Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

2003

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 61 - 90 of 3927

Full-Text Articles in Physical Sciences and Mathematics

Efficient Customizable Middleware, Ravi Pratap Maddimsetty Dec 2003

Efficient Customizable Middleware, Ravi Pratap Maddimsetty

All Computer Science and Engineering Research

The rather large feature set of current Distributed Object Computing (DOC) middleware can be a liability for certain applications which have a need for only a certain subset of these features but have to suffer performance degradation and code bloat due to all the present features. To address this concern, a unique approach to building fully customizable middleware was undertaken in FACET, a CORBA event channel written using AspectJ. FACET consists of a small, essential core that represents the basic structure and functionality of an event channel into which additional features are woven using aspects so that the resulting event …


Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 1. Emissions From Indonesian, African, And Other Fuels, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wei Min Hao, B. H. Saharjo, Darold E. Ward Dec 2003

Comprehensive Laboratory Measurements Of Biomass-Burning Emissions: 1. Emissions From Indonesian, African, And Other Fuels, Ted J. Christian, B. Kleiss, Robert J. Yokelson, R. Holzinger, P. J. Crutzen, Wei Min Hao, B. H. Saharjo, Darold E. Ward

Chemistry and Biochemistry Faculty Publications

[1] Trace gas and particle emissions were measured from 47 laboratory fires burning 16 regionally to globally significant fuel types. Instrumentation included the following: open-path Fourier transform infrared spectroscopy; proton transfer reaction mass spectrometry; filter sampling with subsequent analysis of particles with diameter <2.5 μm for organic and elemental carbon and other elements; and canister sampling with subsequent analysis by gas chromatography (GC)/flame ionization detector, GC/electron capture detector, and GC/mass spectrometry. The emissions of 26 compounds are reported by fuel type. The results include the first detailed measurements of the emissions from Indonesian fuels. Carbon dioxide, CO, CH4, NH3, HCN, methanol, and acetic acid were the seven most abundant emissions (in order) from burning Indonesian peat. Acetol (hydroxyacetone) was a major, previously unobserved emission from burning rice straw (21–34 g/kg). The emission factors for our simulated African fires are consistent with field data for African fires for compounds measured in both …


An Iterative Beam Search Algorithm For Degenerate Primer Selection, Richard Souvenir Dec 2003

An Iterative Beam Search Algorithm For Degenerate Primer Selection, Richard Souvenir

All Computer Science and Engineering Research

Single Nucleotide Polymorphism (SNP) Genotyping is an important molecular genetics process in the early stages of producing results that will be useful in the medical field. Due to inherent complexities in DNA manipulation and analysis, many different methods have been proposed for a standard assay. One of the proposed techniques for performing SNP Genotyping requires amplifying regions of DNA surrounding a large number of SNP loci. In order to automate a portion of this particular method, it is necessary to select a set of primers for the experiment. Selecting these primers can be formulated as the Multiple Degenerate Primer Design …


Resource Configuration And Network Design In Extensible Networks, Sumi Y. Choi Dec 2003

Resource Configuration And Network Design In Extensible Networks, Sumi Y. Choi

All Computer Science and Engineering Research

The goal of packet-switched networks has conventionally been delivering data to users. This concept is changing rapidly as current technologies make it possible to build network processing engines that apply intermediary services to data traffic. This trend introduces an extensive range of ways to develop and operate applications by allowing processing services customized for applications' needs at intermediate network users, as it can relieve individuals from the need to acquire, install, and maintain software in end systems to perform required functions. As such network services become more widely used, it will become increasingly important for service providers to have effective …


Optimal Control Of Delayed Differential-Algebraic Inclusions, Boris S. Mordukhovich, Lianwen Wang Dec 2003

Optimal Control Of Delayed Differential-Algebraic Inclusions, Boris S. Mordukhovich, Lianwen Wang

Mathematics Research Reports

This paper concerns constrained dynamic optimization problems governed by delayed differential-algebraic systems. Dynamic constraints in such systems, which are particularly important for engineering applications, are described by interconnected delay-differential inclusions and algebraic equations. We pursue a two-hold goal: to study variational stability of such control systems with respect to discrete approximations and to derive necessary optimality conditions for both delayed differential-algebraic systems and their finite-difference counterparts using modern tools of variational analysis and generalized differentiation. We are not familiar with any results in these directions for differential-algebraic inclusions even in the delay-free case. In the first part of the paper …


