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Articles 73261 - 73290 of 196426

Full-Text Articles in Engineering

Bow-Tie-Shaped Wideband Conformal Antenna With Wide-Slot For Gps Application, Ratikanta Sahoo, Damera Vakula Jan 2019

Bow-Tie-Shaped Wideband Conformal Antenna With Wide-Slot For Gps Application, Ratikanta Sahoo, Damera Vakula

Turkish Journal of Electrical Engineering and Computer Sciences

In this article, a novel wideband cylindrical conformal antenna using a wide slot in the ground plane is proposed. A bow-tie-shaped patch antenna is designed for Global Positioning System applications. The bandwidth of the antenna is improved by using a similar bow-tie-shaped slot in the ground plane with a larger dimension. The bandwidth is further enhanced by introducing a dumbbell-shaped slit in the patch. The antenna is fed by a 50-$ \Omega $ microstrip line. The proposed planar antenna is printed on a ground plane of size 0.5$ \lambda $ mm$ \times $ 0.5$ \lambda $ mm, where $ \lambda …

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Three-Channel Control Architecture For Multilateral Teleoperation Under Time Delay, Uğur Tümerdem Jan 2019

Three-Channel Control Architecture For Multilateral Teleoperation Under Time Delay, Uğur Tümerdem

Turkish Journal of Electrical Engineering and Computer Sciences

Multilateral teleoperation is an extension of bilateral/haptic teleoperation framework to multiple operators/robots and finds applications in haptic training. As in bilateral teleoperation, time delay is an important problem, and stability and transparency, which quantifies the performance of the teleoperation system, are critical in the design of multilateral control systems. This paper proposes a novel three-channel-based multilateral control architecture with damping injection to guarantee delay-independent L2 stability and high transparency in multilateral teleoperation systems. The theoretical and computational analyses are verified with experiment results.

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Optimal Contract Pricing Of Load Aggregators For Direct Load Control In Smartdistribution Systems, Ali Shayegan-Rad, Ali Zangeneh Jan 2019

Optimal Contract Pricing Of Load Aggregators For Direct Load Control In Smartdistribution Systems, Ali Shayegan-Rad, Ali Zangeneh

Turkish Journal of Electrical Engineering and Computer Sciences

Distribution system operators (DSOs) are interested in demand side participation programs as an efficient and secure resource to manage electricity supply and demand. However, it is usually difficult for DSOs to aggregate demand response of large/small consumers. Thus, in some electricity markets, an entity called an aggregator is defined to aggregate the load response of consumers. In this paper a bilevel scheduling model is proposed to determine the long-term optimal contract price between the DSO and aggregator for executing direct load control in smart distribution systems. The DSO and aggregator are considered as two different agents with individual objectives in …

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Optimal Placement Of Switching And Protection Devices In Radial Distribution Networks To Enhance System Reliability Using The Ahp-Pso Method, Masoud Amohadi, Mahmud Fotuhi Firuzabad Jan 2019

Optimal Placement Of Switching And Protection Devices In Radial Distribution Networks To Enhance System Reliability Using The Ahp-Pso Method, Masoud Amohadi, Mahmud Fotuhi Firuzabad

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new method to determine the optimal number and locations of autorecloser and sectionalizer switches (AR/S) in distribution networks. The costs of AR/S investment, switch maintenance, and undistributed energy as well as reliability coefficients are considered in the objective function. Reliability parameters such as SAIFI, SADI, MAIFI, and ENS are evaluated in the case study system. As a new method, the weights of the reliability parameters are obtained by decision-makers using the analytical hierarchy process (AHP). The optimal size, type, and location of automatic switches are determined by minimizing the objective function using the particle swarm optimization …

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A Developed Flywheel Energy Storage With Built-In Rotating Supercapacitors, Hamidreza Toodeji Jan 2019

A Developed Flywheel Energy Storage With Built-In Rotating Supercapacitors, Hamidreza Toodeji

Turkish Journal of Electrical Engineering and Computer Sciences

Flywheel energy storage can store large amounts of kinetic energy in its rotating parts, but its inertia restricts the rate of power exchange. On the other hand, there is supercapacitor with the ability of exchanging large amounts of instantaneous power. Therefore, the combination of these two systems can significantly improve the dynamic response of conventional flywheel energy storage. This paper proposes a novel design for this combined system in which supercapacitors are located inside the rotating disk. Therefore, supercapacitors can significantly improve the dynamic performance of the flywheel energy storage with trivial effects on its size and weight. Moreover, the …

