Engineering Commons^™

Dependence Of The Performance Of Single Photon Avalanche Diodes On The Multiplication Region Width, David A. Ramirez, Majeed M. Hayat, Mark A. Itzler

Electrical and Computer Engineering Faculty Research and Publications

The dependence of the performance of separate-absorption-multiplication (SAM) single-photon avalanche diodes (SPADs) on the width of the multiplication region is theoretically investigated. The theory is applied to SAM SPADs with InP homojunction multiplication regions and InAlAs-InP heterojunction multiplication regions. In both cases the absorber layer is InGaAs. Two scenarios for the dark counts are considered: (i) low-temperature operation, when the number of dark carriers is dominated by field-assisted mechanisms of band-to-band tunneling and tunneling through defects; and (ii) room-temperature operation, when the number of dark carriers in the multiplication region is dominated by the generation/recombination mechanism. The analysis utilizes a …

A Three-Dimensional Pattern-Space Representation For Volumetric Arrays, William C. Barott, Paul G. Steffes

Publications

A three-dimensional pattern-space representation is presented for volumetric arrays. In this representation, the radiation pattern of an array is formed by the evaluation of the three-dimensional pattern-space on a spherical surface. The scan angle of the array determines the position of this surface within the pattern-space. This pattern-space representation is used in conjunction with a genetic algorithm to minimize the sidelobe levels exhibited by a thinned volumetric array during scanning.

A Reconfigurable Motor For Experimental Emulation Of Stator Winding Inter-Turn And Broken Bar Faults In Polyphase Induction Machines (Journal Article), Chia-Chou Yeh, Gennadi Y. Sizov, Ahmed Sayed-Ahmed, Nabeel Demerdash, Richard J. Povinelli, Edwin E. Yaz, Dan M. Ionel

Electrical and Computer Engineering Faculty Research and Publications

The benefits and drawbacks of a 5-hp reconfigurable induction motor, which was designed for experimental emulation of stator winding interturn and broken rotor bar faults, are presented in this paper. It was perceived that this motor had the potential of quick and easy reconfiguration to produce the desired stator and rotor faults in a variety of different fault combinations. Hence, this motor was anticipated to make a useful test bed for evaluation of the efficacy of existing and new motor fault diagnostics techniques and not the study of insulation failure mechanisms. Accordingly, it was anticipated that this reconfigurable motor would …

Estimating Risk Under Interval Uncertainty: Sequential And Parallel Algorithms, Vladik Kreinovich, Hung T. Nguyen, Songsak Sriboonchitta

Departmental Technical Reports (CS)

In traditional econometrics, the quality of an individual investment -- and of the investment portfolio -- is characterized by its expected return and its risk (variance). For an individual investment or portfolio, we can estimate the future expected return and a future risk by tracing the returns x₁, ..., x_n of this investment (and/or similar investments) over the past years, and computing the statistical characteristics based on these returns. The return (per unit investment) is defined as the selling of the corresponding financial instrument at the ends of, e.g., a one-year period, divided by the buying price …

Intelligence Techniques Are Needed To Further Enhance The Advantage Of Groups With Diversity In Problem Solving, Oscar Castillo, Patricia Melin, J. Esteban Gamez, Vladik Kreinovich, Olga Kosheleva

Departmental Technical Reports (CS)

In practice, there are many examples when the diversity in a group enhances the group's ability to solve problems -- and thus, leads to more efficient groups, firms, schools, etc. Several papers, starting with the pioneering research by Scott E. Page from the University of Michigan at Ann Arbor, provide a theoretical justification for this known empirical phenomenon. However, when the general advise of increasing diversity is transformed into simple-to-follow algorithmic rules (like quotas), the result is not always successful. In this paper, we prove that the problem of designing the most efficient group is computationally difficult (NP-hard). Thus, in …

Mathematical Justification Of Spectral/Covariance Techniques: On The Example Of Arc Detection, Jan Beck, David Nemir, Vladik Kreinovich

Departmental Technical Reports (CS)

Detecting arcing faults is an important but difficult-to-solve practical problem. Many existing methods of arc detection are based upon acquiring a signal that is proportional to current and then making an analysis of the signal's power spectrum (or, equivalently, its covariance function). Since the power spectrum, i.e., the absolute values of the Fourier transform, carries only partial information about the signal, a natural question is: why should we restrict ourselves to the use of this partial information? A related question is caused by the fact that even the most efficient methods still miss some arcing faults and/or lead to false …

Computing With Tensors: Potential Applications Of Physics-Motivated Mathematics To Computer Science, Martine Ceberio, Vladik Kreinovich

Departmental Technical Reports (CS)

In this paper, we explain what are tensors and how tensors can help in computing.