The Approximate Maxium Principle In Constrained Optimal Control, Boris S. Mordukhovich, Ilya Shvartsman Dec 2003

The Approximate Maxium Principle In Constrained Optimal Control, Boris S. Mordukhovich, Ilya Shvartsman

Mathematics Research Reports

The paper concerns optimal control problems for dynamic systems governed by a parametric family of discrete approximations of control systems with continuous time. Discrete approximations play an important role in both qualitative and numerical aspects of optimal control and occupy an intermediate position between discrete-time and continuous-time control systems. The central result in optimal control of discrete approximations is the Approximate Maximum Principle (AMP), which is justified for smooth control problems with endpoint constraints under certain assumptions without imposing any convexity, in contrast to discrete systems with a fixed step. We show that these assumptions are essential for the validity …


Kernel Estimation Of Rate Function For Recurrent Event Data, Chin-Tsang Chiang, Mei-Cheng Wang, Chiung-Yu Huang Dec 2003

Kernel Estimation Of Rate Function For Recurrent Event Data, Chin-Tsang Chiang, Mei-Cheng Wang, Chiung-Yu Huang

Johns Hopkins University, Dept. of Biostatistics Working Papers

Recurrent event data are largely characterized by the rate function but smoothing techniques for estimating the rate function have never been rigorously developed or studied in statistical literature. This paper considers the moment and least squares methods for estimating the rate function from recurrent event data. With an independent censoring assumption on the recurrent event process, we study statistical properties of the proposed estimators and propose bootstrap procedures for the bandwidth selection and for the approximation of confidence intervals in the estimation of the occurrence rate function. It is identified that the moment method without resmoothing via a smaller bandwidth …


United States Patent: Application Of High Spin Polarization Materials In Two Terminal Non-Volatile Bistable Memory Devices, Bernard Doudin, Andrei Sokolov, Cheol-Soo Yang, Lu Yuan, Sy-Hwang Liou Dec 2003

United States Patent: Application Of High Spin Polarization Materials In Two Terminal Non-Volatile Bistable Memory Devices, Bernard Doudin, Andrei Sokolov, Cheol-Soo Yang, Lu Yuan, Sy-Hwang Liou

Sy-Hwang Liou Publications

Disclosed are two terminal bistable memory cells having least two high-spin polarization magnetic material junctions which are separated from one another by electron trap site defect containing insulator. The two terminal bistable memory cells demonstrate stable, low current readable, hysteretic resistance states which are set by the flow of a relatively high, (eg. a milliamp or less), plus or minus polarity D.C. current therethrough, which resistance is monitored by lower magnitude A.C. or D.C. current flow therethrough. Preferred cells have at least one Cr02/Cr203/ CrO2 sequence but typically have multiple Cr02/Cr …


Mangrove Peat Collapse Following Mass Tree Mortality: Implications For Forest Recovery From Hurricane Mitch, Donald R. Cahoon, Philippe Hensel, John M. Rybczyk, Karen L. Mckee, Edward Proffitt, Brian C. Perez Dec 2003

Mangrove Peat Collapse Following Mass Tree Mortality: Implications For Forest Recovery From Hurricane Mitch, Donald R. Cahoon, Philippe Hensel, John M. Rybczyk, Karen L. Mckee, Edward Proffitt, Brian C. Perez

Environmental Sciences Faculty and Staff Publications

  • 1 We measured sediment elevation and accretion dynamics in mangrove forests on the islands of Guanaja and Roatan, Honduras, impacted by Hurricane Mitch in 1998 to determine if collapse of underlying peat was occurring as a result of mass tree mortality. Little is known about the balance between production and decomposition of soil organic matter in the maintenance of sediment elevation of mangrove forests with biogenic soils.
  • 2 Sediment elevation change measured with the rod surface elevation table from 18 months to 33 months after the storm differed significantly among low, medium and high wind impact sites. Mangrove forests suffering …


