• Title/Summary/Keyword: ports

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A Study on the Asia Container Ports Clustering Using Hierarchical Clustering(Single, Complete, Average, Centroid Linkages) Methods with Empirical Verification of Clustering Using the Silhouette Method and the Second Stage(Type II) Cross-Efficiency Matrix Clustering Model (계층적 군집분석(최단, 최장, 평균, 중앙연결)방법에 의한 아시아 컨테이너 항만의 클러스터링 측정 및 실루엣방법과 2단계(Type II) 교차효율성 메트릭스 군집모형을 이용한 실증적 검증에 관한 연구)

  • Park, Ro-Kyung
    • Journal of Korea Port Economic Association
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    • v.37 no.1
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    • pp.31-70
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    • 2021
  • The purpose of this paper is to measure the clustering change and analyze empirical results, and choose the clustering ports for Busan, Incheon, and Gwangyang ports by using Hierarchical clustering(single, complete, average, and centroid), Silhouette, and 2SCE[the Second Stage(Type II) cross-efficiency] matrix clustering models on Asian container ports over the period 2009-2018. The models have chosen number of cranes, depth, birth length, and total area as inputs and container TEU as output. The main empirical results are as follows. First, ranking order according to the efficiency increasing ratio during the 10 years analysis shows Silhouette(0.4052 up), Hierarchical clustering(0.3097 up), and 2SCE(0.1057 up). Second, according to empirical verification of the Silhouette and 2SCE models, 3 Korean ports should be clustered with ports like Busan Port[ Dubai, Hong Kong, and Tanjung Priok], and Incheon Port and Gwangyang Port are required to cluster with most ports. Third, in terms of the ASEAN, it would be good to cluster like Busan (Singapore), Incheon Port (Tanjung Priok, Tanjung Perak, Manila, Tanjung Pelpas, Leam Chanbang, and Bangkok), and Gwangyang Port(Tanjung Priok, Tanjung Perak, Port Kang, Tanjung Pelpas, Leam Chanbang, and Bangkok). Third, Wilcoxon's signed-ranks test of models shows that all P values are significant at an average level of 0.852. It means that the average efficiency figures and ranking orders of the models are matched each other. The policy implication is that port policy makers and port operation managers should select benchmarking ports by introducing the models used in this study into the clustering of ports, compare and analyze the port development and operation plans of their ports, and introduce and implement the parts which required benchmarking quickly.

In-Cylinder Flow Characteristics of a Lean Burn Engine under Steady Conditions for Different Port Shapes (포트형상에 따른 정상상태 조건하에서의 희박엔진 연소실내의 유동특성)

  • 박상봉;이은현;유정열;이준식;최해천
    • Transactions of the Korean Society of Automotive Engineers
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    • v.6 no.3
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    • pp.26-33
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    • 1998
  • An experimental study has been conducted for the three-dimensional in-cylinder swirl flow under steady conditions. Velocity fields are measured by using an LDV at various valve lifts. Effects of geometry of inlet ports on swirl flows are investigated for standard and helical ports. Swirl distributions evaluated from velocity measurements are compared with those obtained from an impulse torque swirl meter. Results show that the helical port generates more intensive swirl than the standard one but it causes red- uction in air flow coefficient. At the lower valve lift, no significant difference is observ- ed in non-dimensional swirl values between two ports because of limited pre-swirl effect, while it becomes significant as the valve lift increases.

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Activation Scheme of Mokpo New Port through a Priority Cargo Attraction Strategy (중점화물유치전략을 통한 목포신항 활성화 방안)

  • Choe, Dong-O
    • Journal of Korea Port Economic Association
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    • v.21 no.4
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    • pp.161-181
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    • 2005
  • This paper investigates the circumstances and conditions of Mokpo Port to develop it as an international logistics stronghold and seeks scheme to maximize the local economic ripple effect through construction and activation of Mokpo New Port. Under the circumstances in which neighboring ports vying with each other have built broad spheres of influence, and competition among ports becomes fierce, a priority cargo attraction strategy should be established by using Mokpo's favorable location compared to other ports in order to ensure that a large quantity of goods is transported from Mokpo New Port. Especially, Mokpo New Port needs to be developed as a vehicles-only exporting port, as well as a port for used car exports and an import port for stones and timber.

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Development Status of Chinese, Japanese and Taiwan Hub-Ports and Korean Port Development Countermeasure (중국, 일본, 대만의 Hub-Port 추진현황과 우리나라 항만개발 대응방안)

  • Hong, Geum-U
    • Journal of Korea Port Economic Association
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    • v.20 no.2
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    • pp.89-100
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    • 2004
  • Because of a recent trend of the open and globalized world economy, international trade is getting bigger and there is a trade competition among many countries, resulting in competition between harbor industries. Therefore, as hub-port development of China, Japan and Taiwan is more actively progressing than any other times, Korea should prepare a powerful management system to take the initiative over them. Above all, a new recognition of the governmental officers in charge of political management about hub-port industry and early development of the northeast hub-port are needed. To maximize its distinctiveness from competitive ports, port sale should be actively managed. As well, as port functions are diverse, accompanied site development should be prepared. In conclusion, in order to improve functions of a port and develop the port as a general complex of physical distribution, the government should encourage the accompanied site development and support preparation of a customs-free area and a general system of physical distribution.

