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Wright State University

1999

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Articles 31 - 46 of 46

Full-Text Articles in Physical Sciences and Mathematics

Anticommuting Derivations, Steen Pedersen Apr 1999

Anticommuting Derivations, Steen Pedersen

Mathematics and Statistics Faculty Publications

We show that the re are no non-trivial closable derivations of a C*-algebra anticommuting with an ergodic action of a compact group, supposing that the set of squares is dense in the group. We also show that the re are no non-trivial closable densely defined rank one derivations on any C*-algebra.


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 3, March 1999, College Of Engineering And Computer Science, Wright State University Mar 1999

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 3, March 1999, 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.


Residual Native Shallow Donor In Zno, David C. Look, Joseph W. Hemsky, J. R. Sizelove Mar 1999

Residual Native Shallow Donor In Zno, David C. Look, Joseph W. Hemsky, J. R. Sizelove

Physics Faculty Publications

High-energy electron irradiation in ZnO produces shallow donors at about EC-30meV. Because the production rate is much higher for Zn-face (0001) than O-face (0001̅ ) irradiation, the donor is identified as a Zn-sublattice defect, most likely the interstitial ZnI or a ZnI-related complex. The donor energy is quite close to that of the unirradiated sample, and of other samples discussed in the literature, strongly suggesting that ZnI (and not VO) is the dominant native shallow donor in ZnO. An exceptionally high displacement threshold energy (∼1.6MeV) is quantitatively explained in terms of a …


Data Integration By Describing Sources With Constraint Databases, Xun Cheng, Guozhu Dong, Tzekwan Lau, Jianwen Su Mar 1999

Data Integration By Describing Sources With Constraint Databases, Xun Cheng, Guozhu Dong, Tzekwan Lau, Jianwen Su

Kno.e.sis Publications

We develop a data integration approach for the efficient evaluation of queries over autonomous source databases. The approach is based on some novel applications and extensions of constraint database techniques. We assume the existence of a global database schema. The contents of each data source are described using a set of constraint tuples over the global schema; each such tuple indicates possible contributions from the source. The “source description catalog” (SDC) of a global relation consists of its associated constraint tuples. Such a method of description is advantageous since it is flexible to add new sources and to modify existing …


Efficient Mining Of Partial Periodic Patterns In Time Series Database, Jiawei Han, Guozhu Dong, Yiwen Yin Mar 1999

Efficient Mining Of Partial Periodic Patterns In Time Series Database, Jiawei Han, Guozhu Dong, Yiwen Yin

Kno.e.sis Publications

Partial periodicity search, i.e., search for partial periodic patterns in time-series databases, is an interesting data mining problem. Previous studies on periodicity search mainly consider finding full periodic patterns, where every point in time contributes (precisely or approximately) to the periodicity. However, partial periodicity is very common in practice since it is more likely that only some of the time episodes may exhibit periodic patterns.

We present several algorithms for efficient mining of partial periodic patterns, by exploring some interesting properties related to partial periodicity, such as the Apriori property and the max-subpattern hit set property, and by shared mining …


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 2, February 1999, College Of Engineering And Computer Science, Wright State University Feb 1999

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 2, February 1999, 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.


Dislocation Scattering In Gan, David C. Look, J. R. Sizelove Feb 1999

Dislocation Scattering In Gan, David C. Look, J. R. Sizelove

Physics Faculty Publications

A theory of charged-dislocation-line scattering is developed within the framework of the Boltzmann transport equation. A fit of the theory to temperature-dependent Hall-effect data in GaN gives dislocation densities which are in excellent agreement with those measured by transmission electron microscopy. This work shows that threading edge dislocations in GaN indeed are electrically active, in agreement with recent theoretical predictions.


Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 1, January 1999, College Of Engineering And Computer Science, Wright State University Jan 1999

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 15, Number 1, January 1999, 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.


03. Preface Of Design And Analysis Of Experiments - 1st Edition, Angela Dean, Dan Voss, Danel Draguljic Jan 1999

03. Preface Of Design And Analysis Of Experiments - 1st Edition, Angela Dean, Dan Voss, Danel Draguljic

Design and Analysis of Experiments

Preface of the first edition of Design and Analysis of Experiments.


