to a problem associate with fuel sloshing. The sloshing phenomena can degrade the stability of control system and in the worst case, interaction between the attitude control system and fuel vibration leading to resonance. In this paper, a full process of nonlinear dynamic modeling of an aerospace launch vehicle with fuel sloshing is given. Then, a new control system based on model reference adaptive filter is proposed and its algorithm is extracted. This controller implemented on the main attitude control system. Finally, numerical simulation of nonlinear model and control system is carried out to examine the performance of the new controller. Results of simulations show that the inconvenient effects of the fuel sloshing by augmenting this control system are reduced and attitude control system performs, satisfactorily.
Digital Article Identifier (DOI):
32
8881
The RK1GL2X3 Method for Initial Value Problems in Ordinary Differential Equations
Abstract: The RK1GL2X3 method is a numerical method for solving initial value problems in ordinary differential equations, and is based on the RK1GL2 method which, in turn, is a particular case of the general RKrGLm method. The RK1GL2X3 method is a fourth-order method, even though its underlying Runge-Kutta method RK1 is the first-order Euler method, and hence, RK1GL2X3 is considerably more efficient than RK1. This enhancement is achieved through an implementation involving triple-nested two-point Gauss- Legendre quadrature.
Digital Article Identifier (DOI):
31
15033
Forecasting Malaria Cases in Bujumbura
Abstract: The focus in this work is to assess which method
allows a better forecasting of malaria cases in Bujumbura ( Burundi)
when taking into account association between climatic factors and
the disease. For the period 1996-2007, real monthly data on both
malaria epidemiology and climate in Bujumbura are described and
analyzed. We propose a hierarchical approach to achieve our
objective. We first fit a Generalized Additive Model to malaria cases
to obtain an accurate predictor, which is then used to predict future
observations. Various well-known forecasting methods are compared
leading to different results. Based on in-sample mean average
percentage error (MAPE), the multiplicative exponential smoothing
state space model with multiplicative error and seasonality performed
better.
Digital Article Identifier (DOI):
30
4650
An investigation on the Effect of Continuous Phase Height on the First and Second Critical Rotor Speeds in a Rotary Disc Contactor
Abstract: A Rotary Disc Contactor with inner diameter of
9.1cm and maximum operating height of 40cm has been used to
investigate break up phenomenon. Water-Toluene, Water as
continuous phase and Toluene as dispersed phase, was selected as
chemical system in the experiments. The mentioned chemical system
has high interfacial tension so it was possible to form big drops
which permit accurate investigation on break up phenomenon as well
as the first and second critical rotor speeds.
In this study, Break up phenomenon has been studied as a function
of mother drop size, rotor speed and continuous phase height. Further
more; the effects of mother drop size and continuous phase height on
the first and second critical rotor speeds were investigated. Finally,
two modified correlations were proposed to estimate the first and
second critical speeds.
Digital Article Identifier (DOI):
29
1920
PZ: A Z-based Formalism for Modeling Probabilistic Behavior
Abstract: Probabilistic techniques in computer programs are becoming
more and more widely used. Therefore, there is a big
interest in the formal specification, verification, and development
of probabilistic programs. In our work-in-progress project, we are
attempting to make a constructive framework for developing probabilistic
programs formally. The main contribution of this paper
is to introduce an intermediate artifact of our work, a Z-based
formalism called PZ, by which one can build set theoretical models of
probabilistic programs. We propose to use a constructive set theory,
called CZ set theory, to interpret the specifications written in PZ.
Since CZ has an interpretation in Martin-L¨of-s theory of types, this
idea enables us to derive probabilistic programs from correctness
proofs of their PZ specifications.
Digital Article Identifier (DOI):
28
5171
Towards a Systematic, Cost-Effective Approach for ERP Selection
Abstract: Existing experiences indicate that one of the most
prominent reasons that some ERP implementations fail is related to
selecting an improper ERP package. Among those important factors
resulting in inappropriate ERP selections, one is to ignore preliminary
activities that should be done before the evaluation of ERP packages.
Another factor yielding these unsuitable selections is that usually
organizations employ prolonged and costly selection processes in
such extent that sometimes the process would never be finalized
or sometimes the evaluation team might perform many key final
activities in an incomplete or inaccurate way due to exhaustion, lack
of interest or out-of-date data. In this paper, a systematic approach
that recommends some activities to be done before and after the
main selection phase is introduced for choosing an ERP package. On
the other hand, the proposed approach has utilized some ideas that
accelerates the selection process at the same time that reduces the
probability of an erroneous final selection.
