• 한국통신학회논문지
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• 제28권5B호
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• pp.466-474
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• 2003

본 논문에서는 최근 효율적이고 경제적인 초고속 광가입자망 기술로서 부각된 Ethernet-PON 시스템을 위한 시뮬레이션 모델을 OPNET을 이용하여 구현한다. 설계한 Ethernet-PON 시스템은 IEEE 802.3ah EFM을 기반으로 요청/허가 TDMA MAC 프로토콜을 사용하며 제어 패킷들의 교환을 통해 등록, 레인징, 동적 대역 할당 등의 기능을 수행한다. 시뮬레이션 모델을 사용하여 초기 등록 절차에서의 성공률과 나중 등록을 위한 지연에 관한 결과를 분석하였다. 또한 사용자의 요구 대역 정보를 기반으로 대역을 동적으로 할당하는 Dynamic TDMA 프로토콜과 사용자의 요구에 관계없이 동등한 대역을 할당하는 Static TDMA 프로토콜의 성능을 채널 이용률 및 큐잉 지연 관점에서 비교하였다. 본 논문에서 구현한 시뮬레이터는 Ethernet-PON 시스템의 설계 과정에서 논의될 수 있는 여러 기술 사항들에 대한 적절한 선택 기준을 모의 실험을 통해 제시할 수 있을 것으로 기대된다.

• 한국시뮬레이션학회논문지
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• 제22권2호
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• pp.1-10
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• 2013

모델링 및 시뮬레이션 기술은 전장 환경을 고려한 실험 환경을 조성하여 무기 체계의 구성 요소에 대한 성능 분석을 실제와 유사하게 할 수 있다. 그러나 이전까지 모델링 및 시뮬레이션에서 개발된 무기체계 모델은 제한된 범위 내에서만 활용되어 확장성이 낮고 재사용성은 크게 고려하지 않았다. 이에 본 연구에서는 재사용성을 고려하여 개발된 컴포넌트에 대한 사용 검증 및 확장성 판단을 위한 검증도구와 컴포넌트를 효율적으로 관리하기 위한 관리 도구를 개발한다. 또한 이전 연구에서 설계한 유도무기체계의 동적 컴포넌트 재구성 아키텍처를 지대공유도무기 SAM(Surface to Air Missile) 교전 시뮬레이터에 적용하여 기 개발된 컴포넌트에 대한 효과도를 확인한다. 그리하여, 동적 컴포넌트 재구성 아키텍처의 시뮬레이션 적용을 통해 컴포넌트 기반의 재사용으로 유도무기체계에 대한 다양한 시스템을 구성하게 되었다.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 1998년도 추계 학술발표회 논문집
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• pp.69-74
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• 1998

• 한국정보통신학회논문지
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• 제3권4호
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• pp.819-830
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• 1999

NAVTEX system is an international automated direct-printing service, broadcast on 5181kHz and 490kHz, for the promulgation of navigational and meteorological warnings and urgent information to ships. With our government's adoption of the international convention for SAR(Search and Rescue) in 1993, various trials for the installation of NAVTEX system have been executed by the government committee, relating laboratory and experts. An important consideration of the installation for NAVTEX system is the availability that could broadcast messages written in korean letter. Also, the receiver which can process the signal demodulated from the two frequencies, 518kHz and 490kHz, should be developed and supplied in domestic. In this paper, the code table and algorithm for conversions between NAVTEX characters and Korean Letters are studied, and signal processing techniques of code conversion are developed. Circuit design and implementation of the NAVTEX simulator using the Direct Digital Synthesizer are discussed, code conversion algorithm and signal processing technique of the NAVTEX transmission are programmed in its circuits. For evaluating the its functional characteristics, receiving module which has I-Q channel structure is designed. From the measurements of simulator, the characteristics show the frequency stability of the $(\pm)2Hz$ and Spurious free dynamic range is -63dBc. And the simulator can generate simultaneously wanted signal and several interfere signals. So, its capability is valuable for designers of the transmitting system and NAVTEX receiver, for provider as testing facilities of the type approval.

