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2019

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Articles 3841 - 3870 of 3906

Full-Text Articles in Computer Sciences

A Novel And Unified Approach For Averaged Channel Capacity And Averagedeffective Capacity Analyses Of Diversity Combining And Multihop Transmissionschemes In Flat Fading Environments, Ferkan Yilmaz, Mohamed-Slim Alouini Jan 2019

A Novel And Unified Approach For Averaged Channel Capacity And Averagedeffective Capacity Analyses Of Diversity Combining And Multihop Transmissionschemes In Flat Fading Environments, Ferkan Yilmaz, Mohamed-Slim Alouini

Turkish Journal of Electrical Engineering and Computer Sciences

n this paper, we introduce an Lp -norm aggregation to present a signal-to-noise ratio expression unified not only for such diversity combining schemes as equal-gain combining, maximal-ratio combining, and selection combining, but also for such transmission techniques as multihop transmission. Accordingly, we propose two moment-generating function-based approaches that both respectively unify the exact analyses of the averaged channel capacity and averaged effective capacity over generalized fading channels with respect to the diversity combining and multihop transmission schemes. Finally, the mathematical formalism is illustrated by numerical special cases and verified by simulations.

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Three-Channel Control Architecture For Multilateral Teleoperation Under Time Delay, Uğur Tümerdem Jan 2019

Three-Channel Control Architecture For Multilateral Teleoperation Under Time Delay, Uğur Tümerdem

Turkish Journal of Electrical Engineering and Computer Sciences

Multilateral teleoperation is an extension of bilateral/haptic teleoperation framework to multiple operators/robots and finds applications in haptic training. As in bilateral teleoperation, time delay is an important problem, and stability and transparency, which quantifies the performance of the teleoperation system, are critical in the design of multilateral control systems. This paper proposes a novel three-channel-based multilateral control architecture with damping injection to guarantee delay-independent L2 stability and high transparency in multilateral teleoperation systems. The theoretical and computational analyses are verified with experiment results.

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Pipelined Adders For Ultralow-Power Wearables, Mansi Jhamb, Tejaswini Dhall, Tamish Verma, Hinduja Puri Jan 2019

Pipelined Adders For Ultralow-Power Wearables, Mansi Jhamb, Tejaswini Dhall, Tamish Verma, Hinduja Puri

Turkish Journal of Electrical Engineering and Computer Sciences

For continuous real-time monitoring of personal health, wearable devices are indispensable. The constraintsof cost, power consumption, and limited device dimensions are the critical issues which need to be handled carefullywhile designing these battery-powered devices. The wearables employ high-end processors dedicated for complex signalprocessing. The core of every digital signal processor is its data path. The arithmetic units like adders constitute thecore of data path and addressing unit. This work proposes a novel low-complexity asynchronous pipelined adder. Theproposed design guarantees great savings in power and latency, which makes it a suitable candidate for low-power high-speed sophisticated wearables. The proposed design consumes …

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Contribution Of Artificial Proprioception On A Dynamic Finger Flexion Task, Mehdi Hojatmadani, Evren Samur Jan 2019

Contribution Of Artificial Proprioception On A Dynamic Finger Flexion Task, Mehdi Hojatmadani, Evren Samur

Turkish Journal of Electrical Engineering and Computer Sciences

There has been a considerable effort to provide sensory feedback for myoelectric prostheses. Among the solutions provided in the literature, sensory substitution is an easy and cost-effective way to provide feedback through different sensory modalities at different locations on the body. In this study, we evaluate the effect of sensory substitution of force and position feedback on a two-degree-of-freedom dynamic finger flexion task. For this purpose, a new methodology and an experimental setup are developed. The experimental methodology is based on the "strength-dexterity test", working on the principle of buckling of compression springs. The experimental setup comprises a haptic interface, …

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Optimal Contract Pricing Of Load Aggregators For Direct Load Control In Smartdistribution Systems, Ali Shayegan-Rad, Ali Zangeneh Jan 2019

