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        검색결과 50

        21.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        In this paper, we used a nonhomogeneous Gaussian regression model (NGR) as the postprocessing techniques to calibrate probabilistic forecasts that take the form of probability density functions for temperature. We also performed the alternative implementation techniques of NGR, which are stationspecific ensemble model output statistics (EMOS) model. These techniques were applied to forecast temperature over Pyeongchang area using 24-member Ensemble Prediction System for Global (EPSG). The results showed that the station-specific EMOS model performed better than the raw ensemble and EMOS model.
        22.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        This paper applied the ensemble model output statistics (EMOS) with truncated normal distribution, which are easy to implement postprocessing techniques, to calibrate probabilistic forecasts of wind speed that take the form of probability density functions. We also considered the alternative implementations of EMOS, which were EMOS exchangeable model and reduced EMOS model. These techniques were applied to the forecasts of wind speed over Pyeongchang area using 51 members of the Ensemble Prediction System for Global (EPSG). The performances were evaluated by rank histogram, mean absolute error, root mean square error and continuous ranked probability score. The results showed that EMOS models with truncated normal distribution performed better than the raw ensemble and ensemble mean. Especially, the reduced EMOS model exhibited better prediction skill than EMOS exchangeable model in most stations of study area.
        23.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        This paper used the Bayesian model averaging (BMA) with gamma distribution that takes the form of probability density functions to calibrate probabilistic forecasts of wind speed. We considered the alternative implementation of BMA, which was BMA gamma exchangeable model. This method was applied for forecasting of wind speed over Pyeongchang area using 51 members of the Ensemble Prediction System for Global (EPSG). The performances were evaluated by rank histogram, means absolute error, root mean square error, continuous ranked probability score and skill score. The results showed that BMA gamma exchangeable models performed better in forecasting wind speed, compared to the raw ensemble and ensemble mean.
        24.
        2016.03 KCI 등재 서비스 종료(열람 제한)
        This paper considers a homogeneous multiple regression (HMR) model and a non-homogeneous multiple regression model, that is, ensemble model output statistics (EMOS), which are easy to implement postprocessing techniques to calibrate probabilistic forecasts that take the form of Gaussian probability density functions for continuous weather variables. The HMR and EMOS predictive means are biascorrected weighted averages of the ensemble member forecasts and the EMOS predictive variance is a linear function of the ensemble variance. We also consider the alternative implementations of HMR and EMOS which constrains the coefficients to be non-negative and we call these techniques as HMR+ and EMOS+, respectively. These techniques are applied to the forecasts of surface temperature over Pyeongchang area using 24-member Ensemble Prediction System for Global (EPSG). The performances are evaluated by rank histogram, residual quantile-quantile plot, means absolute error, root mean square error and continuous ranked probability score (CRPS). The results showed that HMR+ and EMOS+ models perform better than the raw ensemble mean, HMR and EMOS models. In the comparison of HMR+ and EMOS+ models, HMR+ performs slightly better than EMOS+ model in terms of CRPS, however they had a very similar CRPS and if there exists a ensemble spread-skill relationship, it is seen that EMOS is slightly better calibrated than the homogeneous multiple regression model.
        25.
        2016.03 KCI 등재 서비스 종료(열람 제한)
        In this study, we analyzed the performance of calibrated probabilistic forecasts of surface temperature over Pyeongchang area in Gangwon province by using Bayeisan Model Averaging (BMA). BMA has been proposed as a statistical post-processing method and a way of correcting bias and underdispersion in ensemble forecasts. The BMA technique provides probabilistic forecast that take the form of a weighted average of Gaussian predictive probability density function centered on the bias-corrected forecast for continuous weather variables. The results of BMA to calibrate surface temperature forecast from 24-member Ensemble Prediction System for Global (EPSG) are obtained and compared with those of multiple regression. The forecast performances such as reliability and accuracy are evaluated by Rank Histogram (RH), Residual Quantile-Quantile (R-Q-Q) plot, Mean Absolute Error (MAE), Root Mean Square Error (RMSE) and the Continuous Ranked Probability Score (CRPS). The results showed that BMA improves the calibration of the equal weighted ensemble and deterministic-style BMA forecasts performs better than that of the deterministic forecast using the single best member.
