• 한국항해항만학회:학술대회논문집
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• 한국항해항만학회 2004년도 Asia Navigation Conference
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• pp.167-176
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• 2004

The authors have newly developed the “Port Traffic Management System (PTMS)”. The PTMS provides each ship with the detailed planned routes of all the ships entering/leaving the port. This system also has a function to predict the encounter situations between own ship and other ships in the future. Based on information of the present positions, speeds and planned routes of the own ship and other ships, it is possible to predict when and where the own ship will have dangerous encounters with other ships in the future. The software of PTMS was developed from 2001. Then onboard experiments using small training ships equipped with actual AIS were performed in June 2003. From the results of these onboard experiments, the usefulness of PTMS was clarified. In addition to these onboard experiments, the effectiveness of PTMS was confirmed by comprehensive simulator experiments. In the simulator experiments, captains/pilot maneuvered a training ship/container ship in congested waters using PTMS. [t was assumed that all ships have PTMS and send their planned routes. After the simulator experiments, captains/pilot suggested that it is very beneficial if the optimal route of own ship can be automatically calculated. In response to this suggestion, software to calculate the optimal route of own ship using Dynamic Programming was developed. This software calculates the minimum time route from the present position to the destination keeping the danger of collision against other ships under predetermined level. From the result of calculations for multi-encounter situations, it was confirmed that the developed software can provide safe and time-saving route.

• 한국컴퓨터정보학회논문지
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• 제12권5호
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• pp.19-27
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• 2007

본 논문은 일반인들이 여행 시 필요한 최적의 경로를 찾아 주는 웹 사이트를 구현하는 방법을 제안한다. 출발지와 목적지만 주어질 때 최적 경로를 찾아 주는 웹 사이트는 이미 많이 존재한다. 그러나 방문할 도시가 여럿일 때 최적 경로를 찾아주는 사이트는 아직까지 존재하지 않는다. 출발 도시에서 출발하여 경유지를 모두 한번씩 방문하고 출발도시로 되돌아오는 최적 경로를 찾는 문제를 외판원 문제라고 하며, 이 문제는 지수 시간복잡도 문제로 널리 알려져 있다. 본 논문에서는 인공지능 탐색 알고리즘을 적용하여 외판원 문제를 푸는 방법을 웹 시스템으로 구현하였다. 지금까지 소개된 외판원 문제를 푸는 알고리즘은 출발지와 도착지가 동일한데 반하여 최적 경로 문제에서는 출발지와 도착지가 서로 다를 수도 있다. 본 논문이 제안하는 방법은 출발지와 도착지가 동일하거나 아니면 다르더라도 최적의 경로를 찾는다는 점이 기존의 연구와는 다르다. 본 논문에서 구현한 웹 사이트는 사용자에게 출발지, 목적지, 그리고 여러 경유지들을 선택하게 한 다음, 출발지를 출발하여 모든 경유지들을 경유하고 도착지로 도착하는데 비용이 가장 적게 드는 방문 순서를 효율적으로 찾아준다.

• Journal of Communications and Networks
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• 제14권1호
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• pp.91-103
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• 2012

Network mobility (NEMO) based on mobile IP version 6 has been proposed for networks that move as a whole. Route optimization is one of the most important topics in the field of NEMO. The current NEMO basic support protocol defines only the basic working mode for NEMO, and the route optimization problem is not mentioned. Some optimization schemes have been proposed in recent years, but they have limitations. A new NEMO route optimization scheme-involving a combination of the optimized route cache protocol (ORC) and reverse routing header (RRH) and the use of a quota mechanism for optimized sessions (OwR)-is proposed. This scheme focuses on balanced performance in different aspects. It combines the ORC and RRH schemes, and some improvements are made in the session selection mechanism to avoid blindness during route optimization. Simulation results for OwR show great similarity with those for ORC and RRH. Generally speaking, the OwR's performance is at least as good as that of the RRH, and besides, the OwR scheme is capable of setting up optimal routing for a certain number of sessions, so the performance can be improved and the cost of optimal routing in nested NEMO can be decreased.

• 한국CDE학회논문집
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• 제17권2호
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• pp.71-78
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• 2012

Recently, the ratio of fuel cost to the operational cost of a ship is increasing according to the increase of the international oil price. Thus, many studies are being made to reduce the cost; for example, a method for acquiring the sea state information, a method for estimating fuel consumption, a method for determining the ship's optimal route, and so on. However, these studies were not incorporated together and being independently made in different fields. In this study, by improving and incorporating such studies, a method for determining a ship economic route based on the acquisition of the sea state and estimation of fuel consumption was proposed. To evaluate the applicability of the proposed method, it was applied to an optimal routing problem of the ocean area including many islands. The result shows that the proposed method can yield the economic route minimizing fuel consumption.

• 대한교통학회:학술대회논문집
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• 대한교통학회 2000년도 제37회 학술발표회논문집
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• pp.25-47
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• 2000

In route guidance systems fastest-path routing has typically been adopted because of its simplicity. However, empirical studies on route choice behavior have shown that drivers use numerous criteria in choosing a route. The objective of this study is to develop computationally efficient algorithms for identifying a manageable subset of the nondominated (i.e. Pareto optimal) paths for real-time vehicle routing which reflect the drivers' preferences and route choice behaviors. We propose two pruning algorithms that reduce the search area based on a context-dependent linear utility function and thus reduce the computation time. The basic notion of the proposed approach is that ⅰ) enumerating all nondominated paths is computationally too expensive, ⅱ) obtaining a stable mathematical representation of the drivers' utility function is theoretically difficult and impractical, and ⅲ) obtaining optimal path given a nonlinear utility function is a NP-hard problem. Consequently, a heuristic two-stage strategy which identifies multiple routes and then select the near-optimal path may be effective and practical. As the first stage, we utilize the relaxation based pruning technique based on an entropy model to recognize and discard most of the nondominated paths that do not reflect the drivers' preference and/or the context-dependency of the preference. In addition, to make sure that paths identified are dissimilar in terms of links used, the number of shared links between routes is limited. We test the proposed algorithms in a large real-life traffic network and show that the algorithms reduce CPU time significantly compared with conventional multi-criteria shortest path algorithms while the attributes of the routes identified reflect drivers' preferences and generic route choice behaviors well.