Digital Article Identifier (DOI):
27
8798
Interpreting the Out-of-Control Signals of Multivariate Control Charts Employing Neural Networks
Abstract: Multivariate quality control charts show some advantages to monitor several variables in comparison with the simultaneous use of univariate charts, nevertheless, there are some disadvantages. The main problem is how to interpret the out-ofcontrol signal of a multivariate chart. For example, in the case of control charts designed to monitor the mean vector, the chart signals showing that it must be accepted that there is a shift in the vector, but no indication is given about the variables that have produced this shift. The MEWMA quality control chart is a very powerful scheme to detect small shifts in the mean vector. There are no previous specific works about the interpretation of the out-of-control signal of this chart. In this paper neural networks are designed to interpret the out-of-control signal of the MEWMA chart, and the percentage of correct classifications is studied for different cases.
Digital Article Identifier (DOI):
26
15916
Effects Edge end Free-free Boundary Conditions for Analysis Free Vibration of Functionally Graded Cylindrical Shell with Ring based on Third Order Shear Deformation Theory using Hamilton's Principle
Abstract: In this paper a study on the vibration of thin
cylindrical shells with ring supports and made of functionally
graded materials (FGMs) composed of stainless steel and
nickel is presented. Material properties vary along the
thickness direction of the shell according to volume fraction
power law. The cylindrical shells have ring supports which are
arbitrarily placed along the shell and impose zero lateral
deflections. The study is carried out based on third order shear
deformation shell theory (T.S.D.T). The analysis is carried out
using Hamilton-s principle. The governing equations of motion of
FGM cylindrical shells are derived based on shear deformation
theory. Results are presented on the frequency characteristics,
influence of ring support position and the influence of boundary
conditions. The present analysis is validated by comparing results
with those available in the literature.
Digital Article Identifier (DOI):
25
15540
Wind Energy Development in the African Great Lakes Region to Supplement the Hydroelectricity in the Locality: A Case Study from Tanzania
Abstract: The African Great Lakes Region refers to the zone
around lakes Victoria, Tanganyika, Albert, Edward, Kivu, and
Malawi. The main source of electricity in this region is hydropower
whose systems are generally characterized by relatively weak,
isolated power schemes, poor maintenance and technical deficiencies
with limited electricity infrastructures. Most of the hydro sources are
rain fed, and as such there is normally a deficiency of water during
the dry seasons and extended droughts. In such calamities fossil fuels
sources, in particular petroleum products and natural gas, are
normally used to rescue the situation but apart from them being nonrenewable,
they also release huge amount of green house gases to our
environment which in turn accelerates the global warming that has at
present reached an amazing stage. Wind power is ample, renewable,
widely distributed, clean, and free energy source that does not
consume or pollute water. Wind generated electricity is one of the
most practical and commercially viable option for grid quality and
utility scale electricity production. However, the main shortcoming
associated with electric wind power generation is fluctuation in its
output both in space and time. Before making a decision to establish
a wind park at a site, the wind speed features there should therefore
be known thoroughly as well as local demand or transmission
capacity. The main objective of this paper is to utilise monthly
average wind speed data collected from one prospective site within
the African Great Lakes Region to demonstrate that the available
wind power there is high enough to generate electricity. The mean
monthly values were calculated from records gathered on hourly
basis for a period of 5 years (2001 to 2005) from a site in Tanzania.
The documentations that were collected at a height of 2 m were
projected to a height of 50 m which is the standard hub height of
wind turbines. The overall monthly average wind speed was found to
be 12.11 m/s whereas June to November was established to be the
windy season as the wind speed during the session is above the
overall monthly wind speed. The available wind power density
corresponding to the overall mean monthly wind speed was evaluated
to be 1072 W/m2, a potential that is worthwhile harvesting for the
purpose of electric generation.
Digital Article Identifier (DOI):
24
7137
Thermo-mechanical Behavior of Pressure Tube of Indian PHWR at 20 bar Pressure
Abstract: In a nuclear reactor Loss of Coolant accident (LOCA)
considers wide range of postulated damage or rupture of pipe in the
heat transport piping system. In the case of LOCA with/without
failure of emergency core cooling system in a Pressurised Heavy
water Reactor, the Pressure Tube (PT) temperature could rise
significantly due to fuel heat up and gross mismatch of the heat
generation and heat removal in the affected channel. The extent and
nature of deformation is important from reactor safety point of view.