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Thyristor-Based "Phase Hopping" Frequency Conversion Technique, Zhenwang Xu, Jiarui Zhang, Yuchun Yi, Cheng Chen, Jiaqi Yu, Wei Mei, Daiwei Feng Jan 2019

Thyristor-Based "Phase Hopping" Frequency Conversion Technique, Zhenwang Xu, Jiarui Zhang, Yuchun Yi, Cheng Chen, Jiaqi Yu, Wei Mei, Daiwei Feng

Turkish Journal of Electrical Engineering and Computer Sciences

This study proposes a new AC/AC "phase hopping" frequency conversion method based on the analyses of the disadvantages of the conventional cosine wave-crossing method. The advantages of this new method include no circulating current, no dead time, and an output frequency close to the power frequency. This study also introduces the basic principles of the "phase hopping" method and analyzes these principles combined with the voltage phase-changing comparison to that of the cosine wave-crossing method. The "phase hopping" principles are used to analyze the generation of thyristor trigger pulses, including the generation time and duration. A simulation is conducted in …

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Evaluation Of Power System Robustness In Order To Prevent Cascading Outages, Farnaaz Hajbani, Heresh Seyedi, Kazem Zare Jan 2019

Evaluation Of Power System Robustness In Order To Prevent Cascading Outages, Farnaaz Hajbani, Heresh Seyedi, Kazem Zare

Turkish Journal of Electrical Engineering and Computer Sciences

Power system robustness against overload condition is a challenging issue in the fields of power system planning and operation. In this paper, two indices are proposed to evaluate power system robustness. The proposed indices are used to identify critical lines whose failure is due to overload, leading the power system to cascading outages and blackout. The first proposed index is a linear index. The second index is based on graph theory metrics. To prevent cascading outages, system robustness is calculated for all N-1 and N-2 contingencies. The lines whose outages lead to the smallest robustness values are considered as critical …

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Improved Vsm Control Of Pmsg-Based Wind Farms For Transient Stability Enhancement, Mohamed Abbes, Ines Mehouachi, Souad Chebbi Jan 2019

Improved Vsm Control Of Pmsg-Based Wind Farms For Transient Stability Enhancement, Mohamed Abbes, Ines Mehouachi, Souad Chebbi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper analyzes the optimal control strategy of PMSG-based wind farms during faults in order to improve the transient stability of a power system with a high penetration rate of wind power. The investigated control strategies are the unity power factor (UPF), reactive power control (RPC), and particularly the concept of virtual synchronous machine (VSM). The transient stability level is assessed using the critical clearing time index, which was calculated based on trajectory sensitivity analysis. In light of the obtained results, it was found that RPC gives the best transient stability level, followed by the classical VSM control. Hence, an …

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A Fuzzy Model Of Directional Relationships From The Phi-Descriptor, Mohammad Naeem, Nasir Ahmad, Sahib Khan, Asma Gul Jan 2019

A Fuzzy Model Of Directional Relationships From The Phi-Descriptor, Mohammad Naeem, Nasir Ahmad, Sahib Khan, Asma Gul

Turkish Journal of Electrical Engineering and Computer Sciences

Directional spatial relationships are a category of spatial relationships and have applications in the fields of image processing, geographic information systems, natural language processing, and robot navigation. They can be directly extracted from images or can be interpreted from a type of image descriptors called the relative position descriptors. Examples of relative position descriptors are the angle histogram, the force histogram, and the recently proposed phi-descriptor. So far, fuzzy models of directional spatial relationships from the angle histogram and force histograms have been proposed in the literature. These include the compatibility method, the aggregation method, and the method of effective …

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A Novel Metaheuristic Optimization Algorithm: The Monarchy Metaheuristic, Ibtissam Ahmia, Meziane Aider Jan 2019

A Novel Metaheuristic Optimization Algorithm: The Monarchy Metaheuristic, Ibtissam Ahmia, Meziane Aider

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we introduce a novel metaheuristic optimization algorithm named the monarchy metaheuristic (MN). Our proposed metaheuristic was inspired by the monarchy government system. Unlike many other metaheuristics, it is easy to implement and does not need a lot of parameters. This makes it applicable to a wide range of optimization problems. To evaluate the efficiency of the proposed algorithm, we examined it on the traveling salesman problem (TSP) using some benchmark from TSPLIB online library of instances for the TSP. The experimental results indicate that the monarchy metaheuristic is competitive with the other methods that exist in the …

