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Articles 71521 - 71550 of 196680

Full-Text Articles in Engineering

Farsi Document Image Recognition System Using Word Layout Signature, Cem Ergün, Sajedeh Norozpour Jan 2019

Farsi Document Image Recognition System Using Word Layout Signature, Cem Ergün, Sajedeh Norozpour

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a new representation of Farsi words is proposed to present the keyword spotting problems in Farsi document image retrieval. In this regard, we define a signature for each Farsi word based on the word connected component layout. The mentioned signature is shown as boxes, and then, by sketching vertical and horizontal lines, we construct a grid of each word to provide a new descriptor. One of the advantages of this method is that it can be used for both handwritten and machine-printed texts. Finally, to evaluate the performance of our system in comparison to other methods, a …

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Hybix: A Novel Encoding Bitmap Index For Space- And Time-Efficient Query Processing, Naphat Keawpibal, Ladda Preechaveerakul, Sirirut Vanichayobon Jan 2019

Hybix: A Novel Encoding Bitmap Index For Space- And Time-Efficient Query Processing, Naphat Keawpibal, Ladda Preechaveerakul, Sirirut Vanichayobon

Turkish Journal of Electrical Engineering and Computer Sciences

A bitmap-based index is an effective and efficient indexing method for answering selective queries in a read-only environment. It offers improved query execution time by applying low-cost Boolean operators on the index directly, before accessing raw data. A drawback of the bitmap index is that index size increases with the cardinality of indexed attributes, which additionally has an impact on a query execution time. This impact is related to an increase of query execution time due to the scanning of bitmap vectors to answer the queries. In this paper, we propose a new encoding bitmap index, called the HyBiX bitmap …

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Dynamic Physarum Solver: A Bio-Inspired Shortest Path Method Of Dynamically Changing Graphs, Hi̇lal Arslan Jan 2019

Dynamic Physarum Solver: A Bio-Inspired Shortest Path Method Of Dynamically Changing Graphs, Hi̇lal Arslan

Turkish Journal of Electrical Engineering and Computer Sciences

In dynamic graphs, edge weights of the graph change with time and solving the shortest path problem in such graphs is an important real-world problem. The studies in the literature require excessive computational time for computing the dynamic shortest path since determining changing edge weights is difficult especially when the graph size becomes large. In this paper, we propose a dynamic bio-inspired algorithm for finding the dynamic shortest path for large graphs based on Physarum Solver, which is a shortest path algorithm for static graphs. The proposed method is evaluated using three different large graph models representing diverse real-life applications. …

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An Approach To Improve The Performance Of Cooperative Unmanned Vehicle Team, Ömer Ci̇han Kivanç Jan 2019

An Approach To Improve The Performance Of Cooperative Unmanned Vehicle Team, Ömer Ci̇han Kivanç

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a method based on optimal energy management is proposed in order to improve the operational and tactical abilities of collaborative unmanned vehicle teams. Collaborative unmanned systems are used in surveillance, tracking, and military operations. The optimal assignment of these tasks requires cooperation among the vehicles in order to generate a strategy that is efficient with respect to overall mission duration and satisfies all problem constraints. The key motivation behind this paper is to design an unmanned vehicle team that mitigates the disadvantages caused by the structures and characteristics of unmanned ground vehicles (UGVs) and unmanned aerial vehicles …

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Multiellipsoidal Extended Target Tracking With Known Extent Using Sequential Monte Carlo Framework, Süleyman Fati̇h Kara, Emre Özkan Jan 2019

Multiellipsoidal Extended Target Tracking With Known Extent Using Sequential Monte Carlo Framework, Süleyman Fati̇h Kara, Emre Özkan

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we consider a variant of the extended target tracking (ETT) problem, namely the multiellipsoidal ETT problem. In multiellipsoidal ETT, target extent is represented by multiple ellipses, which correspond to the origin of the measurements on the target surface. The problem involves estimating the target's kinematic state and solving the association problem between the measurements and the ellipses. We cast the problem in a sequential Monte Carlo (SMC) framework and investigate different marginalization strategies to find an efficient particle filter. Under the known extent assumption, we define association variables to find the correct association between the measurements and …

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Optimal Training And Test Sets Design For Machine Learning, Burkay Genç, Hüseyi̇n Tunç Jan 2019

Optimal Training And Test Sets Design For Machine Learning, Burkay Genç, Hüseyi̇n Tunç

