• Preventive Nutrition and Food Science
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• 제11권1호
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• pp.17-24
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• 2006

Methanolic and aqueous extracts from 37 seaweed species (10 green and 27 brown seaweeds) collected from Jeju Island coast were prepared at high ($70^{\circ}C$) and room ($20^{\circ}C$) temperatures and examined for cytotoxic activity against 4 tumor cell lines: U937 (human monoblastoid leukemia cell line), HL60 (human promyelocytic leukemia cell line), HeLa (woman cervical carcinoma cell line) and CT26 (mouse colon carcinoma line). Both MeOH extracts of Desmarestia tabacoides and Dictyota dichotoma possessed strong cytotoxic activities against all the tumor cell lines tested, but the aqueous extract exhibited no activity. On the other hand Ecklonia cava showed strong cytotoxic activities for the $20^{\circ}C$ aqueous extract against the three tumor cells except HeLa cell. Sagassum coreanum and Sagassum siliquastrum $20^{\circ}C$ aqueous extracts also exhibited strong cytotoxic activities against U937, HL60, HeLa cells. Even though green seaweeds showed less activity than brown seaweeds, $20^{\circ}C$ aqueous extracts of Codium contractum and Codium fragile exhibited strong cytotoxic activities against HL60 or CT26 cells, respectively.

• 한국대기환경학회지
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• 제15권6호
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• pp.727-738
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• 1999

Total 76 aerosol samples were collected at Sungsan in Cheju Inland by high volume air sample for 1 year, from May 1995 to April 1996, and were analyzed for major elements(Na, Mg, Ca, Al, Fe) and trace elements(Mn, Co, Ni, Zn, Cd, Pb, U) by ICP/AES and ICP/MS. This study aims to determine the concentrations of trace metals and their seasonal variations in the atmosphere of Cheju Island, where is the remote area from pollution sources and also is the midway of transport of Asian continental materials into the western North Pacific. The concentrations of Na and Mg contributed by sea-salt aerosols were similar to those in the western part of Cheju island(Kosan) and in the western coast of Korea(Mallipo). They showed the highest value in summer and the lowest in spring and winter. Crustal metals(Al, Fe, Ca, Mn, Co, U) were 2~3 times lower than those of Mallipo. These metals showed the lowest values in summer and the highest in spring. Pollution-derived metals (Zn, Cd and Pb) were 2~4 times lower than those in Malipo. Some elemental ratios in aerosols grouped by three wind directions(north-northwest, east, and south-southwest) such as Fe/Al and Pb/Zn are presented as useful tracers indicating source areas, and their differentiation may be explained by geology and fuel types of source areas.

• 환경영향평가
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• 제6권1호
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• pp.121-133
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• 1997

EIA should be regarded as an aid to improve the decision making processes because it seeks public opinion and external knowledge in order to ensure the maximum degree of fairness and balance in the final decision as much as possible. According to the above benefits, various decision making systems containing EIA concepts were developed in the area of ground water, traffic, disaster or accident and environment in Cheju Island. But because the development of various decision making systems can be the cause of new impact, it was studied the cause and impact of their development. The major reasons for developing the various decision making system like EIA are the lack of the consideration for the impact of project when it is selected project fulfilling EIA and the increase of the effort for the improvement in the professional quality for one subject without the comprehensive assessment among the subject related to environmental impacts. And the development of the various decision making systems like EIA has caused the several impacts like cost elavoration, the relay of project period, etc. Therefore, after it is improved the problems of present EIA on the comprehensive assessment, the various decision making systems like EIA should be integrated in EIA decision making system.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2004년도 학술대회지
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• pp.253-259
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• 2004

The Jeju Island in Korea is the clean area which the tradition culture is preserved locally well with the nature environment of Heaven's blessing. An air pollution is becoming recently serious problem as the industrial development is proceeded with the urbanization. This study investigates that the atmosphere environment at Jeju area influences on the metal corrosion. A study of the atmosphere corrosion for carbon steel, copper, zinc ana aluminium exposed on five test sites indoors and outdoors. Corrosion results are treated statistically and adjusted to a model previously proposed for carbon steel, copper, zinc and aluminium based on the influence of environmental parameters and main pollutants($SO_2$ and chlorides) on tire atmosphere corrosion of metals. Through this study, we try to set the standards atmosphere corrosion at Jeju Island.

