Abstract: A series of experiments were carried out to study
unsteady behavior of the flow field as well as the boundary layer of
an airfoil oscillating in plunging motion in a subsonic wind tunnel.
The measurements involved surface pressure distribution
complimented with surface-mounted hot-films. The effect of leadingedge
roughness that simulates surface irregularities on the wind
turbine blades was also studied on variations of aerodynamic loads
and boundary layer behavior.
Abstract: The possibilities of mobile technology generate new
demands for vocational teacher trainers to transform their approach
to work and to incorporate its usage into their ordinary educational
practice. This paper presents findings of a focus discussion group
(FDG) session on the usage of iPads within a school of vocational
teacher education (SoVTE). It aims to clarify how the teacher
trainers are using iPads and what has changed in their work during
the usage of iPads. The analytical framework bases on content
analysis and expansive learning cycle. It was not only found what
kind of a role iPads played in their daily practices but it brought also
into attention how a cultural change regarding the usage of social
media and mobile technology was desperately needed in the whole
work community. Thus, the FGD was abducted for developing the
knowledge practices of the community of the SoVTE.
Abstract: The Swine flu outbreak in humans is due to a new
strain of influenza A virus subtype H1N1 that derives in part from
human influenza, avian influenza, and two separated strains of swine
influenza. It can be transmitted from human to human. A
mathematical model for the transmission of Swine flu is developed in
which the human populations are divided into two classes, the risk
and non-risk human classes. Each class is separated into susceptible,
exposed, infectious, quarantine and recovered sub-classes. In this
paper, we formulate the dynamical model of Swine flu transmission
and the repetitive contacts between the people are also considered.
We analyze the behavior for the transmission of this disease. The
Threshold condition of this disease is found and numerical results are
shown to confirm our theoretical predictions.
Abstract: Protein 3D structure prediction has always been an
important research area in bioinformatics. In particular, the
prediction of secondary structure has been a well-studied research
topic. Despite the recent breakthrough of combining multiple
sequence alignment information and artificial intelligence algorithms
to predict protein secondary structure, the Q3 accuracy of various
computational prediction algorithms rarely has exceeded 75%. In a
previous paper [1], this research team presented a rule-based method
called RT-RICO (Relaxed Threshold Rule Induction from Coverings)
to predict protein secondary structure. The average Q3 accuracy on
the sample datasets using RT-RICO was 80.3%, an improvement
over comparable computational methods. Although this demonstrated
that RT-RICO might be a promising approach for predicting
secondary structure, the algorithm-s computational complexity and
program running time limited its use. Herein a parallelized
implementation of a slightly modified RT-RICO approach is
presented. This new version of the algorithm facilitated the testing of
a much larger dataset of 396 protein domains [2]. Parallelized RTRICO
achieved a Q3 score of 74.6%, which is higher than the
consensus prediction accuracy of 72.9% that was achieved for the
same test dataset by a combination of four secondary structure
prediction methods [2].
Abstract: Current spectrums of a high power induction machine was calculated for the cases of full symmetry, static and dynamic eccentricity. The calculations involve integration of 93 electrical plus four mechanical ordinary differential equations. Electrical equations account for variable inductances affected by slotting and eccentricities. The calculations were followed by Fourier analysis of the stator currents in steady state operation. The paper presents the stator current spectrums in full symmetry, static and dynamic eccentricity cases, and demonstrates the harmonics present in each case. The effect of dynamic eccentricity is demonstrating via comparing the current spectrums related to dynamic eccentricity cases with the full symmetry one. The paper includes one case study, refers to dynamic eccentricity, to present the spectrum of the measured current and demonstrate the existence of the harmonics related to dynamic eccentricity. The zooms of current spectrums around the main slot harmonic zone are included to simplify the comparison and prove the existence of the dynamic eccentricity harmonics in both calculated and measured current spectrums.
