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Full-Text Articles in Computer Sciences

A Simple Approach To Extract The Unknown Parameters Of Pv Modules, Ahmed Hussein Jan 2017

A Simple Approach To Extract The Unknown Parameters Of Pv Modules, Ahmed Hussein

Turkish Journal of Electrical Engineering and Computer Sciences

A simple and accurate technique to compute essential parameters needed for electrical characterization of photovoltaic (PV) modules is proposed. A single-diode model of PV modules, including those with series and shunt resistances, is considered accurate and simple. However, PV module datasheets provided by manufacturers provide current-voltage ($I$-$V)$ characteristics as well as the values of selected parameters at standard test conditions (STC), i.e. solar radiation of 1000 W/m$^{2}$, air temperature of 25 $^{\circ}$C, and air mass AM = 1.5. Consequently, important parameters such as series resistance ($R_{s})$, shunt resistance ($R_{sh})$, photocurrent ($I_{ph})$, and diode reverse-saturation current ($I_{o})$ are not provided by …


A Novel Microstrip Diplexer Design With Tunable Bandwidths And Switchable Channels For 4.5g Applications, Ali̇ Kürşad Görür, Pinar Öztürk Özdemi̇r, Eli̇f Güntürkün Şahi̇n, Ceyhun Karpuz Jan 2017

A Novel Microstrip Diplexer Design With Tunable Bandwidths And Switchable Channels For 4.5g Applications, Ali̇ Kürşad Görür, Pinar Öztürk Özdemi̇r, Eli̇f Güntürkün Şahi̇n, Ceyhun Karpuz

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a novel microstrip diplexer with tunable bandwidths and switchable channels is presented by using dual-mode square loop resonators (DMSLRs). Two resonators at different electrical lengths are coupled to input and output ports with lumped capacitors, and the isolation between the output ports is optimized by means of these capacitors. In order to obtain tunable bandwidth in each channel, varactor diodes are located at the orthogonal corners of the proposed resonators. In addition, the proposed resonators have reference patch elements at the lateral arms to provide convenience of varactor diode capacitances, such as perturbation elements. Depending on the …


Analysis And Design Of An Invisibility Cloak Based On Transformation Optics At Microwave Frequencies, Maryam Bayati, Masood Omoomi Jan 2017

Analysis And Design Of An Invisibility Cloak Based On Transformation Optics At Microwave Frequencies, Maryam Bayati, Masood Omoomi

Turkish Journal of Electrical Engineering and Computer Sciences

Invisibility cloaks can be constructed with electromagnetic metamaterials. In this paper, structural metamaterials are used to design an invisibility cloak. To this end, transformation optics is used to design electromagnetic parameters. These parameters are selected so that when we excite the cloak its presence does not perturb radiated fields. Therefore, we formulate the electric field both at the inner and outer parts of the cloak, when the excitation source is placed both inside and outside, and we show that the scattered fields will be suppressed due to its presence. Finally, simulation results verify that the invisibility cloak is well designed …


Method Of Singular Integral Equations In Diffraction By Semi-Infinite Grating: $H$-Polarization Case, Mstislav Kaliberda, Leonid Lytvynenko, Sergey Pogarsky Jan 2017

Method Of Singular Integral Equations In Diffraction By Semi-Infinite Grating: $H$-Polarization Case, Mstislav Kaliberda, Leonid Lytvynenko, Sergey Pogarsky

Turkish Journal of Electrical Engineering and Computer Sciences

Diffraction of the $H$-polarized electromagnetic wave by a semi-infinite strip grating is considered. The scattered field is represented as a superposition of the field induced by the currents on the strips of an infinite periodic grating and the field induced by the correction current excited due to end of the grating. Singular integral equations with additional conditions for infinite and semi-infinite periodic gratings are obtained. The current on the strips and spectral function of scattered field are expressed in terms of the solution of these equations. Numerical results for the near and far fields distribution are represented.


