• Journal of Korean Society of Transportation
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• v.19 no.4
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• pp.85-96
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• 2001

This paper discusses the problem of finding the Origin-Destination(O-D) shortest path in urban road networks that have variable special qualifies such as time windows for passing as well as geometrical special qualities such as U-turn and left-turn prohibition. The focus of this paper is motivated by the problem of finding minimum travel time paths for an advanced traveler information system (ATIS) in the context of intelligent transportation system(ITS) application. The transportation network with variable and geometrical special qualities is a more realistic representation of the urban road network in the real word. But, the traditional and existing shortest path algorithms can not search practical shortest path that variable special quality is reflected. This paper presents a shortest path algorithm which can search reasonable shortest path information for the urban ATIS application within a real time. The algorithm is based on genetic algorithm(GA). The high performance of the proposed algorithm is demonstrated by computer simulations.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.561-565
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• 2005

net-VE 환경에서 다중 사용자들이 정보를 공유하는 경우 교환되는 이벤트 트래픽을 줄이기 위하여 확장 칼만필터를 이용해 객체 이벤트의 가변적 경로예측을 한다. 다중 사용자를 지원하는 3차원 공간 정보공유는 가상환경에 대한 상태정보를 중앙 서버에서 관리하므로 일관성 유지가 용이하다는 장점이 있으나 네트워크에 과중한 부담을 주며, 메시지 병목현상, 확장성이 부족하다는 문제점이 있다. 본 논문에서는 이동되어져온 궤적의 유클리디 실즉치와 칼만 예측치와의 오차 정보인 이노베이션을 사용하여 가변적 경로예측을 하고, net-VE 공유 및 이벤트 필터링 과정을 제안한다.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.206-209
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• 2005

Optimal path search systems to take continuously changed traffic flows into consideration is necessary in order to reduce the cost to get destination. However, to search optimal path in client terminals with low computing power yields high computational cost. Thus, a method with low cost and near optimal path as well is required. In this paper, we propose a path search method using variable heuristic for the sake of reducing operation time. The heuristic is determined by the change of the average speeds of cars located in grid which means a rectangle region.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.3
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• pp.663-668
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• 2010

In driving a car, turns such as left turns, right turns, or u-turns, make the speed of the car decrease considerably. A more straight path, therefore, is probably faster to arrive at the destination than zig-zag path with same distance. In this paper, we have newly proposed the turn heuristic to make more straight path. The path navigation algorithm with turn heuristic(called as TA* algorithm) could enhance the straightness of a path by putting the turned-edges to the turn cost. It requires higher cost to use TA* algorithm than traditional A* algorithm because the straight-edge first searching have increased the search space. We have improved the TA* algorithm into the variable TA* algorithm(called as VTA* algorithm) which adopt the turn-heuristic during the a portion of the whole path.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.11 s.353
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• pp.192-199
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• 2006

Establishment of bandwidth and effective traffic processing are required to treat various traffics according to a rapid increase in Internet traffic. A path setup algorithm was introduced to support backbone franc processing but the failure probability is increasing according to fixed operation in nodes. In other words, fixed maximum permitted time can be raised failure probability. So as to solve this problem, this paper introduces variable path setup time algorithm which support channel service of excessive traffic that is generated from not allowed channel. We proposed GLSP(Generalized Label Switch Path) setup algorithm that use variable path setup time parameters. This algorithm can improve path setup probabilities of backbone network that is composed of fixed way.

