• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.4
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• pp.375-382
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• 2011

Nowadays computer graphic softwares have opened a lot of potential by providing parametric modeling and generative algorithms which are useful not only to describe various geometrical shapes but also to implement a designer's intent in terms of modules systematically. This study has proposed a way of developing a module for generating preliminary structural configuration using such potential computer graphics. Especially parametric modeling and generative algorithm are utilized to define various design alternatives, and moreover use of dynamic graphics enables designers to generate a structural form on one side and a force flow diagram correspondingly provided on the other. This ultimately leads to rational preliminary design of a structural form considering its force flow.

• Journal of the Society of Naval Architects of Korea
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• v.29 no.4
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• pp.36-44
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• 1992

To improve the B-spline form-parameter method being used in preliminary hull form generation, this research considers fuzzy modeling of the relationships among form-parameters based on the actual ship data analysis. Form-parameter values are determined through fuzzy inference. To verify the validity of the proposed fuzzy model the hull forms of actual ships are compared with hull forms generated by fuzzy model.

• Journal of Korean Association for Spatial Structures
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• v.7 no.2 s.24
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• pp.115-124
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• 2007

The initial shape is arrived at by a self-formation process, which accomplishes a form in the natural world, or is determined analytically by considering the equilibrium of initial stress only. Therefore, the self-formation process, which accomplishes a form in the natural world is grasped and the types of modeling techniques available to find the shapes of soft structures are well investigated and classified. To establish a form-finding modeling techniques, the models of string, soap film, fabric, rubber, plaster, and etc. are used. These modeling techniques can be used as a method of understanding the characteristics of structures when the material of model shows similar characteristics. Generally, the model test confirms the structure based on numerical analysis, at the same time it is important preceding process to develop such a program. With the above process, the relationship between model test and numerical analysis becomes a feedback process. Therefore, in this study, two examples which have been accomplished from such a technique are investigated and considered according to modeling process.

• Architectural research
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• v.15 no.2
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• pp.103-109
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• 2013

Various types of building information should be linked to 3D model objects for their effective use by stakeholders. Because Building Information Modeling (BIM) based on 3D is used by different stakeholders, the created BIM need standard guidelines for each purpose, as, for example, for quantity take-off. Thus, this study was conducted to propose guidelines for BIM modeling for quantity take-off in the framework, especially, in the concrete and form. The proposed guidelines adopted each element of the BIM model based on an analysis of the problem of the general BIM model. Moreover, the usability and accuracy of the reinforced structure modeling guidelines were verified by comparing the quantity of the commercial estimation software and the modeling quantity using the proposed modeling guidelines.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.1057-1062
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• 2008

Representing a complex, three-dimensional shape, such as an automobile, requires a large amount of CAD data consisting of millions of approximated discontinuous points, which makes it difficult or even impossible to efficiently optimize the entire shape. For this reason, in this paper, function based design method is proposed to optimize the external shape of an automobile. A vehicle modeling function was defined in the form of a Bernstein polynomial to smoothly express the complex 2D and 3D automobile configurations. The sub-sectional parts of the vehicle modeling function are defined as section functions through classifying each subsection of a box model. It is shown that the use of the vehicle modeling functions has the useful advantages in an aerodynamic shape optimization.

• International Journal of CAD/CAM
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• v.2 no.1
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• pp.13-21
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• 2002

It is not possible to exchange parametric information of CAD models based on the current version of STEP. The design intent can be lost during the STEP transfer of CAD models. The Parametrics Group of ISO/TC184/SC4 has proposed the SMCH schema, which includes constructs for exchange of parametric information. This paper proposes a macro-parametric approach that is intended to provide capabilities to transfer parametric information including design intents. In this approach, CAD models are exchanged in the form of macro files. The macro file contains the history of user commands, which are used in the modeling phase. To exchange CAD models using the macro-parametric approach, the modeling commands of several commercial CAD systems are analyzed. Those commands are classified and a set of standard modeling commands has been defined. Mapping relations between the standard modeling commands and the native modeling commands of commercial CAD systems are defined. The scope of the current version is limited to parts modeling, not assemblies.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.8 no.12
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• pp.49-63
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• 1985