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we describe histogram matching, a metric for measuring the distance of two datasets with exactly the same features, and embed it into a mixed integer programming formulation to partition a dataset into fixed size training and test subsets. The partition is done such that the pairwise distances between the dataset and the subsets are minimized with respect to histogram matching. We then conduct a numerical study using a well-known machine learning dataset. We demonstrate that the training set constructed with our approach provides feature distributions almost the same as the whole dataset, whereas training sets constructed via …

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Efficient Features For Smartphone-Based Iris Recognition, Ritesh Vyas, Tirupathiraju Kanumuri, Gyanendra Sheoran, Pawan Dubey Jan 2019

Efficient Features For Smartphone-Based Iris Recognition, Ritesh Vyas, Tirupathiraju Kanumuri, Gyanendra Sheoran, Pawan Dubey

Turkish Journal of Electrical Engineering and Computer Sciences

Iris recognition has widely been used in personal authentication problems. Recent advances in iris recognition through visible wavelength images have paved the way for the use of this technology in smartphones. Smartphone-based iris recognition can be of significant use in financial transactions and secure storage of sensitive information. This paper presents a hybrid representation scheme for iris recognition in mobile devices. The scheme is called hybrid because it firstly makes use of Gabor wavelets to reveal the texture present in the normalized iris images, and then extracts statistical features from different partitions of Gabor-processed images. The standard mobile-iris database, called …

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Plant Disease And Pest Detection Using Deep Learning-Based Features, Muammer Türkoğlu, Davut Hanbay Jan 2019

Plant Disease And Pest Detection Using Deep Learning-Based Features, Muammer Türkoğlu, Davut Hanbay

Turkish Journal of Electrical Engineering and Computer Sciences

The timely and accurate diagnosis of plant diseases plays an important role in preventing the loss of productivity and loss or reduced quantity of agricultural products. In order to solve such problems, methods based on machine learning can be used. In recent years, deep learning, which is especially widely used in image processing, offers many new applications related to precision agriculture. In this study, we evaluated the performance results using different approaches of nine powerful architectures of deep neural networks for plant disease detection. Transfer learning and deep feature extraction methods are used, which adapt these deep learning models to …

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Domain Adaptation On Graphs By Learning Graph Topologies: Theoretical Analysis And An Algorithm, Eli̇f Vural Jan 2019

Domain Adaptation On Graphs By Learning Graph Topologies: Theoretical Analysis And An Algorithm, Eli̇f Vural

Turkish Journal of Electrical Engineering and Computer Sciences

Traditional machine learning algorithms assume that the training and test data have the same distribution, while this assumption does not necessarily hold in real applications. Domain adaptation methods take into account the deviations in data distribution. In this work, we study the problem of domain adaptation on graphs. We consider a source graph and a target graph constructed with samples drawn from data manifolds. We study the problem of estimating the unknown class labels on the target graph using the label information on the source graph and the similarity between the two graphs. We particularly focus on a setting where …

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A Joint Image Dehazing And Segmentation Model, Haider Ali, Awal Sher, Nosheen Zikria, Lavdi̇e Rada Ülgen Jan 2019

A Joint Image Dehazing And Segmentation Model, Haider Ali, Awal Sher, Nosheen Zikria, Lavdi̇e Rada Ülgen

Turkish Journal of Electrical Engineering and Computer Sciences

Objects and their feature identification in hazy or foggy weather conditions has been of interest in the last decades. Improving image visualization by removing weather influence factors for easy image postprocessing, such as object detection, has benefits for human assistance systems. In this paper, we propose a novel variational model that will be capable of jointly segmenting and dehazing a given image. The proposed model incorporates atmospheric veil estimation and locally computed denoising constrained surfaces into a level set function by performing a robust and efficient image dehazing and segmentation scheme for both gray and color outdoor images. The proposed …

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Can Additional Spectral Bands Be Estimated From Aerial Color Images?, Muhammet Ali̇ Dede, Erchan Aptoula, Yakup Genç Jan 2019

Can Additional Spectral Bands Be Estimated From Aerial Color Images?, Muhammet Ali̇ Dede, Erchan Aptoula, Yakup Genç

Turkish Journal of Electrical Engineering and Computer Sciences

Inspired by the surprising performances of deep generative models, in this paper we present the preliminary results of an overly ambitious task: estimating computationally the additional spectral bands of a color aerial image. We have harnessed the expressive power of deep generative models to estimate the distribution of mostly infrared bands of aerial scenes, using only color RGB channels as input. Our approach has been tested from multiple aspects, including the reconstruction error of the additional bands and the effect of estimated bands on scene classification performance, as well as through the transfer potential of the trained network to a …