Experimental set-ups have been designed and fabricated to simulate
ballooning (radial deformation) of PT for 220 MWe IPHWRs.
Experiments have been conducted by covering the CT by ceramic
fibers and then by submerging CT in water of voided PTs. In both
the experiments, it is observed that ballooning initiates at a
temperature around 665´┐¢C and complete contact between PT and
Caldaria Tube (CT) occurs at around 700´┐¢C approximately. The
strain rate is found to be 0.116% per second. The structural integrity
of PT is retained (no breach) for all the experiments. The PT heatup
is found to be arrested after the contact between PT and CT, thus
establishing moderator acting as an efficient heat sink for IPHWRs.
Digital Article Identifier (DOI):
23
12302
Modeling of Plasticity of Clays Submitted to Compression Test
Abstract: In the forming of ceramic materials the plasticity
concept is commonly used. This term is related to a particular
mechanical behavior when clay is mixed with water. A plastic
ceramic material shows a permanent strain without rupture
when a compressive load produces a shear stress that exceeds
the material-s yield strength. For a plastic ceramic body it
observes a measurable elastic behavior before the yield
strength and when the applied load is removed. In this work, a
mathematical model was developed from applied concepts of
the plasticity theory by using the stress/strain diagram under
compression.
Digital Article Identifier (DOI):
22
4273
Trust Managementfor Pervasive Computing Environments
Abstract: Trust is essential for further and wider acceptance of
contemporary e-services. It was first addressed almost thirty years
ago in Trusted Computer System Evaluation Criteria standard by
the US DoD. But this and other proposed approaches of that
period were actually solving security. Roughly some ten years ago,
methodologies followed that addressed trust phenomenon at its core,
and they were based on Bayesian statistics and its derivatives, while
some approaches were based on game theory. However, trust is a
manifestation of judgment and reasoning processes. It has to be dealt
with in accordance with this fact and adequately supported in cyber
environment. On the basis of the results in the field of psychology
and our own findings, a methodology called qualitative algebra has
been developed, which deals with so far overlooked elements of trust
phenomenon. It complements existing methodologies and provides a
basis for a practical technical solution that supports management of
trust in contemporary computing environments. Such solution is also
presented at the end of this paper.
Digital Article Identifier (DOI):
21
15854
Effect of Surface Pretreatments on Nanocrystalline Diamond Deposited On Silicon Nitride Substrates
Abstract: The deposition of diamond films on a Si3N4 substrate
is an attractive technique for industrial applications because of the
excellent properties of diamond. Pretreatment of substrate is very
important prior to diamond deposition to promote nucleation and
adhesion between coating and substrate. Deposition of
nanocrystalline diamonds films on silicon nitride substrate have been
carried out by HF-CVD technique using mixture of methane and
hydrogen gases. Different pretreatment of substrate including
chemical etching consists of hot acid etching and basic etching and
mechanical etching were used to study the quality of diamond formed
on the substrate. The structure and morphology of diamond coating
have been studied using X-ray Diffraction (XRD) and Scanning
Electron Microscope (SEM) while diamond film quality has been
characterized using Raman spectroscopy. AFM was used to
investigate the effect of chemical etching and mechanical
pretreatment on the surface roughness of the substrates and the
resultant morphology of nanocrystalline diamond. It was found that
diamond film deposited on as-received, basic etched and grinded
substrate shows the morphology of cauliflower while blasted and
acidic etched substrates produce smooth, continuous diamond film.
However, the Raman investigation did not show any deviation in
quality of diamond film for any pretreatment.
Digital Article Identifier (DOI):
20
10491
Automatic Feature Recognition for GPR Image Processing
Abstract: This paper presents an automatic feature recognition
method based on center-surround difference detecting and fuzzy logic
that can be applied in ground-penetrating radar (GPR) image
processing. Adopted center-surround difference method, the salient
local image regions are extracted from the GPR images as features of
detected objects. And fuzzy logic strategy is used to match the
detected features and features in template database. This way, the
problem of objects detecting, which is the key problem in GPR image
processing, can be converted into two steps, feature extracting and
matching. The contributions of these skills make the system have the
ability to deal with changes in scale, antenna and noises. The results of
experiments also prove that the system has higher ratio of features
sensing in using GPR to image the subsurface structures.
