• Journal of the Institute of Convergence Signal Processing
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• v.14 no.2
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• pp.77-81
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• 2013

The international standard AIS, which stands for the safety of ship navigation and vessel traffic management, provides 27 messages to exchange the navigational information of ship. Among 27 messages, message ID 6 and 8 are defined as the binary data format to exchange application specific information and are classified into IFM for international use and RFM for national or regional use. Since international standards are based on English, there have been some needs to exchange data in Hangul text for vessel traffic management to correct the static and dynamic ships' information. In this paper, I analyze international standards to provide a Hangul text messaging service based on RFM and propose a RFM message and a simple protocol to correct information of a ship.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.1B
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• pp.1-8
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• 2012

In this paper, we propose an algorithm to improve collision avoidance in Vehicle-to-Vehicle (V2V) networks based on IEEE 802.11p. Since IEEE 802.11p adopts CSMA/CA as a multiple access scheme and an emergency warning message (EWM) is delivered to behind vehicles in a multi-hop manner, due to transmission collision, the more vehicles in the vehicle chain results in a longer delay. The longer delay increases the possibility of a rear-end collision. In order to ensure message reception with low latency, we consider implicit acknowledgement of a broadcasted EWM message and propose an algorithm to reduce redundant message transactions, called Two-Way Implicit Acknowledgement (TWIA). By simulations, we show that our proposed algorithm can reduce the latency until the last car receives the message by 9% and the success rate every car receives the message within 0.7sec by 12% at 100 fixed-number-of-car environment.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.14 no.1
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• pp.22-30
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• 2015

Recently ITS have been increasingly applied on the roads to resolve traffic problems. Especially, Variable Message Sign (VMS), which is the one of ITS for traffic management and traffic safety, can be used for providing information about road conditions, climate conditions. In this study, data acquisition and statistical analysis were conducted for estimating safety impacts of providing traffic information through VMS. As a result of analyzing traffic characteristics before and after providing traffic information through VMS, average travel speed was decreased and vehicles tended to drive on centerline of lanes in 1st and 2nd lane after providing traffic information through VMS. Also, in order to analyze safety impacts of provided VMS traffic information, traffic safety hazard zone was established in each lane and probability distributions of passing traffic on the study area was estimated through Anderson-Darling Test. As a result of this, safety impacts of VMS traffic information in 1st lane could, on average, increase in left and right side of the lane by 0.69% and 7.07%, respectively. In case of 2nd lane, safety impacts could, on average, increase in left and right side of the lane by 2.71% and 0.02%, respectively.

• Proceedings of the Korea Contents Association Conference
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• 2014.06a
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• pp.229-230
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• 2014

• Journal of information and communication convergence engineering
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• v.19 no.1
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• pp.16-21
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• 2021

In this paper, to prevent accidents of school vehicles used by students, which have emerged as a continuous social problem, a boarding and leaving notification system using Bluetooth beacons is proposed. The platform structure uses Bluetooth, a smartphone, and an application, and provides real-time message reception between parents and teachers. It is not simply a system with Bluetooth capability alone, but also an IcT technology that is closely related to real life using two-way communication. The purpose is to provide user-friendly ICT technology as an integrated system for more practical effects. Two-way exchange of information between parents and teachers using cloud servers is made possible. By using this Bluetooth beacon notification system, safety accidents in student vehicles are reduced, which brings confidence from traffic accidents to schoolchildren of parents and teachers. Therefore, it is expected that parents and teachers are expected to improve their mental stability and quality of life from traffic accidents.

