Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

1988

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 1 - 30 of 1188

Full-Text Articles in Physical Sciences and Mathematics

Symbolic Automation And Numerical Synthesis For Robot Kinematics, Jen Sriwattanathamma, Chung You Ho Dec 1988

Symbolic Automation And Numerical Synthesis For Robot Kinematics, Jen Sriwattanathamma, Chung You Ho

Computer Science Technical Reports

This research analyzes three topics in robot arm kinematics. First, the direct kinematics which determines the Cartesian position and orientation of the end effector for the specified values of joint parameters is analyzed. Second, the differential motions concerning the differential relationships between the command variables in position and orientation of the end effector and the joint-controlled variables are studied. Finally, the inverse kinematics which determines the joint variables for a specified Cartesian position and orientation of the end effector is considered.

This dissertation presents a methodology for incorporating the artificial intelligence types of knowledge into automating solutions for the direct …


A Band And Bound Technique For Simple Random Algorithms, Vernon J. Rego Dec 1988

A Band And Bound Technique For Simple Random Algorithms, Vernon J. Rego

Department of Computer Science Technical Reports

No abstract provided.


Hydrodynamic Forces And Band Formation In Swimming Magnetotactic Bacteria, D. C. Guell, H. Brenners, Richard B. Frankel, H. Hartman Dec 1988

Hydrodynamic Forces And Band Formation In Swimming Magnetotactic Bacteria, D. C. Guell, H. Brenners, Richard B. Frankel, H. Hartman

Physics

Dense suspensions of magnetotactic bacteria form long, thin, stable bands perpendicular to the common, net direction of motion of the cells in a magnetic field. A mechanism for this phenomenon is proposed in which the hydrodynamic coupling between two swimming cells is described in terms of an approximate, far-field solution for the flow around one swimming cell. The calculated hydrodynamic interaction force and torque based upon this analysis are of the correct orders of magnitude and in the right directions to provide a reasonable explanation for band formation and stability.


Machine Knowledge Maniputation Issues In Parallel Compilers, Ko-Yang Wang, Dennis Gannon, Piyush Mehrotra Dec 1988

Machine Knowledge Maniputation Issues In Parallel Compilers, Ko-Yang Wang, Dennis Gannon, Piyush Mehrotra

Department of Computer Science Technical Reports

No abstract provided.


On The Bottleneck And Capacity Assignment Problems, Wojciech Szpankowski Dec 1988

On The Bottleneck And Capacity Assignment Problems, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.


Effects Of Surfaces On Dynamic Percolation, H. K. Janssen, B. Schaub, Beate Schmittmann Dec 1988

Effects Of Surfaces On Dynamic Percolation, H. K. Janssen, B. Schaub, Beate Schmittmann

Beate Schmittmann

The general epidemic process, which is a stochastic multiparticle process belonging to the universality class of dynamic percolation, is studied in a semi-infinite geometry. Critical exponents characterizing the fractal properties are calculated to O(ε) (ε=6-d, where d is the spatial dimension) with use of renormalization-group techniques.


Modified Broyden’S Method For Accelerating Convergence In Self-Consistent Calculations, Duane D. Johnson Dec 1988

Modified Broyden’S Method For Accelerating Convergence In Self-Consistent Calculations, Duane D. Johnson

Duane D. Johnson

A modification to Broyden’s method for obtaining stable and computationally efficient convergence in self-consistent calculations is developed and discussed. The method incorporates the advantages of two schemes proposed by Srivastava and by Vanderbilt and Louie without any increase in complexity. Its improvement over their methods is discussed. The present method is compared with two other widely used convergence methods, simple mixing and Anderson’s method, for the case of the disordered binary alloy Ni0.35Fe0.65 on the verge of a magnetic instability and is shown to be much improved in stability and rate of convergence.


Elliptic Expert: The Design Of An Expert System For Elliptic Partial Differential Equations, Wayne R. Dyksen, Carl R. Gritter Dec 1988

Elliptic Expert: The Design Of An Expert System For Elliptic Partial Differential Equations, Wayne R. Dyksen, Carl R. Gritter

Department of Computer Science Technical Reports

No abstract provided.


