Digital Commons Network^™

Survey Of Routing Algorithms For Computer Networks, Lu Yu, Thomas J. Sager

Computer Science Technical Reports

This thesis gives a general discussion of routing for computer networks, followed by an overview of a number of typical routing algorithms used or reported in the past few years. Attention is mainly focused on distributed adaptive routing algorithms for packet switching (or message switching) networks. Algorithms for major commercial networks (or network architectures) are reviewed as well, for the convenience of comparison.

Increased Optical Damage Resistance In Lithium Niobate, D. A. Bryan, Robert Gerson, H. E. Tomaschke

Physics Faculty Research & Creative Works

We have confirmed greatly improved resistance to photorefractive damage in compositions of lithium niobate containing 4.5 at. % MgO or more. Holographic diffraction measurements of photorefraction demonstrated that the improved performance is due to a hundredfold increase in the photoconductivity, rather than a decrease in the Glass current. The diffraction efficiency shows an Arrhenius dependence on temperature, with an activation energy of 0.1 eV for the damage-resistant compositions, compared with 0.5 eV for undoped or low-magnesium compositions. The damage-resistant compositions are distinguished by a 2.83-μm absorption line instead of the usual 2.87-μm line due to the OH-stretch vibration.

Threshold Effect In Mg-Doped Lithium Niobate, K. L. Sweeney, L. E. Halliburton, D. A. Bryan, R. R. Rice, Robert Gerson, H. E. Tomaschke

Physics Faculty Research & Creative Works

Optical absorption spectra were obtained after reducing (i.e., vacuum annealing) a series of LiNbO3 crystals grown from melts having various Mg concentrations and Li/Nb ratios. A band peaking at 500 nm, and assigned to oxygen vacancies containing two electrons, was the only absorption present in one set of crystals following reduction. In contrast, two overlapping bands peaking near 1200 and 760 nm were present in the other set of crystals immediately after the reduction. The 1200-nm band is assigned to a previously unreported electron trap and the 760-nm band to oxygen vacancies containing only one electron. These data are interpreted …

Microprocessor-Based Pressure Controller, E. Redd, John T. Park

Physics Faculty Research & Creative Works

A device for automatic control of pressure in an ion-atom scattering experiment has been constructed. The system was modeled to achieve the minimum time for transition from one pressure to another. The pressure controller "learns" the system response and iterates the parameters used in "profiling" the valve voltage to reduce the transition time. The device has been used with two different scattering chambers and has worked well with both.

Evaluation Of Plasma Polymers Of Silanes As Adhesion Promoters For Organic Paint, Y. Matsuda, H. Yasuda

Chemistry Faculty Research & Creative Works

Plasma-polymerized coatings were prepared in a bell-jar-type reactor equipped with a magnetron system behind parallel aluminum electrodes using an a.c. source of frequency 10 kHz. Tetramethoxysilane, dimethyldimethoxysilane and hexamethyldisilane were used as monomers. Alkyd paint was coated on titanium plates onto which plasma polymer films had been deposited, to investigate the characteristics of the plasma-deposited films as adhesion promoters. The relationship between the adhesion strength for the paint and the conditions for the plasma polymerization was studied. The properties of the plasma polymers are dependent on the conditions of plasma polymerization manifested by two domains, namely the energy-deficient and the …

Preparation Of Gas Separation Membranes By Plasma Polymerization With Fluoro Compounds, H. Nomura, P. W. Kramer, H. Yasuda

Chemistry Faculty Research & Creative Works

Plasma polymerization coatings were applied for the preparation of gas separation membranes. Mainly fluoro compounds were used as coating materials. The membranes showed good separation characteristics with high flux for gaseous systems. The plasma polymerization composite parameter given by W/FM plays an important role in obtaining excellent separation characteristics. The correlation between the conversion rate DR/FM, where DR is the deposition rate of plasma polymer, and W/FM is useful to consider the plasma polymer character under the different plasma polymerization conditions (discharge power W and monomer flow rate F). The proper conditions for membrane preparation lie in the intermediate region …

A Simple Method For Organizing Nearly Optimal Binary Search Trees, Joy L. Henderson, John R. Metzner

Computer Science Technical Reports

Improving the efficiency of retrieving information concerns users of computer systems involved in many applications- One way of addressing this concern is to organize a sorted sequence into a binary search tree. Knuth's Algorithm K is a bottom-up organization algorithm that always constructs a binary tree which minimizes average search time. However, the cost of executing Algorithm K is prohibitive for a large tree. The aim of this work is to find a less costly method of organizing sorted sequences into nearly-optimal binary search trees.