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Efficient Hierarchical Temporal Segmentation Method For Facial Expression Sequences, Jiali Bian, Xue Mei, Yu Xue, Liang Wu, Yao Ding Jan 2019

Efficient Hierarchical Temporal Segmentation Method For Facial Expression Sequences, Jiali Bian, Xue Mei, Yu Xue, Liang Wu, Yao Ding

Turkish Journal of Electrical Engineering and Computer Sciences

Temporal segmentation of facial expression sequences is important to understand and analyze human facial expressions. It is, however, challenging to deal with the complexity of facial muscle movements by finding a suitable metric to distinguish among different expressions and to deal with the uncontrolled environmental factors in the real world. This paper presents a two-step unsupervised segmentation method composed of rough segmentation and fine segmentation stages to compute the optimal segmentation positions in video sequences to facilitate the segmentation of different facial expressions. The proposed method performs localization of facial expression patches to aid in recognition and extraction of specific …

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Low-Cost Multiple Object Tracking For Embedded Vision Applications, Muhammad Imran Shehzad, Fazal Wahab Karam, Shoaib Azmat Jan 2019

Low-Cost Multiple Object Tracking For Embedded Vision Applications, Muhammad Imran Shehzad, Fazal Wahab Karam, Shoaib Azmat

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a low-cost multiple object tracking (MOT) technique by employing a novel appearance update model for object appearance modeling using K-means. The state-of-the-art work has attained a very high accuracy without considering the real-time aspects necessitated by currently trending embedded vision platforms. The major research on multiple object tracking is used to update the appearance model in every frame while discounting its persistent nature. The proposed appearance update model reduces the computational cost of the state-of-the-art MOT 6-fold by exploiting this facet of persistent appearance over the sequence of frames. To ensure accuracy, the proposed model is tested …

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An Efficient Retrieval Algorithm Of Encrypted Speech Based On Inverse Fast Fourier Transform And Measurement Matrix, Qiuyu Zhang, Zixian Ge, Liang Zhou, Yongbing Zhang Jan 2019

An Efficient Retrieval Algorithm Of Encrypted Speech Based On Inverse Fast Fourier Transform And Measurement Matrix, Qiuyu Zhang, Zixian Ge, Liang Zhou, Yongbing Zhang

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present an efficient retrieval algorithm for encrypted speech based on an inverse fast Fourier transform and measurement matrix. Our approach improves query performance, as well as retrieval efficiency and accuracy, compared to existing content-based encrypted speech retrieval methods. Our proposed algorithm constructs a perceptual hash scheme using perceptual hash sequences from original speech files. By classifying the sequences and applying run-length compression, we decrease the cloud storage required for the hash index. We secure the speech database by encrypting it with Henon chaos scrambling, which offers excellent resistance to attacks. Experimental results show that the robustness, …

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Classification Of The Likelihood Of Colon Cancer With Machine Learning Techniques Using Ftir Signals Obtained From Plasma, Suat Toraman, Mustafa Gi̇rgi̇n, Bi̇lal Üstündağ, İbrahi̇m Türkoğlu Jan 2019

Classification Of The Likelihood Of Colon Cancer With Machine Learning Techniques Using Ftir Signals Obtained From Plasma, Suat Toraman, Mustafa Gi̇rgi̇n, Bi̇lal Üstündağ, İbrahi̇m Türkoğlu

Turkish Journal of Electrical Engineering and Computer Sciences

Colon cancer is one of the major causes of human mortality worldwide and the same can be said for Turkey. Various methods are used for the determination of cancer. One of these methods is Fourier transform infrared (FTIR) spectroscopy, which has the ability to reveal biochemical changes. The most common features used to distinguish patients with cancer and healthy subjects are peak densities, peak height ratios, and peak area ratios. The greatest challenge of studies conducted to distinguish cancer patients from healthy subjects using FTIR signals is that the signals of cancer patients and healthy subjects are similar. In the …

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Key Word Extraction For Short Text Via Word2vec, Doc2vec, And Textrank, Jun Li, Guimin Huang, Chunli Fan, Zhenglin Sun, Hongtao Zhu Jan 2019

Key Word Extraction For Short Text Via Word2vec, Doc2vec, And Textrank, Jun Li, Guimin Huang, Chunli Fan, Zhenglin Sun, Hongtao Zhu

