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2017

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Articles 2581 - 2610 of 2767

Full-Text Articles in Computer Sciences

Improved Resettable Integrator Control For A Bridgeless Interleaved Ac/Dc Converter, Kanimozhi Gunasekaran, Sreedevi Vellithirothi Thazhathu Jan 2017

Improved Resettable Integrator Control For A Bridgeless Interleaved Ac/Dc Converter, Kanimozhi Gunasekaran, Sreedevi Vellithirothi Thazhathu

Turkish Journal of Electrical Engineering and Computer Sciences

Plug-in hybrid electric vehicles (PHEVs) consist of a front-end boost rectifier, which incorporates a power factor correction (PFC) circuit for battery charging. Bridgeless interleaved (BLIL) PFC boost converter topology is proved as a standard PFC converter as it has high efficiency, reduced input current ripple, and reduced electromagnetic interference (EMI). This paper proposes a digital nonlinear control technique that employs a resettable integrator to shape the input current of the converter in phase with the input voltage to achieve high input power factor. This control approach rejects power source and load perturbations better than linear feedback control methods. This is …

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Performance Comparison Of The Notable Acceleration- And Angle-Based Guidance Laws For A Short-Range Air-To-Surface Missile, Bülent Özkan, Mustafa Kemal Özgören, Gökmen Mahmutyazicioğlu Jan 2017

Performance Comparison Of The Notable Acceleration- And Angle-Based Guidance Laws For A Short-Range Air-To-Surface Missile, Bülent Özkan, Mustafa Kemal Özgören, Gökmen Mahmutyazicioğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Short-range air-to-surface missiles have become globally popular in the last two decades. As a performance driver, the type of guidance law gains importance. In this study, proportional navigation, velocity pursuit, and augmented proportional navigation guidance laws, whose resulting guidance commands take the form of lateral acceleration, are applied to a short-range air-to-surface missile against both stationary and maneuvering ground targets. Body pursuit and linear homing guidance laws, which yield angular commands, are additionally applied. Having completed the relevant computer simulations, we conclude that none of the acceleration- and angle-based guidance laws are absolutely superior to the others.

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A New Word-Based Compression Model Allowing Compressed Pattern Matching, Hali̇l Nusret Buluş, Aydin Carus, Altan Mesut Jan 2017

A New Word-Based Compression Model Allowing Compressed Pattern Matching, Hali̇l Nusret Buluş, Aydin Carus, Altan Mesut

Turkish Journal of Electrical Engineering and Computer Sciences

In this study a new semistatic data compression model that has a fast coding process and that allows compressed pattern matching is introduced. The name of the proposed model is chosen as tagged word-based compression algorithm (TWBCA) since it has a word-based coding and word-based compressed matching algorithm. The model has two phases. In the first phase a dictionary is constructed by adding a phrase, paying attention to word boundaries, and in the second phase compression is done by using codewords of phrases in this dictionary. The first byte of the codeword determines whether the word is compressed or not. …

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Robust H$\Infty $ Control For Chaotic Supply Chain Networks, Hamid Norouzi Nav, Mohammad Reza Jahedmotlagh, Ahmad Makui Jan 2017

Robust H$\Infty $ Control For Chaotic Supply Chain Networks, Hamid Norouzi Nav, Mohammad Reza Jahedmotlagh, Ahmad Makui

Turkish Journal of Electrical Engineering and Computer Sciences

A supply chain network (SCN) is a complex nonlinear system involving multiple entities. The policy of each entity in decision-making and the uncertainties of demand and supply (or production) significantly affect the complexity of its behavior. Although several studies have presented information about the measurement of chaos in the supply chain, there has not been an appropriate way to control the chaos in it. In this paper, the chaos control problem is considered for a SCN with a time-varying delay between its entities. The innovation of this paper is the more comprehensive modeling, analysis, and control of chaotic behavior in …

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A Meander Coupled Line Wideband Power Divider With Open Stubs And Dgs For Mobile Application, Sivaprakash Somalinga Chandrasekarani, Sivanantharaja Raja Avaninathan, Pavithra Murugesan Jan 2017

