• 제목/요약/키워드: southwestern Japan

검색결과 68건 처리시간 0.025초

장마철 우리나라 강수의 지속성에 따른 종관 특성의 차이 (Difference of Synoptic Characteristics according to the Persistence of Rainfall in Korea during the Changma Season)

  • 박병익
    • 대한지리학회지
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    • 제45권6호
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    • pp.748-765
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    • 2010
  • 본 연구에서는 장마철 우리나라의 지역 평균 강수량을 이용하여 강수의 지속성에 따른 종관 특성의 차이를 살펴보았다. 그 결과 일강수량 10mm 이상이 4일 이상 지속되는 강수(장기 강수)와 1~2일에 그치는 강수(단기 강수) 사이에는 종관 특성에 차이가 있음을 알았다. 장기 강수의 경우 우리나라 동쪽에 기압능이 발달, 저기압과 전선의 정체를 유도하였고, 또 강수 1일 전에 찬 공기가 화중지방으로 남하, 전선이 활발해져 강수의 지속성에 기여하였다. 단기 강수의 경우 저기압이 우리나라를 정체 없이 통과하였다. 또한 장기 강수와 단기 강수의 경우에 우리나라 부근의 전선이 대류권 전체에 미치는 경압성이 큰 구조를 보였다. 장기 강수의 전선 구조가 일본 남서부 지역 장기 강수의 경우와 다르며, 단기 강수의 경우는 양 지역에서 같다. 이는 장마가 반드시 일본 바이우(Baiu)의 연장선상에 있는 것은 아님을 의미한다.

Pattern Recognition of Meteorological fields Using Self-Organizing Map (SOM)

  • Nishiyama Koji;Endo Shinichi;Jinno Kenji
    • 한국수자원학회:학술대회논문집
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    • 한국수자원학회 2005년도 학술발표회 논문집
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    • pp.9-18
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    • 2005
  • In order to systematically and visually understand well-known but qualitative and rotatively complicated relationships between synoptic fields in the BAIU season and heavy rainfall events in Japan, these synoptic fields were classified using the Self-Organizing Map (SOM) algorithm. This algorithm can convert complex nonlinear features into simple two-dimensional relationships, and was followed by the application of the clustering techniques of the U-matrix and the K-means. It was assumed that the meteorological field patterns be simply expressed by the spatial distribution of wind components at the 850 hPa level and Precipitable Water (PW) in the southwestern area including Kyushu in Japan. Consequently, the synoptic fields could be divided into eight kinds of patterns (clusters). One of the clusters has the notable spatial feature represented by high PW accompanied by strong wind components known as Low-Level Jet (LLJ). The features of this cluster indicate a typical meteorological field pattern that frequently causes disastrous heavy rainfall in Kyushu in the rainy season. From these results, the SOM technique may be an effective tool for the classification of complicated non-linear synoptic fields.

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Evolution of the eastern margin of Korea: constraints on the opening of the East Sea (Japan Sea)

  • Kim, Han-Joon;Jou, Hyeong-Tae;Suk, Bong-Chool
    • 한국지구물리탐사학회:학술대회논문집
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    • 한국지구물리탐사학회 2007년도 특별 심포지엄 논문집
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    • pp.73-83
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    • 2007
  • We interpreted marine seismic profiles in conjunction with swath bathymetric and magnetic data to investigate rifting to breakup processes at the eastern Korean margin that led to the separation of the southwestern Japan Arc. Analysis of rift fault patterns suggests that rifting at the Korean margin was primarily controlled by normal faulting resulting from extension rather than strike-slip deformation. Two extension directions of E-W and NW-SE for rifting are recognized. We interpret that the E-W direction represents initial rifting at the inner margin and the NW-SE direction probably represents the extension in response to tensional tectonics associated with the subduction of the Pacific Plate in the NW direction. No significant volcanism was involved in rifting. In contrast, the inception of sea floor spreading documents a pronounced volcanic phase which appears to reflect asthenospheric upwelling as well as rift-induced convection particularly in the narrow southern margin. We suggest that structural and igneous evolution of the Korean margin, although it is in a back-arc setting, can be explained by the processes occurring at the passive continental margin with magmatism influenced by asthenospheric upwelling.

