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Full-Text Articles in Computer Engineering

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. …


A Quasi-Z-Source Active Neutral Point Clamped Inverter Topology Employingsymmetrical/Unsymmetrical Boost Modulation Control Scheme For Renewableenergy Resources, Rehan Majeed, Danial Saleem, M. Imtiaz Hussain, Muhammad Talha Gul, Muhammad Rehan Usman, Salman Majeed Jan 2019

A Quasi-Z-Source Active Neutral Point Clamped Inverter Topology Employingsymmetrical/Unsymmetrical Boost Modulation Control Scheme For Renewableenergy Resources, Rehan Majeed, Danial Saleem, M. Imtiaz Hussain, Muhammad Talha Gul, Muhammad Rehan Usman, Salman Majeed

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a bipolar quasi-Z-source active neutral point clamped inverter (QZS-ANPCI) topology. It acts as a buck/boost inverter (3-phase, 3-level) to integrate renewable energy resources under their fluctuating DC voltages. We propose a symmetrical/unsymmetrical boost modulation control technique to mitigate the DC-link unbalance voltage problem in an ANPC inverter. This worthwhile control technique exploits voltage-current closedloops on AC and DC sides to regulate the desired parameters. Moreover, the constant boost control (CBC) modulation has provided a switching sequence that generates a symmetrical/unsymmetrical full shoot-through (FST) state for boosting input DC voltage in the proposed inverter. Detailed loss and efficiency …


Exploring Bigram Character Features For Arabic Text Clustering, Dia Eddin Abuzeina Jan 2019

Exploring Bigram Character Features For Arabic Text Clustering, Dia Eddin Abuzeina

Turkish Journal of Electrical Engineering and Computer Sciences

The vector space model (VSM) is an algebraic model that is widely used for data representation in text mining applications. However, the VSM poses a critical challenge, as it requires a high-dimensional feature space. Therefore, many feature selection techniques, such as employing roots or stems (i.e. words without infixes and prefixes, and/or suffixes) instead of using complete word forms, are proposed to tackle this space challenge problem. Recently, the literature shows that one more basic unit feature can be used to handle the textual features, which is the twoneighboring character form that we call microword. To evaluate this feature type, …


A Comparative Study On Handwritten Bangla Character Recognition, Md. Atiqul Islam Rizvi, Kaushik Deb, Md. Ibrahim Khan, Mir Md. Saki Kowsar, Tahmina Khanam Jan 2019

A Comparative Study On Handwritten Bangla Character Recognition, Md. Atiqul Islam Rizvi, Kaushik Deb, Md. Ibrahim Khan, Mir Md. Saki Kowsar, Tahmina Khanam

Turkish Journal of Electrical Engineering and Computer Sciences

Recognition of handwritten Bangla characters has drawn considerable attention recently. The Bangla language is rich with characters of various styles such as numerals, basic characters, and compound and modifier characters. The inherent variation in individual writing styles, along with the complex, cursive nature of characters, makes the recognition task more challenging. To compare the outcomes of handwritten Bangla character recognition, this study considers two different approaches. The first one is classifier-based, where a hybrid model of the feature extraction technique extracts the features and a multiclass support vector machine (SVM) performs the recognition. The second one is based on a …


Adaptive Switching Gain Sliding Mode Control For Speed Regulation In Pmsms, Yanwei Huang, Yuqing Xie, Zheyi Liu Jan 2019

Adaptive Switching Gain Sliding Mode Control For Speed Regulation In Pmsms, Yanwei Huang, Yuqing Xie, Zheyi Liu

Turkish Journal of Electrical Engineering and Computer Sciences

To suppress uncertainties caused by parametric variations or disturbances, an adaptive switching gain (ASG) is proposed for integral sliding mode control (ISMC) to regulate speed in permanent magnet synchronous motors (PMSMs). According to system uncertainties, the ASG is designed to adjust the switching gain to suppress the chattering. The adaptive law is a positive value resulting in an increment of the switching gain when the tracking trajectory is outside the boundary layer. Conversely, it is negative with a decrement of the gain. Further, it improves a convergent rate by the function of the reciprocal of the tracking error when the …


