Engineering Commons^™

Astronaut Eva Exposure Estimates From Cad Model Spacesuit Geometry, Giovanni De Angelis, Brooke M. Anderson, William Atwell, John E. Nealy, Gary D. Qualls, John W. Wilson

Mathematics & Statistics Faculty Publications

Ongoing assembly and maintenance activities at the International Space Station (ISS) require much more extravehicular activity (EVA) than did the earlier U.S. Space Shuttle missions. It is thus desirable to determine and analyze, and possibly foresee, as accurately as possible what radiation exposures crew members involved in EVAs will experience in order to minimize risks and to establish exposure limits that must not to be exceeded. A detailed CAD model of the U.S. Space Shuttle EVA Spacesuit, developed at NASA Langley Research Center (LaRC), is used to represent the directional shielding of an astronaut; it has detailed helmet and backpack …

Induction Machine Broken-Bar Fault Diagnosis Using The Rotor Magnetic Field Space-Vector Orientation, Behrooz Mirafzal, Nabeel Demerdash

Electrical and Computer Engineering Faculty Research and Publications

A new technique based on rotor magnetic field space vector orientation is presented to diagnose broken-bar faults in induction machines operating at steady state. In this technique, stator currents and voltages are used as inputs to compute and subsequently observe the rotor magnetic field orientation, which has a more significant "swing-like" pendulous oscillation in case of broken-bar faults than in healthy operation. It will be shown here that the range of this "pendulous oscillation" is a function of the number of broken bars. Also in this technique, it was found that an inter-turn shorted stator-winding fault, which exhibits similar pendulous …

Design And Evaluation Of Processes For Fuel Fabrication: Quarterly Progress Report #10, Georg F. Mauer

Fuels Campaign (TRP)

The tenth quarter of the project covered the following:

• Mr. Richard Silva continued the development of a simulation model with a Waelischmiller hot cell robot, and is close to completing his M.Sc. thesis project. Rich will likely defend his thesis in April 2004.

• A project review meeting with Dr. Mitch Meyer and other ANL scientists was held in December 2003 at ANL West, Idaho Falls, ID. Dr. Meyer described ANL long term research objectives with regard to transmuter fuel manufacturing.

• Further refinements on Concepts and Methods for Vision-Based Hot Cell Supervision and control, focusing on rule-based object …

Design And Evaluation Of Processes For Fuel Fabrication: Quarterly Progress Report #10, Georg F. Mauer

Fuels Campaign (TRP)

The tenth quarter of the project covered the following:

• Mr. Richard Silva continued the development of a simulation model with a Waelischmiller hot cell robot, and is close to completing his M.Sc. thesis project. Rich will likely defend his thesis in April 2004.

• A project review meeting with Dr. Mitch Meyer and other ANL scientists was held in December 2003 at ANL West, Idaho Falls, ID. Dr. Meyer described ANL long term research objectives with regard to transmuter fuel manufacturing.

• Further refinements on Concepts and Methods for Vision-Based Hot Cell Supervision and control, focusing on rule-based object …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 20, Number 4, February 2004, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

On The Use Of Intervals In Scientific Computing: What Is The Best Transition From Linear To Quadratic Approximation?, Martine Ceberio, Vladik Kreinovich, Lev Ginzburg

Departmental Technical Reports (CS)

In many problems from science and engineering, the measurements are reasonably accurate, so we can use linearization (= sensitivity analysis) to describe the effect of measurement errors on the result of data processing. In many practical cases, the measurement accuracy is not so good, so, to get a good estimate of the resulting error, we need to take quadratic terms into consideration - i.e., in effect, approximate the original algorithm by a quadratic function. The problem of estimating the range of a quadratic function is NP-hard, so, in the general case, we can only hope for a good heuristic. Traditional …

Geometric Approach To Detecting And Locating Cracks In Thin Plates By Lamb Wave Reflection: Case Of Moving Transducer, Jose R. Mares, Roberto A. Osegueda, Nagaswaroopa Kaukuri, Vladik Kreinovich

Departmental Technical Reports (CS)

