• 한국해양공학회지
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• 제16권6호
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• pp.76-81
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• 2002

The purpose of this study is to set up the optimum economical formation of the purse seiner fishing system. For this task, the characteristics of existing purse-seiner fishing system were reviewed, and the possible formations of the fleet in tile purse-seiner fishing system were examined through the reallocation of function for each individual vessel. In addition, economic evaluations of the possible formations of the fleet are carried out. Consequently, it was found that 2-vessel formations have the most economic efficiency. Then, a conceptual system design for the main vessel in the 2-vessel formations was performed. As a result, this paper can be used as a helpful guideline to develop the most profitable and economical fishing system in the fleet type fishery.

• 한국국방경영분석학회지
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• 제8권2호
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• pp.31-35
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• 1982

Recently, Park [1] proposed an algorithm for the optimum spare-part stock level in an (S-1, S) inventory system for small fleet. This paper reports validative GPSS simulation results and numerical experiences with the algorithm.

• 한국항해학회지
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• 제8권1호
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• pp.1-16
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• 1984

The economical property of a shipping enterprise, as well as other transportation industries, is determined by the difference between the freight earned and expense paid. This study can be regarded as a division of optimizing ship allocation to routes under the integrated port transport system. Fleet planning and scheduling require complicated allocations of cargoes to ships and ships to routes in order to optimize the given criterion function for a given forecast period. This paper deals with the optimum ship allocation problem minimizing the operating cost of ships in a shipping company. Optimum fleet operating for a shipping enterprise is very important, since the marine transportation is a form of large quantity transport requiring long-term period, and there is a strong possibility to bring about large amount of loss in operation resulting from a faulty ship allocation. Where there are more than one loading and discharging ports, and a variety of ship's ability in speed, capacity, operating cost etc., and when the amount of commodities to be transported between the ports has been determined, then the ship's schedule minimizing the operating cost while satisfying the transport demand within the predetermined period will be made up. First of all a formula of ship allocation problems will be established and then will be constructed to solve an example by the Integer Programming application after consideration of the ship's ability, supply and demand of commodity, amount of commodity to be transported, operating costs of each ship etc. This study will give good information on deciding intention for a ship oprator or owner to meet the computerization current with shiping management.

• 대한조선학회논문집
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• 제45권2호
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• pp.213-220
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• 2008

The aim of this paper is to build up the design model using ASMOD(Adaptive Spline Modeling of Observation Data) for the optimum scale of fleet, ship particulars and ship speed, etc. ASMOD, which define membership functions of fuzzy rule as B-spline basis function, represents a whole system as the sum of the sub-model. As it reduces the number of division of the space generated by the fuzzy set of input variables, it has a advantage of simplification to model structure and is efficient to represent the non-linear model.

• 어선
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• 제43권
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• pp.31-37
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• 1990

• 한국국방경영분석학회지
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• 제9권2호
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• pp.23-30
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• 1983

A simulation study was conducted to determine optimum capacity of Navy drydock facility using GASP-IV, an advanced FORTRAN-based simulation language, under demands of regular overhauls and emergency repairs by ships of an hypothetical fleet composition. Three year dock usage data was analyzed to produce probability distributions underlying drydock repair demands. The present facility size of two drydocks was simulated and was found to be somewhat short of adequate service capability, showing excessive average waiting time and average queue length. The simulation model was then modified to include an additional drydock of similar size as the other two and a year's simulation was again conducted. All repair needs were quite satisfactorily met and all docks showed very high utilization factor (0.98). This contributed to an increase in the fleet's ship availability from 0.95 to 0.99. This study illustrates the usefulness of simulation technique as a tool for analyzing policy alternatives in military long-term investment areas.