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Data Analysis Through Social Media According To The Classified Crime, Serkan Savaş, Nuretti̇n Topaloğlu Jan 2019

Data Analysis Through Social Media According To The Classified Crime, Serkan Savaş, Nuretti̇n Topaloğlu

Turkish Journal of Electrical Engineering and Computer Sciences

The amount and variety of data generated through social media sites has increased along with the widespread use of social media sites. In addition, the data production rate has increased in the same way. The inclusion of personal information within these data makes it important to process the data and reach meaningful information within it. This process can be called intelligence and this meaningful information may be for commercial, academic, or security purposes. An example application is developed in this study for intelligence on Twitter. Crimes in Turkey are classified according to Turkish Statistical Institute criminal data and keywords are …

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Identifying Criminal Organizations From Their Social Network Structures, Muhammet Serkan Çi̇nar, Burkay Genç, Hayri̇ Sever Jan 2019

Identifying Criminal Organizations From Their Social Network Structures, Muhammet Serkan Çi̇nar, Burkay Genç, Hayri̇ Sever

Turkish Journal of Electrical Engineering and Computer Sciences

Identification of criminal structures within very large social networks is an essential security feat. By identifying such structures, it may be possible to track, neutralize, and terminate the corresponding criminal organizations before they act. We evaluate the effectiveness of three different methods for classifying an unknown network as terrorist, cocaine, or noncriminal. We consider three methods for the identification of network types: evaluating common social network analysis metrics, modeling with a decision tree, and network motif frequency analysis. The empirical results show that these three methods can provide significant improvements in distinguishing all three network types. We show that these …

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A Tree-Based Approach For English-To-Turkish Translation, Özge Bakay, Begüm Avar, Olcay Taner Yildiz Jan 2019

A Tree-Based Approach For English-To-Turkish Translation, Özge Bakay, Begüm Avar, Olcay Taner Yildiz

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present our English-to-Turkish translation methodology, which adopts a tree-based approach. Our approach relies on tree analysis and the application of structural modification rules to get the target side (Turkish) trees from source side (English) ones. We also use morphological analysis to get candidate root words and apply tree-based rules to obtain the agglutinated target words. Compared to earlier work on English-to-Turkish translation using phrase-based models, we have been able to obtain higher BLEU scores in our current study. Our syntactic subtree permutation strategy, combined with a word replacement algorithm, provides a 67 % relative improvement from …

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Fuzzy Logic-Based Disparity Selection Using Multiple Data Costs For Stereo Correspondence, Akhil Appu Shetty, V.I George, C Gurudas Nayak, Raviraj Shetty Jan 2019

Fuzzy Logic-Based Disparity Selection Using Multiple Data Costs For Stereo Correspondence, Akhil Appu Shetty, V.I George, C Gurudas Nayak, Raviraj Shetty

Turkish Journal of Electrical Engineering and Computer Sciences

Stereo matching algorithms are capable of generating depth maps from two images of the same scene taken simultaneously from two different viewpoints. Traditionally, a single cost function is used to calculate the disparity between corresponding pixels in the left and right images. In the present research, we have considered a combination of simple data costs. A new method to combine multiple data costs is presented and a fuzzy-based disparity selection method is proposed. Experiments with different combinations of parameters are conducted and compared through the Middlebury and Kitti Stereo Vision Benchmark.

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Automatic Concept Identification Of Software Requirements In Turkish, Fatma Bozyi̇ği̇t, Özlem Aktaş, Deni̇z Kilinç Jan 2019

Automatic Concept Identification Of Software Requirements In Turkish, Fatma Bozyi̇ği̇t, Özlem Aktaş, Deni̇z Kilinç

Turkish Journal of Electrical Engineering and Computer Sciences

Software requirements include description of the features for the target system and express the expectations of users. In the analysis phase, requirements are transformed into easy-to-understand conceptual models that facilitate communication between stakeholders. Although creating conceptual models using requirements is mostly implemented manually by analysts, the number of models that automate this process has increased recently. Most of the models and tools are developed to analyze requirements in English, and there is no study for agglutinative languages such as Turkish or Finnish. In this study, we propose an automatic concept identification model that transforms Turkish requirements into Unified Modeling Language …

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A Memory-Efficient Canonical Data Structure For Decimal Floating Point Arithmetic Systems Modeling And Verification, Mohammad Saeed Jahangiry, Saeed Safari Jan 2019

