• 제목/요약/키워드: Large vessels

검색결과 520건 처리시간 0.019초

평택항 교통안전특정해역 설정에 관한 연구 (A Study on the Establishment of Specific Traffic Safety Areas at Pyeongtaek Port)

  • 유상록;김득봉;정재용
    • 해양환경안전학회지
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    • 제22권6호
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    • pp.660-670
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    • 2016
  • 본 연구는 평택항을 통항하는 선박의 항해 안전을 확보하기 위해 교통안전특정해역 설정의 필요성을 정량적인 데이터로 제시하고자 하였다. 연구 비교 대상 6개 항만과 평택항과의 안개 일수, 도선 거리, 대형선 입항 척수, 조업 어선 척수를 비교 분석하였다. 연구결과 평택항은 잦은 시계 제한의 영향을 받는 역 조건의 가운데 부산, 부산신항, 울산, 포항항보다 약 3.5 ~ 6배 더 긴 도선 구간을 항해 해야한다. 특히 어장이 형성되는 5 ~ 7월에는 통항로에 위치한 35척의 조업 어선을 피하기 위해 대형선이 역주행하는 상황이 발생하여 상대 선박과의 충돌 위험을 갖는 교통 환경임을 확인하였다. 따라서 평택항 접근수역에 교통안전특정해역으로 설정한다면, 대형선이 조업 어선 보다 법적 우위를 갖게 되므로 통항 안전성을 확보할 수 있을 것으로 판단된다.

해상방제능력 향상을 위한 대형 방제선 도입의 필요성과 운용에 관한 연구 (Study on Need and Use to Large Oil Recovery Vessels for Progress Response Capability on Sea)

  • 문정환;윤종휘
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2009년도 공동학술대회
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    • pp.13-14
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    • 2009
  • 2007년 우리나라 서해에서 발생한 Hebei Spirit호 사고와 1997년 일본의 Nakhodka호 유출사고, 2002년 스페인의 Prestige호 유출사고 등 재난적 유류유출사고를 통해서 대형 방제선박의 필요성을 확인하고, 대형 방제선의 도입과 도입이후, 방제 외 활용방안을 제시함으로 빈번하지는 않지만 천문학적 피해를 발생하는 재난적 유류유출사고에 효율적이고 효과적으로 대응하고자 한다.

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빙해 항행 선박 주요목의 변화 경향에 대한 조사 연구 (A Study on Recent Trends of Principal Particulars m Ice-Transiting Vessel Design)

  • 최경식
    • 한국해양공학회지
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    • 제20권3호
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    • pp.77-81
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    • 2006
  • In this study, design parameters of ice-transiting vessels in the world, currently in service or under construction, were collected and a database of principal particulars for each ship was established. To understand the recent design trend, ice-transiting vessels were categorized into four groups, i.e., conventional icebreakers, icebreaking tug/supply/research vessels, ice-strengthened passenger/car ferry and ice-strengthened cargo vessels. Changes in principal particulars for each group were reviewed and summarized. It was found that the most significant change in the design of ice-transiting vessels was the increment of large size commercial cargo vessels. It is believed that the recent hike of oil prices and booming of Russian economy has resulted in the need for year-round operation with bigger ships in the Baltic Sea and in the Sea of Okhotsk and also along the Northern Sea Route in Russian Arctic Sea.

The investigation of ship maneuvering with hydrodynamic effects between ships in curved narrow channel

  • Lee, Chun-Ki;Moon, Serng-Bae;Jeong, Tae-Gweon
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제8권1호
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    • pp.102-109
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    • 2016
  • The hydrodynamic interaction between two large vessels can't be neglected when two large vessels are closed to each other in restricted waterways such as in a harbor or narrow channel. This paper is mainly concerned with the ship maneuvering motion based on the hydrodynamic interaction effects between two large vessels moving each other in curved narrow channel. In this research, the characteristic features of the hydrodynamic interaction forces between two large vessels are described and illustrated, and the effects of velocity ratio and the spacing between two vessels are summarized and discussed. Also, the Inchon outer harbor area through the PALMI island channel in Korea was selected, and the ship maneuvering simulation was carried out to propose an appropriate safe speed and distance between two ships, which is required to avoid sea accident in confined waters. From the inspection of this investigation, it indicates the following result. Under the condition of $SP_{12}{\leq}0:5L$, it may encounter a dangerous tendency of grounding or collision due to the combined effect of the interaction between ships and external forces. Also considering the interaction and wind effect as a parameter, an overtaken and overtaking vessel in narrow channel can navigate while keeping its own original course under the following conditions; the lateral separation between two ships is about kept at 0.6 times of ship length and 15 degrees of range in maximum rudder angle. On the other hand, two ships while overtaking in curved narrow channel such as Inchon outer harbor in Korea should be navigated under the following conditions; $SP_{12}$ is about kept at 1.0 times of ship length and the wind velocity should not be stronger than 10 m/s.

