Abstract: Double-diffusive steady convection in a partially
porous cavity with partially permeable walls and under the combined
buoyancy effects of thermal and mass diffusion was analysed
numerically using finite volume method.
The top wall is well insulated and impermeable while the bottom
surface is partially well insulated and impermeable and partially
submitted to constant temperature T1 and concentration C1. Constant
equal temperature T2 and concentration C2 are imposed along the
vertical surfaces of the enclosure. Mass suction/injection and
injection/suction are respectively considered at the bottom of the
porous centred partition and at one of the vertical walls.
Heat and mass transfer characteristics as streamlines and average
Nusselt numbers and Sherwood numbers were discussed for different
values of buoyancy ratio, Rayleigh number, and injection/suction
coefficient.
It is especially noted that increasing the injection factor
disadvantages the exchanges in the case of the injection while the
transfer is augmented in case of suction. On the other hand, a critical
value of the buoyancy ratio was highlighted for which heat and mass
transfers are minimized.
Abstract: This paper describes an ongoing study into the quality of service provided by the Irish Revenue Commisioners- online tax filing and collection system. The Irish Revenue On-Line Service (ROS) site has won several awards. In this study, a version of the widely use SERVQUAL measuring instrument, adapted for use with online services, has been modified for the specific case of ROS. In this paper, the theory behind this instrument is set out, the particular problems of evaluating revenue collecting online are examined and the rationale for this approach is explained.
Abstract: This paper examines the relationship between financial
risks and profitability of the conventional and Islamic banks in
Malaysia for the period between 1996 and 2005. The measures of
profitability that have been used in the study are the return on equity
(ROE) and return on assets (ROA) while the financial risks are credit
risk, interest rate risk and liquidity risks. This study employs panel
data regression analysis of Generalised Least Squares of fixed effects
and random effects models. It was found that credit risk has a
significant impact on ROA and ROE for the conventional as well as
the Islamic banks. The relationship between interest rate risk and ROE
were found to be weakly significant for the conventional banks and
insignificant for the Islamic banks. The effect of interest rate risk on
ROA is significant for the conventional banks. Liquidity risk was
found to have an insignificant impact on both profitability measures.
Abstract: Column leach test has been performed to examine the
behavior of leaching of sodium, calcium and potassium in landfills.
In the column leach apparatus, two different layers of contaminated
and uncontaminated soils of different height ratios (ratio of depth of
contaminated soil to the depth of uncontaminated soil) are taken.
Water is poured from an overhead tank at a particular flowrate to the
inlet of the soil column for a certain ponding depth over the
contaminated soil. Subsequent infiltration causes leaching and the
leachates are collected from the bottom of the column. The
concentrations of Na, Ca and K in the leachate are measured using
flame photometry. The experiments are further extended by changing
the rates of flow from the overhead tank to the inlet of the column in
achieving the same ponding depth. The experiments are performed
for different scenarios in which the height ratios are altered and the
variations of concentrations of Na, Ca, and K are observed. The study
brings an estimation of leaching in landfill sites for different heights
and precipitation intensity where a ponding depth is maintained over
the landfill. It has been observed that the leaching behavior of Na,
Ca, and K are not similar. Calcium exhibits highest amount of
leaching compared to Sodium and Potassium under similar
experimental conditions.
Abstract: In the present study, Convective heat transfer
coefficient and pressure drop of Al2O3/water nanofluid in laminar
flow regime under constant heat flux conditions inside a circular tube
were experimentally investigated. Al2O3/water nanofluid with 0.5%
and 1% volume concentrations with 15 nm diameter nanoparticles
were used as working fluid. The effect of different volume
concentrations on convective heat transfer coefficient and friction
factor was studied. The results emphasize that increasing of particle
volume concentration leads to enhance convective heat transfer
coefficient. Measurements show the average heat transfer coefficient
enhanced about 11-20% with 0.5% volume concentration and
increased about 16-27% with 1% volume concentration compared to
distilled water. In addition, the convective heat transfer coefficient of
nanofluid enhances with increase in heat flux. From the results, the
average ratio of (fnf/fbf) was about 1.10 for 0.5% volume
concentration. Therefore, there is no significant increase in friction
factor for nanofluids.
