Abstract: The paper presents a numerical investigation on the
rapid gas decompression in pure nitrogen which is made by using the
one-dimensional (1D) and three-dimensional (3D) mathematical
models of transient compressible non-isothermal fluid flow in pipes.
A 1D transient mathematical model of compressible thermal multicomponent
fluid mixture flow in pipes is presented. The set of the
mass, momentum and enthalpy conservation equations for gas phase
is solved in the model. Thermo-physical properties of multicomponent
gas mixture are calculated by solving the Equation of
State (EOS) model. The Soave-Redlich-Kwong (SRK-EOS) model is
chosen. This model is successfully validated on the experimental data
[1] and shows a good agreement with measurements. A 3D transient
mathematical model of compressible thermal single-component gas
flow in pipes, which is built by using the CFD Fluent code (ANSYS),
is presented in the paper. The set of unsteady Reynolds-averaged
conservation equations for gas phase is solved. Thermo-physical
properties of single-component gas are calculated by solving the Real
Gas Equation of State (EOS) model. The simplest case of gas
decompression in pure nitrogen is simulated using both 1D and 3D
models. The ability of both models to simulate the process of rapid
decompression with a high order of agreement with each other is
tested. Both, 1D and 3D numerical results show a good agreement
between each other. The numerical investigation shows that 3D CFD
model is very helpful in order to validate 1D simulation results if the
experimental data is absent or limited.
Abstract: Digital signature is a useful primitive to attain the integrity and authenticity in various wire or wireless communications. Proxy signature is one type of the digital signatures. It helps the proxy signer to sign messages on behalf of the original signer. It is very useful when the original signer (e.g. the president of a company) is not available to sign a specific document. If the original signer can not forge valid proxy signatures through impersonating the proxy signer, it will be robust in a virtual environment; thus the original signer can not shift any illegal action initiated by herself to the proxy signer. In this paper, we propose a new proxy signature scheme. The new scheme can prevent the original signer from impersonating the proxy signer to sign messages. The proposed scheme is based on the regular ElGamal signature. In addition, the fair privacy of the proxy signer is maintained. That means, the privacy of the proxy signer is preserved; and the privacy can be revealed when it is necessary.
Abstract: Combined therapy using Interferon and Ribavirin is the standard treatment in patients with chronic hepatitis C. However, the number of responders to this treatment is low, whereas its cost and side effects are high. Therefore, there is a clear need to predict patient’s response to the treatment based on clinical information to protect the patients from the bad drawbacks, Intolerable side effects and waste of money. Different machine learning techniques have been developed to fulfill this purpose. From these techniques are Associative Classification (AC) and Decision Tree (DT). The aim of this research is to compare the performance of these two techniques in the prediction of virological response to the standard treatment of HCV from clinical information. 200 patients treated with Interferon and Ribavirin; were analyzed using AC and DT. 150 cases had been used to train the classifiers and 50 cases had been used to test the classifiers. The experiment results showed that the two techniques had given acceptable results however the best accuracy for the AC reached 92% whereas for DT reached 80%.
Abstract: We discuss the convergence property of the minimum residual (MINRES) method for the solution of complex shifted Hermitian system (αI + H)x = f. Our convergence analysis shows that the method has a faster convergence than that for real shifted Hermitian system (Re(α)I + H)x = f under the condition Re(α) + λmin(H) > 0, and a larger imaginary part of the shift α has a better convergence property. Numerical experiments show such convergence properties.
Abstract: In the past, there were many bridge-s collapses due to
lack of bridge structural capacity information. Most of concrete
bridge health was relied on information from visual inspection, which
sometime was inadequate. This study was conducted in order to
investigate relationship between bridge structural condition and
bridge visual condition. This study was a part of a big project
conducted at Department of Highways of Thailand. In this study, 31
bridges including slab-type bridges, plank-girder bridges, prestressed
box-beam bridges, prestressed I-girder bridges and prestressed multibeam
bridges were selected for visual inspection and load test. It was
found a positive correlation between bridge appearance and bridge-s
load carrying capacity. However, statistical characteristic revealed
low correlation between them.
Abstract: The concerns of education and practice of architecture
do not necessarily overlap. Indeed the gap between them could be
seen increasingly and less frequently bridged. We suggest that
changing in architecture education and clarifying the relationship
between these two can help to find and address the opportunities and
unique positions to bridge this gulf.