Optimal Contract Pricing Of Load Aggregators For Direct Load Control In Smartdistribution Systems, Ali Shayegan-Rad, Ali Zangeneh

Turkish Journal of Electrical Engineering and Computer Sciences

Distribution system operators (DSOs) are interested in demand side participation programs as an efficient and secure resource to manage electricity supply and demand. However, it is usually difficult for DSOs to aggregate demand response of large/small consumers. Thus, in some electricity markets, an entity called an aggregator is defined to aggregate the load response of consumers. In this paper a bilevel scheduling model is proposed to determine the long-term optimal contract price between the DSO and aggregator for executing direct load control in smart distribution systems. The DSO and aggregator are considered as two different agents with individual objectives in …

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Optimal Placement Of Switching And Protection Devices In Radial Distribution Networks To Enhance System Reliability Using The Ahp-Pso Method, Masoud Amohadi, Mahmud Fotuhi Firuzabad Jan 2019

Optimal Placement Of Switching And Protection Devices In Radial Distribution Networks To Enhance System Reliability Using The Ahp-Pso Method, Masoud Amohadi, Mahmud Fotuhi Firuzabad

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new method to determine the optimal number and locations of autorecloser and sectionalizer switches (AR/S) in distribution networks. The costs of AR/S investment, switch maintenance, and undistributed energy as well as reliability coefficients are considered in the objective function. Reliability parameters such as SAIFI, SADI, MAIFI, and ENS are evaluated in the case study system. As a new method, the weights of the reliability parameters are obtained by decision-makers using the analytical hierarchy process (AHP). The optimal size, type, and location of automatic switches are determined by minimizing the objective function using the particle swarm optimization …

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Thyristor-Based "Phase Hopping" Frequency Conversion Technique, Zhenwang Xu, Jiarui Zhang, Yuchun Yi, Cheng Chen, Jiaqi Yu, Wei Mei, Daiwei Feng Jan 2019

Thyristor-Based "Phase Hopping" Frequency Conversion Technique, Zhenwang Xu, Jiarui Zhang, Yuchun Yi, Cheng Chen, Jiaqi Yu, Wei Mei, Daiwei Feng

Turkish Journal of Electrical Engineering and Computer Sciences

This study proposes a new AC/AC "phase hopping" frequency conversion method based on the analyses of the disadvantages of the conventional cosine wave-crossing method. The advantages of this new method include no circulating current, no dead time, and an output frequency close to the power frequency. This study also introduces the basic principles of the "phase hopping" method and analyzes these principles combined with the voltage phase-changing comparison to that of the cosine wave-crossing method. The "phase hopping" principles are used to analyze the generation of thyristor trigger pulses, including the generation time and duration. A simulation is conducted in …

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Power Electronic Controller With Time Sharing Switching Strategy For Grid Connected Pv Systems, Maria Jenisha Charles, Ammasaigounden Nanjappagounder, Binu Ben Jose Dharmaian Retnam Jan 2019

Power Electronic Controller With Time Sharing Switching Strategy For Grid Connected Pv Systems, Maria Jenisha Charles, Ammasaigounden Nanjappagounder, Binu Ben Jose Dharmaian Retnam

Turkish Journal of Electrical Engineering and Computer Sciences

The design and implementation of a high-efficiency two-stage power electronic controller for feeding power from a photovoltaic (PV) array to the load/utility grid is proposed. The PV array is connected to the load/utility grid through a boost converter and an inverter. The boost converter is controlled by sinusoidal pulse width modulation (SPWM) pulses so as to get a clamped quasi-sinusoidal waveform at the DC link. The inverter converts the clamped quasi-DC voltage into AC voltage using the SPWM controller. At any time only one switch operates at high frequency, thus yielding reduction in the switching losses of the converters. The …

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Evaluation Of Power System Robustness In Order To Prevent Cascading Outages, Farnaaz Hajbani, Heresh Seyedi, Kazem Zare Jan 2019