This paper portrays work for the development of a Lamb wave scanning method for the detection of defects in thin plates. The approach requires the generation of an ultrasonic A0 and S0-mode Lamb wave using an incident transmitter excited with a tone burst centered at a near non-dispersive frequency. With a fixed relative separation both transmitter and receiving transducer remotely scan a specific line section of the plate. The arrival time information coming from incident and reflected waves contain information associated with the location of reflection surfaces or potential flaws. The Hilbert-Huang transform is applied to the intrinsic mode functions …

From Intervals To? Towards A General Description Of Validated Uncertainty, Vladik Kreinovich, Gracaliz P. Dimuro, Antonio C. Da Rocha Costa

Departmental Technical Reports (CS)

In many real-life situations, we are interested in the physical quantities that are difficult or even impossible to measure directly. To estimate the value of such quantity y, we measure the values of auxiliary quantities x1,...,xn that are related to y by a known functional relation y=f(x1,...,xn), and we then use the results Xi of measuring xi to find the desired estimate Y=f(X1,..,Xn). Due to measurement errors, the measured values Xi are slightly different from the actual (unknown) values xi; as a result, our estimate Y is different from the actual value y=f(x1,...,xn) of the desired quantity.

When xi and …

Text Categorization Based On Phrase Indexing, Hany Seif Habib

Archived Theses and Dissertations

This thesis investigates Information Retrieval (IR) field of research with focus on Text Categorization (TC) area. We study the available techniques and models used for classification of text documents to a predefined set of categories. We use a subset of Reuters - 21578 test collection for our research. We use the first 150 documents for training and the following 100 for testing. We use pre-processing steps such as parsmg, stop-word removal, and stemming using porter stemmer. We identify all possible phrases in a document during the pre-processing stage. We use only adjacent phrases of size two. We learn frequency information …

Connectionist Approaches To Cost-Based Abduction, Emad Abdel-Thalooth Massry Andrews

Archived Theses and Dissertations

No abstract provided.

Ip Traceback Of Denial Of Service Attacks Using Mobile Agents Technology, Ghada Magdi Hashem El-Keissi

Archived Theses and Dissertations

Denial of Service (DoS) attack is considered a critical threat to networks. A DoS is a destructive attack aiming at denying services to legitimate users. An attacker could create an attack that floods a network, disrupts a connection between two computers, or even crashes a computer. Accordingly, legitimate users will not be able to have access to services needed. DoS attacks could originate from a single attacker or it could originate from multiple attackers creating Distributed Denial of Service (DDoS) attacks towards a target victim. One of the main problems ofDoS attacks is the ability of an attacker to forge …

A Step Towards A Well Engineered Component Based Extensible Operating System, Mohamed Fathey Abdel Fattah

Archived Theses and Dissertations

Operating systems are the first developed piece of software for a computer and it is still the first application to run over our computers. Software developers spent a lot of time and efforts to build reliable systems using different philosophies and software engineering strategies. They built monolithic kernels, micro-kernels, pico-kernels, etc. to fulfill users' requirements and hardware developments as well. However, Most of the proposed solutions for operating systems design and implementation are for solving traditional problems. Operating systems are still constructed as a general piece of software used for either machine's resource management or as a virtual machine for …

Performance Evaluation Of Auc Backbone Network Using Simulation And Monitoring Tools, Nabawia Khalil Abdel-Karim

Archived Theses and Dissertations

Networks in the past were defined by the traffic they carried. The network management systems that can track performance statistics, alarms and diagnostics are usually called operations support systems. As number of applications carried over a network grew, networks cannot scale economically. They become large, complex and expensive. Network performance became an important issue to network designers, operators and implementers to design, implement and maintain scalable, reliable and resilient networks. In this research, we developed a comparative analysis for two tools commonly utilized to aid network operations support to arrive at decisions related to network scalability, performance evaluation and renewal. …

Optimal Calibration Of Pet Crystal Position Maps Using Gaussian Mixture Models, Kelly A. Stronger, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

A method is developed for estimating optimal PET gamma-ray detector crystal position maps, for arbitrary crystal configurations, based on a binomial distribution model for scintillation photon arrival. The approach is based on maximum likelihood estimation of Gaussian mixture model parameters using crystal position histogram data, with determination of the position map taken from the posterior probability boundaries between mixtures. This leads to minimum probability of error crystal identification under the assumed model.

