• Title/Summary/Keyword: GPS 프로브

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Integration and Decision Algorithm for Location-Based Road Hazardous Data Collected by Probe Vehicles (프로브 수집 위치기반 도로위험정보 통합 및 판단 알고리즘)

  • Chae, Chandle;Sim, HyeonJeong;Lee, Jonghoon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.17 no.6
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    • pp.173-184
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    • 2018
  • As the portable traffic information collection system using probe vehicles spreads, it is becoming possible to collect road hazard information such as portholes, falling objects, and road surface freezing using in-vehicle sensors in addition to existing traffic information. In this study, we developed a integration and decision algorithm that integrates time and space in real time when multiple probe vehicles detect events such as road hazard information based on GPS coordinates. The core function of the algorithm is to determine whether the road hazard information generated at a specific point is the same point from the result of detecting multiple GPS probes with different GPS coordinates, Generating the data, (3) continuously determining whether the generated event data is valid, and (4) ending the event when the road hazard situation ends. For this purpose, the road risk information collected by the probe vehicle was processed in real time to achieve the conditional probability, and the validity of the event was verified by continuously updating the road risk information collected by the probe vehicle. It is considered that the developed hybrid processing algorithm can be applied to probe-based traffic information collection and event information processing such as C-ITS and autonomous driving car in the future.

A Time Series-based Algorithm for Eliminating Outliers of GPS Probe Data (시계열기반의 GPS 프로브 자료의 이상치 제거 알고리즘 개발)

  • Choi, Kee-Choo;Jang, Jeong-A
    • Journal of Korean Society of Transportation
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    • v.22 no.6
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    • pp.67-77
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    • 2004
  • A treatment of outlier has been discussed. Outliers disrupt the reliability of information systems and they should be eliminated prior to the information and/or data fusion. A time series-based elimination algorithm were proposed and prediction interval, as a criterion of acceptable value width, was obtained with the model. Ten actual link values were used and the best model was identified as IMA(1,1). Although the actual verification was difficult in a sense that the matching process between the eliminated data and model data was not readily available, the proposed model can be successfully used in practice with some calibration efforts.

Bandwidth Broadening for the GPS Microstrip Patch Antenna (GPS용 마이크로스트립 패치안테나의 광대역화)

  • Son, Taeho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.14 no.4
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    • pp.73-79
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    • 2015
  • Enhanced bandwidths of the GPS microstrip patch antennas applied by a Wilkinson power divider and a quadrature hybrid were compared. The square patch was designed, and fed by the two port probes for the circuit application. The Wilkinson power divider and quadrature hybrid circuit were designed, and applied to the patch antenna. The designed patch and two circuits were implemented on the FR4 board, and combined together. The measurement of the bandwidth within a voltage standing wave ratio (VSWR) of 2: 1 were 36.5% (1,200~1,775 MHz) in the case of the Wilkinson power divider and 29.84% (1,230~1,700 MHz) in the case of the quadrature hybrid. Axial ratios (AR) in 3dB were 17.14% bandwidth (1,360~1,630 MHz) and 15.87% bandwidth (1,400~1,650 MHz), respectively. The application of the Wilkinson power divider is wider than that of the quadrature hybrid. The peak gains in the anechoic chamber at the GPS center frequency were measured as 2.84 dBi and 2.75 dBi, respectively.

A Study on the Standard Link-based Travel Speed Calculation System Using GPS Tracking Information (GPS 운행궤적정보를 이용한 표준링크기반 통행속도 산출 시스템 연구)

  • Song, Gil jong;Hwang, Jae Seon;Lim, Jae Jung;Jung, Eui Yong
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.18 no.5
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    • pp.142-155
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    • 2019
  • This study was conducted with the aim of developing a system to collect taxi GPS probe information to prevent link defects and to improve the accuracy of the standard link-based travel speed by determining when to go into and come out the link. For this purpose, a framework and algorithm consisting of a five-step process for standard link-based map matching and individual vehicle travel speed are presented and used it to calculate the average travel speed of the service link. Two on-site surveys of Teheran and Hakdong-ro were conducted to verify the results by the methods proposed in this paper. On the basis of the overall time of the field survey, the deviation in the travel speed was 0.2 km/h and 0.6 km/h, the accuracy was 99% and 96%, and the MAPE(Mean Absolute Percentage Error) was 1% and 4% in Teheran and Hakdong-ro, respectively. These results were more accurate thand those obtained using conventional methodologies without standard links.