Body Mass Of Late Quaternary Mammals (Data Set), Felisa A. Smith, S. Kathleen Lyons, S.K. Morgan Ernest, Kate E. Jones, Kansas State University, Tamar Dayan, Pablo A. Marquet, James H. Brown, John P. Haskell Dec 2003

Body Mass Of Late Quaternary Mammals (Data Set), Felisa A. Smith, S. Kathleen Lyons, S.K. Morgan Ernest, Kate E. Jones, Kansas State University, Tamar Dayan, Pablo A. Marquet, James H. Brown, John P. Haskell

School of Biological Sciences: Faculty Publications

The purpose of this data set was to compile body mass information for all mammals on Earth so that we could investigate the patterns of body mass seen across geographic and taxonomic space and evolutionary time. We were interested in the heritability of body size across taxonomic groups (How conserved is body mass within a genus, family, and order?), in the overall pattern of body mass across continents (Do the moments and other descriptive statistics remain the same across geographic space?), and over evolutionary time (How quickly did body mass patterns iterate on the patterns seen today? Were the Pleistocene …


Leaf And Wood Utilization In The Middle Missouri River, Kim Rager Dec 2003

Leaf And Wood Utilization In The Middle Missouri River, Kim Rager

School of Natural Resources: Dissertations, Theses, and Student Research

No abstract provided.


Measurement Of Conductivity And Charge Storage In Insulators Related To Spacecraft Charging, A Robb Frederickson, Jr Dennison Dec 2003

Measurement Of Conductivity And Charge Storage In Insulators Related To Spacecraft Charging, A Robb Frederickson, Jr Dennison

Journal Articles

Improved experimental methods are discussed for laboratory measurement of conductivity and electric field in insulating spacecraft material intended for space radiation and plasma environments. These measurement techniques investigate the following features: 1) Measurements of conductivity are up to four orders of magnitude smaller than those determined by existing standard methods. 2) Conductivity is altered as radiation accumulates and trapping states fill with electrons. 3) With intense keV electron irradiation, electrons are continually emitted for hours from the irradiated surface after the irradiation ceases. 4) Charging induced by electron irradiation is strongly modified by the electron-hole pairs that the irradiation generates …


Computational Magnetohydrodynamic Investigation Of Flux Compression And Implosion Dynamics In A Z-Pinch Plasma With An Azimuthally Opposed Magnetic Field Configuration, Kyle John Peterson Dec 2003

Computational Magnetohydrodynamic Investigation Of Flux Compression And Implosion Dynamics In A Z-Pinch Plasma With An Azimuthally Opposed Magnetic Field Configuration, Kyle John Peterson

Doctoral Dissertations

Magnetic flux compression is a well established technique for the generation of ultrahigh magnetic fields, large currents, and large energy densities. It has been suggested as a means for power density amplification on Z-pinch generators such as Decade Quad, at Arnold Engineering Development Center, and it may be especially suitable as a means for producing higher powers of K-shell radiation from high atomic number loads such as titanium. Although many one-dimensional models of flux compression on Z-pinch generators exist, an improvement in understanding is needed about the physics and implosion dynamics on a two-dimensional level. To this end, a two-dimensional …


“Design Of Molecular Mechanics Modeling Techniques For Exploring Molecular Recognition Using Cyclodextrins., Shannon Bradley Fox Dec 2003

“Design Of Molecular Mechanics Modeling Techniques For Exploring Molecular Recognition Using Cyclodextrins., Shannon Bradley Fox

Doctoral Dissertations

Molecular mechanics modeling techniques have been developed to study the behavior of cyclodextrins (CDs) in capillary electrophoresis (CE) separations. Using the commercial computational package, Sybyl, the mechanisms of molecular recognition between organic analytes and CDs are investigated.

