• Title/Summary/Keyword: Congestion

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A medical historical study of Dan-kyei's congestion theory mentioned in 『DongEuiBoGam』 (『동의보감(東醫寶鑑)』에 보이는 단계담음론(丹溪痰飮論)의 의사학적(醫史學的) 고찰(考察))

  • Soh, Jin-Baik
    • The Journal of Korean Medical History
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    • v.15 no.1
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    • pp.147-182
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    • 2002
  • By studing the congestion theory of Choo Dan-kyei mentioned in "DongEuiBoGam", I have reached following conclusions. 1. Dan-kyei's congestion theory influenced greatly on "DongEuiBoGam". The congestion theory of "DongEuiBoGam" is built up with several theories centering round on Dan-kyei's theory and Huh-Jun's own opinion in addition. 2. Dan-kyei's congestion theory has given theoretical foundation to the classification and diagnosis of congestion reported in "DongEuiBoGam"-Congestion Chapter. 3. Dan-kyei's congestion theory offers many examples of symptoms reported in "DongEuiBoGam"-Congestion Chapter. It's shown well through outer symptoms, several congestion disease, congestion mass, and "congestion never sudden death", etc. 4. Dan-kyei's congestion theory has influenced greatly on treatment of congestion reported in "DongEuiBoGam"-Congestion Chapter, and it's well shown through spewing method, grand method in congestion treatment and common medicine of congestion, etc. 5. Dan-kyei's congestion theory offers variety of treating methods to symptoms caused by congestion reported in "DongEuiBoGam". It's shown variously through upper stomachache, stomachache, back pain, side pain, "San", joint pain, Summer disease, internal injury, cough and morning sickness, etc.. 6. Dan-kyei's congestion theory has factors that could be operated to common diseases of mordern people. They can be classified as food congestion, alcohol congestion, obstruction congestion and Qi congestion, and they are clinically very efficient.

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A Study on Estimate Model for Peak Time Congestion

  • Kim, Deug-Bong;Yoo, Sang-Lok
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.3
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    • pp.285-291
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    • 2014
  • This study applied regression analysis to evaluate the impact of hourly average congestion calculated by bumper model in the congested area of each passage of each port on the peak time congestion, to suggest the model formula that can predict the peak time congestion. This study conducted regression analysis of hourly average congestion and peak time congestion based on the AIS survey study of 20 ports in Korea. As a result of analysis, it was found that the hourly average congestion has a significant impact on the peak time congestion and the prediction model formula was derived. This formula($C_p=4.457C_a+29.202$) can be used to calculate the peak time congestion based on the predicted hourly average congestion.

A Study on the Improvement of Transmission Efficiency for Multimedia Service Quality (멀티미디어 서비스 품질의 전송 효율성 향상을 위한 연구)

  • 문호선;하동문;김용득
    • Proceedings of the IEEK Conference
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    • 2002.06e
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    • pp.83-86
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    • 2002
  • In this paper while a router is routing all packet to the next hop, it inspects whether there is congestion on this current hop router or not and if the router discovers that it has some congestion, it informs that the packet is experienced to congestion. The packet arrived to next hop including some information about the congestion is processed first and it has wider bandwidth than another packet The amount of congestion is recorded to the DS field of IP header by congestion experience level. In the next hop when the packet including the congestion information is routed, the standard packet dropping ratio of the current router is changed in proportion to congestion experience that is recorded in IP header on of that. When the packet that has experienced congestion before is arrived, the router extends the drop threshold value not to drop the packet. It mean that transferring the audio or video stream, if the packet is already experienced the congestion in another hop, the router can provide the better service quality about 15∼25% than another.

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Airport Congestion Analysis with Big Data Analysis - The Case of Gimpo Airport - (빅데이터 분석을 활용한 공항 혼잡도 분석 - 김포공항 사례를 중심으로 -)

  • Kim, Jin Ah;Kim, Jin Ki
    • Journal of the Korean Society for Aviation and Aeronautics
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    • v.28 no.2
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    • pp.36-46
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    • 2020
  • This study is designed to help customers use more comfortable airports by predicting congestion and congestion times by identifying the traffic routes of passengers in the airport building by day of the week and time by using Wi-Fi sensor collectors, one of the IoT technologies. Analysis of passenger traffic analysis data showed that the most congested time zones were from noon. to 2p.m. for all facilities, which could be used to improve major facilities. Regression analysis of factors affecting congestion found that self-check-in reduces congestion and check-in counters increases congestion. These findings will provide important implications for operations, including congestion management at airports.

Comparative Study of Two Congestion Management Methods for the Restructured Power Systems

  • Manikandan, B.V.;Raja, S. Charles;Venkatesh, P.;Mandala, Manasarani
    • Journal of Electrical Engineering and Technology
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    • v.6 no.3
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    • pp.302-310
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    • 2011
  • Congestion management is one of the most challenging tasks of a system operator to ensure the operation of transmission system within operating limits. In this paper, cluster/zone method and relative electrical distance (RED) method for congestion management are compared based on the considered parameters. In the cluster/zone method, rescheduling of generation is based on user impact on congestion through the use of transmission congestion distribution factors. In the RED method, the desired proportions of generations for the desired overload relieving are obtained. Even after generation rescheduling, if congestion exists, load curtailment option is also introduced. Rescheduling cost, system cost, losses, and voltage stability parameter are also calculated and compared for the above two methods of congestion management. The results are illustrated on sample 6-bus, IEEE 30-bus, and Indian utility 69-bus systems.

