Physical Sciences and Mathematics Commons^™

Kinetics Of Ferroelectric Switching In Ultrathin Films, G. Vizdrik, Stephen Ducharme, V.M. Fridkin, S.G. Yudin

Stephen Ducharme Publications

The kinetics of polarization switching in ultrathin ferroelectric polymer films exhibit a critical behavior; there is a pronounced slowing just above the coercive field and just below the critical temperature. The critical slowing is observed in the switching kinetics of ferroelectric Langmuir-Blodgett films of 70% vinylidene-fluoride and 30% trifluoroethylene copolymer with thickness up to 30 ML. Thicker films exhibit an exponential dependence on the field and temperature that is normally associated with extrinsic switching by domain nucleation and growth. We show that the critical behavior arises naturally from the dynamics of homogeneous intrinsic switching in the context of mean-field theory. …

Thermal Transport Eveluations Related To Waste Package Design -- Model Evaluations -- Task 19, Roald Akberov

Publications (YM)

The purpose of the “Thermal Transport Evaluations Related to Waste Package Design” Task # 19 of Cooperative Agreement Number DE-FC28-98NV12081 was to develop a new CFDHT model for heat transfer and fluid flow in the potential rsepository at the Yucca Mountain, Nevada and to study the effects of forced convection during the pre-closure period and natural convection during the postclosure period. The analysis was performed for the drift dimensions shown in Figure 4-1 below. The intended use of the model is to estimate the velocity and temperature distribution as well as the highest temperature in the drift during the pre-closure …

Effect Of Polarizability Of Halide Anions On The Ionic Salvation In Water Clusters, S. Yoo, Y.A. Lei, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Molecular dynamics simulation has been performed to study the effect of the polarizabilities of model anions on the ionic solvation in water clusters. The primary focus is given to the surface versus interior solvation behavior of the anions. To this end, various combinations of polarizable/nonpolarizable water and anion models were considered. Using the nonpolarizable TIP4P water with polarizable Cl₂ and Br₂ models, the Cl₂ is fully solvated inside the (H₂O) ₆₀ cluster, whereas the Br₂ is partially solvated at the surface of the cluster. However, when the polarizability of the Br₂ is turned …

Long-Range Transportation Planning In Utah: Executive Summary, Dale Blahna, Joanna Endter-Wada, Steve Burr, Michael Butkus, Douglas Gibbons, Christina Klien, Judith Kurtzman, Douglas Reiter

Environment and Society Faculty Publications

This is the Executive Summary of the 2003 Utah Department of Transportation (UDOT) Benchmark Study. The study involved two phases and the USU research team produced two final reports, one for each phase of the research project, and an overarching Executive Summary. The purposes of the 2003 UDOT Benchmark Study conducted by Utah State University (USU) were to provide the Utah Department of Transportation (UDOT) with information for use in its statewide, long-range transportation plan and to provide benchmark data for tracking trends over time. The study was conducted jointly by the Institute for Outdoor Recreation and Tourism and the …

Long-Range Transportation Planning In Utah: Summary Of Research Results From Interviews And Focus Groups, Joanna Endter-Wada, Judith Kurtzman, Michael Butkus, Dale Blahna, Christina Klien, Steve Burr, Douglas Gibbons, Douglas Reiter

Environment and Society Faculty Publications

This is the final Report from Phase II of the 2003 Utah Department of Transportation (UDOT) Benchmark Study. The study involved two phases and the USU research team produced two final reports, one for each phase of the research project, and an overarching Executive Summary. The purposes of the 2003 UDOT Benchmark Study conducted by Utah State University (USU) were to provide the Utah Department of Transportation (UDOT) with information for use in its statewide, long-range transportation plan and to provide benchmark data for tracking trends over time. The study was conducted jointly by the Institute for Outdoor Recreation and …

The Logic Of Peace, Jonathan Schell

New England Journal of Public Policy

Jonathan Schell’s The Unconquerable World points the way out of the devastation of the twentieth century toward another, more peaceful path. And his investigations into the great nonviolent events of modern times — from Gandhi’s independence movement in India to the explosion of civic activity that brought about the surprising collapse of the Soviet Union — suggest foundations of an entirely new kind on which to construct an enduring peace. As Schell makes clear, all-out war, with its risk of human extinction, must cease to play the role of final arbiter. “The Logic of Peace,” printed here, is the final …

