• Title/Summary/Keyword: 해난사고

Search Result 146, Processing Time 0.035 seconds

Analysis on the Stress of Hydraulic Cylinder for Large Vessel by Boundary Element Method (대형선박용 유압실린더에서 경제요소법을 이용한 응력해석)

  • 김옥삼
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.31 no.4
    • /
    • pp.423-434
    • /
    • 1995
  • It was used boundary element method(BEM) and analysed axisymmetric problem to solve hydraulic cylinder for large vessel acting uniform internal pressure(25N/m super(2)) within elastic limit. This paper was utilized the carbon steel tubes for machine structural purposed model, inner radius was 150mm and outer radius was 250mm, axial length was semi-infinite and the isoparametric element was used. The important results obtained in this study were summarized as follows. Radial, tangential and shearing stress occured the maximum stresses(48, -20 and 34MPa) at the inner radius and the minimum stresses(32, -4 and 18MPa) at the outer radius of the hydraulic cylinder for large vessel. But negative signs have meaning compressive stress and stress diminution ratio was about 0.15MPa/mm. The use of isoparametric element raised accuracy and the increment of input data lessened the error in internal point but computer run-time was increased. The double node was improved the internal solutions to settle discontinuity at corner and the double exponential formula lessened error of stress value at boundary neighborhood. And then coincidence between the analytical and exact results is found to be fairly good, showing that the proposed analytical by BEM is reliable.

  • PDF

Observation and Analysis of Movement Characteristics of Drifting Ships (표류선박 거동특성 관측 및 분석)

  • Lee Moonjin;Kang Chang-gu;Yun Jong-hwui
    • Journal of the Korean Society for Marine Environment & Energy
    • /
    • v.8 no.1
    • /
    • pp.17-22
    • /
    • 2005
  • The movement of drifting ships on the sea is closely related to marine environmental forces such as waves, currents, winds, etc. To develop a prediction model for trajectories oi drifting ships, an experiment on the movement of drifting ships was carried out in the Southeastern Sea of Korea. Five types of ships including a lire raft and tour ships with G/T 10tons, G/T 2o tons, G/T 50 tons, and G/T 80 tons, were considered in the experiment. The G/T 50 ton class ship was used as a base ship for obtaining the currents, winds and heading angles of ship following the trajectory. The trajectory of each ship was measured by DGPS(Differential Global Positioning System) and collected using APRS(Automatic Position Reporting System) installed on the base ship. The error range in position fix of DGPS are approximately ±1 m. The drift speed of ship in the experiment was between 3% to 5% of wind speed and drift direction of ship was deflected by ±90° from wind direction. Also, the heading of drifting ship was normal to wind direction.

  • PDF

Realization on the Integrated System of Navigation Communication and Fish Finder for Safety Operation of Fishing Vessel (어선의 안전조업을 위한 항해통신 및 어탐기의 통합시스템 구현)

  • In-suk Kang;In-ung Ju;Jeong-yeon Kim;Jo-cheon Choi
    • Journal of Advanced Navigation Technology
    • /
    • v.25 no.6
    • /
    • pp.433-440
    • /
    • 2021
  • The problem of maritime accidents due to the carelessness of fishing vessels, which is affected by the aging of fishing vessel operators. And there is navigation, communication and fish finder that is installed inside the narrow bridge of a fishing vessel. Therefore these system are monitors as many as of each terminal, which is bad influence on obscuring view of front sea from a fishing vessel bridge. In addition a large problem, it is occurs to reduce of the information recognition ability due to the confusion, which is can not check the display information each of screen equipments. Therefore, there has been demand to simply integrated the equipment, and it has wanted the integrated support system of these equipment. The display must be provided on a fishing vessels such as electronic charts, communications equipments and fish detection into one case. In this paper, the integrated system will be installed the GPS plotter, AIS, VHF-DSC, V-pass, fish finder and power supply in the narrow wheelhouse on a fishing vessel, which is configured in one case and operated by multi function display (MFD). The MFD is integrated to simplify for several multi terminals and provided necessary information on a single screen. This integration fishery support system will has improved in sea safety operation and fishery environment of fishing vessels by this implementation.

Design and Implementation of VDR System for Small and Medium-sized Power Boat (중소형 선박용 항해기록장치 시스템 설계 및 구현)

  • Min, Byoung-Guk;Mo, Chang-Hwan;Kim, Chul-Won;Park, Jong-Hoon
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.10 no.3
    • /
    • pp.341-347
    • /
    • 2015
  • This study aims to design a chief VDR(Voyage Data Recorder) system which is appropriate to small and medium sized vessels and also implement the data about marine communication devices, sensors, etc. to be stored or printed at the navigator when those data are connected to VDR through data communication between marine navigation and VDR which are based on serial communication or internet in order to prove efficiency of the marine navigator. Also, the design of VDR is intended to be small and light in order to expand to apply it to small and medium vessels, which enables to analyze causes of marine accidents precisely through its characteristic functions which are the same as those at "vehicle mounted black-box" (location of the car, image and voice storage) by which the same roles are played on land.

