• 산업경영시스템학회지
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• 제35권4호
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• pp.235-243
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• 2012

The Voronoi diagram of spheres and power diagram have been known as powerful tools to analyze spatial characteristics of weighted points, and these structures have variety range of applications including molecular spatial structure analysis, location based optimization, architectural design, etc. Due to the fact that both diagrams are based on different distance metrics, one has better usability than another depending on application problems. In this paper, we compare these diagrams in various situations from the user's viewpoint, and show the Voronoi diagram of spheres is more effective in the problems based on the Euclidean distance metric such as nearest neighbor search, path bottleneck locating, and internal void finding.

• 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.

• 한국정밀공학회지
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• 제2권3호
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• pp.47-58
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• 1985

The study is concerned with the analysis of the required loads and torque in the Three-Roll Power Spinning Process by using the Method of Force Polygon Diagram. Experiments are carried out using pure lead billets at room temperature. The radial force, the axial force and the torque occurring during the process are calculated theoretically and are compared with the experimental data. An approximate load distribution is known by the Force Polygon Diagram.

• 정보처리학회논문지D
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• 제19D권4호
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• pp.281-292
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• 2012

스마트 폰과 같은 모바일 기기에서 동작하는 응용 소프트웨어는 제한된 배터리 용량으로 인하여 안정적인 서비스를 지속적으로 제공하는데 어려움을 갖는다. 과거에는 배터리의 수명을 연장 시키거나 소모전력이 적은 하드웨어 장치들을 개발하는 것으로 모바일 기기의 소모전력을 관리하였다. 그러나 시스템에 탑재되는 소프트웨어가 복잡해짐에 따라 소프트웨어에 대한 소모전력 분석 연구도 관심을 갖게 되었다. 이러한 연구들 중에서 모델 기반의 소모전력 분석은 코드가 개발되기 이전에 미리 소모전력을 분석하고, 분석 결과를 기반으로 소프트웨어를 개발한다는 측면에서 소모전력 감소를 위한 하나의 중요한 전략으로 인식되어 오고 있다. 따라서 본 논문에서는 소프트웨어의 행위 모델인 UML의 상태기계(State Machine) 다이어그램을 이용하는 소모전력 분석 기법을 제안한다. 제안하는 분석기법은 상태기계 다이어그램을 페트리 넷으로 변환하고, 이의 시뮬레이션을 통해 소모전력을 예측하게 된다.

• 한국경영과학회지
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• 제10권1호
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• pp.41-53
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• 1985

The influence diagram is a new conceptual tool that can be used for structuring a strategic decision problem in decision analysis. It has a graphical representation of probabilistic dependence among variables in the decision problem. In this formal procedures for constructuring the influence diagram and for translating it into the corresponding decision tree are studied. An example that shows the power of the infuence diagram is shown.

• 대한전기학회논문지:전력기술부문A
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• 제53권2호
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• pp.111-120
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• 2004

This paper presents an application of Unified Modeling Language(UML) software technique for developing transmission pricing evaluation package. Also, this paper describes a transmission pricing algorithm applicable to a large-scale power system. The usage-based transmission pricing mechanism is very complex since it requires power flow analysis, fault current analysis, sensitivity evaluation of a transmission line, penalty factors calculation, transmission asset databases, and cost allocation rules, etc. For the efficient and flexible development of the transmission pricing package, a UML. approach is applied, which is composed of a use-case diagram, interaction diagram, class diagram, and package diagram using Rational Rose Unified Process(RUP). The designed transmission pricing package can be efficiently modified and reused as the market environments evolves since it is designed by Object-Oriented Programming(OOP).

• 동력기계공학회지
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• 제2권1호
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• pp.17-24
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• 1998

The combustion regime was discussed using a laser tomography and flame structure diagram. It was shown first how to represent the turbulent burning velocity and flame structural parameters in the dimensionless plane referred to as the flame structure diagram. And then, turbulent flame structure from the obtained images by laser tomography was compared with combustion regime in the Re-Da plane, one of the diagrams, specified by different researchers. As the result, the $u'/S_{L0}$ ratio at the boundary between the wrinkled laminar flame regime and reactant islands flame regime was found to be about 1.5.

• Journal of Multimedia Information System
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• 제3권4호
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• pp.161-168
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• 2016

In this paper, a power flow simulator, which visualizes power flow and system configuration, is proposed and implemented. Generally, it is necessary to prepare a text file with power-system descriptions, which is one of the barriers for power-flow simulations. The proposed simulator has a function of automatic generations of IEEE common data format files from user-drawn power-system diagrams. Therefore, it is possible for users to carry out simulations only by drawing power system on display. In addition, the proposed simulator also has a function that power-system diagram is illustrated automatically from an IEEE common data format file. By using this function, it is possible to visualize amounts and directions of power flows on the bus-system diagram, which helps users to comprehend network dynamics intuitively. Because the proposed simulator allows including renewable-resource generators in power systems, it is useful to evaluate the power distribution system. It is shown in this paper that the proposed simulator can make IEEE common data format files correctly and illustrate intuitive power flow.

• Journal of Power Electronics
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• 제9권4호
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• pp.553-566
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• 2009

In-phase control and energy-optimized control are the two major control strategies proposed for series power quality controllers (SPQC). However quantitative analysis and comparison between these two control strategies is quite limited in previous publications. In this paper, an extensive quantitative analysis is carried out on these two control strategies through phasor diagram approach, and a detailed quantitative comparison is conducted accordingly. The load current is used as the reference phasor, and this leads to a simpler and clearer phasor diagram for the quantitative relationship. Subsequently detailed analysis of SPQC using in-phase control and energy-optimized control are provided respectively, under different modes both for under voltage/voltage sag and for over voltage/voltage swell. The closed form analytic expressions and the curves describing SPQC compensation characteristics are obtained. The detailed system power flow is figured out for each mode, and the detailed quantitative comparison between the two control strategies is then carried out. The comparison covers several aspects of SPQC, such as required compensating voltage magnitude, required capacity of energy storage component, and maximal ride-through time. In the end, computer simulation and prototype experimental results are shown to verify the validity of all the analysis and the result of the comparison.

• Journal of Welding and Joining
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• 제17권3호
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• pp.44-49
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• 1999

Power and industrial plant use various welding processes and many kinds of materials. Thus, it is a difficult task to get the proper welding information. In this research, a welding information system was developed to solve the difficulty. It consists of database system, knowledge base system and diagram analysis programs. Database system contains a large database and various searching method corresponding to the kind of information. A large part of welding information is managed by this database system. Knowledge based system is used for decision of proper welding process and analysis of weld defects. It has conversion program from text to knowledge, and inference mechanism. Finally, Diagram analysis programs carry out the calculation of ferrite content in the weld metal. By the calculation, a crack occurrence can be avoided. The developed system can be a useful tool for welding in the field of power and industrial plant.