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Electrical and Computer Engineering

Selected Works

2011

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Articles 31 - 60 of 191

Full-Text Articles in Engineering

Bayesian Software Health Management For Aircraft Guidance, Navigation, And Control, Johann M. Schumann, Timmy Mbaya, Ole J. Mengshoel Sep 2011

Bayesian Software Health Management For Aircraft Guidance, Navigation, And Control, Johann M. Schumann, Timmy Mbaya, Ole J. Mengshoel

Ole J Mengshoel

Modern aircraft — both piloted fly-by-wire commercial aircraft as well as UAVs — more and more depend on highly complex safety critical software systems with many sensors and computer-controlled actuators. Despite careful design and V&V of the software, severe incidents have happened due to malfunctioning software.

In this paper, we discuss the use of Bayesian networks to monitor the health of the on-board software and sensor system, and to perform advanced on-board diagnostic reasoning. We focus on the development of reliable and robust health models for combined software and sensor systems, with application to guidance, navigation, and control (GN&C). Our …


Integrating Probabilistic Reasoning And Statistical Quality Control Techniques For Fault Diagnosis In Hybrid Domains, Brian Ricks, Craig Harrison, Ole J. Mengshoel Sep 2011

Integrating Probabilistic Reasoning And Statistical Quality Control Techniques For Fault Diagnosis In Hybrid Domains, Brian Ricks, Craig Harrison, Ole J. Mengshoel

Ole J Mengshoel

Bayesian networks, which may be compiled to arithmetic circuits in the interest of speed and predictability, provide a probabilistic method for system fault diagnosis. Currently, there is a limitation in arithmetic circuits in that they can only represent discrete random variables, while important fault types such as drift and offset faults are continuous and induce continuous sensor data. In this paper, we investigate how to handle continuous behavior by using discrete random variables with a small number of states, without using soft evidence, which is a traditional technique for handling continuous sensor data. We do so by integrating a method …


Construction Of A Mobile Spectrophotometer For Mapping Plant Health: Combining Crop Circle™ And Gps Technology, Gregory Keith Bartley Jr., Brandon J. Horvath Sep 2011

Construction Of A Mobile Spectrophotometer For Mapping Plant Health: Combining Crop Circle™ And Gps Technology, Gregory Keith Bartley Jr., Brandon J. Horvath

Gregory Keith Bartley Jr.

With the introduction of GPS technology, came the ability to produce maps of plant cover and health over large areas. By correlating the reflectance values of a plant with its respective GPS coordinates, we can form a bird’s eye view of relative plant health using different colors. The commercialization of high precision GPS receivers has allowed researchers to plot these maps with increased accuracy, limiting error to less than 1 inch.


Constructing New Technology: The Crop Circle Gps Cart In Pictures, Gregory Keith Bartley Jr., Brandon J. Horvath Sep 2011

Constructing New Technology: The Crop Circle Gps Cart In Pictures, Gregory Keith Bartley Jr., Brandon J. Horvath

Gregory Keith Bartley Jr.

The crop circle spectrometer represents a breakthrough in unbiased sensor data. Unlike traditional passive sensors, it pulses light at a speed of 20,000 times per second. With this comes the ability of these filters to discern reflectance measurements from that of natural sunlight, allowing it to be used in environments of sun, shade, and even darkness. From these various reflectance values at different wavelengths, we get measurements of plant health known as vegetation indices. And different vegetation indices can tell us different things about the health of a plant. Couple this with the recent advances in GPS technology, we can …


Pandaa: Physical Arrangement Detection Of Networked Devices Through Ambient-Sound Awareness, Zheng Sun, Aveek Purohit, Kaifei Chen, Shijia Pan, Trevor Pering, Pei Zhang Sep 2011

Pandaa: Physical Arrangement Detection Of Networked Devices Through Ambient-Sound Awareness, Zheng Sun, Aveek Purohit, Kaifei Chen, Shijia Pan, Trevor Pering, Pei Zhang

Zheng Sun

Future ubiquitous home environments can contain 10s or 100s of devices. Ubiquitous services running on these devices (i.e. localizing users, routing, security algorithms) will commonly require an accurate location of each device. In order to obtain these locations, existing techniques require either a manual survey, active sound sources, or estimation using wireless radios. These techniques, however, need additional hardware capabilities and are intrusive to the user. Non-intrusive, automatic localization of ubiquitous computing devices in the home has the potential to greatly facilitate device deployments.

