• 전기학회논문지
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• 제59권5호
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• pp.854-859
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• 2010

Distribution Automation System(DAS) is designed to improve operational efficiency by acquisition and control of remote data using its components such as central computation units, communication network and feeder remote terminal units. A conventional human machine interface of the DAS adopts a schematic diagram which is made by drawing power equipments on the geographic information system map. The single line diagram is more useful than the schematic diagram for the main tasks of distribution system operation such as protective relay coordination, service restoration and loss minimization. Since the configuration of the distribution line is changed according to the relocation of the open tie switches, the auto-drawing algorithm based on the connection between the sections and the switches is an essential technique. This paper proposes a new auto-drawing algorithm for a single line diagram of distribution systems based on tertiary tree and collision avoidance method. The feasibility of the proposed algorithm has been testified for various cases using practical distribution system with 12 feeders.

• 한국전자거래학회지
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• 제9권3호
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• pp.145-154
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• 2004

객체지향 및 컴포넌트지향 소프트웨어 개발 방법론의 클래스의 도출은 개발하려는 소프트웨어의 전체 품질을 결정하는데 중요한 요소이다. 각 방법론에서는 이 부분에 대해 클래스의 정의와 도출하는 방법을 설명하고 있지만 초보 분석자들이 활용하기는 어려운 점이 많다. 그 중, 개념적 갭(conceptual gap)으로 인한 문제는 클래스 도출에 가장 큰 영향을 미친다. 연구에서는 이런 부분을 보완하기 위한 장치로써 세가지 다이어그램을 제안한다. 요구분석과정의 결과를 도식적으로 정리하여 클래스 도출을 보완하기 위한 도구로 정보다이어그램(Information Diagram), 행위다이어그램(Behavior Diagram) 그리고 관리다이어그램(Management Diagram)이다. 세 다이어그램은 시스템의 관련자(stakeholder)가 시스템에 어떤 서비스를 요구하는가에 대한 관점으로 필요한 정보를 찾고, 그에 포함될 수 있는 세부 행위를 분석하고, 누가 이 서비스에 대한 책임이 있는가의 명세이다. 본 연구에서 제안하는 다이어그램들은 기존의 소프트웨어 개발 방법에서 클래스를 도출하는 과정에 활용할 수 있다.

• 한국실내디자인학회논문집
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• 제17권3호
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• pp.156-164
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• 2008

Through staggering advancements of technology and network as we know them as digital revolution, we have established a foundation of space in which we can express reality by eliminating the boundaries between expression, space, and movement. There are many ongoing approaches that aim to overcome the physically-fixed property of space where the mathematical-geometric notion of Voronoi Diagram is one of them. Although the repetitive increment based on self-organization during the process in which space is generated by the Voronoi Diagram forms a pattern and focuses on the formation, its pattern is not restricted to a single method of expression but evolves over self-control. The result of having analyzed spaces generated by the Voronoi Diagram in this study can be summarized as follows. First, the Voronoi computation method with self-organization property creates multiple levels, increments, and evolves through feedbacks among changes with the slightest order and in the absence of control. Secondly, after forming a pattern through such feedbacks comes the differentiation phase due to the presence of different properties. Thirdly, a space that has gone through the generation process retransforms through active interaction between changes and it obtains ambiguous boundaries and a repetitive pattern. This leads to an evolution of space through repetitive increments based on self-organization. Such flexible space creation is supported by various digital technologies where we believe a converging application of these studies, sciences, engineering concepts, and space design is and effective and new method in terms of space creation.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.822-827
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• 2003

Topological maps have drawn more attention recently because they are compact, provide natural interfaces, and are applicable to path planning easily. To build a topological map incrementally, Voronoi diagram was used by many researchers. The Voronoi diagram, however, has difficulty in applying to arbitrarily shaped objects and needs long computation time. In this paper, we present a new method for global topological map from the local topological maps incrementally. The local topological maps are created through a thinning algorithm from a local grid map, which is built based on the sensor information at the current robot position. A thinning method requires simpler computation than the Voronoi diagram. Localization based on the topological map is usually difficult, but additional nodes created by the thinning method can improve localization performance. A series of experiments have been conducted using a two-wheeled mobile robot equipped with a laser scanner. It is shown that the proposed scheme can create satisfactory topological maps.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2011년도 춘계학술대회
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• pp.695-699
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• 2011

The study presents an efficient design method of Venn Diagram that can be used when implementing the quality design of experiments based on generalizability theory. The paper examines four mixed and combined models that are designed by fixed factor, random factor, crossed factor and nested factor. The models considered in this research are $A^*{\times}B^*{\times}C$, (B: $A^*$)${\times}C$, $A{\times}B{\times}C$ and (B: A)${\times}C$.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.833-841
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• 2021

