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Articles 601 - 626 of 626
Full-Text Articles in Physical Sciences and Mathematics
Fiber Optic Chemical Sensors For Water Testing By Using Fiber Loop Ringdown Spectroscopy Technique, Mali̇k Kaya
Fiber Optic Chemical Sensors For Water Testing By Using Fiber Loop Ringdown Spectroscopy Technique, Mali̇k Kaya
Turkish Journal of Electrical Engineering and Computer Sciences
Real-time response, low cost, sensitive and easy setup fiber optic chemical sensors were fabricated by etching a part of single mode fiber in hydrofluoric (HF) acid solution and tested in different water samples such as tap water, DI water, salty and sugar water with different concentrations to record ringdown time (RDT) differences between media due to refractive index differences by employing the fiber loop ringdown (FLRD) spectroscopy technique. Baseline stability of 0.63 % and the minimum detectable RDT of $5.05$ $\mu$s for this kind of fiber optic chemical sensors were obtained. Fabricated sensors were coated with N,N-Diethyl-p-phenylenediamine for the first …
An Encrypted Speech Authentication Method Based On Uniform Subband Spectrumvariance And Perceptual Hashing, Qiuyu Zhang, Denghai Zhang, Liang Zhou
An Encrypted Speech Authentication Method Based On Uniform Subband Spectrumvariance And Perceptual Hashing, Qiuyu Zhang, Denghai Zhang, Liang Zhou
Turkish Journal of Electrical Engineering and Computer Sciences
In a real-world cloud server, a speech signal is prone to suffer various attacks, such as malicious muting and tampering. In such a context, the privacy security of the speech owner will not be guaranteed. In order to achieve content authentication of encrypted speech in the cloud server, an efficient encrypted speech authentication method based on uniform subband spectrum variance and perceptual hashing is proposed. Firstly, the original speech is scrambled by Henon mapping to construct an encrypted speech library in the cloud, through extracting uniform subband spectrum variance of the encrypted speech and constructing a hashing sequence to generate …
Wavelength Sensitivity Of Indium Tin Oxide On Surface Plasmon Resonance Angles, Antonio Ruiz, Carlos Villa Angulo, Ivan Olaf Hernandez-Fuentes
Wavelength Sensitivity Of Indium Tin Oxide On Surface Plasmon Resonance Angles, Antonio Ruiz, Carlos Villa Angulo, Ivan Olaf Hernandez-Fuentes
Turkish Journal of Electrical Engineering and Computer Sciences
Surface plasmon resonance (SPR) is a charge-density oscillation that occurs when a beam of p-polarized monochromatic light impinges with a greater angle than the critical angle in a dielectric-metal interface. Because of the high losses related to metals, the generated surface plasmon waves propagate with high attenuation in the visible and near-infrared spectral regions in most of the dielectric-metal interfaces. An alternative to reduce such losses is to use a transparent indium tin oxide (ITO) film. In this paper, we compared theoretical calculations and experimental measurements of the SPR angle $\theta_{SPR}$ on the interfaces of a borosilicate prism (Bp) and …
Low Power And Low Phase Noise Vco With Dual Current Shaping For Iotapplications, Sajad Nejadhasan, Narges Moazenian, Ebrahim Abiri, Mohammah Reza Salehi
Low Power And Low Phase Noise Vco With Dual Current Shaping For Iotapplications, Sajad Nejadhasan, Narges Moazenian, Ebrahim Abiri, Mohammah Reza Salehi
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, two low phase noise and power consumption VCO circuits, which are suitable for Internet of things (IoT) applications, are proposed. In the first structure, in order to have more control of the current consumption, the current shaping technique is used in the PMOS and NMOS biasing circuit. In the second structure, for increasing the oscillation amplitude and reducing the phase noise, independent biasing for the NMOS section is used. In both structures, to increase the frequency tuning range (FTR), without using a capacitor bank, the varactor is used in the biasing structure. In the first structure the …
Construction And Performance Analysis Of A New Sac-Ocdma Code Based Onlatin Square Matrix, Amel Aissaoui, Latifa Hacini
Construction And Performance Analysis Of A New Sac-Ocdma Code Based Onlatin Square Matrix, Amel Aissaoui, Latifa Hacini
