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Full-Text Articles in Physical Sciences and Mathematics

Image Compression Algorithm With Reduced Blocking Artifacts, Kritika Mittal, Kulbir Singh, Neeru Jindal Jan 2017

Image Compression Algorithm With Reduced Blocking Artifacts, Kritika Mittal, Kulbir Singh, Neeru Jindal

Turkish Journal of Electrical Engineering and Computer Sciences

The modern communication era has led to a proliferation of digital media contents. However, the large volume of data poses difficulties because of increased bandwidth and limited storage space. Hence, this has led to the need for compression techniques. Image compression with block processing allows the coder to adapt to local image statistics and exploit the correlation present among neighboring image pixels. The main degradation factor of block transform coding is blocking artifacts (visually undesirable patterns) at high compression ratios. The degradation occurs because of coarse quantization of the transform coefficients and the independent processing of the blocks. In this …


New Use Of The Hits Algorithm For Fast Web Page Classification, Mohamed Nadjib Meadi, Mohamed Chaouki Babahenini, Abdelmalik Taleb Ahmed Jan 2017

New Use Of The Hits Algorithm For Fast Web Page Classification, Mohamed Nadjib Meadi, Mohamed Chaouki Babahenini, Abdelmalik Taleb Ahmed

Turkish Journal of Electrical Engineering and Computer Sciences

The immense number of documents published on the web requires the utilization of automatic classifiers that allow organizing and obtaining information from these large resources. Typically, automatic web pages classifiers handle millions of web pages, tens of thousands of features, and hundreds of categories. Most of the classifiers use the vector space model to represent the dataset of web pages. The components of each vector are computed using the term frequency inversed document frequency (TFIDF) scheme. Unfortunately, TFIDF-based classifiers face the problem of the large-scale size of input data that leads to a long processing time and an increase in …


Intellimote: A Hybrid Classifier For Classifying Learners' Emotion In A Distributed E-Learning Environment, Lopa Mandal, Rohan Das, Samar Bhattacharya, Pramatha Nath Basu Jan 2017

Intellimote: A Hybrid Classifier For Classifying Learners' Emotion In A Distributed E-Learning Environment, Lopa Mandal, Rohan Das, Samar Bhattacharya, Pramatha Nath Basu

Turkish Journal of Electrical Engineering and Computer Sciences

A huge collection of textual, graphical, audio, and video contents are readily available on the Internet to be used for the purpose of learning. Sentimental feedbacks of learners posted at the end of many of these contents may be considered as genuine reactions of the learners who have gone through the contents. Such learners' sentiments are important inputs for judging the acceptability of a learning material. Analyzing such feedbacks using sentiment analysis techniques can identify the best reusable learning contents that may be used for developing new courseware. This can significantly reduce the time and effort of authoring, which is …


Aqueous Paramagnetic Solutions For Mri Phantoms At 3 T:A Detailed Study On Relaxivities, Kalaivani Thangavel, Emi̇ne Ülkü Saritaş Jan 2017

Aqueous Paramagnetic Solutions For Mri Phantoms At 3 T:A Detailed Study On Relaxivities, Kalaivani Thangavel, Emi̇ne Ülkü Saritaş

Turkish Journal of Electrical Engineering and Computer Sciences

Phantoms with known T$_{1}$ and T$_{2}$ values that are prepared using solutions of easily accessible paramagnetic agents are commonly used in MRI imaging centers, especially with the goal of validating the accuracy of quantitative imaging protocols. The relaxivity parameters of several agents were comprehensively examined at lower B$_{0}$ field strengths, but studies at 3 T remain limited. The main goal of this study is to measure r$_{1}$ and r$_{2}$ relaxivities of three common paramagnetic agents (CuSO$_{4}$, MnCl$_{2}$, and NiCl$_{2})$ at room temperature at 3 T. Separate phantoms were prepared at various concentrations of 0.05-0.5 mM for MnCl$_{2}$ and 1-6 mM …


