• Proceedings of the Korea Information Processing Society Conference
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• 2002.04b
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• pp.1435-1438
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• 2002

미래의 산업으로 부각되고 있는 지능형교통시스템(ITS: Intelligent Transport Systems)은 실시간 데이터의 원활한 전송을 위하여 차량과 노변장치 간의 고속 무선통신 방식인 단거리전용통신(DSRC) 방식을 적용하고 있다. 그러나, DSRC 방식은 실시간 환경에 적합한 축약된 3계층(물리, 데이터링크, 응용계층) 구조로 이뤄져 있으며, 통신영역간에 로밍이나 핸드오프 기능이 결여되어 있어 일반적인 데이터서비스를 제공하기에는 여러 가지 문제점을 안고 있다. 이에, 본 연구에서는 이러한 문제점을 분석하고, DSRC 상에서 효율적인 데이터서비스를 제공할 수 있는 이동에이전트 아키텍처를 제안하였다.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.323-326
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• 2013

최근 지능형 교통 시스템 (ITS) 에 대한 관심이 증가함에 따라 ITS 응용을 지원해 줄 수 있는 차량 에드혹 네트워크 (VANET, Vehicular Ad-Hoc Network) 기술이 주요 이슈로 대두되고 있다. 특히 트랜스포트 계층에서는 종단간 신뢰성이 요구되는 ITS 응용들을 지원하기 위해 TCP를 적용할 필요가 있다. 하지만 VANET 환경에서 TCP는 혼잡 제어 기능의 오동작, 이동성에 의한 경로 재설정 오버헤드, 경쟁(contention) 등으로 인해 throughput을 불필요하게 감소시킬 수 있다. 따라서 VANET 환경에서 TCP 성능을 향상시킬 수 있는 다양한 기법들에 대한 연구가 진행되고 있다. 본 논문에서는 이러한 기법들을 크게 혼잡 탐색 기법, cross-layer 기법으로 나누어 대표적인 두 가지 기법들을 각각 비교, 분석한다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.21 no.3
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• pp.18-29
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• 2022

Recently, cooperative intelligent transport systems (C-ITS) testbeds have been deployed in great numbers, and advanced autonomous driving research using V2X communication technology has been conducted actively worldwide. In particular, the broadcasting services in their beginning days, giving warning messages, basic safety messages, traffic information, etc., gradually developed into advanced network services, such as platooning, remote driving, and sensor sharing, that need to perform real-time. In addition, technologies improving these advanced network services' throughput and latency are being developed on many fronts to support these services. Notably, this research analyzed the network latency requirements of the advanced network services to develop a remote driving service for the droid type low-speed robot based on the 3GPP C-V2X communication technology. Subsequently, this remote driving service's performance was evaluated using system modeling (that included the operator behavior) and simulation. This evaluation showed that a respective core and access network latency of less than 30 ms was required to meet more than 90 % of the remote driving service's performance requirements under the given test conditions.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.2
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• pp.93-104
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• 2023

Currently, the permanent road traffic volume surveys under Road Act are conducted using a intrusive Automatic Vehicle Classification (AVC) equipments to classify 12 categories of vehicles. However, intrusive AVC equipment inevitably have friction with vehicles, and physical damage to sensors due to cracks in roads, plastic deformation, and road construction decreases the operation rate. As a result, accuracy and reliability in actual operation are deteriorated, and maintenance costs are also increasing. With the recent development of ITS technology, research to replace the intrusive AVC equipment is being conducted. However multiple equipments or self-built DB operations were required to classify 12 categories of vehicles. Therefore, this study attempted to prepare a method for classifying 12 categories of vehicles using vehicle specification information of the Vehicle Management Information System(VMIS), which is collected and managed in accordance with Motor Vehicle Management Act. In the future, it is expected to be used to upgrade and diversify road traffic statistics using vehicle specifications such as the introduction of a road traffic survey system using Automatic Number Plate Recognition(ANPR) and classification of eco-friendly vehicles.

• Journal of Internet Computing and Services
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• v.17 no.6
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• pp.81-91
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• 2016

VANET is one of the most developed technologies many people have considered a technology for the next generation. It basically utilizes the wireless technology and it can be used for measuring the speed of the vehicle, the location and even traffic control. With sharing those information, VANET can offer Cooperative ITS which can make a solution for a variety of traffic issues. In this way, safety for drivers, efficiency and mobility can be increased with VANET but data between vehicles or between vehicle and infrastructure are included with private information. Therefore alternatives are necessary to secure privacy. If there is no alternative for privacy, it can not only cause some problems about identification information but also it allows attackers to get location tracking and makes a target. Besides, people's lives or property can be dangerous because of sending wrong information or forgery. In addition to this, it is possible to be information stealing by attacker's impersonation or private information exposure through eavesdropping in communication environment. Therefore, in this paper we propose Privacy Assurance Architecture for VANET to ensure privacy from these threats.

