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Full-Text Articles in Engineering

Optimal Fractional-Order Pid Controller Of Inverter-Based Power Plants For Power Systems Lfo Damping, Mahdi Saadatmand, Babak Mozafari, Gevork Babamalek Gharehpetian, Soodabeh Soleymani Jan 2020

Optimal Fractional-Order Pid Controller Of Inverter-Based Power Plants For Power Systems Lfo Damping, Mahdi Saadatmand, Babak Mozafari, Gevork Babamalek Gharehpetian, Soodabeh Soleymani

Turkish Journal of Electrical Engineering and Computer Sciences

The penetration of inverter-based power plants (IBPPs), such as large-scale photovoltaic (PV) power plants (LPPPs), is ever increasing considering the merits of renewable energy power plants (REPPs). Given that IBPPs are added to power systems or replaced by conventional power plants, they should undertake the most common tasks of synchronous generators. The low-frequency oscillation (LFO) damping through the power system stabilizers (PSSs) of synchronous generators is regarded as one of the common tasks in power plants. This paper proposes an optimal fractional-order proportional-integral-derivative (FOPID) controller implemented in the control loop of IBPPs for LFO damping in power systems. For this …


A Low Dropout Voltage Regulator With A Transient Voltage Spikes Reducer And Improved Figure Of Merit, Guru Prasad, Kumara Shama Jan 2020

A Low Dropout Voltage Regulator With A Transient Voltage Spikes Reducer And Improved Figure Of Merit, Guru Prasad, Kumara Shama

Turkish Journal of Electrical Engineering and Computer Sciences

An area efficient output capacitor-free low dropout [LDO] voltage regulator with an improved figure of merit is presented in this paper. The proposed LDO regulator consists of a novel, dynamically biased error amplifier that reduces overshoot and undershoot voltage spikes arising from abrupt load changes. Source bulk modulation is employed to enhance the current driving capability of the pass transistor. An adaptive biasing scheme is also used along with dynamic biasing to improve the current efficiency of the system. The on-chip capacitor required for proper working of the LDO regulator is only 35 pF. The proposed LDO regulator is designed …


Pulse Width Modulation Control Of Fifteen-Switch Inverter For Four Ac Loads, Gaurav Goyal, Mohan Aware Jan 2020

Pulse Width Modulation Control Of Fifteen-Switch Inverter For Four Ac Loads, Gaurav Goyal, Mohan Aware

Turkish Journal of Electrical Engineering and Computer Sciences

In many studies in the literature, various topologies with reduced switch count are proposed. With the use of these topologies, a lower number of semiconductor switches are required to produce a desired set of voltage. This in turn reduces the size and cost of the inverter. This paper proposes a new reduced switch count topology named "fifteen-switch inverter (FSI)" which is experimentally verified. The FSI has five switches in one leg and have three legs for three phases. It is capable of controlling four three-phase ac loads. In this proposed inverter topology, fifteen switches are used against the twenty four …


Dynamically Updated Diversified Ensemble-Based Approach For Handling Concept Drift, Kanu Goel, Shalini Batra Jan 2020

Dynamically Updated Diversified Ensemble-Based Approach For Handling Concept Drift, Kanu Goel, Shalini Batra

Turkish Journal of Electrical Engineering and Computer Sciences

Concept drift is the phenomenon where underlying data distribution changes over time unexpectedly. Examining such drifts and getting insight into the executing processes at that instance of time is a big challenge. Prediction models should be capable of handling drifts in scenarios where statistical properties show abrupt changes. Various strategies exist in the literature to deal with such challenging scenarios but the majority of them are limited to the identification of a particular kind of drift pattern. The proposed approach uses online drift detection in a diversified adaptive setting with pruning techniques to formulate a concept drift handling approach, named …


A Preliminary Survey On Software Testing Practices In Khyber Pakhtunkhwa Region Of Pakistan, Bushra Latif, Tauseef Rana Jan 2020

