Grid-Connected Quasi-Z-Source Inverter With Battery,
2018
TÜBİTAK
Grid-Connected Quasi-Z-Source Inverter With Battery, Umesh Shinde, Sagar Kottagattu, Sumant Kadwane, Snehal Gawande
Turkish Journal of Electrical Engineering and Computer Sciences
Grid-connected inverters are now increasingly used in distributed microgrid and smart-grid applications. The advantages of a quasi-Z-source inverter (QZSI), like single-stage operation, lower component rating, continuous input current, and common DC rail, led to an investigation of this converter for grid-connected applications. This paper presents a grid-connected QZSI with both AC and DC side controls. A new battery-charging configuration is also suggested across the capacitor through which the DC side control loop is regulated. Fast dynamic response and reduced harmonics are demonstrated through simulation and experimental results.
Sar Image Denoising Based On Patch Ordering In Nonsubsample Shearlet Domain,
2018
TÜBİTAK
Sar Image Denoising Based On Patch Ordering In Nonsubsample Shearlet Domain, Shuaiqi Liu, Qi Hu, Pengfei Li, Jie Zhao, Zhihui Zhu
Turkish Journal of Electrical Engineering and Computer Sciences
Synthetic aperture radar (SAR) has been extensively adopted in a variety of fields, e.g., agriculture and marine fields. In this regard, the improvement of SAR image quality has aroused a wide concern worldwide. In recent years, image processing based on local patches has been very popular and proven feasible. In this paper, a novel SAR image denoising algorithm is proposed in the NSST domain on the basis of patch ordering. First, the shearlet transform is applied to logarithmic transformation of the noisy SAR image. Second, the coefficients of the shearlet are denoised respectively by combining patch ordering and 1D filtering. …
Study On Variability Smoothing Benefits Of Wind Farm Cluster,
2018
TÜBİTAK
Study On Variability Smoothing Benefits Of Wind Farm Cluster, Xuemei Dai, Kaifeng Zhang, Jian Geng, Qianqian Liu, Ying Wang, Yuan Kun, Yahui Qiao, Yonghui Liu
Turkish Journal of Electrical Engineering and Computer Sciences
Smoothing effect is an important characteristic of large scale wind power. In this paper we analyze the smoothing effect from the prospect of output variability. Specifically, the aggregated output variability of a wind farm cluster may be significantly lower than that of an independent wind farm, and this phenomenon is referred to as the variability smoothing effect. In order to quantitatively analyze the variability smoothing effect, this paper introduces the concept of variability costs and evaluates the variability costs of each wind farm and overall wind farm cluster based on an optimal scheduling model. It is found that the variability …
Automated Citation Sentiment Analysis Using High Order N-Grams: A Preliminary Investigation,
2018
TÜBİTAK
Automated Citation Sentiment Analysis Using High Order N-Grams: A Preliminary Investigation, Muhammad Touseef Ikram, Muhammad Tanvir Afzal, Naveed Anwer Butt
Turkish Journal of Electrical Engineering and Computer Sciences
Scientific papers hold an association with previous research contributions (i.e. books, journals or conference papers, and web resources) in the form of citations. Citations are deemed as a link or relatedness of the previous work to the cited work. The nature of the cited material could be supportive (positive), contrastive (negative), or objective (neutral). Extraction of the author's sentiment towards the cited scientific articles is an emerging research discipline due to various linguistic differences between the citation sentences and other domains of sentiment analysis. In this paper, we propose a technique for the identification of the sentiment of the citing …
Cache-Timing Attacks Without A Profiling Phase,
2018
TÜBİTAK
Cache-Timing Attacks Without A Profiling Phase, Ali̇ Can Atici, Cemal Yilmaz, Erkay Savaş
Turkish Journal of Electrical Engineering and Computer Sciences
Theoretically secure cryptographic algorithms can be vulnerable to attacks due to their implementation flaws. Bernstein's attack is a well-known cache-timing attack that uses execution times as the side-channel. The major drawback of this attack is that it needs an identical target machine to perform its profiling phase where the attacker models the cache timing-behavior of the target machine. This assumption makes the attack unrealistic in many circumstances. In this work, we present an effective method to eliminate the profiling phase. We propose a methodology to model the cache timing-behavior of the target machine by trying hypothetical cache behaviors exhaustively. Our …
Ionolab-Map: An Automatic Spatial Interpolation Algorithm For Total Electron Content,
2018
TÜBİTAK
Ionolab-Map: An Automatic Spatial Interpolation Algorithm For Total Electron Content, Muhammet Necat Devi̇ren, Feza Arikan
