화주 직접운항 선대의 운영 최적화 분석

김시화,이경근 한국경영과학회 1998 韓國經營科學會誌 Vol.23 No.4

The Industrial operation is one of the three basic modes of shipping operation with Liner and Tramp operations. Industrial operators usually control vessels of their own or on a time charter to minimize the cost of shipping their cargoes. Such operations abound in shipping of bulk commodities, such as oil, chemicals and ores. This work is concerned with an operational optimization analysis of the fleet owned by a major oil company. a typical Industrial operator. The operational optimization problem of the fleet of a major oil company is divided into two phase problem. The front end corresponds to the optimization problem of the transportation of crude oil. product mix. and the optimization problem of the fleet to meet the seaborne transportation demand derived from the front end. A case study reflecting the practices of an international major oil company is demonstrated to make clear the underlving ideas.

선석할당 계획문제의 최적화에 관한 연구

김시화,김대상 한국항해항만학회 2001 한국항해학회지 Vol.25 No.1

이 논문은 공공 컨테이너 터미널에서 직면하는 선석할당 계획문제를 다루고 있다. 선석할당 계획문제의 주된 논점은 ETA가 주어진 컨데이너 선박들을 어떻게 선석에 할당할 것인가를 결정하는 것이다. 선석할당 계획문제의 세 가지 최적화 모형들은 집합 문제 유형으로 정식화시켜 제시하였다. 또한, 제안된 최적화 모형의 의사결정 변수를 생성하기 위한 경험론적 알고리듬은 선박의 대기시간과 선석 점유율을 사용하여 고안하였다. 계산 실험은 실제 공공 컨데이너 터미널의 데이터로 수행하였으며, 그 결과들은 제안된 최적화 모형들과 경험론적 알고리듬들이 공공 컨테이너 터미널의 선석할당 계획문제에 대하여 유용하게 적용될 수 있음을 제시하고 있다. This paper treats the berth planning problem which is encountered at public container terminals. The main issue of the berth planning problem is to decide how to allocate the berths to scheduled calling containerships of which the ETA' s are given beforehand. Three optimization models for the berth planning problem are proposed in the formulation of set problems. Some heuristic algorithms for generating the decision variables of the models are also devised by using the concept of the ship's waiting time and the modified berth occupancy rate. Computational experiments based on the data arising from the real public container terminal are also carried out and the results are reported to show that the proposed optimization models and the heuristic algorithms for generating the decision variables are applicable and useful for the berth planning problem at public container terminals.

