• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2000.05a
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• pp.195-198
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• 2000

This paper have been analyzed performance of DS-CDMA/QPSK system in short range IVC, and evaluated packet uu rate(PER) in an On-Ray Rician channel model suitable for platoon driving of AVHS that 60GHz millimeter wave is very powerful to MP(multipath-wave). We analyzed probability characteristic of system as variation of Rician factor and user number in One-Ray Rician fading environment and evaluated packet error rate(PER) according to inter-vehicle distance when the BCH channel coding(255,247,1) and diversity schemes is adopted.

• Journal of Auto-vehicle Safety Association
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• v.14 no.4
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• pp.35-42
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• 2022

This paper presents a stochastic model predictive control (SMPC) for stop maneuver of autonomous vehicles considering perception uncertainty of stopped vehicle. The vehicle longitudinal motion should achieve both driving comfortability and safety. The comfortable stop maneuver can be performed by mimicking acceleration profile of human driving pattern. In order to implement human-like stop motion, we propose a reference safe inter-distance and velocity model for the longitudinal control system. The SMPC is used to track the reference model which contains the position uncertainty of preceding vehicle as a chance constraint. We conduct simulation studies of deceleration scenarios against stopped vehicle in urban environment. The test results show that proposed SMPC can execute comfortable stop maneuver and guarantee safety simultaneously.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.68-79
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• 2021

On the Social Internet of Things (SIoT), social activities occur through which the vehicle generates a variety of data, shares them with other vehicles, and sends and receives feedbacks. In order to share reliable information between vehicles, it is important to determine the reliability of a vehicle. In this paper, we propose a vehicle trust evaluation scheme to share reliable information among vehicles. The proposed scheme calculates vehicle trust by considering user reputation and network trust based on inter-vehicle social behaviors. The vehicle may choose to scoring, ignoring, redistributing, etc. in the social activities inter vehicles. Thereby, calculating the user's reputation. To calculate network trust, distance from other vehicles and packet transmission rate are used. Using user reputation and network trust, local trust is calculated. It also prevents redundant distribution of data delivered during social activities. Data from the Road Side Unit (RSU) can be used to overcome local data limitations and global data can be used to calculate a vehicle trust more accurately. It is shown through various performance evaluations that the proposed scheme outperforms the existing schemes.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.10a
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• pp.809-810
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• 2016

In this study, Speed-sensitive vehicle brake using the LED, When the driver presses the brake pedal, range step while being turned in connection taillights brake of the vehicle, such as speed-sensitive vehicle brake using the LED, It is turned on according to the deceleration of the vehicle to be series of points are displayed. The rear vehicle can prevent collision about an abrupt stop of preceding vehicle by perceiving deceleration state of preceding vehicle easier and faster. Also, if the inter-vehicle distance by using an ultrasonic sensor is closer than a certain distance, the emergency light turns on to convey the situation to the driver of the rear vehicle with a buzzer.

• Journal of Communications and Networks
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• v.15 no.2
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• pp.173-178
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• 2013

It is a concern that eco-driving vehicles, because their driving behavior differs from other vehicles due to e.g. e-start, may inhibit smooth traffic flow. Therefore, it is necessary to study the cooperative eco-driving done by a vehicle group, putting "vehicle-to-vehicle communication" and "road-to-vehicle communication" into perspective. Based on these factors, this study aimed to: 1) Analyze fuel consumption rates and driving behaviors of more than one vehicle following an Eco-Driving vehicle. 2) Examine the effect of information on the fuel consumption rate of the preceding vehicles on the following vehicles. As a result, the following findings were obtained: 1) By providing information to multiple following vehicles, the fuel consumption rate of the second vehicle was not lowered, while that of the third one was. 2) It is possible that, when information on fuel consumption of a preceding vehicle is provided to the following one, an inter-vehicular distance is shortened during deceleration to contribute to smooth traffic flow. From the above results, it is suggested that, when targeting a vehicle group, sharing the information on preceding vehicles is effective.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.7
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• pp.878-883
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• 2018

