• Title/Summary/Keyword: Small light buoys

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Analysis on motions characteristics of Floaters using two-dimensional Boundary Element Method (2차원 경계요소법을 이용한 부유체의 운동 특성 연구)

  • Baek, Mi-Seon;Seong, Yu-Chang
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.06a
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    • pp.136-138
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    • 2013
  • Current, standards light buoys as maritime traffic safety facilities have 10 different types of buoys and the smallest size of those is 4.4m. Therefore, making for easy replacement and repair parts for the type of small light buoys is proposed. Meanwhile, position reliability of floaters by external forces in the environment fall and stability examination should be considered for prohibiting accidents as loss. In this paper, a new light buoy is analyzed on Encounter Frequency types using commercial program and fluid forces is simulated on cross-sectional shape of the float using two-dimensional Boundary Element Method(BEM).

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A Study on the Radar Maximum Detectable Range of the Floats of Set-nets and the Floating Corner Reflector (정치망뜸과 부표형 코우너 리프렉터의 레이다 최대심지거이에 대한 연구)

  • 신형일
    • Journal of the Korean Institute of Navigation
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    • v.1 no.1
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    • pp.17-26
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    • 1977
  • A large number of the set-nets are set in Namhaedo coast of Korea. The floats of these set-nets are not only small even in case of large floats but also they scarcely have distinguishable marks such as light buoys or flags, so that they are very hard to be recognized by naked eyes and thus became probable obstacles to navigation for the passing ships and the fishing vessels. In order to research the capability of detecting such nets with Radar, the author investigated a maximum detectable range of the ordinarly large floatsand of a floating corner reflectors of various size and shape by Radar. The results obtained are as follows; 1. A maximum detectable range of large floats at a close range can be calculated by the Radar equation in sufficient accuracy. 2. Large floats of the large set-nets are also detectable by Radar even though it's detectable range boundary was within 0.2-0.65 miles. And the Radar picture of large floats was easier to be found with somewhat higher setting of the gain control on shorter range scale of the 1 mile. 3. Floating corner reflector rather suitable for set-net floats of "S" type reflector proposed in this paper, of which the dimension must be above 17cm in diameter to be detectable by Radar at 2 miles.t 2 miles.

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Design standard for fairway in next generation

  • Ohtsu, Kohei;Yoshimura, Yasuo;Hirano, Masayoshi;Takahashi, Hironao;Tsugane, Masanori;Ohtsu, Kohei
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2006.10a
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    • pp.230-239
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    • 2006
  • The depth, width and alignment of fairway that are main port water facilities should be designed considering the various elements including particulars of design ships, weather and sea conditions around fairway and method of ship-handling. However not only the existing Japanese design standard for fairway and also those of other countries do not take into consideration of such kind of elements and no design standard is made by quantitative analysis. In this circumstance the new design standard (Approach Channels, A Guide for Design) depending on classified various elements and quantitative analysis was proposed in 1997 by PIANC and IAPH. But it was proved that calculated values according to this standard were unfounded and had some problems to output the discontinuous value by small difference of calculation condition because the each value fur each element was simply added. And also it is hard to apply this standard to the design of port water facilities in Japan because this [A Guide for Design] is the design standard for long channels in European port. The proposal of more reasonable Japanese standard will be expected by applying the study result of naval architecture and navigation and by the cooperation of ship operators to use fairway, naval architects to built ships and civil engineers to dredge fairway. The concept of a fairway in 'Design standard fur fairway in next generation' is defined as passage for approach channel) and traffic lane designated by light buoys as navigable water for safe navigation. In 'Design standard for fairway in next generation' depth, width and alignment are picked up among many design elements of a fairway. Design method for those elements is shown based on design ships and navigational environments. This standard shows the method of design for each dimension depending on characteristic on design ship and weather and sea condition. On the other hand, in case of existing fairway, it is possible to decide the size of ship and navigation criteria by opposite analysis.

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