Physical Sciences and Mathematics Commons^™

Performing Cooperative Work And Conferencing On An Intranet Using Java, Thaveeporn Limpanyalers

Theses: Doctorates and Masters

The process of organising, preparing and conducting a meeting is a time consuming one. Additionally, geographic separation compounds the amount of effort required. Within this study, an electronic conferencing system in an Intranet environment is designed and implemented, thus enabling employees in the same organisation to meet up electronically without the dual constraints of time and space. Specifically, the study investigates incorporation of facial expressions and an ongoing polling system. The results demonstrate that a presence of facial expressions helps users to better engage in on-line discussion and that users find an ongoing poll to be useful in determining direction …

Patterns Of Organochlorine Pesticide Contamination In Neotropical Migrant Passerines In Relation To Wintering Range And Wintering Habitat, Jeffrey A. Klemens '98

Honors Projects

Seventy-two Neotropical migrant passerines were analyzed for the presence of 17 organochlorine pesticide residues (aldrin; alpha-BHC; beta-BHC; gamma-BHC; delta-BHC; p,p'-DDD; p,p'-DDE; p,p'-DDT; dieldrin; endosulfan I; endosulfan II; endosulfan sulfate; endrin; endrin aldehyde; heptachlor- heptachlor epoxide; methoxychlor) using standard method of gas chromatography applied to bird tissues. Individuals were colIected along the Mississippi River during May 1996 and represent 11 species (Catharus ustulatus; Geothlypis trichas; Protonotaria citrea; Mniotilta varia; Contopus virens; Dendroica petechia; Ernpidonax minimus; Passerina cyanea; Myiarchus crinitus; Vireo gilvus). The contaminants most frequently detected were p,p'-DDE, dieldrin, and heptachlor epoxide. No significant difference was found between male and female …

The Total Synthesis Of A Conformationally Constrained Organophosphorus Analog Of Acetycholine, Justin Mergott '98

Honors Projects

We propose the total synthesis of a conformationally constrained organophosphorus analog of acetylcholine (5, Scheme 5). This compound will contain two crural centers, one being the phosphorus atom and the other being the pyrrolidine ring carbon beta to the phosphorus atom. The chiral beta carbon is conformationally constrained because it is part of the pyrrolidine ring. Studies with such a compound should allow us to make substantial progress towards the clarification of the stereospecificity of AChE inhibition by OP compounds and eventually help us understand more about the structure of the AChE active site. The synthesis begins with Cbz-L-proline methyl …

Remote Sensing Of Commercial Aircraft Emissions, Peter J. Popp, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

No abstract provided.

Endomorphism Rings And Automorphism Groups Of Separable Torsion-Free Modules Over Valuation Domains, Brendan Goldsmith, P. Zanardo

Book chapter/book

No abstract provided.

Isomorphic Automorphism Groups Of Torsion-Free P-Adic Modules, Brendan Goldsmith, A. L. S. Corner

Book chapter/book

No abstract provided.

A Transaction Model For Mobile Computing, Sanjay Kumar Madria, Bharat Bhargava

Computer Science Faculty Research & Creative Works

We introduce a prewrite operation before a write operation in a mobile transaction to improve data availability. A prewrite operation does not update the state of a data object but only makes visible the value that the data object will have after the commit of the transaction. Once the transaction has read all the values and declares all the prewrites, it can precommit at a mobile host. The remaining transaction's execution is shifted to the stationary host. Writes on a database consume both time and resources at the stationary host and are therefore delayed. A pre-committed transaction's prewrite values are …

Systolic Algorithm For Processing Rle Images, Hao Feng, Fikret Erçal, Filiz Bunyak

Computer Science Faculty Research & Creative Works

Image difference operation is commonly used in on-line automated printed circuit board (PCB) inspection systems as well as many other image processing applications. In this paper, we describe a new systolic algorithm and its system architecture which computes image differences in run-length encoded (RLE) format. The efficiency of this operation greatly affects the overall performance of the inspection system. It is shown that, for images with a high similarity measure, the time complexity of the systolic algorithm is a small constant. A formal proof of correctness for the algorithm is also given in the paper.

