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Enhancement Of Unusual Color In Aerial Video Sequences For Assisting Wilderness Search And Rescue, Bryan S. Morse, Nathan D. Rasmussen, Daniel Thornton Oct 2008

Enhancement Of Unusual Color In Aerial Video Sequences For Assisting Wilderness Search And Rescue, Bryan S. Morse, Nathan D. Rasmussen, Daniel Thornton

Faculty Publications

The use of aerial video for search and surveillance has been popularized by the increased use of camera-equipped unmanned aerial vehicles. For many search applications, objects may also be missed by observers due to their small size, brief visibility, or the inherent monotony of the scene. This paper presents a novel method for automatically emphasizing unusually colored objects to improve their detectability. We use a hue histogram and a local saliency measure to find unusually colored objects, then boost the saturation of these objects while desaturating more common colors, thus drawing the observer’s attention and facilitating video search.

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A Darwinist View Of The Living Constitution, Scott Dodson Oct 2008

A Darwinist View Of The Living Constitution, Scott Dodson

Faculty Publications

The metaphor of a “living” Constitution imports terms from biology into law and, in the process, relies on biology for its meaning. A proper understanding of biology is therefore central to understanding the idea of “living” constitutionalism. Yet despite its rampant use by both opponents and proponents of living constitutionalism, and despite the current fervent debate over whether biology can be useful to the law, no one has evaluated the metaphor from a biological perspective. This Essay begins that inquiry in an interdisciplinary study of law, science, and philology. The Essay first evaluates the metaphor as it is currently used …

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Route To Ponderomotive Entanglement Of Light Via Optically Trapped Mirrors, Christopher Wipf, Thomas Corbitt, Yanbei Chen, Nergis Mavalvala Sep 2008

Route To Ponderomotive Entanglement Of Light Via Optically Trapped Mirrors, Christopher Wipf, Thomas Corbitt, Yanbei Chen, Nergis Mavalvala

Faculty Publications

The radiation pressure of two laser beams detuned from resonance in an optical cavity can create a stable optical trap for a mechanical oscillation mode of a movable cavity mirror. Here it is shown that such a configuration entangles the output light fields via interaction with a mirror that is suspended as a pendulum. The degree of entanglement is quantified spectrally using the logarithmic negativity, and related to the available optical restoring force. Entanglement survives in the experimentally accessible regime of gram-scale masses subject to thermal noise at room temperature. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

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Unified Quantum Convolutional Coding, Mark M. Wilde, Todd A. Brun Sep 2008

Unified Quantum Convolutional Coding, Mark M. Wilde, Todd A. Brun

Faculty Publications

We outline a quantum convolutional coding technique for protecting a stream of classical bits and qubits. Our goal is to provide a framework for designing codes that approach the "grandfather" capacity of an entanglement-assisted quantum channel for sending classical and quantum information simultaneously. Our method incorporates several resources for quantum redundancy: fresh ancilla qubits, entangled bits, and gauge qubits. The use of these diverse resources gives our technique the benefits of both active and passive quantum error correction. We can encode a classical-quantum bit stream with periodic quantum gates because our codes possess a convolutional structure. We end with an …

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Autonomous And Intelligent Radio Switching For Heterogeneous Wireless Networks, Qiuyi Duan, Charles D. Knutson, Lei Wang, Daniel Zappala Sep 2008

Autonomous And Intelligent Radio Switching For Heterogeneous Wireless Networks, Qiuyi Duan, Charles D. Knutson, Lei Wang, Daniel Zappala

Faculty Publications

As wireless devices continue to become more prevalent, heterogeneous wireless networks - in which communicating devices have at their disposal multiple types of radios - will become the norm. Communication between nodes in these networks ought to be as simple as possible; they should be able to seamlessly switch between different radios and network stacks on the fly in order to better serve the user. To make this a possibility, we consider the challenging problems of when two communicating devices should decide to switch to a different radio, and which radio they should choose. We design an Autonomous and Intelligent …

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Sequestration And Ultrasound-Induced Release Of Doxorubicin From Stabilized Pluronic P105 Micelles, John D. Pruitt, William G. Pitt Sep 2008

Sequestration And Ultrasound-Induced Release Of Doxorubicin From Stabilized Pluronic P105 Micelles, John D. Pruitt, William G. Pitt