A Memory-Efficient Canonical Data Structure For Decimal Floating Point Arithmetic Systems Modeling And Verification, Mohammad Saeed Jahangiry, Saeed Safari

Turkish Journal of Electrical Engineering and Computer Sciences

Decimal floating point (DFP) number representation was proposed in IEEE-754-2008 in order to overcome binary floating point inaccuracy. Neglecting binary floating point verification has resulted in significant validity and economic losses. Formal verification can be a solution to similar DFP design problems. Verification techniques aiming at DFP are limited to functional methods whereas formal approaches have been neglected and traditional decision diagrams cannot model DFP representation complexity. In this paper, we propose an efficient canonical data structure that can model DFP properties. Our novel data structure models coefficient, exponent, sign, and bias of a DFP number. We will prove mathematically …

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Formally Analyzed M-Coupon Protocol With Confirmation Code (Mcwcc), Keri̇m Yildirim, Gökhan Dalkiliç, Nevci̇han Duru Jan 2019

Formally Analyzed M-Coupon Protocol With Confirmation Code (Mcwcc), Keri̇m Yildirim, Gökhan Dalkiliç, Nevci̇han Duru

Turkish Journal of Electrical Engineering and Computer Sciences

There are many marketing methods used to attract customers' attention and customers search for special discounts and conduct research to get products cheaper. Using discount coupons is one of the widely used methods for obtaining discounts. With the development of technology, classical paper-based discount coupons become e-coupons and then turn into mobile coupons (m-coupons). It is inevitable that retailers will use m-coupon technology to attract customers while mobile devices are used in daily life. As a result, m-coupon technology is a promising technology. One of the significant problems with using m-coupons is security. Here it is necessary to ensure the …

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Local Directional-Structural Pattern For Person-Independent Facial Expression Recognition, Farkhod Makhmudkhujaev, Md Tauhid Bin Iqbal, Byungyong Ryu, Oksam Chae Jan 2019

Local Directional-Structural Pattern For Person-Independent Facial Expression Recognition, Farkhod Makhmudkhujaev, Md Tauhid Bin Iqbal, Byungyong Ryu, Oksam Chae

Turkish Journal of Electrical Engineering and Computer Sciences

Existing popular descriptors for facial expression recognition often suffer from inconsistent feature description, experiencing poor accuracies. We present a new local descriptor, local directional-structural pattern (LDSP), in this work to address this issue. Unlike the existing local descriptors using only the texture or edge information to represent the local structure of a pixel, the proposed LDSP utilizes the positional relationship of the top edge responses of the target pixel to extract more detailed structural information of the local texture. We further exploit such information to characterize expression-affiliated crucial textures while discarding the random noisy patterns. Moreover, we introduce a globally …

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Motion Blur Image Deblurring Using Edge-Based Color Patches, Xixuan Zhao, Jiangming Kan Jan 2019

Motion Blur Image Deblurring Using Edge-Based Color Patches, Xixuan Zhao, Jiangming Kan

Turkish Journal of Electrical Engineering and Computer Sciences

The shaking of a camera can easily cause blurs in an image. Thus, deblurring is a problem that is worth solving and has always been an active research interest. The color information in an image is an important feature and contains clues for image deblurring that have not been widely exploited. In this paper, we present an efficient and stable blurring kernel estimation method by solving an energy function constructed by a weighted color approximation regularization term. The term is derived from a two-color model, and we use a defined weight to alleviate the color change through the blurring process. …

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Optimal Set Of Eeg Features In Infant Sleep Stage Classification, Maja Cic, Mario Milicevic, Igor Mazic Jan 2019

Optimal Set Of Eeg Features In Infant Sleep Stage Classification, Maja Cic, Mario Milicevic, Igor Mazic

Turkish Journal of Electrical Engineering and Computer Sciences

This paper evaluates six classification algorithms to assess the importance of individual EEG rhythms in the context of automatic classification of infant sleep. EEG features were obtained by Fourier transform and by a novel technique based on the empirical mode decomposition and generalized zero crossing method. Of six evaluated classification algorithms, the best classification results were obtained with the support vector machine for the combination of all presented features from four EEG channels. Three methods of attribute ranking were assessed: relief, principal component analysis, and wrapper-based optimized attribute weights. The outcomes revealed that the optimal selection of features requires one …

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Improvement Of Quantized Adaptive Switching Median Filter For Impulse Noise Reduction In Gray-Scale Digital Images, Haidi Ibrahim, Ahmed Khaldoon Abdalameer Jan 2019

