• Title/Summary/Keyword: Transport speed

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Performance Comparison of ISO / IEC 18000-3 ASK and PJM Mode (ISO/IEC 18000-3 ASK 모드와 PJM 모드의 성능 비교)

  • Kim, Jae-Lim;Yang, Hoon-Gee
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.6
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    • pp.70-80
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    • 2008
  • This paper presents comparison of 18000-3 ASK and PJM mode RFID in terms of reading speed. This is accomplished by counting the occurrences of a few representative blocks which constitute the reader / tag interactions for each mode. To apply FS (frame slotted)-aloha protocol, four Q-algorithms, which are a Q-algorithm suggested in the standard document, a fixed Q-algorithm, a minimum Q-algorithm and the number of tag dependent Q-algorithm, are used. Through some simulations, we present the reading speed of each mode with respect to the Q-algorithm and the comparison of the reading speed between the two modes for each Q-algorithms.

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An Experimental Investigation on Effects of Gas Hydrate Formation Factors For NGH Transport Technology Development (NGH 수송기술 개발을 위한 주요 인자별 제조특성 실험 연구)

  • Kim, You-Na;Shin, Chang-Hoon;Han, Jeong-Min;Shin, Kwang-Sik;Kim, Byoung-Joo;Lee, Jeong-Hwan
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.511-514
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    • 2007
  • Gas hydrate has a unique property that can store a large volume of gas in water as a solid form. Even though investigations for natural gas storage technology have been carried out for several decades, there are still a lot of unsolved problems due to complex formation process, low formation speed, high energy consumption and so on. So, lots of experiments were conducted to overcome these weaknesses and to develop artificial NGH formation technology applicable to industrial-scale storage and commercial transport. In this study, some series of experiments were performed to analyze both stirred and unstirred system especially about the influences of several gas hydrate formation factors such as agitation speed, system temperature, SDS concentration, etc. As a result, optimum range of SDS concentration and temperature that could enhance the storage capacity and shorten the formation time were found. And it is obviously presented that SDS such a kind of surfactant promotes gas hydrate formation dramatically and the quantity of stored gas are proportional to agitation speed in stirred system.

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THE DESIGN OF NETWORK MODEL FOR THE IMPLEMENTATION OF e-VLBI (e-VLBI 구현을 위한 네트워크 모델 설계)

  • Song, Min-Gyu;Byun, Do-Young;Kim, Hyun-Goo;Oh, Se-Jin;Han, Seog-Tae;Roh, Duk-Gyoo;Lee, Bo-Ahn
    • Publications of The Korean Astronomical Society
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    • v.20 no.1 s.24
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    • pp.63-71
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    • 2005
  • e-VLBI was invented to enhance the efficiency of VLBI (Very-Long-Baseline Interferometry) system by transmitting the data via high speed network. Korean VLBI Network (KVN) has a plan to construct e-VLBI system named e-KVN. High speed backbone network and efficient network model are essential to implement successful e-VLBI system. This paper introduces a network model based on PC cluster technology. The present status of high speed backbone network in Korea is overviewed. We suggest that the network link via Korea Advanced Research Network (KOREN) is one of feasible way for e-KVN. We also describe the principles of e-VLBI and protocol for network transmission such as VSI-E (VLBI Standard Interface - Electronic), RTP (Real-Time Transport Protocol) and RTCP (Real-Time Transport Control protocol).

Deploying Ubiquitous Traffic Flow Control System under the ITS Environments (ITS 환경에 유비쿼터스 교통관리시스템 접목 가능성 연구)

  • Park, Eun-Mi;Oh, Hyun-Sun;Suh, Euy-Hyun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.10 no.5
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    • pp.36-46
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    • 2011
  • It is thought traffic flow management under the ubiquitous transportation system has great potential in view of individual vehicle data availability and V2V, V2I two-way communication environments. However, it is expected that deployment of the ubiquitous transportation system takes some time. Therefore it is necessary to evaluate the feasibility of the algorithm under the ITS environment. The speed management algorithm proposed in the previous research is revised to fit for the ITS data collection and information provision environment. And the feasibility of the algorithm is evaluated through simulation experiments.

A Study on Loading/Unloading Methods for High-Speed Container Loading/Unloading System (고속 컨테이너 하역시스템의 하역방법에 관한 연구)

  • 박경택;김선호;김두형
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 1998.10a
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    • pp.167-174
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    • 1998
  • Recently several researches of high speed container ship and loading system are mainly accomplished in U.S.A. and Japan. Its shipping service is not realized but it is realized in near future. To effective use of the feature and efficiency of them, quay, loading/unloading. yard operation system, port management system and connection transport system must be well integrated and operated. Specially, loading /unloading speed of container crane is important for making effective use of them. To speed up loading/unloading system, RO-RO and LO-LO methods that are mostly exclusive system are studied on the container crane with special structure and mechanism to handle individual container or bundle of containers. In this paper these methods are shown. When new high speed loading system of container is desighed, the realistic constrains must be considered.

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Observations of the Cheju Current

  • Suk, Moon-Sik;Pang, Ig-Chan;Teague, William J.;Chang, Kyung-Il
    • Journal of the korean society of oceanography
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    • v.35 no.3
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    • pp.129-152
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    • 2000
  • The Cheju Current (CC), defined here as a mean eastward flow in the Cheju Strait, mostly carries water of high temperature and salinity originating from the Kuroshio in winter and spring, the Cheju Warm Current Water (CWCW). The strong core of the eastward component of the CC is found close to Cheju Island (Cheju-Do, hereafter) in winter and spring with a peak speed of about 17.0 cm/s. The eastward flow weakens towards the northern Cheju Strait, and a weak westward flow occurs occasionally close to the southern coast of Korea. The volume transport ranges from 0.37 to 0.45 Sv(1 Sv=10$^6$ m$^3$/s) in winter and spring. Seasonal thermocline and harocline are formed in summer and eroded in November. The occurrence of the CWCW is confined in the southern Cheju Strait close to Cheju-Do below the seasonal thermocline in summer and fall, and cold water occupies the lower layer north of the CWCW which is thought to be brought into the area from the area west of Cheju-Do along with the CWCW. Stratification acts to increase both the speed of the CC with a peak speed of greater than 30 cm/s and the vertical shear of the along-strait currents. The strong core of the CC detached from the coast of Cheju-Do and shifted to the north during the stratified seasons. The volume transport in summer and fall ranges 0.510.66 Sv, which is about 1.5 times larger than that in winter and spring. An annual cycle of the cross-strait sea level difference shows its maximum in summer and fall and minimum in winter and spring, whose tendency is consistent with the annual variability of the CC and its transport estimated from the ADCP measurements. Moored current measurements west of Cheju-Do indicate the clockwise turning of the CC, and the moored current measurements in the Cheju Strait for 1530 days show the low-frequency variability of the along-strait flow with a period of about 37 days.

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