Data Clustering Using Seed Disperser Ant Algorithm, Wen Liang Chang, Jeevan Kanesan, Anand Jayant Kulkarni, Harikrishnan Ramiah Jan 2017

Data Clustering Using Seed Disperser Ant Algorithm, Wen Liang Chang, Jeevan Kanesan, Anand Jayant Kulkarni, Harikrishnan Ramiah

Turkish Journal of Electrical Engineering and Computer Sciences

Nature-inspired optimization algorithms have become popular in the past decade. They have been applied to solve various kinds of problems. Among these would be data clustering, which has become popular in data mining in recent times due to the data explosion. In the last decade, many metaheuristic algorithms have been used to obtain improved data clustering optimization for solving data mining problems. In this paper, we applied the seed disperser ant algorithm (SDAA), which mimics the evolution of an Aphaenogaster senilis ant colony, and we introduced a modified SDAA that is a hybrid of K-means and SDAA for solving data …


An Adaptive Clustering Segmentation Algorithm Based On Fcm, Jun Yang, Yun-Sheng Ke, Mao-Zheng Wang Jan 2017

An Adaptive Clustering Segmentation Algorithm Based On Fcm, Jun Yang, Yun-Sheng Ke, Mao-Zheng Wang

Turkish Journal of Electrical Engineering and Computer Sciences

The cluster number and the initial clustering centers must be reasonably set before the analysis of clustering in most cases. Traditional clustering segmentation algorithms have many shortcomings, such as high reliance on the specially established initial clustering center, tendency to fall into the local maximum point, and poor performance with multithreshold values. To overcome these defects, an adaptive fuzzy C-means segmentation algorithm based on a histogram (AFCMH), which synthesizes both main peaks of the histogram and optimized Otsu criterion, is proposed. First, the main peaks of the histogram are chosen by operations like histogram smoothing, merging of adjacent peaks, and …


Koch Fractal-Based Hexagonal Patch Antenna For Circular Polarization, Manisha Gupta, Vinita Mathur Jan 2017

Koch Fractal-Based Hexagonal Patch Antenna For Circular Polarization, Manisha Gupta, Vinita Mathur

Turkish Journal of Electrical Engineering and Computer Sciences

The design and performance of an inset feed modified hexagonal patch antenna for possible applications in ultrawideband communication systems is reported. The inset feed hexagonal patch antenna is modified by introducing a fractal up to the second iteration. A right-angled isosceles triangular microstrip antenna is used in the Koch fractal structure on the edges. The proposed antenna is a combination of two standard fractal structures, i.e. Sierpinski and Koch. A rectangular defect in the ground has also been done. The antenna is simulated by applying CST Microwave Studio simulation software. The results are verified by fabricating the antenna and tested …


A New Video Forgery Detection Approach Based On Forgery Line, Işilay Bozkurt, Mustafa Hakan Bozkurt, Güzi̇n Ulutaş Jan 2017

A New Video Forgery Detection Approach Based On Forgery Line, Işilay Bozkurt, Mustafa Hakan Bozkurt, Güzi̇n Ulutaş

Turkish Journal of Electrical Engineering and Computer Sciences

In recent years, we have continually encountered multimedia files in daily life, as evidence in courts, medical records in hospitals, etc. Many multimedia-editing software tools have been developed in parallel to the widespread usage of multimedia files. Thus, forgery operations can be committed by anyone with this software, even if s/he does not have any skill in this field. Authentication of the originality of multimedia files has recently become a popular topic. In this work, we propose a new video forgery detection approach to detect forged frames with better execution and detection capability. Features are extracted from the frames and …


Breast-Region Segmentation In Mri Using Chest Region Atlas And Svm, Aida Fooladivanda, Shahriar Baradaran Shokouhi, Nasrin Ahmadinejad Jan 2017

Breast-Region Segmentation In Mri Using Chest Region Atlas And Svm, Aida Fooladivanda, Shahriar Baradaran Shokouhi, Nasrin Ahmadinejad

