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Articles 13831 - 13860 of 25611

Full-Text Articles in Computer Engineering

A New Segmentation Method Of Cerebral Mri Images Based On The Fuzzy C-Means Algorithm, Mohamed Zaki Abderrezak, Mouatez Billah Chibane, Karim Mansour Jan 2017

A New Segmentation Method Of Cerebral Mri Images Based On The Fuzzy C-Means Algorithm, Mohamed Zaki Abderrezak, Mouatez Billah Chibane, Karim Mansour

Turkish Journal of Electrical Engineering and Computer Sciences

The aim of this work is to present a new method for cerebral MRI image segmentation based on modification of the fuzzy c-means (FCM) algorithm. We used local and nonlocal information distance in the initial function of the robust FCM model. The obtained results of the classification of MRI images showed the effectiveness of the suggested model. Calculation of the similarity index confirms that our method is well adapted to MRI images even in the presence of noise.

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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 …

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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 …

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Effect Of Uniform And Dolph-Chebyshev Excitations On The Performance Of Circular Array Antennas, Mohan Kachalai Narasimman, Yogesh Kumar Choukiker, Srinivasa Rao Zinka, Kannadassan Dhanaraj Jan 2017

Effect Of Uniform And Dolph-Chebyshev Excitations On The Performance Of Circular Array Antennas, Mohan Kachalai Narasimman, Yogesh Kumar Choukiker, Srinivasa Rao Zinka, Kannadassan Dhanaraj

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the design and simulation of microstrip circular antenna arrays and studies the effect of excitation with uniform and Dolph--Chebyshev distribution. With side lobe level of 20 dB and 8 microstrip circular patches, the circular array has been demonstrated with minimum grating lobes. The effects of patch and antenna array length on directivity, radiation patterns, and side lobe are also studied in detail. It is found that these antenna arrays are suitable for radar application.

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Using The Variable Width In A Planar Inductor On Kapton For Optimizing Its Performance, Hayet Kharbouch, Azzedine Hamid, Thierry Lebey, Vincent Bley, Leon Havez, Celine Combette Jan 2017

Using The Variable Width In A Planar Inductor On Kapton For Optimizing Its Performance, Hayet Kharbouch, Azzedine Hamid, Thierry Lebey, Vincent Bley, Leon Havez, Celine Combette

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we examine the design of planar inductors and consider an expansion of the conductor to reduce its resistance. An increase in the number of turns increases the proximity effect, capacitive coupling, and skin effect. The resulting effect will translate into an increase in the area occupied by the inductor and a decrease in the inductors' performances. In order to solve such difficulties, an alternative approach is to design tapered inductors. For the same electrical and geometrical characteristics, a tapered inductor occupies a larger area than a standard inductor. Our approach consists of designing a new concept regarding …

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High Inductance Fractal Inductors For Wireless Applications, Akhendra Kumar Padavala, Bheema Rao Nistala Jan 2017

High Inductance Fractal Inductors For Wireless Applications, Akhendra Kumar Padavala, Bheema Rao Nistala

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents fractal-based inductors for industrial, scientific, and medical applications in a frequency range of 3--500 MHz. The proposed inductors are designed based on the Hilbert space-filling curve and omega-shaped space-filling curve. The fractal inductors are designed and simulated by using a full wave high frequency structural simulator. The Hilbert curve-based fractal loop inductor and omega curve-based fractal loop inductor achieve improvements in the inductance value of 21% to 31% and 11% to 30.88%, respectively, over reported standard inductors. The printed inductors are constructed on 3.2 mm RT/Duroid 5770 substrate and measured with a network analyzer (E8363B). It was …

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S-Visibility Problem In Vlsi Chip Design, Marzieh Eskandari, Mahdieh Yeganeh Jan 2017

S-Visibility Problem In Vlsi Chip Design, Marzieh Eskandari, Mahdieh Yeganeh

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new version of very large scale integration (VLSI) layouts compaction problem is considered. Bar visibility graph (BVG) is a simple geometric model for VLSI chip design and layout problems. In all previous works, vertical bars or other chip components in the plane model gates, as well as edges, are modeled by horizontal visibilities between bars. In this study, for a given set of vertical bars, the edges can be modeled with orthogonal paths known as staircases. Therefore, we consider a new version of bar visibility graphs (BsVG). We then present an algorithm to solve the s-visibility …

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Broadband High Power Stripline Compact Multisection Coupled-Line Coupler For Vhf And Uhf Applications, Mehdi Taherkhani, Arash Ahmadi Jan 2017