선박 수리작업장의 표준공정 및 환경 분석에 관한 연구 (A Study on Standard Process and Environmental Analysis in Ship Repair Workshop)

  • 전창수
    • 한국산업융합학회 논문집
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    • 제24권6_2호
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    • pp.899-908
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    • 2021
  • It is expected that the global market for vessel repair and remodeling will grow up to the scale of about 25 billion dollars by 2023. Korea's shipbuilding industry is leading the world with its international competitiveness in design and production technology. The actual status of vessel repair industry, however, is poor as there are only two or three companies for vessel repair that can deal with large vessels in the area of Gyeongnam. The reason is that civil complaints are filed severely about environmental problems and environment-related regulations are so strict that it is fairly hard to get governmental approval for the operation of a vessel repair workplace. Domestic vessel repair companies mainly target small- and medium-sized vessels. There are only few workplaces that can carry out regular examination or repair work on large vessels such as LNG vessels, and due to the high price of vessel repair, most of the domestic repair work on large vessels including LNG vessels tends to be snatched by markets in Southeast Asia or China. Despite the tremendous domestic demand of Korea that has established the world's first shipbuilding industry and world's sixth biggest harbor infrastructure, its vessel repair industry can be said to be in very poor condition. In order to vitalize vessel repair industry, this study is aimed to analyze the environmental influence of vessel repair workplaces in Gyeongnam where vessel repair companies are concentrated and suggest standard processes by analyzing vessel repair processes precisely.

중국 중원 지역과의 비교를 통하여 본 소흑석구 8501호 석곽묘의 청동예기 (The Bronze Ceremonial Vessels of Xiaoheishigou Stone Cist Tomb 8501 seen through Comparison with the Chinese Zhongyuan Region)

  • 오강원
    • 헤리티지:역사와 과학
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    • 제47권3호
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    • pp.86-107
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    • 2014
  • 영성현(寧城縣) 소흑석구(小黑石溝) 8501호 대형 석곽묘는 중국의 시기 구분으로 서주 후기에 조성된 무덤이다. 그런데 이 무덤에는 중국 중원식 청동예기는 물론 토착식 청동예악기와 토착식과 중원식이 혼합되어 있는 혼합식 청동예기가 다량으로 출토되었다. 소흑석구의 청동예기 조합은 같은 시기 중국 중원 지역의 예제와 정궤제(鼎?制)에 대비하여 볼 때 가장 낮은 신분인 사급(士級) 특일정(特一鼎)에 속한다. 그럼에도 불구하고 중국 중원 지역의 사급 고분들과는 달리 정(鼎)과 궤(?)를 제외한 다른 식기와 주기의 조합에서는 천자와 제후국(공국, 후국) 국군의 수준에 필적한다. 이러한 점은 악기가 부장되어 있는 것을 통해서도 드러난다. 소흑석구 8501호 대형 석곽묘의 청동예기 가운데 토착식과 혼합식은 현지의 금속기 제작 기술을 고려할 때 자체 제작한 것으로 판단된다. 그러나 서주식 청동예기는 형태와 문양은 물론 규격까지 중국 중원 지역과 동일하여 서주에서 제작된 것임이 분명하다. 중국 중원 지역의 여러 제후국에서 제작하여 사용되던 해당 제후국의 보기(寶器)가 소흑석구에 부장된 배경은 하가점상층문화와 서주 사이에 양측과 빈번하게 교류하던 별개의 문화권이 형성되어 있었던 점 등을 고려할 때, 소흑석구 집단에 의한 약탈이라기 보다는 소흑석구 집단과 이들 집단 간의 경제적인 교역과 정치문화적인 상호 관계에 따른 것으로 해석된다.

