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2000

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Articles 751 - 780 of 2919

Full-Text Articles in Physical Sciences and Mathematics

Simpson's Paradox Can Emerge From The N-Player Prisoner's Dilemma: Implications For The Evolution Of Altruistic Behavior, Jeffrey Alan Fletcher, Martin Zwick Jul 2000

Simpson's Paradox Can Emerge From The N-Player Prisoner's Dilemma: Implications For The Evolution Of Altruistic Behavior, Jeffrey Alan Fletcher, Martin Zwick

Systems Science Faculty Publications and Presentations

Simulations of the n-player Prisoner’s Dilemma in multiple populations reveal that Simpson’s paradox can emerge in such game-theoretic situations. The relative proportion of cooperators can decrease in each separate sub-population, while the proportion of cooperators in the total population can nonetheless increase, at least transiently. Factors that determine the longevity of this effect are under investigation. The increase of altruistic behavior exhibited in these simulations is not based on reciprocal altruism, as there are no strategies conditional on other players’ past actions, nor does it depend on kin selection via inclusive fitness, as there are no genes. This model is …


Cryptanalysis Of The M-Permutation Protection Schemes, Hongjun Wu, Feng Bao, Dingfeng Ye, Robert H. Deng Jul 2000

Cryptanalysis Of The M-Permutation Protection Schemes, Hongjun Wu, Feng Bao, Dingfeng Ye, Robert H. Deng

Research Collection School Of Computing and Information Systems

Anderson and Kuhn have proposed the EEPROM modification attack to recover the secret key stored in the EEPROM. At ACISP ’98, Fung and Gray proposed an m-permutation protection scheme against the EEPROM modification attack. At ACISP ’99, Fung and Gray pointed out that in their original scheme, a secret key with too small or too large Hamming weight could be recovered easily. Then they proposed a revised m- permutation protection scheme and claimed that their revised scheme does not leak any information of the secret key. In this paper, we break completely both the original and the revised …


Nonparametric Estimation Of The Cumulative Intensity Function For A Nonhomogeneous Poisson Process From Overlapping Realizations, Bradford L. Arkin, Lawrence Leemis Jul 2000

Nonparametric Estimation Of The Cumulative Intensity Function For A Nonhomogeneous Poisson Process From Overlapping Realizations, Bradford L. Arkin, Lawrence Leemis

Arts & Sciences Articles

A nonparametric technique for estimating the cumulative intensity function of a nonhomogeneous Poisson process from one or more realizations on an interval is extended here to include realizations that overlap. This technique does not require any arbitrary parameters from the modeler, and the estimated cumulative intensity function can be used to generate a point process for simulation by inversion.


Computing The Cumulative Distribution Function Of The Kolmogorov–Smirnov Statistic, John H. Drew, Andrew G. Glen, Lawrence Leemis Jul 2000

Computing The Cumulative Distribution Function Of The Kolmogorov–Smirnov Statistic, John H. Drew, Andrew G. Glen, Lawrence Leemis

Arts & Sciences Articles

We present an algorithm for computing the cumulative distribution function of the Kolmogorov–Smirnov test statistic Dn in the all-parameters-known case. Birnbaum (1952, J. Amer. Statist. Assoc. 47, 425–441), gives an n-fold integral for the CDF of the test statistic which yields a function defined in a piecewise fashion, where each piece is a polynomial of degree n. Unfortunately, it is difficult to determine the appropriate limits of integration for computing these polynomials. Our algorithm performs the required integrations in a manner that avoids calculating the same integrals repeatedly, resulting in shorter computation time. It can be used …


Thermal Lattice Boltzmann Simulation For Multispecies Fluid Equilibration, Linda L. Vahala, Darren Wah, George Vahala, Jonathan Carter, Pavol Pavlo Jul 2000

Thermal Lattice Boltzmann Simulation For Multispecies Fluid Equilibration, Linda L. Vahala, Darren Wah, George Vahala, Jonathan Carter, Pavol Pavlo

