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Computer Engineering Commons

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2019

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Articles 1891 - 1920 of 2060

Full-Text Articles in Computer Engineering

Improving The Redundancy Of Knuth?S Balancing Scheme For Packet Transmissionsystems, Elie Ngomseu Mambou, Ebenezer Esenogho, Hendrik Ferreira Jan 2019

Improving The Redundancy Of Knuth?S Balancing Scheme For Packet Transmissionsystems, Elie Ngomseu Mambou, Ebenezer Esenogho, Hendrik Ferreira

Turkish Journal of Electrical Engineering and Computer Sciences

A simple scheme was proposed by Knuth to generate binary balanced code words from any information word. However, this method is limited in the sense that its redundancy is twice that of the full sets of balanced codes. The gap between Knuth?s algorithm?s redundancy and that of the full sets of balanced codes is significantly considerable. This paper attempts to reduce that gap. Furthermore, many constructions assume that a full balancing can be performed without showing the steps. A full balancing refers to the overall balancing of the encoded information together with the prefix. We propose an efficient way to …


Space-Track Modulation And Coding For High Density Aerial Vehicle Downlinknetworks With Free Space Optical And Visible Light Communications, Burhan Gülbahar Jan 2019

Space-Track Modulation And Coding For High Density Aerial Vehicle Downlinknetworks With Free Space Optical And Visible Light Communications, Burhan Gülbahar

Turkish Journal of Electrical Engineering and Computer Sciences

Aerial vehicles (AVs) have challenges in terms of realizing low complexity and wide coverage area wireless communications architectures, especially for crowded or high density groups of AVs with state-of-the-art free space optical (FSO) and radio frequency (RF) based system designs. FSO architectures generally target point-to-point high gain directional links while requiring strict acquisition and tracking due to the narrow beam width of laser transmitters with challenges of vibration, turbulence, misalignment, atmospheric absorption, scattering, and fading. In this article, a novel multiuser free space optical system design of modulation and coding denoted by space-track modulation and coding (STMC) is proposed for …


Verifiable Dynamic Searchable Encryption, Mohammad Etemad, Alpteki̇n Küpcü Jan 2019

Verifiable Dynamic Searchable Encryption, Mohammad Etemad, Alpteki̇n Küpcü

Turkish Journal of Electrical Engineering and Computer Sciences

Using regular encryption schemes to protect the privacy of the outsourced data implies that the client should sacrifice functionality for security. Searchable symmetric encryption (SSE) schemes encrypt the data in a way that the client can later search and selectively retrieve the required data. Many SSE schemes have been proposed, starting with static constructions, and then dynamic and adaptively secure constructions but usually in the honest-but-curious model. We propose a verifiable dynamic SSE scheme that is adaptively secure against malicious adversaries. Our scheme supports file modification, which is essential for efficiently working with large files, in addition to the ability …


A Postpruning Decision Algorithm Based On Loss Minimization, Ahmed M. Ahmed, Ali̇ Hakan Ulusoy, Ahmet Ri̇zaner Jan 2019

A Postpruning Decision Algorithm Based On Loss Minimization, Ahmed M. Ahmed, Ali̇ Hakan Ulusoy, Ahmet Ri̇zaner

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a post-pruning method known as zero-one loss function pruning (ZOLFP) that is based on zero-one loss function is introduced. The proposed ZOLFP method minimizes the expected loss, rather than evaluating the misclassification error rate of a node and its subtree. The subtree is pruned when expected loss of the node is less than or equal to the sum of the loss of its leaves. The experimental results demonstrate that ZOLFP method outperforms. Un-pruned C4.5 Decision Tree (UDT-C4.5) algorithm, reduced error pruning (REP), and minimum error pruning (MEP) in terms of performance accuracy in all used datasets. It …


A Hybrid Single-Source Shortest Path Algorithm, Hi̇lal Arslan, Murat Manguoğlu Jan 2019

A Hybrid Single-Source Shortest Path Algorithm, Hi̇lal Arslan, Murat Manguoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

