• 제목/요약/키워드: Congestion

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빅데이터 분석을 이용한 지하철 혼잡도 예측 및 추천시스템 (Subway Congestion Prediction and Recommendation System using Big Data Analysis)

  • 김진수
    • 디지털융복합연구
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    • 제14권11호
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    • pp.289-295
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    • 2016
  • 지하철은 버스와 택시에 비해 많은 승객들을 안전하고 신속하게 대량 수송할 수 있는 미래 지향적인 교통수단이다. 지하철 이용자의 증가에 따른 혼잡도 증가는 지하철을 쾌적하게 이용할 수 있는 시민들의 권리를 저해하는 요인 중의 하나이다. 따라서 지하철 내의 혼잡도 예측은 승객의 이용 편의성과 쾌적성을 극대화할 수 방법 중 하나이다. 본 논문에서는 기존의 지하철 혼잡도를 다중 회귀 분석으로 예측하고 빅데이터 처리를 통한 실시간으로 혼잡도를 모니터링하고, 자신의 출발역과 도착역 정보뿐만 아니라 다양한 정보를 추가하여 개인화된 혼잡도 예측 시스템을 제안한다. 제안된 혼잡도 예측 시스템을 적용한 결과 예측혼잡도가 실제혼잡도에 비해 평균 81% 정확도를 보였다. 본 논문에서 제안한 예측 및 추천 어플리케이션을 지하철 고객에 적용하면 지하철 혼잡도 예측과 개인 사용자의 편리성에 도움이 될 것으로 예상된다.

VDS 자료 기반 고속도로 교통혼잡비용 산정 방법론 연구 (Estimation of the Expressway Traffic Congestion Cost Using Vehicle Detection System Data)

  • 김상구;윤일수;박재범;박인기;천승훈;김경현;안현경
    • 한국도로학회논문집
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    • 제18권1호
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    • pp.99-107
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    • 2016
  • PURPOSES : This study was initiated to estimate expressway traffic congestion costs by using Vehicle Detection System (VDS) data. METHODS : The overall methodology for estimating expressway traffic congestion costs is based on the methodology used in a study conducted by a study team from the Korea Transport Institute (KOTI). However, this study uses VDS data, including conzone speeds and volumes, instead of the volume delay function for estimating travel times. RESULTS : The expressway traffic congestion costs estimated in this study are generally lower than those observed in KOTI's method. The expressway lines that ranked highest for traffic congestion costs are the Seoul Ring Expressway, Gyeongbu Expressway, and the Youngdong Expressway. Those lines account for 64.54% of the entire expressway traffic congestion costs. In addition, this study estimates the daily traffic congestion costs. The traffic congestion cost on Saturdays is the highest. CONCLUSIONS : This study can be thought of as a new trial to estimate expressway traffic congestion costs by using actual traffic data collected from an entire expressway system in order to overcome the limitations of associated studies. In the future, the methodology for estimating traffic congestion cost is expected to be improved by utilizing associated big-data gathered from other ITS facilities and car navigation systems.

ATM 망에서 효율적인 TCP 폭주 제어 기법 (An Efficient TCP Congestion Control Scheme in ATM Networks)

  • 최지현;김남희;김변곤;전용일;정경택;전병실
    • 한국정보통신학회논문지
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    • 제7권8호
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    • pp.1653-1660
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    • 2003
  • 본 논문에서는 TCP에서의 트래픽 혼잡에 따른 영향을 최소화시키기 위하여 혼잡제어 윈도우 파라미터인 cwnd와 RTT을 이용한 향상된 TCP 폭주제어 알고리즘을 제안하였다. 제안된 기법에서는 혼잡의 주된 발생을 피할 수 있도록 하였고, 회복 시간에 의해 발생하는 지연과 스위치 버퍼의 사용량을 감소시킬 수 있도록 하였다. 시뮬레이션을 통한 성능 평가 결과 제안된 기법이 기존의 기법보다 성능이 우수함을 확인할 수 있었다. 버퍼 효율에서는 기존의 기법보다 22.56%의 향상이 있었고, 패킷 드롭율은 약 0.1%로 기존의 알고리즘보다 적은 손실을 보여주었다.

한전 실계통의 혼잡처리에 대한 적용사례 (A Case Study of the Congestion Management for the Power System of the Korea Electric Power Cooperation)

  • 송경빈;임규형;백영식
    • 대한전기학회논문지:전력기술부문A
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    • 제50권12호
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    • pp.549-555
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    • 2001
  • Due to the development of information technology, the operating power systems under the deregulated environment has the advantages of a introduction of the market function, a competition in sales and purchases of Power, as well as the difficulty of maintaining reliability on the same or high level with it in a monopolistic market. This paper presents a basic scheme of the congestion management in the Korea electricity market under the deregulated environment. We investigated some cases of the congestion management in the world and the effects of the congestion management in the power systems. A basic idea of the congestion management in the Korea is presented based on the analysis of transmission congestion management in the competitive electricity market.

