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Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 18, Number 5, February 2002, 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.

Process Composition: Quality Of Service Specification, Semantics And Adaptation, Jorge Cardoso, Amit P. Sheth

Kno.e.sis Publications

No abstract provided.

Production Of Nitrogen Acceptors In Zno By Thermal Annealing, N. Y. Garces, N. C. Giles, L. E. Halliburton, G. Cantwell, D. B. Eason, D. C. Reynolds, David C. Look

Physics Faculty Publications

Nitrogen acceptors are formed when undoped single crystals of zinc oxide (ZnO) grown by the chemical-vapor transport method are annealed in air or nitrogen atmosphere at temperatures between 600 and 900 °C. After an anneal, an induced near-edge absorption band causes the crystals to appear yellow. Also, the concentration of neutral shallow donors, as monitored by electron paramagnetic resonance (EPR), is significantly reduced. A photoinduced EPR signal due to neutral nitrogen acceptors is observed when the annealed crystals are exposed to laser light (e.g., 364, 442, 458, or 514 nm) at low temperature. The nitrogens are initially in the nonparamagnetic …

Electrical Characterization Of Vapor-Phase-Grown Single-Crystal Zno, F. D. Auret, S. A. Goodman, M. J. Legodi, W. E. Meyer, David C. Look

Physics Faculty Publications

Gold Schottky-barrier diodes (SBDs) were fabricated on vapor-phase-grown single-crystal ZnO. Deep-level transient spectroscopy, using these SBDs, revealed the presence of four electron traps, the major two having levels at 0.12 eV and 0.57 below the conduction band. Comparison with temperature-dependent Hall measurements suggests that the 0.12 eV level has a temperature activated capture cross section with a capture barrier of about 0.06 eV and that it may significantly contribute to the free-carrier density. Based on the concentrations of defects other than this shallow donor, we conclude that the quality of the vapor-phase-grown ZnO studied here supercedes that of other single-crystal …

Xml-Based Modeling And Simulation: Web Service Technologies And Their Synergy With Simulation, Senthilanand Chandrasekaran, Gregory S. Silver, John A. Miller, Jorge Cardoso, Amit P. Sheth

Kno.e.sis Publications

The World Wide Web has had an huge influence on the computing field in general as well as simulation in particular (e.g., Web-based simulation). A new wave of development based upon XML has started. Two of the most interesting aspects of this development are the Semantic Web and Web services. This paper examines the synergy between Web service technology and simulation. In one direction, Web service processes can be simulated for the purpose of correcting/improving the design. In the other direction, simulation models/components can be built out of Web services. Work on seamlessly using simulation as a part of Web …

Predicting Oral Reading Miscues, Jack Mostow, Joseph Beck, S. Vanessa Winter, Shaojun Wang

Kno.e.sis Publications

This paper explores the problem of predicting specific reading mistakes, called miscues, on a given word. Characterizing likely miscues tells an automated reading tutor what to anticipate, detect, and remediate. As training and test data, we use a database of over 100,000 miscues transcribed by University of Colorado researchers. We explore approaches that exploit different sources of predictive power: the uneven distribution of words in text, and the fact that most miscues are real words. We compare the approaches’ ability to predict miscues of other readers on other text. A simple rote method does best on the most frequent 100 …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 18, Number 4, January 2002, 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.

Towards Nonmonotonic Reasoning On Hierarchical Knowledge, Pascal Hitzler

Computer Science and Engineering Faculty Publications

W.C. Rounds and G.Q. Zhang have recently proposed to study a form of disjunctive logic programming generalized to algebraic domains [RZ01]. This system allows reasoning with information which is hierarchically structured and forms a (suitable) domain. We extend this framework to include reasoning with negative information, i.e. the implicit or explicit absence of bits of information. These investigations will naturally lead to a form of default reasoning which is strongly related to programming with answer sets to stable models, which has recently created much interest amongst artificial intelligence researchers concerned with knowledge representation and reasoning.

Ilp Operators For Propositional Connectionist Networks, Miguel Angel Gutierrez-Naranjo, Pascal Hitzler

Computer Science and Engineering Faculty Publications

No abstract provided.