Java, Java, Java, Chaman Sabharwal

Computer Science Faculty Research & Creative Works

Everyone is talking about Java. The driving force for this chatter is Java''s simplicity and potential power. Java is programming language, and a language for the intranet and the World Wide Web (WWW). Java is a Write On one platform and Run on Many platforms (WORM) language. For network-friendly, platform-independent applications, Java (originally Oak) is an object oriented programming language. Java source code is compiled into a virtual machine code or bytecode. This makes the Java platform independent. It can be placed on a Web site, and executed on the client side on a PC-Intel, Mac, Motorola or UNIX-Solaris machine …

Characterization Of Generalized Haar Spaces, M. Bartelt, W. Li

Mathematics & Statistics Faculty Publications

We say that a subset G of C₀(T, ℝ^k) is rotation-invariant if [Qg: g ∈ G]=G for any k x k orthogonal matrix Q. Let G be a rotation-invariant finite-dimensional subspace of C₀(T, ℝ^k) on a connected, locally compact, metric space T. We prove that G is a generalized Haar subspace if and only if P_G(ƒ) is strongly unique of order 2 whenever P_G(ƒ) is a singleton.

Error Correcting Codes Associated With Complex Hadamard Matrices, I. Heng, C. H. Cooke

Mathematics & Statistics Faculty Publications

For primes p > 2, the generalized Hadamard matrix H(p,pt) can be expressed as H = x^A, where the notation means h_ij = x^aij. It is shown that the row vectors of A represent a p-ary error correcting code. Depending upon the value of t, either linear or nonlinear codes emerge. Code words are equidistant and have minimum Hamming distance d = (p − 1)t. The code can be extended so as to possess N = p²t code words of length pt …

The Adjoint Alternative For Matrix Operators, C. H. Cooke

Mathematics & Statistics Faculty Publications

The following inverse problem is considered: given a matrix B of rank r, does there exist a matrix A such that

B = T(A) = adjoint (A)

where the classical adjoint operation is intended? Conditions are determined on the rank of B which decides whether or not B lies in the range of the matrix adjoint operator.

Steady Incompressible Magnetohydrodynamic Flow Near A Point Of Reattachment, J. M. Dorrepaal, S. Moosavizadeh

Mathematics & Statistics Faculty Publications

The oblique stagnation-point flow of an electrically conducting fluid in the presence of a magnetic field is a highly nonlinear problem whose solution is of interest even in the simplest of geometries. The problem models the flow of a viscous conducting fluid near a point where a separation vortex reattaches itself to a rigid boundary. A similarity solution exists which reduces the problem to a coupled system of four ordinary differential equations which can be integrated numerically. The problem has two independent parameters, the conductivity of the fluid and the strength of the magnetic field. Solutions are tabulated for a …

Database Security: Evaluation Of A Multi-Policy Access Control Model, Fei Dong

Dissertations and Theses @ UNI

As an increasing number of organizations become dependent on access to their data stored in the database, the need for adequate security measures is becoming more and more critical. Enforcing data protection means safeguarding data from unauthorized or improper disclosures or modifications. Access control policies should be independent of the mechanisms that will implement the physical control of access: this allows control mechanism to be available for different policies. Although considerable work was done on access control models and related mechanisms for databases (Castano & Fugini, 1994), current access control models and mechanisms are not flexible enough to meet the …

A Neutron Diffraction Structural Study Of R₂Fe₁₇₋ₓalx(C) (R=Tb,Ho) Alloys, William B. Yelon, H. Luo, Mingxing Chen, W. C. Chang, S. H. Tsai

Physics Faculty Research & Creative Works

No abstract provided.

Neutron Diffraction And Frequency Dependence Of The A.C. Susceptibility Of The System Zncr₂Xal₂-₂Xs₄, M. Hamedoun, A. Hourmatallah, N. Benzakour, K. Mediouri, J. Ilali, William B. Yelon, H. Luo

Physics Faculty Research & Creative Works

No abstract provided.