During the postulated severe accident of nuclear reactor, eutectic reaction leads to low-temperature melting of fuel cladding and early failure of core structure. In order to model eutectic melting with the moving particle semi-implicit (MPS) method, the eutectic reaction model is developed to simulate the eutectic reaction phenomenon. The coupling of mass diffusion and phase diagram is applied to calculate the eutectic reaction with the uniform temperature. A heat transfer formula is proposed based on the phase diagram to handle the heat release or absorption during the process of eutectic reaction, and it can combine with mass diffusion and phase diagram to describe the eutectic reaction with temperature variation. The heat transfer formula is verified by the one-dimensional melting simulations and the predicted interface position agrees well with the theoretical solution. In order to verify the eutectic reaction models, the eutectic reaction of uranium and iron in two semi-infinite domains is simulated, and the profile of solid thickness decrease over time follows the parabolic law. The modified MPS method is applied to calculate Transient Reactor Test Facility (TREAT) experiment, the penetration rate in the simulations are agreeable with the experiment results. In addition, a hypothetical case based on the TREAT experiment is also conducted to validate the eutectic reaction with temperature variation, the results present continuity with the simulations of TREAT experiment. Thus the improved method is proved to be capable of simulating the eutectic reaction in the severe accident.

• 한국강구조학회 논문집
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• 제13권2호
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• pp.163-176
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• 2001

본 논문에서는 뒴비틀림 효과를 고려한 휨비틀림 이론을 기초로 연속곡선보를 해석한다. 먼저 단순곡선보에 대해 미분방정식으로 단면력과 변위를 구한다. 다음 에너지법을 이용하여 n경간 연속곡선보에 대한 탄성방정식으로 연속곡선보의 임의점에서 단면력과 변위의 해를 구한다. 작용하중으로 수직집중하중과 수직등분포하중을 고려하여 해석하였으므로 실제 하중이 작용하는 연속곡선박스거더의 단면력과 변위를 쉽게 구할 수 있다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2022년도 가을 학술논문 발표대회
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• pp.221-222
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• 2022

In this study, the work flow of the construction process was analyzed based on construction monitoring for a building of the middle size beam-column system Precast Concrete(PC) apartment building supplied by LH, and the Arrow Daigram Method(ADM) network diagram of its construction was written. The results of this study are judged to be able to improve productivity by using the PC structure apartment building construction plan to calculate a reasonable construction period and prepare a process management method for the PC structure frame construction.

• 한국해양공학회지
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• 제38권3호
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• pp.115-123
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• 2024

USBL systems are essential for providing accurate positions of autonomous underwater vehicles (AUVs). On the other hand, the accuracy can be degraded by outliers because of the environmental conditions. A failure to address these outliers can significantly impact the reliability of underwater localization and navigation systems. This paper proposes a novel outlier rejection algorithm for AUV localization using Voronoi diagrams and query point calculation. The Voronoi diagram divides data space into Voronoi cells that center on ultra-short baseline (USBL) data, and the calculated query point determines if the corresponding USBL data is an inlier. This study conducted experiments acquiring GPS and USBL data simultaneously and optimized the algorithm empirically based on the acquired data. In addition, the proposed method was applied to a sensor fusion algorithm to verify its effectiveness, resulting in improved pose estimations. The proposed method can be applied to various sensor fusion algorithms as a preprocess and could be used for outlier rejection for other 2D-based location sensors.

• 정보처리학회논문지D
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• 제13D권7호
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• pp.923-930
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• 2006

본 논문에서는 무기체계 임베디드 소프트웨어의 시간 요소를 고려한 TFM(Time Factor Method) 기반의 시스템 테스트 모델을 설계하고, 적용사례를 통하여 결과를 제시한다. 이를 위해 무기체계 임베디드 소프트웨어의 특징과 시스템 테스트 그리고 객체지향 모델의 표현방법인 UML 표기법에 대하여 알아보고, 시스템 테스트 모델 설계를 위한 TFM 접근 방법으로 시간 요소를 고려한 테스트 방법과 시간 요소 측정 방법 그리고 테스트 케이스 선정 알고리즘을 제시한다. 무기체계 임베디드 소프트웨어의 TFM 기반 시스템 테스트 모델은 세 가지 요소 (X,Y,Z) 로 구성되며, 'X' 에서는 최대시간경로를 선정하는 알고리즘을 통해 테스트 케이스가 도출되고, 'Y' 에서는 Sequence Diagram과 관련된 객체를 식별하고, 'Z'에서는 Timing Diagram을 통하여 식별된 각 객체들의 실행시간을 측정한다. 또한 제안한 W:M 기반 시스템 테스트 모델을 '다기능 미사일 방어시스템'에 적용하여 테스트 케이스를 추출하는 방법을 제시한다.