A Meander Coupled Line Wideband Power Divider With Open Stubs And Dgs For Mobile Application, Sivaprakash Somalinga Chandrasekarani, Sivanantharaja Raja Avaninathan, Pavithra Murugesan

Turkish Journal of Electrical Engineering and Computer Sciences

A novel meander coupled line power divider for wide band operation from 0.5 GHz to 2.5 GHz with reduced size for mobile application is proposed in this paper. The wide band operation of the coupled line power divider is obtained using open stubs and defected ground structures. The folding of the coupled line reduces the size of the power divider. The proposed power divider has 65% of size reduction in comparison with the existing power divider. All the S-parameters such as return loss, insertion loss, and isolation at different ports are simulated and measured. Bandwidth of 2 GHz is obtained. …

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On The Independence Of Statistical Randomness Tests Included In The Nist Test Suite, Fati̇h Sulak, Muhi̇ddi̇n Uğuz, Onur Koçak, Ali̇ Doğanaksoy Jan 2017

On The Independence Of Statistical Randomness Tests Included In The Nist Test Suite, Fati̇h Sulak, Muhi̇ddi̇n Uğuz, Onur Koçak, Ali̇ Doğanaksoy

Turkish Journal of Electrical Engineering and Computer Sciences

Random numbers and random sequences are used to produce vital parts of cryptographic algorithms such as encryption keys and therefore the generation and evaluation of random sequences in terms of randomness are vital. Test suites consisting of a number of statistical randomness tests are used to detect the nonrandom characteristics of the sequences. Construction of a test suite is not an easy task. On one hand, the coverage of a suite should be wide; that is, it should compare the sequence under consideration from many different points of view with true random sequences. On the other hand, an overpopulated suite …

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Force And Torque Parameter Estimation For A 4-Pole Hybrid Electromagnet By Anfis Hybrid Learning Algorithm, Murat Atlihan, Bariş Can Yalçin, Kadi̇r Erkan Jan 2017

Force And Torque Parameter Estimation For A 4-Pole Hybrid Electromagnet By Anfis Hybrid Learning Algorithm, Murat Atlihan, Bariş Can Yalçin, Kadi̇r Erkan

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a force and torque estimation method based on an adaptive neuro-fuzzy inference system (ANFIS) has been developed to get rid of multiple integral calculations of air gap coefficients that cause time delay for magnetic levitation control applications. During magnetic levitation applications that contain a 4-pole hybrid electromagnet, multiple integral calculations have to be done for obtaining air gap permanence parameters, and these parameters are needed to calculate force and torque parameters that are produced by the poles of the hybrid electromagnet, which means, if time delay occurs for calculation of permanence parameters, actual force and actual torque …

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Adaptive Joint Block-Weighted Collaborative Representation For Facial Expression Recognition, Zhe Sun, Zhengping Hu, Meng Wang, Shuhuan Zhao Jan 2017

Adaptive Joint Block-Weighted Collaborative Representation For Facial Expression Recognition, Zhe Sun, Zhengping Hu, Meng Wang, Shuhuan Zhao

Turkish Journal of Electrical Engineering and Computer Sciences

Facial expression recognition (FER) plays a significant role in human-computer interactions. Recently, regularized linear representation-based classification has achieved satisfying results in FER. Considering that different blocks in a sample should contribute differently to the representation and classification, we propose an adaptive joint block-weighted collaborative representation-based classification (JBW_CRC) method to effectively exploit the similarity and distinctiveness of different blocks. In JBW_CRC, samples are divided into different blocks and each block of the query sample is represented as a feature vector. Each feature vector is coded on its related block dictionary, which considers the similarity among the feature vectors. Additionally, the distinctiveness …

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Space-Time Block Coded Spatial Modulation Scheme Enhanced By Employing An Intersymbol Phase And Power Allocation, Ahmet Faruk Coşkun Jan 2017

