Physical Sciences and Mathematics Commons^™

Least Squares Approximation Of Bezier Coefficients Provides Best Degree Reduction In The L 2-Norm, J. Peters, U Reif

Department of Computer Science Technical Reports

No abstract provided.

Visualizing Three-Dimensional Configuration Spaces For Mechanical Design, Elisha Sacks, Charles Pisula, Leo Joskowicz

Department of Computer Science Technical Reports

No abstract provided.

Mid-Infrared Visibility Measurements Of Evolved Stars, Jeffrey J. Sudol, H. M. Dyck, R. E. Stencel, D. I. Klebe, M. J. Creech-Eakman

Physics & Engineering Faculty Publications

No abstract provided.

Parity Nonconservation In Neutron Resonances In 133cs, E I. Sharapov, J D. Bowman, Bret E. Crawford, P P J. Delheij, T Haseyama, J N. Knudsen, L Y. Lowie, A Masaike, Y Matsuda, G E. Mitchell, S I. Penttila, H Postma, N R. Roberson, S J. Seestrom, Sharon L. Stephenson, Y-F Yen, V W. Yuan

Physics and Astronomy Faculty Publications

Spatial parity nonconservation (PNC) has been studied in the compound-nuclear states of ¹³⁴Cs by measuring the helicity dependence of the neutron total cross section. Transmission measurements on a thick ¹³³Cs target were performed by the time-of-flight method at the Manuel Lujan Neutron Scattering Center with a longitudinally polarized neutron beam in the energy range from 5 to 400 eV. A total of 28 new p-wave resonances were found, their neutron widths determined, and the PNC longitudinal asymmetries of the resonance cross sections measured. The value obtained for the root-mean-square PNC element M=(0.06_-0.02^+0.25) meV in ^{133 …}

Residual Native Shallow Donor In Zno, David C. Look, Joseph W. Hemsky, J. R. Sizelove

Physics Faculty Publications

High-energy electron irradiation in ZnO produces shallow donors at about E_C-30meV. Because the production rate is much higher for Zn-face (0001) than O-face (0001̅ ) irradiation, the donor is identified as a Zn-sublattice defect, most likely the interstitial Zn_I or a Zn_I-related complex. The donor energy is quite close to that of the unirradiated sample, and of other samples discussed in the literature, strongly suggesting that Zn_I (and not V_O) is the dominant native shallow donor in ZnO. An exceptionally high displacement threshold energy (∼1.6MeV) is quantitatively explained in terms of a …

Can Kiva Accurately Simulate A Gas Turbine Combustor?, John R. Rice

Department of Computer Science Technical Reports

No abstract provided.

Asymptotic Solitons Of The Extended Korteweg–De Vries Equation, Timothy R. Marchant

Faculty of Informatics - Papers (Archive)

The interaction of two higher-order solitary waves, governed by the extended Korteweg–de Vries (KdV) equation, is examined. A nonlocal transformation is used on the extended KdV equation to asymptotically transform it to the KdV equation. The transformation is used to derive the higher-order two-soliton collision and it is found that the interaction is asymptotically elastic. Moreover, the higher-order corrections to the phase shifts suffered by the solitary waves during the collision are found. Comparison is made with a previous result, which indicated that, except for a special case, the interaction of higher-order KdV solitary waves is inelastic, with a coupling, …

Nontoric Hamiltonian Circle Actions On Four-Dimensional Symplectic Orbifolds, S. F. Singer, Janet Talvacchia, N. Watson

Mathematics & Statistics Faculty Works

We construct four-dimensional symplectic orbifolds admitting Hamiltonian circle actions with isolated fixed points, but not admitting any Hamiltonian action of a two-torus. One example is linear, and one example is compact.

Field Station Under Threat, Paul Faulstich

Pitzer Faculty Publications and Research

As reported in the last issue of The Other Side, The Bernard Biological Field Station of the Colleges is slated to be the site of the Keck Graduate Institute, the newest (but yet unbuilt) addition to the Claremont Consortium. With Pitzer casting the sole dissenting vote, the Claremont Colleges approved construction of the Keck Institute on eleven acres of the 85 acre Field Station.

