Physical Sciences and Mathematics Commons^™

On Terminal Assignments That Minimize The Density, Mikhail J. Atallah, Susanne E. Hambrusch

Department of Computer Science Technical Reports

No abstract provided.

Monthly Planet, 1984, February, Sally Toteff, Huxley College Of The Environment, Western Washington University

The Planet

No abstract provided.

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.

Rediflow Multiprocessing, Robert M. Keller, Frank C. H. Lin, Jiro Tanaka

All HMC Faculty Publications and Research

We discuss the concepts underlying Rediflow, a multiprocessing system being designed to support concurrent programming through a hybrid model of reduction, dataflow, and von Neumann processes. The techniques of automatic load-balancing in Rediflow are described in some detail.

Electron Detachment In Negative-Ion Collisions. Ii. The Dynamical Complex Potential, T. S. Wang, John B. Delos

Arts & Sciences Articles

No abstract provided.

Bargaining Sets With Thresholds, Irinel C. Dragan

Mathematics Technical Papers

A concept of bargaining set for cooperative n person games with side payments has been defined by assuming that a player could be attracted in a new coalition only if his supplementary gain exceeds a fixed threshold and could reject a new coalition only if his loss exceeds another fixed threshold. Necessary and sufficient conditions for the existence of the objections with thresholds and for the existence of the counter objections with thresholds associated to couples consisting of a group of players and a coalition structure subjected to some conditions have been proved. These results enabled us to state a …

Las Vegas Wash Multispectral Scanner Survey, T. H. Mace, M. V. Olsen, Environmental Protection Agency

Publications (WR)

At the request of the U.S. Bureau of Reclamation, Boulder City, Nevada, the U.S. Environmental Protection Agency's Environmental Monitoring Systems Laboratory at Las Vegas collected multispectral scanner imagery of Las Vegas Wash on October 1, 1982.

A combined maximum likelihood classification and editing procedure was used to classify the multispectral scanner imagery into 12 categories of land cover. The classification identified four categories of marsh vegetation, one category of riparian, two categories of mixed scrub, and two desert categories. Turbid water and cultivated land formed an "other" category. Area tabulations were formed by georeferencing the classification to the Universal Transverse …

A Resource Survey Of The Coastal Lands From Vlaming Head To Tantabiddi Well, West Cape Range Region, P A. Hesp, J G. Morrissey

Resource management technical reports

The report comprise four parts; a brief review of the area's climate, discussion of the geomorphology of the major landform units, an assessment of the potential erosion hazards of the surveyed landforms, and recommendations for development.

H- And He In A Uniform Magnetic Field: Ground-State Wave Functions, Energies, And Binding Energies For Fields Below 109 G, Chang-Hwan Park, Anthony F. Starace

Anthony F. Starace Publications

Wave functions, energies, and binding energies for the lowest singlet states of H- and He in uniform magnetic fields B<10⁹ G are calculated using an adiabatic approximation in hyperspherical coordinates. In computing the angular part of the wave functions, a coupled expansion in one-electron oblate spheroidal angle functions is used. In addition to contracting the two-electron wave function radially, the magnetic field is found to distort the angular part of the wave function mainly by reducing the ss¹S character of the state and replacing it with an sd ¹D character. Results for energies and binding energies …

Coexistence And Spinodal Curves In Directionally Bonded Liquids Using The Four-Cluster Approximation, Erik Bodegom, Paul H. Meijer

Physics Faculty Publications and Presentations

We derive the phase diagrams and spinodals of binary liquid systems with anisotropic interactions, such as hydrogen-bonded molecules. The work is based on the four-particle cluster variation method, using a different potential for different contact points. It is shown that the introduction of a cluster larger than previously used by Barker and Fock, leads to a considerable improvement in the shape of the phase diagram and avoids some of the difficulties encountered in their calculation. Phase diagrams are displayed for various choices of the parameters: the number of contact points, the interaction potential, and the order of the approximation.

