Computer Engineering Commons^™

Neuro-Fuzzy Soft-Switching Hybrid Filter For Impulsive Noisy Environments, Şaban Özer, Hasan Zorlu

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, a new soft-switching hybrid filter based on a neuro-fuzzy network for impulsive noisy environments is proposed. The hybrid filter was built by combining an adaptive finite impulse response (FIR) filter, an adaptive weighted myriad (WMy) filter, and a soft-switching mechanism based on a neuro-fuzzy (NF) network. Performance of the hybrid filter was tested in \alpha-stable noisy situations and compared with adaptive FIR, WMy, and weighted median (WMd) filter performances. According to the simulation results; the proposed hybrid filter has better performance than the adaptive FIR, WMy, and WMd filters, and has the ability of effectively suppressing the …

Simulation Of Storage Time Versus Reverse Bias Current For P^+N And Pin Diodes, Mehmet Serhat Keserli̇oğlu, Hasan Hüseyi̇n Erkaya

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, the reverse-recovery behaviors of pin and p^+n diodes were simulated as a function of the reverse current and carrier lifetime. For this purpose, a 1-D simulation program was written to solve the semiconductor equations. MatLab partial differential equation solver was used. The reverse recovery response of pin and p^+n diodes was obtained for various values of a resistor in series and of carrier lifetime. The transient response for voltage and current was determined.

Determining Wave Propagation Characteristics Of Mv Xlpe Power Cable Using Time Domain Reflectometry Technique, Ghulam Murtaza Hashmi, Ruslan Papazyan, Matti Lehtonen

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, the wave propagation characteristics of single-phase medium voltage (MV) cross-linked polyethylene (XLPE) power cable are determined using time domain reflectometry (TDR) measurement technique. TDR delivers the complex propagation constant (attenuation and phase constant) of lossy cable transmission line as a function of frequency. The frequency-dependent propagation velocity is also determined from the TDR measurements through the parameters extraction procedure. The calibration of the measuring system (MS) is carried-out to avoid the effect of multiple reflections on the accuracy of measurements. The results obtained from the measurements can be used to localize the discontinuities as well as the …

Asynchronous Signal Processing For Brain-Computer Interfaces, Seda Senay, Luis F. Chaparro, Mingui Sun, Robert Sclabassi, Aydin Akan

Turkish Journal of Electrical Engineering and Computer Sciences

Brain-computer interfaces (BCIs) provide a way to monitor and treat neurological diseases. An important application of BCIs is the monitoring and treatment of epilepsy, a neurological disorder characterized by recurrent unprovoked seizures, symptomatic of abnormal, excessive or synchronous neuronal activity in the brain. BCIs contain an array of sensors that gather and transmit data under the constrains of low-power and minimal data transmission. Asynchronous sigma delta modulators (ASDMs) are considered an alternative to synchronous analog to digital conversion. ASDMs are non-linear feedback systems that enable time-encoding of analog signals, from which the signal can be reconstructed. An efficient reconstruction of …

Fully Integrated Universal Biquads Using Operational Transresistance Amplifiers With Mos-C Realization, Ahmet Gökçen, Selçuk Kilinç, Uğur Çam

Turkish Journal of Electrical Engineering and Computer Sciences

Universal biquadratic filters employing operational transresistance amplifiers are presented. All 5 different second-order filtering functions, namely low-pass, high-pass, band-pass, notch, and all-pass, can be realized. The quality factor of the filters can be adjusted electronically without affecting resonant frequency. The configuration can be made fully integrated based on MOS-C realization, by making use of the current differencing and internally grounded inputs of OTRA. PSpice simulation results are given to verify the theoretical analysis.