Digital Article Identifier (DOI):
19
7232
An Efficient Passive Planar Micromixer with Finshaped Baffles in the Tee Channel for Wide Reynolds Number Flow Range
Abstract: A new design of a planar passive T-micromixer with fin-shaped baffles in the mixing channel is presented. The mixing efficiency and the level of pressure loss in the channel have been investigated by numerical simulations in the range of Reynolds number (Re) 1 to 50. A Mixing index (Mi) has been defined to quantify the mixing efficiency, which results over 85% at both ends of the Re range, what demonstrates the micromixer can enhance mixing using the mechanisms of diffusion (lower Re) and convection (higher Re). Three geometric dimensions: radius of baffle, baffles pitch and height of the channel define the design parameters, and the mixing index and pressure loss are the performance parameters used to optimize the micromixer geometry with a multi-criteria optimization method. The Pareto front of designs with the optimum trade-offs, maximum mixing index with minimum pressure loss, is obtained. Experiments for qualitative and quantitative validation have been implemented.
Digital Article Identifier (DOI):
18
13127
MTSSM - A Framework for Multi-Track Segmentation of Symbolic Music
Abstract: Music segmentation is a key issue in music information
retrieval (MIR) as it provides an insight into the
internal structure of a composition. Structural information about
a composition can improve several tasks related to MIR such
as searching and browsing large music collections, visualizing
musical structure, lyric alignment, and music summarization.
The authors of this paper present the MTSSM framework, a twolayer
framework for the multi-track segmentation of symbolic
music. The strength of this framework lies in the combination of
existing methods for local track segmentation and the application
of global structure information spanning via multiple tracks.
The first layer of the MTSSM uses various string matching
techniques to detect the best candidate segmentations for each
track of a multi-track composition independently. The second
layer combines all single track results and determines the best
segmentation for each track in respect to the global structure of
the composition.
Digital Article Identifier (DOI):
17
15495
The Performance of Disbursement Procedure of Public Works in Thailand
Abstract: This paper analysis performance of disbursement
procedure of public works project in Thailand. The results of
research were summarised based on contracts, submitted invoice,
inspection dated, copies of disbursement dated between client and
their main contractor and interviewed with persons involved in
central and local government projects during 1994-2008 in Thailand.
The data collection was to investigate the disbursement procedure
related to performance in disbursement during construction period
(Planned duration of contract against Actual execution date in each
month). A graphical presentation of a duration analysis of the
projects illustrated significant disbursement formation in each
project. It was established that the shortage of staff, the financial
stability of clients, bureaucratic, method of disbursement and
economics situation has play major role on performance of
disbursement to their main contractors.
Digital Article Identifier (DOI):
16
10085
Mapping Knowledge Model Onto Java Codes
Abstract: This paper gives an overview of the mapping
mechanism of SEAM-a methodology for the automatic generation of
knowledge models and its mapping onto Java codes. It discusses the
rules that will be used to map the different components in the
knowledge model automatically onto Java classes, properties and
methods. The aim of developing this mechanism is to help in the
creation of a prototype which will be used to validate the knowledge
model which has been generated automatically. It will also help to
link the modeling phase with the implementation phase as existing
knowledge engineering methodologies do not provide for proper
guidelines for the transition from the knowledge modeling phase to
development phase. This will decrease the development overheads
associated to the development of Knowledge Based Systems.
Digital Article Identifier (DOI):
15
15424
Exploring Perceptions and Practices About Information and Communication Technologies in Business English Teaching in Pakistan
Abstract: Language Reforms and potential use of ICTs has been a focal area of Higher Education Commission of Pakistan. Efforts are being accelerated to incorporate fast expanding ICTs to bring qualitative improvement in language instruction in higher education. This paper explores how university teachers are benefitting from ICTs to make their English class effective and what type of problems they face in practicing ICTs during their lectures. An in-depth qualitative study was employed to understand why language teachers tend to use ICTs in their instruction and how they are practicing it. A sample of twenty teachers from five universities located in Islamabad, three from public sector and two from private sector, was selected on non-random (Snowball) sampling basis. An interview with 15 semi-structured items was used as research instruments to collect data. The findings reveal that business English teaching is facilitated and improved through the use of ICTs. The language teachers need special training regarding the practices and implementation of ICTs. It is recommended that initiatives might be taken to equip university language teachers with modern methodology incorporating ICTs as focal area and efforts might be made to remove barriers regarding the training of language teachers and proper usage of ICTs.
