• Title/Summary/Keyword: Intelligent transportation systems

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Study on the Operational Effect of Real-time Traffic Signal Control Using the Data from Smart Instersections (스마트교차로 데이터를 활용한 실시간 교통신호제어 운영 효과 분석)

  • Sangwook Lee;Bobae Jeon;Seok Jin Oh;Ilsoo Yun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.22 no.4
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    • pp.48-62
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    • 2023
  • Recently, smart intersections have been installed in many intelligent transportation system projects, but few cases use them for traffic signal operations besides traffic volume collection and statistical analysis. In order to respond to chronic traffic congestion, it is necessary to implement efficient signal operations using data collected from smart intersections. Therefore, this study establishes a procedure for operating a real-time traffic signal control algorithm using smart intersection data for efficient traffic signal operations and improving the existing algorithm. Effect analysis confirmed that intersection delays are reduced and the section speed improves when the offset is adjusted.

A Vehicle-to-Vehicle Communication Protocol Scheme for Forwarding Emergency Information in Intelligent Cars Transportation Systems (지능형 차량 전송시스템에서 긴급정보 전송을 위한 Vehicle-to-Vehicle 통신 프로토콜)

  • Kim, Kyung-Jun;Cha, Byung-Rae;Kim, Chul-Won
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.6 no.2
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    • pp.70-80
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    • 2007
  • Inter-vehicular communication suffers from a variety of the problem on the road, resulting in large delay in propagating emergency warning. An energy depletion as well as a transmission delay may induced by traffic accident. A transmission delay are caused by direct contention from nodes that can hear each other or indirect contention from nodes that can not hear each other, but simultaneously transmit to the same destination. A variety of works have been researched to solve the transmission delay and energy consumption problem in intelligent cars transportation systems. We consider a vehicle-to-vehicle communication protocol for disseminating an emergency information that include end-to-end and energy efficient transmission. In this paper, we propose A vehicle-to-vehicle communication protocol scheme for dissemination emergency information in intelligent cars communication based on IEEE 802.15.3 wireless personal area networks. Results from a simulation study reveal that our scheme can achieves low latency in delivering emergency warnings, and efficiency in consuming energy in stressful road scenarios.

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Secure Cluster Selection in Autonomous Vehicular Networks

  • Mohammed, Alkhathami
    • International Journal of Computer Science & Network Security
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    • v.23 no.1
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    • pp.11-16
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    • 2023
  • Vehicular networks are part of the next generation wireless and smart Intelligent Transportation Systems (ITS). In the future, autonomous vehicles will be an integral part of ITS and will provide safe and reliable traveling features to the users. The reliability and security of data transmission in vehicular networks has been a challenging task. To manage data transmission in vehicular networks, road networks are divided into clusters and a cluster head is selected to handle the data. The selection of cluster heads is a challenge as vehicles are mobile and their connectivity is dynamically changing. In this paper, a novel secure cluster head selection algorithm is proposed for secure and reliable data sharing. The idea is to use the secrecy rate of each vehicle in the cluster and adaptively select the most secure vehicle as the cluster head. Simulation results show that the proposed scheme improves the reliability and security of the transmission significantly.

Design of a Stabilizing Controller for Hybrid systems with as Application to Longitudinal Spacing Control in a Vehicle Platoon (다중 Lyapunov 기방 하이브리드 시스템에 안정화 제어기 설계 및 군집 차량의 종방향 거리 제어시스템의 용용)

  • Kim, Jin-Byun;Park, Jae-Weon;Kim, Young-Ho
    • Journal of Institute of Control, Robotics and Systems
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    • v.7 no.6
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    • pp.477-486
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    • 2001
  • Many physical systems can be modeled by incorporating continuous and discrete event nature together. Such hybrid systems contain both continuous and discrete states that influence the dynamic be-havior of the systems. There has been an increasing interest in thers types of systems during the last dec-ade, mostly due to the growing usage of computers in the control of physical plants but also as a result of the hybrid nature of physical processes. The stability theory for hybrid systems is considered as extension of Lyapunov theory where the existence of an abstract energy function satisfying certain properties verifies stability, called multiple Lyapunov theory. In this paper, a hybrid stabilizing controller is proposed using the control Lyapunov function method and multiple Lyapunov theory, and the proposed method is applied to lon-gitudinal spacing control in a vehicle platoon for intelligent transportation systems(ITS).

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A Study on Introducing Autonomous Public Transportation On-demand Service in Real Time Using Delphi Method (델파이 기법을 활용한 실시간 수요대응 자율주행 대중교통서비스 도입 방안 연구)

  • Joung, Junyoung;Shim, Sangwoo;Kim, Minseok
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.21 no.5
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    • pp.183-196
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    • 2022
  • Public transportation accessibility has been evaluated through minimum level of service for public transportation. However it is evaluated based operators rather than users. This study analyzed the users' accessibility(first-mile, last-mile) to public transportation using altteul transport card data. As a result of user's accessibility of public transportation, rural areas was lower than that in the urban areas. This study calssified type 1 and 2 based average approach time, and average approach time of Type 1 and 2 were more than average approach time of total area. We propsed an efficient introduction of autonomous public transportation on-demand service using delphi survey. As a result of delphi survey, experts agreed on 9 items regarding function, service item, route operation, approach distance, route mileage, punctuality.

PID and Adaptive Controllers for a Transportation Mobile Robot with Fork-Type Lifter

  • Nguyen, Van Vui;Tran, Huu Luat;Kim, Yong-Tae
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.16 no.3
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    • pp.216-223
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    • 2016
  • This paper proposes a new controller design method for a fork-type lifter (FTL) of a transportation mobile robot. The transportation robot needs to pick up a package from a stack on a storage shelf and move on by a planned path in a logistics center environment. The position of the storage shelf is recognized by reading a QR code on the floor, and using this position, the robot can move to reach the storage shelf and pick up the package. PID controllers and an adaptive controller are designed to control the velocity of two wheels and the position of the FTL. An adaptive controller for the lifter is designed to elevate up and down on a slideway to the correct height position of the package on the stack of the storage shelf. The simulation results show that the PID controllers can respond smoothly to the desired angular velocity and the adaptive controller can adapt quickly and correctly to the desired height.

Development of Integrated Transportation Analysis System for Large-scale event (대형 이벤트 대응형 통합교통분석 시스템 개발)

  • Lim, Sung-Han
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.13 no.3
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    • pp.1-9
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    • 2014
  • This study deals with development of Integrated Transportation Analysis System for Large-scale event. Based on case studies, the requirements of the system were defined and the direction of development was established. The large-scale events that require fast and accurate transportation policy were selected. The data warehouse and data mart were developed by integrating the large-scale event data and the traffic data. Business intelligence system was designed and developed users to allow timely decisions.

Developing RDF Meta data Graph for Transportation Open Data Platform (교통데이터 유통을 위한 RDF 메타 데이터 그래프 구축방안)

  • Park, Eun Mi;Kang, Jung Hyun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.20 no.6
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    • pp.110-116
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    • 2021
  • W3C enacted RDF(Resource Description Framework based DCAT meta data standard, which is world-widely accepted so far. To guarantee the inter-operability and integrity of data from various sources and even from various countries, it is considered that transportation meta data should also follow the DCAT standard. But still, to represent the transportation domain-specific features, it is necessary to define new properties and vocabularies in addition to the DCAT standard. This research identified the additional properties and vocabularies for transportation metadata, considering uniqueness of transportation data. The revised RDF schema and RDF graph proposed in this research should be able to lead the transportation open data platform revitalization.