Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2012

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 11701 - 11730 of 12196

Full-Text Articles in Physical Sciences and Mathematics

Discrete Particle Swarm Optimization For The Team Orienteering Problem, Ai̇şe Zülal Şevkli̇, Fati̇h Erdoğan Sevi̇lgen Jan 2012

Discrete Particle Swarm Optimization For The Team Orienteering Problem, Ai̇şe Zülal Şevkli̇, Fati̇h Erdoğan Sevi̇lgen

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel discrete particle swarm optimization (PSO) algorithm is proposed to solve the team orienteering problem (TOP). Discrete evaluation is achieved by redefining all operators and operands used in PSO. To obtain better results, a strengthened PSO, which improves both exploration and exploitation during the search process, is employed. Our algorithm achieves the best known solutions in a short time compared to previous heuristics for the TOP.

Go to article

A Modified Particle Swarm Optimization Algorithm And Its Application To The Multiobjective Fet Modeling Problem, Ufuk Özkaya, Fi̇li̇z Güneş Jan 2012

A Modified Particle Swarm Optimization Algorithm And Its Application To The Multiobjective Fet Modeling Problem, Ufuk Özkaya, Fi̇li̇z Güneş

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a modified particle swarm algorithm to handle multiobjective optimization problems. In multiobjective PSO algorithms, the determination of Pareto optimal solutions depends directly on the strategy of assigning a best local guide to each particle. In this work, the PSO algorithm is modified to assign a best local guide to each particle by using minimum angular distance information. This algorithm is implemented to determine field-effect transistor (FET) model elements subject to the Pareto domination between the scattering parameters and operation bandwidth. Furthermore, the results are compared with those obtained by the nondominated sorting genetic algorithm-II. FET models are …

Go to article

Performance Comparison Of New Nonparametric Independent Component Analysis Algorithm For Different Entropic Indexes, Yusuf Sevi̇m, Ayten Atasoy Jan 2012

Performance Comparison Of New Nonparametric Independent Component Analysis Algorithm For Different Entropic Indexes, Yusuf Sevi̇m, Ayten Atasoy

Turkish Journal of Electrical Engineering and Computer Sciences

Most independent component analysis (ICA) algorithms use mutual information (MI) measures based on Shannon entropy as a cost function, but Shannon entropy is not the only measure in the literature. In this paper, instead of Shannon entropy, Tsallis entropy is used and a novel ICA algorithm, which uses kernel density estimation (KDE) for estimation of source distributions, is proposed. KDE is directly evaluated from the original data samples, so it solves the important problem in ICA: how to choose nonlinear functions as the probability density function (pdf) estimation of the sources.

Go to article

Performance Analysis Of Wind Turbine-Driven Permanent Magnet Generator With Matrix Converter, Ramasamy Bharanikumar, A Nirmal Kumar Jan 2012

Performance Analysis Of Wind Turbine-Driven Permanent Magnet Generator With Matrix Converter, Ramasamy Bharanikumar, A Nirmal Kumar

Turkish Journal of Electrical Engineering and Computer Sciences

Wind energy, among all of the renewable energy sources, has made rapid developments and significant inroads in electrical power systems. With the increased use of wind energy conversion systems (WECSs), several technologies have been developed. Since WECSs are more cost competitive, the comparison of different wind generator systems is the need of the hour. Permanent magnet generators employing these technologies have some significant advantages over conventional generators, such as no need of excitation, low volume and weight, high precision, and deletion of the gearbox. A variable-speed WECS with a permanent magnet generator and a matrix converter is proposed in this …

Go to article

Economic Analysis Of A Wind-Battery Hybrid System: An Application For A House In Gebze, Turkey, With Moderate Wind Energy Potential, Bahti̇yar Dursun, Ci̇han Gökçöl Jan 2012

Economic Analysis Of A Wind-Battery Hybrid System: An Application For A House In Gebze, Turkey, With Moderate Wind Energy Potential, Bahti̇yar Dursun, Ci̇han Gökçöl