• 한국초지조사료학회지
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• 제12권3호
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• pp.41-47
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• 1992

Cheju Island has an optimal environment for herviborous animal production. However, the infrastructure has been degraded under the pressure from the development of tourism and thus the technological development for livestock production has not been great. This is the time to re-evaluate and re-direct the system of livestock production on the island. My suggestions on the development of grassland agriculture on the island are as follows : 1. Grassland area of Cheju, 65,695 ha should be maintained and the local government should try to improve more grasslands which can hold 3 or more cattle per ha on pasture. including enterpriseowned lands. 2. For better management of co-operatives village. the local government should evaluate the conditions of the grasslands yearly after being grazed and suggest a new management method accordingly. 3. In order to strengthen grassland research. it is recommended that Cheju Experiment Station be reorganized as a Grassland Research Institute or Department of Grassland Science be added. 4. [mport of good forage varieties. especially legumes, from foreign countries and distribution to farmers after adaption studies, are required to improve nutritive values of forage produced. 5. Methods for production of good quality forage seeds at rcasonablc prices should be established.

• 한국해양공학회지
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• 제19권5호
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• pp.50-57
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• 2005

This study has been conducted to investigate corrosivity of carbon steel, Cu, Zn and Al for one year from Sept. 2003 to Aug. 2004. A model of ISO 9223-ISO 9226 that represents the relation between metal corrosions and environmental parameters was used for atmospheric corrosion evaluations. Environmental parameters for these evaluations are time of wetness(TOW), $SO_2$ and Chloride. Corrosion rates for four metals which are exposed indoors and outdoors were measured on five locations in Jeju Island; Gosan, Seogwipo, Seongsan, Chuna hill and Jeju city. The environmental factor of atmospheric corrosion of Jeju Island for $SO_2$ class is P0, a clean area. TOW as T3 and T4 indicates that Jeju has the characteristics of a tropical area. Chlorides class within 3 km from the coast show the features of costal area as S2 and S3 classes. Chuna hill show the features of woodland as a S1 class. In Corrosion classes of each site which was measured outdoors is higher than indoors. Gosan is the highest class as the rank of C5, and indicated that they're ranked as C3 or C4.

• 자원환경지질
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• 제28권5호
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• pp.513-518
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• 1995

A granite drilling core (-1200 m) obtained near the Majang cave in east part of the Cheju island. The rock is pinksh in color and has miarolitic cavities. It is coarse-grained rock and consists of quartz, plagioclase, alkali feldspar, biotite and magnetite. The rock shows characteristically micrographic texture. The alkali feldspar is subhedral to anhedral and generally interstitial grains and fonns micrographic texture. K/Ar age of alkali feldspar in the core specimen is $58.14{\pm}1.4Ma $ (early Tertiary). The age, rock features and whole rock chemistry of the rock has strong resemblance to micrographic granites, so called "masanite", in southeastern part of the Korean peninsular. The granitic fragments from drilling core (- 920 m) obtained in Jungmun area in south part of the Cheju island consist of quartz, plagioclase, alkali feldspar and biotite. The fragments in the Jungmun area are similar to granitic xenolith near the Cheju city for the absence of micrographic texture and different alkali feldspar.

• 지질공학
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• 제2권1호
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• pp.70-91
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• 1992

제주도와 오아후섬의 지질은 제3기말에서 제4기초 사이에 걸친 화산활동에 의해 형성된 동일형의 화산도라는 점에서 유사한 특성을 갖는다. 이 두 섬의 지하수 산상은 두가지의 기본적인 요소인 화산암의 투수성과 강수량의 지배를 받는다. 그러나 오아후도에서의 지하수 산상은 광역 화산암의 복합 암맥군에 의해 더 많은 영향을 받는다. 제주도와 오아후도의 지하수 부존형태는 두가지로 분류되는데 고지대의 주수와 해안변에 발달된 기저 지하수가 그것이다. 일반적으로 제주도 지하수의 수질은 생활용수로 적합하나 동부 해안지역의 몇개의 지하수 관정은 과잉양수로 인하여 해수가 침입되었으며 1970년 부터 내륙쪽으로 점점 해수의 영향을 받고 있다. 이러한 해수의 오염현상은 오아후섬의 진주만에서도 비슷하다. 제주도의 신선한 지하수체에 현재 발생되고 있는 이러한 해수오염을 방지하기 위해서는 우선 해안지역을 따라 분포하는 지하수 부존 가능성과 그들을 최대한으로 개발하기 위해 지하수의 유동에 대한 연구가 필요하다.

