• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.344-345
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• 2011

스마트 그리드 산업으로 인하여 신재생에너지의 활용이 중시되고 있는 시점에서 신재생에너지원을 더욱 효율적이고 안정적으로 사용하기 위해서는 에너지 저장장치의 필요성이 부각되고 있다. 신재생 에너지원을 사용하기 위한 부스트 컨버터와 충방전기를 설계시 일반적으로 시뮬레이션을 통해 설계를 하게 된다. 이때, 인덕터와 커패시터를 이상적인 소자라고 생각하고 시뮬레이션 하거나, 실제 하드웨어와 같이 인덕터와 커패시터에 기생하는 저항을 포함시켜 시뮬레이션을 하게 된다. 본 논문에서는 신재생 에너지원을 계통에 사용할 수 있도록 저전압 상태에서의 신재생 에너지원 출력전압을 승압시켜 인버터를 사용할 수 있도록 만들어 주는 부스트 컨버터의 인덕터를 이상적인 경우와 기생저항이 포함된 경우 각각의 조건하에서 충방전기와 연결하였을 경우 충방전기의 설계에 어떠한 영향을 주는지를 알기 위해 부스트 컨버터의 출력 임피던스 수식을 통해 분석한 MATLAB과 PSIM을 통해 시뮬레이션을 하여 증명하였다.

• 한국신재생에너지학회:학술대회논문집
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• 2005.11a
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• pp.607-607
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• 2005

• Journal of the Korean Magnetics Society
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• v.14 no.2
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• pp.65-70
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• 2004

Read out signal and temperature distribution of magnetic amplifying magnetooptical disk were studied. Temperature distribution of recording layer and adjacent layers were calculated when the disk was at rest. Mark size, length and location were simulated from a chain of recording beam pulses. In addition, signal amplitude depending on the shape of the marks, readout signals from the recording layer and amplified marks of the readout layer, were simulated. Simplified thermal conduction model was used to calculate the temperature distribution of recording and adjacent layers as a function of time as well as to calculate the mark size, length and location. Readout signal was calculated by the convolution of the disk reflectivity and the Gaussian beam intensity. Readout signal from the mark in the readout layer amplified to the size of the laser beam fumed out to be twice as large as the signal from the crescent shaped mark in the recording layer.

• The Transactions of the Korean Institute of Power Electronics
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• v.16 no.5
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• pp.511-520
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• 2011

Nowadays, industry of smart grid is important for practical use of the renewable energy. In this situation, it is important to use the energy storage to make more stable and efficient renewable energy sources. The power conditioning systems consist in a boost converter which makes renewable energy source connected with the grid-connected inverter and the charger/discharger which takes the energy transfer between the boost converter and an energy storage. The effects on the controller design of each converter must be investigated to avoid the instability of the entire system. small-signal modelling of the boost converter and charger/discharger have been done and a controller design example is also presented. In this paper, effects on the controller design of the boost converter and the charger/discharger are investigated according to the existence of the parasitic resistance of the boost converter. In conclusion, the parasitic resistance of the inductor should be considered from the aspect of both the frequency domain analysis and time domain simulation using both MATLAB and PSIM.

• Journal of the Korean Magnetics Society
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• v.6 no.3
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• pp.174-178
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• 1996

A method was studied which simulate signal and noise for magneto-optical disk drive system Recorded mark patterns and incident laser beam were modeled and discretized. Using them readout waveformj and amplitude were simulated. Adding Gaussian random noise to the readout signal and executing one dimensional discrete FFT (Fast Fourier Transform) algorithm signal and noise spectrum was estimated. From the spectrum, CNR (Carrier to Noise Ratio) was obtained.

• Journal of the Korea Society for Simulation
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• v.13 no.2
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• pp.23-34
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• 2004

Regenerative simulation (RS) is a method of stochastic steady-state simulation in which output data are collected and analysed within regenerative cycles (RCs). Since data collected during consecutive RCs are independent and identically distributed, there is no problem with the initial transient period in simulated processes, which is a perennial issue of concern in all other types of steady-state simulation. In this paper, we address the issue of experimental analysis of the quality of sequential regenerative simulation in the sense of the coverage of the final confidence intervals of mean values. The ultimate purpose of this study is to determine the best version of RS to be implemented in Akaroa2 [1], a fully automated controller of distributed stochastic simulation in LAN environments.

