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2005

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Articles 3031 - 3060 of 5573

Full-Text Articles in Physical Sciences and Mathematics

Jump Systems And Laminated Manhattan Sets, Jessica Cuomo, Nkiruka Nwasokwa, Vadim Ponomarenko Feb 2005

Jump Systems And Laminated Manhattan Sets, Jessica Cuomo, Nkiruka Nwasokwa, Vadim Ponomarenko

Mathematics Faculty Research

A jump system is a set of lattice points satisfying a certain "two-step" axiom. A Manhattan set is the convex hull of a two-dimensional jump system. Taking multiple Manhattan sets, in layers, forms a three-dimensional object. We determine under what conditions this object is, in turn, a jump system.

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Potential Economic Impacts Of Zebra Mussels On The Hydropower Facilities In The Columbia River Basin, Stephen Phillips, Tim Darland, Mark Sytsma Feb 2005

Potential Economic Impacts Of Zebra Mussels On The Hydropower Facilities In The Columbia River Basin, Stephen Phillips, Tim Darland, Mark Sytsma

Center for Lakes and Reservoirs Publications and Presentations

The purpose of this study was to estimate costs to the Federal Columbia River Power System hydroelectric projects in the event of a zebra mussel infestation.

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Specification Of A Common Framework For Characterizing Alignment, Paolo Bouquet, Marc Ehrig, Jerome Euzenat, Enrico Franconi, Pascal Hitzler, Markus Krotzsch, Luciano Serafini, Giorgos Stamu, York Sure, Sergio Tessaris Feb 2005

Specification Of A Common Framework For Characterizing Alignment, Paolo Bouquet, Marc Ehrig, Jerome Euzenat, Enrico Franconi, Pascal Hitzler, Markus Krotzsch, Luciano Serafini, Giorgos Stamu, York Sure, Sergio Tessaris

Computer Science and Engineering Faculty Publications

Definition of a common framework for characterizing alignment of heterogeneous information. This report describes various approaches towards this goal and shows the relations between them. It also provides a description of the alignment sructure and process.

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Hd 166181 = V815 Herculis, A Single-Lined Spectroscopic Multiple System, Francis C. Fekel, David J. Barlow, Colin D. Scarfe, Sylvie Jancart, Dimitri Pourbaix Feb 2005

Hd 166181 = V815 Herculis, A Single-Lined Spectroscopic Multiple System, Francis C. Fekel, David J. Barlow, Colin D. Scarfe, Sylvie Jancart, Dimitri Pourbaix

Information Systems and Engineering Management Research Publications

We have obtained extensive spectroscopic and velocity spectrometer observations of HD 166181, a previously known single-lined spectroscopic binary. Our improved orbit for the G6 V primary has a period of 1.8098343 days and is circular. Although the lines of additional components have not been detected, radial velocity measurements confirm that the system has additional velocity variations with a period of 2092 days, or 5.73 yr. This long-period orbit has an eccentricity of 0.76. An analysis of the Hipparcos observations produces a well-determined astrometric orbit for the long-period system that has an inclination of 78°. Mass estimates of the components in …

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Securing Application Command Layer Under Jini Services, Tarek Mahmoud Negm Feb 2005

Securing Application Command Layer Under Jini Services, Tarek Mahmoud Negm

Archived Theses and Dissertations

No abstract provided.

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Adaptive Stream Filters For Entity-Based Queries With Non-Value Tolerance Technical Report, Reynold Cheng, Ben Kao, Sunil Prabhakar, Alan Kwan, Yicheng Tu Feb 2005

Adaptive Stream Filters For Entity-Based Queries With Non-Value Tolerance Technical Report, Reynold Cheng, Ben Kao, Sunil Prabhakar, Alan Kwan, Yicheng Tu

Department of Computer Science Technical Reports

No abstract provided.

