• Title/Summary/Keyword: Marine structure

Search Result 2,402, Processing Time 0.026 seconds

A Study on Integrated Information System for Marine Leisure Industry (해양레저 산업의 통합 정보 시스템 구축에 관한 연구)

  • Kim, Y.S.;Kim, D.J.
    • Journal of the Korean Society for Marine Environment & Energy
    • /
    • v.16 no.1
    • /
    • pp.17-24
    • /
    • 2013
  • In order to have market competitiveness in local and global areas, Domestic Marine Leisure Industry business, which is a latecomer in the Marine Leisure industry, should retain a strong market adaptability by reducing time and cost that are required for work of planning, designing, and preparation for product development. To meet above requirements, it is essential that integrated system control extensive marine leisure industry. After ensuring integrated information by figuring out the systematic link between related-industries, the core of this research is to secure information classifications that are not just in the flow of simple serial order, but in that of integration and object-oriented information classifications. For this end, we examine other similar cases in industries using real information system applied to industrial production and Product Lifecycle Management (PLM), Product Data Management (PDM), Digital Manufacturing (DM) and applying the same methodology to review practical application in order to construct the information system, and Work Breakdown Structure (WBS), compared with the case studies. Through this basic task for the marine leisure industry classification system configuration (Work Breakdown Structure, WBS) and utilizing information of driving real companies of marine leisure industry, a unique area of MLWBS (Marine Leisure Work Breakdown Structure, MLWBS) is configured. This Marine Leisure Work Breakdown Structure can be used in various areas of applications like products, design information, engineering, production, purchasing, sales, marketing, AS, utilizing various forms of customer support.

Optimum Structure and Deployment of an Abalone Reef for the Marine Ranching Creation in Jeonnam Archipelago of Korea (전남다도해형 바다목장 조성을 위한 전복초의 적정구조 및 시설방법)

  • Kim, Chang-Gil;Suh, Sung-Ho;Cho, Jae-Kwon;Oh, Tae-Gun;Kim, Chul-Won;Myoung, Jung-Goo;Ryu, Cheong-Ro
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.31 no.8
    • /
    • pp.1005-1012
    • /
    • 2007
  • This study describes the optimum structure and deployment of an abalone reef for marine ranching creation in Jeonnam archipelago of Korea. The structure of an abalone reef was analyzed based upon the functions of both feeding and shelter. Deployments of abalone reefs were considered based upon the stability against waves in water depth shallower than 5 m. Also, the calculation of their stabilities was made to only rocks of abalone modules, and exposure coefficient of rocks used was 1.0 and 0.5. The results show that rocks of both 0.2 and 0.5 ton are unstable under the condition that exposure coefficient is 1.0 at a depth of 5 m, but that they are stable under the condition that exposure coefficient is 0.5. It means that, if the structures(e.g. breakwater blocks) for dissipating the energy of waves and currents are provided, small rocks of 0.2 ton can be used as an abalone reef.

The Application of Structural Stress Method for the Fatigue Strength Assessment of Longi-web Connections (선체 Longi-web 연결부의 피로강도 평가를 위한 구조응력 기법의 적용)

  • Kim, Myung-Hyun;Kim, Jeong-Hwan;Kim, Seong-Min;Kim, Kwang-Seok;Kang, Joong-Kyoo;Heo, Joo-Ho;Kang, Sung-Won
    • Journal of the Society of Naval Architects of Korea
    • /
    • v.45 no.1
    • /
    • pp.81-86
    • /
    • 2008
  • Recently, a mesh-size insensitive structural stress definition that provides a stress state at weld toe with relatively larger mesh size compared to conventional approaches has been proposed. The structural stress definition is based on the elementary structural mechanics theory and provides an effective measure of a stress state in front of weld toe. In this study, as an experimental validation of structural stress method in obtaining the fatigue strength of weldments, a series of fatigue test has carried out for longi-web connections, which are representative of ship-like structures. Based on the result from this study, it is expected to develop a more precise fatigue strength evaluation technique and to reduce time and cost associated with the fatigue design of ship and offshore structures.

