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Measurement Of Population Dynamics In Stimulated Raman Adiabatic Passage, Alina Gearba, H. A. Camp, M. L. Trachy, G. Veshapidze, M.H. Shah, H.U. Jang, B.D. Depaola Jul 2007

Measurement Of Population Dynamics In Stimulated Raman Adiabatic Passage, Alina Gearba, H. A. Camp, M. L. Trachy, G. Veshapidze, M.H. Shah, H.U. Jang, B.D. Depaola

Faculty Publications

The temporal evolution of populations has been directly measured for a three-level ladder system undergoing coherent excitation by stimulated Raman adiabatic passage (STIRAP). The measurement technique makes use of charge transfer as diagnostic. The method is model independent and has a temporal resolution of a few nanoseconds. The temporal evolution is measured for several values of the delay between the pump and Stokes laser pulses that are part of the STIRAP excitation scheme. The corresponding quantum Liouville equations are solved and the results of the calculations are compared with experiment.

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A Dynamic Attribute-Based Load Shedding Scheme For Data Stream Management Systems, Amit Ahuja, Yiu-Kai D. Ng Jul 2007

A Dynamic Attribute-Based Load Shedding Scheme For Data Stream Management Systems, Amit Ahuja, Yiu-Kai D. Ng

Faculty Publications

A data stream being transmitted over a network channel with capacity less than the data transmission rate of the data stream causes sequential network problems. In this paper, we present a new approach for shedding less-informative attribute data from a data stream to maintain a data transmission rate less than the network channel capacity. A scheme for shedding attributes and their data, instead of tuples, becomes imperative in data stream load shedding, since shedding a complete tuple would lead to shedding informative attribute data along with less-informative attribute data in the tuple. Our load shedding approach handles intra-stream, as well …

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Henry George: The Theory Of Distribution In Progress And Poverty, Phillip J. Bryson Jul 2007

Henry George: The Theory Of Distribution In Progress And Poverty, Phillip J. Bryson

Faculty Publications

The core of Henry George's economic theory appeared in his most widely-read book, Progress and Poverty. On the basis of his dramatic "single tax" theory, his work became widely known and gained some avid followers who endeavored to base policy on it. But the work was also of value in George's day and interest in our day because of its economic content. George was not a part of the academic economics establishment of his day and his theory was of strictly classical methodology, but it still had much to commend it. A simple model to present his concepts in more …

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Information Consensus And Its Application In Multi-Vehicle Cooperative Control, Ella Atkins, Randal Beard, Wei Ren Jul 2007

Information Consensus And Its Application In Multi-Vehicle Cooperative Control, Ella Atkins, Randal Beard, Wei Ren

Faculty Publications

In the last two decades, advances in networking and distributed computing have facilitated a paradigm shift from large, monolithic mainframe computers to networks of less expensive, less powerful workstations. One motivation for multi-vehicle systems is to achieve the same gains for mechanically controlled systems as has been gained in distributed computation. Rather than having a single monolithic (and therefore expensive and complicated) machine do everything, the hope is that many inexpensive, simple machines, can achieve the same, or enhanced functionality, through coordination. In essence, the objective is to replace expensive complicated hardware with software and multiple copies of simple hardware. …

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On The Gauge Equivalence Of Twisted Quantum Doubles Of Elementary Abelian And Extra-Special 2-Groups, Christopher Goff, Geoffrey Mason, Siu Hung Ng Jun 2007

On The Gauge Equivalence Of Twisted Quantum Doubles Of Elementary Abelian And Extra-Special 2-Groups, Christopher Goff, Geoffrey Mason, Siu Hung Ng

Faculty Publications

We establish braided tensor equivalences among module categories over the twisted quantum double of a finite group defined by an extension of a group over(G, -) by an abelian group, with 3-cocycle inflated from a 3-cocycle on over(G, -). We also prove that the canonical ribbon structure of the module category of any twisted quantum double of a finite group is preserved by braided tensor equivalences. We give two main applications: first, if G is an extra-special 2-group of width at least 2, we show that the quantum double of G twisted by a 3-cocycle ω is gauge equivalent to …

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Earth Science Mini-Lessons: A Service-Learning Strategy For Improving Attitudes Toward Science Of Preservice Elementary Teachers, K. Thompson, B. R. Bickmore, Charles R. Graham, S. C. Yanchar Jun 2007