Abstract: Sustainable energy usage has been recognized as one
of the important measure to increase the competitiveness of the
nation globally. Many strong emphases were given in the Ninth
Malaysia Plan (RMK9) to improve energy efficient especially to
government buildings. With this in view, a project to investigate the
potential of energy saving in selected building in Universiti Tun
Hussein Onn Malaysia (UTHM) was carried out. In this project, a
case study involving electric energy consumption of the academic
staff office building was conducted. The scope of the study include to
identify energy consumption in a selected building, to study energy
saving opportunities, to analyse cost investment in term of economic
and to identify users attitude with respect to energy usage. The
MS1525:2001, Malaysian Standard -Code of practice on energy
efficiency and use of renewable energy for non-residential buildings
was used as reference. Several energy efficient measures were
considered and their merits and priority were compared. Improving
human behavior can reduce energy consumption by 6% while
technical measure can reduce energy consumption by 44%. Two
economic analysis evaluation methods were applied; they are the
payback period method and net present value method.
Abstract: In recent five decades, textured yarns of polyester fiber produced by false twist method are the most
important and mass-produced manmade fibers. There are
many parameters of cross section which affect the physical and mechanical properties of textured yarns. These parameters
are surface area, perimeter, equivalent diameter, large
diameter, small diameter, convexity, stiffness, eccentricity, and hydraulic diameter. These parameters were evaluated by
digital image processing techniques. To find trends between production criteria and evaluated parameters of cross section, three criteria of production line have been adjusted and different types of yarns were produced. These criteria are
temperature, drafting ratio, and D/Y ratio. Finally the relations between production criteria and cross section parameters were
considered. The results showed that the presented technique can recognize and measure the parameters of fiber cross section in acceptable accuracy. Also, the optimum condition
of adjustments has been estimated from results of image analysis evaluation.
Abstract: This paper deals with the application for contentbased
image retrieval to extract color feature from natural images
stored in the image database by segmenting the image through
clustering. We employ a class of nonparametric techniques in which
the data points are regarded as samples from an unknown probability
density. Explicit computation of the density is avoided by using the
mean shift procedure, a robust clustering technique, which does not
require prior knowledge of the number of clusters, and does not
constrain the shape of the clusters. A non-parametric technique for
the recovery of significant image features is presented and
segmentation module is developed using the mean shift algorithm to
segment each image. In these algorithms, the only user set parameter
is the resolution of the analysis and either gray level or color images
are accepted as inputs. Extensive experimental results illustrate
excellent performance.
Abstract: In this paper, we propose the pre-processor based on
the Evidence Supporting Measure of Similarity (ESMS) filter and also
propose the unified fusion approach (UFA) based on the general
fusion machine coupled with ESMS filter, which improve the
correctness and precision of information fusion in any fields of
application. Here we mainly apply the new approach to Simultaneous
Localization And Mapping (SLAM) of Pioneer II mobile robots. A
simulation experiment was performed, where an autonomous virtual
mobile robot with sonar sensors evolves in a virtual world map with
obstacles. By comparing the result of building map according to the
general fusion machine (here DSmT-based fusing machine and
PCR5-based conflict redistributor considereded) coupling with ESMS
filter and without ESMS filter, it shows the benefit of the selection of
the sources as a prerequisite for improvement of the information
fusion, and also testifies the superiority of the UFA in dealing with
SLAM.
Abstract: In this study it is aimed to determine the level of preservice teachers- computer phobia. Whether or not computer phobia meaningfully varies statistically according to gender and computer experience has been tested in the study. The study was performed on 430 pre-service teachers at the Education Faculty in Rize/Turkey. Data in the study were collected through the Computer Phobia Scale consisting of the “Personal Knowledge Questionnaire", “Computer Anxiety Rating Scale", and “Computer Thought Survey". In this study, data were analyzed with statistical processes such as t test, and correlation analysis. According to results of statistical analyses, computer phobia of male pre-service teachers does not statistically vary depending on their gender. Although male preservice teachers have higher computer anxiety scores, they have lower computer thought scores. It was also observed that there is a negative and intensive relation between computer experience and computer anxiety. Meanwhile it was found out that pre-service teachers using computer regularly indicated lower computer anxiety. Obtained results were tried to be discussed in terms of the number of computer classes in the Education Faculty curriculum, hours of computer class and the computer availability of student teachers.
