• Proceedings of the Korean Geotechical Society Conference
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• 2007.09a
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• pp.639-653
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• 2007

Offshore geotechnical site investigation of the seabed ground has been a key factor of the successful construction of various types of offshore structures like as sea-crossing bridges, submerged tunnels, and other marine facilities. Offshore investigations are not easy tasks because of the wave, wind, tidal ebb and flows, and others. Recent developments of offshore equipment including platforms and testing devices like as maine cone penetrator have inspired us to get more reliable characteristics of the seafloor. General information on the offshore site investigations and technical trends concerned are introduced.

• Journal of Ocean Engineering and Technology
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• v.3 no.2
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• pp.545-545
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• 1989

• Vacuum Magazine
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• v.3 no.2
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• pp.11-16
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• 2016

Tidal current energy is the most interesting renewable resources that have been less harnessed. Korea has globally outstanding tidal current energy resources and it is highly needed to develop a tidal current energy conversion system. It is reported that the total amount of available tidal current energy is approximately 6GW in Korea. A good tidal site candidate is required a large amount of fast moving water, bathymetry and seabed properties, no conflicts with other users and is close to a load and grid interconnection. In this review, we summarized the results of R&D projects regarding tidal current resources, utilization projects and demonstration test bed.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.412-415
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• 2011

최근 빈번히 발생하는 자연재해는 육상과 해상에 걸쳐 광범위하게 발생한다. 이러한 자연재해를 모니터링하고 관리하기 위해서는 지형에 대한 측량과 모델링이 필요하다. 특히 최근에는 해상에서 돌발적인 사고가 빈번히 발생하고 있어, 해저지형에 대한 정밀 측량과 지형모델링이 필요하다. 그러나 해저지형을 측량하기 위해 많이 사용되는 측량 시스템으로 MBES 시스템이 있으나 MBES 자료는 해저지형의 특성에 의해 오류를 포함하고 있어 측량결과에 대한 신뢰도가 감소될 수 있다. 따라서 이 연구에서는 MBES를 이용한 해저지형 측량 자료를 모델링 시 회전변환기법을 적용하는 연구를 시도하여 회전변환기법의 활용성을 분석하였다.

• International Journal of Ocean Engineering and Technology Speciallssue:Selected Papers
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• v.5 no.1
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• pp.14-21
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• 2002

In the present paper, the hydrodynamic properties of a Rahmen-type, flexible, porous breakwater interacting with obliquely or normal- incident small amplitude waves are numerically investigated. This system is composed of dual vertical porous membranes, hinged at the side edges of a submerged horizontal membrane. The dual vertical membranes are extended downward and hinged at seabed. The effects of permeability, Rahmen-type membrane breakwater geometry, pre-tensions on membranes, relative dimensionless wave number, and incident wave headings are thoroughly examined.

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.265-265
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• 2017

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2003.05a
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• pp.22-26
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• 2003

This paper presents a genetic algorithm based autonomic movement algorithm for an autonomous underwater vehicle(AUV) and verified it to simulation. Also, developed program that can do simulation on two dimension and three dimension in seabed environment. The presented algorithm is applicable to a escape from the recursive search and a development of obstacle avoidance system.

• Journal of Microbiology and Biotechnology
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• v.25 no.5
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• pp.723-731
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• 2015

Microalgae hold promise as producers of sustainable biomass for the production of biofuels and other biomaterials. However, the selection of strains with efficient and robust production of desirable resources remains challenging. In this study, we isolated a green microalga from Korea and analyzed its morphological, molecular, and biochemical characteristics. Microscopic and phylogenetic analyses demonstrated that the isolate could be classified into the genus Chlamydomonas, and we designated the isolate Chlamydomonas sp. KIOST -1. Compositions of protein, lipid, and carbohydrate in the microalgal cells were estimated to be 58.8 ± 0.2%, 22.7 ± 1.2%, and 18.5 ± 1.0%, respectively. Similar to other microalgae belonging to Chlorophyceae, the dominant amino acid and monosaccharide in Chlamydomonas sp. KIOST-1 were glutamic acid and glucose. On the other hand, the proportions of saturated fatty acids, monounsaturated fatty acids, and polyunsaturated fatty acids clearly differed from other species in the genus Chlamydomonas, and monounsaturated fatty acids accounted for a large portion (41.3%) of the total fatty acids in the isolate. Based on these results, Chlamydomonas sp. KIOST-1 has advantageous characteristics for biomass production.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.23 no.1
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• pp.118-125
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• 2011

Conventional erosion function apparatus (EFA) which has been used to measure the hydraulic resistance of soil was improved to consider direction change of the current flow. Using improved apparatus, hydraulic resistance capacities of the artificially composed clayey soil and sandy soil were compared. Test result shows that scour rates which were measured under the bi-directional flow were much higher than those measured under unidirectional flow for both type soils. Scour rate of sandy soil was higher than that of clayey soil. Velocity averaged scour rate of specimen which was consolidated under the relatively large consolidation pressure is higher than that of specimen which is consolidated under small consolidation pressure, which means scour problem under bidirectional flow may be more serious for the deep seabed ground.

• Transactions of the KSME C: Technology and Education
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• v.1 no.1
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• pp.33-38
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• 2013

Offshore drilling refers to a mechanical process where a wellbore is drilled through a seabed. It is typically carried out in order to explore for and subsequently extract petroleum which lies in rock formations beneath the seabed. There are many different type of facilities from which offshore drilling operations take place. These include bottom founded drilling rigs, combined drilling and production facilities either bottom founded or floating platforms, and deepwater mobile offshore drilling units including semi-submersibles and drillships. These are capable of operating in water depths up to 3,000 m. In this paper, we introduce the drilling system, which is mounted on the offshore drilling facilities.