A Study on Application of Electric Propulsion System using AFE Rectifier for Small Coastal Vessels

  • Jeon, Hyeonmin;Kim, Seongwan;Kim, Jongsu
    • 해양환경안전학회지
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    • 제24권3호
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    • pp.373-380
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    • 2018
  • The small coastal vessel registered in Korea, small coastal vessels with a gross tonnage of 10 tons or less account for 94.6 % and among them, aged vessels over 16 years age indicate 40.6 %. In order to reduce GHG emissions from small coast vessels, discussions are underway to replace aging ships' propulsion units with eco - friendly propulsion facilities, and the electric propulsion ship is emerging as one of the measures. The electric propulsion system using the DFE rectifier, which was applied in the conventional large commercial vessel, was effective in reducing the harmonics and improving the DC output voltage of the DC link stage, but it occupied a large volume and caused an increase in the overall system price. Therefore, in this paper, we propose an electric propulsion system using AFE rectifier with a small volume of system that can be applied to a small coastal vessel. In order to analyze the effectiveness of the overall system, the load profile was applied to obtain accurate and rapid speed tracking performance of the propulsion motor affected by the speed load. In addition, the power factor and total harmonic distortion factor of the voltage and current on the improved power output side are derived through simulation.

퍼지 클러스터링 방법을 이용한 흉부 혈관의 검출에 관한 연구

  • 황준현;박광석;민병구
    • 한국지능시스템학회논문지
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    • 제1권2호
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    • pp.65-71
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    • 1991
  • A new algorithm is proposed for the automatic detection of pulmonary blood vessels by simulating the human recognition process by the pyramid images. Large and wide vessels are detected from the most compressed level, followed by the detection of small and narrow ones from the less compressed images with FCM(fuzzy c means). As the proposed algorithm detects blood vessels orderly according to their size, there is no need to consdier the variation of parameters and the brance points which should be considered in other detection algorithms.

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Development of Complex Energy Saving Device

  • Lee, Kwi-Joo;An, Jung-Sun
    • 한국해양공학회지
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    • 제26권3호
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    • pp.1-5
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    • 2012
  • A complex energy saving device has been developed for middle class vessels. The propulsive performance of the developed device is described through a model test. The pre-swirl stator, which recovers the rotational energy of the propeller slipstream, is a well-known energy saving device for large vessels. The pre-swirl stator for a large vessel is usually cast as a part of the stern frame and has a high cost. The manufacture of a cast stator for an existing vessel is almost impossible. The complex device that was developed can be fitted on astern frame by welding. The model tests show a 4-6% efficiency gain for middle class vessels with the developed appendages compared to those with bare hulls.

Characteristics of Hypoxic Pulmonary Vasoconstriction of the Rat: Study by the Vessel Size and Location in the Lung

  • Lee, Sang-Jin;Kim, Ki-Whan
    • The Korean Journal of Physiology and Pharmacology
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    • 제3권3호
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    • pp.321-328
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    • 1999
  • Pulmonary blood vessels with diameters of $200{\sim}400\;{\mu}m$ produce considerably more force in response to vasoconstrictor drugs than those which are either smaller or larger. We have therefore investigated whether or not hypoxic pulmonary vasoconstriction (HPV) is more powerful in vessels of these diameters. We have also looked at the possibility that vessels from different regions of the lung respond differently. To do this we have grouped vessels according to their location within the lung as well as by size. We used a small vessel myograph (Cambustion AM10, Cambridge, UK) to study 208 preconstricted $(1\;{\mu}M\;PGF_{2{\alpha}})$ small pulmonary arteries $(300{\sim}800\;{\mu}m$ diameter when stretched to a tension equivalent to 25 mmHg transmural pressure) from 39 rats anaesthetized with 2% inspired halothane. A biphasic contraction was observed in response to hypoxia (ca. 25 mmHg $Po_2).$ The magnitudes of both the first, transient, phase (PT, peak tension) and of the second, sustained, phase (SST, steady state tension) were measured. The latter was measured 40 min after the start of hypoxia. The first phase was most pronounced in vessels with an average diameter of 423 ${\mu}m$ while the second phase was most pronounced in larger vessels (mean diameter 505 ${\mu}m).$ These maximal responses were all seen in vessels somewhat larger than reported by others. The responses of smaller vessels $(400{\sim}500\;{\mu}m)$ did not depend upon their location within the lung, but those of larger vessels $(600{\sim}700\;{\mu}m)$ showed regional differences. Those from the right lobe and those from the base of the lung gave the largest responses. It was especially noticeable that large vessels (631 ${\mu}m$ diameter) from the base of the right lung gave the biggest responses. Thus HPV seems to occur not in a uniform manner, dependent solely to the size of vessels, but it also depends to some degree on the region of the lung from which vessels have been taken. Furthermore, our results suggest that larger vessels, as well as smaller ones, may contribute significantly to HPV.

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