A Preliminary Survey On Software Testing Practices In Khyber Pakhtunkhwa Region Of Pakistan, Bushra Latif, Tauseef Rana

Turkish Journal of Electrical Engineering and Computer Sciences

Conducted to ensure the quality of software products, the software testing process has a great significance in the software development and is the vital step of the verification and validation process. For conforming a software feature to the end user requirements, organizations rely on extensive testing procedures. Despite being the key factor, many of the software development industries/companies do not define/follow a systematic testing process. In this paper, we analyze/learn from the conducted surveys in the past and formulate a questionnaire for a survey in the northern region of Pakistan. To the best of our knowledge, no such survey has …


Adaptive Blind Equalization For A Mimo Chaotic Communication System, Gökçen Çeti̇nel, Cabi̇r Vural Jan 2020

Adaptive Blind Equalization For A Mimo Chaotic Communication System, Gökçen Çeti̇nel, Cabi̇r Vural

Turkish Journal of Electrical Engineering and Computer Sciences

There exist few blind solutions for chaotic MIMO channel equalization. In this work, a chaotic MIMO channel equalization framework is proposed. The objective function to be minimized in the proposed solution is obtained by adopting the objective function developed for chaotic SISO channel equalization. Furthermore, an optimum filter that minimizes the proposed cost function is designed to recover chaotic input signals assuming that the channel is known. The stationary point of the adaptive solution is equal to the optimal filter if the adaptive filter coefficients change sufficiently slowly. The adaptive solution is contrasted with the optimum filter in terms of …


A Novel Chaos-Based Modulation Scheme: Adaptive Threshold Level Chaotic On-Offkeying For Increased Ber Performance, Kenan Altun, Eni̇s Günay Jan 2020

A Novel Chaos-Based Modulation Scheme: Adaptive Threshold Level Chaotic On-Offkeying For Increased Ber Performance, Kenan Altun, Eni̇s Günay

Turkish Journal of Electrical Engineering and Computer Sciences

A novel modulation scheme called adaptive threshold level-chaotic on?off keying (ATL-COOK) is proposed. This scheme is applied to direct chaotic communication (DCC) systems where the chaotic signals are used as carrier signals. The objective of the proposed adaptive method is to increase the low BER versus SNR performance caused by the constant threshold voltage level. In the proposed method, the communication signal received by the receiver circuits was defined as a Dirac delta function and a comparison signal was obtained from this signal. Then the BER versus SNR performance was analyzed and compared with that of various chaotic generator structures …


Towards Human Activity Recognition For Ubiquitous Health Care Using Data From Awaist-Mounted Smartphone, Umar Zia, Wajeeha Khalil, Salabat Khan, Iftikhar Ahmad, Naeem Khatak Jan 2020

Towards Human Activity Recognition For Ubiquitous Health Care Using Data From Awaist-Mounted Smartphone, Umar Zia, Wajeeha Khalil, Salabat Khan, Iftikhar Ahmad, Naeem Khatak

Turkish Journal of Electrical Engineering and Computer Sciences

Understanding human activities is a newly emerging paradigm that is greatly involved in developing ubiquitous health care (u-Health) systems. The aim of these systems is to seamlessly gather knowledge about the patient?s health and, after collecting knowledge, make suggestions to the patient according to his/her health profile. For this purpose, one of the most important ubiquitous communication trends is the smartphone, which has drawn the attention of both professionals and caregivers for monitoring the aging population, childcare, fall detection, and cognitive impairment. Recognizing human actions in a ubiquitous environment is very challenging and researchers have extensively investigated different methods to …


A Modified Relay-Race Algorithm For Floorplanning In Pcb And Ic Design, Mert Vatansever, İsmai̇l Fai̇k Başkaya Jan 2020

A Modified Relay-Race Algorithm For Floorplanning In Pcb And Ic Design, Mert Vatansever, İsmai̇l Fai̇k Başkaya