Obtaining The Secondary Impedance Of Single-Sided Linear Induction Motor With A Double Layer Reaction Rail: A New Approach, Ali̇ Suat Gerçek, Vedat Mehmet Karsli

Turkish Journal of Electrical Engineering and Computer Sciences

In the performance calculations of single-sided linear induction motor (SLIM),the equivalent circuit technique (ECT) is used. In this paper, a new approach is proposed for obtaining the secondary impedance of single-sided linear induction motor (SLIM) with a double layer reaction rail by using the layered secondary model. The proposed method improves the ECT technique by considering the saturation effect and the non-linear complex equivalent relative permeability. This study also examines the contributions of other electromagnetic effects, such as longitudinal end effect and transverse edge effect as well. Our method is applied to the SLIM and computed results of the method …

Online Speed Control Of A Brushless Ac Servomotor Based On Artificial Neural Networks, Si̇bel Partal, İbrahi̇m Şenol, Ahmet Faruk Bakan, Kamuran Nur Beki̇roğlu

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, an alternative approach to speed estimation of brushless AC servomotors is presented. Speed control is realized in the following steps. First, the servomotor was mathematically modelled; the driver system was designed and speed control of the servomotor was accomplished with feedback. Next, a network structure representing the electrical and mechanical properties of the servomotor was built via Artificial Neural Network (ANN) and trained with the results of the first step. The weights obtained from the neural nwork training were inserted into the control algorithm in accordance with the ANN. Finally, speed estimation was achieved based on the …

A Logic Method For Efficient Reduction Of The Space Complexity Of The Attribute Reduction Problem, Mehmet Hacibeyoğlu, Fati̇h Başçi̇ftçi̇, Şi̇rzat Kahramanli

Turkish Journal of Electrical Engineering and Computer Sciences

The goal of attribute reduction is to find a minimal subset (MS) R of the condition attribute set C of a dataset such that R has the same classification power as C. It was proved that the number of MSs for a dataset with n attributes may be as large as (_{n/2}^n) and the generation of all of them is an NP-hard problem. The main reason for this is the intractable space complexity of the conversion of the discernibility function (DF) of a dataset to the disjunctive normal form (DNF). Our analysis of many DF-to-DNF conversion processes showed that approximately …

Performance Evaluation Of Nonparametric Ica Algorithm For Fetal Ecg Extraction, Yusuf Sevi̇m, Ayten Atasoy

Turkish Journal of Electrical Engineering and Computer Sciences

Fetal electrocardiograms (FECG) contain important indications about the health and condition of the fetus. In this respect, it is crucial to apply a robust algorithm to ECG data for extraction of the FECG signal. Most of the independent component analysis (ICA) algorithms used for this purpose rely on simple statistical models. Such algorithms can fail to separate desired signals when the assumed statistical model is inaccurate. Statistical models can be estimated accurately using kernel density estimation methods. Therefore, the kernel density estimation method was used in this paper for building an ICA algorithm (nonparametric ICA: NpICA) and the algorithm was …

A Vision Based Feedback Mechanism For 6-Dof Stewart Platform, Utku Büyükşahi̇n

Turkish Journal of Electrical Engineering and Computer Sciences

Eyes are the most ubiquitous sensors of humankind. However, ``Vision Based Sensors" are not as common as what this fact would suggest. A survey of the previous work on image processing would reveal that the bulk of the research in this area have been conducted since the year 2000. These facts clearly show that image processing is the technology of our century, and is very open to further development. In this work, a system that combines a classical mechanism of the 20th century with the recent technology of the 21st century is presented and the design, theoretical background, the software …

Design And Development Of Workstation For Microparts Manipulation And Assembly, Emrah Deni̇z Kunt, Ahmet Teoman Naskali̇, İslam Shoukry Mohammed Khalil, Asif Sabanovic, Ebubeki̇r Yüksel

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, microassembly system design issues are discussed with requirements, constraints and necessities for the development of an assembly platform, and these issues are shown over a versatile and reconfigurable microassembly workstation which is designed and realized as a research tool for investigation of the problems in microassembly and micromanipulation tasks. First prototype of a workstation and the development of a second prototype with enhancements on mechanical and control structure of the system are presented with details on the configuration of the systems. In addition, several experiments using a workstation are presented both on the first and the second …

Self-Tuning Fuzzy Pd-Based Stiffness Controller Of A 3 \Times 3 Stewart Platform As A Man-Machine Interface, Vasfi̇ Emre Ömürlü, İbrahi̇m Yildiz

