Engineering Commons^™

An Industrial Vision System To Analyze The Wear Of Cutting Tools, Christina Gillmann, Tobias Post, Benjamin Kirsch, Thomas Wischgoll, Jörg Hartig, Bernd Hamann, Hans Hagen, Jan C. Aurich

Computer Science and Engineering Faculty Publications

The wear behavior of cutting tools directly affects the quality of the machined part. The measurement and evaluation of wear is a time consuming process and is subjective. Therefore, an image-based wear measurement that can be computed automatically based on given image series of cutting tools and an objective way to review the resulting wear is presented in this paper. The presented method follows the industrial vision system pipeline where images of cutting tools are used as input which are then transformed through suitable image processing methods to prepare them for the computation of a novel image based wear measurement. …

Panel: Teaching To Increase Diversity And Equity In Stem, Helen H. Hu, Douglas Blank, Albert Chan, Travis E. Doom

Computer Science and Engineering Faculty Publications

TIDES (Teaching to Increase Diversity and Equity in STEM) is a three-year initiative to transform colleges and universities by changing what STEM faculty, especially CS instructors, are doing in the classroom to encourage the success of their students, particularly those that have been traditionally underrepresented in computer science.Each of the twenty projects selected proposed new inter-disciplinary curricula and adopted culturally sensitive pedagogies, with an eye towards departmental and institutional change. The four panelists will each speak about their TIDES projects, which all involved educating faculty about cultural competency. Three of the panelists infused introductory CS courses with applications from other …

An Efficient Global Technique For Solving The Network Constrained Static And Dynamic Economic Dispatch Problem, Aamir Nawaz, Nasir Saleem, Ehtasham Mustafa, Umair Ali Khan

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents a new approach for solving the economic load dispatch (ELD) problem with generator constraints and transmission losses. The constrained globalized Nelder-Mead algorithm is a newly proposed algorithm for solving economic dispatch problems with and without valve-point effects. Convex and nonconvex cost functions with equality and inequality constraints are difficult to optimize. To circumvent these problems, a robust global technique is desirable. In this paper, the constrained globalized Nelder--Mead algorithm is proposed to optimize the ELD problem globally using variance variable probability. To validate the proficiency of the proposed approach, statistical studies have been accomplished for different test …

Comparing Of Phase Shifting Method And One-Dimensional Continuous Wavelet Transform Method For Reconstruction Using Phase-Only Information, Gülhan Ustabaş Kaya, Zehra Saraç

Turkish Journal of Electrical Engineering and Computer Sciences

The one-dimensional continuous wavelet transform method has some advantages in hologram reconstruction, when used in the only phase, compared with the phase shifting method. This paper aims to discuss these advantages. One advantage is related to image quality. Another advantage is less power spent and saving time, because the one-dimensional continuous wavelet transform method uses only one hologram and the phase shifting method uses four holograms for recording and reconstruction processes. One final advantage is that the one-dimensional continuous wavelet transform method can also be used in real-time applications. Within the context of the ongoing optimization studies, this study will …

A Marching Algorithm For Isosurface Extraction From Face-Centered Cubic Lattices, Yusuf Sahi̇lli̇oğlu

Turkish Journal of Electrical Engineering and Computer Sciences

This work provides a novel method that extracts isosurfaces from face-centered cubic (FCC) lattices. It has been theoretically shown that sampling volumetric data on an FCC lattice tiled with rhombic dodecahedra is more efficient than sampling them on a Cartesian lattice tiled with cubes, in that the FCC lattice can represent the same data set as a Cartesian lattice with the same accuracy, yet with approximately 23% fewer samples. This fact, coupled with the good properties of rhombic dodecahedra, encouraged us to develop this related isosurface extraction technique. Thanks to the sparser sampling required by the FCC lattices, the de …

Robust Seed Detection For Coronary Arteries Segmentation Using Thresholded Frangi Response, Sammer Zai, Muhammad Ahsan Ansari, Soon-Young Song, Young Shik Moon

