• 한국경영과학회지
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• 제30권1호
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• pp.1-15
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• 2005

In this paper, we deal with a mesh network design problem arising from the deployment of WDM for the optical internet. The mesh network consists of mesh topology for satisfying traffic demand while minimizing the cost of WDM, OXC, and fiber cables. The problem seeks to find an optimal routing of traffic demands in the network such that the total cost is minimized. We formulate the problem as a mixed-integer programming model and devise a tabu search heuristic procedure. Also we develop an optical internet design system that implements the proposed tabu search heuristic procedure. We demonstrate the computational efficacy of the proposed algorithm, compared with CPLEX 8.0.

• 대한산업공학회지
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• 제26권4호
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• pp.421-430
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• 2000

This paper presents a new approach which uses $A^*$ search and genetic algorithms for solving large scale multi-objective shortest path problem. The focus of this paper is motivated by the problem of finding Pareto optimal paths for an advanced traveler information system(ATIS) in the context of intelligent transportation system(ITS) application. The individual description, the decoding rule, the selection strategy and the operations of crossover and mutation are proposed for this problem. The keynote points of the algorithm are how to represent individuals and how to calculate the fitness of each individual. The high performance of the proposed algorithm is demonstrated by computer simulations.

• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2023년도 제68차 하계학술대회논문집 31권2호
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• pp.689-691
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• 2023

본 논문에서는 시작 노드와 목적지 노드 까지의 최단경로를 중점으로 가장 인접한 경유지를 선택하고 경유지가 다수일 경우 하모니서치 알고리즘을 통해 최적의 경로를 탐색하는 기법을 제안한다. 본 논문의 기법은 기존의 사용자의 현 위치에서 인접한 경유지를 추천해주는 시스템과 달리 목적지까지의 경로 전체에서 가장 인접한경유지를 선택해준다는 차별점이 있다. 그렇게 선택된 경유지들은 하모니서치 알고리즘을 사용하여 최적의 경로를 제안한다. 본 논문의 기법은 최단경로의 이탈을 최소화한 경유지 선택으로 거리, 시간, 비용적 측면에서 효율적이며 길을 헤매서 생기는 불필요한 지연을 최소화할 수 있다. 자율주행, 비행기, 선박, 드론 등 최적 경로 이탈시 큰 손실을 안기거나 위험한 시스템에 적용시 큰 효과를 거둘 수 있다.

• 대한임베디드공학회논문지
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• 제17권1호
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• pp.33-40
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• 2022

With the recent increase in the development of military drones, they are adopted and used as the combat system of battalion level or higher. However, it is difficult to use drones that can be used in battles below the platoon level due to the current conditions for the formation of units in the Korean military. In this paper, therefore, we developed a program drones equipped with a thermal imaging camera and LiDAR sensor for reconnaissance and exploration that can be applied in battles below the platoon level. Using these drones, we studied the possibility and feasibility of drones for small-scale combats that can find hidden enemies, search for an appropriate detour through image processing and conduct reconnaissance and search for battlefields, hiding and cover-up through image processing. In addition to the purpose of using the proposed drone to search for an enemies lying in ambush in the battlefield, it can be used as a function to check the optimal movement path when a combat unit is moving, or as a function to check the optimal place for cover-up or hiding. In particular, it is possible to check another route other than the route recommended by the program because the features of the terrain can be checked from various viewpoints through 3D modeling. We verified the possiblity of flying by designing and assembling in a form of adding LiDAR and thermal imaging camera module to a drone assembled based on racing drone parts, which are open source hardware, and developed autonomous flight and search functions which can be used even by non-professional drone operators based on open source software, and then installed them to verify their feasibility.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권5호
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• pp.939-955
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• 2010

With the progress of IT and mobile positioning technologies, various types of location-based services (LBS) have been proposed and implemented. Finding a shortest path between two nodes is one of the most fundamental tasks in many LBS related applications. So far, there have been many research efforts on the shortest path finding problem. For instance, $A^*$ algorithm estimates neighboring nodes using a heuristic function and selects minimum cost node as the closest one to the destination. Pruning method, which is known to outperform the A* algorithm, improves its routing performance by avoiding unnecessary exploration in the search space. For pruning, shortest paths for all node pairs in a map need to be pre-computed, from which a shortest path container is generated for each edge. The container for an edge consists of all the destination nodes whose shortest path passes through the edge and possibly some unnecessary nodes. These containers are used during routing to prune unnecessary node visits. However, this method shows poor performance as the number of unnecessary nodes included in the container increases. In this paper, we focus on this problem and propose a new border line-based pruning scheme for path routing which can reduce the number of unnecessary node visits significantly. Through extensive experiments on randomly-generated, various complexity of maps, we empirically find out optimal number of border lines for clipping containers and compare its performance with other methods.