The single-source shortest path problem arises in many applications, such as roads, social applications, and computer networks. Finding the shortest path is challenging, especially for graphs that contain a large number of vertices and edges. In this work, we propose a novel hybrid method that first sparsifies a given graph by removing most edges that cannot form the shortest path tree and then applies a classical shortest path algorithm to the sparser graph. Removing all the edges that cannot form the shortest path tree would be expensive since it is equivalent to solving the original problem. Therefore, we propose an …


Path-Oriented Random Testing Through Iterative Partitioning (Ip-Prt), Esmaeel Nikravan, Saeed Parsa Jan 2019

Path-Oriented Random Testing Through Iterative Partitioning (Ip-Prt), Esmaeel Nikravan, Saeed Parsa

Turkish Journal of Electrical Engineering and Computer Sciences

Path-oriented random testing aims at generating a uniformly distributed sequence of test data from a program input domain space to traverse a desired execution path of the program. To this aim, this article proposes a new algorithm to refine a program inputs domain space from invalid subdomains not covering the path. The validity of the subdomains is checked by a constraint propagation method against the path constraints (PCs). The proposed algorithm uses a divide and conquer technique to iteratively split the inputs domain into subdomains and each time refutes those subdomains that are inconsistent with the PCs. The remaining shrunken …


A Comparative Study Of Nonlinear Bayesian Filtering Algorithms For Estimation Ofgene Expression Time Series Data, Nesrine Amor, Asma Meddeb, Sahbi Marrouchi, Souad Chebbi Jan 2019

A Comparative Study Of Nonlinear Bayesian Filtering Algorithms For Estimation Ofgene Expression Time Series Data, Nesrine Amor, Asma Meddeb, Sahbi Marrouchi, Souad Chebbi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper addresses the problem of estimating the time series of a gene expression using nonlinear Bayesian filtering algorithms. The response of gene regulatory networks (GRNs) to functional requirements in the cell and environmental conditions evolves over time. Dynamic biological processes such as cancer progression and treatment recovery depend on the collected genetic profiles. These processes are behind genetic interactions that rewire over the course of time. The GRN was formulated as a nonlinear and non-Gaussian dynamic system defined by the gene measurement model and the unknown state is an evolution of the gene model. However, the GRN has a …


In-Field Failure Assessment Of Tractor Hydraulic System Operation Viapseudospectrum Of Acoustic Measurements, Saurabh Gupta, Mahdi Khosravy, Neeraj Gupta, Hemand Darbari Jan 2019

In-Field Failure Assessment Of Tractor Hydraulic System Operation Viapseudospectrum Of Acoustic Measurements, Saurabh Gupta, Mahdi Khosravy, Neeraj Gupta, Hemand Darbari

Turkish Journal of Electrical Engineering and Computer Sciences

Hydrological working conditions are critical indicators for the maintenance of tractor mechanical systems. This research presents a pseudospectrum approach to analyze the particle pollution level of the hydraulic filter in its aging process and thus on-time prediction and diagnosis of weak or faulty conditions. The practical experiments of pseudospectrum analysis are performed on oil filter sound records. For mobile application purposes, besides deployment of advanced audio recording equipment, three popular brands of cell phones are used. The soundtracks are recorded in different incremental stages of fluid contamination by pollutive particles until being choked based on the ISO4406 standard. The pseudospectrum …


Modified Self-Adaptive Local Search Algorithm For A Biobjective Permutation Flowshop Scheduling Problem, Çi̇ğdem Alabaş Uslu, Berna Dengi̇z, Canan Ağlan, İhsan Sabuncuoğlu Jan 2019

Modified Self-Adaptive Local Search Algorithm For A Biobjective Permutation Flowshop Scheduling Problem, Çi̇ğdem Alabaş Uslu, Berna Dengi̇z, Canan Ağlan, İhsan Sabuncuoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Interest in multiobjective permutation flow shop scheduling (PFSS) has increased in the last decade to ensure effective resource utilization. This study presents a modified self-adaptive local search (MSALS) algorithm for the biobjective permutation flow shop scheduling problem where both makespan and total flow time objectives are minimized. Compared to existing sophisticated heuristic algorithms, MSALS is quite simple to apply to different biobjective PFSS instances without requiring effort or time for parameter tuning. Computational experiments showed that MSALS is either superior to current heuristics for Pareto sets or is incomparable due to other performance indicators of multiobjective problems.


