Physical Sciences and Mathematics Commons^™

Transport Discovery In Wireless Multi-Transport Environments, Shannon B. Barnes, Charles D. Knutson, Ryan W. Woodings

Faculty Publications

In order to utilize multiple transports, devices must discover common mechanisms for communication, a procedure we call Multi-Transport Discovery. The Multi-Transport Discovery algorithm presented in this paper is a four-phase procedure (Transport Probing, Transport Querying, Address-to-Device Mapping, and Transport Accessibility) that can discover common transports within a multi-transport environment. Transport Probing uses a transport-dependent device discovery mechanism to discover an initial link. Transport Querying communicates over the probed link to query additional transports. Address-to-Device Mapping correctly correlates each transport to a remote device. Finally, Transport Accessibility periodically ascertains link availability during an application session.

An Iterative Loop Matching Approach To The Prediction Of Rna Secondary Structures With Pseudoknots, Jianhua Ruan, Weixiong Zhang

All Computer Science and Engineering Research

Motivation: Pseudoknots have generally been excluded from the prediction of RNA secondary structures due to the difficulty in modeling and complexity in computing. Although several dynamic programming algorithms exist for the prediction of pseudoknots using thermodynamic approaches, they are neither reliable nor efficient. On the other hand, comparative methods are more reliable, but are often done in an ad hoc manner and require expert intervention. Maximum weighted matching (Tabaska et. al, Bioinformatics, 14:691-9, 1998), an algorithm for pseudoknot prediction with comparative analysis, suffers from low prediction accuracy in many cases. Here we present an algorithm, iterative loop matching, for predict-ing …

Chlorine Budget And Partitioning During The Stratospheric Aerosol And Gas Experiment (Sage) Iii Ozone Loss And Validation Experiment (Solve), S. M. Schauffler, E. L. Atlas, Stephen G. Donnelly Ph.D., A. Andrews, S. A. Montzka, J. W. Elkins, D. F. Hurst, P. A. Romashkin, G. S. Dutton, V. Stroud

Chemistry Faculty Publications

The amount of chlorine in the stratosphere has a direct influence on the magnitude of chlorine-catalyzed ozone loss. A comprehensive suite of organic source gases of chlorine in the stratosphere was measured during the NASA Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) campaign in the arctic winter of 2000. Measurements included chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halon 1211, solvents, methyl chloride, N2O, and CH4. Inorganic chlorine contributions from each compound were calculated using the organic chlorine measurements, mean age of air, tropospheric trends, and a method to account for mixing in the stratosphere. Total organic …

Grain Boundary Scars And Spherical Crystallography, Mark Bowick, A. R. Bausch

Physics - All Scholarship

We describe experimental investigations of the structure of two-dimensional spherical crystals. The crystals, formed by beads self-assembled on water droplets in oil, serve as model systems for exploring very general theories about the minimum energy configurations of particles with arbitrary repulsive interactions on curved surfaces. Above a critical system size we find that crystals develop distinctive high-angle grain boundaries, or scars, not found in planar crystals. The number of excess defects in a scar is shown to grow linearly with the dimensionless system size. The observed slope is expected to be universal, independent of the microscopic potential.

Penalized Spline Nonparametric Mixed Models For Inference About A Finite Population Mean From Two-Stage Samples, Hui Zheng, Rod Little

The University of Michigan Department of Biostatistics Working Paper Series

Samplers often distrust model-based approaches to survey inference due to concerns about model misspecification when applied to large samples from complex populations. We suggest that the model-based paradigm can work very successfully in survey settings, provided models are chosen that take into account the sample design and avoid strong parametric assumptions. The Horvitz-Thompson (HT) estimator is a simple design-unbiased estimator of the finite population total in probability sampling designs. From a modeling perspective, the HT estimator performs well when the ratios of the outcome values and the inclusion probabilities are exchangeable. When this assumption is not met, the HT estimator …

Trends. Science Is Apolitical As Political, Ibpp Editor

International Bulletin of Political Psychology

This Trends article discusses the nature of science from a political psychological perspective.

