Abstract: Based on the component approach, three kinds of
dynamic load models, including a single –motor model, a two-motor
model and composite load model have been developed for the
stability studies of Khuzestan power system. The study results are
presented in this paper. Voltage instability is a dynamic phenomenon
and therefore requires dynamic representation of the power system
components. Industrial loads contain a large fraction of induction
machines. Several models of different complexity are available for
the description investigations. This study evaluates the dynamic
performances of several dynamic load models in combination with
the dynamics of a load changing transformer. Case study is steel
industrial substation in Khuzestan power systems.
Abstract: Effectiveness of Artificial Neural Networks (ANN)
and Support Vector Machines (SVM) classifiers for fault diagnosis of
rolling element bearings are presented in this paper. The
characteristic features of vibration signals of rotating driveline that
was run in its normal condition and with faults introduced were used
as input to ANN and SVM classifiers. Simple statistical features such
as standard deviation, skewness, kurtosis etc. of the time-domain
vibration signal segments along with peaks of the signal and peak of
power spectral density (PSD) are used as features to input the ANN
and SVM classifier. The effect of preprocessing of the vibration
signal by Discreet Wavelet Transform (DWT) prior to feature
extraction is also studied. It is shown from the experimental results
that the performance of SVM classifier in identification of bearing
condition is better then ANN and pre-processing of vibration signal
by DWT enhances the effectiveness of both ANN and SVM classifier
Abstract: In this paper the authors propose a protocol, which uses Elliptic Curve Cryptography (ECC) based on the ElGamal-s algorithm, for sending small amounts of data via an authentication server. The innovation of this approach is that there is no need for a symmetric algorithm or a safe communication channel such as SSL. The reason that ECC has been chosen instead of RSA is that it provides a methodology for obtaining high-speed implementations of authentication protocols and encrypted mail techniques while using fewer bits for the keys. This means that ECC systems require smaller chip size and less power consumption. The proposed protocol has been implemented in Java to analyse its features and vulnerabilities in the real world.
Abstract: Here, in this work we study correspondence the energy density New agegraphic and the energy density Gauss- Bonnet models in flat universe. We reconstruct Λ and Λ ω for them with 0 ( ) 0 h a t = a t .
Abstract: When designing satellites, one of the major issues aside for designing its primary subsystems is to devise its thermal. The thermal management of satellites requires solving different sets of issues with regards to modelling. If the satellite is well conditioned all other parts of the satellite will have higher temperature no matter what. The main issue of thermal modelling for satellite design is really making sure that all the other points of the satellite will be within the temperature limits they are designed. The insertion of power electronics in aerospace technologies is becoming widespread and the modern electronic systems used in space must be reliable and efficient with thermal management unaffected by outer space constraints. Many advanced thermal management techniques have been developed in recent years that have application in high power electronic systems. This paper presents a Three-Dimensional Modal Transmission Line Matrix (3D-TLM) implementation of transient heat flow in space power electronics. In such kind of components heat dissipation and good thermal management are essential. Simulation provides the cheapest tool to investigate all aspects of power handling. The 3DTLM has been successful in modeling heat diffusion problems and has proven to be efficient in terms of stability and complex geometry. The results show a three-dimensional visualisation of self-heating phenomena in the device affected by outer space constraints, and will presents possible approaches for increasing the heat dissipation capability of the power modules.
Abstract: In this paper, we analyze and test a scheme for the
estimation of electrical fundamental frequency signals from the
harmonic load current and voltage signals.
The scheme was based on using two different Multi Layer
Artificial Neural Networks (ML-ANN) one for the current and the
other for the voltage.
This study also analyzes and tests the effect of choosing the
optimum artificial neural networks- sizes which determine the quality
and accuracy of the estimation of electrical fundamental frequency
signals.
The simulink tool box of the Matlab program for the simulation of
the test system and the test of the neural networks has been used.
Abstract: The linear SEF (Spectral Edge Frequency) parameter
and spectrum analysis method can not reflect the non-linear of EEG.
This method can not contribute to acquire real time analysis and obtain
a high confidence in the clinic due to low discrimination. To solve the
problems, the development of a new index is carried out using the
bispectrum analyzing the EEG(electroencephalogram) including the
non-linear characteristic. After analyzing the bispectrum of the 2
dimension, the most significant power spectrum density peaks appeared abundantly at the specific area in awakening and anesthesia state. These points are utilized to create the new index since many
peaks appeared at the specific area in the frequency coordinate. The measured range of an index was 0-100. An index is 20-50 at an anesthesia, while the index is 90-60 at the awake. New index could afford to effectively discriminate the awake and anesthesia state.
Abstract: This study investigates CO2 mitigation by methanol
synthesis from flue gas CO2 and H2 generation through water
electrolysis. Electrolytic hydrogen generation is viable provided that
the required electrical power is supplied from renewable energy
resources; whereby power generation from renewable resources is yet
commercial challenging. This approach contribute to zero-emission,
moreover it produce oxygen which could be used as feedstock for
chemical process. At ZPC, however, oxygen would be utilized
through partial oxidation of methane in autothermal reactor (ATR);
this makes ease the difficulties of O2 delivery and marketing. On the
other hand, onboard hydrogen storage and consumption; in methanol
plant; make the project economically more competitive.