Energy-Efficient Scheduling For Real-Time Tasks Using Dynamic Slack Reclamation, Vasanthamani Kannaian, Visalakshi Palanisamy Jan 2019

Energy-Efficient Scheduling For Real-Time Tasks Using Dynamic Slack Reclamation, Vasanthamani Kannaian, Visalakshi Palanisamy

Turkish Journal of Electrical Engineering and Computer Sciences

The application domains of portable embedded real-time systems range from safety-critical applications like electronic control units in the automotive sector to entertainment applications like digital cameras and setup boxes in the consumer electronics sector. These systems attract users with multiple and sophisticated functionalities in a single system. The developments in VLSI technology have enabled IC manufacturers to incorporate more features in a single die, which facilitates these multipurpose systems. The increase in features and functionalities has a direct impact on power consumption and has to be strictly accounted for in the design of these embedded systems. The possibility of achieving …


State-Space Identification Of Switching Linear Discrete Time-Periodic Systems Withknown Scheduling Signals, İsmai̇l Uyanik, Hasan Hamzaçebi̇, Mustafa Mert Ankarali Jan 2019

State-Space Identification Of Switching Linear Discrete Time-Periodic Systems Withknown Scheduling Signals, İsmai̇l Uyanik, Hasan Hamzaçebi̇, Mustafa Mert Ankarali

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we propose a novel frequency domain state-space identification method for switching linear discrete time-periodic (LDTP) systems with known scheduling signals. The state-space identification problem of linear time-invariant (LTI) systems has been widely studied both in the time and frequency domains. Indeed, there have been several studies that also concentrated on state-space identification of both continuous and discrete linear time-periodic (LTP) systems. The focus in this study is the family of LDTP systems that switch among a finite set of subsystems triggered by known periodic scheduling signals. We address the state-space identification of such systems in frequency domain …


Between-Host Hiv Model: Stability Analysis And Solution Using Memeticcomputing, Musharif Ahmed, Ijaz Mansoor Qureshi, Muhammad Aamer Saleem, Muhammad Zubair, Saad Zafar Jan 2019

Between-Host Hiv Model: Stability Analysis And Solution Using Memeticcomputing, Musharif Ahmed, Ijaz Mansoor Qureshi, Muhammad Aamer Saleem, Muhammad Zubair, Saad Zafar

Turkish Journal of Electrical Engineering and Computer Sciences

HIV poses a great threat to humanity for two major reasons. First it attacks the immunity system of the body and second, it is epidemic in nature. Mathematical models of HIV have been instrumental in understanding and controlling the infection. In this paper, we solve the between host epidemic model of HIV, described by nonlinear coupled differential equations, by using memetic computing. Under this model, the sexually active population is divided into four classes and we investigate the transfer of individuals from one class to another. The solution consists of Bernstein polynomials whose parameters have been optimized by using differential …


Cloud-Supported Machine Learning System For Context-Aware Adaptive M-Learning, Muhammad Adnan, Asad Habib, Jawad Ashraf, Shafaq Mussadiq Jan 2019

Cloud-Supported Machine Learning System For Context-Aware Adaptive M-Learning, Muhammad Adnan, Asad Habib, Jawad Ashraf, Shafaq Mussadiq

Turkish Journal of Electrical Engineering and Computer Sciences

It is a knotty task to amicably identify the sporadically changing real-world context information of a learner during M-learning processes. Contextual information varies greatly during the learning process. Contextual information that affects the learner during a learning process includes background knowledge, learning time, learning location, and environmental situation. The computer programming skills of learners improve rapidly if they are encouraged to solve real-world programming problems. It is important to guide learners based on their contextual information in order to maximize their learning performance. In this paper, we proposed a cloud-supported machine learning system (CSMLS), which assists learners in learning practical …


Dop: Discover Objects And Paths, A Model For Automated Navigation Andselection In Virtual Environments, Muhammad Raees, Sehat Ullah Jan 2019

