Physical Sciences and Mathematics Commons^™

Monotone Solutions Of A Nonautonomous Differential Equation For A Sedimenting Sphere, Andrew Belmonte, Jon T. Jacobsen, Anandhan Jayaraman

All HMC Faculty Publications and Research

We study a class of integrodifferential equations and related ordinary differential equations for the initial value problem of a rigid sphere falling through an infinite fluid medium. We prove that for creeping Newtonian flow, the motion of the sphere is monotone in its approach to the steady state solution given by the Stokes drag. We discuss this property in terms of a general nonautonomous second order differential equation, focusing on a decaying nonautonomous term motivated by the sedimenting sphere problem

Strike One—You’Re Out! Wildlife Services Helps Reduce Wildlife Conflicts At Airports

Other Bird Strike and Aviation Materials

Collisions between aircraft and wildlife at airports have risen dramatically in recent years as a result of large population increases in many wildlife species, faster airplanes, and the increase in air transportation traffic. Every year between 1991 and 1997, wildlife strikes cost U.S. civil aviation more than $300 million and 500,000 hours of aircraft downtime. About 2,400 bird strikes to civil aircraft are reported each year, and more than 2,500 are reported by the U.S. Air Force. Since 1990, more than 300 deer collisions with aircraft have been reported to the Federal Aviation Administration (FAA).

Collision-Induced Electronic Energy Transfer From V=0 Of The E(0g+) Ion-Pair State In I2: Collisions With I2(X), Christopher J. Fecko , '98, Miriam Arak Freedman , '00, Thomas Alex Stephenson

Chemistry & Biochemistry Faculty Works

The collision-induced electronic energy transfer that occurs when I-2 in the E(0(g)(+)) ion-pair electronic state collides with ground electronic state I-2 has been investigated. We prepare I-2 in single rotational levels in v = 0 of the E state using two-color double resonance laser excitation. The resulting emission spectrum shows that the nearby (DeltaT(e) = -385 cm(-1)) D(0(u)(+)) electronic state is populated. The cross section for collision-induced E -->D energy transfer is found to be IS - 3 Angstrom (2). A range of D state vibrational levels are populated, consistent with a model in which overlap between the initial …

Development Of A Large-Scale Laboratory Facility For Sediment Transport Research, David G. Hamilton, Bruce A. Ebersole, Ernest R. Smith, Ping Wang

Geology Faculty Publications

No abstract provided.

Detecting Steganographic Messages In Digital Images, Hany Farid

Computer Science Technical Reports

Techniques and applications for information hiding have become increasingly more sophisticated and widespread. With high-resolution digital images as carriers, detecting the presence of hidden messages has also become considerably more difficult. It is sometimes possible, nevertheless, to detect (but not necessarily decipher) the presence of embedded messages. The basic approach taken here works by finding predictable higher-order statistics of ``natural'' images within a multi-scale decomposition, and then showing that embedded messages alter these statistics.

Differential Elastic Image Registration, Senthil Periaswamy, Hany Farid

Computer Science Technical Reports

We have applied techniques from differential motion estimation to the problem of automatic elastic registration of medical images. This method models the mapping between images as a locally affine but globally smooth warp. The mapping also explicitly accounts for variations in image intensities. This approach is simple and highly effective across a broad range of medical images. We show the efficacy of this approach on several synthetic and clinical images.

Sistem Perancangan Akademik (Spa), Maideen Nordiana

Student Works (2000-2009)

Sistem Perancangan Akademik dibangunkan untuk membantu para pelajar dan penasihat akademik dalam mendapatkan maklumat berkaitan kursus-kursus pengajian, keputusan peperiksaan dan analisis perancangan akademik pelajar secara atas talian. Sistem ini juga membantu pentadbir dalam menyimpan dan menyebarkan maklumat dengan menggunakan teknologi Web sepenuhnya. Sistem ini membenarkan pencapaian maklumat menerusi Internet dengan menggunakan komputer peribadi. Disamping itu, sistem dilengkapi dengan kebolehan untuk memberi cadangan senarai kursus pendaftaran oleh seseorang pelajar berdasarkan Pungutan Nilai Kumulatif Keseluruhan (PNGK) terbaru mereka, prasyarat-prasyarat kursus dan senarai kursus yang ditawarkan pada semester tersebut. Laporan ini dimulakan dengan bahagian pengenalan di Bab 1. Bab I menerangkan definisi dan …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 18, Number 1, September 2001, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