Perpendicular Transport Of Solar Energetic Particles In Heliospheric Magnetic Fields, Ming Zhang, Jack Randy Jokipii, Robert Bruce Mckibben

Aerospace, Physics, and Space Science Faculty Publications

This paper presents direct observational evidence for large perpendicular diffusive flows of solar energetic particles in heliospheric magnetic fields. Using anisotropy measurements of 40-92 MeV protons obtained by the High-Energy Telescope of the COSPIN consortium on Ulysses at high heliographic latitudes, we find that during several gradual solar particle events, for periods of many hours, the observed particle flow is directed at significant angles to the measured local magnetic field direction, which can only be explained by cross-field diffusion. The variation of the particle flow direction with the magnetic field direction seen in the 2000 July 14 solar energetic particle …

Rank And K-Nullity Of Contact Manifolds, Philippe Rukimbira

Department of Mathematics and Statistics

We prove that the dimension of the 1-nullity distribution N(1) on a closed Sasakian manifold M of rankl is at least equal to 2l−1 provided that M has an isolated closed characteristic. The result is then used to provide some examples of k-contact manifolds which are not Sasakian. On a closed, 2n+1-dimensional Sasakian manifold of positive bisectional curvature, we show that either the dimension of N(1) is less than or equal to n+1 or N(1) is the entire tangent bundle TM. In the latter case, the Sasakian manifold Mis isometric to a quotient of the Euclidean sphere under a finite …

Integrated Weed Management Plan For The Lower Las Vegas Wash, Elizabeth Bickmore

Publications (WR)

The Las Vegas Wash (Wash) is the primary drainage for the metropolitan Las Vegas Valley, eventually finding its way into the Colorado River watershed system. Pursuant to the recommendations of the Water Quality Citizens Advisory Committee, the Las Vegas Wash Coordination Committee (LVWCC) was formed in 1998 to develop a comprehensive plan for the long-term stabilization and management of the Wash. Consisting of representatives from 28 government agencies, businesses, environmental groups and citizens, the LVWCC formulated the Las Vegas Wash Comprehensive Adaptive Management Plan (CAMP) and designated the Southern Nevada Water Authority (SNWA) as the lead agency for the implementation …

Measuring Treatment Effects Using Semiparametric Models, Zhuo Yu, Mark J. Van Der Laan

U.C. Berkeley Division of Biostatistics Working Paper Series

In order to estimate the causal effect of treatments on an outcome of interest, one has to account for the effect of confounding factors which covary with the treatments and also contribute to the outcome of interest. In this paper, we use the semiparametric regression model to estimate the causal parameters. We assume the causal effect of the treatments can be described by the parametric component of the semiparametric regression model. Following the general methodology which was developed in van der Laan and Robins (2002) we give the orthogonal complement of the nuisance tangent space which identifies all the estimating …

Fragile Watermark Based On Polarity Of Pixel Points, C. Kailasanathan

Faculty of Informatics - Papers (Archive)

A fragile watermarking scheme for authenticating images based on the Yeung-Mintzer scheme is proposed in this paper. This scheme does provide a better protection against all the attacks proposed for Yeung-Mintzer scheme. A polar set derived from the image blocks is used in the embedding process. The center pixel values of image blocks are perturbed by small quantities in such a way that the perceptual quality of the image is not modified. This paper also analyse the security level with respect to other attacks.

Gauge-Invariant Initial Conditions And Early Time Perturbations In Quintessence Universes, Michael Doran, Christian M. Müller, Gregor Schäfer, Christof Wetterich

Dartmouth Scholarship

We present a systematic treatment of the initial conditions and evolution of cosmological perturbations in a universe containing photons, baryons, neutrinos, cold dark matter, and a scalar quintessence field. By formulating the evolution in terms of a differential equation involving a matrix acting on a vector comprised of the perturbation variables, we can use the familiar language of eigenvalues and eigenvectors. As the largest eigenvalue of the evolution matrix is fourfold degenerate, it follows that there are four dominant modes with a nondiverging gravitational potential at early times, corresponding to adiabatic, cold dark matter isocurvature, baryon isocurvature and neutrino isocurvature …