Quaternary Alluvial Sequence Of The Upper Pecos River And A Tributary, Glorieta Creek, North-Central New Mexico, Paul Arthur Karas Dec 1988

Quaternary Alluvial Sequence Of The Upper Pecos River And A Tributary, Glorieta Creek, North-Central New Mexico, Paul Arthur Karas

Earth and Planetary Sciences ETDs

Quaternary alluvial deposits preserved on terraces along the Pecos River and a tributary, Glorieta Creek, provide a record of the evolution of these two drainages. Alluvium deposited by the Pecos River can be subdivided into six units on the basis of relative topographic position and degree of soil development on original surfaces. Deposits consist of thin (1 to 10m) veneers on scattered strath terrace remnants. Only four Quaternary alluvial units have been identified along Glorieta Creek. Alluvium deposited by this stream forms nearly continuous fill terraces of thickness equal to or greater than the Pecos River alluvium. Alluvial deposits of …


Hermite Interpolation Of Rational Space Curves Using Real Algebraic Surfaces, Chanderjit Bajaj, Insung Ihm Dec 1988

Hermite Interpolation Of Rational Space Curves Using Real Algebraic Surfaces, Chanderjit Bajaj, Insung Ihm

Department of Computer Science Technical Reports

No abstract provided.


Xellpack: An Interactive Problem Solving Environment For Elliptic Partial Differential Equations, Jophn P. Bonomo, Wayne R. Dyksen Dec 1988

Xellpack: An Interactive Problem Solving Environment For Elliptic Partial Differential Equations, Jophn P. Bonomo, Wayne R. Dyksen

Department of Computer Science Technical Reports

No abstract provided.


Effects Of Autonomy On Maintaining Global Serializability In Heterogeneous Database Systems, W. Du, Ahmed K. Elmagarmid, Y. Leu, S. F. Ostermann Dec 1988

Effects Of Autonomy On Maintaining Global Serializability In Heterogeneous Database Systems, W. Du, Ahmed K. Elmagarmid, Y. Leu, S. F. Ostermann

Department of Computer Science Technical Reports

No abstract provided.


Quasi Serializability: A Correctness Criterion For Interbase, Ahmed K. Elmagarmid Dec 1988

Quasi Serializability: A Correctness Criterion For Interbase, Ahmed K. Elmagarmid

Department of Computer Science Technical Reports

No abstract provided.


A Dimensionality Paradigm For Surface Interrogations, Christoph M. Hoffmann Dec 1988

A Dimensionality Paradigm For Surface Interrogations, Christoph M. Hoffmann

Department of Computer Science Technical Reports

No abstract provided.


Quantitative Footprinting Analysis Using A Dna-Cleaving Metalloporphyrin Complex+, James C. Dabrowiak, Brian Ward, Jerry Goodisman Dec 1988

Quantitative Footprinting Analysis Using A Dna-Cleaving Metalloporphyrin Complex+, James C. Dabrowiak, Brian Ward, Jerry Goodisman

Chemistry - All Scholarship

The results of quantitative footprinting studies involving the antiviral agent netropsin and a DNA-cleaving cationic metalloporphyrin complex are presented. An analysis of the footprinting autoradiographic spot intensities using a model previously applied to footprinting studies involving the enzyme DNase I [Ward, B., Rehfuss, R., Goodisman, J., & Dabrowiak, J. C. (1988) Biochemistry 27, 1198-12051 led to very low values for netropsin binding constants on a restriction fragment from pBR-322 DNA. In this work, we show that, because the porphyrin binds with high specificity to DNA, it does not report site loading information in the same manner as does DNase I. …


Distributed Operation Language For Specification And Processing Of Multidatabase Applications, Marek Rusinkiewicz, Kanchei Loa, Ahmed K. Elmagarmid Dec 1988

Distributed Operation Language For Specification And Processing Of Multidatabase Applications, Marek Rusinkiewicz, Kanchei Loa, Ahmed K. Elmagarmid

Department of Computer Science Technical Reports

No abstract provided.


The Effect Of Solvent Type On The Infrared Spectrum Of Carbon Monoxide Adsorbed At Platinum Electrodes, Mark Anderson, Daniel Blackwood, Thomas Richmond, Stanley Pons Dec 1988

The Effect Of Solvent Type On The Infrared Spectrum Of Carbon Monoxide Adsorbed At Platinum Electrodes, Mark Anderson, Daniel Blackwood, Thomas Richmond, Stanley Pons

Mark R. Anderson

The infrared spectrum of CO adsorbed on a platinum electrode from several solvents was investigated. In N-methylformamide, acetonitrile, and 1,2-dichloroethane, the infrared band attributed to linearly bonded CO had experimental Stark tuning rates of 20 cm−1/V, 22 cm−1/V, and 19 cm−1/V, respectively. For each of these solvents, the potential dependence of the band position was found to be linear for the entire potential range investigated. When methanol was the solvent, the plot of the band position versus potential had three distinctly linear portions, each with a different value for the slope. The behavior is explained in terms of the ability …


