• Title/Summary/Keyword: ocean navigation

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Design and Implementation of Database System for AtoN Simulator (항로표지 시뮬레이터용 데이터베이스 시스템의 설계 및 구현)

  • Oh, Jaeyong;Park, Sekil;Kim, Ah-Young;Lee, Yeong-Ju;Kwon, OhSeok
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.10a
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    • pp.380-381
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    • 2013
  • 국내에는 선박의 안전항해를 위해서 다양한 종류의 항로표지가 설치되어 운영되고 있으며, 각 지방해양항만청에서 개별적으로 관리되고 있다. 현재 운영되고 있는 항로표지의 종류는 유인 등대를 포함하여 등부표, 입표, 음향표지, 전파 표지 등이 있으며, 그 설치 형태와 기능이 너무 다양하기 때문에 일반화 된 형태의 데이터로 통합 관리되지 못하고 있는 실정이다. 한편, 국제항로표지협회(IALA)에서는 항로표지 설계와 배치 계획에 대한 의사 결정을 지원하고 검증할 수 있는 항로표지 시뮬레이터 시스템의 필요성을 제기하고 있으며, 이를 위해서는 국내의 항만별 항로표지 데이터에 대한 통합 데이터베이스 구축이 반드시 필요하다. 본 논문에서는 국내 주요 항만에 설치되어 있는 주요 항로표지의 속성정보를 분석하고, 이를 바탕으로 항로표지 시뮬레이터용 데이터베이스 시스템을 설계하고 구축하는 방법에 대하여 기술한다.

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A Study on the Track of Typhoon in the Northwest Pacific Ocean (북태평양 서부에서 발생하는 강풍의 진로에 관한 연구)

  • 윤종화
    • Journal of the Korean Institute of Navigation
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    • v.18 no.3
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    • pp.19-30
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    • 1994
  • By use of the recent tropical cyclones' data in the Northwest Pacific Ocean, the occurrence frequency and region of typhoon as well as the features of the monthly mean track were analyzed. As the result of this study, (1) mean occurrence frequency of typhoon per year is 27.5, and 68% of total typhoons were formed in July to October and shown the highest frequency in August. (2) The ave-rage duration of typhoons is 8.5 days, and super typhoon which maximum sustained surface wind speeds is more than 130 knots occurs most frequently in October and November. (3) The highest frequency ap-pears around the Caroline, Mariana and Marshall Islands, and in wintertime, typhoon occurs in lower lati-tude comparing with those in summertime. (4) The typhoon track depends upon the distribution of pres-sure system and steering current in neighbouring areas. The mean track of typhoon can be classified into three types such as westward-moving type, northward-moving type and abnormally moving type. The west-ward-moving typhoons make landfall on the southern China by way of the South China Sea in June and July, on mid-part of China in August and September, and on Indo-china Peninsula in October and Novem-ber. The northward-moving typhoons approximately move on north~northwestward track to $20~30^{\circ}N$ from the occurrence region, then recurve to the East Sea through Korean Peninsula and Kyushu Island in June and July, to the Noth Pacific Ocean along the Japanese Islands in August and September and to the North Pacific Ocean through the seas far south off the Japan in October and November.

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Loran-C Multi-chain ToA Positioning using ASF Compensation Concept of eLoran (eLoran ASF 보상 기법을 적용한 Loran-C 다중체인 ToA 측위 방법)

  • Kim, Youngki;Fang, Taehyun;Seo, Kiyeol;Park, Sanghyun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2019.11a
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    • pp.71-72
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    • 2019
  • In this study, we describe a method of measuring position using the Additional Secondary Factor (ASF) compensation technique of the eLoran concept in the situation where only Loran-C signals are received without eLoran time broadcasting. Next, we describe the result of test performed to verify the method. The test results showed the position accuracy within 20m and we found the possibility of the method. The method is expected to be used to verify user positioning accuracy before improving Loran-C to eLoran.

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Nonlinear Potential Flow Analysis for the Hull with a Transom Stern (트랜섬 선미를 가지는 선형의 비선형 포텐셜 유동해석)

  • Choi, Hee-Jong;Lee, Gyoung-Woo;Chang, Yong-Chai
    • Journal of Navigation and Port Research
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    • v.30 no.8 s.114
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    • pp.631-636
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    • 2006
  • In this paper, the wave pattern around the hull with the transom stern advancing on the free surface with a constant speed was taken into consideration. To solve the problem the numerical analysis program was developed using Rankine source panel method based on potential flow analysis technique. The non-linearity of the free surface boundary conditions was fully satisfied. To verify the validity of the developed program the numerical calculations for Athena hull and KCS(KRISO container ship) hull was performed. The results of the numerical computation was compared with the ones of the model test experiment.

