• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1999년도 추계학술대회논문집
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• pp.153-161
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• 1999

For composing the structure model of national maritime power system by system structural modelling, in this study, the 50 basic factors are selected by survey of the extensive and thorough literatures on maritime, sea, maritime power and sea power. And the basic factors are classified into 36 component factors by cluster method. The 9 attributes are extracted by the application of the principle component analysis method, one of the factor analysis method in system engineering, to component factors. We defined the attributes composing the national maritime power system by integration the result of this study and existed our studies relate to this topic. Which are showed in table 8. and we showed the structure model of national maritime power system in figure 3. In table 8, the 9 attributes are as follows: the fundamental power of maritime, shipping and port power, naval power, fishing power, shipbuilding power, the power of ocean research and development, dependency on seaborne trade, the protection power of ocean environment and the will and inclination of government.

• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 1999년도 추계학술대회논문집
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• pp.333-344
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• 1999

Currently many studies on the unmanned gantry crane for the automated container terminal are accomplished. This is needed for the development of large scale, automation, high speed, unmanned system and information system in port facility. In order to do efficient container handling job in port yard, the automated handling system is well adapted to the job environments and all-season weather, In order to realize the automatic and unmanned system for container handling job, the required functions and main structure system are studied. The major problems of operation of the conventional gantry crane are that the vibration of gantry structure body is occurred by operation and that high-speed and precision position-velocity control and the capability to dope to the external disturbances caused by the wind, rain, fog and job environments. In this paper, the fundamental study for establishment of the concept and the dynamic modelling of the major sub system of the unmanned gantry crane is presented. These studies are useful for design and manufacturing of the new concept model of the unmanned gantry crane for efficient operation of the automated container terminal.

• 해양환경안전학회지
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• 제22권7호
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• pp.869-875
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• 2016

본 연구에서는 파랑후측모델링을 통해 우리나라 연안에서의 장기 파랑경향성을 분석하였다. 파랑경향성 분석시 사용한 바람자료는 1979년부터 현재까지 제공하고 있는 ECMWF 바람자료를 사용하였으며, 모델수행 기간은 2001년~2014년으로 14년 동안 수행하였다. 생산된 파랑후측모델링 결과는 국립해양조사원 및 기상청에서 설치한 파랑관측부이 자료를 이용하여 검증하였다. 검증 결과, 태풍 및 폭풍이 발생한 이벤트 상황을 모델이 잘 재현하고 있으며, 정량적인 RMSE 값은 0.5 m로 유의한 결과 값을 보였다. 파랑후측모델링을 통한 최근 14년 동안의 파랑 경향성 분석 결과, 과거에 비해 권역별 파고 2 m 이상 출현율은 전해역 평균 0.082 %/year로 증가하고 있으며, 이는 고파랑이 지속적으로 심화되고 있음을 뜻한다. 이러한 연안 파랑경향성 분석자료는 최근 기후변화에 따른 연안의 취약성평가 및 연안역에서의 침식방지구조물의 방재 설계를 위한 기초자료로 사용 가능하다.

• 한국정밀공학회지
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• 제15권8호
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• pp.174-182
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• 1998

This paper describes a research work of developing a computer-aided design and machining of irregular shaped-sheet metal product for blanking or piercing operation. An approach to the CAD/CAM system is based on the knowledge-based rules. Knowledge for the CAD/CAM system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD and in customer tool kit on the SmartCAM with a personal computer and is composed of nine modules, which are input and shape treatment, flat pattern-layout, production feasibility check, blank-layout, strip-layout, die-layout, data conversion, modelling, and post-processor module. Based on knowledge-based rules, the system is designed by considering several factors, such as material and thickness of product, complexities of blank geometry and punch profile, diameter and material of a wire, and availability of press. This system is capable of generating NC data automatically according to drawings of die-layout module. Results which are carried out in each module will provide efficiencies to the designer and the manufacturer of blanking or piercing die in this field.

