• 한국BIM학회 논문집
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• 제13권2호
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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.

• 정보처리학회논문지A
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• 제10A권5호
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• pp.493-502
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• 2003

최근 웹-기반 XML 응용에 관한 필요성이 급증함에 따라, 이와 관련된 WIDL, OSD, CDF에 관한 연구가 널리 이루어지고 있다. 특히 OSD 포맷은 소프트웨어 패키지와 그들 간의 관계를 정의하는 것으로 CDF 문서 등에서 많이 사용되고 있다. 그러나 아직까지 이에 대한 객체 모델링이 제안된 바 없어, 소프트웨어를 재사용하려는 사람들마다 별도의 양식으로 이들 관계를 표현하고 있는 실정이다. 따라서, 본 논문은 UML의 다양한 관련성을 이용하여 OSD와 CDF문서를 UML클래스 다이어그램으로 사상시키고자 한다. 이를 통해 소프트웨어 패키지간의 구현과 실제 관계를 UML형태로 일관되게 표현할 수 있을 뿐만 아니라 모델링 함수를 통해 XML문서의 구조를 쉽게 파악, 변형을 용이하게 하는 장점이 있다.

• International Journal of Naval Architecture and Ocean Engineering
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• 제6권1호
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• pp.162-174
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• 2014

Most shipbuilding scheduling research so far has focused on the load level on the dock plan. This is because the dock is the least extendable resource in shipyards, and its overloading is difficult to resolve. However, once dock scheduling is completed, making a plan that makes the best use of the rest of the resources in the shipyard to minimize any additional cost is also important. Block assignment planning is one of the midterm planning tasks; it assigns a block to the facility (factory/shop or surface plate) that will actually manufacture the block according to the block characteristics and current situation of the facility. It is one of the most heavily loaded midterm planning tasks and is carried out manually by experienced workers. In this study, a method of representing the block assignment rules using a diagram was suggested through analysis of the existing manual process. A block allocation program was developed which automated the block assignment process according to the rules represented by the diagram. The planning scenario was validated through a case study that compared the manual assignment and two automated block assignment results.

• 산업경영시스템학회지
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• 제41권4호
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• pp.123-130
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• 2018

Triangulation is one of the fundamental problems in computational geometry and computer graphics community, and it has huge application areas such as 3D printing, computer-aided engineering, surface reconstruction, surface visualization, and so on. The Delaunay refinement algorithm is a well-known method to generate quality triangular meshes when point cloud and/or constrained edges are given in two- or three-dimensional space. In this paper, we propose a simple but efficient algorithm to triangulate Voronoi surfaces of Voronoi diagram of spheres in 3-dimensional Euclidean space. The proposed algorithm is based on the Ruppert's Delaunay refinement algorithm, and we modified the algorithm to be applied to the triangulation of Voronoi surfaces in two ways. First, a new method to deciding the location of a newly added vertex on the surface in 3-dimensional space is proposed. Second, a new efficient but effective way of estimating approximation error between Voronoi surface and triangulation. Because the proposed algorithm generates a triangular mesh for Voronoi surfaces with guaranteed quality, users can control the level of quality of the resulting triangulation that their application problems require. We have implemented and tested the proposed algorithm for random non-intersecting spheres, and the experimental result shows the proposed algorithm produces quality triangulations on Voronoi surfaces satisfying the quality criterion.

• Computers and Concrete
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• 제27권3호
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• pp.283-295
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• 2021

Existing meso-scale models of concrete need to refine the mesh grids of aggregate and cement mortar, which may greatly reduce the computational efficiency. To overcome this problem, a novel meso-scale modeling strategy, which is based on rigid body spring method and Voronoi diagram, is proposed in this study to establish the meso-scale model of concrete. Firstly, establish numerical aggregate models according to user-defined programs. Circle aggregates are adopted due to their high efficiency in generation and packing process, and the grading of aggregate are determined according to the distribution curve proposed by Full and Thompson; Secondly, extract the centroids of aggregates, and then develop the Voronoi diagram in which aggregate centroids are defined as initial scatters; Finally, establish the rigid body spring model for concrete based on the Voronoi diagram. Aggregates are represented by rigid blocks, and assumed to be unbreakable. Cement mortar is concentrated into the interface between adjacent blocks and represented by two uniform springs. The number of grids is consistent with that of aggregates in specimens, and no mesh-refinement of aggregates and cement mortar is required. The accuracy and efficiency of the proposed modeling strategy are firstly identified by comparing the numerical results with the experimental ones, and then the applicability of the proposed strategy with different volume percentage occupied by aggregates is investigated.

• Journal of Ship and Ocean Technology
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• 제3권3호
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• pp.1-12
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• 1999

Spectral fatigue damage calculations has been performed on four ships in order to assess the effect that the probabilistic modeling of sea states has on the estimated fatigue life. The damage estimation method is based on the Miner- Palmgren fatigue damage formulation and a spectral approach is used to determine the necessary variances of the stress processes. Both the horizontal and vertical hull girder bending induced stress process together with the local water pressure induced stress process is taken into account. The wave scatter diagrams are applied in the calculations and their fatigue severity is assessed by analyzing the results obtained with the ten scatter diagrams and the four ships. All four ships are analyzed both in full load and ballast conditions and while traveling at both full and reduced speed. It is found that the fatigue severity of a wave scatter diagram is dependent on several parameters, some of these being the extreme wave hight extrapolated from the scatter diagram and the mean zero up-crossing period in conjunction with the ship length . Based on these three parameters and expression is derived in order to calculate one single number describing the fatigue severity of a scatter diagram with respect to a certain ship.