Magnetic And Thermal Properties Of Pr In La₁₋ₓprxbacacu₃O₇ System With 0.0, Rajvir Singh, S. Uma, E. Gmelin, William B. Yelon, V. P. S. Awana, S. X. Dou, A. V. Narlikar, Satish K. Malik

Physics Faculty Research & Creative Works

No abstract provided.

Pressure Induced Reversal Of The Volume Expansion Caused By Interstitial Nitrogen In Nd₂Fe₁₇N₃, R. Luo, William B. Yelon, Yusheng S.. Zhao, M. Ellouze, Ph. I'Héritier, G. K. Marasinghe, Peter C. Ezekwenna, R. B. Von Dreele, William Joseph James

Physics Faculty Research & Creative Works

No abstract provided.

Complete Single-Ionization Momentum Spectra For Strong Perturbation Collisions, Ronald E. Olson, C. J. Wood, H. Schmidt-Böcking, R. Moshammer, J. Ullrich

Physics Faculty Research & Creative Works

The combination of recoil ion and ionized electron momentum spectroscopy provides an unparalleled method to investigate the details of ion-atom collision dynamics in kinematically complete experiments. To predict single ionization scattering behavior at the level now realized by experiment, the classical trajectory three-body Monte Carlo method has been used to obtain complete momenta information for the ionized electron, recoil ion, and projectile in the collision plane defined by the incident projectile and outgoing recoil ion. Strongly coupled systems were considered where the charge state of the projectile divided by the speed of the collision [Formula Presented] is greater than unity. …

Ionization Dynamics In Fast Ion-Atom Collisions. Ii. Final-State Momentum Distributions Of The Ionization Products In Collisions Of He With Bare Carbon Ions, Lokesh C. Tribedi, P. Richard, Y. D. Wang, C. D. Lin, Ronald E. Olson, L. Gulyas

Physics Faculty Research & Creative Works

We have used the energy and angular distributions of the low-energy electron emission cross sections from the preceding paper [Lokesh C. Tribedi et al., Phys. Rev. A 58, 3619 (1998)] to derive the doubly differential final-state longitudinal momentum distributions of the electrons, recoil ions, and projectiles in ion-atom ionization for [Formula Presented] The complementary nature of the electron spectroscopy and the recoil-ion momentum spectroscopy have been investigated using a formulation based on three-body kinematics to explore the ionization dynamics in detail. The influence of the three-body ionization as well as the binary-encounter processes on the recoil-ion (and projectile) longitudinal momentum …

Effect Of Exchange Interactions At Antiferromagnetic/Ferromagnetic Interfaces On Exchange Bias And Coercivity, D. Dimitrov, Shufeng Zhang

Physics Faculty Research & Creative Works

We report on the correlation between unidirectional and uniaxial anisotropy in exchange-biased ferromagnetic Permalloy layers. The dependence of exchange bias and coercivity on temperature and the antiferromagnetic and ferromagnetic layer thickness was studied and compared with the predictions of different theoretical models. A thorough explanation of the experimental data is provided by theoretical extension of Malozemoff's model. © 1998 The American Physical Society.

Comparison Of Median Indicator Kriging With Full Indicator Kriging In The Analysis Of Spatial Data, Donna Hill

Theses : Honours

In the earth sciences, and particularly in the mining of precious metals, data distributions are often strongly positively skewed. When making decisions on the potential profitability of a gold mine, for example, the high values of the distribution are of particular importance. Indicator kriging provides estimates of cumulative distribution functions from which grade tonnage curves may be calculated. Multiple or full indicator kriging requires a semivariogram to be modelled and a kriging system of equations to be solved for each cut off. This can be time consuming and modelling indicator semivariograms at high cut-offs may be difficult because of the …