        26.
        2012.04 KCI 등재 서비스 종료(열람 제한)
        본 연구는 다중시기 원격탐사 자료를 이용하여 서산시의 토지피복 변화를 탐지하고, IPCC SRES 시나리오와 고해수면 복원자료를 바탕으로 해수면 상승에 따른 토지피복별 침수 취약성을 평가하였다. 연구결과, 서산시는 1982년부터 2009년 기간에 논의 면적이 가장 많이 증가하였고, 이밖에 인공구조물, 수역, 나대지, 초지 순이다. 반면, 갯벌 및 산림지, 해양, 밭, 습지는 감소하였다. 서산시의 해수면 상승에 따른 침수면적을 산출한 결과, 인공구조물과 수역 등은 침수 피해 면적이 증가하는 반면, 산림지, 습지, 밭 등은 침수 피해 면적이 감소하였다. 해수면 상승에 따른 침수 위험성을 평가하면, 가장 피해가 먼저 발생하는 곳은 담수호와 농경지 및 연안에 인접한 산업단지 지역이다. 따라서 향후 서산시는 해수면 상승에 대한 다양한 시나리오를 바탕으로 지역 단위 및 토지피복 유형별로 중장기적인 대책을 세우는 것이 필요하다.
        27.
        2012.01 KCI 등재 서비스 종료(열람 제한)
        This study was carried out to investigate the distribution and their change of Pinus densiflora forests by climate change in Mt. Hallasan. The results showed that the areas of P. densiflora forests of Mt. Hallasan varied by region, with a total area of 1,324.3 ha, concentrated mostly in the region 1,000 m - 1,400 m above sea level. The temperate coniferous forest zone are distributed in the upper part of temperate forest zone composed of deciduous broad-leaved trees. Most of the P. densiflora forests in the lower parts were found not to be spreading because they are located close to the deciduous broad-leaved trees. However, the P. densiflora forests in the Sajebi and Pyeonggwe regions composed of the grasslands and shrub forests were found to be spreading. In addition, the altitude of the P. densiflora forests distribution increased by about 50 m and 90 m in the Sajebi and Pyeonggwe regions, respectively. The spread rate is expected to become faster than in the past due to the rate of climate change. The structure of the vegetation in Mt. Hallasan and the changes in the vegetation due to various factors need to be investigated from a long-term point of view.
        28.
        2010.12 KCI 등재 서비스 종료(열람 제한)
        본 논문에서는 6자유도를 갖는 병렬형 기구의 출력 속도 공간에서 성능을 평가할 수 있는 지표를 제안하였다. Manipulability와 condition number에 기반을 둔 성능 지표가 단위계의 볼일치로 인한 물리적 의미의 결함이 없도록 출력공간을 병진속도 공간과 회전속도 공간으로 분리하는 방법을 제안하였다. 각 공간에서 단위 입력에 대용하는 mobility ellipsoid를 정의하여 이를 기반으로 병진운동 출력공간에서 두 종류 성능 지표와 회전운동 공간에서 두 종류의 성능 지표를 제안하였다.
        29.