Turkish Journal of Electrical Engineering and Computer Sciences

An important step for computerized analysis of breast magnetic resonance imaging (MRI) is segmentation of the breast region. Due to the similar signal intensity of fibroglandular tissue and the chest wall, the segmentation process is difficult for breasts with fibroglandular tissue connected to the chest wall. In order to overcome this challenge, a new framework is presented that relies on a chest region atlas. The proposed method first detects the approximated breast-chest wall boundary using an intensity-based operation. A support vector machine (SVM) then determines the connectivity of fibroglandular tissue to the chest wall by the extracted features from the …


Reactive Power Optimization In A Power System Network Through Metaheuristic Algorithms, Chandragupta Mauryan Kuppamuthu Sivalingam, Subramanian Ramachandran, Purrnimaa Shiva Sakthi Rajamani Jan 2017

Reactive Power Optimization In A Power System Network Through Metaheuristic Algorithms, Chandragupta Mauryan Kuppamuthu Sivalingam, Subramanian Ramachandran, Purrnimaa Shiva Sakthi Rajamani

Turkish Journal of Electrical Engineering and Computer Sciences

Reactive power optimization (RPO) in a power system is a rudimentary necessity for the reduction of the loss of power. For the requirement of a unity power factor in the RPO system, the reduction of the system losses is ensured. The pivotal requirements of a power system are inclusive of a perfect compensation technique and methodology for stable reactive power compensation. The proposed concept in this paper utilizes the different reactive power optimization algorithms and performs a comparison. The process is accomplished by the use of IEEE 6-bus, 14-bus, and 30-bus systems to test the optimization technique. The conclusive information …


A Modified Two-Degree Of Freedom-Internal Model Control Configuration For Load Frequency Control Of A Single Area Power System, Bheem Sonker, Deepak Kumar, Paulson Samuel Jan 2017

A Modified Two-Degree Of Freedom-Internal Model Control Configuration For Load Frequency Control Of A Single Area Power System, Bheem Sonker, Deepak Kumar, Paulson Samuel

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose a modified two degree-of-freedom internal model control structure, with dual feedback loop configuration for the load frequency control problem of a single-area power system. Our main objective is to achieve better transient and steady state performance. The predictive model of the proposed configuration is derived through the stability equation method, which preserves the stability of the model. The proposed scheme is simulated for a single-area power system with nonreheated turbine and 50% parametric uncertainty. It is observed from the responses and the performance indices that the proposed control configuration gives better results compared to well-known …


Development And Experimental Evaluation Of A 3d Ultra-Wideband Localization System, Ali Muqaibel Jan 2017

Development And Experimental Evaluation Of A 3d Ultra-Wideband Localization System, Ali Muqaibel

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an ultra-wideband (UWB) synthetic aperture radar system that can perform 3D localization of objects is implemented. The system consists of a moving platform that positions two UWB horn antennas. The 3D image construction is performed using the delay-sum beamforming algorithm. Experiments were performed using two data acquisition techniques, namely, background measurements technique and change detection. The former can be used for imaging stationary targets while the latter is applicable for moving objects. At different distances and orientations from the antennas, various targets were imaged. Through-wall imaging was also considered. The system is augmented with a graphical user …


Two-Bit Transform Using Local Binary Pattern Method For Low-Complexity Block Motion Estimation, Aysun Taşyapi Çelebi̇ Jan 2017

Two-Bit Transform Using Local Binary Pattern Method For Low-Complexity Block Motion Estimation, Aysun Taşyapi Çelebi̇

Turkish Journal of Electrical Engineering and Computer Sciences

Low bit-depth representation-based motion estimation approaches have been drawing considerable attention recently, mainly because of their small hardware footprint. In this paper, a new two-bit transform using a local binary pattern (LBP) for low-complexity motion estimation is proposed. The proposed approach utilizes the LBP method to obtain two-bit representations of video frames in the binarization process. Video frames are transformed into their low bit-depth representations by the LBP and then a motion estimation process is carried out using these binary frames. A Boolean exclusive-OR operation is used to calculate the number of nonmatching points metric instead of the conventional sum …