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the energy demand of a house in Gebze, Turkey, is met by using wind energy as a primary energy source combined with rechargeable batteries. The wind-battery system is simulated by MATLAB while considering that energy continuity is maintained by using a sufficient number of batteries. A life-cycle cost analysis is carried out over a 20-year system lifetime because the operating time of the hybrid system is subject to the turbine life, usually assumed to be 20 years. The wind turbine generators considered are of various nominal powers, ranging from 0.6 to 450 kW. For each wind turbine, …

Go to article

Short-Term Wind Speed Estimation Based On Weather Data, Okan Özgönenel, David W.P. Thomas Jan 2012

Short-Term Wind Speed Estimation Based On Weather Data, Okan Özgönenel, David W.P. Thomas

Turkish Journal of Electrical Engineering and Computer Sciences

For accurate and efficient use of wind power, it is important to know the statistical characteristics, availability, diurnal variation, and prediction of wind speed. Prediction of wind power permits the scheduling of the connection or the disconnection of wind turbines to achieve optimal operating costs. In this paper, a simple and accurate method for predicting wind speed based on weather-sensitive data is presented. The proposed wind speed prediction system is cost-effective and only needs wind speed data at 40 m and weather data to forecast wind speeds at 50 m and 60 m for the current and next months. Hellman …

Go to article

Compact Dual-Band Split-Ring Antenna For 2.4/5.2 Ghz Wlan Applications, Siddik Cumhur Başaran Jan 2012

Compact Dual-Band Split-Ring Antenna For 2.4/5.2 Ghz Wlan Applications, Siddik Cumhur Başaran

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a compact dual-band printed antenna for 2.4/5.2 GHz WLAN applications. The radiating elements of the proposed antenna are composed of rectangular split-ring elements and metallic loadings placed appropriately between the rings. The antenna size is very compact (22 \times 26 \times 1.6 mm), and it can be integrated easily with other RF front-end circuits. It is demonstrated that the proposed antenna can completely cover the required bandwidths of IEEE 802.11b (2.4-2.484 GHz) and IEEE 802.11a (5.15-5.35 GHz) with satisfactory radiation characteristics. Analysis and design of the proposed antenna was carried out with the Ansoft highfrequency structure simulator. …

Go to article

Multiobjective Fet Modeling Using Particle Swarm Optimization Based On Scattering Parameters With Pareto Optimal Analysis, Fi̇li̇z Güneş, Ufuk Özkaya Jan 2012

Multiobjective Fet Modeling Using Particle Swarm Optimization Based On Scattering Parameters With Pareto Optimal Analysis, Fi̇li̇z Güneş, Ufuk Özkaya

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, design-oriented field effect transistor (FET) models are produced. For this purpose, FET modeling is put forward as a constrained, multiobjective optimization problem. Two novel methods for multiobjective optimization are employed: particle swarm optimization (PSO) uses the single-objective function, which gathers all of the objectives as aggregating functions; and the nondominated sorting genetic algorithm-II (NSGA-II) sorts all of the trade-off solutions on the Pareto frontiers. The PSO solution is compared with the Pareto optimum solutions in the biobjective plane and the success of the first method is verified. Furthermore, the resulting FET models are compared with similar FET …

Go to article

A Procedure To Specify The Weighting Matrices For An Optimal Load-Frequency Controller, Silvio José Pinto Simões Mariano, Jose Álvaro Nunes Pombo, Maria Do Rosário Alves Calado, Luis António Fialho Marcelino Ferreira Jan 2012

A Procedure To Specify The Weighting Matrices For An Optimal Load-Frequency Controller, Silvio José Pinto Simões Mariano, Jose Álvaro Nunes Pombo, Maria Do Rosário Alves Calado, Luis António Fialho Marcelino Ferreira

Turkish Journal of Electrical Engineering and Computer Sciences

The linear quadratic optimal regulator is one of the most powerful techniques for designing multivariable control systems. The performance of the system is specified in terms of a cost, which is the integral of a weighted quadratic function of the system state and control inputs, that is to be minimized by the optimal controller. The components of the state cost weighting matrix, Q, and the control cost weighting matrix, R, are ours to choose in mathematically specifying the way we wish the system to perform. Changing these matrices, we can modify the transient behavior of the closed-loop system. This paper …