Turkish Journal of Electrical Engineering and Computer Sciences

Automatic detection of initial seed points has become an essential step towards delineating coronary arteries in coronary computed tomography angiography (CCTA) images due to image inhomogeneity and other factors. Most coronary segmentation algorithms require user interaction for seed point selection, which may lead to erroneous segmentation. In this study, we present an improved technique of seed detection for coronary segmentation using a thresholded Frangi response. Before computing region of interest (ROI), the proposed method first computes the Frangi response of the complete CCTA volume, followed by thresholding with respect to quantile and median values, and then the ROI selection procedure …

A Novel Hybrid Approach Based On A Chaotic Cloud Gravitational Search Algorithm To Complicated Image Template Matching, Weijia Cui, Yuzhu He

Turkish Journal of Electrical Engineering and Computer Sciences

Template matching is the process of accurately extracting the interesting regions in a source image according to reference templates. In this paper, the gravitational search algorithm (GSA) is employed as a novel search strategy for template matching. However, the basic GSA is easily trapped in a local optimum and has a poor exploitation ability. In this paper, to enhance the optimization performance of GSA, a novel cross-search strategy based on chaotic global search (CGS) and cloud local search (CLS) is incorporated into GSA. The new variant is named chaotic cloud GSA (CCGSA). CGS makes full use of the ergodicity of …

A Novel Approach To Solve Transient Stability Constrained Optimal Power Flow Problems, Huy Nguyen-Duc, Linh Tran-Hoai, Dieu Vo Ngoc

Turkish Journal of Electrical Engineering and Computer Sciences

This paper proposes an approach to solve the transient stability constraint optimal power flow (TSC-OPF) problem. The transient stability constraints are expressed as the critical clearing time (CCT) of different contingencies, and are approximated using artificial neural networks (ANNs). The ANNs provide a nonlinear, differentiable mapping between the load flow variables and the CCT. As a result, the TSC-OPF with multiple transient stability constraints can be solved very efficiently with little additional computational burden. The effectiveness of the proposed method is demonstrated with the IEEE 39 bus and the IEEE 300 bus systems.

Low-Power Voltage To A Frequency-Based Smart Temperature Sensor With +0.8/-0.75 $^{\Circ}$C Accuracy For -55 $^{\Circ}$C To 125 $^{\Circ}$C, Mudasir Bashir, Sreehari Rao Patri, Krishna Prasad

Turkish Journal of Electrical Engineering and Computer Sciences

The high power densities in system-on-chips demand accurate, low power, and compact smart temperatures for thermal monitoring. In this paper, a low-power CMOS-based smart temperature sensor, operating in the subthreshold region, for military applications (-55 $^{\circ}$C to 125 $^{\circ}$C) is presented. The sensor exploits the thermal dependency of the threshold voltage of MOS transistors to generate a voltage proportional to absolute temperature ($V_{PTAT})$. A frequency locked loop technique is employed to generate frequency from $V_{PTAT}$. The frequency variation due to temperature is measured by counting the rising edge with an asynchronous 12-bit counter. The large die area and requirement of …

Managing Cities With Urban Computing, Singapore Management University

Research@SMU: Connecting the Dots

SMU Professors Lau Hoong Chuin and Lim Yun Fong are combining their mathematical, computational and business know-how to address challenges facing the inner-city deliveries of orders and shipments.

See the papers:

• A rolling horizon auction mechanism and virtual pricing of shipping capacity for urban consolidation centers
• Achieving economic and environmental sustainabilities in urban consolidation center with bicriteria auction
• Retail precinct management: A case of commercial decentralization in Singapore

Optimization Of Neural Network Architecture For Classification Of Radar Jamming Fm Signals, Alberto Soto

Open Access Theses & Dissertations

Radar jamming signal classification is valuable when situational awareness of radar systems is sought out for timely deployment of electronic support measures. Our Thesis shows that artificial neural networks can be utilized for effective and efficient signal classification. The goal is to optimize an artificial Neural Network (NN) approach capable of distinguishing between two common radar waveforms, namely bandlimited white Gaussian jamming noise (BWGN) and the ubiquitous linearly frequency modulated (LFM) signal. This is made possible by creating a theoretical framework for NN architecture testing that leads to a high probability of detection (PD) and a low probability of false …