Electron Detachment In Negative-Ion Collisions. I. Time-Dependent Theory And Models For A Propagator, T. S. Wang, John B. Delos

Arts & Sciences Articles

A theory of electron detachment in slow collisions of negative ions with atoms is developed. The theory is based on assumptions that are similar to, but more general than, the assumptions made in earlier papers: The motion of the nuclei is described semiclassically, the electronic wave function is expanded in a partially diabatic basis that includes a discrete state and a continuum, and certain couplings are assumed to be small. With such assumptions the Schrödinger equation is reduced to a nondenumerably infinite set of coupled differential equations, and then to a single integro-differential equation (an equation with "memory"). It is …

Computer Studies In Particle Modeling Of Fluid Phenomena, Donald Greenspan

Mathematics Technical Papers

A new, numerical approach is developed for modeling fluid phenomena. Unlike the continuum and statistical mechanics approaches, it uses relatively small sets of quasi-molecular particles which interact in accordance with classical, molecular-type formulas. Computer examples are described and discussed, as is the potential for modeling turbulent behavior.

Simple On The Chip, D. Gannon, J. Panetta

Department of Computer Science Technical Reports

No abstract provided.

Fortran Extensions For Parallel And Vector Computation, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Scs 85: The Space Of Compact Convex Subsets Of A Locally Convex Topological Vector Space, Klaus Keimel

Seminar on Continuity in Semilattices

Source: University archive of the Technische Universität Darmstadt.

Optimal Rotation Problems In Channel Routing, Mikhail J. Atallah, Susanne E. Hambrusch

Department of Computer Science Technical Reports

No abstract provided.

The Effect Of Viscosity On Impact Cratering And Possible Application To The Icy Satellites Of Saturn And Jupiter, Jonathan H. Fink, Donald Gault, Ronald Greeley

Geology Faculty Publications and Presentations

Impact experiments in Newtonian fluids with a range of viscosities of 10^-3 to 60 Pa s demonstrate that transient prater volume and shape (depth-to-diameter: ratio) depend on target viscosity as well as on gravity. Volume is reduced, and depth-to-diameter ratio is increased for cratering events in which viscosity plays a dominant role. In addition to being affected by target kinematic viscosity, viscous scaling is most strongly influenced by projectile diameter, less strongly by projectile velocity, and least strongly by gravity. In a Planetary context, viscols effects can occur for craters formed by small or slow moving impacting bodies, low …

An Artin Relation (Mod 2) For Finite Group Actions On Spheres, Ronald M. Dotzel

Ronald Dotzel

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 …

Cretaceous Calcareous Nannofossils From Deep Sea Drilling Project Leg 77, Southeast Gulf Of Mexico, David K. Watkins, Jay L. Bowdler

Department of Earth and Atmospheric Sciences: Faculty Publications

Five of the six sites drilled during Leg 77 of the Deep Sea Drilling Project yielded Cretaceous sediments. Two of these sites, 535 and 540, form a composite section that spans the upper Berriasian through most of the Cenomanian. Olive black marly limestones in this interval yield relatively rich, well-preserved nannofossil assemblages that allow biostratigraphic subdivision of the sequence. This composite section provides important information on the Early Cretaceous history of the Gulf of Mexico, as well as additional information on tropical Lower Cretaceous nannofossil assemblages. The post-Cenomanian nannofossil (and sedimentary) record is limited to a thin, condensed section of …

Relative Dating Techniques To Distinguish Late Pleistocene-Holocene Continental Sediments, William J. Wayne

Department of Earth and Atmospheric Sciences: Faculty Publications

Radiometric dating, particularly with ¹⁴C, provides ages for those Late Pleistocene and Holocene sediments that contain datable materials. Standard stratigraphic and morphostratigraphic techniques of superposition, geomorphic position, partial overlap, and offlap provide relative chronology in many situations. The use of multiple relative dating (RD) techniques, developed for the study of glacial deposits, makes use of these techniques where possible, but depends heavily on the additional comparison of the results of surface processes that act continuously and more or less uniformly after accumulation is complete. For sediments at the surface that have not been buried, the most important of …