Cyclodextrin-modified capillary electrochromatography (CDCE) experiments were conducted to separate neutral derivitized naphthalene solutes using carboxymethyl-beta-cyclodextrin (CM-b-CD). Grid conformation-searching programs were developed to explore the interaction space between CD and solute and to calculate their interaction energies using molecular mechanics. The interaction energies correlated remarkably well with the separation behavior. It was found that extensive minimization (more than 3000 iterations) was required at each …


Production In Au-Au Collisions, Robert Jason Newby Dec 2003

Production In Au-Au Collisions, Robert Jason Newby

Doctoral Dissertations

This thesis presents the first J/ Ψ production analysis of Au+Au reactions at forward rapidity at p √sNN = 200 GeV. In the second year of RHIC running, design energy was achieved in the collisions of both Au+Au ions and proton+proton reactions. The production of the J/Ψ is measured by the PHENIX experiment in Au+Au collisions as well as in proton-proton collisions. The scientific goal is to investigate the nature of hot, dense nuclear matter capitalizing on the unique properties of the J/ Ψ as a probe of this matter. Recent experimental results by the NA50 collaboration at CERN …


A Modeling Experiment On The Grounding Of An Ice Shelf In The Central Arctic Ocean During Mis 6, Martin Jakobsson, M Siegert, Mark Paton Dec 2003

A Modeling Experiment On The Grounding Of An Ice Shelf In The Central Arctic Ocean During Mis 6, Martin Jakobsson, M Siegert, Mark Paton

Center for Coastal and Ocean Mapping

High-resolution chirp sonar subbottom profiles from the Lomonosov Ridge in the central Arctic Ocean, acquired from the Swedish icebreaker Oden in 1996, revealed large-scale erosion of the ridge crest down to depths of 1000 m below present sea level [Jakobsson, 1999]. Subsequent acoustic mapping during the SCICEX nuclear submarine expedition in 1999 showed glacial fluting at the deepest eroded areas and subparallel ice scours from 950 m water depth to the shallowest parts of the ridge crest [Polyak et al., 2001]. The directions of the mapped glaciogenic bed-forms and the redeposition of eroded material on the Amerasian side of the …


Targeting Methanopterin Biosynthesis To Inhibit Methanogenesis, Razvan Dumitru, Hector Palencia, Scott D. Schroeder, Bree A. Demontigny, James M. Takacs, Madeline E. Rasche, Jess L. Miner, Stephen W. Ragsdale Dec 2003

Targeting Methanopterin Biosynthesis To Inhibit Methanogenesis, Razvan Dumitru, Hector Palencia, Scott D. Schroeder, Bree A. Demontigny, James M. Takacs, Madeline E. Rasche, Jess L. Miner, Stephen W. Ragsdale

James Takacs Publications

This paper describes the design, synthesis, and successful employment of inhibitors of 4-( β -D-ribofuranosyl) aminobenzene-5’-phosphate (RFA-P) synthase, which catalyzes the first committed step in the biosynthesis of methanopterin, to specifically halt the growth of methane-producing microbes. RFA-P synthase catalyzes the first step in the synthesis of tetrahydromethanopterin, a key cofactor required for methane formation and for one-carbon transformations in methanogens. A number of inhibitors, which are N-substituted derivatives of p-aminobenzoic acid (pABA), have been synthesized and their inhibition constants with RFA-P synthase have been determined. Based on comparisons of the inhibition constants among various inhibitors, we propose that the …


Flocking Over 3d Terrain, Joel Gompert Dec 2003

Flocking Over 3d Terrain, Joel Gompert

CSE Technical Reports

A method is presented for animating herds of animals that can follow terrain while being efficient enough to run in real-time. This method involves making simple modifications to Reynolds’ agent-based flocking algorithm. The modifications use only local properties of the terrain, and thus have low complexity. This method focuses on using terrain that can be described as an elevation grid, but it may be extendible to arbitrary terrain. The flocking algorithm with these modifications produces naturally behaving herds that follow the terrain. They will swerve around hills and attempt to follow paths that reduce energy expenditure. The terrain-following rule added …


Pyro: A Python-Based Versatile Programming Environment For Teaching Robotics, D. Blank, D. Kumar, Lisa A. Meeden, H. Yanco Dec 2003

Pyro: A Python-Based Versatile Programming Environment For Teaching Robotics, D. Blank, D. Kumar, Lisa A. Meeden, H. Yanco

Computer Science Faculty Works

In this article we describe a programming framework called Pyro, which provides a set of abstractions that allows students to write platform-independent robot programs. This project is unique because of its focus on the pedagogical implications of teaching mobile robotics via a top-down approach. We describe the background of the project, its novel abstractions, its library of objects, and the many learning modules that have been created from which curricula for different types of courses can be drawn. Finally, we explore Pyro from the students' perspective in a case study.