This paper presents the PANDAA system, a zero-configuration spatial localization system for networked devices based on …


Pandaa: Physical Arrangement Detection Of Networked Devices Through Ambient-Sound Awareness, Zheng Sun, Aveek Purohit, Kaifei Chen, Shijia Pan, Trevor Pering, Pei Zhang Sep 2011

Pandaa: Physical Arrangement Detection Of Networked Devices Through Ambient-Sound Awareness, Zheng Sun, Aveek Purohit, Kaifei Chen, Shijia Pan, Trevor Pering, Pei Zhang

Aveek Purohit

Future ubiquitous home environments can contain 10s or 100s of devices. Ubiquitous services running on these devices (i.e. localizing users, routing, security algorithms) will commonly require an accurate location of each device. In order to obtain these locations, existing techniques require either a manual survey, active sound sources, or estimation using wireless radios. These techniques, however, need additional hardware capabilities and are intrusive to the user. Non-intrusive, automatic localization of ubiquitous computing devices in the home has the potential to greatly facilitate device deployments.

This paper presents the PANDAA system, a zero-configuration spatial localization system for networked devices based on …


Steady-State And Dynamic Performance Of Oman Transmission System With Diesel-Engine Driven Distributed Generation, Omar H. Abdalla, Rashid Al-Badwawi, Hilal Al-Hadi, Hisham Al-Riyami, Ahmed Al-Nadabi Sep 2011

Steady-State And Dynamic Performance Of Oman Transmission System With Diesel-Engine Driven Distributed Generation, Omar H. Abdalla, Rashid Al-Badwawi, Hilal Al-Hadi, Hisham Al-Riyami, Ahmed Al-Nadabi

Omar H. Abdalla

The paper presents simulation studies of installing a number of diesel-engine driven generating units at selected locations in the main transmission system of Oman. A total of 300MW generator units are proposed on a temporary basis to aid in meeting the peak demand in summer 2011. A digital model is developed to simulate the system including central power plants, transmission system, loads and the proposed Distributed Generation (DG). The model includes representation of governor and excitation systems. The simulation studies are performed by using the DIgSILENT PowerFacrory software package. The objective of the studies is to demonstrate effects of the …


Fabricate An 8.35-Ghz Frequency Synthesizer, A. Attaran, Hossein Ameri Mahabadi, M. Moghavvemi Sep 2011

Fabricate An 8.35-Ghz Frequency Synthesizer, A. Attaran, Hossein Ameri Mahabadi, M. Moghavvemi

Hossein Ameri Mahabadi

The article presents information on designing a low-noise frequency synthesizer for achieving low-phase-noise outputs past 8 GHz for digital microwave radios (DMRs). These synthesizers can be used with the DMRs, depending on advanced digital modulation such as quadrature-amplitude-modulation (QAM) and quadrature-phase-shift-keying (QPSK) formats.


Nonlinear Multivariable Modeling Of Solid Oxide Fuel Cells Using Core Vector Regression, M. Mohammadi, M. Raoofat, Hesamoddin Marzooghi, G. B. Gharehpetiangharehpetian Sep 2011

Nonlinear Multivariable Modeling Of Solid Oxide Fuel Cells Using Core Vector Regression, M. Mohammadi, M. Raoofat, Hesamoddin Marzooghi, G. B. Gharehpetiangharehpetian

Hesamoddin Marzooghi

This paper presents new steady-state and dynamic models for solid oxide fuel cells (SOFCs) using core vector regression (CVR). So far, most of conventional SOFC models have been presented based on conversion laws. Due to complex mathematical equations used in these models, they are time-consuming and need large amount of memory to be applied for controller design, especially power electronic interface controller design, generation and load predictions, optimization and other studies. To overcome these problems, some black-box models, such as support vector machine (SVM) and artificial neural network (ANN)-based models have been also proposed for SOFC. In this paper, in …


Patient Safety: What Can Be Done About It?, Steven Dain Aug 2011

Patient Safety: What Can Be Done About It?, Steven Dain

Steven L Dain

Much is said and written about patient safety. In Canada, a small group of dedicated physicians, nurses and engineers participates in the Canadian Standards Association and Standards Council of Canada Advisory Committees writing basic safety and essential performance requirements for a large range of anesthesia, respiratory care and critical care equipment. Over the past several years, in recognition of the globalization of trade and the international nature of medical device design and manufacturing, Canadian Anesthesiologists’ Society members Dr Steven Dain, Dr Karen Brown, Dr Matt Kurrek, Dr Ken LeDez, and Dr Jeremy Sloan have primarily participated in Organization for International …


Led Street Light Research Project, Donald K. Carter, Stephen Quick Aug 2011

Led Street Light Research Project, Donald K. Carter, Stephen Quick

Stephen Quick

The City of Pittsburgh planned to replace its existing 40,000 street lighting fixtures with LED fixtures and engaged the Remaking Cities Institute (RCI) to investigate the full range of potential benefits of a replacement program in business districts. The study team investigated the technological potentials offered by LED lighting, best management practices (BMP) in LED lighting and lessons learned from cities where LED lighting has been installed, as well as the place-making and aesthetic impact of LED lighting and associated technologies. The team also investigated issues raised by the use of LEDs as the light source and issues of replacing …


The Overhaul Of U.S. Patent Law, Ron D. Katznelson Aug 2011

The Overhaul Of U.S. Patent Law, Ron D. Katznelson

Ron D. Katznelson

No abstract provided.


