Abstract: In a recent year usage of VoIP subscription has increased tremendously as compare to Public Switching Telephone System(PSTN). A VoIP subscriber would like to know the exact tariffs of the calls made using VoIP. As the usage increases, the rate of fraud is also increases, causing users complain about excess billing. This in turn hampers the growth of VoIP .This paper describe the common frauds and attack on VoIP based system and make an attempt to solve the billing attack by creating secured channel between caller and callee.
Abstract: In this study, an optimization of supersonic air-to-air ejector is carried out by a recently developed single-objective genetic algorithm based on adaption of sequence of individuals. Adaptation of sequence is based on Shape-based distance of individuals and embedded micro-genetic algorithm. The optimal sequence found defines the succession of CFD-aimed objective calculation within each generation of regular micro-genetic algorithm. A spring-based deformation mutates the computational grid starting the initial individualvia adapted population in the optimized sequence. Selection of a generation initial individual is knowledge-based. A direct comparison of the newly defined and standard micro-genetic algorithm is carried out for supersonic air-to-air ejector. The only objective is to minimize the loose of total stagnation pressure in the ejector. The result is that sequence-adopted micro-genetic algorithm can provide comparative results to standard algorithm but in significantly lower number of overall CFD iteration steps.
Abstract: Discharges in hydrogen, ignited by wire explosion, with current amplitude up to 1.5 MA were investigated. Channel diameter oscillations were observed on the photostreaks. Voltage and current curves correlated with the photostreaks. At initial gas pressure of 5-35 MPa the oscillation period was proportional to square root of atomic number of the initiating wire material. These oscillations were associated with aligned magnetic and gas-kinetic pressures. At initial pressure of 80-160 MPa acoustic pressure fluctuations on the discharge chamber wall were increased up to 150 MPa and there were the growth of voltage fluctuations on the discharge gap up to 3 kV simultaneously with it. In some experiments it was observed abrupt increase in the oscillation amplitude, which can be caused by the resonance of the acoustic oscillations in discharge chamber volume and the oscillations connected with alignment of the gaskinetic pressure and the magnetic pressure, as far as frequencies of these oscillations are close to each other in accordance with the estimates and the experimental data. Resonance of different type oscillations can produce energy density increasing in the discharge channel. Thus, the appropriate initial conditions in the experiment allow to increase the energy density in the discharge channel
Abstract: The objective of present work is to stimulate the
machining of material by electrical discharge machining (EDM) to
give effect of input parameters like discharge current (Ip), pulse on
time (Ton), pulse off time (Toff) which can bring about changes in the
output parameter, i.e. material removal rate. Experimental data was
gathered from die sinking EDM process using copper electrode and
Medium Carbon Steel (AISI 1040) as work-piece. The rules of
membership function (MF) and the degree of closeness to the
optimum value of the MMR are within the upper and lower range of
the process parameters. It was found that proposed fuzzy model is in
close agreement with the experimental results. By Intelligent, model
based design and control of EDM process parameters in this study
will help to enable dramatically decreased product and process
development cycle times.
Abstract: The purpose of this research was to study the inspector performance by using computer based training (CBT). Visual inspection task was printed circuit board (PCB) simulated on several types of defects. Subjects were 16 undergraduate randomly selected from King Mongkut-s University of Technology Thonburi and test for 20/20. Then, they were equally divided on performance into two groups (control and treatment groups) and were provided information before running the experiment. Only treatment group was provided feedback information after first experiment. Results revealed that treatment group was showed significantly difference at the level of 0.01. The treatment group showed high percentage on defects detected. Moreover, the attitude of inspectors on using the CBT to inspection was showed on good. These results have been showed that CBT could be used for training to improve inspector performance.
Abstract: In this study, the precision heading process of
spur gears has been investigated by means of numerical
analysis. The effect of some parameters such as teeth number
and module on the forming force and material flow were
presented. The simulation works were performed rigid-plastic
finite element method using DEFORM 3D software. In order
to validate the estimated numerical results, they were
compared with those obtained experimentally during heading
of spur gear using lead as a model material. Results showed
that the optimum number of gear teeth is between 10 to 20,
that is because of being the specific pressure in its minimum
value.
Abstract: In this work the opportunity of construction of the
qualifiers for face-recognition systems based on conjugation criteria
is investigated. The linkage between the bipartite conjugation, the
conjugation with a subspace and the conjugation with the null-space
is shown. The unified solving rule is investigated. It makes the
decision on the rating of face to a class considering the linkage
between conjugation values. The described recognition method can
be successfully applied to the distributed systems of video control
and video observation.
Abstract: Tumour suppressors are key participants in the
prevention of cancer. Regulation of their expression through
miRNAs is important for comprehensive translation inhibition of
tumour suppressors and elucidation of carcinogenesis mechanisms.
