Breast Boundary Segmentation In Thermography Images Based On Random Walkers,
2017
TÜBİTAK
Breast Boundary Segmentation In Thermography Images Based On Random Walkers, Mehrdad Moghbel, Syamsiah Mashohor, Rozi Mahmud, M.Iqbal Bin Saripan, Suzana Abd Hamid, Suraini Mohamad Sani, Saiful Nizam
Turkish Journal of Electrical Engineering and Computer Sciences
Breast and areola boundary detection and segmentation present the biggest challenge in breast segmentation from thermography images, as breast boundaries, especially in the upper quadrants of the breast, are nonexistent. Many segmentation approaches have been proposed for breast segmentation, such as active contours and snakes, circular Hough transforms, and live wires, but these methods often fail to achieve satisfactory results. With recent advances in image processing techniques, new segmentation concepts are being developed, such as random walkers, which have received high interest from the medical imaging community. In this study, 91 images acquired utilizing a FLIR A320 thermal camera are …
Using Latent Semantic Analysis For Automated Keyword Extraction From Large Document Corpora,
2017
TÜBİTAK
Using Latent Semantic Analysis For Automated Keyword Extraction From Large Document Corpora, Tuğba Önal Süzek
Turkish Journal of Electrical Engineering and Computer Sciences
In this study, we describe a keyword extraction technique that uses latent semantic analysis (LSA) to identify semantically important single topic words or keywords. We compare our method against two other automated keyword extractors, Tf-idf (term frequency-inverse document frequency) and Metamap, using human-annotated keywords as a reference. Our results suggest that the LSA-based keyword extraction method performs comparably to the other techniques. Therefore, in an incremental update setting, the LSA-based keyword extraction method can be preferably used to extract keywords from text descriptions from big data when compared to existing keyword extraction methods.
Statistical Features-Based Comparison Of Analysis And Synthesis Of Normal And Epileptic Electroencephalograms For Various Wavelets, Revati Shriram, Mahalingam Sundhararajan, Supriya Shete, Nivedita Daimiwal
Turkish Journal of Electrical Engineering and Computer Sciences
An electroencephalogram (EEG) is an electrical signal in microvolts captured noninvasively from the brain, which provides important and unique information about the brain. The frequency of an EEG signal lies between 0 and 100 Hz. Decomposition of an EEG signal into various bands such as alpha, beta, delta, theta, and gamma is essential in seizure-related studies. EEGs play a key role in the diagnosis of epileptic seizures and neurological disorders. In this paper, multiple wavelet families for decomposition and reconstruction are explored and are compared based on risk functions and reconstruction measures. While dealing with the wavelets it is a …
Automobile Engine Condition Monitoring Using Sound Emission,
2017
TÜBİTAK
Automobile Engine Condition Monitoring Using Sound Emission, Hamid Ghaderi, Peyman Kabiri
Turkish Journal of Electrical Engineering and Computer Sciences
A wavelet packet transform (WPT) is a well-known technique used for data and signal-processing that has proven to be successful in condition monitoring and fault diagnosis. In this study, using feature extraction based on wavelet transformation, sound signals emitted from automobile engines under both faulty and healthy conditions are analyzed. The intention is to categorize sound signals into both healthy and faulty classes. Sound signals are generated from 4 different automobile engines in both healthy and faulty conditions. The investigated fault is within the ignition system of the engines. In addition, there are other possible problems that may also affect …
Optimal Design Of Voltage Regulators For Static Excitation System In Synchronous Generator To Reduce Shaft-Induced Voltage,
2017
TÜBİTAK
Optimal Design Of Voltage Regulators For Static Excitation System In Synchronous Generator To Reduce Shaft-Induced Voltage, Mahmoud Samieimoghaddam, Mohammad Tavakoli Bina, Masoud Aliakbar Golkar, Shokrollah Shokrikojoori
Turkish Journal of Electrical Engineering and Computer Sciences
Long-term shaft-induced voltage could harm synchronous generators, specifically their bearings and insulators. This paper investigates the reduction of shaft-induced voltage using both a passive filter and an active voltage regulator. An RLC circuit is used as a passive filter, and a DC-DC buck converter is used as an active voltage regulator. As a result, they remove high-frequency spikes, leading to the reduction of shaft-induced voltage. Buck converters show minimum-phase behavior and can pose as stable-casual converters. A 5 kW synchronous generator was considered for the laboratory setup in which a static excitation system using a 6-pulse thyristor rectifier supplies the …