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CMS: Application Layer Cooperative Congestion Control for Safety Messages in Vehicular Networks

  • Lee, Kyu-haeng
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제12권3호
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    • pp.1152-1167
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    • 2018
  • In this paper, I propose an application layer cooperative congestion control scheme for safety message broadcast in vehicular networks, called CMS, that adaptively controls a vehicle's safety message rate and transmit timing based on the channel congestion state. Motivated by the fact that all vehicles should transmit and receive an application layer safety message in a periodic manner, I directly exploit the message itself as a means of estimating the channel congestion state. In particular, vehicles can determine wider network conditions by appending their local channel estimation result onto safety message transmissions and sharing them with each other. In result CMS realizes cooperative congestion control without any modification of the existing MAC protocol. I present extensive NS-3 simulation results which show that CMS outperforms conventional congestion control schemes in terms of the packet collision rate and throughput, especially in a high-density traffic environment.

혼잡해소를 위한 도로건설의 정책효과: 시스템 다이내믹스 이론의 적용 (Policy Impact Analysis of Road Transport Investment via System Dynamics Theory)

  • 권태형
    • 한국시스템다이내믹스연구
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    • 제12권1호
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    • pp.75-87
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    • 2011
  • Congestion problems can be approached from the viewpoint of system dynamics theory. The relationship between road capacity and congestion can be explained by the 'relative control' archetype among four system archetypes suggested by Wolstenholme. There is a balancing feedback loop between road capacity and road congestion. However, there is another balancing loop between road congestion and car traffic volume, which keeps disrupting the equilibrium of the former loop. A system dynamics model, which is based on a partial adjustment model of induced traffic in the literature, is built to simulate three road building scenarios: 'Expanding investment', 'Balancing investment' and 'Frozen road investment' scenarios. The 'Expanding investment' scenario manages to drop congestion levels by 9% over 30 years, however, causing much higher emissions of $CO_2$ than other scenarios. The trade-off relationship between congestion levels and environmental costs must be taken into consideration for road investment policies.

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직류조류계산을 이용한 혼잡비용과 손실비용 평가 (Evaluation of Congestion Cost and Loss Cost using DC Load Flow)

  • 배인수;송우창
    • 조명전기설비학회논문지
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    • 제26권12호
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    • pp.93-98
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    • 2012
  • Economics of available alternatives in the transmission planning are evaluated by the investment cost, loss cost and congestion cost. Congestion/loss cost is calculated in many years and many load levels by unit commitment of generators, optimal dispatch, load flow, judgement about transmission congestion and re-dispatch to reduce the congestion. The greatest difficulties to introduce variable optimization techniques on the transmission planning is the convergence of load flow. In this paper, economics in the transmission planning are evaluated using DC load flow, and case study is conducted on the Korea power system by proposed congestion/loss calculation methods.

Load Shedding Algorithm Using Linear Programming for Congestion Problems by a Major Contingency

  • Shin Ho-Sung;Song Kyung-Bin
    • KIEE International Transactions on Power Engineering
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    • 제5A권4호
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    • pp.371-377
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    • 2005
  • Congestion problems of transmission lines are very important research issues in power system operations. Load curtailment is one of the ways to solve congestion problems by a major contingency. A systematic and effective mechanism for load shedding has been developed by investigating congestion distribution factors and the direct load control program. In this paper, a load shedding algorithm using linear programming for congestion problems by a major contingency is presented. In order to show the effectiveness of the proposed algorithm, it has been tested on the 6-bus sample system and the power system of Korea, and their results are presented.

단일 요금제도에서 혼잡비용의 다단계 분배 방법 연구 (A multi stage allocation method of congestion cost in a uniform pricing)

  • 권태진;정해성;허돈;한태경;허재행;박종근
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 제36회 하계학술대회 논문집 A
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    • pp.739-741
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    • 2005
  • The congestion cost caused by transmission capacities is an important issue in a competitive electricity market. To allocate the congestion cost equitably, the active constraints in a constrained dispatch and the sequence of these constraints should be considered. A multi-stage method which was proposed by H.S. Jung reflects the effects of both the active constraints and the sequence. In a multi-stage method, the types of congestion are analyzed in order to consider the sequence, and the relationship between congestion and the active constraints is derived in a mathematical way. But in some cases, the inactive constraints can affect the congestion sequence and it is reasonable to allocate the congestion cost to them.

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항계내 항로의 해상교통 혼잡도 평가에 관하여 - 울산 신항만의 혼잡도 평가를 기준으로 - (Evaluation of Traffic Congestion in Channels within Harbour Limit -On Channels in Ulsan New Port Development-)

    • 한국항만학회지
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    • 제11권2호
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    • pp.173-189
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    • 1997
  • Whether over taking or parallel sailing of two or more vessels is allowable on marine traffic route or not, the traffic congestion due to traffic volume has to be evaluated separately. In Gaduk-sudo, overtaking or parallel sailing is so allowable that the Bumper Model is introduced to evaluated the traffic congestion. But the channels within the habour limit such as the route of Ulsan New Port are so prohibited overtaking or parallel sailing that the traffic congestion has to be evaluated by using theoretical traffic capacity or by traffic simulation. In this paper, the congestion of Southern New Port and Mipo Port was evaluated the congestion by using theoretical traffic capacity and the other area of Ulsan Port by traffic simulation. The incresed traffic volumes on Ulsan Channels according to Ulsan New Port Development in 2011 were evaluated to have no effect with the traffic congestion.

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