• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1279-1288
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• 2007

A vehicle routing problem with time constraint is one of the must important problem in distribution and logistics. In practice, the service for a customer must start and finish within a given delivery time. This study is concerned about the development of a model to optimize vehicle routing problem under the multi-logistics center problem. And we used a two-step approach with an improved genetic algorithm. In step one, a sector clustering model is developed by transfer the multi-logistics center problem to a single logistics center problem which is more easy to be solved. In step two, we developed a GA-TSP model with an improved genetic algorithm which can search a optimize vehicle routing with given time constraints. As a result, we developed a Network VRP computer programs according to the proposed solution VRP used ActiveX and distributed object technology.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.27-27
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• 1994

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.5
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• pp.609-617
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• 2013

This paper presents a near-minimum time path planning algorithm for autonomous driving. The problem of near-minimum time path planning is an optimization problem in which it is necessary to take into account not only the geometry of the circuit but also the dynamics of the vehicle. The path planning algorithm consists of a candidate path generation and a velocity optimization algorithm. The candidate path generation algorithm calculates the compromises between the shortest path and the path that allows the highest speeds to be achieved. The velocity optimization algorithm calculates the lap time of each candidate considering the vehicle driving performance and tire friction limit. By using the calculated path and velocity of each candidate, we calculate the lap times and search for a near-minimum time path. The proposed algorithm was evaluated via computer simulation using CarSim and Matlab/Simulink.

• Journal of KIISE:Information Networking
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• v.34 no.5
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• pp.328-339
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• 2007

Conventional topology-based routing protocols are not suitable for inter-vehicular communication, where frequent route updates are necessary due to continuous and abrupt changes in network topology Position-based routing protocols are widely accepted to better serve their purpose in such a scenario as they do not require path discovery or maintenance. However they have to deal with the overhead of the location service and inaccurate position information. This paper proposes the MMFP (Multi-hop MAC Forwarding Protocol) for inter-vehicle communication that relies on reachability information collected from received packets in making a forwarding decision without path discovery. The MMFP is designed as an extension to the IEEE 802.11 MAC layer to ensure accuracy in its time-critical operations. This paper also presents some simulation results that demonstrate the superior performance of the MMFP over AODV in a realistic inter-vehicular communication.

• Journal of Korean Society of Transportation
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• v.25 no.5
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• pp.161-172
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• 2007

Vehicles transporting hazardous materials can make huge damage to people, properties and environment by traffic accidents. Therefore, transporting hazardous materials is a big issue with the cutting edge technology of communications in these days. However, despite this situation, Korean government gives limited efforts for systematic management, research and investment about hazardous materials. Accordingly, this research suggests the key path finding algorithm about management of real-time schedule and routes for vehicles transporting hazardous materials. Besides, the case study is progressed in transportation networks of Seoul in order to evaluate the reality of algorithm. Specifically, time-space network transformation is performed for time window attributes. In addition, this study proposes the techniques searching for non-dominated paths considering schedule by the multiobjective shortest path algorithm based on dynamic programming in dynamic transportation networks including multiobjective attributes.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38A no.12
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• pp.1054-1060
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• 2013

This paper proposes a vehicle ad-hoc network (VANET) routing algorithm to reduce the probability of routing path discontinuity in urban intersections. In urban intersections, the vehicles may frequently change their moving directions. It can cause the disconnection of routing path and the increase of a packet transmission delay. In order to resolve this problem, the proposed routing algorithm exploits the information of moving directions in urban intersections. In this way, the proposed algorithm can reduce the probability of the local maximum which causes the increase of the number of routing hops and packet transmission delay. Simulation results show that the proposed algorithm can reduce the local maximum probability by 10% and increase the successful packet transmission ratio by 5% compared to the conventional VANET routing algorithms.

• Journal of the Korea Institute of Military Science and Technology
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• v.25 no.4
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• pp.425-433
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• 2022

This paper studies the method of delivering munitions using both drones and UGVs that are developing along with the 4th Industrial Revolution. While drones are more mobile than UGVs, their loading capacity is small, and UGVs have relatively less mobility than drones, but their loading capacity is better. Therefore, by simultaneously operating these two delivery means, each other's shortcomings may be compensated. In addition, on actual battlefields, time constraints are an important factor in delivering munitions. Therefore, assuming an actual battlefield environment with a time limit, we establish delivery routes that minimize delivery time by operating both drones and UGVs with different capacities and speeds. If the delivery is not completed within the time limit, penalties are imposed. We devised the hybrid genetic algorithm to find solutions to the proposed model, and as results of the experiment, we showed the algorithm we presented solved the actual size problems in a short time.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.584-585
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• 2017

본 연구는 드론 운송시스템에서 드론에 적재되어 있는 화물의 무게에 따른 비행가능거리의 변화를 운송 경로 문제에 적용시킨다. 드론에 적재된 무게에 따른 비행속도와 비행가능거리를 실험을 통해 사전에 수집하고, 이를 고려한 적합도 함수를 유전 알고리즘에 적용한다. 실험 결과 드론의 평균비행가능거리만을 이용한 것 보다 총소요시간을 단축시켜 효율적인 드론 운송시스템의 적용이 가능할 것이다.

• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.509-512
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• 2009

최근 차량용 IT 기술이 발달함에 따라 네비게이션, 위치추적, 인터넷 접수, 원격 차량 진단, 사고감지, 긴급구난, 교통정보 등을 제공하는 서비스들이 등장하고 있다. 또한 차량의 편의성과 안정성을 추구함과 동시에 친환경 등에 대한 요구도 증가하고 있다. 그리고 최근 차량 상호간 정보의 교환이 더욱 필요해짐에 따라 차량간의 무선 통신 기능이 중요해지고 있으며 차량 내의 네트워크 기술에 대한 연구도 필요하다. 현재 차량 내 네트워크로는 CAN, LIN, MOST등의 유선으로 된 버스 시스템을 중심으로 한 차량 제어 시스템과 멀티미디어 시스템으로 크게 구분할 수 있다. 그러나 자동차 내에 장치 배선이 복잡해짐에 따라 차량의 무게 증가, 고장율의 증가, 연비 저하 등으로 이어지고 있다. 이러한 문제를 보완하기 위해 차량 내에 무선 센서 네트워크 시스템과의 통합 개발이 요구되고 있다. 본 논문에서는 빠르게 발전하고 있는 차량 내 네트워크에 대한 기술개발 동향을 분석하고, 유무선 통합형 차량 내 네트워크 응용 서비스들을 제시하고자 한다.

• Proceedings of the Korean Society of Computer Information Conference
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• 2009.01a
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• pp.283-288
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• 2009

고정된 망을 가지지 않고, 이동 호스트로만 이루어져 통신되는 망인 Ad-hoc 네트워크에서 고속으로 이동 중인 차량들 간의 긴급한 정보를 주고받아 고속도로에서의 다중 충돌사고를 미연에 방지할 수 있는 차량 통신 프로토콜을 제안한다. 본 논문에서는 도로위의 차량들은 서로 연계성이 없기 때문에 위치추적시스템인 GPS에서 수신한 거리 값을 연계하여 클러스터를 구성한다. 클러스터를 IEEE 802.11 MAC 계층에서 구성하기 때문에 경로 설정으로 인한 과부하문제를 해소 하였다. 논문에서 제안한 액티브 네트워크 기반의 멀티 홉 라우팅 프로토콜은, Active 네트워크를 이용하여 안정된 통신이 이루어 질수 있도록 한다.