Faculty Publications

Controlled drug delivery from micelles requires that the micelles remain stable when diluted below their critical micelle concentration, such as upon injection into blood. A cross-linked, interpenetrating network of N,N-diethylacrylamide (NNDEA) was polymerized in the core of Pluronic P105 micelles to stabilize temporarily the micelles at concentrations below the critical micellar concentration of free P105. The stabilized Pluronic micelles (called Plurogels) were able to sequester the drug doxorubicin (Dox) and protect HL-60 cells from the drug at concentrations where non-stabilized Pluronic provided no protection. The protection lasted ~ 12 hr, which is similar to the half-life of the particles. Application …

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High-Resolution Surveys Along The Hot Spot–Affected Galapagos Spreading Center: 1. Distribution Of Hydrothermal Activity, Edward T. Baker, Rachel M. Haymon, Joseph A. Resing, Scott M. White, Sharon L. Walker, Ken C. Macdonald, Ko-Ichi Nakamura Sep 2008

High-Resolution Surveys Along The Hot Spot–Affected Galapagos Spreading Center: 1. Distribution Of Hydrothermal Activity, Edward T. Baker, Rachel M. Haymon, Joseph A. Resing, Scott M. White, Sharon L. Walker, Ken C. Macdonald, Ko-Ichi Nakamura

Faculty Publications

The spatial density of hydrothermal activity along most mid-ocean ridges is a robust linear function of spreading rate (or magmatic budget), but extreme crustal properties may alter this relationship. In 2005–2006 we tested the effect of thickened crust on hydrothermal activity using high-resolution mapping of plumes overlying the hot spot–affected Galapagos Spreading Center from 95o to 89o42'W (~560 km of ridge crest). Plume mapping discovered only two active, high-temperature vent fields, subsequently confirmed by camera tows, though strong plume evidence indicated minor venting from at least six other locations. Total plume incidence (ph), the fraction of ridge …

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The Orbital Period And Time-Variable Asymmetric Accretion Disk In The X-Ray Binary-Ms 1603.6+2600 (=Uw Coronae Borealis), Paul A. Mason, Edward L. Robinson, Candace L. Gray, Robert I. Hynes Sep 2008

The Orbital Period And Time-Variable Asymmetric Accretion Disk In The X-Ray Binary-Ms 1603.6+2600 (=Uw Coronae Borealis), Paul A. Mason, Edward L. Robinson, Candace L. Gray, Robert I. Hynes

Faculty Publications

We present CCD photometry of the low-mass X-ray binary UW Coronae Borealis (UW CrB). Its light curve shows eclipses at a period near 111 minutes, but the eclipses vary in depth and shape and often disappear. Restricting our analysis to the deeper eclipses, we find the orbital period to be 110.976722 ± 0.000012 minutes, but the times of mideclipse can deviate by more than 0.025 in phase from the best-fit ephemeris. There is an additional large-amplitude variation with a period of 112.58 ± 0.03 minutes reminiscent of the superhumps seen in the light curves of some cataclysmic variables. The variations …

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A-Priori Analysis Of Conditional Moment Closure Modeling Of A Temporal Ethylene Jet Flame With Soot Formation Using Direct Numerical Simulation, David O. Lignell, John C. Hewson, Jacqueline H. Chen Sep 2008

A-Priori Analysis Of Conditional Moment Closure Modeling Of A Temporal Ethylene Jet Flame With Soot Formation Using Direct Numerical Simulation, David O. Lignell, John C. Hewson, Jacqueline H. Chen

Faculty Publications

Modeling soot formation in turbulent nonpremixed combustion is a difficult problem. Unlike most gaseous combustion species, soot lacks a strong state relationship with the mixture fraction due to unsteady formation rates which overlap transport timescales, and strong differential diffusion between gaseous species and soot. The conditional moment closure model (CMC) has recently been applied to the problem of turbulent soot formation. A challenge in CMC modeling is the treatment of differential diffusion. Three-dimensional direct numerical simulation (DNS) of a nonpremixed ethylene jet flame with soot formation has been performed using a 19 species reduced ethylene mechanism and a four-step, three-moment, …

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Spin Memristive Systems: Spin Memory Effects In Semiconductor Spintronics, Yuriy V. Pershin Dr, M. Di Ventra Sep 2008

