• 약학회지
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• 제16권2호
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• pp.90-96
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• 1972

The author tried to isolate the Vibrio parahaemolyticus from Han River water and river fishes, to investigate the route of contamination by way of marine product and to make clear the survival ability in various kinds of food. The results are as follows: 1. Twenty eight strains of V. parahaemolyticus were identified among 312 samples in Han river from March to August. 2. V. parahaemolyticus was detected in the margenic content of Cyprinus and Anguilla. 3. 9 strains of K-3 type, 5 strains of K-11 type, 8 strains of K-8 type, 6 strains of K-32 type and 1 strain of K-52 type were clarified through K-antiserum reaction.

• Journal of Information Processing Systems
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• 제5권4호
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• pp.237-242
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• 2009

The classical vehicle routing problem (VRP) can be extended by including customers who want to send goods to the depot. This type of VRP is called the vehicle routing problem with pickups and deliveries (VRPPD). This study proposes a novel way to solve VRPPD by introducing a two-phase heuristic routing algorithm which consists of a clustering phase and uses the geometrical center of a cluster and route establishment phase by applying a two-way search of each route after applying the TSP algorithm on each route. Experimental results show that the suggested algorithm can generate better initial solutions for more computer-intensive meta-heuristics than other existing methods such as the giant-tour-based partitioning method or the insertion-based method.

• 대한교통학회지
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• 제24권2호
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• pp.101-112
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• 2006

현재 우리나라의 설계속도는 토로의 기능, 지역특성, 지형에 의해 결정된다. 그러나 도로의 기능을 구분하는 뚜렷한 기준이 없어 적정 설계속도 결정에 설계자의 주관이 개입될 여지가 많으며, 설계에 반영되지 못하는 도로기능이 존재하고, 도로가 통과하는 지역 및 지형적 특성을 제대로 반영하지 못하는 실정이다. 최근 이 문제를 개선한 새로운 기능 재분류와 설계속도 결정기준이 제시된 바 있다. 본 연구에서는 최근 제시된 새로운 설계속도 결정기준에 따라 토로를 재설계하고, 통행속도와 공사비, 안전성 등을 조사 분석하여 기존 방법과 새로운 방법이 어떠한 차이가 있는지 사례분석을 통해 적용성을 평가하였다. 연구 결과 설계속도 결정에 있어 새로운 기준이 기존방법에 비해 우리나라의 자연지형과 지역특성을 정확히 고려하였으며, 설계자의 주관적 판단소지를 크게 줄여주고. 경제적인 방법으로 설계속도와 노선대를 결정하는 것으로 나타났다. 또한 새로운 기준에 따른 설계가 기존방법에 비해 편익은 약간 적었으나. 공사비가 크게 감소하여 B/C분석. NPV, IRR 에서 모두 우수한 것으로 나타났다. EMME/2 상에서 통행배정 결과 각 구간 LOS는 기존방법과 새로운 방법이 거의 차이가 나지 않았으며. 통행속도에서 약 $2{\sim}4km/h$의 미세한 차이가 있었다.

• Industrial Engineering and Management Systems
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• 제7권2호
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• pp.113-125
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• 2008

This paper presents a model for designing cellular manufacturing systems (CMS) by integrating system cost, machine reliability, and preventive maintenance (PM) planning. In a CMS, a part is processed using alternative process routes, each consisting of a sequence of visits to machines. Thus, a level of 'system reliability' is associated with the machines along the process route assigned to a part type. Assuming machine reliabilities to follow the Weibull distribution, the model assigns the machines to cells, and selects, for each part type, a process route which maximizes the overall system reliability and minimizes the total costs of manufacturing operations, machine underutilization, and inter-cell material handling. The model also incorporates a reliability based PM plan and an algorithm to implement the plan. The algorithm determines effective PM intervals for the CMS machines based on a group maintenance policy and thus minimizes the maintenance costs subject to acceptable machine reliability thresholds. The model is a large mixed integer linear program, and is solved using LINGO. The results point out that integrating PM in the CMS design improves the overall system reliability markedly, and reduces the total costs significantly.

• 한국항해학회지
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• 제23권3호
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• pp.45-59
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• 1999

This paper aims, first to analyse the profitability of coastal passenger ships deployed on both subsidized and non-subsidized routes, ie competitive routes, in Korea, second to evaluate them by route, by ship type, and by ship size, and finally to identify whether the ships deployed on subsidized routes are justifiable to receive subsidy from the government. They are followed by the analyses on the profitability of all ships on the coastal routes and their dependence rate of subsidy. The research covers the period of 1995-1997. The research results say that 35% of the total subsidized routes has more than 90% of subsidy dependence rate and that some monopolized routes among subsidized ones with moderate rate of profitability need to be crossed out from the list of subsidy beneficiary. In addition, some ships deployed are not appropriate type in terms of characteristics of route and traffic. One of implications drawn from this study is that the government has to set up a watchdog to monitor subsidized routes, which enables to make them competitive and save the budget.

