• Title/Summary/Keyword: Congestion Management

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Unexpected Complications and Safe Management in Laparoscopic Pancreaticoduodenectomy

  • Yuichi Nagakawa;Yatsuka Sahara;Yuichi Hosokawa;Chie Takishita;Tetsushi Nakajima;Yousuke Hijikata;Kazuhiko Kasuya;Kenji Katsumata;Akihiko Tsuchida
    • Journal of Digestive Cancer Research
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    • v.5 no.1
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    • pp.23-27
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    • 2017
  • Although laparoscopic pancreaticoduodenectomy (LPD) is considered as minimally invasive surgery, an advanced level of laparoscopic skill is still required. LPD comprises various procedures including reconstruction. Therefore, establishment of a safe approach at each step is needed. Prevention of intraoperative bleeding is the most important factor in safe completion of LPD. The establishment of effective retraction methods is also important at each site to prevent vascular injury. I also recommend the "uncinate process first" approach during initial cases of LPD, in which the branches of the inferior pancreaticoduodenal artery are dissected first, at points where they enter the uncinate process. This approach is performed at the left side of the superior mesenteric artery (SMA) before isolating the pancreatic head from the right aspect of the SMA, which allows safe dissection without bleeding. Safe and reliable reconstruction is also important to prevent postoperative complications. Laparoscopic pancreatojejunostomy requires highly skilled suturing technique. Pancreatojejunostomy through a small abdominal incision, as in hybrid-LPD, facilitates reconstruction. In LPD, the surgical view is limited. Therefore, we must carefully verify the position of the pancreaticobiliary limb. A twisted mesentery may cause severe congestion of the pancreaticobiliary limb following reconstruction, resulting in severe complications. We must secure the appropriate position of the pancreaticobiliary limb before starting reconstruction. We describe the incidence of intraoperative and postoperative complications and appropriate technique for safe performance of LPD.

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A Study on COVID-19 Symptoms according to Sasang Constitution (사상체질에 따른 COVID-19 감염증상에 대한 연구)

  • Na-Yoen Kwon;Go Ho Yeon;Shin Mi Ran
    • Journal of Sasang Constitutional Medicine
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    • v.35 no.4
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    • pp.42-54
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    • 2023
  • Objectives This study aims to identify differences in clinical manifestations of COVID-19 between different Sasang constitution. Methods Subjects were recruited from August 29, 2022, to July 11, 2023. COVID-19 clinical symptoms were self-reported via questionnaires. Sasang constitutional diagnosis was performed using the K-PRISM, and Sasang constitutional specialist. Results A total of 66 subjects were recruited for the study, and the Sasang constitutional distribution of the subjects was 19 soyangin, 25 taeeumin, and 22 soeumin. For most of the COVID-19 clinical manifestations, the study found that soyangin experienced symptoms at a higher rate than other constitutions. Among the symptoms observed in the study, sore throat, pantalgia, and cough were severe in all subjects regardless of constitution. Soeumin was more likely to experience abdominal pain, chest pain, and diarrhea, while soyangin was more likely to experience chest pain, nausea/vomiting, diarrhea, and cutaneous symptoms compared to other constitutions. Taeeumin had more sputm, nasal congestion, and skin symptoms, but fewer digestive symptoms. There were differences in the onset and duration of symptoms by constitution. Conclusions This study is an important contribution to our understanding of the differences in response to the COVID-19 virus among different Sasang constitutions. Symptomatic differences between constitutions may have important implications for prevention and treatment strategies for infectious diseases, and personalized treatment and management based on these differences may be needed in the future.

Development of Integrated Traffic Control of Dynamic Merge and Lane Change at Freeway Work Zones in a Connected and Automated Vehicle Environment (자율협력주행차 환경의 고속도로 공사구간 동적합류 및 차로변경 통합제어전략 개발)

  • Kim, Yongju;Ka, Dongju;Kim, Sunho;Lee, Chungwon
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.19 no.3
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    • pp.38-51
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    • 2020
  • A bottleneck and congestion occur when a freeway is closed due to maintenance and construction activities on the freeway. Although various traffic managements have been developed to improve the traffic efficiency at freeway work zones, such as merge control, there is a limit to those controls with human drivers. On the other hand, the wireless communication of connected and automated vehicles (CAVs) enables the operation of advanced traffic management. This study developed a traffic control strategy that integrates Dynamic Merge Control (DMC) and Lane Change Control (LCC) in a CAV environment. DMC operates as an either early or late merge based on the occupancy rate of upstream of the work zone. The LCC algorithm determines the number of vehicles that need to change their lane to balance the traffic volume on open lanes. The simulation results showed that integrated control improves the cumulative vehicle count, average speed upstream, and average network travel time.