        2010.06 KCI 등재 서비스 종료(열람 제한)
        The chromosome number was identified and fluorescence in situ hybridization(FISH) mapping of 5S and 45S rDNAs were conducted for C. minima and C. lanceolata in the genus Codonopsis from Jeju island. In this study, we have confirmed that the somatic metaphase chromosome number determined as 2n=2x=16 was the same as the findings from the previous studies. While the conventional staining method makes it rather difficult to distinguish satellite chromosomes due to high degree of variability, FISH analysis produced the exact number and location of 5S and 45S rDNAs. Both species in the genus Codonopsis have a pair of 5S rDNA and their gene loci were observed on chromosome 3. Although two pairs of 45S rDNAs (one on chromosome 1 and the other on chromosome 8) were identified in both species, the 45S rDNA signals on chromosome 8 in C. minima were significantly weaker than those on chromosome 1. In addition, the 45S rDNA signals on chromosome 1 in C. lanceolata showed that the chromosome is non-homologus. In this study, we have determined cytogenetic characteristics of C. minima and C. lanceolata according to their gene replication patterns.
        30.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        The purpose of the present study was to analyze the vegetation structure and distributional characteristics of Abies koreana forests in Mt. Halla, and to provide basicdata for an ecological study on Abies koreana in Mt. Halla. The results of the analysis showed that the mean importance percentage(M.I.P.) of Abies koreana in the Youngsil and Bangaeoreum and the Azalea field were 28.3%, 23.6%, and 46.4%, respectively. The ratios of DBH (diameter at breast height) to height were similar in all region, except in the Azalea field, where Abies koreana of various ages, both young and old, were found. The species diversity (H) of the upper and lower layers in the Youngsil and Bangaeoreum and in the Azalea field were 0.625 and 0.810, 0.731 and 0.848, and 0.342 and 0.757, respectively. A total of 52 community were distributed at locations higher than 1,300m above sea level. The proportions of each community in the whole Abies koreana forest were 56.5%(Azalea field), 11.0% (Youngsil trail at 1,550-1,650 m above sea level), and 8.1%(Janggumok and Kundurewat region). The total area of the Abies koreana forest was calculated to be 795.3ha by combining all the areas of each community. An Abies koreana forest with the largest area was found at locations 1,500-1,600 m above sea level, taking up 38.8% of the total Abies koreana forest area. For the slopes of the distributional area of Abies koreana, 46.1%(highest proportion) of the total area was 10~25°, and for the azimuth of the distributional area, 17.4%(the highest proportion) of the total area was 0-45°. The vegetation structure showed large differences between areas. It was found, however, that the distribution was mostly in the areas with a relatively gentle slope. It is suggested that research be done to forecast the possible changes in the differences in the vegetation structures between different areas caused by climate changes. In addition, there is a need to monitor the Abies koreana and alpine plants in the subalpine zones of Mt. Halla, which are sensitive to climate change, to obtain the basic data that are necessary for the protection and maintenance of the ecosystem.
        32.
        2008.10 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to provide scientific information for establishing efficient and systematic measures for nature conservation and management in Manjang-gul lava tube. The number of vascular plants was 204 taxa (82 families, 176 genera, 144 species, 1 subspecies, 26 varieties and 1 forma). Of those, pteridophyte were 5 families, 12 genera, 14 species and 1 variety and gymnosperm were 4 families, 6 genera, 5 species and 1 variety. Seventy three families, 149 genera, 157 species, 1 subspecies, 24 varieties and 1 forma in angiosperm composed of 62 families, 123 genera, 137 species, 1 subspecies, 17 varieties and 1 forma in dicotyledon and 11 families, 26 genera, 20 species and 7 varieties in monocotyledon. The number of naturalized plants was 9 families, 17 genera, 18 species and 3 varieties, totaling 21 taxa.
        33.
        2008.08 KCI 등재 서비스 종료(열람 제한)
        4가지 다른 광도조건의 비음처리구에서 2년간 생육한 먼나무 묘목의 총 엽록소 함량은 비음처리 강도가 높아질수록 총 엽록소 함량도 큰 값을 나타냈다. 광합성 특성을 알아보기 위해 조사된 광합성 능력, 엽육내 CO2 농도, 수분이용효율 모두 무처리에서 가장 높은 광합성 효율을 나타냈으며 비음처리별 비교에서도 광도가 낮아질수록 낮은 광합성 효율을 나타냈다. 특히, 가장 낮은 광도조건인 70% 차광처리구는 높은 광도조건에서 가장 낮은 광합성 효율을 나타냈는데 이는 낮은 광도조건에 순화된 광합성 기구가 높은 광도 조건에 적응하지 못한 결과로 사료된다. 잎의 형태적 특성에서는 광도조건이 낮을수록 큰 엽면적을 나타냈으며 단위면적당 건중량은 무처리에서 가장 큰 값을 나타냈다.
