Digital Commons Network^™

Fdtd Modeling Of Common-Mode Radiation From Cables, David M. Hockanson, James L. Drewniak, Todd H. Hubing, Thomas Van Doren

Electrical and Computer Engineering Faculty Research & Creative Works

Radiation from cables attached to printed circuit boards and shielding enclosures is among the primary concerns in meeting FCC Class A and B limits. The finite-difference time-domain (FDTD) method can be employed to model radiation from printed circuit boards and shielding enclosures with complex geometries, but difficulties in modeling wires and cables of arbitrary radii are encountered. Modeling the wire by setting the axial component of the electric field to zero in the FDTD method results in an effective wire radius that is determined by the mesh discretization. Neglecting the wire radius in applications, such as electromagnetic interference (EMI) or …

Anisotropy And Polarization In Charge Changing Collisions Of C⁴⁺ With Na(3s) And Laser Aligned Na(3p), S. Schippers, R. Hoekstra, R. Morgenstern, Ronald E. Olson

Physics Faculty Research & Creative Works

Absolute cross sections for C3+(6→5) emission at 465.7 nm after collisions of C4+ ions with ground state Na(3s) and laser excited aligned Na(3p) atoms are measured over the collision energy range of 3-7 keV amu-1. For Na(3s) polarizations are observed by measuring the linear polarization of the emitted light. In these collisions the polarization is found to be 0.33 and almost independent of the collision energy. Cross sections for collisions with the Na(3p) target are up to five times larger than for collisions with Na(3s). Slightly larger cross sections are measured when the laser excited Na(3p) target is Π-aligned as …

Missouri S&T Magazine, Special Issue--Fall 1996, Miner Alumni Association

Missouri S&T Magazine

No abstract provided.

Incommensurate One-Dimensional Fluctuations In Yba2⁢Cu3⁢O6.93, Herbert A. Mook, Pengcheng Dai, Kamel Salama, Dominic Lee, Fatih Dogan, Gabriel Aeppli, Andrew T. Boothroyd, Mark E. Mostoller

Materials Science and Engineering Faculty Research & Creative Works

A novel neutron scattering technique has been utilized to discover one-dimensional fluctuations with a very sharply defined modulation period of 16.65⁢Å along the b⁡(a) direction in YBa₂⁢Cu_3⁢O_6.93. The fluctuations are found to be absent in the reduced oxygen compound YBa_2⁢Cu_3⁢O_6.15. The wave vector of the fluctuations is consistent with accepted values of 2⁢k_F for the Cu-O chains.

Incommensurate One-Dimensional Fluctuations In Yba₂Cu₃O₆.₉₃, Herbert A. Mook, Pengcheng Dai, Kamel Salama, Dominic Lee, Fatih Dogan, Gabriel Aeppli, Andrew T. Boothroyd, Mark E. Mostoller

Materials Science and Engineering Faculty Research & Creative Works

A novel neutron scattering technique has been utilized to discover one-dimensional fluctuations with a very sharply defined modulation period of 16.65 Å along the b(a) direction in YBa₂Cu₃O_6.93. The fluctuations are found to be absent in the reduced oxygen compound YBa₂Cu₃O_6.15. The wave vector of the fluctuations is consistent with accepted values of 2k_F for the Cu-O chains.

Efficient String Matching Algorithms On Reconfigurable Mesh Architectures, His-Chieh Lee, Fikret Ercal

Computer Science Technical Reports

String matching problem received much attention over the years due to its importance in various applications such as text/file comparison, DNA sequencing, search engines, and spelling correction. Especially with the introduction of search engines dealing with tremendous amount of textual information presented on the world wide web and the research on DNA sequencing, this problem deserves special attention and any algorithmic or hardware improvements to speed up the process will benefit these important applications.