Improvement Of Quantized Adaptive Switching Median Filter For Impulse Noise Reduction In Gray-Scale Digital Images, Haidi Ibrahim, Ahmed Khaldoon Abdalameer

Turkish Journal of Electrical Engineering and Computer Sciences

Digital images may suffer from fixed value impulse noise due to several causes. The noise significantly degrades the quality of the image, which may affect the subsequence image processing. Therefore, a noise reduction technique is required to restore the image. In this paper, a new method, which is called improvement of quantized adaptive switching median filter (IQASMF), has been proposed to reduce the fixed value impulse noise from gray-scale digital images. The implementation of IQASMF has five processing blocks. The first processing block is the noise detection block, where the noise pixel candidates are detected based on the intensity value. …

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On The Stability Of Inverse Dynamics Control Of Flexible-Joint Parallel Manipulators In The Presence Of Modeling Error And Disturbances, Sitki Kemal İder, Ozan Korkmaz, Mustafa Semi̇h Deni̇zli̇ Jan 2019

On The Stability Of Inverse Dynamics Control Of Flexible-Joint Parallel Manipulators In The Presence Of Modeling Error And Disturbances, Sitki Kemal İder, Ozan Korkmaz, Mustafa Semi̇h Deni̇zli̇

Turkish Journal of Electrical Engineering and Computer Sciences

Inverse dynamics control is considered for flexible-joint parallel manipulators in order to obtain a good trajectory tracking performance in the case of modeling error and disturbances. It is known that, in the absence of modeling error and disturbance, inverse dynamics control leads to linear fourth-order error dynamics, which is asymptotically stable if the feedback gains are chosen to make the real part of the eigenvalues of the system negative. However, when there are modeling errors and disturbances, a linear time-varying error dynamics is obtained whose stability is not assured only by keeping the real parts of the frozen-time eigenvalues of …

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Neural Network Controller For Nanopositioning Of A Smooth Impact Drive Mechanism, Xiaohui Lu, Dong Chen, Tinghai Cheng, Zhe Li Jan 2019

Neural Network Controller For Nanopositioning Of A Smooth Impact Drive Mechanism, Xiaohui Lu, Dong Chen, Tinghai Cheng, Zhe Li

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, neural network theory is used to improve the positioning accuracy of smooth impact drive mechanisms (SIDMs), by designing a displacement controller that consists of a neural network identification (NNI) and a neural network controller (NNC). The dynamics of the SIDM are described by the NNI, which consists of an input layer, hidden layer, and output layer. The parameters of the NNI are adjusted using back propagation. The NNC is designed as a proportional-derivative (PD) controller, which is used to accurately control the displacement of the SIDM. The PD parameters are adjusted with an adaptive adjustment algorithm. A …

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A Coordinated Dc Voltage Control Strategy For Cascaded Solid State Transformer With Star Configuration, Zhendong Ji, Yichao Sun, Cheng Jin, Jianhua Wang, Jianfeng Zhao Jan 2019

A Coordinated Dc Voltage Control Strategy For Cascaded Solid State Transformer With Star Configuration, Zhendong Ji, Yichao Sun, Cheng Jin, Jianhua Wang, Jianfeng Zhao

Turkish Journal of Electrical Engineering and Computer Sciences

Cascaded solid-state transformer (SST) can be directly connected to the high-voltage distribution grid, and it has broad applications in the future smart grid, traction locomotive, and renewable energy integration. However, the reliability of the cascaded SST is seriously influenced by the DC voltage and power imbalance issues with this configuration. This paper presents a coordinated DC voltage control strategy for cascaded SST with star configuration, in which the average DC voltage and the balancing DC voltage are controlled separately without current sensors in dual active bridge (DAB) modules. This strategy not only reduces the cost and the complexity of the …

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Assessment Of Techno-Economic Benefits For Smart Charging Scheme Of Electric Vehicles In Residential Distribution System, Kumari Kasturi, Manas Ranjan Nayak Jan 2019

Assessment Of Techno-Economic Benefits For Smart Charging Scheme Of Electric Vehicles In Residential Distribution System, Kumari Kasturi, Manas Ranjan Nayak

