• Title/Summary/Keyword: (Transport Network)

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A Study on Problems Arising from Application of the Retterdam Rules under International Multimodal Transport Contracts (국제복합운송계약에서 로테르담 규칙의 적용상 문제점에 관한 연구)

  • Yang, Jung-Ho
    • THE INTERNATIONAL COMMERCE & LAW REVIEW
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    • v.46
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    • pp.181-210
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    • 2010
  • The continuing advance of multimodal transport with the importance for efficient and effective logistics management emphasizes the need for uniform legal approach to international multimodal transport. However, the current fragmented instrument regulating such transport is being an obstacle to development of multimodal transport as it aggravates confusion and uncertainty. The Rotterdam rules, which was adopted in December 2008 by UNCITRAL, expands its scope of application to door-to-door transport. However, the new rules has some problems in its application to multimodal transport operation as it has been conceived not to regulate general multimodal carriage but to regulate contract of carriage by sea that extends its services to the transport by other modes. This article examines conflict of conventions in the Rotterdam Rules. The applicability of the Rotterdam Rules in international multimodal transport contract and possibility of potential conflict with other transport conventions are analyzed with some hypothetical cases. Furthermore, problems arising from application of the Rotterdam Rules under international multimodal transport Contracts are indicated in the chapter IV.

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Congestion Control of a Priority-Ordered Buffer for Video Streaming Services (영상 스트리밍 서비스를 위한 우선순위 버퍼 혼잡제어 알고리즘)

  • Kim, Seung-Hun;Choi, Jae-Won;Choi, Seung-Sik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.4B
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    • pp.227-233
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    • 2007
  • According to the recent development of network technology, the demands of users are diversified and the needs of multimedia traffic are increasing. In general, UDP(User Datagram Protocol) traffic is used to transport multimedia data, which satisfied the real-time and isochronous characteristics. UDP traffic competes with TCP traffic and incur the network congestion. However, TCP traffic performs network congestion control but does not consider the receiver's status. Thus, it is not appropriate in case of streaming services. In this paper, we solve a fairness problems and proposed a network algorithm based on RTP/RTCP(Real-time Transport Protocol/Realtime Transport Control Protocol) in view of receiver status. The POBA(Priority Ordered Buffer Algorithm), which applies priorities in the receiver's buffer and networks, shows that it provides the appropriate environment for streaming services in view of packet loss ratio and buffer utilization of receiver's buffer compared with the previous method.

An Analysis for Airport Network Characteristics Assuming the Integrated Aviation Market of Korea, China and Japan (공항 네트워크의 특성 분석-한중일 항공시장 통합을 전제로)

  • O, Seong-Yeol;Park, Yong-Hwa;Yun, Sin
    • Journal of Korean Society of Transportation
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    • v.27 no.5
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    • pp.75-82
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    • 2009
  • Air transport markets are composed of airlines' networks through their base airports. The analysis of an air transport market has been focusing on determining the efficiency or competitiveness of airports or airlines in the market using number of routes, number of passengers, transfer rates, revenues, costs, and other data. However, little work has been done in analyzing the airport network itself. Assuming the air transport markets of Korea, China, and Japan are integrated, this paper aims to analyze the characteristics of the resulting airport network. To that end, the degree of connectivity, the degree of closeness, and the betweenness of centrality are employed. The analysis shows that Incheon International Airport is better than most other airports in terms of the degree of connectivity and that of closeness. Airports in Japan, however, exhibit strong connectivity but weak closeness and betweenness of centrality. Although it has low connectivity, Shenyang Airport has a possibility of becoming an attractive point of the integrated market in the future due to its high degree of closeness.

Broadband Content Insertion Technology based on Terrestrial UHD Broadcasting MMT/ROUTE (지상파 UHD 방송 MMT/ROUTE기반 브로드밴드 콘텐츠 삽입 기술)

  • Kim, Doohwan;Lee, Dongkwan;Kim, Kyuheon
    • Journal of Broadcast Engineering
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    • v.24 no.2
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    • pp.329-340
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    • 2019
  • Recently, broadcasting technologies have evolved as high-quality AV services such as domestic terrestrial UHD(Ultra-High Definition) broadcasting have been increasing, and broadcasting standards have been newly defined. Also, as network technology develops, contents are consumed not only in the country but also the world. Accordingly, content insertion technology, which is a method of providing suitable contents in accordance with the national and local environments, will be needed. This paper proposes a content insertion service system model and synchronization scheme using ATSC(Advanced Television Systems Committee) 3.0 Event Signaling standard under heterogeneous network environment of broadcasting network and internet network based on transmission standard DASH(Dynamic Adaptive Streaming over HTTP)/ROUTE(Real time Object delivery Over Unidirectional Transport) and MMT(MPEG Media Transport) of terrestrial UHD broadcasting. It also verifies that the service operates in an environment that meets the broadcast standard.

