|
ISSN:
1998-0140
Year 2009
All papers of the journal were peer reviewed by two
independent reviewers. Acceptance was granted when both
reviewers' recommendations were positive.
Main
Page
Paper
Title, Authors, Abstract (Issue 1, Volume 3, 2009) |
Pages |
Numerical Simulation of
Indonesian Tsunami 2004 at Penang Island in
Peninsular Malaysia Using a Nested Grid Model
Md. Fazlul Karim, Ahmad Izani M Ismail, Mohammed
Ashaque Meah
Abstract: Nested grid modelling
techniques are increasingly being recognized as
methodologies to aid in multiscale modelling of a
variety of atmospheric and oceanic phenomena. A
nested grid model with a fine resolution is used to
simulate the Indonesian tsunami of 2004 along the
coastal belt of Penang Island. The basic primitive
model is depth averaged shallow water equations. A
fine mesh numerical scheme for the Peninsular
Malaysia covering the region between 5?10/ to 5?35/N
and 100? to 100?30/E to record fine orographical
detail of the region of Penang Island has been
nested into a coarse mesh scheme covering the region
approximately between 2° N to 14° N and 91° E to
100.5° E which includes the source region of the
Indonesian tsunami of 2004. The nesting is
accomplished using a scheme Arakawa C staggered grid
arrangement. The solutions are obtained for two
categories: (a) coarse mesh solution, and (b) nested
solution. A nested model is employed in which a
coarse grid model is used to supply the open
boundary conditions for a finer grid. The major
features of the event 2004 along Penang have been
successfully simulated by the nested model.
|
1-8 |
FCM & FPCM Algorithm Based
on Unsupervised Mahalanobis Distances with Better
Initial Values and Separable Criterion
Jeng-Ming Yih, Yuan-Horng Lin, Hsiang-Chuan Liu
Abstract: The fuzzy partition
clustering algorithms are most based on Euclidean
distance function, which can only be used to detect
spherical structural clusters. Gustafson-Kessel (GK)
clustering algorithm and Gath-Geva (GG) clustering
algorithm, were developed to detect non-spherical
structural clusters, but both of them based on
semi-supervised Mahalanobis distance needed
additional prior information. An improved Fuzzy
CMean algorithm based on unsupervised Mahalanobis
distance, FCM-M, was proposed by our previous work,
but it didn’t consider the relationships between
cluster centers in the objective function. In this
paper, we proposed an improved Fuzzy C-Mean
algorithm, FCM-MS, which is not only based on
unsupervised Mahalanobis distance, but also
considering the relationships between cluster
centers, and the relationships between the center of
all points and the cluster centers in the objective
function, the singular and the initial values
problems were also solved. Two real data sets was
applied to prove that the performance of the FCMMS
algorithm gave more accurate clustering results than
the FCM and FCM-M methods, and the ratio method
which is proposed by us is the better of the two
methods for selecting the initial values.
|
9-18 |
The Transmission Model of
P.falciparum and P.Vivax Malaria between Thai and
Burmese
P. Pongsumpun, I. M. Tang
Abstract: The transmission of
Plasmodium falciparum and Plasmodium vivax malaria
of Thais and Burmese is studied through a
mathematical model. The population is separated into
two groups, Thai and Burmese. Each population is
divided into susceptible and infectious subclasses.
The loss of immunity by individuals in the
infectious class causes them to move back into the
susceptible class. Standard dynamical method is used
to analyze the behavior of the model. Two stable
equilibrium states, a disease free state and an
epidemic state are found to be possible in each
population. A disease free equilibrium state in the
Thai population occurs when there are no infected
Burmese entering into the community. When there are
infected Burmese enters into the Thai community, the
epidemic state can occur. It is found that the
disease free state is stable when the threshold
number R0 is less than one. The epidemic state is
stable when (where these threshold numbers are for
the individual populations) are greater than one.
The numerical simulations of our model illustrate
what the results would be for our theoretical model.
|
19-26 |
The Influence of Noise
Kurtosis on the Dynamics of a Harmonic Oscillator
with Fluctuating Frequency
Katrin Laas, Romi Mankin, Astrid Rekker
Abstract: The influence of noise
kurtosis on underdamped motion of a harmonic
oscillator with fluctuating frequency subjected to
an external periodic force and an additive thermal
noise is considered. The colored fluctuations of the
oscillator frequency are modeled as a trichotomous
noise. It is established that the spectral
amplification and variance of the output signal
exhibits a nonmonotonic dependence on the noise
kurtosis, thus demonstrating the phenomenon of noise
kurtosis controlled stochastic resonance. Some
unexpected effects such as hypersensitive response
of spectral amplification to small variations of
noise amplitude, encountered in the case of a large
kurtosis of colored noise are also discussed.
|
27-36 |
Computer-Aided Simulation on
the Reversing Operation of the Two-Phase Induction
Machine
Alecsandru Simion, Leonard Livadaru, Dorin Lucache
Abstract: The paper presents a new
mathematical model of the two-phase induction
machine, called "in total fluxes", which is very
appropriate for the study of the reversing regime.