• Spatial Information Research
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• v.17 no.3
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• pp.361-370
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• 2009

As the increasing interests of spatial information for different application area such as disaster management, there are many researches and development of indoor spatial data models and real-time evacuation management systems. The application requires to determine and optical paths in emergency situation, to support evacuees and rescuers. The optimal path in this study is defined to guide rescuers, So, the path is from entrance to the disaster site (room), not from rooms to entrances in the building. In this study, we propose a time-dependent optimal routing algorithm to develop real-time evacuation systems. The network data that represents navigable spaces in building is used for routing the optimal path. Associated information about environment (for example, number of evacuees or rescuers, capacity of hallways and rooms, type of rooms and so on) is assigned to nodes and edges in the network. The time-dependent optimal path is defined after concerning environmental information on the positions of evacuees (for avoiding places jammed with evacuees) and rescuer at each time slot. To detect the positions of human beings in a building per time period, we use the results of evacuation simulation system to identify the movement patterns of human beings in the emergency situation. We use the simulation data of five or ten seconds time interval, to determine the optimal route for rescuers.

• Proceedings of the IEEK Conference
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• 2009.05a
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• pp.366-368
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• 2009

본 논문에서는 모바일 로봇이 작업하는 공간상에서 빠르고 안전한 최적 경로계획을 수행할 수 있게 하는 가변적 리드 맵을 이용한 장애물 밀집 정보 기반 경로계획을 제안한다. 모바일 로봇이 작업 공간에 대해서 빠르고 안전한 경로계획을 해 클러스터링 기법을 이용하여 정적 및 동적 장애물의 분포에 대한 맵 정보를 재구성하여 정보화 시킨다. 최적의 경로계획을 위해서는 재구성된 장애물 밀집 클러스터 데이터를 이용하여 전통적 기법의 GA 방법을 변형한 최적 경로계획을 수행한다. 제안한 기술의 효율성을 검증하기 위해 그리드 기반 경로계획 중의 하나인 A*알고리즘과 다양한 맵을 이용하여 성능 비교를 수행하였다. 실험결과 제안한 경로계획 기술은 기존 알고리즘 보다 빠른 처리 성능과 동적 장애물이 밀집한 지역을 회피하는 최적 경로계획을 수행함을 확인하였다.

• Journal of Korea Society of Industrial Information Systems
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• v.28 no.2
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• pp.31-45
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• 2023

This study deals with exploring qualitative steps and paths that appear as YouTube users' usage time increases quantitatively. For the study, I applied theories from psychology and neuroscience, subdivided the interval between the personalization algorithm of the recommendation system, and active use and analyzed the relationship between variables in this process. According to the theory behavioral model theory (FBM), variable reward, and dopamine addiction were applied. Personalization algorithms easy clicks as triggers according to associated content presentation functions in behavioral model theory (FBM). Variable rewards increase motivational effectiveness with unpredictability of the content you search, and dopamine nation is summarized as stimulating the dopaminergic nerve to continuously and actively consume content. This study is expected to make an academic and practical contribution in that it divides the purpose of use of content in the personalization algorithm and active use section into four stages from a psychological perspective: first use, reuse, continuous use, and active use, and analyzes the path.

• Journal of IKEEE
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• v.14 no.2
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• pp.58-63
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• 2010

In this paper, design and implementation of multi-modular robots of similar structure to the arthropods for rock path driving. Each module corresponds to an arthropod joint, which has an independent power supply and control equipment including drive and short-range Zigbee wireless communication that were implemented. On various directions and paths each module has the same driving direction and each module is controlled to operate or not by wireless communication. Depending on path condition, each module calculate the speed and torque and depending on the slope of a rough path, the number of active modules can be changed for the efficient driving on a variety of roads conditions. Experimental driving through rough road model, variable multi-module robot is implemented.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2008.10a
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• pp.182-187
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• 2008

It needs to consider of turns during a path-finding on real road network. traveling on real road network, it generally takes less travel time in a more straight path than a zig-zaged path with same source and destination. In this paper, we propose $VTA^*$ algorithm that can reduce the cost of exploring despite increasing the number of turn in comparing with $TA^*$ algorithm. We have implement the proposed $VTA^*$, $TA^*$ which consider the number of turn and a traditional $A^*$ algorithm which dosen't consider the number of turn. The experimental result shows that the cost of exploring is reduced by 7.31 % comparing with $TA^*$ and the number of turn is reduced by 27.95% comparing with $A^*$ approximately.