We present a top-down organization method which yields better average search times than top-down methods …

The Design And Implementation Of The Programming Language Natural, Alan L. Sparks, Thomas J. Sager, Arlan R. Dekock

Computer Science Technical Reports

This paper reports progress on the development of the programming language Natural, currently under design by Dr. Thomas J. Sager at the University of Missouri--Rolla. Natural is a very high-level language with a mathematical flavor, and includes several concepts relatively uncommon in programming language design.

The text also discusses an implementation on the IBM Personal Computer of Mini-Natural, a subset of Natural, and presents examples of programs written in Mini-Natural.

Angular Differential And Total Cross Sections For The Excitation Of Atomic Hydrogen To Its N=2 Level By 25-150-Kev Hydrogen Molecular Ions, Jerry Peacher, Paul J. Martin, Denver G. Seely, Judith E. Aldag, Thomas J. Kvale, E. Redd, D. M. Blankenship, V. C. Sutcliffe, John T. Park

Physics Faculty Research & Creative Works

Experimentally and theoretically determined differential and total cross sections are reported for excitation of atomic hydrogen to its n=2 level by 25-150-keV hydrogen molecular ions. The differential cross sections decrease 3-4 orders of magnitude over the measured center-of-mass scattering-angular range from 0 to 4.5 mrad. The results of a first Born approximation and two other theoretical calculations based upon the Glauber approximation are presented and compared with the experimental results. Both calculations based on the Glauber approximation agree fairly well with the experimental results. The Born approximation agrees moderately well with the experimental results at the very small scattering angles …

A Focus Of Attention Algorithm For Expert Systems, Kevin W. Whiting, Arlan R. Dekock, John Bruce Prater

Computer Science Technical Reports

This research is primarily concerned with increasing the performance of expert systems. A refined focus of attention strategy and its affect on performance are discussed. Early expert systems used a brute force approach to process the knowledge base. Each production rule in the knowledge base was evaluated each cycle. More recently, processing efficiency has been increased by focusing the attention of the inference engine on a subset of the rules by "filtering" for further testing, only rules that could possibly fire given the current content of the context base. Focus of attention as developed in this research increases performance over …

Color Computer Graphics As Applied To Introductory Calculus Instruction, Kathy B. Windhorst, Ralph E. Lee

Computer Science Technical Reports

The use of computer graphics to support and enhance the presentation of introductory calculus concepts is described.

Computer graphics provides more accurate graph sketching, consistent presentations and the ability to develop mathematical models incrementally. The addition of extensive use of color aids even more, adding contrast, color keying, dimensionality, and interest to an illustration.

Ten lessons have been designed, developed, and evaluated. They employ a set of subroutines which interface to the NBC APC microcomputer graphics software. These lessons as developed and evaluated may be used interactively in the classroom or by individuals, or noninteractively in the classroom by the …

Ciegen: A System For Testing Knowledge Base Compilation Heuristics On A Microcomputer, Jayne D. Ward, Billy E. Gillett, Arlan R. Dekock

Computer Science Technical Reports

The expert system has proven itself to be a valuable aid in diagnosing and treating problems in domains requiring expertise. The commercial world has been alerted to this fact and the thrust is to make the expert system portable and available on small computers.

