• 한국CDE학회논문집
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• 제4권2호
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• pp.87-99
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• 1999

We developed a Part Information Brokering System, namely PIBS, that can inter-link part suppliers and buyers using WWW(World Wide Web). The major contribution of this paper is that the system provides a 3D collaboration environment that enables multiple users to share the same workspace where they cooperatively manipulate part features in real time. PIBS carries out two major functions: one to maintain part data in a part library, and the other to provide the means for the clients to cooperate. An object-oriented database is used for the part library which stores apart information registered by part suppliers. VRML(Virtual Reality Modeling Language) the ISO standard for 3D visualization on WWW, is used to represent 3D part models. Several Java programs have been implemented to support synchronous and a synchronous communication of the 3D models. Once the users are interconnected through the system, a user's manipulation of part objects is transparently and instantaneously transmitted to the others. This means that all the participants can are the same view and movement of the 3D part models. Since the system is developed using a Java applet-server architecture, it requires no additional software other than standard web browser. The prototype system has been successfully implemented, and demonstrated its applicability to virtual 3D part information sharing.

• Composites Research
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• 제16권5호
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• pp.7-14
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• 2003

두꺼운 복합재료 구조물의 유한 요소 모델링은 상당히 복잡하다. 일반적인 2차원 유한요소로 모델링 하면 3차원 응력의 영향을 받는 두꺼운 복합재료 구조물의 정확한 해석이 곤란하다. 그러므로 3차원 모델링을 할 수밖에 없으나 이 또한 구조물의 모든 층이 다른 재료 물성치와 다른 적층방향으로 적층되는 경우에는 모델링이 어렵다. 이 논문에서는 등가 물성 모델링 기법을 제안하고, 두꺼운 복합재료 구조물 해석에 수치적 실험을 하였다. 재료와 적증 방향이 같은 층을 그룹화하여 두께 방향의 요소 수를 현저히 감소시켰지만 결과는 상세한 유한요소 모델로 계산한 결과와 충분히 근접했다. 해석과 모델링에는 MSC/NASTRAN과 PATRAN을 사용하였다. 제안된 모델링 기법은 한국항공우주연구원(KARI)에서 설계된 복합재료 로터 허브 시스템 해석에 적용되었다. 제안된 등가 모델링 기술을 이용하여, 쉬운 모델링과 계산시간을 감소시키면서 허브 시스템의 응력 해석과 각 부분의 안전 계수 점검을 수행하였다.

• 한국기계가공학회지
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• 제15권5호
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• pp.86-92
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• 2016

In this study, we used a polymer deposition system, based on fused deposition modeling, to fabricate the 3D scaffold and then fabricated micro-pores on a 3D scaffold using a salt leaching method. Materials included polycaprolactone (PCL) and sodium chloride (NaCl). The 3D porous scaffolds were fabricated according to blending ratio such as PCL (70 wt%)/NaCl (30 wt%) and PCL (50 wt%)/NaCl (50 wt%). The 3D porous scaffolds were observed by scanning electron microscopy. The results showed that 3D porous scaffolds had a deposition width of $500{\mu}m$, contained a pore size of $500{\mu}m$ and below $100{\mu}m$. To evaluate the 3D porous scaffolds for bone tissue engineering, we carried out the cell proliferation experiment using a CCK-8 and a mechanical strength test using a universal testing machine. In summary, the 3D porous scaffold was found to be suitable for cancellous bone of human in accordance with the result of in-vitro cell proliferation and mechanical strength. Thus, a 3D porous scaffold could be a promising approach for effective bone regeneration.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 추계종합학술대회 B
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• pp.348-353
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• 2008

무선센서 네트워크 기술의 응용이 크게 증가함에 따라 저전력 IEEE 802.15.4 호환 무선방식을 활용하는 실내 위치추적기술이 최근에 큰 관심을 모으고 있다. 기존의 실내 위치감지 정보는 2D 영상 기준으로서 정보의 실질적인 전달에 제한적인 기능을 나타내었다. 본 논문에서는 PDA에 대화형 가상현실기술에 바탕을 둔 고정밀 3차원 RSSI 기반의 화면 구성에 초점을 두고있다. 개발된 시스템은 관심영역에서 RF신호의 감쇄를 계산하여 위치정보를 얻은 다음, 이를 3D 실내 가상맵에서의 사용자의 위치로 나타내도록 설계되었다. 이 연구에서는 3차원 모델링을 위해 개발된 VRML(가상현실 모델링 언어)이 3D 실내환경을 설계하는데 활용되었다.