The equations of the model use as main quantities
the rotation angle and the total fluxes of the
windings and exclude the rotation speed, which now
become a secondary quantity that can be calculated
from rotation angle expression. On the basis of this
model, the computer simulation looks into the
behavior of a two-phase induction servomotor with
low inertia when the supply voltages of the two
separate windings have the same magnitude but a
different frequency, under load and no load
operation. The reversing regime is also simulated
under unbalanced supply conditions. The results
offer the perspective to design electromechanical
systems with speed or rotation angle expressed as
harmonic, quasi-harmonic or even random variation
laws.
|
37-47 |
The Methods of Multi
Attribute Analysis in Application to Assess Optimal
Factor Combination in One Experiment
D. Randjelovic, C. Dolicanin
Abstract: Experiments are used by
scientists to affirm their hypothesis, these
experiments are called tests in research, or to
choose the best from available possibilities, these
experiments are called valuations in research in
which group belongs also optimal factor combination
choice in one multifactor and often multivariate
experiments. For decreasing influence ever present
uncontrolled factors i.e. experimental error
researchers make different plans. Mathematical
instruments of most effective plans for experiment
organization are possible to search on the basis of
total random distribution, random block distribution
and some special organized block distribution while
they can most effectively represent complex
multifactor and multivariate experiments. Statistic
analysis for any experiment plan is very complex in
the standard way with analysis of variance and
multiple linear regression and especially in the
case of the optimal factor combination choice. From
other side multiple criteria analysis like modern
science discipline enables an easier way to make
analysis of results of one experiment just in the
case of optimal factor combination choice of one
multifactor and multivariate experiment. Therefore
authors propose multiple criteria analysis
application in analysis of experiment results and in
this paper authors consider application of one
subgroup of these methods, so called multi attribute
decision methods, to which belong and ELECTRA
method. One example of multiple attribute analysis
application in analysis of results of one experiment
is given in the end of this paper.
|
48-57 |
Efficient Mixing in
Microchannel by using Magnetic Nanoparticles
T. N. Le, Y. K. Suh, S. Kang
Abstract: Rapid and efficient mixing
in microchannel using magnetic nanoparticles has
been numerically investigated. The magnetic
nanoparticles are introduced into the microchannel
and are exerted by the external magnetic force to
cause the vortex motion of the fluid for mixing. The
velocity field of the flow and trajectories of the
particles are solved implicitly by using the Finite
Volume Method (FVM). The obtained results illustrate
the significant effects of the magnetic actuation
force, the switching frequency, number of magnetic
nanoparticles on the mixing efficiency. The mixing
properties of the flow predicted by numerical
simulation are studied under the concentration
field, mixing index and Poincare section.
|
58-67 |
Excitation Control of Self
Excited Induction Generator using Genetic Algorithm
and Artificial Neural Network
Dheeraj Joshi, K. S. Sandhu
Abstract: Induction generators which
may be operated in grid or self-excited mode, are
found to be successful machines for wind energy
conversion. Out of these two self-excited mode is
gaining importance due to its ability to convert the
wind energy into electrical energy for large
variations in operating speed. However it has been
found that these machine exhibits a poor voltage
regulation. Steady-state analysis of self excited
induction generator reveals that such generators are
not capable to maintain the terminal voltage and
frequency in the absence of expensive controllers.
In turn addition of such controllers may result into
a fall in popularity of this machine due to its
simplicity. Another simple way to control the
terminal voltage is through excitation control using
series compensation. In this paper artificial
intelligent techniques are used to model the control
strategy for proper reactive compensation under
different operating conditions. Genetic algorithm
along with artificial neural network has been
proposed to estimate the values of shunt and series
excitation capacitance to maintain the terminal and
load voltage. Simulated results as found using
proposed control technique are verified using
experimental results on a test machine. Simulated
results are found to be in close agreement with
experimental results.
|
68-75 |
Paper
Title, Authors, Abstract (Issue 2, Volume 3, 2009) |
Pages |
Estimate to the Trajectory
of Maneuvering Targets by Combining Sensor
Scheduling with Energy Efficient in WSNs
Joy Iong-Zong Chen, Chih-Chung Yu
Abstract: An algorithm by combining
sensor scheduling with energy efficient for tracking
the maneuvering targets with mobile sensor deployed
in WSNs (wireless sensor networks) is proposed to
investigate the tracking performance in the article.
In order to minimize the estimated error, the sensor
sequence and the optimal sensor movement are
scheduled previously and determined first. Thus, the
sensor scheduling is depending on the results from
the evaluation of energy efficient of a sensor node.