Spin Memristive Systems: Spin Memory Effects In Semiconductor Spintronics, Yuriy V. Pershin Dr, M. Di Ventra

Faculty Publications

Recently, in addition to the well-known resistor, capacitor, and inductor, a fourth passive circuit element, named memristor, has been identified following theoretical predictions. The model example used in such case consisted in a nanoscale system with coupled ionic and electronic transport. Here, we discuss a system whose memristive behavior is based entirely on the electron-spin degree of freedom, which allows for a more convenient control than the ionic transport in nanostructures. An analysis of time-dependent spin transport at a semiconductor/ferromagnet junction provides a direct evidence of memristive behavior. Our scheme is fundamentally different from previously discussed schemes of memristive systems …

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Inclusive Ks0ks0 Resonance Production In Ep Collisions At Hera, S. Chekanov, M. Derrick, S. Magill, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, F. Cindolo, M. Corradi, G. Iacobucci, A. Margotti, R. Nania, A. Polini, S. Antonelli, M. Basile, M. Bindi, L. Cifarelli, A. Contin, S. De Pasquale, G. Sartorelli, A. Zichichi, D. Bartsch, I. Brock, H. Hartmann Sep 2008

Inclusive Ks0ks0 Resonance Production In Ep Collisions At Hera, S. Chekanov, M. Derrick, S. Magill, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, P. Antonioli, G. Bari, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, F. Cindolo, M. Corradi, G. Iacobucci, A. Margotti, R. Nania, A. Polini, S. Antonelli, M. Basile, M. Bindi, L. Cifarelli, A. Contin, S. De Pasquale, G. Sartorelli, A. Zichichi, D. Bartsch, I. Brock, H. Hartmann

Faculty Publications

Inclusive KS0KS0 production in ep collisions at the DESY ep collider HERA was studied with the ZEUS detector using an integrated luminosity of 0.5fb-1. Enhancements in the mass spectrum were observed and are attributed to the production of f2(1270)/a20(1320), f2′(1525) and f0(1710). Masses and widths were obtained using a fit which takes into account theoretical predictions based on SU(3) symmetry arguments, and are consistent with the Particle Data Group values. The f0(1710) state, which has a mass consistent with a glueball candidate, was observed with a statistical significance of 5 standard deviations. However, if this state is the same as …

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Oriented Cell Growth On Self-Assembled Bacteriophage M13 Thin Films, Jianhua Rong, L. Andrew Lee, Kai Li, Brandon Harp, Charlene M. Mello, Zhongwei Niu, Qian Wang Sep 2008

Oriented Cell Growth On Self-Assembled Bacteriophage M13 Thin Films, Jianhua Rong, L. Andrew Lee, Kai Li, Brandon Harp, Charlene M. Mello, Zhongwei Niu, Qian Wang

Faculty Publications

Fibrillar M13 bacteriophages were used as basic building blocks to generate thin films with aligned nanogrooves, which, upon chemical grafting with RGD peptides, guide cell alignment and orient the cell outgrowth along defined directions.

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Orbit Closures In The Enhanced Nilpotent Cone, Pramod N. Achar, Anthony Henderson Sep 2008

Orbit Closures In The Enhanced Nilpotent Cone, Pramod N. Achar, Anthony Henderson

Faculty Publications

We study the orbits of G = GL (V) in the enhanced nilpotent cone V × N, where N is the variety of nilpotent endomorphisms of V. These orbits are parametrized by bipartitions of n = dim V, and we prove that the closure ordering corresponds to a natural partial order on bipartitions. Moreover, we prove that the local intersection cohomology of the orbit closures is given by certain bipartition analogues of Kostka polynomials, defined by Shoji. Finally, we make a connection with Kato's exotic nilpotent cone in type C, proving that the closure ordering is the same, and conjecturing …

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Towards Effective Automatic Parallelization For Multicore Systems, Uday Bondhugula, Muthu Baskaran, Albert Hartono, Sriram Krishnamoorthy, J. Ramanujam, Atanas Rountev, P. Sadayappan Sep 2008

Towards Effective Automatic Parallelization For Multicore Systems, Uday Bondhugula, Muthu Baskaran, Albert Hartono, Sriram Krishnamoorthy, J. Ramanujam, Atanas Rountev, P. Sadayappan

Faculty Publications

The ubiquity of multicore processors in commodity computing systems has raised a significant programming challenge for their effective use. An attractive but challenging approach is automatic parallelization of sequential codes. Although virtually all production C compilers have automatic shared-memory parallelization capability, it is rarely used in practice by application developers because of limited effectiveness. In this paper we describe our recent efforts towards developing an effective automatic parallelization system that uses a polyhedral model for data dependences and program transformations. ©2008 IEEE.

