Digital Commons Network^™

Search For Higgs Bosons Decaying To Tau Pairs In Pp Collisions With The D0 Detector, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, Dø Collaboration

Kenneth Bloom Publications

We present a search for the production of neutral Higgs bosons φ decaying into τ⁺ τ^- final states in pp collisions at a center-of-mass energy of 1.96 TeV. The data, corresponding to an integrated luminosity of approximately 1 fb^-1, were collected by the D0 experiment at the Fermilab Tevatron Collider. Limits on the production cross section times branching ratio are set. The results are interpreted in the minimal supersymmetric standard model yielding limits that are the most stringent to date at hadron colliders.

University Of Nebraska At Omaha, August Commencement 2008, University Of Nebraska At Omaha

Commencement Programs

No abstract provided.

Polar-Horizontal Versus Polar-Vertical Reverse-Tilt-Domain Walls: Influence Of A Pretilt Angle Below The Nematic-Isotropic Phase Transition, Ji-Hoon Lee, Timothy J. Atherton, Daeseung Kang, Rolfe G. Petschek, Charles Rosenblatt

Faculty Scholarship

On cooling through the isotropic-to-nematic phase transition in a cell whose substrates induce a large pretilt angle θ0 from the vertical direction, but with no preferential azimuthal orientation, tilt domains appear. The boundary walls between reverse tilt domains are found to be bendlike and twistlike when θ0 (T= TNI) is sufficiently large just below the isotropic-nematic phase transition temperature TNI -i.e., for a nearly planar orientation. Here the director becomes planar approximately midway through the wall, and we refer to this type of wall as "polar horizontal," which is topologically stable. However, if θ0 (T= TNI) is sufficiently small just …

Electrical Actuation Of Electrically Conducting And Insulating Droplets Using Ac And Dc Voltages, Niru Kumari, Vaibhav Bahadur, S V. Garimella

CTRC Research Publications

Electrical actuation of liquid droplets at the microscale offers promising applications in the fields of microfluidics and lab-on-chip devices. Much prior research has targeted the electrical actuation of electrically conducting liquid droplets using dc voltages (classical electrowetting). Electrical actuation of conducting droplets using ac voltages and the actuation of insulating droplets (using dc or ac voltages) has remained relatively unexplored. This paper utilizes an energy-minimization-based analytical framework to study the electrical actuation of a liquid droplet (electrically conducting or insulating) under ac actuation. It is shown that the electromechanical regimes of classical electrowetting, electrowetting under ac actuation and insulating droplet …

Sbml-Sat: A Systems Biology Markup Language (Sbml) Based Sensitivity Analysis Tool, Zhike Zi, Yanan Zheng, Ann E. Rundell, Edda Klipp

Weldon School of Biomedical Engineering Faculty Publications

Background

It has long been recognized that sensitivity analysis plays a key role in modeling and analyzing cellular and biochemical processes. Systems biology markup language (SBML) has become a well-known platform for coding and sharing mathematical models of such processes. However, current SBML compatible software tools are limited in their ability to perform global sensitivity analyses of these models.

Results

This work introduces a freely downloadable, software package, SBML-SAT, which implements algorithms for simulation, steady state analysis, robustness analysis and local and global sensitivity analysis for SBML models. This software tool extends current capabilities through its execution of global sensitivity …

Ramanujan–Slater Type Identities Related To The Moduli 18 And 24, James Mclaughlin, Andrew Sills

Mathematical Sciences: Faculty Publications

We present several new families of Rogers–Ramanujan type identities related to the moduli 18 and 24. A few of the identities were found by either Ramanujan, Slater, or Dyson, but most are believed to be new. For one of these families, we discuss possible connections with Lie algebras. We also present two families of related false theta function identities.

Search For Pair Production Of Doubly Charged Higgs Bosons In The H++H-- → Μ+Μ+Μ-Μ- Final State, V. M. Abazov, Kenneth A. Bloom, Gregory Snow, Dø Collaboration

Kenneth Bloom Publications

We report the results of a search for pair production of doubly charged Higgs bosons via pp → H⁺⁺H^--X → μ⁺μ⁺μ^-μ^-X at √s = 1.96 TeV.We use a data set corresponding to an integrated luminosity of 1.1 fb^-1 collected from 2002 to 2006 by the D0 detector at the Fermilab Tevatron Collider. In the absence of an excess above the standard model background, lower mass limits of M(H^±±_L) > 150 GeV/c² and M(H^±±_R) > 127 GeV/c^{2 …}

The Creation And Impact Of Corporate Mentorship On Student-Led Satellite Projects, Bruce Davis, Mike Grusin, Bryan Helgesen, Chris Koehler