• 제어로봇시스템학회논문지
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• 제5권6호
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• pp.724-733
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• 1999

An effective method of system modeling and dynamic scheduling for the back-end line of semiconductor manufacturing is proposed. The virtual factory, describing semiconductor manufacturing line, is designed in detail, and then a Petri net model simulator is developed for operation and control of the modular cells of the virtual factory. The petri net model is a colored timed Petri nets (CTPNs). The simulator will be utilized to analyze and evaluate various dynamic status and operatons of manufacturing environments. The dynamic schedulaer has a hierarchical structure with the higher for planning level and the lower for dynamic scheduling level. The genetic algorithm is applied to extract optimal conditions of the scheduling algorithm. The proposed dynamic scheduling is able to realize the semiconductor manufacturing environments for the diversity of products, the variety of orders by many customers, the flexibility of order change by changing market conditions, the complexity of manufacturing processes, and the uncertainty of manufacturing resources. The proposed method of dynamic scheduling is more effective and useful in dealing with such recent pressing requirements including on-time delivery, quick response, and flexibility.

• 전기학회논문지
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• 제61권6호
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• pp.810-816
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• 2012

As wind power has increased steadily, the importance of a condition monitoring system is being emphasized to maximize the availability and reliability of a wind turbine. To develop the advanced algorithms for fault detection and lifespan estimation, a wind turbine simulator is essential for verification of the proposed algorithms before applying them to a condition diagnosis & integrity prognosis system. The developed new-type simulator in this paper includes blades and various sensors as well as a motor, a gearbox and a generator of which the existing simulators generally consist. It also has similarity with a 3MW class wind turbine and can be used to acquire operational data from various operation conditions. This paper presents a design method of control logic for the wind turbine simulator, which gives a wind generation method and similar dynamic characteristics with the 3MW wind turbine. Finally, the proposed control logic is verified through experiments.

• 조명전기설비학회논문지
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• 제28권6호
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• pp.106-112
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• 2014

Recently, tidal power generation has gained much attention. South Korea's tidal power generation systems were imported from abroad by turnkey type and have being operated. Therefore, for efficient operation and technological independence of a tidal power system, development of core technology is required. This paper deals with the start stop control system of water turbine generator in the tidal power plant, as one of our development project results. Using the SCADA system, the status and operations of water turbine generator in the tidal power plant, as well as simulation for calculation of maximum power were carried out. A small model type of start stop control device was also developed. In addition, the control system in Sihwa tidal power plant was modeled, and the results obtained by the dynamic simulation were given in graphics by 2D simulator.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2009년도 정보 및 제어 심포지움 논문집
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• pp.323-325
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• 2009

In this paper, we present simulation results of Dynamic Matrix Control(DMC) to a boiler steam temperature. In order to control of steam temperature, we choose the input-output variables and generate the step response model by each input variable's step test. After that, the control structure executes on-line control with optimization using step response model. Proposed controller is applied to the APESS(Doosan company's boiler model simulator) and it is observed that the simulation results show satisfactory performance of proposed control.

• Journal of Electrical Engineering and Technology
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• 제10권6호
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• pp.2249-2255
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• 2015

The use of voltage source converter multi-terminal direct current (VSC-MTDC) systems is anticipated to increase from the introduction of wind farms and super grids in the near future. Effective control of the DC voltage in VSC-MTDC systems is an important research topic. This paper proposes a new dynamic reference-based voltage droop control to control the DC voltage in VSC-MTDC systems more effectively. The main merit of the dynamic reference-based voltage droop control is that it can reduce the steady-state error in conventional voltage droop control by changing references according to the system operating conditions. The performance of the proposed control was tested in a hardware-in-the-loop simulation (HILS) system based on the OPAL-RT real-time digital simulator and four digital signal processing boards.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1989년도 한국자동제어학술회의논문집; Seoul, Korea; 27-28 Oct. 1989
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• pp.1-6
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• 1989

For the design of synergistic hydraulic motion simulator, the load locus method is introduced. The given mass property of load and its velocity profile is resolved into the load locus of each actuator which decides the suitable valve and cylinder. This asymmtic cylinder and 4 way valve system have the pressure oscillation on zero velocity. The variable structure position controller which based on linearized flow equation makes elimination of the unstable pressure oscillation.