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Full-Text Articles in Computer Engineering

A Multiobjective Tuning Approach Of Power System Stabilizers Using Particle Swarm Optimization, Hilal Labdelaoui, Fares Boudjema, Djamel Boukhetala Jan 2016

A Multiobjective Tuning Approach Of Power System Stabilizers Using Particle Swarm Optimization, Hilal Labdelaoui, Fares Boudjema, Djamel Boukhetala

Turkish Journal of Electrical Engineering and Computer Sciences

This work presents an optimal tuning approach of power system stabilizers (PSSs) using multiobjective particle swarm optimization. Two types of PSSs are investigated, the conventional speed-based PSS type and a dual-input PSS type that uses the accelerating power as an additional input. The tuning problem of these PSSs is formulated as a minimization problem of a vector objective function characterizing the damping and the transient performance of the closed-loop system. A 3-machine 9-bus power system example is considered, and the speed-constrained multiobjective particle swarm optimization algorithm is used to solve the optimization problem. The results show that trade-offs exist between …


An Hf/Uhf Dual Mode Rfid Transponder Antenna And Hf Range Extension Using Uhf Wireless Power Transmission, Mustafa Murat Bi̇lgi̇ç, Korkut Yeği̇n Jan 2016

An Hf/Uhf Dual Mode Rfid Transponder Antenna And Hf Range Extension Using Uhf Wireless Power Transmission, Mustafa Murat Bi̇lgi̇ç, Korkut Yeği̇n

Turkish Journal of Electrical Engineering and Computer Sciences

An HF/UHF compatible RFID transponder antenna is designed, simulated, and measured for dual band operation and HF range extension. A dual mode compatible RFID transponder antenna has the benefits of each mode and eliminates the disadvantages of single mode operation. One of the major drawbacks of UHF antennas is their poor performance when the tag is placed on or near metallic objects. To overcome this shortcoming, two-layer substrate with degenerate grounded is used and a 4-turn spiral antenna is placed on the top and bottom parts of the substrate for HF operation. The co-existence of both antennas affects standalone performances …


Common Spatial Pattern-Based Feature Extraction From The Best Time Segment Of Bci Data, Önder Aydemi̇r Jan 2016

Common Spatial Pattern-Based Feature Extraction From The Best Time Segment Of Bci Data, Önder Aydemi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

Feature extraction is one of the most crucial stages in the field of brain computer interface (BCI). Because of its ability to directly influence the performance of BCI systems, recent studies have generally investigated how to modify existing methods or develop novel techniques. One of the most successful and well-known methods in BCI applications is the common spatial pattern (CSP). In existing CSP-based methods, the spatial filters were extracted either by using the whole data trial or by dividing the trials into a number of overlapping/nonoverlapping time segments. In this paper, we developed a CSP-based moving window technique to obtain …


Time Series Adapted Supervised Fuzzy Discretization: An Application To Ecg Signals, Umut Orhan Jan 2016

Time Series Adapted Supervised Fuzzy Discretization: An Application To Ecg Signals, Umut Orhan

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a new method called supervised fuzzy discretization (SFD), which can be used without having expertise on data, is proposed for classifying time series datasets. Because an ECG signal has a partially stationary characteristic, its classification process is more difficult than it would be for completely stationary signals. On the other hand, because the method proposed can be used without having expertise on the data, comprehensive data like ECG signals are enough to introduce one such method. To prove the efficacy of the SFD, RR intervals selected from a common ECG database are used in the classification experiments. …


Optimal Siting And Sizing Of Rapid Charging Station For Electric Vehicles Considering Bangi City Road Network In Malaysia, Mainul Islam, Hussain Shareef, Azah Mohamed Jan 2016

Optimal Siting And Sizing Of Rapid Charging Station For Electric Vehicles Considering Bangi City Road Network In Malaysia, Mainul Islam, Hussain Shareef, Azah Mohamed

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, electric vehicles (EVs) have been seen as a felicitous option towards a less carbon-intensive road transport. The key issue in this system is recharging the EV batteries before they are exhausted. Thus, charging stations (CSs) should be carefully located to make sure EV users can access a CS within their driving range. Considering geographic information and traffic density, this paper proposes an optimization overture for optimal siting and sizing of a rapid CS (RCS). It aims to minimize the daily total cost (which includes the cost of substation energy loss, traveling cost of EVs to the CS, and investment, …