Turkish Journal of Electrical Engineering and Computer Sciences

Stewart Platform (SP) mechanism has wide application area on aerospace and manufacturing industry with its nonlinear structure allowing spatial motion capabilities. However, nonlinearities in the structure of the mechanism lead to complications in the dynamics of the system and result in complex control algorithms for dexterity in motion and force/torque feedback. Therefore, this paper aims to represent stiffness control by means of independent joint fuzzy-PD control algorithm with gain scheduling on an experimental 3 \times 3 SP parallel robotic mechanism to be used as a fly-by-wire flight control unit. Model and real system responses are compared employing stiffness control so …

Parallelizing Scale Invariant Feature Transform On A Distributed Memory Cluster, Stanislav Bobovych

Inquiry: The University of Arkansas Undergraduate Research Journal

Scale Invariant Feature Transform (SIFT) is a computer vision algorithm that is widely-used to extract features from images. We explored accelerating an existing implementation of this algorithm with message passing in order to analyze large data sets. We successfully tested two approaches to data decomposition in order to parallelize SIFT on a distributed memory cluster.

Experimental Analysis Of An Alternator Excited With Photovoltaic Cells For Small Power Plants, Kami̇l Ri̇fat İrfan Güney, Nevzat Onat

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, an automatic voltage regulator fed by photovoltaic (PV) cells was designed for use in small power alternators. The design aimed to increase the energy output of the alternator and to ensure necessary current output from the PV cells to support the synchronous generator excitation system. For energy transformation from small renewable energy sources, designers have favored the use of alternators that produce higher quality electric power, rather than asynchronous generators. We also address the designed system's suitability for real-life application, examining the steady-state performance of the photovoltaic cell excited alternator (PVCEA) with various loads and its behavior …

Delay-Dependent Stability Criteria For Interval Time-Varying Delay Systems With Nonuniform Delay Partitioning Approach, Mehmet Nur Alpaslan Parlakçi

Turkish Journal of Electrical Engineering and Computer Sciences

This paper investigates the conservatism reduction of Lyapunov-Krasovskii based conditions for the stability of a class of interval time-varying delay systems. The main idea is based on the nonuniform decomposition of the integral terms of the Lyapunov-Krasovskii functional. The delay interval is decomposed into a finite number of nonuniform segments with some scaling parameters. Both differentiable delay case and nondifferentiable delay case and unknown delay derivative bound case are taken into consideration. Sufficient delay-dependent stability criteria are derived in terms of matrix inequalities. Two suboptimal delay fractionation schemes, namely, linearization with cone complementary technique and linearization under additional constraints are …

The Forest Overlay Network, Logan Stafman

All Computer Science and Engineering Research

Forest is an overlay network designed for large real-time distributed systems. In particular, we’re interested in virtual worlds that provide high-quality interaction over a constantly changing pattern of communication. Forest is suitable for applications in which many entities send data to a large set of constantly changing entities. By using tree-structured channels, we can create logically isolated private networks which support both unicast and multicast routing. In this paper, we will discuss the core components of Forest and measure the performance of the control elements of the network. We will also provide examples of control sequences and the roles played …

Mercury Blastn Biosequence Similarity Search System: Technical Reference Guide, Jeremy Buhler

All Computer Science and Engineering Research

This guide documents the operation of the Mercury BLASTN system for hardware-accelerated DNA similarity search. It includes detailed information on the syntax and limitations of the system's component commands, as well as a description of the system's hardware platform suitable for administrators who need to maintain a Mercury BLASTN system. Mercury BLASTN is a product of the High Performance COmputational Biology Group at Washington University.

Efficient Deadlock Avoidance For Streaming Computation With Filtering, Jeremy Buhler, Kunal Agrawal, Peng Li, Roger D. Chamberlain

All Computer Science and Engineering Research

In this report, we show that deadlock avoidance for streaming computations with filtering can be performed efficiently for a large class of DAG topologies. We first give efficient algorithms for dummy interval computation in series-parallel DAGs, then generalize our results to a larger graph family, the CS4DAGs, in which every undirected cycle has exactly one source and one sink. Our results show that, for a large set of application topologies that are both intuitively useful and formalizable, the streaming model with filtering can be implemented safely with reasonable compilation overhead.