Design and Simulation of a Monorail Network for the Inter-terminal Transport

  • Truong, Ngoc Cuong;Kim, Hwan-Seong;Kim, In-Yong;Nguyen, Duy Anh;Bao, Long Le Ngoc
    • Journal of Navigation and Port Research
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    • v.44 no.5
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    • pp.382-391
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    • 2020
  • In line with the trend of global transport volume which has increased rapidly over the years, internal transportation in seaports is always conducted with high frequency. Thus, there is always much potential for traffic jams as well as high transportation costs and emissions. Many efforts have been initiated to streamline the inter-terminal container transport (ITT) through the development of automated vehicles and equipment as well as using private transport facilities to overcome these limitations. The purpose of this paper to develop a framework to design, analyze, and validate the efficiency of a new ITT system in a port area based on the monorail network and automatic vehicles. First, the number of shuttles and loaders was determined depending on the transport demand scenario. Next, a simulation model was applied to evaluate the system performance as well as gain more insight into the working process of the ITT system. Finally, by setting goals for the performance indicators, the results showed that the system was highly efficient with 100% of the containers delivered to their destination on time. Besides, a series of other performance tracking was provided to provide insight into the system's capabilities.

A Network Sensor Location Model Considering Discrete Characteristics of Data Collection (데이터 수집의 이산적 특성을 고려한 네트워크 센서 위치 모형)

  • Yang, Jaehwan;Kho, Seung-Young;Kim, Dong-Kyu
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.16 no.5
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    • pp.38-48
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    • 2017
  • Link attributes, such as speed, occupancy, and flow, are essential factors for transportation planning and operation. It is, therefore, one of the most important decision-making problems in intelligent transport system (ITS) to determine the optimal location of a sensor for collecting the information on link attributes. This paper aims to develop a model to determine the optimal location of a sensor to minimize the variability of traffic information on whole networks. To achieve this, a network sensor location model (NSLM) is developed to reflect discrete characteristics of data collection. The variability indices of traffic information are calculated based on the summation of diagonal elements of the variance-covariance matrix. To assess the applicability of the developed model, speed data collected from the dedicated short range communication (DSRC) systems were used in Daegu metropolitan area. The developed model in this study contributes to the enhancement of investment efficiency and the improvement of information accuracy in intelligent transport system (ITS).

Network Jitter Estimation Algorithm for Robust VoIP System in Vehicle Environment (자동차 환경내 안정적인 VoIP 시스템을 위한 네트워크 지터 추정 알고리즘)

  • Seo, Kwang-Duk;Lee, Jin-Ho;Kim, Hyoung-Gook
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.4
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    • pp.93-99
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    • 2011
  • This paper proposes a novel network jitter estimation algorithm for robust VoIP communication system. The proposed method computes the current network environment mode using the differences of arrival time and generation time from sequential received packets. According to the current network environment mode, the jitter variance weights is adjusted to minimize the error for estimating the network jitter. The jitter average and variance are calculated by the autoregressive estimated algorithm, and then the network jitter is estimated by applying the jitter variance weights.

A TCP Performance Enhancement Scheme in Wireless Mesh Networks (무선 메쉬 네트워크에서 TCP 성능 향상 기법)

  • Lee, Hye-Rim;Moon, Il-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.14 no.5
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    • pp.1139-1145
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    • 2010
  • Wireless mesh network is similar to ad-hoc network, so when transferred to the data packet in the wireless environment, interfered factor arise. When TCP(Transport Control Protocol) was created, however as it was design based on wired link, wireless link made more transmission error than wired link. It is existent problem that TCP unfairness and congestion collapse over wireless mesh network. But packet losses due to transmission errors are more frequent. The cause of transmission error in wireless ad-hoc network may be inexactly regarded as indications of network congestion. And then, Congestion Control Algorithm was running by this situation causes the TCP performance degradation. In this paper, proposed TCP can adaptively regulate the congestion window through moving node in the Wireless Mesh Network. And it enhanced the performance.