Selective Harmonics Elimination Pwm With Self-Balancing Dc-Link In Photovoltaic 7-Level Inverter, Khoukha Imarazene, Hachemi Chekireb, El Madjid Berkouk Jan 2016

Selective Harmonics Elimination Pwm With Self-Balancing Dc-Link In Photovoltaic 7-Level Inverter, Khoukha Imarazene, Hachemi Chekireb, El Madjid Berkouk

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new DC-link balancing method for a 7-level inverter fed by a photovoltaic system is proposed. The proposed redundant state technique is associated with selective harmonics elimination (SHE)-PWM instead of space vector (SV)-PWM. The switching angles related to the SHE are computed via the resultant theory method. Moreover, the study of this inverter is carried out on its equivalent matrix model. On the basis of this model, the link between the capacitor voltage, switching states, and load current is established. This allows understanding the switching redundancies' effect on the DC capacitor voltage balance. An algorithm is then …


Computer Vision-Based Control Of An Autonomous Blimp, Korkut Beki̇roğlu, Mario Sznaier, Constantino Lagoa, Bahram Shafai Jan 2016

Computer Vision-Based Control Of An Autonomous Blimp, Korkut Beki̇roğlu, Mario Sznaier, Constantino Lagoa, Bahram Shafai

Turkish Journal of Electrical Engineering and Computer Sciences

The objective of this study is twofold: to approximate a model of a blimp, and to use this model to develop a setup to track a target with the blimp that is outfitted with a wireless camera and radio-controlled propellers. This article presents a powerful method to track any moving or stationary target with an unmanned aerial vehicle by combining the advantages of the proportional derivative (PD) controller, continuously adaptive mean shift (Camshift) algorithm, and pulse width modulation (PWM) method. As a result, it is demonstrated that a decent approximation of blimp behavior is sufficient when using a mathematical model …


Vector Control Of A Three-Phase Parallel Connected Two Motor Single Inverter Speed Sensorless Drive, Gunabalan Ramachandran, Subbiah Veerana, Sanjeevikumar Padmanaban Jan 2016

Vector Control Of A Three-Phase Parallel Connected Two Motor Single Inverter Speed Sensorless Drive, Gunabalan Ramachandran, Subbiah Veerana, Sanjeevikumar Padmanaban

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the performance characteristics of two induction motors of the same parameters and ratings connected in parallel and fed by a single inverter. A nature observer is employed to estimate the rotor speeds and rotor fluxes of both induction motors. It also estimates the load torques of both the motors by load torque adaptation. Under unbalanced load conditions, the speed difference between the two induction motors is reduced by considering the average and differential motor parameters and currents. Mean rotor flux is maintained constant by a rotor flux control scheme and the estimation of rotor angle is carried …


Fuzzy Based Design Of Digital Iir Filter Using Etlbo, Damanpreet Singh, Jaspreet Singh Dhillon Jan 2016

Fuzzy Based Design Of Digital Iir Filter Using Etlbo, Damanpreet Singh, Jaspreet Singh Dhillon

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a population-based robust enhanced teaching--learning-based optimization (ETLBO) algorithm with reduced computational effort and high consistency is applied to design stable digital infinite-impulse response (IIR) filters in a multiobjective framework. Furthermore, a decision-making methodology based on fuzzy set theory is applied to handle nonlinear and multimodal design problems of the IIR digital filter. The original teaching--learning-based optimization (TLBO) algorithm has been remodeled by merging the concepts of opposition-based learning and migration for the selection of good candidates and to maintain diversity, respectively. A multiobjective IIR digital filter design problem takes into consideration magnitude and phase response of the …


An Ipr Protection Scheme Based On Wavelet Transformation And Visual Cryptography, Young Chang Hou, A-Yu Tseng, Zen-Yu Quan, Hsin-Ju Liu Jan 2016

An Ipr Protection Scheme Based On Wavelet Transformation And Visual Cryptography, Young Chang Hou, A-Yu Tseng, Zen-Yu Quan, Hsin-Ju Liu

Turkish Journal of Electrical Engineering and Computer Sciences

As information technology is fast developing, it brings great convenience to our everyday life. However, hackers may also access confidential data illegally and easily from computers over the Internet. Therefore, how to protect property rights against infringement is an essential issue. Digital watermarking is a method that adds personal information to an intellectual property to protect one's ownership rights. Should the intellectual property be disputed, the owner can retrieve the watermark and prove ownership rights. Based on the principles of visual cryptography and the law of large numbers, our study generates shares by comparing pseudorandomly selected value pairs during the …


