• Title/Summary/Keyword: Traffic Congestion Control

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Study on Cases of Priority Traffic Signal System for Emergency Vehicles: Based on a City's Pilot Operation Cases in Chungcheongbukdo Province (긴급차량 우선교통신호시스템 사례에 관한 연구: 충청북도 내 일개도시 시범운영 사례를 중심으로)

  • Kim, Jin-Hyeon;Lee, Hyo-Ju
    • Fire Science and Engineering
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    • v.34 no.1
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    • pp.121-126
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    • 2020
  • The aim of this study is to suggest ways to capitalize on the golden period for timely response to fire and emergency victims. To implement a system to effectively capitalize on the golden period, there is a need for policy measures as well as legal and social consensus. Precedent research has relentlessly mentioned the need for and feasibility of the priority traffic system for emergency vehicles. To this end, the present study involved an analysis of pilot cases of the priority traffic signal system for emergency vehicles introduced in a city during 26 days, from April 3 to 28, 2017. Out of 58 cases registered with the local 1-1-9 fire house, the number of cases that took advantage of the priority traffic system stood at 16 in response to fire and 11 to first-aid operations. Owing to the system, on average, the response time reduced by 3 min and 50 s in case of fire and by 3 min and 30 s for first aid. There were four complaints registered owing to traffic congestion, and the number of car accidents declined to one from six over the same period in the previous year. Based on these findings, it is safe to say that the priority traffic signal system would be effective for emergency vehicles to capitalize on the golden period if issues identified during the pilot run are resolved.

Analysis of Safety and Mobility of Expressway Land Control System (길어깨차로제 시행에 따른 안전성 및 이동성 분석)

  • Park, Sung-ho;Lee, Yoseph;Kang, Sungkwan;Cho, Hyonbae;Yun, Ilsoo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.20 no.3
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    • pp.1-19
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    • 2021
  • The domastic hard shoulder running(HSR) System has been gradually expanding since its initial implementation in September 2007 with the aim of increasing capacity and resolving congestion. Hard Shoulder is used as a space for driver's visual comfort and a place for vehicles to evacuate in case of emergency, but it is replaced by a space for driving when the HSR System is implemented. Therefore, it was intended to determine the improvement effect before and after implementation of the HSR system through safety analysis and mobility analysis. The safety analysis analyzed the impact of traffic accidents by comparing HSR sections and similar sections. The mobility analysis was to determine the improvement effect by quantifying the speed and traffic volume changes before and after HSR System implementation. According to safety yanalysis, there is no effect of reducing traffic accidents when implementing the HSR System. In mobility analysis, the implementation of the HSR System significantly improved the speed of traffic during peak hours and significantly reduces slow and delay hours.

Interference-Prediction based Online Routing Aglorithm for MPLS Traffic Engineering (MPLS 트래픽 엔지니어링을 위한 간섭 예측 기반의 online 라우팅 알고리듬)

  • Lee, Dong-Hoon;Lee, Sung-Chang;Ye, Byung-Ho
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.42 no.12
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    • pp.9-16
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    • 2005
  • A new online routing algerian is proposed in this paper, which use the interference-prediction to solve the network congestion originated from extension of Internet scope and increasing amount of traffic. The end-to-end QoS has to be guaranteed in order to satisfy service level agreements (SLAs) in the integrated networks of next generation. For this purpose, bandwidth is allocated dynamically and effectively, moreover the path selection algorithm is required while considering the network performance. The proposed algorithm predicts the level of how much the amount of current demand interferes the future potential traffic, and then minimizes it. The proposed algorithm considers the bandwidth on demand, link state, and the information about ingress-egress pairs to maximize the network performance and to prevent the waste of the limited resources. In addition, the interference-prediction supports the bandwidth guarantee in dynamic network to accept more requests. In the result, the proposed algorithm performs the effective admission control and QoS routing. In this paper, we analyze the required conditions of routing algorithms, the aspect of recent research, and the representative algorithms to propose the optimized path selection algorithm adequate to Internet franc engineering. Based on these results, we analyze the problems of existing algorithms and propose our algorithm. The simulation shows improved performance by comparing with other algorithms and analyzing them.

