• Korean Journal of Computational Design and Engineering
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• v.10 no.2
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• pp.121-132
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• 2005

There have been several efforts for the investigation of the formal development team which was formed in the IAI to develop a common 2D standard specification between ISO/STEP and IAI/IFC since 2002. As a result, a drafting model has been included in the IFC2.x2 model. However, to be used actively in the construction practice for construction drawing exchange, the IFC model should be extended to the paper space for multiple views, drawing output, and delivery of drawings. Therefore, in this paper, the methodology of relating STEP and IFC has been investigated and schema extension of paper space(drawing sheet, presentation view, view pipeline), complex entity(leader), and dimension(associative) have been achieved. The resulting, IFC model will enable a basic harmonization with KOSDIC. SCADEC, and STEP-CDS by retaining the current IFC architecture. In addition, IT systems for the construction industry can be beneficial from the developed data model.

• Korean Journal of Computational Design and Engineering
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• v.19 no.4
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• pp.347-355
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• 2014

IFC converters and viewers, applicable in the construction field, are being actively developed while, in the civil engineering field, IFC schemata are being developed. To prove the IFC schema grammatically, the existing ISO 10303 30s' pre-processors and post-processors may be used. However, to visually prove the IFC model, the existing commercial 3D modeling software should be converted into the IFC schema of civil engineering field, and a viewer is needed to view it. Thus, this study developed a IFC converter and viewer prototype system to apply BIM in the road field. To express the road line, LandXML was analyzed, and IFC suitable for expressing shapes in the road field was designed. Also, an IFC suitable for bridges with focus on representative bridge structures such as abuts, piers and decks was designed. Further, a converter was developed using AutoCAD's Civil3D and Revit's 3rdp party tools, and software was also developed designed to combine each converted IFC model into one IFC. In addition, a viewer designed to view IFC in the road field was developed to prove the converted IFC. Eight major verification and examination items were selected and used in testing the converted model, and it was confirmed that the viewer normally viewed the IFC schema in the road field. The proposed IFC converter is expected to be used as a visual IFC verification tool in the road field.

• Korean Journal of Construction Engineering and Management
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• v.9 no.3
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• pp.85-94
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• 2008

The process of construction industry basically consists of many complicated phase, such as planning, design, construction, MO&R(Maintenance, Operation, and Repair), and deconstruction. And various participants communicate each other during every phase of process. Since construction components have become more complex and diverse recently, many researches on how to exchange and standardization of building. However, in Korea research on IFC(Industry Foundation Classes) which is a standard for international data exchange have been conducted with only study limited Issues, such as studies on the development of 2D extension model for IFC, researches on 3D or 4D based IFC extension, and etc. This stuff covers tests of the compatibility among commercial 3D CAD programs using IFC file format. Several problems of the current IFC model are retrieved as a result.

• Spatial Information Research
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• v.20 no.5
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• pp.49-56
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• 2012

Recently, various researches have been attempted to link or integrate BIM and GIS. In particular, some of the researches were progressed to convert the data model between the BIM standard model IFC and the GIS standard model CityGML. However, it is hard to utilize the previous research results yet because characteristics and domains of between two data models are very different, In order to obtain the correlation between BIM and GIS, in this research, we analyzed the characteristics between IFC and CityGML objects of each LOD, And, we analyzed the correlation of IFC and CityGML by performing mapping between IFC and CityGML objects from view point of building with these characteristics. In this research, based on these correlation analysis results, we proposed the efficient interrelation plan between IFC and CityGML.

• Journal of KIBIM
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• v.13 no.2
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• pp.37-46
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• 2023

The main objective of this study is to propose a method to enhance building safety using the Industry Foundation Classes (IFC) schema in Building Information Modeling (BIM). To achieve this goal, a fire object relationship diagram is created by using the Model View Definition (MVD) and Property Set (Pset) methodology, as well as the Work Breakdown Structure (WBS) based object relationship analysis. The proposed method illustrates how to represent objects and tasks related to fire prevention and human safety during a building fire, including variables that are relevant to these aspects. Furthermore, the proposed method offers the advantage of considering both the IFC object hierarchy and the project work hierarchy when creating new objects, thereby expanding the attribute information for fire safety and maintenance. However, upon confirmation via an IFC viewer after development, a problem with the accuracy of mapping between attributes and objects arises due to the issue of proxy representation of related object information and newly added object information in standard IFC. Therefore, in future research, a mapping method for fire safety objects will be developed to ensure accurate representation, and the scope of utilization of the fire safety object diagram will be expanded. Furthermore, efforts will be made to enhance the accuracy of object and task representation. This research is expected to contribute significantly to the technological development of building safety and fire facility design in the future.