Judicial Politics, Death Penalty Appeals, And Case Selection: An Empirical Study, John H. Blume, Theodore Eisenberg

Cornell Law Faculty Publications

Several studies try to explain case outcomes based on the politics of judicial selection methods. Scholars usually hypothesize that judges selected by partisan popular elections are subject to greater political pressure in deciding cases than are other judges. No class of cases seems more amenable to such analysis than death penalty cases. No study, however, accounts both for judicial politics and case selection, the process through which cases are selected for death penalty litigation. Yet, the case selection process cannot be ignored because it yields a set of cases for adjudication that is far from a random selection of cases. …

Molecular Dynamics Study Of A Phase-Separating Fluid Mixture Under Shear Flow, Ryoichi Yamamoto, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Molecular dynamics simulation is carried out to study domain structures and rheological properties of a two-dimensional phase-separating binary fluid mixture under shear flow. In the early stage of the phase separation, anisotropic composition fluctuations appear immediately after the quench. As the domain grows, the anisotropy in the composition fluctuations increases. The quenched system eventually reaches a dynamical steady state, in which anisotropic domain structures are preserved. In the steady state, the shortest characteristic length scale R⊥ of domains decreases with increasing shear rate γ̇ as R⊥∼γ̇^-1/3. Stringlike domain structures are observed in the strong shear regime, …

Formation Free Energy Of Clusters In Vapor-Liquid Nucleation: A Monte Carlo Simulation Study, K.J. Oh, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

The formation free energy of clusters in a supersaturated vapor is obtained by a constrained Monte Carlo technique. A key feature of this approach is to set an upper limit to the size of cluster. This maximum cluster size serves essentially as an extra thermodynamic variable that constrains the system. As a result, clusters larger than the critical cluster of nucleation in the supersaturated vapor can no longer grow beyond the limiting size. Like changing the overall density of the system, changing the maximum cluster size also results in a different supersaturation and thereby a different formation free energy. However, …

Geometrodynamical Formulation Of Two-Dimensional Dilaton Gravity, Marco Cavaglia

Physics Faculty Research & Creative Works

Two-dimensional matterless dilaton gravity with an arbitrary dilatonic potential can be discussed in a unitary way, both in the Lagrangian and canonical frameworks, by introducing suitable field redefinitions. The new fields are directly related to the original spacetime geometry and in the canonical picture they generalize the well-known geometrodynamical variables used in the discussion of the Schwarzschild black hole. So the model can be quantized using the techniques developed for the latter case. The resulting quantum theory exhibits the Birkhoff theorem at the quantum level.

Measurement Of ZT0 And Drell-Yan Production Cross Sections Using Dimuons In P̅P Collisions At √S =1.8 Tev, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We present a measurement of Z⁰ boson and Drell-Yan production cross sections in p̅p collisions at √s =1.8 TeV using a sample of 107 pb^-1 accumulated by the Collider Detector at Fermilab. The Drell-Yan cross section is measured in the mass range of M_μμ>40 GeV/c². We compare the measurements with the predictions of quantum chromodynamics in both leading order and next-to-leading order, incorporating the recent parton distribution functions. The measurements are consistent with the standard model expectations.

Megamaser Disks In Active Galactic Nuclei, John F. Kartje, Arieh Königl, Moshe Elitzur

Physics and Astronomy Faculty Publications

Recent spectroscopic and VLBI-imaging observations of bright extragalactic H₂O maser sources have revealed that the megamaser emission often originates in thin circumnuclear disks near the centers of active galactic nuclei (AGNs). Using general radiative and kinematic considerations and taking account of the observed flux variability, we argue that the maser emission regions are clumpy, a conclusion that is independent of the detailed mechanism (X-ray heating, shocks, etc.) driving the collisionally pumped masers. We examine scenarios in which the clumps represent discrete gas condensations (i.e., clouds) and do not merely correspond to velocity irregularities in the disk. We show …

The Prairie Naturalist Volume 31, No.1 March 1999

The Prairie Naturalist

NEST SITE CHARACTERISTICS OF RING-NECKED PHEASANTS IN EASTERN SOUTH DAKOTA ▪ J. R. Purvis, A. E. Gabbert, and L. D. Flake

FIELD EVALUATION OF RADIOTRANSMITTERS FOR NORTHERN POCKET GOPHERS ▪ G. W. Witmer and M. J. Pipas

DISTRlBllTiON OF A MOlJND-BUILDING ANT ON NATIVE AND RESTORED PRAIRIES IN NORTHEASTERN KANSAS ▪ J. Foster and W. D. Kettle

RESULTS OF A WILD TURKEY RELEASE IN KANSAS TALLGRASS PRAIRIE ▪ J. F. Cully, Jr., P. R. Lemons, II, and R. D. Applegate

BODY-SIZE AND AGE'-RELATED MASTICATORY RELATIONSHIPS IN TWO SPECIES OF BLARINA ▪ B. J. Verts, L. N. Carraway, and R. A. …

A Note On Gravity Wave-Driven Volume Emission Rate Weighted Temperature Perturbations Inferred From O₂ Atmospheric And O I 5577 Airglow Observations, Michael P. Hickey Ph.D., Richard L. Walterscheid

Publications

A full-wave dynamical model and chemistry models that simulate ground-based observations of gravity wave-driven O₂ atmospheric and O I 5577 airglow fluctuations in the mesopause region are used to demonstrate that for many observable gravity waves modeling is required to infer temperature perturbation amplitudes from airglow observations. We demonstrate that the amplitude of the altitude-integrated volume emission rate weighted temperature perturbation differs by at least about 30% from the amplitude of the temperature perturbation of the major gas in the vicinity of the peak of the airglow volume emission rate for gravity waves with horizontal phase speeds less than about …

