Engineering Commons^™

Spatiotemporal Databases: Models For Attracting Students To Research, Ágnes Bércesné Novák, Peter Revesz, Zsolt Tuza

CSE Conference and Workshop Papers

In higher education professors often make much effort to introduce their students to research. Unfortunately, the present standard database systems curriculum is composed of well-settled subjects that do not lead to research. The challenge is to bring the research frontier closer to students at beginner level. In this paper we describe how it can be done in the area of spatiotemporal databases. We propose a new database systems curriculum and illustrate its benefits by mentioning several highly succsesful student projects in some recent experimental introductory database systems courses that followed the new curriculum.

Optical System With 1xn Interleaver And Methods Of Making And Using Same, Michael A. Scobey, Lucien P. Ghislain, Dennis J. Derickson, Loren F. Stokes

Electrical Engineering

An optical system and method are disclosed for multiplexing or de-multiplexing channels within a wavelength band. The optical signals carried on the system comprise separate channels 1 through n, each having a unique passband and a center wavelength spaced from the center wavelength of adjacent channels by d nm. The signals are semi-multiplexed, demultiplexed, or semi-demultiplexed by an interleaver comprising optically matched and directly optically coupled etalons. Periodic spectral passbands of width less than d nm, spaced from each other a distance of zd, where z is an integer greater than or equal to 3, are substantially transmitted through the …

Automated Casting Cleaning, Chris Anderson

Graduate Research Papers

The dilemma facing all foundries today is finding a cost effective, efficient, and safe manner in which to clean castings. At the same time produce a cleaned casting that meets consistent quality and delivery expectations. Today nearly 90% of all casting produced are cleaned by the use of manual labor via chipping an grinding. This manual method has proved to be very labor intensive, costly, lacking consistent quality, and carry high rates of injuries. The use of automation to clean castings is in its embryo stage in the foundry industry. The use of automation in the foundry industry, products currently …

Uml Extensions For Real-Time Control Systems, Qimin Gao, Lyndon Brown, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

The use of object oriented techniques and methodologies for the design of real-time control systems appears to be necessary in order to deal with the increasing complexity of such systems. Recently many object-oriented methods have been used for the modeling and design of real-time control systems. We believe that an approach that integrates the advancements in both object modeling and design methods, and real-time scheduling theory is the key to successful use of object oriented technology for real-time software. Surprisingly several past approaches to integrate the two either restrict the object models, or do not allow sophisticated schedulability analysis techniques. …

Viewing The Learning Process: Assessment Via Usability Testing, Vicki M. Eller, Steve Eugene Watkins, Richard H. Hall

Business and Information Technology Faculty Research & Creative Works

Learning through Computer-Based Activities Provides a Multi-Modal Approach in Which the User Can Select the Educational Media and Process. Effective Development of These Activities Requires an Understanding of User Interactivity. Traditional Assessment, Such as Test Scores and Subjective Surveys, Looks at End Results and Attitudes. This Method Does Not Monitor the Learning Process. in Particular Developer Needs to Accommodate Diverse Usage Preferences and Choices. Hence, Assessment Should Involve Usability Measures that Are Quantitative and Qualitative. Usability Testing Records Usage Patterns and User Reactions. a Usability Laboratory Was Created at the University of Missouri-Rolla. It is Supplements the Traditional Assessment for …

Energy Efficient Routing Protocols For Mobile Ad Hoc Networks, Chansu Yu, Ben Lee, Hee Yong Youn

Electrical and Computer Engineering Faculty Publications

Although establishing correct and efficient routes is an important design issue in mobile ad hoc networks (MANETs), a more challenging goal is to provide energy efficient routes because mobile nodes' operation time is the most critical limiting factor. This article surveys and classifies the energy-aware routing protocols proposed for MANETs. They minimize either the active communication energy required to transmit or receive packets or the inactive energy consumed when a mobile node stays idle but listens to the wireless medium for any possible communication requests from other nodes. Transmission power control approach and load distribution approach belong to the former …