Electrical & Computer Engineering Faculty Publications

The equilibration rate for multispecies fluids is examined using thermal lattice Boltzmann simulations. Two-dimensional free-decay simulations are performed for effects of velocity shear layer turbulence on sharp temperature profiles. In particular, parameters are so chosen that the lighter species is turbulent while the heavier species is laminar-and so its vorticity layers would simply decay and diffuse in time. With species coupling, however, there is velocity equilibration followed by the final relaxation to one large co- and one large counter-rotating vortex. The temperature equilibration proceeds on a slower time scale and is in good agreement with the theoretical order of magnitude …


Trading Risk In Mobile-Agent Computational Markets, Jonathan Bredin, David Kotz, Daniela Rus Jul 2000

Trading Risk In Mobile-Agent Computational Markets, Jonathan Bredin, David Kotz, Daniela Rus

Dartmouth Scholarship

Mobile-agent systems allow user programs to autonomously relocate from one host site to another. This autonomy provides a powerful, flexible architecture on which to build distributed applications. The asynchronous, decentralized nature of mobile-agent systems makes them flexible, but also hinders their deployment. We argue that a market-based approach where agents buy computational resources from their hosts solves many problems faced by mobile-agent systems. \par In our earlier work, we propose a policy for allocating general computational priority among agents posed as a competitive game for which we derive a unique computable Nash equilibrium. Here we improve on our earlier approach …


Investigations On The Use Of Ion Mobility Spectrometry For Clinical Chemistry Applications, Henri Parson Patten Jul 2000

Investigations On The Use Of Ion Mobility Spectrometry For Clinical Chemistry Applications, Henri Parson Patten

Theses and Dissertations in Biomedical Sciences

The major objective of this research is to examine ion mobility spectrometry as a rapid screening tool for specific application to clinical chemistry research and laboratory use. Methodology was developed for target analytes representing several classes of physiologically active substances, including anesthetics, illicit drugs, and their metabolites. The IMS characteristics of animal tissues and other compounds such as amino acids and proteins were determined. Quality assurance and control procedures were developed for specific quality data objectives. Criteria were established relating to use of IMS for assessing the precision and accuracy of data, qualitative screening, and semi-quantitative analyses.

It was found …


Enear Redshift-Distance Survey: Cosmological Constraints, Stefano Borgani, Mariangela Bernardi, Luiz N. Da Costa, Gary Wegner Jul 2000

Enear Redshift-Distance Survey: Cosmological Constraints, Stefano Borgani, Mariangela Bernardi, Luiz N. Da Costa, Gary Wegner

Dartmouth Scholarship

We present an analysis of the ENEAR sample of peculiar velocities of field and cluster elliptical galaxies, obtained with Dn-σ distances. We use the velocity correlation function ψ1(r) to analyze the statistics of the field object's velocities, while the analysis of the cluster data is based on the estimate of their rms peculiar velocity Vrms. The results are compared with predictions from cosmological models using linear theory. The statistics of the model velocity field is parameterized by the amplitude η8 = σ8Ω and by the shape parameter Γ of the cold dark matter-like power spectrum. …


Phenomenological Description Of Double-Pion Photoproduction, Andry M. Rakotovao Jul 2000

Phenomenological Description Of Double-Pion Photoproduction, Andry M. Rakotovao

Physics Theses & Dissertations

Double pion photoproduction off proton targets is studied, in the framework of an Effective Lagrangian approach at tree level, based on the coupling of photons and pions to nucleons and resonances. We consider N, Δ(1232), N(1440), N(1520) and N(1535) as intermediate baryonic states and ρ-meson as the intermediate 2π resonance. The general form of the amplitude is presented and total cross sections of the γp → π+π− p, γp → π0π0p and γp → π +π0n processes are evaluated up to Eγ …


Effects Of Elevated Atmospheric Co2 On Root Growth, Turnover And Decomposition In A Scrub Oak Ecosystem, John Joseph Dilustro Jul 2000

Effects Of Elevated Atmospheric Co2 On Root Growth, Turnover And Decomposition In A Scrub Oak Ecosystem, John Joseph Dilustro

