• 한국경영과학회지
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• 제28권2호
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• pp.139-155
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• 2003

The aim of this study is to identify the data traffic capacity of 3G mobile communication networks, especially of cdma2000-1X networks. Three-layered ON/OFF traffic model is used to describe the dynamics of data traffics and the process of data transmission such as packet scheduling. We construct a simulator fully incorporating packet handling process of cdma2000-lX data network as well as three-layered ON/OFF traffic model describing the behavior of source data traffics. To get influence of traffic parameters on performance measures, the extensive simulations were performed for several data sets which are obtained from real trace data or previous studies. The experimental results show that the engineered throughput satisfying QoS criteria is approximately 25% of total capacity. Finally, some proposals to improve the system capacity are followed.

• 정보통신설비학회논문지
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• 제1권1호
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• pp.51-64
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• 2002

This paper analyzes performance measures of a Bluetooth_based mobile home network system. The home network system consists of terminals with Bluetooth interfaces, access points (AP), a home PC, and a gateway A mobile host in wireless terminals uses Mobile IP for supporting the mobility This paper considers four types of data traffic, which are new connection traffic, handoff traffic, Internet data traffic, and control data traffic and suggests a queueing system model of the home network system, where the AP and the home PC are modeled as M/G/1 with four priority queues and the gateway is modeled as M/G/1 with a single queue The generation rate and service time of individual traffic influence their performance measures. Based ell the suggested model, we propose the elapsed time of data traffic in terms of the number of cells, the number of Home PCs, arrival rates of four types of traffic and the service rates of AP/Home PCs/Gateway To analyze influences on the elapsed time with respect to arrival rate of four types of traffic, some examples are given.

• 한국공간정보시스템학회 논문지
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• 제10권4호
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• pp.89-95
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• 2008

본 논문에서는 교통데이터 웨어 하우스에서 데이터 품질 관리를 위한 통합기법을 제안한다. 고속도로 교통관리시스템(FTMS)과 우회도로 교통정보시스템(ARTIS) 으로부터 대용량 교통데이터를 수집하여 데이터 웨어하우스를 구축하기 위한 방안을 기술하고, 다양한 분석을 위한 고품질 교통데이터를 제공하기 위한 통합 데이터 품질관리 기법을 제안하고 구현 평가한다. 제안된 통합 데이터 품질관리 기법을 활용하면 연구자들에게 검증된 고품질 교통데이터를 제공할 수 있고, 데이터처리와 평가를 위한 별도의 비용을 절감할 수 있을 것으로 기대된다.

• 한국ITS학회 논문지
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• 제17권6호
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• pp.144-152
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• 2018

본 연구는 기존 교통정보 수집체계의 한계를 보완하기 위한 수단으로써 드론을 사용하였을 경우 교통량, 속도, 밀도 등의 정보를 단시간에 경제적으로 수집 가능하다는 점에 착안하였으며, 이를 위해 드론을 실제 교통현장 촬영영상 분석을 통해 추출된 핵심 교통정보의 타당성 검증과 더불어 다양한 정보수집시나리오 분석을 통해 최적의 교통정보 추출 방법론을 제시하고자 하였다. 본 연구 수행결과, 드론은 단시간에 경제적인 교통정보수집이 가능한 유용한 정보수집 보완수단임은 물론, 매우 간단하고 직관적인 방법으로 연속류 구간의 서비스수준 판정을 가능하게 해 주는 강점이 있는 것으로 확인되었다.

• Ocean Systems Engineering
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• 제12권3호
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• pp.267-284
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• 2022

A subsea pipeline designed across active shipping lane prones to failure against external interferences such as anchorage activities, hence risk assessment is essential. It requires quantifying the geometric probability derived from ship traffic distribution based on Automatic Identification System (AIS) data. The actual probability density function from historical vessel traffic data is ideal, as for rapid assessment, conceptual study, when the AIS data is scarce or when the local vessels traffic are not utilised with AIS. Recommended practices suggest the probability distribution is assumed as a single peak Gaussian. This study compares several fitted Gaussian distributions and Monte Carlo simulation based on actual ship traffic data in main ship direction in an active shipping lane across a subsea pipeline. The results shows that a Gaussian distribution with five peaks is required to represent the ship traffic data, providing an error of 0.23%, while a single peak Gaussian distribution and the Monte Carlo simulation with one hundred million realisation provide an error of 1.32% and 0.79% respectively. Thus, it can be concluded that the multi-peak Gaussian distribution can represent the actual ship traffic distribution in the main direction, but it is less representative for ship traffic distribution in other direction. The geometric probability is utilised in a quantitative risk assessment (QRA) for subsea pipeline against vessel anchor dropping and dragging and vessel sinking.