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper a family of novel spreading code called Latin square code (LSC) is proposed for spectral amplitude coding-optical code division multiple access (SAC-OCDMA) system. The main feature of the proposed code is the zero cross-correlation which eliminates both multiple access interference (MAI) and phase induced intensity noise (PIIN). The code construction can be easily accomplished using Latin square matrix (LSM) for any weight and number of users. The simplicity in the construction code has made it a compelling candidate for future OCDMA applications. SAC-OCDMA system employing direct decoding is mathematically analyzed and then numerically simulated using Matlab and …
An Efficient Storage-Optimizing Tick Data Clustering Model, Haleh Amintoosi, Masood Niazi Torshiz, Yahya Forghani, Sara Alinejad
An Efficient Storage-Optimizing Tick Data Clustering Model, Haleh Amintoosi, Masood Niazi Torshiz, Yahya Forghani, Sara Alinejad
Turkish Journal of Electrical Engineering and Computer Sciences
Tick data is a large volume of data, related to a phenomenon such as stock market or weather change, with data values changing rapidly over time. An important issue is to store tick data table in a way that it occupies minimum storage space while at the same time it can provide fast execution of queries. In this paper, a mathematical model is proposed to partition tick data tables into clusters with the aim of minimizing the required storage space. The genetic algorithm is then used to solve the mathematical model which is indeed a clustering model. The proposed method …
A Subsynchronous Resonance Prevention For Dfig-Based Wind Farms, Davood Fateh, Ali Akbar Moti Birjandi, Josep M. Guerrero
A Subsynchronous Resonance Prevention For Dfig-Based Wind Farms, Davood Fateh, Ali Akbar Moti Birjandi, Josep M. Guerrero
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, subsynchronous resonance (SSR) instability was accurately analyzed in doubly fed induction generator (DFIG)-based wind farms by the linearization of equations and modal analysis. In addition, the possibility of high compensation for the transmission lines connected to DFIG-based wind farms was provided using a SSR prevention controller (SSRPC). For this purpose, an SSRPC was connected to the output voltage of the grid side converter (GSC) of the DFIG. The GSC output voltage was selected as the connection point of the SSRPC because it directly affects the induction generator effect (IGE) and can be an inhibitor factor in its …
Modelling Sensor Ontology With The Sosa/Ssn Frameworks:A Case Study For Laboratory Parameters, Özlem Aktaş, Mehmet Mi̇lli̇, Sanaz Lakestani̇, Musa Mi̇lli̇
Modelling Sensor Ontology With The Sosa/Ssn Frameworks:A Case Study For Laboratory Parameters, Özlem Aktaş, Mehmet Mi̇lli̇, Sanaz Lakestani̇, Musa Mi̇lli̇
Turkish Journal of Electrical Engineering and Computer Sciences
Recently, the use of sensor-based systems in many areas has led to an exponential increase in the raw sensor data. However, the lack of neither syntactic nor semantic integrity between these sensor data limited their sharing, reusability, and interpretation. These inabilities can cause some problems. For example, different wireless sensor networks may not work together due to the subtle variations in their sensing methods, operating systems, syntax, and data structure. In recent years, to cope with these inabilities, the semantic sensor web approach, which enables us to enrich the meaning of sensor data, has been seen as the critical technology …
Adaptive Modified Artificial Bee Colony Algorithms (Amabc) For Optimization Ofcomplex Systems, Rabi̇a Korkmaz Tan, Şebnem Bora
Adaptive Modified Artificial Bee Colony Algorithms (Amabc) For Optimization Ofcomplex Systems, Rabi̇a Korkmaz Tan, Şebnem Bora
Turkish Journal of Electrical Engineering and Computer Sciences
Complex systems are large scale and involve numerous uncertainties, which means that such systems tend to be expensive to operate. Further, it is difficult to analyze systems of this kind in a real environment, and for this reason agent-based modeling and simulation techniques are used instead. Based on estimation methods, modeling and simulation techniques establish an output set against the existing input set. However, as the data set in a given complex systems becomes very large, it becomes impossible to use estimation methods to create the output set desired. Therefore, a new mechanism is needed to optimize data sets in …
