• Title/Summary/Keyword: Congestion management

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Vision-Based Fast Detection System for Tunnel Incidents (컴퓨터 시각을 이용한 고속 터널 유고감지 시스템)

  • Lee, Hee-Sin;Jeong, Sung-Hwan;Lee, Joon-Whoan
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.9 no.1
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    • pp.9-18
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    • 2010
  • Our country has so large mountain area that the tunnel construction is inevitable and the need of incident detection that provides safe management of tunnels is increasing. In this paper, we suggest a tunnel incident detection system using computer vision techniques, which can detect the incidents in a tunnel and provides the information to the tunnel administrative office in order to help safe tunnel operation. The suggested system enhances the processing speed by using simple processing algorithm such as image subtraction, and ensures the accuracy of the system by focused on the incident detection itself rather than its classification. The system is also cost effective because the video data from 4 cameras can be simultaneously analyzed in a single PC-based system. Our system can be easily extended because the PC-based analyzer can be increased according to the number of cameras in a tunnel. Also our web-based structure is useful to connect the other remotely located tunnel incident systems to obtain interoperability between tunnels. Through the experiments the system has successfully detected the incidents in real time including dropped luggage, stoped car, traffic congestion, man walker or bicycle, smoke or fire, reverse driving, etc.

Comparison Before and After Implementation of Travel Speed in Shoulder-Use Lanes on Expressway (고속도로 갓길차로 운영 전후 소통개선 효과분석)

  • Ko, Eunjeong;Lee, Sujin;Kim, Hyungjoo
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.19 no.2
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    • pp.36-47
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    • 2020
  • The objective of this study is to analyze the effect of the shoulder-use lane, which is a representative traffic management technique that increases the road capacity. The operation of the shoulder-use lane has been actively used as a countermeasure to improve traffic congestion, because it has the effect of improving traffic flow during rush hour. In Korea, the shoulder-use lanes are available at Gyeongbu, Yeongdong, and on the Seoul Outer Ring expressway, and their use is gradually increasing. Therefore, a comprehensive analysis was conducted to analyze the effects of the shoulder-use lane; including 1) analysis of individual shoulder lanes based on a time space diagram, and 2) analysis of shoulder lanes by road axis. These findings can contribute to the efficient installation and operation of shoulder-use lanes on expressways.

A Back-Pressure Algorithm for Lifetime Extension of the Wireless Sensor Networks with Multi-Level Energy Thresholds (센서네트워크 수명 연장을 위한 에너지 임계값 기반 다단계 Back-Pressure 알고리즘)

  • Jeong, Dae-In
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.12B
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    • pp.1083-1096
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    • 2008
  • This paper proposes an energy-aware path management scheme, so-called the TBP(Threshold based Back-Pressure) algorithm, which is designed for lifetime extension of the energy-constrained wireless sensor networks. With the goal of fair energy consumptions, we extensively utilize the available paths between the source and the sink nodes. The traffic distribution feature of the TBP algorithm operates in two scales; the local and the whole routing area. The threshold and the back-pressure signal are introduced for implementing those operations. It is noticeable that the TBP algorithm maintains the scalability by defining both the threshold and the back-pressure signal to have their meanings locally confined to one hop only. Throughout several experiments, we observe that the TBP algorithm enhances the network-wide energy distribution. which implies the extension of the network lifetime. Additionally, both the delay and the throughput outcomes show remarkable improvements. This shows that the energy-aware path control scheme holds the effects of the congestion control.

A Study on Performance Enhancement of the Rate Scheme for ABR Traffic on ATM Networks (ATM 망에서 ABR 트래픽을 위한 Rate 기법이 성능 향상 연구)

  • Lee, Yo-Seob;Yu, Eun-Jin;Chang, Hyun-Hee;Pang, Hea-Ja;Jun, Moon-Seog
    • The Transactions of the Korea Information Processing Society
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    • v.4 no.10
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    • pp.2605-2614
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    • 1997
  • Recently, we are concerned with effective service according as the demand increase for high speed data service. We can use high speed transfer and multiple traffic service on the ATM networks, so we concentrate on preventive-control method rather than reactive-control one. But it is possible to have low QoS and traffic congestion due to unpredictable traffic and burst traffic. Specially, ATM Forum has discussed to standardization of traffic management of ABR(Available Bit Rate) service. Because ABR traffic controls the flow of traffic using the feedback information and the current status information of cell, it allocates bandwidth systematically and dynamically to the user. In this paper, we propose a new Rate-based flow control scheme which adapted double threshold buffer idea. The double threshold buffer controls the traffic control by establishing two threshold in buffer.

