• The Journal of Society for e-Business Studies
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• v.9 no.2
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• pp.123-143
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• 2004

Nowadays, insufficient parking lots give rise to a serious problem. Cars are increased in geometrical progression, but parking lots that takes in cars are relatively limited. Often we spend a lot of time to look for a parking lot because of limited parking lot. To solve this problem, we can use real time parking lot information system provided from mobile vehicles. In this paper, we will tell you how to deliver the parking lot information in real time by construction wireless network environment to be provided real time information and making XML data that is easy to share and to exchange data between applications.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.9 s.351
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• pp.88-98
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• 2006

VANET has several different characteristics from MANET such as high mobility of nodes and frequent change of node density and network topology. Due to these characteristics, the network topology based protocol, often used in MANET, can not be applied to VANET. In this paper, we propose an emergency warning message broadcast protocol using range based relay node selecting algorithm which determines the minimal waiting time spent by a given node before rebroadcasting the received warning message. Because the time is randomly calculated based on the distance between sender node and receiver node, a node chosen as a relay node is assured to have a minimal waiting time, even though it is not located at the border of radio transmission range. The proposed emergency warning message broadcast protocol has low network traffic because it does not need to exchange control messages for message broadcasting. In addition, it can reduce End-to-End delay under circumstances of low node density and short transmission range in VANET.

• Journal of Korea Society of Industrial Information Systems
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• v.14 no.3
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• pp.50-57
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• 2009

We propose a network node search scheme to address the network fragmentation due to high node mobility in the VANET. VANET is very similar to MANET in that a multi-hop ad-hoc network is configured by wireless communication between vehicles without any network infrastructure. However, high speed mobility, high node density, and frequent topology change induce frequent network fragmentation so that overall network traffic can be increased. In this paper, new broadcasting protocol called an adaptive relay node search protocol is proposed to decrease the network fragmentation. It reduces the network fragmentation and network traffic by researching nodes outside the dangerous area only in case of network fragmentation. Simulation results show that the proposed protocol decreases network fragmentation by up to 39.9% and increase informed rate by up to 41.9% compared to the existing broadcasting protocol.

• 한국공간정보시스템학회:학술대회논문집
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• 2004.12a
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• pp.3-8
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• 2004

가정에서건 사무실에서건 혹은 이동 중에도 무선 이동 통신, 인터넷, 각종 디지털 기기를 통해 자유롭게 정보를 교환하고 원하는 서비스를 이용할 수 있는 새로운 네트워크 시대가 열리고 있다. 단순한 운송수단이었던 자동차도 무선 통신과 GPS 기술을 바탕으로 차내 이동형 정보서비스를 지원하는 텔레매틱스 서비스를 도입하면서, 도로상에서 다양한 서비스를 이용할 수 있는 환경을 제공하고 있다. 이로 인해 텔레매틱스 서비스를 위한 핵심기술 개발에 대한 수요도 증가하고 있으며, 그 중에서도 사용자 및 차량으로부터의 서비스 요청을 처리하고, 다양한 컨텐츠 제공자 및 서비스 제공자와의 연계를 지원하기 위한 텔레매틱스 서버에 대한 필요성이 증대되고 있다. 본 논문에서는 항법 맵, POI, 실시간 교통정보 등 텔레매틱스 핵심 컨텐츠를 상호 연계하여 이를 사용자에게 효율적으로 서비스하기 위한 텔레매틱스 컨텐츠 서비스 서버를 설계하였다. 이를 통해 향후 텔레매틱스 서비스를 위한 시스템 구축 시 상호운용성과 확장성을 제공함으로써, 국내 텔레매틱스 서비스의 조기 활성화에 기여할 수 있을 것이다.

