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Software Implementation (software + implementation)

Distribution by Scientific Domains
Information Science and Computing40%
Engineering40%

Selected Abstracts

Hardware-Accelerated Rendering of Photo Hulls

COMPUTER GRAPHICS FORUM, Issue 3 2004
Ming Li
This paper presents an efficient hardware-accelerated method for novel view synthesis from a set of images or videos. Our method is based on the photo hull representation, which is the maximal photo-consistent shape. We avoid the explicit reconstruction of photo hulls by adopting a view-dependent plane-sweeping strategy. From the target viewpoint slicing planes are rendered with reference views projected onto them. Graphics hardware is exploited to verify the photo-consistency of each rasterized fragment. Visibilities with respect to reference views are properly modeled, and only photo-consistent fragments are kept and colored in the target view. We present experiments with real images and animation sequences. Thanks to the more accurate shape of the photo hull representation, our method generates more realistic rendering results than methods based on visual hulls. Currently, we achieve rendering frame rates of 2,3 fps. Compared to a pure software implementation, the performance of our hardware-accelerated method is approximately 7 times faster. Categories and Subject Descriptors (according to ACM CCS): CR Categories: I.3.3 [Computer Graphics]: Picture/Image Generation; I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism. [source]

Grammatical Inference Techniques and Their Application in Ground Investigation

COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 1 2008
Ian Morrey
The data obtained from trial pits can be coded into a form that can be used as sample observations for input to a grammatical inference machine. A grammatical inference machine is a black box, which when presented with a sample of observations of some unknown source language, produces a grammar which is compatible with the sample. This article presents a heuristic model for a grammatical inference machine, which takes as data sentences and non-sentences identified as such, and is capable of inferring grammars in the class of context-free grammars expressed in Chomsky Normal Form. An algorithm and its corresponding software implementation have been developed based on this model. The software takes, as input, coded representations of ground investigation data, and produces as output a grammar which describes and classifies the geotechnical data observed in the area, and also promises the possibility of being able to predict the likely configuration of strata across the site. [source]

Using parallelization and hardware concurrency to improve the performance of a genetic algorithm

CONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 4 2007
Vijay Tirumalai
Abstract Genetic algorithms (GAs) are powerful tools for solving many problems requiring the search of a solution space having both local and global optima. The main drawback for GAs is the long execution time normally required for convergence to a solution. This paper discusses three different techniques that can be applied to GAs to improve overall execution time. A serial software implementation of a GA designed to solve a task scheduling problem is used as the basis for this research. The execution time of this implementation is then improved by exploiting the natural parallelism present in the algorithm using a multiprocessor. Additional performance improvements are provided by implementing the original serial software GA in dedicated reconfigurable hardware using a pipelined architecture. Finally, an advanced hardware implementation is presented in which both pipelining and duplicated hardware modules are used to provide additional concurrency leading to further performance improvements. Copyright © 2006 John Wiley & Sons, Ltd. [source]

Tensor-based matrices in geometrically non-linear FEM

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 15 2005
V. V. Chekhov
Abstract In the framework of the object-oriented paradigm, advantages of using the index-free tensor notation in combination with the concept of generalized tensor-based matrix are considered as being the most corresponding to the paradigm. The advantages reveal itself in the disappearance of a semantic gap between various stages of creation of FEM applications (theoretical inferences, use of the numerical methods, object-oriented software implementation) and, as a result, use of the unified object model in all the stages, as well as simplification of theoretical transformations. Based on the considered approach, a new FEM equation for large strain analysis is developed and its solution technique is outlined. Copyright © 2005 John Wiley & Sons, Ltd. [source]

SOFTWARE ENGINEERING CONSIDERATIONS FOR INDIVIDUAL-BASED MODELS

NATURAL RESOURCE MODELING, Issue 1 2002
GLEN E. ROPELLA
ABSTRACT. Software design is much more important for individual-based models (IBMs) than it is for conventional models, for three reasons. First, the results of an IBM are the emergent properties of a system of interacting agents that exist only in the software; unlike analytical model results, an IBMs outcomes can be reproduced only by exactly reproducing its software implementation. Second, outcomes of an IBM are expected to be complex and novel, making software errors difficult to identify. Third, an IBM needs ,systems software' that manages populations of multiple kinds of agents, often has nonlinear and multi-threaded process control and simulates a wide range of physical and biological processes. General software guidelines for complex models are especially important for IBMs. (1) Have code critically reviewed by several people. (2) Follow prudent release management prac-tices, keeping careful control over the software as changes are implemented. (3) Develop multiple representations of the model and its software; diagrams and written descriptions of code aid design and understanding. (4) Use appropriate and widespread software tools which provide numerous major benefits; coding ,from scratch' is rarely appropriate. (5) Test the software continually, following a planned, multi-level, exper-imental strategy. (6) Provide tools for thorough, pervasive validation and verification. (7) Pay attention to how pseudorandom numbers are generated and used. Additional guidelines for IBMs include: (a) design the model's organization before starting to write code,(b) provide the ability to observe all parts of the model from the beginning,(c) make an extensive effort to understand how the model executes how often different pieces of code are called by which objects, and (d) design the software to resemble the system being mod-eled, which helps maintain an understanding of the software. Strategies for meeting these guidelines include planning adequate resources for software development, using software professionals to implement models and using tools like Swarm that are designed specifically for IBMs. [source]