• 전기학회논문지
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• 제59권5호
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• pp.882-889
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• 2010

This paper presents a method of finding the optimal operating point minimizing a given objective function with 3 phase power flow equations and operational constraints, called 3 phase optimal power flow (3POPF). 3 phase optimal power flow can provide operation and control strategies for the distribution systems with distributed generation assets, which might be frequently in unbalanced conditions assuming that high penetration rate of renewable energy sources in the systems. As the solution technique for 3POPF, this paper adopts a simulation-based method of particle swarm optimization (PSO). In the PSO based 3POPF, a utility function needs to be defined for evaluation of the degree in operational improvement of each particle's current position. To evaluate the utility function, in this paper, NR-based 3 phase power flow algorithm was developed which can deal with looped distributed generation systems. In this paper, illustrative examples with a 5-bus and a modified IEEE 37-bus test systems are given.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.82-88
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• 2002

A simple beam subjected to a uniformly distributed tangential follower force and the successive two moving spring-mass systems upon it constitute this vibration system. The influences of the velocities of the moving spring-mass system, the distance between the successive two moving spring-mass systems and the uniformly distributed tangential follower force have been studied on the dynamic behavior of a simple beam by numerical method. The uniformly distributed tangential follower force is considered within its critical value of a simple beam without the successive two moving spring-mass systems, and three kinds of constant velocities and constant distance of the successive two moving spring-mass systems are also chosen. Their coupling effects on the transverse vibration of the simple beam are inspected too.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1998년도 제13차 학술회의논문집
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• pp.423-428
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• 1998

This paper studies the regional identifiability of spatially-varying parameters in distributed parameter systems of hyperbolic type. Let Ω be a bounded domain of R$^n$and let Ωo be a subregion of the closed domain Ω. The distributed parameter systems having unknown parameters defined on Ω are described by the second order evolution equations in the filbert space L$^2$(Ω) and the observations are made on the subregion Ωo ⊂ Ω. The regional identifiability is formulated as the uniqueness of parameters by the identity of solutions on the subregion. Several regional identifiability results of the spatially-varying parameters of hyperbolic distributed parameter systems are established by means of the Riesz spectral representations.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1999년도 추계학술대회논문집
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• pp.163-175
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• 1999

As the size and complexity of network increase, Distributed Systems Management (DSM) will be significant issue within information network in order to increase the high reliability and to improve the flexibility of network management. The OSI management model has several problems. The key problems are that it does not fully address the problems of how to develop communication protocol in support of DSM, and how to classify the management connection criteria. In this paper, to solve first problem described above, this paper propose the connectionless CMIP(Common Management Information Protocol) to accomplish for effectively managing the distributed management system, and indicate its efficiency; this protocol is available to negotiate among the managing systems, handle the dynamic information. To work out second problem, we introduce the connection criteria in the hierarchy of management systems, and finally evaluate the efficiency of a suggested protocol during cooperative negotiation among the managing systems.

• 인터넷정보학회논문지
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• 제15권5호
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• pp.107-121
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• 2014

분산 시스템은 물리적으로 분산된 컴퓨터들이 네트워크에 의해 유기적으로 연결된 것을 의미한다. 유무선 인터넷의 보편적인 사용으로 인해 사용자는 언제 어디서나 분산 서비스의 이용이 가능하게 되었다. 분산 서비스의 폭발적인 증가는 서비스의 기능적 측면에서의 검증뿐만 아니라 서비스 품질과 관련된 비기능적 요소의 검증도 강하게 요구하고 있다. 분산 서비스를 검증하기 위해서는 분산 시스템에 맞는 테스트 환경을 구축해야 한다. 하지만 분산 시스템은 물리적으로 분산된 노드로 구성되기 때문에 테스트 환경을 구축함에 있어서 단일 시스템의 테스트 환경보다 많은 노력이 요구된다. 이 논문에서 우리는 분산 시스템의 기능 및 비기능 요소의 검증을 위한 테스트 프레임워크를 제안한다. 제안하는 테스트 프레임워크는 메시지 시퀀스 차트(Message Sequence Chart)를 기반으로 테스트 케이스를 자동 생성하며, 물리적으로 분산된 노드를 흉내 낼 수 있는 가상의 분산 노드로 구성된 테스트 드라이버를 포함한다. 테스트 수행 결과는 다양한 그래프와 GUI를 통해서 쉽게 확인할 수 있다. 이 논문에서 제안하는 테스트 프레임워크를 통해 분산 시스템 테스트에 드는 노력을 감소할 수 있고 시스템의 신뢰성을 향상 시킬 수 있을 것이다.