The Probe, Issue 198 – March 1999

The Probe: Newsletter of the National Animal Damage Control Association

NADCA benefits its members
Fifth Annual Wildlife Control Technology Instructional Seminar
Bob Willging Fund Established
Woodstream Drops Victor Traps
Activist Gets 7 Years in Prison
Egret Control Goes Badly
Foxes Threaten Plovers in Maine
Controversy Boils In Arizona Predator Hunt Contests

Abstracts from the 5th Annual Conference of The Wildlife Society

The Prospect of Using Oral Vaccination to Control Rabies in Raccoons in the Northeast -- D.H. Lein and L.L. Bigler
Past and Current Methods for Controlling Rabies in Wildlife -- S.B. Linhart and C.L. Brown
Elimination of Fox Rabies from Ontario, Canada -- CD. Maclnnes
A Computer Model for …

Data Integration By Describing Sources With Constraint Databases, Xun Cheng, Guozhu Dong, Tzekwan Lau, Jianwen Su

Kno.e.sis Publications

We develop a data integration approach for the efficient evaluation of queries over autonomous source databases. The approach is based on some novel applications and extensions of constraint database techniques. We assume the existence of a global database schema. The contents of each data source are described using a set of constraint tuples over the global schema; each such tuple indicates possible contributions from the source. The “source description catalog” (SDC) of a global relation consists of its associated constraint tuples. Such a method of description is advantageous since it is flexible to add new sources and to modify existing …

Efficient Mining Of Partial Periodic Patterns In Time Series Database, Jiawei Han, Guozhu Dong, Yiwen Yin

Kno.e.sis Publications

Partial periodicity search, i.e., search for partial periodic patterns in time-series databases, is an interesting data mining problem. Previous studies on periodicity search mainly consider finding full periodic patterns, where every point in time contributes (precisely or approximately) to the periodicity. However, partial periodicity is very common in practice since it is more likely that only some of the time episodes may exhibit periodic patterns.

We present several algorithms for efficient mining of partial periodic patterns, by exploring some interesting properties related to partial periodicity, such as the Apriori property and the max-subpattern hit set property, and by shared mining …

Infrared Cavity Ringdown Spectroscopy Of Methanol Clusters: Single Donor Hydrogen Bonding, R. A. Provencal, J. B. Paul, K. Roth, C. Chapo, R. N. Casaes, R. J. Saykally, G. S. Tschumper, H. F. Schaefer

Chemistry Faculty Research & Creative Works

Infrared cavity ringdown laser absorption spectroscopy has been used to study the O-H stretching vibrations of jet-cooled methanol clusters in direct absorption. Rovibrational bands for (CH₃OH)₂, (CH₃OH)₃, and (CH₃OH)₄ have been measured. Both bonded and free O-H stretches were measured for the dimer, indicating that its structure is linear. Five bands were assigned to the methanol trimer, indicating the presence of a second cyclic isomer in the molecular beam. A detailed study of the free O-H stretching region shows that methanol clusters larger than dimer must exist in cyclic …

Kinetic Model Of A Space-Based, Br (4 2P1/2 → 4 2P3/2) Laser Pumped By Solar Photolysis Of Ibr, Barry N. Behnken

Theses and Dissertations

A kinetic model of the directly solar-pumped, atomic bromine laser-operating on the Br (4 ²P_1/2 → 4 ²P_3/2) transition under IBr photolysis-was developed, executed, and interpreted. In recognition of an evolving national interest in space-based laser development, the model presumed operation on a space station platform. Results indicate that a well-engineered IBr laser is capable of generating 1.2 kilowatts of continuous-wave (CW) power under a pumping concentration of 20,000 solar units. Such performance translates to an efficiency of roughly 0.29%, appreciably better than the 0.1% ascribed to the heretofore leading solar-pumped competitor. An extensive analysis …

Use Of Diffuse Reflectance Spectroscopy To Determine Desorption Coefficients Of Trichioroethylene From Powdered Soils, Jay H. Foil

Theses and Dissertations

This laboratory thesis investigated the applicability of reflectance spectroscopy as a tool to measure desorption rates by directly observing the change in trichloroethylene bound to surface sites. Diffuse reflectance spectroscopy holds the promise of being a faster technique with minimal sample preparation time. Reflectance spectroscopy's dependence on the surface of the sample is its greatest advantage, as well as its greatest disadvantage. Both high and low resolution scans were made of different soil samples contaminated by trichloroethylene. After the technique of spectral subtraction was used, potential TCE signals were observed from the dolomitic limestone sample. Unfortunately, due to the low …