The goal of this research has been to lay the groundwork for a domain independent expert system builder on a microcomputer. The result of this effort was CIEGEN, a system consisting of a rule compiler, inference engine, and rule generator developed on the IBM PC. It is domain independent, responsible for transforming a knowledge base of …

Full Second-Order Distorted-Wave Calculation Without Approximations For Atomic Excitation By Electron Impact, Don H. Madison

Physics Faculty Research & Creative Works

A new technique has been developed for evaluating second-order distorted-wave amplitudes for atomic excitation without making any approximations. By this technique, second-order amplitudes with arbitrary distorted waves and arbitrary Green's functions in the interaction can be evaluated with comparable difficulty. The utility of the method is demonstrated through a practical calculation of the second-order distorted-wave approximation for electron excitation of the 2p state of hydrogen.

A Graphical Representation Of An Executing Program, Sherry A. Lile, Arlan R. Dekock, John Bruce Prater, Darrow Finch Dawson

Computer Science Technical Reports

This thesis describes the rationale for a computer program used as a teaching aid, as well as, the design, development, and implementation of that computer program. The program is a prototype that displays, line by line, a graphical depiction of a BASIC program being executed. Icons are used to represent FOR-NEXT loops, the contents of variables, I/O, and other programming elements. The internal logic associated with the Arithmetic-Logic Unit is also represented. The purpose is to produce an environment where the student may visualize the processes occurring in memory by viewing a symbolic portrayal of an executing program. The example …

The Optimal Trajectory Modelling Of Robot Manipulators, Mary Claire Miller, Chung You Ho, Arlan R. Dekock

Computer Science Technical Reports

Greater robot capability can be achieved through the use of robot manipulator control systems. Crucial to the success of these control systems is the optimal trajectory modelling of the path traced by the end- effector. To create this optimal path the utilization of B-Spline curve functions will be investigated, and compared to Cubic Spline curve functions.

An Experimental Study Of The Effects Of Modularity On Resource Consumption In Software Development, Alan D. Christiansen, Arlan R. Dekock, John Bruce Prater

Computer Science Technical Reports

Many authors have encouraged the use of modular programming techniques in software development. In fact, there is almost total agreement within industrial and academic circles that modularity is a desirable feature of any software package. Unfortunately, the desirability of modular design is almost always voiced without support from experimental evidence.

This paper consists of an experiment comparing the resource consumption of programmers based on the modularity practices employed during the design and programming phases of software development. The experiment tests the effectiveness of modularity in reducing psychological complexity of software.

The results of the research show that in some cases …

Homogeneous Nucleation Rate For Water, Donald E. Hagen, James L. Kassner

Physics Faculty Research & Creative Works

Homogeneous nucleation rate data for water extending over an exceptionally large domain of rate (J), supersaturation ratio (S), and temperature (T) was recently published. Because it spans a large J-S-T surface, this data constitutes a good test of nucleation theory. Here classical nucleation theory is used to analyze this data. By adjusting only the sticking coefficient, we are able to obtain a good fit between theory and experiment. It was necessary to include an increase in the water molecular density associated with the finite water compressibility.

Magnetic Phase Diagram And Spin Glass Behavior Of Fe₁₋ₓmnₓcl₂·2h₂O, Gary C. Defotis, Christoph Pohl, Spencer A. Pugh, Ekkehard Sinn

Chemistry Faculty Research & Creative Works

The magnetic phase diagram of Fe_1-xMn_xCl₂·2H₂O has been determined. A tetracritical point appears to be present at x ≊ 0.74 and T≊2.8 K. The upper paramagnetic-antiferromagnetic phase boundaries exhibit an unusually rapid descent, and the mixed ordered region below the tetracritical point is quite small. Moreover, regions exhibiting spin glass character also occur in the diagram. The unusually complex behavior is presumably due to the unique constitution of this system: A mixture of two antiferromagnets with different periodicities, competing orthogonal spin anisotropics, competing ferromagnetic and antiferromagnetic near neighbor intrachain exchange interactions, and …

Preparation And Characterization Of Composite Hollow Fiber Reverse Osmosis Membranes By Plasma Polymerization. 2. Reproducibility Of The Plasma Polymerization Process And Durability Of The Resulting Coated Membrane, Y. Matsuzawa, H. Yasuda