Concerning The Stability Of Dichlorodiazene, Gregory S. Tschumper, Michael C. Heaven, Keiji Morokuma

Chemistry Faculty Research & Creative Works

The stability of N2Cl2 with respect to dissociation into N2 + 2Cl has been investigated using ab initio electronic structure techniques. Triple-ζ basis sets with d- and f-functions were required to obtain qualitative agreement between multi-reference and highly correlated single reference methods regarding the stability of the cis- and trans-isomers. The CCSD(T) method predicts a barrier to dissociation of 7-8 kcal mol-1 for the two isomers. CASPT2 barrier heights are substantially smaller (≤1.5 kcal mol^-1), indicating that these species are barely bound. © 2003 Elsevier Science B.V. All rights reserved.

Crop Updates 2003 - -Katanning, Robert F. Park, Robert Loughman, Colin Wellings, Greg Shea, Jocelyn Ball, Natasha Littlewood, Lucy Creagh, Alex Douglas, David Stephens, Ross Brennan, Mike Bolland, Narelle Hill, Phil Michael, Francoise A. Berlandier, Christiaan Valentine, Roy Latta, M. Rodger Beermier, Keith Devenish, Blakely Paynter, Kevin Young, Robin Wilson, Ian Barclay, Robyn Mclean, Jenny Garlinge, Bill Lambe, Neil Venn, Peter Clarke, Frances Hoyle, Leanne Schulz, Judith Devenish

Crop Updates

This session covers sixteen papers from different authors

1. Breeding Cereals for Rust Resistance – are we losing the battle? Robert F. Park, University of Sydney

2. Stripe rust – where to now for the WA wheat industry? Robert Loughman, Department of Agriculture, Colin Wellings, University of Sydney, Greg Shea, Department of Agriculture

3. Oaten hay production, Jocelyn Ball, Natasha Littlewood and Lucy Creagh, Department of Agriculture

4. Don’t rely on ‘Spray and Pray’ Alex Douglas, Department of Agriculture

5. Seasonal outlook: What is in store for 2003, David Stephens, Department of Agriculture

6. No-till copper, phosphorus and zinc …

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Dynamics Of Conformal Maps For A Class Of Non-Laplacian Growth Phenomena, Martin Z. Bazant, Jaehyuk Choi, Benny Davidovitch

Benny Davidovitch

Time-dependent conformal maps are used to model a class of growth phenomena limited by coupled non-Laplacian transport processes, such as nonlinear diffusion, advection, and electro- migration. Both continuous and stochastic dynamics are described by generalizing conformal- mapping techniques for viscous fingering and diffusion-limited aggregation, respectively. A gen- eral notion of time in stochastic growth is also introduced. The theory is applied to simulations of advection-diffusion-limited aggregation in a background potential flow. A universal crossover in mor- phology is observed from diffusion-limited to advection-limited fractal patterns with an associated crossover in the growth rate, controlled by a time-dependent effective Peclet number. …

Consideration Of Possible Mass And Velocity Corrections To Magnetic Cluster Experiments, Z.Y. Liu, Peter A. Dowben, A.P. Popov, David P. Pappas

Peter Dowben Publications

Gadolinium occurs, in natural abundance, as several isotopes. The possible combinations of different gadolinium isotopes dictates that even for a fixed number of atoms in the cluster, clusters of gadolinium atoms will exhibit a range of masses. This and the expected consequence of the translation energy distributions are explored as possible corrections to Stern-Gerlach cluster beam-deflection experiments. Upon closer inspection of the experimental data, we find that the translation energy plus the vibrational temperature distribution may be inhomogeneous. This could be the origin of a long tail to high deflections in the experimental deflection profiles, at low cluster temperatures, in …

Stress Corrosion Cracking Of Type 422 Stainless Steel For Applications In Spallation-Neutron-Target Systems, Ramprashad Prabhakaran

Transmutation Sciences Materials (TRP)

Introduction

• This research program is aimed at evaluating different types of environment-induced degradation of candidate target materials for applications in transmutation of spent nuclear fuels (SNF).

• Transmutation refers to the elimination of long-lived actinides and fission products from SNF.