Accelerating The Solving Of Nonlinear Equations Using The Homotopy Method: Application On Finding The Operating Point Of Complex Circuits, Fathi Dhiabi, Mohamed Boumehraz
Turkish Journal of Electrical Engineering and Computer Sciences
Analog circuits with nonlinear elements (e.g., diode, BJT, and CMOS) and integrated circuits are very complex systems. As a result, they are very difficult to analyze because of the need to generate a nonlinear equation system solution in order to do so. Solving nonlinear equations is still a challenging problem. Iterative methods, however, are frequently used to solve them. This paper describes a method that can be used to both accelerate the solving of nonlinear equations and find the operating point in various integrated circuits by construction of the global homotopy equation of the analog circuit. This is done by …
Design Optimization Of A ĆUk Dc/Dc Converter Based On Reliability Constraints,
2017
TÜBİTAK
Design Optimization Of A ĆUk Dc/Dc Converter Based On Reliability Constraints, Amirreza Zarrin Gharehkoushan, Mehdi Abapour, Amir Farakhor
Turkish Journal of Electrical Engineering and Computer Sciences
Recently, power electronic converters have widely been used in various applications. This has led to concerns about the reliability of power converters and, as a result, their optimal design has attracted a lot of attention. However, the reliability-based optimal design of the Ćuk DC-DC converter has not yet been studied. A new methodology is presented here for the optimal design of the Ćuk converter based on reliability constraints. In this study, the converter is designed to minimize power losses in order to maximize the mean time to failure of the converter. A genetic algorithm is used as the optimization technique, …
Image Compression Algorithm With Reduced Blocking Artifacts,
2017
TÜBİTAK
Image Compression Algorithm With Reduced Blocking Artifacts, Kritika Mittal, Kulbir Singh, Neeru Jindal
Turkish Journal of Electrical Engineering and Computer Sciences
The modern communication era has led to a proliferation of digital media contents. However, the large volume of data poses difficulties because of increased bandwidth and limited storage space. Hence, this has led to the need for compression techniques. Image compression with block processing allows the coder to adapt to local image statistics and exploit the correlation present among neighboring image pixels. The main degradation factor of block transform coding is blocking artifacts (visually undesirable patterns) at high compression ratios. The degradation occurs because of coarse quantization of the transform coefficients and the independent processing of the blocks. In this …
Intrusion Detection In Network Flows Based On An Optimized Clustering Criterion,
2017
TÜBİTAK
Intrusion Detection In Network Flows Based On An Optimized Clustering Criterion, Jaber Karimpour, Shahriar Lotfi, Aliakbar Tajari Siahmarzkooh
Turkish Journal of Electrical Engineering and Computer Sciences
Graph-based intrusion detection approaches consider the network as a graph and detect anomalies based on graph metrics. However, most of these approaches succumb to the cluster-based behavior of the anomalies. To resolve this problem in our study, we use flow and graph-clustering concepts to create a data set first. A new criterion related to the average weight of clusters is then defined and a model is proposed to detect attacks based on the above-mentioned criterion. Finally, the model is evaluated using a DARPA data set. Results show that the proposed approach detects the attacks with high accuracy relative to methods …
Novel Patch Antenna For Multiband Cellular, Wimax, And Wlan Applications,
2017
TÜBİTAK
Novel Patch Antenna For Multiband Cellular, Wimax, And Wlan Applications, Jahanzeb Sarwar Malik, Umair Rafique, Syed Ahsan Ali, Muhammad Arif Khan
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a novel multiband patch antenna has been designed, simulated, and measured for GSM, DCS, IMT, WiMAX, and WLAN (IEEE 802.11 a/b/g/n) applications. The proposed antenna consists of a square patch and square-loop elements (connected through 50$\Omega $ microstrip line) excited by a coaxial feed. With the help of square loop elements, the antenna is able to provide multiband response. The proposed antenna occupies an overall size of 80 $\times $ 80 $\times $ 1.6 mm$^{3}$. The 10 dB bandwidth criterion offers good impedance bandwidth for desired bands. Moreover, gain of the proposed antenna is acceptable with good …
New Use Of The Hits Algorithm For Fast Web Page Classification,
2017
TÜBİTAK
New Use Of The Hits Algorithm For Fast Web Page Classification, Mohamed Nadjib Meadi, Mohamed Chaouki Babahenini, Abdelmalik Taleb Ahmed