Spatio-temporal Changes of Urban Sprawl Process in Seoul Metropolitan Area : Spatial Structure-based Approach (수도권 스프롤 양상의 시공간적 변화 : 공간구조 기반 접근)

  • Lim, Sujin;Kim, Kamyoung
    • Journal of the Korean association of regional geographers
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    • v.22 no.3
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    • pp.628-642
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    • 2016
  • In small countries such as Korea, rapid expansion of cities has been pointed out as the main cause of urban and environmental issues. In order to understand the urban problems caused by urban sprawl and prepare countermeasures for it, urban sprawl must be accurately measured first of all. The purpose of this study is to analyze the spatio-temporal changes of urban sprawl process in Seoul Metropolitan Area using landscape indices which measure the degree of urban sprawl in terms of urban structure such as area, distribution, and shape of urbanized area. FRAGSTATS, which is a tool for landscape analysis, is utilized to calculate landscape indices. Major findings are as follows. First, the urban sprawl in Seoul Metropolitan Area has been continually intensified since the late 1980s and this tendency was more clearer in the 1990s than the 2000s. While leapfrog development is relatively prominent in the 1990s, infilling development is remarkable in the 2000s. Second, the progress and development types of sprawl progress were different according to the zones which are defined based on Seoul Metropolitan Area Readjustment Planning Act. Congestion Restrain Zone shows the highest level of urban sprawl in terms of the evaluated landscape indices, but infilling development was predominant. In Growth Management Zone1, leapfrog development was dominant in the 1990s and infilling development in the 2000s. In Growth Management Zone1, leapfrog development has been continually remarkable since the late 1980s. Nature Conservation Zone shows the lowest level of sprawl, but its sprawl tendency is gradually being intensified. Third, the sprawl tendency in Seoul Metropolitan Area was different according to the distance and direction from Seoul. Urban sprawl was remarkable at Si-Guns close to Seoul in the late 1980s, Si-Guns close to Seoul and the southern part of Seoul in the late 1990s, and the southern and northern parts of Seoul in the late 2000s.

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ea­-RED++: Adding Prediction Algorithm for ea­-RED Router Buffer Management Algorithm (ea-­RED++ : 예측 알고리즘을 적용한 ea-­RED 알고리즘)

