Physical Sciences and Mathematics Commons^™

An Extension Of The Quasicontinuum Treatment Of Multiscale Solid Systems To Nonzero Temperature, Dennis J. Diestler, Z.-B. Wu, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Covering the solid lattice with a finite-element mesh produces a coarse-grained system of mesh nodes as pseudoatoms interacting through an effective potential energy that depends implicitly on the thermodynamic state. Use of the pseudoatomic Hamiltonian in a Monte Carlo simulation of the two-dimensional Lennard-Jones crystal yields equilibrium thermomechanical properties (e.g., isotropic stress) in excellent agreement with “exact” fully atomistic results.

Semiparametric Binary Regression Under Monotonicity Constraints, Moulinath Banerjee, Pinaki Biswas, Debashis Ghosh

The University of Michigan Department of Biostatistics Working Paper Series

Summary: We study a binary regression model where the response variable $\Delta$ is the indicator of an event of interest (for example, the incidence of cancer) and the set of covariates can be partitioned as $(X,Z)$ where $Z$ (real valued) is the covariate of primary interest and $X$ (vector valued) denotes a set of control variables. For any fixed $X$, the conditional probability of the event of interest is assumed to be a monotonic function of $Z$. The effect of the control variables is captured by a regression parameter $\beta$. We show that the baseline conditional probability function (corresponding to …

How (West) Hollywood Adds Up: A Queer Theoretical View Of Mathematics And Mathematicians In Film, Christopher D. Goff

College of the Pacific Faculty Presentations

No abstract provided.

What Are The Building Blocks Of Our Universe?, Kameshwar C. Wali

Physics - All Scholarship

We are told that we are living in a Golden Age of Astronomy. Cosmological Parameters are found with un precedented accuracy. Yet, the known form of matter forms only a small fraction of the total energy density of the universe. Also, a mysterious dark energy dominates the universe and causes acceleration in the rate of expansion.

A Bayesian Method For Finding Interactions In Genomic Studies, Wei Chen, Debashis Ghosh, Trivellore E. Raghuanthan, Sharon Kardia

The University of Michigan Department of Biostatistics Working Paper Series

An important step in building a multiple regression model is the selection of predictors. In genomic and epidemiologic studies, datasets with a small sample size and a large number of predictors are common. In such settings, most standard methods for identifying a good subset of predictors are unstable. Furthermore, there is an increasing emphasis towards identification of interactions, which has not been studied much in the statistical literature. We propose a method, called BSI (Bayesian Selection of Interactions), for selecting predictors in a regression setting when the number of predictors is considerably larger than the sample size with a focus …

Parsing Concurrent Xml, Ionut E. Iacob, Alex Dekhtyar, Kazuyo Kaneko

Computer Science and Software Engineering

Concurrent markup hierarchies appear often in document-centric XML documents, as a result of different XML elements having overlapping scopes. They require significantly different approach to management and maintenance. Management of XML documents composed of concurrent markup has been mostly studied by the document processing community and has attracted attention of computer scientists only recently. In this paper we discuss the architecture of an XML parser for concurrent XML. This parser uses a GODDAG data structure in place of traditional DOM Tree to store concurrent markup on top of the document content and provides a DOM-like API that allows software developers …

Structural Mimicry In Class A G Protein-Coupled Receptor Rotamer Toggle Switches, Sean D. Mcallister, Dow P. Hurst, Judy Barnett-Norris, Diane L. Lynch, Patricia H. Reggio, Mary E. Abood

Faculty Articles

In this study, we tested the hypothesis that a CB₁ TMH3-4-5-6 aromatic microdomain, which includes F3.25(190), F3.36(201), W5.43(280), and W6.48(357), is centrally involved in CB₁ receptor activation, with the F3.36(201)/W6.48(357) interaction key to the maintenance of the CB₁-inactive state. We have shown previously that when F3.36(201), W5.43(280), and W6.48(357) are individually mutated to alanine, a significant reduction in ligand binding affinity is observed in the presence of WIN 55,212-2 and SR141716A but not CP55,940 and anandamide. In the work presented here, we report a detailed functional analysis of the F3.36(201)A, F3.25(190)A, W5.43(280)A, and W6.48(357)A mutant receptors …