승선근무예비역 병역제도의 정착과 향후 대책

김시화 대한민국해양연맹 2007 해양정책 심포지엄 Vol.2007 No.1

장애 정도에 따른 공간적 포용성과 사회참여의 관계

김시화,박인권 한국지역학회 2023 지역연구 Vol.39 No.3

본 연구에서는 신체의 불편함을 가진 사람들의 사회참여를 제고시키기 위해 ‘공간적 포용성’을 개념화하여 장애와 공간적 포용성이 사회참여에 미치는 영향을 실증적으로 규명하는 것을 목적으로 한다. 거주하는 지역의사회·공간적 환경은 신체적 제약으로 인해 활동반경이 좁고 복합적인 장벽에 직면하는 장애인에게 매우 중요하다. 본 연구에서는 지역사회 내에서 장애인들이 비장애인들과 동등하게 관계를 형성하고 안전한 도시공간에서 기본적인 시설과 서비스로의 이용과 접근이 가능한 환경을 갖춘 것으로 장애인 관점의 공간적 포용성을 정의한다. 공간적 포용성은 개인의 관계망, 사회적 환경, 물리적 환경 등 세 가지 차원으로 구성되며, 물리적 환경은 거주 지역의 안전수준/자연환경/생활환경/대중교통 여건/의료서비스 여건 등을 포괄한다. 2019년 지역사회건강조사를 활용하여 장애 여부와 공간적 포용성에 따른 사회참여와의 관계를 2수준 다층회귀모형으로 분석한 결과는 다음과 같다. 첫째, 개인 수준의 개인적 관계망과 지역 수준의 물리적 환경이 사회참여에 미치는 긍정적 영향을 확인하였다. 둘째, 물리적 환경을 5개 하위요인으로 파악하였을 때 개별요소의 유의한 영향 관계는 확인할 수 없었다. 셋째, 지역 수준에서 신뢰할 수 있고 친근한 사회적 환경은 사회참여에 부적인 영향을 미치는 것으로 확인되었다. 이러한분석 결과는 공간적 포용성이 장애인의 사회참여에 효과를 미치고 있음을 실증하고, 장애인의 사회참여 여건 마련및 제고를 위한 도시계획 시사점을 제공한다. The purpose of this study is to conceptually define “spatial inclusivity” and empirically examine the impact of disability severity and spatial inclusivity on social participation among individuals experiencing physical discomfort. The social and spatial environment of the residential area is crucial for individuals with disabilities who face limited activity range and complex barriers due to physical constraints. In this study, spatial inclusivity from the perspective of people with disabilities is defined as establishment of equal relationships with non-disabled individuals within the local community, as well as the availability of basic facilities and services in a safe urban space that allows for access and utilization. This concept consists of three dimensions: individual networks, social environment, and physical environment. The physical environment encompasses safety levels, natural environment, living environment, public transportation conditions, medical services in residential areas. We used the 2019 Community Health Survey to examine the relationship between disability severity, spatial inclusivity, and social participation using a two level regression model. The findings are as follows: Firstly, personal relationships at the individual level and the physical environment at the local level have a positive impact on social participation. Secondly, when identifying dividing the physical environment into five sub-factors, no significant influence of individual factors is found. Thirdly, trustworthy and friendly social environment at the local level has a negative impact on social participation. These results provide empirical evidence that spatial inclusivity has an effect on the social participation of individuals with disabilities and suggest implications for urban planning to create and enhance conditions for the social participation of individuals with disabilities.

Shading Coil의 최적 회로정수 결정에 관한 연구

김시화 한국항해항만학회 1985 한국항해학회지 Vol.9 No.1

It has been generally known that the chattering of an AC electromagnetic contactor due to the fluctuation of attracting force is the primary cause of its abrasion and noise. To reduce this chattering effect, an AC electromagnetic contactor is mostly fitted with a shading coil which works the role to make difference in phases of two distinct components of attracting force. The theoretical interpretation of an AC electromagnetic contactor with shading coil and the equation of its attracting force per unit wattage consumed have already been proposed, however, few explications so far have been made on the determination of optimal circuit constants of shading coil. In this paper, the auther constructs a circuit model of an AC electromagnetic contactor with shading coil which is based on the theoretical interpretation of shading coil examined to be valid by experiments under some assumptions, and defines the equation of attracting force without chattering per unit wattage consumed as a performance function for determining the optimal circuit constants of shading coil. And then, the optimal circuit constants maximizing the performance function are determined by means of computer simulation founded on the above circuit model and the characteristics of those circuit constants are examined with special attention to the coupling coefficient.

