In the construction industry, construction process includes a variety of design stages with cooperation and regulation by many related disciplines. In addition, the construction market is growing and becoming more complex. With this characteristic, design information has become more and more complicated and difficult to manage by the simple and traditional data management methodology. In the practical field, although CAD has been widely available for the last ten years, related disciplines have not shared digital information efficiently. This paper suggests a construction CAD data exchange model that has been developed through investigation and analysis of Korean construction CAD practices and foreign CAD standards. Moreover, this paper investigates a CAD data exchange model using STEP to improve information availability and overcome the limit of CAD systems.

The description of enterprise activities is the basis fur process improvement and information system building. To describe such activities, it is necessary to model the enterprise activities from the abstraction level to the implementation level in a stepwise and integrated form. For this reason, several modeling approaches have been proposed. However, most of them lacked the stepwise or integration aspects although some of them covered overall levels. This study proposes the hierarchical modeling approach for integrating the enterprise activity model from the abstraction level to the implementation level systematically. It is composed of five modeling levels such as function level, process level, task level, document workflow level, and event flow level. This study discusses the definition and characteristics of each level and compare our modeling frame with other modeling methodologies in case study.

Presented in this paper is a CPO tool-path linking procedure optimizing technological objectives, such as dealing with islands (positive and negative) and minimizing tool retractions, drilling holes and slotting. Main features of the proposed algorithm are as follows; 1) a data structure, called a 'TPE-net', is devised to provide information on the parent/child relationships among the tool-path-elements, 2) the number of tool retractions is minimized by a 'tool-path-element linking algorithm'fading a tour through the TPE-net, and 3) the number of drilling holes is minimized by making use of the concept of the 'free space'.

This study proposes an improved genetic algorithm (GA) to derive solutions for facility layout problems having inner walls and passages. The proposed algorithm models the layout of facilities on a flour-segmented chromosome. Improved solutions are produced by employing genetic operations known as selection, crossover, inversion, mutation, and refinement of these genes for successive generations. All relationships between the facilities and passages are represented as an adjacency graph. The shortest path and distance between two facilities are calculated using Dijkstra's algorithm of graph theory. Comparative testing shows that the proposed algorithm performs better than other existing algorithm for the optimal facility layout design. Finally, the proposed algorithm is applied to ship compartment layout problems with the computational results compared to an actual ship compartment layout.

In this paper we present a remeshing algorithm for irregular meshes with boundaries. The irregular meshes are approximated by regular meshes where the topological regularity is essential for the multiresolutional analysis of the given meshes. Normal meshes are utilized to reduce the necessary data size at each resolution level of the regularized meshes. The normal mesh uses one scalar value, i.e., normal offset value which is based on the regular rule of a uniform subdivision, while other remeshing schemes use one 3D vector at each vertex. Since the normal offset cannot be properly used for the boundaries of meshes, we use a combined subdivision scheme which resolves a problem of the proposed normal offset method at the boundaries. Finally, we show an example to see the effectiveness of the proposed scheme to reduce the data size of a mesh model.

This paper describes the design process of super water-saving toilet bowl system by the theory of inventive problem solving (TRIZ). The physical contradiction in TRIZ is defined far saving water in toilet bowl system with preventing the bad smell from septic tank. The super water-saving toilet bowl system is obtained by using the separation principle in time far resolving the physical contradiction. The real system is made using CAD tools. The consumption of water in the system implemented, is estimated about 3 ιcomparing with 13 ι of that in conventional toilet bowl system.

Under the concept of global economy, the enterprises are assigning design and production environments around the world in different areas. In shipbuilding companies, a serious problem of information exchange emerges as companies use traditional hardware and very distinct softwares appropriate to their field of expertise. To overcome the decreased productivity due to the interruption of information, the concept of simultaneous engineering and concurrent design becomes very significant. In this article, the concept of collaborative design based on internet environments is described. Especially, the core technologies to achieve collaborative design environments among shipbuilding companies, ship owners, ship classification societies, model basin, and consulting companies are adopted.

This paper describes the wire EDM (Electric Discharge Machining) CAM system considering a variable taper wire-cut and an unmanned wire EDM during the night. Wire EDM is applicable to all materials that are fairly good electrical conductors, including metals, alloys and most carbide. Thus it provides a relatively simple method for making holes of any desired cross section in materials that are too hard or brittle to be machined by most other methods. In this paper we classify variable taper wire-cut machining patterns and variable taper wire-cut geometries. Also we determine unmanned wire EDM patterns fur the productivity of wire EDM industry. Developed system consists of two modules: 1) Variable taper wire EDM module guarantees the length ratio machining function, the parametric ratio machining function and the marking function. 2) Unmanned wire EDM module guarantees the automatic wire EDM during the night. The proposed system has been tested in the fields and found to be a useful system.