Stochastic Analysis And Performance Evaluation Of Wireless Schedulers, R. Rom, Hwee-Pink Tan

Research Collection School Of Computing and Information Systems

In the last few years, wireless scheduling algorithms have been proposed by supplementing wireline scheduling algorithms with a wireless adaptation scheme. However, Quality of Service (QoS) bounds have either been derived for flows that perceive error-free conditions or a static worst-case channel condition. Such an assumption of the channel condition is unrealistic, since channel errors are known to be bursty in nature. Hence, these bounds are inadequate to characterize the scheduler's QoS performance. Our research focuses on performing an extensive analysis of wireless scheduling in order to derive statistical QoS performance bounds under realistic channel conditions. In this paper, we …

Adaptive Turn-Prohibition Routing Algorithm For The Networks Of Workstations, Amey Bhaskar Shevtekar

Theses

Deadlock occurrence is a critical problem for any computer network. Various solutions have been proposed over last two decades to solve problem of deadlocks in networks using different routing schemes, like up/down routing algorithm used in Myrinet switches. However, most of existing approaches for deadlock-free routing either try to eliminate any possibility of deadlock occurrence, which can result in putting extra restrictions on the routing in the networks or put no restrictions on routing, which leads to other approach namely deadlock recovery. In this thesis emphasis is on developing hybrid approach for routing in wormhole networks, wherein some prohibition is …

Camrit: Control-Based Adaptive Middleware For Real-Time Image Transmission, Xiaorui Wang, Huang-Ming Huang, Venkita Subramonian, Chenyang Lu, Christopher Gill

All Computer Science and Engineering Research

Real-time image transmission is crucial to an emerging class of distributed embedded systems operating in open network environments. Examples include avionics mission re-planning over Link-16, security systems based on wireless camera networks, and online collaboration using camera phones. Meeting image transmission deadlines is a key chal-lenge in such systems due to unpredictable network condi-tions. In this paper, we present the design, modeling, and analysis of CAMRIT, a Control-based Adaptive Middleware framework for Real-time Image Transmission in distributed real-time embedded systems. CAMRIT features a distributed feedback control loop that meets image transmission dead-lines by dynamically adjusting the quality of image tiles. …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 20, Number 3, January 2004, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Using Web Services To Integrate Heterogeneous Simulations In A Grid Environment, J. Mark Pullen, Ryan Brunton, Don Brutzman, David Drake, Michael Hieb, Katherine L. Morse, Andreas Tolk

Computational Modeling & Simulation Engineering Faculty Publications

The distributed information technologies collectively known as Web services recently have demonstrated powerful capabilities for scalable interoperation of heterogeneous software across a wide variety of networked platforms. This approach supports a rapid integration cycle and shows promise for ultimately supporting automatic composability of services using discovery via registries. This paper presents a rationale for extending Web services to distributed simulation environments, including the High Level Architecture (HLA), together with a description and examples of the integration methodology used to develop significant prototype implementations. A logical next step is combining the power of Grid computing with Web services to facilitate rapid …

A Predictive Sensor Network Using Ant System, Rajani Muraleedharan, Lisa Ann Osadciw

Electrical Engineering and Computer Science - All Scholarship

The need for a robust predictive sensor communication network inspired this research. There are many critical issues in a communication network with different data rate requirements, limited power and bandwidth. Energy consumption is one of the key issues in a sensor network as energy dissipation occurs during routing, communication and monitoring of the environment. This paper covers the routing of a sensor communication network by applying an evolutionary algorithm- the ant system. The issues considered include optimal energy, data fusion from different sensor types and predicting changes in environment with respect to time.

Future Of Asynchronous Transfer Mode Networking, Fakhreddine Mohamed Hachfi

Theses Digitization Project

The growth of Asynchronous Transfer Mode (ATM) was considered to be the ideal carrier of the high bandwidth applications like video on demand and multimedia e-learning. ATM emerged commercially in the beginning of the 1990's. It was designed to provide a different quality of service at a speed up 100 Gbps for both real time and non real time application. The turn of the 90's saw a variety of technologies being developed. This project analyzes these technologies, compares them to the Asynchronous Transfer Mode and assesses the future of ATM.