Evaluation Of Power System Robustness In Order To Prevent Cascading Outages, Farnaaz Hajbani, Heresh Seyedi, Kazem Zare

Turkish Journal of Electrical Engineering and Computer Sciences

Power system robustness against overload condition is a challenging issue in the fields of power system planning and operation. In this paper, two indices are proposed to evaluate power system robustness. The proposed indices are used to identify critical lines whose failure is due to overload, leading the power system to cascading outages and blackout. The first proposed index is a linear index. The second index is based on graph theory metrics. To prevent cascading outages, system robustness is calculated for all N-1 and N-2 contingencies. The lines whose outages lead to the smallest robustness values are considered as critical …

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Improved Vsm Control Of Pmsg-Based Wind Farms For Transient Stability Enhancement, Mohamed Abbes, Ines Mehouachi, Souad Chebbi Jan 2019

Improved Vsm Control Of Pmsg-Based Wind Farms For Transient Stability Enhancement, Mohamed Abbes, Ines Mehouachi, Souad Chebbi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper analyzes the optimal control strategy of PMSG-based wind farms during faults in order to improve the transient stability of a power system with a high penetration rate of wind power. The investigated control strategies are the unity power factor (UPF), reactive power control (RPC), and particularly the concept of virtual synchronous machine (VSM). The transient stability level is assessed using the critical clearing time index, which was calculated based on trajectory sensitivity analysis. In light of the obtained results, it was found that RPC gives the best transient stability level, followed by the classical VSM control. Hence, an …

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A Fuzzy Model Of Directional Relationships From The Phi-Descriptor, Mohammad Naeem, Nasir Ahmad, Sahib Khan, Asma Gul Jan 2019

A Fuzzy Model Of Directional Relationships From The Phi-Descriptor, Mohammad Naeem, Nasir Ahmad, Sahib Khan, Asma Gul

Turkish Journal of Electrical Engineering and Computer Sciences

Directional spatial relationships are a category of spatial relationships and have applications in the fields of image processing, geographic information systems, natural language processing, and robot navigation. They can be directly extracted from images or can be interpreted from a type of image descriptors called the relative position descriptors. Examples of relative position descriptors are the angle histogram, the force histogram, and the recently proposed phi-descriptor. So far, fuzzy models of directional spatial relationships from the angle histogram and force histograms have been proposed in the literature. These include the compatibility method, the aggregation method, and the method of effective …

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Heuristic Optimization Techniques For Voltage Stability Enhancement Of Radial Distribution Network With Simultaneous Consideration Of Network Reconfiguration And Dg Sizing And Allocations, Mahiraj Singh Rawat, Shelly Vadhera Jan 2019

Heuristic Optimization Techniques For Voltage Stability Enhancement Of Radial Distribution Network With Simultaneous Consideration Of Network Reconfiguration And Dg Sizing And Allocations, Mahiraj Singh Rawat, Shelly Vadhera

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, heuristic optimization techniques, such as integrated particle swarm optimization (IPSO), teaching--learning-based optimization (TLBO), and Jaya optimization, were applied effectively for the first time to optimize the radial distribution network (RDN) by simultaneously considering reconfiguration of the network and allocation and sizing of the distributed generations (DG). The objectives were to maximize the voltage stability and to minimize the power loss of the network without violating the system constraints. In standard PSO technique, the movement of current particle depends upon global best position and its own best position up to current step. However, if the particle lies too …

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Convex Polygon Triangulation Based On Planted Trivalent Binary Tree\\ And Ballot Problem, Muzafer Saracevic, Aybeyan Seli̇mi̇ Jan 2019

Convex Polygon Triangulation Based On Planted Trivalent Binary Tree\\ And Ballot Problem, Muzafer Saracevic, Aybeyan Seli̇mi̇