Outerplanar Crossing Numbers, The Circular Arrangement Problem And Isoperimetric Functions, Eva Czabarka, Ondrej Sykora, Laszlo A. Szekely, Imrich Vrt'o

Faculty Publications

We extend the lower bound in [15] for the outerplanar crossing number (in other terminologies also called convex, circular and one-page book crossing number) to a more general setting. In this setting we can show a better lower bound for the outerplanar crossing number of hypercubes than the best lower bound for the planar crossing number. We exhibit further sequences of graphs, whose outerplanar crossing number exceeds by a factor of log n the planar crossing number of the graph. We study the circular arrangement problem, as a lower bound for the linear arrangement problem, in a general fashion. We …

Patterns Of Early Lake Evolution In Boreal Landscapes: A Comparison Of Stratigraphic Inferences With A Modern Chronosequence In Glacier Bay, Alaska, Sherilyn C. Fritz, Daniel R. Engstrom, Stephen Juggins

Department of Earth and Atmospheric Sciences: Faculty Publications

The chronosequence approach, which infers temporal patterns of environmental change from a spatial array of modern sites, has been a major tool for studying successional processes. A model of early lake ontogeny in boreal landscapes, developed from a chronosequence of lakes in Alaska, suggests that long-term soil development and related hydrological change produce a loss of alkalinity and base cations, a decrease in pH, an increase in DOC and a transient increase followed by a decrease in lakewater nitrogen concentrations over time. We compare this model of lake ontogeny with patterns of change reconstructed from diatom assemblages in 10 sediment …

The Origin Of Fe Ii Emission In Active Galactic Nuclei, J. A. Baldwin, Gary J. Ferland, K. T. Korista, F. Hamann, A. Lacluyzé

Physics and Astronomy Faculty Publications

We used a very large set of models of broad emission line region (BELR) clouds in active galactic nuclei to investigate the formation of the observed Fe II emission lines. We show that photoionized BELR clouds cannot produce both the observed shape and observed equivalent width of the 2200-2800 Å Fe II UV bump unless there is considerable velocity structure corresponding to a microturbulent velocity parameter v_turb≥100 km s^-1 for the locally optimally emitting cloud models used here. This could be either microturbulence in gas that is confined by some phenomenon such as MHD waves or a …

A Million Secondchandraview Of Cassiopeia A, Una Hwang, J. Martin Laming, Carles Badenes, Fred Berendse, John Blondin, Denis Cioffi, Tracey Delaney, Daniel Dewey, Robert Fesen

Dartmouth Scholarship

We introduce a million second observation of the supernova remnant Cassiopeia A with the Chandra X-Ray Observatory. The bipolar structure of the Si-rich ejecta (northeast jet and southwest counterpart) is clearly evident in the new images, and their chemical similarity is confirmed by their spectra. These are most likely due to jets of ejecta as opposed to cavities in the circumstellar medium, since we can reject simple models for the latter. The properties of these jets and the Fe-rich ejecta will provide clues to the explosion of Cas A.

Deletion/Substitution/Addition Algorithm For Partitioning The Covariate Space In Prediction, Annette Molinaro, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

We propose a new method for predicting censored (and non-censored) clinical outcomes from a highly-complex covariate space. Previously we suggested a unified strategy for predictor construction, selection, and performance assessment. Here we introduce a new algorithm which generates a piecewise constant estimation sieve of candidate predictors based on an intensive and comprehensive search over the entire covariate space. This algorithm allows us to elucidate interactions and correlation patterns in addition to main effects.

In Situ Anomalous Small-Angle X-Ray Scattering From Metal Particles In Supported-Metal Catalysts. I. Theory, H. Brumberger, D. Hagrman, Jerry Goodisman, K. D. Finkelstein

Chemistry - All Scholarship

A supported-metal catalyst can be considered as a mixture of three homogeneous phases: support, void and metal. Information about the metal phase alone can be obtained using anomalous small-angle X-ray scattering (ASAXS), which requires measuring the SAXS for two different wavelengths near the metal's absorption edge. Herein, the conditions that must be obtained so that the difference between the two scattering profiles gives the scattering of the metal alone are presented. In a following contribution, the analysis will be applied to in situ ASAXS measurements made on mordenite impregnated with platinum metal while the temperature and composition of gas in …