Turkish Journal of Electrical Engineering and Computer Sciences
Investigation of the variability of total electron content (TEC) is one of the most important parameters of the observation and monitoring of space weather, which is the main cause of signal disturbance in space-based communication, positioning, and navigation systems. TEC is defined as the total number of electrons on a ray path. The Global Positioning System (GPS) provides a cost-effective solution for the estimation of TEC. Due to various physical and operational disturbances, TEC may have temporal and spatial domain gaps. Global ionospheric maps (GIMs) provide worldwide TEC with 1- to 2-h temporal resolution and $2.5^{\circ}\, \times 5^{\circ}$ spatial resolution …
User Interaction In Hands-Free Gaming: A Comparative Study Of Gaze-Voice And Touchscreen Interface Control,
2018
TÜBİTAK
User Interaction In Hands-Free Gaming: A Comparative Study Of Gaze-Voice And Touchscreen Interface Control, Muhtar Çağkan Uludağli, Cengi̇z Acartürk
Turkish Journal of Electrical Engineering and Computer Sciences
The goal of the present study is to contribute to the research on the use of eye tracking in hands-free gaming. We report the results of an experimental study by using a platform game designed by the authors. The game allowed gaze-voice command control, as well touchscreen control of the interface by the player. We employed a set of performance measures and we measured player engagement as an indicator of user experience. The findings revealed that the players did not improve in game performance when they used the gaze-voice control compared to the touchscreen control. On the other hand, they …
Presenting A Method To Perform Cyber Maneuvers,
2018
TÜBİTAK
Presenting A Method To Perform Cyber Maneuvers, Mohammad Shakibazad, Alijabar Rashidi
Turkish Journal of Electrical Engineering and Computer Sciences
Performing cyber maneuvers in an operational environment is not easy. We need a cyber-situational awareness framework to perform its maneuvers to protect the cyberspace and to cope with its attacks. The battlefield provided has essential information for detecting cybercrime events. The present study resolved the challenges of implementing these maneuvers through dynamic simulation of the cyber battlefield. The cyber battlefield contains detailed information on cyberspace elements, including the vulnerability knowledge repository, the tangible and intangible components of the cyberspace allowing maneuvering, penetration testing, injection attacks, tracking attacks, visualization, evaluation of the impact of cyberattacks, and risk evaluation. By injecting attacks …
An Efficient Recurrent Fuzzy Cmac Model Based On A Dynamic-Group--Based Hybrid Evolutionary Algorithm For Identification And Prediction Applications, Chin-Ling Lee, Chengjian Lin
Turkish Journal of Electrical Engineering and Computer Sciences
This article presents an efficient TSK-type recurrent fuzzy cerebellar model articulation controller (T-RFCMAC) model based on a dynamic-group--based hybrid evolutionary algorithm (DGHEA) for solving identification and prediction problems. The proposed T-RFCMAC model is based on the traditional CMAC model and the Takagi--Sugeno--Kang (TSK) parametric fuzzy inference system. Otherwise, the recurrent network, which imports feedback links with a receptive field cell, is embedded in the T-RFCMAC model, and the feedback units are used as memory elements. The DGHEA, which is a hybrid of the dynamic-group quantum particle swarm optimization (QPSO) and the Nelder--Mead method, is proposed for adjusting the parameters of …
Reducing Power System Model Dimensions Based On Linearization For Static Analysis,
2018
TÜBİTAK
Reducing Power System Model Dimensions Based On Linearization For Static Analysis, Farid Karbalaei, Maryam Jebreilzadeh, Hamidreza Shahbazi
Turkish Journal of Electrical Engineering and Computer Sciences
A reliable solution for determining the effect of a group of contingencies on a power system is to simulate all of them through load flow. It is impossible to simulate any detailed cases through a complete AC load flow solution because of the high number of possible contingencies. For this reason, system dimension reduction methods, which are based on an equivalent of one part of a system, are being used. In this paper we compare our previously proposed network equivalent method with the 2 well-known equivalent methods of Ward and Ward-PV in terms of solving speed and accuracy. The proposed …
Minimizing Path Loss Prediction Error Using K-Means Clustering And Fuzzy Logic,
2018
TÜBİTAK
Minimizing Path Loss Prediction Error Using K-Means Clustering And Fuzzy Logic, Wiyada Bhupuak, Siraphop Tooprakai
Turkish Journal of Electrical Engineering and Computer Sciences