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Multiple venous anastomoses decrease the need for intensive postoperative management in tamai zone I replantations

  • Ryu, Deok Hyeon;Roh, Si Young;Kim, Jin Soo;Lee, Dong Chul;Lee, Kyung Jin
    • Archives of Plastic Surgery
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    • v.45 no.1
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    • pp.58-61
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    • 2018
  • Background Venous anastomosis is an important component of digital replantation, but is not always feasible, as some cases require external bleeding to treat venous congestion in the replanted tissue. In the present study, we evaluated the relationship between the number of vein anastomoses and the survival rate of Tamai zone I replantations. Methods A retrospective review was performed of all patients who underwent replantation of a fingertip amputation between 2014 and 2016. Patient charts were reviewed for demographic information, the mechanism of injury, the number of venous anastomoses, and the use of anticoagulation, external bleeding, and/or leeches. The cohort was divided into 3 groups depending on the number of venous anastomoses: no veins (group 1), a single vein (group 2), and 2 or more veins (group 3). Survival rates and external bleeding rates were analyzed across the groups. Results The review identified 143 fingertip replantations among 134 patients. The overall survival rate was 94% (135 of 143). Failures were due equally to venous complications (n=4, 50%) and to arterial complications (n=4, 50%). Our analysis did not identify any correlation between the number of veins anastomosed and the replant survival rate (P=0.689). However, a greater number of anastomoses was associated with a significantly lower frequency of external bleeding (P=0.017). Conclusions The number of venous anastomoses was not correlated with the survival rate. However, a greater number of venous anastomoses was associated with a decreased need for external bleeding, corresponding to a significant decrease in the need for postoperative monitoring and leech therapy.

Systemic Pulmonary Arteriovenous Fistula - 1 Case Report - (체동맥 폐동정맥루 치험례의 보고 -1례 보고-)

  • 허재학;김영태;성숙환;김주현
    • Journal of Chest Surgery
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    • v.31 no.4
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    • pp.409-412
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    • 1998
  • This is a case report of an operation for the pulmonary arteriovenous fistula supplied from the systemic arteries instead of the pulmonary artery. The operation of systemic arteriovenous pulmonary fistula has formidable technical challenges due to its extensive collateral circulations. A 16 year-old female patient, diagnosed as systemic arteriovenous fistula with multiple tortuous feeding vessels and with hereditary hemorrhagic telangiectasia, was initially managed with arterial embolization before the operation. A 15${\times}$8cm sized huge vascular malformation was removed by RML and RLL bilobectomy. During the operation, we encountered annoying massive bleeding and pulmonary congestion originated in its extensive collateral circulation. The patient was discharged after conservative management without specific problem on the 15th postoperative day. For the safe operation as well as good operative result, it seemed that meticulous ligation of the multiple collateral vessels should be performed prior to that of pulmonary veins.

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Development of a Freeway Incident Detection Model Based on Traffic Congestion Classification Scheme (교통정체상황 분류기법에 기초한 연속류 돌발상황 검지모형 개발 연구)

  • Kim, Young-Jun;Chang, Myung-Soon
    • Journal of Korean Society of Transportation
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    • v.22 no.6
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    • pp.175-196
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    • 2004
  • This study focuses on improving the performance of freeway incident detection by introducing some new measures to reduce false alarms in developing a new incident detection model. The model consists of the 5 major components through which a series of decision makings in determining the given traffic flow condition are made. The decision making process was designed such that the causes of traffic congestions can be accurately classified into several types including incidents and bottlenecks according to their unique characteristics. The model performance was tested and found to be compatible with that of the existing well-recognized models in terms of the detection rate and detection time. It should noted that the model produced much less false alarms than most of the existing models. The study results prove that the initial objective of the study was satisfied as it was an experimental trial to improve the false alarm rate for the incident detection model to be more pactically usable for traffic management purposes.

