• Title/Summary/Keyword: sea state

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Comparing Surplus Production Models for Selecting Effective Stock Assessment Model: Analyzing Potential Yield of East Sea, Republic of Korea (효과적인 자원평가모델 선정을 위한 잉여생산량모델의 비교 분석: 동해 생태계의 잠재생산량 분석을 대상으로)

  • Choi, Min-Je;Kim, Do-Hoon
    • Ocean and Polar Research
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    • v.41 no.3
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    • pp.183-191
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    • 2019
  • This study sought to find which model is most appropriate for estimating potential yield in the East Sea, Republic of Korea. For comparison purposes, the Process-error model, ASPIC model, Maximum entropy model, Observation-error model, and Bayesian state-space model were applied using data from catch amounts and total efforts of the whole catchable fishes in the East Sea. Results showed that the Bayesian state-space model was estimated to be the most reliable among the models. Potential yield of catchable species was estimated to be 227,858 tons per year. In addition, it was analyzed that the amount of fishery resources in 2016 was about 63% of the biomass that enables a fish stock to deliver the maximum sustainable yield.

A Study on the Port State Control (항만국통제에 관한 연구)

  • 이석태
    • Journal of the Korean Institute of Navigation
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    • v.9 no.1
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    • pp.83-93
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    • 1985
  • Sea casulties involving tankers, compared with those incurred by other type of vessels, have become particularly threatening to port State in terms of environmental as well as property damages. As a result, most of developed countries including the U.S.A. and Japan have shown a strong interest in implementing the policy of the Port State Control more rigorously in an attempt to protect themselves from irreparable damages caused by sea casualties involving large vessels. In this paper, the problems associated with the implementation of the Port State Control are analysed and then following recommendations and suggestions are made: ⅰ) The flag nation is urged to improve the quality of personnel associated with the operation of a ship. ⅱ) A closer cooperation between developing nations operating vessels and developed nations adopting the Port State Control is required for a successful implementation of this policy. ⅲ) Port states are advised to give a special attention to vessels carrying hazardous cargoes.

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The Incidence of Malignant Tumors in Environmentally Disadvantaged Regions of Kazakhstan

  • Mamyrbayev, Arstan;Djarkenov, Timur;Dosbayev, Askar;Dusembayeva, Nailya;Shpakov, Anatolyi;Umarova, Gulmira;Drobchenko, Yelena;Kunurkulzhayev, Temirgali;Zhaylybaev, Mukhtar;Isayeva, Gulnar
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.12
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    • pp.5203-5209
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    • 2016
  • Objective: To explore the prevalence of malignant tumors in the adult population through 2003-2014 in parts of the Aral Sea region: a zone of ecological disaster, a zone of ecological crisis and a zone of precritical conditions. Methods: The long-time average annual levels of cancer morbidity stratified by zones of the Aral Sea region and trends of long-time average annual incidence indicators of malignant tumors were identified. Leading cancer localizations in the adult population was established and associations between cancer incidence and environmental pollution were analyzed. In addition, associations between individual risk factors and cancer incidence in the adult population was established. Correlations between a hazard index and the cancer incidence in the adult population were calculated. Results: In all three Aral Sea regions, as well as in Zhanaarkinskii district, leading cancer in adult population was esophageal, stomach, tracheal, lung, hepatobiliary, and breast. Long-time average annual levels of cancer morbidity in adult population living in the Aral sea region is 1.5 times higher comparing to the control region. In particular, long-time average annual levels of cancer morbidity in adult population living in the zone of ecological disaster was 57.2% higher, in the zone of ecological crisis - 61.9% higher, and in the zone of precritical condition - 16.8% higher. Long-time average annual levels in the adult population of the Aral Sea region significantly exceeded control levels for brain and central nervous system cancer, cancer of bone and articular cartilage, and thyroid cancer. Conclusion: It has was established that the total cancer morbidity depended on the total hazard index associated with the inhalation of nickel and the combined cadmium intake (r=0.8).

The right and duties of the coastal state over the continental shelf (연안국의 대륙붕에서의 권리와 의무)

  • Lim, Chae-Hyun;Lee, Yun-Cheol
    • Proceedings of the Korean Society of Marine Engineers Conference
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    • 2006.06a
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    • pp.137-139
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    • 2006
  • The Continental shelf is important part of the coastal states' jurisdiction at sea, because there are many natural resources in continental shelf. This paper examines the concept and legal status of the continental shelf, the limit of the continental shelf, and expecially the rights and duties of the coastal state relating to its continental shelf.