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new technique of generation of convex polygon triangulation based on planted trivalent binary tree and ballot notation. The properties of the Catalan numbers were examined and their decomposition and application in developing the hierarchy and triangulation trees were analyzed. The method of storage and processing of triangulation was constructed on the basis of movements through the polygon. This method was derived from vertices and leaves of the planted trivalent binary tree. The research subject of the paper is analysis and comparison of a constructed method for solving of convex polygon triangulation problem with other methods and …

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A Novel Metaheuristic Optimization Algorithm: The Monarchy Metaheuristic, Ibtissam Ahmia, Meziane Aider Jan 2019

A Novel Metaheuristic Optimization Algorithm: The Monarchy Metaheuristic, Ibtissam Ahmia, Meziane Aider

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we introduce a novel metaheuristic optimization algorithm named the monarchy metaheuristic (MN). Our proposed metaheuristic was inspired by the monarchy government system. Unlike many other metaheuristics, it is easy to implement and does not need a lot of parameters. This makes it applicable to a wide range of optimization problems. To evaluate the efficiency of the proposed algorithm, we examined it on the traveling salesman problem (TSP) using some benchmark from TSPLIB online library of instances for the TSP. The experimental results indicate that the monarchy metaheuristic is competitive with the other methods that exist in the …

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Data Analysis Through Social Media According To The Classified Crime, Serkan Savaş, Nuretti̇n Topaloğlu Jan 2019

Data Analysis Through Social Media According To The Classified Crime, Serkan Savaş, Nuretti̇n Topaloğlu

Turkish Journal of Electrical Engineering and Computer Sciences

The amount and variety of data generated through social media sites has increased along with the widespread use of social media sites. In addition, the data production rate has increased in the same way. The inclusion of personal information within these data makes it important to process the data and reach meaningful information within it. This process can be called intelligence and this meaningful information may be for commercial, academic, or security purposes. An example application is developed in this study for intelligence on Twitter. Crimes in Turkey are classified according to Turkish Statistical Institute criminal data and keywords are …

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Identifying Criminal Organizations From Their Social Network Structures, Muhammet Serkan Çi̇nar, Burkay Genç, Hayri̇ Sever Jan 2019

Identifying Criminal Organizations From Their Social Network Structures, Muhammet Serkan Çi̇nar, Burkay Genç, Hayri̇ Sever

Turkish Journal of Electrical Engineering and Computer Sciences

Identification of criminal structures within very large social networks is an essential security feat. By identifying such structures, it may be possible to track, neutralize, and terminate the corresponding criminal organizations before they act. We evaluate the effectiveness of three different methods for classifying an unknown network as terrorist, cocaine, or noncriminal. We consider three methods for the identification of network types: evaluating common social network analysis metrics, modeling with a decision tree, and network motif frequency analysis. The empirical results show that these three methods can provide significant improvements in distinguishing all three network types. We show that these …

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A Tree-Based Approach For English-To-Turkish Translation, Özge Bakay, Begüm Avar, Olcay Taner Yildiz Jan 2019

A Tree-Based Approach For English-To-Turkish Translation, Özge Bakay, Begüm Avar, Olcay Taner Yildiz

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present our English-to-Turkish translation methodology, which adopts a tree-based approach. Our approach relies on tree analysis and the application of structural modification rules to get the target side (Turkish) trees from source side (English) ones. We also use morphological analysis to get candidate root words and apply tree-based rules to obtain the agglutinated target words. Compared to earlier work on English-to-Turkish translation using phrase-based models, we have been able to obtain higher BLEU scores in our current study. Our syntactic subtree permutation strategy, combined with a word replacement algorithm, provides a 67 % relative improvement from …

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Fuzzy Logic-Based Disparity Selection Using Multiple Data Costs For Stereo Correspondence, Akhil Appu Shetty, V.I George, C Gurudas Nayak, Raviraj Shetty Jan 2019

Fuzzy Logic-Based Disparity Selection Using Multiple Data Costs For Stereo Correspondence, Akhil Appu Shetty, V.I George, C Gurudas Nayak, Raviraj Shetty

Turkish Journal of Electrical Engineering and Computer Sciences

Stereo matching algorithms are capable of generating depth maps from two images of the same scene taken simultaneously from two different viewpoints. Traditionally, a single cost function is used to calculate the disparity between corresponding pixels in the left and right images. In the present research, we have considered a combination of simple data costs. A new method to combine multiple data costs is presented and a fuzzy-based disparity selection method is proposed. Experiments with different combinations of parameters are conducted and compared through the Middlebury and Kitti Stereo Vision Benchmark.