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Secure Referee Selection For Fair And Responsive Peer-To-Peer Gaming, Steven Daniel Webb, Sieteng Soh, Jerry L. Trahan Sep 2008

Secure Referee Selection For Fair And Responsive Peer-To-Peer Gaming, Steven Daniel Webb, Sieteng Soh, Jerry L. Trahan

Faculty Publications

Peer-to-peer (P2P) architectures for Massively Multiplayer Online Games (MMOG) provide better scalability than Client/Server (C/S); however, they increase the possibility of cheating. Recently proposed P2P protocols use trusted referees that simulate/validate the game to provide security equivalent to C/S. When selecting referees from untrusted peers, selecting non-colluding referees becomes critical. Further, referees should be selected such that the range and length of delays to players is minimised (maximising game fairness and responsiveness). In this paper we formally define the referee selection problem and propose two secure referee selection algorithms, SRS-1 and SRS-2, to solve it. Both algorithms ensure the probability …

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Lateral Circulation And Suspended Sediment Transport In A Curved Estuarine Channel: Winyah Bay, Sc, Usa, Yong Hoon Kim, George Voulgaris Sep 2008

Lateral Circulation And Suspended Sediment Transport In A Curved Estuarine Channel: Winyah Bay, Sc, Usa, Yong Hoon Kim, George Voulgaris

Faculty Publications

Shipborne vertical profiles of flow and suspended sediment concentration collected on a transect, across a curved, nonsymmetrical estuarine channel are presented. Analysis of the transient cross-channel momentum balance equation shows that the lateral circulation pattern is controlled by the interaction between centrifugal and lateral baroclinic forcings although those two might not be necessarily in balance as suggested earlier by Seim and Gregg (1997). Instead, differential along-channel advection and local acceleration appear to influence greatly lateral circulation dynamics. During ebb when the water column is highly stratified, the interaction between centrifugal acceleration and opposite-directed lateral baroclinic forcing results in weak lateral …

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Diffusion Models For Animals In Complex Landscapes: Incorporating Heterogeneity Among Substrates, Individuals And Edge Behaviours, John D. Reeve, James T. Cronin, Kyle J. Haynes Sep 2008

Diffusion Models For Animals In Complex Landscapes: Incorporating Heterogeneity Among Substrates, Individuals And Edge Behaviours, John D. Reeve, James T. Cronin, Kyle J. Haynes

Faculty Publications

1. Animals move commonly through a variety of landscape elements and edges in search of food, mates and other resources. We developed a diffusion model for the movement of an insect herbivore, the planthopper Prokelisia crocea, that inhabits a landscape composed of patches of its host plant, prairie cordgrass Spartina pectinata, embedded in a matrix of mudflat or smooth brome Bromus inermis. 2. We used mark-release-resight experiments to quantify planthopper movements within cordgrass-brome and cordgrass-mudflat arenas. A diffusion model was then fitted that included varying diffusion rates for cordgrass and matrix, edge behaviour in the form of a biased random …

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Associated Varieties And Howe's N-Spectrum, Hongyu He Sep 2008

Associated Varieties And Howe's N-Spectrum, Hongyu He

Faculty Publications

Let G be a real semisimple group. Two important invariants are associated with the equivalence class of an irreducible unitary representation of G, namely, the associated variety of the annihilator in the universal enveloping algebra and Howe's N-spectrum, where N is a nilpotent subgroup of G. The associated variety is defined in a purely algebraic way. The N-spectrum is defined analytically. In this paper, we prove some results about the relation between associated variety and N-associated variety, where N is a subgroup of G. We then relate N-associated variety with Howe's N-spectrum when N is abelian. This enables us to …

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Further Results On Input-To-State Stability For Nonlinear Systems With Delayed Feedbacks, Frédéric Mazenc, Michael Malisoff, Zongli Lin Sep 2008

Further Results On Input-To-State Stability For Nonlinear Systems With Delayed Feedbacks, Frédéric Mazenc, Michael Malisoff, Zongli Lin

Faculty Publications

We consider a class of nonlinear control systems for which stabilizing feedbacks and corresponding Lyapunov functions for the closed-loop systems are available. In the presence of feedback delays and actuator errors, we explicitly construct input-to-state stability (ISS) Lyapunov-Krasovskii functionals for the resulting feedback delayed dynamics, in terms of the available Lyapunov functions for the original undelayed dynamics, which establishes that the closed-loop systems are input-to-state stable (ISS) with respect to actuator errors. We illustrate our results using a generalized system from identification theory and other examples. © 2008 Elsevier Ltd. All rights reserved.

