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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 …


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 …


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 Cmos Logarithmic Current Generator, Munir Al Absi, Karama Al Tamimi Jan 2016

A New Cmos Logarithmic Current Generator, Munir Al Absi, Karama Al Tamimi

Turkish Journal of Electrical Engineering and Computer Sciences

A new CMOS current-mode controllable low-voltage and low-power logarithmic function circuit is proposed. The circuit provides good dynamic range, controllable output, and reasonable accuracy and it is insensitive to temperature variations. The circuit operates with $\pm $0.5 V supply, consumes 0.3 $\mu $W, and has a -3 dB frequency of 2.4 MHz. The functionality of the proposed design is confirmed using Tanner T-spice with 0.35 $\mu $m CMOS process.


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 …


A Monte Carlo-Based Poisson's Equation Solver Parallelized With Coarray Fortran, Nevsan Şengi̇l, Özgür Tümüklü, Mehmet Cevdet Çelenli̇gi̇l Jan 2016

A Monte Carlo-Based Poisson's Equation Solver Parallelized With Coarray Fortran, Nevsan Şengi̇l, Özgür Tümüklü, Mehmet Cevdet Çelenli̇gi̇l

Turkish Journal of Electrical Engineering and Computer Sciences

Poisson's equation is found in many scientific problems, such as heat transfer and electric field calculations. Although many different techniques are involved in solving Poisson's equation, we focused on the Monte Carlo method (MCM). We preferred the MCM not only because of its simple algorithm but also for its excellent parallel efficiency. Parallelization is one of the most effective techniques for reducing computation time. Among many parallelization paradigms, such as OpenMP (open multiprocessing), MPI (message passing interface), and PGAS (partitioned global address space), we adopted the PGAS-based Coarray Fortran (CAF). In this paper, we demonstrated that parallelization of Poisson's equation …


Novel Version Of Bi Input-Extended Kalman Filter For Speed-Sensorless Control Of Induction Motors With Estimations Of Rotor And Stator Resistances, Load Torque, And Inertia, Emrah Zerdali̇, Murat Barut Jan 2016

Novel Version Of Bi Input-Extended Kalman Filter For Speed-Sensorless Control Of Induction Motors With Estimations Of Rotor And Stator Resistances, Load Torque, And Inertia, Emrah Zerdali̇, Murat Barut

Turkish Journal of Electrical Engineering and Computer Sciences

This study aims to develop a novel version of bi input-extended Kalman filter (BI-EKF)-based estimation technique in order to increase the number of state and parameter estimations required for speed-sensorless direct vector control (DVC) systems, which perform velocity and position controls of induction motors (IMs). For this purpose, all states required for the speed-sensorless DVC systems, besides the stator resistance $R_{s} $, the rotor resistance $R_{r}$, the load torque $t_{L}$ including the viscous friction term, and the reciprocal of total inertia $1/j_{T}$, are simultaneously estimated by the novel BI-EKF algorithm using the measured phase currents and voltages. The effectiveness of …


Optimal Placing Of Pmus In A Constrained Grid: An Approach, Jyoti Bhonsle, Anjali Junghare Jan 2016

Optimal Placing Of Pmus In A Constrained Grid: An Approach, Jyoti Bhonsle, Anjali Junghare

Turkish Journal of Electrical Engineering and Computer Sciences

Synchronized phasor measurement units (PMUs) are replacing conventional measuring meters in modern power networks. The paradigm of grid monitoring has shifted to a wider area. This offers better monitoring, protection, and control of the overall power grid. This paper presents an approach for optimal placing of PMUs in constrained power grids using the binary integer programming technique. The proposed approach deals with four constraints: 1) observability of network, two cases of fully observable and partially observable networks are investigated; 2) conventional measurements, three cases of zero injection bus and injection measurement, conventional power flow measurement, and both injection and power …


Channel Measurement And Time Dispersion Analysis For Outdoor Mobile Ultrawideband Environment, Solomon Nunoo, Uche Chude-Okonkwo, Razali Ngah, Chollette Chude-Olisah, Yasser Zahedi Jan 2016

Channel Measurement And Time Dispersion Analysis For Outdoor Mobile Ultrawideband Environment, Solomon Nunoo, Uche Chude-Okonkwo, Razali Ngah, Chollette Chude-Olisah, Yasser Zahedi