Impact Of Distributed Generations On Power System Protection Performance, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari Aug 2011

Impact Of Distributed Generations On Power System Protection Performance, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari

Dr. Hadi Zayandehroodi

Though distributed generators (DGs) have significant economic and environmental benefits, increased penetration of DGs will impose significant technical barriers for the efficient and effective operation of bulk power systems. Increased fault current contribution and load flow changes are the major two impacts on utility systems, and these will affect existing protective relaying, especially overcurrent relays. To ensure safe and selective protection relay coordination, the impact of DGs should be taken into account when planning DG interconnection. This paper presents an introduction of DGs and an overview of the impacts of DGs on system protection relay coordination. Several protection issues are …


Pandaa: A Physical Arrangement Detection Technique For Networked Devices Through Ambient-Sound Awareness, Zheng Sun, Aveek Purohit, Philippe De Wagter, Irina Brinster, Chorom Hamm, Pei Zhang Aug 2011

Pandaa: A Physical Arrangement Detection Technique For Networked Devices Through Ambient-Sound Awareness, Zheng Sun, Aveek Purohit, Philippe De Wagter, Irina Brinster, Chorom Hamm, Pei Zhang

Zheng Sun

This demo presents PANDAA, a zero-configuration automatic spatial localization technique for networked devices based on ambient sound sensing. We will demonstrate that after initial placement of the devices, ambient sounds, such as human speech, music, footsteps, finger snaps, hand claps, or coughs and sneezes, can be used to autonomously resolve the spatial relative arrangement of devices, such as mobile phones, using trigonometric bounds and successive approximation.


Integrating Thermodynamic And Observed-Frequency Data For Non-Coding Rna Gene Search, Jennifer Smith, Kay Wiese Aug 2011

Integrating Thermodynamic And Observed-Frequency Data For Non-Coding Rna Gene Search, Jennifer Smith, Kay Wiese

Jennifer A. Smith

Among the most powerful and commonly used methods for finding new members of non-coding RNA gene families in genomic data are covariance models. The parameters of these models are estimated from the observed position-specific frequencies of insertions, deletions, and mutations in a multiple alignment of known non-coding RNA family members. Since the vast majority of positions in the multiple alignment have no observed changes, yet there is no reason to rule them out, some form of prior is applied to the estimate. Currently, observed-frequency priors are generated from non-family members based on model node type and child node type allowing …


Efficient Non-Coding Rna Gene Searches Through Classical And Evolutionary Methods, Jennifer Smith Aug 2011

Efficient Non-Coding Rna Gene Searches Through Classical And Evolutionary Methods, Jennifer Smith

Jennifer A. Smith

Successful non-coding RNA gene searching requires examination of long-range intramolecular base pairing possibilities. This results in search algorithms with extremely long run times such that large-scale use of the algorithms often becomes computationally infeasible. Methods for the efficient search of the solution space are examined. A review of the standard dynamic-programming covariance model search algorithm is given. An analysis of the statistically probable regions of the search space is undertaken and a method of limiting the traditional dynamic-programming algorithm to this region is shown. An alternative search method using a Genetic Algorithm (GA) which favours the probable region of the …


A Comprehensive Review Of Protection Coordination Methods In Power Distribution Systems In The Presence Of Dg, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari Aug 2011

A Comprehensive Review Of Protection Coordination Methods In Power Distribution Systems In The Presence Of Dg, Hadi Zayandehroodi, Azah Mohamed, Hussain Shareef, Marjan Mohammadjafari

Dr. Hadi Zayandehroodi

This paper presents an overview of solutions proposed in the literature for the overcurrent relay coordination problem in the presence of distributed generators (DGs). Furthermore, several protection issues are identified to study the requirements for protection in the presence of DGs, and possible innovative solutions for resolving the operational conflicts between distribution networks and DGs are also discussed.