Biological Sciences Theses & Dissertations

Atmospheric carbon dioxide levels are increasing and predicted to double this century. The implications of this rise on vegetation structure and function are not well understood. Measurement of root growth response to elevated atmospheric carbon dioxide is critical to understanding soil carbon input. I investigated the effects of elevated carbon dioxide on fine root growth and decomposition using open top chambers with both ambient and elevated (700 PPM) CO2 treatments in an oak-palmetto scrub ecosystem at Kennedy Space Center, Florida. Minirhizotron tubes were installed in each elevated and control chamber to allow observation of roots. Each tube was sampled …


Resolution Of Overlapping Spectra By Wavelength Modulation Spectroscopy, Audra Michiele Bullock Jul 2000

Resolution Of Overlapping Spectra By Wavelength Modulation Spectroscopy, Audra Michiele Bullock

Electrical & Computer Engineering Theses & Dissertations

Wavelength modulation absorption spectroscopy is a highly sensitive, non-intrusive technique for probing gaseous species, which employs the well-known principles of modulation spectroscopy in a novel way. With this technique, parameters such as velocity, density, and temperature can be measured with a high degree of precision. The research presented here shows that wavelength modulation is a convenient means of increasing the sensitivity of an absorption spectroscopy measurement because it allows for harmonic detection. The focus of the dissertation is resolution of overlapping spectra by harmonic detection and the advantages gained by performing detection at the higher harmonics, e.g., sixth and eighth. …


Advanced Atmospheric Water Vapor Dial Detection System, Tamer Refaat Jul 2000

Advanced Atmospheric Water Vapor Dial Detection System, Tamer Refaat

Electrical & Computer Engineering Theses & Dissertations

Measurement of atmospheric water vapor is very important for understanding the Earth's climate and water cycle. The remote sensing Differential Absorption Lidar (DIAL) technique is a powerful method to perform such measurement from aircraft and space. This thesis describes a new advanced detection system, which incorporates major improvements regarding sensitivity and size. These improvements include a low noise advanced avalanche photodiode detector, a custom analog circuit, a 14-bit digitizer, a microcontroller for on board averaging and finally a fast computer interface.

This thesis describes the design and validation of this new water vapor DIAL detection system which was integrated onto …


Routing Optimization Through Computer-Aided Simulation, Madhusudhan Akundi Jul 2000

Routing Optimization Through Computer-Aided Simulation, Madhusudhan Akundi

Electrical & Computer Engineering Theses & Dissertations

Routing has always been a challenging field, and the various techniques of mathematics and operations research have been developed. For commercial organizations, routing has begun to receive extensive attention because of the savings gained in terms of time, money, personnel, and the transportation fleet by developing optimized routing networks. Until recently, it was difficult to develop optimized networks due to the computational difficulties of the problem. However, with the advancement in computer technology and processing speeds, it has become possible to simulate a large number of routing scenarios and determine optimal solutions for a given set of constraints. Not only …


A Flowchart Structure For Modification Of A Modsim Process Model, Murali K. Adatrao Jul 2000

A Flowchart Structure For Modification Of A Modsim Process Model, Murali K. Adatrao

Electrical & Computer Engineering Theses & Dissertations

There are many software processes and software development models that support the development of a software model prior to implementation. However, more often than not, these practices are not followed resulting in a lack of documentation of the intended functionality of the software. As a result, software often becomes a black box for later developers. Even a simple bug fix can turn into an exhaustive task for the developers, as they must attempt to infer the intended system behavior. New designers cannot make any changes to the software or extend the software behavior, as the underlying model within the software …


Design Of Adaptive Sliding Mode Fuzzy Control For Robot Manipulator Based On Extended Kalman Filter, Abdelrahman Aledhaibi Jul 2000

Design Of Adaptive Sliding Mode Fuzzy Control For Robot Manipulator Based On Extended Kalman Filter, Abdelrahman Aledhaibi

Mechanical & Aerospace Engineering Theses & Dissertations

In this work, a new adaptive motion control scheme for robust performance control of robot manipulators is presented. The proposed scheme is designed by combining the fuzzy logic control with the sliding mode control based on extended Kalman filter. Fuzzy logic controllers have been used successfully in many applications and were shown to be superior to the classical controllers for some nonlinear systems. Sliding mode control is a powerful approach for controlling nonlinear and uncertain systems. It is a robust control method and can be applied in the presence of model uncertainties and parameter disturbances, provided that the bounds of …