A Call Admission Control Algorithm in 3GPP LTE System for Guarantee of Packet Delay (패킷 지연 보장을 위한 LTE 시스템의 호 수락 제어 알고리즘)

  • Bae, Sueng-Jae;Choi, Bum-Gon;Lee, Jin-Ju;Kwon, Sung-Oh;Chung, Min-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.34 no.6A
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    • pp.458-467
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    • 2009
  • Long Tenn Evolution (LTE) is the next generation mobile phone technology which has being standardized by the Third Generation Partnership Project (3GPP). In the existing mobile communication networks, voice traffic is delivered through circuit switched networks. In LTE, however, all kinds of traffic are transferred through IP based packet switched networks which has best-effort characteristic. Therefore, providing QoS in LTE system is difficult. In order to provide QoS in LTE, RRM is very important. Especially, in part of RRM, call admission control (CAC) performs an important function to reduce network congestion and guarantee a certain level of QoS for on-going calls. In this paper, we propose a CAC algorithm in order to provide QoS for various kinds of services in LTE system. The performance of the proposed algorithm is evaluated with various simulation environments. The results show that the proposed algorithm provides QoS through rejections of requested calls. Especially, the proposed CAC algorithm can be satisfied with packet delay requirement defined in LTE specification.

Early-Onset Postcardiac Injury Syndrome after Percutaneous Coronary Intervention Recovered with Steroids (경피적 관상동맥중재술 후 급성으로 발생한 스테로이드 치료로 회복한 심근 손상 후 증후군)

  • Kim, Min-Jeong;Yoon, Seong-Bo;Lee, Myong Dong;Kim, Si-Ho;Kim, Young Woo
    • The Korean Journal of Medicine
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    • v.93 no.6
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    • pp.565-570
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    • 2018
  • Postcardiac injury syndrome (PCIS) is an inflammatory process that usually occurs within 1 to 6 weeks after an injury to the pericardium, epicardium, or myocardium. As more interventions are performed for complicated coronary artery obstructive lesions, there have been some recent reports on PCIS following percutaneous coronary intervention (PCI). The medical management of PCIS depends on nonsteroidal anti-inflammatory drugs (NSAIDs), in addition to colchicine or steroids. An 80-year-old male patient underwent a PCI. Unfortunately, the guidewire piercing failed but he showed no immediate signs of complication. However, 5 hours after the procedure, he complained of chest discomfort. An electrocardiogram showed widespread ST elevation. Chest X-ray and computed tomography showed pulmonary congestion with pleural effusion, while thoracic echocardiography showed a moderate amount of pericardial effusion. NSAIDs were initiated, but there was no improvement of symptoms. We describe an unusual case of atypical earl onset PCIS after PCI, recovered rapidly by steroids.

Treatment of Severe Pregnancy Rhinitis Using Microdebrider-Assisted Inferior Turbinoplasty: A Case Report (심한 임신성 비염 환자에서 미세분쇄기를 이용한 하비갑개 수술: 증례보고)

  • Shin, Dan Bi;Lee, Jung On;Chun, Tae-Uk;Lee, Tae-Hoon
    • Journal of Rhinology
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    • v.25 no.2
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    • pp.103-107
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    • 2018
  • Pregnancy rhinitis is a relatively common condition. It is characterized by the presence of nasal symptoms, especially nasal congestion, not present prior to pregnancy, but typically present during the last 6 or more weeks of pregnancy, without other signs of respiratory tract infection or any known allergic causes, and disappearing completely within 2 weeks after delivery. Nasal saline irrigation, intranasal steroid spray, and oral antihistamines are usually recommended as the first line of treatment for rhinitis. However, most pregnant women refuse medical treatment for pregnancy rhinitis because of the fear of teratogenicity. Severe pregnancy rhinitis increases the risk of snoring, which has been suggested as having adverse effects on the fetus. In cases where the patients are unable to control their symptoms, pregnancy rhinitis can negatively affect the quality of life (QOL) as well as the pregnancy outcome. Therefore, special caution is required for determining the appropriate diagnosis and treatment modalities for pregnancy rhinitis. Here, we report for the first time, the successful treatment of pregnancy rhinitis that was unresponsive to conservative management and medical therapy by using microdebrider-assisted inferior turbinoplasty at the final stages of pregnancy, along with a review of the relevant literature.