Moreover, due to the targets is varying with time in
the estimation process the EKF (extended Kalman
filtering) technique is applied to predict MSE (mean
square error) of a predicted target. Finally,
simulations by using of the scenario with two and
four maneuvering targets tracking are held to
validate the accuracy of the proposed algorithm, and
the results definitely show the fact that the MSE
will decrease when the right way of the sensor
scheduling is arranged previously.
|
77-84 |
Time Series Modeling using
an Adaptive Gene Expression Programming Algorithm
Alina Barbulescu, Elena Bautu
Abstract: Meteorological time series
are characterized by important spatial and temporal
variation. Model determination and the prediction of
evolution of such series is of high importance for
different practical purposes, even if discovering
evolution patterns in such series is a very
difficult problem. In this article we describe an
adaptive evolutionary technique and we apply it for
modeling the precipitation and temperatures
collected in a region of Romania. The results are
promising for the analysis of such time series.
|
85-93 |
A Multi-Item Production Lot
Size Inventory Model with Cycle Dependent Parameters
Zaid T. Balkhi, Abdelaziz Foul
Abstract: In this paper, a multi-item
production inventory model is considered within a
given time horizon that consists of different time
periods. For each product, production, demand, and
deterioration rates in each period are known.
Shortage for each product is allowed but it is
completely backlogged . The objective is to find the
optimal production and restarting times for each
product in each period so that the overall total
inventory cost for all products is minimized. In
this paper, a formulation of the problem is
developed and optimization techniques are performed
to show uniqueness and global optimality of the
solution.
|
94-104 |
Stochastic Geolithological
Reconstruction coupled with Artificial Neural
Networks Approach for Hydrogeological Modeling
Claudia Cherubini, Fausta Musci, Nicola Pastore
Abstract: When simulating fluid flow
and solute transport a more accurate modeling of the
lithologic, geological and structural characters of
an aquifer is of extreme importance in order to
improve the reliability of the numerical
simulations. On the other hand the information
available for the setting up of a hydrogeological
model is subjected to ambiguities due to not
univocal interpretations or to uncertainties linked
to the methodologies of measurement of the variables
of interest. Therefore, hydrogeological
characterization of heterogeneous aquifers, if
carried out up to a high degree of detail, should
not identify a univocal model but a set of
“equifinal” solutions. In the present paper the
application of Artificial Neural Network approach
coupled with a Nested Sequential Indicator
simulation has allowed to obtain the distribution of
hydrogeologic parameters that are not only
conditioned by the in situ measured values but also
by the soft information coming from geolithology.
The results show a fairly good relationship between
parameters such as Transmissivity and Storage
coefficient and the geolithologic architecture of
the examined aquifer.
|
105-114 |
Formal Transformation from
NFA to Z Notation by Constructing Union of Regular
Languages
Nazir Ahmad Zafar, Nabeel Sabir, Amir Ali
Abstract: Capturing functionalities
and modeling control behavior are primary
requirements in design and development of a complex
system. Automata theory plays a vital role in
modeling behavior while Z notation is an ideal
specification language for describing state space of
a system. Consequently, integration of automata and
Z notation will be a useful tool facilitating and
increasing modeling power for complex systems.
Further, nondeterministic finite automata (NFA) may
have different implementations and therefore it is
needed to verify the transformation from diagrams to
code. If we describe formal specification of a given
nondeterministic finite automata before implementing
then confidence over transformation can be
increased. In this paper, we have combined NFA and Z
and a linkage is established between these
approaches. At this level of integration, we have
given a formal procedure to transform NFA to Z. A
string accepter is designed and then extended to the
language accepter. Finally, NFA accepting union of
two regular languages is constructed by describing
formal specification of their relationships. The
specification is analyzed and validated using Z/EVES
tool.
|
115-122 |
Identification of the
De-synchronization, Synchronization and Forced
Oscillation Phenomenon of a Nonlinear System
Marius-Constantin O.S. Popescu, Onisifor V. Olaru,
Valentina E. Balas
Abstract: The phenomena of
de-synchronization, synchronization, and forced
oscillation has been investigation using describing
function theory for a two input and two output
nonlinear system containing saturation-type
nonlinearities and subjected to high-frequency
deterministic signal for the purpose of limit cycle
quenching. The analytical results have been compared
with the results of digital simulation Matlab-Simulink
for a typical example varying the nonlinear element.
|
123-132 |
Equilibrium Dynamic Systems
Intelligence
Marius-Constantin O.S. Popescu, Onisifor V. Olaru,
Nikos E. Mastorakis
Abstract: Most work in Artificial
Intelligence reviews the balance of classic game
theory to predict agent behavior in different
positions. In this paper we introduce steady
competitive analysis. This approach bridges the gap
between the standards of desired paths of artificial
intelligence, where a strategy must be selected in
order to ensure an end result and a balanced
analysis. We show that a strategy without risk level
is able to guarantee the value obtained in the Nash
equilibrium, by more scientific methods of classical
computers. Then we will discuss the concept of
competitive strategy and illustrate how it is used
in a decentralized load balanced position, typical
for network problems. In particular, we will show
that when there are many agents, it is possible to
guarantee an expected final result, which is a 8/9
factor of the final result obtained in the Nash
equilibrium. Finally, we will discuss about
extending the above concept in Bayesian game and
illustrate its use in a basic structure of an
auction.
|
133-142 |
Suggestions of
Nanotechnology Park and Observations on Industrial
Challenges
Ahmet Karakas
Abstract: This study aims to clarify
the establishment of the Nanotechnology Park in
South Wales .The feasibility is observed through a
survey, and reliability of the survey participants
is justified with question structures. As the idea
is a unique concept, the survey outcome is analyzed
together with recent research and it is aimed to
fill the gap in the field. Due to the nature of
nanotechnology organizations, the challenges of the
industry as well as the researchers are observed.