• Journal of Advanced Marine Engineering and Technology
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• 제30권6호
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• pp.760-769
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• 2006

This paper proposes an autopilot system using a fuzzy PID controller to satisfy performances required for the automatic navigation of ships under various marine circumstances. The existing autopilot system using a PD type controller has difficulties in eliminating a steady-state error and compensating nonlinear characteristics of ships. The autopilot system using the proposed fuzzy PID controller has a self-tuning ability, an ability to compensate nonlinear characteristics, and an ability to turn at constant angular velocity. Therefore. it can naturally make a steady-state error zero, compensate nonlinear dynamic effect of ships, have an adaptability to parameter variation owing to shallow water effect, and have an ability to turn ship's course rapidly without overshoot through procedures of acceleration, constant, and deceleration of angular velocity for large course-changing.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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• pp.531-533
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• 2003

This study aims at discussing the future trend of the community bus and attempted to route selection by using GIS for the welfare-type community bus, which satisfies the need of elderly and physically handicapped persons in Nagasaki City. In doing so, we have conducted field survey in some sample cities of Kyushu, Japan for taking lessons from the present state analysis of community bus already operating there. As a result of the study, we have been able to identify some best possible routes for the community bus operation in Nagasaki City, which meets the requirement of the welfare community as well as of the general passengers.

• Journal of the Korean Physical Society
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• 제73권12호
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• pp.1867-1872
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• 2018

This study proposes a route for surface modification for p-type cobalt oxide-based gas sensors. We deposit a thin layer of Ni on the Co oxide film by sputtering process and annealed at $350^{\circ}C$ for 15 min in air, which changes a typical sputtered film surface into one interlaced with a high density of hemispherical nanoparticles. Our in-depth materials characterization using transmission electron microscopy discloses that the microstructure evolution is the result of an extensive inter-diffusion of Co and Ni, and that the nanoparticles are nickel oxide dissolving some Co. Sensor performance measurement unfolds that the surface modification results in a significant sensitivity enhancement, nearly 200% increase for toluene (at $250^{\circ}C$) and CO (at $200^{\circ}C$) gases in comparison with the undoped samples.

• 한국건설관리학회논문집
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• 제10권4호
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• pp.101-110
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• 2009

본 연구는 기존 시공단계 중심의 VR시뮬레이션 활용체계를 설계단계까지 확장하여 도로의 최적 설계정보 지원을 위한 시각화 분석 기능을 개발하는 것이 목적이다. 연구에서는 설계지원을 위한 VR기능으로 도보 선형(alignment)에 의한 토공 시뮬레이션, 대안 노선 선정 시뮬레이션 구조물 타입 선정 시뮬레이션 및 지하시설물 분석 시뮬레이션 기능들을 제안하고 있다. 이러한 VR시뮬레이션 기능을 통해 노선 및 토공 상태의 시각적 확인이 가능하고, 대안 노선의 가상적인 모의 배치를 수행함으로써 최적 설계노선을 선정할 수 있다. 이를 위해 본 연구에서는 도로설계정보 지원을 위한 VR시뮬레이션 기능 개발 방법론 및 시스템(VR Presenter)을 구현하며, VR기능을 적용한 개선된 도로설계 프로세스를 제안하고 있다.

• 대한교통학회지
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• 제34권6호
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• pp.570-579
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• 2016

Stepwise 환승계수(이하 STC)는 환승회수 증가에 따라 환승비용을 실제보다 많게 인식하도록 한다. 통행시간과 최소환승회수 정보를 제공하는 것은 이러한 경향을 감안하는 취지이다. STC가 포함된 경로탐색문제는 비가산성비용을 포함하며 최적조건의 비성립으로 경로열거가 요구된다. 따라서 대중교통망에서 STC를 고려하는 경로탐색에 대한 이론적 검토를 통해서 경로탐색의 실패를 우회하는 방안이 요구된다. 본 연구는 STC가 포함되는 대중교통망에서 확률적 통행배정모형에 대하여 검토한다. 비가산성 경로문제를 완화하는 방안으로 유입링크기반 전체경로삭제기법을 활용하는 방안을 제안한다. 전체경로삭제기법은 출발지에서 도착지까지 서로 상이한 경로의 구성된 가능경로집합을 구축하기 용이하다. STC를 반영한 경로기반 Logit 모형을 대중교통통행배정기법으로 구축한다.