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Measuring The Deposited Energy By The Scintillation Calorimeter In The Atic Experiment, A. D. Panov, V. I. Zatsepin, N. V. Sokolskaya, J. H. Adams, H. S. Ahn, G. L. Bashindzhagyan, J. W. Watts, J. P. Wefel, J. Wu, O. Ganel, T. G. Guzik, R. M. Gunashingha, J. Isbert, K. C. Kim, M. Christl, E. N. Kouznetsov, M. I. Panasyuk, E. S. Seo, J. Chang, W. K.H. Schmidt, A. R. Fazely Sep 2008

Measuring The Deposited Energy By The Scintillation Calorimeter In The Atic Experiment, A. D. Panov, V. I. Zatsepin, N. V. Sokolskaya, J. H. Adams, H. S. Ahn, G. L. Bashindzhagyan, J. W. Watts, J. P. Wefel, J. Wu, O. Ganel, T. G. Guzik, R. M. Gunashingha, J. Isbert, K. C. Kim, M. Christl, E. N. Kouznetsov, M. I. Panasyuk, E. S. Seo, J. Chang, W. K.H. Schmidt, A. R. Fazely

Faculty Publications

The purpose of the ATIC balloon experiment is to measure the energy spectra of primary cosmic rays with individual charge resolution from protons to iron over the energy range from ∼ 50 GeV to 200 TeV. The particle energy is measured by a bismuth germanate (BGO) scintillation calorimeter. The procedure of calorimeter calibration is described, in particular, calibration of the temperature dependence of the calorimeter sensitivity using the data of in-flight measurements. A technique for determining the energy deposited in the calorimeter in view of the temperature dependence of its sensitivity is presented. The maximum systematic error in determining the …

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Deep Inelastic Inclusive And Diffractive Scattering At Q2 Values From 25 To 320 Gev2 With The Zeus Forward Plug Calorimeter, S. Chekanov, M. Derrick, S. Magill, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, P. Antonioli, G. Bari, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, F. Cindolo, M. Corradi, G. Iacobucci, A. Margotti, R. Nania, A. Polini, S. Antonelli, M. Basile, M. Bindi, L. Cifarelli, A. Contin, S. De Pasquale, G. Sartorelli, A. Zichichi, D. Bartsch Sep 2008

Deep Inelastic Inclusive And Diffractive Scattering At Q2 Values From 25 To 320 Gev2 With The Zeus Forward Plug Calorimeter, S. Chekanov, M. Derrick, S. Magill, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, P. Antonioli, G. Bari, L. Bellagamba, D. Boscherini, A. Bruni, G. Bruni, F. Cindolo, M. Corradi, G. Iacobucci, A. Margotti, R. Nania, A. Polini, S. Antonelli, M. Basile, M. Bindi, L. Cifarelli, A. Contin, S. De Pasquale, G. Sartorelli, A. Zichichi, D. Bartsch

Faculty Publications

Deep inelastic scattering and its diffractive component, e p → e′ γ* p → e′ X N, have been studied at HERA with the ZEUS detector using an integrated luminosity of 52.4 pb-1. The MX method has been used to extract the diffractive contribution. A wide range in the centre-of-mass energy W (37-245 GeV), photon virtuality Q2 (20-450 GeV2) and mass MX (0.28-35 GeV) is covered. The diffractive cross section for 2 < MX < 15 GeV rises strongly with W, the rise becoming steeper as Q2 increases. The data are also presented in terms of the diffractive structure function, F2D (3), of the proton. For fixed Q2 and fixed MX, xP F2D (3) shows a strong rise as xP → 0, where xP is the fraction of the proton momentum carried by the pomeron. For Bjorken-x < 1 × 10-3, xP F2D (3) shows positive log Q2 scaling violations, while for x ≥ 5 × 10-3 negative scaling violations are observed. The diffractive structure function is compatible with being leading twist. The data show that Regge factorisation is broken. © 2008 Elsevier B.V. All rights reserved.