Go to article

A Simulator Based On An Energy-Efficient Gpr Algorithm Modified For The Scanning Of All Types Of Regions, Levent Seyfi̇, Ercan Yaldiz Jan 2012

A Simulator Based On An Energy-Efficient Gpr Algorithm Modified For The Scanning Of All Types Of Regions, Levent Seyfi̇, Ercan Yaldiz

Turkish Journal of Electrical Engineering and Computer Sciences

An improved simulator is presented for the simulation of an energy-efficient ground-penetrating radar (GPR) using the 2D finite-difference time-domain method in the MATLAB environment. This simulator is novel in that it improves on previous work that did not involve scanning a buried object or the intermittent sublayer beneath the ground using an energy-efficient algorithm. The present simulator examines the scanned region and automatically chooses either a common algorithm or an energy-efficient algorithm, depending on the region. The simulator provides the possibility of using an energy-efficient GPR without the need for the operator to determine the suitability of the scanned region. …

Go to article

Joint Source-Channel Coding For Error Resilient Transmission Of Static 3d Models, Mehmet Oğuz Bi̇ci̇, Andrey Norkin, Gözde Akar Jan 2012

Joint Source-Channel Coding For Error Resilient Transmission Of Static 3d Models, Mehmet Oğuz Bi̇ci̇, Andrey Norkin, Gözde Akar

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, performance analysis of joint source-channel coding techniques for error-resilient transmission of three dimensional (3D) models are presented. In particular, packet based transmission scenarios are analyzed. The packet loss resilient methods are classified into two groups according to progressive compression schemes employed: Compressed Progressive Meshes (CPM) based methods and wavelet based methods. In the first group, layers of CPM algorithm are protected unequally by Forward Error Correction (FEC) using Reed Solomon (RS) codes. In the second group, embedded bitstream obtained from wavelet based coding is protected unequally with FEC as well. Both groups of methods are scalable with …

Go to article

Investigating The Relation Between Optimum Guard Interval And Channel Delay Spread For A Mc-Cdma System, Çeti̇n Kurnaz, Hülya Gökalp Jan 2012

Investigating The Relation Between Optimum Guard Interval And Channel Delay Spread For A Mc-Cdma System, Çeti̇n Kurnaz, Hülya Gökalp

Turkish Journal of Electrical Engineering and Computer Sciences

This paper demonstrates a novel approach to determining the optimum guard interval for a multicarrier code division multiple access (MC-CDMA) system. Analytical expressions for useful and interference power are derived as a basis for comparison. From these, an expression for the signal-to-noise ratio of a detected bit is derived and used to determine the optimum guard interval for a given channel profile and system parameters. In contrast to other works, we use channel models based on actual measurements and we highlight important differences from theoretical models to support our approach. From our results, we propose an empirical rule for optimum …

Go to article

A Novel Three-Phase Transformer Hysteresis Model In Matlab^{Tm} Simulink, Okan Özgönenel, Kami̇l Ri̇fat İrfan Güney, Ömer Usta, Hasan Di̇ri̇k Jan 2012

A Novel Three-Phase Transformer Hysteresis Model In Matlab^{Tm} Simulink, Okan Özgönenel, Kami̇l Ri̇fat İrfan Güney, Ömer Usta, Hasan Di̇ri̇k

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new transformer model displaying hysteresis using the MATLAB{\texttrademark} Simulink environment. The proposed model displays a complete scheme for the simulation of 3-phase transformers. The new model is mainly based on the transmission line model and the Jiles-Atherton model of a power system using lumped parameters. Jiles-Atherton model parameters were determined by curve fitting and numerical optimization iteration. The developed model is particularly suitable for fault analysis and protective relaying studies under harmonic conditions where the transformer is driven into the nonlinear regime. The performance of the method was evaluated by both theorical and experimental data.