Abstract: A novel feature selection strategy to improve the recognition accuracy on the faces that are affected due to nonuniform illumination, partial occlusions and varying expressions is proposed in this paper. This technique is applicable especially in scenarios where the possibility of obtaining a reliable intra-class probability distribution is minimal due to fewer numbers of training samples. Phase congruency features in an image are defined as the points where the Fourier components of that image are maximally inphase. These features are invariant to brightness and contrast of the image under consideration. This property allows to achieve the goal of lighting invariant face recognition. Phase congruency maps of the training samples are generated and a novel modular feature selection strategy is implemented. Smaller sub regions from a predefined neighborhood within the phase congruency images of the training samples are merged to obtain a large set of features. These features are arranged in the order of increasing distance between the sub regions involved in merging. The assumption behind the proposed implementation of the region merging and arrangement strategy is that, local dependencies among the pixels are more important than global dependencies. The obtained feature sets are then arranged in the decreasing order of discriminating capability using a criterion function, which is the ratio of the between class variance to the within class variance of the sample set, in the PCA domain. The results indicate high improvement in the classification performance compared to baseline algorithms.
Abstract: There has been considerable growth in the issue of
food & beverage safety in Thailand. This is important because the
level of satisfaction in food & beverage safety has impacts on travel
decision made by foreign tourists. Therefore, this paper was aimed to
test if there is any significant gender effect in the level of satisfaction
of food & beverage safety made by foreign tourists in Thailand. In
addition, this paper utilized the Chi Square test of independent to test
if there was an association between gender and sickness because of
food and if there was an association between gender and the
perception of food safety standard. During January to June, 2012, a
total of 400 foreign tourist respondents, 200 male as well as 200
female foreign tourists, were interviewed at the departure lounge at
Suvarnabhumi airport, Thailand. The findings revealed the
astonishing result that there was no significant effect of gender. Also,
there was no significant difference in the association between gender
and being sick because of food as well as the association between
gender and the perception on the standard of food safety during their
trip in Thailand.
Abstract: We describe an effective method for image encryption
which employs magnitude and phase manipulation using carrier
images. Although it involves traditional methods like magnitude and
phase encryptions, the novelty of this work lies in deploying the
concept of carrier images for encryption purpose. To this end, a
carrier image is randomly chosen from a set of stored images. One
dimensional (1-D) discrete Fourier transform (DFT) is then carried
out on the original image to be encrypted along with the carrier
image. Row wise spectral addition and scaling is performed between
the magnitude spectra of the original and carrier images by randomly
selecting the rows. Similarly, row wise phase addition and scaling is
performed between the original and carrier images phase spectra by
randomly selecting the rows. The encrypted image obtained by these
two operations is further subjected to one more level of magnitude
and phase manipulation using another randomly chosen carrier image
by 1-D DFT along the columns. The resulting encrypted image is
found to be fully distorted, resulting in increasing the robustness
of the proposed work. Further, applying the reverse process at the
receiver, the decrypted image is found to be distortionless.
Abstract: Supply network management adopts a systematic
and integrative approach to managing the operations and
relationships of various parties in a supply network. The objective
of the manufactures in their supply network is to reduce inventory
costs and increase customer satisfaction levels. One way of doing
that is to synchronize delivery performance. A supply network can
be described by nodes representing the companies and the links
(relationships) between these nodes. Uncertainty in delivery time
depends on type of network relationship between suppliers. The
problem is to understand how the individual uncertainties influence
the total uncertainty of the network and identify those parts of the
network, which has the highest potential for improving the total
delivery time uncertainty.
Abstract: Skin color can provide a useful and robust cue
for human-related image analysis, such as face detection,
pornographic image filtering, hand detection and tracking,
people retrieval in databases and Internet, etc. The major
problem of such kinds of skin color detection algorithms is
that it is time consuming and hence cannot be applied to a real
time system. To overcome this problem, we introduce a new
fast technique for skin detection which can be applied in a real
time system. In this technique, instead of testing each image
pixel to label it as skin or non-skin (as in classic techniques),
we skip a set of pixels. The reason of the skipping process is
the high probability that neighbors of the skin color pixels are
also skin pixels, especially in adult images and vise versa. The
proposed method can rapidly detect skin and non-skin color
pixels, which in turn dramatically reduce the CPU time
required for the protection process. Since many fast detection
techniques are based on image resizing, we apply our
proposed pixel skipping technique with image resizing to
obtain better results. The performance evaluation of the
proposed skipping and hybrid techniques in terms of the
measured CPU time is presented. Experimental results
demonstrate that the proposed methods achieve better result
than the relevant classic method.