Small Satellite Conference

Over the past year, strong relationships have developed between a team of students at the University of Colorado and industry mentors. These students, who are participating in the University Nanosat 5 Program, have found that professional mentorship is a critical part of the learning experience. It has resulted in an increased motivation to succeed, and a more comprehensive level of real-world thinking when designing satellites. The participating professionals also find the experience rewarding and go out of their way to accommodate student needs. At the corporate level, involvement with student projects provides company exposure to rising engineers, networking with other …

Today’S Students – Tomorrow’S Engineers: Jump-Starting The Transition From University To Industry , David Klumpar

Small Satellite Conference

Evidence suggests that the nationwide production of Science Technology, Engineering, and Mathematics graduates qualified for employment in the aerospace enterprise is insufficient to meet current and future demand. A unique program at the Space Science and Engineering Laboratory (SSEL) at Montana State University (MSU) has been training a new generation of engineers and scientists through direct hands-on immersion in small satellite design and development. This program jump-starts the college to workplace transition by intimately involving undergraduate (and graduate) students in the hands-on design, development, test, and flight and operations of space flight systems. The extracurricular program is based upon the …

Tj3sat – Unique Challenges Of Building A Small Satellite Within A High School Environment, Carlos Niederstrasser, Adam Kemp, Joy Lee, Ashley Lewis, Nishad Samant, Joel Stein

Small Satellite Conference

In 2006 Thomas Jefferson High School for Science and Technology (TJHSST) and Orbital Sciences Corporation announced a new initiative to have students from TJHSST design and build the first ever high-school satellite. Leveraging the large body of prior work done in the CubeSat community, and under the mentorship of Orbital Sciences engineers, TJHSST students are in the design phase of their new CubeSat dubbed TJ3Sat. The TJ3Sat payload consists of a digital voice synthesizer that will be accessible to the general amateur radio community. The launch of TJ3Sat is currently scheduled for mid 2009. Unlike most other student satellite programs, …

Summer Mustang, August 14, 2008

Cal Poly Student Newspaper

Student newspaper of California Polytechnic State University, San Luis Obispo, CA.

Experimental Investigation Of An American Five-String Banjo, Laurie A. Stephey, Thomas R. Moore

Student-Faculty Collaborative Research Publications

An experimental investigation of an American five-string banjo is reported. The acoustic spectra of the strings are analyzed and it is found that in many ways banjo strings behave in a manner similar to those on a piano. The terminating impedance presented to the strings at the bridge is reported and it is found to be generally much lower than the characteristic impedance of the strings. It is also shown that, for a properly tuned banjo, the mode shapes of the membrane are symmetric about the center even though there is a large asymmetric force due to the off-center placement …

Algorithmic Dimensionality Reduction For Molecular Structure Analysis, Evangelos A. Coutsias, W. Michael Brown, Shawn Martin, Sara N. Pollock, Jean-Paul Watson

Branch Mathematics and Statistics Faculty and Staff Publications

Dimensionality reduction approaches have been used to exploit the redundancy in a Cartesian coordinate representation of molecular motion by producing low-dimensional representations of molecular motion. This has been used to help visualize complex energy landscapes, to extend the time scales of simulation, and to improve the efficiency of optimization. Until recently, linear approaches for dimensionality reduction have been employed. Here, we investigate the efficacy of several automated algorithms for nonlinear dimensionality reduction for representation of trans, trans-1,2,4-trifluorocyclo-octane conformation\u2014a molecule whose structure can be described on a 2-manifold in a Cartesian coordinate phase space. We describe an efficient approach for a …

Stimulated Brillouin Scattering Phase Conjugation In Fiber Optic Waveguides, Steven M. Massey

Theses and Dissertations

The objective of this research effort was to demonstrate the path to continuous wave, coherent beam combination through stimulated Brillouin scattering phase conjugation in optical fiber. This work experimentally determined the fiber parameters necessary for phase conjugation in step-index optical fiber. Continuous wave phase conjugation using stimulated Brillouin scattering in step-index fibers was achieved for the first time with a fidelity of 0.8 and a threshold power of 16 W in a 15-m fiber with 0.13 NA. A fidelity of 0.8 was also achieved using 40 m of fiber with 0.06-NA and a threshold power of 15 W. The fidelity …

