• Journal of the Society of Naval Architects of Korea
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• v.41 no.3
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• pp.41-48
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• 2004

Ship is being operated under a highly dynamic environments and many factors are related with ship's collision and those factors are interacting. So, the analysis on ship's collision causes are very important to prepare countermeasures which will ensure the safe navigation. This study analysed the ship's collision data over the past 10 years(1991-2000), which is compiled by Korea Marine Accidents Inquiry Agency. The analysis confirmed that ‘ship's collision' is occurred most frequently and the cause is closely related with human factor. The main purpose of this study is to propose risk control measures of ship's collision. For this, the structure of human factor is analysed by the questionnaire methodology. Marine experts were surveyed based on major elements that were extracted from the human factor affecting to ship's collision. FSM has been widely adopted in modeling a dynamic system which is composed of human factors. Then, the structure analysis on the causes of ship's collision are performed using FSM. This structure model could be used in understanding and verifying the procedure of real ship's collision. Furthermore it could be used as the model to prevent ship's collision and reduce marine accidents.

• Earthquakes and Structures
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• v.21 no.6
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• pp.587-599
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• 2021

The modified-ECOMAC approach to monitor and investigate health of structure in marine platforms was evaluated in this research. The material properties of structure were defined based on the real platform located in Persian Gulf. The nonlinear time-history analyses were undertaken using the marine natural waves. The modified-ECOMAC approach was designed to act as the solution of the best sensor placement according to structural dynamic behavior of structure. This novel method uses nonlinear time-history analysis results as an exact seismic response despite the common COMAC algorithms utilize the eigenvalue responses. The processes of modified-ECOMAC criteria were designed and developed by author of this paper as a toolbox of Matlab. The Results show that utilizing an efficient ECOMAC method in SHM process leads to detecting the critical weak points of sensitive marine platforms to make better decision about them. The statistical results indicate that considering modified ECOMAC based on seismic waves analysis has an acceptable accuracy on identify the sensor location. The average of statistical comparison of COMAC and ECOMAC via modal and integrated analysis, had a high MAE of 0.052 and RSME of 0.057 and small R2 of 0.504, so there is significant difference between them.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.268-268
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• 2012

• Journal of Microbiology and Biotechnology
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• v.32 no.4
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• pp.504-513
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• 2022

Chitin deacetylase (CDA) inhibitors were developed as novel antifungal agents because CDA participates in critical fungal physiological and metabolic processes and increases virulence in soil-borne fungal pathogens. However, few CDA inhibitors have been reported. In this study, 150 candidate CDA inhibitors were selected from the commercial Chemdiv compound library through structure-based virtual screening. The top-ranked 25 compounds were further evaluated for biological activity. The compound J075-4187 had an IC50 of 4.24 ± 0.16 µM for AnCDA. Molecular docking calculations predicted that compound J075-4187 binds to the amino acid residues, including active sites (H101, D48). Furthermore, compound J075-4187 inhibited food spoilage fungi and plant pathogenic fungi, with minimum inhibitory concentration (MIC) at 260 ㎍/ml and minimum fungicidal concentration (MFC) at 520 ㎍/ml. Therefore, compound J075-4187 is a good candidate for use in developing antifungal agents for fungi control.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.24 no.1
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• pp.128-138
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• 2019

Effects of feeding type and food resource availability on community structure of mollusks inhabiting hard-bottom subtidal areas were investigated. By following guidance from several references, mollusks observed in this study were divided into 5 groups according to feeding type - 1) grazing, 2) filter feeding, 3) deposit feeding, 4) omnivorous and 5) predation. The results showed that both grazing and filter feeders were the most numerous, explaining grazing type in the East Sea accounting for 47.9%, 32.6% in the South Sea and 29.6% for filter feeding, and filter feeding as a dominant feeding type in Yellow Sea accounting for 42.3%. Results of this study showed distinctive difference in community structure depending on mechanism of feeding type and geographical areas where sampling took place. With the results, attempts were made to understand whether community structure could be affected by feeding type or feeding availability and found out that community structure depended heavily on food resource availability. In the East Sea where marine algal density was high, the algal community in the forms of thick-leathery and sheet often occurred in water column with high transparency which provides proper environment for growth. In the South Sea where grazing and filter feeding types were predominated similarly, the algal density was high, but had the relative highest phytoplankton density. Whereas in the Yellow Sea showing the lowest algal biomass compared to the one in the East and the South Sea, and phytoplankton density was similar to those. It might be a adequate environment for filter feeders than grazers. This study concluded that community structure of mollusks showing high abundance was present where food resource availability with types and quantity was high.

• Journal of Advanced Marine Engineering and Technology
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• v.21 no.5
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• pp.584-590
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• 1997

Harbour marine steel structures, which are served in severe marine environment, should be protected in appropriate method to reduce corrosion problems. Cathodic protection, one of the protection methods in terms of practical and economical point of view is being widely used to marine steel structures mentioned above. Recently it has been reported that the life of Al alloy anode with sacrificial anode for protection of harbour marine steel structures was shortened significantly than the original design life. In this study, the optimum cathodic protection design of harbour marine steel structures was investigated with parameter of sea water pollution degree.