• Applied Chemistry for Engineering
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• v.5 no.6
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• pp.917-924
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• 1994

In this paper, we briefly introduce applications of optimum de-inking agent by waste-paper recycling stimulation technology. From the aspects of environmental protection and efficient use of natural sources requirement of recycle paper and higher quality pulp will be increasing. By developement of high-performance de-inking agents and its system, we would like to contribute for advance of waste paper treatment technology and higher quality pulp recycling.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2009.10a
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• pp.62-63
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• 2009

A monitoring system of collision risk among multiple ships is newly-designed in order to reduce human error and make vessel traffic control more effective. By using AIS data as ships' navigational information, an estimation algorithm of collision risk among multiple ships is newly-designed. To consider ships' course of now and future, collision risks of multiple ships can be calculated by using fuzzy algorithm. To test the performance of new algorithm, replay simulations are carried out on actual AIS data collected from VTS center of Ulsan harbor in Korea. The AIS data include 25 ships' information for two hours. In this paper, the features of newly-designed estimation algorithm of collision risk and the results of replay simulation are discussed.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.138-138
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• 2011

GTL(Gas to Liquid) 합성유 생산 공정은 크게 합성가스 개질공정(reformer), FT 반응공정, upgrading 공정으로 구성된다. 본 연구에서는 FT 반응기에 유입되는 합성가스의 생산공정인 개질공정 최적화 시뮬레이션을 수행하였다. 기존에 HYSYS 공정 모사 tool로 구현한 개질공정 모델에 dynamic simulation을 적용하여 공정 운전 시간 변화에 따른 온도/압력/조성의 일정범위 별 생산 가스의 성분비를 모사하고자 한다. Dynamic 공정 시뮬레이션은 모사 대상 공정의 운전 시간 별 결과값 변화를 산출할 수 있는 방법으로 기존 정상상태(steady-state) 시뮬레이션에 비해 현실 공정의 운전 변수를 보다 더 정확하게 반영할 수 있는 장점이 있다. 본 시뮬레이션은 1bpd급 GTL 파일럿 플랜트의 설계 자료를 근거로 수행되었으며, 향후 운전 데이터를 feedback하여 최적의 운전 매뉴얼 도출자료로 활용코자 한다. 아울러, 다음의 시간 변화별 모사 결과 데이터들을 산출하고 공정의 최적운전 조건을 분석하고자 한다. - 시간에 따른 공정의 온도/압력 변화, 이에 연동되는 반응기 출구의 1) $H_2$/CO 비율, 2) $CH_4$ conversion, 3) $CO_2$ conversion 본 연구의 결과 데이터를 1bpd급 GTL 플랜트 내 합성가스 개질공정의 운전조건 최적화에 적용코자 하며, 이는 개질반응기의 안정적인 연속운전을 통한 GTL 통합공정의 운전 효율향상에 기여 가능하리라 기대된다. 향후 개질공정의 후단공정인 FT 합성공정 시뮬레이션 과업과 연계하여 GTL 통합공정 시뮬레이션 및 최적화에 따른 실증 규모의 스케일업 기반 데이터를 마련할 수 있을 것이다.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.180-181
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• 2010

An estimation algorithm of collision risk among multiple ships has been developed in order to reduce human error and prevent collision accidents. The algorithm is designed to calculate the collision risk among ships based on Fuzzy theory by using AIS data as traffic information. In this paper, to validate the algorithm, the AIS data of actual collision accident, which occurred between a product carrier and a cargo carrier in Busan harbor in 2009 are collected. The replay simulation is carried out on the actual AIS data and the collision risk is calculated in real time. In this paper, the features of the estimation algorithm of collision risk and the results of replay simulation based on AIS data of actual collision accident are discussed.