Abstract: Generation system reliability assessment is an
important task which can be performed using deterministic or
probabilistic techniques. The probabilistic approaches have
significant advantages over the deterministic methods. However,
more complicated modeling is required by the probabilistic
approaches. Power generation model is a basic requirement for this
assessment. One form of the generation models is the well known
capacity outage probability table (COPT). Different analytical
techniques have been used to construct the COPT. These approaches
require considerable mathematical modeling of the generating units.
The unit-s models are combined to build the COPT which will add
more burdens on the process of creating the COPT. Decimal to
Binary Conversion (DBC) technique is widely and commonly applied
in electronic systems and computing This paper proposes a novel
utilization of the DBC to create the COPT without engaging in
analytical modeling or time consuming simulations. The simple
binary representation , “0 " and “1 " is used to model the states o f
generating units. The proposed technique is proven to be an effective
approach to build the generation model.
Abstract: For cognitive radio networks, there is a major
spectrum sensing problem, i.e. dynamic spectrum management. It is
an important issue to sense and identify the spectrum holes in
cognitive radio networks. The first-order derivative scheme is usually
used to detect the edge of the spectrum. In this paper, a novel
spectrum sensing technique for cognitive radio is presented. The
proposed algorithm offers efficient edge detection. Then, simulation
results show the performance of the first-order derivative scheme and
the proposed scheme and depict that the proposed scheme obtains
better performance than does the first-order derivative scheme.
Abstract: This work presents a numerical model developed to
simulate the dynamics and vibrations of a multistage tractor gearbox.
The effect of time varying mesh stiffness, time varying frictional
torque on the gear teeth, lateral and torsional flexibility of the shafts
and flexibility of the bearings were included in the model. The model
was developed by using the Lagrangian method, and it was applied to
study the effect of three design variables on the vibration and stress
levels on the gears. The first design variable, module, had little effect
on the vibration levels but a higher module resulted to higher bending
stress levels. The second design variable, pressure angle, had little
effect on the vibration levels, but had a strong effect on the stress
levels on the pinion of a high reduction ratio gear pair. A pressure
angle of 25o resulted to lower stress levels for a pinion with 14 teeth
than a pressure angle of 20o. The third design variable, contact ratio,
had a very strong effect on both the vibration levels and bending
stress levels. Increasing the contact ratio to 2.0 reduced both the
vibration levels and bending stress levels significantly. For the gear
train design used in this study, a module of 2.5 and contact ratio of
2.0 for the various meshes was found to yield the best combination
of low vibration levels and low bending stresses. The model can
therefore be used as a tool for obtaining the optimum gear design
parameters for a given multistage spur gear train.
Abstract: Optimal routing in communication networks is a
major issue to be solved. In this paper, the application of Tabu Search
(TS) in the optimum routing problem where the aim is to minimize
the computational time and improvement of quality of the solution in
the communication have been addressed. The goal is to minimize the
average delays in the communication. The effectiveness of Tabu
Search method is shown by the results of simulation to solve the
shortest path problem. Through this approach computational cost can
be reduced.
Abstract: In this paper, we propose a solution to the motion
control problem of a 2-link revolute manipulator arm. We require the
end-effector of the arm to move safely to its designated target in a
priori known workspace cluttered with fixed circular obstacles of
arbitrary position and sizes. Firstly a unique velocity algorithm is
used to move the end-effector to its target. Secondly, for obstacle
avoidance a turning angle is designed, which when incorporated into
the control laws ensures that the entire robot arm avoids any number
of fixed obstacles along its path enroute the target. The control laws
proposed in this paper also ensure that the equilibrium point of the
system is asymptotically stable. Computer simulations of the
proposed technique are presented.