Objectives

• Evaluate susceptibility of candidate target materials to stress corrosion cracking (SCC) and localized corrosion (pitting and crevice) in neutral and acidic aqueous environments at ambient and elevated temperatures

• Determine the extent and morphology of cracking in tested materials as functions of experimental and environmental variables including pH, temperature, loading conditions and specimen geometry

• Develop mechanistic …

Electrochemical Detection Of Oxidative Stress, Alice Harper, Mark Anderson

Mark R. Anderson

No abstract is currently available.

Vacuum Choices And The Predictions Of Inflation, Christian Armendariz-Picon, Eugene A. Lim

Physics - All Scholarship

In the presence of a short-distance cutoff, the choice of a vacuum state in an inflating, non-de Sitter universe is unavoidably ambiguous. The ambiguity is related to the time at which initial conditions for the mode functions are specified and to the way the expansion of the universe affects those initial conditions. In this paper we study the imprint of these uncertainties on the predictions of inflation. We parametrize the most general set of possible vacuum initial conditions by two phenomenological variables. We find that the generated power spectrum receives oscillatory corrections whose amplitude is proportional to the Hubble parameter …

Method Of Solubilizing Carbon Nanotubes In Organic Solutions, Robert C. Haddon, Mark A. Hamon

Chemistry Faculty Patents

Carbon nanotubes are dissolved in organic solutions by attaching an aliphatic carbon chain (which may contain aromatic residues) so as to render the carbon nanotubes soluble.

Probing Tectonic Topography In The Aftermath Of Continental Convergence In Central Europe, S Cloetingh, F Horvath, C Dinu, R A. Stephenson, G Bertotti, G Bada, L Matenco, D Garcia-Castellanos, P Andriessen, R Wortel, W Spakman, V Mocanu, C Langereis, W Krijgsman, J Fokkema, G Drykoningen, B Ambrosius, F Neubauer, L Fodor, T Dunai, E Willingshofer, A Nador, K Leever, M Tarapoanca, I Panea, I Vasiliev, G Paicu, A Van Der Hoven, James H. Knapp, Camelia C. Diaconescu, St Freimueller

Faculty Publications

Continental topography is at the interface of processes taking place at depth in the Earth,at its surface,and above it.Topography influences society, not only in terms of slow processes of landscape change and earthquakes,but also in terms of how it affects climate.The Pannonian Basin–Carpathian Orogen System in Central and Eastern Europe represents a key natural laboratory for the development of a new generation of models for ongoing orogeny and its effect on continental topography development (Figure 1).This system comprises some of the best documented sedimentary basins in the world,located within the Alpine orogenic belt, at the transition between the western European …

Studies Of Monolayer Films As Adhesion Promoters, Huimin Li, Mark Anderson

Mark R. Anderson

No abstract is currently available.

Capillary Electrophoresis To Determine Oxidative Stress, Stephanie Hooper, Mark Anderson

Mark R. Anderson

No abstract is currently available.

Hard X-Ray Polarimeter For Gamma-Ray Bursts And Solar Flares, Mark L. Mcconnell, J Ledoux, John R. Macri, James M. Ryan

Space Science Center

We report on the development of a dedicated polarimeter design that is capable of studying the linear polarization of hard X-rays (50-300 keV) from gamma-ray bursts and solar flares. This compact design, based on the use of a large area position-sensitive PMT (PSPMT), is referred to as GRAPE (Gamma-RAy Polarimeter Experiment). The PSPMT is used to determine the Compton interaction location within an array of small plastic scintillator elements. Some of the photons that scatter within the plastic scintillator array are subsequently absorbed by a small centrally-located array of CsI(Tl) crystals that is read out by an independent multi-anode PMT. …

Development Of Czt Strip Detector Modules For 0.05- To 1-Mev Gamma-Ray Imaging And Spectroscopy, James M. Ryan, B Donmez, John R. Macri, M Mcclish, Mark L. Mcconnell, R S. Miller, Mark Widholm, L A. Hamel, Manuel Julien

Space Science Center

We report progress in our study of cadmium zinc telluride (CZT) strip detectors featuring orthogonal coplanar anode contacts. We specifically report on the performance, characterization and stability of 5 and 10 mm thick prototype CZT detectors fabricated using material from several manufacturers. Our ongoing work includes laboratory and simulation studies aimed at optimizing and developing compact, efficient, high performance detector modules for 0.05 to 1 MeV gamma radiation measurements with space-based instrumentation. The coplanar anode strip configuration retains many of the performance advantages of pixel detectors yet requires far fewer electronic channels to perform both 3-d imaging and spectroscopy. Minimizing …