Broadband High Power Stripline Compact Multisection Coupled-Line Coupler For Vhf And Uhf Applications, Mehdi Taherkhani, Arash Ahmadi

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a broadband stripline multisection coupled-line coupler is designed and fabricated. The coupler has 50 dB coupling in the frequency range of 30 to 1000 MHz. The coupler is designed by cascading several unit section couplers consisting of two unequal length coupled line sections connected by different length uncoupled transmission lines. The unequal length coupled line sections with different coupling coefficients introduce a degree of freedom for bandwidth improvement and can help to reduce the overall dimensions of the multisection coupler. A lumped-element compensating circuit is used in series with the coupling port of the coupler to flatten …

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Sample Group And Misplaced Atom Dictionary Learning For Face Recognition, Meng Wang, Zhengping Hu, Zhe Sun, Mei Zhu, Mei Sun Jan 2017

Sample Group And Misplaced Atom Dictionary Learning For Face Recognition, Meng Wang, Zhengping Hu, Zhe Sun, Mei Zhu, Mei Sun

Turkish Journal of Electrical Engineering and Computer Sciences

Latest research results have demonstrated the effectiveness of both sparse (or collaborative) representation and dictionary learning for problem solving in face recognition and other signal classification. Considering the fact that an informative dictionary helps a lot in sparse coding, a novel model that consists of group dictionary learning and high-quality joint kernel collaborative representation was proposed in this paper, where rich information from original and virtual space was mined and constructed as a sample group space to improve classification accuracy. Meanwhile, joint kernel collaborative representation with an $\ell_{2}$-regularization-based classifier was used to capture more nonlinear structure and minimize the time …

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

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

Turkish Journal of Electrical Engineering and Computer Sciences

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

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

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

Turkish Journal of Electrical Engineering and Computer Sciences

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

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

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

Turkish Journal of Electrical Engineering and Computer Sciences

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

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Ann-Based Shepwm Using A Harmony Search On A New Multilevel Inverter Topology, Fayçal Chabni, Rachid Taleb, M'Hamed Helaimi Jan 2017

Ann-Based Shepwm Using A Harmony Search On A New Multilevel Inverter Topology, Fayçal Chabni, Rachid Taleb, M'Hamed Helaimi

Turkish Journal of Electrical Engineering and Computer Sciences

This article presents the application of the harmony search (HS) optimization algorithm for selective harmonic elimination PWM (SHEPWM) in a new topology of multilevel inverters with reduced number of electronic switching elements. The main objective of the harmonic elimination strategy is eliminating undesired low-rank harmonics in order to improve the quality of the output waveform. The harmonic elimination strategy is achieved by solving a system of nonlinear equations. In this paper harmony search optimization is applied using artificial neural networks (ANNs) on a new 21-level inverter topology. The algorithm is based on a music improvisation process. MATLAB programming software is …

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Visual Data Mining, Syeda Sadiya Jan 2017

Visual Data Mining, Syeda Sadiya

All Graduate Projects

Occlusion is one of the major problems for interactive visual knowledge discovery and data mining in the process of finding patterns in multidimensional data.This project proposes a hybrid method that combines visual and analytical means to deal with occlusion in visual knowledge discovery called as GLC-S which uses visualization of n-D data in 2D in a set of Shifted Paired Coordinates (SPC). A set of Shifted Paired Coordinates for n-D data consists of n/2 pairs of common Cartesian coordinates that are shifted relative to each other to avoid their overlap. Each n-D point A is represented as a directed graph …

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A Machine Learning Approach For Enhancing Security And Quality Of Service Of Optical Burst Switching Networks, Adel Dabash A. Rajab Jan 2017

A Machine Learning Approach For Enhancing Security And Quality Of Service Of Optical Burst Switching Networks, Adel Dabash A. Rajab

Theses and Dissertations

The Optical Bust Switching (OBS) network has become one of the most promising switching technologies for building the next-generation of internet backbone infrastructure. However, OBS networks still face a number of security and Quality of Service (QoS) challenges, particularly from Burst Header Packet (BHP) flooding attacks. In OBS, a core switch handles requests, reserving one of the unoccupied channels for incoming data bursts (DB) through BHP. An attacker can exploit this fact and send malicious BHP without the corresponding DB. If unresolved, threats such as BHP flooding attacks can result in low bandwidth utilization, limited network performance, high burst loss …

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Data Masking, Encryption, And Their Effect On Classification Performance: Trade-Offs Between Data Security And Utility, Juan C. Asenjo Jan 2017