Earth Science Mini-Lessons: A Service-Learning Strategy For Improving Attitudes Toward Science Of Preservice Elementary Teachers, K. Thompson, B. R. Bickmore, Charles R. Graham, S. C. Yanchar

Faculty Publications

Science instruction in elementary school classrooms is frequently lacking in the United States. One factor that impacts the amount and quality of science instruction is teacher attitudes toward science. The Earth Science Mini-Lesson Project is a strategic program created to help improve preservice elementary school teachers' attitudes toward science in a one-semester college class. Students participating in this project create earth science mini-lessons on topics taken from the Utah Core Curriculum Standards and teach them to elementary students at a local Title I grade school. Attitude survey results from both semesters showed that this service-learning outreach program positively affected students' …

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Biology Intensive Orientation For Students (Bios): A Biology "Boot Camp", Sheri Maples Wischusen, E. William Wischusen Jun 2007

Biology Intensive Orientation For Students (Bios): A Biology "Boot Camp", Sheri Maples Wischusen, E. William Wischusen

Faculty Publications

The Biology Intensive Orientation for Students (BIOS) Program was designed to assess the impact of a 5-d intensive prefreshman program on success and retention of biological science majors at Louisiana State University. The 2005 pilot program combined content lectures and examinations for BIOL 1201, Introductory Biology for Science Majors, as well as learning styles assessments and informational sessions to provide the students with a preview of the requirements of biology and the pace of college. Students were tracked after their BIOS participation, and their progress was compared with a control group composed of students on the BIOS waiting list and …

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A Volumish Theorem For The Jones Polynomial Of Alternating Knots, Oliver T. Dasbach, Xiao Song Lin Jun 2007

A Volumish Theorem For The Jones Polynomial Of Alternating Knots, Oliver T. Dasbach, Xiao Song Lin

Faculty Publications

The Volume Conjecture claims that the hyperbolic volume of a knot is determined by the colored Jones polynomial. Here we prove a "Volumish Theorem" for alternating knots in terms of the Jones polynomial, rather than the colored Jones polynomial: The ratio of the volume and certain sums of coefficients of the Jones polynomial is bounded from above and from below by constants. Furthermore, we give experimental data on the relation of the growths of the hyperbolic volume and the coefficients of the Jones polynomial, both for alternating and nonalternating knots.

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Uniform Estimates For Eulerian-Lagrangian Methods For Singularly Perturbed Time-Dependent Problems, Hong Wang, Kaixin Wang Jun 2007

Uniform Estimates For Eulerian-Lagrangian Methods For Singularly Perturbed Time-Dependent Problems, Hong Wang, Kaixin Wang

Faculty Publications

We prove a priori optimal-order error estimates in a weighted energy norm for several Eulerian–Lagrangian methods for singularly perturbed, time-dependent convection-diffusion equations with full regularity. The estimates depend only on certain Sobolev norms of the initial and right-hand side data, but not on ε or any norm of the true solution, and so hold uniformly with respect to ε. We use the interpolation of spaces and stability estimates to derive an ε-uniform estimate for problems with minimal or intermediate regularity, where the convergence rates are proportional to certain Besov norms of the initial and right-hand side data.

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Structural Analysis Of Csos1a And The Protein Shell Of The Halothiobacillus Neapolitanus Carboxysome, Yingssu Tsai, Michael R. Sawaya, Gordon C. Cannon, Fei Cai, Eric B. Williams, Sabine Heinhorst, Cheryl A. Kerfeld, Todd O. Yeates Jun 2007

Structural Analysis Of Csos1a And The Protein Shell Of The Halothiobacillus Neapolitanus Carboxysome, Yingssu Tsai, Michael R. Sawaya, Gordon C. Cannon, Fei Cai, Eric B. Williams, Sabine Heinhorst, Cheryl A. Kerfeld, Todd O. Yeates

Faculty Publications

The carboxysome is a bacterial organelle that functions to enhance the efficiency of CO2 fixation by encapsulating the enzymes ribulose bisphosphate carboxylase/ oxygenase (RuBisCO) and carbonic anhydrase. The outer shell of the carboxysome is reminiscent of a viral capsid, being constructed from many copies of a few small proteins. Here we describe the structure of the shell protein CsoS1A from the chemoautotrophic bacterium Halothiobacillus neapolitanus. The CsoS1A protein forms hexameric units that pack tightly together to form a molecular layer, which is perforated by narrow pores. Sulfate ions, soaked into crystals of CsoS1A, are observed in the pores of the …