Financial and organizational difficulties of the
start-up companies are observed, including the
constraints of the industry and research
institutions. The outline and proposed issues to be
considered are addressed for a nanotechnology park.
Multi-disciplined field structure is observed and
criticized with the current applications. Further
research recommendations are pointed out through
finalizing this study.
|
143-151 |
Checking Simulations of a
Geolithological Model Obtained by Means of Nested
Truncated Bigaussian Method
Claudia Cherubini, Fausta Musci, Nicola Pastore
Abstract: Characterizing the spatial
distribution of major lithotypes and their
relationships is a key aspect in the process of
hydrogeological modeling of aquifers in that
assignment of lithotypes-specific hydraulic and
hydrochemical properties requires the knowledge of
the layout of the lithotypes themselves. Truncated
bigaussian simulation is a procedure derived from
the truncated Gaussian model, used to simulate
random sets, and, in particular, variable geological
characteristics, expressed as categorical variables.
Anyway, in cases of many lithotypes having not
homogeneous spatial behaviors, this methodology
might not explain at best the relations existing
among the lithotypes themselves; a more general
method is therefore required to represent this
variability. In this paper, that concerns a site
whose geologic asset has already been reconstructed,
in order to better characterize the aquifer
geolithological architecture, nested simulation for
a macro-unit of the previously realized
geolithologic model has been carried out, together
with a check phase of the results obtained by the
mentioned simulation. The proposed methodology can
represent a useful instrument for the modeling of
complex geological layouts other than in the
detailed characterizations of hydrogeological
studies, for a better interpretation of the complex
phenomena that take place in groundwater circulation
and contaminant propagation.
|
152-161 |
A Simulation Study of
Additive Outlier in ARMA (1, 1) Model
Azami Zaharim, Rafizah Rajali, Raden Mohamad Atok,
Ibrahim Mohamed, Khamisah Jafar
Abstract: Abnormal observation due to
an isolated incident such as a recording error is
known as additive outlier and it is often found in
time series. Since extreme value of additive
outliers may contribute to the inaccuracy of model
specification, proper detection procedure is
significant to avoid such error. Equations that
explain the nature of an additive outlier and the
test statistics pertaining to it are discussed in
this article. This is followed by two separate
simulation studies that are conducted to investigate
the sampling behavior and detection performance of
the test statistics in ARMA (1, 1) models. Results
for the first simulation study show that the test
statistics is an increasing function of sample size.
Whilst in the other simulation study we see that the
performance of the test statistics improves as large
magnitudes of outlier effect are used.
|
162-169 |
Paper
Title, Authors, Abstract (Issue 3, Volume 3, 2009) |
Pages |
Short Term Electricity Load
Demand Forecasting in Indonesia by Using Double
Seasonal Recurrent Neural Networks
Suhartono, Alfonsus Julanto Endharta
Abstract: Neural networks have
apparently enjoyed con-siderable success in practice
for predicting short-term hourly electricity demands
in many countries. Forecasting of short-term hourly
electricity in some countries usually is done by
employing classical time series methods such as
Winter’s method and Double Seasonal ARIMA model.
Recently, Feed-Forward Neural Net-works (FFNN) is
also applied for electricity demand forecasting,
including in Indonesia. The application of Double
Seasonal ARIMA for forecasting short-term
electricity load demands in most cities in Indonesia
shows that the model contains both order of
autoregressive and moving average. Moving average
order can not be represented by FFNN. In this paper,
we use an architecture of Neural Network that able
to represent moving average order, i.e.
Elman-Recurrent Neural Network (RNN). As a case
study, we use data of hourly electricity load demand
in Mengare, Gresik, Indo-nesia. The results show
that the best ARIMA model for forecasting these data
is ARIMA
([1,2,3,4,6,7,9,10,14,21,33],1,8)(0,1,1)24(1,
1,0)168. There are 14 innovational outliers detected
from this ARIMA model. We use 4 different
architectures of RNN particu-larly for the inputs,
i.e. the input units are similar to ARIMA model
predictors, similar to ARIMA predictors plus 14
dummy outliers, the 24 multiplied lagged of the
data, and the combination of 1 lagged and the 24
multiplied lagged plus minus 1. The results show
that the best network is the last one, i.e., Elman-RNN(22,3,1).