Geometric Acoustic Modeling Of The Lds Conference Center, Heather Smith

Theses and Dissertations

This thesis discusses the process of modeling a 21,000 seat fan-shaped auditorium using methods of geometric acoustics. Two commercial geometric acoustics software packages were used in the research: CATT-Acoustic™ 8.0 and EASE™ 4.1. The process first included creating preliminary models of the hall using published absorption coefficients for its surfaces and approximate scattering coefficients based on current best-known techniques. A detailed analysis determined the minimum numbers of rays needed in both packages to produce reliable results with these coefficient values. It was found that 100,000 rays were needed for CATT™ and 500,000 rays were needed for EASE™. Analysis was also …

Locating A Radioactive Waste Repository In The Ring Of Fire, Mick Apted, Kelvin Berryman, Neil Chapman, Mark Cloos, Charles B. Connor, Kazumi Kitayama, Steve Sparks, Hiroyuki Tsuchi

School of Geosciences Faculty and Staff Publications

The scientific, technical, and sociopolitical challenges of finding a secure site for a geological repository for radioactive wastes have created a long and stony path for many countries. Japan carried out many years of research and development before taking its first steps in site selection.

The Nuclear Waste Management Organization of Japan (NUMO) began looking for a high-level waste repository site (HLW, vitrified residue from reprocessing power reactor fuel) 2 years ago. Over the next 10–20 years, NUMO hopes to find a site to dispose of ∼20,000 tons of HLW in a robustly engineered repository constructed at a depth of …

Modified Quantum Trajectory Dynamics Using A Mixed Wave Function Representation, Sophya Garashchuk, Vitaly A. Rassolov

Faculty Publications

Dynamics of quantum trajectories provides an efficient framework for description of various quantum effects in large systems, but it is unstable near the wave function density nodes where the quantum potential becomes singular. A mixed coordinate space/polar representation of the wave function is used to circumvent this problem. The resulting modified trajectory dynamics associated with the polar representation is nonsingular and smooth. The interference structure and the nodes of the wave function density are described, in principle, exactly in the coordinate representation. The approximate version of this approach is consistent with the semiclassical linearized quantum force method [S. Garashchuk and …

Groundwater Flow And Thermal Modeling To Support A Preferred Conceptual Model For The Large Hydraulic Gradient North Of Yucca Mountain, Phil Oberlander, Greg Pohll, Drew Coleman, Raymond E. Keeler, Amy J. Smiecinski

Publications (YM)

This task will create a two-dimensional, saturated zone, vertical cross-section model of groundwater flow and thermal transport through the large hydraulic gradient (LHG). This model is referenced herein as the thermal model. The scope of this study is limited to presenting a postulated hydrogeologic configuration of the LHG. The conceptualization will include the use of postulated hydrogeologic structures and material properties. The thermal model will be spatially limited to the area immediately upgradient and downgradient of the LHG and will not reproduce the many hydrogeologic features of the existing regional and site-scale models. The thermal model will be orientated north …

An Exploratory Study That Examines Perceptions, By The Regulated Community, On The Effectiveness Of Air Quality Permitting For Clark County, By The Department Of Air Quality And Environmental Management, Scott Jelinek

UNLV Theses, Dissertations, Professional Papers, and Capstones

The Clean Air Act of 1970 (CAA) made the Environmental Protection Agency (EPA) responsible for establishing and maintaining federal programs that control air quality. In turn, each state was delegated responsibility for air quality within its borders, although this responsibility may be shared with Native Americans or tribal lands. In many states, jurisdiction has been delegated to regional or local agencies that are then responsible for air quality in their respective air basins. Even though terrain or water bodies define the physical boundaries of air basins, they are usually designated by County boundaries for regulatory convenience (Wooley, David R., 1997).

