• 한국측량학회지
• /
• 제25권1호
• /
• pp.1-8
• /
• 2007

최근 주상복합형의 주거공간, 지하철, 대형쇼핑몰 등 건물내부가 복잡하고 대규모인 공간에서 머무르는 시간과 기회가 날로 증가하고 있다. 건물이 복잡할수록 건물 내에서 사람들이 원하는 목적지에 도착하기까지 보다 많은 시행착오를 겪으면서 이동하게 된다. 시행착오를 줄이고, 보다 빠르게 이동하기 위해서는 최단경로를 탐색하여 제공하는 시스템이 필요하게 된다. 이러한 대규모 공간 내에서의 최적이동경로에 대한 정보는 특히 화재나 정전, 테러위협과 같은 응급상황에서 더욱 필요로 하게 된다. 이에 본 연구에서는 Raster GIS기반의 데이터구조 상에서 $A^*$알고리즘을 사용한 최단경로 탐색기법을 비교, 분석하고자 한다. 평상시에는 건물내부에서의 위치 이동시에 필요한 최단 경로를 제공하고, 응급상황에서는 탐색시간을 최소화하여 대피 경로를 제공하는 방안을 제시하였으며, 이를 캠퍼스 건물을 이용하여 예시하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• 제10권7호
• /
• pp.3100-3116
• /
• 2016

With the rapid development of urban traffic system and fast increasing of vehicle numbers, the traditional centralized ways to generate the source-destination shortest path in terms of travel time(the optimal path) encounter several problems, such as high server pressure, low query efficiency, roads state without in-time updating. With the widespread use of smart cameras in the urban traffic and surveillance system, this paper maps the optimal path finding problem in the dynamic road network to the shortest routing problem in the smart camera networks. The proposed distributed optimal path generation algorithm employs the delay routing and caching mechanism. Real-time route update is also presented to adapt to the dynamic road network. The test result shows that this algorithm has advantages in both query time and query packet numbers.

• 한국국방경영분석학회지
• /
• 제17권2호
• /
• pp.72-89
• /
• 1991

In transportation network problems, it is often desirable to select multiple number of the shortect paths. On problems of finding these paths, algorithms have been developed to choose single shortest path, k-shortest paths and k-shortest paths via p-specified nodes in a network. These problems consider the time as the main factor. In wartime, we must consider availability as well as time to determine the shortest transportation path, since we must take into account enemy's threat. Therefore, this paper addresses the problem of finding the shortest transportation path considering both time and availability. To accomplish the objective of this study, values of k-shortest paths are computed using the algorithm for finding the k-shortest paths. Then availabilties of those paths are computed through simulation considering factors such as rates of suffering attack, damage and repair rates of the paths. An optimal path is selected using any one of the four decision rules that combine the value and availability of a path.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2015년도 추계 학술논문 발표대회
• /
• pp.170-171
• /
• 2015

Resource procurement and material handling are considered as a significant part of construction project especially in large or tall building construction site. There are multiple variables that must be considered in a construction site during finishing work such as movement of materials, equipments, and workers. Therefore, it is difficult for construction workers to find the material handling path solely by intuition. The aim of this study is to propose a real-time path finding model suitable for complicated logistics flow in the field. The model explores the optimal transport path of finishing material with its basis on optimization algorithm, and it determines the direction of the Smart Sign. The proposed model is expected to be utilized for planning of efficient finishing material handling.

• 한국시뮬레이션학회논문지
• /
• 제14권3호
• /
• pp.21-31
• /
• 2005

In state-of-the-art games, characters can move in a goal-directed manner so that they can move to the goal position without colliding obstacles. Many path-finding methods have been proposed and implemented for these characters and most of them use the A* search algorithm. When .the map is represented with a regular grid of squares or a navigation mesh, it often takes a long time for the A* to search the state space because the number of cells used In the grid or the mesh increases for higher resolution. Moreover the A* search on the grid often causes a zigzag effect, which is not optimal and realistic. In this paper we propose to use visibility graphs to improve the search time by reducing the search space and to find the optimal path. We also propose a method of taking into account the size of moving characters in the phase of planning to prevent them from colliding with obstacles as they move. Simulation results show that the proposed method performs better than the grid-based A* algorithm in terms of the search time and space and that the resulting paths are more realistic.