Offset-Free Adaptive Nonlinear Model Predictive Control With Disturbance Observer For Dc-Dc Buck Converters, Bahareh Vatankhah, Mohammad Farrokhi Jan 2017

Offset-Free Adaptive Nonlinear Model Predictive Control With Disturbance Observer For Dc-Dc Buck Converters, Bahareh Vatankhah, Mohammad Farrokhi

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this paper is to design a nonlinear model predictive control for DC-DC buck converters to track constant reference signals with zero steady-state error. The online trained neural network (NN) model is employed as the predictor and the steady-state error, which is called the offset, is studied in the presence of the changes in system parameters and the external disturbances. The stability of the closed-loop system is investigated using the Lyapunov direct theory. The proposed method can provide offset-free behavior in the presence of constant disturbances. For rejecting nonconstant disturbances, a nonlinear disturbance observer based on the NN …


An Ultrafast All-Optical Switch Based On A Nonlinear Photonic Crystal Waveguide Using Single Crystal P-Toluene Sulfonate, Mahdi Taheri, Masood Omoomi Jan 2017

An Ultrafast All-Optical Switch Based On A Nonlinear Photonic Crystal Waveguide Using Single Crystal P-Toluene Sulfonate, Mahdi Taheri, Masood Omoomi

Turkish Journal of Electrical Engineering and Computer Sciences

A novel design of an all-optical switch is proposed based on a nonlinear photonic crystal Mach-Zehnder interferometer (PC-MZI) to get the maximum switching speed and the minimum consuming power. As far as we know, this is the first study using a nonlinear polymer in one of the PC-MZI arms for realizing the switching phenomenon. All used components, such as bends, waveguides, and splitters, were individually optimized. Finite difference time domain and plane wave expansion methods were also utilized for the simulation of light propagation in the proposed structures.


Bayesian Estimation Of Discrete-Time Cellular Neural Network Coefficients, Hakan Meti̇n Özer, Ati̇lla Özmen, Habi̇b Şenol Jan 2017

Bayesian Estimation Of Discrete-Time Cellular Neural Network Coefficients, Hakan Meti̇n Özer, Ati̇lla Özmen, Habi̇b Şenol

Turkish Journal of Electrical Engineering and Computer Sciences

A new method for finding the network coefficients of a discrete-time cellular neural network (DTCNN) is proposed. This new method uses a probabilistic approach that itself uses Bayesian learning to estimate the network coefficients. A posterior probability density function (PDF) is composed using the likelihood and prior PDFs derived from the system model and prior information, respectively. This posterior PDF is used to draw samples with the help of the Metropolis algorithm, a special case of the Metropolis-Hastings algorithm where the proposal distribution function is symmetric, and resulting samples are then averaged to find the minimum mean square error (MMSE) …


Rapidly Converging Solution For P-Centers In Nonconvex Regions, Monika Mangla, Deepak Garg Jan 2017

Rapidly Converging Solution For P-Centers In Nonconvex Regions, Monika Mangla, Deepak Garg

Turkish Journal of Electrical Engineering and Computer Sciences

This paper aims to locate $p$ resources in a nonconvex demand plane having $n $demand points. The objective of the location problem is to find the location for these $p$ resources so that the distance from each of $n$ demand points to its nearest resource is minimized, thus simulating a $p$-center problem. We employ various geometrical structures for solving this location problem. The suggested approach is also capable of finding the optimal value of $p$ so that all demand points have at least one resource at a distance $\Delta $, where $\Delta $ is the maximum permissible distance for emergency …


Edge Distance Graph Kernel And Its Application To Small Molecule Classification, Mehmet Tan Jan 2017

Edge Distance Graph Kernel And Its Application To Small Molecule Classification, Mehmet Tan

