• Korean Journal of Remote Sensing
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• v.15 no.1
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• pp.61-71
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• 1999

Several physical phenomena on the sea surface are analyzed from SAR images of South Sea areas, Korea. Strong wave patterns propagating in southerly direction are seen in ERS-1 SAR image on October 11, 1994, and a wave directional spectrum is calculated from this image using the SAR modulation transfer function. RADARSAT SAR image of August 15, 1996 reveals internal waves in northern coastal waters of Cheju Island. Analysis indicates that the internal waves may have been generated by the tidal currents traveling over the shallow bottom of the stratified water in the summer during the tidal changeovers fro ebb to flood and shows patterns of trains of solitons. RADARSAT SAR image taken 3 days after the oil spill accident near Goeje Isalnd on April 3, 1997 detects distinct oil slicks from the accident area but also shows slicks near the coast caused by wind sheltering of coastal mountains and chemical-biological activities.

• Journal of Convergence for Information Technology
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• v.11 no.10
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• pp.151-158
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• 2021

The purpose of this paper is to examine the concept of computational thinking in an easy-to-understand way for non-computer majors. First, It is necessary to expand from the problem-solving perspective to the perspective of problem discovery and creation ability, and establish it as a thinking ability that can cultivate human-like thinking, that is, creative thinking. Second, the concept of computational thinking can be viewed not only in the cognitive aspect but also in the emotional motive and attitude aspect. Third, systematic design of teaching methods is needed based on the expansion of the concept to computational thinking that helps learners to improve their reflective ability. It is expected that the results of this study will serve as basic research for various attempts in terms of the purpose and teaching method of computational thinking education in the future.

• Korean Journal of Ichthyology
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• v.34 no.4
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• pp.225-230
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• 2022

The single postlarval specimen (7.53 mm in standard length) of Thalassoma quinquevittatum (Lay & Bennett, 1839), belongs to the family Labridae, was collected by a bongo net from the southern coastal waters of Jeju-do Island, Korea in November 2020. T. quinquevittatum has a deeply curved dorsal contour before the dorsal fin, the oval eyes, and no melanophores throughout the body. While T. amblycephalum has a slightly curved dorsal contour before the center of the dorsal fin, the circular eyes, and few melanophores on the body. A molecular analysis based on 548 base pairs sequences in the mitochondrial DNA cytochrome c oxidase subunit I region shows that the specimen was closely matched to adult T. quinquevittatum (K2P distance=0.002-0.005). We report the first record of T. quinquevittatum in Korean waters, and suggest its new Korean name "Da-seot-jul-saek-dong-nol-rae-gi".

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.359-365
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• 1994

A oat (Avena sativa) cultivar, 'Guiri 16', was seeded on Oct. 9, Oct. 24, Nov. 9, Nov. 24, Dec. 9 of 1991 and 1992 to determine usefulness of growing degree days (GDD) for predicting growth duration and the optimum seeding date of oats for grains in Cheju province. The later the seeding, the greater the number of days to emergence but the fewer the number of days to heading and maturity. As seeding was delayed, accumulated GDD from seeding to emergence generally tended to decrease but was less subjective to a constant downward tend over seeding date than the number of days. Accumulated GDD from emergence ot heading decreased with delaying seeding and accumulated GDD from heading to maturity decreased as seeding was delayed up to Nov. 24. As seeding was delayed from Oct. 9 to Dec. 9, to Dec. 9, leaf area index at heading decreased from 7.7 to 5.1 and dry matter yield at maturity from 1920 to 823 kg /10a in 1992-1993, and culm length 120 to 89cm on an average of 1991-1992 and 1992-1993. While the number of grains per panicle and test weight were not affected by seeding date in 1991-1992 and 1992-1993, the number of panicles per m$^2$ and grain yield were decreased when oats were seeded earlier or later than Nov. 9. 1000 grain weight was not affected by seeding date in 1991-1992 but greatest at Nov. 9 seeding in 1992-1993. The results indicate that optimum seeding date of oats in Cheju province would be early November. November.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.489-499
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• 1998

Gonadal development, reproductive cycle and embryonic development of the marbled rockfish, Sebastiscus marmoratus were investigated histologically. A total of 1,035 specimens were collected from the Cheju Island from July of 1992 to May of 1996. Gonadosomatic index (GSI) in female reached the maximum during October to March, thereafter, the values decreased from Norvember to April. GSI in male reached the maximum in September (before one to three months of the female's maximum), thereafter, the values rapidly decreased from October to December. The annual reproductive cycle can be divided into five stages in female and four stages in male: females, Growing(June to September), Mature(September to February), Ripe and copulation(October to March), Gestation and parturition(November to April), Degenerative and resting(December to May); in males, Growing(April to July), Mature(August to November), Ripe and copulation(September to December), and Degenerstive and resting(November to March). Size frequency distribution of eggs and larvae showed non-synchrony. Maternal larvae parturition occurred one or two time during November to April. Mean length of the larvae parturition was 3.5 mm. Mean number of eggs and maternal larvae for the 15 cm minimum class of female was 58,377, and fecundity increased with the increase of total length and body weight.