Design Optimization Of Distribution Transformers With Nature-Inspired Metaheuristics: A Comparative Analysis, Levent Alhan, Nejat Yumuşak Jan 2017

Design Optimization Of Distribution Transformers With Nature-Inspired Metaheuristics: A Comparative Analysis, Levent Alhan, Nejat Yumuşak

Turkish Journal of Electrical Engineering and Computer Sciences

Many economies in the world have adopted energy-efficiency requirements or incentive programs mandating or promoting the use of energy-efficient transformers. On the other hand, increases in transformer efficiency are subject to increases in transformer weight and size, sometimes as much as 50% or more. The transformer manufacturing industry is therefore faced with the challenge to develop truly optimum designs. Transformer design optimization (TDO) is a mixed-integer nonlinear programming problem having a complex and discontinuous objective function and constraints, with the objective of detailed calculation of the characteristics of a transformer based on national and/or international standards and transformer user requirements, …


On The Performance Of Newsworthy Meta-Heuristic Algorithms Based On Point Of View Fuzzy Modelling, Ci̇han Karakuzu Jan 2017

On The Performance Of Newsworthy Meta-Heuristic Algorithms Based On Point Of View Fuzzy Modelling, Ci̇han Karakuzu

Turkish Journal of Electrical Engineering and Computer Sciences

Heuristic algorithms are used for optimizing a large diversity of engineering problems. In this study, the performance of six commonly used and cited meta-heuristic algorithms (MhAs) is compared based on point of view fuzzy modelling. In this study, the simplest version of MhAs is specifically used to observe and evaluate their natural optimization performances. For the comparisons, dynamic system modelling using a neuro-fuzzy system (NFS) was studied. Obtained results were evaluated based on commonly used statistical metrics, and then each algorithm was ranked according to these metrics. Based on the computed average ranks, the best MhA among the six MhAs …


Power Search Algorithm (Psa) For Combined Economic-Emission Dispatch Problems Considering Valve Point Effects In Economic Load Dispatch, Prakash Arumugam, Ravichandran Coimbatore Subramanian Jan 2017

Power Search Algorithm (Psa) For Combined Economic-Emission Dispatch Problems Considering Valve Point Effects In Economic Load Dispatch, Prakash Arumugam, Ravichandran Coimbatore Subramanian

Turkish Journal of Electrical Engineering and Computer Sciences

Economic load dispatch has become the prime and major concern in power system networks. Use of nonrenewable fuels as an input to power systems results in toxic gas emission and depletion of resources for future generations. Allocation of optimal power to generators serves as a solution to this issue. The suggested power search algorithm (PSA) is a novel solution for the reduction of the fuel cost, emissions, and power loss. This algorithm searches its solution inside the search space from minimum to maximum in case of forward search. The global optimum solution is obtained with much less execution time compared …


Neoteric Chaff Generation Method Of Fingerprint Fuzzy Vault, Nancy Singla, Sanjeev Sofat, Manvjeet Kaur Jan 2017

Neoteric Chaff Generation Method Of Fingerprint Fuzzy Vault, Nancy Singla, Sanjeev Sofat, Manvjeet Kaur

Turkish Journal of Electrical Engineering and Computer Sciences

Authentication using biometrics has an edge over traditional authentication mechanisms. Fuzzy vault is an eminent biometric cryptosystem technique that aims to protect a secret using a biometric template. Authorized users can, however, access the secret by providing the valid biometric. In a fuzzy vault, noise is incorporated in the form of chaff points in order to increase the security. While implementing fuzzy vault schemes in real scenarios, the most critical but computing-intensive and time-consuming task is chaff generation. In this paper, a neoteric method for chaff generation is proposed, which is less time-consuming in generating large numbers of chaff points.