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On the Evaluation of Seakeeping Performance in consideration of nominal speed loss ships in a seaway (선박의 속도저하를 고려한 냉항성능 평가에 관한 연구)

  • 김순갑;공길영
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.2 no.1
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    • pp.47-55
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    • 1996
  • This paper intends to evaluate the seakeeping performance in consideration of nominal speed loss of ships in a seaway. Authors calculate the nominal speed loss in the Sea State of Beaufort Scale 6, 7 & 8 and obtain each response amplitude of ship;s motion by New Strip Method in consideration of them. This study presents some results of the seakeeping performance by the maximum dangerouseness of ships on each sea state.

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Development of Sea Clutter Model for Performance Analysis of Naval Multi Function Radar (함정용 다기능 레이다 성능 분석을 위한 해상 클러터 모델 설계)

  • Jeon, Woo-Joong;Kim, Hyun-Seung;Park, Myung-Hoon;Jung, Dong-Min;Kwon, Se-Woong;Jo, Myeong-Hoon;Kang, Yeon-Duk;Yoo, Seung-Ki
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.20 no.2
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    • pp.109-115
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    • 2020
  • As the maritime targets that threaten allies become lower, smaller, and faster, the need for analysis and modeling of clutter according to sea state increases. Clutter according to the sea state has a great influence on radar performance, such as lowering the probability of detection of low-altitude small maritime targets. In this paper, to analyze the detection performance of a multi function radar for a ship, a sea clutter model suitable for the radar operating environment is selected from several sea clutter models, and analysis of low-altitude, small target detection under a clutter is performed. By using the actual data of the already mounted radar for maritime target detection, four known clutter models have been implemented for each sea state and compared with the actual data. Through this, by selecting a clutter model that best reflects the actual radar environment, reliability of the clutter model is improved. Subsequently, the selected model is used to detect the detectable distance to the low-altitude small target.

A Study on the Relative Bow Motion in Irrugular Sea (불규칙해면에서 선수부의 상대운동에 관한 연구)

  • 윤점동;김종훈;김기윤
    • Journal of the Korean Institute of Navigation
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    • v.13 no.2
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    • pp.37-55
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    • 1989
  • When a ship is sailing on the sea, she has the six-degrees of freedom of motion. It means that she meets a lot of dangerous situations. Especially, when the VLCC is travelling in irregular sea, the slamming, the deck-wetness and the propeller racing are occured with the sea state she is on. These are the representative steps that a heave-to and a scudding are used for a ship building , but for a predominance in both. The author intends to clarify this problem theoretically. The methods of statistical calculation are based with the ITTC spectral formulation and with the assumption that the wave height histogram follows the Rayleigh distribution. In this study, the author gives an attention on the relative bow motion to a wave in the irregular sea. It is verified that the relative diplacement at the bow to sea level in the following sea is less than that in the head sea. It is confirmed that, therefore, one have to sail with scudding when he is threatened to heave-to at a rough sea. But he must bear the propeller racing in mind in the cases.

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Pozzolan Activity of Heat-treated Dredged Sea Soil (소성된 항만준설토의 포졸란 반응성 분석)

  • Moon, Hoon;Kim, Ji-Hyun;Lee, Jae-Yong;Chung, Chul-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.43-44
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    • 2016
  • Large amount of dredged sea soil is produced in southeast seashore region in during harbor maintenance. Disposal of dredged sea soil has become difficult due to the environmental regulation. Therefore, disposal of dredged sea soil method is to landfill. But, the capacity of the landfill limit state and if the size of the dredged sea soil is in the range of silt or clay, it cannot be used as reclamation material because ground subsidence occur. In this study, analyzed the pozzolanic activity of dredged sea soil. Analysis of the results showed a pozzolanic activity of dredged sea soil. In addition, incorporation of heat treated dredged sea soil increase both 28 and 56 day compressive strength of mortar specimen.

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An Analysis of Inquiry for Motion Sickness Incidence of the Training Ship, Kaya, due to the Ship Motion (실습선 가야호의 선체운동에 따른 멀미도 조사 분석)

  • Han, Seung-Jae;Ha, Young-Rok;Kim, Jong-Hwa;Lee, Jong-Gun;Lee, Seung-Chul;Kim, In-Chul
    • Journal of Fisheries and Marine Sciences Education
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    • v.26 no.2
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    • pp.430-436
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    • 2014
  • Excessive motion of the ship in rough sea would affect body's fatigue, cognitive ability, motion sickness, and the proficiency of activity. Among them symptoms of motion sickness are similar to fatigue and nausea. Motion sickness causes sudden degradations of ability to perform tasks in physical and psychological aspects, and causes delays or failure in mental activity, and also takes a significant amount of time recovering. In this study, questionnaire for MSI(Motion Sickness Incidence) survey was taken for the students aboard the training ship of Kaya to the open sea far from land. Motion sickness analysis was performed as comparing the results of questionnaire based on sea state, incident angle, economical speed, and location in the ship.