Turkish Journal of Electrical Engineering and Computer Sciences
The immense number of documents published on the web requires the utilization of automatic classifiers that allow organizing and obtaining information from these large resources. Typically, automatic web pages classifiers handle millions of web pages, tens of thousands of features, and hundreds of categories. Most of the classifiers use the vector space model to represent the dataset of web pages. The components of each vector are computed using the term frequency inversed document frequency (TFIDF) scheme. Unfortunately, TFIDF-based classifiers face the problem of the large-scale size of input data that leads to a long processing time and an increase in …
Significant Insights Into The Operation Of Dc-Link Voltage Control Of A Shunt Active Power Filter Using Different Control Algorithms: A Comparative Study, Nor Farahaida Abdul Rahman, Mohd Amran Mohd Radzi, Azura Che Soh, Norman Mariun, Nasrudin Abd Rahim
Turkish Journal of Electrical Engineering and Computer Sciences
A comparative study between a conventional DC-link voltage control algorithm (CDVCA) and a self-charging DC-link voltage control algorithm (SDVCA) is presented. It focuses on the principle operation of both algorithms and their impacts on the performance of a shunt active power filter (SAPF) operation. All analyses are based on the step response of DC-link voltages under different start-up times of the SAPF and different initial DC-link voltage values. Other considered parameters are the ripple factor (RP) of DC-link voltages, estimated and measured DC-link charging currents, and total harmonic distortion (THD) value of supply currents. Thus, this study provides new insights …
Dielectric Backed Conducting Strips As Inductive Element In Spatial Band-Pass Filter Design,
2017
TÜBİTAK
Dielectric Backed Conducting Strips As Inductive Element In Spatial Band-Pass Filter Design, Habib Ghorbaninejad, Ali Ghajar
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper a new method has been presented to design spatial band-pass filters consisting of dielectric backed conducting strips. This approach uses an equivalent circuit model in which determined inductive elements are spaced at intervals about half wavelength. To realize the proposed method, the inductive elements have been replaced by dielectric backed conducting strips located at intervals about half wavelength. Half wavelength transmission line sections act as resonators. In this manner the wideness and spacing of strips in each dielectric backed conducting strip, as well as the distance between them, is determined by fitting the characteristic (transfer function) of …
Intellimote: A Hybrid Classifier For Classifying Learners' Emotion In A Distributed E-Learning Environment,
2017
TÜBİTAK
Intellimote: A Hybrid Classifier For Classifying Learners' Emotion In A Distributed E-Learning Environment, Lopa Mandal, Rohan Das, Samar Bhattacharya, Pramatha Nath Basu
Turkish Journal of Electrical Engineering and Computer Sciences
A huge collection of textual, graphical, audio, and video contents are readily available on the Internet to be used for the purpose of learning. Sentimental feedbacks of learners posted at the end of many of these contents may be considered as genuine reactions of the learners who have gone through the contents. Such learners' sentiments are important inputs for judging the acceptability of a learning material. Analyzing such feedbacks using sentiment analysis techniques can identify the best reusable learning contents that may be used for developing new courseware. This can significantly reduce the time and effort of authoring, which is …
Techno-Economic Analysis Using Different Types Of Hybrid Energy Generation For Desert Safari Camps In Uae,
2017
TÜBİTAK
Techno-Economic Analysis Using Different Types Of Hybrid Energy Generation For Desert Safari Camps In Uae, Ali Aziz
Turkish Journal of Electrical Engineering and Computer Sciences
Remote areas in UAE are still fully powered by diesel generators. The rapid rise in the prices of petroleum products and environmental concerns have led to demand for hybrid renewable energy generators. Advances in renewable energy technologies impart further impetus to techno-economic power production. Protecting the landscape and demography of the desert by optimizing the power supply cost via an efficient hybrid power system is the key issue. Simulation results on the cross utilization of a photovoltaic/wind/battery/fuel-cell hybrid-energy source to power the off-grid living space are presented. Simultaneous exploitation of different renewable energy sources to power off-grid applications together with …