Gene Order Phylogeny Of The Genus Prochlorococcus, Haiwei Luo, Jian Shi, William Arndt, Jijun Tang, Robert Friedman

Faculty Publications

Background
Using gene order as a phylogenetic character has the potential to resolve previously unresolved species relationships. This character was used to resolve the evolutionary history within the genus Prochlorococcus, a group of marine cyanobacteria.

Methodology/Principal Findings
Orthologous gene sets and their genomic positions were identified from 12 species of Prochlorococcus and 1 outgroup species of Synechococcus. From this data, inversion and breakpoint distance-based phylogenetic trees were computed by GRAPPA and FastME. Statistical support of the resulting topology was obtained by application of a 50% jackknife resampling technique. The result was consistent and congruent with nucleotide sequence-based and gene-content based …

Ballot Mark Detection, Elisa H. Barney Smith, Daniel Lopresti, George Nagy

Electrical and Computer Engineering Faculty Publications and Presentations

Optical mark sensing, i.e., detecting whether a "bubble" has been filled in, may seem straightforward. However, on US election ballots the shape, intensity, size and position of the marks, while specified, are highly variable due to a diverse electorate. The ballots may be produced and scanned by poorly maintained equipment. Yet near-perfect results are required. To improve the current technology, which has been subject to criticism, components of a process for identifying marks on an optical sense ballot are evaluated. When marked synthetic ballots are compared to an unmarked ballot, the absolute difference of adaptive thresholded images gives best detection …

A Special-Purpose Architecture For Solving The Breakpoint Median Problem, Jason D. Bakos, Panormitis E. Elenis

Faculty Publications

In this paper, we describe the design for a co-processor for whole-genome phylogenetic reconstruction. Our current design performs a parallelized breakpoint median computation, which is an expensive component of the overall application. When implemented on a field-programmable gate array (FPGA), our hardware breakpoint median achieves a maximum speedup of 1005times over software. When the coprocessor is used to accelerate the entire reconstruction procedure, we achieve a maximum application speedup of 417times. The results in this paper suggest that FPGA-based acceleration is a promising approach for computationally expensive phylogenetic problems, in spite of the fact that the involved algorithms are based …

Improving Reversal Median Computation Using Commuting Reversals And Cycle Information, William Arndt, Jijun Tang

Faculty Publications

In the past decade, genome rearrangements have attracted increasing attention from both biologists and computer scientists as a new type of data for phylogenetic analysis. Methods for reconstructing phylogeny from genome rearrangements include distance-based methods, MCMC methods, and direct optimization methods. The latter, pioneered by Sankoff and extended with the software suites GRAPPA and MGR, is the most accurate approach, but is very limited due to the difficulty of its scoring procedure—it must solve multiple instances of the reversal median problem to compute the score of a given tree. The reversal median problem is known to be NP-hard and all …

Multi-Break Rearrangements And Breakpoint Re-Uses: From Circular To Linear Genomes, Max A. Alekseyev

Faculty Publications

Multi-break rearrangements break a genome into multiple fragments and further glue them together in a new order. While 2-break rearrangements represent standard reversals, fusions, fissions, and translocations, 3-break rearrangements represent a natural generalization of transpositions. Alekseyev and Pevzner (2007a, 2008a) studied multi-break rearrangements in circular genomes and further applied them to the analysis of chromosomal evolution in mammalian genomes. In this paper, we extend these results to the more difficult case of linear genomes. In particular, we give lower bounds for the rearrangement distance between linear genomes and for the breakpoint re-use rate as functions of the number and proportion …

A New Simplified Derivation Of Nash Bargaining Solution, Tanja Magoc, Vladik Kreinovich

Departmental Technical Reports (CS)

In the 1950s, the Nobel Prize winner John F. Nash has shown that under certain conditions, the best solution to the bargaining problem is when the product of the (increase in) utilities is the largest. Nash's derivation assumed that we are looking for strategies that assign a single situation to each bargaining situation. In this paper, we propose a simplified derivation of Nash bargaining solution that does not requires this assumption.

