• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2003.05a
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• pp.268-269
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• 2003

줄새우 (Palaemon paucidens De Haan, 1844)는 징거미새우과 (Palaemonidae)에 속하는 줄새우속 (Genus Palaemon)의 한 종이다. 줄새우류 (Palaemonid shrimps)는 담수지역에서 하구지역, 해양까지 환경의 변화 폭이 매우 큰 지역에 다양하게 서식하는 종으로서 우리나라에서는 13종이 분포하는 것으로 알려져 있다 (국립수산진흥원, 2001). (중략)

• Journal of the Korea institute for structural maintenance and inspection
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• v.28 no.1
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• pp.53-60
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• 2024

Compressive strength in concrete has many affecting parameters and varies with exposure conditions. Although the concrete has same mix proportions, its properties are different with exposure conditions, and sea-environment can be classified into three groups such as tidal, atmospheric, and sea submerged region particularly. In this study, compressive strength was evaluated on 7-year-cured concrete and the results from previous equations (KDS, ACI, CEB, and JSCE) were compared with them. Furthermore the strength and carbonation progress were evaluated on concrete cured for 7 years exposed to three different sea environment. Three levels of w/c (water to cement) ratio (0.37, 0.42, and 0.47) and three different exposure conditions (tidal, atmospheric, and submerged) were considered. The results from wet-cured condition are all higher than those from the previously proposed equations, and the results from different sea exposure conditions (tidal, atmospheric, and submerged region) were lower than those from wet-cured condition. A reduction of strength was evaluated with increasing w/c ratio and the minimum strength was evaluated in the sea-submerged conditions. Several experimental constants applicable to the previous equations were obtained from regression analysis since the strength change with w/c ratios were not considered in those equations. Regarding carbonation depth with different exposure conditions, higher carbonation depth clearly was observed with increasing w/c ratios, and evaluated in the order of atmospheric, submerged, and tidal region. Considerable carbonation depth was observed in submerged and tidal region due to sulfate ion and dissloved carbon dioxide as well.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.179-180
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• 2000

본 연구는 전라남도 완도군 고금면과 강진군 마량면 사이의 마도수도를 횡단하여 건설될 예정인 고금-마량간의 연육교 가설공사로 인하여 발생할 수 있는 주변해역에 있어서의 환경변화를 사전에 예측하기 위하여 수행되었다. 마도수도는 수로폭이 약 800∼1800 m이고 평균수심이 20 m정도로서 동서방향의 흐름이 탁월한 수로이다. (중략)

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.4
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• pp.307-313
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• 2014

Recent interest in the increased structural performance and durability evaluation of this concrete structure in a salt damage environment is increasing. The most secure and reliable method of accelerated corrosion test is a method to carry out the rebar corrosion monitoring can be exposed directly to the marine test site exposure. However, long-term exposure testinghas the disadvantage that a long period is necessary. So, a lot of research on RC of salt damage environment have beenpromoted as alternatives to replace this. However, accelerated corrosion test, in the short term only is appropriate and is but an accelerated test method to evaluate the critical chlorine concentration, there is a difficult problem that you still get the answer. It is one of the correlation problems accelerated test correspond to a certain period of exposure environment. Therefore, in this study, to clarify the differences rebar corrosion beginning, through the actual corrosion accelerated test in corrosion time and laboratory test chamber of the structure of the marine environment results in both environments, it is an object of correlation coefficient derived.

• Journal of the Korean Society of Marine Environment & Safety
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• v.12 no.3 s.26
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• pp.211-218
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• 2006

Recently, many ships such as fishing boats, cargo ships, high speed ferry boats are visiting Mokpo harbor. In particular, many marine accidents have been occurred at this area due to the narrow channel, a thick fog, the existing of the shallow waters etc. However there is no suitable ships' routeing system which takes account of today's traffic situations in this area. This study aims at the settling of hazardous factors to mitigate the danger to vessels in Mokpo harbor and to secure the safety of maritime environment.

• Proceedings of KOSOMES biannual meeting
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• 2006.11a
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• pp.283-289
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• 2006

This study is a preparation for the application of FSA (Formal Safety Assessment) to the fire safety of ships. FSA is the new-fashioned methodology proposed to prevent ships from the accidents. To make a base of the fire safety assessment about ship's fire protection design and Classification Society rule, statistical informations for the fire safety engineering are investigated. From results, the necessity of new criterion for ship's fire safety design, the need to study the human behavior in the evacuation from fire, and the development of new fire progress model considering special situations in ships are acknowledged.

