Digital Commons Network^™

Modeling The Incubation Period Of Anthrax, Ron Brookmeyer, Elizabeth Johnson, Sarah Barry

Ron Brookmeyer

Models of the incubation period of anthrax are important to public health planners because they can be used to predict the delay before outbreaks are detected, the size of an outbreak and the duration of time that persons should remain on antibiotics to prevent disease. The difficulty is that there is little direct data about the incubation period in humans. The objective of this paper is to develop and apply models for the incubation period of anthrax. Mechanistic models that account for the biology of spore clearance and germination are developed based on a competing risks formulation. The models predict …

Coefficient Of Bohm Diffusion In Fully Ionized Plasma And Its Theoretical Proof, Ahmad Talaei, Reza Amrollahi

Ahmad Talaei

A Note On Empirical Likelihood Inference Of Residual Life Regression, Ying Qing Chen, Yichuan Zhao

Yichuan Zhao

Mean residual life function, or life expectancy, is an important function to characterize distribution of residual life. The proportional mean residual life model by Oakes and Dasu (1990) is a regression tool to study the association between life expectancy and its associated covariates. Although semiparametric inference procedures have been proposed in the literature, the accuracy of such procedures may be low when the censoring proportion is relatively large. In this paper, the semiparametric inference procedures are studied with an empirical likelihood ratio method. An empirical likelihood confidence region is constructed for the regression parameters. The proposed method is further compared …

Guiding Of Laser Beams In Plasmas By Radiation Cascade Compression, Serguei Y. Kalmykov, Gennady Shvets

Serge Youri Kalmykov

The near-resonant beatwave excitation of an electron plasma wave (EPW) can be employed for generating trains of few-fs electromagnetic pulses in rarefied plasmas. The EPW produces a co-moving index grating that induces a laser phase modulation at the beat frequency. Consequently, the cascade of sidebands red- and blue-shifted from the fundamental by integer multiples of the beat frequency is generated in the laser spectrum. When the beat frequency is lower than the electron plasma frequency, the phase chirp enables laser beatnote compression by the group velocity dispersion [S. Kalmykov and G. Shvets, Phys. Rev. E 73, 46403 (2006)]. In the …

Modeling An Outbreak Of Anthrax, Ron Brookmeyer

Ron Brookmeyer

Introduction

On October 2, 2001 a sixty-three-year-old Florida man who worked as a photo editor at a media publishing company was admitted to an emergency department complaining of nausea, vomiting, and fever. His symptoms began four days earlier on a recreational trip to North Carolina. The man died shortly thereafter. An astute clinician quickly made the surprising diagnosis of inhalational anthrax, which is a serious and deadly disease. The diagnosis was surprising because inhalational anthrax is extremely rare; only 18 cases were reported in the United States between 1900 and 1978. Public health officials at first believed that the Florida …

Optimizing The Expected Overlap Of Survey Samples Via The Northwest Corner Rule, Lenka Mach, Philip T. Reiss, Ioana Schiopu-Kratina

Philip T. Reiss

In survey sampling there is often a need to coordinate the selection of pairs of samples drawn from two overlapping populations so as to maximize or minimize their expected overlap, subject to constraints on the marginal probabilities determined by the respective designs. For instance, maximizing the expected overlap between repeated samples can stabilize the resulting estimates of change and reduce the costs of first contacts; minimizing the expected overlap can avoid overburdening respondents with multiple surveys. We focus on the important special case in which both samples are selected by simple random sampling without replacement (SRSWOR) conducted independently within each …

A Content-Driven Reputation System For The Wikipedia, B. Thomas Adler, Luca De Alfaro

Luca de Alfaro

On-line forums for the collaborative creation of bodies of information are a phenomenon of rising importance; the Wikipedia is one of the best-known examples. The open nature of such forums could benefit from a notion of reputation for its authors. Author reputation could be used to flag new contributions from low-reputation authors, and it could be used to allow only authors with good reputation to contribute to controversial or critical pages. A reputation system for the Wikipedia would also provide an incentive to give high-quality contributions.