An Aspect-Based Approach To Checking Design Constraints At Run-Time, Yoonsik Cheon, Carmen Avila, Steve Roach, Cuauhtemoc Munoz, Neith Estrada, Valeria Fierro, Jessica Romo

Departmental Technical Reports (CS)

Design decisions and constraints of a software system can be specified precisely using a formal notation such as the Object Constraint Language (OCL). However, they are not executable, and assuring the conformance of an implementation to its design is hard. The inability of expressing design constraints in an implementation and checking them at runtime invites, among others, the problem of design drift and corrosion. We propose runtime checks as a solution to mitigate this problem. The key idea of our approach is to translate design constraints written in a formal notation such as OCL into aspects that, when applied to …

On Chromatic Numbers Of Space-Times: Open Problems, Olga Kosheleva, Vladik Kreinovich

Departmental Technical Reports (CS)

No abstract provided.

A Paradox Of Altruism: How Caring About Future Generations Can Result In Poverty For Everyone (Game-Theoretic Analysis), Tanja Magoc, Vladik Kreinovich

Departmental Technical Reports (CS)

Political and social activists are rightfully concerned about future generations: whenever a country borrows money, or an environmental situation worsens, this means, in effect, that we impose an additional burdens on future generations. There is clearly a conflict between the present generation's actions and interests and the welfare of the future generations. There exists a mathematical toolbox that provides solutions to many well-defined conflict situations: namely, the toolbox of game theory. It therefore seems reasonable to apply game theory techniques to the conflict between the generations. In this paper, we show that we need to be very cautious about this …

Viability Of Travel-Time Sensitivity Testing For Estimating Uncertainty Of Tomographic Velocity Models: A Case Study, Matthew G. Averill, Kate C. Miller, Vladik Kreinovich, Aaron A. Velasco

Departmental Technical Reports (CS)

Seismic tomography is now a common approach to estimating velocity structure of the Earth, regardless of whether the data sources are earthquake recordings or controlled sources such as explosions, airguns or Vibroseis. Seismic tomography is convenient to implement because it requires little to no a priori knowledge of Earth structure and is much less time consuming than forward modeling schemes. Despite its convenience, the method still lacks satisfactory quantitative assessments of model reliability. Here we explore the viability of applying travel-time sensitivity testing that uses a modified Cauchy distribution as its statistical foundation to assessing the uncertainty in velocity models …

Evaluating Shape Correspondence For Statistical Shape Analysis: A Benchmark Study, Brent C. Munsell, Pahal Dalal, Song Wang

Faculty Publications

This paper introduces a new benchmark study to evaluate the performance of landmark-based shape correspondence used for statistical shape analysis. Different from previous shape-correspondence evaluation methods, the proposed benchmark first generates a large set of synthetic shape instances by randomly sampling a given statistical shape model that defines a ground-truth shape space. We then run a test shape-correspondence algorithm on these synthetic shape instances to identify a set of corresponded landmarks. According to the identified corresponded landmarks, we construct a new statistical shape model, which defines a new shape space. We finally compare this new shape space against the ground-truth …

Implementing Arabic-To-English Machine Translation Using The Role And Reference Grammar Linguistic Model, Yasser Salem, Arnold Hensman, Brian Nolan

Conference Papers

This paper presents work-in-progress investigating the development of a rule-based lexical framework for Arabic language processing using the Role and Reference Grammar (RRG) linguistic model. A system, called UniArab is introduced in this research to support the framework. The paper outlines the conceptual structure of UniArab System, which utilizes the framework and translates the Arabic language into another natural language. Also, this paper explores how the characteristics of the Arabic language will effect the development of a Machine Translation (MT) tool from Arabic to English. Several distinguishing features of Arabic pertinent to MT will be explored in detail with reference …