A Steganographic Approach To Hide Secret Data In Digital Audio Based On Xor Operands Triplet Property With High Embedding Rate And Good Quality Audio, Krishna Bhowal, Debasree Chanda Sarkar, Sushanta Biswas, Partha Pratim Sarkar
Turkish Journal of Electrical Engineering and Computer Sciences
In this paper, a unique and transparent data hiding algorithm based on XOR operands triplet (XOT) is proposed. In XOT, an XOR operation applied on any two members of a triplet provides the third member of the same triplet. Taking advantage of the low computational complexity and fascinating properties of the XOR operator, it is possible to embed 4-ary secret digits with negligible changes in the host digital audio. The proposed scheme has been designed to ensure that a minimum number of bit alterations happen in the host digital audio during the data hiding process, which also increases the security …
Adaptive Sliding Mode With Time Delay Control Based On Convolutions For Power Flow Reference Tracking Using A Vsc-Hvdc System,
2017
TÜBİTAK
Adaptive Sliding Mode With Time Delay Control Based On Convolutions For Power Flow Reference Tracking Using A Vsc-Hvdc System, Amar Hamache, Mohand Outahar Bensidhoum, Hachemi Chekireb
Turkish Journal of Electrical Engineering and Computer Sciences
This paper deals with the design of an adaptive sliding mode with a time delay control based on convolutions (ASMTDCC) approach for a voltage source converter (VSC) high voltage direct current (HVDC) transmission system for power flow reference tracking over a wide range of operating conditions considering parameter variations and external disturbances. For this purpose, the model of a VSC-HVDC transmission system connecting two asynchronous electrical grids is developed. The problem of designing an ASMTDCC feedback scheme, via a control strategy, is addressed seeking a better performance. For ensuring robust behavior and reducing chattering, the ASMTDCC scheme is realized based …
Electrocardiogram Signal Analysis For R-Peak Detection And Denoising With Hybrid Linearization And Principal Component Analysis, Harjeet Kaur, Rajni Rajni
Turkish Journal of Electrical Engineering and Computer Sciences
In the areas of biomedical and healthcare, electrocardiogram (ECG) signal analysis is one of the major aspects of research. The accuracy in the detection of subtle characteristic features in ECG is of great significance. This paper deals with an algorithm based on hybrid linearization and principal component analysis for ECG signal denoising and R-peak detection. The ECG data have been taken from the MIT-BIH Arrhythmia Database for performance evaluation. The signal is denoised by applying the hybrid linearization method, which is an arrangement of the extended Kalman filter along with discrete wavelet transform, and then principal component analysis is employed …
Implementation Of Energy Management And Demand Side Management Of A Solar Microgrid Using A Hybrid Platform,
2017
TÜBİTAK
Implementation Of Energy Management And Demand Side Management Of A Solar Microgrid Using A Hybrid Platform, Leo Raju, Milton Sakaya, Senthilkumaran Mahadevan
Turkish Journal of Electrical Engineering and Computer Sciences
This paper presents the implementation of the advanced distributed energy management and demand side management of a solar microgrid by a multiagent system (MAS) coordination approach. The proposed approach is built upon a hybrid platform in which a solar microgrid, modelled in MATLAB/Simulink, is controlled by a MAS implemented in Java Agent Development Framework (JADE), bringing the MAS closer to the real-time application. Novel control strategies are designed to implement all the smart grid features in the microgrid. The Simulink model is controlled by strategic action of agents in JADE, a multithreaded computing platform, through a middleware, multiagent control using …
Modified Control Of The Matrix Converter-Based Drive For Voltage Sag Impact Reduction,
2017
TÜBİTAK
Modified Control Of The Matrix Converter-Based Drive For Voltage Sag Impact Reduction, Gytis Petrauskas, Gytis Svinkunas
Turkish Journal of Electrical Engineering and Computer Sciences
Faults in transmission and distribution networks often cause voltage sags. Direct matrix converter (DMC)-based drives are a new generation of electrical drives. Unlike the conventional two-stage diode supply-side inverter drive, the DMC drive has no direct current (DC) link capacitor and no capacitor charging-time delay before operation. The absence of a DC link makes the DMC-based drive more sensitive to voltage sags. The above-mentioned faults in transmission and distribution networks could degrade the DMC drive's performance and reliability. This paper investigates possible kinds and levels of voltage sags, dependency on network configuration, and the behavior of the DMC-based drive under …
