• Korean Journal of Ichthyology
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• v.12 no.1
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• pp.62-70
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• 2000

Annual reproductive cycle of the file fish, Stephanolepis cirrhifer (Temminck et Schlegel), was histologically investigated. Samples were collected monthly in the coastal waters of Chungmun, south of Cheju Island, Korea from July 1997 to June 1999. In males and females of S. cirrhifer, the values of GSI (gonadosomatic index) were similar to the changes of water temperature and day length. GSI values in males and females were reached the maximum in June. Reproductive cycle could be divided into the following successive stages: in females, growing stage (February to May), mature stage (May to June), spawning stage (June to August), degenerative and resting stage (September to December), and in males, growing stage (February to April), mature stage (May to June), spent stage (June to August), degenerative and resting stage (September to January), respectively. Throughout histological observation of the ovary in the spawning period, the species belong to an asynchronous and multiple spawner.

• KSBB Journal
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• v.21 no.2
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• pp.164-169
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• 2006

In this study, we investigated the biological activity of antioxidant and antibacterial activity of Indigenous Plants, Jeju-Island., which, using water were extracted. The reducing activity on the 1,1-diphenyl-2-picrylhydrazyl(DPPH) radical and $O^{2-}$ and OH radical scavenging potential, in search for antioxidation activities of Indigenous Plants, were sequentially screened. Among the ten plant parts, Prunella vulgaris var. aleutica Fernald. flower had the highest antioxidative activity. Hot water extracts of ten indigenous plants were screened for antibacterial activity 13 fish pathogenic bacteria by agar diffusion method. Among the various Hot water extracts, the Prunella vulgaris var. aleutica Fernald, Gleichenia japonica Spreng, Microlepia marginata(panzer) Christ., Perilla frutescens var. japonica Hara. showed relatively strong antibacterial activities in the order.

• Proceedings of the Speleological Society Conference
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• 1993.07a
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• pp.163-172
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• 1993

Cheju island is situated at about 90km south of southern most tip of the Korean peninsula. Its shape is an ellips with size of 80$\times$40$km^2$, and it is characterized by a symmetrical form whose peak is Mt. Halla (1950m). Major chemical composition of the rock samples from Manjang gul cave is determined by XRF using the fundamental parameter method consisting of fully auto quantitative analysis, semi quantitative analysis (order estimation) and group quantitative analysis. Judging from chemical composition ($SiO_2 = 53.07Wt% Fe_2 O_3=11.34Wt%, MgO=6.48Wt%, Na_2 O=3.07Wt%, K_2 O=1.05Wt%$), this rocks may belong to non alkalic basalt. K-Ar ages of two rocks samples from the Manjang gul cave are also determined. The discrepancy of K-Ar ages is found. They are 0.03Ma and 0.42Ma, respectively. This paper describes some problems experienced in dating young volcanic rocks and then discusses chemical composition, X-ray fluorescence analysis and the age of the formation of a lava tunnel such as Manjang gul cave in cheju Island.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.76-76
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• 2003

Eleven wrasse species inhabit the coastal waters of Jeju Island, Korea. They are the target of leisure fishing and are considered good eating. We investigated the distribution of standard length (SL) by sex of wrasse in Jeju coastal waters for Halichores poecilopterus, H. tenuispinis, Pseudolabrus japonicus, and Pteragogus flagellifera. A cross-section of the ovary showed the ovarian cavity and ovarian lamellae containing oocytes. A cross-section of the testis showed many lobules containing spermatogonia and spermatocytes. A cross-section of a gonad undergoing sex reversal showed the regression or reduction of oocytes and some spermatocytes located in the ovarian lamellae. A cross-section of a sex-reversed testis showed the primary structure of the ovary, with spermatocytes distributed in the epithelium of the lamellae, and reformed seminiferous ducts in the basement lamellae. (중략)

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.399-403
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• 1996

Total 938 actinomycete strains were isolated from 59 soil samples collected at Cheju island. All of these isolates were identified to the genus level based on morphological and physiological characteristics. As the result, 62.6% of those isolates were Streptomyces, 16.4% were Micromonospora, 8.6% were Nocardioform group, 2.2% were Actinomadura, 1.7% were Microbispora, 1.6% were Nocardiopsis, 1.0% were Streptosporangium, and 5.9% were the others. As the sources of soil, Streptomyces and Microbispora were abundant in grassland soil, Streptomyces and Micromonospora were abundant in field soil, and Micromonospora were abundant in forest soil. Especially, Nocardioform strains were abundant in natural caves.