Revised Polyhedral Conic Functions Algorithm For Supervised Classification, Gürhan Ceylan, Gürkan Öztürk
Revised Polyhedral Conic Functions Algorithm For Supervised Classification, Gürhan Ceylan, Gürkan Öztürk
Turkish Journal of Electrical Engineering and Computer Sciences
In supervised classification, obtaining nonlinear separating functions from an algorithm is crucial for prediction accuracy. This paper analyzes the polyhedral conic functions (PCF) algorithm that generates nonlinear separating functions by only solving simple subproblems. Then, a revised version of the algorithm is developed that achieves better generalization and fast training while maintaining the simplicity and high prediction accuracy of the original PCF algorithm. This is accomplished by making the following modifications to the subproblem: extension of the objective function with a regularization term, relaxation of a hard constraint set and introduction of a new error term. Experimental results show that …
Improving The Efficiency Of Dnn Hardware Accelerator By Replacing Digitalfeature Extractor With An Imprecise Neuromorphic Hardware, Majid Mohammadi Rad, Omid Sojodishijani
Improving The Efficiency Of Dnn Hardware Accelerator By Replacing Digitalfeature Extractor With An Imprecise Neuromorphic Hardware, Majid Mohammadi Rad, Omid Sojodishijani
Turkish Journal of Electrical Engineering and Computer Sciences
Mixed-signal in-memory computation can drastically improve the efficiency of the hardware implementing machine learning (ML) algorithms by (i) removing the need to fetch neural network parameters from internal or external memory and (ii) performing a large number of multiply-accumulate operations in parallel. However, this boost in efficiency comes with some disadvantages. Among them, the inability to precisely program nonvolatile memory devices (NVM) with neural network parameters and sensitivity to noise prevent the mixed-signal hardware to perform a precise and deterministic computation. Unfortunately, these hardware-specific errors can get magnified while propagating along with the layers of the deep neural network. In …
A Mechanism Of Qos Differentiation Based On Offset Time And Adjusted Burstlength In Obs Networks, Viet Minh Nhat Vo, Trung Duc Pham, Thanh Chuong Dang, Van Hoa Le
A Mechanism Of Qos Differentiation Based On Offset Time And Adjusted Burstlength In Obs Networks, Viet Minh Nhat Vo, Trung Duc Pham, Thanh Chuong Dang, Van Hoa Le
Turkish Journal of Electrical Engineering and Computer Sciences
Quality of service (QoS) differentiation is an integral component of any networking system, particularly, with the current and future great diversity of users? applications and their manifold requirements. In optical burst switching (OBS) networks, there are two approaches for QoS differentiation: one is based on offset time and the other is based on burst length. This paper presents a mechanism of QoS differentiation based on both offset time and burst length, in which the offset times are calculated to achieve a complete isolation of data loss between priority classes and the burst length is adaptively adjusted according to the feedbacked …
Diagnosis Of Speed Sensor Faults In An Induction Machine Based On A Robustadaptive Super-Twisting Observer, Mohammed Zakaria Kari, Abdelkader Mechernene, Sidi Mohammed Meliani, Ibrahim Guenoune
Diagnosis Of Speed Sensor Faults In An Induction Machine Based On A Robustadaptive Super-Twisting Observer, Mohammed Zakaria Kari, Abdelkader Mechernene, Sidi Mohammed Meliani, Ibrahim Guenoune
Turkish Journal of Electrical Engineering and Computer Sciences
The present paper aims to determine a robust sensor fault-tolerant controller based on fuzzy logic using a robust adaptive super-twisting observer for the control of an induction machine and an inverter set by a state estimation method. The speed sensor is considered in the present case. The modular structure of the fault-tolerant control (FTC) scheme allows integrating this sensor within the existing closed-loop system, and the observer can therefore be designed independently. This article presents a new method to develop a fuzzy decision system that provides faulttolerant control. This paper also aims at detecting the mechanical speed sensor faults. The …