Dop: Discover Objects And Paths, A Model For Automated Navigation Andselection In Virtual Environments, Muhammad Raees, Sehat Ullah

Turkish Journal of Electrical Engineering and Computer Sciences

Navigation and selection are the two interaction tasks often needed for the manipulation of an object in a synthetic world. An interface that supports automatic navigation and selection may increase the realism of a virtual reality (VR) system. Such an engrossing interface of a VR system is possible by incorporating machine learning (ML) into the realm of the virtual environment (VE). The use of intelligence in VR systems, however, is a milestone yet to be achieved to make seamless realism in a VE possible. To improve the believability of an intelligent virtual agent (IVA), this research work presents DOP (Discover …


Patient Comfort Level Prediction During Transport Using Artificial Neural Network, Zeljko Jovanovic, Marija Blagojevic, Dragan Jankovic, Aleksandar Peulic Jan 2019

Patient Comfort Level Prediction During Transport Using Artificial Neural Network, Zeljko Jovanovic, Marija Blagojevic, Dragan Jankovic, Aleksandar Peulic

Turkish Journal of Electrical Engineering and Computer Sciences

Since patient comfort during transport is a matter of paramount importance, this paper aims to determine the possibilities of applying neural networks for its prediction and monitoring. Specific objectives of the research include monitoring and predicting patient transport comfort, with subjective assessment of comfort by medical personnel. An original Android application that collects signals from an accelerometer and a GPS sensor was used with the aim of achieving the research goals. The collected signals were processed and a total of twelve parameters were calculated. A multilayer perceptron was created in the proposed research. The evaluation results indicate acceptable accuracy and …


Toxicity Prediction Of Small Drug Molecules Of Aryl Hydrocarbon Receptor Using Aproposed Ensemble Model, Vishan Kumar Gupta, Prashant Singh Rana Jan 2019

Toxicity Prediction Of Small Drug Molecules Of Aryl Hydrocarbon Receptor Using Aproposed Ensemble Model, Vishan Kumar Gupta, Prashant Singh Rana

Turkish Journal of Electrical Engineering and Computer Sciences

Quantitative structure-activity relationships and quantitative structure?property relationships have proved their usefulness for predicting toxicities of drug molecules regarding their biological activities. In silico toxicity prediction techniques are essential for reducing testing on rodents (in vivo) and for a less time-consuming and more cost-efficient alternative for the identification of toxic effects at an early stage of drug development. The authors aim to build a prediction model for better assessment of toxicity to quickly and efficiently test whether certain chemical compounds have the potential to disrupt the processes in the human body that may adversely affect human health. Here, we have proposed …


Available Transfer Capability Enhancement With Facts Using Hybrid Pi-Pso, Abubakar Sadiq Ahmad, Sunusi Sani Adamu, Muhammad Buhari Jan 2019

Available Transfer Capability Enhancement With Facts Using Hybrid Pi-Pso, Abubakar Sadiq Ahmad, Sunusi Sani Adamu, Muhammad Buhari

Turkish Journal of Electrical Engineering and Computer Sciences

In deregulation, growth in electrical loads necessitates improving power delivery, while nondiscriminatory access to transmission grid is a requirement. Deregulation causes a significant rise in transactions, which requires adequate transfer capability to secure economic transactions. In sustainable power delivery, FACTS devices are deployed to enhance available transfer capability (ATC). However, the high investment cost of FACTS makes the problem formulation a multiobjective optimization: power transfer maximization and minimization of FACTS sizes. Furthermore, due to the complexity in optimizing the control variables of voltage source converter types of FACTS, often the solution results in local optima and high computational time. This …


Robust Power System State Estimation By Appropriate Selection Of Tolerance Forthe Least Measurement Rejected Algorithm, Mohammad Shoaib Shahriar, Ibrahim Omar Habiballah Jan 2019

Robust Power System State Estimation By Appropriate Selection Of Tolerance Forthe Least Measurement Rejected Algorithm, Mohammad Shoaib Shahriar, Ibrahim Omar Habiballah

