• 플랜트 저널
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• 제9권3호
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• pp.43-47
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• 2013

발전 플랜트의 발전량 최적화 및 발전효율 최적화는 에너지공학을 전공한 전문가일지라도 이해하기 힘든 개념이다. 본 연구에서는 엑서지 및 엑서지율이라는 열역학적 상태값을 적용하여 에너지 공학을 전공하지 않은 일반인일지라도 발전량 및 발전효율 최적화 개념을 쉽게 이해할 수 있는 차트가 개발되었다. 발전소의 성능을 파악할 수 있는 대표적인 물성치는 주증기의 온도 및 압력이다. 개발된 차트에서는 주증기의 온도 및 압력에 따른 최대 발전량 곡선과 최대 효율 곡선이 도시되어 있으므로, 해석하고자 하는 발전소의 온도 및 압력을 차트에 적용하여 그 발전소가 얼마만큼 최대 발전량과 최대 효율에 접근해 있는지를 쉽게 파악할 수 있다.

• 한국안전학회지
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• 제20권4호
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• pp.20-28
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• 2005

In this paper, the methodology for the reliability estimation of buried pipeline with longitudinal gouges and dent is presented and the limit state of buried pipeline is formulated by failure assessment diagram(FAD). The reliability of buried pipeline with defects has been estimated by using a theory of failure probability. The failure probability is calculated by using the FORM(first order reliability method) and Monte Carlo simulation. The results out of two procedures have been compared each other. It is found that the FORM and Monte Carlo simulation give similar results for varying boundary conditions and various random variables. Furthermore, it is also recognized that the failure probability increases with increasing of dent depth, gouge depth, gouge length, operating pressure, pipe outside radius and decreasing the wall thickness. And it is found that the analysis by using the failure assessment diagram gives highly conservative results than those by using the theory of failure probability.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.281.1-281.1
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• 2013

Shape control of gold nanocrystal is still one of the most important challenges remaining to achieve geometry dependent properties. Thus far, several strategies have been developed to control the shape of nanoparticles, such as adding capping agents and diverse additives or adjusting the temperature and pH. Here, we used an already established seed-mediated method that allowed us to focus on controlling the growth stage. Cetyltrimethylammonium bromide (CTAB) and ascorbic acid (AA) were used as the ligand and the reducing agent, respectively, without using any additional additives during the growth stage. We investigated how the relative ratio of CTAB and AA concentrations could be a major determinant of nanoparticle shape over a wide concentration range of CTAB and AA. As a result, a morphology diagram was constructed experimentally that covered the growth conditions of rods, cuboctahedra, cubes, and rhombic dodecahedra. The trends in the morphology diagram emphasize the importance of the interplay between CTAB and AA. Furthermore, high-index faceted gold nanocrystal was obtained by two step seeded growth. Already synthesized cubic particles developed into hexoctahedral nanocrystal consisting of 48 identical {321} facets, which indicates that the growth of gold nanocrystal is affected by initial morphology of seed particles. The hexoctahedral gold nanoparticles can be used in catalysis and optical applications which exploiting their unique geometry. Our research can provide useful guidelines for designing various facetted geometries.

• 한국산업융합학회 논문집
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• 제9권2호
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• pp.117-122
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• 2006

This paper is to provide some of the analysis procedures of the FAD(Failure Assessment Diagram), which is applied th the safety test of the atomic pressure vessels and other structures. Harrison proposed R-6 Diagram, and Bloom developed the method of DPFAD(Deformation Plasticty Failure Assessment Diagram). Analysis of J-integration of the plastic materials give the failure test curve for the materials with serious work hardening effect. J value was obtained form both FEM(Finite Element Mothod) and the experiment using compact type specimen for J=JIC, and the results were compared. In this study, the results of analysis using DPFAD and the factors affecting DPFAD in Static fatigue and fracture were reviewed. It was shown that the concept of DPFAD can be applied to test the safety of the structures.

• 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.

• 소프트웨어공학소사이어티 논문지
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• 제24권1호
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• pp.1-7
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• 2011

MVC는 유지보수가 쉬워 효율적인 개발이 가능한 아키텍처이다. 웹과 PC환경의 애플리케이션뿐만 아니라 모바일 애플리케이션 개발에 많이 적용됨에 따라 그에 대한 테스팅 또한 중요하다. 기존에 MVC 아키텍처를 적용한 개발에 초점을 둔 연구는 많았으나 MVC 아키텍처의 특성을 고려한 효율적인 테스팅을 위한 연구는 많지 않았다. 따라서 본 논문에서는 MVC 아키텍처 기반 애플리케이션의 효율적이고 정확한 테스팅을 위한 연구를 진행한다. 모델-뷰-컨트롤러의 융합된 상태를 담았던 기존의 상태 다이어그램을 뷰 상태와 모델-컨트롤러 상태 다이어그램으로 분리하고 테스트 케이스를 작성한 후, 테스트를 진행한다.

• 한국도시철도학회논문집
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• 제6권4호
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• pp.287-298
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• 2018

본 연구는 철도안전관리체계 기술기준의 11.7 철도관제를 중심으로 철도교통관제사의 다양한 측면에서 업무를 이해하고 실무적 제언을 하고자 한 논문이다. 분석방법으로는 시스템다이내믹스의 소프트적 방법인 인과순환지도를 작성하여 11.7철도관제의 업무를 분석하였다. 그리고 4개 철도운영기관 별 11.7 철도관제를 비교분석 하여 운영기관 별 관제업무의 특징들을 비교하여 철도관제업무의 중요성과 향후 실무적 개선안을 제시하고자 하였다.

• 스마트미디어저널
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• 제11권8호
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• pp.37-46
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• 2022

현대건축의 설계 과정에서 다이어그램(diagram)은 설명의 도구, 생성의 도구로 가장 많이 사용되고 있다. 많은 건축가들이 스스로 자신의 작품을 설명하거나 만들어 가는 과정에서 다이어그램을 이용하고 있으며, 프로그램에 대한 개념과 이를 표현하는 다이어그램은 단순한 매체의 역할을 넘어 실재적 건축 설계 과정 속에서 수용자들에게 창조적 작업의 일환으로써 받아들여지고 있다. 이에 본 연구의 목적은 지난 30년간 건축공간구성에서의 프로세스를 나타내는 도구로서 다이어그램을 시대별로 정의하여 건축 과정에서 다이어그램을 통한 건축가의 다양한 사용방법과 디자인 과정에서 적용된 다이어그램의 작동 과정을 비교 분석해 보고자 한다.

• 한국안전학회지
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• 제37권5호
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• pp.1-6
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• 2022

In this study, to confirm the effects of the mixed load of normal and shear forces acting on a fixing bolt, fatigue design criteria were developed by varying the loading angle and conducting tensile and fatigue tests. After evaluating and comparing the test results under different loading angles, the evaluation criteria were selected. These evaluation criteria were then applied to develop the design criteria. An Arcan fixture was designed and manufactured to simultaneously apply a mixed load of normal and shear forces to the fixing bolt of a turntable, and a fatigue test was conducted. S-N diagrams for various loading angles were obtained, and a 1% P-S-N diagram of failure probability was determined using statistical processing techniques. Our results show that failures of the fixing bolt can be prevented using these diagrams as a basis for developing fatigue design criteria.

• 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.