Minimum Mean-Squared Error Estimation Of Mel-Frequency Cepstral Coefficients Using A Novel Distortion Model, Kevin M. Indrebo, Richard J. Povinelli, Michael T. Johnson

Electrical and Computer Engineering Faculty Research and Publications

In this paper, a new method for statistical estimation of Mel-frequency cepstral coefficients (MFCCs) in noisy speech signals is proposed. Previous research has shown that model-based feature domain enhancement of speech signals for use in robust speech recognition can improve recognition accuracy significantly. These methods, which typically work in the log spectral or cepstral domain, must face the high complexity of distortion models caused by the nonlinear interaction of speech and noise in these domains. In this paper, an additive cepstral distortion model (ACDM) is developed, and used with a minimum mean-squared error (MMSE) estimator for recovery of MFCC features …

Complexity Of Some Geometric Problems, Marcus Schaefer

Technical Reports

We show that recognizing intersection graphs of convex sets has the same complexity as deciding truth in the existential first-order theory of the reals. Comparing this to similar results on the rectilinear crossing number and intersection graphs of line segments, we argue that there is a need to recognize this level of complexity as its own class.

Ceg 420/620: Computer Architecture, Jack Jean

Computer Science & Engineering Syllabi

No abstract provided.

Ceg 453/653: Embedded Systems, Jack Jean

Computer Science & Engineering Syllabi

No abstract provided.

Ceg 210: Pc Networking I, Karen Meyer

Computer Science & Engineering Syllabi

Introduction to networking technologies including infrastructure and architectures, standards, protocols and directory services, administration, security and management. Integrated lecture and lab.

Ceg 433/633: Operating Systems, Prabhaker Mateti

Computer Science & Engineering Syllabi

Overview of operating systems internals. File-system usage and design, process usage and control, virtual memory, multi user systems, access control. Course projects use C++ language.

Ceg 460/660: Introduction To Software Computer Engineering, Jeffrey Mcdonald

Computer Science & Engineering Syllabi

This course is concerned with the techniques of designing and constructing large programs. Some of the required basic concepts necessarily have to be developed using small programs as examples. To this extent we also study programming-in-the-small. The overall objectives are to present an overview of issues in the development of sot1ware, to discuss terminology, to illustrate via example case studies, and to give sufficiently detailed advice on how to develop quality software. Hands-on experience is emphasized through the use of homework and a class project.

Ceg 724: Computer Vision I, Arthur A. Goshtasby

Computer Science & Engineering Syllabi

This course covers basic techniques for low-level and some mid-level vision. The techniques include: camera calibration, image filtering and edge detection, image segmentation and feature selection, and stereo depth perception.

Ceg 436/636: Mobile Computing, Yong Pei

Computer Science & Engineering Syllabi

Increasingly.. people, computers and microelectronic devices are being linked together to bring to life the communications mantra: anybody, anything, anytime, anywhere. This junior/senior/graduate course provides an in-depth study of networking protocol and system design in the area of wireless networking and mobile computing. It will help engineering and computer science students establish a solid foundation in concepts, architecture, design, and performance evaluation of mobile computing principle, protocols and applications. It will also introduce students to a few hot topics in wireless networking and mobile computing research such as mobile IP, wireless TCP, 802. l l, agent techniques, etc. The course …

Ceg 221: Advanced C Programming For Engineers, Robert Helt

Computer Science & Engineering Syllabi

This course introduces advanced constructs, algorithms, and data structures in the C programming language. Emphasis is on problem solving and techniques useful to engineers. Topics include functions, array, pointers, structures as well as sorting algorithms, linked lists, complex numbers, stacks, queues, hash tables, and binary trees.

Ceg 220: Introduction To C Programming For Engineers I, Jay Dejongh

Computer Science & Engineering Syllabi

This course provides a general introduction to computers as a problem-solving tool using the C programming language. Emphasis is on algorithms and techniques useful to engineers. Topics include data representation, debugging, and program verification. 4 credit hours. Prerequisite: MTH 229 (Calculus I) or EGR 101 (Engineering Mathematics).