Turkish Journal of Electrical Engineering and Computer Sciences

Modern power systems are highly complicated and nonlinear in nature. Accurate estimation of the power system states (voltage-magnitude and phase-angle) is required for the secure operation of the power system. The presence of bad-data measurements in meters has made this estimation process challenging. An efficient estimator should detect and eliminate the effect of bad data during the estimation process. Least measurement rejected (LMR) is a robust estimator that has been found successful in dealing with various categories of bad data. The performance of LMR depends upon the proper selection of a tolerance for each measurement. This paper presents a novel …


Wavelet Energy-Based Stable And Unstable Power Swing Detection Scheme Fordistance Relays, Naga Chaitanya Munukutla, Venkata Siva Krishna Rao Gadi, Ramamoorty Mylavarapu Jan 2019

Wavelet Energy-Based Stable And Unstable Power Swing Detection Scheme Fordistance Relays, Naga Chaitanya Munukutla, Venkata Siva Krishna Rao Gadi, Ramamoorty Mylavarapu

Turkish Journal of Electrical Engineering and Computer Sciences

Distance relays are susceptible to maloperation during postfault power oscillations in the system. This unintended operation of relays may lead to power system blackout. It is due to their inability to distinguish a stable from an unstable power swing and to take a tripping decision appropriately. This research paper proposes a fast and wavelet energy-based method to detect stable and unstable power swings for distance relays. The proposed method computes the angular velocity of an equivalent machine developed from the measurements available at a bus. The energy in the low frequency band of the equivalent machine angular velocity will assist …


Real-Time Implementation Of Electronic Power Transformer Based On Intelligentcontroller, Hakan Açikgöz, Ökkeş Fati̇h Keçeci̇oğlu, Mustafa Şekkeli̇ Jan 2019

Real-Time Implementation Of Electronic Power Transformer Based On Intelligentcontroller, Hakan Açikgöz, Ökkeş Fati̇h Keçeci̇oğlu, Mustafa Şekkeli̇

Turkish Journal of Electrical Engineering and Computer Sciences

Along with the rapid advances in power electronics and semiconductor technology, electronic power transformers (EPTs), which are expected to replace conventional power transformers in the future, are being developed and designed. This study presents the dynamic performance of the intelligent controller structure in the control of an EPT. The EPT structure, consisting of the input, isolation, and output stages, is designed for experimental and simulation studies. A three-phase pulse width modulation (PWM) rectifier is used to rectify the grid voltages at the input stage of EPT. The DC-bus voltage of the three-phase PWM rectifier is controlled by a neuro-fuzzy controller …


Design Of Energy Recovery Systems: Thermoelectric Combi Boiler Generator Andpower Analysis, Abdullah Hakan Yavuz Jan 2019

Design Of Energy Recovery Systems: Thermoelectric Combi Boiler Generator Andpower Analysis, Abdullah Hakan Yavuz

Turkish Journal of Electrical Engineering and Computer Sciences

Gas-fired combi boilers are commonly used to meet the need for heating and general-purpose hot water in developing countries. In this study, a thermoelectric combi boiler generator (TECBG) was developed. When the boiler is operated, cold water flows through the cold surface of TECBG and enters the boiler. In the same way, it is used by flows through the hot surface of TECBG in heated water. Thus, temperature difference occurrs between the surfaces of TECBG. The temperature difference is converted into electrical energy by Seebeck effect. The proposed system was implemented on a domestic combi boiler. The maximum temperature difference …


Optimal Dg Allocation For Enhancing Voltage Stability And Minimizing Power Loss Using Hybrid Gray Wolf Optimizer, Salah Kamel, Ayman Awad, Hussein Abdel-Mawgoud, Francisco Jurado Jan 2019

Optimal Dg Allocation For Enhancing Voltage Stability And Minimizing Power Loss Using Hybrid Gray Wolf Optimizer, Salah Kamel, Ayman Awad, Hussein Abdel-Mawgoud, Francisco Jurado