Closed Streamlines In Flow Visualization, Thomas Wischgoll

Computer Science and Engineering Faculty Publications

Vector Fields occur in many of the problems in science and engineering. In combustion processes for instance, vector fields describe the flow of the gas. This process can be enhanced using vector field visualization techniques. Also wind tunnel experiments can be analyzed. An example is the design of an air wing. The wing can be optimized to crate a smoother flow around it. Vector field visualization methods help the engineer to detect critical features of the flow. Consequently, feature detection methods gained great importance during the last years.

Topological methods are often used to visualize vector fields because they clearly …

On The Regularity Of Solutions To Fully Nonlinear Elliptic Equations Via The Liouville Property, Qingbo Huang

Mathematics and Statistics Faculty Publications

We show that any C^1,1 solution to the uniformly elliptic equation F(D²u) = 0 must belong to C^2,α, if the equation has the Liouville property.

Domain Functionals And Exit Times For Brownian Motion, Chaocheng Huang, David Miller

Mathematics and Statistics Faculty Publications

Two domain functionals describing the averaged expectation of exit times and averaged variance of exit times of Brownian motion from a domain, respectively, are studied.

Absolutely Continuous Jacobi Operators, Steen Pedersen

Mathematics and Statistics Faculty Publications

No abstract provided.

Donor And Acceptor Concentrations In Degenerate Inn, David C. Look, H. Lu, William J. Schaff, J. Jasinski, Z. Liliental-Weber

Physics Faculty Publications

A formalism is presented to determine donor (N_D) and acceptor (N_A) concentrations in wurtzitic InN characterized by degenerate carrier concentration (n) and mobility (μ). The theory includes scattering not only by charged point defects and impurities, but also by charged threading dislocations, of concentration N_dis. For a 0.45-μm-thick InN layer grown on Al₂O₃ by molecular beam epitaxy, having N_dis = 5×10¹⁰ cm⁻², determined by transmission electron microscopy, n(20 K) = 3.5×10¹⁸ cm⁻³ and μ(20 K) = 1055 cm^{2 …}

The Fixed-Point Theorems Of Priess-Crampe And Ribenboim In Logic Programming, Pascal Hitzler, Anthony K. Seda

Computer Science and Engineering Faculty Publications

Sibylla Priess-Crampe and Paulo Ribenboim recently established a general fixed-point theorem for multivalued mappings defined on generalized ultrametric spaces, and introduced it to the area of logic programming semantics. We discuss, in this context, the applications which have been made so far of this theorem and of its corollaries. In particular, we will relate these results to Scott-Ershov domains, familiar in programming language semantics, and to the generalized metrics of Khamsi, Kreinovich, and Misane which have been applied, by these latter authors, to logic programming. Amongst other things, we will also show that a unified treatment of the fixed-point theory …

Characterizing Logic Programming Semantics With Level Mappings, Pascal Hitzler, Matthias Wendt

Computer Science and Engineering Faculty Publications

Declarative semantics in logic programming and nonmonotonic reasoning are often defined via fixed points of semantic operators. While many relationships between different semantics known from the literature have been studied, a uniform treatment is still missing. In this paper, we provide uniform operator-free characterizations for some of the most important semantics, more precisely, for the stable, the well-founded, and the Fitting semantics, for the weakly-perfect model semantics, and for the least model semantics for negation-free programs.

High Spatial Resolution Thermal Conductivity Of Bulk Zno (0001), Diana I. Florescu, L. G. Mourokh, Fred H. Pollak, David C. Look, G. Cantwell, X. Li

Physics Faculty Publications

We measured high spatial/depth resolution 300 K thermal conductivity κ of the Zn and O surfaces of two bulk n-type ZnO (0001) samples, grown by a vapor-phase transport method, using scanning thermal microscopy (SThM). The thermal investigation was performed in both point-by-point (∼2 μm resolution) and area-scan modes. On the first sample κ=1.16±0.08 (Zn face)/1.10±0.09 (O face) W/cm K while for the second material κ=1.02±0.07 (Zn face)/0.98±0.08 (O face) W/cm K. These are the highest κ values reported on ZnO. A correlation between SThM area-scan readings and surface topography was established by simultaneously performing atomic force microscopy scans. The …

The Latent Maximum Entropy Principle, Shaojun Wang, Ronald Rosenfeld, Yunxin Zhao, Dale Schuurmans

Kno.e.sis Publications

We present an extension of Jaynes' maximum entropy principle to handle latent variables. We use an EM algorithm that incorporates nested iterative scaling to approximately calculate maximum entropy solutions for this principle, and give a proof of its convergence.