We present in this paper a novel type of content-driven reputation system for Wikipedia …

Injection, Trapping, And Acceleration Of Electrons In A Three-Dimensional Nonlinear Laser Wakefield, Serguei Y. Kalmykov, Leonid M. Gorbunov, Patrick Mora, Gennady Shvets

Serge Youri Kalmykov

It is demonstrated that the accelerating and focusing phases of the nonlinear three-dimensional axisymmetric laser wake can almost entirely overlap starting from a certain distance behind the laser pulse in homogeneous plasma. Such field structure results from the curvature of phase fronts due to the radially inhomogeneous relativistic shift of plasma frequency. Consequently, the number of trapped low-energy electrons can be much greater than that predicted by the linear wake theory. This effect is favorable for quasi-monoenergetic acceleration of a considerable charge (several hundreds of pC) to about 1 GeV per electron in the plasma wakefield driven by an ultrashort …

Snapshots Of Laser Wakefields, Nicholas H. Matlis, Steven A. Reed, Stepan S. Bulanov, Vladimir Chvykov, Galina Kalintchenko, Takeshi Matsuoka, Pascal Rousseau, Victor Yanovsky, Anatoly Maksimchuk, Serguei Y. Kalmykov, Gennady Shvets, Michael C. Downer

Serge Youri Kalmykov

Tabletop plasma accelerators can now produce GeV-range electron beams and femtosecond X-ray pulses, providing compact radiation sources for medicine, nuclear engineering, materials science and high-energy physics. In these accelerators, electrons surf on electric fields exceeding 100 GeV m^{−1}, which is more than 1,000 times stronger than achievable in conventional accelerators. These fields are generated within plasma structures (such as Langmuir waves or electron density ‘bubbles’) propagating near light speed behind laser or charged-particle driving pulses. Here, we demonstrate single-shot visualization of laser-wakefield accelerator structures for the first time. Our ‘snapshots’ capture the evolution of multiple wake periods, detect structure variations …

Use Of Unbiased Estimating Equations To Estimate Correlation In Generalized Estimating Equation Analysis Of Longitudinal Trials, Wenguang Sun, Justine Shults, Mary Leonard

Justine Shults

In a recent publication, Wang and Carey (Journal of the American Statistical Association, 99, pp. 845-853, 2004) presented a new approach for estimation of the correlation parameters in the framework of generalized estimating equations (GEE). They considered correlated continuous, binary and count data with a generalized Markov correlation structure that includes the first-order autoregressive AR(1) and Markov structures as special cases. They made detailed comparisons with pseudo-likelihood (PL) and the first stage of quasi-least squares (QLS), a two-stage approach in the framework of generalized estimating equations (GEE). In this note we extend their comparisons for the second (bias corrected) stage …

Censored Data Regression In High-Dimension And Low-Sample Size Settings For Genomic Applications, Hongzhe Li

Hongzhe Li

New high-throughput technologies are generating various types of high-dimensional genomic and proteomic data and meta-data (e.g., networks and pathways) in order to obtain a systems-level understanding of various complex diseases such as human cancers and cardiovascular diseases. As the amount and complexity of the data increase and as the questions being addressed become more sophisticated, we face the great challenge of how to model such data in order to draw valid statistical and biological conclusions. One important problem in genomic research is to relate these high-throughput genomic data to various clinical outcomes, including possibly censored survival outcomes such as age …

Creating Custom Containers With Generative Techniques, Gabriel A. Moreno

Gabriel A. Moreno

Component containers are a key part of mainstream component technologies, and play an important role in separating nonfunctional concerns from the core component logic. This paper addresses two different aspects of containers. First, it shows how generative programming techniques, using AspectC++ and metaprogramming, can be used to generate stubs and skeletons without the need for special compilers or interface description languages. Second, the paper describes an approach to create custom containers by composing different non-functional features. Unlike component technologies such as EJB, which only support a predefined set of container types, this approach allows different combinations of non-functional features to …

What Users Say They Want In Documentation, David G. Novick, Karen Ward

David G. Novick

While earlier work provided a partial view of users’ preferences about manuals, for most users in most work contexts the important question remains open: What do users want in documentation? This paper presents the results of a study in which a diverse cross-section of 25 users was interviewed in depth about their needs and preferences with respect to software help systems, whether printed or on-line, that they use at work. The study’s participants indicated that they preferred documentation, whether online or printed, that is easy to navigate, provides explanations at an appropriate level of technical detail, enables finding as well …

Magnifying-Lens Abstraction For Markov Decision Processes, Luca De Alfaro, Pritam Roy