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Assessment Of Multi Media & Web Based Instruction In A Science Technology & Society Course, Patricia Backer Jun 2007

Assessment Of Multi Media & Web Based Instruction In A Science Technology & Society Course, Patricia Backer

Faculty Publications

Multimedia can be a powerful tool in exploring the nature of the world around us, including its technological systems. This paper describes the assessment of self-paced multimedia and web- based modules that are used in an advanced General Education (GE) course in the College of Engineering at San José State University. The development of these modules began in 1994 and has undergone many revisions. Currently, four of the seven units in this class are taught using either multimedia CDs or web-based material.The General Education course, Technology and Civilization (TECH 198), is designed to introduce students to the realm of history …

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Technology And Gender Issues: Development And Assessment Of A Freshman General Education Course In The College Of Engineering, Patricia Backer Jun 2007

Technology And Gender Issues: Development And Assessment Of A Freshman General Education Course In The College Of Engineering, Patricia Backer

Faculty Publications

This class, Technology VS Women, explores the interaction of gender with technology and answers questions such as: Is technology a “male” science? Is modern technology compatible to both male and female users? What does history tell us about the role of women at work relating to technology? The ideas presented in this course challenges some commonly held myths and misconceptions about technology in our society. This course focuses on the technological changes since 1900 and how they have affected both men and women. The effect of cultural biases and perspectives on the working and educational environments also are addressed. This …

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Measurement Of K0S, Λ And Λ Production At Hera, S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, L. Rinaldi Jun 2007

Measurement Of K0S, Λ And Λ Production At Hera, S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, L. Rinaldi

Faculty Publications

The production of the neutral strange hadrons K0S, Λ and Λ has been measured in ep collisions at HERA using the ZEUS detector. Cross sections, baryon-to-meson ratios, relative yields of strange and charged light hadrons, Λ (Λ) asymmetry and polarization have been measured in three kinematic regions: Q2 > 25 GeV2; 5 < Q2 < 25 GeV2; and in photoproduction (Q 2 0). In photoproduction the presence of two hadronic jets, each with at least 5 GeV transverse energy, was required. The measurements agree in general with Monte Carlo models and are consistent with measurements made at e+e- colliders, except for an enhancement of baryon relative to meson production in photoproduction. © Springer-Verlag / Società Italiana di Fisica 2007.

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Active Learning For Part-Of-Speech Tagging: Accelerating Corpus Annotation, George Busby, Marc Carmen, James Carroll, Robbie Haertel, Deryle W. Lonsdale, Peter Mcclanahan, Eric K. Ringger, Kevin Seppi Jun 2007

Active Learning For Part-Of-Speech Tagging: Accelerating Corpus Annotation, George Busby, Marc Carmen, James Carroll, Robbie Haertel, Deryle W. Lonsdale, Peter Mcclanahan, Eric K. Ringger, Kevin Seppi

Faculty Publications

In the construction of a part-of-speech annotated corpus, we are constrained by a fixed budget. A fully annotated corpus is required, but we can afford to label only a subset. We train a Maximum Entropy Markov Model tagger from a labeled subset and automatically tag the remainder. This paper addresses the question of where to focus our manual tagging efforts in order to deliver an annotation of highest quality. In this context, we find that active learning is always helpful. We focus on Query by Uncertainty (QBU) and Query by Committee (QBC) and report on experiments with several baselines and …

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Multiscale Mode Dynamics Of A Tethered Membrane, Ras B. Pandey, Kelly L. Anderson, B. L. Farmer Jun 2007

Multiscale Mode Dynamics Of A Tethered Membrane, Ras B. Pandey, Kelly L. Anderson, B. L. Farmer

Faculty Publications

Stochastic dynamics of a tethered membrane with a bond-fluctuating coarse-grained Monte Carlo simulation shows, in addition to diffusion, nondiffusive behavior sensitive to the type of membrane, its size, and quality of the solvent. Motion of the membrane’s center node is described by the variation of the mean-square displacement (R2n) with time step (t), i.e., R2n∝t2ν with the exponent ν≃1/8−1∕6 in the short time followed by subdiffusive power laws (i.e., ν∼1∕5, 1∕10) in the intermediate time regimes before reaching diffusion ν=1. The crossover between in-plane wrinkle modes is identified from the segmental (node) motion of the membrane.