Statistical Methods For Polarimetric Imagery, Daniel A. Lemaster

Theses and Dissertations

Estimation theory is applied to a physical model of incoherent polarized light to address problems in polarimetric image registration, restoration, and analysis for electro-optical imaging systems. In the image registration case, the Cramer-Rao lower bound on unbiased joint estimates of the registration parameters and the underlying scene is derived, simplified using matrix methods, and used to explain the behavior of multi-channel linear polarimetric imagers. In the image restoration case, a polarimetric maximum likelihood blind deconvolution algorithm is derived and tested using laboratory and simulated imagery. Finally, a principal components analysis is derived for polarization imaging systems. This analysis expands upon …

On Graph Isomorphism And The Pagerank Algorithm, Christopher J. Augeri

Theses and Dissertations

A graph is a key construct for expressing relationships among objects, such as the radio connectivity between nodes contained in an unmanned vehicle swarm. The study of such networks may include ranking nodes based on importance, for example, by applying the PageRank algorithm used in some search engines to order their query responses. The PageRank values correspond to a unique eigenvector typically computed by applying the power method, an iterative technique based on matrix multiplication. The first new result described herein is a lower bound on the execution time of the PageRank algorithm that is derived by applying standard assumptions …

First Flight Results Of The Delfi-C3 Satellite Mission, W.J. Ubbels, C.J.M Verhoeven, R.J. Hamann, E. Gill, J. Bouwmeester

Small Satellite Conference

Delfi-C3 is a 3-unit CubeSat nanosatellite developed at Delft University of Technology by students and staff from the faculty of Aerospace Engineering and the faculty of Electrical Engineering, Mathematics and Computer Science with engineering support from ISIS – Innovative Solutions In Space BThe project started in December 2004 and the satellite was launched on April 28th 2008 with a Polar Satellite Launch Vehicle from India. The prime mission objective of Delfi-C3 is to act as a technology test bed for two payloads: Thin Film Solar Cells, as developed by the company Dutch Space, and an Autonomous Wireless Sun Sensor developed …

A Low-Power Dual-Processor Computing System For Advanced Nanosatellite Missions, Nathaniel Colson, Paul Moonjelly, David Filmer

Small Satellite Conference

This paper discusses the design of the Flight Computing System for PurdueSat – a 2-U CubeSat being developed at the School of Aeronautics & Astronautics, Purdue University. The satellite employs sophisticated attitude determination algorithms and autonomous attitude control using magnetorquers as the only actuators, which requires substantial computation at runtime. To meet these computational demands, we have developed a unique dualprocessor computing system that is capable of handling computationally intense algorithms, while still maintaining ultra-low levels of power consumption. These characteristics are achieved by the optimal combination of two highly energy-efficient computers – a Digital Signal Processor geared towards large …

A Quick Optimization Of A Rocket Trajectory Using Mcmc Method, Masashi Miura, Yohsuke Nambu, Masaaki Sugimoto, Hajime Yokota, Akane Uemichi

Small Satellite Conference

In these years, small satellites have grown in performance greatly and it is important to develop the good launcher for small satellites. One of the promising launch systems for small satellites is air launch. In Japan there is no successful small launch vehicle as it is now and some researchers have proposed air launch rockets using existing solid motors. To achieve air launch, some new technologies are necessary. As candidate of the one of such new technologies, the quick optimization of the rocket trajectory with MCMC (Markov chain Monte Carlo) method is introduced in this paper.

Development Of A Micro-Thruster Impulse Measurement System Using Optical Sensors, Young-Keun Chang, Suk-Jin Kang, Hyea-Ran Cho

Small Satellite Conference

A new method for measuring performance of a micro-thruster is suggested in this paper. A few thrust stands have been developed for measuring micro-level thrusts. This paper describes a different measurement method that can minimize the calibration involved in the measurements, while providing the capability of directly measuring the produced minimum impulse bit. The underlying theory and the theoretical background for the measurement mechanism are described here. The theory and method is verified using computer simulation, and the result is given in this paper. The theory has also been tested on an actual hardware. The prototype measurement system has been …

On-Orbit Spacecraft Inertia And Rate Sensor Scale Factor Estimation For Microsatellites, Philip Ferguson

Small Satellite Conference

A key challenge in testing and operating small satellites is the determination of the moment of inertia. Attitude control systems engineers use the moment of inertia to develop closed loop pointing controllers as well as accurate feed-forward pointing commands that predict the satellite’s motion. Traditionally, engineers measure the satellite moment of inertia using a mass properties table. However, for small, relatively lightweight satellites, this process is error-prone and costly regardless of the satellite size. This paper presents a novel on-orbit inertia-estimation technique. The algorithm is based on standard non-linear function solvers that can be run on the ground and requires …

Generalized Random Walks, Their Trees, And The Transformation Method Of Option Pricing, Thomas Gordon Stewart