Chemistry Faculty Research & Creative Works

The reproducibility of the plasma polymerization process was examined in a semicontinuous coating of hollow fibers, 6 fibers in lengths of approximately 12-15 m, by evaluating the performance of reverse osmosis membranes. The uniformity of the coating along the length of hollow fibers, as well as the reproducibility of the process, was found to be satisfactory when electrodes were conditioned in the actual conditions of plasma polymerization to be employed and plasma polymerization conditions were carefully controlled. The durability of the coated hollow fibers was then investigated in the following test media: hot water, low pH, high pH, and 0.1% …

Preparation And Characterization Of Composite Hollow Fiber Reverse Osmosis Membranes By Plasma Polymerization. 1. Design Of Plasma Reactor And Operational Parameters, P. J. Heffernan, K. Yanaglhara, Y. Matsuzawa, E. E. Hennecke, E. W. Hellmuth, H. Yasuda

Chemistry Faculty Research & Creative Works

Composite hollow fiber reverse osmosis membranes were prepared by depositing a thin layer (10-50 nm) of plasma polymers on hollow fibers with porous walls (made of polysulfone). The coating was carried out in a semicontinuous manner with six strands of substrate fibers. Operational parameters which influence reverse osmosis characteristics of composite membranes were investigated. © 1984, American Chemical Society. All rights reserved.

Elastic Differential Cross Sections For Small-Angle Scattering Of 25-, 40-, And 60-Kev Protons By Atomic Hydrogen, Eduard P. Rille, Jerry Peacher, E. Redd, Thomas J. Kvale, Denver G. Seely, D. M. Blankenship, Ronald E. Olson, John T. Park

Physics Faculty Research & Creative Works

Elastic angular differential cross sections for small-angle scattering of protons by atomic hydrogen have been measured. The technique utilized unambigously distinguishes the elastically and inelastically scattered ions. The cross sections fall monotonically by 3 orders of magnitude in the angular range from 0.5 to 3.0 mrad, in the center-of-mass system. The experimental data obtained are in very good agreement with a multistate calculation and in fair agreement with both our Glauber-approximation and classical-trajectory Monte Carlo results.

An Improved Algorithm For Generating Minimal Perfect Hash Functions, Thomas J. Sager

Computer Science Technical Reports

A minimal perfect hash function (MPHF) is a function from a set of M objects to the first M non-negative integers. MPHF's are useful for the compact storage and fast retrieval of frequently used objects such as reserved words in a programming language or commonly employed words in a natural language. In this paper we improve on an earlier result and present an algorithm for generating MPHF's with an expected time complexity proportional to M⁴. We also give a MPHF for the 256 most frequently used words in the English language.

Parallelism In The Language, Natural, Thomas J. Sager

Computer Science Technical Reports

Natural is a language designed to provide a vehicle for the expression of abstract programming concepts clearly and precisely in a natural and mathematical form. The concept of parallelism can be expressed both explicitly and implicitly in the language, Natural. Due to relative freedom from side-effects and the use of a special value, undef, subexpressions can often be evaluated in parallel. The for and do statements both allow for a parallel mode of execution. A builtin functional, prlleval, creates functions which can evaluate their arguements in a parallel mode. In addition, the concept of module allows for the definition of …

A New Method For Generating Minimal Perfect Hash Functions, Thomas J. Sager

Computer Science Technical Reports

A perfect hash function, PHF, is an injection, F, from a set, W, of M objects into the set consisting of the first N non-negative integers where N>=M. If N=M then F is a minimal perfect hash function, MPHF. PHFs are useful for the compact storage and fast retrieval of frequently used objects such as reserved words in a programming language or commonly employed words in a natural language.