• Transactions of the Korean Society of Automotive Engineers
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• v.22 no.7
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• pp.40-47
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• 2014

This paper proposes a matching method of GIS lane information with a vehicle position using camera image to reduce DGPS error. Images of straight road are taken using a camera that is installed on the front center of the vehicle, and the distance between the vehicle and the lane are estimated using the images. The current GIS lane data is matched by comparing the estimated distance and the measured distance using a DGPS. Inverse perspective mapping is used to minimize the error of image processing from the heading angle, and single buffering method is applied to decide the exact moment of GIS match. Through practical test on the highway, feasibility of the GIS matching using camera image is confirmed.

• Journal of the Korean Institute of Intelligent Systems
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• v.23 no.1
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• pp.35-45
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• 2013

A autonomous vehicle requires improved and robust perception systems than conventional perception systems of intelligent vehicles. In particular, single sensor based perception systems have been widely studied by using cameras and laser radar sensors which are the most representative sensors for perception by providing object information such as distance information and object features. The distance information of the laser radar sensor is used for road environment perception of road structures, vehicles, and pedestrians. The image information of the camera is used for visual recognition such as lanes, crosswalks, and traffic signs. However, single sensor based perception systems suffer from false positives and true negatives which are caused by sensor limitations and road environments. Accordingly, information fusion systems are essentially required to ensure the robustness and stability of perception systems in harsh environments. This paper describes a perception system for autonomous vehicles, which performs information fusion to recognize road environments. Particularly, vision and laser radar sensors are fused together to detect lanes, crosswalks, and obstacles. The proposed perception system was validated on various roads and environmental conditions with an autonomous vehicle.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.10 no.4
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• pp.86-92
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• 2011

ITS(Intelligent Transport System) has been researched actively to guarantee the smooth traffic and the safety of the vehicle. In recent, as the sensor for the measurement of distance between vehicles, the FMCW radar system in millimeter wave band has been interested in ITS. Actually, 47, 60, 77, 94 and 139 GHz have been assigned for the vehicle radar frequencies in Europe and Japan. However, the performances of the FMCW radar are deteriorated due to the interferences from the surrounding radars and mobile devices. In this paper, in order to model and simulate the performance of FMCW radar under the exterior interference, we propose a new performance parameter, RER(Radius Error Rate), which contains the information of the range error due to the interferences, and show the effectiveness of the proposed parameter.

• Journal of Korean Society of Transportation
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• v.27 no.5
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• pp.113-124
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• 2009

This paper suggests a new approach for providing information for driver safety at signalized intersections. Particularly dangerous situations at signalized intersections such as red-light violations, accelerating through yellow intervals, red-light running, and stopping abruptly due to the dilemma zone problem are considered in this study. This paper presents the development of a dangerous vehicle determination algorithm by collecting real-time vehicle speeds and times from multiple point detectors when the vehicles are traveling during phase-change. For an evaluation of this algorithm, VISSIM is used to perform a real-time multiple detection situation by changing the input data such as various inflow-volume, design speed change, driver perception, and response time. As a result the correct-classification rate is approximately 98.5% and the prediction rate of the algorithm is approximately 88.5%. This paper shows the sensitivity results by changing the input data. This result showed that the new approach can be used to improve safety for signalized intersections.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.5
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• pp.160-166
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• 2018

This paper proposes an advanced suspension system and reports its performance in the framework of the preview control algorithm based on the RPS (road profile sensing) system and MSD system with the multi-stage damping characteristics. Typical disturbance inputs that cause excessive vibration and steering instability of an automobile are irregular obstacles that protrude or sink into the road surface to be driven. The control performance can be improved if information on the existence and shape function of its obstacle is known. Based on the results of the previous study, advanced research that uses the actuating system has been processed to be commercialized practically. For this purpose, a switching algorithm between the control logic and the multi-stage damping system was developed and its connectivity is presented. To verify the applicability of an actual vehicle, the proposed control system was implemented in full vehicle models and simulations were performed. The proposed system using the 3-DS actuator system, which is applied for structural simplicity, can improve the ride comfort and steering stability. In addition, the results indicate the feasibility of the intelligently controlled suspension system.