Turkish Journal of Electrical Engineering and Computer Sciences

High penetration of photovoltaic and wind turbine-based distributed generators (DGs) can help reduce carbon emissions which is an important goal for the whole world. DG can be used to improve the voltage stability, present generation reserve/emergency, and consequently, the system power quality can be improved. However, it is very important to select the right size and location of a DG so that the power system can increase the gained benefits of such an installation to the maximum. In this paper, a hybrid optimization technique is proposed to determine the optimal allocation of DG in the standard IEEE 33-bus radial distribution …


Transmission Expansion Planning Based On A Hybrid Genetic Algorithm Approachunder Uncertainty, Ercan Şenyi̇ği̇t, Selçuk Mutlu, Bi̇lal Babayi̇ği̇t Jan 2019

Transmission Expansion Planning Based On A Hybrid Genetic Algorithm Approachunder Uncertainty, Ercan Şenyi̇ği̇t, Selçuk Mutlu, Bi̇lal Babayi̇ği̇t

Turkish Journal of Electrical Engineering and Computer Sciences

Transmission expansion planning (TEP) is one of the key decisions in power systems. Its impact on the system?s operation is excessive and long-lived. The aim of TEP is to determine new transmission lines effectively for a current transmission grid to fulfill the model objectives. However, to obtain a solution, especially under uncertainty, is extremely difficult due to the nonlinear mixed-integer structure of the TEP problem. In this paper, first genetic algorithm (GA) approaches for TEP are reviewed in the literature and then a new hybrid GA with linear modeling is proposed. The proposed GA method has a flexible structure and …


A New Hybrid Gravitational Search-Teaching-Learning-Based Optimization Methodfor The Solution Of Economic Dispatch Of Power Systems, Mehmet Fati̇h Tefek, Harun Uğuz Jan 2019

A New Hybrid Gravitational Search-Teaching-Learning-Based Optimization Methodfor The Solution Of Economic Dispatch Of Power Systems, Mehmet Fati̇h Tefek, Harun Uğuz

Turkish Journal of Electrical Engineering and Computer Sciences

The economic dispatch problem (EDP) is a complex, constrained, and nonlinear optimization problem. In the EDP, the active power bus should operate between the minimum and maximum bus limits to minimize the fuel cost. In this study, a fast, efficient, and reliable hybrid gravitational search algorithm-teaching learning based optimization (GSA-TLBO) method was proposed for the purpose of solving the EDP in power systems. The proposed method separates the search space into two sections as global and local searching. In the first part, searching was carried out by GSA method effectively to form the second search space. In the second part, …


Automatic Generation Control Analysis Of Power System With Nonlinearities Andelectric Vehicle Aggregators With Time-Varying Delay Implementing A Novel Control Strategy, Nimai Charan Patel, Binod Kumar Sahu, Manoj Kumar Debnath Jan 2019

Automatic Generation Control Analysis Of Power System With Nonlinearities Andelectric Vehicle Aggregators With Time-Varying Delay Implementing A Novel Control Strategy, Nimai Charan Patel, Binod Kumar Sahu, Manoj Kumar Debnath

Turkish Journal of Electrical Engineering and Computer Sciences

Automatic generation control (AGC) also known as load frequency control plays a vital role in interconnected power system for frequency regulation. Electric vehicles (EVs) with battery as the storage device can participate in frequency regulation service. In practice, a large number of EVs are aggregated as a single unit called EV aggregator for participation in frequency regulation service in AGC system. Participation of EV aggregators in AGC system for frequency regulation will be encouraged in near future because EVs have less environmental pollution than the conventional vehicles. However, participation of EV aggregators in AGC system may introduce time delay which …


Design Optimization Using Dielectric Slab For Efficient Microwave Heating, Sofiya Ali Mekonnen, Si̇bel Yeni̇kaya Jan 2019

Design Optimization Using Dielectric Slab For Efficient Microwave Heating, Sofiya Ali Mekonnen, Si̇bel Yeni̇kaya

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, usage of a dielectric slab on the top and bottom sides, on the top side, and on the bottom side of a clay sample was presented as a means of improving heating efficiency in multimode applicator. In order to accomplish the optimization procedure, we used four different dielectric slab types having different thickness values. The simulated results show that by using additional dielectric slab it is possible to increase the electric field intensity inside the applicator and obtain higher power absorption rates within the sample and high-efficiency designs.