The comparison of forecast accuracy shows that
Elman-RNN yields less MAPE than ARIMA model. Thus,
Elman-RNN(22,3,1) is the best method for forecasting
hourly electricity load demands in Mengare, Gresik,
Indonesia.
|
171-178 |
A Handling Management System
for Freight with the Ambient Calculus
Toru Kato, Masahiro Higuchi
Abstract: This paper proposes a
freight management system that ensures the
correctness of container handling during shipping.
The system determines the correctness by comparing
container handling, which is sensed by IC tags, with
formal models (formulae) written in the ambient
calculus. The ambient calculus is a formal
description language that is suitable for expressing
freight systems with nested structures that
dynamically change. The management system generates
formulae automatically from several documents used
in real freight systems. An implementation of the
system and the results of a simple experiment using
it are presented.
|
179-186 |
A General and Dynamic
Production Lot Size Inventory Model
Zaid T. Balkhi, Ali S. Haj Bakry
Abstract: A dynamic inventory model
with deteriorating items in which each of the
production ,the demand and the deterioration rates,
as well as all cost parameters are assumed to be
general functions of time is considered in this
paper. Besides, shortages are allowed but are
partially backordered. . Both inflation and time
value of money are taken into account. The objective
is to minimize the total net inventory cost . The
relevant model is built , solved Necessary and
sufficient conditions for a unique and global
optimal solution are derived. An illustrative
example is provided and numerically verified.
|
187-195 |
Monitoring and Control System
of a Separation Column for 13C Enrichment by
Cryogenic Distillation of Carbon Monoxide
Eva-Henrietta Dulf, Clement Festila, Francisc Dulf
Abstract: In incipient stage for
laboratory experiments, a monitoring and control
based on human operators is usual. Using the
acquired experience, a computer monitoring and even
control is necessary and possible. In the actual
developing plan to apply the cryogenic technology
for the production of the 13C isotope by industrial
scale, an efficient and safe operation is a strong
reason to conceive and to apply a modern computer
based monitoring and control strategy. The actual
hardware possibilities of the computer systems and
valuable interfaces enable cheap, easy-to-apply and
efficient monitoring and control systems. For a
complex equipment like a cryogenic isotope
separation column, it was selected a common PC
interfaced with a series of robust input-output
modules, ICP-CON, I-7000 Series, from ICP-DAS as
data acquisition and control functions. Based on
general separation process and column operation
descriptions, this particular application is
developed using the intuitive Labview visual
programming language. The front panel of the
monitoring system has numerical and graphical
indicators, buttons for available options, alarms to
warn the user that a problem appeared in the
process. The control system is conceived for the
liquid nitrogen level control and the liquid carbon
monoxide level control. In the actual stage, the
control functions are analyzed only by simulation.
|
196-203 |
The Proposed Fuzzy Logic
Navigation Approach of Autonomous Mobile Robots in
Unknown Environments
O. Hachour
Abstract: In this paper we discuss
the ability to deal with a fuzzy logic navigation
approach for intelligent autonomous mobile robots in
unknown environments. The aim of this work is to
develop hybrid intelligent system combining Fuzzy
Logic (FL) and Expert System (ES). This combination
provides the robot the possibility to move from the
initial position to the final position (target)
without collisions. This combination is necessary to
bring the machine behaviour near the human one in
reasoning, decision-making and action. That was the
current reason to replace the classical approaches
related to navigation problems by the current
approaches based on the fuzzy logic and expert
system. The robot moves within the environment by
sensing and avoiding the obstacles coming across its
way towards the unknown target. The focus is on the
ability to move and on being self-sufficient to
evolve in an unknown environment. The proposed
hybrid navigation strategy is designed in a grid-map
form of an unknown environment with static unknown
obstacles. This approach must make the robot able to
achieve these tasks: to avoid obstacles, and to make
ones way toward its target by ES_FL system capturing
the behavior of a human expert. The integration of
ES and FL has proven to be a way to develop useful
real-world applications, and hybrid systems
involving robust adaptive control. The proposed
approach has the advantage of being generic and can
be changed at the user demand. The results are
satisfactory to see the great number of environments
treated. The results are satisfactory and promising.
|
204-218 |
Nonlinear Spatiotemporal
Analysis and Modeling of Signal Transduction
Pathways Involving G Protein Coupled Receptors
Chontita Rattanakul, Titiwat Sungkaworn , Yongwimon
Lenbury, Meechoke Chudoung, Varanuj Chatsudthipong,
Wannapong Triampo, Boriboon Novaprateep
Abstract: Cell behavior and
communication are regulated by a complex network of
intracellular and extracellular signal transduction
pathways. In this paper, a model of signaling
process involving G proteins is analyzed. The model
incorporates reaction-diffusion mechanisms involving
reactants that interact with each other on the
cellular membrane surface and its proximity. The
ligand-receptor complexes and the inhibiting agents
in the process may diffuse over the cell membrane,
and the signal transduction is mediated by the
membrane bound G protein leading to biochemical
intra-cellular reaction and the production of the
second messenger or other desired functional
responses. Weakly nonlinear stability analysis is
carried out in order to investigate the dynamic and
steady-state properties of the model. Turing-type
patterns are shown to robustly form under conditions
on the system parameters which characterize the
formation of stationary symmetry breaking
structures; stripes and hexagonal arrays of spots or
nets. Some recent experimental studies are then
mentioned in support of our theoretical predictions.