Importance-Based Signal Detection And Parameter Estimation With Applications To New Particle Search, Hati̇ce Doğan, Nasuf Sönmez, Güleser Kalayci Demi̇r Jan 2019

Importance-Based Signal Detection And Parameter Estimation With Applications To New Particle Search, Hati̇ce Doğan, Nasuf Sönmez, Güleser Kalayci Demi̇r

Turkish Journal of Electrical Engineering and Computer Sciences

One of the hardest challenges in data analysis is perhaps the detection of rare anomalous data buried in a huge normal background. We study this problem by constructing a novel method, which is a combination of the Kullback?Leibler importance estimation procedure based anomaly detection algorithm and linear discriminant classifier. We choose to illustrate it with the example of charged Higgs boson (CHB) search in particle physics. Indeed, the Large Hadron Collider experiments at CERN ensure that CHB signal must be a tiny effect within the irreducible W-boson background. In simulations, different CHB events with different characteristics are produced and judiciously …


Particle Swarm Optimization Approach To Optimal Design Of An Afpm Tractionmachine For Different Driving Conditions, Naghi Rostami Jan 2019

Particle Swarm Optimization Approach To Optimal Design Of An Afpm Tractionmachine For Different Driving Conditions, Naghi Rostami

Turkish Journal of Electrical Engineering and Computer Sciences

Axial flux permanent magnet (AFPM) machines can be employed as the traction motor of electric vehicles due to their high torque capability, high efficiency, modular and compact construction, and capability of integration with other mechanical components in integrated systems. Besides, the system efficiency can be further improved by optimal design of the selected electric machine. In this paper, an AFPM machine is optimized against two well-known driving cycles called the New European Drive Cycle (NEDC) and US06 and the influence of the driving cycle on the obtained machine parameters is evaluated. US06 is the more demanding driving cycle and thus …


Design Of A Substrate Integrated Waveguide Matrix Amplifier, Shabnam Ahamadi Andevari, Gholamreza Moradi Jan 2019

Design Of A Substrate Integrated Waveguide Matrix Amplifier, Shabnam Ahamadi Andevari, Gholamreza Moradi

Turkish Journal of Electrical Engineering and Computer Sciences

Developments in microwave systems have increased the need for matrix amplifiers, which provide both high gain and wide frequency bands. The aim of this paper is to design a novel 2x4 matrix amplifier with a substrate integrated waveguide (SIW)-based power divider and combiner and a microstrip gain equalizer in the X and low Ku frequency bands. The proposed amplifier can be easily integrated with any microstrip, rectangular waveguide, or SIW-based circuits. The analysis and design of the amplifier is performed using two full wave simulators with different computational techniques (finite element method and finite integration technique) to verify the results. …


Symptom-Aware Hybrid Fault Diagnosis Algorithm In The Network Virtualization Environment, Yuze Su, Xiangru Meng, Xiaoyang Han, Qiaoyan Kang Jan 2019

Symptom-Aware Hybrid Fault Diagnosis Algorithm In The Network Virtualization Environment, Yuze Su, Xiangru Meng, Xiaoyang Han, Qiaoyan Kang

Turkish Journal of Electrical Engineering and Computer Sciences

As an important technology in next-generation networks, network virtualization has received more and more attention. Fault diagnosis is the crucial element for fault management and it is the process of inferring the exact failure in the network virtualization environment (NVE) from the set of observed symptoms. Although various traditional fault diagnosis algorithms have been proposed, the virtual network has some new characteristics, which include inaccessible fault information of the substrate network, inaccurate network observations, and a dynamic embedding relationship. To solve these challenges, a symptom-aware hybrid fault diagnosis (SAHFD) algorithm in the NVE is proposed in this paper. First, a …


