• Title/Summary/Keyword: Harbor Limit

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Basic Analysis for Improvement of Mooring Stability Under Long Wave Impact

  • Ha, Chang-Sik;Moon, Seung-Hyo;Lee, Joong-Woo
    • Journal of Navigation and Port Research
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    • v.41 no.5
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    • pp.329-336
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    • 2017
  • This study suggests a general process of analyzing the mooring and cargo handling limit waves, which is an incident to the new energy port under long wave agitation. To reduce damages of ships and harbor structures due to strong wave responses, it is necessary to predict the change of wave field in the mooring berth to make the proper decision by dock master. The berthing area at a new LNG port in the east coast of Korea in this study is frequently affected by oscillations from waves of 8.5~13s periods in the wintertime. The long period waves give difficulties on port operation by lowering the annual berthing ratio. It needs to find the event waves from the real time offshore wave records, which cause over the mooring limits. For that purpose, the wave records from field measurement and offshore wave buoy were analyzed. From numerical simulation, the response characteristics of long period waves in the berthing area were deduced with or without breakwater expansion plan, analyzing the offshore field wave data collected for two years. Some event wave cases caused over the cargo handling and mooring limits as per the standard Korean port design guideline, and those were used for the decision of port operation by dock master, comparing with the real time offshore wave observations.

Analysis of Measuring Limit of Echo Sounding by Turbidity (탁도에 따른 Echo Sounder 관측 한계 분석)

  • Kim Yong-bo
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.23 no.2
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    • pp.197-203
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    • 2005
  • Dredging and reclaiming on coast, harbor construction etc. of when construct, the interest about efficiency and accuracy of sounding by measurement condition very rise. However, there are only a few studies on the accuracy improvement concerning water depth sounding condition. In this study, among the precision decline main causes of sounding, 1 suggested the characteristics of sounding data acquired by echo sounder with increasing of turbidity and the critical turbidity range under a given transducer frequency. For this, I acquired sounding data by inputting turbidity inducer artificially in artificial water tank. And then achieved regression analysis. Conclusion are as following Sounding Capabilities can be divided into three ranges according to the turbidity . normal range, critical range and the range where data can not be obtained by an echo sounder. When the turbidity exceeds $217\~259$ NTU which was considered as critical range, depth sounding was impossible.

A Study on the Minimum Safety Distance between Navigation Vessels based on Vessel Operator's Safety Consciousness (선박운항자 안전 의식에 기초한 선박통항 최소 이격거리에 관한 연구)

  • Park, Young-Soo;Jeong, Jae-Yong;Kim, Jong-Sung
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.16 no.4
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    • pp.401-406
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    • 2010
  • Vessel Operator has been navigating with subjective sate distance in accordance with night & daytime, fore & aft, port & stbd abeam and visibility situation. This sate distances may different depending on inside & outside harbor limit, current, wind and visibility situation. By now, the concept of proper sate distance between navigating vessels has been adopted in Korea, using the early 1980's foreign data. And the safe distance is being used with the same value without any consideration of inside & outside harbor and the kind of vessel. So it is necessary to evaluate or search proper distance concept based on different sate consciousness of Korean manners. This paper aims to develop the basic model for marine traffic evaluation and the new model of marine traffic congestion. Also this paper proposes the basic control guideline of vessel traffic service center. The result of this study showed that minimum sate distance should be 4.4L forward, 3.1L aft and 26L abeam in case of good visibility in daytime, considering various parameters such as visibility, day and night. Some differences Here found between the existing minimum sate distance and the new minimum sate distance derived from the result of this study.

A Design for the Symbol Park and the Waterfront Park for the Second Stage Development in the Eastern Rear Complex of Gwangyang Harbor (광양항 동측배후단지 2단계 사업지구 상징공원 및 수변공원 설계)

  • Hong Hyoung-Soon;Kim Do-Kyong;Jeong Han-Ho
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.3 s.116
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    • pp.104-119
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    • 2006
  • The eastern rear business complex of the Gwangyang Harbor (second stage) has undergone the 'alternative bid' process by which a construction company is selected based on their suggestions for an alternative plan and the bid for the construction expenses is based on the previously completed original plan, thereby implicitly accepting the arrangement and scale of the park which was presented in the original plan. It is possible, however, that the concept and plan of each park needs to be approached in a new way within the extent of given design guidelines. This study focuses on the alternative plan process and the Symbol Park (the second neighborhood park) and Waterfront Park (the third neighborhood park) among the five neighborhood parks in the eastern rear business complex (second stage). These two parks provide scale and function for the structure of the park and greenways system at the eastern rear complex. The neighboring waterway is a significant resource for emphasizing the pre-development features of the site. The alternative plan process focuses on determining the resources for the park's plan based on the environmental analyses of the site and utilizing the results. That is, through an analysis of the current state, all available resources are determined and the facilities and activities are derived based on these results. By this, Symbol Park and Waterfront Park reflect the regional features of the eastern rear complex, and these parks will feasibly perform the role of the region's key parte. The limit of this study is the fact that there is no chance for landscape architecture to actively play a role in the creation of the master plan, land utilization plan, and plan for the complex. Therefore there is a problem that the function scale and location of the park are not distributed appropriately in the rear complex. Also the plan for protecting the waterway's shore, a significant resource, only considers the structural stability of the engineering works, degrading the visual and ecological quality. These experiences will be used as a case for further designing the industrial complex and for the resulting park plan.