Theoretical Study Of The Magnetic Ordering In Rare-Earth Compounds With Face-Centered-Cubic Structure, Chun-Gang Duan, Renat F. Sabirianov, Jianjun Liu, Wai-Ning Mei, Peter A. Dowben, John R. Hardy

Peter Dowben Publications

We present a detailed theoretical study of the magnetic ordering in heavy rare-earth compounds with a face-centered-cubic structure. In addition to the exchange interactions which are counted up to the third nearest neighbors, the effect of the dipolar interactions and magnetic anisotropic effect are also included in our model Hamiltonian. The interactions parameters are obtained from first-principles band-structure calculations by fitting the total energies of different magnetic configurations to the Heisenberg Model. Thus from utilizing the Monte Carlo simulations, we explained the formation of different magnetic structures in the rare-earth compounds.

Noncollinear Spin States And Competing Interactions In Half-Metals, Ralph Skomski, Jian Zhou, Peter A. Dowben, David J. Sellmyer

Peter Dowben Publications

The high-field spin structure of magnetic perovskites and related magnetoresistive materials is investigated by model calculations. Competing exchange as well as real-structure-dependent random field, random anisotropy, and Dzyaloshinskii–Moriya interactions yield a noncollinear magnetic structure that may be called a spin colloid. The noncollinear structure, which contributes to the zero- and finite-temperature spin mixing and reduces the magnetoresistance, is strongly field dependent. © 2005 American Institute of Physics. [DOI: 10.1063/1.1851412]

Proposed Experimental Actions For Water Years 2005-2006 Colorado River, Arizona, In Glen Canyon National Recreation Area And Grand Canyon National Park, U.S. Department Of The Interior, Bureau Of Reclamation, National Park Service, U.S. Geological Survey

All U.S. Government Documents (Utah Regional Depository)

In September 2002 the Bureau of Reclamation, National Park Service (NPS), and U.S. Geological Survey released an environmental assessment (EA) on proposed experimental releases from Glen Canyon Dam and removal of non‐native fish from the Colorado River in Grand Canyon, Arizona (Bureau of Reclamation, NPS, and USGS 2002). The experiment was developed by the Grand Canyon Monitoring and Research Center of the U.S. Geological Survey (GCMRC), cooperating scientists, and the Technical Work Group (TWG) of the Glen Canyon Dam Adaptive Management Program (GCDAMP). It was recommended to the Secretary of the Interior by the Adaptive Management Work Group (AMWG), a …

Social Engineering In The Age Of Ai, Mohammad A. Saleh

Cybersecurity Undergraduate Research Showcase

The next great invention is artificial intelligence. AI has grown rapidly over the last 15 years and has brought both advantages and disadvantages to everyday society. One of the most concerning disadvantages highlighted in recent years is the rise of social engineering attacks. Social engineering comes in many different forms, making it difficult to identify at times. With the development of AI, these attacks have become even harder to detect, prevent, and stop. This research essay explores the different types of AI-driven social engineering attacks, how they occur, why they happen, and the impact they have on individuals and organizations.

A Geometrical Approach To N=2 Super Yang-Mills Theory On The Two Dimensional Lattice, Simon Catterall

Physics - All Scholarship

We propose a discretization of two dimensional Euclidean Yang-Mills theories with N=2 supersymmetry which preserves exactly both gauge invariance and an element of supersymmetry. The approach starts from the twisted form of the continuum super Yang Mills action which we show may be written in terms of two real Kahler-Dirac fields whose components transform into each other under the twisted supersymmetry. Once the theory is written in this geometrical language it is straightforward to discretize by mapping the component tensor fields to appropriate geometrical structures in the lattice and by replacing the continuum exterior derivative and its adjoint by appropriate …

Disorder-Induced Depression Of The Curie Temperature In Mechanically Milled Gdal2, Marco Morales Torres, D. S. Williams, P. M. Shand, C. Stark, T. M. Pekarek, Lanping Yue, V. Petkov, Diandra Leslie-Pelecky

Diandra Leslie-Pelecky Publications

The effect of disorder on the ferromagnetic transition is investigated in mechanically milled GdAl₂. GdAl₂ is a ferromagnet when crystalline and a spin glass when amorphous. Mechanical milling progressively disorders the alloy, allowing observation of the change from ferromagnetic to a disordered magnetic state. X-ray diffraction and pair-distribution-function analysis are used to determine the grain size, lattice parameter, and mean-squared atomic displacements. The magnetization as a function of temperature is described by a Gaussian distribution of Curie temperatures. The mean Curie temperature decreases with decreasing lattice parameter, where lattice parameter serves as a measure of defect concentration. …