A Measurement Way on the Effectiveness of Port Investment: Congestion Model Approach (항만투자의 유효성 측정방법: congestion모형 접근)

  • 박노경
    • Journal of Korea Port Economic Association
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    • v.19 no.2
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    • pp.33-53
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    • 2003
  • The purpose of this paper is to investigate the effectiveness of port investemnt which is one of the important elements for measuring the port efficiency by using congestion approach of DEA(Data Envelopment Analysis). Congestion is said to be present when increases in inputs result in input reductions. Congestion approach takes the forms of weak input disposability and strong input disposability. Empirical analysis by using congestion approach in this paper identified inefficiencies in the inputs including port investment, and indicated inefficient ports like the ports of Sokcho, Gunsan, Pohang, and Seoguipo which shows the large amount of slacks with congestion especially in terms of port investment. Therefore these ports should examine the reason about the inefficiency of port investment. The main policy implication based on the findings of this study is that The Ministry of Maritime Affairs & fisheries in Korea should introduce congestion approach when the amount of port investment to each port is decided.

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A Study on the Effectiveness of Port Investment: Congestion Model Approach (항만투자의 유효성 분석 - congestion모형 접근 -)

  • 박노경
    • Proceedings of the Korea Port Economic Association Conference
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    • 2003.07a
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    • pp.221-242
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    • 2003
  • The purpose of this paper is to investigate the effectiveness of port investment which is one of the important elements for measuring the port efficiency by using congestion approach of DEA(Data Envelopment Analysis). Congestion is said to be present when increases in inputs result in ouput reductions. Congestion approach takes the forms of weak input disposability and strong input disposability. Empirical analysis by using congestion approach in this paper identified inefficiencies in the inputs including port investment, and indicated inefficient ports like the ports of Sokcho, Gunsan, Pohang, and Seoguipo which shows the large amount of slacks with congestion especially in terms of port investment. Therefore these ports should examine the reason about the inefficiency of port investment. The main policy implication based on the findings of this study is that The Ministry of Maritime Affairs & Fisheries in Korea should introduce congestion approach when the amount of port investment to each port is decided.

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Optimal Siting of UPFC for Reducing Congestion Cost by using Shadow Prices

  • Lee, Kwang-Ho;Moon, Jun-Mo
    • KIEE International Transactions on Power Engineering
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    • v.11A no.4
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    • pp.21-26
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    • 2001
  • As competition is introduced in the electricity supply industry, congestion becomes a more important issue. Congestion in a transmission network occurs due to an operating condition that causes limit violations on the transmission capacities. Congestion leads to inefficient use of the system, or causes additional costs (Congestion cost). One way to reduce this inefficiency or congestion cost is to control the transmission flow through the installation of UPFC (Unified Power Flow Controller). This paper also deals with an optimal siting of the UPFC for reducing congestion cost by using shadow prices. A performance index for an optimal siting is defined as a combination of line flow sensitivities and shadow prices. The proposed algorithm is applied to the sample system with a condition, which is concerning the quadratic cost functions. Test results show that the siting of the UPFC is optimal to minimize the congestion cost by the proposed algorithm.

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DCCP based Congestion Control Scheme to support Mobility of Devices on Ubiquitous Computing Environment (유비쿼터스 컴퓨팅 환경에서 단말의 이동성을 지원하기 위한 DCCP 기반의 혼잡 제어 정책)

  • Park Si-Yong;Kim Sung-Min;Lee Tae-Hoon;Chung Ki-Dong
    • Journal of KIISE:Information Networking
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    • v.33 no.1
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    • pp.59-75
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    • 2006
  • In this paper, we propose a congestion control scheme to control the congestion due to the mobility of ubiquitous devices on ubiquitous computing environment. Especially, this congestion control scheme provides a reverse congestion avoidance state which can classify between packet error by features of wireless network and packet dropping by congestion. Also, it provides a slow stop state which can minimize bandwidth waste due to congestion control. The proposed congestion control scheme controls more adaptive than existing congestion control schemes. The proposed congestion control scheme is designed based on DCCP(Datagram Congestion Control Protocol) being proposed by IETF(Internet Engineering Task Force) and implemented on the Linux kernel. In simulation results, the proposed congestion control scheme provides good bandwidth throughput in wireless network as well as in wired network.

Early Rate Adaptation Protocol in DiffServ for Multimedia Applications (멀티미디어 서비스를 위한 DiffServ 망에서의 빠른 혼잡 제어 알고리즘)

  • Park Jonghun;Yoo Myungsik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.1B
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    • pp.39-46
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    • 2005
  • As the multimedia application traffic takes more portion in the internet traffic, it is necessary to control the network congestion through the congestion control protocol. In addition, the QoS-enabled networks such as DiffServ become an indispensable technology when running the multimedia applications. However, the previously proposed end-to-end congestion control algorithms take the round trip time to react the network congestion. Thus, as the RTT becomes larger, the reaction against the congestion gets delayed further, while the network congestion gets worse. In addition the performance of end-to-end congestion control algorithm is degraded if the QoS-enabled network runs the congestion control mechanism in the network level without any coordination between them. In this paper, we propose the early rate adaptation protocol for the DiffServ network which effectively linke the congestion control algorithm at the host and the congestion mechanism in the network together. By taking advantage of early congestion notification from the network it is possible to react the network congestion more quickly and effectively.