• 전기학회논문지P
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• 제52권2호
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• pp.74-80
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• 2003

In this paper, a robust two-degree-of-freedom(TDF) the speed control system using $H_{\infty}$ optimization method and real genetic algorithm is proposed for the robust stability and the robust performance in dc servo motor system. This control system composed of feedback and feedforward controller. The feedback(FB) controller with $H_{\infty}$ optimization method is designed for real genetic algorithm that is model matching problem using mixed sensitivity function. The feedforward(FF) controller with $H_{\infty}$optimization method is minimized the error between transfer function of the optimal model and the overall transfer function. The proposed robust two-degree-of-freedom speed control system is simulated to the dc servo motor. By the simulation, feedback controller can obtain the robust stability property and feedforward controller can obtain the robust performance property under modelling error. The performance of the dc servo motor is analyzed by the experiment setting. The validity of the proposed method is verified through being compared with pid(proportional integrated differential)control system design method for the dc servo motor.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2013년도 제47차 동계학술대회논문집 21권1호
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• pp.295-298
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• 2013

미래 전장 환경하의 복합/다종 무기체계를 대상으로 하는 군수 시뮬레이션 모델링 방법론은 기존의 에이전트 시스템에서 실시간성 및 신뢰성뿐만 아니라, 국내 군수 환경을 수용할 수 있는 모델이어야 한다. 본 논문에서는 이 같은 전장상황이라는 특수성에 맞는 다중 에이전트 기반의 모델링 방법론을 제안하다. 다중 에이전트 시스템에서 효과적으로 모델링하기 위하여 군수 시뮬레이션의 모델을 Information, Function model 로 나누고 에이전트 시스템의 중추적인 역할을 하는 Agent Management System(AMS) 을 Management model 로 구성한다. 제안하는 모델링 방법론은 다양한 도메인에서도 구성하기 적합하여 확장성과 유연성의 이점이 있으며, 각 모델이 플러그인 형식으로 구현되어 유사한 도메인에 적용할 때 재사용성이 높은 모델링 방법론을 제시한다.

• 산업공학
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• 제21권1호
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• pp.85-95
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• 2008

Reliability prediction serves many purposes during the life of a system, so several methods have been developed to predict the parts and systems reliability. MIL-HDBK-217F, among the those methods, has been widely used as a requisite tool for the reliability prediction which is applied to nuclear power plants and their safety regulations. This paper presents the reliability prediction for the DSP(Digital Signal Processor) module composed of three assemblies. One of the assemblies has a monitoring and self test function which is used to enhance the module reliability. The reliability of each assembly is predicted by MIL-HDBK-217F. Based on these predicted values, Markov modelling is finally used to predict the module reliability. Relax 7.7 software of Relax software corporation is used because it has many part libraries and easily handles Markov processes modelling.

• 한국생산제조학회지
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• 제21권4호
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• pp.570-574
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• 2012

Spread of household air conditioning system is continued to be increased. Axial fan in the external unit of air conditioning system is for ventilation and air supplying unit, and the related products have been widely adopted as household electronics, automobile engine, big sized blower in factory, tunnel, and subway. In this study, commercial 3-winged propeller fan is modified to shape and modified to 2-winged fan for the airflow increase and cost reduction. Using 3D modelling, the fan shape is modified, and analysis flow is adopted to provide the way to airflow increase and reduce cost while maintaining the same wind capacity.

• 한국통신학회논문지
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• 제22권6호
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• pp.1356-1364
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• 1997

This paper presents a modelling and implementation scheme of a multi directory which provides location and supplementary information of multiple applications in distributed environments. An extrended directory schema and extended DIT(Directory Information Tree) model is proposed for the multi directory. For implementation scheme, an implementation example adapted for the DFR(Document Filing and Retrieval) is shown. In addition, a configuration model for interworking between the DFR and the multi directory, an association mechanisms between two application's operations are also described. In a distributed environment, the interworking between the DFR and a multi directory implemented by using QUIPU 8.0 of ISODE(ISO Development Environment) directory system is tested. Based on the result of this paper, an extended model ofthe directory system is proposed for providing search operation of various application' objects.

• 한국정보통신학회논문지
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• 제14권7호
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• pp.1544-1550
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• 2010

비선형 동적 시스템을 모델링하기 위해 GMDH(Group Method of Data Handling)를 적용한 많은 연구들이 수행되어 왔다. 그러나 모델링의 정확성을 위해서는 계산량이 크게 증가한다. 그러므로 본 논문에서는 입력 데이터를 취사선택하는 기준을 점감적으로 조정함으로써 적어도 정확성을 유지하면서 전형적인 GMDH의 단점인 과도한 계산을 피할 수 있는 방법을 제안한다. 컴퓨터 시뮬레이션 결과, GMDH 알고리듬의 계산량을 성공적으로 줄일 수 있었고 에러율도 소폭 줄일 수 있었다.