• Title/Summary/Keyword: 연안 전기

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The Extention and Implementation of User-defined AIS AtoN for Marine Safety Information Service (해양안전정보서비스를 위한 사용자정의 AIS AtoN확장 및 실험)

  • Park, In-Hwan;Hwang, Seung-Wook;Lee, Seo-Jeong
    • Journal of Navigation and Port Research
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    • v.33 no.6
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    • pp.423-428
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    • 2009
  • Recently, the marine traffics have been increased along with enlargement of overseas commerce. Increasing the marine traffic may make higher the risk of marine accidents. Especially, the rate of accidents on costal area are more frequently. As if the marine safety information can be afforded to vessel and shore, the accident rate would be down. AIS AtoN is the navigational safety support device which is subject to functional requirements of IALA and technical standards of ITU. In this paper, we extend and implement the user-defined specification of AIS AtoN with message 21 for AIS basic information, messsage 6 for status report and message 12/14 for safety management.

A Study on the Application of Hybrid Propulsion System for Fishing Vessels (어선용 복합 추진시스템 적용을 위한 연구)

  • Jung-Ho Noh
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.28 no.7
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    • pp.1238-1243
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    • 2022
  • The International Maritime Organization is at the forefront of strengthening gas emission regulations for ships globally. The Korean government needs to apply measures to reduce emissions, such as setting a basic roadmap for greenhouse gas reduction. In addition, there is an urgent need to introduce a new efficient propulsion system that can reduce gas emissions. This includes applications to fishing vessels, which account for 90.6% of the greenhouse gas emissions from ships sailing along domestic coasts. In this study, an electric-combined propulsion system applicable to domestic coastal fishing vessels was developed. The target ship to which the electric-combined propulsion system could be applied was selected. A simulation system was constructed using MATLAB/Simulink to compare the expected fuel consumption when applying the developed complex electric propulsion system to the propulsion system mounted on the selected target fishing vessel. Through simulations, the differences in fuel consumption between the mechanical propulsion system and the electric hybrid propulsion system (both when charging and not charging the battery on land) were confirmed. The results show that fuel consumption can be decreased by approximately 13% and 16% when applying the electric-combined propulsion system.

The Hearing Ability of the Scorpion Fish Sebastiscus marmoratus to Audible Sound 1. The Auditory Threshold (수중 가청음에 의한 쏨뱅이의 청각 능력 1. 청각 문턱치)

  • 이창현;박용석;문종욱;김석종;안장영;서두옥
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.2
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    • pp.156-160
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    • 1999
  • This experiment was carried out to investigate the auditory threshold of the scorpion fish Sebastiscus marmoratus which was suitable for Marine ranching by a classical respiatory conditioning technique using a sound coupled with a delayed electric shock. The thresholds were determined by analyzing the electrocardiogram. The auditory thresholds were observed among the 12 fish with much difference from 100Hz to 300Hz. The audible range of the scorpion fish extended from 80 to 800Hz with a peak sensitivity of 90㏈(0㏈= $1\mu$Pa) at 100Hz. As the frequency became higher than 300Hz, the auditory threshold increased rapidly. The scorpion fish was least sensitive to sound of 500Hz among 6 frequency points and the value was about 12㏈.

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Technical Trend of Seawater Desalination Plant Using Renewable Energy (신재생에너지를 활용한 해수담수화플랜트 개발동향과 전망)

  • Choi, Jae-Baek;Jeong, Chang-Hee;Park, Seung-Gyu
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1368-1369
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    • 2011
  • 이 연구는 최근 물 부족시대를 대비한 차세대 기술로 각광 받고 있는 해수담수화설비의 동력을 기존의 화석연료에서 신재생에너지로 전환하고 있는 세계적인 추세와 기술동향을 살펴보고 국내 적용 가능성을 검토한 것이다. 특히 태양열, 태양광, 풍력 등을 활용하여 MENA(Middle East Asia & North Africa), 스페인, 지중해 연안 등의 지역에서 추진 중인 프로젝트의 성과를 살펴보고, 이를 토대로 극심한 물 부족으로 불편을 겪고 있는 국내 해안 도서지역에 적용할 수 있는 방안을 검토하였다.