Human Error Analysis Technique and Its Application to Marine Accidents

  • Na, Seong;Kim, Hong-Tae;Kim, Hye-Jin;Ha, Wook-Hyun
    • Journal of Navigation and Port Research
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    • v.34 no.2
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    • pp.145-152
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    • 2010
  • The management of safety at sea is based on a set of internationally accepted regulations and codes, governing or guiding the design and operation of ships. The regulations most directly concerned with human safety and protection of the environment are, in general, agreed internationally through the International Maritime Organization(IMO). IMO has continuously dealt with safety problems and, recognized that the human element is a key factor in both safety and pollution prevention issues(IMO, 2010). This paper proposes a human error analysis methodology which is based on the human error taxonomy and theories (SHELL model, GEMS model and etc.) that were discussed in the IMO guidelines for the investigation of human factors in marine casualties and incidents. In this paper, a cognitive process model, a human error analysis technique and a marine accident causal chains focused on human factors are discussed, and towing vessel collision accidents are analyzed as a case study in order to examine the applicability of the human error analysis technique to marine accidents. Also human errors related to those towing vessel collision accidents and their underlying factors are discussed in detail.

Ship Stability Calculation for Cause Analysis of No. 501 Oryong Sinking Accident

  • Lee, Sang-Gab;Lee, Jae-Seok;Ki, Jee-Hun
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2018.11a
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    • pp.248-255
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    • 2018
  • Deep-sea fishing vessel No. 501 Oryong was fully flooded through the openings and was sunk down to the bottom of sea due to the very rough sea weather on the way of evasion after fishing operation in the Bearing Sea with many crews dead and/or missed. In this study, calculation of ship stability was carried out using KST-SHIP(ship calculation system of KST), considering the effect of flow fluid and fish catch arrangement according to the progress of its sinking accident, and damage stability was analyzed. For this study, intact stability calculation of its accident ship under the full load departure condition and its calculation result were verified by comparing with each other, and intact stability according to displacement from the departure of accident ship just before the accident was calculated and analyzed. Damage stability was calculated according to the progress during sinking accident and also analyzed.

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3D Numerical Investigation on Reservoir System for an Overtopping Wave Energy Convertor

  • Jin, Jiyuan;Liu, Zhen;Hong, Key-Yong;Hyun, Beom-Soo
    • Journal of Navigation and Port Research
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    • v.36 no.2
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    • pp.97-103
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    • 2012
  • Overtopping Wave Energy Convertor (OWEC) is an offshore wave energy convertor, which comprises the circular ramp and reservoir. It collects the overtopped waves and converting water pressure head into electric power through the hydro-turbines installed in the vertical duct, which is fixed in the sea bed. The performance of OWEC can be represented by the operating water heads of the device, which depends on the amount of the wave water overtopping into the reservoir. In the present paper, the reservoir with the duct connecting to the sea water are studied in the 3D numerical wave tank, which has been developed based on the computational fluid dynamics software Fluent 6.3. Both the overtopping motion and the discharges of the reservoir are investigated together, and several shape parameters and incident wave conditions are varied to demonstrate their effects on the performance of OWEC.

Adaptive Bandwidth Algorithm for Optimal Signal Tracking of DGPS Reference Receivers

  • Park, Sang-Hyun;Cho, Deuk-Jae;Seo, Ki-Yeol;Suh, Sang-Hyun
    • Journal of Navigation and Port Research
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    • v.31 no.9
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    • pp.763-769
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    • 2007
  • A narrow loop noise bandwidth method is desirable to reduce the error of raw measurements due to the thermal noise. However, it degrades the performance of GPS initial synchronization such as mean acquisition time. And it restricts the loop noise bandwidth to a fixed value determined by the lower bound of the allowable range of carrier-to-noise power ratio, so that it is difficult to optimally track GPS signal. In order to make up for the weak points of the fixed-type narrow loop noise bandwidth method and simultaneously minimize the error of code and carrier measurements, this paper proposes a stepwise-type adaptive bandwidth algorithm for DGPS reference receivers. In this paper, it is shown that the proposed adaptive bandwidth algorithm can provide more accurate measurements than those of the fixed-type narrow loop noise bandwidth method, in view of analyzing the simulation results between two signal tracking algorithms. This paper also carries out sensitivity analysis of the proposed adaptive bandwidth algorithm due to the estimation uncertainty of carrier-to-noise power ratio. Finally the analysis results are verified by the experiment using GPS simulator.

A Structural Response Estimation and Response Amplitude Operator of Floating Type Salvage Crane (부유식 인양크레인의 운동응답특성과 구조응답 평가)

  • Oh, Young-Cheol;Gim, Ok-Sok;Lee, Gyoung-Woo;Ko, Jae-Yong
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2013.06a
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    • pp.132-133
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    • 2013
  • Ship salvage crane is to salvage the equipment safely, this type of crane in the shipyard's large ships or port is being used a lot of container etc. Such a salvage crane was installed on the land and it is built to use the harbour facilities. In this paper, the response amplitude operator and the wave exiting force of floating type salvage crane is calculated and it is performed to structural response estimation.

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A study on survey on the user's opinions of the water-front in Seoul Hangang Park Banpo area (서울 한강시민공원 반포지구에서의 수변공간의식 조사)

  • Yang, Dong-Cheon;Kon, Masayuki;Ahn, Chang-Su;Lee, Myung-Kwon
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2012.10a
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    • pp.35-36
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    • 2012
  • This study had a survey on the user opinions of the water-front in seoul Hangang Park Banpo area. The survey was carried out individual interviews in the place where it can be directly overlooked the Han-river. And the results were analyzed in percentage terms. As a result, the highest rank in age structure is 33 percent of people in their twenties, and the following is 23.5 percent of thirties. ${\cdots}{\cdots}$(amount of)${\cdots}{\cdots}$.

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