• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
• /
• pp.375-378
• /
• 2003

This paper presents a study on the power factor improvement of the Wind turbine Generation System(WTGS) at Haeng-won wind farm in Jeju Island. Vestas WTGS named V47 as a model system is selected in this paper, and has 660 kW Power ratings. In this system, power factor correction is controlled by the conventional method with power condenor bank. So, model system at Haeng-won wind farm has very low power factor in the area of low wind speed, which is from 4 m/s to 6 m/s. This is caused by the power factor correction using power condenser bank To improve the power factor in the area of low wind speed, we used the static var compensator(SVC) using current controlled PWM power converter by IGBT switching device. finally, to verify the profosed method, the results of computer simulation using Psim program are presented to support the discussion.

• 한국수산과학회지
• /
• 제36권3호
• /
• pp.306-316
• /
• 2003

We conducted a time-series analysis of temperature and salinity of sea water around Jeju Island, Korea. Monthly mean temperature and salinity was influenced by precipitation and weather conditions on Jeju as well as by oceanographic conditions of the open sea such as the Tsushima Warm Current and sea water in coastal areas. Salinity of Jeju coastal waters was the highest in April, and it was always over 34.00 psu with tiny fluctuation between December and June. Due to the effects of the Tsushima Warm Current, Jeju coastal waters maintained high salinity and stability. Low salinity and its large fluctuations during summer were closely associated with the China Coastal Water and precipitation in Jeju. The place of the lowest water temperature was the northeast coasts of Jeju (Gimneong, Hado, Jongdalri). In winter, as warmer water of the Tsushima Warm Current appeared in western area of Jeju dwindled flowing along the northern coasts of Jeju area and becoming cool, the lowest water temperature often appeared locally in Gimnyeong and its vicinitly in summer. The Tsushima Warm Current flows into the east entrance of Jeju Strait, but its influence is weak because of geometry and strong vertical mixing due to fast tidal currents.

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

• 자원환경지질
• /
• 제28권5호
• /
• pp.513-518
• /
• 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.

• 생명과학회지
• /
• 제14권6호
• /
• pp.986-990
• /
• 2004

2002년 5월에서 7월사이 한국 근해로부터 총 가검물 50례 중에서 V. vulnificus은 5균주가 분리되었고, API 20E kit의동정률이 $89.4\~93.7\%$로 나타났다. V. vulnificus 16S rDNA를 증폭하여 얻은 산물을 cloning하여 염기서열을 결정하고 분석한 결과 V. vulnificus로 확인되었다. 동정된 분리균주들의 cell lysates을 SDS-PAGE로 분석하였고 표준균주로 사용된 V. vulnificus ATCC 27562와 분리 균주들을 비교해 본 결과 단백밴드pattern이 많은 차이를 보였으나 외막단백질은 V. vulnificus간에는 공통의 밴드가 확인되었으나 V. parahaemolyticus 와는 차이를 보였다.

• 지구물리
• /
• 제3권1호
• /
• pp.13-24
• /
• 2000

제주도 내의 13개의 수준점에서 GPS를 측정하였으며, 이에 의한 GPS/Levelling 지오이드와 PNU95 지오이드를 비교, 분석하여 보았다. GPS의 측정결과 각. 수준점의 타원체 높이를 ${\pm}3\;cm$ 이내의 정밀도로 측정하였다. 계산된 GPS/Levelling 지오이드는 제주도의 지형 변화를 잘 나타내고 있으며, 제주도에서 지오이드와 지형의 상관식은 다음과 같다. $$N\;=\;0.001082\;{\times}\;h\;+\;25.458\;{\pm}\;0.227\;s.d.$$ 계산된 GPS/Levelling 지오이드와 PNU95 지오이드는 잘 일치하고 있으며 두 지오이드의 RMS 차이는 0.14 m이다.

