Abstract: This study investigated climatic factors associated
with influenza cases in Southern Thailand. The main aim for use
regression analysis to investigate possible causual relationship of
climatic factors and variability between the border of the Andaman
Sea and the Gulf of Thailand. Southern Thailand had the highest
Influenza incidences among four regions (i.e. north, northeast, central
and southern Thailand). In this study, there were 14 climatic factors:
mean relative humidity, maximum relative humidity, minimum
relative humidity, rainfall, rainy days, daily maximum rainfall,
pressure, maximum wind speed, mean wind speed, sunshine duration,
mean temperature, maximum temperature, minimum temperature,
and temperature difference (i.e. maximum – minimum temperature).
Multiple stepwise regression technique was used to fit the statistical
model. The results indicated that the mean wind speed and the
minimum relative humidity were positively associated with the
number of influenza cases on the Andaman Sea side. The maximum
wind speed was positively associated with the number of influenza
cases on the Gulf of Thailand side.
Abstract: In recent years, the underground water sources in
southern Taiwan have become salinized because of saltwater
intrusions. This study explores the adsorption characteristics of
activated carbon on salinizing inorganic salts using isothermal
adsorption experiments and provides a model analysis. The
temperature range for the isothermal adsorption experiments ranged
between 5 to 45 ℃, and the amount adsorbed varied between 28.21 to
33.87 mg/g. All experimental data of adsorption can be fitted to both
the Langmuir and the Freundlich models. The thermodynamic
parameters for per chlorate onto granular activated carbon were
calculated as -0.99 to -1.11 kcal/mol for DG°, -0.6 kcal/mol for DH°,
and 1.21 to 1.84 kcal/mol for DS°. This shows that the adsorption
process of granular activated carbon is spontaneously exothermic. The
observation of adsorption behaviors under low ionic strength, low pH
values, and low temperatures is beneficial to the adsorption removal of
perchlorate with granular activated carbon.
Abstract: Recent research result has shown that two multidelay
feedback systems can synchronize each other under different
schemes, i.e. lag, projective-lag, anticipating, or projectiveanticipating
synchronization. There, the driving signal is significantly
complex due that it is constituted by multiple nonlinear transformations
of delayed state variable. In this paper, a secure communication
model is proposed based on synchronization of coupled multidelay
feedback systems, in which the plain signal is mixed with a complex
signal at the transmitter side and it is precisely retrieved at the receiver
side. The effectiveness of the proposed model is demonstrated and
verified in the specific example, where the message signal is masked
directly by the complex signal and security is examined under the
breaking method of power spectrum analysis.
Abstract: The wave function at the origin is an important quantity in studying many physical problems concerning heavy quarkonia. This is because that it is using for calculating spin state hyperfine splitting and also crucial to evaluating the production and decay amplitude of the heavy quarkonium. In this paper, we present the variational method by using the single-parameter wave function to estimate the WFO for the ground state of heavy mesons.
Abstract: The interdependences among stock market indices
were studied for a long while by academics in the entire world. The
current financial crisis opened the door to a wide range of opinions
concerning the understanding and measurement of the connections
considered to provide the controversial phenomenon of market
integration. Using data on the log-returns of 17 stock market indices
that include most of the CEE markets, from 2005 until 2009, our
paper studies the problem of these dependences using a new
methodological tool that takes into account both the volatility
clustering effect and the stochastic properties of these linkages
through a Dynamic Conditional System of Simultaneous Equations.
We find that the crisis is well captured by our model as it provides
evidence for the high volatility – high dependence effect.
Abstract: Equilibrium and rate based models have been applied
in the simulation of methyl tertiary-butyl ether (MTBE) synthesis
through reactive distillation. Temperature and composition profiles
were compared for both the models and found that both the profiles
trends, though qualitatively similar are significantly different
quantitatively. In the rate based method (RBM), multicomponent
mass transfer coefficients have been incorporated to describe
interphase mass transfer. MTBE mole fraction in the bottom stream is
found to be 0.9914 in the Equilibrium Model (EQM) and only 0.9904
for RBM when the same column configuration was preserved. The
individual tray efficiencies were incorporated in the EQM and
simulations were carried out. Dynamic simulation have been also
carried out for the two column configurations and compared.