|
219-229 |
Evaluating a Maintenance
Department in a Service Company
Mª C. Carnero
Abstract: Maintenance has evolved
from a tactical subject to being considered a
strategic one due to its implications in
availability, safety, quality and costs. Once
maintenance policies have been set-up, different
factors must be controlled so that the appearance
and development of deficiencies in the maintenance
department can be detected; for this purpose an
evaluating maintenance process is developed in this
paper by means of an additive model constructed by
Hiview software. The audit is applied to a hospital
where these areas are especially relevant as a
result of their direct influence on the quality of
the patients/ welfare service.
|
230-237 |
Adaptation of a k-epsilon
Model to a Cartesian Grid Based Methodology
Stephen M. Ruffin, Jae-Doo Lee
Abstract: Despite the high cost of
memory and CPU time required to resolve the boundary
layer, a viscous unstructured grid solver has many
advantages over a structured grid solver such as the
convenience in automated grid generation and vortex
capturing by solution adaption. In present study, an
unstructured Cartesian grid solver is developed on
the basis of the existing viscous solver, NASCART-GT.
Instead of a cut-cell approach, an immersed boundary
approach is applied with ghost cell boundary
condition, which can be easily applied to a moving
grid solver. The standard k-e model by Launder and
Spalding is employed for the turbulence modeling,
and a new wall function approach is devised for the
unstructured Cartesian grid solver. In this study,
the methodology is validated and the efficiency of
the developed boundary condition is tested in 2-D
flow field around a flat plate, NACA0012 airfoil,
and axisymmetric hemispheroid.
|
238-245 |
Rotorcraft Flowfield
Prediction Accuracy and Efficiency using a Cartesian
Grid Framework
Stephen M. Ruffin, Jae-Doo Lee
Abstract: Despite the high cost of
memory and CPU time required to resolve the boundary
layer, a viscous unstructured grid solver has many
advantages over a structured grid solver such as the
convenience in automated grid generation and shock
or vortex capturing by solution adaption. In present
study, an unstructured Cartesian grid solver is
applied and results evaluated in rotorcraft
flowfields. Recently, an existing solver, NASCART-GT
was modified to use an immersed boundary approach
(instead of a cut-cell approach). This approach is
applied with ghost cell boundary condition, which
increases the accuracy and minimizes unphysical
fluctuations of the flow properties. The standard
k-epsilon model by Launder and Spalding is employed
for the turbulence modeling, and a new wall function
was incorporated for the unstructured Cartesian grid
solver. This model was previously only validated for
2-D flows, but in the present paper is applied to
3-D rotorcraft flowfields. For rotor modeling, an
actuator disk model is chosen, since it is efficient
and is widely verified in the study of the
rotor-fuselage interaction. The full three
dimensional calculations of Euler and RANS equations
are performed for the GT rotor model and ROBIN
configuration to test implemented actuator disk
model along with the developed turbulence modeling.
|
246-255 |
A Distributed Algorithm for
XOR-Decompression with Stimulus Fragment Move to
Reduce Chip Testing Costs
Mohammed Almulla, Ozgur Sinanoglu
Abstract: Various techniques were
used to reduce the test time and cost of chip
development, some of which achieved their objective
by reducing the test data volume through the
implementation of compression technologies such as
XOR-based decompressors. In the presence of XOR
decompressor, the delivery of acceptable (encodable)
test patterns can be challenging. To overcome this
problem, the Align-Encode technique was introduced
to manipulate the distribution of care bits in the
test pattern in aim to increase the delivery of more
encodable test patterns. The implementation of the
Align-Encode algorithm proved that this algorithm
suffers a major drawback when applied on large test
patterns. In this paper, we propose a distributed
algorithm for realizing the Align-Encode objectives
but for large scale problems. This algorithm is
designed to run on a scalable distributed
environment. Moreover, it exploits the nature of the
problem in order to make significant improvements in
performance with respect to chip testing time as
well as the number of encodable test patterns
generated, which reflects positively on the cost of
chip development and in test data compression as a
result.
|
256-265 |
The Effect of some Physical
and Geometrical Parameters on Improvement of the
Impact Response of Smart Composite Structures
F. Ashenai Ghasemi, A. Shokuhfar, S. M. R. Khalili,
G. H. Payganeh, K. Malekzadeh
Abstract: This article presents a
complete analytical model to study the role of the
shape memory alloys (SMAs) on improvement the impact
response of the smart composite structures. The role
of some physical and geometrical parameters such as
the volume fraction, the orientation and the
location of the SMA wires on the contact force
history, the deflection, the in-plane strains and
stresses of the structures is investigated in
details. Also the effect of density of the impactor
to the plate ratio and the elastic modulus of the
impactor to the plate ratio on the contact force
history and the deflection of the plate is studied.