The Behavior Of The Infrared Spectrum Of Carbon Monoxide Adsorbed At Platinum Electrodes From Non-Aqueous Solvents, Mark Anderson, Daniel Blackwood, Stanley Pons Dec 1988

The Behavior Of The Infrared Spectrum Of Carbon Monoxide Adsorbed At Platinum Electrodes From Non-Aqueous Solvents, Mark Anderson, Daniel Blackwood, Stanley Pons

Mark R. Anderson

Electrochemical oxidation of vanadium hexacarbonyl anion, V(Co)6 in aprotic solvents results in formation of the V(0) complex which decomposes to form CO in high concentrations next to the electrode surface. As a result, CO is more rapidly adsorbed on the surface than by conventional methods. Surface reflection infrared spectroscopy shows that the potential dependent frequency shift for the infrared active bands due to CO adsorbed on platinum is 19 cm−1/V in 1,2-dichloroethane and 22 cm−1/V in acetonitrile, which are considerably less than the 30 cm−1/V observed in aqueous systems.


Convex Decompositions Of Simple Polyhedra, Chanderjit Bajaj, Tamal K. Dey Dec 1988

Convex Decompositions Of Simple Polyhedra, Chanderjit Bajaj, Tamal K. Dey

Department of Computer Science Technical Reports

No abstract provided.


Microstructure Of Epitaxial Ybba2Cu3O7 Superconducting Films Grown By A New Liquid-Gas-Solidification Technique, C.H. Chen, H.S. Chen, Sy_Hwang Liou Dec 1988

Microstructure Of Epitaxial Ybba2Cu3O7 Superconducting Films Grown By A New Liquid-Gas-Solidification Technique, C.H. Chen, H.S. Chen, Sy_Hwang Liou

Sy-Hwang Liou Publications

We have studied the microstructures of epitaxial YbBa2Cu3O7 superconducting films grown on SrTiO3 [100] and [110] substrates by a new liquid-gas-solidification processing technique. Films grown on SrTiO3 [100] and [110] substrates are epitaxially oriented with [001] and [110] axes normal to the film surface. Twinned domains of ~200 Å in size are observed in the [001] oriented films. Most defects observed can be attributed to the presence of stacking faults along the c axis. The presence of Cu-O bilayer defects is also observed. Rapid oxygen diffusion in the liquid phase is found to …


Non-Algorithmic Load Imbalance Effects For Domain Decomposition Methods On A Hypercube, Dan C. Marinescu, John R. Rice Dec 1988

Non-Algorithmic Load Imbalance Effects For Domain Decomposition Methods On A Hypercube, Dan C. Marinescu, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.


A Parallel Implementation Of Stickel's Ac Unification Algorithm In A Message-Passing Environment, David John Kleikamp, Ralph W. Wilkerson Dec 1988

A Parallel Implementation Of Stickel's Ac Unification Algorithm In A Message-Passing Environment, David John Kleikamp, Ralph W. Wilkerson

Computer Science Technical Reports

Unification algorithms are an essential component of automated reasoning and term rewriting systems. Unification finds a set of substitutions or unifiers that, when applied to variables in two or more terms, make those terms identical or equivalent. Most systems use Robinson's unification algorithm or some variant of it. However, terms containing functions exhibiting properties such as associativity and commutativity may be made equivalent without appearing identical. Systems employing Robinson's unification algorithm must use some mechanism separate from the unification algorithm to reason with such functions. Often this is done by incorporating the properties into a rule base and generating equivalent …


A System For The Diagnosis Of Faults Using A First Principles Approach, Barbara A. Smith, Ralph W. Wilkerson Dec 1988

A System For The Diagnosis Of Faults Using A First Principles Approach, Barbara A. Smith, Ralph W. Wilkerson

Computer Science Technical Reports

One of the primary areas of application of Artificial Intelligence is diagnosis. Diagnosis from first principles is a diagnostic technique which uses knowledge of the designed structure and function of a device to determine the possible causes of the malfunction.

This work builds on the foundation of a theory of diagnosis by implementing and extending the theory. A correction to the algorithm which defines the theory is presented. The theory is extended for multiple sets of observations of the system and measurement data.

A fundamental problem in diagnosis is selecting the measurement which will be of the most benefit in …


Polymer Science In Romania I: "Petru Poni" Institute Of Macromolecular Chemistry, Iasi, Romania, Otto Vogl, Cristofor I. Simionescu, Ioan I. Negulescu Dec 1988

Polymer Science In Romania I: "Petru Poni" Institute Of Macromolecular Chemistry, Iasi, Romania, Otto Vogl, Cristofor I. Simionescu, Ioan I. Negulescu

Emeritus Faculty Author Gallery

No abstract provided.


