We investigate the construction of prefix-free and fix-free codes with specified codeword compositions. We present a polynomial time algorithm which constructs a fix-free code with the same codeword compositions as a given code for a special class of codes called distinct codes. We consider the construction of optimal fix-free codes which minimize the average codeword cost for general letter co...

The performance of maximum-likelihood decoding of a serial concatenation comprising a high-rate block code, convolutional code, or a turbo code, a uniform interleaver, and a partial-response channel with additive white Gaussian noise will be addressed. The effect of a channel precoder on the system performance is also considered. Bitand word-error-rate estimates based upon properties of the ave...

This is the design report for the Transform components of the Digital Fortran compiler, later inherited by the Compaq and HP Fortran compilers for Tru64 Unix running on Alpha. Transform is that part of the compiler which deals with High Performance Fortran (HPF) data mapping directives and parallel constructs. This report describes the data structures and internal transformations needed to turn...

This paper presents a simple contrast enhancement algorithm based on histogram equalization (HE). The proposed algorithm performs a piecewise affine transform of the intensity levels of a digital image such that the new histogram function will be approximately uniform (as with HE), but where the stretching of the range is locally controlled to avoid brutal noise enhancement. We call this algori...

In this paper, polar codes for the m-user multiple access channel (MAC) with binary inputs are constructed. It is shown that Arıkan’s polarization technique applied individually to each user transforms independent uses of a m-user binary input MAC into successive uses of extremal MACs. This transformation has a number of desirable properties: (i) the ‘uniform sum rate’ of the original MAC is pr...

FLASH 3 beta is the latest release of a parallel Adaptive Mesh Refinement (AMR) code for simulating thermonuclear flashes. It can be easily adapted with other modules as required to solve various different physical problems. Poisson’s equation is a second–order partial differential equation which is used to calculate the gravitational force on a system of particles. It can be solved efficiently...

Citation of scientific materials published on the Internet is often cumbersome because of unwieldy uniform resource locators (URLs). The authors describe a format for URLs that simplifies citation of scholarly materials. Its use depends on a simple HTML device, the "refresh page." Uniform citation would follow this format: [Author I. Title of article. http:// domain/year/month-day(e#).html]. Th...

——In this paper, polar codes for the -user multiple access channel (MAC)with binary inputs are constructed. It is shown that Arikan’’s polarization technique applied individually to each user transforms independent uses of an -user binary input MAC into successive uses of extremal MACs. This transformation has a number of desirable properties: 1) the ““uniform sum-rate”” of the original MAC is ...

A mutual information inspired nonbinary coded modulation design with non-uniform shaping is proposed. Instead of traditional power of two signal constellation sizes, we design 5-QAM, 7-QAM and 9-QAM constellations, which can be used in adaptive optical networks. The non-uniform shaping and LDPC code rate are jointly considered in the design, which results in a better performance scheme for the ...

This paper presents a novel approach to synthesize low power FSMs using non-uniform code length. Switching activity is reduced by decreasing the expected number of state bits switched less than dlog jSje. The state set S of the FSM is decomposed into two sets based on the limit state probabilities. The state set with very high probability is encoded with less than dlog jSje bits. The other stat...