Search For ΝΜ→ΝE Oscillations In The Nomad Experiment, Nomad Collaboration, P. Astier, D. Autiero, A. Baldisseri, M. Baldo-Ceolin, M. Banner, G. Bassompierre, K. Benslama, N. Besson, I. Bird, B. Blumenfeld, F. Bobisut, J. Bouchez, S. Boyd, A. Bueno, S. Buyatov, L. Camilleri, A. Cardini, P. W. Cattaneo, V. Cavasinni, Roberto Petti, Et. Al.

Faculty Publications

We present the results of a search for ν_µ → ν_e oscillations in the NOMAD experiment at CERN. The experiment looked for the appearance of ν_e in a predominantly ν_µ wide-band neutrino beam at the CERN SPS. No evidence for oscillations was found. The 90% confidence limits obtained are ∆m² < 0.4 eV² for maximal mixing and sin²(2θ)−3 for large ∆m². This result excludes the LSND allowed region of oscillation parameters with ∆m² ≳∆10 eV².

Large Nc And Chiral Dynamics, Joseph Schechter, Masayasu Harada, Francesco Sannino

Physics - All Scholarship

We study the dependence on the number of colors of the leading pi pi scattering amplitude in chiral dynamics. We demonstrate the existence of a critical number of colors for and above which the low energy pi pi scattering amplitude computed from the simple sum of the current algebra and vector meson terms is crossing symmetric and unitary at leading order in a truncated and regularized 1/Nc expansion. The critical number of colors turns out to be Nc=6 and is insensitive to the explicit breaking of chiral symmetry. Below this critical value, an additional state is needed to enforce the …

Seasonal Deuterium Excess In A Tien Shan Ice Core: Influence Of Moisture Transport And Recycling In Central Asia, Karl J. Kreutz, Cameron P. Wake, Vladimir B. Aizen, L. Dewayne Cecil, Hans-Arno Synal

Earth Science Faculty Scholarship

Stable water isotope (delta(18)O, deltaD) data from a high elevation (5100 masl) ice core recovered from the Tien Shan Mountains, Kyrgyzstan, display a seasonal cycle in deuterium excess (d = deltaD - 8* delta(18)O) related to changes in the regional hydrologic cycle during 1994 - 2000. While there is a strong correlation (r(2) = 0.98) between delta(18)O and dD in the ice core samples, the regression slope (6.9) and mean d value (23.0) are significantly different than the global meteoric water line values. The resulting time-series ice core d profile contains distinct winter maxima and summer minima, with a yearly …

Flexible Multichannel Blind Deconvolution, An Investigation, Ah Chung Tsoi, L. S. Ma

Faculty of Informatics - Papers (Archive)

In this paper, we consider the issue of devising a flexible nonlinear function for multichannel blind deconvolution. In particular, we consider the underlying assumption of the source probability density functions. We consider two cases, when the source probability density functions are assumed to be uni-modal, and multimodal respectively. In the unimodal case, there are two approaches: Pearson function and generalized exponential function. In the multimodal case, there are three approaches: mixture of Gaussian functions, mixture of Pearson functions, and mixture of generalized exponential functions. It is demonstrated through an illustrating example that the assumption on the source probability density functions …

Refrigerator With Phonon Filters: An Application Of The Phonon Deficit Effect In Superconducting Tunnel Junctions, G. G. Melkonyan, Armen Gulian

Mathematics, Physics, and Computer Science Faculty Articles and Research

Nonequilibrium phenomena in thin solid films can result in cooling effects. These types of effects were predicted theoretically a while ago, and only recently were demonstrated experimentally in superconductor-insulator-normal metal (SIN) tunnel junctions. Since then, there is a growing interest in tunneling effects for the purpose to develop on-chip refrigerators. Thin film devices have the advantage of being extremely compact, operate in a continuous mode, dissipate little power, and can easily be integrated in cryogenic detectors. Currently these refrigerators can generate cooling in the order of 100 mK in an environment of 0.3–0.5 K. There are reasons to expect that …