Turkish Journal of Electrical Engineering and Computer Sciences

Graph classification is an important problem in graph mining with various applications in different fields. Kernel methods have been successfully applied to this problem, recently producing promising results. A graph kernel that mostly specifies classification performance has to be defined in order to apply kernel methods to a graph classification problem. Although there are various previously proposed graph kernels, the problem is still worth investigating, as the available kernels are far from perfect. In this paper, we propose a new graph kernel based on a recently proposed concept called edge distance-k graphs. These new graphs are derived from the original …


A Frequency-Reconfigurable Elliptical Monopole Antenna For Cognitive Radio Networks, Santasri Koley, Debjani Mitra Jan 2017

A Frequency-Reconfigurable Elliptical Monopole Antenna For Cognitive Radio Networks, Santasri Koley, Debjani Mitra

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an elliptical disk monopole antenna with seven switchable states, including an ultrawideband (UWB) state and six narrowband states, is presented. It consists of an elliptical disk radiator to operate in the UWB mode for cognitive radio (CR) sensing. To operate in the narrowband mode, the antenna is fed through a defected ground structure (DGS) integrated microstrip line. Frequency reconfigurability is achieved by changing the DGS slot length using six electronic switches. The simple proposed design can cover a wide range of frequency bands from 0.75 to 12 GHz, has an omnidirectional radiation pattern with high gain, and …


Modeling Of Time Delay-Induced Multiple Synchronization Behavior Of Interneuronal Networks With The Izhikevich Neuron Model, Yüksel Çakir Jan 2017

Modeling Of Time Delay-Induced Multiple Synchronization Behavior Of Interneuronal Networks With The Izhikevich Neuron Model, Yüksel Çakir

Turkish Journal of Electrical Engineering and Computer Sciences

The synchronization behavior of the networks of fast-spiking interneurons is investigated by using one of the phenomenological neural network models, the Izhikevich model. Since electrical and chemical synapses exist within the same networks of inhibitory cells, delayed inhibitory and fast electrical synapses are coupled in the simulations. The effects of hybrid synapses in promoting synchronous activity in neural networks are investigated with short and long time delays. The distinct frequency bands observed in electroencephalography and magnetoencephalography signals are determined using the raster plots of neural networks. For quantitative comparison of activities in networks, the degree of synchrony in the network …


Application Of Reinforcement Learning For Active Noise Control, Seyed Amir Hoseini Sabzevari, Majid Moavenian Jan 2017

Application Of Reinforcement Learning For Active Noise Control, Seyed Amir Hoseini Sabzevari, Majid Moavenian

Turkish Journal of Electrical Engineering and Computer Sciences

Active noise control (ANC) systems are used to reduce the sound noise level by generating antinoise signals. M-Estimators are widely employed in ANC systems for updating the adaptive FIR filter taps used as the system controller. Observing the state-of-the-art M-estimators design shows that there is a need for further improvements. In this paper, a feedback ANC based on the reinforcement learning (RL) method is proposed. The sensitivity of the constant parameter in the RL method is checked. The effectiveness of the proposed method is proven by comparing the results with previous feedforward studies through computer simulations.


Impact Of Distributed Generator Controllers On The Coordination Of Overcurrent Relays In Microgrid, Niraj Kumar Choudhary, Soumya Ranjan Mohanty, Ravindra Kumar Singh Jan 2017

Impact Of Distributed Generator Controllers On The Coordination Of Overcurrent Relays In Microgrid, Niraj Kumar Choudhary, Soumya Ranjan Mohanty, Ravindra Kumar Singh

Turkish Journal of Electrical Engineering and Computer Sciences

In the presence of distributed generators (DGs) the fault current sensed by relay in the forward direction is larger than that in the reverse direction. Thus, it is required to have different relay settings for both forward and reverse directions. This paper investigates the impact of DG controller operating modes on the coordination of conventional and dual setting overcurrent relays (OCRs). The different DG control modes are voltage control mode (VCM) and current control mode (CCM). A comparative study of protection coordination is presented in both the operating modes of the DG. This scheme is tested on a 3-bus meshed …