A Cooperative Neural Network Approach For Enhancing Data Traffic Prediction, Salihu Aish Abdulkarim, Isa Abdullahi Lawal Jan 2017

A Cooperative Neural Network Approach For Enhancing Data Traffic Prediction, Salihu Aish Abdulkarim, Isa Abdullahi Lawal

Turkish Journal of Electrical Engineering and Computer Sciences

This paper addresses the problem of learning a regression model for the prediction of data traffic in a cellular network. We proposed a cooperative learning strategy that involves two Jordan recurrent neural networks (JNNs) trained using the firefly algorithm (FFA) and resilient backpropagation algorithm (Rprop), respectively. While the cooperative capability of the learning process ensures the effectiveness of the regression model, the recurrent nature of the neural networks allows the model to handle temporally evolving data. Experiments were carried out to evaluate the proposed approach using high-speed downlink packet access data demand and throughput measurements collected from different cell sites …


Proposing A New Clustering Method To Detect Phishing Websites, Morteza Arab, Mohammad Karim Sohrabi Jan 2017

Proposing A New Clustering Method To Detect Phishing Websites, Morteza Arab, Mohammad Karim Sohrabi

Turkish Journal of Electrical Engineering and Computer Sciences

Phishing websites are fake ones that are developed by ill-intentioned people to imitate real and legal websites. Most of these types of web pages have high visual similarities to hustle the victims. The victims of phishing websites may give their bank accounts, passwords, credit card numbers, and other important information to the designers and owners of phishing websites. The increasing number of phishing websites has become a great challenge in e-business in general and in electronic banking specifically. In the present study, a novel framework based on model-based clustering is introduced to fight against phishing websites. First, a model is …


A Probabilistic Scenario-Based Framework For Solving Stochastic Dynamic Economic Emission Dispatch With Unit Commitment, Yachao Zhang, Kaipei Liu, Xiaobing Liao, Liang Qin, Xueli An Jan 2017

A Probabilistic Scenario-Based Framework For Solving Stochastic Dynamic Economic Emission Dispatch With Unit Commitment, Yachao Zhang, Kaipei Liu, Xiaobing Liao, Liang Qin, Xueli An

Turkish Journal of Electrical Engineering and Computer Sciences

This paper establishes a probabilistic scenario-based framework for the stochastic dynamic economic emission dispatch with unit commitment (SDEED-UC) problem, by considering wind power integration. The scenario generation and reduction method are implemented to describe wind power uncertainty. Accordingly, each wind power scenario is analyzed separately to determine the on/off status of the units. As for a predetermined significance level, the UC scheduling solution can be obtained with a probabilistic point of view, considering all the original scenarios. Then the SDEED problem is converted into a number of deterministic scheduling problems. For each scenario in the reduced set, an enhanced multiobjective …


A Novel Empirical Sir-To-Cqi Mapping Rule For Dc-Hsdpa Systems, Çeti̇n Kurnaz, Begüm Korunur Engi̇z, Murat Oğuz Esenalp Jan 2017

A Novel Empirical Sir-To-Cqi Mapping Rule For Dc-Hsdpa Systems, Çeti̇n Kurnaz, Begüm Korunur Engi̇z, Murat Oğuz Esenalp

Turkish Journal of Electrical Engineering and Computer Sciences

This study aims to determine the mapping rule for signal-to-interference ratio (SIR) to channel quality indicator (CQI) based on DC-HSDPA real field measurements. The measurements were performed using the TEMS Investigation Tool at 85 different propagation mediums. The measurement results showed that the SIR-to-CQI mapping methods in the literature were insufficient to characterize actual radio environments; thus, proposal of a new empirical SIR-to-CQI mapping rule was aimed. This rule provides substantially better performance than the existing methods, and with this rule CQI can be generated from SIR with an accuracy of around 90% for DC-HSDPA systems.