Two-Electron Lamb Shifts And 1s2s 3s1-1s2p 3pj Transition Frequencies In Helium-Like Ions [1], S. P. Goldman, Gordon W. F. Drake

Physics Publications

The leading terms in the 1/Z expansion of the two-electron Bethe logarithm are calculated for the states 1s2 1S0, 1s2s 1S1, 1s2s 3S1, 1s2p 1P1 and 1s2p 3PJ by the use of a novel finite basis set method. The resulting QED terms are combined with other relativistic and mass polarisation corrections to obtain total transition frequencies. The results are compared with recent measurements in helium-like ions from Li+ to Fe24+.

Sea Grant College Designation Program, Virginia Institute Of Marine Science, School Of Marine Science, College Of William And Mary

Miscellaneous

October 25, 1984. The designation of the Virginia Sea Grant Program as the nation's twentieth National Sea Grant College Program in January 1984, recognized that the Sea Grant activities in Virginia were providing state and national leadership in the marine sciences and related fields.

Water Current, Volume 16, No. 1, January/February 1984

Water Current Newsletter

Director's Report
Water Policy Alternatives
Computerized Pivot Management Tested
Federal Water Publications
Research Review: Water Conservation Through Limited Irrigation of Corn and Grain Sorghum in the Great Plains
Call for Papers

Causes Of Uprooting And Breakage Of Specimen Giant Sequoia Trees, Douglas D. Piirto, W. Wayne Wilcox, John R. Parmeter, Jr., David L. Wood

Natural Resources Management and Environmental Sciences

A study of the causes of uprooting and stem failure in old-growth giant sequoia (Sequoia gigantea [Lindl.] Decne) indicated many factors, depending upon the type of failure (by root, stem, or earth). Advanced decay and fire scars were the most frequently associated with failure. In 21 of 33 study trees, one-third or more of the roots were judged too decayed to provide support. Twenty-seven study trees possessed basal fire scars, and 26 fell toward the scarred side. Nine Basidiomycetes, including Fomes annosus, Poria albipellucida, Poria incrassata, and Armillaria mellea, were associated with decayed wood. Carpenter ants were found …

Enumeration Of Permutations By Descents, Idescents, Imajor Index, And Basic Components, Don Rawlings

Mathematics

Multivariable extensions of classic permutation cycle structure results are obtained by counting permutations by descents, idescents, imajor index, and basic components.

Hydrogeochemical Aspects Of Surface Mine Reclamation In The Northern Great Plains, Gerald H. Groenewold, Robert D. Koob

Office of the Provost Scholarship

Studies of several coal-mining sites in western North Dakota have resulted in the development of a hydrogeochemical model which accounts for the observed chemical characteristics of subsurface water in undisturbed settings. Critical hydrogeochemical processes include sulfide oxidation, gypsum precipitation and dissolution, carbonate mineral dissolution and cation exchange.

In the semi-arid climate of western North Dakota, the near-surface several meters of the landscape is constantly subjected to alternate wetting/drying. This mechanism is the key to hydrogeochemical evolution of both pore water in the rooting zone and subsurface water that eventually reaches the water table.

Recent refinements in the hydrogeochemical model have …

The Historical Development Of The Yakima-Tieton Irrigation District And Its Present Effect On Life In The Area Encompassing The District, Werner E. Lemke

All Graduate Projects

Irrigation played a very important role in the development of the Yakima Valley as we know it today. The Yakima-Tieton Irrigation District was chosen to show how an irrigation system functions and the part it plays on the lives of the plants, animals and people in its area. A brief historical study of the Tieton Division of the Yakima Project was made. The construction of the Tieton Unit was studied. A slide lecture with an accompanying tape was developed to acquaint junior high school students with the purpose, function and affects of the Yakima-Tieton Irrigation District.