• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.5
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• pp.38-48
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• 2007

In ubiquitous environment, sensor networks that sense and transmit surrounding data without human intervention will become more important. If sensors are installed for detecting vehicles and measuring their speed in the road and that real-time information is given to drivers, it will be very effective for enhancing safety and controlling traffic in the road. In this paper, we proposed a new reliable and real-time sensor MAC protocol between AP and sensor nodes in order to provide real-time traffic flow information based on ubiquitous sensor networks. The proposed MAC allocates one TDMA slot for each sensor node on the IEEE 802.15.4 based channel structure, introduces relayed communication for distant sensors, and adopts a frame structure that supports retransmission for the case of errors. In addition, the proposed MAC synchronizes with AP by using beacon and adopts a hybrid tracking mode that supports economic power consumption according to various traffic situations, We implemented a simulator for the proposed MAC by using sim++ and evaluated various performances. The simulation results show that the proposed MAC reduces the power consumption and reveals excellent performance in real-time application systems.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.3
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• pp.160-174
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• 2023

LiDAR plays a key role in autonomous vehicles, and to improve its visibility, it is necessary to improve its performance and the detection objects. Accordingly, this study proposes a shape for traffic safety signs that is advantageous for self-driving vehicles to recognize. Improvement plans are also proposed using a shape-recognition algorithm based on point cloud data collected through LiDAR sensors. For the experiment, a DBSCAN-based road-sign recognition and classification algorithm, which is commonly used in point cloud research, was developed, and a 32ch LiDAR was used in an actual road environment to conduct recognition performance tests for 5 types of road signs. As a result of the study, it was possible to detect a smaller number of point clouds with a regular triangle or rectangular shape that has vertical asymmetry than a square or circle. The results showed a high classification accuracy of 83% or more. In addition, when the size of the square mark was enlarged by 1.5 times, it was possible to classify it as a square despite an increase in the measurement distance. These results are expected to be used to improve dedicated roads and traffic safety facilities for sensors in the future autonomous driving era and to develop new facilities.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.5
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• pp.607-617
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• 2014

This paper proposed the M&S(Modeling & Simulation) method of channel characterization of satellite communication in the operating area of satellite OTM(On-The-Move) terminal. In M&S, received signal profile was acquired by HTZ warfare software which uses 3 dimensional map including building, road information and geographical features, and then was analyzed statistically. And a received signal profile and its statistics from M&S data were compared with those from measured data. The research showed that the simulated received signal profile matched the measured one about 74.8 percent and simulated statistics matched well as roadside trees were excluded.

• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.225-233
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• 2011

In this paper, we propose a remote control station based on the awareness of various combat field situation in order for operating multiple unmanned ground vehicles. Our remote control station is capable of sending a variety of messages designed for carrying out the skillful movement for collaborate among unmanned ground vehicles, gathering the information related with combat field situation, and completing the assigned missions which are described by operator in advance. To verify the effectiveness of our proposal, we develop the sophisticated remote control station and conduct a great many remote operating tests for multiple unmanned ground vehicles.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5D
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• pp.597-607
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• 2008

ATIS(Advanced Traffic Information System) provide valuable information as the travel time and traffic congestion, detour, traffic accident information to drivers, so it is being in the spotlight. But so far, the study on the consumer satisfaction with providing traffic information is incomplete. So, this study run a Canonical discriminant analysis and a Canonical correlation analysis by a QuantificationIItheory based on a Traffic Information Satisfaction image data through questionnaires, and found out the factors with influence on the consumer satisfaction. And this study definitely found out the correlation between consumer's recognition and traffic information satisfaction through understanding the change on the recognition about traffic information satisfaction by a QuantificationItheory. Finally, this study found out the change on the sensibility recognition of drivers by running the principal component anlysis, developed the traffic information satisfaction evaluation model considering the change on the recognition by using the structural equation model.