Turkish Journal of Electrical Engineering and Computer Sciences

Floorplanning is a fundamental design step in the physical design of printed circuit boards (PCBs) and integrated circuits (ICs), as it handles the complexity of layout design. From a computational point of view, the floorplanning problem is an NP hard problem, and the size of the search space grows exponentially with increasing numbers of modules. Thus, the algorithm used is an essential factor for speed and quality of the floorplanning process. Although polynomial-time floorplanning algorithms can be implemented when solution space is limited to slicing floorplans, optimal solutions often exist only in the nonslicing floorplan search space. Various stochastic algorithms …


Optimal Design Of A Flux Reversal Permanent Magnet Machine As A Wind Turbinegenerator, Majid Ghasemian, Farzad Tahami, Zahra Nasiri-Gheidari Jan 2020

Optimal Design Of A Flux Reversal Permanent Magnet Machine As A Wind Turbinegenerator, Majid Ghasemian, Farzad Tahami, Zahra Nasiri-Gheidari

Turkish Journal of Electrical Engineering and Computer Sciences

Flux reversal permanent magnet generators are well suited for use as wind turbine generators owing to their high torque generation ability and magnetic gear. However, they suffer from poor voltage regulation due to their high winding inductance. In this paper, a design optimization method is proposed for flux reversal generators in wind turbine applications. The proposed method includes a new multiobjective function. Cost, volume of the generator, and mass of the permanent magnet are considered in it independently and simultaneously. Besides the new objective function, the main superiority of this paper compared with published papers is considering winding inductance in …


Novel Random Models Of Entity Mobility Models And Performance Analysis Ofrandom Entity Mobility Models, Meti̇n Bi̇lgi̇n Jan 2020

Novel Random Models Of Entity Mobility Models And Performance Analysis Ofrandom Entity Mobility Models, Meti̇n Bi̇lgi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

It has become possible to collect data from geographically large areas with smart devices that are prevalently used today. Sensors that are integrated into smart devices make it possible for these devices to receive and transmit data wirelessly. The most important problem of this model that is known as mobile crowd sensing and that allows inferences on the data obtained from its users is lack of data. The main reason for this problem is the lack of sufficient usage of the sensors on devices by the user. To increase the amount of data collected, while users may be incentivized in …


A Priority-Based Queuing Model Approach Using Destination Parameters Forreal-Time Applications On Ipv6 Networks, Sadetti̇n Demi̇r, İbrahi̇m Özçeli̇k Jan 2020

A Priority-Based Queuing Model Approach Using Destination Parameters Forreal-Time Applications On Ipv6 Networks, Sadetti̇n Demi̇r, İbrahi̇m Özçeli̇k

Turkish Journal of Electrical Engineering and Computer Sciences

In the early days of the Internet architecture, the most important aim is to transmit data over packet switched networks. The traditional Internet architecture used in these networks lacks quality of service. However, today, as realtime applications increase, it is needed. There are approaches to improving the quality of service using the flow label field in the Internet Protocol version 6 header. In this study, a novel algorithm that uses destination network parameters to reduce queuing and end-to-end delay is created. A round-robin-based time-aware priority queue new model is used within this algorithm. Data packets using this proposed queue are …


Hubble: An Optical Link Management System For Dense Wavelength Divisionmultiplexing Networks, Yekta Türk, Engi̇n Zeydan, İbrahi̇m Fati̇h Merci̇mek, Engi̇n Danişman Jan 2020

Hubble: An Optical Link Management System For Dense Wavelength Divisionmultiplexing Networks, Yekta Türk, Engi̇n Zeydan, İbrahi̇m Fati̇h Merci̇mek, Engi̇n Danişman

Turkish Journal of Electrical Engineering and Computer Sciences

Timely detection of Dense Wavelength Division Multiplexing (DWDM) link quality and service performance problems of fiber deployment are important and critical for telecommunication operators. In this paper, we propose a new methodology for network fault detection inside optical transmission systems deployed in a real-operator environment and present the working principles of the system. Our new calculation methodology is used for joint fiber and DWDM link quality evaluation inside the proposed High-level Unified BackBone Link Examiner (HUBBLE) platform. At the end of the paper, we also detail some of the benefits, challenges, and opportunities of automation in DWDM networks using the …