Go to article

Improved Square Properties Of Idea, Mete Akgün, Hüseyi̇n Demi̇rci̇, Mahmut Şami̇l Sağiroğlu, Pinar Kavak Jan 2012

Improved Square Properties Of Idea, Mete Akgün, Hüseyi̇n Demi̇rci̇, Mahmut Şami̇l Sağiroğlu, Pinar Kavak

Turkish Journal of Electrical Engineering and Computer Sciences

Block cipher encryption algorithms generally process on word structures of fixed length such as 8 or 16-bits. IDEA is one of the most widely used block ciphers and operates on 16-bit words. Square analysis is a method that exploits the word structure of block ciphers. Some square distinguishers of IDEA are given in previous studies. The best attacks against IDEA use square-like techniques. In this paper, we focus on the square properties of the IDEA block cipher. We consider all fixed word combinations of the plaintext to investigate the structural behavior of the algorithm. We observe that the cipher can …

Go to article

Voltage- And Current-Controlled High Cmrr Instrumentation Amplifier Using Cmos Current Conveyors, Hamdi̇ Ercan, Sezai̇ Alper Teki̇n, Mustafa Alçi Jan 2012

Voltage- And Current-Controlled High Cmrr Instrumentation Amplifier Using Cmos Current Conveyors, Hamdi̇ Ercan, Sezai̇ Alper Teki̇n, Mustafa Alçi

Turkish Journal of Electrical Engineering and Computer Sciences

A new approach to the design of an instrumentation amplifier using only 2 CMOS current-controlled conveyors and an active resistor is introduced. The new approach, which has no passive components, offers a wide bandwidth and a high common-mode rejection ratio (CMRR). Electronically controllable gain by voltage and current is also obtained by this new circuit. The circuit is simulated using the parameters of a 0.35-\mu m TSMC CMOS technology. Theoretical analysis of the circuits was carried out, and the performance of the block circuit was confirmed through PSpice simulation results.

Go to article

Simulated Annealing Algorithm-Based Elman Network For Dynamic System Identification, Adem Kalinli Jan 2012

Simulated Annealing Algorithm-Based Elman Network For Dynamic System Identification, Adem Kalinli

Turkish Journal of Electrical Engineering and Computer Sciences

One of the well-known recurrent neural networks is the Elman network. Recently, it has been used in applications of system identification. The network has feedforward and feedback connections. It can be trained essentially as a feedforward network by means of the basic backpropagation algorithm, but its feedback connections have to be kept constant. For training success, it is important to select the correct values for the feedback connections. However, finding these values manually can be a lengthy trial-and-error process. This paper investigates the use of the simulated annealing (SA) algorithm to obtain the weight values of both the feedforward and …

Go to article

Low-Complexity Channel Estimation For Ofdm Systems In High-Mobility Fading Channels, Mahmut Yalçin, Aydin Akan, Hakan Doğan Jan 2012

Low-Complexity Channel Estimation For Ofdm Systems In High-Mobility Fading Channels, Mahmut Yalçin, Aydin Akan, Hakan Doğan

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, multicarrier transmission is very popular because of the high data rate requirement of wireless systems. Orthogonal frequency-division multiplexing (OFDM) is a special case of multicarrier transmission. It is considered an effective technique for frequency-selective channels because of its spectral efficiency, its robustness in different multipath propagation environments, and its ability of combating intersymbol interference. Losing subchannel orthogonality causes interchannel interference, but many conventional channel estimators assume that the channel is time-invariant during one OFDM symbol. This assumption causes error floors along the OFDM symbol for high-mobility cases. In this paper, we propose 2-dimensional pilot symbol-assisted channel estimation for wireless …

Go to article

Healthface: A Web-Based Remote Monitoring Interface For Medical Healthcare Systems Based On A Wireless Body Area Sensor Network, İsmai̇l Kirbaş, Cüneyt Bayilmiş Jan 2012

Healthface: A Web-Based Remote Monitoring Interface For Medical Healthcare Systems Based On A Wireless Body Area Sensor Network, İsmai̇l Kirbaş, Cüneyt Bayilmiş