Turkish Journal of Electrical Engineering and Computer Sciences

Ultrawideband (UWB) technology offers short-range high-data transmission rates. Most researchers in recent times have focused on indoor UWB channel measurements and in instances where outdoor cases were reported, they focused on static scenarios. This paper reports on mobile outdoor channel measurements typical of roadway and recreation park Infostation scenarios. It also chronicles the delay spread as well as channel stationarity analysis of the measurement data. We carried out measurements in the 3.1-5.3 GHz frequency range in various line-of-sight scenarios. The results of this research show that the delay spread values generally decrease with increasing mobile speed. Additionally, the degree of …


The Self-Adaptive Alternating Direction Method For The Multiarea Economic Dispatch Problem, Yaming Ren, Shumin Fei, Haikun Wei Jan 2016

The Self-Adaptive Alternating Direction Method For The Multiarea Economic Dispatch Problem, Yaming Ren, Shumin Fei, Haikun Wei

Turkish Journal of Electrical Engineering and Computer Sciences

The alternating direction method has been used widely in the power systems field for solving the multiarea dispatch problem. However, experience with applications has shown that the convergence rate of the alternating direction method depends significantly on the selection of the penalty parameter of the linear consistency constraint. Typically, it is difficult to obtain the optimal penalty parameter in advance. In this paper, for the purpose of solving this problem, we propose centralized and distributed self-adaptive penalty parameter strategies that allow the value of the penalty parameter to increase or decrease based on the information from each iteration. Simulation results …


A Problem Approximation Surrogate Model (Pasm) For Fitness Approximation In Optimizing The Quantization Table For The Jpeg Baseline Algorithm, Vinoth Kumar Balasubramanian, Karpagam Manavalan Jan 2016

A Problem Approximation Surrogate Model (Pasm) For Fitness Approximation In Optimizing The Quantization Table For The Jpeg Baseline Algorithm, Vinoth Kumar Balasubramanian, Karpagam Manavalan

Turkish Journal of Electrical Engineering and Computer Sciences

The quantization table in the baseline Joint Photographic Experts Group (JPEG) algorithm plays an important role in compression/quality trade-off. Hence the detection of the optimal quantization table is viewed as an optimization problem. The genetic algorithm (GA) is an attractive optimization tool by many researchers for this application due to its ability in dealing with complex problems. In spite of its advantages, the GA requires more computation time to achieve an optimal solution if it has an expensive fitness evaluation. This paper proposes a problem approximation surrogate model (PASM) for fitness approximation to assist the GA in optimizing the quantization …


A 0.18-$\Mu $M Current-Mode Asynchronous Sigma-Delta Modulator Design, Balkir Kayaalti, Ömer Ceri̇d, Günhan Dündar Jan 2016

A 0.18-$\Mu $M Current-Mode Asynchronous Sigma-Delta Modulator Design, Balkir Kayaalti, Ömer Ceri̇d, Günhan Dündar

Turkish Journal of Electrical Engineering and Computer Sciences

In this study a first-order asynchronous current-mode sigma-delta modulator has been designed and simulated. Asynchronous sigma-delta modulators eliminate the continuous time sigma-delta modulator's problem of signal-to-noise ratio degradation due to clock jitter by avoiding the use of sampling in the modulator loop. Moreover, they provide a higher signal-to-noise ratio even with low-order filters. Thus, considerably low power consumption can be achieved with fewer circuit components. The current mode enables designers to scale the circuits according to different supply voltages and operating currents. In this work, design steps for an asynchronous sigma-delta modulator have been given taking into account its ideal …


Direct Radio Frequency Sampling Methodology For Multiple Signals In An Energy-Sparse Spectrum, Tauqeer Ahmed, Noor Muhammad Khan Jan 2016

Direct Radio Frequency Sampling Methodology For Multiple Signals In An Energy-Sparse Spectrum, Tauqeer Ahmed, Noor Muhammad Khan