Orchestration Within The Sonification Of Basic Data Sets, Charlie Cullen, Eugene Coyle

Conference papers

The use of sonification as a means of representing and analysing data has become a growing field of research in recent years and as such has become a far more accepted means of working with data. Existing work carried out as part of this research has focused primarily on the sonification of DNA/RNA sequences and their subsequent protein structures for the purposes of analysis. This sonification work raised many questions as regards the need for sequences to be set to music in a standard manner so that different strands could be analysed by comparison, and hence the orchestration and instrumentation …

A Book Management System Elibrary, Shanpeng Song

Theses Digitization Project

"eLibrary" is a book management software application that runs on Microsoft Windows platforms. The software incorporates a Windows Explorer like interface and XML/XSL to display book details. The purpose of this project is to build a full-featured, commerical-quality software package to help people manage their books (either printed or electronic). The goal is for eLibrary to be a complete solution for people who wish to build their own personal electronic library catalog.

A Genetic Algorithms Approach To Learning Communication And Coordination In Simulated Robots, Chris Sotzing

Senior Scholar Papers

This project is motivated by an existing robot system for mapping unknown environments and attempts to improve its effectiveness through the use of genetic algorithms. Using a robot simulator, the mapping system is created using simulated robots and a simulated environment. The robots are controlled by a supervisor agent that makes the high-level decisions about tasks for individual robots to complete to accomplish the mapping effort. This research investigates the ability of adding a genetic algorithm learning component to the supervisor to improve its ability to coordinate the robotic agents.

A Comparative Evaluation Of .Net Remoting And Java Rmi, Taneem Ibrahim

Inquiry: The University of Arkansas Undergraduate Research Journal

Distributed application technologies such as Micrososoft.NET Remoting, and Java Remote Method Invocation (RMI) have evolved over many years to keep up with the constantly increasing requirements of the enterprise. In the broadest sense, a distributed application is one in which the application processing is divided among two or more machines. Distributed middleware technologies have made significant progress over the last decade. Although Remoting and RMI are the two of most popular contemporary middleware technologies, little literature exists that compares them. In this paper, we study the issues involved in designing a distributed system using Java RMI and Microsoft.NET Remoting. In …

Graduate School Of Computer And Information Sciences Master's Degree Programs 2004, Nova Southeastern University

College of Engineering and Computing Course Catalogs

No abstract provided.

Orthogonal Spreading Sequences Constructed Using Hall’S Difference Set, Jennifer Seberry, Le Chung Tran, Yejing Wang, Beata J. Wysocki, Tadeusz Wysocki, Ying Zhao

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In the paper we propose a new set of orthogonal spreading sequences based on the Hadamard matrix of order 32 constructed using the Hall difference set. The proposed sequences are characterised by low peaks in the aperiodic cross-correlation functions and have also good aperiodic auto-correlation properties.

Modified Convolutional Interleavers And Their Performance In Turbo Codes, Sina Vafi, Tadeusz Wysocki

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

In previous work,we have presented application of a model of the convolutional interleaver in turbo codes acting as a block interleaver through inserting a number of stuff bits equal to the number of interleaver memories at the end of each data 6lock.h order to get better turbo codes performance, the interleaver with larger period, which increases the number of stuff bits and educes effective channel bandwidth usage, has been suggested. In this paper, we introduce a modification to this interleaver improving turbo codes performance without increasing the interleaver period. This is carried out by increasing distance of adjacent bits that …

Two Complex Orthogonal Space-Time Codes For Eight Transmit Antennas, Le Chung Tran, J. Seberry, Yejing Wang, B. J. Wysocki, T. A. Wysocki, Tianbing Xia, Ying Zhao

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

Two new constructions of complex orthogonal space-time block codes of order 8 based on the theory of amicable orthogonal designs are presented and their performance compared with that of the standard code of order 8. These new codes are suitable for multi-modulation schemes where the performance can be sacrificed for a higher throughput.

The Effect Of Imperfect Carrier Recovery On The Performance Of The Diversity Antenna Selection Technique In Wireless Channels Utilizing Dstm, Le Chug Tran, Tadeusz Wysocki, Jennifer Seberry, Alfred Mertins

Department of Electrical and Computer Engineering: Faculty Publications (to 2015)

his paper examines the effect of imperfect carrier phase/frequency recovery at the receiver on the bit error performance of our diversity antenna selection technique (AST) proposed for channels utilizing Differential Space-Time Modulation (DSTM). The tolerance of differential detection associated with the proposed AST to phase/frequency errors is then analyzed.