An Inter-Domain Attack Mitigating Solution, Gökhan Akin, Ozan Bük, Erdem Uçar Jan 2020

An Inter-Domain Attack Mitigating Solution, Gökhan Akin, Ozan Bük, Erdem Uçar

Turkish Journal of Electrical Engineering and Computer Sciences

Online services on the Internet are increasing day by day, and in parallel, the number of cyber-attacks is rapidly increasing. These attacks are not always about data theft, but they can cause severe damage by denial of service attacks. Intrusion Prevention System products that many organizations use at the border of their enterprise networks are not strong enough to protect against DoS attacks. The typical way to mitigate such attacks is to get support from a service provider. However, a service provider only provides solutions for the traffic originating from itself. If the source of attack is in another ISP …


Coordinated Charging Of Electric Vehicles Including Customer Options For Slow Orfast Charging, Swapna Ganapaneni, Srinivasa Varma Pinni Jan 2020

Coordinated Charging Of Electric Vehicles Including Customer Options For Slow Orfast Charging, Swapna Ganapaneni, Srinivasa Varma Pinni

Turkish Journal of Electrical Engineering and Computer Sciences

Transportation system electrification in the world decreases the gasoline consumption that leads to increase in usage of number of plug in electric vehicles (PEVs). PEV is a bidirectional resource which, while playing the role of a resource, poses challenges in its management. These vehicles are to be charged at a residential standard outlet or in a corporate car charging station. This paper mainly aims to maximize the benefits of a customer who comes to a charging station for charging their vehicle. An incentive-based cost mechanism is introduced to optimally schedule the vehicles; this mechanism minimizes the overall charging cost, considers …


A Multibeam Subarrayed Time-Modulated Linear Array, Uğur Yeşi̇lyurt, İhsan Kanbaz, Ertuğrul Aksoy Jan 2020

A Multibeam Subarrayed Time-Modulated Linear Array, Uğur Yeşi̇lyurt, İhsan Kanbaz, Ertuğrul Aksoy

Turkish Journal of Electrical Engineering and Computer Sciences

In conventional time-modulated arrays (TMAs), because of the usage of the RF-switch, harmonics are generated at multiples of the modulation frequency. In this study, the synthesis of time-modulated arrays has been analyzed for cognitive radio (CR) systems, in which these harmonics are suitably exploited for more efficient utilization of the spectrum. In order to accomplish the desired pattern at requested harmonic frequencies, a new excitation strategy with sinusoidal signals is proposed. The use of sinusoidal waveforms creates independent beams, allowing independent steering capability. Moreover, by utilizing the subarray structure, it is possible to have a smaller number of excitation functions …


Measurement Of Sound Velocity In Oil Wells Based On Fast Adaptive Median Filtering, Wei Zhou, Juan Liu, Liqun Gan Jan 2020

Measurement Of Sound Velocity In Oil Wells Based On Fast Adaptive Median Filtering, Wei Zhou, Juan Liu, Liqun Gan

Turkish Journal of Electrical Engineering and Computer Sciences

Measurement of sound velocity in oil wells has long been a challenging industrial issue due to the difficulty in obtaining clear oil pipe coupling waves in strong noise. In this paper, a novel sound velocity measurement method is developed for the dynamic liquid level of oil wells based on fast adaptive median filtering. First, to solve the noise interference problem in the reflected oil pipe coupling wave, a fast adaptive median filtering algorithm is proposed to obtain an accurate oil pipe coupling wave. Then a curve fitting method based on range discrete coefficient is developed to estimate the sound velocity …


Event-Based Summarization Of News Articles, Feri̇de Savaroğlu Tabak, Vesi̇le Evri̇m Jan 2020

Event-Based Summarization Of News Articles, Feri̇de Savaroğlu Tabak, Vesi̇le Evri̇m