Multivalued Mappings, Fixed-Point Theorems And Disjunctive Databases, Pascal Hitzler, Anthony K. Seda Jan 1999

Multivalued Mappings, Fixed-Point Theorems And Disjunctive Databases, Pascal Hitzler, Anthony K. Seda

Computer Science and Engineering Faculty Publications

In this paper, we discuss the semantics of disjunctive programs and databases and show how multivalued mappings and their fixed points arise naturally within this context. A number of fixed-point theorems for multivalued mappings are considered, some of which are already known and some of which are new. The notion of a normal derivative of a disjunctive program is introduced. Normal derivatives are normal logic programs which are determined by the disjunctive program. Thus, the well-known single-step operator associated with a normal derivative is single-valued, and its fixed points can be found by well-established means. It is shown how fixed …


Stability Of A Semilinear Cauchy Problem, Yi Liu, Yi Li, Yinbin Deng Jan 1999

Stability Of A Semilinear Cauchy Problem, Yi Liu, Yi Li, Yinbin Deng

Mathematics and Statistics Faculty Publications

A report of progress in linear and nonlinear partial differential equations, microlocal analysis, singular partial differential operators, spectral analysis and hyperfunction theory. The papers aretaken from a conference on partial differential equations and their applications, held in Wuhan.


On The Exactness Of An S-Shaped Bifurcation Curve, Philip Korman, Yi Li Jan 1999

On The Exactness Of An S-Shaped Bifurcation Curve, Philip Korman, Yi Li

Mathematics and Statistics Faculty Publications

For a class of two-point boundary value problems we prove exactness of an S-shaped bifurcation curve. Our result applies to a problem from combustion theory, which involves nonlinearities like for .


Maintaining Transitive Closure Of Graphs In Sql, Guozhu Dong, Leonid Libkin, Jianwen Su, Limsoon Wong Jan 1999

Maintaining Transitive Closure Of Graphs In Sql, Guozhu Dong, Leonid Libkin, Jianwen Su, Limsoon Wong

Kno.e.sis Publications

It is common knowledge that relational calculus and even SQL are not expressive enough to express recursive queries such as the transitive closure. In a real database system, one can overcome this problem by storing a graph together with its transitive closure and maintaining the latter whenever updates to the former occur. This leads to the concept of an incremental evaluation system, or IES.

Much is already known about the theory of IES but very little has been translated into practice. The purpose of this paper is to fill in this gap by providing a gentle introduction to and …


Infoharness: Managing Distributed, Heterogeneous Information, Kshitij Shah, Amit P. Sheth Jan 1999

Infoharness: Managing Distributed, Heterogeneous Information, Kshitij Shah, Amit P. Sheth

Kno.e.sis Publications

Today, important information is scattered in so many places, formats, and media, that getting the right information at the right time and place is an extremely difficult task. Developing a single software product, for example, includes the creation of documents ranging from the requirements specification and project schedules to marketing presentations, multimedia tutorials, and more. Each document may be created by a different person using a different tool, and each may be stored in a different place. InfoHarness is an information integration system, platform, and tool set that addresses these problems, managing huge amounts of heterogeneous information in a distributed …


Processes Driving The Networked Economy, Amit P. Sheth, Will Van Der Aalst, I. Budak Arpinar Jan 1999

Processes Driving The Networked Economy, Amit P. Sheth, Will Van Der Aalst, I. Budak Arpinar

Kno.e.sis Publications

The authors propose that an organic workflow-process technology will power the evolution of information system architectures. The authors outline three likely stages of architectural evolution in the context of a networked economy and discuss critical gaps in the current technology with respect to their envisioned future.


Synthesis Of Benzoxazoles Containing Allyl Crosslinking Sites Via Claisen Rearrangements, Leslie K. Hutson Jan 1999

Synthesis Of Benzoxazoles Containing Allyl Crosslinking Sites Via Claisen Rearrangements, Leslie K. Hutson

Browse all Theses and Dissertations

The reaction of diethyl 2,5-dihydroxyterephthalate with allyl bromide/K2CO3 in DMF followed by hydrolysis provided 2,5-di(allyloxy)terephthalic acid. The conversion of 2,5-di (allyloxy)terephthalic acid to 1,4-di(2-benzoxazolyl)-2,5-di(allyloxy)benzene in PPSE was unsuccessful. However, the reaction of 1,4-di(2-benzoxazolyl)-2,5- dihydroxybenzene with allyl bromide/K2CO3 provided 1,4-di(2-benzoxazolyl)-2,5- di(allyloxy)benzene. DSC analysis indicated that 1,4-di(2-benzoxazolyl)-2,5- di(allyloxy)benzene undergoes a Claisen rearrangement to the corresponding diallyl product. The synthesis of 2-allyloxy-1,4-di(2-benzoxazolyl)benzene was carried out using 2-hydroxy-1,4-di(2-benzoxazolyl)benzene as starting material. DSC analysis was inconclusive with respect to a Claisen rearrangement. The reaction of 2-allyloxybenzoic acid with 2,2-bis(3-amino-4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane in PPSE was unsuccessful but the reaction of 2,2-bis(2-(2-hydroxyphenyl)-5-benzoxazolyl)-1,1,1,3,3,3-hexafluoropropane with allyl bromide/K2CO3 in DMF provided 2,2-bis(2-(2- …