Abstract: In this paper, genetic algorithm (GA) opmization technique is applied to design Flexible AC Transmission System (FACTS)-based damping controllers. Two types of controller structures, namely a proportional-integral (PI) and a lead-lag (LL) are considered. The design problem of the proposed controllers is formulated as an optimization problem and GA is employed to search for optimal controller parameters. By minimizing the time-domain based objective function, in which the deviation in the oscillatory rotor speed of the generator is involved; stability performance of the system is improved. The proposed controllers are tested on a weakly connected power system subjected to different disturbances. The non-linear simulation results are presented to show the effectiveness of the proposed controller and their ability to provide efficient damping of low frequency oscillations. It is also observed that the proposed SSSC-based controllers improve greatly the voltage profile of the system under severe disturbances. Further, the dynamic performances of both the PI and LL structured FACTS-controller are analyzed at different loading conditions and under various disturbance condition as well as under unbalanced fault conditions..
Abstract: This paper presents the impact study of apparent
reactance injected by series Flexible AC Transmission System
(FACTS) i.e. Thyristor Controlled Series Reactor (TCSR) on the
measured impedance of a 400 kV single electrical transmission line
in the presence of phase to earth fault with fault resistance. The study
deals with an electrical transmission line of Eastern Algerian
transmission networks at Group Sonelgaz (Algerian Company of
Electrical and Gas) compensated by TCSR connected at midpoint of
the line. This compensator used to inject active and reactive powers
is controlled by three TCSR-s. The simulations results investigate the
impacts of the TCSR on the parameters of short circuit calculation
and parameters of measured impedance by distance relay in the
presence of earth fault for three cases study.
Abstract: In this paper, Fabless Prototyping Methodology is
introduced for the design and analysis of MEMS devices.
Conventionally Finite Element Analysis (FEA) is performed before
system level simulation. In our proposed methodology, system level
simulation is performed earlier than FEA as it is computationally less
extensive and low cost. System level simulations are based on
equivalent behavioral models of MEMS device. Electrostatic
actuation based MEMS Microgripper is chosen as case study to
implement this methodology. This paper addresses the behavioral
model development and simulation of actuator part of an
electrostatically actuated Microgripper. Simulation results show that
the actuator part of Microgripper works efficiently for a voltage range
of 0-45V with the corresponding jaw displacement of 0-4.5425μm.
With some minor changes in design, this range can be enhanced to
15μm at 85V.
Abstract: This paper mainly proposes an efficient modified
particle swarm optimization (MPSO) method, to identify a slidercrank
mechanism driven by a field-oriented PM synchronous motor.
In system identification, we adopt the MPSO method to find
parameters of the slider-crank mechanism. This new algorithm is
added with “distance" term in the traditional PSO-s fitness function to
avoid converging to a local optimum. It is found that the comparisons
of numerical simulations and experimental results prove that the
MPSO identification method for the slider-crank mechanism is
feasible.
Abstract: In this paper, a new Genetic Algorithm (GA) based
methodology is proposed to optimize the Degree of Hybridization
(DOH) in a passenger parallel hybrid car. At first step, target
parameters for the vehicle are decided and then using ADvanced
VehIcle SimulatOR (ADVISOR) software, the variation pattern of
these target parameters, across the different DOHs, is extracted. At
the next step, a suitable cost function is defined and is optimized
using GA. In this paper, also a new technique has been proposed for
deciding the number of battery modules for each DOH, which leads
to a great improvement in the vehicle performance. The proposed
methodology is so simple, fast and at the same time, so efficient.
Abstract: There have been many games developing simulation
of soccer games. Many of these games have been designed with
highly realistic features to attract more users. Many have also
incorporated better artificial intelligent (AI) similar to that in a real
soccer game. One of the challenging issues in a soccer game is the
cooperation, coordination and negotiation among distributed agents
in a multi-agent system. This paper focuses on the incorporation of
multi-agent technique in a soccer game domain. The better the
cooperation of a multi-agent team, the more intelligent the game will
be. Thus, past studies were done on the robotic soccer game because
of the better multi-agent system implementation. From this study, a
better approach and technique of multi-agent behavior could be
select to improve the author-s 2D online soccer game.