Trust Negotiation For Authentication And Authorization In Healthcare Information Systems, Charles D. Knutson, Kent E. Seamons, Tore L. Sundelin, David K. Vawdrey

Faculty Publications

The expanding availability of health information in an electronic format is strategic for industry-wide efforts to improve the quality and reduce the cnst of health care. The implementation of electronic medical record systems has been hindered by inadequate security provisions. This paper describes the use of frust negotiation as a framework for providing authentication and access control services in healthcare information systems. nust negotiation enables two parties with no pre-existing relationship to establish the trust necessary to perform sensitive transactions via the mutual disclosure of attributes contained within digital credentials. An extension of this system, surrogate irusf negoikiion is introduced …

Impact Of Frustrated Singularities On Magnetic Island Evolution, B. D. Jemella, M. A. Shay, J. F. Drake, B. N. Rogers

Dartmouth Scholarship

The growth of magnetic islands is explored using the magnetohydrodynamic model in a simple slab system in which the value of the tearing mode stability parameter Δ′ can be varied continuously. Unless the system is close to marginal stability reconnection is controlled by Sweet-Parker current layers, whose formation is a consequence of the inherent singular structure of magnetic island equilibria.

Distributions Of Trace Gases And Aerosols During The Dry Biomass Burning Season In Southern Africa, Parikhit Sinha, Peter V. Hobbs, Robert J. Yokelson, Donald R. Blake, Song Gao, Thomas W. Kirchstetter

Chemistry and Physics Faculty Articles

Vertical profiles in the lower troposphere of temperature, relative humidity, sulfur dioxide (SO₂), ozone (O₃), condensation nuclei (CN), and carbon monoxide (CO), and horizontal distributions of twenty gaseous and particulate species, are presented for five regions of southern Africa during the dry biomass burning season of 2000. The regions are the semiarid savannas of northeast South Africa and northern Botswana, the savanna-forest mosaic of coastal Mozambique, the humid savanna of southern Zambia, and the desert of western Namibia. The highest average concentrations of carbon dioxide (CO₂), CO, methane (CH₄), O₃, …

Schema Matching And Data Extraction Over Html Tables, Cui Tao

Theses and Dissertations

Data on the Web in HTML tables is mostly structured, but we usually do not know the structure in advance. Thus, we cannot directly query for data of interest. We propose a solution to this problem for the case of mostly structured data in the form of HTML tables, based on document-independent extraction ontologies. The solution entails elements of table location and table understanding, data integration, and wrapper creation. Table location and understanding allows us to locate the table of interest, recognize attributes and values, pair attributes with values, and form records. Data-integration techniques allow us to match source records …

Transition Probabilities In Kr Ii And Kr Iii Spectra, Stevan Djenize, Vladimir Milosavljevic, Milan S. Dimitrijevic

Articles

On the basis of the relative line intensity ratio (RLIR) method, transition probability values of the spontaneous emission (Einstein's A values) of 14 transitions in the singly (Kr II) and 7 transitions in doubly (Kr III) ionized krypton spectra have been obtained relatively to the reference A values related to the 435.548 nm Kr II and 324.569 nm Kr III, the most intensive transitions in the Kr II and Kr III spectra. Our Kr III transition probability values are the first data obtained experimentally using the RLIR method. A linear, low–pressure, pulsed arc operated in krypton discharge was used as …

Sedimentary Aggregates In The Peoria Loess Of Nebraska, Usa, Joseph A. Mason, Peter M. Jacobs, Richard S. B. Greene

Department of Earth and Atmospheric Sciences: Faculty Publications

Loess grain size data used to infer transport direction or wind strength are generally derived from vigorously disaggregated samples. However, these data may not adequately represent the effective particle size distribution during loess transport, if the transported dust contained aggregates of fine-grained material. Thin sections of minimally altered C and BC horizons in the late Pleistocene Peoria Loess of Nebraska, USA, indicate the presence of aggregates with diameters of 30–1000 Am. The larger aggregates (>250 μm) are unlikely to have been transported, and are interpreted as the result of soil faunal activity and other pedogenic processes after deposition. Aggregates …

Complex Multiplication Symmetry Of Black Hole Attractors, Monika Lynker, Vipul Periwal, Rolf Schimmrigk

Faculty Articles

We show how Moore’s observation, in the context of toroidal compactifications in type IIB string theory, concerning the complex multiplication structure of black hole attractor varieties, can be generalized to Calabi-Yau compactifications with finite fundamental groups. This generalization leads to an alternative general framework in terms of motives associated to a Calabi-Yau variety in which it is possible to address the arithmetic nature of the attractor varieties in a universal way via Deligne’s period conjecture.