Abstract: In the last decades, the problem of perforation
damage has been considered as the major factor for the
reduction of oil productivity. Underbalance perforation is
considered as one of the best means to minimize or overcome
this problem. By maintaining wellbore pressure lower than
formation pressure, perforation damage could be minimize or
eliminated. This can be achieved by the use of nontraditional
lightweight completion fluid. This paper presents the effect of
natural clay in formulating nontraditional completion fluid to
ensure successful perforation job and increase of production
rate. Natural clay is used as homogenizing agent to create a
stable and non-damaging low-density completion fluid.
Results indicate that the addition of natural clay dramatically
increase the stability of the final fluids. In addition, field test
has shown that the application of nontraditional completion
fluid increases oil production by three folds.
Abstract: Degradation of polymeric insulation systems of
electrical equipments increases the space charge density and the
concentration of electrical dipoles. By consequence, the maximum
values and the slopes of absorption/resorption (A/R) currents can
change with insulation systems ageing. In this paper, an analysis of
the nature of the A/R currents and the importance of their
components, especially the polarization current and the current given
by the space charge, is presented. The experimental study concerns
the A/R currents measurements of plane samples (made from
CALMICAGLAS tapes), virgin and thermally accelerated aged. The
obtained results show that the ageing process produces an increase of
the values and a decrease of shapes of the A/R currents. Finally, the
possibility of estimating insulations ageing state and lifetime from
A/R currents measurements is discussed.
Abstract: The aim of this paper is to investigate the effect of
mean size of industry on survival of new firms in East-Azarbaijan
province through 1981-2006 using hazard function. So the effect of
two variables including mean employment of industry and mean
capital of industry are investigated on firm's survival. The Industry &
Mine Ministry database has used for data gathering and the data are
analyzed using the semi-parametric cox regression model. The results
of this study shows that there is a meaningful negative relationship
between mean capital of industry and firm's survival, but the mean
employment of industry has no meaningful effect on survival of new
firms.
Abstract: This paper is concerned with an epidemic model with delay. By using the comparison theorem of the differential equation and constructing a suitable Lyapunov functional, Some sufficient conditions which guarantee the permeance and existence of a unique globally attractive positive almost periodic solution of the model are obtain. Finally, an example is employed to illustrate our result.
Abstract: Key management represents a major and the most
sensitive part of cryptographic systems. It includes key generation,
key distribution, key storage, and key deletion. It is also considered
the hardest part of cryptography. Designing secure cryptographic
algorithms is hard, and keeping the keys secret is much harder.
Cryptanalysts usually attack both symmetric and public key
cryptosystems through their key management. We introduce a
protocol to exchange cipher keys over insecure communication
channel. This protocol is based on public key cryptosystem,
especially elliptic curve cryptosystem. Meanwhile, it tests the cipher
keys and selects only the good keys and rejects the weak one.
Abstract: When it comes to last, it is regarded as the critical
foundation of shoe design and development. A computer aided
methodology for various last form designs is proposed in this study.
The reverse engineering is mainly applied to the process of scanning
for the last form. Then with the minimum energy for revision of
surface continuity, the surface reconstruction of last is rebuilt by the
feature curves of the scanned last. When the surface reconstruction of
last is completed, the weighted arithmetic mean method is applied to
the computation on the shape morphing for the control mesh of last,
thus 3D last form of different sizes is generated from its original form
feature with functions remained. In the end, the result of this study is
applied to an application for 3D last reconstruction system. The
practicability of the proposed methodology is verified through later
case studies.
Abstract: Internet is without any doubt the fastest and effective mean of communication making it possible to reach a great number of people in the world. It draws its base from exchange points. Indeed exchange points are used to inter-connect various Internet suppliers and operators in order to allow them to exchange traffic and it is with these interconnections that Internet made its great strides. They thus make it possible to limit the traffic delivered via the operators of transits. This limitation allows a significant improvement of the quality of service, a reduction in the latency time just as a reduction of the cost of connection for the final subscriber. Through this article we will show how the installation of an IXP allows an improvement and a diversification of the services just as a reduction of the Internet connection costs.