Robust Scale-Invariant Normalization And Similarity Measurement For Time Series Data, Ariyawat Chonbodeechalermroong

Chulalongkorn University Theses and Dissertations (Chula ETD)

Classification is one of the most prevalent tasks in time series mining. Dynamic Time Warping and Longest Common Subsequence are well-known and widely used algorithms to measure similarity between two time series sequences using non-linear alignment. However, these algorithms work best when the time series pair has similar amplitude scaling. Unfortunately, sensor data and most real-world time series data usually contain noise, missing values, outlier, and variability or scaling in both axes, which is not suitable for the widely used Z-normalization. This research introduces the Local Feature Normalization (LFN) and its Local Scaling Feature (LSF), which can be used to …

Enhanced Breast Cancer Classification With Automatic Thresholding Using Support Vector Machine And Harris Corner Detection, Mohammad Taheri

Electronic Theses and Dissertations

Image classification and extracting the characteristics of a tumor are the powerful tools in medical science. In case of breast cancer medical treatment, the breast cancer classification methods can be used to classify input images as benign and malignant classes for better diagnoses and earlier detection with breast tumors. However, classification process can be challenging because of the existence of noise in the images, and complicated structures of the image. Manual classification of the images is timeconsuming, and need to be done only by medical experts. Hence using an automated medical image classification tool is useful and necessary. In addition, …

Adaptive Audio Classification Framework For In-Vehicle Environment With Dynamic Noise Characteristics, Haitham Alsaadan

Electronic Theses and Dissertations

With ever-increasing number of car-mounted electric devices that are accessed, managed, and controlled with smartphones, car apps are becoming an important part of the automotive industry. Audio classification is one of the key components of car apps as a front-end technology to enable human-app interactions. Existing approaches for audio classification, however, fall short as the unique and time-varying audio characteristics of car environments are not appropriately taken into account. Leveraging recent advances in mobile sensing technology that allows for an active and accurate driving environment detection, in this thesis, we develop an audio classification framework for mobile apps that categorizes …

Application Of Nearly Linear Solvers To Electric Power System Computation, Lisa L. Grant

Doctoral Dissertations

"To meet the future needs of the electric power system, improvements need to be made in the areas of power system algorithms, simulation, and modeling, specifically to achieve a time frame that is useful to industry. If power system time-domain simulations could run in real-time, then system operators would have situational awareness to implement and avoid cascading failures, significantly improving power system reliability. Several power system applications rely on the solution of a very large linear system. As the demands on power systems continue to grow, there is a greater computational complexity involved in solving these large linear systems within …

A High-Dimensional Data Quality Metric Using Pareto Optimality, Tobias Post, Thomas Wischgoll, Bernd Hamann, Hans Hagen

Computer Science and Engineering Faculty Publications

The representation of data quality within established high-dimensional data visualization techniques such as scatterplots and parallel coordinates is still an open problem. This work offers a scale-invariant measure based on Pareto optimality that is able to indicate the quality of data points with respect to the Pareto front. In cases where datasets contain noise or parameters that cannot easily be expressed or evaluated mathematically, the presented measure provides a visual encoding of the environment of a Pareto front to enable an enhanced visual inspection.

Availability Of Datasets For Digital Forensics–And What Is Missing, Cinthya Grajeda, Frank Breitinger, Ibrahim Baggili

Electrical & Computer Engineering and Computer Science Faculty Publications

This paper targets two main goals. First, we want to provide an overview of available datasets that can be used by researchers and where to find them. Second, we want to stress the importance of sharing datasets to allow researchers to replicate results and improve the state of the art. To answer the first goal, we analyzed 715 peer-reviewed research articles from 2010 to 2015 with focus and relevance to digital forensics to see what datasets are available and focused on three major aspects: (1) the origin of the dataset (e.g., real world vs. synthetic), (2) if datasets were released …