  • Lee, Jong-Hyun;Lim, Hye-Young;Hwang, Jun;Kim, Young-Chan
    • Proceedings of the Korean Information Science Society Conference
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    • 2003.10c
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    • pp.298-300
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    • 2003
  • ea­RED(Efficient Adaptive RED)[1][2]는 다수의 TCP 커넥션이 경쟁하는 병목구간에서 인터넷 라우터 버퍼를 능동적으로 관리하는 다양한 AQM(Active Queue Management) 알고리즘 중의 하나로 RED 라우터 버퍼 관리 알고리즘의 성능을 개선한 라우터 버퍼 관리 알고리즘이다. RED 라우터가 TD 라우터와 같은 네트워크 퍼포먼스를 유지하면서 TCP 커넥션 간 페어니스를 향상시키기 위해서는 link bandwidth. active 커넥션 수. congestion level 등에 대한 네트워크 상태를 고려하여 파라미터에 적절한 값을 설정해야만 한다. 문제는 다이내믹하게 변하는 네트워크 상황에 적합한 파라미터 값을 초기에 설정해주는 것이 매우 어렵다는 점이다. [3]. ea­RED는 max threshold와 min threshold 값을 네트워크 상황에 따라 동적으로 조절함으로써 이런 문제를 해결했고, 기존 RED에 비해 라우터 버퍼는 50% 정도만 사용하면서도, 페어니스 인덱스(Fairness Index)[4]가 최대 41.42% 개선되었다. [1] [2] 그러나 송신 TCP 커넥션의 수가 늘어날수록 성능향상에 대한 효과가 감소되었고, 드롭 패킷수가 TD나 RED 라우터 버퍼관리 알고리즘에 비해 많았기 때문에 라우터의 출력(output) 총 패킷 용량이 최대 약 2.3% 정도 TD나 RED 라우터 버퍼관리 알고리즘에 비해 적었다. 이 부분을 개선하기 위해 기존 ea­RED 알고리즘에 LR_Lines 예측 알고리즘을 적용한 ea­RED++ 알고리즘을 구현하였고, 실험 결과 페어니스 인덱스는 기존 ea­RED에 비해 최대 약 30% 정도 향상되었고, 총 output 패킷 용량의 손실률은 최대 50%정도 감소하여 기존 ea­RED에 비해 향상된 성능을 보여주었다.웍스 네트워크상의 다양한 디바이스들간의 네트워크 다양화와 분산화 기능을 얻을 수 있었고, 기존의 고가의 해외 솔루션인 Echelon사의 LonMaker 소프트웨어를 사용하지 않고도 국내의 순수 솔루션인 리눅스 기반의 LonWare 3.0 다중 바인딩 기능을 통해 저 비용으로 홈 네트워크 구성 관리 서버 시스템 개발에 대한 비용을 줄일 수 있다. 기대된다.e 함량이 대체로 높게 나타났다. 점미가 수가용성분에서 goucose대비 용출함량이 고르게 나타나는 경향을 보였고 흑미는 알칼리가용분에서 glucose가 상당량(0.68%) 포함되고 있음을 보여주었고 arabinose(0.68%), xylose(0.05%)도 다른 종류에 비해서 다량 함유한 것으로 나타났다. 흑미는 총식이섬유 함량이 높고 pectic substances, hemicellulose, uronic acid 함량이 높아서 콜레스테롤 저하 등의 효과가 기대되며 고섬유식품으로서 조리 특성 연구가 필요한 것으로 사료된다.리하였다. 얻어진 소견(所見)은 다음과 같았다. 1. 모년령(母年齡), 임신회수(姙娠回數), 임신기간(姙娠其間), 출산시체중등(出産時體重等)의 제요인(諸要因)은 주산기사망(周産基死亡)에 대(對)하여 통계적(統計的)으로 유의(有意)한 영향을 미치고 있어 $25{\sim}29$세(歲)의 연령군에서, 2번째 임신과 2번째의 출산에서 그리고 만삭의 임신 기간에, 출산시체중(出産時體重) $3.50{\sim}3.99kg$사이의 아이에서 그 주산기사망률(周産基死亡率)이 각각 가장 낮았다. 2. 사산(死産)과 초생아사망(初生兒死亡)을 구분(區分)하여 고려해 볼때 사산(死産)은 모성(母性)의 임신력(姙娠歷)과 매우 밀접한 관련이 있는 것으로 사료(思料)되었고 초생아사망(初生兒死亡)은 미숙아(未熟兒)와 이에 관련된 병

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Implementing Special Transportation Management Zone System for Dongdaemoon Garment District (동대문 의류밀집상가 교통혼잡특별관리구역 사례연구)

  • 황기연;엄진기;이종운;조용학
    • Journal of Korean Society of Transportation
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    • v.18 no.6
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    • pp.7-17
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    • 2000
  • The Purpose of this study is to test the effectiveness of Special Transportation Management Zone system (TZ) when it is applied to Dongdaemoon commercial zone located in downtown Seoul. The study consists of two Parts ; the legal components of TZ and the case study on Dongdaemoon district. The case study includes the analysis of current traffic situation on the study zone, the design of implemention alternative for each component of TZ, the framework of impact analysis system, and the analysis results. The study finds, if 2,000 won mandatory parking fee on drivers parking in the buildings only with over 10 parking spaces and over 3.000$m^2$ in floor area, strong illegal parking enforcement, and Pro-hibition of parking passenger cars whose last digit plate number matches with the last digit of date, are implemented in the zone simultaneously, the traffic speed increases to 20.56km/h which is above the target set in the zone. In conclusion, we find that TZ2 can be an effective tool relieving traffic congestion in Seoul, and that it is necessary for introducing TZ in Seoul that relevant laws should be revised and expecting problems should be overcome.

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Development of Freeway Traffic Incident Clearance Time Prediction Model by Accident Level (사고등급별 고속도로 교통사고 처리시간 예측모형 개발)

  • LEE, Soong-bong;HAN, Dong Hee;LEE, Young-Ihn
    • Journal of Korean Society of Transportation
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    • v.33 no.5
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    • pp.497-507
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    • 2015
  • Nonrecurrent congestion of freeway was primarily caused by incident. The main cause of incident was known as a traffic accident. Therefore, accurate prediction of traffic incident clearance time is very important in accident management. Traffic accident data on freeway during year 2008 to year 2014 period were analyzed for this study. KNN(K-Nearest Neighbor) algorithm was hired for developing incident clearance time prediction model with the historical traffic accident data. Analysis result of accident data explains the level of accident significantly affect on the incident clearance time. For this reason, incident clearance time was categorized by accident level. Data were sorted by classification of traffic volume, number of lanes and time periods to consider traffic conditions and roadway geometry. Factors affecting incident clearance time were analyzed from the extracted data for identifying similar types of accident. Lastly, weight of detail factors was calculated in order to measure distance metric. Weight was calculated with applying standard method of normal distribution, then incident clearance time was predicted. Prediction result of model showed a lower prediction error(MAPE) than models of previous studies. The improve model developed in this study is expected to contribute to the efficient highway operation management when incident occurs.