Discovering The Relationships Between Yarn And Fabric Properties Using Association Rule Mining, Peli̇n Yildirim, Derya Bi̇rant, Tuba Alpyildiz Jan 2017

Discovering The Relationships Between Yarn And Fabric Properties Using Association Rule Mining, Peli̇n Yildirim, Derya Bi̇rant, Tuba Alpyildiz

Turkish Journal of Electrical Engineering and Computer Sciences

Investigation of the effects of yarn parameters on fabric quality and finding important parameters to achieve desired fabric properties are important issues for the design process with the aim to meet the needs of the textile industry and the consumer for complex and specific requirements of functionality. Despite many statistical and mathematical studies that predict and reveal specific properties of utilized yarn and fabric materials, a number of challenges continue to exist when evaluated in many perspectives, such as discovering complex relationships among material properties in data. Data mining plays an important role in discovering hidden patterns from fabric data …


A Random Number Generator For Lightweight Authentication Protocols: Xorshiftr+, Umut Can Çabuk, Ömer Aydin, Gökhan Dalkiliç Jan 2017

A Random Number Generator For Lightweight Authentication Protocols: Xorshiftr+, Umut Can Çabuk, Ömer Aydin, Gökhan Dalkiliç

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the results of research that aims to find a suitable, reliable, and lightweight pseudorandom number generator for constrained devices used in the Internet of things. Within the study, three reduced versions of the xorshift+ generator are built. They are tested using the TestU01 suite as well as the NIST suite to measure their ability to produce randomness and performance values along with some other existing generators. The best of our reduced variations according to our tests, called the xorshiftR+, demonstrated great suitability for lightweight devices considering its randomness, performance, and resource usage.


Stock Daily Return Prediction Using Expanded Features And Feature Selection, Hakan Gündüz, Zehra Çataltepe, Yusuf Yaslan Jan 2017

Stock Daily Return Prediction Using Expanded Features And Feature Selection, Hakan Gündüz, Zehra Çataltepe, Yusuf Yaslan

Turkish Journal of Electrical Engineering and Computer Sciences

Stock market prediction is a very noisy problem and the use of any additional information to increase accuracy is necessary. In this paper, for the stock daily return prediction problem, the set of features is expanded to include indicators not only for the stock to be predicted itself but also a set of other stocks and currencies. Afterwards, different feature selection and classification methods are utilized for prediction. The daily close returns of the 3 most traded stocks (GARAN, THYAO, and ISCTR) in Borsa İstanbul (BIST) are predicted using indicators computed on those stocks, indicators for all the other stocks …


An Improved Omthd Technique For An N-Level Cascaded Multilevel Inverter With Adjustable Dc Sources, Hamidreza Toodeji Jan 2017

An Improved Omthd Technique For An N-Level Cascaded Multilevel Inverter With Adjustable Dc Sources, Hamidreza Toodeji

Turkish Journal of Electrical Engineering and Computer Sciences

Optimal minimization of total harmonic distortion (OMTHD) and selective harmonic elimination (SHE) switching techniques are usually employed to reduce generated harmonics of multilevel inverters. In the former technique, the THD of waveform is reduced without elimination of any harmonic order and the latter, in contrast, eliminates selected harmonic orders. In this paper, the harmonic elimination ability of the SHE technique is added to OMTHD and an improved OMTHD technique is proposed for an n-level cascaded multilevel inverter with adjustable DC sources. The main novelty of this switching technique is elimination of some harmonic orders, beside THD minimization. Moreover, optimal DC …


On The Design Of Equal Division Single-Band Filtering Dividers With An Extended Transmission Line And Resistor As Isolation Elements, Zafar Bedar Khan, Huiling Zhao Jan 2017

On The Design Of Equal Division Single-Band Filtering Dividers With An Extended Transmission Line And Resistor As Isolation Elements, Zafar Bedar Khan, Huiling Zhao

Turkish Journal of Electrical Engineering and Computer Sciences

This paper introduces a new scheme for effective output port isolation and return loss in RF-filtering divider design. The proposed design incorporates an extended transmission line and a conventional resistor as isolation elements. The technique has a simpler microstrip circuit implementation when it comes to the integration of a single-band band-pass filter with a Wilkinson power divider to achieve simultaneous filtering-dividing action. It is established that if a band-pass filter with a certain fractional-bandwidth is matched to 70.7 $\Omega $, a transmission line section and isolation resistor are sufficient for achieving reasonable output port return loss and isolation in the …