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A Study on the ventilation Technology for Indoor Air Quality Improvement (실내 공기질 개선을 위한 환기기술에 관한 연구)

  • Chang Tae-Hyun;Cho Hyun-Wook
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.5
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    • pp.540-551
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    • 2005
  • In this research, We'll focus on warm environment and ventilation characteristics when utilizing intake ports, exhaust port and 4-way cassettes for removing heat and polluted air. Four way cassettes have been typical air conditioning units for offices since the multi air-conditioner was introduced. The following installation cases will also be discussed: 1) 4-way cassette's operation without intake ports and exhaust port. 2) Effect of the position of intake port and exhaust ports. 3) cooling air flow, temperature. distribution and local supply index according to the air flow rate from 4-way cassettes.

A Fundamental Study on the Improvement of Harbour Tranquility and Water Quality of Fishing Port (어항의 정온도 향상과 수질개선을 위한 기초적 연구)

  • Ryu, Cheong-Ro;Kim, Jong-Hwa;Park, Jong-Hwa
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.26 no.4
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    • pp.341-352
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    • 1990
  • The purpose of this research is to develop the design/control method that can be used for the improvement of harbour tranquility and water quality of fishing ports. For this end, firstly, the hydraulic environmental characteristics of fishing ports in the coastal waters of the Korean Peninsula are analysed and discussed combined with disasters of facilities and vessels in the ports. Secondly the problems of water quality control is pointed out considered with the improvement measures of harbour tranquility such as the methods of lengthen of main breakwaters and construction of wave absorbing structures. Finally, the control characteristics of composite functions of water quality and tranquility of fishing port are discussed and the improved control method si proposed using the experimental results for the various measures. The proposed measure is proved to be a applicable method to improve these two main functions on the design of fishing port.

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A study on the effect improving in-cylinder flow on fast and lean burn in a gasoline engine (가솔린엔진의 연소실내 유동개선에 의한 급속희박 연소효과에 관한 연구)

  • 강건용;엄종호;정동수
    • Journal of the korean Society of Automotive Engineers
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    • v.14 no.3
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    • pp.80-89
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    • 1992
  • An experimental study of in-cylinder of flow and combustion characteristics in two gasoline engines of different intake ports which are denoted as original port and masked shroud head (MSH) ports is presented. The flows generated by the MSH and the original port are invest- igated by laser Doppler velocimeter(LDV) under steady flow and motoring (non-firing) condit -ions. Combustion characteristics with different swirl levels produced by two intake ports are analyzed by combustion pressure measurement and statistical calculation. The swirl inside the cylinder of the MSH port engine is found to be much higher than the original port, and the MSH has a large eddy motion of cylinder diameter size. Using ensemble average method to valuate engine turbulence under motoring condition, the MSH port engine is shown to have h -igher turbulence intensity than the original port, so that the effect of the MSH port on fast burn is shown. Also the cyclic variations of peak pressure and the reaching time in the MSH port are apparently reduced.

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Strategy Development plan of Maritime Logistics IT (항만물류 정보화 발전방향)

  • Park, Jeong-Cheon
    • Proceedings of the Korea Port Economic Association Conference
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    • 2007.07a
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    • pp.37-50
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    • 2007
  • Taking advantage of geographical position of Korea located on the main route of world-wide service, Port Logistics Industry can be strategic industry which secures international competitiveness necessary for Korea to be hub of Northeast Asian's logistics. Along with the advent of super large container vessel, world ports environment changed from "milkway" type, which means vessel calls every port for service to "Hub & Spoke" type, which means vessel calls regional central port and feeder service for the rest ports. As environment changes, regional ports in Northeast Asia are competing each other tougher and tougher and introducing or developing port logistics information system based on state-of-the-art technology in order to adapt themselves to new environment, thus to be Hub port. Taking this situation into consideration, we want to define clearly the meaning and scope of port logistics IT and review the global trend of port logistics IT. Finally we want to find future development of port logistics IT which we have to achieve.

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Development of a Vent Analysis Method for Multiple Compartments Connected Through Multiple Ports (다중 Port로 연결된 다중 격실 Vent 해석 기법 개발)

  • Ok, Ho-Nam;Kim, In-Sun
    • 유체기계공업학회:학술대회논문집
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    • 2006.08a
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    • pp.547-550
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    • 2006
  • An analysis method is developed for the prediction of venting in multiple compartments which are connected in series or parallel through multiple ports. The existing method by the authors is modified to remove the limitation in number of ports and compartments, and the more general polytropic relation or solution of the additional energy equation replaces the previous isentropic relation allowing the prediction of pressure rise in addition to pressure drop. The accuracy of the method is verified by comparison with the results by NASA Flap code for the problem of pressure drop in a payload in the Space Shuttle cargo bay. It is expected that this method will be a useful tool in prediction of the pressure variation in a payload or payload capsule without mentioning the payload fairing itself.

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PREDICTION OF THE ORIFICE DISCHARGE COEFFICIENT USING COMPUTATIONAL FLUIDS DYNAMICS (전산유동해석을 이용한 ORIFICE 방출 계수 예측)

  • Ok, H.;Kim, I.
    • 한국전산유체공학회:학술대회논문집
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    • 2006.10a
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    • pp.147-150
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    • 2006
  • Vent ports are installed on the walls of closed compartments of a launch vehicle to control the pressure drop in the compartments. The ports can be modelled as an orifice, and the accurate prediction of the discharge coefficient of an orifice is essential for the design of vent ports. Experimental methods have been used to determine the discharge coefficients for various shapes of orifices, and extensive databases are available. Wind tunnel tests have been also done to evaluate the effect of interaction between venting outflow and freestream for limited conditions. The goal of the present research is to predict the discharge coefficient of an orifice using CFD and evaluate the accuracy of the method, especially for the orifices exposed to the external flow.

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