• Fisheries and Aquatic Sciences
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• 제5권4호
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• pp.281-286
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• 2002

Artificial reefs were set on a sandy bottom substratum at 8m, 10m and 13m depths along the coast in Muronohana, Ikata, Japan. Succession of seaweed communities was observed monthly or bimonthly from February 1999 to August 2000 on artificial reefs. Within one month, the diatom colonized on the reefs with coverage of $100\%$. After three months, Enteromorpha intestinalis and Colpomenia sinuosa dominated on the reef in the spring. Seaweed flora decreased during the summer and the dominant species were several species of Melobesioidea. In the winter, the seaweeds grew up again and the dominant species on the each reef were Sargassum spp., Ecklonia kurome and Padina arborescens after one year. The dominant species in the algal succession process changed from diatoms to the perennial seaweeds such as Sargassum spp., E. kurome and P. arborescens. Thus, the pattern of succession of the dominant species and the degree of domination were changed by the season, water depth and the recruitment of spores and eggs from the mature alga around the reefs.

• Journal of Periodontal and Implant Science
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• 제47권6호
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• pp.402-415
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• 2017

Purpose: The aim of this study was to determine the effects of patterned human periodontal ligament stem cell (hPDLSC) sheets fabricated using a thermoresponsive substratum. Methods: In this study, we fabricated patterned hPDLSC sheets using nanotopographical cues to modulate the alignment of the cell sheet. Results: The hPDLSCs showed rapid monolayer formation on various surface pattern widths. Compared to cell sheets grown on flat surfaces, there were no significant differences in cell attachment and growth on the nanopatterned substratum. However, the patterned hPDLSC sheets showed higher periodontal ligamentogenesis-related gene expression in early stages than the unpatterned cell sheets. Conclusions: This experiment confirmed that patterned cell sheets provide flexibility in designing hPDLSC sheets, and that these stem cell sheets may be candidates for application in periodontal regenerative therapy.

• 생태와환경
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• 제41권2호
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• pp.137-143
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• 2008

The abundance and community structure of epilithic diatoms grown on different substrata were investigated in two first-order streams located in a limestone and granite area, north of the Suzuka Mountains in Central Japan. Experiments were conducted as follows: limestone and granite without algae were submerged in their own streambed or another stream station and incubated for seven weeks, while limestone and granite with algae were transferred to another stream station and incubated at the same time. The diatom biomass was consistently high in the lime-stone station experiments compared to those at the granite station. In addition, there was more diatom biomass on granite substrata than on the limestone substrata at both stations. The present results suggested that the difference in water chemistry including the major nutrient concentrations was the limiting factor for algal growth in these two streams; however, when the water chemistry was the same in each stream, the difference in substratum characteristics became the important factor affecting the diatom abundance. The diatom community grown on the transferred substrata with and without algae became similar to those grown on the original substrata in each stream during the incubation period. It was suggested that the effect of the substrata characteristics on the diatom community structure was rather small.

• 한국양식학회지
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• 제15권2호
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• pp.111-117
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• 2002

이 연구에서는 북방대합의 안정적인 인공 종묘생산을 위한 기초지식을 얻고자 채묘방법과 치패의 성장 및 사육 방법에 따른 성장과 생존율을 조사하였다. 채묘는 모래저질이 효과적이었으며, 특히 모래입자가 250 $\mu\textrm{m}$이하의 초미세사질에서 높은 성장과 생존율을 보였다. 각장 1.4 mm의 치패는 30일째에 4.6 mm로, 50일째에 8.2 mm로 성장하였으며, 각장(SL)에 대한 각고(SH), 각폭(SB), 전중(TW) 및 각중(SW)의 상대성장식은 아래와 같았다. 각고의 상대성장식 SH : 0.7351SL+0.2272 (r$^2$ : 0.9600) 각폭의 상대성장식 SB : 0.4037SL+0.2112 (r$^2$ : 0.9452) 전중의 상대성장식 W : 0.2824SL$\^$2.7020/ (r$^2$ : 0.9820) 각중의 상대성장식 SW : 0.4021SL$\^$2.0217/ (r$^2$ : 0.6169) 치패 사육을 위한 저질은 미세사질이 효과적이었으며,1∼2개체/$\textrm{cm}^2$의 밀도에서 성장과 생존율이 양호하였다. 먹이생물은 C. calcitrans가 가장 빠른 성장을 보였으며, 다음으로 혼합구와 I. galbana, P. lutheri, T. suecica 순 이었다.

• ALGAE
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• 제21권1호
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• pp.49-59
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• 2006

A total of twenty one species of marine macro-algae were reported from 460 kms long Orissa coast in the east coast of India. Of these 9 species belongs to Chlorophyta, 2 to Phaeophyta and 10 to Rhodophyta. The low species richness compared with southern and western coasts of India was due to lack of rocky and/or coral substratum. Enteromorpha usneoides and Gelidium divaricatum were reported first from India. Enteromorpha linza, E. clathrata, Colpomenia sinuosa, Dictyota dichotoma, Catenella impudica, Compsopogon aeruginosus and Grateloupia lithophila were the new records for Orissa coast.

• Animal Systematics, Evolution and Diversity
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• 제10권2호
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• pp.199-205
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• 1994

실험실내에서 곤봉히드라의 생활사를 조사하였다. 히드라는 생활사 중에 플라눌라 유생 단계와 해파리 단계가 있으나 곤봉히드라의 생활사에는 해파리 단계가 없고 플라눌라 유생 단계만 나타났다. 수정란으로부터 부화한 플라눌라 유생은 약 21시간동안 부착하는데 적합한 저질(substratum)을 찾아 배양기 바닥을 기어다니다가 고착한 다음, 폴립을 형성하였다.