Abstract: This paper presents the methodology from machine
learning approaches for short-term rain forecasting system. Decision
Tree, Artificial Neural Network (ANN), and Support Vector Machine
(SVM) were applied to develop classification and prediction models
for rainfall forecasts. The goals of this presentation are to
demonstrate (1) how feature selection can be used to identify the
relationships between rainfall occurrences and other weather
conditions and (2) what models can be developed and deployed for
predicting the accurate rainfall estimates to support the decisions to
launch the cloud seeding operations in the northeastern part of
Thailand. Datasets collected during 2004-2006 from the
Chalermprakiat Royal Rain Making Research Center at Hua Hin,
Prachuap Khiri khan, the Chalermprakiat Royal Rain Making
Research Center at Pimai, Nakhon Ratchasima and Thai
Meteorological Department (TMD). A total of 179 records with 57
features was merged and matched by unique date. There are three
main parts in this work. Firstly, a decision tree induction algorithm
(C4.5) was used to classify the rain status into either rain or no-rain.
The overall accuracy of classification tree achieves 94.41% with the
five-fold cross validation. The C4.5 algorithm was also used to
classify the rain amount into three classes as no-rain (0-0.1 mm.),
few-rain (0.1- 10 mm.), and moderate-rain (>10 mm.) and the overall
accuracy of classification tree achieves 62.57%. Secondly, an ANN
was applied to predict the rainfall amount and the root mean square
error (RMSE) were used to measure the training and testing errors of
the ANN. It is found that the ANN yields a lower RMSE at 0.171 for
daily rainfall estimates, when compared to next-day and next-2-day
estimation. Thirdly, the ANN and SVM techniques were also used to
classify the rain amount into three classes as no-rain, few-rain, and
moderate-rain as above. The results achieved in 68.15% and 69.10%
of overall accuracy of same-day prediction for the ANN and SVM
models, respectively. The obtained results illustrated the comparison
of the predictive power of different methods for rainfall estimation.
Abstract: Cardiovascular diseases, principally atherosclerosis, are responsible for 30% of world deaths. Atherosclerosis is due to the formation of plaque. The fatty plaque may be at risk of rupture, leading typically to stroke and heart attack. The plaque is usually associated with a high degree of lumen reduction, called a stenosis.It is increasingly recognized that the initiation and progression of disease and the occurrence of clinical events is a complex interplay between the local biomechanical environment and the local vascular biology. The aim of this study is to investigate the flow behavior through a stenosed artery. A physical experiment was performed using an artery model and blood analogue fluid. An axisymmetric model constructed consists of contraction and expansion region that follow a mathematical form of cosine function. A 30% diameter reduction was used in this study. The flow field was measured using particle image velocimetry (PIV). Spherical particles with 20μm diameter were seeded in a water-glycerol-NaCl mixture. Steady flow Reynolds numbers are 250. The area of interest is the region after the stenosis where the flow separation occurs. The velocity field was measured and the velocity gradient was investigated. There was high particle concentration in the recirculation zone. High velocity gradient formed immediately after the stenosis throat created a lift force that enhanced particle migration to the flow separation area.
Abstract: This research was conducted to determine responses
of chickpeas to drought in different periods (early period, late period,
no-irrigation, two times irrigation as control). The trial was made in
“Randomized Complete Block Design" with three replications on
2010 and 2011 years in Konya-Turkey. Genotypes were consisted
from 7 lines of ICARDA, 2 certified lines and 1 local population. The
results showed that; as means of years and genotypes, early period
stress showed highest (207.47 kg da-1) seed yield and it was followed
by control (202.33 kg da-1), late period (144.64 kg da-1) and normal
(106.93 kg da-1) stress applications. The genotypes were affected too
much by drought and, the lowest seed was taken from non-irrigated
plots. As the means of years and stress applications, the highest
(196.01 kg da-1) yield was taken from genotype 22255. The reason of
yield variation could be derived from different responses of
genotypes to drought.