• Korean Journal of Computational Design and Engineering
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• v.21 no.4
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• pp.378-388
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• 2016

As the needs for the mega-sized, high-rise and irregular shape of building increase, domestic application of BIM in construction industry is increasing in recent years. In this circumstance, interests in BIM modeling and modeling detail level have been also increased. BIM that is based on a three-dimensions, requires a specific and precise building expressions. And model expression level required for each phase such as design, construction, and maintenance of the construction project could be different as its needs. Because that it is not clear to define the criteria for the expression level of construction BIM model, It is difficult to decide how detail and what to model is appropriate in the practical application of BIM model. It could be the reason why the productivity in construction project became lower and lower. In this study we consider the way how to improve the productivity of BIM and analyze the appropriate representation level of construction BIM model through the experts' survey. The results of study could suggest the basis for an appropriate expression level of construction BIM model.

• Korean Journal of Computational Design and Engineering
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• v.21 no.3
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• pp.281-295
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• 2016

Lately, the management of domestic BIM performance is quite lacking, as the evaluation and management data from successful cases of BIM implementation both on projects and in companies, and related effects (time, cost and other physical gains) are not well kept for future use in BIM development. In order to overcome the above obstacles, a systematic approach to evaluating BIM adoption with focus on particular elements like BIM implementation environment and processes, and the physical factors yielded by BIM, is necessary. In this study, objective and detailed assessment indicators and weights that are appropriate for the domestic situation were derived through research for purposes of developing a web-based BIM maturity measurement program that is tailor-made for the Korean construction atmosphere. Through a company's self-maturity measurement, excellent quality of BIM deliverables and output can be achieved and managed. Furthermore, the domestic BIM capacity can gradually increase since design firms' BIM capability can be judged during procurement basing on measurement indicators.

• Korean Journal of Computational Design and Engineering
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• v.22 no.1
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• pp.37-43
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• 2017

3D printing techniques can be used in various application fields and many researches have been reported. FDM (Fused Deposition modeling) can make multi-material or multi-color models with the simultaneous use of two or more filaments. In a dual-nozzle FDM printers, while the active nozzle is working, the remaining nozzle will be idle. The remaining molten resins inside an idle nozzle can ooze out unwantedly. The spill over from the resting nozzle produces unwanted remaining on the fabricated product. In this research, we suggest a method for optimizing building position of a model to minimize the unwanted spill-over that could possibly contaminate the final product. The method is based on minimizing the two intersection volumes. The first intersection volume is obtained by intersecting the volume defined by the first material and the Minkowski sum between the volume of the first material and the vector obtained by subtracting the center point of the first nozzle from the center point of the second nozzle. The second intersection volume can be obtained by reversing the role of the first and second volumes and nozzles. Some results obtained from the implementation using the Parasolid (Siemens) geometric modeling kernel is presented.

• Korean Journal of Computational Design and Engineering
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• v.22 no.1
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• pp.59-69
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• 2017

Internal capacity of a refrigerator is an important indicator for design and purchasing criteria. The components facing the internal space may have holes or gaps between parts. In traditional way, design engineers manually remodeled the parts to fill the holes and the gaps for enclosed boundary of the internal space. Then they calculated internal volume by subtracting the assembly of parts from its enclosing volume. However, filling holes and gaps is not an automated process requiring a plenty of labor and time. In this research, we have developed a voxel-based method to estimate the internal volume of a refrigerator automatically. It starts transforming all components facing the interior space into voxels and fills all holes and gaps automatically by the developed hole-filling algorithm to form a completely closed boundary of the assembly. Then, it identifies the boundary voxels that are facing to the internal voxels with any part of the component. After getting the intersection points between the boundary voxels and the surfaces of components, it generates the boundary surface of triangular facets with the intersection points. Finally, it estimates the internal volume by adding volume of each tetrahedron composed of a triangle of boundary surface and an arbitrary point.

• Korean Journal of Computational Design and Engineering
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• v.10 no.2
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• pp.133-142
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• 2005

This paper proposes an object-oriented conceptual information model of mechanical assemblies, named open assembly model (OAM). The proposed assembly model primarily defines hierarchical relationships between parts and subassemblies. Together with the assembly hierarchy. the model also provides a way to represent tolerances, kinematic information, and parametric assembly constraints. Relational information such as mating conditions and degree of freedom between parts and subassemblies is captured via assembly features and relationships thereof. The information model is described using class diagrams of the Unified Modeling Language (UML), and instance diagrams are used to exemplify the proposed information model. The conceptual model presented in this paper is an integrated information model for assembly representation, which could supply necessary information for tolerance analysis and synthesis, kinematic simulation, and assembly simulation. Such a conceptual information model plays an important role for the exchange of information between modeling, analysis and planning systems. Hence, the proposed model could serve as a framework for developing data exchange standards of mechanical assemblies. The proposed model is demonstrated through a case study of a planetary gear assembly.