• 대한공간정보학회지
• /
• 제20권4호
• /
• pp.89-95
• /
• 2012

최근 자전거 이용 활성화를 위한 계획들은 다른 연구들에 비해 비교적 낮다. 또한, 자전거 도로의 접근성 측면의 연구들이 활발히 진행되고 있으나, 지형적 요소와 이용자의 특성을 고려한 연구는 부족하다. 자전거 이용자는 지형적 요소로 경사도와 교차로의 영향을 많이 받으며, 최적 거리의 노선을 요구한다. 본 연구는 자전거 활용에 있어서 통학에서 경로선택을 할 때 지형적 요소를 고려한 최적 노선을 선택하는 경로기법을 제시한다. 이를 위해 최적경로의 연산에 있어서 경사도와 교차로를 고려한 식을 도출하였다. 제시된 변형식은 송파 일대에 적용하여 편도와 왕복으로 실험하였으며, 일반적인 최적경로와 비교하여 제시하였다.

• Spatial Information Research
• /
• 제19권1호
• /
• pp.83-91
• /
• 2011

The route finding analysis is an essential geo-related decision support tool in a LBS(Location based Services) and previous researches related to route guidance have been mainly focused on route guidances for vehicles. However, due to the recent spread of personal computing devices such as PDA, PMP and smart phone, route guidance for pedestrians have been increasingly in demand. The pedestrian route guidance is different from vehicle route guidance because pedestrians are affected more surrounding environment than vehicles. Therefore, pedestrian path finding needs considerations of factors affecting walking. This paper aimed to extract factors affecting walking and charting the factors for application factors affecting walking to pedestrian path finding. In this paper, we found various factors about environment of road for pedestrian and extract the factors affecting walking. Factors affecting walking consist of 4 categories traffic, sidewalk, network, safety facility. We calculated weights about each factor using analytic hierarchy process (AHP). Based on weights we calculated scores about each factor's attribute. The weight is maximum score of factor. These scores of factor are used to optimal pedestrian path finding as path finding cost with distance, accessibility.

• 한국경영과학회지
• /
• 제16권1호
• /
• pp.1-12
• /
• 1991

This paper studies an optimal algorithm for the Maximum Origin-Destination Flor Path (MODFP) in an acyclic transportation network. We define a Pseudo-Flow each are so that it can give an upper bound to the total flow of a given path. And using the K-th Shortest Path algorithm we obtain upper bound of MODF which is decreasing as the number of searched path grows. Computational Complexity of optimal algorithm is O(K + m) $n_{2}$), K being the total number of searched path. We proved that the problem complexity of finding MODFP in an acyclic network is NP-hard, showing that the-satisfiability problem can be polynomialy reduced to this problem. And we estimated the average of the number K as being (m/n)$^{1,08}$ Exp (0.00689gm) from the computational experiments.

• Journal of Mechanical Science and Technology
• /
• 제18권5호
• /
• pp.753-761
• /
• 2004

In this paper, an efficient method for generating 5-axis cutting data for a turbine blade is presented. The interference elimination of 5-axis cutting currently is very complicated, and it takes up a lot of time. The proposed method can generate an interference-free tool path, within an allowance range. Generating the cutting data just point to the cutting process and using it to obtain NC data by calculating the feed rate, allows us to maintain the proper feed rate of the 5-axis machine. This paper includes the algorithms for: (1) CL data generation by detecting an interference-free heel angle, (2) finding the optimal tool path interval considering the cusp-height, (3) finding the adaptive feed rate values for each cutter path, and (4) the inverse kinematics depending on the structure of the 5-axis machine, for generating the NC data.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
• /
• pp.418-418
• /
• 2000

This paper proposes a path planning algorithm for mobile robot. To generate an optimal path and minimum time path for a mobile robot, we use the Genetic Algorithm(GA) and Visibility Graph. After finding a minimum-distance between start and goal point, the path is revised to find the minimum time path by path-smoothing algorithm. Simulation results show that the proposed algorithms are more effective.