Physical Sciences and Mathematics Commons^™

Low-Temperature Thermochronology Of The San Gabriel And San Bernardino Mountains, Southern California: Constraining Structural Evolution, Ann Blythe, M House, J Spotila

Ann Blythe

No abstract provided.

Slip Inversion On Complex Fault Surfaces Using Angular Elastic Dislocations, Phillip Resor, L Maerten, F Maerten

Phillip G Resor

We present a new 3D slip-inversion method based on the analytical solution of an angular dislocation in a linear-elastic, homogeneous, isotropic, whole- or half-space. The approach uses a boundary element method (BEM) that employs planar triangular elements of constant displacement to model fault surfaces. Discretization of surfaces into triangular boundary elements allows the construction of complex 3D fault surfaces with irregular tipline and no overlaps or gaps. A damped least squares method is used to minimize the functional ¶llel.b-d∥2+ɛ^{2}∥ bigtriangledown .b∥ ^{2},where b represents the slip distribution on the faults, φ the influence coefficient matrix and d the observed deformation …

A Compilation Of Soybean Ests: Generation And Analysis, Elizabeth Shoop, R. Schoemaker, Et Al

Elizabeth Shoop

No abstract provided.

Logic, Optimization And Constraint Programming, John Hooker

John Hooker

No abstract provided.

The Microwave Heating Of Three-Dimensional Blocks: Semi-Analytical Solutions, Prof. Tim Marchant

Tim Marchant

The microwave heating of three-dimensional blocks, by the transverse magnetic waveguide mode TM11, is considered in a long rectangular waveguide. The governing equations are the forced heat equation and a steady-state version of Maxwell's equations, while the boundary conditions take into account both convective and radiative heat loss. Semi-analytical solutions, valid for small thermal absorptivity, are found using the Galerkin method. The electrical conductivity and the thermal absorptivity are assumed to be temperature dependent, while both the electrical permittivity and magnetic permeability are taken to be constant. Both a quadratic relation and an Arrhenius-type law are used for the temperature …

Environmental Justice And Regional Inequality In Southern California: Implications For Future Research, Manuel Pastor, C Porras, James Sadd

James Sadd

Environmental justice offers researchers new insights into the juncture of social inequality and public health and provides a framework for policy discussions on the impact of discrimination on the environmental health of diverse communities in the United States. Yet, causally linking the presence of potentially hazardous facilities or environmental pollution with adverse health effects is difficult, particularly in situations in which diverse populations are exposed to complex chemical mixtures. A community-academic research collaborative in southern California sought to address some of these methodological challenges by conducting environmental justice research that makes use of recent advances in air emissions inventories and …

Integrating Environmental Justice And The Precautionary Principle In Research And Policy Making: The Case Of Ambient Air Toxics Exposures And Health Risks Among Schoolchildren In Los Angeles, Rachel Morello-Frosch, Manuel Pastor, James Sadd

James Sadd

Two policy frameworks, environmental justice and the precautionary principle, have begun to transform traditional approaches to environmental policy making and community organizing related to public health. Despite having several important overlapping policy goals, little effort has been made to purposefully integrate these two frameworks. This article discusses preliminary research on environmental inequality in ambient air toxics exposures and associated health risks among schoolchildren in the Los Angeles Unified School District. Results indicate that children of color, namely, Latinos and African Americans, bear the highest burden of estimated cancer and noncancer health risks associated with ambient air toxics exposures while they …

Detecting Mitochondrial Permeability Transition By Confocal Imaging Of Intact Cells Pinocytically Loaded With Calcein, Rachel Jones, Alison Smail, Mark Wilson

Mark R Wilson

When studied in vitro, mitochondrial permeability transition (MPT) is associated with an increase in mitochondrial permeability to solutes up to 1500 Da in mass and a loss of electrical potential difference across the inner mitochondrial membrane (delta psi mit). The MPT has been implicated as being important in cellular calcium homeostasis, autophagy and cell death via necrosis and apoptosis. Thus, it is important to develop a valid technique for accurate measurement of this phenomenon in intact cells. We developed a procedure for the detection of MPT in intact cells that avoids disadvantages associated with earlier approaches. In this new technique, …