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Phylogenetic Reconstruction From Transpositions, Feng Yue, Meng Zhang, Jijun Tang Sep 2008

Phylogenetic Reconstruction From Transpositions, Feng Yue, Meng Zhang, Jijun Tang

Faculty Publications

Background
Because of the advent of high-throughput sequencing and the consequent reduction in the cost of sequencing, many organisms have been completely sequenced and most of their genes identified. It thus has become possible to represent whole genomes as ordered lists of gene identifiers and to study the rearrangement of these entities through computational means. As a result, genome rearrangement data has attracted increasing attentions from both biologists and computer scientists as a new type of data for phylogenetic analysis. The main events of genome rearrangements include inversions, transpositions and transversions. To date, GRAPPA and MGR are the most accurate …

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Windsat Passive Microwave Polarimetric Signatures Of The Greenland Ice Sheet, David G. Long, Li Li, Peter Gaiser, Mary R. Albert, Elizabeth M. Twarog Sep 2008

Windsat Passive Microwave Polarimetric Signatures Of The Greenland Ice Sheet, David G. Long, Li Li, Peter Gaiser, Mary R. Albert, Elizabeth M. Twarog

Faculty Publications

WindSat has systematically collected the first global fully polarimetric passive microwave data over both land and ocean. As the first spaceborne polarimetric microwave radiometer, it was designed to measure ocean surface wind speed and direction by including the third and fourth Stokes parameters, which are mostly related to the asymmetric structures of the ocean surface roughness. Although designed for wind vector retrieval, WindSat data are also collected over land and ice, and this new data has revealed, for the first time, significant land signals in the third and fourth Stokes parameter channels, particularly over Greenland and the Antarctic ice sheets. …

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Improving Live Sequence Chart To Automata Transformation For Verification, Rahul Kumar, Eric G. Mercer Aug 2008

Improving Live Sequence Chart To Automata Transformation For Verification, Rahul Kumar, Eric G. Mercer

Faculty Publications

This paper presents a Live Sequence Chart (LSC) to automata transformation algorithm that enables the verification of communication protocol implementations. Using this LSC to automata transformation a communication protocol implementation can be verified using a single verification run as opposed to previous techniques that rely on a three stage verification approach. The novelty and simplicity of the transformation algorithm lies in its placement of accept states in the automata generated from the LSC. We present in detail an example of the transformation as well as the transformation algorithm. Further, we present a detailed analysis and an empirical study comparing the …

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A Secure Group Communication Architecture For Autonomous Unmanned Aerial Vehicles, Adrian N. Phillips, Barry E. Mullins, Richard Raines, Rusty O. Baldwin Aug 2008

A Secure Group Communication Architecture For Autonomous Unmanned Aerial Vehicles, Adrian N. Phillips, Barry E. Mullins, Richard Raines, Rusty O. Baldwin

Faculty Publications

This paper investigates the application of a secure group communication architecture to a swarm of autonomous unmanned aerial vehicles (UAVs). A multicast secure group communication architecture for the low earth orbit (LEO) satellite environment is evaluated to determine if it can be effectively adapted to a swarm of UAVs and provide secure, scalable, and efficient communications. The performance of the proposed security architecture is evaluated with two other commonly used architectures using a discrete event computer simulation developed using MATLAB. Performance is evaluated in terms of the scalability and efficiency of the group key distribution and management scheme when the …

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Precipitation Rates And Atmospheric Heat Transport During The Cenomanian Greenhouse Warming In North America: Estimates From A Stable Isotope Mass-Balance Model, David F. Ufnar, Greg A. Ludvigson, Luis González, Darren R. Gröcke Aug 2008

Precipitation Rates And Atmospheric Heat Transport During The Cenomanian Greenhouse Warming In North America: Estimates From A Stable Isotope Mass-Balance Model, David F. Ufnar, Greg A. Ludvigson, Luis González, Darren R. Gröcke