Empirical Single Frequency Network Threshold For Dvb-T2 Based On Laboratory Experiments, Bundit Ruckveratham, Sathaporn Promwong Jan 2019

Empirical Single Frequency Network Threshold For Dvb-T2 Based On Laboratory Experiments, Bundit Ruckveratham, Sathaporn Promwong

Turkish Journal of Electrical Engineering and Computer Sciences

DVB-T2 broadcasting with a single frequency network (SFN) allows an efficient management of frequency utilization and extends the coverage area, which will enable more people to view a broadcast. The SFN mode also increases the concentration of the signal in overlap areas. However, some difference of overlap areas in actual use of SFN networks may have some degradation of the received signal due to the effect of the SFN. In this research, we analyze SFN broadcasting in SISO mode. This paper represents the effects of delays on the SFN signal over different delay times within the guard interval (GI) by …


A Comprehensive Methodology To Evaluate The Performance Of A Cooperative Wireless Network, Aykut Kalaycioğlu, Ahmet Akbulut, Asim Egemen Yilmaz, Di̇lek Arslan Jan 2019

A Comprehensive Methodology To Evaluate The Performance Of A Cooperative Wireless Network, Aykut Kalaycioğlu, Ahmet Akbulut, Asim Egemen Yilmaz, Di̇lek Arslan

Turkish Journal of Electrical Engineering and Computer Sciences

Performance evaluation of a cooperative wireless communication network depends on several parameters. Many of the studies, in fact, take a limited number of performance metrics individually to reach a conclusion about the performance of a network. Besides, in general, some performance metrics might be in conflict. Thus, ignoring the combined effect of all performance criteria in the network may lead to an incorrect conception of the overall communication performance of the network. Therefore, in this study, a comprehensive evaluation methodology in terms of various metrics is proposed to calculate the performance of a cooperative wireless communication network deployment using a …


A No-Reference Framework For Evaluating Video Quality Streamed Through Wireless Network, Muhammad Uzair, Robert D. Dony, Mohsin Jamil, Khawaja Bilal Ahmad Mahmood, Muhammad Nasir Khan Jan 2019

A No-Reference Framework For Evaluating Video Quality Streamed Through Wireless Network, Muhammad Uzair, Robert D. Dony, Mohsin Jamil, Khawaja Bilal Ahmad Mahmood, Muhammad Nasir Khan

Turkish Journal of Electrical Engineering and Computer Sciences

In this work, a no-reference framework is proposed for the video quality estimation streamed through the wireless network. The work presents a comprehensive survey of the existing full reference (FR), reduced reference (RR), and no-reference (NR) algorithms. A comparison has been made among existing algorithms, i.e. in terms of subjective correlation and feasibility to use these algorithms in wireless architecture, to describe the necessity of the proposed framework to overcome the limitations of the existing algorithms. A brief summary of our previously published algorithms, i.e. NR blockiness, NR blur, NR network, NR just noticeable distortion, and RR, has also been …


A Heuristic Algorithm To Find Rupture Degree In Graphs, Rafet Durgut, Tufan Turaci, Hakan Kutucu Jan 2019

A Heuristic Algorithm To Find Rupture Degree In Graphs, Rafet Durgut, Tufan Turaci, Hakan Kutucu

Turkish Journal of Electrical Engineering and Computer Sciences

Since the problem of Konigsberg bridge was released in 1735, there have been many applications of graph theory in mathematics, physics, biology, computer science, and several fields of engineering. In particular, all communication networks can be modeled by graphs. The vulnerability is a concept that represents the reluctance of a network to disruptions in communication after a deterioration of some processors or communication links. Furthermore, the vulnerability values can be computed with many graph theoretical parameters. The rupture degree $r(G)$ of a graph $G=(V,E)$ is an important graph vulnerability parameter and defined as $r(G)=max\{\omega(G-S)- S -m(G-S):\omega(G-S)\geq2, S\subset V \}$, where …