Determination Of The Striking Distance Of A Lightning Rod Using Finite Element Analysis, Ab Halim Abu Bakar, Alyaa Zainal Abidin, Hazlee Illias, Hazlie Mokhlis, Syahirah Abd Halim, Nor Hidayah Nor Hassan, Chia Kwang Tan Jan 2016

Determination Of The Striking Distance Of A Lightning Rod Using Finite Element Analysis, Ab Halim Abu Bakar, Alyaa Zainal Abidin, Hazlee Illias, Hazlie Mokhlis, Syahirah Abd Halim, Nor Hidayah Nor Hassan, Chia Kwang Tan

Turkish Journal of Electrical Engineering and Computer Sciences

The problems related to electromagnetic waves transmitted by lightning strikes can be studied through physical lightning models based on laboratory results. The main concern of these models is determining the striking distance between the leader tip and the lightning rod during lightning occurrences. The striking distance is a significant factor in designing the lightning protection system. However, models using finite element analysis (FEA) for this purpose are less likely to be found in the literature. Therefore, in this work, a geometry model of a lightning rod and leader was developed using available FEA software. The model was used to determine …


Performance Comparison Of Adaptive Digital Predistortion Algorithms Using Adaptation Time For Mobile Wimax Power Amplifier Applications, Ji-Yeon Kim, Jong-Heon Kim Jan 2016

Performance Comparison Of Adaptive Digital Predistortion Algorithms Using Adaptation Time For Mobile Wimax Power Amplifier Applications, Ji-Yeon Kim, Jong-Heon Kim

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose that adaptation time be considered a parameter for evaluating the performance of digital filter algorithms in adaptive digital predistorted high-power amplifiers. An adaptive predistorted high-power amplifier with an average power of 37.5 dBm was designed and fabricated for mobile worldwide interoperability for microwave access (WiMAX) test signals. For performance comparisons using adaptation time, several effective algorithms (such as the least-mean-squares (LMS), recursive-least-squares (RLS), and affine projection (AP) algorithms) were implemented. According to the experimental results, the RLS and AP algorithms achieved a similar linearity improvement of 11 dBr. However, the AP algorithm had the advantage …


Optimization Of Pid Parameters Using Bbbc For A Multiarea Agc Scheme In A Deregulated Power System, Nagendra Kumar, Vishal Kumar, Barjeev Tyagi Jan 2016

Optimization Of Pid Parameters Using Bbbc For A Multiarea Agc Scheme In A Deregulated Power System, Nagendra Kumar, Vishal Kumar, Barjeev Tyagi

Turkish Journal of Electrical Engineering and Computer Sciences

Automatic generation control (AGC) is an important service used for the secure and reliable operation of a power system. In this paper, a suitable AGC scheme for a deregulated environment has been studied for various load perturbation scenarios. A proportional integral derivative (PID) controller has been utilized to control the real power output of the generators. The optimal parameters of the PID controller have been determined using the big bang big crunch (BBBC) algorithm, (BBBC-PID). The performance of the BBBC-PID controller has been checked on three different sized multiarea power systems. The results obtained with the applied algorithm have also …


Speech Steganalysis Based On The Delay Vector Variance Method, Osman Hi̇lmi̇ Koçal, Emrah Yürüklü, Erdoğan Di̇laveroğlu Jan 2016

Speech Steganalysis Based On The Delay Vector Variance Method, Osman Hi̇lmi̇ Koçal, Emrah Yürüklü, Erdoğan Di̇laveroğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This study investigates the use of delay vector variance-based features for steganalysis of recorded speech. Because data hidden within a speech signal distort the properties of the original speech signal, we designed a new audio steganalyzer that utilizes delay vector variance (DVV) features based on surrogate data in order to detect the existence of hidden data. The proposed DVV features are evaluated individually and together with other chaotic-type features. The performance of the proposed steganalyzer method is also discussed with a focus on the effect of different hiding capacities. The results of the study show that using the proposed DVV …


Development Of Derivation Of Inverse Jacobian Matrices For 195 6-Dof Gsp Mechanisms, Meti̇n Toz, Serdar Küçük Jan 2016

Development Of Derivation Of Inverse Jacobian Matrices For 195 6-Dof Gsp Mechanisms, Meti̇n Toz, Serdar Küçük

