• 한국CDE학회논문집
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• 제16권1호
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• pp.11-20
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• 2011

A structured beam laser is often used to scan object and make 3D model. Multiple cameras are inevitable to see occluded areas, which is the main reason of the high price of the scanner. In this paper, a low cost 3D foot scanner is developed using one camera and two mirrors. The camera and two mirrors are located below and above the foot, respectively. Occluded area, which is the top of the foot, is reflected by the mirrors. Then the camera measures 3D point data of the bottom and top of the foot at the same time. Then, the whole foot model is reconstructed after symmetrical transformation of the data reflected by mirrors. The reliability of the scan data depends on the accuracy of the parameters between the camera and the laser. A calibration method is also proposed and verified by experiments. The results of the experiments show that the worst errors of the system are 2 mm along x, y, and z directions.

• 한국측량학회지
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• 제25권6_1호
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• pp.565-574
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• 2007

Because of most current cadastral systems maintain 2D geometric descriptions of parcels linked to administrative records, the system may not reflect current tendency to use space above and under the surface. The land has been used in multi-levels, e.g. constructions of multi-used complex buildings, subways and infrastructure above/under the ground. This cadastre situation of multilevel use of lands cannot be defined as cadastre objects (2D parcel-based) in the cadastre systems. This trend has requested a new system in which right to land is clearly and indisputably recorded because a right of ownership on a parcel relates to a space in 3D, not any more relates to 2D surface area. Therefore, this article proposes a 3D spatial data model to represent geometrical and topological data of 3D (property) situation on multilevel uses of lands in 3D cadastre systems, and a conceptual 3D cadastral model in Korea to design a conceptual schema for a 3D cadastre. Lastly, this paper presents the results of an experimental implementation of the 3D Cadastre to perform topological analyses based on 3D Network Data Model to identify spatial neighbors.

• 한국의류학회지
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• 제32권9호
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• pp.1478-1486
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• 2008

The human body composed of concave and convex curvatures, and the current 3D scanning technology which involves inherent measurement errors make it difficult to extract distinct curvature plot directly. In this study, a method of extracting the clear curvature plot and its application to the cycling pants design were proposed. We have developed the ergonomic pattern from the 3D human body reflecting cycling posture. For the ergonomic design line on the 3D human body, the 3D information on the lower part of four male bodies with flexed posture was analyzed. The 3D scan data of four subjects were obtained using Cyberware. As results, the iteration of the tessellated shell was executed 100 times to obtain optimized curvature plots of the muscles on the body surface, and the boundaries of the curvature plots were applied to the design lines. Maximum(Max-pattern) and mean curvature plots(Mean-pattern) were adopted in the design line of the cycling pants, and performance of those lines was compared with that of conventional princess line(Con-pattern). The average error of total area and length in the 2D pattern developed from the 3D flexed body surface in this study were very minimal($4.58cm^2$(0.19%) and 0.15mm(0.46%)), which was within the range of tolerable limits in clothing production. The pattern obtained from the flexed body reflecting cycling posture already included the contraction and extension of the cycling skin, so that the extra ease for movement and good fit was not need to be considered.

• 한국공작기계학회논문집
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• 제12권1호
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• pp.50-57
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• 2003

In this paper, an automated design and 3-D modeling system of an axial fan and a boss for cooling towers was developed. API and parametric design Provided by a commercial solid-modeler are engaged to automate modeling process. Design data of the boss are assumed to be given by a user with design experiences while the fan from the fan design program using three-dimensional flow analysis. An algorithm avoiding the interferences between fans and a boss is developed. The design data are registered on the database not only to remove duplicate design but also to transfer the data to ERP system.