The John Muir Newsletter, Winter 2003/2004, The John Muir Center For Environmental Studies Dec 2003

The John Muir Newsletter, Winter 2003/2004, The John Muir Center For Environmental Studies

Muir Center Newsletters, 1981-2015

Newsletter ^ERSnY OF THE PACIFIC, STOCKTON. CA Volume 14, Number l Winter 2008-2004 John Mum and Civilization Corinne Wong, Clackamas, Oregon (Editor's note: Corinne Wong is a graduating senior double majoring in Environmental Studies and Geosciences. In addition, Wong is a student athlete in women's basketball at the University of the Pacific. This paper was prepared in the Fall of 2002 for an undergraduate course, "John Muir and the Environment.") J-ohn Muir was very much a man of nature. He was a geologist, botanist, mountaineer, nature writer, and, as most commonly recognized, a conservationist. His love for nature is a …


The Extratropical Transition Of Tropical Cyclones: Forecast Challenges, Current Understanding, And Future Directions, Sarah C. Jones, Patrick A. Harr, Jim Abraham, Lance F. Bosart, Peter J. Bowyer, Jenni L. Evans, Deborah E. Hanley, Barry N. Hanstrum, Robert E. Hart, Francois Lalaurette, Mark R. Sinclair, Roger K. Smith, Chris Thorncroft Dec 2003

The Extratropical Transition Of Tropical Cyclones: Forecast Challenges, Current Understanding, And Future Directions, Sarah C. Jones, Patrick A. Harr, Jim Abraham, Lance F. Bosart, Peter J. Bowyer, Jenni L. Evans, Deborah E. Hanley, Barry N. Hanstrum, Robert E. Hart, Francois Lalaurette, Mark R. Sinclair, Roger K. Smith, Chris Thorncroft

Applied Aviation Sciences - Prescott

A significant number of tropical cyclones move into the midlatitudes and transform into extratropical cyclones. This process is generally referred to as extratropical transition (ET). During ET a cyclone frequently produces intense rainfall and strong winds and has increased forward motion, so that such systems pose a serious threat to land and maritime activities. Changes in the structure of a system as it evolves from a tropical to an extratropical cyclone during ET necessitate changes in forecast strategies. In this paper a brief climatology of ET is given and the challenges associated with forecasting extratropical transition are described in terms …


Surface "Waves" On Byrd Glacier, Antarctica, D. Reusch, Terence J. Hughes Dec 2003

Surface "Waves" On Byrd Glacier, Antarctica, D. Reusch, Terence J. Hughes

Earth Science Faculty Scholarship

Byrd Glacier has one of the largest ice catchment areas in Antarctica, delivers more ice to the Ross Ice Shelf than any other ice stream, and is the fastest of these ice streams. A force balance, combined with a mass balance, demonstrates that stream flow in Byrd Glacier is transitional from sheet flow in East Antarctica to shelf flow in the Ross Ice Shelf. The longitudinal pulling stress, calculated along an ice flowband from the force balance, is linked to variations of ice thickness, to the ratio of the basal water pressure to the ice overburden pressure where Byrd Glacier …


Minerva 2003, The Honors College Dec 2003

Minerva 2003, The Honors College

Minerva

This inaugural issue of Minerva includes an article on the inauguration of the University of Maine Honors College; a discussion of Honors Living-Learning communities, Colvin and Balentine Halls; and an article on the introduction of the Honors Read tutorial course. Other highlights include an article on Honors travel to Washington D.C. and Chicago.


Return To The Wild, John C. Jahoda Dec 2003

Return To The Wild, John C. Jahoda

Bridgewater Review

No abstract provided.


Energy Scaling Law For Buildings, David W. Hafemeister Dec 2003

Energy Scaling Law For Buildings, David W. Hafemeister

Physics

This paper is an ode to my friend Hendrik. We collaborated on hyperfine interactions from 1962 to 1984, when he was colleague and friend. Since then I have been working on the Physics of Societal Issues (Springer Verlag, 2003). The paper below models energy use in buildings, which could save considerable energy with well-designed buildings.