• Journal of Environmental Science International
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• v.20 no.11
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• pp.1437-1445
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• 2011

The adsorption performance of lead ion was studied using five zeolites (Na-P1, sodalite (SOD), analcime (ANA), nepheline hydrate (JBW), cancrinite (CAN)) synthesized from Jeju scoria. The adsorption performances of lead ion decreased in the order of Na-P1 > SOD > ANA > JBW > CAN. These results showed that the synthetic zeolite with a higher cationic exchange capacity showed a higher adsorption performance. The uptake of lead ion by synthetic zeolites were described by Freundlich model better than Langmuir model. The adsorption kinetics of lead ion by synthetic zeolites fitted the pseudo 2nd order kinetics better than pseudo 1st order kinetics. The effective diffusion coefficients of lead ion by synthetic zeolites were ten times higher than the zeolite A synthesized from coal fly ash.

• The Korean Journal of Malacology
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• v.12 no.1
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• pp.19-31
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• 1996

국내 11개 지역(경기도 옹진군 덕적도, 경기도 의정부시 소요산, 강원도 춘천시, 충청남도 태안군 안홍, 경상북도 울릉군 울릉도, 전라북도 부안군 변산, 전라남도 신안군 홍도, 흑산도 비금도, 진도, 제주도)에서 채집된 달팽이 (A. despecta sieboleiana)를 대상으로 외부형태 분석과 동위효소를 검출하여 각 지역 집단간의 형태적, 유전적 유연관계와 변이 정도를 연구한 결과는 다음과 같다. 외부형태에 의한 집단간 유연관계는 안홍과 덕적도집단(average taxonomic distance, D=0.358)이 형태적으로 가장 유사한 집단으로 나타났다. Polyacrylamide gel을 사용하여 11가지의 동위효소를 검출한 결과 AKP, ACP, AO, EST, GPD, HBDH, LDH, SDH, XDH의 동위효소에서 유전적 다형현상이 나타났다. 전 집단의 평균 다형형의 빈도는 59.19%이며 이형접합자 빈도는 0.263이고 각 집단의 유전적 차이치는 춘천과 울릉도 집단이 0.066(genetic distance)으로 가장 높은 유사성을 보였다. 지리적 분포에 따른 외부형태 변이와 유전적 변이와의 관계는 유의성이 없었다.

• Proceedings of the Korea Information Processing Society Conference
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• 2010.11a
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• pp.1501-1502
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• 2010

DualCore 혹은 MultiCore 플랫폼의 보급에 따라 높은 시간복잡도를 갖는 응용들도 사용자의 컴퓨터나 단말에서 수행되어 다양한 서비스를 제공할 수 있게 되었다. 본 논문에서는 관광 스케줄을 효율적으로 결정하기 위한 다중목적지 방문 문제에 대해 이중 쓰레드에 기반한 서치 스페이스 탐색 알고리즘을 구현한다. 이는 Traveling Salesman Problem의 한 종류로서 O(n!) 시간 복잡도를 갖고 있으며 검색시의 독립성때문에 각 쓰레드는 병렬적으로 최적의 스케줄을 탐색할 수 있다. 또 현재까지 발견된 최적값을 기반으로 부분 경로의 비용이 이미 최적값을 넘는 경우는 하위 탐색을 제거하여 상당한 성능의 향상을 가져온다. 2.4 GHz Intel(R) Core DuoCPU와 3 GB 메모리로 구성된 플랫폼 상에서 구현된 서비스는 11개의 목적지에 대한 방문 스케줄을 생성함에 있어서 단일 쓰레드 버전은 14.196초, 이중 쓰레드 버전은 6.411초, 제약조건을 포함한 이중 쓰레드 버전은 0.14초에 최적의 스케줄을 찾아낼 수 있다.

• Korean Journal of Environment and Ecology
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• v.26 no.5
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• pp.635-653
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• 2012

Vascular plants of Oruem in region of Jeju-City were investigated 454 taxa totally; 116 families, 301 genera, 359 species, 3 subspecies, 78 varieties and 14 forms. In the studied Oruems in region of Jeju-City within altitude 800m, evergreen tree forests does not range and a lot of Pines thunbergii forest and Cryptomeria japonica and Chamaecyparis obtusa plantation forest were. The endemic species of Oruem in region of Jeju-City were 14 taxa such as Asarum maculatum, Hepatica insularis, Cardamine glechomifolia etc. The floristics degree categorized by the specific distribution of plant species were total 116 Taxa, that is, V grade species Magnolia kobus, Aconitum japonicum subsp. napiforme, Ligularia taquetii etc, 6 kinds be, IV grade species Rubus ribisoideus, Ligustrum salicinum, Carex macrandrolepis etc, 16 kinds be, III grade species Illicium anisatum, Hydrangea petiolaris, Rubus schizostylus etc, 37 kinds be, II grade species Pseudostellaria coreana, potentilla dickinsii, Euonymus pauciflorus etc, 6 kinds and I grade species Sphenomeris chinensis, Pteris multifida, Machilus thunbergii etc, be. 51 kinds were confirmed. Rare and Endemic Plant Species of Korea Forest Service were 11 taxa such as Asarum maculatum, Aconitum japonicum subsp. napiforme and Magnolia kobus etc. Naturalized plant were confirmed 31 taxons with Rumex acetosella, Hypochaeris radicata and Sisyrinchium atlanticum etc.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.38 no.1
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• pp.11-19
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• 2002

We studied the characteristics of catch fluctuation and distribution of yellow tail resources in Korean Waters from 1991 to 2000. The obtained results are summarized as follow, The distribution of yellow tail resources in Korean Waters was showed by mooving north-ward groups from Spring to Autumn and south-ward groups from Autumn to Winter with they passed Winter and spawned from the south of Jeju Island and Tsushima current. Therefore, the fishing ground of yellow tail by handline fishing around Marado targets a school of yellow tails which migrate south-ward so as to winter and spawn.