Buckets: Smart Objects For Digital Libraries, Michael L. Nelson Jul 2000

Buckets: Smart Objects For Digital Libraries, Michael L. Nelson

Computer Science Theses & Dissertations

Discussion of digital libraries (DLs) is often dominated by the merits of various archives, repositories, search engines, search interfaces and database systems. While these technologies are necessary for information management, information content and information retrieval systems should progress on independent paths and each should make limited assumptions about the status or capabilities of the other. Information content is more important than the systems used for its storage and retrieval. Digital information should have the same long-term survivability prospects as traditional hardcopy information and should not be impacted by evolving search engine technologies or vendor vagaries in database management systems.

Digital …


Electroweak Structure Of Three-And Four-Body Nuclei, Laura Elisa Marcucci Jul 2000

Electroweak Structure Of Three-And Four-Body Nuclei, Laura Elisa Marcucci

Physics Theses & Dissertations

This work reports results for (i) the elastic electromagnetic form factors of the trinucleons; (ii) the nuclear response functions of interest in [ee'] experiments, at excitation energies below the deuteron breakup threshold; (iii) the astrophysical S-factor for proton weak capture on 3He (the hep reaction). The initial and final state wave functions are calculated using the correlated hyperspherical harmonics method, from a realistic Hamiltonian consisting of the Argonne v18 two-nucleon and Urbana IX three-nucleon interactions. The nuclear electroweak charge and current operators include one- and many-body components. The predicted magnetic form factor of …


Conservation Conundrum, Robert L. Brownell Jr., Barbara E. Curry, Peter Daszak, Andrew A. Cunningham, Alex D. Hyatt Jun 2000

Conservation Conundrum, Robert L. Brownell Jr., Barbara E. Curry, Peter Daszak, Andrew A. Cunningham, Alex D. Hyatt

United States Department of Commerce: Staff Publications

P. Daszak, A. A. Cunningham, and A. D. Hyatt present a convincing argument in their Review "Emerging infectious diseases of wildlife-threats to biodiversity and human health" (Science's Compass, 21 Jan., p. 443) that emerging infectious diseases (EIDs) pose a risk to wildlife, and they suggest that EIDs most often result from a change in the ecology of the pathogen or the host (or both). A situation they did not mention is that in some cases, the protection of threatened species can increase the risk of an EID outbreak by allowing a close association between wildlife and domestic animals where one …


Struktura Emisji Związków Fluoru Z Hutnictwa Żelaza Na Przykładzie Huty Katowice, Marian Mazur, Robert Oleniacz, Marek Bogacki Jun 2000

Struktura Emisji Związków Fluoru Z Hutnictwa Żelaza Na Przykładzie Huty Katowice, Marian Mazur, Robert Oleniacz, Marek Bogacki

Robert Oleniacz

As recently as a dozen or so years ago ferrous metallurgy was known as one of the biggest source of fluorine compound emissions to the atmosphere. Nevertheless production technology and raw material changes occurring in this industry cause continuous decreasing of their participation in the total fluorine emission. On the ground of investigations that have been carried out in the Katowice Steelworks (Poland) in the last few years, participation of particular technological processing in the water-soluble fluorine compound emissions (which are regarded as toxic) were presented in the paper, as well as a position of fuel combustion process (that take …


Analiza Możliwości Likwidacji Stref Ochronnych Wokół Wybranych Zakładów Przemysłu Hutniczego I Koksochemicznego, Marian Mazur, Robert Oleniacz, Marek Bogacki Jun 2000

Analiza Możliwości Likwidacji Stref Ochronnych Wokół Wybranych Zakładów Przemysłu Hutniczego I Koksochemicznego, Marian Mazur, Robert Oleniacz, Marek Bogacki

Robert Oleniacz

Polish industrial plants with protective zones delimited in the past, have been faced with the necessity to liquidation of these zones before 2005. At the same time the plants must not cause any harmful influence over environment outside the area which they have title deed to. Determination of the current range of this impact is very important due to the high costs of a possible purchase of land exposed to the harmful effects. The study analyzes the possibility of verifying the course of borders two existing protective zones: around Katowice Steelworks and Coking Plant "Przyjaźń" in Dąbrowa Górnicza (the first …


