Papers by Author: Ichiro Hagiwara

Abstract: New structure patterns of metal panel are used in modern life such as Truss Core Panel (TCP). It is used as flooring or wall material in train, car, aircraft, and buildings etc. at present. Beyond the traditional material, the new patterns have lighter weight and harder stiffness. However, in general, there are difficulties in forming truss core panel, which should be getting forming limit and developed. In this paper, firstly forming limitation is discussed for tetrahedral truss core. Secondly improved hotforming simulation was set for improvement.

Abstract: This paper explains and demonstrates a novel method of photorealistic simulation of two natural atmospheric phenomena, namely Emei Glory and Fog. Emei Glory is a natural phenomenon and can be observed in the area of famous Emei Mountain in China. The back-scattering effect of water droplet in fog causes this phenomenon. We use Mie scattering theory to simulate the glory and fog. Then calculate the spectral scatter intensity. For rendering, we adopt the method of single scattering integral to generate the whole scene by exploiting the parallel computation power of GPU. We demonstrate our synthetic results compared with the photographs at last.

Abstract: Over the past decades, Distributed Systems (DS) have been adopted for industrial applications to improve the system efficiency because distributed architecture has advantages in resource utilization, fault toleration .etc. Multi-Agent System (MAS) arises from combination of the theories of artificial intelligence and distributed systems. One character of MAS is their self-organization, so how to implement an effective mechanism for self-organization of agents is important to a MAS system, this paper describes the design and implementation of a Mobile-C based agent management system, in which Mobile-C was adopted as the implementation platform, and this paper also described an agent-based cooperative design application using this system to manage all the agents involved.

Abstract: In this paper, a robust tetrahedral mesh generation method based on Advancing Front technique is proposed. The proposed method inherits advantages of Delaunay method and Advancing Front method, such as efficiency of Delaunay method and maintaining the given boundary triangle mesh exactly of advancing front method. Tetrahedral mesh is generated from the given triangle surface mesh. This method mainly includes three stages. Firstly, the minimum container box of the triangular surface mesh is calculated and points are inserted into the box. Then the proper point is selected out to generate tetrahedron’s layers from surface to the interior volume of the model, so g the surface mesh can be maintained. The operation is simplified, and calculation efficiency is also higher than common Advancing Front method. At last, triangle intersection is examined. This technique allows generating the tetrahedral mesh with high quality elements with surface mesh preservation. A shoes model with both convex and concave surface is chosen for the experiment. The result clarified the robust and high efficiency of the proposed algorithm.

Abstract: Surface reconstruction and NURBS surface generation based on 3D surface mesh partitioning are more essential today. In this paper, we present a new method of automatic partitioning complex surface meshes into the bounded regions with four corner points (quadrilateral regions) based on using control points (notches) for NURBS surface generation. The procedure of this method consists of 4 major steps: (1) the 3D polygons mapping into 2D polygons; (2) convex decomposition of the polygons in the 2D space; (3) subdivision of each polygons into quadrilateral regions; (4) mapping the received 2D regions onto the 3D original surface mesh. Main contribution in this paper is automatic partitioning of the 3D segmented parts of complex surfaces into quadrilateral regions based on combination of segmentation, mapping, and subdivision techniques. Automatic partitioning allows us to create not rectangular but quadrilateral regions without using any user-dependent parameters for further NURBS surface generation.

Abstract: Scheduling for the flexible job shop is very important in fields of production management. To solve the multi–objective optimization in flexible job shop scheduling problem (FJSP), the FJSP multi-objective optimization model is constructed. The cost, quality and time are taken as the optimization objectives. An improved strength Pareto evolutionary algorithm (SPEA2+) is put forward to optimize the multi-objective optimization model parallelly. The algorithm uses a new model of a Multi-objective genetic algorithm that includes more effective crossover and could obtain diverse solutions in the objective and variable spaces to archive the Pareto optimal sets for FJSP multi-objective optimization. Then an approach based on fuzzy set theory was developed to extract one of the Pareto-optimal solutions as the best compromise one. The optimization results were compared with those obtained by NSGA-II and POS. At last, an instance of flexible job shop scheduling problem in automotive industry is given to illustrate that the proposed method can solve the multi-objective FJSP effectively.