Turkish Journal of Electrical Engineering and Computer Sciences

In recent years, with the increase of available digital information on the Web, the time needed to find relevant information is also increased. Therefore, to reduce the time spent on searching, research on automatic text summarization has gained importance. The proposed summarization process is based on event extraction methods and is called an event-based extractive single-document summarization. In this method, the important features of event extraction and summarization methods are analyzed and combined together to extract the summaries from single-source news documents. Among the tested features, six features are found to be the most effective in constructing good summaries. The …


Design Of A Low Pass Filter Using Rhombus-Shaped Resonators With An Analyticallc Equivalent Circuit, Mohsen Hookari, Saeed Roshani, Sobhan Roshani Jan 2020

Design Of A Low Pass Filter Using Rhombus-Shaped Resonators With An Analyticallc Equivalent Circuit, Mohsen Hookari, Saeed Roshani, Sobhan Roshani

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new method is presented for the design of a low pass filter (LPF) based on an LC equivalent circuit. Firstly, new formulas are proposed to calculate an LC equivalent circuit of a rhombus-shaped resonator. Secondly, the transfer function and transmission zero of the rhombus-shaped resonator are extracted, based on the presented formulas. Then other rhombus-shaped resonators are designed, based on the extracted formulas. The proposed filter has a cut-off frequency with an attenuation level of 3 dB at 1.54 GHz. The obtained return loss and insertion loss in the pass band are 16 dB and 0.1 …


Short Unsegmented Pcg Classification Based On Ensemble Classifier, Sinam Ajitkumar Singh, Swanirbhar Majumder Jan 2020

Short Unsegmented Pcg Classification Based On Ensemble Classifier, Sinam Ajitkumar Singh, Swanirbhar Majumder

Turkish Journal of Electrical Engineering and Computer Sciences

Diseases associated with the heart are one of the main reasons of death worldwide. Hence, early examination of the heart is important. For analysis of cardiac disorders, a study of heart sounds is a crucial and beneficial approach. Still, automated classification of heart sounds is a challenging task that mainly depends on segmentation of heart sounds and derivation of features using segmented samples. In the literature available for PCG classification provided by PhysioNet/CinC Challenge 2016, most of the research has focused on enhancing the accuracy of the classification model based on complicated segmentation processes and has failed to improve the …


Dynamic Software Rejuvenation In Web Services: A Whale Optimizationalgorithm-Based Approach, Kimia Rezaei Kalantari, Ali Ebrahimnejad, Homayun Motameni Jan 2020

Dynamic Software Rejuvenation In Web Services: A Whale Optimizationalgorithm-Based Approach, Kimia Rezaei Kalantari, Ali Ebrahimnejad, Homayun Motameni

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we suggest a method for determining the restarting time for web services to increase availability, known as rejuvenation. We consider different parameters such as number of users, maximum service request number, response time, and throughput of a web service to determine its restarting time. Software rejuvenation is an effective technique to counteract software aging in continuously running applications such as web service-based systems. In these systems, web services are allocated based on the needs of the receivers and facilities of servers. One of the challenges while assigning web services is selecting the appropriate server to reduce faults. …


Ternary Logical Naming Convention And Application In Ternary Optical Computers, Shuang Li, Yi Jin Jan 2020

Ternary Logical Naming Convention And Application In Ternary Optical Computers, Shuang Li, Yi Jin

Turkish Journal of Electrical Engineering and Computer Sciences

This article introduces the ternary logical naming convention, which was newly discovered in the study of logical units of ternary optical computers (TOCs). First, the design principle and design specification of the ternary logical naming convention are elaborated in detail and several examples are given to illustrate the use of the naming convention. Second, taking the modified signed-digit (MSD) adder of the TOC as an example, the naming convention is applied to build four ternary logical units of the MSD adder, and the implementation method of pipelined addition is introduced. Finally, the correctness of the ternary logical naming convention proposed …


