• 제목/요약/키워드: high latitude

검색결과 337건 처리시간 0.026초

The Study on Flora and Distribution Characteristics of Orchidaceae on Moor

  • Rho, Jae-Hyun
    • 한국환경과학회지
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    • 제12권2호
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    • pp.179-184
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    • 2003
  • Total 7 moors, Yong-neup on Mt. Daeam, Chilbo Mt. moor, Dogapsa-neup on Mt. Wolchul, Wangdeungiae-neup on Mt. Jiri, Mujechi-neup on Mt. Jungjok, Buljae-neup on Mt. Kyungak and Geoinri-neup on Dongsang, were investigated by literatures and survey. Distribution, conditions, and similarity of dominant species and Orchidaceae on moor were analyzed. The results are follows; There are total 46 wetland plant species observed more than twice from 7 moors. The plants classified as constancy class V, which are appeared more than 80%, are Iris ensata var. spontane, Juncus effusus var. decipiens, Sanguisorba tenuifolia var. alba, Habenaria linearifolia, Sium ninsi, Lobelia sessilifolia, Lastrea theiyptoris, and Eupatorium chinensis var. simplicifolium. Highly appearing Orchidaceae, which was classified to constancy class IV plant, are Habenaria linearifolia, Pogonia japonica, Eipactis thunbergii, and Platanthera mandarinorum. They are the typical index plants of the moors. Habitual environment of Habenaria radiate and Platanthera hologlottis can be affected by environmental aspects such as latitude, altitude and the water quality. However those of Habenaria linearifolia, Epipactis thunbergii, and Pogonia japonica are not affected by latitude and altitude, but may be determined by water condition of wetland. As the result of similarity index analysis for appearance of Orchidaceae identifying each moors in the view of species composition, swamps at Dogapsa-neup and Buljae-neup are very similar. However Yong-neup is totally different from those of Dogapsa-neup and Buljae-neup. Yong-neup had shown the high similarity indices of 0.85 and 0.75 with Wangdeungiae-neup and Mujechi-neup, respectively. Growth properties of wild Orchidaceae at wetland were almost similar. Platanthera mandarinorum and Liparis kumokiri had characteristics of good adaptability. Most of them need light. Pogonia was the only long-day plant. The flowering time of these Orchidaceae was from May to September.

기후변화와 농업생산의 전망과 대책 (Climate Change and Coping with Vulnerability of Agricultural Productivity)

  • 윤성호;임정남;이정택;심교문;황규홍
    • 한국농림기상학회지
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    • 제3권4호
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    • pp.220-237
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    • 2001
  • Over the 20th century global temperature increase has been 0.6$^{\circ}C$. The globally averaged surface temperature is projected to increase by 1.4 to 5.8$^{\circ}C$ over the period 1990 to 2100. Nearly all land areas will have higher maximum temperature and minimum temperature, and fewer cold days and frost days. More intense precipitation events will take plate over many areas. Over most mid-latitude continental interiors will have increased summer continental drying and associated risk of drought. By 2100, if the annual surface temperature increase is 3.5$^{\circ}C$, we will have 15.9$^{\circ}C$ from 12.4$^{\circ}C$ at present. Also the annual precipitation will range 1,118-2,447 mm from 972-1,841 mm at present in Korea. Consequently the average crop periods for summer crops will be 250 days that prolonged 32 days than at present. In the case of gradual increase of global warming, an annual crop can be adapted to the changing climate through the selection of filial generations in breeding process. The perennial crops such as an apple should be shifted the chief producing place to northern or high latitude areas where below 13.5$^{\circ}C$ of the annual surface temperature. If global warming happens suddenly over the threshold atmospheric greenhouse gases, then all ecosystems will have tremendous disturbance. Agricultural land-use plan, which state that farmers decide what to plant, based on their climate-based advantages. Therefore, farmers will mitigate possible negative imparts associated with the climate change. The farmers will have application to use agricultural meteorological information system, and agricultural long-range weather forecast system for their agroecosystems management. The ideal types of crops under $CO_2$ increase and climate change conditions are considered that ecological characteristics need indispensable to accomplish the sustainable agriculture as the diversification of genetic resources from yield-oriented to biomass-oriented characteristics with higher potential of $CO_2$ absorption and primary production. In addition, a heat-and-cold tolerance, a pest resistance, an environmental adaptability, and production stability should be also incorporated collectively into integrated agroecosystem.