• 한국정보시스템학회:학술대회논문집
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• 한국정보시스템학회 1996년도 추계학술발표회 발표논문집
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• pp.199-204
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• 1996

It is discussed how to determine the home location of idle vehicles in an AGVS with a loop guide path in a way of maximizing the request-call response probabilities for all demand. Optimal home position is selected by solving the simultaneous equations easily. Static positioning strategy is analyzed in which a single home position is allocated to which every vehicle is routed whenever it becomes idle. The cases of unidirectional guidepath is considered only. We provide a numerical example to illustrate the search algorithm developed for the case and compare the searched optimal solutions with the others.

• 대한안전경영과학회:학술대회논문집
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• 대한안전경영과학회 2008년도 추계학술대회
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• pp.649-658
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• 2008

This paper investigates the optimal nesting system for a board. A hybrid method is used to search the optimal solution for rectangular nesting problem. This method is composed of heuristic approach algorithm. An engineer's experience of board nesting in which a loss occurred to sheet because of various individual error and diffidence. So, item layout at resource sheet were evaluated in engineering algorithm logic in which specially designed was installed. The nesting system consists of Lisp and Visual Basic. The system was controlled by AutoCAD so as to best item batch path test.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권10호
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• pp.4738-4753
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• 2018

Efficient rendezvous node selection and routing algorithm (RNSRA) for wireless sensor networks with mobile sink that visits rendezvous node to gather data from sensor nodes is proposed. In order to plan an optimal moving tour for mobile sink and avoid energy hole problem, we develop the RNSRA to find optimal rendezvous nodes (RN) for the mobile sink to visit. The RNSRA can select the set of RNs to act as store points for the mobile sink, and search for the optimal multi-hop path between source nodes and rendezvous node, so that the rendezvous node could gather information from sensor nodes periodically. Fitness function with several factors is calculated to find suitable RNs from sensor nodes, and the artificial bee colony optimization algorithm (ABC) is used to optimize the selection of optimal multi-hop path, in order to forward data to the nearest RN. Therefore the energy consumption of sensor nodes is minimized and balanced. Our method is validated by extensive simulations and illustrates the novel capability for maintaining the network robustness against sink moving problem, the results show that the RNSRA could reduce energy consumption by 6% and increase network lifetime by 5% as comparing with several existing algorithms.

• 인터넷정보학회논문지
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• 제11권3호
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• pp.131-137
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• 2010

현재 많은 박물관들이 유비쿼터스 기술과 함께 자신의 형태를 바꾸어 가고 있다. 기존에 유물에 부착된 정적인 텍스트 기반 정보만을 방문객에게 제공하는 전통적인 박물관과 달리, 이러한 유비쿼터스 박물관은 각종 PDA 혹은 휴대폰을 통해 유물에 대한 텍스트 정보뿐만이 아니라 음성, 동영상 등의 다양한 형태의 정보를 제공하고 있다. 그러나 이러한 기존 유비쿼터스 박물관은 각 방문객에게 유물 중심적인 정보만을 매우 단편적인 방법으로 제공하는 데 그치고 있다. 이러한 불리한 특성은 모든 방문객에게 획일적인 관람경로만을 제공하여 전시실의 혼잡을 야기하는 문제점이 있다. 이러한 한계성은 방문객에게 자신의 선호를 고려하여 보다 다양하고 유용한 유물 정보 제공에 대한 가장 큰 장벽이 될 수 있다. 본 논문에서는 방문객의 선호도에 따라 편안한 박물관 관람을 제공하는 새로운 최적의 관람 경로 검색 알고리즘을 제안한다. 또한 방문객의 박물관 관람 시 방문객들이 몇몇 쏠림 지역으로 모이는 것을 예방함으로써 박물관 관람의 편안함을 최대로 향상시키도록 한다.

• 한국정보과학회논문지:정보통신
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• 제32권3호
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• pp.310-317
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• 2005

모바일 애드흑 네트워크는 기존의 시스템처럼 인증기관(Certificate Authority)이나 중앙 집중화된 서버를 통해 노드들에 대한 신뢰와 온라인 접근을 제공하지 않는다. 그러나, 시스템의 노드들은 서로 안전하게 데이타를 주고받기 위해서 경로를 탐색하는 것뿐만 아니라, 서로를 신뢰할 수 있게 하는 과정이 반드시 필요하다. 이러한 이유 때문에 온라인 신뢰기관이나 인증 저장 공간을 요구했던 전통적인 보안 구조는 안전한 애드혹 네트워크에는 적합하지 않다. 이에 본 논문에서는 애드흑 네트워크 환경에서 효과적인 플러딩(flooding) 기법을 사용하여 노드 사이에 '안전하고 효과적인 최적의 인증경로탐색기법을 제안한다. 이 시스템은 브로드캐스팅(broadcasting)을 통해 목적지만을 찾는 일반적인 라우팅 프로토콜만을 의미하는 것이 아니라, 통신하고자 하는 노드를 안전하고 효과적으로 탐색하며, 찾아진 경로 또한 그 경로에 있는 노드간의 신뢰를 통해 검증하는 과정을 포함한다.