Catálogo de publicaciones - libros

In this paper a new point-based computational method of intersection for ray tracing is presented. With global illumination we gain a higher rendering speed of ray tracing compared with previous methods. During pre-process, an important attribute is added to each point. During rendering, an intersection algorithm different from previous ones has been demonstrated to yield satisfactory results.

An implementation scheme for solving complicated multi-restriction optimization problems of decision of agile virtual enterprise partners selection is presented based on particle swarm optimization (PSO) algorithm. The particle-flying space, objective function and fitness function are constructed. Experiments are performed to examine the proposed approach. Comparisons with the analytic hierarchy process (AHP) and genetic algorithm (GA) show that the proposed method is effective and feasible.

In order to solve the problems of low description ability and interactivity in current workflow management systems, an interactive workflow management function model (IWMFM) is proposed. On the basis of using IWMFM to model the business process in the method of hierarchies, an algorithm of workflow process interaction based on the event-driven mechanism is put forward. Combining IWMFM and a formalized orgnization-role model, an algorithm of role analysis based on responsibility is given to implement the flexible role analysis during the interaction. Practical application shows that the proposed model has some advantages in enhancing description ability, reducing modelling complexity, strengthening interactivity between processes and improving flexibility in role analysis.

In this paper, a relatively flexible filter model called extended adaptive weighted averaging (EAWA) filter model is proposed, by which some particular filters can be designed via selecting an appropriate pixel of interest (POI) and defining a weight distribution function for the filter according to some specified requirements.

Buffer overflow is the most dangerous attack method that can be exploited. According to the statistics of CERT (Computer Emergency Readiness Team), buffer overflow accounts for 50% of the current software vulnerabilities, and this ratio is going up. Considering a subset of C language and Mini C, this paper presents an abstract machine model that can realize buffer overflow detection, which is based on operation semantic. Thus, the research on buffer overflow detection can be built on strict descriptions of operation semantic. Not only the correctness can be assured, but also the system can be realized and extended easily.

A novel quantum coding mechanism is proposed to solve the travelling salesman problem (TSP) based on the quantum-inspired evolutionary algorithm. It adopts Q-bit individual to encode the visited sequence of the cities and employs the quantum rotation gate to adjust the population dynamically. Experimental results of 14 cities show that the proposed approach is feasible and effective for small-scale TSPs, which indicates a promising novel approach for solving TSPs.

A modified coevolution algorithm is proposed and applied to fuzzy modelling. Two populations are evolved in the evolutionary processes with parallel running: membership functions by genetic algorithm (GA) and rule sets by genetic programming (GP). Based on rough set theory, the significance of the attributes of the sample data sets is used to benefit the evolution. Moreover, a tree-pruning operator is introduced in GP to limit the code bloat.

In this talk we combine a meshless (MFS) with different regularization methods to solve Cauchy problems of elliptic differential operators. The main idea of MFS is to approximate the unknown solution by a linear combination of fundamental solutions whose singularities are located outside the computational domain. Three regularization methods based on the singular value decomposition with four different choice strategies for regularization parameters are proposed.

The Smoothed Particle Hydrodynamics (SPH) method is used to simulate the dynamics of the underwater explosion (UNDEX) surrounded by an iron wall. One-dimensional vertical elastic oscillation of an iron stick and oscillation of an explosive gas caused by UNDEX surrounded by rigid walls are examined to verify the solid model and the UNDEX model focusing on the interaction between the explosive gas and the surrounding water, and the results agree well with the theoretical value and the previous study. In the simulation result, the shock wave impacts the iron wall, and the wave propagates in the iron wall and reflects at the interface. The SPH method qualitatively reproduces the dynamics of UNDEX surrounded by the iron wall. A potential of the SPH method for a prediction of the explosion damage is demonstrated in the present study.

This paper presents an investigation of effects of various parameters used in 3D SPH simulation of classical Taylor-bar test. The investigation focuses on density evolution approaches, material strength models, smoothing length adaptation schemes and sensitivity of artificial viscosity constants. Based on the comparisons on the numerical results obtained, some conclusions are made which are useful in future SPH applications to solid impact and penetration problems.