Modeling And Analysis Of Soft-Test/Repair For Ccd-Based Digital X-Ray Systems, Byoungjae Jin, Nohpill Park, Koshy M. George, Minsu Choi, Mark B. Yeary

Electrical and Computer Engineering Faculty Research & Creative Works

Modern X-ray imaging systems evolve toward digitization for reduced cost, faster time-to-diagnosis, and improved diagnostic confidence. For the digital X-ray systems, charge coupled device (CCD) technology is commonly used to detect and digitize optical X-ray image. This paper presents a novel soft-test/repair approach to overcome the defective pixel problem in CCD-based digital X-ray systems through theoretical modeling and analysis of the test/repair process. There are two possible solutions to cope with the defective pixel problem in CCDs: one is the hard-repair approach and another is the proposed soft-test/repair approach. Hard-repair approach employs a high-yield, expensive reparable CCD to minimize the …

Parallel Microgenetic Algorithm Design For Photonic Crystal And Waveguide Structures, J. Cai, L. Li, Gregory P. Nordin, J. Jiang

Faculty Publications

We have developed a powerful parallel genetic algorithm design tool for photonic crystal and waveguide structures. The tool employs a small-population-size genetic algorithm (microgenetic algorithm) for global optimization and a two-dimensional finite-difference time-domain method to rigorously design and optimize the performance of photonic devices. We discuss the implementation and performance of this design tool. We demonstrate its application to two photonic devices, a defect taper coupler to connect conventional waveguides and photonic crystal waveguides, and a sharp 90˚ waveguide bend for low index contrast waveguides.

Ultracompact High-Efficiency Polarizing Beam Splitter With A Hybrid Photonic Crystal And Conventional Waveguide Structure, J. Cai, S. Kim, Gregory P. Nordin, J. Jiang

Faculty Publications

We propose an ultracompact high-efficiency polarizing beam splitter that operates over a wide wavelength range and is based on a hybrid photonic crystal and a conventional waveguide structure. Within a small area (15 mm 3 10 mm), this polarizing beam splitter separates TM- and TE-polarized modes into orthogonal output waveguides. Results of simulations with the two-dimensional finite-difference time-domain method show that 99.3% of TM-polarized light is def lected by the photonic crystal structure (with a 28.0-dB extinction ratio), whereas 99.0% of TE-polarized light propagates through the structure (with a 32.2-dB extinction ratio). Wave vector diagrams are employed to explain the …

Multiple Uav Cooperative Search Under Collision Avoidance And Limited Range Communication Constraints, Randal W. Beard, Timothy W. Mclain

Faculty Publications

This paper focuses on the problem of cooperatively searching, using a team of unmanned air vehicles (UAVs), an area of interest that contains regions of opportunity and regions of potential hazard. The objective of the UAV team is to visit as many opportunities as possible, while avoiding as many hazards as possible. To enable cooperation, the UAVs are constrained to stay within communication range of one another. Collision avoidance is also required. Algorithms for team-optimal and individually-optimal/team-suboptimal solutions are developed and their computational complexity compared. Simulation results demonstrating the feasibility of the cooperative search algorithms are presented.

Extended Hough Methodology For 3d Feature Detection, Rufus H. Cofer, Samuel Peter Kozaitis, Jihun Cha

Electrical Engineering and Computer Science Faculty Publications

In an effort to make automatically detect image features for pattern recognition, we described a 3-dimensional (3-D) Hough transform. We describe two interlocking theoretical extensions to greatly enhance the Hough transform's ability to handle finite lineal features and allow directed search for various features while balancing memory and computational complexity. We computed the 2-D Hough transform of 1-D slices of an image which results in a 2-D to 3-D transform. Features such as line segments will cluster in a particular location so that both line orientation and spatial extent can be determined. This approach allows the Hough transform to be …