Abstract: Pipeline ADCs are becoming popular at high speeds
and with high resolution. This paper discusses the options of number
of bits/stage conversion techniques in pipelined ADCs and their
effect on Area, Speed, Power Dissipation and Linearity. The basic
building blocks like op-amp, Sample and Hold Circuit, sub converter,
DAC, Residue Amplifier used in every stage is assumed to be
identical. The sub converters use flash architectures. The design is
implemented using 0.18
Abstract: Many works have been carried out to compare the
efficiency of several goodness of fit procedures for identifying
whether or not a particular distribution could adequately explain a
data set. In this paper a study is conducted to investigate the power
of several goodness of fit tests such as Kolmogorov Smirnov (KS),
Anderson-Darling(AD), Cramer- von- Mises (CV) and a proposed
modification of Kolmogorov-Smirnov goodness of fit test which
incorporates a variance stabilizing transformation (FKS). The
performances of these selected tests are studied under simple
random sampling (SRS) and Ranked Set Sampling (RSS). This
study shows that, in general, the Anderson-Darling (AD) test
performs better than other GOF tests. However, there are some
cases where the proposed test can perform as equally good as the
AD test.
Abstract: Electronic Systems are the core of everyday lives.
They form an integral part in financial networks, mass transit,
telephone systems, power plants and personal computers. Electronic
systems are increasingly based on complex VLSI (Very Large Scale
Integration) integrated circuits. Initial electronic design automation is
concerned with the design and production of VLSI systems. The next
important step in creating a VLSI circuit is Physical Design. The
input to the physical design is a logical representation of the system
under design. The output of this step is the layout of a physical
package that optimally or near optimally realizes the logical
representation. Physical design problems are combinatorial in nature
and of large problem sizes. Darwin observed that, as variations are
introduced into a population with each new generation, the less-fit
individuals tend to extinct in the competition of basic necessities.
This survival of fittest principle leads to evolution in species. The
objective of the Genetic Algorithms (GA) is to find an optimal
solution to a problem .Since GA-s are heuristic procedures that can
function as optimizers, they are not guaranteed to find the optimum,
but are able to find acceptable solutions for a wide range of
problems. This survey paper aims at a study on Efficient Algorithms
for VLSI Physical design and observes the common traits of the
superior contributions.
Abstract: The two significant overvoltages in power system,
switching overvoltage and lightning overvoltage, are investigated in
this paper. Firstly, the effect of various power system parameters on
Line Energization overvoltages is evaluated by simulation in ATP.
The dominant parameters include line parameters; short-circuit
impedance and circuit breaker parameters. Solutions to reduce
switching overvoltages are reviewed and controlled closing using
switchsync controllers is proposed as proper method.
This paper also investigates lightning overvoltages in the
overhead-cable transition. Simulations are performed in
PSCAD/EMTDC. Surge arresters are applied in both ends of cable to
fulfill the insulation coordination. The maximum amplitude of
overvoltages inside the cable is surveyed which should be of great
concerns in insulation coordination studies.
Abstract: The global chaos synchronization for a class of time-delayed power systems is investigated via observer-based approach. By employing the concepts of quadratic stability theory and generalized system model, a new sufficient criterion for constructing an observer is deduced. In contrast to the previous works, this paper proposes a theoretical and systematic design procedure to realize chaos synchronization for master-slave power systems. Finally, an illustrative example is given to show the applicability of the obtained scheme.
Abstract: This paper describes the evolution of language
politics and the part played by political leaders with reference to
the Dravidian parties in Tamil Nadu. It explores the interesting
evolution from separatism to coalition in sustaining the values of
parliamentary democracy and federalism. It seems that the
appropriation of language politics is fully ascribed to the DMK
leadership under Annadurai and Karunanidhi. For them, the Tamil
language is a self-determining power, a terrain of nationhood, and
a perennial source of social and political powers. The DMK
remains a symbol of Tamil nationalist party playing language
politics in the interest of the Tamils. Though electoral alliances
largely determine the success, the language politics still has
significant space in the politics of Tamil Nadu. Ironically, DMK
moves from the periphery to centre for getting national recognition
for the Tamils as well as for its own maximization of power. The
evolution can be seen in two major phases as: language politics for
party building; and language politics for state building with three
successive political processes, namely, language politics in the
process of separatism, representative politics and coalition. The
much pronounced Dravidian Movement is radical enough to
democratize the party ideology to survive the spirit of
parliamentary democracy. This has secured its own rewards in
terms of political power. The political power provides the means to
achieve the social and political goal of the political party.
Language politics and leadership pattern actualized this trend
though the movement is shifted from separatism to coalition.