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Measurement Of D* ± Meson Production In E± P Scattering At Low Q2, S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, L. Rinaldi May 2007

Measurement Of D* ± Meson Production In E± P Scattering At Low Q2, S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, L. Rinaldi

Faculty Publications

The production of D* ± (2010) mesons in e± p scattering in the range of exchanged photon virtuality 0.05 < Q2 < 0.7 GeV2 has been measured with the ZEUS detector at HERA using an integrated luminosity of 82 pb-1. The decay channels D* + → D0 π+ with D0 → K- π+ and corresponding antiparticle decay were used to identify D* mesons and the ZEUS beampipe calorimeter was used to identify the scattered electron. Differential D* cross sections as functions of Q2, inelasticity, y, transverse momentum of the D* meson, pT (D*), and pseudorapidity of the D* meson, η (D*), have been measured in the kinematic region 0.02 < y < 0.85, 1.5 < pT (D*) < 9.0 GeV and | η (D*) | < 1.5. The measured differential cross sections are in agreement with two different NLO QCD calculations. The cross sections are also compared to previous ZEUS measurements in the photoproduction and DIS regimes. © 2007 Elsevier B.V. All rights reserved.

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Jet-Radius Dependence Of Inclusive-Jet Cross Sections In Deep Inelastic Scattering At Hera, S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, L. Rinaldi May 2007

Jet-Radius Dependence Of Inclusive-Jet Cross Sections In Deep Inelastic Scattering At Hera, S. Chekanov, M. Derrick, S. Magill, S. Miglioranzi, B. Musgrave, D. Nicholass, J. Repond, R. Yoshida, Margarita C. K. Mattingly, M. Jechow, N. Pavel, A. G. Yagües Molina, S. Antonelli, P. Antonioli, G. Bari, M. Basile, L. Bellagamba, M. Bindi, D. Boscherini, A. Bruni, G. Bruni, L. Cifarelli, F. Cindolo, A. Contin, M. Corradi, S. De Pasquale, G. Iacobucci, A. Margotti, R. Nania, A. Polini, L. Rinaldi

Faculty Publications

Differential inclusive-jet cross sections have been measured for different jet radii in neutral current deep inelastic ep scattering for boson virtualities Q2 > 125 GeV2 with the ZEUS detector at HERA using an integrated luminosity of 81.7 pb-1. Jets were identified in the Breit frame using the kT cluster algorithm in the longitudinally inclusive mode for different values of the jet radius R. Differential cross sections are presented as functions of Q2 and the jet transverse energy, ET, Bjet. The dependence on R of the inclusive-jet cross section has been measured for Q2 > 125 and 500 GeV2 and found to be …

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Sea Surface Pco2‐Sst Relationships Across A Cold‐Core Cyclonic Eddy: Implications For Understanding Regional Variability And Air‐Sea Gas Exchange, Feizhou Chen, Wei‐Jun Cai, Claudia R. Benitez-Nelson, Yongchen Wang May 2007

Sea Surface Pco2‐Sst Relationships Across A Cold‐Core Cyclonic Eddy: Implications For Understanding Regional Variability And Air‐Sea Gas Exchange, Feizhou Chen, Wei‐Jun Cai, Claudia R. Benitez-Nelson, Yongchen Wang

Faculty Publications

[1] This study is designed to improve the understanding of how biologically productive, cold‐core cyclonic eddies affect sea surface pCO2 in the lee of the main Hawaiian Islands in the subtropical North Pacific Gyre. We identified three unique relationships between pCO2 and sea surface temperature (SST). A positive correlation between pCO2 and SST was observed in the waters surrounding the eddy suggesting surface CO2 is controlled primarily by thermodynamics. In contrast, a negative relationship was observed within the eddy core as a result of the upwelling of CO2‐enriched subsurface waters. A third relationship existed throughout the rest …

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Spin Blockade At Semiconductor/Ferromagnet Junctions, Yuriy V. Pershin Dr, Massimiliano Di Ventra May 2007

Spin Blockade At Semiconductor/Ferromagnet Junctions, Yuriy V. Pershin Dr, Massimiliano Di Ventra

Faculty Publications

We study theoretically extraction of spin-polarized electrons at nonmagnetic semiconductor/ferromagnet junctions. The outflow of majority-spin electrons from the semiconductor into the ferromagnet leaves a cloud of minority-spin electrons in the semiconductor region near the junction, forming a local spin-dipole configuration at the semiconductor/ferromagnet interface. This minority-spin cloud can limit the majority-spin current through the junction, creating a pronounced spin blockade at a critical current. We calculate the critical spin-blockade current in both planar and cylindrical geometries and discuss possible experimental tests of our predictions.