Hierarchical Scheduling For Multicores With Multilevel Cache Hierarchies, Kunal Agrawal, Jim Sukha

All Computer Science and Engineering Research

Cache-locality is an important consideration for the performance in multicore systems. In modern and future multicore systems with multilevel cache hierarchies, caches may be arranged in a tree of caches, where a level k cache is shared between Pk processors, called a processor group, and Pk increases with k. In order to get good performance, as much as possible, subcomputations that share more data should execute on processors which share a lower-level cache. Therefore, the number of cache misses in these systems depends on the scheduling decisions, and a scheduler is responsible for not just achieving good load-balance and low …

Near Optimal Rate Selection For Wireless Control Systems, Abusayeed Saifullah, Chengjie Wu, Paras Babu Tiwari, You Xu, Yong Fu, Chenyang Lu, Yixin Chen

All Computer Science and Engineering Research

With the advent of industrial standards such as WirelessHART, process industries are now gravitating towards wireless control systems. Due to limited bandwidth in a wireless network shared by multiple control loops, it is critical to optimize the overall control performance. In this paper, we address the scheduling-control co-design problem of determining the optimal sampling rates of feedback control loops sharing a WirelessHART network. The objective is to minimize the overall control cost while ensuring that all data flows meet their end-to-end deadlines. The resulting constrained optimization based on existing delay bounds for WirelessHART networks is challenging since it is non-differentiable, …

Distributed Channel Allocation Algorithms For Wireless Sensor Networks, Abusayeed Saifullah, You Xu, Chenyang Lu, Yixin Chen

All Computer Science and Engineering Research

Interference between concurrent transmissions can cause severe performance degradation in wireless sensor networks (WSNs). While multiple channels available in WSN technology such as IEEE 802.15.4 can be exploited to mitigate interference, channel allocation can have a significant impact on the performance of multi-channel communication. This paper proposes a set of distributed algorithms for near-optimal channel allocation in WSNs with theoretical bounds. We first consider the problem of minimizing the number of channels needed to remove interference in a WSN, and propose both receiver-based and link-based distributed channel allocation protocols. For WSNs with an insufficient number of channels, we formulate a …

Feedback Thermal Control Of Real-Time Systems On Multicore Processors, Yong Fu, Nicholas Kottenstette, Chenyang Lu, Xenofon D. Koutsoukos

All Computer Science and Engineering Research

Real-time systems face significant challenges in thermal management with their adoption of modern multicore processors. While earlier research on feedback thermal control has shown promise in dealing with the uncertainties in the thermal characteristics, multicore processors introduce new challenges that cannot be handled by previous solutions designed for single-core processors. Multicore processors require the temperatures and real-time performance of multiple cores to be controlled simultaneously, leading to multi-input-multi-output (MIMO) control problems with inter-core thermal coupling. Furthermore, current Dynamic Voltage and Frequency Scaling (DVFS) mechanisms only support a finite set of states, leading to discrete control variables that cannot be handled …

Energy-Efficient Low Power Listening For Wireless Sensor Networks In Noisy Environments, Mo Sha, Gregory Hackmann, Chenyang Lu

All Computer Science and Engineering Research

Low Power Listening (LPL) is a common MAC-layer technique for reducing energy consumption in wireless sensor networks, where nodes periodically wake up to sample the wireless channel to detect activity. However, LPL is highly susceptible to false wakeups caused by environmental noise being detected as activity on the channel, causing nodes to spuriously wake up in order to receive nonexistent transmissions. In empirical studies in residential environments, we observe that the false wakeup problem can significantly increase a node's duty cycle, compromising the benefit of LPL. We also find that the energy-level threshold used by the Clear Channel Assessment (CCA) …

Diagnosis Of Multiple Scan-Chain Faults In The Presence Of System Logic Defects, Zhen Chen, Sharad C. Seth, Dong Xiang, Bhargab B. Bhattacharya