Improvement of F-GCRA Algorithm for ATM-GFR Service (ATM-GFR 서비스를 위한 F-GCRA 알고리즘 개선)

  • Park, In-Yong
    • The KIPS Transactions:PartC
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    • v.13C no.7 s.110
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    • pp.889-896
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    • 2006
  • ATM Forum has defined a guaranteed frame rate (GFR) service to serve Internet traffic efficiently. The GFR service provides virtual connections (VCs) for minimum cell rate (MCR) guarantees and allows them to fairly share the residual bandwidth. And ATM Forum has recommended a frame-based generic cell rate algorithm (F-GCRA) as a frame classifier, which determines whether an Am cell is eligible to use the guaranteed bandwidth in a frame level. An ATM switch accommodates cells in its buffer or drops them in a frame level according to current buffer occupancy. A FIFO shared buffer has so simple structure as to be feasibly implemented in switches, but has not been able to provide an MCR guarantee for each VC without buffer management based on per-VC accounting. In this paper, we enhance the F-GCRA frame classifier to guarantee an MCR of each VC without buffer management based on per-VC accounting. The enhanced frame classifier considers burstness of TCP traffic caused by congestion control algorithm so as to enable each VC to use its reserved bandwidth sufficiently. In addition, it is able to alleviate the unfairness problem in usage of the residual bandwidth. Simulation results show that the enhanced frame classifier satisfies quality of services (QoSs) of the GFR service for the TCP traffic.

Design of Experiment and Analysis Method for the Integrated Logistics System Using Orthogonal Array (직교배열을 이용한 통합물류시스템의 실험 설계 및 분석방법)

  • Park, Youl-Kee;Um, In-Sup;Lee, Hong-Chul
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.12
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    • pp.5622-5632
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    • 2011
  • This paper presents the simulation design and analysis of Integrated Logistics System(ILS) which is operated by using the AGV(Automated Guided Vehicle). To maximize the operation performances of ILS with AGV, many parameters should be considered such as the number, velocity, and dispatching rule of AGV, part types, scheduling, and buffer sizes. We established the design of experiment in a way of Orthogonal Array in order to consider (1)maximizing the throughput; (2)maximizing the vehicle utilization; (3)minimizing the congestion; and (4)maximizing the Automated Storage and Retrieval System(AS/RS) utilization among various critical factors. Furthermore, we performed the optimization by using the simulation-based analysis and Evolution Strategy(ES). As a result, Orthogonal Array which is conducted far fewer than ES significantly saved not only the time but the same outcome when compared after validation test on the result from the two methods. Therefore, this approach ensures the confidence and provides better process for quick analysis by specifying exact experiment outcome even though it provides small number of experiment.

Impacts of Delivery Vehicle Routing on Different Inventory Strategies and Network Configurations (재고전략 및 네트워크 구성에 따른 배송차량의 운영특성 연구)

  • Won, Min-Su;Gang, Gyeong-U
    • Journal of Korean Society of Transportation
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    • v.28 no.5
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    • pp.91-106
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    • 2010
  • Recently, interest in supply chain management is rising along with the increasing oil prices and traffic congestion. In particular, people started studying the issue, but realized that advantageous strategies for suppliers and retailers are not always advantageous to a carrier. Therefore, in this study the atuhors set up a simulation scenario to understand delivery vehicle routing problems under various inventory policies, namely Economic Order Quantity (EOQ) and Periodic Order Quantity (POQ) and network configurations. First, the authors made a virtual supply chain. Then they analyzed characteristics of delivery vehicle routing under various inventory policies (EOQ and POQ) and network configurations. As a result, the POQ inventory policy decreases the number of vehicles, the number of drivers, and the service time of vehicles. Also, the centralized network increases the load factor of vehicles and decreases the service time of vehicles. In other words, the centralized network and the POQ inventory policy are better for the carrier. These results show a savings of 15,556,806 won ($13,389.10) in a month: a reduction of 17%.