Space Charge Structure Of A Glow Discharge In The Presence Of A Longitudinal Inhomogeneity, Frank A. Tersigni

Theses and Dissertations

A survey of space charge structures arising due to inhomogeneities in glow discharges was conducted. Space charge structures associated with tube geometries, the cathode sheath, striations, and shockwaves were examined. Space charge effects on the Electron Energy Distribution Function (EEDF) were explored for a geometric inhomogeneity using an approximate nonlocal solution to the one dimensional Boltzmann equation after Godyak. The approximate solution partially captured qualitative aspects of space charge effects on the EEDF. Simplification of collisional effects and adaptation of an approximate electric field restricted quantitative comparisons with experimental data. It is recommended that any future analysis of space charge …

Parallel Data Mining With The Message Passing Interface Standard On Clusters Of Personal Computers, Lonnie P. Hammack

Theses and Dissertations

Piles of personal computers (PoPCs) have begun to challenge the performance of the traditional Massively Parallel Processors (MPPs) and the less traditional networks of workstations (NOWs) as platforms for parallel computing. Large clusters of PCs have reached and at times exceeded the performance of modern MPPs at a fraction of the cost. Built with commodity components, these clusters can be constructed for about half the cost of a comparable NOW. The primary competing operating systems (OIS) in use on PoPCs are Linux and Windows NT. This thesis investigation compares the performance of an NT cluster with that of a Linux …

A Modeling And Simulation Approach To Analyze The Workload Associated With The Growth Of Network Router Access Control Lists, Douglas R. Lomsdalen

Theses and Dissertations

Organizations can no longer isolate their networks from the rest of the world and still remain competitive. An organization willing to compete in the world market must take the necessary precautions to protect its network, the systems located on those networks, and its mission critical data. There are performance issues associated with the use of access control lists (ACL); however, if ACLs are implemented properly and periodically reviewed, a secure network can be attained. This research attempts to determine how the growth of an ACL affects packet flow and router CPU consumption, and also identify the specific length of an …

An Improved Thunderstorm Forecast Index For Cape Canaveral, Florida, James A. Everitt

Theses and Dissertations

This thesis creates a new algorithm to replace the Neumann-Pfeffer Thunderstorm Index (NPTI). The 45th Weather Squadron at Patrick AFB, Florida, uses the NPTI as an objective means of determining the probability of thunderstorm occurrence at Cape Canaveral. The probability is used for mission planning and resource protection, and increasing the accuracy of NPTI can potentially save billions of dollars for the United States space program. Stratified logistical regressions are performed and probability equations are derived for May through September using upper air data and surface observations for Cape Canaveral. A logistical regression of NPTI was also performed. Variables include …

Gps Signal Offset Detection And Noise Strength Estimation In A Parallel Kalman Filter Algorithm, Barry J. Vanek

Theses and Dissertations

Measurements from Global Positioning System (GPS) satellites are subject to corruption by signal interference and induced offsets. This thesis presents two independent algorithms to ensure the navigation system remains uncorrupted by these possible GPS failures. The first is a parameter estimation algorithm that estimates the measurement noise variance of each satellite. A redundant measurement differencing (RMD) technique provides direct observability of the differenced white measurement noise samples. The variance of the noise process is estimated and provided to the second algorithm, a parallel Kalman filter structure, which then adapts to changes in the real-world measurement noise strength. The parallel Kalman …

Fisheries Research Report No. 113 - Catch, Effort And The Conversion From Gill Nets To Traps In The Peel-Harvey And Cockburn Sound Blue Swimmer Crab (Portunus Pelagicus) Fisheries, Roy Melville-Smith, Mark Cliff, Sonia M. Anderton

Fisheries research reports

Over the last few years, there has been considerable interest on the part of commercial fishers to move away from using gill nets, the traditional method for fishing for blue swimmer crabs in Western Australia (WA), to fishing with traps. Blue swimmer crab fisheries in WA are regulated by effort controls and most gill net fishers are restricted to hauling 1,000 metres (1,200 metres in the case of Cockburn Sound) of gill net per day.

The fieldwork in this study was initiated in March 1994 in Cockburn Sound and in January 1996 in the Peel-Harvey Estuary. It was aimed at …

Deuel County Test-Hole Logs: Nebraska Water Survey Test-Hole Report No. 25, Robert F. Diffendal Jr.

Robert F. Diffendal, Jr., Publications

In 1930, the Conservation and Survey Division (CSD) of the University of Nebraska and the United States Geological Survey began a program of cooperative groundwater studies in Nebraska. Since then test drilling by use of rotary drilling equipment has been an integral part of that program. This report contains logs of all the test holes drilled in the county under the program as well as those drilled by the Conservation and Survey Division with financial assistance from other government agencies.

The map in this report shows the location of all test holes drilled in the county since 1942.

Present techniques …