New Patterson-Wiedemann Type Functions With 15 Variables In The Generalized Rotation-Symmetric Class, Selçuk Kavut Jan 2017

New Patterson-Wiedemann Type Functions With 15 Variables In The Generalized Rotation-Symmetric Class, Selçuk Kavut

Turkish Journal of Electrical Engineering and Computer Sciences

Recently, it was shown that there is no Boolean function on 15 variables with nonlinearity greater than 16276 in the class of functions that are invariant under the action of GF(2$^{3})^{\ast }\times GF(2^{5})^{\ast }$. In this study, we consider some important subsets of this class and perform an efficient enumeration of the 15-variable Patterson-Wiedemann (PW) type functions with nonlinearity greater than the bent concatenation bound 16256 in the generalized classes of both 3-RSBFs and 5-RSBFs for which the corresponding search spaces are 2$^{28.2}$ and 2$^{47.85}$, respectively. For the case of 3-RSBFs, we find that there are 32 functions with nonlinearity …


Effect Of Stator Permanent Magnet Thickness And Rotor Geometry Modifications On The Minimization Of Cogging Torque Of A Flux Reversal Machine, Bheeman Vidhya, Kandadai Nagaratnam Srinivas Jan 2017

Effect Of Stator Permanent Magnet Thickness And Rotor Geometry Modifications On The Minimization Of Cogging Torque Of A Flux Reversal Machine, Bheeman Vidhya, Kandadai Nagaratnam Srinivas

Turkish Journal of Electrical Engineering and Computer Sciences

This paper attempts to examine the effect of stator-rotor geometry on the minimization of cogging torque of a flux reversal generator (FRG). With respect to stator geometry, height (or thickness) of the permanent magnets of the stator poles was varied and cogging torque minimization was observed. With respect to rotor geometry, the following cases were considered: a) rotor pole arc variation and b) V-shaped punches on the rotor pole. The characterization of FRG under these cases for the observation of the effects on cogging torque was performed using three-dimensional finite element analysis. From the results of simulation, a model was …


Probabilistic Day-Ahead System Marginal Price Forecasting With Ann For The Turkish Electricity Market, Erdem Özgüner, Osman Bülent Tör, Ali̇ Nezi̇h Güven Jan 2017

Probabilistic Day-Ahead System Marginal Price Forecasting With Ann For The Turkish Electricity Market, Erdem Özgüner, Osman Bülent Tör, Ali̇ Nezi̇h Güven

Turkish Journal of Electrical Engineering and Computer Sciences

This study presents a system day-ahead hourly market clearing price forecasting tool for the day-ahead (DA) market and a system DA hourly marginal price forecasting tool for the real-time market of the Turkish electric market (TEM). These forecasting tools are developed based on artificial neural networks (ANNs). A series of historical price data of the TEM are utilized to model and optimize the ANN structure and to develop the ANN-based price forecasting tool. The methodology used to select the optimum ANN architecture provides the minimum daily mean absolute percentage error for both day-ahead market prices in the TEM. Performances of …


Horizontal Directional Drilling Pilot Bore Simulation, Paulius Tervydis, Ruta Jankuniene Jan 2017

Horizontal Directional Drilling Pilot Bore Simulation, Paulius Tervydis, Ruta Jankuniene

Turkish Journal of Electrical Engineering and Computer Sciences

Various underground communications (water or gas supply systems, sewage, power lines) have been installed in recent years using trenchless technologies, i.e. horizontal directional drilling (HDD). This technique by its nature does not disturb the traffic and is environmentally friendly. One must be aware that, with HDD, pipeline building time is shortened. With respect to the above, HDD is especially effective in highly populated or industrial areas. However, it is necessary to ensure that HDD works, in order to prevent damage to installed underground facilities. The aim of this work is to propose a user-friendly and inexpensive simulation tool with required …