Optimized Multilayer Perceptron With Dynamic Learning Rate To Classify Breast Microwave Tomography Image, Chulwoo Pack

Electronic Theses and Dissertations

Most recently developed Computer Aided Diagnosis (CAD) systems and their related research is based on medical images that are usually obtained through conventional imaging techniques such as Magnetic Resonance Imaging (MRI), x-ray mammography, and ultrasound. With the development of a new imaging technology called Microwave Tomography Imaging (MTI), it has become inevitable to develop a CAD system that can show promising performance using new format of data. The platform can have a flexibility on its input by adopting Artificial Neural Network (ANN) as a classifier. Among the various phases of CAD system, we have focused on optimizing the classification phase …

The Rock 2017, School Of Engineering And Computer Science

The Rock

No abstract provided.

The Impact Of Sampling Frequency And Amplitude Modulation Index On Low Order Harmonics In A 3-Phase Sv-Pvm Voltage Source Inverter, Qamil Kabashi, Myzafere Limani, Nebi Caka, Milaim Zabeli

Turkish Journal of Electrical Engineering and Computer Sciences

Nowadays, variable speed AC motors are widely used in industry and there are many speed adjustment techniques available. In the last decade there has been a trend towards the use of space vector PWM--IGBT inverters, due to easier digital realization and better utilization of the DC bus. Every power inverter produces a total harmonic distortion (THD) on its output that causes extra losses in stator of induction motors. By eliminating a number of low order voltage/current harmonics it is possible to reduce harmonic losses (stator losses) and mechanical oscillations in general. This could be achieved by implementing filters in the …

Neville Interpolation-Based Normal Estimation, Buse Meli̇s Özyildirim, Ulus Çevi̇k

Turkish Journal of Electrical Engineering and Computer Sciences

Displaying useful and meaningful information from 3D data is known as volume rendering. Ray casting is one of the most frequently used direct volume rendering methods. It consists of data preparation, sampling, classification, compositing, and shading steps. Normal values are needed for efficient shading. However, 3D volumetric data are discrete and cannot be used directly for shading. Hence, the estimation of normal values, at each voxel on the surface, is needed for realistic shading. In normal estimation, the use of small voxel neighborhoods results in the staircase effect. On the other hand, the use of larger voxel neighborhoods causes loss …

A Computer-Based Modification Solution For Old Type Of Electro-Controlled Mechanical Jacquard Looms, Mahmut Aykaç, Ercan Yildiz, Abdurrahman Oğuz

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, we modified the old type of electro-controlled mechanical Jacquard looms for the carpet weaving industry by substituting a Jacquard controller with a modern computer running software called the "Weaving Control System", which has also been developed in the context of this study. By this modification, the Jacquard controller, which requires expensive electronic components and maintenance, has been discarded, and a contemporary computer-based solution that is easy to control and use, and cheap to install and maintain, has been employed in the place of the Jacquard controller. Even though the proposed solution has been tested on the Schleicher-type …

A 2-D Analytical Model For Cylindrical Gate Tunnel Fet (Cg-Tfet) Based On Center Potential, Sidhartha Dash, Guru Prasad Mishra

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, a 2-D cylindrical gate tunnel FET (CG-TFET) model is developed based on the potential at the center of cylinder. The center potential is obtained by Laplace solution in the cylindrical coordinate system and the accuracy is validated using a 2-D TCAD device simulator. The tunneling of charge carriers in the CG-TFET is analyzed using the center potential and the results are compared to the surface potential-based model. The drain current is formulated using the initial tunneling point and tunneling path, which further helps to obtain the threshold voltage of this model. The effect of gate engineering and …

Full Occlusion Handling For Pedestrian Tracking Via Hybrid System, Xiaoyu Zhang, Shiqiang Hu, Huanlong Zhang, Xing Hu

Turkish Journal of Electrical Engineering and Computer Sciences

Occlusion and lack of visibility even in sparse crowd scenes make it difficult to track individual pedestrians correctly and consistently, particularly in a single view. We present a novel pedestrian tracking approach that connects tracking with reidentification to locate and maintain the identity of certain people who may be occluded for a long time. First, two models are constructed. One model tracks the pedestrian and trains a classifier, while the other model reidentifies the pedestrian of interest from detection results with the trained classifier. Secondly, we design a set of transition rules for model switching. Finally, the two models work …