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Combinatorial Fusion Criteria For Robot Mapping, Damian M. Lyons, D. Frank Hsu, Qiang Ma, Liang Wang May 2007

Combinatorial Fusion Criteria For Robot Mapping, Damian M. Lyons, D. Frank Hsu, Qiang Ma, Liang Wang

Faculty Publications

We address the problem of sensor fusion for stereo and ultrasound depth measurements for map building for a robot operating in a cluttered environment. In such a situation it’s difficult to make useful and realistic assumpt ions about the sensor or environment statistics. Combinatorial Fusion Analysis is used to develop an approach to fusion with unknown sensor and environment statistics. A metric is proposed that shows when fusion from a set of fusion alternatives will produ ce a more accurate estimation of depth than either sonar or stereo alone and when not. The metric consists of two crit eria: (a) …

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Disambiguation Of Overlapping Experiences By Neurons In The Medial Entorhinal Cortex., Lipton Pa, White Ja, Eichenbaum H May 2007

Disambiguation Of Overlapping Experiences By Neurons In The Medial Entorhinal Cortex., Lipton Pa, White Ja, Eichenbaum H

Faculty Publications

No abstract provided.

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To Repair Or Not To Repair: Helping Ad Hoc Routing Protocols To Distinguish Mobility From Congestion, Qiuyi Duan, Roger Pack, Manoj Pandey, Lei Wang, Daniel Zappala May 2007

To Repair Or Not To Repair: Helping Ad Hoc Routing Protocols To Distinguish Mobility From Congestion, Qiuyi Duan, Roger Pack, Manoj Pandey, Lei Wang, Daniel Zappala

Faculty Publications

In this paper we consider the problem of distinguishing whether frame loss at the MAC layer has occurred due to mobility or congestion. Most ad hoc routing protocols make the faulty assumption that all frame loss means the destination node has moved, resulting in significant overhead as they initiate the repair of routes that have not been broken. We design a mobility detection algorithm, MDA, that properly detects the cause of a lost frame, then coordinates with the routing protocol so that it reacts properly. This approach dramatically reduces routing protocol overhead and significantly increases application throughput. We use a …

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Reconstruction And Higher-Dimensional Geometry, Hongyu He May 2007

Reconstruction And Higher-Dimensional Geometry, Hongyu He

Faculty Publications

Tutte proved that, if two graphs, both with more than two vertices, have the same collection of vertex-deleted subgraphs, then the determinants of the two corresponding adjacency matrices are the same. In this paper, we give a geometric proof of Tutte's theorem using vectors and angles. We further study the lowest eigenspaces of these adjacency matrices. © 2006 Elsevier Inc. All rights reserved.

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The Structure Of The 3-Separations Of 3-Connected Matroids Ii, James Oxley, Charles Semple, Geoff Whittle May 2007

The Structure Of The 3-Separations Of 3-Connected Matroids Ii, James Oxley, Charles Semple, Geoff Whittle

Faculty Publications

The authors showed in an earlier paper that there is a tree that displays, up to a natural equivalence, all non-trivial 3-separations of a 3-connected matroid. The purpose of this paper is to show that if certain natural conditions are imposed on the tree, then it has a uniqueness property. In particular, suppose that, from every pair of edges that meet at a degree-2 vertex and have their other ends of degree at least three, one edge is contracted. Then the resulting tree is unique. © 2006 Elsevier Ltd. All rights reserved.

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Frobenius-Schur Indicators And Exponents Of Spherical Categories, Siu Hung Ng, Peter Schauenburg May 2007

Frobenius-Schur Indicators And Exponents Of Spherical Categories, Siu Hung Ng, Peter Schauenburg

Faculty Publications

We obtain two formulae for the higher Frobenius-Schur indicators: one for a spherical fusion category in terms of the twist of its center and the other one for a modular tensor category in terms of its twist. The first one is a categorical generalization of an analogous result by Kashina, Sommerhäuser, and Zhu for Hopf algebras, and the second one extends Bantay's 2nd indicator formula for a conformal field theory to higher degrees. These formulae imply the sequence of higher indicators of an object in these categories is periodic. We define the notion of Frobenius-Schur (FS-)exponent of a pivotal category …