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The Development of Multi-channel Electrical Conductivity Monitoring System and its Application in the Coastal Aquifer (다채널 전기전도도 모니터링 시스템의 개발과 연안지역 공내수 모니터링에 대한 적용 사례)

  • Shin, Je-Hyun;Hwang, Se-Ho;Park, Kwon-Gyu;Park, Yun-Seong;Byun, Joong-Moo
    • Geophysics and Geophysical Exploration
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    • v.8 no.2
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    • pp.156-162
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    • 2005
  • Particularly in research related to seawater intrusion the change of fluid electrical conductivity is one of major concerns, and effective monitoring can help to optimize a water pumping performance in coastal areas. Special considerations should be given to the mounting of sensors at proper depth during the monitoring design since the vertical distribution of fluid electrical conductivity is sensitive to the characteristics of seawater intrusion zone. This tells us the multi-channel electrical conductivity monitoring is of paramount consequence. It, however, is a rare event when this approach becomes routinely available in that commonly used commercial stand-alone type sensors are very expensive and inadequate for a long term monitoring of electrical conductivity or water level due to their restricted storage and difficulty of real-time control. For this reason, we have developed a real-time monitoring system that could meet these requirements. This system is user friendly, cost-effective, and easy to control measurement parameters - sampling interval, acquisition range, and others. And this devised system has been utilized for the electrical conductivity monitoring in boreholes, Yeonggwang-gun, Korea. Monitoring has been consecutively executed for 24 hours, and the responses of electrical conductivity at some channels have been regularly increased or decreased while pumping up water. It, with well logging data implemented before/after pumping water, verifies that electrical conductivity changes in the specified depths originate from fluid movements through sand layer or permeable fractured rock. Eventually, the multi-channel electrical conductivity monitoring system makes an effective key to secure groundwater resources in coastal areas.

Factors Affecting the Electrical Properties of Bentonite Slurry (벤토나이트 슬러리의 전기적 특성에 대한 영향인자 분석)

  • Yoo, Dong-Ju;Oh, Myoung-Hak;Kim, Yong-Sung;Park, Jun-Boum
    • Journal of the Korean Geotechnical Society
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    • v.22 no.10
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    • pp.21-32
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    • 2006
  • Factors affecting the electrical properties of bentonite slurry were identified and electric conduction mechanism in slurry was examined. Electrical conductivity of bentonite and soil-bentonite slurry linearly increases with the bentonite content. Test result indicated that the change In electrical conductivity of slurry was mainly caused by dissolved cations from bentonite particles. The relationship between electrical conductivity and bentonite content was affected by the initial electrical conductivity of slurry solution and fine content in soil-bentonite mixture. Such influences were evaluated and the calibrated relationships were suggested. Based on the suggested relationship between electrical conductivity and bentonite content, bentonite content in various bentonite and soil-bentonite slurry can be quantitatively evaluated by using electrical conductivity measurement method.

Applicability of Resistivity/Capacitance Measurement on CPT Module for Investigation of Subsurface Contamination (지반 오염도 조사를 위한 전기비저항/정전용량 측정콘의 적용성 평가)

  • Oh, Myoung-Hak;Kim, Yong-Sung;Park, Jun-Boum
    • Journal of the Korean Geotechnical Society
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    • v.22 no.7
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    • pp.45-54
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    • 2006
  • Resistivity cone penetrometer test (RCPT) can be employed at a relatively low cost for in-situ delineation of subsurface contamination. While the resistivity measurement has a potential to investigate the subsurface contamination, resistivity measurements alone will lead to some degree of ambiguity in the results. In this study, capacitance measurement was incorporated into the RCPT to overcome the ambiguity inherent in electrical resistivity measurements. This study is focused on verifying the applicability of resistivity and capacitance measurements of CPT module to provide information on subsurface contaminated by heavy metal and petroleum hydrocarbon. Laboratory model tests were performed to evaluate the sensitivity of the measured resistivity and relative capacitance on the water content and different types of contaminants. Test results show that simultaneous measurement of electrical resistivity and capacitance can give more reliable information on subsurface contamination. Electrical measurements of the CPT module showed high applicability to be used in detecting saturated soils contaminated by heavy metal and diesel plume floating above the groundwater table.