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AFLP 마커를 이용한 조릿대 개체군의 식물지리학적 연구 (A phytogeographical study of Sasa borealis populations based on AFLP analysis)

  • 김일룡;유다솜;최홍근
    • 식물분류학회지
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    • 제45권1호
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    • pp.29-35
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    • 2015
  • 본 연구는 전국에 분포하는 조릿대[Sasa borealis (Hack.) Makino & Shibata]의 12 개체군을 대상으로 유전다양성을 분석하고, 이러한 분석 결과를 식물지리학적인 해석을 통하여 기후변화와 같은 변화 요인을 객관적으로 측정하고 예측할 수 있는 방법을 제시하기 위해 수행되었다. AFLP (amplified fragment length polymorphism) 분석을 통한 유전다양성 조사 결과, 조릿대 개체군의 유전다양성(PPL = 37.2%, h = 0.143, I = 0.205)과 유전적 분화도($G_{ST}$= 0.324, ${\theta}^B$=0.395)는 비교적 높은 수준으로 나타났다. AMOVA (Analysis of molecular variance) 분석 결과에서도 전체 유전적 변이 중 47.7%가 개체군 간 변이에 의한 것으로 나타났다. 그리고 조릿대 개체군들의 유전다양성은 위도가 높아짐 따라 감소하는 것이 확인 되었으며, 이는 남방계 식물인 조릿대의 분포가 낮은 위도에서 높은 위도로 전파된 과정과 일치하는 것으로 해석할 수 있다. 따라서 식물 개체군의 AFLP 분석 결과를 위도 변화와 비교 분석함으로써 기후변화에 따른 분포 변화의 정도를 파악하고 주요 식물의 보전 전략을 세우는 데 필요한 정보를 제공할 수 있다.

RCP 시나리오 기반 WRF를 이용한 CORDEX-동아시아 2단계 지역의 가까운 미래 극한기온 변화 전망 (Near Future Projection of Extreme Temperature over CORDEX-East Asia Phase 2 Region Using the WRF Model Based on RCP Scenarios)

  • 서가영;최연우;안중배
    • 대기
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    • 제29권5호
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    • pp.585-597
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    • 2019
  • This study evaluates the performance of Weather Research and Forecasting (WRF) model in simulating temperature over the COordinated Regional climate Downscaling EXperiment-East Asia (CORDEX-EA) Phase 2 domain for the reference period (1981~2005), and assesses the changes in temperature and its extremes in the mid-21st century (2026~2050) under global warming based on Representative Concentration Pathway (RCP) scenarios. MPI-ESM-LR forced by two RCP scenarios (RCP2.6 and RCP8.5) is used as initial and lateral boundary conditions. Overall, WRF can capture the observed features of temperature distribution reflecting local topographic characteristic, despite some disagreement between the observed and simulated patterns. Basically, WRF shows a systematic cold bias in daily mean, minimum and maximum temperature over the entire domain. According to the future projections, summer and winter mean temperatures over East Asia will significantly increase in the mid-21st century. The mean temperature rise is expected to be greater in winter than in summer. In accordance with these results, summer (winter) is projected to begin earlier (later) in the future compared to the historical period. Furthermore, a rise in extreme temperatures shows a tendency to be greater in the future. The averages of daily minimum and maximum temperatures above 90 percentiles are likely to be intensified in the high-latitude, while hot days and hot nights tend to be more frequent in the low-latitude in the mid-21st century. Especially, East Asia would be suffered from strong increases in nocturnal temperature under future global warming.

단일주파수 GNSS 수신기용 실시간 전리층 지연 보정 모델 비교 : Klobuchar 모델과 NeQuick 모델 (Comparison of Real-Time Ionospheric Delay Correction Models for Single-Frequency GNSS Receivers : Klobuchar Model and NeQuick Model)