Global Stabilization Of A Class Of Fractional-Order Delayed Bidirectional Associativememory Neural Networks, Zhanying Yang, Xiaoyun Tang, Jie Zhang Jan 2019

Global Stabilization Of A Class Of Fractional-Order Delayed Bidirectional Associativememory Neural Networks, Zhanying Yang, Xiaoyun Tang, Jie Zhang

Turkish Journal of Electrical Engineering and Computer Sciences

This paper focuses on the stabilization problem of a class of fractional-order bidirectional associative memory neural networks with time delays. Based on feedback control, a sufficient condition is derived to achieve the global stabilization of systems by using the fractional inequality, the Lyapunov stability theory, and the comparison principle. In particular, this kind of control scheme is proved to be robust in the presence of external disturbances when the feedback gains are sufficiently large. In addition, a condition is obtained to achieve the global quasi-stabilization of systems with some external disturbances, and the corresponding error bound is estimated. Finally, some …


Privacy Issues In Post Dissemination On Facebook, Burcu Sayi̇n Günel, Serap Şahi̇n, Dimitris G. Kogias, Charalampos Z. Patrikakis Jan 2019

Privacy Issues In Post Dissemination On Facebook, Burcu Sayi̇n Günel, Serap Şahi̇n, Dimitris G. Kogias, Charalampos Z. Patrikakis

Turkish Journal of Electrical Engineering and Computer Sciences

With social networks (SNs) being populated by a still increasing numbers of people who take advantage of the communication and collaboration capabilities that they offer, the probability of the exposure of people's personal moments to a wider than expected audience is also increasing. By studying the functionalities and characteristics that modern SNs offer, along with the people's habits and common behaviors in them, it is easy to understand that several privacy risks may exist, many of which people may be unaware of. In this paper, we focus on users' interactions with posts in a social network (SN), using Facebook as …


Increasing Bluetooth Low Energy Communication Efficiency By Presetting Protocol Parameters, Dusan Hatvani, Dominik Macko Jan 2019

Increasing Bluetooth Low Energy Communication Efficiency By Presetting Protocol Parameters, Dusan Hatvani, Dominik Macko

Turkish Journal of Electrical Engineering and Computer Sciences

Standard protocols are important regarding the compatibility of devices provided by different vendors. However, specific applications have various requirements and do not always need all features offered by standard protocols, making them inefficient. This paper focuses on standard Bluetooth Low Energy modifications, reducing control overhead for the intended healthcare application. Specifically, the connection establishment, device pairing, and connection parameter negotiations have been targeted. The simulation-based experiments showed over 20 times reduction of control-overhead time preceding a data transmission. It does not just directly increase the energy efficiency of communication; it also prolongs the time for sensor-based end devices to spend …


Lightweight Signature Scheme To Protect Intellectual Properties Of Internet Of Things Applications In System On Chip Field-Programmable Gate Arrays, Kokila Jagadeesh, Ramasubramanian Natarajan Jan 2019

Lightweight Signature Scheme To Protect Intellectual Properties Of Internet Of Things Applications In System On Chip Field-Programmable Gate Arrays, Kokila Jagadeesh, Ramasubramanian Natarajan

Turkish Journal of Electrical Engineering and Computer Sciences

Billions of smart objects in the edge devices offer advanced connectivity to networks which increase the security and complexity of the Internet of things (IoT) applications. To make such entities smarter heterogeneous intellectual property (IP) cores from multiple service providers are reused in system on chip platform. Enabling both chip and IP protection at post fabrication level is imperative. The IoT-based IP cores are signed with the hybrid physical unclonable function and finite state machine model to protect from cloning, misuse, unauthorized user access, and physical attacks. The extended finite-state machine is used to verify the signature, which reduces the …


Solving Vehicle Routing Problem For Multistorey Buildings Using Iterated Local Search, Osman Gökalp, Aybars Uğur Jan 2019