• ALGAE
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• 제19권2호
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• pp.107-114
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• 2004

Patterns of epilithic algal colonization on artificial substrata (unglazed ceramic tiles) were investigated from 23rd April to 3rd July 1999 at weekly intervals over a 10 weeks period outside and inside the mesocosm in Togyo reservoir within the Civilian Passage Restriction Line near Demilitarized Zone (DMZ) in Korea. The highest standing crops of epilithic algae was 1,798$\cdot$10³ cells$\cdot$$cm^{-2}$ outside the mesocosm on 26th June and also inside the mesocosm those was 2,391$\cdot$10³ cells$\cdot$$cm^{-2}$ on 26th June, 9 weeks after the experiment began. The dominants outside the mesocosm were Achnanthes minutissima, Navicula bicephala, Oscillatoria angusta, Synedra delicastissima, S. tenuissima, S. ulna v. danica and Tabellaria flocculosa, and those inside the mesocosm were Achnanthes minitissima, Coenochloris polycocca, Fragilaria crotonenesis, Peridinium cinctum, Synedra delicatissima, Tabellaria flocculosa and Ulothrix subtilissima. Diatoms were most abundant and Achnanthes minutissima was the most important species colonizing on the tiles. Chlorophyll-a content was highest value of 5.4 mg$\cdot$$m^{-2}$ on 19th June after 8 weeks growth outside the mesocosm and was 24.4 mg$\cdot$$m^{-2}$ on 26th June, 9 weeks after the experiment began on tiles inside the mesocosm. It was also shown that unglazed ceramic tiles were a more suitable substratum for colonization than the glass slides. Consequently the substratum selection plays an important role in the colonization by the epilithic algal community.

• Structural Engineering and Mechanics
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• 제61권2호
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• pp.245-253
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• 2017

The increasing lack of good quality soils allowing the development of roadway, motorway, or railway networks, as well as large scale industrial facilities, necessitates the use of reinforcement techniques. Their aim is the improvement of the global performance of compressible soils, both in terms of settlement reduction and increase of the load bearing capacity. Among the various available techniques, the improvement of soils by incorporating vertical stiff piles appears to be a particularly appropriate solution, since it is easy to implement and does not require any substitution of significant soft soil volumes. The technique consists in driving a group of regularly spaced piles through a soft soil layer down to an underlying competent substratum. The surface load being thus transferred to this substratum by means of those reinforcing piles, which illustrates the case of a piled embankment. The differential settlements at the base of the embankment between the soft soil and the stiff piles lead to an "arching effect" in the embankment due to shearing mechanisms. This effect, which can be accentuated by the use of large pile caps, allows partial load transfer onto the pile, as well as surface settlement reduction, thus ensuring that the surface structure works properly. A technique for producing rigid piles has been developed to achieve in a single operation a rigid circular pile associated with a cone shaped head reversed on the place of a rigid circular pile. This technique has been used with success in a pile-supported road near Bourgoin-Jallieu (France). In this article, a numerical study based on this real case is proposed to highlight the functioning mode of this new technique in the case of industrial slabs.

• 응용통계연구
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• 제31권5호
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• pp.621-636
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• 2018

정보적 표본설계 기법을 적용하여 무응답의 영향을 줄이기 위한 연구가 진행되고 있다. 특히 초모집단모형(super population model)에 포함된 오차의 분포가 정규분포를 따르고 응답률이 지수함수를 따를 때 지수형 응답률 정보를 모수추정에 사용함으로써 추정의 정확성이 향상되는 것으로 알려져 있다. 최근 Chung과 Shin (2017)은 정보적 표본설계의 가중치를 구하기 위해 세부 층을 등간격으로 나누는 방법을 고려하였으며 세부 층의 개수가 추정의 정확성에 영향을 주는 것을 확인하였다. 이에 본 연구에서는 주어진 표본 규모에 따른 최적의 세부 층 개수와 최적의 층 경계를 구하기 위해 등간격, 분위수, LH 알고리즘을 이용하여 층을 나누는 방법을 살펴보았으며 모의실험을 통하여 각 방법의 결과를 비교하였다. 또한 다양한 형태의 보조변수 분포를 이용하여 실무에서 사용할 수 있는 세부 층 경계와 세부 층 개수를 정하는 기준을 제안하였다.

• 한국수산과학회지
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• 제28권5호
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• pp.667-676
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• 1995

군산 연안 조간대에 있어서 1993년 6월에서 1994년 5원까지 조사한 동죽(M. veneriformis)의 침강과 가입 및 성장, 생산량에 대하여 조사하였다. 동죽의 부유유생의 높은 밀도는 1993년 6월 19일에서 7월 3일에 관찰되었으며, 침강된 치패의 크기는 250um에서 350um였고, 평균밀도는 약 $601\;inds\cdot\;m^{-3}$이었다. 유생의 침강에 의한 가입은 주로 1993년 6월 중순에서 7월 중순에 이루어 졌으며, 유생의 침강시 저질에 따른 선택성은 없었다 그러나 침강한 치패는 환경(저질, 노출시간, 성패의 밀도)에 의하여 사망율이 결정되었다. 평균 각장에 의하여 추정한 동죽의 성장은 가입 초기에 있어서 과소평가 되었으며, 성장기는 11월 중순까지이고, 겨울철에는 정지하였다. 0세군의 연간생산은 2,900 g\cdot\;m^{-2}\;\cdot\;yr^{-1}$으로 나타났으며, 회전율은 약 4.94 (Crisp, 1984)와 4.91 (Ricker, 1978)로 추정 되었다.