AHP 를 활용한 철도차량 주요안전부품 우선순위 선정방법 연구

김시화(Si Hwa Kim),유영준(Yoyng Jun Yoo),정해진(Hai Jin Jung),김종운(Jong Woon Kim),이원영(Won Young Lee) 한국철도학회 2016 한국철도학회 학술발표대회논문집 Vol.2016 No.10

철도차량은 많은 승객을 수송하는 편리한 교통수단으로서 수많은 부품으로 구성되어 있다. 이러한 역할을 하기 위한 철도차량 부품은 개별적, 유기적으로 동작하면서 높은 안전성이 요구되고 있다. 하지만 부품 고장으로 인한 안전사고는 끊임없이 발생하고 있다. 국토교통부는 철도안전법 개정에 따른 철도안전 관리체계 승인 및 검사 시행 지침을 제정, 고시하여, 철도 운영기관은 안전운행과 관련한 주요부품을 선정하여 관리하도록 되어 있으나, 대부분의 철도차량 운영 기관은 주요안전부품 선정 시 체계적인 방법 보다는 부품고장 이력을 바탕으로 주요부품을 선정하고 있다. 본 논문에서는 계층적 의사결정 방법(Analytic Hierarchy Process, AHP)을 활용한 부품별 중요도와 가중치 부여 방식의 주요 안전부품 우선순위 선정방법을 제시하고자 한다. Railway vehicle is composed of many parts as a convenient transportation of transporting many passengers. Railway vehicle components for these roles are separate, organically operated, high safety is demanded. However, accidents due to component failure is constantly generated. Ministry of Land, Infrastructure and Transport has established the approval and inspection implementation guidelines of railway safety management system with the revision of the Railway Safety Act, and notice, railway operating agency is adapted to manage the selection of key components related to safe driving There, most of the railway vehicle operating agency, at the time of the major safety components selection, but not in a systematic way, based on the failure history of parts, has selected the main parts. In this paper, we try to present a hierarchical decision-making methods (Analytic Hierarchy Process, AHP) method of selecting the priorities of the major safety components of the weighting scheme parts another important degree of leverage.

유조선 운항일정계획 의사결정지원 시스템의 개발에 관한 연구

김시화(Si-Hwa Kim),이희용(Hee Yong Lee) 한국항해항만학회 1996 한국항해항만학회 학술대회논문집 Vol.1 No.-

Vessels in the world merchant fleet generally operate in either liner or bulk trade. The supply and the demand trend of general cargo ship are both on the ebb, however, those trend of tankers and containers are in slight ascension. Oil tankers are so far the largest single vessel type in the world fleet and the tanker market is often cited as a textbook example of perfect competition. Some shipping statistics in recent years show that there has been a radical fluctuation in spot charter rate under easy charterer's market. This implies that the proper scheduling of tankers under spot market fluctuation has the great potential of improving the owner's profit and economic performance of shipping. This paper aims at developing the TS-DSS(Decision Support System for Tanker Scheduling) in the context of the importance of scheduling decisions. TS-DSS is defined as a DSS based on the optimization models for tanker scheduling. The system has been developed through the life cycle of systems analysis, design, and implementation to be user-friendly system. The performance of the system has been tested and examined by using the data edited under several tanker scheduling scenarios and thereby the effectiveness of TS-DSS is validated satisfactorily. The authors conclude the paper with the comments on the need of appropriate support environment such as data-based DSS and network system for successful implementation of the TS-DSS.