• Korean Journal of Computational Design and Engineering
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• v.11 no.5
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• pp.335-343
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• 2006

Design changes for an original surface model are frequently required in a manufacturing area: for example, when the physical parts are modified or when the parts are partially manufactured from analogous shapes. In this case, an efficient 3D model updating method by locally adding scan data for the modified area is highly desirable. For this purpose, this paper presents a new procedure to update an initial model that is composed of combinatorial triangular facets based on a set of locally added point data. The initial surface model is first created from the initial point set by Tight Cocone, which is a water-tight surface reconstructor; and then the point cloud data for the updates is locally added onto the initial model maintaining the same coordinate system. In order to update the initial model, the special region on the initial surface that needs to be updated is recognized through the detection of the overlapping area between the initial model and the boundary of the newly added point cloud. After that, the initial surface model is eventually updated to the final output by replacing the recognized region with the newly added point cloud. The proposed method has been implemented and tested with several examples. This algorithm will be practically useful to modify the surface model with physical part changes and free-form surface design.

• Korean Journal of Computational Design and Engineering
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• v.13 no.4
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• pp.286-295
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• 2008

Construction industry, which is a composite industry being performed by organic combination of various tasks, gives birth to a various of information in the stages of planning, designing, and maintenance management. In particular, the drawing information is broad in the scope of use because it contains all information about buildings as wall as bid, materials, contracts. Therefore, the management of drawing information security is one of the most important factors, which determines the success of failure of business. The major findings and result of this study are as follows to control the distributed drawing information in the collaboration environment. 1) Analysis for function and practical use of DRM in the construction industry. 2) Proposal for applications of DRM that can secure IFC model-based drawing information in the collaboration environment. 3) Extraction from additional IFC entities to apply DRM to part 21 physical files 4) Analysis for functions which are necessary in DRM application prototype system and development of the system. 5) Development IFC model-based DRM prototype system.

• Korean Journal of Computational Design and Engineering
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• v.13 no.4
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• pp.243-254
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• 2008

As modular production becoming increasingly widespread in globalized manufacturing industries, sub modules or parts of the final product are being provided by many suppliers. Some part suppliers design their own products for themselves. In some cases, part suppliers provide the same type of product to multiple OEM companies. Because all part suppliers and OEM companies typically cannot use the same CAD system, engineering change in the CAD model of one company cannot be directly propagated to related CAD models of other companies. Even if two companies use the same CAD system, it may be difficult to share their CAD model owing to corporate security policy. In this paper, a neutral reference model that consists of a neutral skeleton model and an external reference data model is proposed as a new medium for the sharing and propagation of engineering change information among collaborating companies.

• Korean Journal of Computational Design and Engineering
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• v.17 no.2
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• pp.79-90
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• 2012

In digital virtual manufacturing simulation, Digital Human widely used to optimal workplace design, enhancing worker safety in the workplace, and improving product quality. However, the case of ergonomics simulation solutions to support digital human modeling, Optimal DHM (Digital Human Model) data needed to develop and perform DHM will collect information related to the production process. So simulation developer has burden of collecting information. In this study, to overcome the limitations of existing solutions, we proposed the ADAGIO(Automated Digital humAn model development for General assembly usIng Ontology) framework. The ADAGIO framework was developed for DHM ontology to support optimal deployment of digital virtual environment and in order to ensure consistency of simulation components that are required for simulation modeling was made of a library.

• Korean Journal of Computational Design and Engineering
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• v.1 no.1
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• pp.20-32
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• 1996

The boundary evaluation technique for Boolean operation on non-manifold models which is regarded as the most popular and powerful method to create and modify 3-D CAD models has been developed. This technique adopted the concept of Merge and Selection in which the CSG tree for Boolean operation can be edited quickly and easily. In this method, the merged set which contains complete information about primitive models involved is created by merging primitives one by one, then the alive entities are selected following the given CSG tree. This technique can support the hybrid representation of B-rep(Boundary Representation) and CSG(Constructive Solid Geometry) tree in a unified non-manifold model data structure, and expected to be used as a basic method for many modeling problems such as data representation of form features, and the interference between them, and data representation of conceptual models in design process, etc.