Riser Design For Green Sand And Ductile Iron Castings, K. Michael Kuebler

Graduate Research Papers

Shrinkage defects in ductile iron riser contacts has long been one of the most frustrating defects to eliminate for the foundry engineer. While process variation can definitively contribute to the occurrence of these defects most can be prevented if the risers are properly designed and/or applied to the castings to be fed. There are several proven methods for the designing risers some of which go back over 40 years ago. There are also new methods available today with the advancements of simulation software. Four of these riser design methods were evaluated for their ability to produce an internally sound casting …

Preliminary Assessment Of Experimental Sophomore Ee Courses, James G. Harris, Kena Burke

Electrical Engineering

In academic year 2001-2002, an experimental yearlong sequence of courses was taught to EE and CPE majors that replaced the traditional circuits and electronics sequence of required courses. The experimental sequence consisted of three quarters, with the first quarter devoted to digital signal processing, and the next two quarters formed from an integrated approach to circuits and electronics. The two sections of students who took the experimental course now are taking the junior year required courses in their major. An assessment is being made to compare the experimental students with a cohort of traditional students. Preliminary results are given for …

Double-Scaled Potential Profile In A Group-Iii Nitride Alloy Revealed By Monte Carlo Simulation Of Exciton Hopping, K. Kazlauskas, G. Tamulaitis, A. Zukauskas, M. A. Khan, J. W. Yang, J. Zhang, Grigory Simin, M. S. Shur, R. Gaska

Faculty Publications

The temperature dependences of the peak position and width of the photoluminescence band in Al_0.1In_0.01Ga_0.89N layers were explained by Monte Carlo simulation of exciton localization and hopping. The introduction of a doubled-scaled potential profile due to inhomogeneous distribution of indium allowed obtaining a good quantitative fit of the experimental data. Hopping of excitons was assumed to occur through localized states distributed on a 16 meV energy scale within the In-rich clusters with the average energy in these clusters dispersed on a larger (42 meV) scale.

Oci-Based Group Communication Support In Corba, Dongman Lee, Dukyun Nam, Hee Yong Youn, Chansu Yu

Electrical and Computer Engineering Faculty Publications

Group communication is a useful mechanism guaranteeing consistency among replicated objects. The existing approaches do not allow transparent plug-in of group communication protocols into CORBA. They either require modification of CORBA or OS, or provide no room for incorporating group communication transport protocols into CORBA. We thus propose a generic group communication framework that allows transparent plug-in of various group communication protocols with no modification of existing CORBA. We extend the open communications interface (OCI) to support interoperability, reusability of existing group communication, and independency on ORB and OS. We also define the group communication inter-ORB protocol (GCIOP) as a …

Design And Characterization Of Null Convention Self-Timed Multipliers, Satish K. Bandapati, Scott C. Smith, Minsu Choi

Electrical and Computer Engineering Faculty Research & Creative Works

Self-timed multipliers, designed using the delay-insensitive null convention logic (NCL) paradigm, were analyzed. NCL require less power, generate less noise, produce less electromagnetic interference, and allow easier reuse of components. Simulation results show a large variance in circuit performance in terms of power, area, and speed. NCL paradigm also represent bit-serial, iterative, and fully parallel multiplication architectures. They reduce the effort required to ensure correct operation under all timing scenarios, compared to equivalent synchronous designs.

Melanoma And Seborrheic Keratosis Differentiation Using Texture Features, Srinivas V. Deshabhoina, Scott E. Umbaugh, William V. Stoecker, Randy Hays Moss, Subhashini K. Srinivasan

Chemistry Faculty Research & Creative Works

Purpose: To explore texture features in two-dimensional images to differentiate seborrheic keratosis from melanoma.