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Atomic Force Microscopy Investigation Of Virus Aggregation And Assembly At Chemical Templates Formed By Scanned Probe Nanolithography, Chin Li Cheung, S. -W. Chung, J. J. De Yoreo, A. Chatterji, T. Lin, J. E. Johnson Feb 2005

Atomic Force Microscopy Investigation Of Virus Aggregation And Assembly At Chemical Templates Formed By Scanned Probe Nanolithography, Chin Li Cheung, S. -W. Chung, J. J. De Yoreo, A. Chatterji, T. Lin, J. E. Johnson

Barry Chin Li Cheung Publications

Aggregation and assembly of macromolecules are important processes in a number of scientific fields including structural biology, medicine, and materials science. For example, growth of well-ordered two-dimensional (2-D) arrays and bulk crystals remains the rate-limiting step in macromolecular structure determination. Uncontrolled aggregation of proteins is the source of a number of devastating pathologies such as Creutzfeldt-Jakob syndrome. Moreover, the demonstrated ability of engineered viruses and proteins to act as templates for growth of inorganic nanostructures is driving a need for methods to deterministically pattern their assembly at surfaces in order to fabricate hierarchical materials and devices.

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Development Of A Personal Diet Plan Database Application For Persons With Severe Food Allergies, Heather Suzanne Ward Feb 2005

Development Of A Personal Diet Plan Database Application For Persons With Severe Food Allergies, Heather Suzanne Ward

Regis University Student Publications (comprehensive collection)

This project will research, analyze, design, and implement a computerized system that will assist patients in creating a personal diet plan based upon a "rotation diet." This diet, specifically designed for patients with severe food allergies, requires that a patient may only eat a particular food every n days (where n is any number), and foods from the same biological food family every n days. Currently, patients use either pen-and-paper or a computerized spreadsheet to create weekly or monthly food meal plans for the diet plan. The meal plans are usually transferred by hand to their daily or weekly shopping …

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Characteristics Of Instabilities In The Mesopause Region Over Maui, Hawaii, Feng Li, Alan Z. Liu, Gary R. Swenson Feb 2005

Characteristics Of Instabilities In The Mesopause Region Over Maui, Hawaii, Feng Li, Alan Z. Liu, Gary R. Swenson

Physical Sciences - Daytona Beach

Characteristics of convective and dynamical instabilities in the mesopause region (between 85 and 100 km) over Maui, Hawaii (20.7ºN, 156.3ºW) are investigated using 19 nights, ~133 hours of high-resolution wind and temperature data obtained by the University of Illinois Na wind/temperature lidar during the Maui Mesosphere and Lower Thermosphere (Maui MALT) campaigns. The mean probabilities of convective and dynamical instabilities are observed to be ~3 and 10%, respectively, but there is considerable night-to-night variation. At any given time the probability that an unstable condition is found at some altitudes in the 85–100 km range is 90%. The Maui MALT data …

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Counting Lattice Points In Admissible Adelic Sets, Lenny Fukshansky Feb 2005

Counting Lattice Points In Admissible Adelic Sets, Lenny Fukshansky

CMC Faculty Publications and Research

Lecture given at the Midwest Number Theory Conference for Graduate Students and Recent PhDs II, February 2005.

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The Aronsson-Euler Equation For Absolutely Minimizing Lipschitz Extensions With Respect To Carnot-Carathéodory Metrics, Thomas Bieske, Luca Capogna Feb 2005

The Aronsson-Euler Equation For Absolutely Minimizing Lipschitz Extensions With Respect To Carnot-Carathéodory Metrics, Thomas Bieske, Luca Capogna

Mathematics Sciences: Faculty Publications

We derive the Euler-Lagrange equation (also known in this setting as the Aronsson-Euler equation) for absolute minimizers of the L ∞ variational problem inf∥∇ 0u∥L∞(Ω), u = g ε Lip(∂Ω) on ∂Ω, where Ω ⊂ G is an open subset of a Carnot group, ∇ 0u denotes the horizontal gradient of u: Ω ℝ R, and the Lipschitz class is defined in relation to the Carnot-Carathéodory metric. In particular, we show that absolute minimizers are infinite harmonic in the viscosity sense. As a corollary we obtain the uniqueness of absolute minimizers in a large class of groups. This result extends …

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Laser Based Synchrotron Radiation, Kim Ta Phuoc, Frederic Burgy, Jean-Philippe Rousseau, Victor Malka, Antoine Rousse, Rahul Shah, Donald P. Umstadter, Alexander Puhkov, Sergei Kiselev Feb 2005

Laser Based Synchrotron Radiation, Kim Ta Phuoc, Frederic Burgy, Jean-Philippe Rousseau, Victor Malka, Antoine Rousse, Rahul Shah, Donald P. Umstadter, Alexander Puhkov, Sergei Kiselev

Donald Umstadter Publications

Beams of x rays in the kiloelectronvolt energy range have been produced from laser-matter interaction. Here, energetic electrons are accelerated by a laser wakefield, and experience betatron oscillations in an ion channel formed in the wake of the intense femtosecond laser pulse. Experiments using a 50 TW laser (30 fs duration) are described, as well as comparisons with numerical simulations. These results pave the way of a new generation of radiation in the x-ray spectral range, with a high collimation and an ultrafast pulse duration, produced by the use of compact laser system.