Abstract: This paper describes a one-dimensional numerical model for natural gas production from the dissociation of methane hydrate in hydrate-capped gas reservoir under depressurization and thermal stimulation. Some of the hydrate reservoirs discovered are overlying a free-gas layer, known as hydrate-capped gas reservoirs. These reservoirs are thought to be easiest and probably the first type of hydrate reservoirs to be produced. The mathematical equations that can be described this type of reservoir include mass balance, heat balance and kinetics of hydrate decomposition. These non-linear partial differential equations are solved using finite-difference fully implicit scheme. In the model, the effect of convection and conduction heat transfer, variation change of formation porosity, the effect of using different equations of state such as PR and ER and steam or hot water injection are considered. In addition distributions of pressure, temperature, saturation of gas, hydrate and water in the reservoir are evaluated. It is shown that the gas production rate is a sensitive function of well pressure.
Abstract: Studies regarding the determination of population
trend of Lipaphis erysimi (kalt.) and its associated natural enemies in
different Brassica lines along with the effect of gamma radiation on
their population were conducted at Agricultural Research Farm,
Malakandher, Khyber Pakhtunkhwa Agricultural University
Peshawar during spring 2006. Three different Brassica lines F6B3,
F6B6 and F6B7 were used, which were replicated four times in
Randomized Complete Block Design. The data revealed that aphid
infestation invariably stated in all three varieties during last week of
February 2006 (1st observation). The peak population of 4.39 aphids
leaf-1 was s recorded during 2nd week of March and lowest population
of 1.02 aphids leaf-1 was recorded during 5th week of March. The
species of lady bird beetle (Coccinella septempunctata) and Syrphid
fly (Syrphus balteatus) first appeared on 24th February with a mean
number of 0.40 lady bird beetle leaf-1 and 0.87 Syrphid fly leaf-1,
respectively. At the time when aphid population started to increase
the peak population of C. septempunctata (0.70 lady bird beetle leaf-
1) and S. balteatus (1.04 syrphid fly leaf-1) was recorded on the 2nd
week of March. Chrysoperla carnea appeared in the 1st week of
March and their peak population was recorded during the 3rd week of
March with mean population of 1.46 C. carnea leaf-1. Among all the
Brassica lines, F6B7 showed comparatively more resistance as
compared to F6B3 F6B6. F6B3 showed least resistance against L.
erysimi, which was found to be the most susceptible cultivar. F6B7
was also found superior in terms of natural enemies. Maximum
number of all natural enemies was recorded on this variety followed
by F6B6. Lowest number of natural enemies was recorded in F6B3.
No significant effect was recorded for the effect of gamma radiation
on the population of aphids, natural enemies and on the varieties.
Abstract: In this paper, the local grid refinement is focused by
using a nested grid technique. The Cartesian grid numerical method is
developed for simulating unsteady, viscous, incompressible flows
with complex immersed boundaries. A finite volume method is used in
conjunction with a two-step fractional-step procedure. The key aspects
that need to be considered in developing such a nested grid solver are
imposition of interface conditions on the inter-block and accurate
discretization of the governing equation in cells that are with the
inter-block as a control surface. A new interpolation procedure is
presented which allows systematic development of a spatial
discretization scheme that preserves the spatial accuracy of the
underlying solver. The present nested grid method has been tested by
two numerical examples to examine its performance in the two
dimensional problems. The numerical examples include flow past a
circular cylinder symmetrically installed in a Channel and flow past
two circular cylinders with different diameters. From the numerical
experiments, the ability of the solver to simulate flows with
complicated immersed boundaries is demonstrated and the nested grid
approach can efficiently speed up the numerical solutions.