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Improving Anomaly Detection In Bgp Time-Series Data By New Guide Features And Moderated Feature Selection Algorithm, Mahmoud Hashem, Ahmed Bashandy, Samir Shaheen Jan 2019

Improving Anomaly Detection In Bgp Time-Series Data By New Guide Features And Moderated Feature Selection Algorithm, Mahmoud Hashem, Ahmed Bashandy, Samir Shaheen

Turkish Journal of Electrical Engineering and Computer Sciences

The Internet infrastructure relies on the Border Gateway Protocol (BGP) to provide essential routing information where abnormal routing behavior impairs global Internet connectivity and stability. Hence, employing anomaly detection algorithms is important for improving the performance of BGP routing protocol. In this paper, we propose two algorithms; the first is the guide feature generator (GFG), which generates guide features from traditional features in BGP time-series data using moving regression in combination with smoothed moving average. The second is a modified random forest feature selection algorithm which is employed to automatically select the most dominant features (ASMDF). Our mechanism shows that …

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A Memory-Efficient Canonical Data Structure For Decimal Floating Point Arithmetic Systems Modeling And Verification, Mohammad Saeed Jahangiry, Saeed Safari Jan 2019

A Memory-Efficient Canonical Data Structure For Decimal Floating Point Arithmetic Systems Modeling And Verification, Mohammad Saeed Jahangiry, Saeed Safari

Turkish Journal of Electrical Engineering and Computer Sciences

Decimal floating point (DFP) number representation was proposed in IEEE-754-2008 in order to overcome binary floating point inaccuracy. Neglecting binary floating point verification has resulted in significant validity and economic losses. Formal verification can be a solution to similar DFP design problems. Verification techniques aiming at DFP are limited to functional methods whereas formal approaches have been neglected and traditional decision diagrams cannot model DFP representation complexity. In this paper, we propose an efficient canonical data structure that can model DFP properties. Our novel data structure models coefficient, exponent, sign, and bias of a DFP number. We will prove mathematically …

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Automatic Concept Identification Of Software Requirements In Turkish, Fatma Bozyi̇ği̇t, Özlem Aktaş, Deni̇z Kilinç Jan 2019

Automatic Concept Identification Of Software Requirements In Turkish, Fatma Bozyi̇ği̇t, Özlem Aktaş, Deni̇z Kilinç

Turkish Journal of Electrical Engineering and Computer Sciences

Software requirements include description of the features for the target system and express the expectations of users. In the analysis phase, requirements are transformed into easy-to-understand conceptual models that facilitate communication between stakeholders. Although creating conceptual models using requirements is mostly implemented manually by analysts, the number of models that automate this process has increased recently. Most of the models and tools are developed to analyze requirements in English, and there is no study for agglutinative languages such as Turkish or Finnish. In this study, we propose an automatic concept identification model that transforms Turkish requirements into Unified Modeling Language …

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Formally Analyzed M-Coupon Protocol With Confirmation Code (Mcwcc), Keri̇m Yildirim, Gökhan Dalkiliç, Nevci̇han Duru Jan 2019

Formally Analyzed M-Coupon Protocol With Confirmation Code (Mcwcc), Keri̇m Yildirim, Gökhan Dalkiliç, Nevci̇han Duru

