• 월간포장계
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• 통권101호
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• pp.168-171
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• 2001

• 한국정밀공학회지
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• 제26권12호
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• pp.138-145
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• 2009

Custom medical treatment is being widely adapted to lots of medical applications. A technology for 3D modeling is strongly required to fabricate medical implants for individual patient. Needs on true 3D CAD data of a patient is strongly required for tissue engineering and human body simulations. Medical imaging devices show human inner section and 3D volume rendering images of human organs. CT or MRI is one of the popular imaging devices for that use. However, those image data is not sufficient to use for medical fabrication or simulation. This paper mainly deals how to generate 3D geometry data from those medical images. A new image processing technology is introduced to reconstruct 3D geometry of a human body vacancy from the medical images. Then a surface geometry data is reconstructed by using Marching cube algorithm. Resulting CAD data is a custom 3D geometry data of human vacancy. This paper introduces a novel 3D reconstruction process and shows some typical examples with implemented software.

• 한국멀티미디어학회논문지
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• 제9권8호
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• pp.1010-1019
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• 2006

캐드(CAD) 시스템은 우리가 사용하는 대부분의 산업 제품을 제작하는데 필수적으로 사용되고 있는 중요한 기술로 알려져 있다. 캐드 기술은 컴퓨터 그래픽스 기술의 발달과 더불어 상업용 3차원 캐드 시스템으로 영역을 확장해 나가고 있다. 특히, 신발제조와 같은 특수한 영역의 캐드 시스템들도 3차원 캐드로 발전해 나가고 있다. 그러나 캐드 소프트웨어의 개발의 어려움으로 인해 소수의 메이저급 캐드 소프트웨어 회사를 제외하고는 대부분이 3차원 개념을 제공하는 AutoCAD에 종속적인 소프트웨어를 개발하고 있다. 뿐만 아니라 실제의 작업 현장에서 일하는 많은 신발 캐드 디자이너들은 직접 신발 디자인을 종이에 그리는 교육을 받아 3차원 캐 보다는 2차원 캐드에 더 익숙하고, 작업 효율도 훨씬 뛰어남을 보이고 있다. 이에 본 연구에서는 현장 실무자들의 작업 방식과 3차원 캐드 소프트웨어가 주는 장점을 결합한 3차원 신발 캐드 시스템을 설계 할 것이다. 본 시스템은 다른 신발 캐드 시스템들과 달리 OpenGL을 기반으로 하여 어느 플랫폼에서 잘 작동하도록 설계할 것이다. 또한 3차원 신발 설계 시스템에서 가장 중요한 부분인 3차원 캐드데이터와 2차원 캐드 데이터의 호환 방법을 제시하고, 다양한 크기의 신발 제작에 필수적인 여러 할출(grading) 기법을 제시할 것이다.

• 복식
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• 제65권1호
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• pp.104-117
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• 2015

Recently, the fashion industry has been integrating with The IT industry in order to develop in various ways. This study looks into ways to utilize the 3D CAD system, which would reduce time and cost while producing samples, and strengthen the communication between the brand and its cooperators by deploying knit designs using Knit CAD system's 3D virtual clothing program. The research method was reference, Internet resources 3D fashion CAD system and 3D Knit CAD system. Based on the data, simulation of the complete design of 4 deployed knit designs was done by using 3D virtual clothing program of the Knit CAD system utilizing knit design elements. One of each design element among the virtual clothing designs was chosen to produce real clothing, and the experts did verification on the appearance assessment of 3D virtual clothing knit designs of the Knit CAD system. As a result, 3D virtual clothing knit design of the Knit CAD system proved itself as an efficient system in terms of time and cost.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.435-438
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• 2001

Reverse engineering technology refers to the process that creates a CAD model of an existing part using measuring devices. Recently, non-contact scanning devices have become more accurate and the speed of data acquisition has increased drastically. However, they generate thousands of points per second and various types of point data. Therefore, it becomes a major issue to handle the huge amount and various types of point data. To generate a CAD model from scanned point data efficiently, these point data should be well arranged through point data handling processes such as data reduction and segmentation. This paper proposes a new point data handling method using 3D grids. The geometric information of a part is extracted from point cloud data by estimating normal values of the points. The non-uniform 3D grids for data reduction and segmentation are generated based on the geometric information. Through these data reduction and segmentation processes, it is possible to create CAD models autmatically and efficiently. The proposed method is applied to two quardric medels and the results are discussed.