Space-Time Block Coded Spatial Modulation Scheme Enhanced By Employing An Intersymbol Phase And Power Allocation, Ahmet Faruk Coşkun

Turkish Journal of Electrical Engineering and Computer Sciences

This paper provides a brief and insightful examination of the advantages achieved by employing combined phase offsetting and power allocation mechanisms in the space-time block coded (STBC) transmission of spatial modulation schemes with cyclic structure (CSM). In order to achieve increased coding gain distances (CGDs) between transmitted code words (CWs), the power allocation mechanism is cascaded to the constellation mapping process of a STBC-CSM scheme, and the optimal power and phase weights for the conveyed information symbols, together with the phases for each CW, are searched by a heuristic algorithm based on differential evolution that yields the best CGD available …

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Promoting Peak Shaving While Minimizing Electricity Consumption Payment For Residential Consumers By Using Storage Devices, Simona Oprea, Adela Bara, Mahmut Erkut Cebeci̇, Osman Bülent Tör Jan 2017

Promoting Peak Shaving While Minimizing Electricity Consumption Payment For Residential Consumers By Using Storage Devices, Simona Oprea, Adela Bara, Mahmut Erkut Cebeci̇, Osman Bülent Tör

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, smart meters, sensors, and advanced electricity tariff mechanisms such as time-of-use (ToU), critical peak pricing tariff, and real time tariff enable electricity consumption optimization for residential consumers. The main scope of such mechanisms is to promote peak shaving, which leads to minimization of technical losses and avoidance (or delay) of grid onerous investments. This paper proposes a method to determine the optimum capacity of a storage device (SD) that significantly contributes to peak shaving of electricity consumption for residential consumers. Detailed modelling of diverse electric appliances' behavior and consumers' necessities is addressed in order to determine the optimum capacity …

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Feedback Delay Compensation Of A Visual Servoing System Using A Piecewise Continuous And Current Estimator-Based Observer, Abdeldafia Mohammed, Haoping Wang, Yang Tian Jan 2017

Feedback Delay Compensation Of A Visual Servoing System Using A Piecewise Continuous And Current Estimator-Based Observer, Abdeldafia Mohammed, Haoping Wang, Yang Tian

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a piecewise continuous current estimator-based observer is proposed to estimate a plant's states using sampled and delayed measurements. The advantage of the proposed technique is simple in terms of analysis and design. Moreover, the proposed observer can compensate the time delay when the delay equals the sampling period. Comprehensive stability analysis of the designed observer is performed. In addition, to assess the efficiency and effectiveness of the proposed observer, a numerical comparative study with a Kalman filter-based observer is established and the simulation results are demonstrated.

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The Reduction Of Semiconductor Devices In A Flying Capacitor-Based Multilevel Converter For Use As An Sssc, Mana Rokhafrooz, Ali Mosallanejad Jan 2017

The Reduction Of Semiconductor Devices In A Flying Capacitor-Based Multilevel Converter For Use As An Sssc, Mana Rokhafrooz, Ali Mosallanejad

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes the use of a static synchronous series compensator (SSSC) to increase the power capacity of a 230 KV transmission line. The power capacity is increased by 30%. The proposed SSSC is a 21-level inverter based on the cascade connection of improved double flying capacitor multicell (CI-DFCM) converter. The main advantages of the CI-DFCM multilevel inverter are the low number of power-electronic devices, as well as reduction in the number and voltage diversity of flying capacitors in comparison with other flying capacitor-based inverters. The CI-DFCM multilevel inverter uses only two flying capacitors in each phase. The theory of …

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Fault Location Determination For Transmission Lines With Different Series-Compensation Levels Using Transient Frequencies, Düzgün Akmaz, Mehmet Sali̇h Mami̇ş, Müslüm Arkan, Mehmet Emi̇n Tağluk Jan 2017

Fault Location Determination For Transmission Lines With Different Series-Compensation Levels Using Transient Frequencies, Düzgün Akmaz, Mehmet Sali̇h Mami̇ş, Müslüm Arkan, Mehmet Emi̇n Tağluk

