Physical Sciences and Mathematics Commons^™

Tr-2008003: Unified Nearly Optimal Algorithms For Structured Integer Matrices And Polynomials, Victor Y. Pan, Brian Murphy, Rhys E. Rosholt

Computer Science Technical Reports

No abstract provided.

Tr-2008004: Additive Preconditioning For Matrix Computations, Victor Y. Pan, Dmitriy Ivolgin, Brian Murphy, Rhys Eric Rosholt, Yuqing Tang, Xiaodong Yan

Computer Science Technical Reports

No abstract provided.

Tr-2008005: Weakly Random Additive Preconditioning For Matrix Computations, Victor Y. Pan, Dmitriy Ivolgin, Brian Murphy, Rhys Eric Rosholt, Yuqing Tang, Xiaodong Yan

Computer Science Technical Reports

No abstract provided.

Tr-2008016: An Analysis Of Entries In The First Tac Market Design Competition, Jinzhong Niu, Kai Cai, Simon Parsons, Peter Mcburney

Computer Science Technical Reports

No abstract provided.

Topological And Categorical Properties Of Binary Trees, Homeira Pajoohesh

Publications and Research

Binary trees are very useful tools in computer science for estimating the running time of so-called comparison based algorithms, algorithms in which every action is ultimately based on a prior comparison between two elements. For two given algorithms A and B where the decision tree of A is more balanced than that of B, it is known that the average and worst case times of A will be better than those of B, i.e., ₸A(n) ≤₸B(n) and TWA (n)≤TWB (n). Thus the most balanced and the most imbalanced binary trees play a main role. Here we consider them as semilattices …

Tr-2008006: Additive Preconditioning, Eigenspaces, And The Inverse Iteration, Victor Y. Pan, Xiaodong Yan

Computer Science Technical Reports

No abstract provided.

Tr-2008009: Solving Homogeneous Linear Systems With Weakly Randomized Additive Preprocessing, Victor Y. Pan, Guoliang Qian

Computer Science Technical Reports

No abstract provided.

Tr-2008010: The Logic Of Justification, Sergei Artemov

Computer Science Technical Reports

No abstract provided.

Tr-2008014: Why Do We Need Justification Logic?, Sergei Artemov

Computer Science Technical Reports

No abstract provided.

Anatomy Of An Arabetic Type Design, Saad D. Abulhab

Publications and Research

Arabetic type design, like type design in general, should not be limited by rigid rules, other than those advocating open choice and user options. But as with all design fields, highlighting certain principles and guidelines is crucial to realizing a successful project. In an Arabetic font design environment, such guidelines and principles should reveal deeper understanding of various scripts visual and behavioral defining characteristics rather than mere traditional calligraphic and handwriting norms. A main goal of this study is to emphasize that designing Arabetic fonts is much easier than it is portrayed, and designers of all backgrounds should be more …

Removing Long-Term Errors From The Avhrr Observation Based On Normalized Difference Vegetation Index (Ndvi), Md Zahidur Rahman, Leonid Roytman, Atiqur Rahman, Felix Kogan, Runa Jesmin

Publications and Research

This paper investigates Normalized Difference Vegetation Index (NDVI) stability in the NOAA/NESDIS Global Vegetation Index (GVI) data during 1982-2003. Advanced Very High Resolution Radiometer (AVHRR) weekly data for the five NOAA afternoon satellites for the China dataset is studied, for it includes a wide variety of different ecosystems represented globally. It was found that data for the years 1988, 1992, 1993, 1994, 1995 and 2000 are not stable enough compared to other years because of satellite orbit drift, and AVHRR sensor degradation. It is assumed that data from NOAA-7 (1982, 1983), NOAA-9 (1985, 1986), NOAA-11 (1989, 1990), NOAA-14 (1996, 1997), …

Formulas For The Fourier Series Of Orthogonal Polynomials In Terms Of Special Functions, Nataniel Greene

Publications and Research

An explicit formula for the Fourier coefficient of the Legendre polynomials can be found in the Bateman Manuscript Project. However, formulas for more general classes of orthogonal polynomials do not appear to have been worked out. Here we derive explicit formulas for the Fourier series of Gegenbauer, Jacobi, Laguerre and Hermite polynomials. The methods described here apply in principle to a class of polynomials, including non-orthogonal polynomials.