Turkish Journal of Electrical Engineering and Computer Sciences

Day by day huge amounts data are produced, and evaluation of these data becomes more difficult. The data obtained should provide meaningful, correct, and accurate information. Therefore, all data must be separated into clusters correctly, and the right information from these clusters must be obtained. Having the correct clusters depends on the clustering algorithm that is used. There are many clustering algorithms. The density-based methods are very important among the groups of clustering methods, as they can find arbitrary shapes. An advanced model of the density-based spatial clustering of applications with noise (DBSCAN) algorithm, called fuzzy neighborhood DBSCAN Gaussian means …

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A Hybrid Sentiment Analysis Method For Turkish, Buket Erşahi̇n, Özlem Aktaş, Deni̇z Kilinç, Mustafa Erşahi̇n Jan 2019

A Hybrid Sentiment Analysis Method For Turkish, Buket Erşahi̇n, Özlem Aktaş, Deni̇z Kilinç, Mustafa Erşahi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a hybrid methodology for Turkish sentiment analysis, which combines the lexicon-based and machine learning (ML)-based approaches. On the lexicon-based side, we use a sentiment dictionary that is extended with a synonyms lexicon. Besides this, we tackle the classification problem with three supervised classifiers, naive Bayes, support vector machines, and J48, on the ML side. Our hybrid methodology combines these two approaches by generating a new lexicon-based value according to our feature generation algorithm and feeds it as one of the features to machine learning classifiers. Despite the linguistic challenges caused by the morphological structure of Turkish, the …

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Extending A Sentiment Lexicon With Synonym--Antonym Datasets: Swnettr++, Fati̇h Sağlam, Burkay Genç, Hayri̇ Sever Jan 2019

Extending A Sentiment Lexicon With Synonym--Antonym Datasets: Swnettr++, Fati̇h Sağlam, Burkay Genç, Hayri̇ Sever

Turkish Journal of Electrical Engineering and Computer Sciences

In our previous studies on developing a general-purpose Turkish sentiment lexicon, we constructed SWNetTR-PLUS, a sentiment lexicon of 37K words. In this paper, we show how to use Turkish synonym and antonym word pairs to extend SWNetTR-PLUS by almost 33 % to obtain SWNetTR++, a Turkish sentiment lexicon of 49K words. The extension was done by transferring the problem into the graph domain, where nodes are words, and edges are synonym--antonym relations between words, and propagating the existing tone and polarity scores to the newly added words using an algorithm we have developed. We tested the existing and new lexicons …

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Automatic Landing Of A Low-Cost Quadrotor Using Monocular Vision And Kalman Filter In Gps-Denied Environments, Mohammad Fattahi Sani, Maryam Shoaran, Ghader Karimian Jan 2019

Automatic Landing Of A Low-Cost Quadrotor Using Monocular Vision And Kalman Filter In Gps-Denied Environments, Mohammad Fattahi Sani, Maryam Shoaran, Ghader Karimian

Turkish Journal of Electrical Engineering and Computer Sciences

Unmanned aerial vehicles are becoming an important part of the modern life. Despite some recent advances in GPS-aided navigation of quadrotors, the concern of crash and collision still overshadows their reliability and safety, especially in GPS-denied environments. Therefore, the necessity for developing fully automatic methods for safe, accurate, and independent landing of drones increases over time. This paper investigates the autolanding process by focusing on an accurate and continuous position estimation of the drone using a monocular vision system and the fusion with the inertial measurement unit and ultrasonic sensors' data. An ARUCO marker is used as the landing pad, …

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A Process-Tolerant Low-Power Adder Architecture For Image Processing Applications, Bharat Garg, G K. Sharma Jan 2019

A Process-Tolerant Low-Power Adder Architecture For Image Processing Applications, Bharat Garg, G K. Sharma

Turkish Journal of Electrical Engineering and Computer Sciences

The aggressive CMOS technology scaling in the sub-100-nm regime leads to highly challenging VLSI design due to the presence of unreliable components. The delay failures in arithmetic units are increasing rapidly due to the increased effect of process variation (PV) in scaled technology. This paper introduces a novel process-tolerant low-power adder (Prot-LA) architecture for error-tolerant applications. The proposed Prot-LA architecture segments the operands into two parts and computes addition of the upper parts in carry-propagate, whereas it computes the lower parts in a carry-free manner. In the Prot-LA, the number of bits in carry-propagate and carry-free additions can be reconfigured …