• Proceedings of the Korean Information Science Society Conference
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• 1998.10b
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• pp.487-489
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• 1998

원자력 발전소와 같이 환경적으로 큰 재난을 가져 올 수 있는 시스템에서는 전체 시스템을 구축하기 전에 구축하고자 하는 시스템의 안전성을 보장할 수 있는지의 여부와 그러한 시스템의 조작자들의 훈련을 위해 실시간 시뮬레이션이 반드시 필요하다. 본 논문에서는 원자력 발전소의 SIS(Safety Injection System)를 실시간 객체 TMO(Time-triggered Message Triggered Model)를 이용 모델링하는 기법과, 분산 실시간 객체 플랫폼인 WTMOS위에서 구현된 SIS 시뮬레이션 시스템에 대해 기술하였다.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.6
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• pp.127-135
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• 2017

Recently, the most brand new vehicles contain a lot of ECU for comfortable and safety driving environments. For efficient communication network among ECUs, almost car manufactures use CAN protocol which enables to decrease the number of communication lines dramatically and ensures higher data transmission reliability. However, CAN dose not ensure authentication of CAN data frame. So it is vulnerable to replay-attack on CAN data frame. This paper proposes the practical message authentication technique for In-vehicle CAN. To transmit data and MAC together, it is very useful to use the short length of MAC after considering limited space of CAN data frame. However to ensure safety of MAC, additional technique is required. We suggested a message authentication technique that can be usefully applied to build a safety network inside the vehicle because it considers limited data payload of CAN.

• Journal of Advanced Navigation Technology
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• v.23 no.6
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• pp.548-553
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• 2019

Along with advanced vehicle to vehicle (V2V) communication technologies, platooning is regarded as one of the most promising form of autonomous driving solutions in order to increase road capacity. In this paper, we propose a novel V2V transmission scheme for safety message dissemination in platooning. The proposed scheme enhances the efficiency of channel access and multi-vehicle orthogonal frequency division multiple access (OFDMA) transmission by taking advantage of triggered uplink access technique and null data packet feedback report protocol introduced in the sixth generation WLAN standard, IEEE 802.11ax. The simulation results prove that the proposed scheme outperforms the conventional IEEE 802.11 transmission scheme throughout all measured vehicle density range.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.4
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• pp.78-85
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• 2011

In vehicle ad-hoc network (VANET) environments, traffic related information such as accident information, emergency information and real time traffic condition have to be delivered to on-board-unit (OBU) or/and road-side-equipment (RSE) for preventing traffic accidents in advance. In this paper, we introduce a Multi-Channel MAC (MCM) since the existing single channel operation may cause packet transmission delay and unexpected communication failure. To offer a seamless safety message transmission during the various services, it is necessary to manage the MAC scheduler in wireless access in vehicular environments (WAVE) systems. The MCM consists of MAC softwares and MAC hardwares where the former and the later ones are implemented with real time operation system based C language and FPGA module with VHDL language, respectively. The performance and QoS are verified by practical measurements and compared with the scheme using single channel operation.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.16 no.2
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• pp.609-631
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• 2022

The main goal of VANETs is to improve the safety of all road users. Therefore, the accuracy and trustworthiness of messages transmitted in VANETs are essential, given that life may rely on them. VANETs are provided with basic security services through the use of public key infrastructure-based authentication. However, the trust of users is still an open issue in VANETs. It is important to prevent bogus message attacks from internal vehicles as well as protect vehicle privacy. In this paper, we propose a trust management scheme that ensures trust in VANETs while maintaining vehicle privacy. The trust scheme establishes trust between vehicles where a trust value is assigned to every vehicle based on its behavior and messages are accepted only from vehicles whose trust value is greater than a threshold, therefore, protecting VANETs from malicious vehicles and eliminating bogus messages. If a traffic event happens, vehicles upload event messages to the reachable roadside unit (RSU). Once the RSU has confirmed that the event happened, it announces the event to vehicles in its vicinity and records it into the blockchain. Using this mechanism, RSUs are prevented from sending fake or unverified event notifications. Simulations are carried out in the context of bogus message attacks to evaluate the trust scheme's reliability and efficiency. The results of the simulation indicate that the proposed scheme outperforms the compared schemes and is highly resistant to bogus message attacks.