Luca de Alfaro

We present a novel abstraction technique which allows the analysis of reachability and safety properties of Markov decision processes with very large state spaces. The technique, called magnifying-lens abstraction, copes with the state-explosion problem by partitioning the state-space into regions, and by computing upper and lower bounds for reachability and safety properties on the regions, rather than on the states. To compute these bounds, magnifying-lens abstraction iterates over the regions, considering the concrete states of each region in turn, as if one were sliding across the abstraction a magnifying lens which allowed viewing the concrete states. The algorithm adaptively refines …

Emisja Zanieczyszczeń Powietrza Z Procesu Grafityzacji Wyrobów Drobnych, Marian Mazur, Robert Oleniacz, Marek Bogacki, Przemysław Szczygłowski

Robert Oleniacz

The paper presents the research results of the air pollutant emissions from the graphitising process of fine carbon products in the Acheson furnace (discharge capacity 5,5 Mg). Research was performed for two kinds of raw material inputs (based on petroleum coke and pitch coke). Approximately 40-hours measurement series were carried out for each material including mainly such substances like carbon monoxide, hydrocarbons, nitrogen oxides, sulphur dioxide, hydrogen sulphide, carbon disulphide, ammonia, benzene, toluene, xylenes, total dust, tar substances and polycyclic aromatic hydrocarbons. Both average and maximum concentrations and mass streams in the flue gases and average emission factors were presented …

Sequences, Series, And Function Approximation, Lawrence Stout

Lawrence N. Stout

Sequences are important in approximation: the usual representation of real numbers using decimals is in fact the process of giving a sequence of rational numbers approximation the real number in question successively better as more decimal places are given. These decimal approximation sequences are actually rather special: successive decimal approximations never get smaller (so the sequence is monotone nondecreasing) and two approximations which agree to the kth decimal place differ by at most 10-k (so the sequence is a Cauchy sequence: to make two values in the sequence close to each other all you need to do is take them …

Reflections On Wallace, Charles H. Smith

Charles Kay Smith

The Localized Dynamics Of A Ca2+Channel (30-Minute Talk), Borbala Mazzag, Christoper Tignanelli, Gregory D. Smith

Borbala Mazzag

No abstract provided.

The Karst Of West-Central Florida, Lee J. Florea

Lee J Florea, PhD, P.G.

Caves, the cornerstone feature of karst aquifers, are little understood in Florida. This dissertation, which analyzes the morphology, elevation, lithologic setting, and hydrology of caves in west-central Florida, demonstrates that the karst of the unconfined Floridan aquifer differs from the paradigm view of karst presented in modern geology textbooks. The differences reflect setting: eogenetic (west-central Florida) vs. telogenetic (conventional).

Models Of Forbidden Line Emission Profiles From Axisymmetric Stellar Winds., R. Ignace, A. Brimeyer

Richard Ignace

A number of strong infrared forbidden lines have been observed in several evolved Wolf–Rayet (WR) star winds, and these are important for deriving metal abundances and testing stellar evolution models. In addition, because these optically thin lines form at large radius in the wind, their resolved profiles carry an imprint of the asymptotic structure of the wind flow. This work presents model forbidden line profile shapes formed in axisymmetric winds. It is well known that an optically thin emission line formed in a spherical wind expanding at constant velocity yields a flat-topped emission profile shape. Simulated forbidden lines are produced …

The Structure And Thermochemistry Of 3:4,5:6-Dibenzo-2-Hydroxymethylene-Cyclohepta-3,5-Dienenone ( 1 ) And Some Related Compounds, Stefan Perişanu, Iulia Contineanu, Mircea D. Banciu, Hui Zhao, Nigam Rath, James Chickos

James Chickos

No abstract provided.

An Open Framework Supporting Multimedia Web Services, Jia Zhang, Jen-Yao Chung

Jia Zhang

No abstract provided.

Cryptogram Decoding For Optical Character Recognition, Gary Huang, Erik G. Learned-Miller, Andrew Mccallum

Erik G Learned-Miller

OCR systems for printed documents typically require large numbers of font styles and character models to work well. When given an unseen font, performance degrades even in the absence of noise. In this paper, we perform OCR in an unsupervised fashion without using any character models by using a cryptogram decoding algorithm. We present results on real and artificial OCR data.

