11,011 research outputs found
A Question of Food Intake: The Impact of Living Arrangement and Meal Factors on Total Daily Caloric Intake
There has been dramatic weight gain among college students during their collegiate years. A food diary can give much insight of a college student’s life. The purpose of this study is to analyze the food intake of college-aged students taking in factors such as the size of meal, the foods being eaten, the location of the meal, and if the meal was eaten with others. This research will examine how the student’s food intake throughout the day may affect their overall food calorie intake
Two Compact Incremental Prime Sieves
A prime sieve is an algorithm that finds the primes up to a bound . We say
that a prime sieve is incremental, if it can quickly determine if is
prime after having found all primes up to . We say a sieve is compact if it
uses roughly space or less. In this paper we present two new
results:
(1) We describe the rolling sieve, a practical, incremental prime sieve that
takes time and bits of space, and
(2) We show how to modify the sieve of Atkin and Bernstein (2004) to obtain a
sieve that is simultaneously sublinear, compact, and incremental.
The second result solves an open problem given by Paul Pritchard in 1994
Sieving for pseudosquares and pseudocubes in parallel using doubly-focused enumeration and wheel datastructures
We extend the known tables of pseudosquares and pseudocubes, discuss the
implications of these new data on the conjectured distribution of pseudosquares
and pseudocubes, and present the details of the algorithm used to do this work.
Our algorithm is based on the space-saving wheel data structure combined with
doubly-focused enumeration, run in parallel on a cluster supercomputer
Approximately counting semismooth integers
An integer is -semismooth if where is an integer with
all prime divisors and is 1 or a prime . arge quantities of
semismooth integers are utilized in modern integer factoring algorithms, such
as the number field sieve, that incorporate the so-called large prime variant.
Thus, it is useful for factoring practitioners to be able to estimate the value
of , the number of -semismooth integers up to , so that
they can better set algorithm parameters and minimize running times, which
could be weeks or months on a cluster supercomputer. In this paper, we explore
several algorithms to approximate using a generalization of
Buchstab's identity with numeric integration.Comment: To appear in ISSAC 2013, Boston M
Elliptic generation of composite three-dimensional grids about realistic aircraft
An elliptic method for generating composite grids about realistic aircraft is presented. A body-conforming grid is first generated about the entire aircraft by the solution of Poisson's differential equation. This grid has relatively coarse spacing, and it covers the entire physical domain. At boundary surfaces, cell size is controlled and cell skewness is nearly eliminated by inhomogeneous terms, which are found automatically by the program. Certain regions of the grid in which high gradients are expected, and which map into rectangular solids in the computational domain, are then designated for zonal refinement. Spacing in the zonal grids is reduced by adding points with a simple, algebraic scheme. Details of the grid generation method are presented along with results of the present application, a wing-body configuration based on the F-16 fighter aircraft
Three-dimensional zonal grids about arbitrary shapes by Poisson's equation
A method for generating 3-D finite difference grids about or within arbitrary shapes is presented. The 3-D Poisson equations are solved numerically, with values for the inhomogeneous terms found automatically by the algorithm. Those inhomogeneous terms have the effect near boundaries of reducing cell skewness and imposing arbitrary cell height. The method allows the region of interest to be divided into zones (blocks), allowing the method to be applicable to almost any physical domain. A FORTRAN program called 3DGRAPE has been written to implement the algorithm. Lastly, a method for redistributing grid points along lines normal to boundaries will be described
A computer program to generate two-dimensional grids about airfoils and other shapes by the use of Poisson's equation
A method for generating two dimensional finite difference grids about airfoils and other shapes by the use of the Poisson differential equation is developed. The inhomogeneous terms are automatically chosen such that two important effects are imposed on the grid at both the inner and outer boundaries. The first effect is control of the spacing between mesh points along mesh lines intersecting the boundaries. The second effect is control of the angles with which mesh lines intersect the boundaries. A FORTRAN computer program has been written to use this method. A description of the program, a discussion of the control parameters, and a set of sample cases are included
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