Motion Planning For Multiple Mobile Robots Using Dynamic Networks, Christopher M. Clark, Stephen M. Rock, Jean-Claude Latombe

Computer Science and Software Engineering

A new motion planning framework is presented that enables multiple mobile robots with limited ranges of sensing and communication to maneuver and achieve goals safely in dynamic environments. To combine the respective advantages of centralized and de-centralized planning, this framework is based on the concept of centralized planning within dynamic robot networks. As the robots move in their environment, localized robot groups form networks, within which world models and robot goals can be shared. Whenever a network is formed, new information then becomes available to all robots in this network. With this new information, each robot uses a fast, centralized …

Use Of Frightening Devices In Wildlife Damage Management, Jason M. Gilsdorf, Scott E. Hygnstrom, Kurt C. Vercauteren

United States Department of Agriculture Wildlife Services: Staff Publications

Wildlife is often responsible for causing extensive damage to personal property, human health and safety concerns, and other nuisance problems because of their feeding, roosting, breeding, and loafing habits. Frightening devices are tools used in integrated wildlife damage management to reduce the impacts of animals, but the effectiveness of such devices is often variable. An animal’s visual and auditory capabilities affect how the animal will respond to a stimulus. Frightening devices include pyrotechnics, gas exploders, effigies, lights, lasers, reflective objects, guard animals, bioacoustics, and ultrasonic devices. We examined scientific literature on the use of frightening devices to reduce bird and …

Percolation Of Satisfiability In Finite Dimensions, Alan Middleton, J. M. Schwarz

Physics - All Scholarship

The satisfiability and optimization of finite-dimensional Boolean formulas are studied using percolation theory, rare region arguments, and boundary effects. In contrast with mean-field results, there is no satisfiability transition, though there is a logical connectivity transition. In part of the disconnected phase, rare regions lead to a divergent running time for optimization algorithms. The thermodynamic ground state for the NP-hard two-dimensional maximum-satisfiability problem is typically unique. These results have implications for the computational study of disordered materials.

Exact Lattice Supersymmetry From Topological Field Theory, Simon Catterall

Physics - All Scholarship

We discuss the connection between supersymmetric field theories and topological field theories and show how this connection may be used to construct local lattice field theories which maintain an exact supersymmetry. It is shown how metric independence of the continuum topological field theory allows us to derive the lattice theory by blocking out of the continuum in a deformed geometry. This, in turn, allows us to prove the cut-off independence of certain supersymmetric Ward identities.

Demonstration Of A Typical Ontology-Based Collaborative Agents System: Seaway, Anthony Wood, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

In San Luis Obispo we have seventy-seven SEAWAY systems which are being prepared for fielding, and we are deep into the design of the follow on version. So, we are discussing a decision support system which is operational. Before we explore SEAWAY, we probably ought to talk about defining decision making problems and applying decision support.

In the case where the senior decision maker has poor decision skills, even the best decision support will make only the most marginal of difference. However, good decision support can make a huge difference if you have just an adequate decision process and adequate …

Proceedings Of The 2003 Onr Decision-Support Workshop Series: Developing The New Infostructure, Collaborative Agent Design Research Center

Collaborative Agent Design (CAD) Research Center

In August of 1998 the Collaborative Agent Design Research Center (CADRC) of the California Polytechnic State University in San Luis Obispo (Cal Poly), approached Dr. Phillip Abraham of the Office of Naval Research (ONR) with the proposal for an annual workshop focusing on emerging concepts in decision-support systems for military applications. The proposal was considered timely by the ONR Logistics Program Office for at least two reasons. First, rapid advances in information systems technology over the past decade had produced distributed, collaborative computer-assistance capabilities with profound potential for providing meaningful support to military decision makers. Indeed, some systems based on …