The Umass Mobile Manipulator Uman: An Experimental Platform For Autonomous Mobile Manipulation, Dov Katz, Emily Horrell, Yuandong Yang, Brendan Burns, Thomas Buckley, Anna Grishkan, Volodymyr Zhylkovskyy, Oliver Brock, Erik G. Learned-Miller

Erik G Learned-Miller

Object identification is the task of identifying specific objects belonging to the same class such as cars. We often need to recognize an object that we have only seen a few times. In fact, we often observe only one example of a particular object before we need to recognize it again. Thus we are interested in building a system which can learn to extract distinctive markers from a single example and which can then be used to identify the object in another image as “same ” or “different”. Previous work by Ferencz et al. introduced the notion of hyper-features, which …

Selective Light-Induced Desorption: The Mechanism Of Photoalignment Of Liquid Crystals At Adsorbing Solid Surfaces, V. G. Nazarenko, O. P. Boiko, A. B. Nych, Yu. A. Nastishin, V. M. Pergamenshchik, Philip J. Bos

Philip J. Bos

We demonstrate experimentally that bare solid surfaces with adsorbed organic molecules can orient liquid crystals after UV light irradiation. The detailed structure and behavior of the surface-adsorbed molecules are not important to the effect: just their UV light absorption should depend on their orientation. The only requirement to the solid substrates is their transparency to the UV light. The universal reason for the photoinduced anisotropy in such systems is that photons clean from the surface those molecules that absorb them most intensively. This is a kind of light rubbing resulting in the anisotropic ablation of the adsorbed material.

Bi-Level Clustering Of Mixed Categorical And Numerical Biomedical Data, Bill Andreopoulos, Aijun An, Xiaogang Wang

William B. Andreopoulos

Economics Of Information Security Investment In The Case Of Simultaneous Attacks, C. Derrick Huang, Qing Hu, Ravi S. Behara

Qing Hu

With billions of dollars being spent on information security related products and services each year, the economics of information security investment has become an important area of research, with significant implications for management practices. Drawing on recent studies that examine optimal security investment levels under various attack scenarios, we propose an economic model that considers simultaneous attacks from multiple external agents with distinct characteristics, and derive optimal investments based on the principle of benefit maximization. The relationships among the major variables, such as systems vulnerability, security breach probability, potential loss of security breach, and security investment levels, are investigated via …

Pomiary Wielkości Cząstek W Powietrzu W Czasie Rzeczywistym, Marek Bogacki, Robert Oleniacz, Marian Mazur, Stanisław Kamiński

Robert Oleniacz

The paper presents the new method for measurements of air particulate size distribution in real time using Kamika Infrared Particulate Sizer type P (IPS-P) with isokinetic air sampler. The device makes it possible to classify (sort) air particulates according to size into 256 granularity classes from about 0.4 µm up to 300 µm. Tests of the IPS-P prototype were conducted in Warsaw at the turn of 2005/2006 and some measurement results were presented in the work.

English title: Measurements of the particulate size distribution in the air in real-time.

A Research Capability On Management Of Engineering And Technology, Arcot Desai Narasimhalu

Arcot Desai NARASIMHALU

Companies, private and publicly funded research institutions have been engaged in research projects and research programs. This paper describes a research capability maturity model for managing technological innovations. The insights for this proposal were derived from studying a variety of research organizations for managing technological innovations in a publicly funded research institute in Singapore. The model was implemented over a period of time with different degrees of success in Kent Ridge Digital Labs, Singapore which has since been renamed Institute for Infocomm Research. The suggested maturity model has five layers – Ad-Hoc, Directed, Managed, Optimized, and Outsourced. Every research organization …

Pre-Disaster Planning And Mitigation And Its Impact On Comprehensive Emergency Management And The Nation: Pre-Disaster Mitigation (Pdm) Program And The Population Protected, Thomas Lyons Carr Iii

Thomas Lyons (Thom) Carr III Appl.Sc., CEM

A Project for a Professional Degree submitted to The Faculty of School of Engineering and Applied Science of The George Washington University in partial fulfillment of the requirements for the degree of Applied Scientist of Engineering Management May 21, 2006

On October 10, 2000, The Disaster Mitigation Act of 2000 (DMA 2000 or DMA 2K) (Public Law 106-390) was enacted, amending the Robert T. Stafford Relief and Emergency Assistance Act and established new requirements for the national for hazard mitigation planning. States, Tribes, territories, and local governments now must have an approved mitigation plan in place prior to receiving certain …