• 수산해양기술연구
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• 제32권3호
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• pp.266-272
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• 1996

The distribution and abundance of fish in the Cheju southeastern area was studied by the combined hydroacoustic and bottom trawl surveys in April 1994 and in July 1995, respectively. The main purpose of these investigations was to provide the basic data for this management and the biomass estimation of commercially important demersal fish stocks in this area. The hydroacoustic surveys were performed by using a 50 kHz scientific echo sounder system with a microcomputer-based echo integrator. Acoustical measurements of fish abundance and distribution were conducted along the cruise tracks of research vessel and during all trawl hauls by continuous echo sounding. The average weight-normalized target strength for demersal fish aggregations was derived from the relationship between the mean volume backscattering strength for the depth strata of trawl hauls and the weight per cubic meter of trawl catches. The geographical distribution of fish stocks in the 1994 survey area was investigated in relation to oceanographic conditions. The results obtained can be summarized as follows: 1. From the 1994 and 1995 survey data, the relationship between the mean volume backscattering strength (, dB) for the depth strata of trawl hauls and the weight (W, kg/$m^3$) per cubic meter of trawl catches was expressed by the following equation = - 32.8+ lOlog(W) The average weighted-target strength value at 50 kHz derived from this equation was .. 32.8 dB/kg. 2. In 1994 and 1995, both surveys showed a trend of decreasing fish abundance toward the southern area of the Cheju Island with high densities offish along the west coast ofth.e Tsushima Island. The highest demersal concentrations in the southern area of the CheJu Island appeared in bottom waters colder than $12^{\circ}C.$. . 3. From the results of combined bottom trawl and hydroacoustic surveys, the estunated fish densities in the southeastern area of the Cheju Island were 1.5488 x $10^-4$kg/$m^3$ in the 1994 surveyand 1.9498 x $10^-4$kg/$m^3$ in the 1995 survey, respectively.

• 대한지하수환경학회지
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• 제1권1호
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• pp.33-50
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• 1994

제주도 지하수자원의 산출특성을 규명키 위하여 총 455개 기존관정의 자료를 전산처리하여 지역별 대수성 수리특성을 규명하였다. 제주도는 주로 현무암내에 협재된 화산쇄설층, crinker층과 현무암의 1 및 2차 유효공극이 주 대수대의 역할을 하며 이들은 기저, 준기저 및 상위대수층으로 구성되어 있다. 본도 대수층의 평균 투수량계수는 29,300 $m^2$/일이며 평 균 저유계수는 0.12로써 자유면 대수층을 이루고 있다. 종합적인 물수지 분석을 실시한 바 본도에 부존된 지하수 부존량은 약 440억 ㎥이고, 년평균 강수량은 33.9억 ㎥으로써 이 중 하천유출량은 6.38억㎥/년이며, 증발산량은 12.56억 ㎥/년(37%)이고 지하수함양량은 년평균 강수량의 44.1%에 해당하는 14.94억㎥이다. 본도에 부존된 지하수의 최적 개발가능량(sustainable yield) 을 각 지역별로 정량적으로 계산한 결과 그 양은 함양량의 41%에 해당하는 6.2억㎥/년(1,689,000 ㎥/일) 정도였으며 잔여 8.74억㎥/년(2,404,000㎥/일)은 해안이나 해저용천의 형태로 유출된다. 특히 최근에 실시한 심부 시추조사 자료에 의하면 EL-120$\pm$68m 부근에 저투수성 해성 퇴적층(일명 세화리층)이 분포되어 있는 것으로 판명되었으며 과거 서귀포층군으로 알려진 저투수성 퇴적층이 북서부와 서부 일원에서 EL-70m 부근에 널리 분포되어 있어 서귀포층군과 세화리층의 명확한 구분이 필요하다. 만일 이러한 저투수성 퇴적층이 제주도의 기저층을 이루는 경우 제주도 내에 부존된 지하수는 주로 준기저 지하수일 것이며 이는 제주도 지하수의 산출특성에 결정적인 영향을 미칠 것이다.