Operational Strategies of a Bus-Exclusive Lane Using Barrier Transfer Systems to Control Tidal Traffic Flows (비대칭적 중방향 교통류 대응을 위한 이동식 중앙분리대 활용 버스전용차로 도입 전략 분석)

  • Kim, Taewan;Chung, Younshik;Jeon, Gyo Seok;Kim, Wongil
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.42 no.2
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    • pp.209-217
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    • 2022
  • Lane management with a central variable lane(s) (or reversible lane) where the traffic flow is temporarily reversed in one or more lanes during peak periods has been evaluated as an effective strategy to alleviate congestion caused by tidal traffic flows. However, due to traffic safety issues, such a movable barrier system can be considered as an alternative to supplement the existing its operation facilities such as static and/or dynamic signs and special pavement markings. In addition, when combined with a bus exclusive lane strategy, its effectiveness could be greatly increased. The objective of this study is to propose a feasibility analysis procedure for operational strategies of a bus-exclusive lanes using a barrier transfer system (BTS) for urban expressways. To this end, a case study was conducted on two urban expressways on the west side of the Han River in Seoul. As a result, temporary operation during rush hour in the morning was found to be most effective. The results presented in this study are expected to serve as a basis for establishing bus-exclusive lane operation strategies using similar systems in the future.

A Solution for Congestion and Performance Enhancement using Dynamic Packet Bursting in Mobile Ad Hoc Networks (모바일 애드 혹 네트워크에서 패킷 버스팅을 이용한 혼잡 해결 및 성능향상 기법)

  • Kim, Young-Duk;Yang, Yeon-Mo;Lee, Dong-Ha
    • Journal of KIISE:Information Networking
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    • v.35 no.5
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    • pp.409-414
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    • 2008
  • In mobile ad hoc networks, most of on demand routing protocols such as DSR and AODV do not deal with traffic load during the route discovery procedure. To solve the congestion and achieve load balancing, many protocols have been proposed. However, the existing load balancing schemes has only considered avoiding the congested route in the route discovery procedure or finding an alternative route path during a communication session. To mitigate this problem, we have proposed a new scheme which considers the packet bursting mechanism in congested nodes. The proposed packet bursting scheme, which is originally introduced in IEEE 802.11e QoS specification, is to transmit multiple packets right after channel acquisition. Thus, congested nodes can forward buffered packets promptly and minimize bottleneck situation. Each node begins to transmit packets in normal mode whenever its congested status is dissolved. We also propose two threshold values to define exact overloaded status adaptively; one is interface queue length and the other is buffer occupancy time. Through an experimental simulation study, we have compared and contrasted our protocol with normal on demand routing protocols and showed that the proposed scheme is more efficient and effective especially when network traffic is heavily loaded.

Vehicle control system base on the low power long distance communication technology(NB-IoT)

  • Kim, Sam-Taek
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.6
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    • pp.117-122
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    • 2022
  • In this paper, we developed a vehicle control terminal using IoT and low-power long-distance communication (NB-IoT) technology. This system collects information on the location and status of a parked vehicle, and transmits the vehicle status to the vehicle owner's terminal in real time with low power to prevent vehicle theft, and in the case of a vehicle in motion, When primary information about the vehicle, such as an impact, is collected and transmitted to the server, the server analyzes the relevant data to generate secondary information on traffic congestion, road damage, and safety accidents. By sending it, you can know the exact arrival time of the vehicle at its destination. This terminal device is an IoT gateway for a vehicle and can be connected to various wired and wireless sensors inside the vehicle. In addition, the data collected from vehicle maintenance, efficient operation, and vehicles can be usefully used in the private or public sector.

A New Packet Forwarding Architecture For Fairness Improvement in Wireless Sensor Network (무선 센서 네트워크 환경에서 공정성 향상을 위한 새로운 패킷 전송 구조)

  • Song, Byung-Hun;Lee, Hyung-Su;Ham, Kyung-Sun
    • Proceedings of the KIEE Conference
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    • 2004.11c
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    • pp.215-217
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    • 2004
  • In wireless sensor networks, fair allocation of bandwidth among different nodes is one of the critical problems that effects the serviceability of the entire system. Fair bandwidth allocation mechanisms, like fair queuing, usually need to maintain state, manage buffers, and perform packet scheduling on a per flow basis, and this complexity may prevent them from being cost-effectively implemented and widely deployed. It is a very important and difficult technical issue to provide packet scheduling architecture for fairness in wireless sensor networks. In this paper, we propose an packet scheduling architecture for sensor node, called FISN (Fairness Improvement Sensor Network), that significantly reduces this implementation complexity yet still achieves approximately fair bandwidth allocations. Sensor node for sensing estimate the incoming rate of each sensor device and insert a label into each transmission packet header based on this estimate. Sensor node for forwarding maintain no per flow state; they use FIFO packet scheduling augmented by a probabilistic dropping algorithm that uses the packet labels and an estimate of the aggregate traffic at the gathering node. We present the detailed design, implementation, and evaluation of FISN using simulation. We discuss the fairness improvement and practical engineering challenges of implementing FISN in an experimental sensor network test bed based on ns-2.