Digital Article Identifier (DOI):
14
13534
Laser Excited Nuclear γ -Source of High Spectral Brightness
Abstract: This paper considers various channels of gammaquantum
generation via an ultra-short high-power laser pulse
interaction with different targets.We analyse the possibilities to create
a pulsed gamma-radiation source using laser triggering of some
nuclear reactions and isomer targets. It is shown that sub-MeV
monochromatic short pulse of gamma-radiation can be obtained with
pulse energy of sub-mJ level from isomer target irradiated by intense
laser pulse. For nuclear reaction channel in light- atom materials, it is
shown that sub-PW laser pulse gives rise to formation about million
gamma-photons of multi-MeV energy.
Digital Article Identifier (DOI):
13
9020
Manufacturing Dispersions Based Simulation and Synthesis of Design Tolerances
Abstract: The objective of this work which is based on the
approach of simultaneous engineering is to contribute to the
development of a CIM tool for the synthesis of functional design
dimensions expressed by average values and tolerance intervals. In
this paper, the dispersions method known as the Δl method which
proved reliable in the simulation of manufacturing dimensions is
used to develop a methodology for the automation of the simulation.
This methodology is constructed around three procedures. The first
procedure executes the verification of the functional requirements by
automatically extracting the functional dimension chains in the
mechanical sub-assembly. Then a second procedure performs an
optimization of the dispersions on the basis of unknown variables.
The third procedure uses the optimized values of the dispersions to
compute the optimized average values and tolerances of the
functional dimensions in the chains. A statistical and cost based
approach is integrated in the methodology in order to take account of
the capabilities of the manufacturing processes and to distribute
optimal values among the individual components of the chains.
Digital Article Identifier (DOI):
12
7119
Comparative Study of Decision Trees and Rough Sets Theory as Knowledge ExtractionTools for Design and Control of Industrial Processes
Abstract: General requirements for knowledge representation in
the form of logic rules, applicable to design and control of industrial
processes, are formulated. Characteristic behavior of decision trees
(DTs) and rough sets theory (RST) in rules extraction from recorded
data is discussed and illustrated with simple examples. The
significance of the models- drawbacks was evaluated, using
simulated and industrial data sets. It is concluded that performance of
DTs may be considerably poorer in several important aspects,
compared to RST, particularly when not only a characterization of a
problem is required, but also detailed and precise rules are needed,
according to actual, specific problems to be solved.
Digital Article Identifier (DOI):
11
7482
A Simple Affymetrix Ratio-transformation Method Yields Comparable Expression Level Quantifications with cDNA Data
Abstract: Gene expression profiling is rapidly evolving into a
powerful technique for investigating tumor malignancies. The
researchers are overwhelmed with the microarray-based platforms
and methods that confer them the freedom to conduct large-scale
gene expression profiling measurements. Simultaneously,
investigations into cross-platform integration methods have started
gaining momentum due to their underlying potential to help
comprehend a myriad of broad biological issues in tumor diagnosis,
prognosis, and therapy. However, comparing results from different
platforms remains to be a challenging task as various inherent
technical differences exist between the microarray platforms. In this
paper, we explain a simple ratio-transformation method, which can
provide some common ground for cDNA and Affymetrix platform
towards cross-platform integration. The method is based on the
characteristic data attributes of Affymetrix- and cDNA- platform. In
the work, we considered seven childhood leukemia patients and their
gene expression levels in either platform. With a dataset of 822
differentially expressed genes from both these platforms, we carried
out a specific ratio-treatment to Affymetrix data, which subsequently
showed an improvement in the relationship with the cDNA data.
Digital Article Identifier (DOI):
10
11823
A New Direct Updating Method for Undamped Structural Systems
Abstract: A new numerical method for simultaneously updating mass and stiffness matrices based on incomplete modal measured data is presented. By using the Kronecker product, all the variables that are to be modified can be found out and then can be updated directly. The optimal approximation mass matrix and stiffness matrix which satisfy the required eigenvalue equation and orthogonality condition are found under the Frobenius norm sense. The physical configuration of the analytical model is preserved and the updated model will exactly reproduce the modal measured data. The numerical example seems to indicate that the method is quite accurate and efficient.
