• 한국CDE학회논문집
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• 제21권4호
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• pp.417-425
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• 2016

Especially for resolving BIM data compatibility issue, as one of recently raised BIM technology issues, has also been improved by using open BIM, representatively using IFC (Industry Foundation Classes) format. As shown in many case studies, usefulness of BIM technology is increasing day by day, and the IFC-based open BIM technology is essential in recent AEC projects where the productive collaboration is of importance. One of current problems in actual projects is that there is a conflict between conventional ways and newly developed BIM ways. Using both conventional and new technologies leads construction workers to having more work loads, consequently the efficiency and productivity of on-site workers have been decreased. Thus, it is strongly necessary to facilitate 3D BIM models to extract and generate 2D precision drawings in automation, especially using open BIM technologies. Some native BIM authoring tools have limitations in there automatic generation of 2D drawings, and there is no standardized mechanism to generate 2D drawings from heterogeneous applications. For this reason, this paper aims to develop an automated stand-alone program to generate 2D drawings in automation using IFC file, totally independent from various BIM authoring tools. By using the application described in this paper, any type of general drawings such as plan, section and elevation can be extracted without additional efforts. The development approach described in this paper, based on the open BIM technologies, has a strong impact to the current process especially in the perspective of enhancing productivity when we need to find out a trade-off in-between conventional and new approaches.

• 한국기계가공학회지
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• 제18권8호
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• pp.91-97
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• 2019

A method for generating 3D solid models and drawings for a rotor in the steam turbine is proposed. One of the most important design steps is generating the drawing for manufacturing it. This step is a very routine and time-consuming job because each drawing is composed of several kinds of views and many dimensions. To achieve automation for this activity, rotor profiles are composed of 2D entity groups with attributes. Based on this, the improved design process is developed as follows. First, the rotor profiles can be selected by searching for 2D entity groups using the related attributes. Second, the profiles are connected sequentially so that an entire rotor profile is determined. The completed profile is used to generate 2D drawings automatically, especially views, dimensions, and 3D models. The proposed method is implemented using a commercial CAD/CAM system, Unigraphics, and API functions written in C-language and applied to the rotor of steam turbines. Some illustrative examples are provided to show the effectiveness of the proposed method.

• 대한조선학회논문집
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• 제43권3호
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• pp.362-374
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• 2006

Currently, all design information of a hull structure is being first defined on 2D drawings not 3D CAD model at the initial ship design stage and then transferred to following design stages through the 2D drawings. This is caused by the past design practice, limitation on time, and lack of hull structural CAD systems supporting the initial design stage. As a result, the following design tasks such as the process planning and scheduling are being manually performed using the 2D drawings. For solving this problem, a data structure supporting the initial design stage is proposed and a prototype system is developed based on the data structure. The applicability of the system is demonstrated by applying it to various examples. The results show that the system can be effectively used for generating the 3D CAD model of the hull structure at the initial design stage.

• 한국정보과학회논문지:시스템및이론
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• 제34권12호
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• pp.665-682
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• 2007

라인 드로잉은 적은 표현으로 물체에 대찬 많은 정보를 줄 수 있다는 점 때문에 비사실적 렌더링 분야에서 중요시되고 있다. 하지만 라인 드로잉에 대한 연구는 이차원 영상에 비해 물체에 대한 정보가 충분한 삼차원 모델을 대상으로 주로 이루어졌다. 본 논문에서는 이차원 영상을 라인 드로잉 형태로 표현하는 효과적인 방법을 제시한다. 이를 위한 알고리즘은 크게 필터링, 선 연결, 스타일화 세 단계로 나뉜다. 필터링 단계에서는 영상의 어느 부분에 선이 그려질지를 우도 함수를 이용하여 예상한다. 선 연결 단계에서 필터링 결과를 클러스터링 및 그래프 검색을 이용하여 연결, 라인 스트로크들을 찾아낸다. 마지막 스타일화 단계에서는 찾아낸 라인 스트로크들을 곡선 근사, 텍스쳐 매핑 등을 이용하여 여러 비사실적 렌더링 형태로 표현한다. 이러한 방법을 이용하여 실제 이차원 영상에서 라인 스트로크를 얻고, 디테일 제어를 적용하여 여러 가지 원하는 스타일의 라인 드로잉을 만들 수 있다.