Turkish Journal of Electrical Engineering and Computer Sciences

The wireless body area sensor network (WBASN) is a type of wireless sensor network. The wireless sensor nodes in a WBASN are placed on, near, or within a human body. In a medical healthcare system, WBASNs continuously provide healthcare monitoring, especially of elderly or ill people, wherever the patient goes. Wireless nodes sense and process human vital signs such as heart rate, blood pressure, body temperature, and respiration. They then send collected data to a medical center via a base station in order for medical professionals to monitor the patient's health. In the medical center, doctors and caregivers need monitoring …

Go to article

Optimization And Coordination Of Svc-Based Supplementary Controllers And Psss To Improve Power System Stability Using A Genetic Algorithm, Ali Darvish Falehi, Mehrdad Rostami, Aref Doroudi, Abdolaziz Ashrafian Jan 2012

Optimization And Coordination Of Svc-Based Supplementary Controllers And Psss To Improve Power System Stability Using A Genetic Algorithm, Ali Darvish Falehi, Mehrdad Rostami, Aref Doroudi, Abdolaziz Ashrafian

Turkish Journal of Electrical Engineering and Computer Sciences

In this piaper, a lead-lag structure is proposed as a main damping controller for a static VAR compensator (SVC) to diminish power system oscillations. To confirm the transient performance of the proposed controller, it was compared to a proportional integral derivative (PID) damping controller. Power system stability improvement was thoroughly examined using these supplementary damping controllers as well as a power system stabilizer i(PSS). The generic algorithm (GA) is well liked in the academic environment due to its immediate perceptiveness, ease of performance, and ability to impressively solve highly nonlinear objectives. Thus, the GA optimization technique was applied to solve …

Go to article

A New Multipath Channel Transformation Technique, Tuğrul Çavdar Jan 2012

A New Multipath Channel Transformation Technique, Tuğrul Çavdar

Turkish Journal of Electrical Engineering and Computer Sciences

A new channel transformation technique is introduced in this paper The technique is employed on the receiver side and has 2 filters. The first filter is the inverse complex conjugate of the estimated channel. The profile of this filter's output is triangular. The taps of the second filter are calculated according to the output of the first filter to produce an exponentially decreasing profile. This technique transforms most channel profiles to exponentially decreasing channel profiles. Thus equalizers adopting the proposed technique may have better bit error rates and lower computational complexity on frequency-selective channels. This paper evaluates the efficiency of …

Go to article

Forecasting Natural Gas Consumption In İstanbul Using Neural Networks And Multivariate Time Series Methods, Ömer Fahretti̇n Demi̇rel, Seli̇m Zai̇m, Ahmet Çalişkan, Pinar Özuyar Jan 2012

Forecasting Natural Gas Consumption In İstanbul Using Neural Networks And Multivariate Time Series Methods, Ömer Fahretti̇n Demi̇rel, Seli̇m Zai̇m, Ahmet Çalişkan, Pinar Özuyar

Turkish Journal of Electrical Engineering and Computer Sciences

The fast changes and developments in the world's economy have substantially increased energy consumption. Consequently, energy planning has become more critical and important. Forecasting is one of the main tools utilized in energy planning. Recently developed computational techniques such as genetic algorithms have led to easily produced and accurate forecasts. In this paper, a natural gas consumption forecasting methodology is developed and implemented with state-of-the-art techniques. We show that our forecasts are quite close to real consumption values. Accurate forecasting of natural gas consumption is extremely critical as the majority of purchasing agreements made are based on predictions. As a …

Go to article

Cascade Fuzzy Logic Control Of A Single-Link Flexible-Joint Manipulator, İsmai̇l Hakki Akyüz, Zafer Bi̇ngül, Selçuk Ki̇zi̇r Jan 2012