The first order shear deformation theory as well as
the Fourier series method was utilized to solve the
governing equations of the composite plate
analytically. The interaction between the impactor
and the plate was modeled with the help of two
degrees of freedom system consisting of
springs-masses. The Choi's linearized contact model
was used in the analysis. The results of the above
research indicated that the use of the SMA wires
inside the smart composite structures improve the
global behavior of the structure against the impact.
The smart composite structures damp more uniformly
and rapidly after the impact.
|
266-274 |
Transmission Network
Dynamics of Plasmodium Vivax Malaria
P. Pongsumpun, I. M. Tang
Abstract: One of the top ten killer
diseases in the world is Malaria. In each year,
there are between 300 to 500 million clinical
episodes of malaria and 1.5 to 2.7 million deaths
worldwide. The malaria disease is caused by the
multiplication of protozoa parasite of the genus
Plasmodium. Malaria in humans is due to 4 types of
malaria parasites such that Plasmodium falciparum,
Plasmodium vivax, Plasmodium malariae and Plasmodium
ovale. P.vivax malaria differs from P. falciparum
malaria in that a person suffering from P. vivax
malaria can experience relapses of the disease.
Between the relapses, the malaria parasite will
remain dormant in the liver of the patient, leading
to the patient being classified as being in the
dormant class. In this paper, the dynamical model of
P. vivax malaria is formulated to see the network
distribution of this disease.
|
275-282 |
Mathematical Model of
Plasmodium Vivax and Plasmodium Falciparum
Malaria
P. Pongsumpun, I. M. Tang
Abstract: Malaria is transmitted to
the person by the biting of infectious Anopheles
mosquitoes. This infectious disease caused by the
parasite genus Plasmodium. Four species of this
parasite cause human malaria, namely, Plasmodium
vivax, Plasmodium falciparum, Plasmodium ovale and
Plasmodium malariae. The difference between P.vivax
and P. falciparum is that a person suffering from P.
vivax infection can suffer relapses of the disease.
This is due the parasite being able to remain
dormant in the liver of the cases where it is able
to re-infect the case after a passage of time.
During this stage, the case is classified as being
in the dormant class. The model to describe the
transmission between falciparum and vivax malaria
consists of a human population divided into four
classes, the susceptible, the infectious, the
dormant and the recovered classes. The vector
population is separated into two classes, the
susceptible and infectious classes. We analyze our
model by using standard dynamic modeling method. Two
stable equilibrium states, a disease free state E0
and an endemic state E1, are found to be possible.
It is found that the E0 state is stable when a basic
reproductive number R0 is less than one. If R0 is
greater than one, the endemic state E1 is stable.
The conditions for the local stability of each
equilibrium state are established. The numerical
simulations are shown to confirm the results.
|
283-290 |
Practical Approaches for the
Design of an Agricultural Machine
Zhiying Zhu, Toshio Eisaka
Abstract: The precision agriculture
has been progressing rapidly to improve the
efficiency of operation with the quality and
consistency of products. Intelligent machines with
high-tech sensors have been developed exploiting
information technology and getting widely used. On
most of farms, however, there still works simple
inexpensive agricultural machines. From cost saving
and sustainable development point of view,
utilization of existing facilities can be
significant alternative strategy. In this paper, we
propose two design methods to improve an existing
agricultural machine. One is modifying relevant
structural parameters of the existing machine by
numerical optimization. The other is appending an
actuator and a controller to a machine and then
employing simultaneous optimization of both
controller and machine parameters. We also compared
their performance and robustness.
|
291-298 |
Dynamic of Electrical Drive
Systems with Heating Consideration
Boteanu Niculae, Popescu Marius-Constantin, Manolea
Gheorghe, Anca Petrisor
Abstract: In this paper it is
considered an electric drive with static torque with
constant component and speed proportional component.
Using the classic calculus of variations is
determined the extremal control and trajectory and
the overheating that ensures maximum exploitation of
the system resources represented by the achievement
of a maximum variation of speed in the acceleration
processes
|
299-308 |
H-infinity Approach Control
for Regulation of Active Car Suspension
Jamal Ezzine, Francesco Tedesco
Abstract: There are many types of car
suspensions control. H1 control of vehicle
suspension is studied in the literature for a brave
time ago. We can define active suspensions as
control systems incorporating a parallel spring and
an electronically controlled damper. The
contribution of this paper relies on H1 control
design to improve comfort and road holding of the
car, and on control validation through simulation on
an quarter Car and Half Car model with
seat-passengers of the suspensions system. In this
paper an H1 controller is designed for a actuated
active suspension system of a quarter-modelled and
half-modelled with seat-passengers vehicle in a
cascade feedback structure. In this paper we will
make a comparison between application of quarter car
and half car model. In the framework of Linear
Matrix Inequality (LMI) optimization, constrained H1
active suspensions are designed on half-car models.