Turkish Journal of Electrical Engineering and Computer Sciences

One of the key issues in robotics is finding high-performance manipulator structures. To evaluate the performance of a parallel manipulator, researchers mostly use kinematic performance indices (such as condition number, minimum singular value, dexterity, and manipulability), which are based on inverse Jacobian matrices. Driving the inverse Jacobian matrix of even one parallel manipulator is a very cumbersome process. However, in this paper, general equations for the inverse Jacobian matrices of 195 GSP mechanisms are symbolically derived by considering 4 basic leg types having 1 angular and 4 distance constraints. With the help of these general equations, the development of the …


Assessment Of The Maximum Loadability Point Of A Power System After Third Zone Of Distance Relay Corrective Actions, Zahra Moravej, Sajad Bagheri Jan 2016

Assessment Of The Maximum Loadability Point Of A Power System After Third Zone Of Distance Relay Corrective Actions, Zahra Moravej, Sajad Bagheri

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the operation of a system and distance relay is improved during voltage instability by using an improved strategy. After detecting the voltage instability, the third zone is blocked. However, the system is prone to voltage collapse. Shunt capacitor compensation and a load shedding scheme can be used to protect the system from voltage collapse conditions. Load shedding plans can be performed based on a reduction in the power flow in the line where the relay is located. The reason is that the minimum eigenvalue of the load flow Jacobian (reduced and unreduced Jacobians) is increased and the …


Evaluation Of Hearing Loss Simulation Using A Speech Intelligibility Index, Umut Ariöz, Banu Günel Jan 2016

Evaluation Of Hearing Loss Simulation Using A Speech Intelligibility Index, Umut Ariöz, Banu Günel

Turkish Journal of Electrical Engineering and Computer Sciences

Hearing loss simulation (HLS) is a useful tool for hearing studies, since finding large numbers of hearing-impaired volunteers with various levels of hearing loss is usually a problem. Correct simulation of the hearing impaired ear should take into account different suprathreshold effects, such as reduced frequency selectivity, reduced audibility, and loudness recruitment. Although these effects can be implemented using various algorithms, so far they have not been evaluated in detail taking into account subject dependency, effect of noisy environment, and phonetic characteristics of test words. In this study, for the purpose of evaluating the HLS, a speech intelligibility index (SII) …


Stability Assessment Of Isolated Six-Phase Induction Generator Feeding Static Loads, Kiran Singh, Girish Kumar Singh Jan 2016

Stability Assessment Of Isolated Six-Phase Induction Generator Feeding Static Loads, Kiran Singh, Girish Kumar Singh

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the stability analysis of a six-phase self-excited induction generator (SP-SEIG) based on the eigenvalue stability criteria for its linearized model. This demonstrates the small signal stability behavior during steady-state operating conditions. The eigenvalue approach also establishes an opportunity to correlate eigenvalues with machine parameters. The investigation in this paper reveals that the eigenvalues are dependent upon the machine parameters, and the most critical parameter is the variation in magnetizing inductance (L$_{m})$. The eigenvalues are varied in accordance with the machine variables and give focus to the stabilization of the SP-SEIG. A particular voltage build-up phenomenon is also …


A Generalized Algorithm For Space Vector Modulation In Multilevel Inverters, Erkan Meşe Jan 2016

A Generalized Algorithm For Space Vector Modulation In Multilevel Inverters, Erkan Meşe

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a new space vector pulse width modulation (SVPWM) algorithm for multilevel inverters that achieves a minimum number of switch state changes in one sampling cycle in order to reduce switching losses. The algorithm can be implemented with minimum computational burden and it does not require any look-up tables. The essence of the technique is to exploit the redundancy of switching functions in the implementation of the voltage vectors and dividing the entire vector space into three sectors in which switching functions have some common features. Careful observations showed that these common features lend themselves to be expressed …


A Novel Voltage Control Strategy In Collaboration With Information Technology Domains Through The Holonic Architecture, Javad Ansari, Mehdi Ghazavi Dozein, Ahad Kazemi Jan 2016

A Novel Voltage Control Strategy In Collaboration With Information Technology Domains Through The Holonic Architecture, Javad Ansari, Mehdi Ghazavi Dozein, Ahad Kazemi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a novel framework for voltage control based on holonic architecture, with a priority action of local controllers. The proposed architecture is a hierarchical distributed structure in which two various information technology domains called the energy management system holon and flexible AC transmission system holon are defined. In the proposed structure, a dynamic reconfiguring method for holons is used to reduce the time of corrective actions in the case of emergencies.


