Jin-Xiang Dong

Ant colony search algorithms for optimal packing problem

Ant Colony optimization takes inspiration from the behavior of real ant colony to solve optimization problems. This paper presents a parallel model for ant colony to solve the optimal packing problem. The problem is represented by a directed graph so that the objective of the original problem becomes to find the shortest closed circuit on the graph under the problem-specific constraints. A number of artificial ants are distributed on the graph and communicate with one another through the pheromone trails which are a form of the long-term memory guiding the future exploration of the graph. The algorithm supports the parallel computation and facilitates quick convergence to the optimal solution. The performance of the proposed method as compared to those of the genetic-based approaches is very promising.

Real-time rendering of raining animation based on the graphics hardware acceleration

We present an efficient method for simulation of raining phenomenon in real time by taking advantage of the parallelism and programmability of GPU (graphic processing unit). Our implementation of the method is based on particle systems and collision detection. Splashing of raindrop is simulated using a series of stylized textures and rotations of point sprites. Taking into account human perception in raining phenomenon of real world, the effects such as light influence, depth of field, motion blur, have been applied. The test results show that our method is efficient and is feasible to solve the problem of 3D raining simulation in real time for more general environment with complex geometry.

A parallel algorithm of polygons packing based on ant colony

This paper presents a novel algorithm for optimal packing problem by combining ant colony algorithm with BLF (bottom-left-fill) heuristic approach. The proposed algorithm not only automatically looks for the best sequence of the polygons and each polygons optimum rotation by ant colony algorithm but also implements the exact layout with the BLF heuristic algorithm. Moreover, the algorithm supports the parallel computation and facilitates quick convergence to the optimal solution. The experimental results show the effectiveness of our algorithm comparing with the other methods.

Model compression and transmission in collaborative CAD

CAD systems increasingly require distributed collaborative design capabilities to meet the designers at different geographical locations to co-develop parts. It involves transmitting the CAD models back and forth among the systems in a distributed design environment. However, it is very difficult to apply because the CAD models are always very complex and the current network bandwidth is limited. In this paper, some important work about the compression and transmission of CAD models through the network is elaborated. Meanwhile, because a feature-based model always contains many extruded and revolved features, then we propose a new approach to transmission of feature-based models to deal with these extruded and revolved features. This approach can effectively cut down the transmission delay of the feature-based models, especially when the model contains many extruded and revolved features.

A hybrid registration of medical images using intensity information and landmark points

This paper proposes a hybrid registration approach of medical images using intensity information and landmark points. In our scheme, the transformation function is obtained by interpolating discrete landmark points with the local constraint deformation. Then the intensity information is employed to improve the transformation function by minimizing the criterion SSD (sum of squared differences) with Lagrangian multipliers and Newton method. The experimental results show that the landmark information alone is generally not sufficient to accurately register the images and the incorporation of intensity information significantly improves the results

Concurrency conflicts solving for collaborative feature modeling

Most of current collaborative feature modeling systems use the token-passing method as its collaborative strategy that makes the collaborative design between multi-clients inflexible and inefficient. Based on the analysis of feature operation in collaborative environment, we propose a new method to solve the concurrency conflicts, an enhanced naming mechanism for collaborative feature modeling to preserve the design intensions, and a process for non-locked multi-client collaborative design. The algorithms have been implemented in a prototype system integrating C++, Java3D and VML, CORBA technologies. Flexibility and efficiency in collaborative feature modeling environment have been achieved in our system.