In this paper, we present three algorithms for string matching on reconfigurable mesh architectures. Given a text T of length n and a pattern P of …

Fast Algorithms For Maze Routing On An Rmesh, Fikret Ercal, H. C. Lee

Computer Science Technical Reports

The routing problem is one of the most widely studied problems in VLSI design. Mazerouting algorithms are used in VLSI routing and robot path planning. Efficiency of the parallel maze routing algorithms which were mostly based on Lee's algorithm is poor. In this paper, we propose time-efficient algorithms to solve the maze-routing problem on a reconfigurable mesh architecture. The constant-time algorithms presented include: (i) testing the existence of specific types of paths between two terminals, (ii) finding an absolute shortest path (ASP) and a shortest duplex-path (SDP). In addition, fast algorithms are presented for finding the shortest triplex-path (STP) and …

Run Time Security Evaluation For Distributed Applications, Cristina Serban, Bruce M. Mcmillin

Computer Science Technical Reports

Formal security specifications for a distributed application can be checked for compliance at run-time, during the execution of the application. We propose the RunTime Security Evaluation (RTSE) method which makes use of executable security assertions, histories/traces of events, and operational evaluation in the distributed environment to ensure the security specifications regarding the confidentiality and integrity requirements for the application are fulfilled at run-time. A model problem is used to aid in developing the security requirements formally, and assessment of the RTSE method is given based on the results obtained for the implementation of the model problem. The elements necessary for …

Binary Nucleation Kinetics. Iii. Transient Behavior And Time Lags, Barbara Ellen Wyslouzil, Gerald Wilemski

Physics Faculty Research & Creative Works

Transient binary nucleation is more complex than unary because of the bidimensionality of the cluster formation kinetics. To investigate this problem qualitatively and quantitatively, we numerically solved the birth-death equations for vapor-to-liquid phase transitions. Our previous work [J. Chem. Phys 103, 1137 (1995)] showed that the customary saddle point and growth path approximations are almost always valid in steady state gas phase nucleation and only fail if the nucleated solution phase is significantly nonideal. The current work demonstrates that in its early transient stages, binary nucleation rarely, if ever, occurs via the saddle point. This affects not only the number …

Charge-Dipole Model For The Universal Field Dependence Of Mobilities In Molecularly Doped Polymers, David H. Dunlap, Paul Ernest Parris, Vasudev M. Kenkre

Physics Faculty Research & Creative Works

Using the general result that the mobility μ, of charge carriers driven in a spatially correlated random potential by an electric field E can be expressed in terms of the Laplace transform of a particular correlation function related to the random potential, we demonstrate that the exponential dependence of μ on √E universally observed in molecularly doped polymers arises naturally from the interaction of charge carriers with randomly distributed permanent dipoles.

Incommensurate One-Dimensional Fluctuations In Yba2cu3o6.93, Herbert A. Mook, Pengcheng Dai, K. Salama, D. Lee, Fatih Dogan, G. Aeppli, A. T. Boothroyd, M. E. Mostoller

Materials Science and Engineering Faculty Research & Creative Works

A novel neutron scattering technique has been utilized to discover one-dimensional fluctuations with a very sharply defined modulation period of 16.65 Å along the ba direction in YBa₂Cu₃O_6.93. The fluctuations are found to be absent in the reduced oxygen compound YBa₂Cu₃O_6.15. The wave vector of the fluctuations is consistent with accepted values of 2kF for the Cu-O chains.

Applying Informal Cooperative Learning Groups Techniques In The Classroom, Susan L. Murray

Engineering Management and Systems Engineering Faculty Research & Creative Works

The application of informal cooperative learning (CL) groups techniques in the courses including operation research, and computer simulation, is discussed. The informal CL activities can be accomplished in small groups consisting of two or three students. It increases student participation and revitalizing passive lecturers. Students work example problems or homework problems in groups.

A New Chip-Set For Astra Digital Radio, Werner Bradinal, Christoph Moeller, Timothy A. Philpot, Mike Rose

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This chip-set provides the channel and source decoding functions for ASTRA Digital Radio (ADR) receivers. An overview of the system is given together with a summary of the main features of the ICs. The chip-set offers a flexible, but optimum solution to meet the requirements for low cost consumer sets.