This research proposes an algorithmic scheme based on k-means clustering and fuzzy logic to minimize path loss prediction error. The proposed k-means fuzzy scheme concurrently utilizes the area topographical variability and multiple path loss prediction models to mitigate the prediction error inherent in the independent use of a conventional path loss model. Vegetation density, manmade structures, and transmission-receiver distances are the fuzzy inputs and the conventional path loss models the output: the free space loss, Walfisch--Ikegami, HATA, ECC-33, Stanford University Interim, and ERICSSON models. The experimental results show that the path loss prediction error of the k-mean fuzzy scheme is …
Performance Estimation And Analysis Of Power Line Communication Using Single-Ended Loop Testing,
2018
TÜBİTAK
Performance Estimation And Analysis Of Power Line Communication Using Single-Ended Loop Testing, Bharathi Mayilswamy, Amsaveni Avinashiappan
Turkish Journal of Electrical Engineering and Computer Sciences
Using the electricity infrastructure for broadband data transmission is known as power line communication (PLC). The quality of broadband connectivity over a power line is a strong function of the line topology. Two-step hybrid single-ended loop testing (SELT) to estimate the open port loop topology of power lines is discussed in this paper. Correlation time domain reflectometry (CTDR) at different sockets is used to construct the initial topology. Optimization-based frequency domain reflectometry (FDR) is employed to ascertain more accurate power line topology. The discussed method has the advantage of reusing the existing DSL modem for the measurement and no prior …
An Automatic Extraction Algorithm Of High Voltage Transmission Lines From Airborne Lidar Point Cloud Data,
2018
TÜBİTAK
An Automatic Extraction Algorithm Of High Voltage Transmission Lines From Airborne Lidar Point Cloud Data, Xiaojun Shen, Chuan Qian, Yong Du, Xinle Yu, Rui Zhang
Turkish Journal of Electrical Engineering and Computer Sciences
To improve the effectiveness and generality of existing methods of high voltage (HV) transmission lines extraction, this paper proposes a novel automatic extraction method of HV transmission lines using airborne LIDAR point cloud data by incorporating the geography of transmission corridors and the distribution characteristics of airborne LIDAR point cloud data. The proposed method results in the separation of ground objects by using a differentiation height threshold segmentation algorithm based on subspace features, which divide long-distance space into several small-distance space sets to improve the generality of the algorithm. A height density segmentation algorithm is used to locate transmission towers …
Optimal Coordination Of Overcurrent Protection In The Presence Of Sfcl And Distributed Generation,
2018
TÜBİTAK
Optimal Coordination Of Overcurrent Protection In The Presence Of Sfcl And Distributed Generation, Saeed Asgharigovar, Heresh Seyedi, Shahram Parchehbaf Dibazari
Turkish Journal of Electrical Engineering and Computer Sciences
As power demand is increased, power generation and especially distributed generation (DG) are being developed. Therefore, power distribution systems become increasingly complicated and short circuit level in distribution grids is being augmented. Thereby, installation of a superconducting fault current limiter (SFCL) is a logical solution to decrease the fault current level in a distribution network. Preventing distribution system degradation by high fault currents, lower equipment ratings, and economic issues are the advantages of SFCL in distribution grids. However, SFCL installation causes delayed operation of the existing overcurrent protection and requires recoordination of the relays. In addition, disconnecting the SFCL from …
Research On Power-Frequency Electromagnetic Interference Model Of Multicore Twisted Signal Cable Of High-Speed Railway,
2018
TÜBİTAK
Research On Power-Frequency Electromagnetic Interference Model Of Multicore Twisted Signal Cable Of High-Speed Railway, Bowen Zhang, Jiangjian Xie, Zhixin Wang, Jin Yang, Hao Yan
Turkish Journal of Electrical Engineering and Computer Sciences
With the increase in the traction power of high-speed railways, the power-frequency electromagnetic interference of traction current to the signal cables becomes increasingly more severe. In this paper, the calculation model of the magnetic interference to signal cable was established on the MATLAB/Simulink platform based on the multiconductor transmission line theory. This model took SPTYWPL03-8B 8-core twist signal cable as an example and the power-frequency interference of external current to the signal cable was analyzed theoretically. In addition, experiments on electromagnetic interference of double-ended and single-ended signal cables were performed to validate the simulation model. Experiments showed that the relative …