An Experimental Study Of Indoor Rss-Based Rf Fingerprinting Localization Using Gsm And Wi-Fi Signals, Gökhan Çeli̇k, Hasari̇ Çelebi̇, Hakan Paşa Partal, Engi̇n Zeydan, İlyas Alper Karatepe, Ahmet Sali̇h Er Jan 2017

An Experimental Study Of Indoor Rss-Based Rf Fingerprinting Localization Using Gsm And Wi-Fi Signals, Gökhan Çeli̇k, Hasari̇ Çelebi̇, Hakan Paşa Partal, Engi̇n Zeydan, İlyas Alper Karatepe, Ahmet Sali̇h Er

Turkish Journal of Electrical Engineering and Computer Sciences

Localization of mobile users in indoor environments has many practical applications in daily life. In this paper, we study the performance of the received signal strength (RSS)-based radio frequency (RF) fingerprinting localization method in a shopping mall environment considering both calibration and practical measurement cases. In the calibration case, the test data for the RSS fingerprinting database are built offline by receiving signals from Global System for Mobile Communications (GSM) base stations, which are collected by a dedicated measurement tool, i.e. the Test Mobile System. In order to see the localization performance, the k-nearest neighbors (K-NN) and random decision forest …


Matching Points Of Interest With User Context: An Ann Approach, Özgün Yilmaz Jan 2017

Matching Points Of Interest With User Context: An Ann Approach, Özgün Yilmaz

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the design and development of an artificial neural network (ANN) for similarity value calculation in a context-aware system is proposed. This neural network is used by the neural agent of the iConAwa system. Since iConAwa is an intelligent, context-aware, multiagent system, it provides mobile users with context-aware information and services, and also provides communication with each other. Context and points of interest are modeled in a flexible and extensible way by using ontologies. iConAwa derives high-level implicit context from low-level explicit context by inference performed over the context ontology. This approach decouples context reasoning from the source …


Dynamic Slot-Based Carrier Scheduling Scheme For Downlink Multimedia Traffic Over Lte Advanced Networks With Carrier Aggregation, Ramachandran Vijayarani, Lakshmanan Nithyanandan Jan 2017

Dynamic Slot-Based Carrier Scheduling Scheme For Downlink Multimedia Traffic Over Lte Advanced Networks With Carrier Aggregation, Ramachandran Vijayarani, Lakshmanan Nithyanandan

Turkish Journal of Electrical Engineering and Computer Sciences

Carrier aggregation (CA) in long-term evolution advanced (LTE-A) networks is a promising tool for providing bandwidth extension for high data rate communication. In CA, the efficient scheduling of carriers has imposed a new challenge in the design of delay-sensitive carrier scheduling for mobile multimedia applications. In this paper, a new dynamic slot-based carrier scheduling scheme has been proposed for efficient resource allocation to support the quality of service (QoS) of mobile traffic over CA transmission. The key idea of this scheduling is the allocation of slots for each component carrier based on the queue state information, taking into consideration the …


Flexible (2 $\Times $ 1) Mimo Antenna With Electromagnetic Band Gap Unit Cell For Wimax Applications, Hussein Qasim Al-Fayyadh, Abdulghafor Abdulghafar Abdulhameed, Abdulkareem Swadi Abdullah, Haider Mohammed Alsabbagh Jan 2017

Flexible (2 $\Times $ 1) Mimo Antenna With Electromagnetic Band Gap Unit Cell For Wimax Applications, Hussein Qasim Al-Fayyadh, Abdulghafor Abdulghafar Abdulhameed, Abdulkareem Swadi Abdullah, Haider Mohammed Alsabbagh

Turkish Journal of Electrical Engineering and Computer Sciences

A flexible (2 $\times $ 1) multiple-input, multiple-output (MIMO) antenna with an electromagnetic band gap (EBG) unit cell is designed and measured. The proposed MIMO antenna is based on a circular slotted patch antenna to work at 3.5 GHz. An EBG unit cell is used to reduce the effect of the inherent mutual coupling produced between the closely spaced MIMO elements. The results show that the measured mutual coupling has been reduced by -11.6 dB (from -10 dB to -21.6 dB), and the measured realized gain has been increased by 1.074 dBi (from 1.59 dBi to 2.66 dBi). An improvement …