Abstract: The present work describes a computational study of
aerodynamic characteristics of GLC305 airfoil clean and with 16.7
min ice shape (rime 212) and 22.5 min ice shape (glaze 944).The
performance of turbulence models SA, Kε, Kω Std, and Kω SST
model are observed against experimental flow fields at different
Mach numbers 0.12, 0.21, 0.28 in a range of Reynolds numbers
3x106, 6x106, and 10.5x106 on clean and iced aircraft airfoil
GLC305. Numerical predictions include lift, drag and pitching
moment coefficients at different Mach numbers and at different angle
of attacks were done. Accuracy of solutions with respect to the
effects of turbulence models, variation of Mach number, initial
conditions, grid resolution and grid spacing near the wall made the
study much sensitive. Navier Stokes equation based computational
technique is used. Results are very close to the experimental results.
It has seen that SA and SST models are more efficient than Kε and
Kω standard in under study problem.
Abstract: Today-s business has inevitably been set in the global supply chain management environment. International transportation has never played such an important role in the global supply chain network, because movement of shipments from one country to another tends to be more frequent than ever before. This paper studies international transportation problems experienced by an international transportation company. Because of the limited fleet capacity, the transportation company has to hire additional trucks from two countries in advance. However, customer-s shipment information is uncertain, and decisions have to be made before accurate information can be obtained. This paper proposes a stochastic mixed 0-1 programming model to solve the international transportation problems under uncertain demand. A series of experiments demonstrate the effectiveness of the proposed stochastic model.
Abstract: Gas condensate Reservoirs show complicated thermodynamic behavior when their pressure reduces to under dew point pressure. Condensate blockage around the producing well cause significant reduction of production rate as well bottom-hole pressure drops below saturation pressure. The main objective of this work was to examine the well test analysis of naturally fractured lean gas condensate reservoir and investigate the effect of condensate formed around the well-bore on behavior of single phase pseudo pressure and its derivative curves. In this work a naturally fractured lean gas condensate reservoir is simulated with compositional simulator. Different sensitivity analysis done on Corry parameters and result of simulator is feed to analytical well testing software. For consideration of these phenomena eighteen compositional models with Capillary number effect are constructed. Matrix relative permeability obeys Corry relative permeability and relative permeability in fracture is linear. Well testing behavior of these models are studied and interpreted. Results show different sensitivity analysis on relative permeability of matrix does not have strong effect on well testing behavior even most part of the matrix around the well is occupied with condensate.
Abstract: Simulation and modeling computer programs are
concerned with construction of models for analyzing different
perspectives and possibilities in changing conditions environment.
The paper presents theoretical justification and evaluation of
qualitative e-learning development model in perspective of advancing
modern technologies. There have been analyzed principles of
qualitative e-learning in higher education, productivity of studying
process using modern technologies, different kind of methods and
future perspectives of e-learning in formal education. Theoretically
grounded and practically tested model of developing e-learning
methods using different technologies for different type of classroom,
which can be used in professor-s decision making process to choose
the most effective e-learning methods has been worked out.
Abstract: This paper explains the cause of nonlinearity in floor
attenuation hither to left unexplained. The performance degradation
occurring in air interface for GSM signals is quantitatively analysed
using the concept of Radiating Columns of buildings. The signal
levels were measured using Wireless Network Optimising Drive Test
Tool (E6474A of Agilent Technologies). The measurements were
taken in reflected signal environment under usual fading conditions
on actual GSM signals radiated from base stations. A mathematical
model is derived from the measurements to predict the GSM signal
levels in different floors. It was applied on three buildings and found
that the predicted signal levels deviated from the measured levels
with in +/- 2 dB for all floors. It is more accurate than the prediction
models based on Floor Attenuation Factor. It can be used for
planning proper indoor coverage in multi storey buildings.
Abstract: The paper addresses a problem of optimal staffing in
open shop environment. The problem is to determine the optimal
number of operators serving a given number of machines to fulfill the
number of independent operations while minimizing staff idle. Using
a Gantt chart presentation of the problem it is modeled as twodimensional
cutting stock problem. A mixed-integer programming
model is used to get minimal job processing time (makespan) for
fixed number of machines' operators. An algorithm for optimal openshop
staffing is developed based on iterative solving of the
formulated optimization task. The execution of the developed
algorithm provides optimal number of machines' operators in the
sense of minimum staff idle and optimal makespan for that number of
operators. The proposed algorithm is tested numerically for a real life
staffing problem. The testing results show the practical applicability
for similar open shop staffing problems.