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Study of International trend for AUGT(Automated Urban Guided Transport) safe requirements (AUGT 안전요구사항의 국제적 동향 연구)

  • Lee, Hoon-Goo;Choi, Kwon-Hee;Jo, Yong-Gyun;Lee, Young-Ho;Hwang, Hyeon-Chyeol
    • Proceedings of the KIEE Conference
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    • 2009.04a
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    • pp.195-197
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    • 2009
  • It is a proven fact with the opening of the Seoul metro line number 1 in 1974 traffic congestion on the roads has decreased and the efficiency of people transportation in general has greatly been enhanced in the downtown and surrounding areas of Seoul. Even today construction of new subway lines are under way and many more are being planned due to the easy access to stations, short waiting and average travel times, compared with personal vehicles, contributing to the efficiency of the public transportation systems that are linking the downtown areas and also the intercity systems in moving passengers during rush hour and times of special event. Since the labour costs of the train operator in any large city based subway system accounts for a major part of the operating costs per kilometer and to ensure cost efficient operations, especially during non-peak hours, it is necessary to implement an unmanned(auto-driven) subway system. In order to implement such a system it is imperative that the on-board and wayside signalling control systems be fully automated as well. Only through proper examination of safety procedures not only by the AUGT(Automated Urban Guided Transport)system but also by ail the international standards organizations involved can safely and stability be ensured.

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A Study on Take-off and Landing Experimental System for Development of Power Platforms for Electric Vertical Take-Off and Landing Air Mobility (전기 수직이착륙 항공모빌리티용 동력플랫폼 개발을 위한 이착륙 실험시스템 연구)

  • Jun-Seong, Weon;Kwang-Hyun Ro
    • Journal of the Korean Society of Industry Convergence
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    • v.26 no.4_2
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    • pp.639-648
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    • 2023
  • In modern society, UAM (Urban Air Mobility) transportation system is being developed as an alternative to urban traffic congestion and environmental problems, and electric vertical take-off and landing (eVTOL) is a combination of vertical take-off and landing function and electric power. It is attracting attention as an innovative next-generation transportation method as an eco-friendly alternative that reduces noise and air pollution by providing efficient mobility within the city. Since eVTOL development requires designing and implementing airframes suitable for various mission purposes, the power system needs to be developed as a platform concept before airframe development. In this study, we empirically proposed a test bench concept equipped with a stable power supply and an efficient control system, essential in developing a power platform with a combined function in the form of a fuselage and module type specialized for various mission purposes. The proposed drivetrain platform test bench consists of a system verifying the stable take-off and landing software and a power platform adjusting the motor's thrust. It will serve as a verification system that can be developed.

Unstable Approach Mitigation Based on Flight Data Analysis (비행 데이터 분석 기반의 불안정 접근 경감방안)

  • Kim, Hyeon Deok
    • Journal of Advanced Navigation Technology
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    • v.25 no.1
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    • pp.52-59
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    • 2021
  • According to the International Air Transport Association (IATA), 61% of the accidents occurred during the approach and landing phase of the flight, with 16% of the accidents caused by unstable access of the commercial aircraft. It was identified that the pilot's unstable approach and poor manipulation of correction led to accidents by continuing the excessive approach without go-around manuever. The causes of unstable access may vary, including airport approach procedures, pilot error, misplanning, workload, ATC (Air Traffic Contol) congestion, etc. In this study, we use the flight data analysis system to select domestic case airports and aircraft type where unstable approach events occur repeatedly. Through flight data analysis, including main events, airport approach procedures, pilot operations, as well as various environmental factors such as weather and geographical conditions at the airport. It aims to identify and eliminate the tendency of unstable approach events and the causes and risks of them to derive implications for mitigating unstable approach events and for developing navigation safety measures.