An Automated Eye Disease Recognition System From Visual Content Of Facial Imagesusing Machine Learning Techniques, Ashrafi Akram, Rameswar Debnath Jan 2020

An Automated Eye Disease Recognition System From Visual Content Of Facial Imagesusing Machine Learning Techniques, Ashrafi Akram, Rameswar Debnath

Turkish Journal of Electrical Engineering and Computer Sciences

Many eye diseases like cataracts, trachoma, or corneal ulcer can cause vision problems. Progression of these eye diseases can only be prevented if they are recognized accurately at the early stage. Visually observable symptoms differ a lot among these eye diseases. However, a wide variety of symptoms is necessary to be analyzed for the accurate detection of eye diseases. In this paper, we propose a novel approach to provide an automated eye disease recognition system using visually observable symptoms applying digital image processing techniques and machine learning techniques such as deep convolution neural network (DCNN) and support vector machine (SVM). …


Correlation Coefficients Of Pythagorean Hesitant Fuzzy Sets And Their Applicationto Radar Lpi Performance Evaluation, Cheng Xiu Yang, Qianzhe Wang, Weidong Peng, Shaoting Pei Jan 2020

Correlation Coefficients Of Pythagorean Hesitant Fuzzy Sets And Their Applicationto Radar Lpi Performance Evaluation, Cheng Xiu Yang, Qianzhe Wang, Weidong Peng, Shaoting Pei

Turkish Journal of Electrical Engineering and Computer Sciences

Evaluating low probability of intercept (LPI) performance is the first step to design parameters and arrange radar resources. In the evaluation process it is hard to rely on the intercept receiver?s working scenarios and operating parameters. On the other hand, indicators that affect the LPI performance of radiating side are difficult to consider comprehensively. Thus, building an effective evaluation system is crucial. This research considers the natural parameters of radar extracted from a radiating scenario. Subsequently, a number of criteria are selected, including spatial, time, frequency domain, polarization status, energy status, and waveform features. A multidomain radar LPI performance evaluation …


Piezoresistive Disposable Weight Sensor With Increased Sensitivity, Kuter Erdi̇l, Tuğçe Ayraç, Ömer Gökalp Akcan, Yi̇ği̇t Dağhan Gökdel Jan 2020

Piezoresistive Disposable Weight Sensor With Increased Sensitivity, Kuter Erdi̇l, Tuğçe Ayraç, Ömer Gökalp Akcan, Yi̇ği̇t Dağhan Gökdel

Turkish Journal of Electrical Engineering and Computer Sciences

This study presents the design, simulation, implementation, and experimental characterization of a paperbased perforated disposable weight sensor system with a double piezoresistive layer. The demonstrated system is designed to achieve highly sensitive weight sensing operations with low-cost materials. For that purpose, the main fabrication material of the proposed disposable sensor is selected as a 289 $\mu$m thick Strathmore 400 series Bristol paper. Approximately 48 $\mu$m thick piezoresistive graphite paste is coated onto both sides of the paper-based cantilever beam with the aim of acquiring more sensitive weight-sensing capability. Additionally, the proposed paper-based structure has rows of closely spaced perforations at …


A Fast Text Similarity Measure For Large Document Collections Using Multireference Cosine And Genetic Algorithm, Hamid Mohammadi, Seyed Hossein Khasteh Jan 2020

A Fast Text Similarity Measure For Large Document Collections Using Multireference Cosine And Genetic Algorithm, Hamid Mohammadi, Seyed Hossein Khasteh

Turkish Journal of Electrical Engineering and Computer Sciences

One of the critical factors that make a search engine fast and accurate is a concise and duplicate free index. In order to remove duplicate and near-duplicate (DND) documents from the index, a search engine needs a swift and reliable DND text document detection system. Traditional approaches to this problem, such as brute force comparisons or simple hash-based algorithms, are not suitable as they are not scalable and are not capable of detecting near-duplicate documents effectively. In this paper, a new signature-based approach to text similarity detection is introduced, which is fast, scalable, and reliable and needs less storage space. …