• Advances in Computational Design
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• 제4권2호
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• pp.155-177
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• 2019

Operation and Maintenance (O&M) phase is the main contributor to the total lifecycle cost of a building. Previous studies have described that Building Information Models (BIM), if available with detailed asset information and their properties, can enable rapid troubleshooting and execution of O&M tasks by providing the required information of the facility. Despite the potential benefits, there is still rarely BIM with Mechanical, Electrical and Plumbing (MEP) assets and properties that are available for O&M. BIM is usually not in possession for existing buildings and generating BIM manually is a time-consuming process. Hence, there is a need for an automated approach that can reconstruct the MEP systems in BIM. Previous studies investigated automatic reconstruction of BIM using architectural drawings, structural drawings, or the combination with photos. But most of the previous studies are limited to reconstruct the architectural and structural components. Note that mechanical components in the building typically require more frequent maintenance than architectural or structural components. However, the building mechanical drawings are relatively more complex due to various type of symbols that are used to represent the mechanical systems. In order to address this challenge, this paper proposed a symbol recognition framework that can automatically recognize the different type of symbols in the building mechanical drawings. This study applied vector-based computer vision techniques to recognize the symbols and their properties (e.g., location, type, etc.) in two vector-based input documents: 2D drawings and the symbol description document. The framework not only enables recognizing and locating the mechanical component of interest for BIM reconstruction purpose but opens the possibility of merging the updated information into the current BIM in the future reducing the time of repeated manual creation of BIM after every renovation project.

• 한국건축시공학회지
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• 제20권3호
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• pp.289-296
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• 2020

본 연구는 철근 배근과 관련된 증강현실을 구현할 수 있도록 2D 도면에서 배근 정보를 자동으로 추출하여 3D 배근 모델을 생성하는 방법론을 제시하였다. 사용자가 쉽게 도면정보를 획득할 수 있도록 휴대용 단말기에 내장된 카메라를 이용하여 도면을 촬영한 후 화상 인식(Image Recogni-tion)과 문자 인식(OCR; Optical Character Recognition) 도구를 활용하여 배근 정보를 추출하는 방법을 제시하였다. 또한, 게임 엔진을 활용하여 도면에서 추출된 정보를 입력받아 자동으로 3D 부재를 모델링하고 이를 실제 이미지와 중첩해서 배근 모델을 검토할 수 있는 증강현실 앱을 구현하였다. 기존에 개발된 프로그래밍 도구를 활용하여 제시한 방법론에 적용할 수 있도록 세부 내용을 기술하였으며, 건설현장에서 전형적인 부재를 대상으로 철근 배근 증강현실 모델을 구현한 결과를 검토하였다. 제시된 증강현실 배근 모델 자동 생성 방법론은 배근 교육이나 시공검토에 활용될 수 있을 것으로 기대된다.

• 한국CDE학회논문집
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• 제10권4호
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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.

• 한국정보과학회논문지:시스템및이론
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• 제37권2호
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• pp.110-125
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• 2010

본 논문은 이차원 영상으로부터 시각적으로 효과적인 정보를 제공할 수 있는 라인 드로잉 영상을 생성하는 방법을 제시한다. 본 방법은 기존의 단순한 에지 추출 방법과 달리 사람의 라인 드로잉 과정을 적용하여 직관적이면서 효과적인 결과를 생성하며, 크게 라인 추출, 라인 렌더링, 사용자 지시의 세단계로 구성된다. 라인 추출 단계에서는 우도 함수를 이용하여 물체의 중요한 경계 부분을 효과적으로 예측함으로써 라인을 추출한다. 추출된 라인을 실제 렌더링하는 라인 렌더링 단계에서는, 중요한 라인과 세부 라인의 구분 및 초점의 정확도를 표현하기 위하여 라인의 특징 크기와 번짐 정도를 고려하고, 이를 다양한 스타일로 표현하기 위해 텍스쳐 형태의 라인 영상을 적용한다. 마지막으로 사용자 지시 단계에서는 자동으로 생성된 라인의 모양이나 위치를 사용자 상호작용으로 수정할 수 있다. 이 때 사용자 입력에 대한 즉각적인 반응을 위해 라인 추출의 대부분의 과정이 GPU 상에서 구현된다. 제시된 방법의 결과로 사용자는 이차원 영상으로부터 중요한 부분과 초점이 맞는 부분의 표현 및 스타일을 원하는 대로 조절한 라인 드로잉을 얻을 수 있고, 또한 이를 자유롭게 수정할 수 있다.