The mincycle algorithm for finding PHFs executes with an expected time complexity proportional to M⁴ and has been used successfully on sets of cardinality up to 256. The mincycle …

Dipole Moment And Potential Energy Functions Of The X ¹Σ + And A 1Σ+ States Of Nah, W. T. Zemke, Ronald E. Olson, K. K. Verma, W. C. Stwalley, B. Liu

Physics Faculty Research & Creative Works

Calculated radiative transition probabilities between all vibrational levels in the X 1Σ+ state (υ=0-21) and in the A 1Σ+ state (υ=0-32) of NaH are given. In addition, the calculated spontaneous emission lifetimes for vibrational- rotational levels (J=0,1) and the calculated dipole moments for these same levels are given. The calculations use new hybrid potential energy curves based on Rydberg-Klein-Rees (RKR) and ab initio potential curves. The RKR curve for the X state is new. The calculations use new ab initio dipole moment functions of internuclear distance. © 1984 American Institute of Physics.

Program Modeling And Control Synthesis For Robotic Manipulators, Ramiz Najib Ballou

Masters Theses

"The control and programming methodology of industrial robots is becoming increasingly important. The speed and accuracy of data generation, and the performance of the robot are considered the most important factors in robotics control.

This paper presents and discusses algorithms that solve for the inverse solution for a given point in space at a very high speed based on the top down abstract method. The algorithms are independent of any specific type of manipulator configuration or programming language. The algorithms were implemented or the IBM-PC using the FORTRAN language to control the Armdroid robot. The program generates 500 sets of …

Approximate Tolerance Limits And Confidence Limits On Reliability For The Gamma Distribution, Lee J. Bain, Max Engelhardt, Wei Kei Shiue

Mathematics and Statistics Faculty Research & Creative Works

No abstract provided.

Aphasia After Left Thalamic Infarction, Philip B. Gorelick, Daniel B. Hier, Louis Benevento, Susan Levitt, Walter Tan

Chemistry Faculty Research & Creative Works

We Examined a 70-Year-Old Woman Who Became Aphasic after a Left Thalamic Infarction. Computed Tomographic Scan Showed Injury that Was Largely Limited to the Ventral Anterior and Rostral Ventral Lateral Thalamic Nuclei. Speech Was Characterized by Reduced Voice Volume, Impaired Auditory and Reading Comprehension, Perseverations, Intermittent Use of Jargon, Fluctuations in the Ability to Perform Confrontation Naming, Extraneous Intrusions, Verbal Paraphasia, Intact Repetition Skills, and Fluent Speech that Was Laconic But Grammatically Correct. We Propose that the Deficits after Left Thalamic Injury Can Be Grouped into the Following Four Large Clusters: Extrapyramidal Deficits (Decreased or Fading Voice Volume), Deficits in …

Molecular Motion And Phases In An Equimolar Phosphatidylcholine/Ethylene Glycol System, David W. Larsen, Shankar B. Rananavare, Frank E. Stary, Magda Elnokaly, Stig Friberg

Chemistry Faculty Research & Creative Works

An equimolar mixture of phosphatidylcholine and ethylene glycol was studied by pulsed proton NMR at temperatures between 100 and 430 K. Relaxation times T1, T1ρ, and T1D, and second moments, M2, were measured. The system is lamellar liquid crystalline at room temperature, but at least four phases are present within the temperature range studied. Phase transitions were confirmed by DSC. Activation barriers were estimated for methyl reorientation, choline group motion, and chain motion. Models to describe the various motions and the role of spin diffusion are discussed. The relationship of the parameters for the present system to those for the …

Solubilization Of Calcium Dodecyl Sulfate In A Micellar Solution And In Lamellar Liquid Crystal, Stig Friberg, David W. Osborne

Chemistry Faculty Research & Creative Works

Calcium dodecyl sulfate (CDS) was solubilized in the aqueous micellar solution of sodium dodecyl sulfate and in the lamellar liquid crystal obtained from water, sodium dodecyl sulfate and decanal. The solubilization of CDS in the micellar solution was strongly increased with the concentration of sodium dodecyl sulfate while the maximum amount of CDS solubilized in the liquid crystal remained similar. The solubilization in the micellar solution was gradually increased with the alcohol content with a sudden reduction to zero at the decanol/sodium-dodecyl-sulfate ratio marking the end of the micellar region with no calcium soap being present. The dependence of the …