Optimal Policies For Investment With Time-Varying Return Distributions, Douglas Steigerwald, Doncho Donchev, Svetlozar Rachev

Douglas G. Steigerwald

We develop a model in which investors must learn the distribution of asset returns over time. The process of learning is made more difficult by the fact that the distributions are not constant through time. We consider risk-neutral investors who have quadratic utility and are selecting between two risky assets. We determine the time at which it is optimal to update the distribution estimate and, hence, alter portfolio weights. Our results deliver an optimal policy for asset allocation, that is, the sequence of time intervals at which it is optimal to switch between assets, based on stochastic optimal control theory. …

Thermoelectric Properties Of K[Subscript 2]Bi[Subscript 8-X]Sb[Subscript X]Se[Subscript 13] Solid Solutions And Se Doping [Et Al.], Theodora Kyratski, Jeffrey Dyck, Wei Chen

Jeffrey Dyck

Our efforts to improve the thermoelectric properties of β-K2Bi8Se13, led to systematic studies of solid solutions of the type β-K2Bi8−xSbxSe13. The charge transport properties and thermal conductivities were studied for selected members of the series. Lattice thermal conductivity decreases due to the mass fluctuation generated in the lattice by the mixed occupation of Sb and Bi atoms. Se excess as a dopant was found to increase the figure-of merit of the solid solutions.

Calculation Of The Stability Index In Parameter-Dependent Calculus Of Variations Problems: Buckling Of A Twisted Elastic Strut, Randy Paffenroth, Robert Manning, Kathleen Hoffman

Randy C. Paffenroth

No abstract provided.

Evidence That Clusterin Has Discrete Chaperone And Ligand Binding Sites, Johnathon Lakins, Stephen Poon, Simon Easterbrook-Smith, John Carver, Martin Tenniswood, Mark Wilson

Mark R Wilson

Clusterin is the first identified extracellular mammalian chaperone and binds to a wide variety of partly unfolded, stressed proteins. Clusterin also binds to many different unstressed ligands including the cell surface receptor low density lipoprotein receptor-related protein-2 (LRP-2). It is unknown whether clusterin binds to all of these many ligands via one or more binding sites. Furthermore, the region(s) of clusterin involved in these many binding interactions remain to be identified. As part of an investigation of these issues, we expressed recombinant human clusterin in the yeast Pichia pastoris. The resultant protein had variable proteolytic truncations of the C-terminal region …

International Supplement To Graptolite Macroevolution: Phylogenetic Analysis And Testing Hypotheses Of Directional Change, Daniel Goldman

Daniel Goldman

Funding agency: National Science Foundation Amount: $12,058.00 Year: 2002/2 yrs.

Spectra Of Composition Operators On The Bloch And Bergman Spaces, Karen Saxe, B. Maccluer

Karen Saxe

No abstract provided.

Numerical Solitary Wave Interaction: The Order Of The Inelastic Effect, Prof. Tim Marchant

Tim Marchant

Solitary wave interaction is examined using an extended Benjamin-Bona-Mahony (eBBM) equation. This equation includes higher-order nonlinear and dispersive effects and is is asymptotically equivalent to the extended Korteweg-de Vries (eKdV) equation. The eBBM formulation is preferable to the eKdV equation for the numerical modelling of solitary wave collisions, due to the stability of its finite-difference scheme. In particular, it allows the interaction of steep waves to be modelled, which due to numerical instability, is not possible using the eKdV equation. Numerical simulations of a number of solitary wave collisions of varying nonlinearity are performed for two special cases corresponding to …

Wide Plate Margin Deformation, Southern Central America And Northwestern South America, Casa Gps Observations, James Kellogg

James N Kellogg

Global Positioning System (GPS) data from southern Central America and northwestern South America were collected during 1991, 1994, 1996, and 1998 in Costa Rica, Panama, Ecuador, Colombia and Venezuela. These data reveal wide plate boundary deformation and escape tectonics occurring along an approximately 1400 km length of the North Andes; locking of the subducting Nazca plate and strain accumulation in the Ecuador-Colombia forearc; ongoing collision of the Panama arc and Colombia; and convergence of the Caribbean plate with Panama and South America. Elastic modeling of observed horizontal displacements in the Ecuador forearc is consistent with partial locking (50%) in the …

Sustainable Versus Unsustainable Propositions, John Dernbach

John C. Dernbach

No abstract provided.