Turkish Journal of Electrical Engineering and Computer Sciences

Connecting multiple electric vehicles (EVs) to a power system network for the purpose of charging has major setbacks like decrease in power quality, instability in voltage profile, and increase in power losses and thus electricity price. This paper focuses on devising an optimal charging scheme to reduce the negative impacts of EVs' presence in the distribution network by limiting the charging process to only off-peak demand periods when the electricity price is comparatively lower. The salp swarm algorithm, an efficient, fast, and reliable optimization technique, is used to obtain the optimal locations for the EVs and their charging schedule in …

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Lung Segmentation In Chest Radiographs Using Fully Convolutional Networks, Rahul Hooda, Ajay Mittal, Sanjeev Sofat Jan 2019

Lung Segmentation In Chest Radiographs Using Fully Convolutional Networks, Rahul Hooda, Ajay Mittal, Sanjeev Sofat

Turkish Journal of Electrical Engineering and Computer Sciences

Automated segmentation of medical images that aims at extracting anatomical boundaries is a fundamental step in any computer-aided diagnosis (CAD) system. Chest radiographic CAD systems, which are used to detect pulmonary diseases, first segment the lung field to precisely define the region-of-interest from which radiographic patterns are sought. In this paper, a deep learning-based method for segmenting lung fields from chest radiographs has been proposed. Several modifications in the fully convolutional network, which is used for segmenting natural images to date, have been attempted and evaluated to finally evolve a network fine-tuned for segmenting lung fields. The testing accuracy and …

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Approximation Of Planar Curves, Malik Zawwar Hussain, Ayesha Shakeel, Maria Hussain Jan 2019

Approximation Of Planar Curves, Malik Zawwar Hussain, Ayesha Shakeel, Maria Hussain

Turkish Journal of Electrical Engineering and Computer Sciences

In the present article, we have developed the $G^{2}$-approximation scheme for planar curves arising in science, engineering, computer-aided design, computer-aided manufacturing, and many other fields. The obtained results reveal that the proposed method is a significant addition to the approximation of planar curves. The method is illustrated using different numerical examples. The smaller absolute error confirms the applicability and efficiency of the proposed method.

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Cache Pressure-Aware Caching Scheme For Content-Centric Networking, Xi Luo, Ying An Jan 2019

Cache Pressure-Aware Caching Scheme For Content-Centric Networking, Xi Luo, Ying An

Turkish Journal of Electrical Engineering and Computer Sciences

Content centric networking (CCN) is a new networking paradigm to meet the growing demand for content access in the future. Because of its important role in accelerating content retrieval and reducing network transmission load, in-network caching has become one of the core technologies in CCN and has attracted wide attention. The existing caching schemes often lack sufficient consideration of node cache status and the temporal validity of user requests, and thus the cache efficiency of the network is greatly reduced. In this paper, a cache pressure-aware caching scheme is proposed, which comprehensively takes into account various factors such as content …

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A Novel Adaptive Hysteresis Dc-Dc Buck Converter For Portable Devices, Sung Sik Park, Ju Sang Lee, Sang Dae Yu Jan 2019

A Novel Adaptive Hysteresis Dc-Dc Buck Converter For Portable Devices, Sung Sik Park, Ju Sang Lee, Sang Dae Yu

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new technique that adjusts the hysteresis window depending on the variations in load current caused by a voltage-mode circuit to reduce the voltage and current ripples. Moreover, a compact current-sensing circuit is used to provide an accurate sensing signal for achieving fast hysteresis window adjustment. In addition, a zero-current detection circuit is also proposed to eliminate the reverse current at light loads. As a result, this technique reduces the voltage ripple below 8.08 mV$_{\rm pp}$ and the current ripple below 93.98 mA$_{\rm pp}$ for a load current of 500 mA. Circuit simulation is performed using 0.18 …

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A Novel Design Of An Electromagnetically Levitated Vibrational Viscometer For Biomedical And Clinical Applications, Ali̇ Akpek Jan 2019

A Novel Design Of An Electromagnetically Levitated Vibrational Viscometer For Biomedical And Clinical Applications, Ali̇ Akpek

Turkish Journal of Electrical Engineering and Computer Sciences

Accurate determination of the viscosity behavior of fluids is extremely important, especially for biomedical and clinical applications. For example, blood viscosity is used to detect cardiovascular diseases in patients. Like blood, all body fluids and biochemical solvents used in biomedical studies are very limited resources. Therefore, a viscometer that is especially focused for biomedical and clinical applications should have the ability to obtain viscosity results from a reservoir as small as possible, in a range as wide as possible and in a period of time as short as possible. The measurements must be accurate even when the fluid temperatures shift …

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