Solving Vehicle Routing Problem For Multistorey Buildings Using Iterated Local Search, Osman Gökalp, Aybars Uğur

Turkish Journal of Electrical Engineering and Computer Sciences

Vehicle routing problem (VRP) which is a well-known combinatorial optimisation problem that has many applications used in industry is also a generalised form of the travelling salesman problem. In this study, we defined and formulated the VRP in multistorey buildings (Multistorey VRP) for the first time and proposed a solving method employing iterated local search metaheuristic algorithm. This variant of VRP has a great potential for turning the direction of optimisation research and applications to the vertical cities area as well as the horizontal ones. Routes of part picking or placing vehicles/humans in multistorey plants can be minimised by this …


An Algorithm For Line Matching In An Image By Mapping Into An $N$-Dimensional Vector Space, Rayi̇mbek Sultanov, Ahmet Atakan, Rita Ismailova Jan 2019

An Algorithm For Line Matching In An Image By Mapping Into An $N$-Dimensional Vector Space, Rayi̇mbek Sultanov, Ahmet Atakan, Rita Ismailova

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a minimal length difference algorithm for construction of a line in an image by solving the problem of optimal contour approximation. In this algorithm, a method for finding interest points is proposed, and the object matching (classification) is done by mapping interest points onto a vector space. In cases where the lines in the representation of the images are not smooth, the algorithm converges rapidly. The results of the experiments showed that for convergence of the contour simplification, there were 5-6 iterations for $n = 13$. To check how close the curve approximation calculated by the algorithm …


An Improved Imperialist Competitive Algorithm For Global Optimization, Ting You, Yueli Hu, Peijiang Li, Yinggan Tang Jan 2019

An Improved Imperialist Competitive Algorithm For Global Optimization, Ting You, Yueli Hu, Peijiang Li, Yinggan Tang

Turkish Journal of Electrical Engineering and Computer Sciences

The imperialist competitive algorithm (ICA), inspired by sociopolitical behavior in the real world, is a new optimization algorithm. The ICA shows great potential to solve complex optimization problems. In order to improve the ICA's exploration ability and speed up its convergence, two improved schemes are proposed in this paper. The first scheme presents a new possession probability in the imperialistic competition phase. Inspired by geopolitics, not only the power of the empire but also the distance between the imperialists are taken into account in calculating the new possession probability. The second scheme introduces the wavelet mutation operator into the original …


Schedulability Analysis Of Real-Time Multiframe Cosimulations On Multicore Platforms, Muhammad Uzair Ahsan, Mehmet Hali̇t Seyfullah Oğuztüzün Jan 2019

Schedulability Analysis Of Real-Time Multiframe Cosimulations On Multicore Platforms, Muhammad Uzair Ahsan, Mehmet Hali̇t Seyfullah Oğuztüzün

Turkish Journal of Electrical Engineering and Computer Sciences

For real-time simulations, the fidelity of simulation depends not only on the functional accuracy of simulation but also on its timeliness. It is helpful for simulation designers if they can analyze and verify that a simulation will always meet its timing requirements without unnecessarily sacrificing functional accuracy. Abstracting the simulated processes simply as software tasks allows us to transform the problem of verifying timeliness into a schedulability analysis problem where tasks are checked as to whether they are schedulable under the timing constraints or not. In this paper we extend a timed automaton-based framework due to Fersman and Yi for …


Reusable And Interactive Classes: A New Way Of Object Composition, Saeid Masoumi, Ali Mahjur Jan 2019

Reusable And Interactive Classes: A New Way Of Object Composition, Saeid Masoumi, Ali Mahjur

Turkish Journal of Electrical Engineering and Computer Sciences

Separating object features from base classes is one of the popular ways of software development. Some popular programming approaches like object-oriented programming, feature-oriented programming, and aspect-oriented programming follow this approach. There are four advantages of using features: 1) Instantiability: the ability to create instances of a feature, 2) Reusability: the quality of a feature being reusable in many compositions, 3) Loosely coupled composability: the ability to compose/decompose features easily at object instantiation time (not offering new data types for compositions), and 4) Interactability: the ability of a feature to crosscut (interact with) other features inside the object. Existing approaches do …