Cascade Fuzzy Logic Control Of A Single-Link Flexible-Joint Manipulator, İsmai̇l Hakki Akyüz, Zafer Bi̇ngül, Selçuk Ki̇zi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the design and control of a single-link flexible-joint robot manipulator. A cascade fuzzy logic controller (FLC) was used to remove link vibrations and to obtain fast trajectory tracking performance. The cascade FLC structure includes 3 different FLCs. The input variables of the first and the second FLCs are the motor rotation angle error, its derivative, and the end-point deflection error its derivative, respectively. The outputs of these controllers are the inputs of the third FLC, which yields the control signal to the flexible robot arm. All of the FLCs were embedded in a DS1103 real-time control board. …

Go to article

Circuit Model And Parasitic Parameter Extraction Of The Spark Plug In The Ignition System, Quandi Wang, Yali Zheng, Jihui Yu, Jin Jia Jan 2012

Circuit Model And Parasitic Parameter Extraction Of The Spark Plug In The Ignition System, Quandi Wang, Yali Zheng, Jihui Yu, Jin Jia

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a circuit model of the spark plug in the ignition system for conducted electromagnetic interference (EMI). Based on the spark plug's current discharge channel, the circuit model of the spark plug is established with the parasitic parameters and the air-gap model. The parasitic parameters of the spark plug are extracted with the finite element method, and the air-gap model of the spark plug is analyzed using the electric circuit principles and the air-discharge theory. The simulation and measurement results validate this model. Furthermore, this model confirms that the spark plug discharge is the main conducted EMI source …

Go to article

Short-Term Nodal Congestion Price Forecasting In A Large-Scale Power Market Using Ann With Genetic Optimization Training, Majid Moazzami, Rahmat Allah Hooshmand Jan 2012

Short-Term Nodal Congestion Price Forecasting In A Large-Scale Power Market Using Ann With Genetic Optimization Training, Majid Moazzami, Rahmat Allah Hooshmand

Turkish Journal of Electrical Engineering and Computer Sciences

In a daily power market, price and load forecasting are the most important signals for the market participants. In this paper, an accurate feed-forward neural network model with a genetic optimization Levenberg-Marquardt back propagation training algorithm is employed for short-term nodal congestion price forecasting in different zones of a large-scale power market. The use of genetic algorithms for neural network training optimization has a remarkable effect on the accuracy of price forecasting in a large-scale power market. The necessary data for neural network training are obtained by solving optimal power flow equations that take into account all effective constraints at …

Go to article

Packet Traffic Features Of Ipv6 And Ipv4 Protocol Traffic, Cebrai̇l Çi̇fli̇kli̇, Ali̇ Gezer, Abdullah Tuncay Özşahi̇n Jan 2012

Packet Traffic Features Of Ipv6 And Ipv4 Protocol Traffic, Cebrai̇l Çi̇fli̇kli̇, Ali̇ Gezer, Abdullah Tuncay Özşahi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, the IPv6 protocol is in a transition phase in operational networks. The ratio of its traffic volume is increasing day by day. The many provided facilities for IPv6 connection increasethe total IPv6 traffic load. IPv6-over-IPv4 tunnels, pilot programsto provide IPv6 connections, IPv6/IPv4 dual stack operating systems,and free IPv6 tunnel brokers cause the IPv6 protocol to expand quickly. For efficient resource utilization, the characteristics of network traffic should be determined accurately. Many traffic characterization studies regarding IPv4 have demonstrated that most of the network traffic is self-similar. Self-similarity causes significant impacts on network performance. With the increasing volume of IPv6 …

Go to article

Neutral Current Wave Shape Analysis Using Wavelet For Diagnosis Of Winding Insulation Of A Transformer, Patthi Sridhar, Birendra Prasad Singh, Pulapa Venkata Kanaka Rao Jan 2012

Neutral Current Wave Shape Analysis Using Wavelet For Diagnosis Of Winding Insulation Of A Transformer, Patthi Sridhar, Birendra Prasad Singh, Pulapa Venkata Kanaka Rao