• 융합정보논문지
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• 제9권10호
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• pp.56-63
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• 2019

본 연구는 외국인의 국내 관광의 최적의 경로 도출하는데 그 목적이 있다. 이를 위해 국내관광 관련 포털 사이트 데이터를 참고하여 빅데이터 분석 툴인 R을 활용하여 분석을 시도하였다. 분석결과 국내 방문 외국인의 가장 방문 빈도수가 높은 곳과 최단시간 경로, 최저 비용의 경로를 도출하였다. 이를 통해 관광상품의 성공요인은 한국만의 특유한 문화가 보이는 곳으로 상품을 구성해야 한다는 결론을 도출하게 되었다. 본 연구의 결과는 국내 관광 상품을 기획하는 단계에서 실무적인 지침으로 활용이 가능할 것으로 보인다.

• 한국위험물학회지
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• 제3권1호
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• pp.28-36
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• 2015

In early 2011, the Fukushima nuclear power plant had greater damage due to earthquake in Japan, and the awareness of safety has increased. In particular, special response systems should be required to handle disaster situations in plant sites which are likely to occur for large disasters. In this study, a program is designed to set up optimum escape routes, by a smart phone application, when a disaster situation occurs. This program could get information of the cumulative damage from sensors and display the escape route of the smallest damage in real-time on the screen. Utilizing our application in real-time evacuation has advantage in reducing cumulative damage. The optimal evacuation route, focusing on horizontal path, is calculated based on getting the data of fire, detected radioactivity and hazardous gas. Thus, using our application provides information of optimal evacuation to people who even can not hear sensor alarms or do not know geography, without requiring additional costs except fixed sensors or server network deployment cost. As a result, being informed of real-time escape route, the user could behave rapidly with suitable response to individual situation resulting in improved evacuation than simply reacting to existing warning alarms.

• 디지털콘텐츠학회 논문지
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• 제6권1호
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• pp.55-62
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• 2005

개인휴대단말기(Personal Digital Assistant : PDA)와 CPS 수신기 및 전자 지도를 결합하여 차량 항법 소프트웨어를 개발하는 연구는 최근 활발하게 연구되고있다[1],[2]. 많은 웹사이트에서 전자 지도를 이용한 다양한 서비스를 제공하고 있다. 이들 서비스 중 사용자가 지정한 두 지점 사이의 최적, 최단 거리를 계산해주는 서비스는 매우 유용하게 사용되고 있는 서비스중의 하나이다. 이러한 최적거리 및 최단거리 계산 서비스는 택배 등 물류부분에서 많이 사용되어진다. 물류시스템에서는 차량관제 시스템을 구축하여 물류차량의 최적 이동경로를 파악하고 관리함으로써 비용절간 차량 및 인력활용의 효율성을 높일 수 있다[2]. 본 연구에서는 물류차량의 이동방향과 배송지의 위치를 고려한 최적경로를 계산함으로써 배송지의 위치에 맞게 최단경로 알고리즘을 개발하였으며, 최적경로 알고리즘은 빠른 시간에 최적경로를 찾기 위해 유전자 알고리즘을 도입하였다[3]. 이러한 방법을 사용함으로써 많은 경유지를 거치는 경우라도 빠른시간 안에 최적의 경로를 찾을 수 있다.

• 대한공간정보학회지
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• 제13권4호
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• pp.39-46
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• 2005

본 연구는 가능교통량과 가상주행을 통한 최적후보 노선선정에 군을 선정한 다음 최적 노선 선정에 관한 연구이다. 노선선정은 예비타당성조사, 기본 및 실시설계단계 등을 충분히 검토한 다음 도로를 설계하게 된다. 다양해진 도로이용자의 요구사항은 도로설계를 할 때부터 반영되어야 하나 기존방법은 2차원적인 지형요소를 고려하기 때문에 불규칙한 지형에 대한 적정 설계기준을 포함하지 못하고 있다. 본 연구에서는 후보노선을 선정을 위해 가상교통량분석과 주행을 실시하였다. 3차원 자료구축 구조물의 가상도로주행에서 모의관측으로 경관 및 지형 분석을 실시하여 최적노선을 선정하였다. 가상교통량과 3차원 모의관측기법을 통하여 도로건설 후에 미치는 자연환경과 조화되는 경관분석이 가능하고 조망권 차단 등 지역주민들과 마찰이 예상되는 부분에서 객관적인 해석이 가능하였다.

• 한국정밀공학회지
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• 제29권4호
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• pp.469-478
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• 2012

This study aims to discover the optimal pipe layout for a ship, which generally needs a lot of time, efforts and experiences. Genetic algorithm was utilized to search for the optimum. Here the optimum stands for the minimum pipe length between two given points. Genetic algorithm is applied to planar pipe layout problems to confirm plausible and efficiency. Sub-programs are written to find optimal layout for the problems. Obstacles are laid in between the starting point and the terminal point. Pipe is supposed to bypass those obstacles. Optimal layout between the specified two points can be found using the genetic algorithm. Each route was searched for three case models in two-dimensional plane. In consequence of this, it discovered the optimum route with the minimized distance in three case models. Through this study, it is possible to apply optimization of ship pipe route to an actual ship using genetic algorithm.