Optimized Idling Grid-Connection Strategy For Synchronous Condenser, Jianxiang Shi, Heqing Huang, Teng Liu, Wei Mu, Jianfeng Zhao
Optimized Idling Grid-Connection Strategy For Synchronous Condenser, Jianxiang Shi, Heqing Huang, Teng Liu, Wei Mu, Jianfeng Zhao
Turkish Journal of Electrical Engineering and Computer Sciences
The rise of large-scale HVDC transmission technology has introduced new requirements for dynamic reactive power compensation in power systems. The new generation of synchronous condensers is independent of grid voltage and does not need to be dragged by a coaxial prime mover, which can improve the dynamic reactive power compensation of the power grid. This new generation of synchronous condensers is dragged by the static frequency converter to a 105% rated speed, after which the static frequency converter logs out. In the process of idling, the excitation mode switching is completed and the unit is connected to the grid simultaneously. …
An Improved Memetic Genetic Algorithm Based On A Complex Network As Asolution To The Traveling Salesman Problem, Hadi Mohammadi, Kamal Mirzaie, Mohammad Reza Mollakhalili Meybodi
An Improved Memetic Genetic Algorithm Based On A Complex Network As Asolution To The Traveling Salesman Problem, Hadi Mohammadi, Kamal Mirzaie, Mohammad Reza Mollakhalili Meybodi
Turkish Journal of Electrical Engineering and Computer Sciences
A genetic algorithm (GA) is not a good option for finding solutions around in neighborhoods. The current study applies a memetic algorithm (MA) with a proposed local search to the mutation operator of a genetic algorithm in order to solve the traveling salesman problem (TSP). The proposed memetic algorithm uses swap, reversion and insertion operations to make changes in the solution. In the basic GA, unlike in the real world, the relationship between generations has not been considered. This gap is resolved using the proposed complex network to allow selection among possible solutions. The degree measure has been used for …
Comparative Study Between Measured And Estimated Wind Energy Yield, Ayman Alquraan, Mohammed Al-Mahmodi, Ashraf Radaideh, Hussein Al-Masri
Comparative Study Between Measured And Estimated Wind Energy Yield, Ayman Alquraan, Mohammed Al-Mahmodi, Ashraf Radaideh, Hussein Al-Masri
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a power-speed (P-V) model of the wind turbine by assuming three different functions for the first performance region; cubic, quadratic and uncorrected cubic. These three functions have been compared with the manufacturer models of five different wind turbines which were installed in five different locations in Jordan; Tafila, Hofa, Fujeij, Al Rajef, and Deahan. The wind turbine of these wind farms are considered as large scale HAWT in the range of Mw. The generated P-V models are developed by applying a new method described in this paper which is basically based on generating a multiplier factor x. …
Variable Gain High Order Sliding Mode Control Approaches For Pmsg Basedvariable Speed Wind Energy Conversion System, Ameen Ullah, Laiq Khan, Qudrat Khan, Saghir Ahmad
Variable Gain High Order Sliding Mode Control Approaches For Pmsg Basedvariable Speed Wind Energy Conversion System, Ameen Ullah, Laiq Khan, Qudrat Khan, Saghir Ahmad
Turkish Journal of Electrical Engineering and Computer Sciences
This research article proposes two different variants of variable gain higher-order sliding mode control (HOSMC) strategy for a variable-speed wind energy conversion system (WECS) based on a permanent magnet synchronous generator (PMSG). The main objective is to extract the maximum wind power with reduced chattering and mechanical stress. The main flaw of the classical sliding mode control (SMC) is the high-frequency switching, called chattering, which is alleviated by employing HOSMC strategies. The control law design is based on a super-twisting algorithm (STA) and a real-twisting algorithm (RTA) with variable gains. The proposed control techniques inherit the property of robustness and …
Performance Optimisation Of A Sensing Chamber Using Fluid Dynamics Simulationfor Electronic Nose Applications, Punjan Dohare, Sudeshna Bagchi, Amol P. Bhondekar