Accurate Indoor Positioning With Ultra-Wide Band Sensors, Taner Arsan Jan 2020

Accurate Indoor Positioning With Ultra-Wide Band Sensors, Taner Arsan

Turkish Journal of Electrical Engineering and Computer Sciences

Ultra-wide band is one of the emerging indoor positioning technologies. In the application phase, accuracy and interference are important criteria of indoor positioning systems. Not only the method used in positioning, but also the algorithms used in improving the accuracy is a key factor. In this paper, we tried to eliminate the effects of off-set and noise in the data of the ultra-wide band sensor-based indoor positioning system. For this purpose, optimization algorithms and filters have been applied to the raw data, and the accuracy has been improved. A test bed with the dimensions of 7.35 m × 5.41 m …


Development Of A Supervised Classification Method To Construct 2d Mineral Mapson Backscattered Electron Images, Mahmut Camalan, Mahmut Çavur Jan 2020

Development Of A Supervised Classification Method To Construct 2d Mineral Mapson Backscattered Electron Images, Mahmut Camalan, Mahmut Çavur

Turkish Journal of Electrical Engineering and Computer Sciences

The Mineral Liberation Analyzer (MLA) can be used to obtain mineral maps from backscattered electron (BSE) images of particles. This paper proposes an alternative methodology that includes random forest classification, a prospective machine learning algorithm, to develop mineral maps from BSE images. The results show that the overall accuracy and kappa statistic of the proposed method are 97% and 0.94, respectively, proving that random forest classification is accurate. The accuracy indicators also suggest that the proposed method may be applied to classify minerals with similar appearances under BSE imaging. Meanwhile, random forest predicts fewer middling particles with binary and ternary …


Prediction Of Railway Switch Point Failures By Artificial Intelligence Methods, Burak Arslan, Hasan Ti̇ryaki̇ Jan 2020

Prediction Of Railway Switch Point Failures By Artificial Intelligence Methods, Burak Arslan, Hasan Ti̇ryaki̇

Turkish Journal of Electrical Engineering and Computer Sciences

In recent years, railway transport has been preferred intensively in local and intercity freight and passenger transport. For this reason, it is of utmost importance that railway lines are operated in an uninterrupted and safe manner. In order to carry out continuous operation, all systems must continue to operate with maximum availability. In this study, data were collected from switch motors, which are the important equipment of railways, and the related equipment and these data were evaluated with sector experience and the results related to the failure status of the switch points were revealed. The obtained results were processed with …


Design And Characterization Of A Compact Single-Layer Multibeam Array Antennausing An 8×8 Butler Matrix For 5g Base Station Applications, Intan Izafina Idrus, Tarik Abdul Latef, Narendra Kumar Aridas, Mohamad Sofian Abu Talip, Yoshihide Yamada, Tengku Faiz Tengku Mohmed Noor Izam, Tharek Abd. Rahman Jan 2020

Design And Characterization Of A Compact Single-Layer Multibeam Array Antennausing An 8×8 Butler Matrix For 5g Base Station Applications, Intan Izafina Idrus, Tarik Abdul Latef, Narendra Kumar Aridas, Mohamad Sofian Abu Talip, Yoshihide Yamada, Tengku Faiz Tengku Mohmed Noor Izam, Tharek Abd. Rahman

Turkish Journal of Electrical Engineering and Computer Sciences

A multibeam array antenna employing a Butler matrix is a promising solution for fifth generation (5G) base stations. Due to inaccurate phase differences between output ports in the Butler matrix, the radiation characteristics could show incorrect main beam directions. In addition, the literature has also reported the issue of high amplitude imbalance in the Butler matrix. This paper presents a single-layer multibeam array antenna fed by an 8×8 Butler matrix operating at 28 GHz for 5G base station applications' a more cost-effective solution for large-scale production. The Butler matrix consists of twelve quadrature hybrids, sixteen crossovers, and eight phase shifters. …