• 대한토목학회논문집
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• 제40권1호
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• pp.87-95
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• 2020

4차 산업혁명 시대의 도래와 IoT 기술의 접목을 통하여 건설산업을 발전 시키기 위한 다양한 연구가 국내·외에서 진행되고 있다. 특히 다수다종의 건설장비가 투입되는 대단지 토공현장에서 건설장비의 관제 시스템은 생산성 증대를 위하여 매우 중요하다. 이러한 이유로 건설장비 최적운영 플릿관리 시스템이 개발되었고, 현장에서 적용과정 중에 문제점이 도출되어 단계별로 개선이 필요하게 되었다. 건설장비 최적운영 플릿관리시스템의 현장 적용과정을 검증하기 위해 실제 현장에 사용되었던 데이터와 본 시스템을 이용하여 생성된 현장자료를 입력하고 시뮬레이션을 통해 데이터를 비교하여 생산성 분석을 진행하였다. 분석은 굴삭기와 덤프에 국한하여 진행하였으며, 분석결과 시간당 작업율이 4 %대로 증가, 반면에 원가는 4 %로 감소되는 것으로 나타났다. 적용한 현장에 따라서 분석결과는 상이할 수 있지만, 토공현장 단지사업에서 장비의 작업량 증가와 원가 감소를 보여준 것은 생산성 증대를 검증한 것으로 사료된다.

• 한국항해학회지
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• 제15권3호
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• pp.1-11
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• 1991

As increasing needs of marine transportation , world merchant fleet and ship's size were enlarged and it caused frequent disasters in human lives and natural environment. By the reason of the above, they started to establish the Vessel Traffic System (VTS) at the European coast in 1960' and most of advanced contries established and managed it to prevent the sea traffic accidents in these days. The concept of traffic control at sea can be divided into three types. First, the initial gathering of informations about ship's identity and movement etc.. Second, monitoring of the traffic flow and amendment of instructions. Third , organization and direction of ships by allocating routes and speeds. Where the goal of traffic control is safety of traffics and developing effectiveness of navigation channel, if traffic volume is less tan channel capacity then the above first or second level of control would be sufficient but if it is bigger than that , more positive policy of control should be adopted as same as third type of the above. In this paper where the strategy of VTS is focused on the control of traffic density to be spread equality, as possible , all over the navigation channels and also improvement of effectiveness , it suggests algorithm to assign the vessels to the channels with balanced traffic density , and other algorithms using D.P. to sequence the vessels assigned to one channel in optimum order which decreases the mean waiting time in sense of channel effectiveness with numerical examples.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2008년도 추계학술대회B
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• pp.2845-2849
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• 2008

Long Term Asset Management(LTAM) means a plan developed by using LCM(Life Cycle Management) process for optimum life cycle management of significant plant assets at each plant across the fleet. As a part of development of LTAM Strategies on nuclear turbines, a method so as to determine the future failure rates for low pressure turbine facilities at a nuclear plant was studied and developed by using both plant specific and industry-wide performance data. INPO's EPIX data were analyzed and some failure rate evaluation values considering preventive maintenance practices were calculated by using EPRI's PM Basis software. As the result, failure rate functions applicable to a priori and a posteriori replacement of low pressure turbines at a nuclear plant were developed and utilized in an assessment of economics of LCM alternatives on the nuclear turbine facilities in the respects of 40-year and 60-year operation bases.

• 벤처창업연구
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• 제9권2호
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• pp.81-86
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• 2014

본 논문에서는 그룹교체 정책과 예비품 재고정책을 동시에 고려하여 최적화하는 방안을 제시한다. 일반적으로 보전정책들은 예비품의 재고가 늘 가용하다고 가정하고 있으나 예비품의 재고 확보 여부에 의해 보전활동은 영향을 받을 수밖에 없다. 동일한 여러 유닛들이 동시에 운용될 때 이용되는 그룹교체정책을 바탕으로 이를 지원하기 위한 최적 재고수준을 결정한다. 일정한 개수의 유닛이 고장 나는 시점에서 그룹교체를 수행한다. 예비품의 재고는 일정 횟수의 그룹교체를 할 만큼 주문하여 유지한다. 보전비용과 재고비용 등 운용비용을 최소화할 수 있는 최적의 그룹교체 주기와 재고수준을 구한다.