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Mathematics & Statistics

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Displaying 301 - 325 of 473

DEoptim: An R Package for Global Optimization by Differential Evolution

May 1, 2011
Author(s)
Katharine M. Mullen, David Ardia , David L. Gil, Donald A. Windover, James P. Cline
This article describes the R package DEoptim which implements the differential evolution algorithm for the global optimization of a real-valued function of a real-valued parameter vector. The implementation of differential evolution in DEoptim interfaces

A Survey of Binary Covering Arrays

April 7, 2011
Author(s)
James F. Lawrence, Raghu N. Kacker, Yu Lei, David R. Kuhn, Michael Forbes
Two-valued covering arrays of strength t are 0--1 matrices having the property that for each t columns and each of the possible 2t sequences of t 0's and 1's, there exists a row having that sequence in that set of t columns. Covering arrays are an

Arithmetic Progressions on Edwards Curves

February 8, 2011
Author(s)
Dustin Moody
We look at arithmetic progressions on elliptic curves known as Edwards curves. By an arithmetic progression on an elliptic curve, we mean that the x-coordinates of a sequence of rational points on the curve form an arithmetic progression. Previous work has

Approximating the Number of Bases for Almost All Matroids

February 1, 2011
Author(s)
Brian D. Cloteaux
We define a class of matroids A for which a fully polynomial randomized approximation scheme (fpras) exists for counting the number of bases of the matroids. We then show that as the number of elements in a matroid increases, the probability that a matroid

Changes

January 3, 2011
Author(s)
Isabel M. Beichl

Derivation of Isosceles Trapezoidal Distribution

December 1, 2010
Author(s)
Raghu N. Kacker, James F. Lawrence
It is known that, if the mid-point of a rectangular distribution is specified, the half-width is inexactly known, and the state of knowledge about the half-width may be represented by a narrower rectangular distribution then the resulting distribution

Biological Cell Feature Identification by a Modified Watershed-Merging Algorithm

November 24, 2010
Author(s)
David E. Gilsinn, Kiran Bhadriraju, John T. Elliott
Biological cells are composed of many subsystems and organelles. The subsystem called the cytoskeleton is composed of long rod-shaped structures. They give the cell form and help attach the cell to the substrate and neighbors. One of the filaments is

Bicubic B-Spline Surface Approximation of Invariant Tori

October 20, 2010
Author(s)
Sita Ramamurti, David E. Gilsinn
The invariant torus of a coupled system of Van der Pol oscillators is approximated using bicubic B-splines. The paper considers the case of strong nonlinear coupling. In particular, the shapes of invariant torii for the Van der Pol coupling parameter $

A New Analysis of the False-Positive Rate of a Bloom Filter

October 15, 2010
Author(s)
Ken Christensen, Allen L. Roginsky, Miguel Jimeno
A Bloom filter is a space-efficient data structure used for probabilistic set membership testing. When testing an object for set membership, a Bloom filter may give a false positive. The analysis of the false positive rate is key to understanding the Bloom

Modelling Type Ia Supernova Light Curves

September 15, 2010
Author(s)
Bert W. Rust, Dianne M. O'Leary, Katharine M. Mullen
Type Ia supernova light curves are characterized by a rapid rise from zero luminosity to a peak value, followed by a slower quasi-exponential decline. The rise and peak last for a few days, while the decline persists for many months. It is widely believed

Metrological Compatibility and Statistical Consistency

September 5, 2010
Author(s)
Raghu N. Kacker, Ruediger Kessel, Klaus-Dieter Sommer, Xin Bian
The traditional concept of consistency in multiple evaluations of the same measurand is statistical. The statistical view of consistency does not match the modern view of uncertainty in measurement; in particular, it does not apply to the results of

Practical Near-Collisions for Reduced Round Blake, Fugue, Hamsi and JH

August 23, 2010
Author(s)
Meltem Sonmez Turan, Erdener Uyan
A hash function is near-collision resistant, if it is hard to find two messages with hash values that differ in only small number of bits. In this study, we used hill climbing methods to find near-collisions for some of the second round SHA-3 candidates

On Feedback Functions of Maximum Length Nonlinear Feedback Shift Registers

August 2, 2010
Author(s)
Cagdas Calik, Meltem Sonmez Turan, Ferruh Ozbudak
Feedback shift registers are basic building blocks for many cryptographic primitives. Due to the insecurities of Linear Feedback Shift Register (LFSR) based systems, the use of Nonlinear Feedback Shift Registers (NFSRs) became more popular. In this work

Performance Measurements for Evaluating Static and Dynamic Multiple Human Detection and Tracking Systems in Unstructured Environments

June 30, 2010
Author(s)
Bodt Bodt, Richard Camden, Harry A. Scott, Adam S. Jacoff, Tsai H. Hong, Tommy Chang, Richard J. Norcross, Anthony Downs, Ann Virts
The Army Research Laboratory (ARL) Robotics Collaborative Technology Alliance (CTA) conducted an assessment and evaluation of multiple algorithms for real-time detection of pedestrians in Laser Detection and Ranging (LADAR) and video sensor data taken from

Remembering Paul Garabedian

June 15, 2010
Author(s)
Geoffrey B. McFadden
Paul R. Garabedian, a leader in the field of computational science, passed away on May 13th, 2010, at his home in Manhattan at the age of 82 after a long battle with cancer. During the course of sixty years of research on the faculties at Stanford and New

The NIST Handbook of Mathematical Functions

May 12, 2010
Author(s)
Frank W. Olver, Daniel W. Lozier, Ronald Boisvert, Charles W. Clark
The NIST Handbook of Mathematical Functions supplies validated reference information in 36 chapters on a wide selection of important mathematical functions, covering the properties necessary for their use in scientific applications, together with general

Estimating Volumes of Near-spherical Molded Artifacts

May 3, 2010
Author(s)
David E. Gilsinn, Bruce R. Borchardt, Amelia Tebbe
The Food and Drug Administration (FDA) is conducting research on developing reference lung cancer cancer lesions, called phantoms, to test computed tomography (CT) scanners and their software. FDA loaned two semi-spherical phantoms to the National

Waveform metrology and a quantitative study of regularized deconvolution

May 1, 2010
Author(s)
Paul D. Hale, Andrew M. Dienstfrey
We present methodology and preliminary results of a Monte-Carlo simulation to perform a quantified analysis of regularized deconvolution in the context of full waveform metrology. We analyze the behavior of different regularized inversion methods with

Onset of Convection in Binary Liquid Layers

March 24, 2010
Author(s)
Geoffrey B. McFadden, Sam R. Coriell, Aaron Lott
We perform linear stability calculations for horizontal bilayers of a two-component fluid that can undergo a phase transformation, taking into account both buoyancy effects and thermocapillary effects in the presence of a vertical temperature gradient
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