Turkish Journal of Electrical Engineering and Computer Sciences

In software defined radio (SDR) systems, it is desirable to down-convert multiple RF signals simultaneously by placing an analogue-to-digital converter (ADC) as near the antenna as possible. Radio frequency (RF) subsampling is one of the established methodologies used by radio receivers to directly down-convert and digitize RF signals. In this paper, we propose a novel direct RF sampling method to find out the minimum sampling frequency for an evenly spaced spectrum comprising multiband RF signals. However, it can also be applied to nonuniformly spaced signals with slight modification. The proposed methodology describes a set of rules to achieve the lowest …


Fpga Implementation Of A Hevc Deblocking Filter For Fast Processing Of Super High Resolution Applications, Awais Khan, Gulistan Raja Jan 2016

Fpga Implementation Of A Hevc Deblocking Filter For Fast Processing Of Super High Resolution Applications, Awais Khan, Gulistan Raja

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes the architecture of a deblocking filter (DBF) that removes blocking artifacts in new emerging High Efficiency Video Coding (HEVC). A parallel architecture for both normal and strong filtering modes of HEVC is proposed. Distributed memories and two data paths increase the parallelism and make the architecture more efficient. The proposed architecture is described by Verilog and implemented on FPGA. The architecture can realize real time to compute 4K UHD video at 30 fps by using 46.65 million clocks with total equivalent gate count of 46K. The maximum delay time for output to come after taking input for …


Variation Of Photovoltaic System Performance Due To Climatic And Geographical Conditions In Turkey, Betül Bektaş Eki̇ci̇ Jan 2016

Variation Of Photovoltaic System Performance Due To Climatic And Geographical Conditions In Turkey, Betül Bektaş Eki̇ci̇

Turkish Journal of Electrical Engineering and Computer Sciences

This study focuses on the effect of climatic and geographical factors on the performance of photovoltaic systems. For this purpose, 4 different cities (Antalya, İstanbul, Elazığ, and Erzurum) from different climatic zones according to TS 825 Thermal Insulation Requirements in Buildings were selected. The monthly average global and diffuse solar radiation of the cities was calculated numerically with the long-term sunshine duration data (between 1990 and 2012) taken from the Turkish State Meteorological Service. The yearly electric energy generated by the grid-connected photovoltaic systems assumed to be located on the flat roofs of building samples were calculated for each of …


Sinusoidal Current Injection Based On A Line-Commutated Inverter For Single-Phase Grid-Connected Renewable Energy Sources, Murat Ünlü, Sabri̇ Çamur, Ersoy Beşer, Bi̇rol Ari̇foğlu Jan 2016

Sinusoidal Current Injection Based On A Line-Commutated Inverter For Single-Phase Grid-Connected Renewable Energy Sources, Murat Ünlü, Sabri̇ Çamur, Ersoy Beşer, Bi̇rol Ari̇foğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new power electronic interface based line-commutated inverter (LCI) for dc power injection to the grid. The proposed system involves a simple power electronic converter and controller interface using a single-phase LCI. The controller has been developed that can inject a high quality sinusoidal current to the utility grid from the dc source. By this means, ac side harmonic filters and the harmonic cancellation technique are eliminated. The proposed system facilitates controlling the injected current with a controllable power factor of operation. The complete system has been modeled in MATLAB/Simulink and tested experimentally with the laboratory prototype. …


A New Method For Active Power Factor Correction Using A Dual-Purpose Inverter In A Flyback Converter, Seyed Mohsen Hoseini, Seyed Mohammad Sadeghzadeh, Yousef Alinejad Beromi Jan 2016

A New Method For Active Power Factor Correction Using A Dual-Purpose Inverter In A Flyback Converter, Seyed Mohsen Hoseini, Seyed Mohammad Sadeghzadeh, Yousef Alinejad Beromi

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new active method for power factor correction (PFC) is presented and applied to a single-stage AC/DC flyback converter to reduce the total harmonic distortion of the input current, achieve better power factor compensation, and improve converter reliability. The proposed circuit consists of a low-power portable dual-purpose inverter that can work in 2 main modes. In the normal mode of converter operation, the PFC circuit operates as an active harmonic filter compensator. In the second mode, which occurs in converter outage conditions, the inverter behaves as a sinusoidal backup voltage power supply for the converter by using …


Firefly Algorithm With Multiple Workers For The Power System Unit Commitment Problem, Banumalar Koodalsamy, Manikandan Bairavan Veerayan, Chandrasekaran Koodalsamy, Sishaj Pulikottil Simon Jan 2016