Data Masking, Encryption, And Their Effect On Classification Performance: Trade-Offs Between Data Security And Utility, Juan C. Asenjo

CCAC Theses and Dissertations

As data mining increasingly shapes organizational decision-making, the quality of its results must be questioned to ensure trust in the technology. Inaccuracies can mislead decision-makers and cause costly mistakes. With more data collected for analytical purposes, privacy is also a major concern. Data security policies and regulations are increasingly put in place to manage risks, but these policies and regulations often employ technologies that substitute and/or suppress sensitive details contained in the data sets being mined. Data masking and substitution and/or data encryption and suppression of sensitive attributes from data sets can limit access to important details. It is believed …

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An Online Approach For Feature Selection For Classification In Big Data, Nasrin Banu Nazar, Radha Senthilkumar Jan 2017

An Online Approach For Feature Selection For Classification In Big Data, Nasrin Banu Nazar, Radha Senthilkumar

Turkish Journal of Electrical Engineering and Computer Sciences

Feature selection (FS), also known as attribute selection, is a process of selection of a subset of relevant features used in model construction. This process or method improves the classification accuracy by removing irrelevant and noisy features. FS is implemented using either batch learning or online learning. Currently, the FS methods are executed in batch learning. Nevertheless, these techniques take longer execution time and require larger storage space to process the entire dataset. Due to the lack of scalability, the batch learning process cannot be used for large data. In the present study, a scalable efficient Online Feature Selection (OFS) …

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A Novel Ddcc+ Based First-Order Current-Mode Active-C All-Pass Filter Using A Grounded Capacitor, Remzi̇ Arslanalp Jan 2017

A Novel Ddcc+ Based First-Order Current-Mode Active-C All-Pass Filter Using A Grounded Capacitor, Remzi̇ Arslanalp

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a novel first-order current-mode active-C all-pass filter based on a companding idea is proposed. In the design of the filter, a state space method is used. The proposed structure consists of only two plus-type differential difference current conveyors, nine external MOSFETs, and a single grounded capacitor. The dominant advantages of the proposed filter are briefly described as follows: offering resistorless design, consuming low power, having an electronic tunability property of its pole frequency, and not suffering from the disadvantage of any passive component matching conditions. By cascading two all-pass filters in a closed negative feedback loop, a …

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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.

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A Novel Approach For Extracting Ideal Exemplars By Clustering For Massivetime-Ordered Datasets, Ömer Faruk Ertuğrul Jan 2017

A Novel Approach For Extracting Ideal Exemplars By Clustering For Massivetime-Ordered Datasets, Ömer Faruk Ertuğrul

Turkish Journal of Electrical Engineering and Computer Sciences

The number and length of massive datasets have increased day by day and this yields more complex machine learning stages due to the high computational costs. To decrease the computational cost many methods were proposed in the literature such as data condensing, feature selection, and filtering. Although clustering methods are generally employed to divide samples into groups, another way of data condensing is by determining ideal exemplars (or prototypes), which can be used instead of the whole dataset. In this study, first the efficiency of traditional data condensing by clustering approach was confirmed according to obtained accuracies and condensing ratios …

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Evaluation Of Distance Education Websites: A Hybrid Multicriteria Approach, Mehmet Kabak, Eren Özceylan, Meti̇n Dağdevi̇ren, Tolga Genç Jan 2017

Evaluation Of Distance Education Websites: A Hybrid Multicriteria Approach, Mehmet Kabak, Eren Özceylan, Meti̇n Dağdevi̇ren, Tolga Genç

Turkish Journal of Electrical Engineering and Computer Sciences

This study provides an evaluation model that prioritizes the relative weights of various distance education websites. The proposed approach consists of four sequential steps. In the first step, 25 different subcriteria under 4 major criteria are gathered from the existing literature. Identified criteria are weighted by stakeholders of distance education websites using the analytic network process outlined in the second step. In the third step, the technique for order preference by similarity to ideal solution method is applied in order to rank the 15 different Turkish distance education website alternatives. Finally, in the fourth step, different scenario analyses are applied …

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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.