We studies the possibility of 1521 miRNAs to bind with 873 mRNAs
of human tumour suppressors using RNAHybrid 2.1 and ERNAhybrid
programmes. Only 978 miRNAs were found to be
translational regulators of 812 mRNAs, and 61 mRNAs did not have
any miRNA binding sites. Additionally, 45.9% of all miRNA binding
sites were located in coding sequences (CDSs), 33.8% were located
in 3' untranslated region (UTR), and 20.3% were located in the
5'UTR. MiRNAs binding with more than 50 target mRNAs and
mRNAs binding with several miRNAs were selected. Hsa-miR-5096
had 15 perfectly complementary binding sites with mRNAs of 14
tumour suppressors. These newly indentified miRNA binding sites
can be used in the development of medicines (anti-sense therapies)
for cancer treatment.
Abstract: Accounts of language acquisition differ significantly in their treatment of the role of prediction in language learning. In particular, nativist accounts posit that probabilistic learning about words and word sequences has little to do with how children come to use language. The accuracy of this claim was examined by testing whether distributional probabilities and frequency contributed to how well 3-4 year olds repeat simple word chunks. Corresponding chunks were the same length, expressed similar content, and were all grammatically acceptable, yet the results of the study showed marked differences in performance when overall distributional frequency varied. It was found that a distributional model of language predicted the empirical findings better than a number of other models, replicating earlier findings and showing that children attend to distributional probabilities in an adult corpus. This suggested that language is more prediction-and-error based, rather than on abstract rules which nativist camps suggest.
Abstract: The biological activity of A. pullulans isolates against
species of the genus Fusarium, bacteria of the genus Azotobacter and
pseudomonads colonizing wheat kernels was evaluated. A field
experiment was carried out in 2009-2011, in north-eastern Poland.
Winter wheat (cv. Bogatka) plants were sprayed with a cell
suspension of A. pullulans at a density of 106 - 108 per cm3 water at
the stem elongation stage and the heading stage. Untreated plants
served as control. The abundance of epiphytic yeasts, bacteria of the
genus Azotobacter, pseudomonads and Fusarium pathogens on wheat
grain was estimated at harvest and after six months’ storage. The
average size of yeast communities was significantly greater on wheat
kernels treated with a cell suspension of A. pullulans, compared with
control samples. In 2010-2011, biological control reduced the
abundance of some species of the genus Fusarium.
Abstract: The aims of this study were to compare the
differences of being good membership behavior among faculties and
staffs of Suan Sunandha Rajabhat University with different sex, age,
income, education, marital status, and working period, and
investigate the relationships between organizational commitment and
being good membership behavior. The research methodology
employed a questionnaire as a quantitative method. The respondents
were 305 faculties and staffs of Suan Sunandha Rajabhat University.
This research used Percentage, Mean, Standard Deviation, t-test,
One-Way ANOVA Analysis of Variance, and Pearson’s Product
Moment Correlation Coefficient in data analysis. The results showed
that organizational commitment among faculties and staffs of Suan
Sunandha Rajabhat University was at a high level. In addition,
differences in sex, age, income, education, marital status, and
working period revealed differences in being good membership
behavior. The results also indicated that organizational commitment
was significantly related to being good membership behavior.
Abstract: In this research, the authors analyze network stability
using agent-based simulation. Firstly, the authors focus on analyzing
large networks (eight agents) by connecting different two stable small
social networks (A small stable network is consisted on four agents.).
Secondly, the authors analyze the network (eight agents) shape which
is added one agent to a stable network (seven agents). Thirdly, the
authors analyze interpersonal comparison of utility. The “star-network
"was not found on the result of interaction among stable two small
networks. On the other hand, “decentralized network" was formed
from several combination. In case of added one agent to a stable
network (seven agents), if the value of “c"(maintenance cost of per
a link) was larger, the number of patterns of stable network was
also larger. In this case, the authors identified the characteristics of a
large stable network. The authors discovered the cases of decreasing
personal utility under condition increasing total utility.
Abstract: This paper presents the outcomes of a qualitative
study which aims to investigate the pedagogical potentials of serious
games in the preparation of future teachers. The authors discuss the
existing problems and barriers associated with the organization of
teaching practices in Bulgaria as part of the pre-service teacher
training, as well as the attitudes and perceptions of the interviewed
academics, teachers and trainees concerning the integration of serious
games in the teaching practicum. The study outcomes strongly
confirm the positive attitudes of the respondents to the introduction
of virtual learning environments for the development of professional
skills of future teachers as a supplement to the traditional forms of
education. Through the inclusion of serious games it is expected to
improve the quality of practical training of pre-service teachers as
they overcome many of the problems identified in the existing
teaching practices. The outcomes of the study will inform the design
of the educational simulation software which is part of the project
SimAula Tomorrow's Teachers Training.