Visualizing And Understanding Large-Scale Bayesian Networks, Michele Cossalter, Ole J. Mengshoel, Ted Selker Aug 2011

Visualizing And Understanding Large-Scale Bayesian Networks, Michele Cossalter, Ole J. Mengshoel, Ted Selker

Ole J Mengshoel

Bayesian networks are a theoretically well-founded approach to represent large multi-variate probability distributions, and have proven useful in a broad range of applications. While several software tools for visualizing and editing Bayesian networks exist, they have important weaknesses when it comes to enabling users to clearly understand and compare conditional probability tables in the context of network topology, especially in large-scale networks. This paper describes a system for improving the ability for computers to work with people to develop intelligent systems through the construction of high-performing Bayesian networks. We describe NetEx, a tool developed as a Cytoscape plugin, which allows …


Virtual Power Lab - D.E.I. Dayalbagh, D. K. Chaturvedi Dr. Aug 2011

Virtual Power Lab - D.E.I. Dayalbagh, D. K. Chaturvedi Dr.

D. K. Chaturvedi Dr.

Electrical Machines and Power systems are the back bone of electrical engineering and play a vital role in industry. Hence, it is essential for electrical engineering students to learn the concepts of power systems and machines. Unfortunately, the students are loosing interest in lab work due to various reasons like unavialability of experimental setups, lack of qualified and motivated lab staff, lab timing, etc. To overcome these problems the virtual Power labs are very important to impart quality experiments.


Software Health Management With Bayesian Networks, Ole J. Mengshoel, Johann M. Schumann Aug 2011

Software Health Management With Bayesian Networks, Ole J. Mengshoel, Johann M. Schumann

Ole J Mengshoel

No abstract provided.


Comments On "Timing Estimation And Resynchronization For Amplify-And-Forward Communication Systems”, Hani Mehrpouyan, Steven D. Blostein Aug 2011

Comments On "Timing Estimation And Resynchronization For Amplify-And-Forward Communication Systems”, Hani Mehrpouyan, Steven D. Blostein

Hani Mehrpouyan

This correspondence first shows that the Cramer-Rao lower bound (CRLB) derivations in the above paper are incorrect. In addition, contrary to the claims in the above paper, the assumptions of perfect timing offset estimation and matched-filtering at the relays affect the generality of the analytical results and cannot be justified assumption.


Emp: A Brief Tutorial, George H. Baker Iii Jul 2011

Emp: A Brief Tutorial, George H. Baker Iii

George H Baker

A nuclear detonation at altitudes from about 30 to 500 kilometers generates a strong electromagnetic pulse (EMP) that propagates to points on the ground within the line-of-sight of the burst. For bursts above 100 kilometers, electronics can be affected over continental scale areas. The EMP induces large voltages and currents in antennas and cables of electronic systems that will upset operation or damage circuit components if protection measures are not present. The article provides a brief tutorial on EMP environments, effects and protection.


High Power Electromagnetic Weapons: A Brief Tutorial, George H. Baker Iii Jul 2011

High Power Electromagnetic Weapons: A Brief Tutorial, George H. Baker Iii

George H Baker

High power electromagnetic weapons, also referred to as high power radiofrequency (HPRF) weapons, are a type of directed energy weapons. The system effects of high power electromagnetic environments are well recognized by world scientific and military communities. Former CIA Director John Deutch has said that, "the electron is the ultimate precision-guided weapon." In the course of the investigation ofnuclear EMP effects on electronics during the Cold War period, it became evident that garden variety, unprotected electronics would malfunction, in some cases burn out, in the presence of electromagnetic fields in the hundreds to thousands of volts per meter. The EMP …


Integrated Software And Sensor Health Management For Small Spacecraft, Johann Schumann, Ole J. Mengshoel, Timmy Mbaya Jul 2011

Integrated Software And Sensor Health Management For Small Spacecraft, Johann Schumann, Ole J. Mengshoel, Timmy Mbaya

Ole J Mengshoel

Despite their size, small spacecraft have highly complex architectures with many sensors and computer-controlled actuators. At the same time, size, weight, and budget constraints often dictate that small spacecraft are designed as single-string systems, which means that there are no or few redundant systems. Thus, all components, including software, must operate as reliably. Faults, if present, must be detected as early as possible to enable (usually limited) forms of mitigation. Telemetry bandwidth for such spacecraft is usually very limited. Therefore, fault detection and diagnosis must be performed on-board. Further restrictions include low computational power and small memory.