• Animal Systematics, Evolution and Diversity
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• v.3 no.2
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• pp.225-236
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• 1987

1986년 9월 30일부터 1987년 4월 24일까지의 조사기간에 제두도의 12개 지소에서 채집한 표본들과 조사기간 이전에 추자군도를 포함한 제두도 해역에서 채집된 미동정 표본들을 동정하고 문헌상의 기록들을 종합하여 제주도 해역 집게류의 분류목록을 작성하였다. 이 분류목록에는 9과 34종이 포함되어 있다. 이 중에서 제주도 해역 미기록종은 2종이었고 Dardanus pedunculatus(Herbst)는 한국 미기록종이므로 새로이 기재하고 그림도 작성하였다. 제주도 해역의 집게류 34종은 한국기지종 58종의 58.6%에 해당되며 34종 중에서 17종(50%)은 제주도 해역에서만 기록되었다. 34종 중 7종(20.6%)이 남방형이었고, 34종 중 서식처가 밝혀진 24종주에서 사질과 암석 바닥에 서식하는 종이 18종(75%)이었다. 이와 같은 사실들은 제주도 해역의 해황과 제주도 연안의 저질과 일치한다.

• The Transactions of the Korea Information Processing Society
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• v.3 no.1
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• pp.160-166
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• 1996

In 2D and 3D computer graphics, fractal techniques have been applied ter rain models. In general, a specific 3D terrain model such as Cheju or Uleung Island could not beformulated by statistical fractalsowing to the randomeffects. However, by locating the control points on the edges and the surface of a specific terrain such as Cheju Island, a similar shape of the terrain model can be simulated. This paper presents the way of formulating a specific 3D terrain model by the statistical fractals with fixed midpoints.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.127-129
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• 2005

Construction of wind power plant is increasing rapidly because Jeju island is known as the most suitable place for wind power plant. Rut wind power plant is difficult electric power control and it has a rapid electric power fluctuation. Such a problem has a bad influence on electric power network in small electric network like Jeju. Therefore, we forecast the amount of wind power plant construction by weather information and the rate of utilization for existing facility. We investigate the contribution degree for electric Power demand, economic effect, the case of power network influence. So we forecast influence of wind power plant for Jeju power network's operation in the near future.

• Journal of Plant Biology
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• v.33 no.2
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• pp.141-146
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• 1990

Germination and vegetative growth of Enteromorpha multiramosa Bliding from Pyoson, Cheju Island were investigated in laboratory under various combinations of temperature (5-$25^{\circ}C$) and salinity (8-48$^{\circ}C$). Percent level of germination was relatively high at all combinations of the two factors. The highest value among the combinations was revealed at 15$^{\circ}C$ and 32$\textperthousand$. Dry weight also was fairly high at all levels of combination with maximum value at 2$0^{\circ}C$ and 32$\textperthousand$. Analysis of variance for germination and growth was completed respectively and polynomial prediction models were constructed. F ratio revealed that all factors had a significant effect (p<0.001) on percentage of germination and dry weight, and their interactions also were significant (p<0.001), although the F ratio of interactions was far less than that for either the separate effect of temperature or salinity. Response surface of polynomial equation represented that temperature influenced less than salinity on germination, while it effected remarkably on vegetative growth, so the Enteromorpha multiramosa was kept to visible macrothalli from winter to spring in Cheju Island.

• Journal of Plant Biology
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• v.33 no.2
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• pp.127-134
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• 1990

Three marine species of Cladophora (Cladophoraceae, Chlorophyta) commonly occurred on the coast of Cheju Island, Cladophora conchopheria Sakai, C. gracilis (Griff.) Kutzing and C. wrightiana Harvey were described morphologically, considering their taxonomic characters. C. conchopheria Sakai, specifically growing on the surface of Lunella coronata, is a very minute plant of 550-990 ${\mu}{\textrm}{m}$ in height and has intracuticular adventitious rhizoids borne from the lower portion of the first to fourth segments. C. gracilis occurs on calm habitat and shows a pseudosympodial growth with pectinate branchlets. c. wrightiana always produces protoplasmic protuberances at the node of middle portion of thallus. It grows to 30 cm or more in height and is dark green in subtidal bottom.