• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2001년도 봄 학술발표회 논문집
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• pp.69-75
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• 2001

It is very important to secure the marine vessels during entire loading and off-loading operations. The environment influences on loading conditions. the western coastal area of Korea is characterized as a strong current due to a high tidal range. The tension of mooring lines varies as per the current and wave changing its magnitude during the day. A proper mooring arrangement and design of mooring line should be determined as per environment conditions. In this study, a 50,000 DWT container ship being moored is investigated numerically. The dynamic tension of mooring lines is estimated by MORA (Mooring Response Analysis) software. Environmental conditions of selected offshore terminal site are plugged as input data. The mooring line tensions are obtained for various wave frequencies per wave directions. The results demonstrate the change of tensions of lines and the allowable range of safe conditions in berthed mooring.

• 한국해양공학회지
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• 제13권2호통권32호
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• pp.18-25
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• 1999

Western coastal ports of Korea experience severe tidal range with up to 9.7 meter between high and low tides. The significant water level variation implicates many operational difficulties during loading and un-loading from cargo ships. To overcome problems due to tide and to secure the continuous loading operation, a new loading system for container cargo called "container pallet system" is developed and introduced in the paper. Three types of structure forms, offshore structural deck, double bottom structural form and the mixed form, are inverstigated with MSC/NASTRAN software. The results prove that the mixed type structure with truss enforcement is found to be the most appropriate for the region.

• 한국패류학회지
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• 제9권2호
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• pp.68-84
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• 1993

A study on the distribution and seasonal changes of the benthic macroinvertebrate community was performed on the 4 intertidal rocky shores of Biyang-do in Chehu Island throughout four seasons from January 1992 to january 1993. The macroinvertebrates composed of 8 phyla, 15 classes, 31 orders, 71 families, 168 species. The seasonal appearing species were 135 species in summer, 127 species in spring, 124 species in winter and 121 species in autumn, respectively. The dominant species of the upper zones were Nodilittorina exigua, Nerita japonica, Pollicipes mitella, the middle zones were Turbo coronata coreensis, Monodonta neritoides, petrolisthes japonicus and the lower zones were Pagurus samuelis, Chthamalus pilsbryi, Chlorostoma argyrostoma lischkei. The community dominance indices of the upper zones were much higher than the middle and lower zones. The seasonal appearnace in species in the lower zones were remarkable, but individual numbes were not. Species diversity and evenness in all investigated zones were highest in spring and lowest in winter. But species richness was highest in summer, lowest in autumm.

• 한국수산과학회지
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• 제48권5호
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• pp.776-782
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• 2015

We examined the community structure of fish off the coast of Jindo Island in response to a cold water appearance in the southwestern sea of Korea each August between 2013–2015. Using a gape net with wings, we collected 31 taxa during the study period, wherein the most dominant species was Engraulis japonicus. Collichthys lucidus and Neosalanx andersoni, which are mainly distributed in the western sea of Korea, increased in abundance and were dominant in August 2013, possibly due to the apparent intrusion of cold water (< 19°C) from offshore into the coastal waters of Jindo Island. Meanwhile, Scomberomorus niphonius and Sardinella zunasi, which are known as warmwater migratory species, increased in abundance and were dominant in August 2015, likely influenced by the warmer water (> 20°C) at the coast, which resulted in a noticeable lessening of the cold water in the study area. However, no significant differences were observed in fish community structure in the month of August between 2013–1015. This implies that the small-scale spatial and temporal variations in the cold water had limited effects on the fish community structure, even though the abundances of several dominant species varied in the coastal waters.

• 한국환경과학회지
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• 제11권7호
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• pp.651-662
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• 2002

Weather elements were observed by the AWS (Automatic Weather System) and dustfall particles were collected by the modified American dust jar (wide inlet bottle type) at 4 sampling sites in Busan area from March. 1999 to February, 2000. Thirteen chemical species (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Ni, Pb, Si, and Zn) were analyzed by AAS and ICP. The purposes of this study were to estimate qualitatively various bulk deposition flux of dustfall and insoluble components by applying regional and seasonal wind intensity. Frequency of wind speed were found in order of low(1-3m/s), very low(<1m/s), medium(3-8m/s) and high(>8m/s), and annual mean had higher range at low(1-3m/s) for 56.3%. Strong negative linear correlation were observed between dustfall and wind direction (northeastern and eastern), but strong positive linear correlation were observed between dustfall and wind direction (western and northwestern) at industrial, commercial and coastal zone(p<0.05). While a negative correlation were observed between wind speed frequency of very low(<1 m/s) and dustfall, and positive correlation were observed between wind speed frequency of low(1-3m/s) and dustfall in coastal zone(p<0.05). The correlation coefficient was observed 0.556 between wind speed frequency of low(1-3m/s) and Ni by commercial zone(p<0.05). The correlation coeffcient show well-defined insoluble trace metals (Al, Ca, Cr, Cu, Fe, Pb, and Zn) and wind speed frequency of low(1-3m/s) at coastal zone, which was found significant difference(p<0.01).