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, based on the theory of traveling waves, the fault distances on long transmission lines with various series-compensation levels are determined using transient current and voltage frequencies. Transmission lines with series compensation are modeled using Alternative Transients Program software with frequency-dependent effects on the line included in the simulation. The transient current and voltage signals are obtained from the model. A fast Fourier transform is used for frequency-domain conversion and fault location is estimated from the frequencies of fault-generated harmonics in the transient spectrum. The algorithm is implemented in MATLAB. To investigate the effect of compensation on accuracy, …

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The Design Of A Novel And Portable Energy Performance-Measuring Device For Household Refrigerators, İlhan Koşalay, Okan Bi̇ngöl, Hakki Gökhan İlk, Mahmut Yildirim, Burçi̇n Özkaya Jan 2017

The Design Of A Novel And Portable Energy Performance-Measuring Device For Household Refrigerators, İlhan Koşalay, Okan Bi̇ngöl, Hakki Gökhan İlk, Mahmut Yildirim, Burçi̇n Özkaya

Turkish Journal of Electrical Engineering and Computer Sciences

Refrigerators are one of the main devices used in our daily lives, and they play important roles in storing food and maintaining its freshness. Refrigerator manufacturing is improving day by day and it is important for the appliance to present a diverse array of functions to its users, since usage requirements vary from region to region. For this purpose, refrigerators must pass through various performance tests like an energy efficiency test while they are produced in factories. Factories have designated testing rooms for these performance tests. After the products' release, technical services and customers do not have such a luxury …

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Performance Analysis Of The Link Selection For Secure Device-To-Device Communications With An Untrusted Relay, Sonia Naderi, Mohammad Reza Javan Jan 2017

Performance Analysis Of The Link Selection For Secure Device-To-Device Communications With An Untrusted Relay, Sonia Naderi, Mohammad Reza Javan

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we study the performance of the selection combining and switch and stay combining methods in secure cooperative device-to-device (D2D) communications underlying a cellular network where an untrusted amplify and forward relay helps D2D communications. In our model, we specifically consider the interference from the cellular system over the D2D pair and the interference from the D2D pair over the cellular system. We assume that D2D communication is performed in such a way that the required outage probability of the cellular system is preserved. We obtain an exact closed-form expression for the lower bound of secrecy outage probability …

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Median Filtering Detection Based On Variations And Residuals In Image Forensics, Kang Hyeon Rhee Jan 2017

Median Filtering Detection Based On Variations And Residuals In Image Forensics, Kang Hyeon Rhee

Turkish Journal of Electrical Engineering and Computer Sciences

To attain a robust feature vector for median filtering detection (MFD) in digital forgery images, this paper presents a short feature vector that is made up of three types of feature sets. The first set is defined by the variation to be the 3-D length in the gradient difference of the intensity values of the adjacent row and column line pairs in the image, respectively. The second set is defined by the variation in the coefficient difference of the Fourier transform to be the 3-D length in the adjacent line pairs. The last set is defined by the residual image …

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Fault Location In Distribution Systems With Dg Based On Similarity Of Fault Impedance, Zahra Moravej, Omid Hajhossani, Mohammad Pazoki Jan 2017

Fault Location In Distribution Systems With Dg Based On Similarity Of Fault Impedance, Zahra Moravej, Omid Hajhossani, Mohammad Pazoki

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new method for locating a fault in distribution systems using the similarity of fault impedance. A four-step approach is proposed to locate the fault in the networks. First, pre- and during-fault voltages from smart feeders along the primary feeders are measured. Second, three-phase impedance to calculate fault current corresponding to voltage deviation from each smart meter is achieved. Third, a relation between fault current and fault impedance for each type of fault is extracted. Finally, based on the similarity of the estimated fault impedance for each bus, an error index is calculated. Moreover, an auxiliary process …

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Experimental Analysis Of The Temperature Dependence Of The Brillouin Gain Spectrum In Short-Length Single-Mode Fiber, Murat Yücel, Hali̇m Haldun Göktaş, Murat Yücel, Nai̇l Ferhat Öztürk, Abdullah Erkam Gündüz Jan 2017