Digital Article Identifier (DOI):
9
13276
Analysis of Combustion, Performance and Emission Characteristics of Turbocharged LHR Extended Expansion DI Diesel Engine
Abstract: The fundamental aim of extended expansion concept is
to achieve higher work done which in turn leads to higher thermal
efficiency. This concept is compatible with the application of
turbocharger and LHR engine. The Low Heat Rejection engine was
developed by coating the piston crown, cylinder head inside with
valves and cylinder liner with partially stabilized zirconia coating of
0.5 mm thickness. Extended expansion in diesel engines is termed as
Miller cycle in which the expansion ratio is increased by reducing the
compression ratio by modifying the inlet cam for late inlet valve
closing. The specific fuel consumption reduces to an appreciable level
and the thermal efficiency of the extended expansion turbocharged
LHR engine is improved.
In this work, a thermodynamic model was formulated and
developed to simulate the LHR based extended expansion
turbocharged direct injection diesel engine. It includes a gas flow
model, a heat transfer model, and a two zone combustion model. Gas
exchange model is modified by incorporating the Miller cycle, by
delaying inlet valve closing timing which had resulted in considerable
improvement in thermal efficiency of turbocharged LHR engines. The
heat transfer model, calculates the convective and radiative heat
transfer between the gas and wall by taking into account of the
combustion chamber surface temperature swings. Using the two-zone
combustion model, the combustion parameters and the chemical
equilibrium compositions were determined. The chemical equilibrium
compositions were used to calculate the Nitric oxide formation rate by
assuming a modified Zeldovich mechanism. The accuracy of this
model is scrutinized against actual test results from the engine. The
factors which affect thermal efficiency and exhaust emissions were
deduced and their influences were discussed. In the final analysis it is
seen that there is an excellent agreement in all of these evaluations.
Digital Article Identifier (DOI):
8
1647
Experimental Investigation of Phase Distributions of Two-phase Air-silicone Oil Flow in a Vertical Pipe
Abstract: This paper reports the results of an experimental study
conducted to characterise the gas-liquid multiphase flows
experienced within a vertical riser transporting a range of gas-liquid
flow rates. The scale experiments were performed using an
air/silicone oil mixture within a 6 m long riser. The superficial air
velocities studied ranged from 0.047 to 2.836 m/ s, whilst
maintaining a liquid superficial velocity at 0.047 m/ s. Measurements
of the mean cross-sectional and time average radial void fraction
were obtained using a wire mesh sensor (WMS). The data were
recorded at an acquisition frequency of 1000 Hz over an interval of
60 seconds. For the range of flow conditions studied, the average
void fraction was observed to vary between 0.1 and 0.9. An analysis
of the data collected concluded that the observed void fraction was
strongly affected by the superficial gas velocity, whereby the higher
the superficial gas velocity, the higher was the observed average void
fraction. The average void fraction distributions observed were in
good agreement with the results obtained by other researchers. When
the air-silicone oil flows were fully developed reasonably symmetric
profiles were observed, with the shape of the symmetry profile being
strongly dependent on the superficial gas velocity.
Digital Article Identifier (DOI):
7
15449
Slugging Frequency Correlation for Inclined Gas-liquid Flow
Abstract: In this work, new experimental data for slugging
frequency in inclined gas-liquid flow are reported, and a new
correlation is proposed. Scale experiments were carried out using a
mixture of air and water in a 6 m long pipe. Two different pipe
diameters were used, namely, 38 and 67 mm. The data were taken
with capacitance type sensors at a data acquisition frequency of 200
Hz over an interval of 60 seconds. For the range of flow conditions
studied, the liquid superficial velocity is observed to influence the
frequency strongly. A comparison of the present data with
correlations available in the literature reveals a lack of agreement. A
new correlation for slug frequency has been proposed for the inclined
flow, which represents the main contribution of this work.
Digital Article Identifier (DOI):
6
6990
The Effect of Mixture Velocity and Droplet Diameter on Oil-water Separator using Computational Fluid Dynamics (CFD)
Abstract: The characteristics of fluid flow and phase separation
in an oil-water separator were numerically analysed as part of the
work presented herein. Simulations were performed for different
velocities and droplet diameters, and the way this parameters can
influence the separator geometry was studied.