Marine Algal Flora and Community Structure in Beakryoung-do, Western Coast of Korea (서해 백령도 연안의 해조상 및 군집구조)

  • Yong Yi, Kim;Ju Hee, Kim;Young Sik, Kim
    • Journal of Marine Bioscience and Biotechnology
    • /
    • v.14 no.2
    • /
    • pp.102-111
    • /
    • 2022
  • Beakryoung-do is located in the north along the western coast of South Korea. Owing to its geographical limitations, not many studies have been conducted on marine algae in this region. This study aims to investigate the marine algal flora and the community structure in the intertidal and subtidal zones of Nampo-ri, Beakryoung-myeon, Ongin-gun, Incheon regions of South Korea. The study was conducted from August 2015 to June 2016 during all seasons. A total of 95 algal species, including 7 green algae, 12 brown algae, and 76 red algae were collected and identified; 52 algal species were found in the intertidal zone and 83 in the subtidal zone. The vertical distribution of algae from upper to lower intertidal zone was Neorhodomela aculeata - Caulacanthus okamurae, Gelidiophycus freshwateri - Neorhodomela aculeata, Caulacanthus okamurae - Sargassum thunbergii, Caulacanthus okamurae. Findings indicated that Sargassum thunbergii and Neorhodomela aculeata were the biomass-dominant species in the intertidal zone and Corallina officinalis and Undaria pinnatifida were biomass-dominant in the subtidal zone. Average values of marine algae biomass in the intertidal and subtidal zones were 252.6 g wet weight m-2 and 291.9 g wet weight m-2, respectively. Further, 38 new species were found in Beakryoung-do, with 25 of them specifically found in the subtidal zone. More studies on marine algal flora in the subtidal zone are needed to understand the changes in marine flora along the western coast.

Hydroelastic Response Analysis of Very Large Floating Structures Including the Hydrodynamic Forces due to Elastic Motions in Waves (탄성거동에 의한 유체력을 고려한 초대형 부유식 구조물의 유탄성응답 해석)

  • Kim, Chuel-Hyun;Lee, Chang-Ho;Lee, Seung-Chul;Goo, Ja-Sam
    • Journal of Ocean Engineering and Technology
    • /
    • v.20 no.6 s.73
    • /
    • pp.101-107
    • /
    • 2006
  • Recently, with the increase in requirements for marine development, a marine urbanism is being visualized, with more and more huge-scale structures at the scope of the ocean space utilization. In particular, a pontoon-type structure has attracted attention, since The Floating Structures Association of Japan proposed a new concept as the most suitable one of floating airports. The Very Lage Floating Structure (VLFS) is considered a flexible structure, for a quite large length-to-breadth ratio and its geometrical flexibility. The main objective of this study is to makean exact and convenient prediction about the hydro-elastic response on very large offshore structures in waves. The numerical approach for the hydro-elastic responses is based on the combination of the three dimensional source distribution method and the dynamic response analysis method, which assumed a dividing pontoon type structure, as many rigid bodies connected elastic beam elements. The established hydo-elastic theory was applied to the radiation forces caused by motions of a whole structure, formulated using the global coordinate system, which has the origin at the center of the structure. However, in this paper, we took radiation forces, occurred by individual motions of floating bodies, into consideration. The calculated results show good agreement with the experimental and calculated results by Yago.

Seasonal Dynamics of Marine Benthic Communities in Intertidal Zone of Gwangyang Bay, Southern Coast of Korea

  • Yoo, Jong-Su
    • Ocean and Polar Research
    • /
    • v.25 no.4
    • /
    • pp.519-528
    • /
    • 2003
  • Species composition and community structure of marine benthic community were studied in the intertidal zone of Jijindo Island, Gwangyang Bay. A total of 85 species of benthic marine plants including the 5 Cyanophyta, 9 Chlorophyta, 13 Phaeophyta, 56 Rhodophyta and 2 Magnoliophyta that were listed. The community structure was represented by Gelidium divaricatum in the upper zone, Celidium divalicatum and Ulva pertusa in the middle, and Ulva pertusa, Chondria crassicaulis, Chondracanthus intermedia and Sargassum thunbergii in the lower intertidal zone. The dominant species in the rnscro-zoobenthic community were Chthamalux challengeri in the upper and middle, Littorina brevicula between the upper and middle, and Mytilus edulis and Crassostrea gigas in the middle and lower intertidal zones. The economic benthic organisms such as Undaria pinnatifida, Mytilus edulis, and Crassostrea gigas found in the lower intertidal zone were frequently disturbed due to their collection by local resident. Therefore, it is necessary to record the correct information pertaining to these cases. The species diversity indices estimated kom different sources were quite different. They were 2.22 derived from frequency, 1.67 based on coverage, 2.17 based on sum of frequency and coverage and 2.04 derived from importance value. Species diversity and number of algal species in Gwangyang Bay have noticeably decreased, compared with their previously reported status. It is estimated that their decreases were caused by changes in the marine environment, especially pertaining to the polychaete community resulting from reclamation and dredging activity undertaken for the industrial development.