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Hydrogen Production System With Fuzzy Logic-Controlled Converter, Sali̇h Nacar, Seli̇m Öncü Jan 2019

Hydrogen Production System With Fuzzy Logic-Controlled Converter, Sali̇h Nacar, Seli̇m Öncü

Turkish Journal of Electrical Engineering and Computer Sciences

Electrolyte current must be controlled in the water electrolysis systems. For this purpose, the power converter for the cell stack of the electrolyzer used in industrial hydrogen production is realized. A series resonant converter, which is suitable for high input voltage and low output current applications, is used as power stage of the electrolyzer. The high-frequency transformer is used for the impedance matching. While the system is running, the electrical resistance of the electrolyzer changes continuously; thus, fuzzy logic controller (FLC) is used to control the output current of the power converter. In this study, a 700-W converter prototype is …

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Fast Nonsingular Terminal Decoupled Sliding-Mode Control Utilizing Time-Varying Sliding Surfaces, Ferhun Yorgancioğlu, Soydan Redif Jan 2019

Fast Nonsingular Terminal Decoupled Sliding-Mode Control Utilizing Time-Varying Sliding Surfaces, Ferhun Yorgancioğlu, Soydan Redif

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a fast form of nonsingular, terminal, decoupled, sliding-mode control, which utilizes time-varying sliding surfaces, is proposed for a class of fourth-order, single-input, multioutput, nonlinear systems. The novel control law features a fast term, in the manner of fast terminal sliding-mode control, which markedly improves the finite-time sliding-mode convergence speed near zero. Numerical simulation results, which are illustrated with a cart-pole inverted pendulum system and a ball-beam system, demonstrate that the proposed control law achieves, in general, favorable transient response and lower steady-state errors compared to state-of-the-art decoupled terminal sliding-mode control methods.

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Hybrid Parliamentary Optimization And Big Bang-Big Crunch Algorithm For Global Optimization, Soner Kiziloluk, Ahmet Bedri̇ Özer Jan 2019

Hybrid Parliamentary Optimization And Big Bang-Big Crunch Algorithm For Global Optimization, Soner Kiziloluk, Ahmet Bedri̇ Özer

Turkish Journal of Electrical Engineering and Computer Sciences

Researchers have developed different metaheuristic algorithms to solve various optimization problems. The efficiency of a metaheuristic algorithm depends on the balance between exploration and exploitation. This paper presents the hybrid parliamentary optimization and big bang-big crunch (HPO-BBBC) algorithm, which is a combination of the parliamentary optimization algorithm (POA) and the big bang-big crunch (BB-BC) optimization algorithm. The intragroup competition phase of the POA is a process that searches for potential points in the search space, thereby providing an exploration mechanism. By contrast, the BB-BC algorithm has an effective exploitation mechanism. In the proposed method, steps of the BB-BC algorithm are …

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Identifying Preferred Solutions In Multiobjective Combinatorial Optimization Problems, Banu Lokman, Mustafa Murat Köksalan Jan 2019

Identifying Preferred Solutions In Multiobjective Combinatorial Optimization Problems, Banu Lokman, Mustafa Murat Köksalan

Turkish Journal of Electrical Engineering and Computer Sciences

We develop an evolutionary algorithm for multiobjective combinatorial optimization problems. The algorithm aims at converging the preferred solutions of a decision-maker. We test the performance of the algorithm on the multiobjective knapsack and multiobjective spanning tree problems. We generate the true nondominated solutions using an exact algorithm and compare the results with those of the evolutionary algorithm. We observe that the evolutionary algorithm works well in approximating the solutions in the preferred regions.

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Investigation On Communication Aspects Of Multiple Swarm Networked Robotics, Shahzad Ali, Zenib Khan, Ahmad Din, Mahmood Ul Hassan Jan 2019

Investigation On Communication Aspects Of Multiple Swarm Networked Robotics, Shahzad Ali, Zenib Khan, Ahmad Din, Mahmood Ul Hassan

Turkish Journal of Electrical Engineering and Computer Sciences

Swarm robotics is an emerging field of robotics and is envisioned to play a vital role in surveillance and search/rescue operations. Most of the existing works on swarm networked robotics address the problem of formation movement or the communication aspects within a swarm. However, none of the existing works consider multiple swarms. Even for the case of single swarms, researchers use unrealistic assumptions with respect to communication, leading to unrealistic results. In this paper, we evaluate the performance of multiple swarms considering realistic assumptions with respect to communication. To the best of our knowledge, it will be the first time …