Turkish Journal of Electrical Engineering and Computer Sciences

There are many marketing methods used to attract customers' attention and customers search for special discounts and conduct research to get products cheaper. Using discount coupons is one of the widely used methods for obtaining discounts. With the development of technology, classical paper-based discount coupons become e-coupons and then turn into mobile coupons (m-coupons). It is inevitable that retailers will use m-coupon technology to attract customers while mobile devices are used in daily life. As a result, m-coupon technology is a promising technology. One of the significant problems with using m-coupons is security. Here it is necessary to ensure the …

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Detection Of Hemorrhage In Retinal Images Using Linear Classifiers And Iterative Thresholding Approaches Based On Firefly And Particle Swarm Optimization Algorithms, Kemal Adem, Mahmut Heki̇m, Seli̇m Demi̇r Jan 2019

Detection Of Hemorrhage In Retinal Images Using Linear Classifiers And Iterative Thresholding Approaches Based On Firefly And Particle Swarm Optimization Algorithms, Kemal Adem, Mahmut Heki̇m, Seli̇m Demi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

We propose a novel iterative thresholding approach based on firefly and particle swarm optimization to be used for the detection of hemorrhages, one of the signs of diabetic retinopathy disease. This approach consists of the enhancement of the image using basic preprocessing methods, the segmentation of vessels with the help of Gabor and Top-hat transformation for the removal of the vessels from the image, the determination of the number of regions with hemorrhages and pixel counts in these regions using firefly algorithm (FFA) and particle swarm optimization algorithm (PSOA)-based iterative thresholding, and the detection of hemorrhages with the help of …

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Local Directional-Structural Pattern For Person-Independent Facial Expression Recognition, Farkhod Makhmudkhujaev, Md Tauhid Bin Iqbal, Byungyong Ryu, Oksam Chae Jan 2019

Local Directional-Structural Pattern For Person-Independent Facial Expression Recognition, Farkhod Makhmudkhujaev, Md Tauhid Bin Iqbal, Byungyong Ryu, Oksam Chae

Turkish Journal of Electrical Engineering and Computer Sciences

Existing popular descriptors for facial expression recognition often suffer from inconsistent feature description, experiencing poor accuracies. We present a new local descriptor, local directional-structural pattern (LDSP), in this work to address this issue. Unlike the existing local descriptors using only the texture or edge information to represent the local structure of a pixel, the proposed LDSP utilizes the positional relationship of the top edge responses of the target pixel to extract more detailed structural information of the local texture. We further exploit such information to characterize expression-affiliated crucial textures while discarding the random noisy patterns. Moreover, we introduce a globally …

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Accurate And Compact Stochastic Computations By Exploiting Correlation, Hamdan Abdellatef, Mohamed Khalil Hani, Nasir Shaikh-Husin Jan 2019

Accurate And Compact Stochastic Computations By Exploiting Correlation, Hamdan Abdellatef, Mohamed Khalil Hani, Nasir Shaikh-Husin

Turkish Journal of Electrical Engineering and Computer Sciences

Recent studies have shown, contrary to what was previously believed, that by exploiting correlation in stochastic computing (SC) designs, more accurate SC circuits with low area cost can be realized. However, if these basic SC circuits or blocks are cascaded in series to form a large complex system, correlation between stochastic numbers (SNs) from one block to the next would be lost; thus, inaccuracies are introduced. In this study, we propose correlating circuits to be used in building complex correlated SC systems. One of the circuits is the correlator that restores lost correlations between two SNs due to previous processing. …

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A Multiseed-Based Svm Classification Technique For Training Sample Reduction, Imran Sharif, Debasis Chaudhuri Jan 2019

A Multiseed-Based Svm Classification Technique For Training Sample Reduction, Imran Sharif, Debasis Chaudhuri

Turkish Journal of Electrical Engineering and Computer Sciences

A support vector machine (SVM) is not a popular method for a very large dataset classification because the training and testing time for such data are computationally expensive. Many researchers try to reduce the training time of SVMs by applying sample reduction methods. Many methods reduced the training samples by using a clustering technique. To reduce its high computational complexity, several data reduction methods were proposed in previous studies. However, such methods are not effective to extract informative patterns. This paper demonstrates a new supervised classification method, multiseed-based SVM (MSB-SVM), which is particularly intended to deal with very large datasets …