A Study of the Development Safety Criteria for Hybrid Electrical Propulsion Fishing Boats (전기복합 추진어선의 안전기준 개발에 관한 연구)

  • Cheol eon Kang;Chul ho Baek;Sung hun Kim;Chan jae Lee
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.29 no.2
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    • pp.207-214
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    • 2023
  • Ships emit significant amounts of air pollution. To reduce ship emissions, the government has implemented the Eco-Friendly Ship Act to improve the marine air environment, under which the use of eco-friendly ships that use eco-friendly energy as a power source encouraged and technologies to reduce marine pollution are developed. Therefore, the revision of relevant laws and systems such as inspection and facility standards for the safe operation of eco-friendly ships is urgently needed, especially those for fishing vessels, which account for the majority of domestic coastal vessels. This study defines the core equipment for the application of electric complex propulsion systems to fishing boats and presents a minimum safety standard plan for the adoption and dissemination of eco-friendly fishing boats.

A Feasibility Study of AMT Application to Tidal Flat Sedimentary Layer (갯벌 지역의 하부퇴적층에 대한 AMT 탐사의 적용 가능성 평가)

  • Kwon, Byung-Doo;Lee, Choon-Ki;Park, Gye-Soon;Choi, Su-Young;Yoo, Hee-Young;Choi, Jong-Keun;Eom, Joo-Young
    • Journal of the Korean earth science society
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    • v.28 no.1
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    • pp.64-74
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    • 2007
  • The marine seismic prospecting using a research vessel in the shallow sea near the coastal area has certain limits according to the water depth and survey environment. Also, for the electrical resistivity survey at seashore area, one may need a specially designed high-voltage source to penetrate the very conductive surface layer. Therefore, we have conducted a feasibility study on the application of magnetotelluric method (MT), a passive geophysical method, on investigating of shallow marine environment geology. Our study involves both theoretical modeling and field survey at the tidal flat area which represent the very shallow marine environment. We have applied the audio-frequency magnetotelluric (AMT) method to the intertidal deposits of Gunhung Bay, west coast of Korea, and analysed the field data both qualitatively and quantitatively to investigate the morphology and sedimentary stratigraphy of the tidal flat. The inversion of AMT data well reveals the upper sedimentary layer of Holocene intertidal sediments having a range of 13-20 m thickness and the erosional patterns at the unconformable contact boundary. However, the AMT inversion results tend to overestimate the depth of basement (30-50 m) when compared with the seismic section (27-33 m). Since MT responses are not significantly sensitive to the resistivity of middle layer or the depth of basement, the AMT inversion result for basement may have to be adjusted using the comparison with other geophysical information like seismic section or logging data if possible. But, the AMT method can be an effective alternative choice for investigating the seashore area to get important basic informations such as the depositional environment of the tidal flat, sea-water intrusion and the basement structure near the sea shore.

Free Oscillation Analysis in the Coastal Area using Integrated Finite Difference Method (적분차분법을 이용한 연안역에서의 해수고유진동해석)

  • LEE Byung-Gul
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.27 no.6
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    • pp.782-786
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    • 1994
  • Integrated finite difference method (IFDM) is used to solve one dimensional free oscillation problem in the coastal area. To evaluate the solution accuracy of IFDM in free oscillation analysis, two finite difference equations based on area discretization method and point discretization method are derived from the governing equations of free oscillation, respectively. The difference equations are transformed into a generalized eigenvalue problem, respectively. A numerical example is presented, for which the analytical solution is available, for comparing IFDM to conventional finite difference equation (CFDM), qualitatively. The eigenvalue matrices are solved by sub-space iteration method. The numerical results of the two methods are in good agreement with analytical ones, however, IFDM yields better solution than CFDM in lower modes because IFDM only includes first order differential operator in finite difference equation by Green's theorem. From these results, it is concluded that IFDM is useful for the free oscillation analysis in the coastal area.

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