• 국제학술발표논문집
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• The 9th International Conference on Construction Engineering and Project Management
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• pp.1253-1253
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• 2022

Although the construction industry is changing from a 2D-based to a 3D BIM-based management process, 2D drawings are still used as standards for permits and construction. For this reason, 2D deliverables extracted from 3D BIM are one of the essential achievements of BIM projects. However, due to technical and institutional problems that exist in practice, the process of extracting 2D deliverables from BIM requires additional work beyond generating 3D BIM models. In addition, the consistency of data between 3D BIM models and 2D deliverables is low, which is a major factor hindering work productivity in practice. To solve this problem, it is necessary to build BIM data that meets information requirements (IRs) for extracting 2D deliverables to minimize the amount of work of users and maximize the utilization of BIM data. However, despite this, the additional work that occurs in the BIM process for drawing creation is still a burden on BIM users. To solve this problem, the purpose of this study is to increase the productivity of the BIM process by automating the process of extracting 2D deliverables from BIM and securing data consistency between the BIM model and 2D deliverables. For this, an expert interview was conducted, and the requirements for automation of the process of extracting 2D deliverables from BIM were analyzed. Based on the requirements, the types of drawings and drawing expression elements that require automation of drawing generation in the design development stage were derived. Finally, the method for developing automation technology targeting elements that require automation was classified and analyzed, and the process for automatically extracting BIM-based 2D deliverables through templates and rule-based automation modules were derived. At this time, the automation module was developed as an add-on to Revit software, a representative BIM authoring tool, and 120 rule-based automation rulesets, and the combinations of these rulesets were used to automatically generate 2D deliverables from BIM. Through this, it was possible to automatically create about 80% of drawing expression elements, and it was possible to simplify the user's work process compared to the existing work. Through the automation process proposed in this study, it is expected that the productivity of extracting 2D deliverables from BIM will increase, thereby increasing the practical value of BIM utilization.

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2008년도 정기학술발표대회 논문집
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• pp.297-300
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• 2008

1990년대 3D CAD가 출현한 이후, 최근 BIM(Building Information Modeling)이 이슈화되고 있다. BIM이라 함은 건설 프로젝트 생애주기 전반에 걸쳐 생성되는 정보를 3D Model과 함께 관리하는 것으로, 건설 프로젝트 각 분야의 정보들을 3D 모델과 연동하는 프로세스를 가지고 있다. 이에 견적 분야에서도 3D 모델로부터 자재의 물량을 산출하는 연구들이 진행되어 오고 있으며, 국내l에서 상용화된 견적 프로그램을 국내 건설 프로젝트에 적용하려는 시도가 이루어지고 있다. 그러나 이는 2D 도면으로부터 물량을 산출하는 기존의 견적방식보다 작업시간 및 생산성 측면에서 효율성이 떨어질 뿐만 아니라, 국외 견적 업무는 국내 견적과 다른 방식으로 이루어지고 있기 때문에 국외 상용 프로그램을 국내 건설 프로젝트에 적용하는데 한계가 있다. 그러므로 국내 건설 프로젝트에서 3D 기반 견적 프로그램을 활용하지 못하고 있다. 본 연구에서는 국내 실정에 적합한 3D 기반 견적 프로그램 개발을 위해 우선적으로 고려되어야 할 3D CAD로부터 물량 정보를 견적 프로그램으로 전달하는 3D CAD와 물량산출 연동 프로그램을 제안하고자 한다.