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Reinforcement Learning-Based Output Feedback Control Of Nonlinear Systems With Input Constraints, Pingan He, Jagannathan Sarangapani Feb 2005

Reinforcement Learning-Based Output Feedback Control Of Nonlinear Systems With Input Constraints, Pingan He, Jagannathan Sarangapani

Electrical and Computer Engineering Faculty Research & Creative Works

A novel neural network (NN) -based output feedback controller with magnitude constraints is designed to deliver a desired tracking performance for a class of multi-input-multi-output (MIMO) discrete-time strict feedback nonlinear systems. Reinforcement learning in discrete time is proposed for the output feedback controller, which uses three NN: 1) a NN observer to estimate the system states with the input-output data; 2) a critic NN to approximate certain strategic utility function; and 3) an action NN to minimize both the strategic utility function and the unknown dynamics estimation errors. The magnitude constraints are manifested as saturation nonlinearities in the output feedback …

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The Perpendicular Magnetic Anisotropy Of Copt/Au Multilayer Films, T. Yokota, Lei Gao, R. Zhang, Leighann Nicholl, M. L. Yan, David J. Sellmyer, Sy-Hwang Liou Feb 2005

The Perpendicular Magnetic Anisotropy Of Copt/Au Multilayer Films, T. Yokota, Lei Gao, R. Zhang, Leighann Nicholl, M. L. Yan, David J. Sellmyer, Sy-Hwang Liou

Sy-Hwang Liou Publications

We have studied the magnetic properties of Au (2 nm)/Co50Pt50 (3 nm)/Au (2 nm) multilayer films prepared on amorphous Al2O3/Si and (0 0 1) MgO substrates. The as-deposited films on both substrates are magnetically soft with an FCC structure and exhibit a perpendicular anisotropy. After annealing at 500 °C, the sample on the Al2O3/Si substrate has become magnetically isotropic but the sample on the MgO substrate still has perpendicular anisotropy with FCT structure. This film deposited on the MgO substrate did not show a strong perpendicular anisotropy due to …

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Impact Of Changes In Natural Uv Radiation On Pigment Composition, Physiological And Morphological Characteristics Of The Antarctic Moss, Grimmia Antarctici., Sharon A. Robinson, J. D. Turnbull, C. E. Lovelock Feb 2005

Impact Of Changes In Natural Uv Radiation On Pigment Composition, Physiological And Morphological Characteristics Of The Antarctic Moss, Grimmia Antarctici., Sharon A. Robinson, J. D. Turnbull, C. E. Lovelock

Faculty of Science - Papers (Archive)

The impact of ambient UV-B radiation on the endemic bryophyte, Grimmia antarctici, was studied over 14 months in East Antarctica. Over recent decades, Antarctic plants have been exposed to the largest relative increase in UV-B exposure as a result of ozone depletion. We investigated the effect of reduced UV and visible radiation on the pigment concentrations, surface reflectance and physiological and morphological parameters of this moss. Plexiglass screens were used to provide both reduced UV levels (77%) and a 50% decrease in total radiation. The screen combinations were used to separate UV photoprotective from visible photoprotective strategies, since these bryophytes …

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R120g Αb-Crystallin Promotes The Unfolding Of Reduced Α-Lactalbumin And Is Inherently Unstable., T. M. Treweek, A. Rekas, R. A. Lindner, Mark J. Walker, J. A. Aquilina, C. V. Robinson, J. Horwitz, M. Der Perng, R. A. Quinlan, J. A. Carver Feb 2005

R120g Αb-Crystallin Promotes The Unfolding Of Reduced Α-Lactalbumin And Is Inherently Unstable., T. M. Treweek, A. Rekas, R. A. Lindner, Mark J. Walker, J. A. Aquilina, C. V. Robinson, J. Horwitz, M. Der Perng, R. A. Quinlan, J. A. Carver

Faculty of Science - Papers (Archive)