Multi-Dimensional Regression Analysis Of Time-Series Data Streams, Yixin Chen, Guozhu Dong, Jiawei Han, Benjamin W. Wah, Jianyong Wang

Kno.e.sis Publications

Real-time production systems and other dynamic environments often generate tremendous (potentially infinite) amount of stream data; the volume of data is too huge to be stored on disks or scanned multiple times. Can we perform on-line, multi-dimensional analysis and data mining of such data to alert people about dramatic changes of situations and to initiate timely, high-quality responses? This is a challenging task.

In this paper, we investigate methods for online, multi-dimensional regression analysis of time-series stream data, with the following contributions: (1) our analysis shows that only a small number of compressed regression measures instead of the complete stream …

Managing Semantic Content For The Web, Amit P. Sheth, Clemens Bertram, David Avant, Brian Hammond, Krzysztof Kochut, Yashodhan Warke

Kno.e.sis Publications

By associating meaning with content, the Semantic Web will facilitate search, interoperability, and the composition of complex applications. A recent Scientific American article described the Semantic Web as 'an extension of the current Web in which information is given well-defined meaning, better enabling computers and people to work in cooperation.' Not long ago, researchers at a Stanford University symposium predicted that this second phase of the Web would be as revolutionary as the Web itself.

Authorization And Access Control Of Application Data In Workflow Systems, Shengli Wu, Amit P. Sheth, John A. Miller, Zongwei Luo

Kno.e.sis Publications

Workflow Management Systems (WfMSs) are used to support the modeling and coordinated execution of business processes within an organization or across organizational boundaries. Although some research efforts have addressed requirements for authorization and access control for workflow systems, little attention has been paid to the requirements as they apply to application data accessed or managed by WfMSs. In this paper, we discuss key access control requirements for application data in workflow applications using examples from the healthcare domain, introduce a classification of application data used in workflow systems by analyzing their sources, and then propose a comprehensive data authorization and …

Workflow Quality Of Service, Jorge Cardoso, Amit P. Sheth, John A. Miller

Kno.e.sis Publications

Workflow management systems (WfMSs) have been used to support various types of business processes for more than a decade now. In ecommerce processes, suppliers and customers define a binding agreement or contract between the two parties, specifying quality of service (QoS) items such as products or services to be delivered, deadlines, quality of products, and cost of service. Management of such QoS directly impacts success of organizations participating in e-commerce. Organizations operating in modern markets require an excellent degree of quality of service management. Products and services must be available to customers with well-defined specifications. A good management of quality …

A Proposed Undergraduate Bioinformatics Curriculum For Computer Scientists, Travis E. Doom, Michael L. Raymer, Dan E. Krane, Oscar Garcia

Kno.e.sis Publications

Bioinformatics is a new and rapidly evolving discipline that has emerged from the fields of experimental molecular biology and biochemistry, and from the the artificial intelligence, database, and algorithms disciplines of computer science. Largely because of the inherently interdisciplinary nature of bioinformatics research, academia has been slow to respond to strong industry and government demands for trained scientists to develop and apply novel bioinformatics techniques to the rapidly-growing, freely-available repositories of genetic and proteomic data. While some institutions are responding to this demand by establishing graduate programs in bioinformatics, the entrance barriers for these programs are high, largely due to …

Selected Synthetic Studies Of Nlo Pi-Bridges And Thermally Stable Monomers, Stacey Marie Fauley

Browse all Theses and Dissertations

The molecular weights of two series of PEEK polymers were determined using gel permeation chromatography (GPC). The first series contains oxyalkylene linkages. The other series contains oxyethylene linkages. The synthesis of several thermally stable monomers has been investigated. These monomers include 9,9-dihexylfluorene-2,7-dicarboxaldehyde, 2,7-bis(bromomethyl)-9,9- dibutylfluorene and 2,7-bis(hydroxymethyl)-9,9-diethylfluorene. These monomers can be used to form polymers that will contain short conjugated segments separated by nonconjugated segments. The synthesis of 50 g of each of the following monomers was accomplished: bis(3-methylphenyl) phenylphosphine oxide, bis(4-methylphenyl)phenylphosphine oxide, bis(3- carboxyphenyl)phenylphosphine oxide and bis(4-carboxyphenyl)phenylphosphine oxide. These monomers will be used in a polymerization to form polybenzoxazoles. The …