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Revision Of The Nonequilibrium Thermal Dissociation And Stringent Washing Approaches For Identification Of Mixed Nucleic Acid Targets By Microarrays, Alex E. Pozhitkov, Robert D. Stedtfeld, Syed A. Hashsham, Peter A. Noble May 2007

Revision Of The Nonequilibrium Thermal Dissociation And Stringent Washing Approaches For Identification Of Mixed Nucleic Acid Targets By Microarrays, Alex E. Pozhitkov, Robert D. Stedtfeld, Syed A. Hashsham, Peter A. Noble

Faculty Publications

Microarray experiments typically involve washing steps that remove hybridized nonspecific targets with the purpose of improving the signal- to- noise ratio. The quality of washing ultimately affects downstream analysis of the microarray and interpretation. The paucity of fundamental studies directed towards understanding the dissociation of mixed targets from microarrays makes the development of meaningful washing/ dissociation protocols difficult. To fill the void, we examined activation energies and preexponential coefficients of 47 perfect match ( PM) and double- mismatch ( MM) duplex pairs to discover that there was no statistical difference between the kinetics of the PM and MM duplexes. Based …

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Model-Independent Measurement Of The Excited Fraction In A Magneto-Optical Trap, M. H. Shah, H. A. Camp, M. L. Trachy, G. Veshapidze, M.A. Gearba, B.D. Depaola May 2007

Model-Independent Measurement Of The Excited Fraction In A Magneto-Optical Trap, M. H. Shah, H. A. Camp, M. L. Trachy, G. Veshapidze, M.A. Gearba, B.D. Depaola

Faculty Publications

In many experiments involving a magneto-optical trap (MOT) it is of great importance to know the fraction of atoms placed in an excited state due to the trapping process. Generally speaking, researchers have had to use overly simplistic and untested models to estimate this fraction. In this work, the excited fractions of 87Rb atoms in a MOT are directly measured using a charge transfer technique, for a range of MOT parameters. Simple models are then fit to the measured fractions. Using the results of this work, the excited fraction of 87Rb atoms trapped in a MOT can be …

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Products Of Characters With Few Irreducible Constituents, Edith Adan-Bante May 2007

Products Of Characters With Few Irreducible Constituents, Edith Adan-Bante

Faculty Publications

We study the solvable groups G that have an irreducible character χ ∈ Irr(G) such that χ--χ has at most two nonprincipal irreducible constituents.

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Experimental Characterization Of The Outdoor Mimo Wireless Channel Temporal Variation, Michael A. Jensen, Karl F. Warnick, Jon W. Wallace, Ajay Gummalla, Harry B. Lee May 2007

Experimental Characterization Of The Outdoor Mimo Wireless Channel Temporal Variation, Michael A. Jensen, Karl F. Warnick, Jon W. Wallace, Ajay Gummalla, Harry B. Lee

Faculty Publications

Time-variant multiple-input multiple-output (MIMO) channels are measured in an outdoor campus environment at 2.45 GHz with directional patch arrays and omnidirectional monopole arrays. A number of useful metrics are proposed for quantifying time variation in MIMO channels: eigenvalue level crossing rate, eigenvector angular deviation, and capacity loss for delayed transmit and receive channel state information (CSI). Measurements in four different environments confirm the strong correlation between angular spread of multipath and MIMO channel time variability. The rate of time variation is also strongly influenced by the type of array, indicating that directional elements may be advantageous for highly mobile environments. …

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The Relationship Between Antenna Loss And Superdirectivity In Mimo Systems, Michael A. Jensen, Nicolas W. Bikhazi May 2007

The Relationship Between Antenna Loss And Superdirectivity In Mimo Systems, Michael A. Jensen, Nicolas W. Bikhazi

Faculty Publications

Multiple-input multiple-output (MIMO) communication systems can theoretically use array superdirectivity to optimally exploit the propagation channel. This superdirectivity leads to very large capacity bounds, particularly when the antennas are closely spaced. However, because superdirective behavior is difficult to achieve in practice, new capacity bounds have been formulated for the case where the level of array superdirectivity is constrained. Existing capacity analyses limit the superdirectivity in a suboptimal way. In this paper, the impact of superdirectivity in the capacity solution is limited by introducing finite ohmic loss in the transmit and receive antenna elements. Computational results reveal that even a small …

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