Canadian Cooperative Wildlife Health Centre, Annual Report 2003-2004 (English)

Canadian Cooperative Wildlife Health Centre: Newsletters and Publications

About the CCWHC
What We Do
Wildlife Disease Surveillance
Wildlife Disease Surveillance - Highlights from 2003
CCWHC Information Technology Centre
Information Services
Education
Wildlife Disease Response and Management
Publications and Reports
Financial Report for 2003-2004 - Revenues
Financial Report for 2003-2004 - Expenses
Staff and Associates of the Canadian Cooperative Wildlife Health Centre 2003-04

Improved Signal Integrity In Ieee 1149.1 Boundary Scan Designs, Efren De Jesus Rangel Taboada

Theses and Dissertations

This work is an analysis of solutions to problems derived from inherent timing and signal integrity issues in the use and application of the IEEE 1149.1 Standard at the board level in conjunction with its test system. Setup or hold times violations may occur in a boundary scan chain using IEEE 1149.1 compliant devices. A practical study of the TDI-TDO scan data path has been conducted to show where problems may arise in relationship to a particular board topology and test system. This work points to differences between passing and failing scan path tests for problem characterization. Serial data flow …

Geocoronal Hydrogen Studies Using Fabry-Perot Interferometers, S. M. Nossal, E. J. Mierkiewicz, F. L. Roesler, J. Bishop, R. J. Reynolds

Publications

Ground based Fabry-Perot observations of solar excited geocoronal hydrogen fluorescence emissions are one of the primary means of studying the neutral upper atmosphere [Atreya et al., 1975; Meriwether et al., 1980; Yelle and Roesler, 1985; Shih et al., 1985; Kerr et al., 2001a,b; He et al., 1993; Nossal et al., 1993, 1998, 2004; Bishop et al., 2001; Mierkiewicz, 2002; and references therein]. Excellent reviews of early ground-based geocoronal Balmer α observations are found in: Krassovsky et al. [1966], Krassovsky [1971], Donahue [1964, 1966], Tinsley [1974], Fahr and Shizgal [1983] and Kerr et al. [2001a]. Instruments onboard satellites and rockets also …

Direct Comparison Between Phase Locked Oscillator And Direct Resonance Oscillator In The Noncontact Atomic Force Microscopy Under Ultrahigh Vacuum, Byung I. Kim

Physics Faculty Publications and Presentations

I have demonstrated the advantage of the phase locked oscillator (PLO) over the conventional direct resonance oscillator (DRO) in noncontact mode atomic force microscopy (AFM) under ultrahigh vacuum. Direct comparison between PLO and DRO has been made in terms of background noise level, temporal response, and stability. Compared to the DRO method without phase coherence, the experimental results show that the PLO method is more effective in reducing the noise level and enhancing the stability over all force regimes in UHV noncontact AFM. The noise reduction and stability enhancement in PLO indicate the important role of the phase coherent effect …

A Conversation With R. Clifford Blair On The Occasion Of His Retirement, Shlomo S. Sawilowsky

Theoretical and Behavioral Foundations of Education Faculty Publications

An interview was conducted on 23 November 2003 with R. Clifford Blair on the occasion on his retirement from the University of South Florida. This article is based on that interview. Biographical sketches and images of members of his academic genealogy are provided.

Spatially Adaptive Bayesian P-Splines With Heteroscedastic Errors, Ciprian M. Crainiceanu, David Ruppert, Raymond J. Carroll

Johns Hopkins University, Dept. of Biostatistics Working Papers

An increasingly popular tool for nonparametric smoothing are penalized splines (P-splines) which use low-rank spline bases to make computations tractable while maintaining accuracy as good as smoothing splines. This paper extends penalized spline methodology by both modeling the variance function nonparametrically and using a spatially adaptive smoothing parameter. These extensions have been studied before, but never together and never in the multivariate case. This combination is needed for satisfactory inference and can be implemented effectively by Bayesian \mbox{MCMC}. The variance process controlling the spatially-adaptive shrinkage of the mean and the variance of the heteroscedastic error process are modeled as log-penalized …