  • 이창문;박관동;이상욱
    • 한국측량학회지
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    • 제28권4호
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    • pp.413-420
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    • 2010
  • 현재 전리층 지연은 GNSS 측량의 가장 큰 오차이다. 단일 주파수 수신기 사용자는 전리층 지연을 모델링 하거나 보정하기 위하여 전리층 보정 알고리즘을 적용해야 한다. 실시간 보정이 가능한 전리층 모델로는 항법메시지로 제공되는 GPS의 Klobuchar 모델과 Galileo의 NeQuick 모델이 있다. 이 연구에서는 두 모델의 효용성을 계절과 위도에 따라 평가하였다. 첫 번째 검증으로, 각 계절별로 수원 GPS 상시관측소 상공의 연직방향 총전자수를 산출하였다. 두 번째 검증으로는 위도가 서로 다른 3개 상시관측소(철원, 수원, 제주)에서의 VTEC을 계산해 관측소 위도와의 상관성을 분석하였다. 산출된 총전자수는 전지구 전리층 모델인 GIM 모델과 IRI 모델에서 제공하는 총전자수와 비교하였다. 그리고 GIM 모델과 IRI 모델을 기준으로 Klobuchar 모델과 NeQuick 모델의 RMS 차이를 각각 산출하였다. 그 결과, 계절과 관측소 위도와 무관하게 NeQuick 모델의 RMS 차이가 Klobuchar 모델의 RMS 차이보다 약 0.01~3.50 TECU 낮게 나타났다.

THEMIS Pi2 observations near dawn and dusk sectors in the inner magnetosphere

  • Kwon, Hyuck-Jin;Kim, Khan-Hyuk;Lee, Dong-Hun;Takahashi, K.;Park, Young-Deuk;Bonnell, J.W.
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2010년도 한국우주과학회보 제19권1호
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    • pp.40.3-40.3
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    • 2010
  • The most frequently suggested source for Pi2 pulsations in the inner magnetosphere (L < 4) is standing fast-mode waves trapped in the plasmasphere (i.e., plasmaspheric resonances). They have been considered as the source of low-latitude Pi2 pulsations. The plasmaspheric resonance model suggests that compressional fast-mode waves can be detected at all local times inside the plasmasphere provided reflection of the wave energy is efficient. Until now, however, there are no reports about compressional Pi2s observed in the dayside inner magnetosphere. That is, there is longitudinal limit of inner magnetosphere. In February 2008, THEMIS probes were near dawn and/or dusk sides, which are the transition regions between the nightside and dayside, in the inner magnetosphere (L = 2-4) when low-altitude Pi2s were identified at Bohyun (L = 1.35) station in Korea. Using the THEMIS electric field data, we examined if Pi2s are excited by longitudinally localized disturbances. We found that compressional Pi2s having high coherence with a low-latitude Pi2 pulsation occur on dawnside. However, any compressional pulsations in the Pi2 frequency band were not detected on duskside. This indicates that compressional Pi2s disappear near the duskside. Our observations are discussed with spatial plasmaspheric structure and possible Pi2 mechanisms.

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하늘다람쥐(Pteromys volans)의 형태적 특성: 성적이형성 및 위도에 따른 형태학적 특성 비교 (Morphological Characteristics of Siberian Flying Squirrel (Pteromys volans): Sexual Dimorphism and Camparison of Morphological Characteristics in Different Latitudes)

  • 김준수;전종훈;이우신;김종우
    • 한국산림과학회지
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    • 제108권1호
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    • pp.133-137
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    • 2019
  • 하늘다람쥐의 형태적 특성을 파악하기 위해 강원도 원주시 백운산에서 2014년 4월부터 2016년 3월까지 하늘다람쥐의 6가지 외부형태적 특성에 대한 측정을 실시하고 분석하였다. 그 결과 하늘다람쥐는 암컷이 수컷보다 큰 암컷편향적 성적이형성을 나타내는 것으로 확인되었다. 이는 단독 생활을 하고 암컷 혼자 새끼를 키우는 하늘다람쥐의 번식전략과 관련이 있는 것으로 보인다. 국내와 핀란드, 일본에서 파악된 하늘다람쥐의 외부형태 측정치 중 체중과 머리-몸통의 길이를 비교한 결과, 모두 핀란드와 일본 그리고 한국 순서대로 위도가 높은 지역이 크게 나타났다. 이러한 형태적 특성의 차이는 분포 지역 위도에 따른 기후와 서식환경 차이에 따른 것으로 생각되며, 추후 체중과 머리-몸통의 길이 이외의 외부형태 측정치에 대한 비교 연구가 필요할 것으로 생각된다.