Multiclass Semantic Segmentation Of Faces Using Crfs, Khalil Khan, Nasir Ahmad, Khalil Ullah, Irfanud Din Jan 2017

Multiclass Semantic Segmentation Of Faces Using Crfs, Khalil Khan, Nasir Ahmad, Khalil Ullah, Irfanud Din

Turkish Journal of Electrical Engineering and Computer Sciences

Multiclass semantic image segmentation is widely used in a variety of computer vision tasks, such as object segmentation and complex scene understanding. As it decomposes an image into semantically relevant regions, it can be applied in segmentation of face images. In this paper, an algorithm based on multiclass semantic segmentation of faces is proposed using conditional random fields. In the proposed model, each node corresponds to a superpixel, while the neighboring superpixels are connected to nodes through edges. Unlike previous approaches, which rely on three or four classes, the label set is extended here to six classes, i.e. hair, eyes, …


Bandwidth Allocation For Multiple Iptv Users Sharing The Same Link: A Case Study Of Telecom Of Kosovo, Arianit Maraj, Adrian Shehu, Dardan Maraj, Ruzhdi Sefa Jan 2017

Bandwidth Allocation For Multiple Iptv Users Sharing The Same Link: A Case Study Of Telecom Of Kosovo, Arianit Maraj, Adrian Shehu, Dardan Maraj, Ruzhdi Sefa

Turkish Journal of Electrical Engineering and Computer Sciences

Almost all operators today are facing constant requests for multiple video services in a single household. In these situations, video services have to compete for finite network bandwidth and other equipment resources. Each of them requires different bandwidth capacities. This dynamic behavior can jeopardize both quality of service and quality of experience. One should keep in mind that some video channels require more bandwidth than others. Telecom of Kosovo (TK) is facing the same issues. The encoders at TK are not scalable and they treat all video streams equally, without taking into consideration the fact that some video streams require …


Optimal Fusion Of Multiple Gnss Signals Against Spoofing Sources, Selçuk Şahi̇n, Abedallatif Baba, Tolga Sönmez Jan 2017

Optimal Fusion Of Multiple Gnss Signals Against Spoofing Sources, Selçuk Şahi̇n, Abedallatif Baba, Tolga Sönmez

Turkish Journal of Electrical Engineering and Computer Sciences

Electronic attacks such as spoofing are becoming an increasing threat for satellite-based navigation receivers. The aim of this paper is to develop a preventive method against such electronic attacks. In our scheme, the localization system uses four different Global Navigation Satellite Systems (GNSSs): GPS, Galileo, GLONASS, and Compass. The signals received from these satellite systems will be fused inferentially and will be tracked according to a linear model. The linear model that we developed is solved with a Kalman filter and simulated under different scenarios. When a discrepancy is detected in the output of one of the GNSS receivers due …


Fpga-Based Soc For Hardware Implementation Of A Local Histogram-Based Video Shot Detector, Abdessalem Ben Abdelali, Mohamed Nidhal Krifa, Abdellatif Mtibaa Jan 2017

Fpga-Based Soc For Hardware Implementation Of A Local Histogram-Based Video Shot Detector, Abdessalem Ben Abdelali, Mohamed Nidhal Krifa, Abdellatif Mtibaa

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present a video application example and its implementation in a reconfigurable system-on-chip (SOC) platform. The proposed platform employs the benefits of field programmable gate array (FPGA) technology. A prototype based on a Xilinx Virtex-5 FPGA is developed. The application includes a video shot boundary detection module based on the local histogram (LH) technique. Diverse hardware module versions corresponding to different quantization levels and architectural solutions for an LH-based shot detection system are presented. The developed modules have different hardware resource occupations and can be used in a dynamic way to allow flexible management of the target …