This paper is focused on the introduction of the types of models and explanation of the fundamental concepts and theory for development and use of the corporate planning and modeling system. Nowadays, a great deal of companies have been or experimenting with some form of a corporate planning and modeling system to support managerial and strategic decision making. From previous studies it was noted that most applications have tended to be financially based. This trend will probably continue. However, with the software and hardware currently available it is likely that companies will move more toward integrated models that link marketing, production, as will as financial areas. More emphasis will undoubtedly be placed on the use of econometric modeling, since this subelement of the overall planning and modeling process is closely tied to the market place and the economy. At any rate, wherever the development of corporate planning and modeling system is directed, clear understanding for the fundamental concepts and elements of the system is settled in advance in order to develope and use it.

• Asia pacific journal of information systems
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• v.9 no.1
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• pp.115-142
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• 1999

Legacy applications are valuable assets that should be integrated into next generation business systems. To gain this advantage, progressive companies can reverse engineer the legacy business operations. This paper presents a form-driven object-oriented reverse engineering(FORE) methodology by the use of business forms to recover semantics of legacy applications. They retain the user-oriented contents of business and thus are easily understandable. Our form driven object-oriented reverse engineering methodology consists of five phases: form and usage analysis, form object slicing, object structure modeling, scenario design, and model integration. Knowledge about form structure and user interaction with legacy applications is used to capture the design semantics. An object model, which consists of an object structure model and scenario results from such form knowledge. The resulting object model is more likely to help reverse engineers understand and reuse legacy systems.

• Korean Journal of Computational Design and Engineering
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• v.10 no.4
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• pp.244-253
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• 2005

In the initial ship design stage of shipyards, the hull form design, the basic design (compartment modeling and ship calculation), and the hull structural design are being performed by different systems. Thus, the problem on interfaces between these systems occurs. To solve this, we developed the hull form design system 'EzHULL' and the compartment modeling and ship calculation system 'EzCOM-PART' for developing finally an integrated ship design system. And, in this study, we present an object-oriented hull structural design .system 'EzSTRUCT', which is developed recently. A structural design in an initial design stage can be frequently changed, because the design is not firmly determined yet. Therefore, designers perform the simplified structural modeling with bigger structural parts (or objects) such as deck, longitudinal bulkhead, etc. in the initial design stage, and the detailed structural modeling with smaller structural parts such as plate, seam, slot, etc. in the detailed design stage. However, the existing hull structural CAD system used in a shipyard is not efficient in generating a 3D CAD model in the initial design stage, because it has difficulty in handling frequent changes in design. Therefore, designers initially draw 2D drawings in the initial design stage, and generate the 3D CAD model from these 2D drawings in the detailed design and production design stages. In this study, the hull structural design system, which can efficiently generate a 3D CAD model through rapid modeling at an initial design stage, was developed in this study To evaluate the applicability of the developed system, we applied it to hull structural modeling of various ships such as a VLCC, a bulk carrier, etc. As a result, it could efficiently generate a 3D CAD model of a hull structure.

• Explosives and Blasting
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• v.23 no.3
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• pp.27-42
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• 2005

An explosion modeling technique was developed by using the spherical discrete element code, $PFC^{3D}$, which can be used to model the dynamic stress wave propagation phenomenon. The modeling technique is simply based on an idea that the explosion pressure should be applied to a $PFC^{3D}$ particle assembly not in the form of an external force (body force), but in the form of a contact force (surface force). The stress wave propagation modeling was conducted by simulating the experimental approach based on the Hopkinson's effect combined with the spatting phenomenon that had previously been developed to determine the dynamic tensile strength of Inada granite. As a result, the stress wave velocity obtained by the proposed modeling technique was 4167 m/s, which is merely $3\%$ lower than the actual wave velocity of 4300 m/s for an Inada granite.