Inverse Wavelet Reconstruction For Resolving The Gibbs Phenomenon, Nataniel Greene

Publications and Research

The Gibbs phenomenon refers to the lack of uniform convergence which occurs in many orthogonal basis approximations to piecewise smooth functions. This lack of uniform convergence manifests itself in spurious oscillations near the points of discontinuity and a low order of convergence away from the discontinuities. Here we describe a numerical procedure for overcoming the Gibbs phenomenon called the inverse wavelet reconstruction method. The method takes the Fourier coefficients of an oscillatory partial sum and uses them to construct the wavelet coefficients of a non-oscillatory wavelet series.

Arkansas Wildlife Gets Report Card At Conference, Aldemaro Romero Jr.

Publications and Research

No abstract provided.

Iterated Aluthge Transforms: A Brief Survey, Jorge Antezana, Enrique R. Pujals, Demetrio Stojanoff

Publications and Research

Given an r × r complex matrix T, if T = U|T| is the polar decomposition of T, then the Aluthge transform is defined by

∆(T) = |T|^1/2U|T|^1/2.

Let ∆ⁿ(T) denote the n-times iterated Aluthge transform of T, i.e. ∆⁰(T) = T and ∆ⁿ(T) = ∆(∆ⁿ⁻¹(T)), n ∈ N. In this paper we make a brief survey on the known properties and applications of …

Rigidity And Stability For Isometry Groups In Hyperbolic 4-Space, Youngju Kim

Dissertations, Theses, and Capstone Projects

It is known that a geometrically finite Kleinian group is quasiconformally stable. We prove that this quasiconformal stability cannot be generalized in 4-dimensional hyperbolic space. This is due to the presence of screw parabolic isometries in dimension 4. These isometries are topologically conjugate to strictly parabolic isometries. However, we show that screw parabolic isometries are not quasiconformally conjugate to strictly parabolic isometries. In addition, we show that two screw parabolic isometries are generically not quasiconformally conjugate to each other. We also give some geometric properties of a hyperbolic 4-manifold related to screw parabolic isometries.

A Fuchsian thrice-punctured sphere group has …

Reasoning About The Behavior Of Aspect-Oriented Programs, Neelam Soundarajan, Raffi Khatchadourian, Johan Dovland

Publications and Research

Aspect-oriented programming (AOP) has become increasingly popular over the last few years. At the same time, reasoning about the behavior of these programs poses serious challenges. In this paper, we present a rely-guarantee approach to such reasoning. The rely-guarantee approach has proven useful in reasoning about concurrent and distributed programs. We show that some of the key problems encountered in reasoning about aspect-oriented programs are similar to those encountered in reasoning about concurrent programs; and that the rely-guarantee approach, appropriately modified, helps address these problems. We illustrate our approach with a simple example.

An Update On Groundwater Conditions At The Site Of The York College Cuny Campus In Southeastern Queens County, New York City, Nazrul I. Khandaker, Stanley Schleifer, Zarine Ali, Edward A. Molteni

Publications and Research

The wells operated by the Jamaica Water Supply Company in Queens represent the only large scale utilization of groundwater for public water supply in New York City in recent years. These wells were shut down, for the most part, beginning in 1996. Since that time, water table elevations in the area, which had been drawn down by the withdrawal activity of the Jamaica Water Supply Company, have risen significantly causing some high groundwater problems, including flooding of basements. The New York City Department of Environmental Protection (NYCDEP) has held public hearings on a contemplated resumption of ground water withdrawal in …

Automated Refactoring Of Legacy Java Software To Enumerated Types, Raffi Khatchadourian, Jason Sawin, Atanas Rountev

Publications and Research

Modern Java languages introduce several new features that offer significant improvements over older Java technology. In this article we consider the new enum construct, which provides language support for enumerated types. Prior to recent Java languages, programmers needed to employ various patterns (e.g., the weak enum pattern) to compensate for the absence of enumerated types in Java. Unfortunately, these compensation patterns lack several highly-desirable properties of the enum construct, most notably, type safety. We present a novel fully-automated approach for transforming legacy Java code to use the new enumeration construct. This semantics-preserving approach increases type safety, produces code that is …

1139-3159_Nir_Spex, Dagny L. Looper

Publications and Research

No abstract provided.