α-Crystallin is the principal lens protein which, in addition to its structural role, also acts as a molecular chaperone, to prevent aggregation and precipitation of other lens proteins. One of its two subunits, αB-crystallin, is also expressed in many non-lenticular tissues, and a natural missense mutation, R120G, has been associated with cataract and desminrelated myopathy, a disorder of skeletal muscles (Vicart et al., 1998, Nature Genet. 20:92-95). In the present study, real-time 1H NMR spectroscopy showed that the ability of R120G αB-crystallin to stabilize the partially folded, molten globule state of α- lactalbumin was significantly reduced in comparison with wild …

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A Modular Integer Gcd Algorithm, Kenneth Weber, Vilmar Trevisan, Luiz Felipe Martins Feb 2005

A Modular Integer Gcd Algorithm, Kenneth Weber, Vilmar Trevisan, Luiz Felipe Martins

Mathematics and Statistics Faculty Publications

This paper describes the first algorithm to compute the greatest common divisor (GCD) of two n-bit integers using a modular representation for intermediate values U, V and also for the result. It is based on a reduction step, similar to one used in the accelerated algorithm [T. Jebelean, A generalization of the binary GCD algorithm, in: ISSAC '93: International Symposium on Symbolic and Algebraic Computation, Kiev, Ukraine, 1993, pp. 111–116; K. Weber, The accelerated integer GCD algorithm, ACM Trans. Math. Softw. 21 (1995) 111–122] when U and V are close to the same size, that replaces U by (U-bV)/p, where …

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Ecological Science And Sustainability For The 21st Century, Margaret A. Palmer, Emily S. Bernhardt, Elizabeth A. Chornesky, Scott L. Collins, Andrew P. Dobson, Clifford S. Duke, Barry D. Gold, Robert B. Jacobson, Sharon E. Kingsland, Rhonda H. Kranz, Michael J. Mappin, M. Luisa Martinez, Florenza Micheli, Jennifer L. Morse, Michael L. Pace, Mercedes Pascual, Stephen S. Palumbi, Oj Reichman, Alan R. Townsend, Monica G. Turner Feb 2005

Ecological Science And Sustainability For The 21st Century, Margaret A. Palmer, Emily S. Bernhardt, Elizabeth A. Chornesky, Scott L. Collins, Andrew P. Dobson, Clifford S. Duke, Barry D. Gold, Robert B. Jacobson, Sharon E. Kingsland, Rhonda H. Kranz, Michael J. Mappin, M. Luisa Martinez, Florenza Micheli, Jennifer L. Morse, Michael L. Pace, Mercedes Pascual, Stephen S. Palumbi, Oj Reichman, Alan R. Townsend, Monica G. Turner

Environmental Science and Management Faculty Publications and Presentations

Ecological science has contributed greatly to our understanding of the natural world and the impact of humans on that world. Now, we need to refocus the discipline towards research that ensures a future in which natural systems and the humans they include coexist on a more sustainable planet. Acknowledging that managed ecosystems and intensive exploitation of resources define our future, ecologists must play a greatly expanded role in communicating their research and influencing policy and decisions that affect the environment. To accomplish this, they will have to forge partnerships at scales and in forms they have not traditionally used. These …

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Hydroxy Double Salt Anion Exchange Kinetics: Effects Of Precursor Structure And Anion Size, Everson Kandare, Jeanne Hossenlopp Feb 2005

Hydroxy Double Salt Anion Exchange Kinetics: Effects Of Precursor Structure And Anion Size, Everson Kandare, Jeanne Hossenlopp

Chemistry Faculty Research and Publications

H NMR spectroscopy and powder X-ray diffraction have been used to explore the details of anion exchange reactions of two layered hydroxy double salts (HDSs), zinc copper hydroxy acetate (ZCA), nickel zinc hydroxy acetate (NZA), and a related layered material, zinc hydroxy acetate (ZHA), at room temperature (21−22 °C). Reactions that followed Avrami−Erofe'ev kinetics with respect to temporal profiles for acetate release, ZCA with butyrate (k = 1.7 × 10-3 s-1), and octanoate (k = 0.79 × 10-3 s-1) anions, as well as ZHA with octanoate (k = 2.6 × 10 …

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Sulfide Mineralization Within Modern, Deep-Sea Marine Sediments And Oxygenation Of The Early Earth, Matthew K. Thompson, Walter S. Borowski Feb 2005

Sulfide Mineralization Within Modern, Deep-Sea Marine Sediments And Oxygenation Of The Early Earth, Matthew K. Thompson, Walter S. Borowski