조생종 벼의 평야지 재배에 따른 등숙 온도 차이에 의한 전분구조 및 종자 저장단백질 특성 연구 (Effects of Ripening Temperature on Starch Structure and Storage Protein Characteristics of Early Maturing Rice Varieties during Grain Filling)

  • 곽지은;이점식;원용재;박향미;곽강수;김미정;이춘기;김선림;윤미라
    • 한국작물학회지
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    • 제63권2호
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    • pp.77-85
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    • 2018
  • 본 시험은 조생종 벼의 평야지 재배에 따른 등숙 온도 차이에 의한 전분구조와 종자 저장단백질 특성 차이를 평가하여 쌀 품질향상을 위한 기초자료 제공을 위해 수행하였다. 이를 위해 조생종 벼 8 품종을 철원 및 등숙기 온도가 상대적 고온조건인 수원에서 재배하여 품질 분석을 수행하였다. 등숙시 고온 조건에서는 일반 조건보다 쌀 완전미율, 아밀로스 함량, 식미총평 점수가 낮은 반면 단백질 함량은 높았다. 전분구조 특성 차이를 평가한 결과, 고온 조건에서는 일반 조건에 비해 아밀로펙틴의 단쇄 사슬길이(DP < 12) 분포비율이 낮은 반면, 중쇄(DP 13-24) 및 장쇄사슬 길이(DP > 25) 분포비율은 높았다. 저장단백질 특성 차이를 평가한 결과, 등숙기 고온 조건의 시료에서는 알부민과 글로불린 함량에는 차이가 없는 반면, 글루텔린 함량은 높고, 프롤라민 함량은 낮았다. 글루텔린의 서브유닛을 분석한 결과, 염기성 글루텔린 조성은 두 지역 간 차이가 없었으나 산성 글루텔린은 등숙기 고온 조건에서 유의하게 높았으며, 특히 ${\alpha}$-1(약 36 kDa)과 ${\alpha}$-3(약 40.6 kDa) 서브유닛의 함량이 높았다. 선행연구에서 고온등숙 조건에서 프롤라민의 감소는 보고가 되었으나, 산성 글루텔린 증가와 관련된 사항은 현재까지 보고된 바가 없어, 향후 이 부분에 대한 추가 검토가 필요할 것으로 고찰된다.

High Dispersion Spectra of the Elliptical Planetary Ring Nebula NGC 6803

  • 이성재;형식
    • 천문학회보
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    • 제37권1호
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    • pp.80.1-80.1
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    • 2012
  • NGC 6803 is an elliptical ring shape planetary nebula. We analyzed the high dispersion spectra which had been observed with the Hamilton Echelle Spectrograph attached to the 3-m Shane telescope of Lick Observatory. We also investigated the low dispersion UV spectral data obtained with the 60-cm interstellar ultraviolet explorer. Diverse excitation lines were found from neutral to quadruply ionized ions. The temperature diagnostic lines indicate relatively low electron temperatures, i.e., $T_{\epsilon}{\leq}9500$ K for most lines except for [ClIV] - 11,500 K. In spite of its simplistic bi-laterally symmetrical elliptical shape, the nebula appears to be very complex of a hugh density range from 1300 to 80,000 $cm^3$. A comparison of the two epoch data suggests that the density increase occurred in the high excitation line zone near the inner boundary. We derived the chemical abundances of He, C, N, O, Ne, S, Ar, Cl, and K. The chemical abundances of NGC 6803 are enhanced compared with the average Galactic planetary nebula. Our self-consistent photo-ionization model study implies that the effective temperature of the central star is 90,000 K and its luminosity is 2400 $L_{\odot}$. The evolutionary track suggests that the progenitor of NGC 6803 was about 0.9 -- 1.0 $M_{\odot}$ star, which might be born from a metal-rich zone near the galactic disk, but now relocated into the present high Galactic latitude.

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Fuji HR series의 임상평가 (Clinical Evaluation of Fuji HR-series)

  • 강대현;신동식;김영환;강홍석;이인자;허준
    • 대한방사선기술학회지:방사선기술과학
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    • 제11권2호
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    • pp.21-26
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    • 1988
  • Newly developed orthochromatic film HR series have many different types according to high speed, high resolution and special latitude. And now authors have practiced various screen-film combinations, those were usual regular type Fuji new RX film-LT screen and orthochromatic type HR films-rare earth G3, G4 screens. As a result of the experiment, we obtained high speed with high resolution and expansion of diagnostic range on the following combinations compared with usual new RX/LT series. Those combinations were RXO-G and HR-L films to skull, HR-G films to knee joint and hand part, HR-L film to abdomen. Therefore it may be desirable to select adquate kinds of HR series films according to investigated parts.

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