Digestibility, Nitrogen Excretion, And Mean Retention Time By North American Porcupines (Erethizon Dorsatum) Consuming Natural Forages, Laura A. Felicetti, Lisa A. Shipley, Gary W. Witmer, Charles T. Robbins Jun 2000

Digestibility, Nitrogen Excretion, And Mean Retention Time By North American Porcupines (Erethizon Dorsatum) Consuming Natural Forages, Laura A. Felicetti, Lisa A. Shipley, Gary W. Witmer, Charles T. Robbins

United States Department of Agriculture Wildlife Services: Staff Publications

North American porcupines (Erethizon dorsatum) subsist predominantly on low-protein, high-fiber, high-tannin diets. Therefore, we measured the porcupine's ability to digest dry matter, fiber, and protein by conducting digestion trials on eight natural forages and one pelleted ration varying in concentration of fiber, nitrogen, and tannins. On these diets, dry matter intake ranged from 5 to 234 g/kg 0.75/d and dry matter digestibility ranged from 62% to 96%. Porcupines digested highly lignified fiber better than many large hindgut fermenters and ruminants. The porcupine's ability to digest fiber may be explained, in part, by their lengthy mean retention time …


Changes In Electron-Phonon Coupling Across A Bulk Phase Transition In Copolymer Films Of Vinylidene Fluoride (70%) With Trifluoroethylene (30%), C. N. Borca, Shireen Adenwalla, Jaewu Choi, Lee Robertson, H. You, V. M. Fridkin, S. P. Palto, N. Petukhova, Stephen Ducharme, Peter A. Dowben Jun 2000

Changes In Electron-Phonon Coupling Across A Bulk Phase Transition In Copolymer Films Of Vinylidene Fluoride (70%) With Trifluoroethylene (30%), C. N. Borca, Shireen Adenwalla, Jaewu Choi, Lee Robertson, H. You, V. M. Fridkin, S. P. Palto, N. Petukhova, Stephen Ducharme, Peter A. Dowben

Peter Dowben Publications

We present evidence for a change in electron - phonon coupling across a bulk phase transition. Below the lattice stiffening transition at around 160 K, there is a change in the diffracted peak width observed by neutron and X-ray scattering techniques. Also, the electronic band structure of the copolymer is shifting in binding energy below 160 K, decreasing the density of states near the Fermi level. The value of the effective Debye temperature above the transition temperature is approximately 50 K, while below 160 K, the value of the Debye parameter is 245 K. We postulate that the coupling between …


Parameter Tracking For Stochastic Time-Varying Systems, Zheng Li Jun 2000

Parameter Tracking For Stochastic Time-Varying Systems, Zheng Li

Faculty of Informatics - Papers (Archive)

Describes a method for tracking fast time-varying parameters of dynamic systems under stochastic disturbances. Auxiliary information is used in addition to the plant input and output for better tracking accuracy.


Essentials Of K-Essence, Christian Armendariz-Picon, V. Mukhanov, Paul J. Steinhardt Jun 2000

Essentials Of K-Essence, Christian Armendariz-Picon, V. Mukhanov, Paul J. Steinhardt

Physics - All Scholarship

We recently introduced the concept of "k-essence" as a dynamical solution for explaining naturally why the universe has entered an epoch of accelerated expansion at a late stage of its evolution. The solution avoids fine-tuning of parameters and anthropic arguments. Instead, k-essence is based on the idea of a dynamical attractor solution which causes it to act as a cosmological constant only at the onset of matter-domination. Consequently, k-essence overtakes the matter density and induces cosmic acceleration at about the present epoch. In this paper, we present the basic theory of k-essence and dynamical attractors based on evolving scalar fields …


Solvability Of A Parabolic Boundary Value Problem With Internal Jump Condition, Kurt M. Bryan, Lester Caudill Jun 2000

Solvability Of A Parabolic Boundary Value Problem With Internal Jump Condition, Kurt M. Bryan, Lester Caudill

Mathematical Sciences Technical Reports (MSTR)

We examine a model for the propagation of heat through a one-dimensional object with an interior ''flaw". The flaw is modeled as a nonlinear relationship between the flux and temperature jump at an interior point of the object. Under realistic hypotheses, the resulting nonlinear initial boundary value problem is shown to have a unique and suitably smooth solution.