Performance Optimisation Of A Sensing Chamber Using Fluid Dynamics Simulationfor Electronic Nose Applications, Punjan Dohare, Sudeshna Bagchi, Amol P. Bhondekar
Turkish Journal of Electrical Engineering and Computer Sciences
The sensor chamber plays a significant role in order to improve the performance of an electronic nose in terms of stability, repeatability, reproducibility, and sensitivity. Fluid dynamics simulations of six different configurations of 3D sensing chambers are presented to facilitate the efficient design of an electronic nose system comprising 64 sensor arrays. Numerical simulations were carried out to investigate the gas (zero air) flow behaviour inside these chambers under steady-state conditions for velocities ranging from 0.1 to 2 m/s using ANSYS software. Design optimisation was performed in terms of area coverage, velocity, and mass fraction. The results show that the …
Exhaustive Hard Triplet Mining Loss For Person Re-Identification, Chao Xu, Xiang Sun, Ziliang Chen, Shoubiao Tan
Exhaustive Hard Triplet Mining Loss For Person Re-Identification, Chao Xu, Xiang Sun, Ziliang Chen, Shoubiao Tan
Turkish Journal of Electrical Engineering and Computer Sciences
Person reidentification (Re-ID) is an important task in computer vision and has many applications in videobased surveillance. Recently, the triplet loss has been popular in the deep learning framework for person Re-ID. It is particularly important to note that the selection of hard triplets has significant influence on the performance of the learned deep model. However, the existing triplet losses only focus on some specific forms of hard triplets, thus leading to weaker generalization capability. To address this issue, we propose a novel variant of the triplet loss, named exhaustive hard triplet mining loss (EHTM), which is able to deal …
Design Of A Miniaturized Planar Microstrip Wilkinson Power Divider With Harmonic Cancellation, Saeedeh Lotfi, Saeed Roshani, Sobhan Roshani
Design Of A Miniaturized Planar Microstrip Wilkinson Power Divider With Harmonic Cancellation, Saeedeh Lotfi, Saeed Roshani, Sobhan Roshani
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a compact microstrip Wilkinson power divider is designed and proposed using rectangularshaped resonator cells. The presented resonator cells are used instead of quarter-wave length branches in the traditional structure to reduce the circuit size, increase the bandwidth, and eliminate the unwanted harmonics. The designed resonator behavior is studied analytically and the locations of transmission zeros are investigated using transfer function andLCequivalentcircuitmethods. The proposed power divider(PD)operates at 2GHz frequency and suppresses the 2nd to 14th unwanted harmonics. The proposed PD achieves approximately 50% size reduction and 40%fractional bandwidth (FBW). The abilities of desirable size reduction and harmonic suppression …
Automated Labeling Of Terms In Medical Reports In Serbian, Aldina Avdic, Ulfeta Marovac, Dragan Jankovic
Automated Labeling Of Terms In Medical Reports In Serbian, Aldina Avdic, Ulfeta Marovac, Dragan Jankovic
Turkish Journal of Electrical Engineering and Computer Sciences
Nowadays, many electronic health reports (EHRs) are stored daily. They consist of the structured part and of an unstructured section written in natural language. Due to the limited time for medical examination, EHRs are short reports which often contain errors and abbreviations. Therefore it is a challenge to process an EHR and extract knowledge from this part of the text for different purposes. This paper compares the results of three proposed methods for automatic labeling of medical terms in unstructured parts of EHRs. All words are categorized as words within the medical domain (symptoms, diagnoses, therapies, anatomy, specialties etc.) and …
Influence Of Varying Magnet Pole-Arcs And Step-Skew On Permanent Magnet Ac Synchronous Motor Performance, Meti̇n Aydin, Oğuzhan Ocak, Yücel Demi̇r
Influence Of Varying Magnet Pole-Arcs And Step-Skew On Permanent Magnet Ac Synchronous Motor Performance, Meti̇n Aydin, Oğuzhan Ocak, Yücel Demi̇r
Turkish Journal of Electrical Engineering and Computer Sciences