Abstract: This paper examines the depiction of Muslim militants in Thai newspapers in 2004. Stuart Hall-s “representation" and “public idioms" are used as theoretical frameworks. Critical Discourse Analysis is employed as a methodology to examine 240 news articles from two leading Thai language newspapers. The results show that the militants are usually labeled as “southern bandits." This suggests that they are just a culprit of the violence in the deep south of Thailand. They are usually described as people who cause turbulence. Consequently, the military have to get rid of them. However, other aspects of the groups such as their political agenda or the failures of the Thai state in dealing with the Malay Muslims were not mention in the news stories. In the time of violence, the researcher argues that this kind of newspaper coverage may help perpetuate the discourse of Malay Muslim, instead of providing fuller picture of the ongoing conflicts.
Abstract: Stress Concentration Factors are significant in
machine design as it gives rise to localized stress when any change in
the design of surface or abrupt change in the cross section occurs.
Almost all machine components and structural members contain
some form of geometrical or microstructural discontinuities. These
discontinuities are very dangerous and lead to failure. So, it is very
much essential to analyze the stress concentration factors for critical
applications like Turbine Rotors. In this paper Finite Element
Analysis (FEA) with extremely fine mesh in the vicinity of the
blades of Steam Turbine Rotor is applied to determine stress
concentration factors. A model of Steam Turbine Rotor is shown in
Fig. 1.
Abstract: In the present study, a steady-state simulation model
has been developed to evaluate the system performance of a
transcritical carbon dioxide heat pump system for simultaneous water
cooling and heating. Both the evaporator (including both two-phase
and superheated zone) and gas cooler models consider the highly
variable heat transfer characteristics of CO2 and pressure drop. The
numerical simulation model of transcritical CO2 heat pump has been
validated by test data obtained from experiments on the heat pump
prototype. Comparison between the test results and the model
prediction for system COP variation with compressor discharge
pressure shows a modest agreement with a maximum deviation of
15% and the trends are fairly similar. Comparison for other operating
parameters also shows fairly similar deviation between the test
results and the model prediction. Finally, the simulation results are
presented to study the effects of operating parameters such as,
temperature of heat exchanger fluid at the inlet, discharge pressure,
compressor speed on system performance of CO2 heat pump, suitable
in a dairy plant where simultaneous cooling at 4oC and heating at
73oC are required. Results show that good heat transfer properties of
CO2 for both two-phase and supercritical region and efficient
compression process contribute a lot for high system COPs.
Abstract: An effort estimation model is needed for softwareintensive
projects that consist of hardware, embedded software or
some combination of the two, as well as high level software
solutions. This paper first focuses on functional decomposition
techniques to measure functional complexity of a computer system
and investigates its impact on system development effort. Later, it
examines effects of technical difficulty and design team capability
factors in order to construct the best effort estimation model. With
using traditional regression analysis technique, the study develops a
system development effort estimation model which takes functional
complexity, technical difficulty and design team capability factors as
input parameters. Finally, the assumptions of the model are tested.
Abstract: Networked schools have become a feature of
education systems in countries that seek to provide learning
opportunities in schools located beyond major centres of population.
The internet and e-learning have facilitated the development of
virtual educational structures that complement traditional schools,
encouraging collaborative teaching and learning to proceed. In rural
New Zealand and in the Atlantic Canadian province of
Newfoundland and Labrador, e-learning is able to provide new ways
of organizing teaching, learning and the management of educational
opportunities. However, the future of e-teaching and e-learning in
networked schools depends on the development of professional
education programs that prepare teachers for collaborative teaching
and learning environments in which both virtual and traditional face
to face instruction co-exist.
Abstract: A parallel computational fluid dynamics code has been
developed for the study of aerodynamic heating problem in hypersonic
flows. The code employs the 3D Navier-Stokes equations as the basic
governing equations to simulate the laminar hypersonic flow. The cell
centered finite volume method based on structured grid is applied for
spatial discretization. The AUSMPW+ scheme is used for the inviscid
fluxes, and the MUSCL approach is used for higher order spatial
accuracy. The implicit LU-SGS scheme is applied for time integration
to accelerate the convergence of computations in steady flows. A
parallel programming method based on MPI is employed to shorten
the computing time. The validity of the code is demonstrated by
comparing the numerical calculation result with the experimental data
of a hypersonic flow field around a blunt body.