Lava Caves Of The Republic Of Mauritius, Indian Ocean, Gregory J. Middleton

International Journal of Speleology

In their Underground Atlas, MIDDLETON & WALTHAM (1986) dismissed Mauritius as: “very old volcanic islands with no speleological interest”. Recent investigations indicate this judgement is inaccurate; there are over 50 significant caves, including lava tube caves up to 687 m long (one 665 m long was surveyed as early as 1769) and 35 m wide. Plaine des Roches contains the most extensive system of lava tube caves with underground drainage rising at the seashore. Notable fauna includes an insectivorous bat and a cave swiftlet (Collocalia francica), the nests of which are unfortunately prized for ‘soup”. The caves …

On The Structure Of Graphs With Few P4s, Luitpold Babel, Stephan Olariu

Computer Science Faculty Publications

We present new classes of graphs for which the isomorphism problem can be solved in polynomial time. These graphs are characterized by containing — in some local sense — only a small number of induced paths of length three. As it turns out, every such graph has a unique tree representation: the internal nodes correspond to three types of graph operations, while the leaves are basic graphs with a simple structure. The paper extends and generalizes known results about cographs, P₄-reducible graphs, and P₄-sparse graphs.

Iowa Prairie: Original Extent And Loss, Preservation And Recovery Attempts, Daryl D. Smith

Journal of the Iowa Academy of Science: JIAS

Iowa's prairie has to be assessed in the context of the pre- and post-agriculturally dominated ecosystem in which it now exists. This requires an understanding of prairies and of society's perspective of prairies. Therefore, the attitudes of people through time have to be considered; (1) those who were involved in the demise of the prairie, (2) those who helped saved the pieces of the prairie and (3) those who may be called upon to recover the prairie ecosystem.

Front Matter

Journal of the Iowa Academy of Science: JIAS

No abstract provided.

Iowa Academy Of Science Membership Directory, 1998-99, Iowa Academy Of Science

Iowa Academy of Science Documents

Contents:

Editorial Board, Journal ... 5
Committees ... 6
Sections ... 18
ISTS Regional Directors ... 22
Awards of Merit ... 24
Excellence in Science Teaching Awards ... 25
Past Presidents ... 26
Membership Roster ... 27
Corporate Sponsors ... 35

Buckets: Aggregative, Intelligent Agents For Publishing, Michael L. Nelson, Kurt Maly, Stewart N. T. Shen, Mohammad Zubair

Computer Science Faculty Publications

Buckets are an aggregative, intelligent construct for publishing in digital libraries. The goal of research projects is to produce information. This information is often instantiated in several forms, differentiated by semantic types (report, software, video, datasets, etc.). A given semantic type can be further differentiated by syntactic representations as well (PostScript version, PDF version, Word version, etc.). Although the information was created together and subtle relationships can exist between them, different semantic instantiations are generally segregated along currently obsolete media boundaries. Reports are placed in report archives, software might go into a software archive, but most of the data and …

Creating A Canonical Scientific And Technical Information Classification System For Ncstrl+, Melissa E. Tiffany, Michael L. Nelson

Computer Science Faculty Publications

The purpose of this paper is to describe the new subject classification system for the NCSTRL+ project. NCSTRL+ is a canonical digital library (DL) based on the Networked Computer Science Technical Report Library (NCSTRL). The current NCSTRL+ classification system uses the NASA Scientific and Technical (STI) subject classifications, which has a bias towards the aerospace, aeronautics, and engineering disciplines. Examination of other scientific and technical information classification systems showed similar discipline-centric weaknesses. Traditional, library-oriented classification systems represented all disciplines, but were too generalized to serve the needs of a scientific and technically oriented digital library. Lack of a suitable existing …

A Fast Parallel Algorithm To Recognize P4-Sparse Graphs, Rong Lin, Stephan Olariu

Computer Science Faculty Publications

A number of problems in mobile computing, group-based collaboration, automated theorem proving, networking, scheduling, and cluster analysis suggested the study of graphs featuring certain “local density” characteristics. Typically, the notion of local density is equated with the absence of chordless paths of length three or more. Recently, a new metric for local density has been proposed, allowing a number of such induced paths to occur. More precisely, a graphG is called P4-sparse if no set of five vertices inG induces more than one chordless path of length three. P4-sparse graphs generalize the well-known class of cographs corresponding to …