|
309-316 |
Paper
Title, Authors, Abstract (Issue 4, Volume 3, 2009) |
Pages |
Redefining Chaos: Devaney-Chaos
for Piecewise Continuous Dynamical Systems
Byungik Kahng
Abstract: One of the most widely
accepted definition of chaos is the one by Devaney,
which we will call Devaney-chaos. The purpose of our
research is to investigate how the first two
characteristic properties of Devaney-chaos are
affected by the presence of the discontinuity, and
subsequently, what kind of adjustments must be made
to improve Devaney-chaos so that it can be applied
to discontinuous dynamical systems as well as
continuous systems. Under the aforementioned
adjustments, we prove that the first two adjusted
conditions of Devaney-chaos can be successfully used
to characterize the complex orbit-behavior of
piecewise continuous dynamical systems. Also, we
show that the straightforward application of
unadjusted Devaney-chaos is too inclusive when the
system is discontinuous, consequently necessitating
the afore-mentioned adjustments. We use the
classification theorems of the singularities of the
invertible planar piecewise isometric dynamical
systems as the main tools.
|
317-326 |
Fuzzy Logic Control System
Modelling
Jelenka B.Savkovic-Stevanovic
Abstract: In this paper fuzzy logic
theory was studied and applied to the process
control system. The paper presents an intelligent
control system design. In order to perform the state
prediction necessary to the fuzzy logic controller
the system was developed based on input/output data.
The investigation was performed by simulation. As a
case study a distillation packed column was
investigated. The controller has been based on the
process inverse dynamic control. An advanced fuzzy
control model was derived. The dynamic response has
been applied to predict and control the distillate
composition and distillate flow rate to feed flow
rate and feed composition disturbance. The obtained
results show improving products quality control,
determine optimum set points, and a troubleshooting
day to day operating problem.
|
327-334 |
Investigating the
Heterodimerization Process Among Receptors by Monte
Carlo Cellular Automaton Simulation
A. Wisitsorasak, W. Triampo, D. Triampo, C. Modchang,
Y. Lenbury
Abstract: It has become well known
that simulation can be used to investigate complex
biomedical systems in situations where traditional
methodologies are difficult or too costly to be used.
In this paper, Monte Carlo cellular automaton
simulation is employed to study heterodimerization
of receptor proteins. A computer program, based on a
simple random walk of receptor molecules over a
fixed lattice, has been written to simulate the
diffusion and association of receptors over a two-dimensional
membrane. The interaction and dynamics of these
particles is in the form of the lattice Hamiltonian.
The formation of two-dimensional clusters of
receptors in a defined area of surface membrane is
investigated. In particular, we measure the number
of dimers throughout the dynamics and try to define
the power law that governs the process.
|
335-345 |
Modelling of Oil-filled
Transformer
Marius-Constantin O. S. Popescu, Nikos E. Mastorakis,
Liliana N. Popescu-Perescu
Abstract: The purpose of this article
is to analyse the tansformer thermal and loss of
life models will be studied. Based on the thermal
model adopted by International Standards, small
improvements to increase model accuracy are
presented and a comparative study of resulted
accuracy under different load and ambient
temperature profiles is performed.
|
346-355 |
Applications of Genetic
Algorithms in Electrical Engineering
Marius-Constantin O. S. Popescu, Nikos E. Mastorakis,
Liliana Popescu-Perescu
Abstract: In this paper were
presented the main directions of genetic algorithms.
There is a large class of interesting problems that
have not yet been developed fast algorithms. Many of
these problems are problems which occur frequently
optimized in applications. The studies of this work
will allow us to compare the results from different
methods of determining these parameters and
especially those based on genetic algorithms.
|
356-365 |
Design of a Configurable All
Terrain Mobile Robot Platform
Gokhan Bayar, A. Bugra Koku, E. Ilhan Konukseven
Abstract: With the increased funding
from various agencies, research conducted in the
field of mobile robotics has significantly increased
during the last couple of decades. Due to wide range
of applications mobile robots of different sizes and
capabilities are required in the field. Despite the
wide spectrum of applications to be developed for
mobile robots, available platforms on the market for
research purposes are very few in number, and
limited in their capability for multi-purpose use.
Evidently purchasing new platforms for different
applications is not a feasible solution for
conducting research. Driven by the motive of having
a configurable research platform, a mobile robot
referred to as CoMoRAT (Configurable Mobile Robot
for All Terrain Applications) has been designed and
manufactured at METU. CoMoRAT can be driven by
wheels, tracks or both. Besides its ability to ride
effectively on various terrains, robot body is
designed in such a way that adding new hardware to
the platform requires minimal manufacturing and
installation effort. This paper presents the design
and construction details as well as the performance
tests conducted on CoMoRAT.
|
366-373 |
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