• International conference on construction engineering and project management
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• 2020.12a
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• pp.157-166
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• 2020

Automated rebar fabrication, which requires effective information exchange between model designers and fabricators, has brought the integration and interoperability of data from different sources to the notice of both academics and industry practitioners. Industry Foundation Classes (IFC) was one of the most commonly used data formats to represent the semantic information of prefabricated components in buildings, whereas the data format utilized by rebar fabrication machine is BundesVereinigung der Bausoftware (BVBS), which is a numerical data structure exchanging reinforcement information through ASCII encoded files. Seamless transformation between IFC and BVBS empowers the automated rebar fabrication and improve the construction productivity. In order to improve data interoperability between IFC and BVBS, this study presents an IFC extension based on the attributes required by automated rebar fabrication machines with the help of Information Delivery Manual (IDM) and Model View Definition (MVD). IDM is applied to describe and display the information needed for the design, construction and operation of projects, whereas MVD is a subset of IFC schema used to describe the automated rebar fabrication workflow. Firstly, with a rich pool of vocabularies practitioners, OmniClass is used in information exchange between IFC and BVBS, providing a hierarchy classification structure for reinforcing elements. Then, using International Framework for Dictionaries (IFD), the usage of each attribute is defined in a more consistent manner to assist the data mapping process. Besides, in order to address missing information within automated fabrication process, a schematic data mapping diagram has been made to deliver IFC information from BIM models to BVBS format for better data interoperability among different software agents. A case study based on the data mapping will be presented to demonstrate the proposed IFC extension and how it could assist/facilitate the information management.

• Journal of KIBIM
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• v.11 no.3
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• pp.22-33
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• 2021

In order to maximize the use of BIM, all data related to individual elements in the model must be correctly assigned, and it is essential to check whether it corresponds to the IFC entity classification. However, as the BIM modeling process is performed by a large number of participants, it is difficult to achieve complete integrity. To solve this problem, studies on semantic integrity verification are being conducted to examine whether elements are correctly classified or IFC mapped in the BIM model by applying an artificial intelligence algorithm to the 2D image of each element. Existing studies had a limitation in that they could not correctly classify some elements even though the geometrical differences in the images were clear. This was found to be due to the fact that the geometrical characteristics were not properly reflected in the learning process because the range of the region to be learned in the image was not clearly defined. In this study, the CRF-RNN-based semantic segmentation was applied to increase the clarity of element region within each image, and then applied to the MVCNN algorithm to improve the classification performance. As a result of applying semantic segmentation in the MVCNN learning process to 889 data composed of a total of 8 BIM element types, the classification accuracy was found to be 0.92, which is improved by 0.06 compared to the conventional MVCNN.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.375-378
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• 2010

본 논문은 엔지니어링 문서정보를 준구조화된 XML 문서로 변환하고 이를 3차원 교량 모델과 연계하는 방법을 제시한다. 이를 위해 먼저 구조계산서의 세부 목차에 따른 문서구조를 추출하는 기법을 이용하여 3차원 교량모델을 구성하는 각 부재와 매핑되는 구조계산서 문서의 일부를 프로그램 상에서 자동으로 추출하기 위한 모듈을 개발하였다. 또한 3차원 교량모델의 정보를 운영하기 위해 IFC 기반의 교량정보모델을 개발하였다. 개발된 정보모델은 교량요소들의 논리적 구성체계를 공간적 요소, 물리적 요소 및 그룹 요소별로 표현할 수 있도록 지원한다. 이와 같이 개발된 기술을 이용하여 3차원 교량모델 뷰어에서 구조계산서의 정보를 검색하기 위한 시범 툴을 개발하였으며, 4개의 단위 교량으로 구성된 복합형식의 교량에 대한 3차원 모델을 구축하고 각 교량에 대한 구조계산서 또한 XML 문서로 변환하였다. 이와 같이 구축된 두 정보체계에서 사용자가 선택한 임의의 구성요소에 관한 세부 문서정보의 조회가 가능함을 보임으로써 제시된 방법의 적합성을 검증하였다.

• Journal of KIBIM
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• v.9 no.4
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• pp.31-40
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• 2019

With Building Information Modeling(BIM) becoming the de facto standard for data sharing in the AEC industry, additional needs have increased to ensure the data integrity of BIM models themselves. Although the Industry Foundation Classes provide an open and neutral data format, its generalized schema leaves it open to data loss and misclassifications This research applied deep learning to automatically classify BIM elements and thus check the integrity of BIM-to-IFC mappings. Multi-view CNN(MVCC) and PointNet, which are two deep learning models customized to learn and classify in 3 dimensional non-euclidean spaces, were used. The analysis was restricted to classifying subtypes of architectural walls. MVCNN resulted in the highest performance, with ACC and F1 score of 0.95 and 0.94. MVCNN unitizes images from multiple perspectives of an element, and was thus able to learn the nuanced differences of wall subtypes. PointNet, on the other hand, lost many of the detailed features as it uses a sample of the point clouds and perceived only the 'skeleton' of the given walls.

• Journal of the Korea Society of Computer and Information
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• v.25 no.12
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• pp.1-15
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• 2020

In this paper, we propose a novel method for converting the existing 2D processes in the design and construction phase of civil engineering, to the future BIM-based processes. First, we compare and analyze the actual application processes of the outputs of the existing 2D method and the outputs of the 3D BIM method, for the whole process of BIM design of earthworks and road structures and integrated utilization of quantity, process(4D) and construction cost(5D), in view of life-cycle. The proposed method acquire the outputs of the design phase integrating IFC international common standard file information and CBS/OBS/WBS standard classification scheme information, and acquire the outputs of the construction stage by using an integrated utilization module for quantity, process(4D) and construction cost(5D). Ultimately, we intend to commercialize the step by step technologies for BIM design and construction in civil engineering by using the proposed method.