Pestalotiolide A, a New Antiviral Phthalide Derivative from a Soft Coral-derived Fungus Pestalotiopsis sp.

  • Jia, Yan-Lai;Guan, Fei-Fei;Ma, Jie;Wang, Chang-Yun;Shao, Chang-Lun
    • Natural Product Sciences
    • /
    • v.21 no.4
    • /
    • pp.227-230
    • /
    • 2015
  • Chemical investigation of the fermentation broth of a Soft Coral-Derived fungus Pestalotiopsis sp., led to the isolation of a new phthalide derivative, pestalotiolide A (1), three known analogues (2, 3 and 4), along with 5'-O-acetyl uridine (5) first isolated as a natural product. The structure of the new compound (1) was established by comprehensive spectroscopic analysis and chemical methods. Compounds 1 - 4 possessed varying degrees of antiviral activities, which was reported for the first time. Compared to the positive control ribavirin ($IC_{50}=418.0{\mu}M$), pestalotiolide A (1) exhibited significant anti-EV71 activity in vitro, with an $IC_{50}$ value of $27.7{\mu}M$. Furthermore, the preliminary structure-activity relationship of antiviral activities was also discussed.

Repair Procedure and Structural Strength Analysis to Damage of Moon-Pool Structure for Drillship During Construction (드릴쉽 건조 중 문풀 구조 수정 작업 및 구조적 안정성 검토)

  • Yoo, In-Sang;Sohn, Sang-Young;Baek, Seung-Jung;Choi, Young-Lack;Yoo, Hae-Kun;Yoon, Ki-Jeong
    • Special Issue of the Society of Naval Architects of Korea
    • /
    • 2011.09a
    • /
    • pp.12-16
    • /
    • 2011
  • During the shipbuilding construction, the repair works will be occurred by various reasons such as the natural disaster, mistakes of engineers or workers, defect of material, and so on. The one of the engineer's responsibilities is to design considering every possibility and to prevent the repair works due to the mistakes during construction stages, but actually it is very difficult and impossible to avoid every mistake. However, it is also the responsibility of engineers to find the best solution for the unavoidable mistakes which is to maintain the capacity of vessel and guarantee the safety for the repair works considering the construction schedules and economic cost. In this paper, it will be introduced the brief of repair works to the structural damage of the moon-pool structure in drillship which is built in our shipyard. For the verification of the structural strength, the fatigue analysis has been carried out based on the guide of Classification society. Furthermore, the modifications of structure design and welding procedure have been applied to avoid the stress concentration in the moon-pool structure.

  • PDF

Isolation and Structure Determination of Streptochlorin, an Antiproliferative Agent from a Marine-derived Streptomyces sp. 04DH110

  • Shin, Hee-Jae;Jeong, Hyun-Sun;Lee, Hyi-Seung;Park, Song-Kyu;Kim, Hwan-Mook;Kwon, Ho-Jeong
    • Journal of Microbiology and Biotechnology
    • /
    • v.17 no.8
    • /
    • pp.1403-1406
    • /
    • 2007
  • An antiproliferative agent, streptochlorin, was isolated from the fermentation broth of a marine actinomycete isolated from marine sediment. Phylogenetic analysis of the 16S rRNA gene sequence indicated that the strain belongs to the genus Streptomyces. Bioactivity guided fractionation of the culture extract by solvent partitioning, ODS open flash chromatography, and reversed-phase HPLC gave a pure compound, streptochlorin. Its structure was elucidated by extensive 2D NMR and mass spectral analyses. Streptochlorin exhibited significant antiproliferative activity against human cultured cell lines.