• 한국정보통신설비학회:학술대회논문집
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• 2007.08a
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• pp.50-54
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• 2007

현재 국내에서 ITS(Intelligent Transport Systems) 통신방식으로 이 용되고 있는 DSRC 방식은 TTA(한국정보통신기술협회)의 기술표준으로서 대전시,전주시에 적용되어 BIS(Bus Information Service)에 이용되고 있고,최근 고속도로 ETCS(Electronic Toll Collection System)가 DSRC방식으로 전국고속도로 Tollgate 에서 2007년 연말에 개통될 예정이다. DSRC 방식은 2000년에 TTA(한국정보통신기술협회)에서 기술표준이 제정되어 현재 1Mbps 의 Data 용량을 가진다. DSRC 방식의 물리링크 변조방식은 ASK(Amplitude Shift Keying)로 ITS 확장 서비스 적용을 위해 변조방식을 QPSK(Quadrature Phase Shift Keying )로 개선하게 되면 이론적으로 4배의 Data Rate 향상이 이루어진다. 물리적인 RF 변조방식을 ASK에서 QPSK로 바꿔 간단히 Data Rate을 개선하게 되면 회로구현의 경제성이 향상되어 DSRC 응용 서비스가 활성화 될 것이다.

• Journal of Korea Multimedia Society
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• v.20 no.9
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• pp.1519-1526
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• 2017

The existing DSRC(Dedicated Short Range Communication) scheme has a limitation in providing various services through short-range wireless communication. Therefore, it is necessary to develop an intelligent WAVE/DSRC hybrid wireless platform that can improve data transmission speed and extend the effective communication range. This paper introduces WAVE/DSRC integrated platform technology using WAVE(Wireless Access in Vehicle Environments) to overcome the disadvantages of DSRC. First, the desinged software configuration of the WAVE/DSRC integrated platform is described. Then each task operation scheme and WAVE software design are described. By applying the WAVE/DSRC integrated platform, we can compensate the shortcomings of DSRC. It can provide more accurate and reliable services.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.6
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• pp.29-41
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• 2017

In this study, we used individual trip data to estimate a macroscopic fundamental diagram (MFD) that relates flow (or production) to density (or state) in Daegu metropolitan city. The individual trip data were generated by processing data that were collected from DSRC-based (dedicated short range communication) traffic data collection system. Using the processed individual trip data, we first examined whether the assumptions for MFD are valid, and then the relation between outflow and accumulation was estimated in our study site. As a result, we found that i) the assumptions are valid to construct MFD; and ii) the reproducible and well-defined MFDs exist in the network level.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.1 s.4
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• pp.109-116
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• 2004

The signal in wireless multi-path channel is affected by fading and ISI because of high data rate transmission, so the signal has the high error rate. The present modulation and demodulation method of DSRC system can not expect sufficient for providing data service over 1 Mbps, so the channel equalization and advanced modulation and demodulation methods are required. OFDM method is generally Inon as an effective technique for high data rate transmission system, since it can prevent ISI by inserting a guard interval. However, a guard interval longer than channel delay spread has to be used in each OFDM symbol period, thus resulting a considerable loss in the efficiency of channel utilization. Therefore the equalizer is necessary to cancel ISI to accommodate advanced ISI service with higher bit rate and longer channel delay spread condition. In this thesis, the channel equalizer for the OFDM-DSRC system was designed and its performance in a multi-path fading environment was evaluated with computer simulation. As a result, the performance of Pseudo LMMSE equalizer for the OFDM-DSRC has been improved comparing with LS equalizer at higher bit rate transmission system.