Theses and Dissertations

The random walk is a powerful model. Chemistry, Physics, and Finance are just a few of the disciplines that model with the random walk. It is clear from its varied uses that despite its simplicity, the simple random walk it very flexible. There is one major drawback, however, to the simple random walk and the geometric random walk. The limiting distribution is either normal, lognormal, or a levy process with infinite variance. This thesis introduces an new random walk aimed at overcoming this drawback. Because the simple random walk and the geometric random walk are special cases of the proposed …

An Infrastructure For Performance Measurement And Comparison Of Information Retrieval Solutions, Gary Saunders

Theses and Dissertations

The amount of information available on both public and private networks continues to grow at a phenomenal rate. This information is contained within a wide variety of objects, including documents, e-mail archives, medical records, manuals, pictures and music. To be of any value, this data must be easily searchable and accessible. Information Retrieval (IR) is concerned with the ability to find and gain access to relevant information. As electronic data repositories continue to proliferate, so too, grows the variety of methods used to locate and access the information contained therein. Similarly, the introduction of innovative retrieval strategies—and the optimization of …

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.

I. Thermodynamics And Magnetism Of Cu2ocl2 Ii. Repairs To Microcalorimeter The "2"S Are Subscripts, And The Second 2 Is Preceded By A Lower Case L, Not A One, Thomas J. Parry

Theses and Dissertations

Adiabatic calorimetry provides accurate and precise specific heat (Cp) data. From this data, thermodynamic functions may be calculated. Cu2OCl2, melanothallite, became of interest as part of a study of a particular thermochemical cycle. The experimental specific heat data and the calculated thermodynamic functions are reported here. Free energies of formation, calculated from the thermodynamic functions, suggest the particular cycle of interest with this compound as an intermediate is not feasible; uncertainty as to the accuracy of CuO and CuCl2 data used in the calculations indicate further study may be necessary. Upon collection of the specific heat data, an antiferromagnetic transition …

Autonomous And Intelligent Radio Switching, Quiyi Duan

Theses and Dissertations

With the proliferation of mobile applications and the abundance of wireless devices, it is increasingly common for devices to support multiple radios. When two devices are communicating they should choose the best available radio based on user preference and application requirements. This type of “radio switching” should happen automatically, so that the system optimizes performance dynamically. To achieve this objective, we design an Autonomous and Intelligent Radio Switching (AIRS) system to leverage the radio heterogeneity common in today's wireless devices. The AIRS system consists of three key components. First, we design a radio preference evaluation module to dynamically select the …

Tooth Engagement Evaluation Of Involute Spline Couplings, Robert R. Robins

Theses and Dissertations

Spline couplings are used in applications involving high torque; however, due to variations in teeth clearances, all teeth in spline couplings do not engage simultaneously, causing some of the teeth to carry a disproportionately large portion of the total load. Variations in tooth-to-tooth clearances mean the first pair of teeth to engage will carry more load and fail sooner. This has lead to an industry practice of designing splines around the criteria that only 25-50% of the teeth on a spline coupling will engage and carry the load, and the load is generally assumed to be uniformly distributed. This research …

Newsroom, Georgia Southern University

Newsroom (2006-2023)

• Georgia Southern University honors two outstanding faculty members in College of Liberal Arts and Social Sciences
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• Georgia Southern University Welcomes New Faculty Members
• Georgia Southern University Holds Fall Convocation

Defining A Fire Year For Reporting And Analysis Of Global Interannual Fire Variablility, Luigi Boschetti, David P. Roy

GSCE Faculty Publications

The interannual variability of fire activity has been studied without an explicit investigation of a suitable starting month for yearly calculations. Sensitivity analysis of 37 months of global MODIS active fire detections indicates that a 1-month change in the start of the fire year definition can lead, in the worst case, to a difference of over 6% and over 45% in global and subcontinental scale annual fire totals, respectively. Optimal starting months for analyses of global and subcontinental fire interannual variability are described. The research indicates that a fire year starting in March provides an optimal definition for annual global …

Duts: Targeted Case Studies, Hui Nee Chin, Sebastian Elbaum, Matthew B. Dwyer, Matthew Jorde

School of Computing: Technical Reports

Our previous studies of DUTs addressed research questions of effectiveness, efficiency, and robustness with respect to one software artifact, Siena, and we believe the findings generalize to similar artifacts. Still, we realize that existing studies suffer from threats to validity. Specifically, the selected artifact provided limited exposure to CR in the presence of deeper heap structures, extensive software changes, and high number of methods invocations. We start to address those threats to the validity of our findings by investigating the performance of CR in the presence of such settings.
The findings in this report reveal that the performance of the …