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Consortium for Mathematics and its Applications

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Difference Equations in Genetics

The evolution of many allele frequencies can be understood through the use of difference equations. Let n represent (equallyspaced) discrete points in time or generations, and let A(n) represent the size of a population at time n. A first-order...

Parabolic Wave Equations

The last fifteen years or so have seen enormous research activity in the development of parabolic wave equations (PWEs). These were first discovered by a pair of Soviet scientists shortly after World War 11, during their investigations of different...

The Curious History of Trigonometry

Current trigonometry texts begin with trigonometric ratios, continue through the solution of right and other triangles, and go on to applications to the familiar problems on the height of a tree or the distance across a lake. The presentation leads one...

Genetic Algorithms in Optimization

Genetic algorithms (GAS) are iterative processes for finding good solutions to optimization problems. GAS operate on a population of individuals which represents a set of potential solutions to a given problem. We usually think of such a population at...

Toward a Clean and Lively Calculus

A recent publication, Toward a Lean and Lively Calculus [Douglas 19871, contains reports and articles on the teaching of calculus. In his review of the book, R.W. Hamming [I9881 maintains that the calculus texts currently in use are very much alike,...

A.R. Meijer

The problem of the title, that of flipping a coin by telephone, was proposed and solved by Manuel Blum [19821. One cannot do better in sketching the problem than by quoting the first paragraph of his abstract: Alice and Bob want to flip a coin by...

Simulated Annealing

Many problems in engineering, planning, and manufacturing can be modeled as that of minimizing or maximizing a cost function over a finite set of discrete variables. This class of combinatorial optimization problems has received much attention over the...

More Angles on the Lifeguard Problem

The lifeguard problem is a reincarnation of one of the first problems to which calculus was applied; and, as with many old chestnuts, it continues to draw attention. Whitley solved this problem and suggested an approximation strategy for his lifeguard...

Multigrid Methods

Most physical phenomena, whether in the area of fluid dynamics, electricity, magnetism, heat flow and other domains can be described by PDEs. MG was first successfully applied to PDEs that have outcomes that change with respect to space but not time,...

Neural Networks

The power and usefulness of neural networks is demonstrated by the success of the TNA (Thermal Neutron Analysis) project, developed by SAIC (Science Applications International Corp.). TNA is a neural-network-based machine used at airports that detects...

Wavelets: A New Tool in Applied Mathematics

The subject of wavelets has been around for less than ten years. Yet it seems to be popping up everywhere. The major reason for this is its usefulness in applications. Wavelets reduce the data requirements in fields such as image analysis and signal...

Hamming Distance and Its Discovery

There are many ways of describing the discovery of error-correcting codes, and I will place the emphasis on the mathematics involved. Their discovery is a good illustration of Pasteur's rule: Luck favors the prepared mind. In 1946-47, I was using a...

Digital Signatures

When you receive a letter that apparently was sent by your acquaintance John Smith, how do you know that he is indeed the sender? The answer is obvious: You verify that the signature at the bottom of the letter looks like his, has not been changed from...

Limitless Calculus via Ethereal Numbers

Newton and Leibniz were independent originators of the calculus in the last half of the seventeenth century, and both thought in terms of infinitesimals, at least initially. Infinitesimals were somewhat problematic, and their use was severely...

Undergraduate Research Opportunities in Combinatorial Games

Combinatorial game theory was axiomatized by Conway [I9761 and was developed by Berlekamp, Conway, and Guy [19821. It has provided insight into many mathematical games (including games on graphs, Nim variants, and Sprouts) as well as some more popular...

Curve Interpolation and Coding Theory

Whether it is downloading files from the Internet, having conversations between cell phones, or sending information from a laptop to a printer, we often want to transmit data in situations where we need to worry about interference from other signals...

Cutoffs and Thresholds in the Democratic Primaries

The 2008 Democratic Primary season was one of the most riveting in recent history in part because of the lengthy contest between New York Senator Hillary Clinton and Illinois Senator Barack Obama. Of the eight candidates who mounted national campaigns,...

Computational Complexity

From the earliest days of computing, the development of efficient methods of calculation has played a key role in expanding the diversity of problems computers can solve. Computational complexity studies the measurement of resources, especially time...

Mystery of the Orient

A good mystery often begins with its main characters innocently pursuing a commonplace activity. In this instance, one of us (Goldman) was working on a study of trends in fertility and mortality in the Republic of Korea. To cope with some of the gaps...