This paper proposes a method for transmitting instruction between vehicles in a moving situation using RC Car having camera. Information of preceding RC Car was transmitted by LED using Optical Camera Communication(OCC). Rear RC Car follows the preceding one by analyzing transmitted OCC data based on image processing. Through this procedure, the information reception ratio according to the distance change of two RC Cars is confirmed. Through experiments, we showed that our proposed scheme enables the possibility of vehicle platooning.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.7C
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• pp.544-553
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• 2012

A vehicle localization technology is an essential component to support many smart-vehicle applications, e.g. collision warning, adaptive cruise control, and so on. In this paper, we present a new vehicle localization algorithm based on the fusion of the sensing estimates from the local sensors and the GPS estimates from the inter-vehicle communications. The proposed algorithm consists of the greedy location data mapping algorithm and the position refinement algorithm. The former maps a sensing estimate with a GPS estimate based on the distance between themselves, and then the latter refines the GPS estimate of the subject vehicle based on the law of large numbers. From the numerical results, we demonstrate that the accuracy of the proposed algorithm outperforms that of the existing GPS estimates by at least 30 % in the longitudinal direction and by at least 60% in the lateral direction.

• The KIPS Transactions:PartC
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• v.14C no.7
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• pp.571-582
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• 2007

Vehicular ad-hoc networks is temporarily established through inter-vehicle communication without any additional infrastructure aids. It requires a immediate message propagation because it mainly deals with critical traffic information such as traffic accidents. The distance-based broadcast scheme is one of the representative broadcast schemes for vehicular ad-hoc network. In this scheme, a node to disseminate messages is selected based on a distance from a source node. However, a message propagation delay will be increased if the relay nodes are not placed at the border of transmission range of the source node. In particular, when the node density is low, the message propagation delay is getting longer. In this paper, we propose a time-window reservation based relay node selection scheme. A node receiving the alert message from the source node has its time-window and randomly selects its waiting time within the given time-window range. A proportional time period of the given time-window is reserved in order to reduce the message propagation delay. The experimental results show that the proposed scheme has shorter message propagation delay than the distance-based broadcast scheme irrespective of node density in VANET. In particular, when the node density is low, the proposed scheme shows about 26% shorter delay and about 46% better performance in terms of compound metric, which is a function of propagation latency and network traffic.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.64-79
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• 2023

This study reviewed the process of applying the Monte Carlo simulation technique to the traffic allocation problem of metropolitan subways. The analysis applied the assumption of a normal distribution in which the travel time information of the inter-station sample is the basis of the probit model. From this, the average and standard deviation are calculated by separating the traffic between stations. A plan was proposed to apply the simulation with the weights of the in-vehicle time of individual links and the walking and dispatch interval of transfer. Long-distance traffic with a low number of samples of 50 or fewer was evaluated as a way to analyze the characteristics of similar traffic. The research results were reviewed in two directions by applying them to the Seoul Metropolitan Subway Network. The travel time between single stations on the Seolleung-Seongsu route was verified by applying random sampling to the in-vehicle time and transfer time. The assumption of a normal distribution was accepted for sample sizes of more than 50 stations according to the inter-station traffic sample of the entire Seoul Metropolitan Subway. For long-distance traffic with samples numbering less than 50, the minimum distance between stations was 122Km. Therefore, it was judged that the sample deviation equality was achieved and the inter-station mean and standard deviation of the transport card data for stations at this distance could be applied.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.53 no.7
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• pp.465-472
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• 2004

Analog CPPN-based optimal road boundary detection algorithm for autonomous vehicle is proposed. The CPPN is a massively connected analog parallel array processor. In the paper, the dynamic programming which is an efficient algorithm to find the optimal path is implemented with the CPPN algorithm. If the image of road-boundary information is utilized as an inter-cell distance, and goals and start lines are positioned at the top and the bottom of the image, respectively, the optimal path finding algorithm can be exploited for optimal road boundary detection. By virtue of the parallel and analog processing of the CPPN and the optimal solution of the dynamic programming, the proposed road boundary detection algorithm is expected to have very high speed and robust processing if it is implemented into circuits. The proposed road boundary algorithm is described and simulation results are reported.