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Articles 1 - 9 of 9

Full-Text Articles in Mathematics

Peak-To-Mean Power Control In Ofdm, Golay Complementary Sequences, And Reed–Muller Codes, James A. Davis, Jonathan Jedwab Nov 1999

Peak-To-Mean Power Control In Ofdm, Golay Complementary Sequences, And Reed–Muller Codes, James A. Davis, Jonathan Jedwab

Department of Math & Statistics Faculty Publications

We present a range of coding schemes for OFDM transmission using binary, quaternary, octary, and higher order modulation that give high code rates for moderate numbers of carriers. These schemes have tightly bounded peak-to-mean envelope power ratio (PMEPR) and simultaneously have good error correction capability. The key theoretical result is a previously unrecognized connection between Golay complementary sequences and second-order Reed–Muller codes over alphabets ℤ2h. We obtain additional flexibility in trading off code rate, PMEPR, and error correction capability by partitioning the second-order Reed–Muller code into cosets such that codewords with large values of PMEPR are isolated. …


Recounting Fibonacci And Lucas Identities, Arthur T. Benjamin, Jennifer J. Quinn Nov 1999

Recounting Fibonacci And Lucas Identities, Arthur T. Benjamin, Jennifer J. Quinn

All HMC Faculty Publications and Research

No abstract provided in this article.


A Short Proof That ‘Proper = Unit’, Kenneth P. Bogart, Douglas B. West Apr 1999

A Short Proof That ‘Proper = Unit’, Kenneth P. Bogart, Douglas B. West

Dartmouth Scholarship

A short proof is given that the graphs with proper interval representations are the same as the graphs with unit interval representations.


Automorphic Subsets Of The N-Dimensional Cube Are Translations Of Cwatsets, Matthew Lepinski Apr 1999

Automorphic Subsets Of The N-Dimensional Cube Are Translations Of Cwatsets, Matthew Lepinski

Mathematical Sciences Technical Reports (MSTR)

It is known that automorphic subsets are generalizations of cwatsets. In this paper we show that an automorphic subset is the translation of some cwatset, and therefore that each automorphic subset is internally isomorphic to a cwatset.


Unevening The Odds Of "Even Up", Arthur T. Benjamin, Jennifer J. Quinn Apr 1999

Unevening The Odds Of "Even Up", Arthur T. Benjamin, Jennifer J. Quinn

All HMC Faculty Publications and Research

No abstract provided in this article.


Single-Change Circular Covering Designs, John P. Mcsorley Feb 1999

Single-Change Circular Covering Designs, John P. Mcsorley

Articles and Preprints

A single-change circular covering design (scccd) based on the set [v] = {1, . . . ,v} with block size k is an ordered collection of b blocks, B = {B1, . . . ,Bb}, each Bi ⊂ [v], which obey: (1) each block differs from the previous block by a single element, as does the last from the first, and, (2) every pair of [v] is covered by some Bi. The object is to minimize b for a fixed v and k. …


Some Recent Developments In Difference Sets, James A. Davis, Jonathan Jedwab Jan 1999

Some Recent Developments In Difference Sets, James A. Davis, Jonathan Jedwab

Department of Math & Statistics Faculty Publications

There are five known parameter families for (v, k, λ, n)- difference sets satisfying gcd(v, n)>1: the Hadamard, McFarland, Spence, Davis-Jedwab, and Chen families. The authors recently gave a recursive unifying construction for difference sets from the first four families which relies on relative difference sets. We give an overview of this construction and show that, by modifying it to use divisible difference sets in place of relative difference sets, the recent difference set discoveries of Chen can be brought within the unifying framework. We also demonstrate the recursive use of an auxiliary construction for …


A Unified Approach To Difference Sets With Gcd(V, N) > 1, James A. Davis, Jonathan Jedwab Jan 1999

A Unified Approach To Difference Sets With Gcd(V, N) > 1, James A. Davis, Jonathan Jedwab

Department of Math & Statistics Faculty Publications

The five known families of difference sets whose parameters (v, k, λ; n) satisfy the condition gcd(v,n) > 1 are the McFarland, Spence, Davis-Jedwab, Hadamard and Chen families. We survey recent work which uses recursive techniques to unify these difference set families, placing particular emphasis on examples. This unified approach has also proved useful for studying semi-regular relative difference sets and for constructing new symmetric designs.


Optimization Methods For Logical Inference, Vijay Chandru, John Hooker Dec 1998

Optimization Methods For Logical Inference, Vijay Chandru, John Hooker

John Hooker

No abstract provided.