School of Computing: Conference and Workshop Papers

We present a combined hardware-software based approach to scan-chain diagnosis, when the outcome of a test may be affected by system faults occurring in the logic outside of the scan chain. For the hardware component we adopt the double-tree scan (DTS) chain architecture, which has previously been shown to be effective in reducing power, volume, and application time of tests for stuck-at and delay faults. We develop a version of flush test which can resolve a multiple fault in a DTS chain to a small number of suspect candidates. Further resolution to a unique multiple fault is enabled by the …

2-Edge-Connectivity And 2-Vertex-Connectivity With Fault Containment, Abusayeed Saifullah

All Computer Science and Engineering Research

Self-stabilization for non-masking fault-tolerant distributed system has received considerable research interest over the last decade. In this paper, we propose a self-stabilizing algorithm for 2-edge-connectivity and 2-vertex-connectivity of an asynchronous distributed computer network. It is based on a self-stabilizing depth-first search, and is not a composite algorithm in the sense that it is not composed of a number of self-stabilizing algorithms that run concurrently. The time and space complexities of the algorithm are the same as those of the underlying self-stabilizing depth-first search algorithm.

Implementation And Evaluation Of Mixed-Criticality Scheduling Approaches For Periodic Tasks, Huang-Ming Huang, Christopher Gill, Chenyang Lu

All Computer Science and Engineering Research

Traditional fixed-priority scheduling analysis for periodic task sets is based on the assumption that all tasks are equally critical to the correct operation of the system. Therefore, every task has to be schedulable under the scheduling policy, and estimates of tasks’ worst case execution times must be conservative in case a task runs longer than is usual. To address the significant under-utilization of a system’s resources under normal operating conditions that can arise from these assumptions, three main approaches have been proposed: priority assignment, period transformation, and zero-slack scheduling. However, to date there has been no quantitative comparison of system …

Generating Muscle Driven Arm Movements Using Reinforcement Learning, Alex S. Broad

All Computer Science and Engineering Research

This project focuses on using Reinforcement Learning to optimize arm dynamics through muscle control for desired trajectories. The goal of this project was to create a tool that can be used to gain a better understanding of the arm’s muscles and collect information that is useful in many other disciplines such as biomechanics, anthropology, medicine and robotics. I developed biologically realistic models of primate arm's using Stanford’s SimTK software, an open-source tool for modeling musculoskeletal structures. I then made use of Differential Dynamic Programming in order to generate novel movements from first principles and optimize motion over a specified trajectory. …

Development And Human Performance Evaluation Of A Ground Vehicle Robotic Force-Feedback Tele-Operation System, Ankur Saraf

Wayne State University Theses

ABSTRACT

DEVELOPMENT AND HUMAN PERFORMANCE EVALUATION OF A GROUND VEHICLE ROBOTIC FORCE-FEEDBACK TELE-OPERATION SYSTEM

by

ANKUR SARAF

May 2011

Advisor: Dr. Abhilash K. Pandya.

Major: Electrical Engineering.

Degree: Master of Science.

Modern tele-operation systems are trying to take into account haptic and audio information in addition to visual data to provide as feedback to the tele-operator.This research emphasizes on the development of hardware and software architecture to enhance the tele-operation capabilities of omni-directional inspection robot (ODIS). The system enhances the tele-operation capabilities by introducing force-feedback to the tele-operators. The conventional joystick is replaced with Novint Falcon haptic joystick which gets …

Control Of A Single Ground Vehicle Using Aerial And Onboard Camera Views, Vishal Lowalekar

Wayne State University Theses

Controlling a ground vehicle using only onboard and aerial camera views, can be a tedious task, as it is challenging for the operator to estimate information about the robots location and orientation using only these view. However the visual data can be sufficient for computerized calculation of this information even in the absence of other sensors. This approach is of interest to the military because the use of passive sensors instead of active sensors (e.g. LIDAR) would be easier and more reliable and would not give off detectable signatures.

The goal of this research was to control a ground vehicle …

Ceg 233: Linux And Windows, Prabhaker Mateti

Computer Science & Engineering Syllabi

This is a freshman-level 4 credit hour course conducted in a 10-week term. Its goal is to develop in the minds of students an effective operational model of computer systems running either Linux or Windows. This course is lab-oriented.