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Optimal Set Of Eeg Features In Infant Sleep Stage Classification, Maja Cic, Mario Milicevic, Igor Mazic Jan 2019

Optimal Set Of Eeg Features In Infant Sleep Stage Classification, Maja Cic, Mario Milicevic, Igor Mazic

Turkish Journal of Electrical Engineering and Computer Sciences

This paper evaluates six classification algorithms to assess the importance of individual EEG rhythms in the context of automatic classification of infant sleep. EEG features were obtained by Fourier transform and by a novel technique based on the empirical mode decomposition and generalized zero crossing method. Of six evaluated classification algorithms, the best classification results were obtained with the support vector machine for the combination of all presented features from four EEG channels. Three methods of attribute ranking were assessed: relief, principal component analysis, and wrapper-based optimized attribute weights. The outcomes revealed that the optimal selection of features requires one …

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Improvement Of Quantized Adaptive Switching Median Filter For Impulse Noise Reduction In Gray-Scale Digital Images, Haidi Ibrahim, Ahmed Khaldoon Abdalameer Jan 2019

Improvement Of Quantized Adaptive Switching Median Filter For Impulse Noise Reduction In Gray-Scale Digital Images, Haidi Ibrahim, Ahmed Khaldoon Abdalameer

Turkish Journal of Electrical Engineering and Computer Sciences

Digital images may suffer from fixed value impulse noise due to several causes. The noise significantly degrades the quality of the image, which may affect the subsequence image processing. Therefore, a noise reduction technique is required to restore the image. In this paper, a new method, which is called improvement of quantized adaptive switching median filter (IQASMF), has been proposed to reduce the fixed value impulse noise from gray-scale digital images. The implementation of IQASMF has five processing blocks. The first processing block is the noise detection block, where the noise pixel candidates are detected based on the intensity value. …

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Boltzmann Analysis Of Electron Swarm Parameters In Chf3+Cf4 Mixtures, Hidir Düzkaya, Süleyman Sungur Tezcan Jan 2019

Boltzmann Analysis Of Electron Swarm Parameters In Chf3+Cf4 Mixtures, Hidir Düzkaya, Süleyman Sungur Tezcan

Turkish Journal of Electrical Engineering and Computer Sciences

The electron drift velocity, mean energy, ionization, attachment, effective ionization coefficient, limit electrical field, and synergism of pure CHF3 (fluoroform), pure CF4 (tetrafluoromethane), and CHF3+CF4 gas mixtures are calculated by Boltzmann equation analysis in a wide range of density normalized electrical fields (E/N). The finite difference method is used to solve the two-term approximation of the Boltzmann equation under steady-state Townsend conditions. To our knowledge, no previous electron swarm parameters of these mixtures have been published. At constant E/N values, the electron mean energies and drift velocities increase with decreasing CHF3 content. The addition of CF4 into the mixture increases …

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Comparative Analysis Of A Novel Topology For Single-Phase Z-Source Inverter With Reduced Number Of Switches, Himanshu Sharma, Rintu Khanna, Neelu Jain Jan 2019

Comparative Analysis Of A Novel Topology For Single-Phase Z-Source Inverter With Reduced Number Of Switches, Himanshu Sharma, Rintu Khanna, Neelu Jain

Turkish Journal of Electrical Engineering and Computer Sciences

Z-source inverter has recently been introduced to overcome the limitations of conventional voltage source inverter. This paper deals with a novel topology of single-phase Z-source inverter (ZSI). This topology reduced the number of passive elements and active switches in order to make the inverter cheaper and smaller in size compared to traditional ZSI. Detailed analysis of the proposed topology is presented in this paper which includes calculations of boost factor, total harmonic disorder, magnitude of output voltage etc. Modulation technique used to control the switching of the proposed inverter is explained in detail. This paper also compares the proposed topology …

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