Application Of Domination Integrity Of Graphs In Pmu Placement In Electric Power Networks,
2018
TÜBİTAK
Application Of Domination Integrity Of Graphs In Pmu Placement In Electric Power Networks, Mariappan Saravanan, Ramalingam Sujatha, Raman Sundareswaran, Muthu Selvan Balasubramanian
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, we propose the application of the concept of power domination integrity to an electric power network. A phasor measurement unit (PMU) is used to analyze and control the power system by measuring voltage phase in electrical nodes and transmission lines. Due to the high cost of PMUs, it is necessary to minimize the number of PMUs such that the depth of observability is ensured. Placing PMUs in a network can be formulated as a graph theoretic problem of finding the minimum number of nodes (PMUs) in a graph that has a maximum number of links with other …
Real-Time Power System Dynamic Security Assessment Based On Advanced Feature Selection For Decision Tree Classifiers,
2018
TÜBİTAK
Real-Time Power System Dynamic Security Assessment Based On Advanced Feature Selection For Decision Tree Classifiers, Qusay Al-Gubri, Mohd Aifaa Mohd Ariff
Turkish Journal of Electrical Engineering and Computer Sciences
This paper proposes a novel algorithm based on an advanced feature selection technique for the decision tree (DT) classifier to assess the dynamic security in a power system. The proposed methodology utilizes symmetrical uncertainty (SU) to reduce the data redundancy in a dataset for DT classifier-based dynamic security assessment (DSA) tools. The results show that SU reduces the dimension of the dataset used for DSA significantly. Subsequently, the approach improves the performance of the DT classifier. The effectiveness of the proposed technique is demonstrated on the modified IEEE 30-bus test system model. The results show that the DT classifier with …
A Novel Single-Inductor Eight-Channel Light-Emitting Diode Driver For Low Power Display Backlight Applications,
2018
TÜBİTAK
A Novel Single-Inductor Eight-Channel Light-Emitting Diode Driver For Low Power Display Backlight Applications, Magesh Kannan Parthasarathy, Nagarajan Ganesan
Turkish Journal of Electrical Engineering and Computer Sciences
A novel decoder-based single-inductor eight-channel light-emitting diode (LED) driver circuit for low power display backlight applications has been proposed. Uniform brightness in the display provides better picture clarity, which can be achieved by providing uniform DC currents to all channels in the backlight arrangement. Existing systems use individual current regulators for each channel, which fails to provide uniform current to individual channels. Instead, uniform current is provided to all eight channels in the proposed system as the same current is distributed to all channels using time-multiplexing by a 3 $\times $ 8 decoder and a 3-bit binary up-counter. A digital …
Modified Acceleration Feedback For Practical Disturbance Rejection In Motor Drives,
2018
TÜBİTAK
Modified Acceleration Feedback For Practical Disturbance Rejection In Motor Drives, Ahmet Gürhanli
Turkish Journal of Electrical Engineering and Computer Sciences
Acceleration feedback techniques have been used in control systems for a long time in order to improve the stiffness. Basically, the acceleration of the motor is calculated using speed or position measurements and the current command is adjusted using the acceleration data for avoiding deviations from the commanded speed. This method has to deal with two challenges. The first challenge is calculating the acceleration correctly. If it is calculated by double differentiation of position feedback of a servo motor, it may lead to a high amount of noise. On the other hand, if observer techniques are used, the error and …
Feature Selection Algorithm For No-Reference Image Quality Assessment Using Natural Scene Statistics,
2018
TÜBİTAK
Feature Selection Algorithm For No-Reference Image Quality Assessment Using Natural Scene Statistics, Imran Fareed Nizami, Muhammad Majid, Khawar Khurshid
Turkish Journal of Electrical Engineering and Computer Sciences
Images play an essential part in our daily lives and the performance of various imaging applications is dependent on the user?s quality of experience. No-reference image quality assessment (NR-IQA) has gained importance to assess the perceived quality, without using any prior information of the nondistorted version of the image. Different NR-IQA techniques that utilize natural scene statistics classify the distortion type based on groups of features and then these features are used for estimating the image quality score. However, every type of distortion has a different impact on certain sets of features. In this paper, a new feature selection algorithm …