A Dynamic-Trend Exponential Smoothing Model, Don Miller, Dan Williams

Publications and Research

Forecasters often encounter situations in which the local pattern of a time series is not expected to persist over the forecasting horizon. Since exponential smoothing models emphasize recent behavior, their forecasts may not be appropriate over longer horizons. In this paper, we develop a new model in which the local trend line projected by exponential smoothing converges asymptotically to an assumed future long-run trend line, which might be an extension of a historical long-run trend line. The rapidity of convergence is governed by a parameter. A familiar example is an economic series exhibiting persistent long-run trend with cyclic variation. This …

Automated Refactoring Of Legacy Java Software To Enumerated Types, Raffi Khatchadourian, Jason Sawin, Atanas Rountev

Publications and Research

Modern Java languages introduce several new features that offer significant improvements over older Java technology. In this article we consider the new enum construct, which provides language support for enumerated types. Prior to recent Java languages, programmers needed to employ various patterns (e.g., the weak enum pattern) to compensate for the absence of enumerated types in Java. Unfortunately, these compensation patterns lack several highly-desirable properties of the enum construct, most notably, type safety. We present a novel fully-automated approach for transforming legacy Java code to use the new enumeration construct. This semantics-preserving approach increases type safety, produces code that is …

Rely-Guarantee Approach To Reasoning About Aspect-Oriented Programs, Raffi Khatchadourian, Neelam Soundarajan

Publications and Research

Over the last few years, the question of reasoning about aspect-oriented programs has been addressed by a number of authors. In this paper, we present a rely-guarantee approach to such reasoning. The rely-guarantee approach has proven extremely successful in reasoning about concurrent and distributed programs. We show that some of the key problems encountered in reasoning about aspect-oriented programs are similar to those encountered in reasoning about concurrent programs; and that the rely-guarantee approach, appropriately modified, helps address these problems. We illustrate our approach with a simple example.

The Impact Of Receiver Aperture Design And Telescope Properties On Lidar Signal-To-Noise Ratio Improvements, Yasser Hassebo, Khaled El Sayed

Publications and Research

Range and sensitivities of lidar measurements in daylight are limited by sky background noise power (BGP). This is particularly important for Raman lidar techniques where the Raman backscattered signal is relatively weak. This often restricts Raman lidar measurements to nighttime where BGP is absent. The background noise elimination is particularly important in daytime measurements in case where full overlap between laser beam and receiver telescope field-of-view (FOV) is necessary. Results of numerical simulations for a vertically pointing Lidar show that significant improvements in Lidar signal to noise ratio (SNR) can be obtained, by minimizing the detected sky BGP. This can …

Tr-2007011: Numerical Computation Of Determinants With Additive Preconditioning, V. Y. Pan, B. Murphy, G. Qian, R. E. Rosholt, I. Taj-Eddin

Computer Science Technical Reports

No abstract provided.

Tr-2007010: Error-Free Computations Via Floating-Point Operations, V. Y. Pan, B. Murphy, G. Qian, R. E. Rosholt

Computer Science Technical Reports

No abstract provided.

Tr-2007007: Independent Component Analysis: An Introduction, Rave Harpaz

Computer Science Technical Reports

No abstract provided.

Tr-2007009: Computations In The Null Spaces With Additive Preprocessing, Victor Y. Pan

Computer Science Technical Reports

No abstract provided.

Tr-2007014: The Schur Aggregation And Extended Iterative Refinement, V. Y. Pan, B. Murphy, R. E. Rosholt

Computer Science Technical Reports

No abstract provided.

Tr-2007001: On Developing User Interfaces For Children In Educational Virtual Reality Environments, Lori Scarlatos, Rebecca Friedman

Computer Science Technical Reports

No abstract provided.