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한국(韓國) 경상남도(慶尙南道) 언양도폭(彦陽圖幅) 및 북서부(北西部) 울산도폭(蔚山圖幅) 지역산(地域産) 화강암질암(花崗岩質岩)의 K-Ar 연대(年代) (K-Ar dating on granitic rocks from the Eonyang- and the northwestern part of Ulsan-quardrangle, Kyeongsang-nam-do, Korea)

  • 이윤종;우에다 요시오
    • 자원환경지질
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    • 제9권3호
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    • pp.127-134
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    • 1976
  • The K-Ar age determined on six granitic rocks samples from the Eonyang- and the northwestern part of Ulsan-quardrangle, Kyeongsang-nam-do, Korea, ranges from $87{\times}10^6$ years to $58{\times}10^6$ years. Three of the samples belong to the upper Cretaceous ($87{\times}10^6-71{\times}10^6years$) and three to the late Cretaceous-early Tertiary ($63{\times}10^6-58{\times}10^6years$) in age. The early Tertiary ages are measured first on the "Younger Granites" in Korea. These two emplacement periods of granitic rocks are representative that the former is correlated to north Kyushu-Seto Inland belt ($95{\times}10^6-75{\times}10^6years$) and the later to Sanin-central Honshu belt ($65{\times}10^6-50{\times}10^6years$), in southwestern Japan.

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First Record of the Family Dryopidae (Coleoptera) in Korea with Taxonomic Notes on Elmomorphus brevicornis and Elmomorphus amamiensis

  • Jung, Sang Woo;Bae, Yeon Jae
    • Animal Systematics, Evolution and Diversity
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    • 제30권1호
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    • pp.1-8
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    • 2014
  • The Dryopidae (Coleoptera) is composed of approximately 300 species worldwide belonging to 33 genera; however, members of the family have not been recorded in Korea. We collected and recorded adult specimens of Elmomorphus brevicornis Sharp (=E. brevicornis brevicornis Sharp) on piles of submerged twigs and branches of a decayed tree (Prunus sp.) from a mountain stream in southwestern Korea with a comparison of the type specimens of E. brevicornis amamiensis Nomura from Japan. Both of the subspecies are raised to the species level herein. Redescription, photographs, line drawings of diagnostic characteristics, distribution map, habitat, and taxonomic notes for Elmomorphus brevicornis are provided.

울릉분지의 고환경과 화산활동 특성에 관한 연구 : 퇴적환경 (Paleoenvironments and Volcanism of the Ulleung Basin : Sedimentary Environment)

  • 박맹언;이광훈;송용선
    • 한국수산과학회지
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    • 제29권4호
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    • pp.481-496
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    • 1996
  • The last Sea is a typical bark-arc basin consisting of basins, plateaus, ridges, and seamounts. The Ulleng Basin, located in the southwestern corner of the last Sea, contains thick Neogene sedimentary sequence. Analysis of over 2,500 km of single-channel seismic reflection data suggests that hemipelagic sedimentation prevailed over much of the basin during the late Miocene and pelagic sedimentation became more dominant during the Pliocene. During the Pleistocene terrigeneous sediments transported by turbidity currents and other gravity flows, together with continuous hemipelagic settling, resulted in well-stratified sedimentary layers. Influx of terrigenous sediments during the Pleistocene formed depocenters in the western and southern parts of the basins. In the Ulleung Interplain Gap, where the Ulleung Basin joins the deeper Japan Basin, sediment waves suggesting bottom current activities are seen.

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Genetic Structure in Korean Populations of Hosta capitata (Liliaceae)

  • Chung, Myong-Gi
    • Journal of Plant Biology
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    • 제37권3호
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    • pp.277-284
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    • 1994
  • I investigated levels of genetic diversity, population genetic structure, and gene flow in Hostacapitata, a herbaceous perennial native to South Korea and southwestern Japan. Starch gel electrophoresis was conducted on leaves collected from 310 plants in 19 Korean populations. Twenty-two of 25 putative loci examined were polymorphic in at least one populatin and the mean number of alleles per locus was 1.65. In addition, mean expected heterozygosity within populations (Hep=0.153) was higher than average values for species with similar life history traits. Significant differences in allele frequency were detected between populations at all loci (P<0.01), and slightly over 30% of the genetic variation was found among populatins (GST=0.308). Indirect estimates of the number of migrants per generation (Nm) (0.506, calculated from GST; 0.852, calculated from the mean frequency of ten private alleles) indicate that gene flow is restricted among the isolated Korean populations of H. capitata. Factors contributing to the high levels of genetic differentiation among populations of H. capitata include small and discrete populations, human disturbance, and low frequencies of pollinator foraging behavior.