A Study on the Relative Distance in Taking Action to Avoid Ship`s Collision (선박충돌회피를 위한 피항개시거리에 관한 연구)

  • 김기윤
    • Journal of the Korean Society of Fisheries and Ocean Technology
    • /
    • v.19 no.2
    • /
    • pp.99-105
    • /
    • 1983
  • In the Steering and Sailing Rules of International Regulations for Preventing Collicions at Sea, 1972, any relative distance between two vessels necessary for taking action to avoid collision in head-on situation is not referred. In this paper, the author analyzed the ship's collision avoiding actions from a viewpoint of ship motions and worked out mathematical formulas to calculate the relative distances necessary for collision avoiding actions. Figuring out the values of maneuvering indices through experiments of actual ships, the author applied these values to the calculationg formulas and calculated the minimum safe relative distances. On the assumption that two vessels same in size and condition are approaching each other in head-on situation, the minimum safe relative distance was calculated as 5.0 times, sufficient safe relative one as 10.0 times their own length.

  • PDF

A Design and Implementation of Digital Vessel Context Diagnosis System Based on Context Aware (상황 인식 기반 해양 디지털 선박 상황 진단 시스템 구현 및 설계)

  • Song, Byoung-Ho;Choi, Myeong-Soo;Kwon, Jang-Woo;Lee, Sung-Ro
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.35 no.6B
    • /
    • pp.859-866
    • /
    • 2010
  • Digital vessels can occur large a disaster at sea because vessels in fire and collision in case of certain unforeseen circumstances. In this paper, We propose digital vessel context monitoring system through risk analysis. We propose environment information analysis system using wireless sensor that have to acquire marine environment and context of marine digital vessel. For conducting simulation, we chose 300 data sets to train the neural network. As a result, we obtained about 96% accuracy for fire risk context and we obtained 88.7% accuracy for body of vessel risk context. To improve the accuracy of the system, we implement a FEC (Forward Error Correction) block. We implemented digital vessel context monitoring system that transmitted to diagnosis result in CDMA.

Dynamics modeling and Estimation of Manoeuvrability for Tug-Barge Systems (예부선의 동역학 모델링 및 조종 성능 추정법 개발)

  • Yeo, Dong-Jin;Han, Seong-Hwan;Kim, Dong-Jin;Kim, Yeon-Gyu
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
    • /
    • 2009.10a
    • /
    • pp.40-41
    • /
    • 2009
  • In general, ships are towed to keep the safe operations in harbor or channel by tug boats. Due to increase in ocean traffic, many accidents are happened in harbor or channel in these days. Therefore it is necessary to predict manoeuvrability of tug-barge system, and to assure the safety of that system. Turg-barge system is composed of tug boat, barge, and towing cable, connecting both ships. Manoeuvring equations of tug-barge system are suggested, and the scopes of model tests are discussed to establish the mathematical models for tug boats in this paper.

  • PDF

Topographical Change Monitoring of the Sandbar and Estimation of Suspended Solid Flux in the Nakdong River Estuary - Focused on Jinudo - (낙동강 하구역 사주지형 변동과 부유사(SS) 수송량 산정 - 진우도를 중심으로 -)

  • Lee, I.C.;Lim, S.P.;Yoon, H.S.;Kim, H.T.
    • Journal of the Korean Society for Marine Environment & Energy
    • /
    • v.11 no.2
    • /
    • pp.70-77
    • /
    • 2008
  • In this study, to establish countermeasure from marine casualties as a basic study fur long-term prediction of topographical change around Jinudo in the Nakdong river estuary, spatio-temporal topographical change monitoring was carried out. Also, in order to estimate the deposition variations concerning SS (Suspended Solid) flux which moved at St.S1 during neap and spring tide, respectively. From the topographical monitoring, it was found that the annual mean ground level and deposition rate were 141 mm and 0.36 mm/day and all parts except the northern part of Jinudo had the active topographical changes and a tendency to annually deposit. From vertical distribution of SS net fluxes, $SS_{LH}$ (latitudinal SS net flux) during spring tide overall flows average 28 $kg/m^2/hr$ (eastward), and $SS_{LV}$ (longitudinal SS net flux) flows average 11.1 $kg/m^2/hr$ (northward). And, $SS_{LH}$ overall flows average 4.8 $kg/m^2/hr$ (eastward), and $SS_{LV}$ flows average 1.5 $kg/m^2/hr$ (northward) during neap tide similar with spring tide. The depth averaged values of the latitudinal and longitudinal SS net fluxes during spring tide were approximately 6 times higher than those during neap tide. As result of, it was considered that topographical change of southern part of Jinudo was affected by resuspension of bottom sediments due to strong current in bottom layer during flood flow.