EKU Faculty and Staff Scholarship

The Earth’s atmosphere and oceans have not always been oxygenated. The exact pathway and timing of the oxygenation of the Earth’s early oceans is poorly constrained, although it appears that oxygenation was essentially complete by the beginning of the Cambrian (545 million years ago). Indeed, the appearance and diversification of the first animals may have been dependent on threshold levels of oxygen. Eventually we intend to use the sulfur isotopic composition of sulfide minerals (iron monosulfides and pyrite) present in sedimentary rocks to reconstruct the oxygenation of Proterozoic oceans, but first must strive to understand sulfide mineral formation in the …

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The Maastrichtian Record From Shatsky Rise (Northwest Pacific): A Tropical Perspective On Global Ecological And Oceanographic Changes, Tracy D. Frank, Deborah J. Thomas, R. Mark Leckie, Michael A. Arthur, Paul R. Brown, Kelly Jones, Jackie A. Lees Feb 2005

The Maastrichtian Record From Shatsky Rise (Northwest Pacific): A Tropical Perspective On Global Ecological And Oceanographic Changes, Tracy D. Frank, Deborah J. Thomas, R. Mark Leckie, Michael A. Arthur, Paul R. Brown, Kelly Jones, Jackie A. Lees

Department of Earth and Atmospheric Sciences: Faculty Publications

We present new isotopic and micropaleontological data from a depth transect on Shatsky Rise that record the response of the tropical Pacific to global biotic and oceanographic shifts during the mid-Maastrichtian. Results reveal a coupling between the upper ocean, characterized by a weak thermocline and low to intermediate productivity, and intermediate waters. During the earliest Maastrichtian, oxygen and neodymium isotope data suggest a significant contribution of relatively warm intermediate water from the North Pacific. Isotopic shifts through the early Maastrichtian suggest that this warmer water mass was gradually replaced by cooler waters originating in the Southern Ocean. Although the cooler …

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Southern Nevada Interagency Partnership & Interagency Volunteer Program, Public Lands Institute Feb 2005

Southern Nevada Interagency Partnership & Interagency Volunteer Program, Public Lands Institute

Get Outdoors Nevada

The Interagency Volunteer Program – with the coordination of a full-time project manager – expects to work collectively in recruiting, training, managing, supporting, recognizing, and promoting the long-term involvement of volunteers in Southern Nevada, which will result in increased conservation stewardship on these unique public lands.

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Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, S. Kolesnikov, E. Shwageraus, A. Galperin Feb 2005

Dissolution, Reactor, And Environmental Behavior Of Zro2-Mgo Inert Fuel Matrix: Neutronic Evaluation Of Zro2-Mgo Inert Fuels, E. Fridman, S. Kolesnikov, E. Shwageraus, A. Galperin

Fuels Campaign (TRP)

This report presents the results of the Task 3, defined in working program as: evaluation of burnable poison designs. Adopting the basic design of a standard PWR and Pu loadings required for 18-month cycle (results of Task 2), this part of the program is aimed to estimate performance of each BP design and BP material to address challenges of Fertile-Free Fuel (FFF) Concept. Finally, an optimal BP design will be developed and an overall feasibility of FFF concept will be determined. Basically, the main challenge encountered in neutronic design for a FFF core is to develop reactivity control system which …

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Wayne E. Sabbe Arkansas Soil Fertility Studies 2004, Nathan A. Slaton Feb 2005

Wayne E. Sabbe Arkansas Soil Fertility Studies 2004, Nathan A. Slaton

Arkansas Agricultural Experiment Station Research Series

Rapid technological changes in crop management and production require that the research efforts also be presented in an expeditious manner. The contributions of soil fertility and fertilizers are major production factors in all Arkansas crops. The studies described within will allow producers to compare their practices with the university’s research efforts. Additionally, soil test data and fertilizer sales are presented to allow comparisons among years, crops, and other areas within Arkansas.