• 한국의상디자인학회지
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• 제22권1호
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• pp.1-13
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• 2020

The purpose of this study is to create a 3D avatar from 3D human body shape data using the CLO 3D virtual clothing program and to verify the feasibility of avatar production using the virtual clothing system for verifying size and shape. The research method was to select one virtual representative model that is the closest to the mean size of each body item for each age group. Using the 3D human body scan shape of a 40-69 years old male was applied to the CLO 3D virtual wearing system. Using the CLO 3D Avatar conversion menu, we verified the feasibility of creating a 3D avatar that reproduces the human body scan shape. In the dimension comparison between the 3D avatar and the fictitious representative model, the dimension difference was noticeable in height, circumference, and length. However, as a result, the converted 3D avatar showed less than a 5% difference in most human dimensions. In addition, since the body shape and posture were reproduced similarly, the utilization of the avatar was verified.

• 한국CDE학회논문집
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• 제14권2호
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• pp.96-104
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• 2009

It gradually becomes important to study on how to efficiently integrate and manage plant lifecycle data such as 2D schematic and 3D solid data, logical configuration data, and equipment specifications data. From this point of view, converting plant design data from various systems into neutral data independent from any commercial systems is one of important technologies for the operation and management of plants which usually have a very long period of life. In order to achieve this goal, a neutral model for efficient integration and management of plant data was defined. After schema mapping between one of specification-driven plant design systems and the neutral model was performed, a plant data translator is also implemented according to the mapping result. Finally, by experiments with nuclear power plant design, the feasibility of the translator was demonstrated.

• 한국CDE학회논문집
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• 제10권1호
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• pp.70-75
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• 2005

A 3D solid element mesh generation algorithm was newly developed. 3D surface points of global rectangular coordinates were supplied by a 3D laser scanner. The algorithm is strait forward and simple but it generates mixed solid elements such as hexagonal, pyramid and prism types. Then, the surface triangular or rectangular elements were generated from the solid elements. The key of the algorithm is elimination of elements and 3D adaptive surface smoothing using given 3D surface point data.

• 산업공학
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• 제24권1호
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• pp.58-70
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• 2011

As more individuals and organizations participate in the complex design process of manufacturing industry, collaborative product development and management of the global supply chain have become more popular. Although the product quality concerns once focused on the manufacturing process, they are now directed at earlier stages of the design cycle where the engineering product is created as a 3D CAD model. In this paper, we describe the current state of product data quality activities in the manufacturing industry and the yardstick to measure 3D CAD data quality. Moreover we introduce a quality assurance method through the result of statistical analysis of 3D CAD models and suggest a six sigma level of CAD data quality by analyzing 76 samples provided from three Korean automotive companies.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.152-157
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• 2001

This paper is to model a 3D-shape product applying mathematically the data acquired from a 30 scanner and using an Automatic Design Program. The research studied in th reverse engineering up to now has been developed continuously and surprisingly. However, forming 3D-shape sol id models in CAE and CAM. based on the research, the study leaves much to be desired. Especially, analyses and studies reverse-designing automatically using measured data after manufacturing. Consequently, we are going to acquire geometric data using an 30 scanner in this study with which we will open a new field of reverse engineering by a program which can design a 3D-shape solid model in a CDA-based program automatically. Utilization of this program make it possible to minimize time in designing a product and establish a ADS(Automatic design system) program library to using all of the data from reverse engineering.

• 한국정밀공학회지
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• 제28권7호
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• pp.834-850
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• 2011

In this paper, a novel tissue engineering scaffold design method based on triply periodic minimal surface (TPMS) is proposed. After generating the hexahedral elements for a 3D anatomical shape using the distance field algorithm, the unit cell libraries composed of triply periodic minimal surfaces are mapped into the subdivided hexahedral elements using the shape function widely used in the finite element method. In addition, a heterogeneous implicit solid representation method is introduced to design a 3D (Three-dimensional) bio-mimetic scaffold for tissue engineering from a sequence of computed tomography (CT) medical image data. CT image of a human spine bone is used as the case study for designing a 3D bio-mimetic scaffold model from CT image data.