U.S.-Japan Seminar: "Synthesis, Properties And Reactions Of Specialty Polymers", Otto Vogl, Hiroshi Sumitomo Dec 1988

U.S.-Japan Seminar: "Synthesis, Properties And Reactions Of Specialty Polymers", Otto Vogl, Hiroshi Sumitomo

Emeritus Faculty Author Gallery

No abstract provided.


Wetlands Board Bulletin Vol. Iii, No. 3, Virginia Institute Of Marine Science Dec 1988

Wetlands Board Bulletin Vol. Iii, No. 3, Virginia Institute Of Marine Science

Virginia Wetlands Reports

  • Recycling The Greenhouse Effect, Sea Level Rise, and Their Impact on Tidal Wetlands. Julie G. Bradshaw
  • City of Norfolk/Profiles of Wetlands Board Members.


The Soils Of The Salmon Gums District, Western Australia, George Henry Burvill Dec 1988

The Soils Of The Salmon Gums District, Western Australia, George Henry Burvill

Technical Bulletins

Most of the soils are grey and brown solonized soils. The subsoils, to about 2 m, are calcareous sandy clays with limestone rubble, but there are three main surface variations: sandy surfaced, 5-30 cm deep, passing abruptly to the sandy clay subsoil with lime nodules. The Circle Valley sand and Scaddan sand are major types. Scaddan sand has a domed subsoil clay. Powdery calcareous sandy loam; and clay loam and clay with some lime in the subsoil, but less than in 1 and 2.


Safe Disposal Of Pesticide Containers And Residue, Doug Johnson, Monroe Rasnake, James Martin Dec 1988

Safe Disposal Of Pesticide Containers And Residue, Doug Johnson, Monroe Rasnake, James Martin

Soil Science News and Views

The use of pesticides (herbicides, insecticides, fungicides, etc.) has been an important factor in improving productivity of American agriculture to the point that quantity and quality of food and fiber produced by American farmers is unequalled in the world. However, in recent years, increased concern is being expressed regarding potential harmful effects of pesticide use on the environment. Most farmers want to know how to safely handle pesticides and dispose of waste materials, and the pesticide industry is working hard to develop better systems for handling pesticides. However, poor disposal practices are still too common.


Nuclear-Spin Relaxation In Molecular Solids With Reorienting Methyl And T-Butyl Groups: The Spectral Density And The State Of The Solid, Peter A. Beckmann, Audrey I. Hill, Ellen B. Kohler, Hong Yu Dec 1988

Nuclear-Spin Relaxation In Molecular Solids With Reorienting Methyl And T-Butyl Groups: The Spectral Density And The State Of The Solid, Peter A. Beckmann, Audrey I. Hill, Ellen B. Kohler, Hong Yu

Physics Faculty Research and Scholarship

There are two solid phases which either have a large hysteresis of at least 90 K, or are both stable below 200 K. The sample melts at 262 K. We interpret the high-temperature phase R-versus-T-1 data with three models. First, we adopt a one-correlation-time model using a Davidson-Cole spectral density which suggests that there is a distribution of correlation times, or, equivalently, a distribution of activation energies for t-butyl and methyl group reorientation. In this case, the methyl and t-butyl reorientation is characterized by a cutoff activation energy of 17±1 kJ/mol which is to be compared with 18±1 kJ/mol in …


Parenago 1540: A Pre-Main-Sequence Double-Lined Spectroscopic Binary Near The Orion Trapezium, Laurence A. Marschall, Robert D. Mathieu Dec 1988

Parenago 1540: A Pre-Main-Sequence Double-Lined Spectroscopic Binary Near The Orion Trapezium, Laurence A. Marschall, Robert D. Mathieu

Physics and Astronomy Faculty Publications

Spectroscopic and photometric observations of the star Parenago 1540 (V = 11.3), located 10 arcmin west of the Trapezium in Orion, have shown the star to be a pre-main-sequence double-lined spectroscopic binary. Thirty-seven radial-velocity measurements were obtained from which the orbital elements of the binary were determined, in particular an orbital period P = 33.73 + 0.03 days and an eccentricity of e = 0.12 + 0.01. High-dispersion spectra reveal strong Li 6707 A absorption lines in each of the components of P1540. A spectrum at lower dispersion also shows strong Ca II H and K emission lines, not …