Abstract: Properties of cement pastes with fine-ground ceramics
used as an alternative binder replacing Portland cement up to 20% of
its mass are investigated. At first, the particle size distribution of
cement and fine-ground ceramics is measured using laser analyser.
Then, the material properties are studied in the early hardening
period up to 28 days. The hydration process of studied materials is
monitored by electrical conductivity measurement using TDR
sensors. The changes of materials- structures within the hardening are
observed using pore size distribution measurement. The compressive
strength measurements are done as well. Experimental results show
that the replacement of Portland cement by fine-ground ceramics in
the amount of up to 20% by mass is acceptable solution from the
mechanical point of view. One can also assume similar physical
properties of designed materials to the reference material with only
Portland cement as binder.
Abstract: Today many countries have the ambitious purposes of long-term and continuous development: constant growth of competitiveness, maintenance of a high standard of living of the population, leadership in the world market. One of the best possible ways of achievement of these purposes is a transition of the countries to innovative economy. The paper presents the analyses of problems of forming of innovative receptivity to innovations and creation of «innovative society». Creation of an innovative culture in a society and increase of the level of prestige of innovative activity are the best ways of developing of innovative processes. The base of the analysis is a comparing of Russia and different developed countries according to the level of some indictors of innovative activity.1
Abstract: A universal current-mode biquad is described which
represents an economical variant of well-known KHN (Kerwin,
Huelsman, Newcomb) voltage-mode filter. The circuit consists of
two multiple-output OTAs and of two grounded capacitors. Utilizing
simple splitter of the input current and a pair of jumpers, all the basic
2nd-order transfer functions can be implemented. The principle is
verified by Spice simulation on the level of a CMOS structure of
OTAs.
Abstract: Optical burst switching (OBS) has been proposed to
realize the next generation Internet based on the wavelength division
multiplexing (WDM) network technologies. In the OBS, the burst
contention is one of the major problems. The deflection routing has
been designed for resolving the problem. However, the deflection
routing becomes difficult to prevent from the burst contentions as the
network load becomes high. In this paper, we introduce a flow rate
control methods to reduce burst contentions. We propose new flow
rate control methods based on the leaky bucket algorithm and
deflection routing, i.e. separate leaky bucket deflection method, and
dynamic leaky bucket deflection method. In proposed methods, edge
nodes which generate data bursts carry out the flow rate control
protocols. In order to verify the effectiveness of the flow rate control in
OBS networks, we show that the proposed methods improve the
network utilization and reduce the burst loss probability through
computer simulations.
Abstract: In this paper we propose a novel RF LDMOS structure which employs a thin strained silicon layer at the top of the channel and the N-Drift region. The strain is induced by a relaxed Si0.8 Ge0.2 layer which is on top of a compositionally graded SiGe buffer. We explain the underlying physics of the device and compare the proposed device with a conventional LDMOS in terms of energy band diagram and carrier concentration. Numerical simulations of the proposed strained silicon laterally diffused MOS using a 2 dimensional device simulator indicate improvements in saturation and linear transconductance, current drivability, cut off frequency and on resistance. These improvements are however accompanied with a suppression in the break down voltage.
Abstract: Direction of Arrival estimation refers to defining a mathematical function called a pseudospectrum that gives an indication of the angle a signal is impinging on the antenna array. This estimation is an efficient method of improving the quality of service in a communication system by focusing the reception and transmission only in the estimated direction thereby increasing fidelity with a provision to suppress interferers. This improvement is largely dependent on the performance of the algorithm employed in the estimation. Many DOA algorithms exists amongst which are MUSIC, Root-MUSIC and ESPRIT. In this paper, performance of these three algorithms is analyzed in terms of complexity, accuracy as assessed and characterized by the CRLB and memory requirements in various environments and array sizes. It is found that the three algorithms are high resolution and dependent on the operating environment and the array size.
Abstract: The nexus between language and culture is so
intertwined and very significant that language is largely seen as a
vehicle for cultural transmission. Culture itself refers to the aggregate
belief system of a people, embellishing its corporate national image
or brand. If we conceive national rebranding as a campaign to
rekindle the patriotic flame in the consciousness of a people towards
its sociocultural imperatives and values, then, Nigerian indigenous
linguistic flame has not been ignited. Consequently, the paper
contends that the current national rebranding policy remains a myth
in the confines of the elitists' intellectual squabble. It however
recommends that the use of our indigenous languages should be
supported by adequate legislation and also propagated by Nollywood
in order to revamp and sustain the people’s interest in their local
languages. Finally, the use of the indigenous Nigerian languages
demonstrates patriotism, an important ingredient for actualizing a
genuine national rebranding.