• 한국지구과학회지
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• 제37권4호
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• pp.200-210
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• 2016

지음향 모델링은 퇴적층과 기반암의 해저 지층을 통해 전파되는 음파 특성을 예측하기 위해 사용된다. 이 연구는 동해 한국대륙주변부의 정동진 해역에서 50 m 퇴적층 심도의 4개 지음향 모델을 구성하였다. 지층 모델은 고해상 에어건 탄성파 자료, SBP 자료, 퇴적물 코어에 근거한다. P파 속도는 신호투과법에 의해 측정되었고, 압전기 트랜스듀서의 공진 중심 주파수는 1 MHz를 유지하였다. 42개 P파 속도와 41개 음감쇠 측정이 세 개 코어 퇴적물에서 수행되었다. 실제 모델링을 위해, 모델의 P파 속도는 Hamilton 방법을 이용하여 해저면 아래 현장 심도 속도로 보정하였다. 연안 지층의 이 지음향 모델은 동해 정동진 해역에서 지음향 특성의 수직/수평 변화를 반영하는 지음향/수중음향 실험을 위해 활용될 것이다.

• 상하수도학회지
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• 제22권1호
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• pp.65-71
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• 2008

급속 혼화공정에서 응집제의 동력학적 수화반응 특성을 고려하여 1초 이내의 순간혼합을 제시하고 있으며, 이러한 이론에 근거하여 설치된 Pump Diffusion Mixer(PDM)의 관내 응집제 확산 분포특성을 조사하였다. D=1,200mm 관경에서 압력수 유량비에 따라 응집제 주입지점으로부터 4.5D되는 지점에서 관 단면의 지점별 제타 전위를 측정하여 평가한 결과, 압력수의 유량비가 2%에서는 분사속도가 낮아 관 단면에 응집제가 골고루 분사되지 못하는 것으로 조사되었다. 그러나 압력수 유량비가 4% 이상이 되면 비교적 균등하게 혼합되며, 8%에서는 관 단면 전체에 균등하게 확산 분포되는 것으로 나타났다.

• 한국토양비료학회지
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• 제47권4호
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• pp.254-261
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• 2014

The scientific information between microbial activities and chemical properties of reclaimed tidal soil is not enough to apply for reclamation projects. This study was conducted to investigate the relation between chemical properties and microbial activities of reclaimed tidal lands located at western coastal area (25 samples from Nampo, Ewon, Sukmoon and Shihwa sites). Most of the reclaimed soils showed chemical characteristics as salinity soil except Nampo site. The major component influenced the salinity of reclaimed soil was identified as a sodium from the relationship between EC and exchangeable cation. With an increase in EC of soil, the population of mesophilic bacteria decreases whereas halotolerant and halophilic bacteria increases. The population of mesophilic bacteria increased with an increase in both organic matter and dehydrogenase activity. However, the population of halotolerant and halophilic bacteria decreased with an increase in organic matter. Based on the relation between chemical property and microbial activity of reclaimed tidal soil, electrical conductivity and organic matter as chemical properties of soil, population of mesophilic bacteria, halotolerant and halophilic bacteria and dehydrogenase activity as microbial activities could be the major parameters for reclamation process.

• 한국식생활문화학회지
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• 제2권1호
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• pp.45-54
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• 1987

This paper is a part of the regional characteristics of Korean chotkal. The kinds and materials of Korean chotkals are studied by interviewing local people living in 142 different regions which are bigger than 'myon' in size. Regions are classified according to the structural style of commoner's house. Regional characteristics of chotkal are analyzed and interpreted with natural environmental factor. The rest of my further interested subject will be followed in later issues ; the ways of preservation, period of fermentation according to the regional characteristics and uses of Korean chotkal. The results of this study can be summerized as follows, 1. There are 145 different kinds. 2. Raw materials of 145 kinds of chotkal are devided roughly into five groups ; (1) fishes in 87 kinds (2) Pelecypoda and Gastropoda in 14 kinds (3) Cephalopoda in 10 Kinds (4) Crustacea in 32 kinds and (5) Holothuroidea and Echinoidea in 2 kinds. They can also be classified according to the parts of individual material ; (1) body or flesh in 118 kinds (2) internal organs in 15 kinds and (3) eggs in 12 kinds. Regions are devided into four provinces ; 'Kwanso', 'Chungbu', 'Nambu', and 'Kwanbuk' in which the number of different kinds of chotkal are 32, 41, 99 and 34, respectively. Raw materials vary because of the distribution of marine life in different regions. Fishes and Cephalopoda are used in all four regions, Pelecypoda and Gastropoda in 'Kwanso', 'Chungbu' and western part of 'Nambu' regions. Different species of Crustacea used in each different regions ; sea crab and sea shrimp in the western coastal area, fresh water crab in the field area, fresh water shrimp in 'Chollado', mantis crab at 'Shihung-gun' in 'Kyonggi-do', Holothuroidea and Echinoidea are used in 'Nambu' regions. Chotkal are not used at all in six local districts which are located in inland areas where the transportation is inconvenient.

• 한국토양비료학회지
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• 제48권4호
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• pp.262-270
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• 2015

The scientific information between microbial community and chemical properties of reclaimed tidal soil is not enough to understand the land reclamation process. This study was conducted to investigate the relation between chemical properties and microbial activities of soils from reclaimed tidal lands located at south-western coastal area (42 samples from Goheuong, Samsan, Bojun, Kunnae, Hwaong and Yeongsangang sites). Most of the reclaimed soils showed chemical characteristics as salinity soil based on EC. Only $Na^+$ in exchangeable cation was dependent on EC of reclaimed soil, whereas other cations such as $K^+$, $Ca^{2+}$, and $Mg^{2+}$ were independent on EC. The mesophilic bacteria decreased with an increase in EC of soil. Microbial population increased with soil organic content in the range of $0{\sim}10g\;kg^{-1}$ and dehydrogenase activity less than $100{\mu}g-TPF\;g^{-1}h^{-1}$. Microbial population of soils from reclaimed tidal lands was closely related to the microbial community containing hydrolytic enzyme activities of cellulase, amylase, protease, and lipase.