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The East Asiatic genera and endemic genera of the Pteridophytes in China

  • Zhang, Xian-Chun
    • 식물분류학회지
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    • 제33권4호
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    • pp.309-338
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    • 2003
  • China, the largest country in East Asia, has a pteridoflora of over 2000 species, belonging to about 220 genera in 63 families. There are about 28 East Asiatic genera of Pteridophytes and 6 genera specifically endemic to China. Most of these genera are oligotypic or monotypic groups. Five distribution patterns of the East Asiatic genera are distinguished, i.e., I. Sino-Himalayan type, 10 genera; II. Sino-Japanese type, 4 genera; III. Japan-Himalayan type, 6 genera; IV. Temperate East Asiatic type, 3 genera; and V. Tropical East Asiatic type, 5 genera. The Chinese endemic genera are mainly distributed in southwestern China. The distribution, ecology, taxonomy, and systematics of these genera are discussed.

언양(彦陽) 및 울산지역(蔚山地域) 화강암질암류(花崗岩質岩類)의 암석화학적(岩石化學的) 연구(硏究) (Petrochemistry of granitic rocks from the Eonyang and the Ulsan area)

  • 이윤종
    • 자원환경지질
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    • 제13권2호
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    • pp.69-79
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    • 1980
  • Granitic rocks, from the Eonyang and the northwestern part of Ulsan area, were mainly studied from the petrochemical point of view. From field work, microscopic observation and the result of K-Ar ages, these granitic rocks are divided into six rock types of a, b, c, d, e and e', of which modal composition are given. Type a, c, e and e' are mainly granodiorite, type b is adamellite, and type d is granodiorite, adamellite and others (porphyritic rock, porphyry and felsitic rocks). Bulk chemical analyses of 22 samples of the granitic rocks are given. The petrographical and petrochemical characteristics of these rocks are discussed briefly. In the petrochemical compositions with their characteristic variation trends of several oxides and norm Or-Ab-An triangular diagram, type a, b and c show some similarity to that of San-yo granite of Japan and younger granite of Ogcheon geosynclinal zone, and then, type e and e', to San-in granite of Japan. But, some of granitic rock samples of type d are similar to San-yo granite and the others of type d to San-in granite because this type is composed of porphyritic rock, porphyry and felsitic rocks. According to the result of K-Ar ages (1976, Lee et al.) of rock samples from type a, b and care Cretaceous, on the otherwise, type d, e and e', are Tertiary granitic rocks. Judging from these evidences, granitic rocks in the area are correlated to the Cretaceous and Tertiary granitic rocks in the, southwestern Japan, that is, type a, band c are correlated to San-yo granite, and type d, e and e' to San-in granite.

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東海 西南 海域의 플랑크톤 硏究(II) 식물플랑크톤-현존량, 미세플랑크톤 및 1차 생산- (Studies on the Plankton in the southwestern Waters of the East Sea (Sea of Japan) (II) Phytoplankton -Standing crop, nanofraction, and primary production-)

  • 심재형;이원호;박상윤
    • 한국해양학회지
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    • 제20권3호
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    • pp.37-54
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    • 1985
  • 1984년 5월과 10월, 2회에 걸쳐 동해 서남 해역에서 조사한 수온, 클로로필-a, 영양염, 식물플랑크톤 및 일차생산에 관한 자료를 토대로 하여 대산 수역의 phytohydrography를 논의하였다. 식물플랑크톤의 종별 양적분포로 부터 특성 해수의 이전 환경을 추측할 수 있었는데, 이는 해양물리${\cdot}$화학적인 자료만으로는 기대하기 어려운 결과였다. 울기 및 감포 부근 해역의 상층부에서는, 그 하층에 근접한 냉수로 부터 영양염을 공급받아, 높은 일차생산력, 높은 클로로필-a 및 낮은 미세플랑크톤 비율 등의 특징이 나타났다. 반면에 대마난류수에는 매우 낮은 일차생산력, 빈약한 현존량 및 극히 높은 미세플랑크톤 비율 등의 특징이 나타나 좋은 대조를 이루었다. 연구해역에서 식물플랑크톤의 세포수 뿐만 아니라 클로로필-a 및 일차생산량에서도 미세플랑크톤이 압도적으로 우세함을 확인하였다. 이는 한반도 전해역 가운데 난류수가 예외적으로 강하게 유입되는 연구해역의 생물해양학적 특성을 잘 반영해 주는 현상이다.

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