In this paper, …


Design, Modeling And Control Strategy Of Pv/Fc Hybrid Power System, Dr. Adel A. Elbaset Jul 2011

Design, Modeling And Control Strategy Of Pv/Fc Hybrid Power System, Dr. Adel A. Elbaset

Dr. Adel A. Elbaset

This paper describes development of a general methodology of an autonomous PV/FC system composed of photovoltaic (PV), electrolyzer, hydrogen storage tank and fuel cell (FC). The aim of this paper is to determine optimum design, control strategy, economic and performance of a PV/FC hybrid power generation system without battery storage taking into account all losses in the system. The paper also presents a computer program based on Matlab software to determine optimum design, control strategy, economic and performance of an autonomous PV/FC hybrid power generation system. The computer program develops to size system components in order to match the load …


Desinging Of Ann Based Speed Controller For Phase Controlled Dc Motor, R.S Naga Kumar Ganugula Jul 2011

Desinging Of Ann Based Speed Controller For Phase Controlled Dc Motor, R.S Naga Kumar Ganugula

R.S Naga Kumar Ganugula

For electrical drives good dynamic performance is mandatory so as to respond to the changes in command speed and torques, so various speed control techniques are being used for real time applications. The speed of a dc motor can be controlled using various controllers like PI- Controller, Artificial Neural Network (ANN) controller. ANN theory is recently getting increasing emphasis in process control applications. The paper describes application of ANN in a speed control system that uses a phase-controlled bridge converter and a separately excited DC machine. The ANN controller for current and speed loops are implemented in MATLAB/SIMULINK, replacing the …


Exposing To Emf, Prof Dr. Mahmoud Moghavvemi, Farhang Alijani, Hussein Ameri, Maryam Ashayer Soltani Jul 2011

Exposing To Emf, Prof Dr. Mahmoud Moghavvemi, Farhang Alijani, Hussein Ameri, Maryam Ashayer Soltani

Professor Mahmoud Moghavvemi

In the recent years, by developing the usage of new popular Electronic-Communication gadgets and home appliances like Mobile Phones and Microwave Ovens which are mostly

sources of Electromagnetic Wave Radiation, a severe public concern regarding the sideeffects “whether positive or negative” on human health and environment has been arisen. It means that there are new challenging issues rather than old one “the exposing to low radiofrequency emissions” which have been studied for past decades. Indeed, for more than 100 years, human has exposed to the Radio-waves radiation from Radio & TV broadcasting

transmitters besides the Radar and point to point …


Exposing To Emf, Mahmoud Moghavvemi, Farhang Alijani, Hossein Ameri Mahabadi, Maryami Ashayer Soltan Jul 2011

Exposing To Emf, Mahmoud Moghavvemi, Farhang Alijani, Hossein Ameri Mahabadi, Maryami Ashayer Soltan

Hossein Ameri Mahabadi

No abstract provided.


Vuv Absorption Cross Section Of Benzene, Relevance For Titan’S Atmosphere, F-J. Capalbo, Y. Bénilan, N. Fray, M. Schwell, Et. Es-Sebbar, N. Champion, T. Koskinen, R. Yelle Jul 2011

Vuv Absorption Cross Section Of Benzene, Relevance For Titan’S Atmosphere, F-J. Capalbo, Y. Bénilan, N. Fray, M. Schwell, Et. Es-Sebbar, N. Champion, T. Koskinen, R. Yelle

Dr. Et-touhami Es-sebbar

Saturn's largest satellite, Titan, is the only one in the Solar System known to have a thick N2/CH4, planet like atmosphere. The dissociation of these principal components and the recombination of the products make this atmosphere to be rich in organic compounds of high interest for astrobiology. Solar and stellar occultations observed by the Ultraviolet Imaging Spectrograph (UVIS) on board the Cassini spacecraft can be used to characterize the composition of Titan’s upper atmosphere (400 – 1400 km). The results depend strongly on the knowledge of the molecular absorption cross sections of the atmospheric constituents (Ferradaz et al. 2009). This …


Fault Classification Of Series-Compensated Transmission Lines Using Support Vector Machine, Almoataz Youssef Abdelaziz Jul 2011

Fault Classification Of Series-Compensated Transmission Lines Using Support Vector Machine, Almoataz Youssef Abdelaziz

Almoataz Youssef Abdelaziz

Recently, series compensation is widely used in transmission. However, this creates several problems to conventional protection approaches. This paper presents overcurrent protection and fault classification approach for series compensated transmission line using support vector machine (SVM). Postfault three lines current samples for half cycle are used as inputs to SVMs. The time taken for fault classification is 10 ms after the fault inception. Four SVMs are used; three SVMs (SVMa, SVMb and SVMc) are used for faulty phase detection and last SVM (SVMg) is used for ground detection. The polynomial kernel SVM is designed to provide the optimal classification conditions. …