Abstract: Although the field of parametric Pattern Recognition (PR) has been thoroughly studied for over five decades, the use of the Order Statistics (OS) of the distributions to achieve this has not been reported. The pioneering work on using OS for classification was presented in [1] for the Uniform distribution, where it was shown that optimal PR can be achieved in a counter-intuitive manner, diametrically opposed to the Bayesian paradigm, i.e., by comparing the testing sample to a few samples distant from the mean. This must be contrasted with the Bayesian paradigm in which, if we are allowed to compare the testing sample with only a single point in the feature space from each class, the optimal strategy would be to achieve this based on the (Mahalanobis) distance from the corresponding central points, for example, the means. In [2], we showed that the results could be extended for a few symmetric distributions within the exponential family. In this paper, we attempt to extend these results significantly by considering asymmetric distributions within the exponential family, for some of which even the closed form expressions of the cumulative distribution functions are not available. These distributions include the Rayleigh, Gamma and certain Beta distributions. As in [1] and [2], the new scheme, referred to as Classification by Moments of Order Statistics (CMOS), attains an accuracy very close to the optimal Bayes’ bound, as has been shown both theoretically and by rigorous experimental testing.
Abstract: Synchronization between 0.1 Hz oscillations in heart rate and blood pressure is studied and its change during vertical tilt is evaluated in 37 myocardial infarction patients. Two groups of patients are identified with decreased and increased, respectively, synchronization of the studied oscillations as a response to a tilt test. It is shown that assessment of synchronization of 0.1 Hz oscillations as a response to vertical tilt can be used as a guideline for selecting optimal dose of beta-blocker treatment in post-myocardial infarction patients.
Abstract: Several researchers have proposed methods about
combination of Genetic Algorithm (GA) and Fuzzy Logic (the use of
GA to obtain fuzzy rules and application of fuzzy logic in
optimization of GA). In this paper, we suggest a new method in
which fuzzy decision making is used to improve the performance of
genetic algorithm. In the suggested method, we determine the alleles
that enhance the fitness of chromosomes and try to insert them to the
next generation.
In this algorithm we try to present an innovative vaccination in the
process of reproduction in genetic algorithm, with considering the
trade off between exploration and exploitation.
Abstract: Business Process Management (BPM) helps in optimizing the business processes inside an enterprise. But BPM architecture does not provide any help for extending the enterprise. Modern business environments and rapidly changing technologies are asking for brisk changes in the business processes. Service Oriented Architecture (SOA) can help in enabling the success of enterprise-wide BPM. SOA supports agility in software development that is directly related to achieve loose coupling of interacting software agents. Agility is a premium concern of the current software designing architectures. Together, BPM and SOA provide a perfect combination for enterprise computing. SOA provides the capabilities for services to be combined together and to support and create an agile, flexible enterprise. But there are still many questions to answer; BPM is better or SOA? and what is the future track of BPM and SOA? This paper tries to answer some of these important questions.
Abstract: Due to adverse pressure gradient along the diverging
walls of wide-angled diffusers, the attached flow separates from
one wall and remains attached permanently to the other wall in a
process called stalling. Stalled diffusers render the whole fluid flow
system, in which they are part of, very inefficient. There is then an
engineering need to try to understand the whole process of diffuser
stall if any meaningful attempts to improve on diffuser efficiency
are to be made. In this regard, this paper provides a data bank
contribution for the mean flow-field in wide-angled diffusers where
the complete velocity and static pressure fields, and pressure recovery
data for diffusers in the fully stalled flow regime are experimentally
measured. The measurements were carried out at Reynolds numbers
between 1.07×105 and 2.14×105 based on inlet hydraulic diameter
and centreline velocity for diffusers whose divergence angles were
between 30Ôùª and 50Ôùª. Variation of Reynolds number did not significantly
affect the velocity and static pressure profiles. The wall static
pressure recovery was found to be more sensitive to changes in the
Reynolds number. By increasing the velocity from 10 m/s to 20 m/s,
the wall static pressure recovery increased by 8.31%. However, as the
divergence angle was increased, a similar increase in the Reynolds
number resulted in a higher percentage increase in pressure recovery.
