• Journal of Electrical Engineering and Technology
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• 제7권5호
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• pp.745-752
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• 2012

Transverse flux machine (TFM) has been proved to be very suitable for high-torque, low-speed, and direct-drive situation in industry. But the complex structures and costly permanent magnets (PMs) are two key limitations of its wide range of applications. This paper proposes a new claw pole TFM (ACPTFM) which features an assembled claw pole stator and using the lamination steels material to overcome the complex structures. By combining response surface methodology (RSM) with design of experiment, an optimum design method is put forward to improve the PM's contribution to the torque in order to save the PM's amount. The optimum design results demonstrate the validity of the proposed optimum design method and the optimized model. Eventually, the finite-element analysis (FEA) calculation method, which is used in the optimization process, is verified by the experiments in a prototype.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.200-207
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• 2006

A new formal standardization methodology of the structural design document information is proposed in this paper. The standardization process is divided into three steps: pre-process of the collected sample document (CSD), construction of the document structure, and definition of the occurrence of each element in the document. During the pre-process, the detail document contents in the CSD are indexed with templates defined in this study, and the indexed CSD is translated into XML Schema (XSD) formal Afterwards the degree of confidences of all elements between the temporary standard document (TSD) and the translated CSD are calculated by using the XML schema matching algorithm; the TSD is then updated. This second step is repeated until all of the CSD are compared. In the final step, the common elements and unbounded elements are extracted by determining the occurrence of the temporary document elements, and the standardized document schema is exported in the XSD format. The case study dealing with the structural calculation documents show that the ,proposed methodology can be effectively used to build a XML -based information model of structural design documents.

• 한국시뮬레이션학회논문지
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• 제10권2호
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• pp.33-46
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• 2001

Recently, the usage of containers in marine transportation is rapidly increasing. The problem of ship stability is important because of its direct influence to the loss of the human-life, ship, and merchandise. However, the assessment for ship stability during container loading/unloading in port is dependent on human experience only. On the other hand, the emerging information and communication technologies of shipbuilding industrial environments are rapidly changing. To respond to the situation, a new paradigm has been matured with new concepts such as the concrete method. Especially, all the efforts are shown to be concentrated to realize the concept of Simulation Based Design(SBD) based on three dimensional Computer Aided Design(CAD) model. In this paper, ship model-based simulation methodology for design and operation of ship is suggested, and for the verification of suggested methodology, the system for stability assessment of ship during container loading/unloading was developed using ENVISION, a general-purpose simulation system. The developed system consists of geometric modeling subsystem, basic calculation subsystem, and Computer Aided Engineering(CAE) subsystem. In addition, interface to CAE/CAD /simulation system such as SIKOB and ENVISION is provided.

• Nuclear Engineering and Technology
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• 제53권3호
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• pp.967-973
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• 2021

In 2011, an earthquake and subsequent tsunami hit the Fukushima Daiichi Nuclear Power Plant, causing simultaneous accidents in several reactors. This accident shows us that if there are several reactors on site, the seismic risk to multiple units is important to consider, in addition to that to single units in isolation. When a seismic event occurs, a seismic-failure correlation exists between the nuclear power plant's structures, systems, and components (SSCs) due to their seismic-response and seismic-capacity correlations. Therefore, it is necessary to evaluate the multi-unit seismic risk by considering the SSCs' seismic-failure-correlation effect. In this study, a methodology is proposed to obtain the seismic-response-correlation coefficient between SSCs to calculate the risk to multi-unit facilities. This coefficient is calculated from a probabilistic multi-unit seismic-response analysis. The seismic-response and seismic-failure-correlation coefficients of the emergency diesel generators installed within the units are successfully derived via the proposed method. In addition, the distribution of the seismic-response-correlation coefficient was observed as a function of the distance between SSCs of various dynamic characteristics. It is demonstrated that the proposed methodology can reasonably derive the seismic-response-correlation coefficient between SSCs, which is the input data for multi-unit seismic probabilistic safety assessment.

• 대한토목학회논문집
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• 제28권6D호
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• pp.923-929
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• 2008

3차원 공간데이터에 대한 요구가 증가하면서 지형뿐만 아니라 건물에 대한 모형화는 아주 중요한 부분을 차지하고 있다. 본 연구에서는 라이다자료만을 이용하여 계산량과 사용자의 개입을 최소화한 건물의 경계를 추출하는 방법론을 제시하였다. 그 특징은 점기반처리와 영상기반처리의 장점을 융합하여 1차 건물의 경계를 개략적으로 검색한 후 다시 원 라이다 자료를 분석하여 제약조건이 부가된 불규칙삼각망을 형성하여 건물의 경계를 정하였다. 그 후 건물의 면적과 한 변의 길이 등을 고려하여 건물의 형상을 갖도록 처리하였다. 제안한 방법론은 실제 라이다자료를 이용하여 검증하였으며 수치지도와 비교를 통해서 효용성을 입증하였다.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2009년도 추계학술대회 논문집
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• pp.295-296
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• 2009

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.875-877
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• 2003

This paper use fault location algorithm for single-phase-to-ground faults on the teed circuit of a parallel transmission line that use only local end voltage and current information. When Newton-Raphson iteration method is used, the Initial value may cause error or cause not suitable result. Suggested new calculation model uses NVP methodology, which is one of the fault tolerance technology to solve this problem. EMTP simulation result has shown effectiveness of the algorithm under various conditions.