Faculty Publications

Stable isotope mass-balance modeling results of meteoric δ18O values from the Cenomanian Stage of the Cretaceous Western Interior Basin (KWIB) suggest that precipitation and evaporation fluxes were greater than that of the present and significantly different from simulations of Albian KWIB paleohydrology. Sphaerosiderite meteoric δ18O values have been compiled from the Lower Tuscaloosa Formation of southwestern Mississippi (25°N paleolatitude), The Dakota Formation Rose Creek Pit, Fairbury Nebraska (35°N) and the Dunvegan Formation of eastern British Columbia (55°N paleolatitude). These paleosol siderite δ18O values define a paleolatitudinal gradient ranging from − 4.2‰ VPDB at 25°N …

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Doping A Semiconductor To Create An Unconventional Metal, N. Manyala, J. F. Ditusa, G. Aeppli, A. P. Ramirez Aug 2008

Doping A Semiconductor To Create An Unconventional Metal, N. Manyala, J. F. Ditusa, G. Aeppli, A. P. Ramirez

Faculty Publications

Landau-Fermi liquid theory, with its pivotal assertion that electrons in metals can be simply understood as independent particles with effective masses replacing the free electron mass, has been astonishingly successful. This is true despite the Coulomb interactions an electron experiences from the host crystal lattice, lattice defects and the other ∼1022 cm -3 electrons. An important extension to the theory accounts for the behaviour of doped semiconductors. Because little in the vast literature on materials contradicts Fermi liquid theory and its extensions, exceptions have attracted great attention, and they include the high-temperature superconductors, silicon-based field-effect transistors that host two-dimensional metals, …

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Geometric Phases And Bloch-Sphere Constructions For Su (N) Groups With A Complete Description Of The Su(4) Group, D. Uskov, A. R.P. Rau Aug 2008

Geometric Phases And Bloch-Sphere Constructions For Su (N) Groups With A Complete Description Of The Su(4) Group, D. Uskov, A. R.P. Rau

Faculty Publications

A two-sphere ("Bloch" or ''Poincare'') is familiar for describing the dynamics of a spin- 1/2 particle or light polarization. Analogous objects are derived for unitary groups larger than SU(2) through an iterative procedure that constructs evolution operators for higher-dimensional SU (N) in terms of lower-dimensional ones. We focus, in particular, on the SU(4) of two qubits which describes all possible logic gates in quantum computation and entangled states in quantum-information sciences. For a general Hamiltonian of SU(4) with 15 parameters, and for Hamiltonians of its various subgroups so that fewer parameters suffice, we derive Bloch-like rotation of unit vectors analogous …

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Recombination Fluorescence In Ultracold Neutral Plasmas, Scott D. Bergeson, F. Robicheaux Aug 2008

Recombination Fluorescence In Ultracold Neutral Plasmas, Scott D. Bergeson, F. Robicheaux

Faculty Publications

We present the first measurements and simulations of recombination fluorescence from ultracold neutral calcium plasmas. This method probes three-body recombination at times less than 1 µs, shorter than previously published time scales. For the lowest initial electron temperatures, the recombination rate scales with the density as n22, significantly slower than the predicted n3. Recombination fluorescence opens a new diagnostic window in ultracold plasmas. In most cases it probes deeply bound level populations that depend critically on electron energetics. However, a perturbation in the calcium 4snd Rydberg series allows our fluorescence measurements to probe the population in weakly bound levels that …

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Structure Of The Thioredoxin-Like Domain Of Yeast Glutaredoxin 3, Lydia M. Gibson, Nin N. Dingra, Caryn E. Outten, Lukasz Lebioda Aug 2008

Structure Of The Thioredoxin-Like Domain Of Yeast Glutaredoxin 3, Lydia M. Gibson, Nin N. Dingra, Caryn E. Outten, Lukasz Lebioda

Faculty Publications

Yeast glutaredoxin 3 (Grx3) is a cytosolic protein that regulates the activity of the iron-responsive transcriptional activator Aft1. This member of the monothiol glutaredoxin family contains a thioredoxin-like domain and a glutaredoxin-like domain, which both possess a monothiol active site. The crystal structure of the thioredoxin-like domain has been determined at 1.5 Å resolution and represents the first published structure of this domain for the monothiol glutaredoxin family. The loop containing the signature motif WAxxC is partially disordered, indicating a greater degree of flexibility in this region compared with classical dithiol thioredoxins with a WCGPC active-site motif.

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