  • PDF

Korean Ocean Forecasting System: Present and Future (한국의 해양예측, 오늘과 내일)

  • Kim, Young Ho;Choi, Byoung-Ju;Lee, Jun-Soo;Byun, Do-Seong;Kang, Kiryong;Kim, Young-Gyu;Cho, Yang-Ki
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
    • /
    • v.18 no.2
    • /
    • pp.89-103
    • /
    • 2013
  • National demands for the ocean forecasting system have been increased to support economic activity and national safety including search and rescue, maritime defense, fisheries, port management, leisure activities and marine transportation. Further, the ocean forecasting has been regarded as one of the key components to improve the weather and climate forecasting. Due to the national demands as well as improvement of the technology, the ocean forecasting systems have been established among advanced countries since late 1990. Global Ocean Data Assimilation Experiment (GODAE) significantly contributed to the achievement and world-wide spreading of ocean forecasting systems. Four stages of GODAE were summarized. Goal, vision, development history and research on ocean forecasting system of the advanced countries such as USA, France, UK, Italy, Norway, Australia, Japan, China, who operationally use the systems, were examined and compared. Strategies of the successfully established ocean forecasting systems can be summarized as follows: First, concentration of the national ability is required to establish successful operational ocean forecasting system. Second, newly developed technologies were shared with other countries and they achieved mutual and cooperative development through the international program. Third, each participating organization has devoted to its own task according to its role. In Korean society, demands on the ocean forecasting system have been also extended. Present status on development of the ocean forecasting system and long-term plan of KMA (Korea Meteorological Administration), KHOA (Korea Hydrographic and Oceanographic Administration), NFRDI (National Fisheries Research & Development Institute), ADD (Agency for Defense Development) were surveyed. From the history of the pre-established systems in other countries, the cooperation among the relevant Korean organizations is essential to establish the accurate and successful ocean forecasting system, and they can form a consortium. Through the cooperation, we can (1) set up high-quality ocean forecasting models and systems, (2) efficiently invest and distribute financial resources without duplicate investment, (3) overcome lack of manpower for the development. At present stage, it is strongly requested to concentrate national resources on developing a large-scale operational Korea Ocean Forecasting System which can produce open boundary and initial conditions for local ocean and climate forecasting models. Once the system is established, each organization can modify the system for its own specialized purpose. In addition, we can contribute to the international ocean prediction community.

The Study of Keumcheonchang in ChungJu (충주 금천창 연구)

  • Cho, Gil Hwan
    • Korean Journal of Heritage: History & Science
    • /
    • v.41 no.1
    • /
    • pp.35-55
    • /
    • 2008
  • This paper is written to results of excavated ChungJu ChangDong site located in ChungJu and the article Keumcheonchang in Joseonwangjosilrok. The structure rerics of compositing cornerstone-distance 420cm has been showing to Keumcheonchang of legend in region people. The solution to problems is that the enforcement of the river-shipping service linking Han River and NakDong River. King Taejong commanded the new tax-warehouse of 200 Kan to built at Keumcheon in ChungJu and named Keumcheonchang for the receipt of innner region and KyengSang Province. King Sejo established the foundation of the government owned tax-grain transportation systerm for the strong centralization by the sovereign right. This logistic system is gone the middle and the latter of Joseon Dynasty. Joseon Dynasty is absolutely dependent the national finance for government operation on the tax-grain from HaSamDo(ChungCheong JeonLa KyengSang) region. JoUn(tax-grain transportation by shipping) is the best logistic system in Korea surrounding sea. Joseon Dynasty has refomed the logistics base on GoRyeo's system that the Tax-grain transportation system by shipping. There is the tax-warehouses reducing from 13 numbers to 9 numbers and making up for the weak points in the matter of the Japanese Pirate and the ship wreck in transporting in the sea. The ship wreck in the sea specially make the matters of the reducing tax and political issues. We know that Keumcheonchang is operated ChuaSuCham(the government agency for taxgrain transportation by shipping at a warehouse) from King Taejong 11(1,411)year to King Sejo 11 (1,465)year. There is the result of enforcement the river-shipping service system for social stabilization and forward their new ideal in the first half Joseon Dynasty.