• International Journal of Highway Engineering
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• v.16 no.4
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• pp.127-134
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• 2014

PURPOSES : To operate more efficient traffic management system, it is utmost important to detect the change in congestion level on a freeway segment rapidly and reliably. This study aims to develop classification method of congestion change type. METHODS: This research proposes two classification methods to capture the change of the congestion level on freeway segments using the dedicated short range communication (DSRC) data and the vehicle detection system (VDS) data. For developing the classification methods, the decision tree models were employed in which the independent variable is the change in congestion level and the covariates are the DSRC and VDS data collected from the freeway segments in Korea. RESULTS : The comparison results show that the decision tree model with DSRC data are better than the decision tree model with VDS data. Specifically, the decision tree model using DSRC data with better fits show approximately 95% accuracies. CONCLUSIONS : It is expected that the congestion change type classified using the decision tree models could play an important role in future freeway traffic management strategy.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.2 no.1 s.2
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• pp.93-100
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• 2003

In this farer, An ADSRC(Advanced Dedicated Short Range Communication) packet communication system developed by ETRI is introduced. The ADSRC system has been developed to provide high-speed, short-range wireless racket communication in roadside environment for mobile office services. The requirements of the ADSRC system for mobile office services and the system design specification to meet them with regard to mobile of nce environment are discussed. The ADSRC packet communication systems consist of the MAC(Medium Access Control) Processor block the OFDM() modem block and the RF block. The MAC processor block handles medium access control. The OFDM modem transmits data packets at up to 24Mbps adaptively and recovers the data from RF block. The ADSRC packet communication system architecture is described.

• Journal of the Korea Society for Simulation
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• v.9 no.2
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• pp.103-118
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• 2000

ITS(Intelligent Transportation System) is an advanced system which can effectively handle the current transportation problems. DSRC(Dedicated Short Range Communication) is considered as a promising technology since it has the capability of two-way communication and can serves to implement various ITS services. In this paper, we study DSRC based ITS telecommunication traffic analysis and suggest an architecture and network design of telecommunication network for DSRC services. We also perform a simulation study to validate the proposed network architecture and design for Metropolitan Seoul Area with various network alternatives. In this simulation, we use actual traffic data and road characteristics from Seoul area and use our DSRC service configuration.

• Journal of Navigation and Port Research
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• v.29 no.1 s.97
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• pp.23-28
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• 2005

The signal in wireless multi-path channel is affected by fading and ISI because of high data rate transmission, so the signal has the high error rate. The present modulation and demodulation method of DSRC system can not expect sufficient for providing data service over 1 Mbps, so the channel equalization and advanced modulation and demodulation methods are required. OFDM is generally known as an effective technique for high data rate transmission system, since it can prevent ISI by inserting a guard interval. However, a guard interval longer than channel delay spread has to be used in each OFDM symbol period, thus resulting a considerable loss in the efficiency of channel utilization Therefore the equalizer is necessary to cancel ISI to accommodate advanced ITS service with higher bit rate and longer channel delay spread condition In this paper, the channel equalizer for the OFDM -DSRC system was designed and its performance in a multi-path fading environment was evaluated with computer simulation.

• Proceedings of the IEEK Conference
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• 2002.06a
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• pp.187-190
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• 2002

In this paper, we deal with performance improvement of OBE for automatic gate clearance system by using DSRC network of 5.8GHz ISM band. A data format is improved to represent Rx and Tx information which is need to perform clearance at the gate of container terminal. An error message caused by data discordance is added to Previous data format. A graphic LCD monitor is used to control a character font and use Korean.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.6
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• pp.1873-1879
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• 2014

There are various methodologies to forecast the travel time using real-time data but the K-nearest neighborhood (KNN) method in general is regarded as the most one in forecasting when there are enough historical data. The objective of this study is to evaluate applicability of KNN method. In this study, real-time and historical data of toll collection system (TCS) traffic flow and the dedicated short range communication (DSRC) link travel time, and the historical path travel time data are used as input data for KNN approach. The proposed method investigates the path travel time which is the nearest to TCS traffic flow and DSRC link travel time from real-time and historical data, then it calculates the predicted path travel time using weight average method. The results show that accuracy increased when weighted value of DSRC link travel time increases. Moreover the trend of forecasted and real travel times are similar. In addition, the error in forecasted travel time could be further reduced when more historical data could be available in the future database.