Firefly Algorithm With Multiple Workers For The Power System Unit Commitment Problem, Banumalar Koodalsamy, Manikandan Bairavan Veerayan, Chandrasekaran Koodalsamy, Sishaj Pulikottil Simon

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes an improved firefly (FF) algorithm with multiple workers for solving the unit commitment (UC) problem of power systems. The UC problem is a combinatorial optimization problem that can be posed as minimizing a quadratic objective function under system and unit constraints. Nowadays, highly developed computer systems are available in plenty, and proper utilization of these systems will reduce the time and complexity of combinatorial optimization problems with large numbers of generating units. Here, multiple workers are assigned to solve a UC problem as well as the subproblem, namely economic dispatch (ED) in distributed memory models. The proposed …


A Comparative Analysis Of Wind Speed Probability Distributions For Wind Power Assessment Of Four Sites, Vaishali Sohoni, Shivcharan Gupta, Rajeshkumar Nema Jan 2016

A Comparative Analysis Of Wind Speed Probability Distributions For Wind Power Assessment Of Four Sites, Vaishali Sohoni, Shivcharan Gupta, Rajeshkumar Nema

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, five probability distribution functions are employed to fit the wind speed data from four different geographical locations in the world in a preliminary analysis. These wind regimes are selected such that they represent wide ranges of mean wind speeds and present different shapes of wind speed histograms. The wind speed data used for modelling consist of 10-min average SCADA data from three US wind farms and hourly averages recorded at a weather station in Canada. Out of the five, three functions, namely Weibull, Rayleigh, and gamma, which provide a better fit to the data, are selected to …


Modeling, Control, And Power Management For A Grid-Integrated Photo Voltaic, Fuel Cell, And Wind Hybrid System, Ezhilarasan Ganesan, Subhranhsu Sekhar Dash, Chinmaya Samanta Jan 2016

Modeling, Control, And Power Management For A Grid-Integrated Photo Voltaic, Fuel Cell, And Wind Hybrid System, Ezhilarasan Ganesan, Subhranhsu Sekhar Dash, Chinmaya Samanta

Turkish Journal of Electrical Engineering and Computer Sciences

Power management in a grid-integrated power system consisting of distributed renewable energy sources is necessitated by ever-increasing energy consumption, the high cost of production, the limited resource of fossil fuel, and the worsening global environment. Wind and solar power generation are two of the most promising renewable power generation technologies. The growth of wind and photovoltaic (PV) power generation systems has exceeded the most optimistic levels of expectations. Fuel cells (FCs) also have great potential to be green power sources of the future because of the many merits they have, such as high efficiency and zero or low emission of …


Iec 61850-Based Islanding Detection And Load Shedding In Substation Automation Systems, Cagil Ozansoy, Keith Frearson Jan 2016

Iec 61850-Based Islanding Detection And Load Shedding In Substation Automation Systems, Cagil Ozansoy, Keith Frearson

Turkish Journal of Electrical Engineering and Computer Sciences

Distributed generation (DG) systems are common within industrial plants and allow continuity of supply to critical loads. In cases when DG cannot support the entire system load, islanding detection (ID) and load shedding (LS) schemes are required. Such an automation scheme serves to monitor the connection to the grid and generation-load imbalance, and it controls the load shedding process. The design of such schemes has undergone significant revolution from electromechanical relays and PLC systems to the use of communications-enabled intelligent electronic devices. This paper discusses the design of an IEC 61850-based smart ID and LS scheme using a complete system …


Double Bow-Tie Fss For X-Band And K$_U$-Band Operations With Its Parametric Analyses, Selma Çi̇ğdem, Ci̇han Tunca, Sultan Can, Asim Egemen Yilmaz Jan 2016

Double Bow-Tie Fss For X-Band And K$_U$-Band Operations With Its Parametric Analyses, Selma Çi̇ğdem, Ci̇han Tunca, Sultan Can, Asim Egemen Yilmaz