Methods: A systematic approach to consistent classification of skin tumors is described. Texture features, based on the second-order histogram, were used to identify the features or a combination of features that could consistently differentiate a malignant skin tumor (melanoma) from a benign one (seborrheic keratosis). Two hundred and seventy-one skin tumor images were separated into training and test sets for accuracy and consistency. Automatic induction was applied to generate classification rules. Data analysis and modeling tools were used to gain further insight into the feature space. …

A Four-Level Crossing Dc/Dc Converter Based Drive System, X. Kou, Keith Corzine

Electrical and Computer Engineering Faculty Research & Creative Works

This paper introduces a novel crossing front-end dc/dc converter for a four-level drive system which provides a voltage boost as well as dc capacitor bank voltage regulation. The primary advantage of the proposed converter is that it simplifies the control of the four-level diode-clamped inverter since capacitor voltage balancing is not required by the inverter control. Furthermore, the inverter modulation index can be varied up to its physical limitation. An average-value model of the converter is derived and used for insight and analysis of the converter operation. Detailed simulations of the four-level drive system demonstrate the effectiveness of the proposed …

Kalman Filtering For Fuzzy Discrete Time Dynamic Systems, Daniel J. Simon

Electrical and Computer Engineering Faculty Publications

This paper uses Kalman filter theory to design a state estimator for noisy discrete time Takagi–Sugeno (T–S) fuzzy models. One local filter is designed for each local linear model using standard Kalman filter theory. Steady state solutions can be found for each of the local filters. Then a linear combination of the local filters is used to derive a global filter. The local filters are time-invariant, which greatly reduces the computational complexity of the global filter. The global filter is shown to be unbiased and (under certain conditions) stable. In addition, under the approximation of uncorrelatedness among the local models, …

Synergetic Control For Dc-Dc Boost Converter: Implementation Options, Enrico Santi, Antonello Monti, Donghong Li, Karthik Proddutur, Roger A. Dougal

Faculty Publications

The theory of synergetic control was introduced in a power electronics context in a previous paper. In this paper, we review the theory, then focus on some practical aspects with reference to both simulations and actual hardware. In particular, we address management of the current limit condition and solve it with several different approaches. Adaptive and other control laws are also introduced to improve the control performance. The various controls are evaluated by applying the classical voltage reference step test and the step load test.

An Improved Simulation Model For Spaceborne Scatterometer Measurements, David G. Long, Peter K. Yoho

Faculty Publications

Development of scatterometer designs and applications requires extensive data simulation. The advancing capabilities of instruments motivates our proposal for an improved simulation model for noisy scatterometer measurements. Previous simulation models do not separately account for the two forms of random variation - signal fading and additive noise - which affect scatterometer measurements. The proposed model is able to generate data that are statistically equivalent (in a mean and variance sense) to actual instrument measurements by accounting for both variations, while maintaining ease of implementation. The model is particularly adept at handling design tradeoffs related to signal-to-noise ratios by appropriately separating …

Vector Dissipativity Theory For Discrete-Time Large-Scale Nonlinear Dynamical Systems, Wassim M. Haddad, Qing Hui, Vijaysekhar Chellaboina, Sergey Nersesov

Department of Electrical and Computer Engineering: Faculty Publications

In analyzing large-scale systems, it is often desirable to treat the overall system as a collection of interconnected subsystems. Solution properties of the large-scale system are then deduced from the solution properties of the individual subsystems and the nature of the system interconnections. In this paper, we develop an analysis framework for discrete-time large-scale dynamical systems based on vector dissipativity notions. Specifically, using vector storage functions and vector supply rates, dissipativity properties of the discrete-time composite large-scale system are shown to be determined from the dissipativity properties of the subsystems and their interconnections. In particular, extended Kalman-Yakubovich-Popov conditions, in terms …

Modified Diamond Dipole Antenna For Ultra Wideband Communications Using Finite Difference Time Domain Method, Srinivas Desamsetty

FIU Electronic Theses and Dissertations

The aim of this thesis is to analyze and design ultra wideband antennas for personal communication devices using Finite Difference Time Domain (FDTD) method. Initially diamond dipole, an ultra wideband antenna is selected from the literature and analyzed. The shape of the diamond dipole is modified in such a way that the straight-line base of the two triangular arms (near the feed) is replaced with an arc. The resulting antenna is named as modified diamond dipole. Performance is observed by varying radius of curvature of base of triangular arms (for constant flare angle) and by varying flare angle (for constant …