Nonsolar Astronomy With The Reuven Ramaty High Energy Solar Spectroscopic Imager (Rhessi), David M. Smith, Robert P. Lin, K Hurley, Wayne Coburn, G J. Hurford, Claudia Wigger, W Hajdas, Alex Zehnder, Mark L. Mcconnell

Space Science Center

The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) is a NASA Small Explorer satellite designed to study hard x-ray and gamma-ray emission from solar flares. In addition, its high-resolution array of germanium detectors can see photons from high-energy sources throughout the Universe. Here we discuss the various algorithms necessary to extract spectra, lightcurves, and other information about cosmic gamma-ray bursts, pulsars, and other astrophysical phenomena using an unpointed, spinning array of detectors. We show some preliminary results and discuss our plans for future analyses. All RHESSI data are public, and scientists interested in participating should contact the principal author.

Development And Evaluation Of A Geographic Information System Based Method To Estimate Flooding Susceptibility In An Area Of Broward County, Florida, Carolyn J. Anderson

FIU Electronic Theses and Dissertations

The objective of this study was to develop a GIS-based multi-class index overlay model to determine areas susceptible to inland flooding during extreme precipitation events in Broward County, Florida. Data layers used in the method include Airborne Laser Terrain Mapper (ALTM) elevation data, excess precipitation depth determined through performing a Soil Conservation Service (SCS) Curve Number (CN) analysis, and the slope of the terrain. The method includes a calibration procedure that uses "weights and scores" criteria obtained from Hurricane Irene (1999) records, a reported 100-year precipitation event, Doppler radar data and documented flooding locations. Results are displayed in maps of …

Evolution Of Gases And Particles From A Savanna Fire In South Africa, Peter V. Hobbs, Parikhit Sinha, Robert J. Yokelson, Ted J. Christian, Donald R. Blake, Song Gao, Thomas W. Kirschsetter, Tica Novakov, Peter Pilewskie

Chemistry and Biochemistry Faculty Publications

[1] Airborne measurements of particles and gases from a 1000-ha savanna fire in South Africa are presented. These measurements represent the most extensive data set reported on the aging of biomass smoke. The measurements include total concentrations of particles (CN), particle sizes, particulate organic carbon and black carbon, light-scattering coefficients, downwelling UV fluxes, and mixing ratios for 42 trace gases and 7 particulate species. The ratios of excess nitrate, ozone, and gaseous acetic acid to excess CO increased significantly as the smoke aged over ∼40–45 min, indicating that these species were formed by photochemistry in the plume. For 17 other …

A Semiparametric Model Selection Criterion With Applications To The Marginal Structural Model, M. Alan Brookhart, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

Estimators for the parameter of interest in semiparametric models often depend on a guessed model for the nuisance parameter. The choice of the model for the nuisance parameter can affect both the finite sample bias and efficiency of the resulting estimator of the parameter of interest. In this paper we propose a finite sample criterion based on cross validation that can be used to select a nuisance parameter model from a list of candidate models. We show that expected value of this criterion is minimized by the nuisance parameter model that yields the estimator of the parameter of interest with …

Gaussian And Mean Curvatures Of Rational Bézier Patches, Thomas W. Sederberg, Jianmin Zheng

Faculty Publications

This note derives formulae for Gaussian and mean curvatures for tensor-product and triangular rational Bézier patches in terms of the respective control meshes. These formulae provide more geometric intuition than the generic formulae from differential geometry.