A Novel Direct Torque Control Using Second Order Continuous Sliding Mode Of A Doubly Fed Induction Generator For A Wind Energy Conversion System, Zinelaabidine Boudjema, Rachid Taleb, Youcef Djeriri, Adil Yahdou

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper a new robust direct torque control strategy based on second order continuous sliding mode and space vector modulation of a doubly fed induction generator integrated in a wind energy conversion system is presented. The conventional direct torque control (C-DTC) with hysteresis regulators has significant flux and torque ripples at steady-state operation and also the switching frequency varies in a wide range. The proposed DTC technique based on second order continuous sliding mode control reduces flux, current, and torque ripples. It also narrows down the switching frequency variations in induction machine control. Two different sliding surfaces such as …

A Methodology To Include Real-Life Failure Data In The Failure Rate Estimation Of Power Distribution Systems, Mojtaba Gilvanejad, Hossein Askarian Abyaneh, Kazem Mazlumi

Turkish Journal of Electrical Engineering and Computer Sciences

Random failure rates are usually assumed as constant values in reliability calculations. In this paper, this topic is investigated using stochastic models of uncertain phenomena like lightning, cold load pickup, and overloading, which result in random failures. An algorithm is developed to estimate the random failure rates in distribution networks during their lifetime. This algorithm stochastically generates the random failures as well as sustained failures as a result of equipment wear-out state due to the aging process and finally estimates the total number of temporary/sustained failures in a period of the network lifetime. The results of applying this algorithm to …

Experimental Evaluation And Fdtd Method For Predicting Electromagnetic Fields In The Near Zone Radiated By Power Converter Systems, Mohammed Laour, Redouane Tahmi, Christian Vollaire

Turkish Journal of Electrical Engineering and Computer Sciences

This paper presents the study of conducted electromagnetic interference (EMI) currents flowing through the power cables of a DC-DC converter system and its correlation with the near field radiated from these cables. The radiated emission measurement contains a common mode (CM) and a differential mode (DM), and accurate separation of the radiated emissions of these two modes is necessary. The finite-difference time-domain (FDTD) method is used to predict the electromagnetic radiation caused by CM currents and DM currents. An experimental bench has been designed to allow access to the measurement of EMI disturbances at various sensitive places. The CM and …

Whole Body Motion Control Of Humanoid Robots Using Bilateral Control, Emre Sariyildiz, Hakan Temeltaş

Turkish Journal of Electrical Engineering and Computer Sciences

This paper deals with the whole body motion control problem of humanoid robots by using automatic and bilateral control methods. Advanced motion controllers are proposed so that human daily life activities, such as walking on an uneven terrain and contacting an unknown object, can be performed. It is shown that the uncertainty of environmental impedance variation is one of the main challenging issues in the design of the automatic control systems, i.e. a humanoid robot may easily lose its stability when it contacts an unstructured environment. A novel bilateral control method is proposed for humanoid robots so as to overcome …

Ionolab-Ray: A Wave Propagation Algorithm For Anisotropic And Inhomogeneous Ionosphere, Esra Erdem, Feza Arikan

Turkish Journal of Electrical Engineering and Computer Sciences

A high-frequency (HF) radio wave propagation model based on ray tracing for anisotropic, inhomogeneous, and time-varying ionosphere is developed to form the basis for a user-friendly modular algorithm. The algorithm IONOLAB-RAY applies the principles of ray tracing through the spherical 3D grid model of the ionosphere. The physical parameters of the ionosphere in each voxel are obtained from the ionosphere model IRI-Plas-G. The refractive index of each voxel is calculated with the Appleton-Hartree formula, which includes electron cyclotron frequency, collision frequency, and anisotropicity due to the geomagnetic field. The developed propagation algorithm allows the input of total electron content (TEC) …

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 …