Turkish Journal of Electrical Engineering and Computer Sciences

Insulation failure within the windings of a power transformer arises due to over voltages, under voltages, notches, glitches, etc. A widely used technique to detect these power transformer insulation failures during an impulse test is the comparison of neutral current waveforms. Any shift in the recorded waveforms between reduced and full voltage confirms the existence of a fault in the windings. Hence, a proper analysis of neutral current waveforms is necessary to assess the condition of the insulation of power transformer winding. In order to carry out a wave shape analysis, a 61 MVA, 11.5/230 kV generator transformer is used …

Go to article

Finite Element Modeling Of A Superconducting Fault Current Limiter, Lale Ergene, J. Keith Nelson, Raghunath Parthasarathi Jan 2012

Finite Element Modeling Of A Superconducting Fault Current Limiter, Lale Ergene, J. Keith Nelson, Raghunath Parthasarathi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper summarizes the work done to show finite element modeling results on a high temperature superconductor fault current limiter (FCL). The paper also gives the small mock-up design of the matrix FCL and its finite element model (FEM). It also discusses the limitations of the FEM and explains how the results from the FEM compare with the experimental data derived for the configuration. A 3-dimensional FEM has been used because of the structure of the real geometry, which does not show any plane or axisymmetric features.

Go to article

Context Gathering And Management For Centralized Context-Aware Handover In Heterogeneous Mobile Networks, Behrouz Shahgholi Ghahfarokhi, Naser Movahhedinia Jan 2012

Context Gathering And Management For Centralized Context-Aware Handover In Heterogeneous Mobile Networks, Behrouz Shahgholi Ghahfarokhi, Naser Movahhedinia

Turkish Journal of Electrical Engineering and Computer Sciences

Context-aware handover decision has recently been considered as a candidate for next-generation heterogeneous wireless networks. The context-aware handover methods proposed in the literature differ in some aspects, including the location of the handover decision (distributed or centralized). Depending on the location of the decision point, the appropriate part of the context knowledge should be transferred in those methods. This paper proposes a context gathering mechanism for a policy-based context-aware handover method, which implements mobile-initiated and network assisted handover. The proposed network context gathering mechanism is based on a media-independent handover (MIH) framework and the paper justifies the usability of the …

Go to article

Skewed Alpha-Stable Distributions For Modeling And Classification Of Musical Instruments, Mehmet Erdal Özbek, Mehmet Emre Çek, Feri̇t Acar Savaci Jan 2012

Skewed Alpha-Stable Distributions For Modeling And Classification Of Musical Instruments, Mehmet Erdal Özbek, Mehmet Emre Çek, Feri̇t Acar Savaci

Turkish Journal of Electrical Engineering and Computer Sciences

Music information retrieval and particularly musical instrument classification has become a very popular research area for the last few decades. Although in the literature many feature sets have been proposed to represent the musical instrument sounds, there is still need to find a superior feature set to achieve better classification performance. In this paper, we propose to use the parameters of skewed alpha-stable distribution of sub-band wavelet coefficients of musical sounds as features and show the effectiveness of this new feature set for musical instrument classification. We compare the classification performance with the features constructed from the parameters of generalized …

Go to article

Localized Power-Aware Routing With An Energy-Efficient Pipelined Wakeup Schedule For Wireless Sensor Networks, Taner Çevi̇k, Abdül Hali̇m Zai̇m, Derya Yiltaş Jan 2012

Localized Power-Aware Routing With An Energy-Efficient Pipelined Wakeup Schedule For Wireless Sensor Networks, Taner Çevi̇k, Abdül Hali̇m Zai̇m, Derya Yiltaş

Turkish Journal of Electrical Engineering and Computer Sciences

Depending on the evolutions in electronics, wireless sensor networks (WSNs) have been very popular in many areas of human life such as health, industry, and military. This popularity has drawn the attention of many researchers toward WSNs. WSNs are especially favorable in conditions in which it is physically difficult and dangerous for human beings to gather information. Therefore, the lifetime of those networks must be as long as possible, since it would also be infeasible to replace the energy-depleted sensors with new ones, as they may be deployed in such geographical areas that are difficult and dangerous for human beings …

Go to article

First Prev Next Last