Experimental Analysis Of The Temperature Dependence Of The Brillouin Gain Spectrum In Short-Length Single-Mode Fiber, Murat Yücel, Hali̇m Haldun Göktaş, Murat Yücel, Nai̇l Ferhat Öztürk, Abdullah Erkam Gündüz

Turkish Journal of Electrical Engineering and Computer Sciences

The Brillouin backscattered wave was examined in a short-length single-mode fiber at different ambient temperatures using a 1553-nm wavelength laser source. To obtain Brillouin scattering depending on the temperature change in a 95-m long single-mode fiber cable, the Brillouin optical time domain reflectometry (BOTDR) technique was used. In this technique, a 1553 nm wavelength signal was sent from one side of the test fiber. The FC/APC connector was attached to the other end of the test fiber. The temperature parameters of the single-mode fiber cables of different brands and types can be obtained using Brillouin scattering. The Brillouin frequency shift …

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A Spatial Load Forecasting Method Based On Load Regularity Analysis, Bai Xiao, Tongtong Liu Jan 2017

A Spatial Load Forecasting Method Based On Load Regularity Analysis, Bai Xiao, Tongtong Liu

Turkish Journal of Electrical Engineering and Computer Sciences

A new method, based on regularity analysis of cellular load, is presented to determine the reasonable maximum of the load density index method of spatial load forecasting (SLF). Through analysis of cellular historical load data, each cellular load is decomposed into regular and random components. The regular part is used to reveal the regularity of the cellular load in different cycles, using random components to describe and characterize the intrinsic error of the cellular load. Adverse effects that occur by eliminating random components to suppress the intrinsic error allow extraction of the maximum of the regular part as the Class …

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Concurrent Optimal Design Of Tcsc And Pss Using Symbiotic Organisms Search Algorithm, Muwaffaq Alomoush Jan 2017

Concurrent Optimal Design Of Tcsc And Pss Using Symbiotic Organisms Search Algorithm, Muwaffaq Alomoush

Turkish Journal of Electrical Engineering and Computer Sciences

The symbiotic organisms search (SOS), which has been recently introduced, is a robust powerful metaheuristic global optimizer. This nature-inspired algorithm imitates the symbiotic interaction strategies in an ecosystem exercised by organisms involved in interrelationships to survive and reproduce. One of the main beneficial features of the SOS in contrast to many other competent metaheuristic algorithms is that the algorithm does not need any specific algorithm parameters or tuning process. This paper applies the SOS algorithm to simultaneously design optimal controllers of a power system equipped with both a power system stabilizer (PSS) and a thyristor-controlled series compensator (TCSC). The algorithm …

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Inverse Kinematics Of A 7-Dof Redundant Robot Manipulator Using The Active Set Approach Under Joint Physical Limits, Modjtaba Rouhani, Sima Ebrahimabadi Jan 2017

Inverse Kinematics Of A 7-Dof Redundant Robot Manipulator Using The Active Set Approach Under Joint Physical Limits, Modjtaba Rouhani, Sima Ebrahimabadi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new approach for an online solution of the inverse kinematics problem based on nonlinear optimization for robots with joint physical constraints. The inverse kinematics problem is stated as a constrained nonlinear optimization problem and is solved using Kuhn--Tucker conditions analysis. The nonlinear multivariable optimization problem is locally converted into independent local linear constrained subproblems and each subproblem is analytically solved. For each joint, position limits and velocity limits are considered as physical constraints. The proposed structure benefits from a very low complexity design. The proposed method is fast and requires few calculations. The convergence of the …

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Generalized Referenceless Image Quality Assessment Framework Using Texture Energy Measures And Pattern Strength Features, Jayashri Bagade, Kulbir Singh, Yogesh Dandawate Jan 2017

Generalized Referenceless Image Quality Assessment Framework Using Texture Energy Measures And Pattern Strength Features, Jayashri Bagade, Kulbir Singh, Yogesh Dandawate