• 한국염색가공학회지
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• 제31권3호
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• pp.214-224
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• 2019

This investigation reported the simulation technologies to design the 3-dimensional fabrics such as 3 dimensional multi-layered fabric, 3 dimensional braided fabric and spacer fabric. The simulation system or software has been actively used to develop products of 3 dimensional fabric which can be reduced development costs and time. Thus, many countries such as Japan, Germany, China, and U.K. show great interests on simulation technologies for developing new materials and processes including 3 dimensional fabric field. In this study, simulation systems have been reviewed for the 3 dimensional fabric design system from Mikawa Textile Research Center, Japan; ProCad and ProFab from Karl Mayer and Texion, Germany; xComposites from China; TexGen from Nottingham University, U.K.; TexPro from Young Woo CnI, Korea, respectively.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.487-492
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• 2009

A large-scaled research project titled "Intelligent Excavating System (IES)" sponsored by Korean government has launched in 2006. An issue of real-time 3D terrain modeling has become a crucial point for successful implementation of IES due to many application limitations of state-of-the-art techniques developed in various high-technology fields. Many feasible technologies such as laser scanning, structured lighting and so on were widely reviewed by professionals and researchers for one year. Various efforts such as literature reviews, interviews, and indoor experiments make us select a structural light technique and stereo vision technique as appropriate techniques for accomplishment of real-time 3D terrain modeling. It, however, revealed that off-the-shelf products of structural light and stereo-vision technique had many technical problems which should be resolved for practical applications in IES. This study introduces diverse methods modifying off-the-shelf package of the structural light method, one of feasible techniques and eventually allowing this technique to be successfully utilized for achieving fundamental research goals. This study also presents many efforts to resolve practical difficulties of this technique considering basic characteristics of excavating operations and particular environment of construction sites. Findings showed in this study would be beneficial for other researchers to conduct new researches for application of vision techniques to construction fields by provision of detail issues about practical application and diverse practical methods as solutions overcoming these issues.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.721-724
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• 2005

In this study the spatial distribution characters of forest in forest damaged area were first considered by analyzing spatial data and monitoring forest landscape. Then suitable tree species on each site were selected through the weighted score analysis of GIS analysis methods. Finally, the best forest stand arrangement method could be presented on the 3D based simulation system for the advanced reforestation technology in Korea. For this purpose, the virtual reforestation system was implemented by using the concept of virtual GIS and CBD (Component Based Development) method. By use of this system the change offorest landscape of burnt forest area some years after reforestation practice could be detected and monitored by applying the site index and 3D modeling method.

• 대한기계학회논문집A
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• 제28권8호
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• pp.1116-1124
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• 2004

In these days, a vehicle simulator has been developed with a VR(Virtual Reality) system. A VR system must provide a vehicle simulator with natural interaction, sufficient immersion and realistic images. In addition, a VR system must present a driver with the realistic driving situation. To achieve these, it is important to obtain a fast and uniform rendering performance regardless of the complexity of virtual worlds. In this paper, the factors to improve the reality for the VR based vehicle simulator have been investigated. For the purpose, the modeling and the rendering methods which offer an improved performance for complex VR applications as the 3D road model have been implemented and verified. Then, we experiment on the influence of graphic and sound factors to the driver, and analyze each result for improving the reality such as the driver's viewport, the form of texture, the lateral distance of the side object, and the sound effect. These factors are evaluated on the driving system which is constructed for qualitative analysis. The research results could be used for improving the reality of the VR based vehicle simulator.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.188-193
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• 2004

3차원 모델링은 다양한 safety-enhancement applications 과 프로젝트 관리 시스템에서의 as-built data acquisition에 이용될 수 있다. 본 연구의 목적은 효과적인 방법으로 건설 현장을 3차원 모델로 형상화 할 수 있는 3차원 공간 모델링 방법을 제시하고 실제 건설 현장에서의 실험을 통하여 제시한 방법을 검증하는 것이다. 본 논문에서는 제안된 건설현장을 형상화하기 위한 모델링 알고리듬들과 여러 장소들로부터 얻는 data를 하나의 coordinate system으로 변환하기 위한 coordinate transformation 알고리듬에 대한 설명을 포함하였다. 제안된 모델링 방법의 건설 현장에 대한 실제 적용성을 검증하기 위해 실제 건설 현장에서의 모델링 실험에 대한 결과가 논의되었으며 이러한 결과는 본 연구에서 제안된 모델링 방법이 건설 현장을 효과적으로 3차원 모델로 형상화하는 것을 보여준다.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2002년도 학술대회지
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• pp.531-534
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• 2002

건설 프로젝트는 갈수록 대형화${\cdot}$복잡화되고 있으며, 이에 따라 대형 건설업체들은 시간적${\cdot}$지리적으로 상이한 환경의 많은 프로젝트를 수행하는 것이 오늘날의 현실이다. 이러한 흐름에 따라 Collaboration System을 포함한 여러 종류의 웹 기반 정보시스템들을 구축${\cdot}$활용하고 있는 실정이다. 그러나, 시스템들의 내용을 살펴보면, 2차원 평면 위주의 도면 및 Picture들을 활용하여 공사 진행 정도 및 현황을 체크하고 확인하는데 국한되어 있다. 따라서, 해외-본사 간 지리적${\cdot}$문화적 차이가 존재하는 상이한 환경에서 설계 변경 등과 같은 문제 발생 시 원활한 문제 해결 저해 및 시간적 지연을 야기시키고 있다. 이에 본 연구에서는 세부적으로 Web 3D 및 3D 라이브러리들을 소개하고, 결과적으로 Web 3D을 이용한 3차원 공사 구조물 모델링 활용 방안을 제시해 보고자 한다.