Methodology for Evaluating Cycling Environment using GPS-based Probe Bicycle Speed Data (GPS프로브 자전거 주행속도를 이용한 자전거 주행환경 평가방법론)

  • Hong, Du-Ho;Kil, Eun-Ji;Kim, Su-Jin;Joo, Shin-Hye;Oh, Cheol
    • International Journal of Highway Engineering
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    • v.14 no.2
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    • pp.73-81
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    • 2012
  • The bicycle is an environment-friendly transport mode leading to a more sustainable transportation system. To innovatively increase the use of bicycle as a significant transport mode, bicycling-friendly roadway environment should be provided. From this perspective, the scientific and effective assessment of roadway environment in term of the bicyclist perception for safety and comfortability is of keen interest. This study develops a methodology for evaluation cycling environment using probe bicycles. A global positioning system(GPS) based speedometer was used to collect bicycle speed data. Cycling comfortability index(CCI) was derived for the purpose of evaluating cycling environment. The proposed CCI can be effectively used as an assessment tool in the field of bicycle transportation.

Analysis on Accuracy of GPS installed in Digital Tachograph of Commercial vehicles (사업용 차량의 프로브 활용 가능성 평가를 위한 디지털운행기록계 위치정보 정확도 분석)

  • Sim, HyeonJeong;Chae, Chandle;Kang, Minju;Lee, Jonghoon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.18 no.6
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    • pp.164-175
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    • 2019
  • Installation of digital tachograph, black box, and ADAS have been enforced to commercial vehicles for preventing violent driving and accidents by the Traffic Safety Act in Korea. Nevertheless, the damage caused by road hazards has increased 1.5 times in 2016 compared to 2013. So, developing new technologies that can identify road hazard using the sensors installed in commercial vehicles are conducting by the Ministry of Land, Infrastructure and Transport. As a part of the technologies, this research analyze the error range of GPS installed in commercial vehicles that vary according to the driving speed. As a result, the average error was 9.72m at the driving speed of 100km/h, and the error was 2.1 times larger than the average error of 4.69m at the driving speed of 40km/h. The event point proper integration/separation range(m) was analyzed to be 20m with a recognition rate of 90% or more at the same point regardless of driving speed. The results of this research can be used as basic data for improving the accuracy of location-based data would be collected using commercial vehicles.

Extraction of Hazardous Freeway Sections Using GPS-Based Probe Vehicle Speed Data (GPS 프로브 차량 속도자료를 이용한 고속도로 사고 위험구간 추출기법)

  • Park, Jae-Hong;Oh, Cheol;Kim, Tae-Hyung;Joo, Shin-Hye
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.3
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    • pp.73-84
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    • 2010
  • This study presents a novel method to identify hazardous segments of freeway using global positioning system(GPS) based probe vehicle data. A variety of candidate contributing factors leading to higher potential of accident occurrence were extracted from the probe vehicle dataset. The research problem was defined as a classification problem, then a well-known classifier, bayesian neural network was adopted to solve the problem. A binary logistic regression technique was also used for selecting salient input variables. Test results showed that the proposed method is promising in extracting hazardous freeway sections. The outcome of this study will be effectively used for evaluating the safety of freeway sections and deriving countermeasures to prevent accidents.

Design of Broadband Microstrip patch Antenna for the GPS (GPS용 광대역 마이크로스트립 패치안테나 설계)

  • Shin, Kyung Hwan;Lee, Yong Chang;Son, Taeho
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.17 no.5
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    • pp.128-134
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    • 2018
  • In this paper, two ports feeding a microstrip patch antenna using a quadrature hybrid circuit was proposed to enhance the bandwidth for the global positioning system(GPS). The square patch was designed, and the probe feeding was applied. The quadrature hybrid chip circuit for two-port feeding was designed, and output ports that have a 90-degree phase difference feed to the patch antenna. The designed patch and quadrature hybrid circuit were implemented on an FR4 board, and were combined. The measurement of the bandwidth within a voltage standing wave ratio(VSWR) of 2:1 and axial ratio(AR) in 3dB were wide band as 29% BW (1,230~1,700 MHz) and 15.87% BW (1,400~1,650 MHz), respectively. Antenna gain were measured 2.75dBi at the center frequency.

Methodology for Processing GPS-based Bicycle Speed Data for Monitoring Bicycle Traffic (자전거 모니터링을 위한 자료처리 프로세스 개발 및 응용 - GPS기반 자전거 속도자료를 중심으로)

  • Rim, Heesub;Joo, Shinhye;Oh, Cheol
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.13 no.3
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    • pp.10-24
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    • 2014
  • Bicycle is a useful transportation mode that is healthy, emission-free, and environmentally compatible. Although large efforts have been made to promote the use of bicycling to date, there still exist various hurdles and limitations. One of the key issues to increase bicycling is how to gather bicycle-related data from the field and to generate valuable information for both users and operations agencies. This study proposes a method to process bicycle trajectory data which is obtained from tracing global positioning systems(GPS) equipped bicycle, which is defined as the probe bicycle. The proposed method is based on the concept of statistical quality control of data. In addition, a data collection and processing scenario in support of public bicycle system is presented. The outcomes of this study would be valuable fundamentals for developing bicycle traffic information systems that is a part of future intelligent transportation systems(ITS).