Structural And Magnetic Studies On Prba2fe3o8, V. P.S. Awana, Latika Menon, S. K. Malik, Apurva Mehta, Sanjay Mishra, William B. Yelon

Physics Faculty Research & Creative Works

It is known that Fe moments order antiferromagnetically with Néel temperature, TN, above 700 K in RBa2Fe3O7-δ with R=Y and Eu, and Pr moments order antiferromagnetically in PrBa2Cu3,O7-δ, with TN of 17 K. We have synthesized PrBa2Fe3O8 to study the ordering of Pr and Fe moments. From X-ray and neutron diffraction studies, this compound is found to crystallize in the tetragonal structure (space group P4/mmm). 57Fe Mössbauer studies show a complex hyperfine split pattern at 77 K, but a doublet superimposed on a six-line pattern at 300 K implying that some of the Fe moments order magnetically between 77 and …

Measurement Parameter Optimization For Surface Crack Detection In Metals Using An Open-Ended Waveguide Probe, R. Zoughi, Stoyan I. Ganchev, Christian J. Huber

Electrical and Computer Engineering Faculty Research & Creative Works

Fatigue and stress induced surface crack detection in metals is an important practical issue. A newly developed microwave inspection approach, using an open-ended rectangular waveguide, has proved to be an effective tool for detecting such cracks. This novel microwave approach overcomes some of the limitations associated with the standard detection methods for surface crack detection. In addition, this approach is applicable to exposed, filled (with a dielectric such as dirt, rust, etc.) and cracks under dielectric coatings such as paint. This paper presents the basic foundation of this surface crack detection methodology along with the ways by which measurement parameters …

Characterization Of Vasoactive Intestinal Peptide Receptors On Human Megakaryocytes And Platelets, Sang K. Park, Thomas A. Olson, Nuran Ercal, Monica Summers, M. Sue O'Dorisio

Chemistry Faculty Research & Creative Works

Vasoactive intestinal peptide receptor I (VIPRI) expression was examined in megakaryocytes using reverse transcriptase-polymerase chain reaction (RT- PCR). VIPRI protein was characterized in platelet membranes using covalent crosslinking techniques. Human megakaryocytes were isolated from suspension cultures of cord blood and adult bone marrow mononuclear cells using a murine monoclonal antibody to human platelet glycoprotein IIB/IIIA (CD41) and immunomagnetic beads. RT-PCR primers were constructed for the VIP, VIPRI, and VIPRII genes as well as for megakaryocyte specific genes, c-mpl and platelet factor 4 (PF-4). VIP, VIPRI, c-mpl, and PF-4 were coexpressed in megakaryocyte mRNA. Southern blot analysis confirmed the expression of …

The Missouri Miner, May 23, 1996

The Missouri Miner Newspaper

No abstract provided.

Multi-Component Perfusion Chromatography In Fixed Bed And Periodic Counter Current Column Operation, G. A. Heeter, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

A mathematical model of multi-component dynamic adsorption in columns with spherical perfusive and spherical purely diffusive adsorbent particles with a bidisperse porous structure is constructed, solved, and used to study the performance of a binary adsorption system in a single-column fixed-bed process and in a two-column periodic countercurrent process in which the adsorbent is equally distributed over two beds. The total length of the two-column periodic counter-current system is equal to the length of the single-column fixed-bed system. The performance of fixed-bed and periodic counter-current systems with both perfusive and purely diffusive adsorbent particles is examined for different values of …

The Missouri Miner, May 16, 1996

The Missouri Miner Newspaper

No abstract provided.

A Classical Analysis Of Proton Collisions With Ground-State And Excited, Aligned Sodium Targets, C. J. Lundy, Ronald E. Olson

Physics Faculty Research & Creative Works

The dependence of electron capture and ionization processes on the pre-collision electronic distribution is examined for the systems H+ + Na(3s, 3pΣ, 3pΠ) primarily in the energy range 1-15 keV. Populations of the capture and ionization channels as well as the coherence of the post-collision electronic distribution of the capture product are formulated using the classical trajectory Monte Carlo (CTMC) method. Total capture and ionization cross sections arising from initially aligned Na(3p) targets exhibit transient behaviour near the velocity-matching energy of 5.7 keV. This observation is described in terms of anisotropy parameters; anisotropy effects are also analysed for the capture …