Abstract: This paper aims to select the optimal location and
setting parameters of TCSC (Thyristor Controlled Series
Compensator) controller using Particle Swarm Optimization (PSO)
and Genetic Algorithm (GA) to mitigate small signal oscillations in a
multimachine power system. Though Power System Stabilizers
(PSSs) are prime choice in this issue, installation of FACTS device
has been suggested here in order to achieve appreciable damping of
system oscillations. However, performance of any FACTS devices
highly depends upon its parameters and suitable location in the
power network. In this paper PSO as well as GA based techniques are
used separately and compared their performances to investigate this
problem. The results of small signal stability analysis have been
represented employing eigenvalue as well as time domain response in
face of two common power system disturbances e.g., varying load
and transmission line outage. It has been revealed that the PSO based
TCSC controller is more effective than GA based controller even
during critical loading condition.
Abstract: Hearing impairment is the number one chronic
disability affecting many people in the world. Background noise is
particularly damaging to speech intelligibility for people with
hearing loss especially for sensorineural loss patients. Several
investigations on speech intelligibility have demonstrated
sensorineural loss patients need 5-15 dB higher SNR than the normal
hearing subjects. This paper describes Discrete Hartley Transform
Power Normalized Least Mean Square algorithm (DHT-LMS) to
improve the SNR and to reduce the convergence rate of the Least
Means Square (LMS) for sensorineural loss patients. The DHT
transforms n real numbers to n real numbers, and has the convenient
property of being its own inverse. It can be effectively used for noise
cancellation with less convergence time. The simulated result shows
the superior characteristics by improving the SNR at least 9 dB for
input SNR with zero dB and faster convergence rate (eigenvalue ratio
12) compare to time domain method and DFT-LMS.
Abstract: In power systems, protective relays must filter their
inputs to remove undesirable quantities and retain signal quantities of
interest. This job must be performed accurate and fast. A new
method for filtering the undesirable components such as DC and
harmonic components associated with the fundamental system
signals. The method is s based on a dynamic filtering algorithm. The
filtering algorithm has many advantages over some other classical
methods. It can be used as dynamic on-line filter without the need of
parameters readjusting as in the case of classic filters. The proposed
filter is tested using different signals. Effects of number of samples
and sampling window size are discussed. Results obtained are
presented and discussed to show the algorithm capabilities.
Abstract: Process control and energy conservation are the two
primary reasons for using an adjustable speed drive. However,
voltage sags are the most important power quality problems facing
many commercial and industrial customers. The development of
boost converters has raised much excitement and speculation
throughout the electric industry. Now utilities are looking to these
devices for performance improvement and reliability in a variety of
areas. Examples of these include sags, spikes, or transients in supply
voltage as well as unbalanced voltages, poor electrical system
grounding, and harmonics. In this paper, simulations results are
presented for the verification of the proposed boost converter
topology. Boost converter provides ride through capability during
sag and swell. Further, input currents are near sinusoidal. This
eliminates the need of braking resistor also.
Abstract: Smart Grids employ wireless sensor networks for
their control and monitoring. Sensors are characterized by limitations
in the processing power, energy supply and memory spaces, which
require a particular attention on the design of routing and data
management algorithms.
Since most routing algorithms for sensor networks, focus on
finding energy efficient paths to prolong the lifetime of sensor
networks, the power of sensors on efficient paths depletes quickly,
and consequently sensor networks become incapable of monitoring
events from some parts of their target areas. In consequence, the
design of routing protocols should consider not only energy
efficiency paths, but also energy efficient algorithms in general.
In this paper we propose an energy efficient routing protocol for
wireless sensor networks without the support of any location
information system. The reliability and the efficiency of this protocol
have been demonstrated by simulation studies where we compare
them to the legacy protocols. Our simulation results show that these
algorithms scale well with network size and density.
Abstract: Knowledge of an organization does not merely reside
in structured form of information and data; it is also embedded in
unstructured form. The discovery of such knowledge is particularly
difficult as the characteristic is dynamic, scattered, massive and
multiplying at high speed. Conventional methods of managing
unstructured information are considered too resource demanding and
time consuming to cope with the rapid information growth.
In this paper, a Multi-faceted and Automatic Knowledge
Elicitation System (MAKES) is introduced for the purpose of
discovery and capture of organizational knowledge. A trial
implementation has been conducted in a public organization to
achieve the objective of decision capture and navigation from a
number of meeting minutes which are autonomously organized,
classified and presented in a multi-faceted taxonomy map in both
document and content level. Key concepts such as critical decision
made, key knowledge workers, knowledge flow and the relationship
among them are elicited and displayed in predefined knowledge
model and maps. Hence, the structured knowledge can be retained,
shared and reused.
Conducting Knowledge Management with MAKES reduces work
in searching and retrieving the target decision, saves a great deal of
time and manpower, and also enables an organization to keep pace
with the knowledge life cycle. This is particularly important when
the amount of unstructured information and data grows extremely
quickly. This system approach of knowledge management can
accelerate value extraction and creation cycles of organizations.