The simulations were carried out using the software package
Fluent 6.2, which is designed for numerical simulation of fluid flow
and mass transfer. The model consisted of a cylindrical horizontal
separator. A tetrahedral mesh was employed in the computational
domain. The condition of two-phase flow was simulated with the
two-fluid model, taking into consideration turbulence effects using
the k-ε model.
The results showed that there is a strong dependency of phase
separation on mixture velocity and droplet diameter. An increase in
mixture velocity will bring about a slow down in phase separation
and as a consequence will require a weir of greater height. An
increase in droplet diameter will produce a better phase separation.
The simulations are in agreement with results reported in literature
and show that CFD can be a useful tool in studying a horizontal oilwater
separator.
Digital Article Identifier (DOI):
5
15668
Human Elastin-derived Biomimetic Coating Surface to Support Cell Growth
Abstract: A new sythetic gene coding for a Human
Elastin-Like Polypeptide was constructed and expressed. The
recombinant product was tested as coating agent to realize a
surface suitable for cell growth. Coatings showed peculiar
features and different human cell lines were seeded and
cultured. All cell lines tested showed to adhere and proliferate
on this substrate that has been shown also to exert a specific
effect on cells, depending on cell type.
Digital Article Identifier (DOI):
4
5924
Application of Multi-objective Optimization Packages in Design of an Evaporator Coil
Abstract: A novel methodology has been used to design an
evaporator coil of a refrigerant. The methodology used is through a
complete Computer Aided Design /Computer Aided Engineering
approach, by means of a Computational Fluid Dynamic/Finite
Element Analysis model which is executed many times for the
thermal-fluid exploration of several designs' configuration by an
commercial optimizer. Hence the design is carried out automatically
by parallel computations, with an optimization package taking the
decisions rather than the design engineer. The engineer instead takes
decision regarding the physical settings and initializing of the
computational models to employ, the number and the extension of the
geometrical parameters of the coil fins and the optimization tools to
be employed. The final design of the coil geometry found to be better
than the initial design.
Digital Article Identifier (DOI):
3
5960
Development of a Pipeline Monitoring System by Bio-mimetic Robots
Abstract: To explore pipelines is one of various bio-mimetic
robot applications. The robot may work in common buildings such as
between ceilings and ducts, in addition to complicated and massive
pipeline systems of large industrial plants. The bio-mimetic robot finds
any troubled area or malfunction and then reports its data. Importantly,
it can not only prepare for but also react to any abnormal routes in the
pipeline. The pipeline monitoring tasks require special types of mobile
robots. For an effective movement along a pipeline, the movement of
the robot will be similar to that of insects or crawling animals. During
its movement along the pipelines, a pipeline monitoring robot has an
important task of finding the shapes of the approaching path on the
pipes. In this paper we propose an effective solution to the pipeline
pattern recognition, based on the fuzzy classification rules for the
measured IR distance data.
Digital Article Identifier (DOI):
2
6830
Inverse Dynamic Active Ground Motion Acceleration Inputs Estimation of the Retaining Structure
Abstract: The innovative fuzzy estimator is used to estimate the
ground motion acceleration of the retaining structure in this study. The
Kalman filter without the input term and the fuzzy weighting recursive
least square estimator are two main portions of this method. The
innovation vector can be produced by the Kalman filter, and be
applied to the fuzzy weighting recursive least square estimator to
estimate the acceleration input over time. The excellent performance
of this estimator is demonstrated by comparing it with the use of
difference weighting function, the distinct levels of the measurement
noise covariance and the initial process noise covariance. The
availability and the precision of the proposed method proposed in this
study can be verified by comparing the actual value and the one
obtained by numerical simulation.
Digital Article Identifier (DOI):
1
11040
Design of High-speed Modified Booth Multipliers Operating at GHz Ranges
Abstract: This paper describes the pipeline architecture of
high-speed modified Booth multipliers. The proposed multiplier
circuits are based on the modified Booth algorithm and the pipeline
technique which are the most widely used to accelerate the
multiplication speed. In order to implement the optimally pipelined
multipliers, many kinds of experiments have been conducted. The
speed of the multipliers is greatly improved by properly deciding the
number of pipeline stages and the positions for the pipeline registers to
be inserted. We described the proposed modified Booth multiplier
circuits in Verilog HDL and synthesized the gate-level circuits using
0.13um standard cell library. The resultant multiplier circuits show
better performance than others. Since the proposed multipliers operate
at GHz ranges, they can be used in the systems requiring very high
performance.
Digital Article Identifier (DOI):