Design Of Inverted-F Antenna For Long-Term Evolution-Based Wireless Handhelddevices, Paulkani Iyampalam, Indumathi Ganesan Jan 2019

Design Of Inverted-F Antenna For Long-Term Evolution-Based Wireless Handhelddevices, Paulkani Iyampalam, Indumathi Ganesan

Turkish Journal of Electrical Engineering and Computer Sciences

In this article, a compact triple-band inverted-F antenna for long-term evolution (LTE)-based wireless handheld devices is presented. The proposed antenna comprises three arms, namely the radiating arm, shorting arm, and feeding arm. The structure of the designed antenna looks like an inverted F with folded L-shaped strip antenna. It has three resonant frequencies of 795, 2050, and 3405 MHz with a reflection coefficient of --11.7 dB, --15.1 dB, and --30.5 dB, respectively. The size of the suggested antenna is 10 $\times$ 35 $\times$ 0.8 mm$^3$ and it is built on the FR-4 substrate which is more compact and easy to …


Effect Of Orientation Of Rf Sources Maintained Within The Enclosures On Electricalshielding Effectiveness Performance, İbrahi̇m Bahadir Başyi̇ği̇t, Abdullah Genç, Selçuk Helhel Jan 2019

Effect Of Orientation Of Rf Sources Maintained Within The Enclosures On Electricalshielding Effectiveness Performance, İbrahi̇m Bahadir Başyi̇ği̇t, Abdullah Genç, Selçuk Helhel

Turkish Journal of Electrical Engineering and Computer Sciences

The effect of single aperture metallic enclosures on electrical shielding effectiveness (ESE) has been investigated. Simulations and measurements have been obtained for comparison. The effects of orientation of transmitting antenna (source orientation) with respect to aperture length have been studied at 2.60?9 GHz as a novelty, and this gives details of IC RF source orientation in an enclosure. In the case of square apertures on an enclosure, a higher ESE value is obtained with respect to a rectangular aperture. As a case study, when the aperture width of the enclosure is decreased from 75 to 18.75 mm, the frequency bandwidth …


Electromagnetic Radiation Exposure Of Multioperator Co-Sited Urban Base Stations, Ni̇yazi̇ Korkut Uluaydin, Tomasz Dlugosz, Şaban Seli̇m Şeker Jan 2019

Electromagnetic Radiation Exposure Of Multioperator Co-Sited Urban Base Stations, Ni̇yazi̇ Korkut Uluaydin, Tomasz Dlugosz, Şaban Seli̇m Şeker

Turkish Journal of Electrical Engineering and Computer Sciences

Mobile network operators (MNOs) concurrently use different generations of wireless technologies. The base stations (BSs) of different technology generations are co-located in order to decrease operational costs. Furthermore, the MNOs cooperate in order to co-site their base stations. Such an urban site includes more than 25 actively radiating antennas on average with different frequencies and modulations. Electromagnetic radiation (EMR) measurements performed in such an environment may have reduced accuracy. In this paper, the authors propose a new approach for the measurement of EMR in multiple mobile technology interwoven urban BS sites, where more than one operator exists. The maintenance activities …


Thd Minimization For Z-Source-Based Inverters With A Novel Sinusoidal Pwmswitching Method, Davood Ghaderi Jan 2019

Thd Minimization For Z-Source-Based Inverters With A Novel Sinusoidal Pwmswitching Method, Davood Ghaderi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a modified sinusoidal pulse width modulation (SPWM) switching method for one-phase and investigated two-phase impedance-source inverter structures. The proposed structure generates pulses for a quasi- Z-source converter and this block produces a unilateral voltage sine wave in the block's output. This signal is applied to the inverter as its input wave. For this purpose, the novel SPWM method is proposed for power switches while being switched complementarily. Two power switches are used in the structure to generate the pure sinusoidal output voltage and to minimize total harmonic distortion (THD), which is an essential parameter in inverter design. …