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Ecological Analysis Of Nutrient, Plankton And Benthic Communities In Farmington Bay And The Great Salt Lake, Utah (2004), Amy M. Marcarelli, Wayne A. Wurtsbaugh Feb 2005

Ecological Analysis Of Nutrient, Plankton And Benthic Communities In Farmington Bay And The Great Salt Lake, Utah (2004), Amy M. Marcarelli, Wayne A. Wurtsbaugh

Watershed Sciences Faculty Publications

In Fall 2004, the Aquatic Ecology Practicum class at Utah State University finished a third year of research on limnological and ecological characteristics of Farmington Bay and Gilbert Bays of the Great Salt Lake. Our previous research has produced interesting findings in Farmington Bay, including hypereutrophy (Marcarelli et a!. 2001), high phosphorus loading into the Bay, overnight water column anoxia linked to high winds (Wurtsbaugh et a!. 2002), potential predator control of brine shrimp, and high levels of hydrogen sulfide in the sediment and deep brine layer (Marcarelli et a!. 2003). These class findings have lead to increased interest in …

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Strong Electric Fields From Positive Lightning Strokes In The Stratosphere, R. H. Holzworth, M. C. Mccarthy, J. N. Thomas, J. Chin, T. M. Chinowsky, Michael J. Taylor, O. Pinto Jr. Feb 2005

Strong Electric Fields From Positive Lightning Strokes In The Stratosphere, R. H. Holzworth, M. C. Mccarthy, J. N. Thomas, J. Chin, T. M. Chinowsky, Michael J. Taylor, O. Pinto Jr.

All Physics Faculty Publications

A balloon payload launched in Brazil has measured vector electric fields from lightning at least an order of magnitude larger than previously reported above 30 km in the stratosphere. During the flight hundreds of lightning events were recorded, including several positive cloud to ground lightning strokes. A two stroke flash, with small (15 kA peak current) and moderate (53 kA) positive strokes at a horizontal range of 34 km, produced field changes over 140 V/m at 34 km altitude. On-board optical lightning detection, recorded with GPS timing, coupled with ground based lightning location gives high time resolution for study of …

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Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 5, February 2005, College Of Engineering And Computer Science, Wright State University Feb 2005

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 21, Number 5, February 2005, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A six page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

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A New Blind Method For Detecting Novel Steganography, Brent T. Mcbride, Gilbert L. Peterson, Steven C. Gustafson Feb 2005

A New Blind Method For Detecting Novel Steganography, Brent T. Mcbride, Gilbert L. Peterson, Steven C. Gustafson

Faculty Publications

Steganography is the art of hiding a message in plain sight. Modern steganographic tools that conceal data in innocuous-looking digital image files are widely available. The use of such tools by terrorists, hostile states, criminal organizations, etc., to camouflage the planning and coordination of their illicit activities poses a serious challenge. Most steganography detection tools rely on signatures that describe particular steganography programs. Signature-based classifiers offer strong detection capabilities against known threats, but they suffer from an inability to detect previously unseen forms of steganography. Novel steganography detection requires an anomaly-based classifier. This paper describes and demonstrates a blind classification …

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Graphs Whose Minimal Rank Is Two: The Finite Fields Case, Wayne Barrett, Hein Van Der Holst, Raphael Loewy Feb 2005

Graphs Whose Minimal Rank Is Two: The Finite Fields Case, Wayne Barrett, Hein Van Der Holst, Raphael Loewy

Faculty Publications

Let F be a finite field, G = (V,E) be an undirected graph on n vertices, and let S(F,G) be the set of all symmetric n × n matrices over F whose nonzero off-diagonal entries occur in exactly the positions corresponding to the edges of G. Let mr(F,G) be the minimum rank of all matrices in S(F,G). If F is a finite field with p^t elements, p does not = 2, it is shown that mr(F,G) ≤ 2 if and only if the complement of G is the join of a complete graph with either the union of at most …

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Transient Response Of Arrow Vcsels, Chyng Wen Tee, S. F. Yu, R. V. Penty, I. H. White Feb 2005

Transient Response Of Arrow Vcsels, Chyng Wen Tee, S. F. Yu, R. V. Penty, I. H. White

Research Collection Lee Kong Chian School Of Business

The transient response of antiresonant reflecting optical waveguide (ARROW) vertical-cavity surface-emitting lasers (VCSELs) is analyzed. It is found that under current modulation, the radiation loss of the transverse-leaky mode decreases during the state of the lasers but increases during the state. Numerical analysis shows that this variation in radiation loss is due to the carrier-induced refractive-index depression that arises from spatial-hole-burning of carrier concentration. It is noted that the increment in radiation loss during the state can be used to prevent net modal gain of the transverse-leaky mode from reacquiring threshold after turn-off. Hence, a new method to design ARROW, …

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