Biological Permanent Magnets, Richard B. Frankel Dec 2003

Biological Permanent Magnets, Richard B. Frankel

Physics

Magnetotactic bacteria orient and migrate along magnetic field lines. Each cell is essentially a self-propelled magnetic dipole. The magnetic properties of these bacteria have been determined by a variety of techniques, including pulsed hysteresis measurements on single cells.


Isotropic Loop Quantum Cosmology With Matter. Ii. The Lorentzian Constraint, F. Hinterleitner, Seth Major Dec 2003

Isotropic Loop Quantum Cosmology With Matter. Ii. The Lorentzian Constraint, F. Hinterleitner, Seth Major

Articles

The Lorentzian Hamiltonian constraint is solved for isotropic loop quantum cosmology coupled to a massless scalar field. As in the Euclidean case, the discreteness of quantum geometry removes the classical singularity from the quantum Friedmann models. In spite of the absence of the classical singularity, a modified DeWitt initial condition is incompatible with a late-time smooth behavior. Further, the smooth behavior is recovered only for positive or negatives times but not both. An important feature, which is shared with the Euclidean case, is a minimal initial energy of the order of the Planck energy required for the system to evolve …


The Translocation Of Golden Perch, Murray Cod And Australian Bass, Into And Within Western Australia, For The Purposes Of Recreational Stocking, Domestic Stocking And Commercial And Non-Commercial Aquaculture. A Discussion Paper., Department Of Fisheries Dec 2003

The Translocation Of Golden Perch, Murray Cod And Australian Bass, Into And Within Western Australia, For The Purposes Of Recreational Stocking, Domestic Stocking And Commercial And Non-Commercial Aquaculture. A Discussion Paper., Department Of Fisheries

Fisheries management papers

This discussion paper has been prepared to provide information to assist in assessment of the possible impact of the translocation of golden perch (Macquaria ambigua), Murray cod (Maccullochella peelii peelii) and Australian bass (Macquaria novemaculeata) into and within Western Australia, for the purposes of recreational stocking, domestic stocking, commercial and non-commercial aquaculture. In assessing the translocation of any aquatic species, economic and social benefits must be balanced with biological and environmental risks.


Viewer-Based Directional Querying For Mobile Applications, Keith Gardiner, James Carswell Dec 2003

Viewer-Based Directional Querying For Mobile Applications, Keith Gardiner, James Carswell

Conference papers

With the steady and fast advancements in the integration of geographic information systems and mobile location-based services, interest in exploiting this technology for Cultural Heritage (CH) data sharing has become apparent. In this area there has been an increasing need to integrate positional information with non-positional data and add a spatial dimension to the definition of a users “context”. In this paper we describe an implementation of a viewer-based directional query processor that operates on an Oracle Spatial database. The spatial position and orientation are taken from the viewer’s perspective. Using this frame of reference a view-port is defined in …


In-Field Labeling Of Western Corn Rootworm Adults (Coleoptera: Chrysomelidae) With Rubidium, Timothy M. Nowatzki, Bradley Niimi, Kelli J. Warren, Sean Putnam, Lance J. Meinke, David C. Gosselin, F. Edwin Harvey, Thomas E. Hunt, Blair Siegfried Dec 2003

In-Field Labeling Of Western Corn Rootworm Adults (Coleoptera: Chrysomelidae) With Rubidium, Timothy M. Nowatzki, Bradley Niimi, Kelli J. Warren, Sean Putnam, Lance J. Meinke, David C. Gosselin, F. Edwin Harvey, Thomas E. Hunt, Blair Siegfried

School of Natural Resources: Faculty Publications

Field and laboratory studies were conducted in 2000 and 2001 to determine the feasibility of mass marking western corn rootworm adults, Diabrotica virgifera virgifera LeConte, with RbCl in the field. Results showed that application of rubidium (Rb) in solution to both the soil (1 g Rb/plant) and whorl (1 g Rb/plant) of corn plants was optimal for labeling western corn rootworm adults during larval development. Development of larvae on Rb-enriched corn with this technique did not significantly influence adult dry weight or survival. Rb was also highly mobile in the plant. Application of Rb to both the soil and the …