• 대한수의학회지
• /
• 제30권4호
• /
• pp.507-510
• /
• 1990

A preliminary survey of Sarcocystis species in the slaughtered cattle in Cheju was undertaken during May through October 1989, using digested diagnostic technique for the heart, the esophagus and the dorsal muscles of the neck specimens digested in 0.5% trypsin solution. The results obtained were summarized as follows. 1. The overall infection rate of Sarcocystis in a total of 218 slaughtered cattle was as high as 36.7% with the highest frequencies in the esophagus muscles(21. 6%), followed by in the dorsal muscles of the neck(19.1%) and in the heart rnuscles(17.9%). 2. Age difference was noticed as 64.3% in the cattle older than five years in comparison with 41.7%, 34.4%, in the group of two to four years and in the group of younger than two years respectively. 3. It was also noticed that the prevalence in the Brahman cross breed was higher(40.0%) than in any other breeds. 4. Regional distribution of Sarcocystis infections was observed as 75.0% in south-east area, 50.0% 44.7%, 35.0%, 32.0% and 20.6% in the areas of Seogwipo city, north-west, south-west, Cheju city and northeast area respectively. 5. According to the type of rearing the infection rate in the ranch type farm was noticed with and in the stock farms(36.2%).

• Journal of the korean society of oceanography
• /
• 제37권3호
• /
• pp.187-195
• /
• 2002

The characteristics of surface circulation in the Yellow Sea and the East China Sea are discussed by analyzing a great deal of current data observed by 142 sets of mooring buoy and 58 sets of drifters trajectories collected in the Yellow Sea and the East China Sea through domestic and abroad measurements. Some major features are demonstrated as bellow: 1) Tsushima Warm Current flows away from the Kuroshio and has multiple sources in warm half year and comes only from Kuroshio surface water in cold half year. 2) Taiwan Warm Current comes mainly from the Taiwan Strait Water in warm half year and comes from the intruded Kuroshio surface water and branches near 27N in cold half year. 3) The Changjiang Diluted Water turns towards Cheju Island in summer and flows southward along the coastal line in winter. 4) The study sea area is an eddy developing area, especially in the southern area of Cheju Island and northern area of Taiwan.

• 한국주거학회논문집
• /
• 제6권2호
• /
• pp.69-76
• /
• 1995

Recent opening of the era of local government and management randers study tasks concerning the improvement of the housing conditions by improving the problems in the residential conditions of the cheju Island region so as to help improve the life qualities of this legion make the area as an international resort place, and thus develop the indentify in the heat of the people in this region. The suggestions based on the study for the improvement of housing environment are summarized as follows: (1) To improve the collective housing. housing construction plan shall b made in harmony with the skylines of the Hanra mountain alongside the East-West rides across the long diameter of the oval shape of the Island, which includes 1) the construction of housing complex in harmony with and taking advantage of the natural scene of the area. and 2) the construction of variable housing readjustable in accordance with each family structure of variable housings for multi-families, which are believed not to provide quality housing conditions. Shall be entrained. (2) Encouraging the construction of detached house : 1) construction of housings in which three generations can reside together according to the traditional family structure in the region. 2) construction of the pastoral housings. 3) construction of tenement housings partitioned for each two families. 4) development of sliver town in the rural area. (3) Using the construction mateials produced in the Cheju I land will help promote the development of identity in the heart of the people in this region.

• 수산해양기술연구
• /
• 제32권3호
• /
• pp.257-265
• /
• 1996

The combined hydroacoustic and bottom trawl surveys were conducted in the Cheju southeastern area by the training ship "KAYA" belong to Pukyong National University in July 1995 and the traning ship "NAGASAKI MARl]" belong to Nagasaki University in April 1994, respectively. The main purpose of the investigations was to provide the basic data for the management and the biomass estimation of commercially important demersal fish stocks in this area. Fish samples were collected by bottom trawling from 10 trawl stations randomly selected in the survey area, and the species and length compositions of trawl catches were examined. The fish school target strength for demersal fish aggregations was related to the catchability of trawl net with a 90 mm mesh codend. The most abundant species in the 1995 trawl stations were Japanese flying squid, sword tip squid and red horsehead and that of the 1994 trawl stations Japanese flying squid and blackmouth goosefish. The average weight per cubic meter of trawl catches collected by bottom trawling in the Cheju southeastern area were $1.0791{\times}lO^-4$kg/$m^3$ in the 1994 survey area and $1.3636{\times}lO^-4$kg/$m^3$ in the 1995 survey area, respectively. The catch data by cover net suggest that the efficiency of trawl net could affect the weight normalized target strength values for demersal fish aggregations. That is, the average target strength per unit of weight dropped from - 33.1 dB/kg using the total catch by codend and cover net to - 30.5 dB/kg using only the catch data by codend, and a change of2.6 dB/kg was observed.ange of2.6 dB/kg was observed.