• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.24 no.2
• /
• pp.172-176
• /
• 2015

In this research, a tool was developed to automate one-dimensional finite element analysis (1D FEA) for design of a machine tool spindle. Based on object-oriented programing, this tool employs the objects of a CAD system to construct a geometric model and then to convert it into the FE model of 1D beams at the workbenches of the CAD system with minimum data to define the spindle such as bearing positions and cross-sections of the shaft. Graphic user interfaces were developed for users to interact with the tool. This tool is helpful in identifying a near optimal design of the spindle with the automation of the FEA process with numerous design changes in minimum time and efforts. It is also expected to allow even design engineers to perform the FEA in search of an optimal design of the machine tool spindle.

• The KIPS Transactions:PartD
• /
• v.8D no.1
• /
• pp.32-43
• /
• 2001

Due to the limitation of data modeling power and the view update ambiguity, relational view is limitedly used for engineering applications. On the contrary, object-oriented database view would playa vital role in defining custom interface for engineering applications because the above two limitations of the relational view are overcome by the object-oriented view. Above all, engineering application data interface should fully support updates. More specifically, updates against the data interface needs to be unambiguously defined and its semantic behavior should be equal to base schema updates'. For this purpose, we define the notion of update semantic preserving which means that view updates displays the same semantics as base schema. Besides, in order to show the feasibility of this characteristics, specific and concrete algorithms for update preserving updates are presented for a CAD specialized object-oriented database view - MultiView. This paper finds that in order that virtual classes coudld form a schema with 'isa' relationships rather than just a group of classes, the update semantics on the virtual classes should be defined such that the implied meaning of 'isa' relationships between classes are not to be violated. Besides, as its sufficiency conditions, we derived the update semantics and schema constituable conditions of the virtual classes that make view schemas look like base schemas. To my best knowledge, this is the first research that presents the sufficiency conditions by which we could defined object-oriented views as integrated schemas rather than as separate classes.

• Journal of Ocean Engineering and Technology
• /
• v.12 no.3 s.29
• /
• pp.86-95
• /
• 1998

CAD/CAM program developers have made substantial progress in enabling engineers to design, analyze, visualize, visualize, and simulate the performance of structures and systems. Many researchers, however, agree that there is still a way to go before the existing commercial computer software can be used in ship structural analysis to their full potential as solvers which can identify opportunities to reduce man-hours and cut costs. CAD systems used for these works in ship yards are general-purposed and not custom-tailored for ship structures, which force end-users to do tiresome and routine works. The new preprocessor "MeshGen" announced in this study can load several ship types and user-friendly generate their FE meshes employing the object-oriented approach based on the parametric and top-down design. Also "MeshGen" reduces dramatically the time required to prepare CAD models under window-based environments on desktop personal computers and makes it much easier and faster for end-users to change topology and material properties.

• Journal of the Society of Naval Architects of Korea
• /
• v.31 no.3
• /
• pp.19-30
• /
• 1994

The modeling of a product data is becomming more and more important in engineering environment, especially for the development of CAD/CAM system as a basis of computer integrated manufacturing system. Model is a formalized representation of the real world, and modeling is the task to identify, abstract, and formalize the product information into an unambiguous representation. In this study, the piping system, one of typical product of ship outfitting system, is modeled. The STEP idea is followed to provide a common mechanism to represent the product information throughout the life-cycle, and the object oriented paradigm is used in the analysis and design of the model. The definitions given within this model are independent of the specific application domain so that the same methodology can be used for other purpose.