Abstract: Recurrence of aneurysm rupture can be attributed to
coil migration and compaction. In order to verify the effects of
hemodynamics on coil compaction and migration, we analyze the
forces and displacements on the coil bundle using a computational
method. Lateral aneurysms partially filled coils are modeled, and
blood flow fields and coil deformations are simulated considering
fluid and solid interaction. Effects of aneurysm neck size and parent
vessel geometry are also investigated. The results showed that coil
deformation was larger in the aneurysms with a wider neck. Parent
vessel geometry and aneurysm neck size also affected mean pressure
force profiles on the coil surface. Pressure forces were higher in wide
neck models with curved parent vessel geometry. Simulation results
showed that coils in the wide neck aneurysm with a curved parent
vessel may be displaced and compacted more easily.
Abstract: This article deals to describe the simulation
investigation of the digital phase locked loop implemented in
software (SDPLL). SDPLL has been developed for speed drives of an
induction motor in scalar strategy. A drive was implemented and
simulation results are presented to verify the robustness against motor
parameter variation and regulation speed.
Abstract: This paper discusses a qualitative simulator QRiOM
that uses Qualitative Reasoning (QR) technique, and a process-based
ontology to model, simulate and explain the behaviour of selected
organic reactions. Learning organic reactions requires the application
of domain knowledge at intuitive level, which is difficult to be
programmed using traditional approach. The main objective of
QRiOM is to help learners gain a better understanding of the
fundamental organic reaction concepts, and to improve their
conceptual comprehension on the subject by analyzing the multiple
forms of explanation generated by the software. This paper focuses
on the generation of explanation based on causal theories to explicate
various phenomena in the chemistry subject. QRiOM has been tested
with three classes problems related to organic chemistry, with
encouraging results. This paper also presents the results of
preliminary evaluation of QRiOM that reveal its explanation
capability and usefulness.
Abstract: This paper gives a study about forging solution to
deploy the fixed wireless access (FWA) in the band 3300-3400MHz
instead of 3400-3600MHz to eschew the harmful interference
between from the FWA towards fixed satellite services receiver
presented in this band. The impact of FWA services toward the FSS
and the boundaries of spectrum emission mask had been considered
to calculate the possible Guard band required in this case. In
addition, supplementary separation distance added to improve the
coexistence between the two adjacent bands. Simulation had been
done using Matlab software base on ITU models reliance on the most
popular specification used for the tropical weather countries. Review
the current problem of interference between two systems and some
mitigation techniques which adopted in Malaysia as a case study is a
part of this research.
Abstract: In this paper methodology to exploit creeping wave
for body area network BAN communication reliability are described.
Creeping wave propagation effects are visualized & analyzed.
During this work Dipole, IA antennas various antennas were
redesigned using existing designs and their propagation
characteristics were verified for optimum performance when used on
BANs. These antennas were then applied on body shapes-including
rectangular, spherical and cylindrical so that all the effects of actual
human body can be taken nearly into account. Parametric simulation
scheme was devised so that on Body channel characterization can be
visualized at front, curved and back region. In the next phase
multiple inputs multiple output MIMO scheme was introduced where
virtual antennas were used in order to diminish the effects of
antennas on the propagation of waves. Results were, extracted and
analyzed at different heights. Finally based on comparative
measurement and analysis it was concluded that on body propagation
can be exploited to gain spatial diversity.
Abstract: In this paper we proposed the use of Huffman
coding to reduce the PAR of an OFDM system as a distortionless
scrambling technique, and we utilize the amount saved in the
total bit rate by the Huffman coding to send the encoding table
for accurate decoding at the receiver without reducing the
effective throughput. We found that the use of Huffman coding
reduces the PAR by about 6 dB. Also we have investigated the
effect of PAR reduction due to Huffman coding through testing
the spectral spreading and the inband distortion due to HPA with
different IBO values. We found a complete match of our
expectation from the proposed solution with the obtained
simulation results.
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: 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.