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

Dynamical Relativistic Effects In Photoionization: Spin-Orbit-Resolved Angular Distributions Of Xenon 4d Photoelectrons Near The Cooper Minimum, H. Wang, G. Snell, Oliver Hemmers, M. M. Sant'anna, I. A. Sellin, N. Berrah, Dennis W. Lindle, P. C. Deshmukh, N. Haque, S. T. Manson

Environmental Studies Faculty Publications

Two decades ago, it was predicted [Y. S. Kim et al., Phys. Rev. Lett. 46, 1326 (1981)] that relativistic effects should alter the dynamics of the photoionization process in the vicinity of Cooper minima. The present experimental and theoretical study of the angular distributions of Xe 4d_3/2 and 4d_5/2 photoelectrons demonstrates this effect for the first time. The results clearly imply that relativistic effects are likely to be important for intermediate- Z atoms at most energies.

Environment-Induced Degradation And Crack-Growth Studies Of Candidate Target Materials: Aaa Task-4 Quarterly (June 1 – August 31, 2001) Report, Ajit K. Roy, Brendan O'Toole

Transmutation Sciences Materials (TRP)

The subject task entitled “Hydrogen-Induced Embrittlement of Candidate Target Materials for Applications in Spallation-Neutron-Target Systems” had commenced during the quarter ending on August 31, 2001. A research account has been established, contracts for both faculty and students have been prepared, and efforts are well underway to embark on the related research activities, as proposed.

As the title of this project implies, the primary objective of this task is to evaluate the effect of hydrogen on environment-assisted cracking of candidate materials for applications in spallationneutron- target (SNT) systems such as accelerator production of tritium (APT) and accelerator transmutation of waste (ATW). …

Carbon Dynamics In Peat Bogs: Insights From Substrate Macromolecular Chemistry, Kuder Tomasz, Michael A. Kruge

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The macromolecular compositions of subfossil plants from boreal Sphagnum bogs and restiad bogs (New Zealand) have been studied by pyrolysis-gas chromatography/mass spectrometry to evaluate the extent of degradation in the anoxic zone (catotelm) of a peat bog. Degradation of vascular plant polysaccharides was apparent only into the upper catotelm. Sphagnum was degraded more slowly than vascular plants, but no cessation of degradation was observed. The inferred rate of degradation varied depending on type of plant, extent of aerobic, precatotelmic degradation, and mode of litter deposition (rooting versus at the surface). Environmental forcing on anaerobic carbon dynamics would potentially be largest …

Progressive Transmission Of Spatial Data Over The Www: Challenges, James Carswell

Conference papers

Progressive transmission of raster images over the WWW has been successfully applied to provide users with coarser versions of the data before downloading a complete image. In the vector domain, progressive transmission remains a challenging topic. Increasing the level of detail of a vector dataset is a complex process that does not simply imply adding pixels to it. In this paper we present a survey of existing models for progressive transmission of spatial data and discuss open problems and challenges related to the progressive transmission of geographic maps in vector format. Finally, we propose a model based on a client-server …

Improving Cluster Utilization Through Set Based Allocation Policies, Quinn O. Snell, Julio C. Facelli, Brian D. Haymore, David B. Jackson

Faculty Publications

While clusters have already proven themselves in the world of high performance computing, some clusters are beginning to exhibit resource inefficiencies due to increasing hardware diversity. Much of the success of clusters lies in the use of commodity components built to meet various hardware standards. These standards have allowed a great level of hardware backwards compatibility that is now resulting in a condition referred to as hardware 'drift' or heterogeneity. The hardware heterogeneity introduces problems when diverse compute nodes are allocated to a parallel job, as most parallel jobs are not self-balancing. This paper presents a new method that allows …

Exploiting Image Indexing Techniques In Dct Domain, Chong-Wah Ngo, Ting-Chuen Pong, Ronald T. Chin

Research Collection School Of Computing and Information Systems

This paper is concerned with the indexing and retrieval of images based on features extracted directly from the JPEG discrete cosine transform (DCT) domain. We examine possible ways of manipulating DCT coefficients by standard image analysis approaches to describe image shape, texture, and color. Through the Mandala transformation, our approach groups a subset of DCT coefficients to form ten blocks. Each block represents a particular frequency content of the original image. Two blocks are used to model rough object shape; nine blocks to describe subband properties; and one block to compute color distribution. As a result, the amount of data …

Ultraconvergence Of Zz Patch Recovery At Mesh Symmetry Points, Zhimin Zhang, Runchang Lin

Mathematics Research Reports

Ultraconvergence property of the Zienkiewicz-Zhu gradient patch recovery technique based on local discrete least squares fitting is established for a large class of even-order finite elements. The result is valid at all rectangular mesh symmetry points. Different smoothing strategies are discussed. Superconvergence recovery for the Q8 element is proved and ultraconvergence numerical examples are demonstrated.