Minimization or elimination of cogging torque is a significant issue in permanent magnet (PM) motor design process. There are some design techniques to reduce or eliminate this unwanted torque components in PM motors. This paper focuses on two different design techniques, varying magnet pole-arc and step-skew, to reduce cogging torque component in radial flux PM synchronous motors. Different design points which consider pulsating torque components and back-EMF harmonics are obtained via finite element analysis (FEA) for a low power industrial PM motor. A prototype motor is manufactured for one of the desired designs and is tested experimentally. Good agreement is …
Improving Coverage Method Of Autonomous Drones For Environmental Monitoring, Ömür Yildirim, Revna Acar Vural, Klaus Diepold
Improving Coverage Method Of Autonomous Drones For Environmental Monitoring, Ömür Yildirim, Revna Acar Vural, Klaus Diepold
Turkish Journal of Electrical Engineering and Computer Sciences
With the rapid developments of unmanned aerial vehicles (UAVs), usage of UAVs is increasing to bring autonomy for complicated processes such as environmental monitoring. Because of the complexity of the problem, environmental monitoring tasks are highly demanding in terms of time and resources. To reduce expensive costs of operations, improvements on autonomous observation capabilities has a key role. In this work, we offer coverage improvements for our autonomous environmental monitoring system. We compared different path planning approaches to find out the optimum path planning solution. Simulation results showed that required task execution time and required resources are decreased by usage …
A New Smart Networking Architecture For Container Network Functions, Gülsüm Atici, Pinar Bölük
A New Smart Networking Architecture For Container Network Functions, Gülsüm Atici, Pinar Bölük
Turkish Journal of Electrical Engineering and Computer Sciences
5G slices have challenging application demands from a wide variety of fields including high bandwidth, low latency and reliability. The requirements of the container network functions which are used in telecommunications are different from any other cloud native IT applications as they are used for data plane packet processing functions, together with control, signalling and media processing which have critical processing requirements. This study aims to discover high performing container networking solution by considering traffic loads and application types. The behaviour of several container cluster networking solutions -- Flannel, Weave, Libnetwork, Open Virtual Networking for Open vSwitch and Calico -- …
Binary Multicriteria Collaborative Filtering, Emre Yalçin, Alper Bi̇lge
Binary Multicriteria Collaborative Filtering, Emre Yalçin, Alper Bi̇lge
Turkish Journal of Electrical Engineering and Computer Sciences
Collaborative filtering is specialized in suggesting appropriate products and services to the users concerning personal characteristics and past preferences without requiring any effort of users. It might be more efficient to collect preferences of users based on multiple subcriteria of products and services. For this purpose, researchers propose multicriteria recommender systems that are convenient for more accurate and useful evaluation of items. Insuchsystems, it might be preferable tocollect binary ratings instead of numerical ones due to the large number of subcriteria. However, there is a gap in the literature to satisfy a binary preferences-based multicriteria recommender system. In this study, …
A New Grid Partitioning Technology For Location Privacy Protection, Yue Sun, Lei Zhang, Jing Li, Zhen Zhang
A New Grid Partitioning Technology For Location Privacy Protection, Yue Sun, Lei Zhang, Jing Li, Zhen Zhang
Turkish Journal of Electrical Engineering and Computer Sciences
Nowadays, the location-based service (LBS) has become an essential part of convenient service in people's daily life. However, the untrusted LBS servers can store lots of information about the user, such as the user's identity, location, and destination. Then the information can be used as background knowledge and combined with the query frequency of the user to launch the inference attack to obtain user's privacy. In most of the existing schemes, the author considers the algorithm of virtual location selection from the historical location of the user. However, the LBS server can infer the user's location information on the historical …