Turkish Journal of Electrical Engineering and Computer Sciences

Referenceless image quality assessment is a challenging and critical problem in today's multimedia applica\-tions. Texture patterns in images are normally at high frequencies compared to lower ones. Due to the effect of distortions during acquisition, compression, and transmission, texture deviation artifacts are generated that cause a granular effect in the image. Other artifacts, such as blocking, affect high frequencies in an image, causing distorted edges. Combining the analysis of texture deviation and other artifacts helps in determining the quality of an image. The proposed approach uses variation in the energy of pixels to quantify the quality of an image. These …

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Prognosis Of Muscular Dystrophy With Extrinsic And Intrinsic Descriptors Through Ensemble Learning, Sathyavikasini Kalimuthu, Vijaya Vijayakumar Jan 2017

Prognosis Of Muscular Dystrophy With Extrinsic And Intrinsic Descriptors Through Ensemble Learning, Sathyavikasini Kalimuthu, Vijaya Vijayakumar

Turkish Journal of Electrical Engineering and Computer Sciences

Muscular dystrophy is a neuromuscular disorder that impairs the functioning of the locomotive muscles. Large deletion and duplication mutations in the gene sequences pave the way for these muscular dystrophies. Any heritable change can be used as input in computational studies such as pattern and classification models. Mutated gene sequences are generated by adopting the positional cloning approach on the reference cDNA sequence with mutational information from the Human Gene Mutational Database (HGMD). The extrinsic and intrinsic descriptors of the mutated gene sequence are indispensable to identifying the disease. This work describes a computational approach of building a disease classification …

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A Model Of Optimal Burst Assembly For Delay Reduction At Ingress Obs Nodes, Viet Minh Nhat Vo, Van Hoa Le, Hoang Son Nguyen Jan 2017

A Model Of Optimal Burst Assembly For Delay Reduction At Ingress Obs Nodes, Viet Minh Nhat Vo, Van Hoa Le, Hoang Son Nguyen

Turkish Journal of Electrical Engineering and Computer Sciences

Burst assembly plays an important role in reducing the end-to-end delay of packets transported through optical burst switching (OBS) networks. Several methods have been proposed to reduce the delay of the packets buffered at ingress OBS nodes. However, these have created significant estimation errors, which result in wasting the reserved bandwidth or increasing the delay of excess packets. In this paper, we propose a model of optimal burst assembly for delay reduction, which minimizes the estimation error, eliminates the excess packets, and decreases the blocking probability of scheduling.

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A Novel Optical Flow-Based Representation For Temporal Video Segmentation, Samet Akpinar, Ferdanur Alpaslan Jan 2017

A Novel Optical Flow-Based Representation For Temporal Video Segmentation, Samet Akpinar, Ferdanur Alpaslan

Turkish Journal of Electrical Engineering and Computer Sciences

Temporal video segmentation is a field of multimedia research enabling us to temporally split video data into semantically coherent scenes. In order to develop methods challenging temporal video segmentation, detecting scene boundaries is one of the more widely used approaches. As a result, representation of temporal information becomes important. We propose a new temporal video segment representation to formalize video scenes as a sequence of temporal motion change information. The idea here is that some sort of change in the optical flow character determines motion change and cuts between consecutive scenes. The problem is eventually reduced to an optical flow-based …

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Low-Frequency Exposure Analysis Using Electric And Magnetic Field Measurements And Predictions In The Proximity Of Power Transmission Lines In Urban Areas, Hamza Feza Carlak, Şükrü Özen, Süleyman Bi̇lgi̇n Jan 2017

Low-Frequency Exposure Analysis Using Electric And Magnetic Field Measurements And Predictions In The Proximity Of Power Transmission Lines In Urban Areas, Hamza Feza Carlak, Şükrü Özen, Süleyman Bi̇lgi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

