• Proceedings of the KSME Conference
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• 2004.11a
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• pp.893-898
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• 2004

The hydraulic cylinder is used for actuating a sluice gate which controls the volume of water in the reservoir. Generally, the one cylinder type is used to operate the sluice gate. In order to reduce the required cylinder force to operate the sluice gate significantly, the sequentially operated-hydraulic cylinders type is designed and the optimal locating points of cylinders are searched using the complex method that is one kind of constrained direct search method.

• 한국신재생에너지학회:학술대회논문집
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• 2011.11a
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• pp.49.2-49.2
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• 2011

본 논문에서는 대용량 태양광 PCS의 병렬운전 알고리즘에 대해 제안한다. 제안한 알고리즘은 dc-link 전압을 이용하여 PCS를 독립적으로 제어한다. 일반적으로 태양광 PCS는 정격용량 또는 그 근처에서 최대 효율을 낸다. 제안한 알고리즘은 일사량이 적을 시 일부 PCS만 작동하도록 하여 전력 변환 효율을 높인다. 항상 모든 PCS가 작동하는 것이 아니라 필요한 수량만 작동하도록 하고, 작동하는 PCS도 순차적으로 바꿔서, 전제 시스템의 수명을 늘리는 효과도 있다. 또한 일부 PCS가 고장이 날 경우 다른 PCS가 작동하도록 하여 태양광 발전이 멈추지 않고 계속 발전할 수 있도록 한다.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.734-737
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• 1991

본 고는 공학적 안전설비 작동계통 보조계전기 캐비넷의 설계과정을 위하여 작성되었다. 공학적 안전설비 작동계통 설계는 순차적인 과정을 밟아서 진행이 되므로, 설계담당자(Cognizant Engineer)는 그 작업순서를 이해하여야 하며, 각 과정마다 필요한 자료들과 생산해야될 결과물들을 정확히 파악하여야만 설계가 원활히 수행될 수 있다. 또한, 설계과정은 많은 연계 업무가 있으므로, 서로 주고받아야 할 자료들의 종류 및 그 시기를 예상할 수 있어야 한다. 그리하여, 본 내용에서는 공학적 안전설비 작동계통 보조전기 캐비넷의 특성에 따라 연계요건서, 설계시방서 및 개념적인 도면을 중심적으로 기술하였으며, 기기설계(Component Design)와 제작설계(Manufacturing Engineering) 및 현장지원(Field Supports)은 아직까지도 미비한 점이 많으나, 담당자(Cognizant Engineer)가 아는 바대로 작성하였다.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.47 no.5
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• pp.9-17
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• 2010

Corrective control compensates the stable-state behavior of asynchronous sequential machines so that the closed-loop system can be changed in a desirable way. Using corrective control, we present a novel fault tolerance scheme that overcomes permanent faults for asynchronous sequential machines. When a permanent fault occurs to an asynchronous machine, the fault is not recovered forever while the machine is irreversibly stuck in a set of failure states. But, if the machine has control redundancy in the limited behavior range, corrective control can be applied to solve the fault tolerance problem against permanent faults. We present the condition on detecting permanent faults and the existence condition of an appropriate corrective controller. The design procedure for the proposed controller is described in a case study.

• Journal of the Korea Society of Computer and Information
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• v.14 no.5
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• pp.29-36
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• 2009

Sequential pattern mining, which discovers frequent subsequences as patterns in a sequence database, is an important data mining problem with broad applications. Since a sequential pattern in DNA sequences can be a motif, we studied to find sequential patterns in DNA sequences. Most previously proposed mining algorithms follow the exact matching with a sequential pattern definition. They are not able to work in noisy environments and inaccurate data in practice. Theses problems occurs frequently in DNA sequences which is a biological data. We investigated approximate matching method to deal with those cases. Our idea is based on the observation that all occurrences of a frequent pattern can be classified into groups, which we call approximated pattern. The existing PrefixSpan algorithm can successfully find sequential patterns in a long sequence. We improved the PrefixSpan algorithm to find approximate sequential patterns. The experimental results showed that the number of repeats from the proposed method was 5 times more than that of PrefixSpan when the pattern length is 4.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.443-451
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• 2022

The paper delves into the elaborate intermediating mechanisms of the association between coaching leadership and safety behavior. To do that, this study tried to identify the sequential mediating effects of employee's meaningfulness of work and perceived organizational support between coaching leadership and safety behavior. By utilizing 3-wave survey data from 250 employees in Korean companies with conducting structural equation modeling(SEM), this paper found that coaching leadership had a positive influence on safety behavior through sequential mediating effect of employee's meaninfulness of work and perceived organizational support.

• Proceedings of the Korea Information Processing Society Conference
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• 2023.11a
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• pp.376-377
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• 2023

스마트홈은 기술 시스템, 자동화 프로세스, 원격 제어 기기 등을 아파트나 주택에서 사용하는 것을 말한다. 주요 목적은 가정에서 삶의 질과 편의성을 높이는 것이다. 현재의 스마트홈은 사용자의 원격 제어 방식을 사용하고 있다. 이러한 방식은 고정된 시간에만 스마트홈이 작동하도록 한다는 문제가 있었다. 연관분석과 순차분석을 통해 AI가 상황과 사용자의 취향을 학습한다면, 스스로 최적화된 패턴을 제공할 수 있을 것이다.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2012.05a
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• pp.63-64
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• 2012

A pyrotechnic actuated device (PAD) is a component that delivers high power in remote environments by combustion of a self-contained energy source. Historically, the design of these devices has been largely empirical and considered to be an art. In this study, an overview for developing an analytical model is introduced that efficiently evaluates performance of PAD. The model is integrated by three parts of different disciplines that are coupled in sequence with each other. First is the solid explosive burning to form product gas within an actuator and transport to an expansion chamber. Second is the insertion of initially tapered piston into a small hole by gas pressure in the chamber. Third is the shear cutting of the diaphragm from the piston to enable gas flow into the conduit. Some results of preliminary study for each of three parts are introduced in the presentation.

• Proceedings of the KIPE Conference
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• 2017.11a
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• pp.121-122
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• 2017

ITER AC/DC 컨버터(Converter)는 핵융합 발생을 위해 토카막의 초전도코일에 제어된 전류를 공급하여 플라즈마 발생, 형상 유지, 소멸하는 기능을 한다. 만일 컨버터 또는 초전도코일에 이상이 발생하면 즉시 보호동작이 실행되어야 한다. 이를 위해 설계된 F-LIC(Fast Local Interlock Controller)은 즉시 작동하여 Bypass 및 Make Switch 트리거, 차단기 작동 등을 순차적으로 수행한다. ITER Interlock System의 기기는 중요성이 고려되어 높은 신뢰도가 요구된다. 본 논문에서는 F-LIC 회로분석과 Telcordia SR-332 Standard에 의한 부품고장률 산출방법을 사용하여 FMEDA를 분석하고, 이를 통하여 회로구성 부품의 고장이 미치는 영향과 F-LIC 제어모듈의 SIL-2 등급의 적합성을 분석하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.15 no.1
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• pp.45-54
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• 2011

A program aiming at predicting dynamic characteristics of a Liquid Rocket Engine(LRE) was developed and examined to trace entire LRE operation. In the startup period, transient characteristics of the propellant flows were predicted and validated with hydraulic tests data. An arrangement of each component for the pipelines was based on an operating circuit of open cycle LRE. The flow rate ratio for the gas generator and the main chamber was determined to mimic that of real open cycle LRE. Individual component modeling at its transient was completed and was integrated into the system prediction program. Essential parameters of the component dynamic characteristics were examined in an integrated fashion.