Discrete Modeling I,, Joe Demaio, Virginia Watson

Joe DeMaio

Mathematical Models In Biology, Borbala Mazzag

Borbala Mazzag

No abstract provided.

On The Convergence Of Puck Clustering Systems, S. Kazadi, A. Abdul-Khaliq, R. Goodman

Sanza Kazadi

Asymptotically Constant Solutions Of Functional Difference Systems, William F. Trench

William F. Trench

No abstract provided.

Analysis And Classification Of Nonlinear Dispersive Evolution Equations In The Potential Representation, Andrei Ludu

Andrei Ludu

No abstract provided.

Dimensionality-Reducing Expansion, Boundary Type Quadrature Formulas, And The Boundary Element Method, Tian-Xiao He

Tian-Xiao He

This paper discusses the connection between boundary quadrature formulas constructed by using solutions of partial differential equations and boundary element schemes.

Features For Word Spotting In Historical Manuscripts, Toni M. Rath, R. Manmatha

R. Manmatha

For the transition from traditional to digital libraries, the large number of handwritten manuscripts that exist pose a great challenge. Easy access to such collections requires an index, which is currently created manually at great cost. Because automatic handwriting recognizers fail on historical manuscripts, the word spotting technique has been developed: the words in a collection are matched as images and grouped into clusters which contain all instances of the same word. By annotating ``interesting clusters," an index that links words to the locations where they occur can be built automatically.

Due to the noise in historical documents, selecting the …

What Do We Learn From The Local Geometry Of Glass-Forming Liquids?, Francis W. Starr, S. Sastry, J. F. Douglas, S. C. Glotzer

Francis Starr

No abstract provided.

Word Image Matching Using Dynamic Time Warping, Toni M. Rath, R. Manmatha

R. Manmatha

Libraries and other institutions are interested in providing access to scanned versions of their large collections of handwritten historical manuscripts on the web or on CDROMs. Providing convenient access to a collection requires an index which is manually created at great labour and expense. Since current handwriting recognizers do not perform well on historical documents, a technique called word spotting has been developed. It addresses the need for indexing single-author handwritten historical manuscripts in a new way: word images are matched to form clusters which contain occurrences of the same word throughout a collection. By annotating ``interesting" clusters, an index …

A Formal Approach To Score Normalization For Metasearch, H. Sever, R. Manmatha

R. Manmatha

Meta-search, or the combination of the outputs of different search engines in response to a query, has been shown to improve performance. Since the scores produced by different search engines are not comparable, researchers have often decomposed the metasearch problem into a score normalization step followed by a combination step. Combination has been studied by many researchers. While appropriate normalization can affect performance, most of the normalization schemes suggested are ad hoc in nature.

In this paper, we propose a formal approach to normalizing scores for meta-search by taking the distributions of the scores into account. Recently, it has been …

An Fmri Study Of Bilingual Sentence Comprehension And Workload, Mihoko Hasegawa, Patricia A. Carpenter, Marcel Adam Just

Marcel Adam Just

No abstract provided.

A Critical Examination Of Tdt’S Cost Function, R. Manmatha, Ao Feng, James Allan

R. Manmatha

Topic Detection and Tracking (TDT) tasks are evaluated using a cost function. The standard TDT cost function assumes a constant probability of relevance P(rel) across all topics. In practice, P(rel) varies widely across topics. We argue using both theoretical and experimental evidence that the cost function should be modified to account for the varying P(rel).

The Single Particle Potential In Mean-Field Theory, Peter Palffy-Muhoray

Peter Palffy-Muhoray

The problem of determining the single particle energy in a mean-field description of interacting particles is considered. It is shown that the single particle energy must satisfy two consistency conditions, and a general procedure for obtaining the single particle energy from the pair energy is proposed. Interacting dipolar systems are examined, current approaches in the literature are discussed, and the usefulness of the proposed method is demonstrated.