• 한국안전학회지
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• 제37권2호
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• pp.18-27
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• 2022

Construction accidents are difficult to prevent because several different types of activities occur simultaneously. The current method of accident analysis only indicates the number of occurrences for one or two variables and accidents have not reduced as a result of safety measures that focus solely on individual variables. Even if accident data is analyzed to establish appropriate safety measures, it is difficult to derive significant results due to a large number of data variables, elements, and qualitative records. In this study, in order to simplify the analysis and approach this complex problem logically, data preprocessing techniques, such as latent class cluster analysis (LCCA) and predictor importance were used to discover the most influential variables. Finally, the correlation was analyzed using an alluvial flow diagram consisting of seven variables and fourteen elements based on accident data. The alluvial diagram analysis using reduced variables and elements enabled the identification of accident trends into four categories. The findings of this study demonstrate that complex and diverse construction accident data can yield relevant analysis results, assisting in the prevention of accidents.

• 디자인학연구
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• 제19권5호
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• pp.75-84
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• 2006

본 연구의 주 내용은 UN Studio의 다이어그램 사례를 중점적으로 분석해봄으로써 공간디자인 다이어그램의 개념적 내용과 구성 요소 및 실질적 활용방법에 대해 알아보는 것이다. 사례연구를 통해 분석된 연구결과는 다음과 같다. 첫째, 공간 다이어그램에 표현되고 있는 개념적 내용은 모티브, 흐름, 관계, 분포의 네 가지로 구분된다. 둘째, 공간 다이어그램은 디자인 프로세스의 프로그램 개발, 개략적인 디자인, 초기 디자인의 단계에서 주로 사용된다. 셋째, 사례 다이어그램들에 기초한 다이어그램 구성요소의 내용은 크게 다섯 가지, 컨텍스트 분석, 객체 분석, 시간/행위 분석, 조형 분석, 공간 분석으로 나눌 수 있다. 넷째, 다이어그램의 실질적 활용에 있어서 모티브를 개념적으로 표현한 다이어그램은 조형 분석에 주로 활용될 수 있으며, 흐름을 개념적으로 표현한 다이어그램은 시간/행위 분석과 객체 분석에 주로 활용될 수 있다. 관계를 개념적으로 표현한 다이어그램은 공간 분석에 가장 많이 활용 될 수 있으며, 그 다음으로 컨텍스트 분석과 조형분석에 활용 될 수 있다. 분포를 개념적으로 표현한 다이어그램은 공간분석에 주로 활용될 수 있다. 이와 같은 연구 결과를 실무 및 교육의 디자인 프로젝트에 적극적으로 활용한다면 디자인 정오의 구조화뿐만 아니라 디자인 발상과 전개에 도움이 될 것이다.

• 정보처리학회논문지D
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• 제13D권1호
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• pp.67-74
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• 2006

소프트웨어 개발 과정에서 보안 요구사항 식별은 그 중요성으로 최근에 관심이 주목되고 있다. 그러나 기존 방법들은 보안 요구사항 식별 방법과 절차가 명확하지 않았다. 본 논문에서는 소프트웨어 개발자가 보안 위협 위치의 상태전이도로부터 보안 요구사항을 식별하는 절차를 제안한다. 이과정은 상태전이도를 작성하는 부분과 어플리케이션 의존적인 보안 요구사항을 식별하는 부분으로 구성된다. 상태전이도 작성은 1) 공격자가 소프트웨어 취약성을 이용하여 자산을 공격한다는 것에 기반하여 기존에 발생했던 보안 실패 자료를 이용하여 소프트웨어의 취약성을 위협하는 위치를 식별하고, 2) 식별된 위협 위치에 해당하는 소프트웨어 취약성을 방어, 완화시킬 수 있는 상태전이도를 작성하는 과정으로 이루어진다. 어플리케이션 의존적인 보안 요구사항 식별과정은 1) 기능 요구사항을 분석 한 후, 위협 위치를 파악하고, 각 위협 위치 에 해당하는 상태전이도를 적용하고, 2) 상태전이도를 어플리케이션 의존적인 형태로 수정한 후, 3) 보안 요구사항 추출 규칙을 적용하여 보안요구사항을 작성하는 과정으로 구성된다. 제안한 방법은 소프트웨어 개발자가 소프트웨어 개발 초기에 모델을 적용하여 쉽게 보안 요구사항을 식별하는데 도움을 준다.

• 소성∙가공
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• 제27권2호
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• pp.115-122
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• 2018

Most domestic and international standards on the forming limit diagram (FLD) including ISO 12004-2, use a 'position-dependent method,' which determines the forming limit from a strain distribution measured on the specimen after necking or fracture. However, the position-dependent method has inherent problems such as the incidence of asymmetry of a strain distribution, the estimation of missing data near fracture, the termination time of test, and the deformation due to the new stress equilibrium after a fracture, which is blamed for causing sometimes a significant lab-to-lab variation. The 'time-dependent method,' which is anticipated to be a new international standard for evaluating the forming limit, is expected to greatly improve these intrinsic disadvantages of the position-dependent method. It is because the time-dependent method makes it possible to identify and accurately determine the forming limit, just before the necking point from the strain data as continuously measured in a short time interval. In this study, we propose a new time-dependent method based on a Gaussian fitting of strain acceleration with the introduction of 'normalized correlation coefficient.' It has been shown in this study that this method can determine the forming limit very stably and gives a higher value, which is in comparison with the results of the previously studied position-dependent and time-dependent methods.