Results 1 - 10 of 12,772

Near Shannon limit error-correcting coding and decoding

by Claude Berrou, Alain Glavieux, Punya Thitimajshima , 1993
"... Abstract- This paper deals with a new class of convolutional codes called Turbo-codes, whose performances in terms of Bit Error Rate (BER) are close to the SHANNON limit. The Turbo-Code encoder is built using a parallel concatenation of two Recursive Systematic Convolutional codes and the associated ..."
Abstract - Cited by 1776 (6 self) - Add to MetaCart
Abstract- This paper deals with a new class of convolutional codes called Turbo-codes, whose performances in terms of Bit Error Rate (BER) are close to the SHANNON limit. The Turbo-Code encoder is built using a parallel concatenation of two Recursive Systematic Convolutional codes

A Data Locality Optimizing Algorithm

by Michael E. Wolf, Monica S. Lam , 1991
"... This paper proposes an algorithm that improves the locality of a loop nest by transforming the code via interchange, reversal, skewing and tiling. The loop transformation algorithm is based on two concepts: a mathematical formulation of reuse and locality, and a loop transformation theory that unifi ..."
Abstract - Cited by 804 (16 self) - Add to MetaCart
, and Givens QR factorization. Performance evaluation indicates that locality optimization is especially crucial for scaling up the performance of parallel code.

Parallel Code Sequences

by Erik J. Morse, Erik J. Morse, Erik J. Morse
"... Debugging and testing of parallel programs is difficult due to the nondeterminism introduced by parallel constructs. In this paper we discuss previously proposed solutions, including: static source code analysis, problem based systems that describe and recognize problematic event occurences, reverse ..."
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Debugging and testing of parallel programs is difficult due to the nondeterminism introduced by parallel constructs. In this paper we discuss previously proposed solutions, including: static source code analysis, problem based systems that describe and recognize problematic event occurences

A Parallel Code for Structure Detection

by A. Pagliaro, U. Becciani , 1999
"... We describe a parallel code aimed at 3-D structure detection (mainly in astrophysical fields) and at the morphological analysis of the objects recovered. The method is based on a multi-scale technique and exploits wavelet transforms and segmentation analysis. The wavelet transform allows us to f ..."
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We describe a parallel code aimed at 3-D structure detection (mainly in astrophysical fields) and at the morphological analysis of the objects recovered. The method is based on a multi-scale technique and exploits wavelet transforms and segmentation analysis. The wavelet transform allows us

Adaptive Parallelism in Compiler-Parallelized Code

by Mary W. Hall, Margaret Martonosi - IN PROC. OF THE 2ND SUIF COMPILER WORKSHOP
"... As moderate-scale multiprocessors become widely used, we foresee an increased demand for effective compiler parallelization and efficient management of parallelism. While parallelizing compilers are achieving success at identifying parallelism, they are less adept at pre-determining the degree of pa ..."
Abstract - Cited by 20 (0 self) - Add to MetaCart
As moderate-scale multiprocessors become widely used, we foresee an increased demand for effective compiler parallelization and efficient management of parallelism. While parallelizing compilers are achieving success at identifying parallelism, they are less adept at pre-determining the degree

Deriving Parallel Codes via Invariants

by Wei-ngan Chin, Siau-cheng Khoo, Zhenjiang Hu, Masato Takeichi
"... . Systematic parallelization of sequential programs remains a major challenge in parallel computing. Traditional approaches using program schemes tend to be narrower in scope, as the properties which enable parallelism are difficult to capture via ad-hoc schemes. In [CTH98], a systematic approac ..."
Abstract - Cited by 9 (5 self) - Add to MetaCart
. The enhancement enables the parallelization of a class of recursive functions with conditional and tupled constructs, which were not possible previously. We further show how such invariants can be discovered and verified systematically, and demonstrate the power of our methodology by deriving a parallel code

Scheduler Activations: Effective Kernel Support for the User-Level Management of Parallelism

by Thomas E. Anderson, Brian N. Bershad, Edward D. Lazowska, Henry M. Levy - ACM Transactions on Computer Systems , 1992
"... Threads are the vehicle,for concurrency in many approaches to parallel programming. Threads separate the notion of a sequential execution stream from the other aspects of traditional UNIX-like processes, such as address spaces and I/O descriptors. The objective of this separation is to make the expr ..."
Abstract - Cited by 475 (21 self) - Add to MetaCart
the expression and control of parallelism sufficiently cheap that the programmer or compiler can exploit even fine-grained parallelism with acceptable overhead. Threads can be supported either by the operating system kernel or by user-level library code in the application address space, but neither approach has

Interprocedural Transformations for Parallel Code Generation

by Mary W. Hall, Ken Kennedy, Kathryn S. McKinley - IN PROCEEDINGS OF SUPERCOMPUTING '91 , 1991
"... We present a new approach that enables compiler optimization of procedure calls and loop nests containing procedure calls. We introduce two interprocedural transformations that move loops across procedure boundaries, exposing them to traditional optimizations on loop nests. These transformations are ..."
Abstract - Cited by 41 (14 self) - Add to MetaCart
are incorporated into a code generation algorithm for a shared-memory multiprocessor. The code generator relies on a machine model to estimate the expected benefits of loop parallelization and parallelism-enhancing transformations. Several transformation strategies are explored and one that minimizes total

Data abstractions for portable parallel codes

by Javier Fresno, Arturo Gonzalez-escribano, Diego R. Llanos
"... Development of parallel software is a very complex task. Many details, such as domain type, partition method, or mapping scheme, should be considered during the implementation phase. However, they are usually taken into account in the design phase because the developers do not have the appropriate a ..."
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abstractions. This causes that small conceptual changes, for example a modi-fication in the distribution policy, imply the developing of an application from scratch. The result is that it is not always possible to obtain portable and efficient parallel codes. In this paper, we present a programming methodology

Fast Folding and Comparison of RNA Secondary Structures (The Vienna RNA Package)

by Ivo L. Hofacker, Walter Fontana, Peter F. Stadler, L. Sebastian Bonhoeffer, Manfred Tacker, Peter Schuster
"... Computer codes for computation and comparison of RNA secondary structures, the Vienna RNA package, are presented, that are based on dynamic programming algorithms and aim at predictions of structures with minimum free energies as well as at computations of the equilibrium partition functions and bas ..."
Abstract - Cited by 809 (117 self) - Add to MetaCart
Computer codes for computation and comparison of RNA secondary structures, the Vienna RNA package, are presented, that are based on dynamic programming algorithms and aim at predictions of structures with minimum free energies as well as at computations of the equilibrium partition functions
Results 1 - 10 of 12,772