Modular Symbols And Hecke Operators, Paul E. Gunnells Jun 2000

Modular Symbols And Hecke Operators, Paul E. Gunnells

Paul Gunnells

We survey techniques to compute the action of the Hecke operators on the cohomology of arithmetic groups. These techniques can be seen as generalizations in different directions of the classical modular symbol algorithm, due to Manin and Ash-Rudolph. Most of the work is contained in papers of the author and the author with Mark McConnell. Some results are unpublished work of Mark McConnell and Robert MacPherson.


Rare-Earth Boride Thin Film System, Peter A. Dowben, Zenchen Zhong, David J. Sellmyer Jun 2000

Rare-Earth Boride Thin Film System, Peter A. Dowben, Zenchen Zhong, David J. Sellmyer

Peter Dowben Publications

Disclosed is a system made by a method for depositing rare-earth boride onto the surface of a substrate which is submerged in an organic solution of borane and a rare-earth halide. Application of electromagnetic radiation, preferably in the visible wavelength range, through a mask near the surface of the submerged substrate, drives the formation and deposition of rare-earth boride onto a substrate in desired patterns.


The Primordial Helium Abundance: Toward Understanding And Removing The Cosmic Scatter In The Dy/Dz Relation, D. R. Ballantyne, Gary J. Ferland, P. G. Martin Jun 2000

The Primordial Helium Abundance: Toward Understanding And Removing The Cosmic Scatter In The Dy/Dz Relation, D. R. Ballantyne, Gary J. Ferland, P. G. Martin

Physics and Astronomy Faculty Publications

We present results from photoionization models of low-metallicity H II regions. These nebulae form the basis for measuring the primordial helium abundance. Our models show that the helium ionization correction factor (ICF) can be nonnegligible for nebulae excited by stars with effective temperatures larger than 40,000 K. Furthermore, we find that when the effective temperature rises to above 45,000 K, the ICF can be significantly negative. This result is independent of the choice of stellar atmosphere. However, if an H II region has an [O III] λ5007/[O I] λ6300 ratio greater than 300, then our models show that, regardless of …


Search For A W′ Boson Via The Decay Mode W′→Μν Μ In 1.8 Tev Pp̅ Collisions, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration Jun 2000

Search For A W′ Boson Via The Decay Mode W′→Μν Μ In 1.8 Tev Pp̅ Collisions, F. Abe, Kenneth A. Bloom, Collider Detector At Fermilab Collaboration

Kenneth Bloom Publications

We report the results of a search for a W′ boson produced in pp̅ collisions at a center-of-mass energy of 1.8 TeV using a 107 pb-1 data sample recorded by the Collider Detector at Fermilab. We consider the decay channel W′→ μνμ and search for anomalous production of high transverse mass μνμ lepton pairs. We observe no excess of events above background and set limits on the rate of W′ boson production and decay relative to standard model W boson production and decay using a fit of the transverse mass distribution observed. If we assume standard …


Can We Protect Agricultural Land And The Scenic Rural Landscape? The Spatial Effects Of Three Land Protection Strategies In The Eastern United States, Elizabeth Brabec, Chip Smith Jun 2000

Can We Protect Agricultural Land And The Scenic Rural Landscape? The Spatial Effects Of Three Land Protection Strategies In The Eastern United States, Elizabeth Brabec, Chip Smith

Elizabeth Brabec

In order to assess the efficacy of the three most common types of agricultural land conservation in the United States, this study analyzes the spatial and visual quality of a purchase of development rights program and two regulatory programs — cluster and the transfer of development rights. The study compares the effectiveness of programs that have been in place for periods of 6 to 18 years, surveying three different communities in the urban fringe: 1. the transfer of development rights program in Montgomery County, Maryland, in effect since 1981, 2. Riverhead, New York’s farmland development rights acquisition program, administered by …