• Nuclear Engineering and Technology
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• 제50권3호
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• pp.396-410
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• 2018

To assist operators to properly assess the current situation of the plant, accurate fault diagnosis methodology should be available and used. A reliable fault diagnosis method is beneficial for the safety of nuclear power plants. The major idea proposed in this work is integrating the merits of different fault diagnosis methodologies to offset their obvious disadvantages and enhance the accuracy and credibility of on-line fault diagnosis. This methodology uses the principle component analysis-based model and multi-flow model to diagnose fault type. To ensure the accuracy of results from the multi-flow model, a mechanical simulation model is implemented to do the quantitative calculation. More significantly, mechanism simulation is implemented to provide training data with fault signatures. Furthermore, one of the distance formulas in similarity measurement-Mahalanobis distance-is applied for on-line failure degree evaluation. The performance of this methodology was evaluated by applying it to the reactor coolant system of a pressurized water reactor. The results of simulation analysis show the effectiveness and accuracy of this methodology, leading to better confidence of it being integrated as a part of the computerized operator support system to assist operators in decision-making.

• 방사성폐기물학회지
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• 제1권1호
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• pp.1-10
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• 2003

1992년 리우 환경개발회의에서 채택된 Agenda 21에서 방사성폐기물의 안전관리를 위한 정책방향이 결정된 후, 국제연합은 방사성폐기물 안전관리를 지속 가능한 발전의 범위에 포함하여 국제원자력기구의 주관 하에 관련 지표의 개발 및 적용을 추진하고 있다. 2002년 국제원자력기구는 방사성폐기물관리에 관한 지속가능 발전지표를 확정하고 현재 운영중인 방사성폐기물 데이터베이스 시스템인 NEWMDB와 연계하여 회원국의 방사성폐기물관리 체계 및 현황을 정량적인 지표로 평가할 예정이다. 본 논문에서는 방사성폐기물에 관한 지속가능 발전지표의 도입근거와 적용상의 한계점을 분석하고, 국제원자력기구가 제시한 지표의 평가방법과 표준화된 절차를 도식화하였다. 도출된 평가절차에 따라 우리나라를 포함한 주요 국가의 방사성폐기물관리 체계 및 현황자료를 이용하여 각 국의 방사성폐기물관리에 관한 지속가능 발전지표를 평가하고 그 결과를 비교 분석하였다. 또한 지표의 향상을 통해 국내 방사성폐기물관리의 지속 가능성을 제고할 수 있는 방안을 도출하였다.

• 한국항만경제학회지
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• 제28권2호
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• pp.95-111
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• 2012

광양항 이용고객을 대상으로 2005년 이후 광양항 컨테이너부두 서비스품질 조사가 수행되었다. 광양항 조사의 분석결과는 서비스 평가체계 중 가장 중요한 서비스차원간의 가중치 산정절차가 수립되지 않아 연차별 또는 경쟁항만 간 정확한 비교가 어려웠다. 특히 가중치 산정에 전문적으로 활용되는 계층분석법에 의한 산정결과가 연차별로 특정 평가항목에 대해서는 90%이상씩 변동하는 등 안정성이 매우 낮아 비교가 불가능했다. 이에 본 연구는 광양항 항만 서비스기업의 품질평가체계를 발전시켜 비용 및 시간 효과적인 품질평가 및 관리 체계의 수립을 지원하는데 목적이 있다. 이를 위해 광양항 이용고객들을 대상으로 2007년~2009년 설문 자료에 확인적 요인분석을 적용하여 서비스품질 평가를 위한 연차별로 안정적이며 비교 가능한 가중치를 사후적으로 산정하는 방법을 제시하고 산정하였다. 새롭게 제안된 방법은 설문항목을 줄이면서 보다 과학적이고 정확한 서비스품질 평가체계를 구축할 수 있게 해주었다. 이 연구를 활용하여 서비스품질을 정확하게 측정할 수 있게 되면, 기간별 및 선도기업과 비교를 통해 항만기업의 경쟁력을 높일 수 있을 것이다.