The Synthesis Of Bromoethoxy And Vinylbenzyloxy Substituted Nlo Chromophores, Michael Joseph Matuszewski

Browse all Theses and Dissertations

Multiphoton-absorption processes have recently attracted growing interest because of the potential impact on a wide spectrum of applications, ranging from data storage to photodynamic therapy. From the materials standpoint, particular interest is centered in designing chromophores that exhibit a large two-photon cross-section. The current research is focused on establishing synthetic routes that lead to the formation of derivatives of N,N-diphenyl-(7-benzothiazol-2-yl)-9,9-diethyl-9H-fluoren-2-ylamine which contain meta functionalization. A bromoethoxy functionalized chromophore, N-phenyl-N-(3-(2-bromoethoxy)phenyl)-7-(benzothiazol-2-yl)-9,9-diethyl-9H-fluoren- 2-ylamine , was synthesized and used as a polymer pendent while a vinylbenzyloxy chromophore, N-phenyl-N-(3-(4-vinylbenzyloxy)phenyl)-7- (benzothiazol-2-yl)-9,9-diethyl-9H-fluoren-2-ylamine, was synthesized as a hydrosilation substrate. A compound containing three chromophores, 1,3,5-tris(3-(N-phenyl- 4-(7-(benzothiazol-2-yl)-9,9-diethyl-9H-fluoren-2- ylanilino)phenoxymethyl)benzene, has …

Polariton And Free-Exciton-Like Photoluminescence In Zno, D. C. Reynolds, David C. Look, B. Jogai, T. C. Collins

Physics Faculty Publications

An unusual photoluminescence line X has been observed in ZnO at an energy between that of the common donor-bound excitons (DBEs) and the free excitons (FEs). In the presence of a high carrier concentration, induced by a second below-band gap laser, the DBEs decrease in intensity, due to screening, and both the FEs and X increase. Thus, X has free-exciton, rather than bound-exciton, character. However, its electric-field vector lies in the plane perpendicular to the c axis, as is also found for the DBEs. The appearance of X is discussed in terms of the polariton picture.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 18, Number 3, November 2001, 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.

Thermal Stability Of Isolated And Complexed Ga Vacancies In Gan Bulk Crystals, K. Saarinen, T. Suski, I. Grzegory, David C. Look

Physics Faculty Publications

We have applied positron annihilation spectroscopy to show that 2-MeV electron irradiation at 300 K creates primary Ga vacancies in GaN with an introduction rate of 1 cm^-1. The Ga vacancies recover in long-range migration processes at 500–600 K with an estimated migration energy of 1.5 (2) eV. Since the native Ga vacancies in as-grown GaN survive up to much higher temperatures (1300–1500 K), we conclude that they are stabilized by forming complexes with oxygen impurities. The estimated binding energy of 2.2 (4) eV of such complexes is in good agreement with the results of theoretical calculations.

Electrical Characterization Of 1.8 Mev Proton-Bombarded Zno, F. D. Auret, S. A. Goodman, M. Hayes, M. J. Legodi, H. A. Van Laarhoven, David C. Look

Physics Faculty Publications

We report on the electrical characterization of single-crystal ZnO and Au Schottky contacts formed thereon before and after bombarding them with 1.8 MeV protons. From capacitance–voltage measurements, we found that ZnO is remarkably resistant to high-energy proton bombardment and that each incident proton removes about two orders of magnitude less carriers than in GaN. Deep level transient spectroscopy indicates a similar effect: the two electron traps detected are introduced in extremely low rates. One possible interpretation of these results is that the primary radiation-induced defects in ZnO may be unstable at room temperature and anneal out without leaving harmful defects …

Knowledge Discovery In Biological Datasets Using A Hybrid Bayes Classifier/Evolutionary Algorithm, Michael L. Raymer, Leslie A. Kuhn, William F. Punch

Kno.e.sis Publications

A key element of bioinformatics research is the extraction of meaningful information from large experimental data sets. Various approaches, including statistical and graph theoretical methods, data mining, and computational pattern recognition, have been applied to this task with varying degrees of success. We have previously shown that a genetic algorithm coupled with a k-nearest-neighbors classifier performs well in extracting information about protein-water binding from X-ray crystallographic protein structure data. Using a novel classifier based on the Bayes discriminant function, we present a hybrid algorithm that employs feature selection and extraction to isolate salient features from large biological data sets. The …