Keyframe-Based Video Mosaicing For Historical Ottoman Documents, Edi̇z Şaykol Jan 2016

Keyframe-Based Video Mosaicing For Historical Ottoman Documents, Edi̇z Şaykol

Turkish Journal of Electrical Engineering and Computer Sciences

Image mosaicing is a trendy research area in computer vision in recent years. Instead of images, video frames can be mosaiced to form a larger aggregate. In both cases, merging computations generally depend on the common parts in consecutive images, which are called overlapping regions. The presence of mobile devices with a camera provides higher image and video acquisition; hence video mosaicing techniques can be utilized to digitize and to create high resolution historical document images for later use in browsing and retrieval systems. Here, we present a technique to create high resolution images of historical Ottoman documents from video. …


Fast Image Search On A Vq Compressed Image Database, Mehmet Yakut Jan 2016

Fast Image Search On A Vq Compressed Image Database, Mehmet Yakut

Turkish Journal of Electrical Engineering and Computer Sciences

A fast and efficient image search method is developed for a compressed image database using vector quantization (VQ). An image search on an image database requires an exhaustive sequential scan of all the images, given the similarity measure. If compressed images are dealt with, images are decompressed as an initial operation and then the previously mentioned exhaustive search is performed using the predetermined similarity measure. If the images in the database are compressed using VQ, the image search process is reduced to codebook index match tests. A pixel by pixel similarity test of two images computationally costs too much. This …


An Attribute Or Tuple Timestamping In Bitemporal Relational Databases, Canan Atay Jan 2016

An Attribute Or Tuple Timestamping In Bitemporal Relational Databases, Canan Atay

Turkish Journal of Electrical Engineering and Computer Sciences

Much of the research on bitemporal databases has focused on the modeling of time-related data with either attribute or tuple timestamping. While the attribute-timestamping approach attaches bitemporal data to attributes, the tuple-timestamping approach splits the object's history into several tuples. Although there have been numerous studies on bitemporal data models, there is no work contrasting these two common approaches in terms of system performance and ease of use. In this paper, we compared interval-based attribute- and tuple-timestamped bitemporal data models by running sample queries to measure processing time, and then we evaluated their usability by using the same data. Our …


A New Step-Size Searching Algorithm Based On Fuzzy Logic And Neural Networks For Lms Adaptive Beamforming Systems, Walter Orozco-Tupacyupanqui, Mariko Nakano-Miyatake, Hector Perez Meana Jan 2016

A New Step-Size Searching Algorithm Based On Fuzzy Logic And Neural Networks For Lms Adaptive Beamforming Systems, Walter Orozco-Tupacyupanqui, Mariko Nakano-Miyatake, Hector Perez Meana

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel algorithm based on fuzzy logic and neural networks is proposed to find an approximation of the optimal step size $\mu $ for least-mean-squares (LMS) adaptive beamforming systems. A new error ensemble learning (EEL) curve is generated based on the final prediction value of the ensemble-average learning curve of the LMS adaptive algorithm. This information is classified and fed into a back propagation neural network, which automatically generates membership functions for a fuzzy inference system. An estimate of the optimal step size is obtained using a group of linguistic rules and the corresponding defuzzification method. Computer …


A New Compression Algorithm For Fast Text Search, Aydin Carus, Altan Mesut Jan 2016

A New Compression Algorithm For Fast Text Search, Aydin Carus, Altan Mesut

Turkish Journal of Electrical Engineering and Computer Sciences

We propose a new compression algorithm that compresses plain texts by using a dictionary-based model and a compressed string-matching approach that can be used with the compressed texts produced by this algorithm. The compression algorithm (CAFTS) can reduce the size of the texts to approximately 41% of their original sizes. The presented compressed string matching approach (SoCAFTS), which can be used with any of the known pattern matching algorithms, is compared with a powerful compressed string matching algorithm (ETDC) and a compressed string-matching tool (Lzgrep). Although the search speed of ETDC is very good in short patterns, it can only …


Hardware Implementation Of A Scale And Rotation Invariant Object Detection Algorithm On Fpga For Real-Time Applications, Murat Peker, Hali̇s Altun, Fuat Karakaya Jan 2016

Hardware Implementation Of A Scale And Rotation Invariant Object Detection Algorithm On Fpga For Real-Time Applications, Murat Peker, Hali̇s Altun, Fuat Karakaya