• 한국산학기술학회논문지
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• 제8권4호
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• pp.775-780
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• 2007

쾌속조형기술(Rapid Prototyping Technology)은 설계단계에 있는 3차원 모델을 시제품(Prototype)으로 다른 중간과정 없이 빠르게 생성하는 새로운 기술을 말한다. CAD 모델 데이터는 3차원 형상 시스템이지만 모니터 화면이나 문서로 출력할 때는 2차원으로 밖에 표시되지 않는다. 반면에 쾌속조형기술은 설계된 3차원 CAD 데이터를 2차원 단면 데이터로 변환한 후 RP(Rapid Prototyping)공정을 적용하여 순차적으로 적층해 감으로써 CAD 데이터와 같은 3차원 입체 형상을 제작하게 된다. 그러나 RP 시스템은 매우 가격이 비싸서 칫솔이나 완구 등과 같은 생활용품을 제작하는 중소기업에서는 구입하기 어려운 상황이다. 본 논문에서는 오픈소스를 사용하여 RP 기술을 구현함으로써 저렴한 가격으로 구매할 수 있는 RP 시스템을 개발하기 위한 3차원 제어시스템을 제안하였다.

• 한국CDE학회논문집
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• 제20권2호
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• pp.145-158
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• 2015

ISO 15926 is an international standard for the sharing and integration of plant lifecycle information. Plant design data consist of logical configuration, equipment specifications, 2D piping and instrument diagrams (P&IDs), and 3D plant models (shape data). Although 3D computer-aided design (CAD) data is very important data across the plant lifecycle, few studies on the exchange of 3D CAD data using ISO 15926 have been conducted so far. For this, we analyze information requirements regarding plant 3D design in the process industry. Based on the analysis, ISO 15926 templates are defined for the representation of constructive solid geometry (CSG) - based 3D design data. Since system environments for 3D CAD modeling and Semantic Web technologies are different from each other, we present system architecture for processing and visualizing plant 3D design data in the Web Ontology Language (OWL) format. Through the visualization test of ISO 15926-based 3D design data for equipment with a prototype system, feasibility of the proposed method is verified.

• 한국정밀공학회지
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• 제31권12호
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• pp.1085-1091
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• 2014

Recently, 3D printing has received increasing attention due to its boundless potentials. Because 3D printing starts from 3D geometry information, computer-aided design (CAD) is an essential technology to build 3D geometry data. These days, education of 3D CAD for engineering students has been changed from the theoretical lecture to practical design training using commercial CAD software. As a result, open-ended design projects have replaced the traditional theoretical examinations to evaluate students' outcomes. However, such design projects are not enough to evaluate students' outcomes because their results are expressed in two-dimensional ways. In this paper, applications of 3D printing in engineering design education are discussed by describing the procedure and outcomes of design projects. It was found that the use of 3D printing could improve students' outcomes by fabricating real physical models out of their designs.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.645-648
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• 2008

초고층 복합공간이 증가하면서 건축물의 공간에서는 매우 복잡하고 다양한 상황들이 연출되는데, 이에 대한 관리는 아직도 관리자가 획득한 제한된 정보에 근거해서 내린 의사결정에 의존하고 있다. 그러나 인간의 능력은 한정된 시간 동안에, 제한된 정보를 분석하여, 상황에 맞는 적절한 조치를 취하는 데에는 한계가 있다. 이러한 한계점을 극복하기 위해 첨단 정보기술을 융합한 유비쿼터스 시스템을 이용할 수 있는 방안을 제안하고자 한다. 본 논문은 객체 지향 3D 데이터에 관한 연구 현황을 조사하여 3D 데이터 추출 방안, 시스템간의 데이터 교환 방안, 현재 객체 지향 3D 데이터의 활용 상황 등에 대한 정보를 수집하고, 다중이용시설물의 일반적인 공간 정보를 3D CAD 정보에서 추출하여 GIS 시스템으로 보낼 방안을 수립하고자 한다.

• 한국CDE학회논문집
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• 제21권1호
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• pp.78-89
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• 2016

When a plant owner requests plant 3D CAD models in the format that a shipbuilding company does not use, the shipyard manually re-models plant 3D CAD models according to the owner's requirement. Therefore, it is important to develop a technology to compare the re-modeled plant 3D CAD models with original ones and to quantitatively evaluate similarity between two models. In the previous study, we developed a graphic user interface (GUI)-based comparison system where a user evaluates similarity between original and re-modeled plant 3D CAD models for piping design at the level of unit. However, an offshore plant consists of thousands of units and thus a system which compares several plant 3D CAD models at unit-level without human intervention is necessary. For this, we developed a new batch model comparison system which automatically evaluates similarity of several unit-level plant 3D CAD models using an extensible markup language (XML) file storing file location and name data about a set of plant 3D CAD models. This paper suggests system configuration of a batch-mode-based comparison system and discusses its core functions. For the verification of the developed system, comparison experiments for offshore plant 3D piping CAD models using the system were performed. From the experiments, we confirmed that similarities for several plant 3D CAD models at unit-level were evaluated without human intervention.