DEA에 의한 지방해양수산청 효율성 비교 분석에 관한 연구

이남규,김시화,Lee, Nam-Kyu,Kim, Si-Hwa 한국항해항만학회 2008 한국항해항만학회지 Vol.32 No.1

본 연구의 목적은 DEA를 사용하여 지방해양수산청의 생산효율성과 경쟁력을 측정하고자 하는 것이다. 선형문제 분석기 EMS를 사용하여 기술적 효율성 프론티어로 부터 한 방향 또는 다른 방향의 거리를 측정한다. 투입지향 측정은 산출 요소를 유지한 상태에서 효율성을 위한 투입요소의 감소치를 측정한다. 이와 같이 산출지향 측정은 입력 요소를 유지한 상태에서 효율성에 필요한 산출수치를 측정하고 무지향 측정은 효율성 개선을 위하여 투입과 산출에 대해 양방향으로 필요한 수치를 측정한다. DEA를 사용한 분석결과에 따라 비효율적 지방해양수산청은 항만행정과 공공기관의 생산 효율성을 강화하기 위하여 상대적으로 효율적인 지방해양수산청을 벤치마킹할 것이 권고된다. 생산효율성에 관한 자료는 모든 활용영역에서 정책 입안자에게 방법론을 제공하고 다양한 체제에서 운용할 수 있는 기초가 될 것이다. The purpose of this paper is to measure the productive efficiency and competitive strength of Regional Maritime Affairs and Fisheries Office using the DEA. Using EMS(Efficiency Measurement System) which is LP solver, quantifies in one way or another a "distance" to the efficient frontier of the technology. An input oriented measure quantifies the input reduction which is necessary to become efficient holding the output constant. Symmetrically, an output oriented measure quantifies the necessary to become efficient holding the inputs constant. A non-oriented measure quantifies necessary improvements when both inputs and outputs can be improved simultaneously. According to the analysis result of the DEA method, inefficient Regional Maritime Affairs and Fisheries Office should recommend benchmarking reference Regional Maritime Affairs and Fisheries Office in order to enhance the productive efficiency of port administration and a public institution. Besides data on productive efficiency serves as a tool for policy-makers at all levels of activity and is essential for improving the efficiency with which the various systems operate.

네트워크 모형화에 의한 최적 항로 결정

이희용,김시화,Lee, Hee-Yong,Kim, Si-Hwa 한국항해항만학회 2001 한국항해학회지 Vol.25 No.3

Optimum Ship Routing can be defined as \"The selection of an optimum track for a transoceanic crossing by the application of long-range predictions of wind, waves and currents to the knowledge of how the routed vessel reacts to these variables\". This paper treats the methodology how to solve optimum ship routing problem by network modeling and reveals the validity of the network model by some numerical experiments.periments.

Broad-Band Design of Lumped-Element 3dB Quadrature Hybrid

Dong Il KIM(金東一),Se Mo CHUNG(鄭世謨),Si Hwa KIM(金是和) 한국통신학회 1985 韓國通信學會論文誌 Vol.10 No.6

컨테이너의 최적 적하계획을 위한 PPGA

김길태(Kil-Tae Kim),조석제(Seok-Jae Cho),진강규(Gang-Gyoo Jin),김시화(Si-Hwa Kim) 한국항해항만학회 2004 한국항해항만학회지 Vol.28 No.6

컨테이너 적하계획은 항만 장비운용의 효율성을 결정짓는 주요 요인 중 하나이다. 적하계획 문제에 유전알고리즘을 응용할 때 처리작업 수가 많게 되면, 기존의 방법으로 많은 시간이 걸린다. 이 문제를 해결하기 위하여 본 논문에서는 이주모델과 링구조 기반의 의사병렬 유전알고리즘을 개발하고 컨테이너의 최적 적하순서를 결정하는 문제에 적용하여 그 유효성을 밝힌다. The container load planning is one of key factors for efficient operations of handling equipments at container ports. When the number of containers are large, finding a good solution using the conventional genetic algorithm is very time consuming. To obtain a good the ring topology is developed. The performance of the PPGA is demonstrated through a test problem of determining the optimal loading sequence of the containers.