Turkish Journal of Electrical Engineering and Computer Sciences

A hardware implementation of a computationally light, scale, and rotation invariant method for shape detection on FPGA is devised. The method is based on histogram of oriented gradients (HOG) and average magnitude difference function (AMDF). AMDF is used as a decision module that measures the similarity/dissimilarity between HOG vectors of an image in order to classify the object. In addition, a simulation environment implemented on MATLAB is developed in order to overcome the time-consuming and tedious process of hardware verification on the FPGA platform. The simulation environment provides specific tools to quickly implement the proposed methods. It is shown that …


The Impact Of Disabling Suspicious Node Communications On Network Lifetime In Wireless Ad Hoc Sensor Networks, Zeydi̇n Pala, Ni̇hat İnanç Jan 2016

The Impact Of Disabling Suspicious Node Communications On Network Lifetime In Wireless Ad Hoc Sensor Networks, Zeydi̇n Pala, Ni̇hat İnanç

Turkish Journal of Electrical Engineering and Computer Sciences

In wireless sensor networks (WSNs), the data observed by different nodes must be relayed safely to the base station over intermediate nodes. In the network environment, some sensor nodes can act suspiciously when they enter someone else's control or due to other equipment failure. Data packets that are sent through suspicious nodes may be randomly dropped or may be not delivered as desired. In this paper, we investigate the impact of disabling suspicious nodes communications on network lifetime through a linear programming framework. We build a mathematical programming framework and perform comprehensive numerical analysis. Our results show that the decrease …


Optimization Design Of A Doubly Salient 8/6 Srm Based On Three Computational Intelligence Methods, Fares Rebahi, Amar Bentounsi, Houssem Rafik El-Hana Bouchekara, Redjem Rebbah Jan 2016

Optimization Design Of A Doubly Salient 8/6 Srm Based On Three Computational Intelligence Methods, Fares Rebahi, Amar Bentounsi, Houssem Rafik El-Hana Bouchekara, Redjem Rebbah

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this paper is to optimize an 8/6 doubly salient switched reluctance machine using three computational intelligence methods, which include particle swarm optimization, a genetic algorithm, and differential evolution. Three cases are investigated where different parameters are considered like the stator pole arc, rotor pole arc, and ratios, which define the stator yoke and rotor thickness. The objective functions considered are the average torque and the torque-to-weight functions. The simulations are carried out using MATLAB and FEMM software. The optimal results found are compared with the initial design, and it is shown that high improvements are achieved.


A New Dictionary-Based Preprocessor That Uses Radix-190 Numbering, Mete Eray Şenergi̇n, Erhan Ali̇ri̇za İnce Jan 2016

A New Dictionary-Based Preprocessor That Uses Radix-190 Numbering, Mete Eray Şenergi̇n, Erhan Ali̇ri̇za İnce

Turkish Journal of Electrical Engineering and Computer Sciences

Various scholarly works in the literature have pointed out that placing a preprocessor in front of a standard postcompressor would help achieve higher gains while compressing natural-language text files. Ever since, there has been much research on preprocessors to improve the gain attained by concatenated systems. With the same goal in mind our paper proposes a new word-based preprocessor named METEHAN190 (M190) and contrasts its performance with four other state-of-the-art preprocessors. Throughout the experiments source files from the Wall Street Journal (WSJ) archive, and the Calgary, Canterbury, Gutenberg, and Pizza and Chili corpora were used. Postcompressors adapted were Prediction by …


Some Observations On No-Load Losses Of An Asymmetrical Six-Phase Synchronous Machine, Arif Iqbal, Girish Kumar Singh, Vinay Pant Jan 2016

Some Observations On No-Load Losses Of An Asymmetrical Six-Phase Synchronous Machine, Arif Iqbal, Girish Kumar Singh, Vinay Pant

Turkish Journal of Electrical Engineering and Computer Sciences

The use of multiphase (more than three-phase) ac machines is well adopted in different high power applications and the evaluation of different losses (no load losses, short circuit load loss, friction and windage losses, and stray loss) in multiphase machines is extremely important for the correct determination of their operating performance. Therefore, the paper presents a detailed experimental investigation of an asymmetrical (30$^{\circ}$ displacement between the two winding sets) six-phase synchronous machine for determination of different losses under no-load condition. Moreover, a comparative study of losses for a six-phase and three-phase synchronous machine has also been performed. The results are …