Turkish Journal of Electrical Engineering and Computer Sciences

This paper demonstrates double bow-tie frequency selective surface (FSS) geometry for X-band applications with a bandwidth value of 1.82 GHz and K$_u$-band applications with a bandwidth value of 3.44 GHz. Throughout this study, parametric analyses of the proposed structure are also performed. Alterations in the reflection and transmission characteristics of this specially designed structure by virtue of defined variables are analyzed. Those variables are determined by considering the geometric and material properties of the proposed structure. To analyze the reflection and transmission coefficients, two different simulators, namely the High Frequency Structure Simulator (ANSYS HFSS), which is based on the finite …


Leveraging Linked Open Data Information Extraction For Data Mining Applications, Rajesh Mahule, Om Prakash Vyas Jan 2016

Leveraging Linked Open Data Information Extraction For Data Mining Applications, Rajesh Mahule, Om Prakash Vyas

Turkish Journal of Electrical Engineering and Computer Sciences

The linked open data cloud, with a huge volume of data from heterogeneous and interlinked datasets, has turned the Web into a large data store. It has attracted the attention of both developers and researchers in the last few years, opening up new dimensions in machine learning and knowledge discovery. Information extraction procedures for these processes use different approaches, e.g., template-based, federated to multiple sources, fixed depth link traversal, etc. They are limited by problems in online access to datasets' SPARQL endpoints, such as servers being down for maintenance, bandwidth narrowing, limited numbers of access points to datasets in particular …


Applying Metaheuristic Optimization Methods To Design Novel Adaptive Pi-Type Fuzzy Logic Controllers For Load-Frequency Control In A Large-Scale Power Grid, Thimaiphuong Dao, Yaonan Wang, Ngockhoat Nguyen Jan 2016

Applying Metaheuristic Optimization Methods To Design Novel Adaptive Pi-Type Fuzzy Logic Controllers For Load-Frequency Control In A Large-Scale Power Grid, Thimaiphuong Dao, Yaonan Wang, Ngockhoat Nguyen

Turkish Journal of Electrical Engineering and Computer Sciences

Due to the complexity and diversity of large-scale power systems in practice, designing load-frequency control (LFC) strategies against load variations faces big challenges to ensure the stability and economy of the network. The focus of this paper is to design a novel adaptive PI-type fuzzy logic (FL)-based LFC architecture for solving the LFC problem in such an interconnected electric power grid. Applying 2 biologically inspired optimization methods, namely particle swarm optimization method and a genetic algorithm, the membership functions and rule base of a basic PI-type FL model were parameterized and optimized simultaneously and successfully. An online self-tuning method was …


Speech Recognition Using Ann And Predator-Influenced Civilized Swarm Optimization Algorithm, Teena Mittal, Rajendra Kumar Sharma Jan 2016

Speech Recognition Using Ann And Predator-Influenced Civilized Swarm Optimization Algorithm, Teena Mittal, Rajendra Kumar Sharma

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a hybrid optimization technique, predator-influenced civilized swarm optimization, by integrating civilized swarm optimization (CSO) and predator-prey optimization (PPO) techniques. CSO is the integration of the attributes of particle swarm optimization and a society civilization algorithm (SCA). In the SCA, the swarm is divided into a few societies, and each society has its own society leader (SL); other individuals of the society are termed society members. The combination of all such societies forms a civilization, and the best-performing SL becomes the civilization leader (CL). In CSO, SLs and members update their positions through the guidance of their own …


Balancing Exploration And Exploitation By Using Sequential Execution Cooperation Between Artificial Bee Colony And Migrating Birds Optimization Algorithms, Hasan Makas, Nejat Yumuşak Jan 2016

Balancing Exploration And Exploitation By Using Sequential Execution Cooperation Between Artificial Bee Colony And Migrating Birds Optimization Algorithms, Hasan Makas, Nejat Yumuşak

Turkish Journal of Electrical Engineering and Computer Sciences

The artificial bee colony (ABC) algorithm is a metaheuristic search method inspired by bees' foraging behaviour. With its global search ability in scout bee phase, it can easily escape from local optimum traps in the problem space. Therefore, it is good at exploration. The migrating birds optimization (MBO) algorithm is another recent metaheuristic search method. It simulates birds' V flight formation, which minimizes energy consumption during flight. The MBO algorithm achieves a good convergence to the global optimum by using its own unique benefit mechanism. That is, it has a good exploitation capability. This paper aimed to combine the good …