대사증후군의 위험요소를 가진 중년여성의 체중관리 프로그램의 효과

김시화,유옥경,변문선,차연수,박태선 대한비만학회 2014 The Korean journal of obesity Vol.23 No.2

Background: Middle aged women at menopause lack strength which leads to decline in their physical activity. As a result, they are more prone to obesity and are at risk of associated disorders. Therefore, middle aged obese women have higher risk of mortality resulting from cardiovascular diseases, diabetes, hypertension and hyperlipidemia. The metabolic syndrome management programs are insufficient in helping middle aged women cope with age related metabolic disorders. Methods: The objective of this study was to evaluate the effects of weight management program in 46 aged women (including 16 halfway dropouts) with BMI <23 kg/m2 in Jeollabukdo region. The anthropometry, blood pressure, serum biochemistry, DEXA, dietary behavior, knowledge on nutrition, and nutritional intake data of the subjects were assessed before and after undergoing the weight management program. Results: Bodyweight, BMI, and body fat percentage of the subjects were significantly (P<0.001) decreased after the weight management program. Also the blood glucose (P<0.01) and LDL-cholesterol (P<0.05) levels were significantly decreased, whereas HDL-cholesterol (P<0.001) was significantly increased. The DEXA results indicated that body fat mass and body fat percentage were significantly decreased, but the lean mass increased significantly (P<0.001). Furthermore, improvements were noted in 10 out of the 15 dietary behavior questions and 6 out of 15 nutrition knowledge’s questions (P<0.05). Energy intake was decreased significantly (P<0.001). Conclusion: This study suggests that weight management program improves many obesity related parameters as in body fat mass and serum lipid biochemistry thus, promoting a positive health effect. 배경: 여성은 중년기가 되면 폐경이라는 신체적 변화를 경험하면서체력이 급속히 저하되고, 신체활동량은 감소되어 비만으로 이어질 수있으며, 이 시기의 비만은 심장질환, 당뇨, 고혈압 및 고지혈증 발생에직 · 간접적인 영향을 미쳐 건강한 노년을 맞이하는데 부정적인 영향을 미칠 수 있다. 하지만 이러한 문제점에도 불구하고 우리나라에서는 중년여성을 대상으로 한 대사증후군질환관리 프로그램이 미흡한실정이다. 방법: 전라북도 내 거주하는 체질량지수 23 이상의 중년 여성 46명(중도탈락자 16명 포함)을 대상으로 대사증후군 위험요소를 가진 중년여성을 위한 건강교육과 조리실습, 운동 프로그램으로 이루어진 복합적인 체중관리프로그램을 6개월간 실시하여 그 효과를 평가하고자수행되었다. 체중관리프로그램을 실시 한 후 프로그램 실시 전과 후의 신체계측, 혈압 및 혈액생화학적검사, DEXA 촬영, 식행동 및 영양지식 변화와 영양섭취실태 조사하여 프로그램의 효과를 판정하였다. 결과: 체중관리프로그램 후 연구대상자들의 체중과 체질량지수, 체지방량이 유의적으로 감소하였고(P< 0.001), 체지방률도 유의적으로감소하였다(P< 0.01). 혈액생화학적검사 결과 혈당(P< 0.01)과 LDL-콜레스테롤(P<0.05)이 유의하게 감소하였으며, HDL-콜레스테롤(P< 0.001)은 증가하였다. DEXA 촬영 결과에서는 체지방량과 체지방률은 유의적으로 감소하고, 제지방량은 유의하게 증가하였다(P<0.001). 식행동에서는 15항목 중 10개 항목이 유의적으로 개선되었으며 (P< 0.05), 영양지식에서도 15개 항목 중 6개 항목이 개선되는 결과를 보였다(P< 0.05). 에너지 섭취량은 프로그램 종료 후 유의적으로 감소하였다(P< 0.001). 결론: 연구 결과 체지방 감소 등 신체구성분이 유의적으로 변화하였으며, 혈액생화학적 성상이 개선되어 본 프로그램이 연구대상자의 건강에 긍정적인 영향을 미쳤다고 사료된다.