Disk Scheduling With Shortest Cumulative Access Time First Algorithms, Nai̇l Akar, Çağlar Tunç, Mark Gaertner, Fati̇h Erden Jan 2017

Disk Scheduling With Shortest Cumulative Access Time First Algorithms, Nai̇l Akar, Çağlar Tunç, Mark Gaertner, Fati̇h Erden

Turkish Journal of Electrical Engineering and Computer Sciences

A new class of scheduling algorithms is proposed for disk drive scheduling. As opposed to choosing the request with the shortest access time in conventional shortest access time first (SATF) algorithms, we choose an ordered sequence of pending I/O requests at the scheduling instant with the shortest cumulative access time. Additionally, we introduce flexibility for forthcoming requests to alter the chosen sequence. Simulation results are provided to validate the effectiveness of the proposed disk scheduler. Throughput gains of 3% and above are shown to be attainable, although this occurs at the expense of increased computational complexity.


A Stable Marriage-Based Request Routing Framework For Interconnection Cdns, Bo Huang, Lijian Zou, Xiaowen Tong, Xiaoqun Yuan Jan 2017

A Stable Marriage-Based Request Routing Framework For Interconnection Cdns, Bo Huang, Lijian Zou, Xiaowen Tong, Xiaoqun Yuan

Turkish Journal of Electrical Engineering and Computer Sciences

Content delivery network (CDN) interconnection is a promising solution to addressing the limited service scale of CDNs. It scales the CDN's service footprint through the cooperation of CDNs without significantly changing the existing network architecture. However, in a CDN interconnection system, CDNs are independent of each other and each pursues its own goals, which means that cooperation is hard to establish and easy to break. In our paper, we propose a stable marriage-based routing framework to establish a strong cooperation service for CDNs and to select the `optimal' server for each request among the cooperative CDNs. To this end, we …


A Linear Magnetorheological Brake With Multipole Outer Coil Structure For High On-State And Low Off-State Force Outputs, Özgür Başer, Mehmet Alper Demi̇ray, Aytuğ Baş, Ergi̇n Kiliç, Gali̇p Ozan Erol Jan 2017

A Linear Magnetorheological Brake With Multipole Outer Coil Structure For High On-State And Low Off-State Force Outputs, Özgür Başer, Mehmet Alper Demi̇ray, Aytuğ Baş, Ergi̇n Kiliç, Gali̇p Ozan Erol

Turkish Journal of Electrical Engineering and Computer Sciences

A wide range of braking forces, from near zero to high values, is required in specific applications such as forces in haptic devices or steering stability in motorcycles. Classical piston cylinder type magnetorheological (MR) brakes are not suitable for these applications due to their high off-state forces. In this paper, a new linear type MR brake employing shear mode braking principle with a multipole outer coil structure is presented for high on-state and low off-state force outputs. To implement this device, an analytical model of the brake is derived by using magnetic circuit analysis to determine braking force. Magnetic finite …


Nonlinear Model Predictive Control Based On Fuzzy Wavelet Neural Network And Chaos Optimization, Mehrnoush Davanipour, Hanieh Asadipooya Jan 2017

Nonlinear Model Predictive Control Based On Fuzzy Wavelet Neural Network And Chaos Optimization, Mehrnoush Davanipour, Hanieh Asadipooya

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a combined controller is proposed for nonlinear dynamical systems. The controller is constructed by a fuzzy wavelet network and nonlinear model predictive control. Chaotic optimization, which is fast and robust, is applied to generate optimized controlled input in nonlinear model predictive control. The ability of the fuzzy wavelet neural network and the proposed controller is shown by simulation. It is illustrated that the proposed method is able to increase the speed of tracking in addition to having very little steady state error. Using chaotic optimization makes the controller robust in the presence of noise.


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.


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. …


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 …


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.


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 …