• Journal of the Korean earth science society
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• v.21 no.1
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• pp.23-39
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• 2000

To search out the characteristics of the lower and the upper atmospheric vertical structure, we selected the island(Oeyoundori Ochun-myen Poryeng city Chung-Nam) as an observation site, which is thought to represent the characteristics of ocean well, and observed the vertical structure of the atmosphere by Radiosonde. By using the results of the observation, we analyzed the changes of relative humidity(RH), temperature and wind when the cyclone and the anticyclone passed and compared the results in case of each event. To compare the vertical structure of the ocean atmosphere with those of the continent we analyzed the values observed with using Radiosonde at Osan site. Through this study, we found that relative humidity changed as the cyclone and the anticyclone passed. That is, when the cyclone came, RH increased first in the upper atmosphere than in the lower and when the high came, RH in the upper decreased sharply to 10%. And the variations of relative humidity in ocean are bigger than those in continent. In the future, we plan to f d out the relation between the vapor water in ocean and continent seasonally and daily through the observation in ocean and continent at same time.

• Journal of Navigation and Port Research
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• v.30 no.4
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• pp.309-314
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• 2006

Community structure and biodiversity of benthic marine algae were studied in the rocky shore of Phohang New Port, Yeoungil Bay. A total of 79 species of marine algae including 8 Chlorophyta, 23 Phaeophyta and 48 Rhodophyta are listed. The dominant algal species were Corallina pilulifera in all seasons, and Sargassum homeri in winter. Lomentaria catenata, Lomentaria hakodatensis, Grateloupia laceolata, Sargassum thunbergii, Chondria crassicaulis, Ulva pertusa, and Hypnea charoides were subdominant at different seasons. The algal biomass per unit area of the benthic algal community in Pohang New Port under construction was 14506 - 398.93 g dry wt m-2, which means that its annually averaged value is 273.45 g dry wt m-2 . The seasonal change in algal biomass showed highs in winter and spring, and lows in summer and autumn. The algal species diversity (H') based on algal biomass was 2.07 annually in average, with 2.42 in winter, 2.65 in spring, 1.79 in summer and 1.43 in autumn. It was high in winter and spring seasons and low in summer and autumn seasons. It is caused by that spring and winter are the profitable growth time for algae and species components in this study were dominated by the annual or seasonal rather than perennial plants.

• Ocean and Polar Research
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• v.31 no.4
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• pp.327-338
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• 2009

Zooplankton community structure was investigated in the Saemangeum region in March, May, July and October of 2007 and 2008 in order to understand the potential effect of post construction of Saemangeum dyke on their temporal and spatial distribution. Mean abundance of zooplankton in the inner and outer area of the dyke, except for dinoflagellate Noctiluca scintillans, ranged from 173 to 15,830 ind.m$^{-3}$, showing higher variability in the inner area compared to the outer area. Zooplankton abundance was higher in the outer area than the inner area in 2007, and vice versa in 2008. In the inner area of the dyke, zooplankton abundance was the highest in May 2007 and March 2008. In the outer area of the dyke, abundance was the highest in October 2007 and July 2008. Brackish species such as Tortanus derjugini and Pseudodiaptomus inopinus were dominant prior to construction of the dyke, and appeared less frequently in the inner area. Marine zooplankton taxa such as juvenile hydromedusa, and calanoid copepods Acartiahongi and Paracalanus parvus s.l. dominated both areas of the dyke. In CCA analysis, zooplankton community structure in the inner and outer area was similar in March and May, but different in July and October. Temperature, salinity and COD were important environmental factors affecting zooplankton community structure. These results suggest that zooplankton community structure in the inner and outer area of Saemangeum dyke are significantly affected by whether the sluice gates are closed or open.

• The Korean Journal of Malacology
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• v.32 no.4
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• pp.289-295
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• 2016

Study on characteristics of the molluscan community structure and relationship between the structure and environmental variables in the abyssal plain of the East Sea was carried out for 5 years, starting from 2009 until the end of 2015 except 2010 and 2011. The water depth at the study site is approximately 1,600 m at minimum, and maximum depth of 2,000 m and a total of 16 molluscan species including Aplacophora, Gastropoda and Bivalvia were observed. Species with the highest biomass was Thyasira tokunagai, followed by Yoldiella philippiana which were observed at 9 sampling stations every year. Among 4 sampling stations having various depths (1,600/ 1,700/ 1,800/ 2,000 m), the highest diversity for species was observed at water depths of 1,600 m and 1,700 m, but found the lowest at 1,800 m. Both abundance and biomass were found to be negative correlations with water depth (p < 0.05), however, showed a positive correlation with the concentrations of organic matters (p < 0.01, p < 0.05). However, it is interesting to note that both Thyasira tokunagai (biomass, 82.6%; abundance, 44.1%) and Yoldiella philippiana (biomass, 15.9%; abundance, 4.7%) did not show distinctive correlations with water depth as well as concentrations of organic matters (p > 0.05). Therefore, it could be concluded that community structure of both Thyasira tokunagai and Yoldiella philippiana did not appear to be affected by water depth and concentrations of organic matters but geographical characteristics.