Detection Of Fraud Risks In Retailing Sector Using Mlp And Svm Techniques, Davut Pehli̇vanli, Süleyman Eken, Ebu Beki̇r Ayan Jan 2019

Detection Of Fraud Risks In Retailing Sector Using Mlp And Svm Techniques, Davut Pehli̇vanli, Süleyman Eken, Ebu Beki̇r Ayan

Turkish Journal of Electrical Engineering and Computer Sciences

In today's business conditions, where business activities are spreading over a wide geographical area, fraud auditing processes have crucial importance especially for the retailing sector which has a high branch network. In the retailing sector, especially purchasing processes are subject to high fraud risks. This paper shows that it is possible to detect fraudulent processes by applying data mining techniques on operational data related to purchasing activities. Within this scope, in order to detect the fraudulent purchasing operations, support vector machine (SVM) models with different kernels and artificial neural networks methods have been used and successful results have been achieved. …


A Robust Ensemble Feature Selector Based On Rank Aggregation For Developing New Vo\Textsubscript{2}Max Prediction Models Using Support Vector Machines, Fatih Abut, Mehmet Fati̇h Akay, James George Jan 2019

A Robust Ensemble Feature Selector Based On Rank Aggregation For Developing New Vo\Textsubscript{2}Max Prediction Models Using Support Vector Machines, Fatih Abut, Mehmet Fati̇h Akay, James George

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes a new ensemble feature selector, called the majority voting feature selector (MVFS), for developing new maximal oxygen uptake (VO2max) prediction models using a support vector machine (SVM). The approach is based on rank aggregation, which meaningfully utilizes the correlation among the relevance ranks of predictor variables given by three state-of-the-art feature selectors: Relief-F, minimum redundancy maximum relevance (mRMR), and maximum likelihood feature selection (MLFS). By applying the SVM combined with MVFS on a self-created dataset containing maximal and submaximal exercise data from 185 college students, several new hybrid (VO2max) prediction models have been created. To compare the …


Incremental Author Name Disambiguation Using Author Profile Models And Self-Citations, Ijaz Hussain, Sohail Asghar Jan 2019

Incremental Author Name Disambiguation Using Author Profile Models And Self-Citations, Ijaz Hussain, Sohail Asghar

Turkish Journal of Electrical Engineering and Computer Sciences

Author name ambiguity in bibliographic databases (BDs) such as DBLP is a challenging problem that degrades the information retrieval quality, citation analysis, and proper attribution to the authors. It occurs when several authors have the same name (homonym) or when an author publishes under several name variants (synonym). Traditionally, much research has been conducted to disambiguate whole bibliographic database at once whenever some new citations are added in these BDs. However, it is more time-consuming and discards the manual disambiguation effects (if any). Only a few incremental author name disambiguation methods are proposed but these methods produce fragmented clusters which …


Biometric Person Authentication Framework Using Polynomial Curve Fitting-Based Ecg Feature Extraction, Şahi̇n Işik, Kemal Özkan, Semi̇h Ergi̇n Jan 2019

Biometric Person Authentication Framework Using Polynomial Curve Fitting-Based Ecg Feature Extraction, Şahi̇n Işik, Kemal Özkan, Semi̇h Ergi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

The applications of modern biometric techniques for person identification systems rapidly increase for meeting the rising security demands. The distinctive physiological characteristics are more correctly measurable and trustworthy since previous measurements are not appropriately made for physiological properties. While a variety of strategies have been enabled for identification, the electrocardiogram (ECG)-based approaches are popular and reliable techniques in the senses of measurability, singularity, and universal awareness of heartbeat signals. This paper presents a new ECG-based feature extraction method for person identification using a huge amount of ECG recordings. First of all, 1800 heartbeats for each of the 36 subjects have …