Abstract: This paper presents a new approach for setting
frequency relays based on the dynamic of power system. A
simplified model of the power system based on the load-frequency
control loop will be developed to be used instead of the complete
model of the power system. The effects of the equipments and their
responses on the frequency variations of the power plant will be
investigated and then a method for adaptive settings of frequency
relays will be explained. The proposed method will be investigated
by analyzing a simplified model of a power plant by MATLAB
software.
Abstract: Information and communication technology (ICT) has
become, within a very short time, one of the basic building blocks of
modern society. Many countries now understanding the importance
of ICT and mastering the basic skills and concepts of it as part of the
core of education. Organizations, experts and practitioners in the
education sector increasingly recognizing the importance of ICT in
supporting educational improvement and reform. This paper
addresses the convergence of ICT and education. When two
technologies are converging to each other, together they will generate
some great opportunities and challenges. This paper focuses on these
issues. In introduction section, it explains the ICT, education, and
ICT-enhanced education. In next section it describes need of ICT in
education, relationship between ICT skills and education, and stages
of teaching learning process. The next two sections describe
opportunities and challenges in integrating ICT in education. Finally
the concluding section summaries the idea and its usefulness.
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.
Abstract: The objective of this paper is to study the analysis and testing for determining the torsional stiffness of the student formula-s space frame. From past study, the space frame for Chulalongkorn University Student Formula team used in 2011 TSAE Auto Challenge Student Formula in Thailand was designed by considering required mass and torsional stiffness based on the numerical method and experimental method. The numerical result was compared with the experimental results to verify the torsional stiffness of the space frame. It can be seen from the large error of torsional stiffness of 2011 frame that the experimental result can not verify by the numerical analysis due to the different between the numerical model and experimental setting. In this paper, the numerical analysis and experiment of the same 2011 frame model is performed by improving the model setting. The improvement of both numerical analysis and experiment are discussed to confirm that the models from both methods are same. After the frame was analyzed and tested, the results are compared to verify the torsional stiffness of the frame. It can be concluded that the improved analysis and experiments can used to verify the torsional stiffness of the space frame.
Abstract: The scope of this research was to study the relation between the facial expressions of three lecturers in a real academic lecture theatre and the reactions of the students to those expressions. The first experiment aimed to investigate the effectiveness of a virtual lecturer-s expressions on the students- learning outcome in a virtual pedagogical environment. The second experiment studied the effectiveness of a single facial expression, i.e. the smile, on the students- performance. Both experiments involved virtual lectures, with virtual lecturers teaching real students. The results suggest that the students performed better by 86%, in the lectures where the lecturer performed facial expressions compared to the results of the lectures that did not use facial expressions. However, when simple or basic information was used, the facial expressions of the virtual lecturer had no substantial effect on the students- learning outcome. Finally, the appropriate use of smiles increased the interest of the students and consequently their performance.
Abstract: Phishing, or stealing of sensitive information on the
web, has dealt a major blow to Internet Security in recent times. Most
of the existing anti-phishing solutions fail to handle the fuzziness
involved in phish detection, thus leading to a large number of false
positives. This fuzziness is attributed to the use of highly flexible and
at the same time, highly ambiguous HTML language. We introduce a
new perspective against phishing, that tries to systematically prove,
whether a given page is phished or not, using the corresponding
original page as the basis of the comparison. It analyzes the layout of
the pages under consideration to determine the percentage distortion
between them, indicative of any form of malicious alteration. The
system design represents an intelligent system, employing dynamic
assessment which accurately identifies brand new phishing attacks
and will prove effective in reducing the number of false positives.
This framework could potentially be used as a knowledge base, in
educating the internet users against phishing.