Theater-Level Stochastic Air-To-Air Engagement Modeling Via Event Occurrence Networks Using Piecewise Polynomial Approximation, David R. Denhard

Theses and Dissertations

This dissertation investigates a stochastic network formulation termed an event occurrence network (EON). EONs are graphical representations of the superposition of several terminating counting processes. An EON arc represents the occurrence of an event from a group of (sequential) events before the occurrence of events from other event groupings. Events between groups occur independently, but events within a group occur sequentially. A set of arcs leaving a node is a set of competing events, which are probabilistically resolved by order relations. An important EON metric is the probability of being at a particular node or set of nodes at time …

Analysis And Numerical Solution Of An Integral Equation Method For Electromagnetic Scattering From A Cavity In A Ground Plane, Eric T. Howe

Theses and Dissertations

In this research the electromagnetic scattering of a plane wave from a two-dimensional cavity embedded in an infinite, perfectly conducting ground plane is investigated. The plane wave is assumed to be under transverse electric (TE) polarization with respect to the x-axis. The cavity may be empty or filled with an arbitrary homogeneous, lossy material. A coupled set of scalar integral equations that govern the electromagnetic scattering is implemented. An approximate solution to the scalar integral equations is found via a Method of Moments (MoM) algorithm. The algorithm is implemented in a computer code, and approximations to the total magnetic field …

Composition Operators And A Pull-Back Measure Formula, Valentin Matache

Mathematics Faculty Publications

A pull-back measure formula obtained in some particular cases by E. A. Nordgren and this author is generalized in the framework of boundary measures for zero-free Nevanlinna class fuctions on the unit polydisk. The formula is used to characterize the zero-free Nevanlinna class functions which are solutions of Schröder's equation induced by a polydisk automorphism ϕ (i.e. to determine the zero-free functionsf belonging to the Nevanlinna class which are solutions of the functional equationf ° π=λf, for some constant λ), thus generalizing earlier results obtained by R. Mortini and this author.

Online Bayesian Tree-Structured Transformation Of Hmms With Optimal Model Selection For Speaker Adaptation, Shaojun Wang, Yunxin Zhao

Kno.e.sis Publications

This paper presents a new recursive Bayesian learning approach for transformation parameter estimation in speaker adaptation. Our goal is to incrementally transform or adapt a set of hidden Markov model (HMM) parameters for a new speaker and gain large performance improvement from a small amount of adaptation data. By constructing a clustering tree of HMM Gaussian mixture components, the linear regression (LR) or affine transformation parameters for HMM Gaussian mixture components are dynamically searched. An online Bayesian learning technique is proposed for recursive maximum a posteriori (MAP) estimation of LR and affine transformation parameters. This technique has the advantages of …

Determining Matric Stress With The Modified Cam Clay Energy Relationship, Richard A. Rohlf, Larry G. Wells

Biosystems and Agricultural Engineering Faculty Publications

The stress generated by matric suction, or matric stress, was determined at points along the stress path with an analytical and experimental procedure based on the modified Cam clay energy relationship. Matric stress was found to be approximately constant at large strain for constant water content triaxial compression tests. Matric stress was included in both shear and volume relationships in a critical–state soil model that employed the modified Cam clay yield function. Shear was modeled with a constant matric stress. Slope of the normal compression and recompression lines was adjusted for matric stress using a state function that expressed matric …

Dirt Road Corrugations, Temple H. Fay, Keith A. Hardie, Stephan V. Joubert

Faculty Publications

WE CONSIDER FACTORS INFLUENCING the build-up of corrugations on dirt roads and the reactions of vehicles to them. We suggest that corrugations are (at least in part) a consequence of a natural tangential oscillation of the tread surface of the car lure that occurs when the vehicle is being driven or braked. Secondly, we suggest that the unpleasant vibration experienced by a vehicle passing over a corrugated road is the result of a beat produced by the difference of the frequency of oscillation of its own tyres and the frequency of the stimulation received by the vehicle due to passage …

Quantile Regression, Kevin F. Hallock, Roger Koenker

Economics Faculty Publications

Quantile regression as introduced by Koenker and Bassett seeks to extend ideas of quantiles to the estimation of conditional quantile functions--models in which quantiles of the conditional distribution of the response variable are expressed as functions of observed covariates.