Abstract: In order to investigate a PROX microreactor
performance, two-dimensional modeling of the reacting flow
between two parallel plates is performed through a finite volume
method using an improved SIMPLE algorithm. A three-step surface
kinetics including hydrogen oxidation, carbon monoxide oxidation
and water-gas shift reaction is applied for a Pt-Fe/γ-Al2O3 catalyst
and operating temperatures of about 100ºC. Flow pattern, pressure
field, temperature distribution, and mole fractions of species are
found in the whole domain for all cases. Also, the required reactive
length for removing carbon monoxide from about 2% to less than 10
ppm is found. Furthermore, effects of hydraulic diameter, wall
temperature, and inlet mole fraction of air and water are investigated
by considering carbon monoxide selectivity and conversion. It is
found that air and water addition may improve the performance of
the microreactor in carbon monoxide removal in such operating
conditions; this is in agreement with the pervious published results.
Abstract: In pressure vessels contain hydrogen, the role of
hydrogen will be important because of hydrogen cracking problem. It
is difficult to predict what is happened in metallurgical field spite of a
lot of studies have been searched. The main role in controlling the
mass diffusion as driving force is related to stress. In this study, finite
element analysis is implemented to estimate material-s behavior
associated with hydrogen embrittlement. For this purpose, one model
of a pressure vessel is introduced that it has definite boundary and
initial conditions. In fact, finite element is employed to solve the
sequentially coupled mass diffusion with stress near a crack front in a
pressure vessel. Modeling simulation intergrarnular fracture of AISI
4135 steel due to hydrogen is investigated. So, distribution of
hydrogen and stress are obtained and they indicate that their
maximum amounts occur near the crack front. This phenomenon is
happened exactly the region between elastic and plastic field.
Therefore, hydrogen is highly mobile and can diffuse through crystal
lattice so that this zone is potential to trap high volume of hydrogen.
Consequently, crack growth and fast fracture will be happened.
Abstract: The present paper is oriented to classification and application of agent technique in simulation of anticipatory systems, namely those that use simulation models for the aid of anticipation. The main ideas root in the fact that the best way for description of computer simulation models is the technique of describing the simulated system itself (and the translation into the computer code is provided as automatic), and that the anticipation itself is often nested.
Abstract: The use of technology is increasingly adopted to
support flexible learning in Higher Education institutions. The
adoption of more sophisticated technologies offers a broad range of
facilities for communication and resource sharing, thereby creating a
flexible learning environment that facilitates and even encourages
students not to physically attend classes. However this emerging
trend seems to contradict class attendance requirements within
universities, inevitably leading to a dilemma between amending
traditional regulations and creating new policies for the higher
education institutions. This study presents an investigation into
student engagement in a technology enhanced/driven flexible
environment along with its relationship to attainment. We propose an
approach to modelling engagement from different perspectives in
terms of indicators and then consider what impact these indicators
have on student academic performance. We have carried out a case
study on the relation between attendance and attainment in a flexible
environment. Although our preliminary results show attendance is
quantitatively correlated with successful student development and
learning outcomes, our results also indicate there is a cohort that did
not follow such a pattern. Nevertheless the preliminary results could
provide an insight into pilot studies in the wider deployment of new
technology to support flexible learning.
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.
Abstract: Understanding driving behavior is a complicated
researching topic. To describe accurate speed, flow and density of a
multiclass users traffic flow, an adequate model is needed. In this
study, we propose the concept of standard passenger car equivalent
(SPCE) instead of passenger car equivalent (PCE) to estimate the
influence of heavy vehicles and slow cars. Traffic cellular automata
model is employed to calibrate and validate the results. According to
the simulated results, the SPCE transformations present good
accuracy.
Abstract: Nowadays, offshore's complicated facilities need their
own communications requirements. Nevertheless, developing and
real-world applications of new communications technology are faced
with tremendous problems for new technology users, developers and
implementers. Traditional systems engineering cannot be capable to
develop a new technology effectively because it does not consider
the dynamics of the process. This paper focuses on the design of a
holistic model that represents the dynamics of new communication
technology development within offshore industry. The model shows
the behavior of technology development efforts. Furthermore,
implementing this model, results in new and useful insights about the
policy option analysis for developing a new communications
technology in offshore industry.
Abstract: In this paper, a new alignment method based on the particle swarm optimization (PSO) technique is presented. The PSO algorithm is used for locating the optimal coupling position with the highest optical power with three-degrees of freedom alignment. This algorithm gives an interesting results without a need to go thru the complex mathematical modeling of the alignment system. The proposed algorithm is validated considering practical tests considering the alignment of two Single Mode Fibers (SMF) and the alignment of SMF and PCF fibers.