Hgcdte Focal Plane Array Cost Modeling, Thomas J. Sanders, Glenn T. Hess

Electrical Engineering and Computer Science Faculty Publications

Focal plane arrays (FPAs) are used in many applications for detecting infrared (IR) radiation where normal sight with light in the visible spectrum is not possible. To effectively detect this IR radiation, complex semiconductor diodes, cooled to low temperatures, are usually used. The most common of these semiconductor materials is the II-VI alloy semiconductor system using HgCdTe, which is often called MCT. Focal plane arrays with over 1000 pixels have been fabricated. The cost of these very complex systems is becoming a very important consideration in decisions of where to use these FPAs. The focal plane array actually consists of …

Polyphase Filter With Low-Pass Response, Vladimir I. Prodanov, Peter Kiss, Mihai Banu

Electrical Engineering

A complex low-pass filter that reduces the influence of component mismatch. The filter includes a first filter section for effecting a first single pole transfer function and a second filter section for effecting a second single pole transfer function, where the first and the second single pole transfer functions collectively define a conjugate pair of poles. In higher order low-pass filters, an optimal cascade order follows a shoestring pattern.

Modeling, Fabrication, And Optimization Of Niobium Cavities: Phase Iii Quarterly Report, Robert A. Schill Jr., Mohamed Trabia

Transmutation Sciences Materials (TRP)

Niobium cavities are important parts of the integrated NC/SC high-power linacs. Over the years, researchers in several countries have tested various cavity shapes. They concluded that elliptically shaped cells are the most appropriate shape for superconducting cavities. The need for very clean surfaces lead to the use of a buffered chemical polishing produce for surface cleaning to get good performance of the cavities. The third phase concludes the experimental a fluid flow study and optimization study. The first quarter and second quarter of phase three also begins the experimental set-up of secondary emission studies from niobium in superconducting mode. This …

The Effect Of Pruning And Compression On Graphical Representations Of The Output Of A Speech Recognizer, Yang Liu, Mary P. Harper, Michael T. Johnson, Leah H. Jamieson

Electrical and Computer Engineering Faculty Research and Publications

Large vocabulary continuous speech recognition can benefit from an efficient data structure for representing a large number of acoustic hypotheses compactly. Word graphs or lattices have been chosen as such an efficient interface between acoustic recognition engines and subsequent language processing modules. This paper first investigates the effect of pruning during acoustic decoding on the quality of word lattices and shows that by combining different pruning options (at the model level and word level), we can obtain word lattices with comparable accuracy to the original lattices and a manageable size. In order to use the word lattices as the input …

Combined Beamforming And Space-Time Block Coding With Sparse Array Antennas, Robert H. Morelos-Zaragoza, Mohammad Ghavami

Faculty Publications

No abstract provided.

Examination Of Focused Beam Propagation Through A Finite Non-Reciprocal Planar Chiral Slab Using Complex Fresnel Coefficients And Dual Transforms, Monish Ranjan Chatterjee, Sumit Nema, Partha P. Banerjee

Electrical and Computer Engineering Faculty Publications

Recently, uniform plane wave propagation across a nonchiral-chiral interface was examined via the development of appropriate Fresnel coefficients. In this extension, propagation of focused uniform and profiled beams through a finite, planar nonreciprocal chiral slab is investigated using complex Fresnel coefficients via angular plane wave decomposition and dual transforms.

Statistical Approach To The Emi Modeling Of Large Asics By A Single Noise-Current Source, Giulio Antonini, James L. Drewniak, Marco Leone, Antonio Orlandi, Vittorio Ricchiuti

Electrical and Computer Engineering Faculty Research & Creative Works

Large and complex ASICs are source of propagating noise inside the powerbus planes. A lumped noise source model is proposed and validated by means of a statistics based method.