Crop Updates 2003 - Geraldton, David Stephens, James Fisher, Ian Edwards, Dennis Wise, Andrew Young, Robert Loughman, Ciara Beard, Greg Shea, Blakely Paynter, Roslyn Jettner, Kevin Young, Kevin Walden, Geoff Thomas, Robin Wilson, Iain Barclay, Robyn Mclean, Jenny Garlinge, Bill Lambe, Neil Venn, Peter Clarke, Martin Harries, Bob French, Wayne Parker, Murray Blyth, Peter Norris, Greg Lyle, Katheryn Steadman, Amanda Ellery, Sally C. Peltzer, Kari-Lee Falconer, Russell Speed, Terry Piper, Harmohinder Dhammu, Bindi Webb, Paul Blackwell, Phil Logue, Nigel Moffat, Rohan Ford, Miles Obst, Frances Hoyle, Leanne Schulz, Judith Devenish, Peter Newman, Grant Morrow, Ian Foster, Darshan Sharma, Marnie Thomas, Graham Walton, Hasan Zaheer, Paul Carmody, Mike Clarke, Paul Raper

Crop Updates

This session covers twenty eight papers from different authors

1. Seasonal Outlook: What is in store for 2003, David Stephens, Department of Agriculture

2. Examining The Management Options For Wheat Crops In The Coming Season, James Fisher, Department of Agriculture

3. GMO’s – what do they offer? Ian Edwards, Grain Bio Tech Australia Pty Ltd

4. The Big Gamble – Wheat prices for 2003, Dennis Wise, Profarmer

5. Market outlook for other grains, Andrew Young, General Manager Agricorp

6. Stripe rust – where to now for the WA wheat industry? Robert Loughman, Ciara Beard and Greg Shea, Department of Agriculture

7. Baudin …

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Raman Spectroscopy Of Rhombohedral P4o10, Sean J. Gilliam, Scott Kirkby, Clifton N. Merrow, Daniel Zeroka, Ajit Banerjee, James O. Jensen

Scott J. Kirkby

Balanced Configurations Of Lattice Vectors And Gkz-Rational Toric Fourfolds In P^6, Eduardo Cattani, Alicia Dickenstein

Eduardo Cattani

We introduce a notion of balanced configurations of vectors. This is motivated by the study of rational A-hypergeometric functions in the sense of Gelfand, Kapranov and Zelevinsky. We classify balanced configurations of seven plane vectors up to GL(2,R)-equivalence and deduce that the only gkz-rational toric four-folds in P6 are those varieties associated with an essential Cayley configuration. We show that in this case, all rational A-hypergeometric functions may be described in terms of toric residues. This follows from studying a suitable hyperplane arrangement.

Multiple Jet Production At Low Transverse Energies In Pp̅ Collisions At √S = 1.8 Tev, V. M. Abazov, Gregory R. Snow, D0 Collaboration

Gregory Snow Publications

We present data on multiple production of jets with transverse energies near 20 GeV in pp̅ collisions at √s =1.8 TeV. QCD calculations in the parton-shower approximation of PYTHIA and HERWIG and the next-to-leading order approximation of JETRAD are compared to the data for one, two, three, and four jet inclusive production. Transverse energy spectra and multiple jet angular and summed transverse-energy distributions are adequately described by the shower approximation while next-to-leading order calculations describe the data poorly.

Three-Dimensional Structure Of Magnetic Reconnection In A Laboratory Plasma, C. D. Cothran, Matthew Joseph Landreman , '03, Michael R. Brown, W. H. Matthaeus

Physics & Astronomy Faculty Works

The local three-dimensional structure of magnetic reconnection has been measured for the first time in a magnetohydrodynamic (MHD) laboratory plasma at the Swarthmore Spheromak Experiment. An array of 600 magnetic probes which resolve ion inertial length and MHD time scale dynamics on a single shot basis measured the magnetic structure of partial spheromak merging events. Counter-helicity spheromaks merge rapidly, and reconnection activity clearly self-generates a local component of B which breaks the standard 2D symmetry at the ion inertial scale. Consistent with prior results, no reconnection is observed for co-helicity merging.

On The Initial Conditions For Brane Inflation, Scott Watson, Robert H. Brandenberger, G. Geshnizjani

Physics - All Scholarship

String theory gives rise to various mechanisms to generate primordial inflation, of which ``brane inflation'' is one of the most widely considered. In this scenario, inflation takes place while two branes are approaching each other, and the modulus field representing the separation between the branes plays the role of the inflaton field. We study the phase space of initial conditions which can lead to a sufficiently long period of cosmological inflation, and find that taking into account the possibility of nonvanishing initial momentum can significantly change the degree of fine tuning of the required initial conditions.