Experimental results showed that regardless of the wall to which
the flow was attached, both the velocity and pressure fields were
replicated with discrepancies below 2%.
Abstract: In the current decade, wireless sensor networks are
emerging as a peculiar multi-disciplinary research area. By this
way, energy efficiency is one of the fundamental research themes
in the design of Medium Access Control (MAC) protocols for
wireless sensor networks. Thus, in order to optimize the energy
consumption in these networks, a variety of MAC protocols are
available in the literature. These schemes were commonly evaluated
under simple network density and a few results are published on
their robustness in realistic network-s size. We, in this paper, provide
an analytical study aiming to highlight the energy waste sources in
wireless sensor networks. Then, we experiment three energy efficient
hybrid CSMA/CA based MAC protocols optimized for wireless
sensor networks: Sensor-MAC (SMAC), Time-out MAC (TMAC)
and Traffic aware Energy Efficient MAC (TEEM). We investigate
these protocols with different network densities in order to discuss
the end-to-end performances of these schemes (i.e. in terms of energy
efficiency, delay and throughput). Through Network Simulator (NS-
2) implementations, we explore the behaviors of these protocols with
respect to the network density. In fact, this study may help the multihops
sensor networks designers to design or select the MAC layer
which matches better their applications aims.
Abstract: Social-economic variables influence transportation
demand largely. Analyses of discrete choice model consider
social-economic variables to study traveler-s mode choice and
demand. However, to calibrate the discrete choice model needs to have
plenty of questionnaire survey. Also, an aggregative model is
proposed. The historical data of passenger volumes for high speed rail
and domestic civil aviation are employed to calibrate and validate the
model. In this study, models with different social-economic variables,
which are oil price, GDP per capita, CPI and economic growth rate,
are compared. From the results, the model with the oil price is better
than models with the other social-economic variables.
Abstract: The success of an electronic system in a System-on- Chip is highly dependent on the efficiency of its interconnection network, which is constructed from routers and channels (the routers move data across the channels between nodes). Since neither classical bus based nor point to point architectures can provide scalable solutions and satisfy the tight power and performance requirements of future applications, the Network-on-Chip (NoC) approach has recently been proposed as a promising solution. Indeed, in contrast to the traditional solutions, the NoC approach can provide large bandwidth with moderate area overhead. The selected topology of the components interconnects plays prime rule in the performance of NoC architecture as well as routing and switching techniques that can be used. In this paper, we present two generic NoC architectures that can be customized to the specific communication needs of an application in order to reduce the area with minimal degradation of the latency of the system. An experimental study is performed to compare these structures with basic NoC topologies represented by 2D mesh, Butterfly-Fat Tree (BFT) and SPIN. It is shown that Cluster mesh (CMesh) and MinRoot schemes achieves significant improvements in network latency and energy consumption with only negligible area overhead and complexity over existing architectures. In fact, in the case of basic NoC topologies, CMesh and MinRoot schemes provides substantial savings in area as well, because they requires fewer routers. The simulation results show that CMesh and MinRoot networks outperforms MESH, BFT and SPIN in main performance metrics.
Abstract: Internet addiction has become a critical problem on
adolescents in Taiwan, and its negative effects on various dimensions
of adolescent development caught the attention of educational and
psychological experts. This study examined the correlation between
cognitive (locus of control) and emotion (emotion venting strategies)
factors on internet addiction of adolescents in Taiwan. Using the
Compulsive Internet Use (CIU) and the Emotion Venting Strategy
scales, a survey was conducted and 215 effective samples (students
ranging from12 to14 years old) returned. Quantitative analysis
methods such as descriptive statistics, t-test, ANOVA, Pearson
correlations and multiple regression were adopted. The results were as
follows: 1. Severity of Internet addiction has significant gender
differences; boys were at a higher risk than girls in becoming addicted
to the Internet. 2. Emotion venting, locus of control and internet
addiction have been shown to be positive correlated with one another.
3. Setting the locus of control as the control variable, emotion venting
strategy has positive and significant contribution to internet addiction.
The results of this study suggest that coaching deconstructive emotion
strategies and cognitive believes are encouraged to integrate with
actual field work.