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A Reduced-Order Observer Based On Stator Flux Estimation With Straightforward Parameter Identification For Sensorless Control Of Dfigs, Rahim Ajabi Farshbaf, Mohammad Reza Azizian, Vahid Eslampanah Jan 2017

A Reduced-Order Observer Based On Stator Flux Estimation With Straightforward Parameter Identification For Sensorless Control Of Dfigs, Rahim Ajabi Farshbaf, Mohammad Reza Azizian, Vahid Eslampanah

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new reducer-order observer for sensorless control of doubly fed induction generators (DFIGs), based on the Luenberger algorithm. Stable operation of the suggested observer is also considered in the design guidelines. Stator flux is selected as the state variable for the observer and its estimation error is used to correct the observer operation. The gain matrix of the proposed observer is calculated on the basis of flux error dynamics. The adaptation mechanism of the proposed observer is selected based on an estimation of rotor currents. A proportional integrator (PI) block is used in the structure of the …

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Robust Control For Line-Of-Sight Stabilization Of A Two-Axis Gimbal System, Mehmet Baskin, Mehmet Kemal Leblebi̇ci̇oğlu Jan 2017

Robust Control For Line-Of-Sight Stabilization Of A Two-Axis Gimbal System, Mehmet Baskin, Mehmet Kemal Leblebi̇ci̇oğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Line-of-sight stabilization against various disturbances is an essential property of gimbaled imaging systems mounted on mobile platforms. In recent years, the importance of target detection from higher distances has increased. This has raised the need for better stabilization performance. For that reason, stabilization loops are designed such that they have higher gains and larger bandwidths. As these are required for good disturbance attenuation, sufficient loop stability is also needed. However, model uncertainties around structural resonances impose strict restrictions on sufficient loop stability. Therefore, to satisfy high stabilization performance in the presence of model uncertainties, robust control methods are required. In …

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Automated Module For Characterization Of Reference Standards Of Capacitance By Impedance-Matrix Method, Satish Singh, Thomas John Jan 2017

Automated Module For Characterization Of Reference Standards Of Capacitance By Impedance-Matrix Method, Satish Singh, Thomas John

Turkish Journal of Electrical Engineering and Computer Sciences

An automated module has been developed, implemented, and validated for the characterization of four-terminal-pair capacitance standards using an impedance-matrix method. These air-dielectric capacitance standards are being used as reference or transfer standards of capacitance at high frequency across national metrology institutes worldwide. In the reported work, an automated characterization module performs the acquisition of reference capacitance and residual capacitive parameters from an ultraprecision capacitance bridge. It also acquires single-port reactances of the capacitance standard from an impedance analyzer at frequencies ranging from 40 MHz to 100 MHz. The acquired capacitive and reactance parameters are stored structurally in arrays from where …

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Led Printers And Safe Fonts As Effective Protection Against The Formation Of Unwanted Emission, Ireneusz Kubiak Jan 2017

Led Printers And Safe Fonts As Effective Protection Against The Formation Of Unwanted Emission, Ireneusz Kubiak

Turkish Journal of Electrical Engineering and Computer Sciences

Due to the widespread use of computer equipment, electromagnetic protection of processed data is still an issue. Structurally modified commercial equipment is used to protect devices against this phenomenon. The acquisition costs of such modified devices are enormous. However, the market offers information devices with very low susceptibility to electromagnetic infiltration. Safe fonts are a new solution in the protection of sensitive information against electromagnetic infiltration processes. The use of safe fonts not only increases resistance to electromagnetic eavesdropping but also makes it impossible. These devices are computer printers that use a slat with hundreds of LEDs arranged in several …

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Fractional-Order Controller Design In Frequency Domain Using An Improved Nonlinear Adaptive Seeker Optimization Algorithm, Mano Ranjan Kumar, Vishwa Deepak, Subhojit Ghosh Jan 2017

Fractional-Order Controller Design In Frequency Domain Using An Improved Nonlinear Adaptive Seeker Optimization Algorithm, Mano Ranjan Kumar, Vishwa Deepak, Subhojit Ghosh

Turkish Journal of Electrical Engineering and Computer Sciences

Two nonlinear adaptive versions of the conventional seeker optimization algorithm (SOA) have been proposed for the design of fractional-order controllers using frequency domain specifications. The highly nonlinear and undetermined nature of equations resulting from controller design specifications rules out obtaining a closed-form solution. In this regard, the controller design task has been formulated as an optimization problem and solved using modified variants of the SOA. With the nonlinear adaptation of tuning parameters, the proposed variants of the SOA increase the probability of finding global optima along with improved convergence speed. This has been achieved by incorporating exponential weighting and chaotic …

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

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

Turkish Journal of Electrical Engineering and Computer Sciences

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

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

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

Turkish Journal of Electrical Engineering and Computer Sciences

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

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

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

Turkish Journal of Electrical Engineering and Computer Sciences

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

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