해운 및 항만운송에 적용된 의사결정분석에 관한 연구

김시화 한국항해항만학회 1988 한국항해학회지 Vol.12 No.1

Decision Science or Decision Analysis can be described as a scientific methodolog to provide suitable quantitative information for the decision maker to be able to selected the best feasible alternative on the given decision environment and thus we can say that where there are decision problems, there needs the decision analysis to be applied to them. International shipping is generally said to be the cheapest and most widely used means of transport in international trade and each of the hundreds of seaport. So far as the decision makings in the shipping and port transportation are concerned, of real importance is to understand what the decision problems in each of shipping and port transportation really are and to recognize the meaning of relevance between shipping and seaport in the outworn phrase, that is to say, "The chain is as strong as its weakest link." This paper is intended to present a literature survey on the applied decision analysis to shipping and port transportation problems which have actually been involved in the wide variety of decision environment. At first, the author suggests four divisional framework such as decision analysis in each field of Shipping Economics, Management and Operations of Shipping, Port Economics, and Port Operation and Management, according to the main concern of the decision environment, and then the literature surveys on those four major divisions are described including the problems and solution approaches in each case. The author concludes the paper with the comment on the need of joint research around this area by citing the phrase of "a process of updating the decision makers' intuitions."s' intuitions."quot;

자동화선의 평균예상전문가시스템 개발에 관한 연구

김시화 한국항해항만학회 1991 한국항해학회지 Vol.15 No.2

This paper intends to develop a Prototype Expert Collision Avoidance System by introducing expert system techniques into the decision block of anti-collision loop. The problem domain of this study is characterized and specified by combining the concepts of anti-collision loop and knowledge -based system for collision avoidance. Domain in knowledge which may originates from the appropriate sources such as the International Regulations for Preventing Collision at Sea 1972, Marine Traffic Laws, and many texts on the subject of anticollision navigation and good seamanship is acquired and formalized into the knowledge-base system using production rule. Finally, a Prototype Expert Collision Avoidance System is built by using the CLIPS, developed by AIS NASA written in and fully integrated with the C language, and some test-and-run results of the system are demonstrated and examined. The author considers the proposed system which is named PECAS to be meaningful as a test bed for a further refined Expert Collision Avoidance System on board the Automated Ship.

인더스트리얼 캐리어를 위한 통합 선대관리 지원시스템

김시화,허강이 한국항해항만학회 1999 한국항해학회지 Vol.23 No.4

This paper aims at developing an integrated fleet management support system for industrial carriers who usually control the vessels of their own or on a time charter to minimize the cost of shipping their cargoes. The work is mainly concerned with the operational management problem of the fleet owned by a major oil company, a typical industrial carrier. The optimal fleet management problem for the major oil company can be divided into two phase problem. The front end corresponds to the production operation problem of the transportation of crude oil, the refinery operation, and the distribution of product oil to comply with the demand of the market. The back end is to tackle the fleet scheduling problem to meet the seaborne transportation demand derived from the front end. Relevant optimization models for each phase are proposed and described briefly. Then a user-friendly integrated fleet management support system is built based on the proposed optimization models for both ends under Windows environment. A case study reflecting the practices of fleet management problem for the major oil company is carried out by using the system.

인더스트리얼 캐리어를 위한 선대운영의 최적화에 관한 연구

김시화,곽민석 한국항해항만학회 1998 한국항해학회지 Vol.22 No.4

There are three basic modes of operation of ships: liner, tramp and industrial operations. Industrial operations, where the owner of the cargo, i.e. the industrial carrier controls the ships, abound in the shipment of bulk commodities, such as oil, chemicals and ores. Industrial carriers strive to minimize the shipping cost of their cargoes. This paper is concerned with the operational optimization problem of a fleet owned by major international oil company. The major oil company is a holding corporation for a group of oil producing, transporting, refining, and marketing companies located in various countries throughout the world. The operational optimization problem of the fleet is divided into two-phases. The front end corresponds to the optimization of transporting crude oil, product mix, and the distribution of product oil to meet market demand. The back end tackles the operational optimization problem of the fleet to meet the transportation demand derived from the front end. A case study is carried out with the H major oil company problem composed by reflecting the practices of an international major oil company. The results are summarized and examined in the point of optimization for the total operation of the H major oil company and the operational optimization problem of the fleet. The paper concludes with the remark that the results of the study might be useful and applicable in practices of these related decision problems.