I See Ek: A Lightweight Technique To Reveal Exploit Kit Family By Overall Url Patterns Of Infection Chains, Emre Süren, Peli̇n Angin, Nazi̇fe Baykal Jan 2019

I See Ek: A Lightweight Technique To Reveal Exploit Kit Family By Overall Url Patterns Of Infection Chains, Emre Süren, Peli̇n Angin, Nazi̇fe Baykal

Turkish Journal of Electrical Engineering and Computer Sciences

The prevalence and nonstop evolving technical sophistication of exploit kits (EKs) is one of the most challenging shifts in the modern cybercrime landscape. Over the last few years, malware infections via drive-by download attacks have been orchestrated with EK infrastructures. Malicious advertisements and compromised websites redirect victim browsers to web-based EK families that are assembled to exploit client-side vulnerabilities and finally deliver evil payloads. A key observation is that while the webpage contents have drastic differences between distinct intrusions executed through the same EK, the patterns in URL addresses stay similar. This is due to the fact that autogenerated URLs …


Adaptive Canonical Correlation Analysis For Harmonic Stimulation Frequencies Recognition In Ssvep-Based Bcis, Sahar Sadeghi, Ali Maleki Jan 2019

Adaptive Canonical Correlation Analysis For Harmonic Stimulation Frequencies Recognition In Ssvep-Based Bcis, Sahar Sadeghi, Ali Maleki

Turkish Journal of Electrical Engineering and Computer Sciences

Steady-state visual evoked potential (SSVEP) is the brain's response to quickly repetitive visual stimulus with a certain frequency. To increase the information transfer rate (ITR) in SSVEP-based systems, due to the frequency resolution restriction, we are forced to broaden the frequency range, which causes harmonic frequencies to come into the stimulation frequency range. Conventional canonical correlation analysis (CCA) may be associated with error for SSVEP frequency recognition at stimulation frequencies with harmonic relations. The number of harmonics considered to construct reference signals are determined adaptively; for frequencies whose second harmonic exists in the frequency range, two harmonics are used, and …


A Hybrid Of Fuzzy Theory And Quadratic Function For Estimating And Refining Transmission Map, Jyun-Yu Jhang, Chengjian Lin, Kuu-Young Young, Chin-Teng Lin Jan 2019

A Hybrid Of Fuzzy Theory And Quadratic Function For Estimating And Refining Transmission Map, Jyun-Yu Jhang, Chengjian Lin, Kuu-Young Young, Chin-Teng Lin

Turkish Journal of Electrical Engineering and Computer Sciences

In photographs captured in outdoor environments, particles in the air cause light attenuation and degrade image quality. This effect is especially obvious in hazy environments. In this study, a fuzzy theory is proposed to estimate the transmission map of a single image. To overcome the problem of oversaturation in dehazed images, a quadratic-function-based method is proposed to refine the transmission map. In addition, the color vector of the atmospheric light is estimated using the top 1\% of the brightest light area. Finally, the dehazed image is reconstructed using the transmission map and the estimated atmospheric light. Experimental results demonstrate that …


Application Of Fuzzy Logic On Astronomical Images' Focus Measures, Alaa Hamdy, Farag Elnagahy, Islam Helmy Jan 2019

Application Of Fuzzy Logic On Astronomical Images' Focus Measures, Alaa Hamdy, Farag Elnagahy, Islam Helmy

Turkish Journal of Electrical Engineering and Computer Sciences

Focus accuracy is an essential factor that affects the quality of astronomical observations. The accurate measurement of celestial objects' properties depends on focus. Automatic focusing is necessary for celestial imaging systems. This paper presents a modified focus measure operator. It also proposes the use of fuzzy logic to transform images because of its tolerance of imprecise and incomplete data. The focus operators are applied to two sequences of star clusters' observations. The experimental results show that the suggested measure's overall score exceeds those of previous operators.