Present Day Kinematics Of The Eastern California Shear Zone From A Geodetically Constrained Block Model, S. C. Mcclusky, S. C. Bjornstad, B. H. Hager, R. W. King, B. J. Meade, M. Meghan Miller, F. C. Monastero, B. J. Souter

All Faculty Scholarship for the College of the Sciences

We use Global Positioning System (GPS) data from 1993–2000 to determine horizontal velocities of 65 stations in eastern California and western Nevada between 35° and 37° N. We relate the geodetic velocities to fault slip rates using a block model that enforces path integral constraints over geologic and geodetic time scales and that includes the effects of elastic strain accumulation on faults locked to a depth of 15 km. The velocity of the Sierra Nevada block with respect to Nevada is 11.1±0.3 mm/yr, with slip partitioned across the Death Valley, (2.8±0.5 mm/yr), Panamint Valley (2.5±0.8 mm/yr), and Airport Lake/Owens Valley …

African Black Beetle In Vineyards, Diana Fisher, Stewart Learmonth

Bulletins 4000 -

The African black beetle, Heteronychus arator, is an important pest of horticultural crops, ornamentals and pastures in Western Australia. They also attack lawns and are commonly referred to as the black lawn beetle. This beetle was first recorded in Australia during the 1920s and originates from southern Africa where it is a major establishment pest of maize.

Thermal Activation Between Landau Levels In The Organic Superconductor Β″-(Bedt-Ttf)2sf5ch2cf2so3, Gary L. Gard, M. S. Nam, A. Ardavan, J. A. Symington, J. Singleton, N. Harrison, C. H. Mielke, J. A. Schlueter, Rolf Walter Winter

Chemistry Faculty Publications and Presentations

We show that Shubnikov–de Haas oscillations in the interlayer resistivity of the organic superconductor β″-(BEDT-TTF)₂SF₅CH₂CF₂SO₃ become very pronounced in magnetic fields ~60T. The conductivity minima exhibit thermally activated behavior that can be explained simply by the presence of a Landau gap, with the quasi-one-dimensional Fermi surface sheets contributing negligibly to the conductivity. This observation, together with complete suppression of chemical potential oscillations, is consistent with an incommensurate nesting instability of the quasi-one-dimensional sheets.

Dynamics Of The "Pgmcc" Multicast Congestion Control Protocol, Chin-Ying Wang, Sonia Fahmy

Department of Computer Science Technical Reports

No abstract provided.

Intelligent Grouping Of Tcp Flows For Coordinated Congestion Management, Hoi Chang, Rajeev Gopalakrishna, Venkatesh Prabhakar

Department of Computer Science Technical Reports

No abstract provided.

Tcp Congestion Control: Overview And Survey Of Ongoing Research, Sonia Fahmy, Tapan Prem Karwa

Department of Computer Science Technical Reports

No abstract provided.

The Blazhko Effect Of The Rr Lyrae Star Dr Andromedae, Kevin M. Lee, Edward G. Schmidt

Edward Schmidt Publications

We have obtained 551 new V and R observations of the RR Lyrae star DR Andromedae. Our data set is consistent with a primary period of 0.563118 days; however, the light curve of DR And cannot be well described by a single period. We conclude that DR And demonstrates the Blazhko effect with a Blazhko period of approximately 57.5 days.

Revegetation Information And Training Needs Of Western Australia's Extension Intermediaries : A Qualitative And Quantitative Market Research Report, Stephen Lloyd

Agriculture reports

Report on a survey conducted in 2001 for the Department of Agriculture Western Australia's Farm Forestry and Revegetation (FF&R) Project, of 'Intermediaries', that is, those persons who mediate between those with expertise in revegetation and those who require the information. The survey was instigated in order to improve the flow, quality and utility of information as required by intermediaries, and to identify further training needs.