In recent years, increasing energy demand has resulted in more loading in power transmission lines and correspondingly more electric and magnetic field occurrence. In this paper, electric and magnetic field levels around high voltage power transmission lines are measured and then calculated analytically by simulating the realistic case. Moreover, the field levels around these power lines have been predicted using multilayer perceptron artificial neural network (ANN) and generalized regression neural network models. Typical 154 kV power transmission line facilities of Turkey have been studied. Electric and magnetic field levels in the proximity of power transmission lines have been predicted with …

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New Approach To Design A Compact Triband Bandpass Filter Using A Multilayer Structure, Sohrab Majidifar, Mohsen Hayati Jan 2017

New Approach To Design A Compact Triband Bandpass Filter Using A Multilayer Structure, Sohrab Majidifar, Mohsen Hayati

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a triband bandpass filter is presented using a dual-layer structure. Three H-shaped resonators are utilized in the proposed structure. The first and third resonators are placed at the top and bottom layers, respectively. The second resonator is divided into two parts: one half is on the top and the other half is at the bottom. The effective permittivity at the first and second layers is different, resulting in different resonant frequencies. The fabricated triband bandpass filter operates at 5.44/6.98/8.36 GHz, with fractional bandwidths of 6.6% 6% 2.9% and measured minimal insertion losses of 1.9/1.7/2 dB.

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Design Of A Sharp Response Microstrip Lowpass Filter Using Taper Loaded And Radial Stub Resonators, Sohrab Majidifar, Mohsen Hayati Jan 2017

Design Of A Sharp Response Microstrip Lowpass Filter Using Taper Loaded And Radial Stub Resonators, Sohrab Majidifar, Mohsen Hayati

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a compact microstrip lowpass filter with a wide stopband and a very sharp roll-off. This structure consists of two dual taper-loaded resonators that are connected to the radial stubs. The resonators are described using an LC model, and its Z- and S-parameters are extracted as a function of the LC component. In the proposed filter, cut-off frequency is placed at 1.76 GHz, roll-off rate is higher than 142 dB/GHz, insertion loss is less than 0.42 dB from DC to 1.5 GHz, and rejection is greater than -24 dB from 1.88 to 15.2 GHz. The proposed filter is …

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A Low Power Memoryless Rom Design Architecture For A Direct Digital Frequency Synthesizer, Salah Alkurwy, Sawal Ali, Md.Shabiul Islam, Md. Faizul Idros Jan 2017

A Low Power Memoryless Rom Design Architecture For A Direct Digital Frequency Synthesizer, Salah Alkurwy, Sawal Ali, Md.Shabiul Islam, Md. Faizul Idros

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a novel, memoryless, read-only memory (ROM) design architecture for a direct digital frequency synthesizer (DDFS). A pipelining technique is proposed to increase the phase accumulator (PA) throughput. However, this technique increases the number of registers as the pipeline stages increase. The shifted clocking technique is used to reduce the pipelined PA registers. The wave symmetry technique is applied to store (0: $\pi $/2) of the sine wave. The ROM is partitioned into three four-bit sub-ROMs based on the angular decomposition technique and trigonometric identity. A novel approach of memoryless ROM design technique is proposed and implemented in …

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A New Proposal For The Design Of Hybrid Ac/Dc Microgrids Toward High Power Quality, Pouria Goharshenasan Khorasani, Mahmood Joorabian, Seyed Ghodratolah Seifosadat Jan 2017

A New Proposal For The Design Of Hybrid Ac/Dc Microgrids Toward High Power Quality, Pouria Goharshenasan Khorasani, Mahmood Joorabian, Seyed Ghodratolah Seifosadat

Turkish Journal of Electrical Engineering and Computer Sciences

Considering the advantages of DC microgrids, the extension of the conventional AC distribution grid can be implemented using a DC microgrid. This justifies the realization of a hybrid AC/DC microgrid. In the present study, a new global solution is presented to improve the power quality and to fully compensate the reactive power of an AC microgrid using DC bus capacity while introducing a new design for a hybrid AC/DC microgrid. In the new design, back-to-back connections of two series and parallel converters, as well as the presentation of new controllers and simultaneous utilization of an earthing switch, are proposed. The …

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