A Study on the Assessment of the Marine Traffic Safety through Construction of the Jeju New Harbor (제주신항의 해상교통안전성평가에 관한 연구)

  • Kim, Chang-Je;Chae, Yang-Bum;Ye, Beyong-Duck;Gang, Song-Jin;Kim, Won-Ouk;Jong, Jae-Yong
    • Journal of Navigation and Port Research
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    • v.26 no.1
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    • pp.112-119
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    • 2002
  • In accordance with the development plans of Jeju for international free city, Jeju new harbor will be constructed cosidering supporting Jeju city as an international tour city, safe arrival and departure at the terminal of 80.000G/T cruise ship. In this study, we used a full-mission ship handling simulator adopting 80.000G/T cruise ship manoeuvered at the planned Juju international cruise terminal. Five masters who have had a long experience of shop maneuvering ware called to carry out the simulations of which No. 1 , Np. 2, and No.4 scenario of simulation were tried twice, completed the total of 10 times and No.3 scenario of simulation once, reached at the total of 5 time. The marine traffic safety was assessed in terms of 1) the closest point of approach(CPA) to breakwater and quay in the vicinty and the probability of crossing fairway limit, 2)subjective evaluation such as the mental burden and the maneuvering disfficulty of shiphanders and 3) the opinions of shiphandlers. From th result of this simulation, we have a conclusion that the 80.000G/T cruise ship can be maneuvered safely at the planned terminal.

Combined Chlorite-Monochloramine Application for Controlling Nitrifying and Heterotrophic Bacteria in Drinking Water Distribution System (상수관망에서 Chlorite-Monochloramine 소독제를 이용한 질산화 세균 및 종속영양세균의 제어)

  • Park, Se-Keun;Kim, Yeong-Kwan;Choi, Sung-Chan
    • Korean Journal of Microbiology
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    • v.49 no.4
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    • pp.321-327
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    • 2013
  • In the present work, the reactors that harbor bacterial biofilms including ammonia-oxidizing bacteria (AOB) and heterotrophic bacteria were treated with a continuous dose of chlorite ($0.66{\pm}0.01mg/L$) either with or without monochloramine at $1.77{\pm}0.03mg/L$. Both chlorite alone and combined chlorite-monochloramine applications effectively reduced biofilm and bulk AOB levels to near or below the detection limit ($0.6MPN/cm^2$ and 0.2 MPN/ml). The combined chlorite-monochloramine application exhibited greater AOB inactivation than chlorite alone. Unlike AOB, heterotrophic plate count (HPC) was unaffected by chlorite alone. In contrast to chlorite-only application, a combination of chlorite and monochloramine resulted in a significant reduction in HPC levels with log reductions of 3.1 and 3.0 for biofilm and bulk water, respectively. The results demonstrate that the combined chlorite-monochloramine application can provide an effective treatment for the inhibition of AOB and heterotrophic bacteria in a drinking water distribution system.

A Study on A Proper Application for The Navigational Rules in The Public Order in Open Port Act (개항질서법상 항법적용)

  • JI, Sang-Won
    • Journal of Navigation and Port Research
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    • v.28 no.5
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    • pp.359-364
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    • 2004
  • When sea going vessel approaches her destination port, marine traffic density is increased, especially, the marine traffic is concentrated in the entrance channel and the fairway in the inner harbour is more narrow. Therefore, special navigational rules for preventing collision at sea is needed in the inner harbour. Hence there are the rules in The Public Order in Open Port Act in Korea But, in the case of conflict of navigational rule concerned, it is possible to be raised a question that which rule shall be applied preferentially. Also, it is necessary to understand the exact meaning of the navigational rules in The Public Order in Open Port Act. Because the misunderstanding of the rule is caused the collision Therefore, this paper aims to discuss the exact meaning of the navigational rule concerned in the view of legal basis and suggest the principles for a proper application of it.

Analysis of Tidal Asymmetry and Flood/Ebb Dominance around the Yeomha Channel in the Han River Estuary (한강하구 염하수로 주변에서의 조석·조류 비대칭과 창·낙조 우세 분석)

  • Yoon, Byung-Il;Woo, Seung-Buhm
    • Journal of Korea Water Resources Association
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    • v.45 no.9
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    • pp.915-928
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    • 2012
  • Han River estuary (HRE) is located at the middle of the western coast of Korea, and tidal currents were measured at 4 stations in this estuary during the winter season, and previously observed tide data was analyzed. The results of amplitude ratio of $M_4/M_2$ showed that increasing upward to estuary in the HRE. Tide harmonic constants of relative phase $2M_2-M_4$ represent flood dominance, with under 180 degree. But this method has a limit of analysis that typically based on the non-linear distortion of the tidal current in tidal lagoon system where freshwater discharge is assumed to be relatively small. The results of statistically tidal current data indicated that ebb current velocity would be great unlike tide data. Ebb and flood duration time is calculated by slack time of tidal current showed that ebb duration time is longer than flood. The results of correlation of analysis show high value (0.9) between tidal current stations from Incheon harbor to north entrance of Yeomha channel. We reconstructed to find the reasons for the features of ebb dominance the results of harmonic analysis. As major component ($M_2$) in combination with shallow water component ($M_4$), the tidal curve was presented flood dominance that has a flood current is stronger. However, these curve were changed to ebb dominance add up the non-harmonic components that had ebb direction flow by calculated tidally averaged current. The characteristic of enhancement on ebb is showed around the Yeomha channel in the HRE, because averaged flow which acts seaward such as long-term tidal current components due to non-linear effect and freshwater which overcome the flood current.