• Journal of the Korea institute for structural maintenance and inspection
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• v.26 no.2
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• pp.18-27
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• 2022

In this study, the time-dependent chloride ingress behavior in GGBFS concrete was evaluated considering marine exposure conditions and the properties of concrete mixtures. The concrete mixture for this study had 3 levels of water to binder ratio and the substitution rate of GGBFS, and outdoor exposure tests were performed considering submerged area, tidal area, and splash area. According to the evaluation results of diffusion coefficient considering properties of concrete mixtures, as the substitution rate of GGBFS increased, the decreasing rate of the diffusion coefficient decreased based on exposure periods of 730 days(2 years). As the evaluation result of the diffusion behavior according to the marine exposure conditions, the diffusion coefficient was evaluated in the order of submerged area, tidal area, and splash area. In tidal area, a relatively high diffusion coefficient was evaluated due to the repetition of wet and dry seawater. In this study, the effects of GGBFS substitution rate on the decreasing behavior of apparent chloride diffusion coefficient was analyzed in consideration of exposure conditions and periods. Linear regression analysis was performed with apparent chloride diffusion coefficient as output value and GGBFS substitution rate as input value. After 730 days of exposure, the effect of GGBFS on diffusion coefficient was significantly reduced. Even for OPC concrete, after 730 days, the diffusion coefficient was as low as that of GGBFS concrete, so the gradient of the regression equation decreased significantly. It is thought that improved durability performance for chloride ingress can be secured before 730 days through the use of GGBFS.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.5
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• pp.583-590
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• 2018

The objective of this study is to present a resistance performance map developed using the dimension parameters of a bilge keel appendage attached to a fishing vessel using CFD. The dimension parameters consist of three length and breadth measures of a bilge keel appendage from nine selected cases. The size of a bilge keel attached to an existing ship should be 90 % of the ship length and 5 % of the ship breadth. In this study, bilge keels with a length of 63 %, 77 % and 90 % and a breadth of 5 %, 7 % and 9 % were considered based on ship length and breadth. The effective power in each of the nine cases was predicted using CFD. Based on results from an existing ship, effective power in the case with the shortest length and longest breath was reduced by 0.3 %. The case with the longest length and breadth showed an increase in effective power of 1.7 %. The case with the shortest length and breadth showed a decrease in effective power of 2.3 %. The proposed map can be utilized to select dimensions according to the sailing and work patterns of fishing vessels from the perspective of resistance performance.

• Korean Journal of Remote Sensing
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• v.14 no.2
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• pp.117-128
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• 1998

Topex/Poseidon satellite, launched in Auguest 1992, has provided more 5 years of very good quality data. Efficient improvements, either about instrumental accuracy or about sea level data correction, have been made so that Topex/Poseidon has become presently a wonderful tool for many researchers. The first mission data of 73 cycles, September 1992 - August 1994, was used to our study in order to know characteristics of environmental correction factors in the Amsterdam-Crozet-Kerguelen region of the South Indian Ocean. According to standard procedures as defined under user handbook for sea surface height data processes, then we have chosen cycles 43 as the cycle of reference because this cycle has provided the completed data for measurement points and has presented the exacted position of ground track compared to another cycles. It was computed variations of various factors for correction in ascending ground track 103(Amsterdam-Kerguelen continental plateau) and descending ground track170 (Crozet basin). Here the variations of ionosphere, dry troposphere, humid troposphere, electromagnetic bias, elastic tide and loading tide were generally very smaller as a few of cm, but the variations of oceanic tide(30-35cm) and inverted barometer(15-30cm) were higher than another factors. For the correction of ocean tide, our model(CEFMO: Code d' Elements Finis pour la Maree Oceanique) - This is hydrodynamic model that is very well applicated in all oceanic situations - was used because this model has especially good solution in the coastal and island area as the open sea area. Conclusionally, it should be understood that the variation of ocean free surface is mainly under the influence of tides(>80-90%) in the Amsterdam - Crozet- Kerguelen region of the South Indian Ocean.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2000.05a
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• pp.420-421
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• 2000

함평만은 만 주위로 갯벌 조간대가 잘 발달되어 있으며, 폭이 약1.8km인 북서 방향의 입구를 통하여 외해와 연결되는 반폐쇄적 지형 특성을 나타낸다. 또한 최대폭 12km, 길이 17km, 최대 수심 23m로서 우리나라의 여타 내만과는 달리 주변에 인구 밀집 지역과 산업시설이 없어 비교적 인위적인 오염의 영향을 적게 받고 있다. 특히 함평만은 주변의 해안이 침식되어 조간대로 퇴적될 뿐 아니라 만 전체에 영향을 미치고 있어 입도가 조립하고 우리나라 여타 내만들과는 다른 독특한 환경을 지니고 있다. 본 연구는 서남해역에 위치한 함평만 조하대의 저서동물 군집 구조와 공간 분포 양상을 환경과 연관시켜 파악함으로서 이 해역의 군집구조를 파악하고 생태계 변화를 추적하는 기초자료로 사용코자 하는데 주안점을 두었다. (중략)