• Journal of IKEEE
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• v.18 no.3
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• pp.427-434
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• 2014

The Multihop Routing of vehicle communication environment is difficult to maintain due to heavy fluctuation of network topology and routing channel according to the movement of the vehicle, road property, vehicle distribution. We implemented GeoNetworking on the basis of ETSI(European Telecommunication Standard Institute) to maintain the vehicle safety service. GeoNetworking has its own way that delivers the data through the Unicast and Broadcast. In this paper, we compared performance index such as packet delivery ratio, end-to-end delay about GeoNetworking using the QualNet Network Simulator. Previous research assessed performance of GeoUnicast. This research has been additionally performed about GeoBroadcast, and we progressed algorithm performance through the comparison of CBF(Contention based Forwarding) of GeoUnicast with Greedy forwarding of GeoBroadcast.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.8 no.4
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• pp.53-64
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• 2009

Inter-vehicular communication that propagates information without infrastructures has drawn a lot of interest. However, it is difficult to apply conventional ad-hoc routing protocols directly in inter-vehicular communication due to frequent changes in the network topology caused by high mobility of the vehicles. MMFP(Multi-hop MAC Forwarding) is a unicast forwarding protocol that transport packets based on the reachability information instead of path selection or position information. However, delivering public safety messages informing road conditions such as collision, obstacles and fog through inter-vehicular communication requires broadcast rather than unicast since these messages contain information valuable to most drivers within a close proximity. Flooding is one of the simplest methods for multi-hop broadcast, but it suffers from reduced packet delivery-ratio and high transmission delay due to an excessive number of duplicated packets. This paper presents two multi-hop broadcast protocols for inter-vehicular communication that extend the MMFP. UMHB(Unreliable Multi-Hop Broadcast) mitigates the duplicated packets of MMFP by limiting the number of nodes to rebroadcast packets. UMHB, however, still suffers from low delivery ratio. RMHB(Reliable Multi-Hop Broadcast) uses acknowledgement and retransmission in order to improve the reliability of UMHB at the cost of increase in transmission delay, which we show through simulation is within an acceptable range for collision avoidance application.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.11
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• pp.5272-5277
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• 2011

By mobile technique and vehicle industry development, vehicle service industry based on Intelligent network as telematics service will be more raised. Most of countries expect its industrial market so that many researches and standardization are being advanced. For the telematics service, the vehicle safety technique will be very important so that its research should be expected. Hence, in this paper, we propose a design mechanism for the alerting car accident to identify or avoid dangerous accident by the network of cars.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2015.10a
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• pp.211-215
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• 2015

It comes into the spotlight as the new Blue Ocean in which the connected car industry in which the car and mobile communication technology is convergence. All sorts of infortainments services connecting with the portable electronic device(Smart phone, tablet PC, and MP3 player) and car are rapidly grown. The Connected car emphasizes the vehicle connectivity with the concept that the car has communication with the around on a real time basis and it provides the safety and expedience to the operator and using the thing of Internet (IoT) in the car and supports the application, presently, the entertainment service including the real-time Navigation, parking assistant function, not only the remote vehicle control and management service but also Email, multimedia streaming service, SNS and with the platform. Intelligent vehicle network is studied as the kind according to MANET(Mobile Ad Hoc Network) for the safety operation of the cars of the road and improving the efficiency of the driving. The intelligent vehicle network is comprised for the driving information offering changing rapidly of the communication(V2V: Vehicle to Vehicle) between the car and the car, communication(V2I : Vehicle to Infrastructure) between the infrastructure and the car, and V2X (Vehicle to Nomadic).

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.18 no.4
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• pp.183-189
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• 2018

With the recent advancement of vehicle wireless communication technology, many vehicular clouds have been proposed. The existing research focused on cloud services through data collection based on vehicular networks of mobile V2V (Vehicle-to-Vehicle) and V2I (Vehicle-to-Infrastructure). In this paper, we present a vehicular datacenter model that utilizes the vehicle in the parking space as a resource for the datacenter. Also, we derive resource allocation strategy based on the expected execution time considering the leave rate of each vehicle in our vehicular datacenter model. Simulation results show that our proposed resource allocation strategies outperform the existing strategy in terms of mean execution time.

• The Journal of the Korea institute of electronic communication sciences
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• v.7 no.1
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• pp.21-26
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• 2012

This paper presents a real-time image transferring and localization system utilizing HSDPA, a commercial wireless network system. A novel image compression algorithm is developed based on MPEG4 to comply with uploading bandwidth of 130 kbps and QVGA image transmission of 30 fps. Aiming at being embedded in moving vehicles, the proposed system has a small size, low power consumption, and robustness to disturbances. We validate the performance of the system by presenting captured images of transferring video and localization data. Our system can be applied to real-time surround monitoring in moving vehicles or real-time ecology observation in remote places.