• 전기의세계
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• 제19권2호
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• pp.21-23
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• 1970

Necessary conditions of optimal distributed parameter control systems, Hamiltons coanonical equations, welerstress condition, transversality condition and boundary condition are obtained, when the control function is constrained and the performance index takes on the general form. Also it is concluded that the lumped parameter system is the special case of the distributed parameter system.

• International Journal of Automotive Technology
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• 제5권4호
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• pp.269-276
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• 2004

There has been considerable activity in recent years in developing timing analysis algorithms for distributed real-time control systems. However, it is difficult for control engineers to analyze the timing behavior of distributed real-time control systems because the algorithms was developed in a software engineer's position and the calculation of the algorithm is very complex. Therefore, there is a need to develop a timing analysis tool, which can handle the calculation complexity of the timing analysis algorithms in order to help control engineers easily analyze or develop the distributed real-time control systems. In this paper, an interactive timing analysis tool, called RAT (Response-time Analysis Tool), is introduced. RAT can perform the schedulability analysis for development of distributed real-time control systems. The schedulability analysis can verify whether all real-time tasks and messages in a system will be completed by their deadlines in the system design phase. Furthermore, from the viewpoint of end-to-end scheduling, RAT can perform the schedulability analysis for series of tasks and messages in a precedence relationship.

• 한국소음진동공학회논문집
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• 제13권3호
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• pp.202-209
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• 2003

A simply supported beam subjected to a uniformly distributed tangential follower force and the two successively moving spring-mass systems upon it constitute this vibration system. The influences of the velocities of the moving spring-mass system, the distance between two successively moving spring-mass systems and the uniformly distributed tangential follower force have been studied on the dynamic behavior of a simply supported beam by numerical method. The uniformly distributed tangential follower force is considered within its critical value of a simply supported beam without two successively moving spring-mass systems, and three kinds of constant velocities and constant initial displacement of two successively moving spring-mass systems are also chosen. Their coupling effects on the transverse vibration of the simply supported beam are inspected too. In this study the simply supported beam is deflected with small vibration proportional to natural frequency of the moving spring-mass systems. According to the increasing of initial displacement of the moving spring-mass systems the amplitude of the small vibration of the simply supported beam is increased due to the spring force. The velocity of the moving spring-mass system more affect on the transverse deflection of simply supported beam than other factors of the system and the effect is dominant at high velocity of the moving spring-mass systems.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제4권1호
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• pp.29-33
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• 2004

I propose a personalized digital library system (PDLS) based on an advanced distributed agent platform. The new platform is developed by improving the DECAF (Distributed Environment-Centered Agent Framework) which is one of the conventional distributed agent development toolkits. Also, a mobile ORB (Object Request Broker), Voyager, and a new multi agent negotiation algorithm are adopted to develop the advanced platform. The new platform is for mobile multi agents as well as the distributed environment, whereas the DECAF is for the distributed and non-mobile environment. From the results of the simulation the searched time of PDLS is lower, as the numbers of servers and agents are increased. And the user satisfaction is four times greater than the conventional client-server model. Therefore, the new platform has some optimality and higher performance in the distributed mobile environment.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2007년도 한국컴퓨터종합학술대회논문집 Vol.34 No.1 (A)
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• pp.151-152
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• 2007