• 자동차안전학회지
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• 제14권2호
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• pp.45-50
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• 2022

The vehicle motion in urban environment is determined by surrounding traffic flow, which cause understanding the flow to be a factor that dominantly affects the motion planning of the vehicle. The traffic flow in this urban environment is accessed using various urban infrastructure information. This paper represents a color recognition algorithm for traffic lights to perceive traffic condition which is a main information among various urban infrastructure information. Deep learning based vision open source realizes positions of traffic lights around the host vehicle. The data are processed to input data based on whether it exists on the route of ego vehicle. The colors of traffic lights are estimated through pixel values from the camera image. The proposed algorithm is validated in intersection situations with traffic lights on the test track. The results show that the proposed algorithm guarantees precise recognition on traffic lights associated with the ego vehicle path in urban intersection scenarios.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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• pp.262-265
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• 2008

We design level 1 traffic thematic map for common data structure. Level 1 means the road that can passing cars. If public office and private company use this form, they can save amount of money from overlapping update. And widely use of traffic analysis, navigation and traffic information system. For design common data structure we compared several data structure(traffic thematic map, ITS standard node/link, Car navigation map), and generalization these characteristic data. After generalization we considered about application parts. It can use of public part(traffic analysis, road management, accident management) and private part(car navigation, map product, marketing by variable analysis) etc.

• 한국전자통신학회논문지
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• 제9권12호
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• pp.1373-1380
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• 2014

교통정보서비스에서 정확한 통행량과 통행속도를 산출하기 위해서는 기본적으로 제공되는 GPS 데이터의 품질이 보장되어야 한다. 그렇지만, 통신비용의 문제로 인하여 GPS 데이터를 제공하는 Probe 차량으로부터 제한된 GPS 데이터가 제공이 된다면 정확한 정보를 제공하기 어렵다. 본 논문에서는 제한된 GPS 데이터로 인하여 손실되는 링크들을 위상정보와 결합시켜 복원시킨 후, 통행 속도를 산출하는 알고리즘을 개발하였다. 이를 적용한 S시의 T 교통정보서비스는 이전보다 더 정확한 통행량 및 통행 속도를 시민들에게 제공할 수 있게 되었다.

• 한국자동차공학회논문집
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• 제25권3호
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• pp.317-325
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• 2017

The EDR(Event Data Recorder) is a part of the ACU(Airbag Control Unit) functions mounted on a vehicle. EDR data have pre-crash data and post-crash data. Pre-crash data are recorded within 5 sec from time zero(AE) with 0.5 sec resolution, and reveal vehicle speed, engine rotation speed, throttle opening, brake pedal operation, acceleration pedal position and steering angle, etc. Using this EDR data, the investigation of a traffic accident can become more objective and scientific. Crash tests of three vehicles equipped with EDR function had been performed successfully. Evaluation of EDR data reliability had also been performed using Vbox and PC-Crash's sequence table function. Based on the results, we could confirm EDR data's reliability and availability for Traffic Accident Analysis by the series of this process.

• 한국ITS학회 논문지
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• 제17권3호
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• pp.87-97
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• 2018

교통사고 관련 제보는 비정형 데이터로서 교통사고를 유발한 가해자나 피해자의 관점이 아닌, 교통사고 발생 지점과 구간, 시간대에 있었던 타 운전자의 관점에서 생성된 교통정보의 가치를 가지고 있다. 그러나, 비정형 데이터인 교통제보가 빅 데이터로서 교통사고 통계나 교통관련 연구에 활용되지 못하였으나, 텍스트 마이닝 기법을 활용한 본 연구를 통해 비정형의 빅 데이터를 시각화하고 해석하여, 기존의 정형 데이터에서 분석하지 못한 정보를 도출할 수 있었다. 그리고 교통사고 발생으로 인한 도로상 영향을 파악할 수 있었다. 이러한 분석으로 교통제보의 트랜드를 파악하고, 운전자가 제보하는 "도로명", "지점명", "시간대"를 추출하였으며, 교통사고 발생으로 다른 운전자에게 가장 많은 영향을 미치는 지점과 구간의 파악이 가능하였다. 향후 실제 교통사고 데이터와 결합하여 교통제보와의 상관성 분석 등을 통해 비정형 데이터의 활용방안을 모색할 계획이다.