• Korean Journal of Computational Design and Engineering
• /
• v.2 no.4
• /
• pp.222-236
• /
• 1997

Conventional solid or surface modeling systems cannot represent both the complete solid model and the abstract model in a unified framework. Recently, non-manifold modeling systems are proposed to solve this problem. This paper describes FlexDesigner, an open kernel system for modeling non-manifold models. It summarizes the data structure for non-manifold models, system design methodology, system modularization, and the typical characteristics of each module in the system. A data structure based on partial-topological elements is adopted to represent the relationship among topological elements. It is efficient in the usage of memory and has topological completeness compared with other published data structures. It can handle many non-manifold situations such as isolate vertices, dangling edges, dangling faces, a mixed dimensional model, and a cellular model. FlexDesigner is modularized hierarchically and designed by the object-oriented methodology for reusability. FlexDesigner is developed using the C++ and OpenGL on both SGI workstation and IBM PC.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2005.06a
• /
• pp.982-986
• /
• 2005

Digital Manufacturing is a technology to facilitate effective product developments and agile productions by digital environments representing the physical and logical schema and the behavior of real manufacturing system including manufacturing resources, processes and products. A digital virtual factory as a well-designed and integrated environment is essential for successful applications of this technology. In this research, we constructed a sophisticated digital virtual factory by measuring and 3-D CAD modeling using parametric methods. Specific parameters of each objects were decided by object-oriented schema of the digital factory. It is expected that this method is very useful for constructions of a digital factory, and helps to manage diverse information and re-use 3D models.

• Journal of Korea Multimedia Society
• /
• v.9 no.6
• /
• pp.693-699
• /
• 2006

Object-oriented databases (OODBs) have been adopted for managing non-standard applications such as computer-aided design (CAD), office document management and many multimedia applications. One of the major characteristics of OODBs is class hierarchy where a subclass is allowed to inherit the definitions defined on its superclasses. In this paper, I present the evaluation metrics for class hierarchy quality in OODBs. These metrics are developed to determine if a concurrency control scheme can achieve good performance or not on a given class hierarchy. I first discuss the existing concurrency control schemes for OODBs. Then I provide evaluation metrics based on structural information and access frequency information in class hierarchies. In order to discuss significance of the proposed performance metrics, an analytical model is developed. Analysis results show that the performance metrics are important factor in concurrency control performance. I consider both single inheritance and multiple inheritance. The proposed metrics can be used to provide guidelines on how to design class hierarchy of an OODB for maximizing the performance of concurrency control technique.

• Korean Journal of Computational Design and Engineering
• /
• v.7 no.3
• /
• pp.202-209
• /
• 2002

It is difficult to support collaborative design with a conventional ship CAD system which manages design information using files. In this research, file storage has been replaced with a database. This paper describes the OpenDIS which is an interface between the geometric kernel and the database. Its main purpose is to implement the CAD system which has the STEP database as the native storage. A prototype CAD system has been implemented using that OpenDIS interface which is implemented by OpenCascade geometric kernel and the Objectstore object-oriented database. The STEP methodology is used as the database schema. This CAD system has been applied to the hull design of a ship in order to verify the usefulness of the interface.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• 2008.11a
• /
• pp.645-648
• /
• 2008

Due to the rapid increase super high-rise buildings and multi-complex spaces, the space of a staged a very complex and variety of situations occur in the space of the building. The management is still based on limited information obtained by the administrator depends on the decision is made. However, the ability of human beings during a limited time, analysis limited information, and there is a limit to take the appropriate action and situation. To overcome these limitations high information technology that can be fused to take advantage of ubiquitous system is to offer. The aim of this study is on object-oriented 3D data and collected information about the status of the 3D data extraction, to exchange data between systems, the use of object-oriented 3D data, and I studied common space information of a multi-use facilities extracted from 3D CAD information to send to the GIS system.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1995.10a
• /
• pp.1022-1027
• /
• 1995

We present a framework of an intelligent design support system for embodiment design of machine tools which can support efficiently and systematically the machine design by utilizing design knowledge such as objects(part), know-how, public, evaluation, and procedures. The design knowledge of machining center has been accumulated through interview with design experts of machine tool companies. The processes of embodiment design of machining center are established. We also introduce a hybrid knowledge representation so that the systm can easily deal with various and complicated design knowledge. The intelligent design system is being developed on the basis of object-oriented programming, and all parts of a design object, machining center, are also classified by the object-oriented modeling. For the demonstration of effectiveness of the suggested system, a structural design system for machine tools is implemented.