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Performance Comparison Of Optimization Algorithms In Lqr Controller Design For A Nonlinear System, Ümi̇t Önen, Abdullah Çakan, İlhan İlhan Jan 2019

Performance Comparison Of Optimization Algorithms In Lqr Controller Design For A Nonlinear System, Ümi̇t Önen, Abdullah Çakan, İlhan İlhan

Turkish Journal of Electrical Engineering and Computer Sciences

The development and improvement of control techniques has attracted many researchers for many years. Especially in the controller design of complex and nonlinear systems, various methods have been proposed to determine the ideal control parameters. One of the most common and effective of these methods is determining the controller parameters with optimization algorithms.In this study, LQR controller design was implemented for position control of the double inverted pendulum system on a cart. First of all, the equations of motion of the inverted pendulum system were obtained by using Lagrange formulation. These equations were linearized by Taylor series expansion around the …

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Novel Node Deployment Scheme And Reliability Quantitative Analysis For An Iot-Based Monitoring System, Yinghua Tong, Liqin Tian, Jing Li Jan 2019

Novel Node Deployment Scheme And Reliability Quantitative Analysis For An Iot-Based Monitoring System, Yinghua Tong, Liqin Tian, Jing Li

Turkish Journal of Electrical Engineering and Computer Sciences

The Internet of things (IoT) is highly suitable for military, environmental, agricultural, and other remote real-time monitoring applications. A reliable topology ensures a stable and dependable monitoring system. Considering the research of an IoT-based air pollution monitoring system for industrial emissions as background, this study proposes a novel dual redundant node deployment scheme. Specifically, hexagonal clustering is proposed for the internal regions. In addition, relationship and quantification formulas for a monitoring area are presented, and the communication range, total number of layers of the topology, and number of cluster headers are determined. Interruptions in a monitoring system may reduce the …

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Queue Length Feedback-Based Solution Of Tcp Incast In Data Center Networks, Hasnain Ahmed, Junaid Arshad Jan 2019

Queue Length Feedback-Based Solution Of Tcp Incast In Data Center Networks, Hasnain Ahmed, Junaid Arshad

Turkish Journal of Electrical Engineering and Computer Sciences

The Internet offers a large number of applications and services that we use on a daily basis. These widely used applications are hosted on large-scale, high-performance computing systems called data centers. The performance of TCP is inefficient in many-to-one communication, which is a common traffic pattern in data center networks. This many-to-one communication causes significant packet losses followed by timeouts, which consequently results in throughput collapse in data center networks; this problem is known as TCP Incast. In this paper, we present a queue length feedback-based solution to mitigate TCP Incast. The scheme has two parts: i) a novel queue …

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Large-Scale Round-Trip Delay Time Analysis Of Ipv4 Hosts Around The Globe, Ali̇ Gezer Jan 2019

Large-Scale Round-Trip Delay Time Analysis Of Ipv4 Hosts Around The Globe, Ali̇ Gezer

Turkish Journal of Electrical Engineering and Computer Sciences

Design and optimization of many network applications, services, protocols, and routing protocols can be improved with delay-related measurement for a better operation over the Internet. Many experimental delay measurements have been performed on predetermined end-to-end connections with a less number of hosts compared to our study. This study aims to investigate up-to-date round-trip delay time measurement results over the Internet through pinging random IPv4 addresses from three vantage points located in the United States, Turkey, and Japan. Considering different time periods in a day and in consecutive 5 years, we performed a large-scale round-trip delay time analysis study by sending …

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Impact Of The Primary User On The Secondary User Blocking Probability In Cognitive Radio Sensor Networks, Mohammad Mehdi Hassani, Reza Berangi Jan 2019

Impact Of The Primary User On The Secondary User Blocking Probability In Cognitive Radio Sensor Networks, Mohammad Mehdi Hassani, Reza Berangi

Turkish Journal of Electrical Engineering and Computer Sciences

With the increasing usage of wireless sensor network technologies, their unlicensed bands become overcrowded. To address this challenge, cognitive radio technology with the dynamic spectrum access policy has merged with Wireless Sensor Network to overcome spectrum underutilization. The Cognitive Radio Sensor Network (CRSN) has emerged as a promising solution to overcome spectrum scarcity in a resource-constrained wireless sensor network. In CRSN, TCP has to cope with a new type of packet loss due to the primary users (PU) arrival, known here as a secondary user (SU) blocking loss. In this paper SU blocking loss is modelled by a discrete-time Markov …

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