평균-분산 최적화 모형을 이용한 로버스트 선박운항 일정계획

박나래(Nareh Park),김시화(Si-Hwa Kim) 한국경영과학회 2016 韓國經營科學會誌 Vol.41 No.2

This paper presented a robust ship scheduling model using the quadratic programming problem. Given a set of available carriers under control and a set of cargoes to be transported from origin to destination, a robust ship scheduling that can minimize the mean-variance objective function with the required level of profit can be modeled. Computational experiments concerning relevant maritime transportation problems are performed on randomly generated configurations of tanker scheduling in bulk trade. In the first stage, the optimal transportation problem to achieve maximum revenue is solved through the traditional set-packing model that includes all feasible schedules for each carrier. In the second stage, the robust ship scheduling problem is formulated as mentioned in the quadratic programming. Single index model is used to efficiently calculate the variance-covariance matrix of objective function. Significant results are reported to validate that the proposed model can be utilized in the decision problem of ship scheduling after considering robustness and the required level of profit.

해양 석유 생산 및 수송 최적화 문제에 관한 연구

김창수(Chang Soo Kim),김시화(Si Hwa Kim) 한국항해항만학회 2015 한국항해항만학회지 Vol.39 No.4

해양 석유 생산은 '해양'이라는 특성에 기인하는 여러 가지 변수를 동반하면서 막대한 비용과 시간을 필요로 한다. 모든 관련된 프로세스는 인명, 환경 그리고 재산의 손실을 줄이기 위한 치밀한 일련의 계획에 의하여 통제된다. 이 논문은 해양 석유 생산 및 수송의 최적화 문제를 다룬다. 문제 영역의 범위를 정의하기 위해 해양 석유 생산 및 수송 네트워크를 제시하고 그 문제를 해결하기 위한 혼합정수계획모형을 구축하였다. 제안된 최적화 모형의 타당성을 확인하기 위해 가상의 해양 유전과 수요 시장을 바탕으로 MS Office Excel의 해찾기를 이용하여 계산실험들을 수행하였다. 해양 석유 생산 및 수송 네트워크 하위 흐름은 해양 유전에서 생산된 원유를 수요 시장으로 배분하는 해사수송문제가 된다. 이 해사수송문제를 해결하기 위해 집합 패킹 모형을 이용하여 구축된 MoDiSS(Model-based DSS in Ship Scheduling)를 사용하였다. 이러한 연구결과들은 실제적인 해양 석유 생산 및 수송 최적화 문제에 의미 있게 적용될 수 있으리라 사료된다. The offshore oil production requires a huge amount of cost and time accompanied by multiple variables due to the peculiar nature of 'offshore'. And every process concerned is controlled by elaborate series of plans for reducing loss of lives, environment and property. This paper treats an optimization problem for offshore oil production and transportation. We present an offshore production and transportation network to define scope of the problem and construct a mixed integer linear programming model to tackle it. To demonstrate the validity of the optimization model presented, some computational experiments based on hypothetical offshore oil fields and demand markets are carried out by using MS Office Excel solver. The downstream of the offshore production and transportation network ends up with the maritime transportation problem distributing the crude oil produced from offshore fields to demand markets. We used MoDiSS(Model-based DSS in Ship Scheduling) which was built to resolve this maritime transportation problem. The paper concludes with the remark that the results of the study might be meaningfully applicable to the real world problems of offshore oil production and transportation.

On the optimum ship routing by network modeling

Hee-Yong Lee(이희용),Si-Hwa Kim(김시화),Jae-Uk Song 한국항해항만학회 2001 한국항해항만학회 학술대회논문집 Vol.3 No.-

Optimum Ship Routing can be defined as "The selection of an optimum track for a transoceanic crossing by the application of long-range predictions of wind, waves and currents to the knowledge of how the routed vessel reacts to these variables". This paper treats the methodology how to solve optimum ship routing problem by network modeling and reveals the validity of the network model by some numerical experiments.

블록/트랜스포터 비를 고려한 최적 블록트랜스포터 운영계획

김정민(Jeong Min Kim),김시화(Si hwa Kim) 한국항해항만학회 2017 한국항해항만학회 학술대회논문집 Vol.2017 No.춘계