State-Selective Electron Capture In Low Velocity Multiply Charged Ion, Helium Collisions, A. Cassimi, S. Duponchel, X. Flechard, P. Jardin, P. Sortais, D. Hennecart, Ronald E. Olson

Physics Faculty Research & Creative Works

Recoil ion momentum spectroscopy has been applied to study low energy, state-selective single electron capture by highly charged projectiles. The specific systems investigated are fully stripped 6.82 keV/u Ne10+ 6.82 keV/u Ar18+ on He. Measurements of the He+ recoil ion longitudinal momenta are used to determine the final n-state dependence of the captured electron. Simultaneous measurement of the transverse momenta of the recoil ion yields information about the impact parameter dependence of the reaction and the reaction window for electron capture. © 1996 The American Physical Society.

The Missouri Miner, May 09, 1996

The Missouri Miner Newspaper

No abstract provided.

The Missouri Miner, May 02, 1996

The Missouri Miner Newspaper

No abstract provided.

Shear Wall Design Guide, Steel In Residential Construction Advisory Group

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

No abstract provided.

New Methods In Finite First-Order Model Search, Olga Shumsky, Fikret Ercal, Ralph W. Wilkerson

Computer Science Technical Reports

An automated first-order theorem prover, armed with appropriate strategies, will find a proof of a true conjecture, but will, in theory, run indefinitely if no proof exists. In reality, if no proof exists, the execution will be terminated by user-defined constraints, such as running time or memory usage limit. In this case the the question of validity of the conjecture remains unanswered. An automated first-order model generator gives one the ability to find counterexamples, if any exist, showing that the conjecture is invalid. A model generator also helps find the illustrations of previously proved theorems. It can be viewed as …

Application Of Neural Networks To The Non-Destructive Testing Of Aluminum Cans, B. Balasubramaniam, Daniel .. Clair

Computer Science Technical Reports

Neural Networks are used to c lassify aluminum beverage containers as acceptable or non acceptable, depending upon their wall thicknesses. For each can, the thickness of the wall of the can at different points is measured using a non-destructive, ultra-sound technique. These measureI\}ents are then applied as inputs to the networks and the classification is provided as the output Three architectures, one unsupervised and two supervised, are tested. Their performances are analyzed and compared and the paradigm best suited to the problem is selected.

Computer Assisted Control Of Robotic Rock Drilling Equipment Using Rock Face Image Mapping, William Robert Macneil, Peter (C. Y.)(Chung You) Ho

Computer Science Technical Reports

Use of a totally unmanned mining robot is an ideal solution in removing humans from the dangerous underground mining environment. However, a complete autonomous system is a long way from reality. In the meantime, steps towards that goal can be made and integrated into current mining technology to take away some of the risk and stress from the miner making him more alert and the environment safer for those that do have to be undergroμnd. For our purposes here, the machine will be an automated robotic platform with the intelligence necessary for accurate placement of the drill tip on an …

The Missouri Miner, May 01, 1996

The Missouri Miner Newspaper

No abstract provided.

A Fuzzy Logic Based Approach To Direct Load Control, K. Bhattacharyya, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

Demand side management programs are strategies designed to alter the shape of the load curve. In order to successfully implement such a strategy, customer acceptance of the program is vital. It is thus desirable to design a model for direct load control which may accommodate customer preferences. This paper presents a methodology for optimizing both customer satisfaction and utility unit commitment savings, based on a fuzzy load model for the direct load control of appliances

Dispersion Comparison For Dsi- And Tensor-Based Nonorthogonal Fdtd, Hao Shi, James L. Drewniak

Electrical and Computer Engineering Faculty Research & Creative Works

An explicit formulation of the finite-difference time-domain-discrete surface integral (FDTD-DSI) technique has allowed a rigorous study of numerical dispersion for the method. The study shows that the DSI- and tensor-based FDTD methods do not have the same numerical dispersion relation. It also clarifies the recently reported discrepancies in the dispersion relation between the two approaches. This study also shows that the tensor-based FDTD algorithm exhibits better dispersion properties for a two-dimensional uniformly skewed mesh.