        34.
        2008.06 KCI 등재 서비스 종료(열람 제한)
        New somatic chromosome numbers and karyotype analyses of 33 medicinal herbs (30 genera, 23 families) in Korea were investigated. The chromosome numbers of 4 taxa, Euryale ferox, Rodgersia podophylla, Cirsium japonicum var. ussurience, Eehinops setifer, showed results that are different from previous reports. Among 33 taxa, 23 taxa were reported for the first time, and karyotype analyses were newly conducted for 2 taxa (Tiarella polyphylla, Crepidiastrum denticulatum) in Korea. In addition, we observed for the first time the new chromosome numbers for 4 taxa distributed evenly over the world (Lindera erythrocarpa, Corylopsis glabrescens var. gotoana, Ardisia crenata, Callicarpa japonica var. luxurians).
        35.
        2007.11 KCI 등재 서비스 종료(열람 제한)
        Illicium anisatum was bred under four different light intensity. Those condition were full sunlight(PPFD 1600μmol m-2 s-1), 30% treatment(PPFD 400 μmol m-2 s-1), 50% treatment(PPFD 250 μmol m-2 s-1) and 70% treatment(PPFD 100 μmol m-2 s-1), respectively. Chlorophyll a and b were increased according to decrease of light intensity. Thirty percent and 50% treatment had not significant different in chlorophyll a and b. Thirty percent treatment was shown the best photosynthetic activity through invested photosynthetic rate, intercellular CO2 concentration and water use efficiency. Photosynthetic activity trend of 50% treatment was similar to 30% treatment. Seventy percent treatment was shown the best photosynthetic activity at low light intensity but that was decreased to lower value than 30% and 50% treatment under high intensity. Control, bred full sunlight, was shown the worst photosynthetic activity at measured all light intensity. That result could imply that was caused by photoinhibition because of long term exposed of shade tolerant plant at high light intensity. Leaf characteristics had not significant different in leaf length, width and area but leaf dry weight had similar trend to photosynthetic activity.
        36.
        2007.11 KCI 등재 서비스 종료(열람 제한)
        This study was performed to get more knowledge on the flora and their life form spectrum in the Hallasan Natural Reserve. The vascular plants include 83 species 35 genera 12 families of pteridophytes, 5 varieties 5 species 3 families of gymnosperm, 100 taxa in 2 varieties 98 species 58 genera 8 families of monocotyledon and 362 taxa in 3 forma 10 varieties 349 species 186 genera 65 families of dicotyledon in Hallasan Natural Reserve. The total of vascular plants is 550 taxa in 3 forma 11 varieties 536 species 284 genera 88 families. Among these, 204 species in total including 19 species of pteridophytes, 2 species of conifers, 45 species of monocotyledon and 138 species of dicotyledon are found only in the Hallasan Natural Reserve. The pteridophyte-quotient is 4.52 and floristic richness is 1.94. In the analysis of life form spectrum, there are 190 species (34.5%) of hemicryptophytes and 122 species (22.2%) of geophytes so that two life forms take large portions, 312 species (56.7%) of the vegetation in Hallasan Natural Reserve. Megaphanerophytes and microphanerophytes take 14.5% including 80 species followed by 83 species (15.1%) of nanophanerophytes, 42 species (7.6%) of chamaephytes, 29 species (5.3%) of therophytes, 24 species (4.4%) of hydrophytes and 18 species (3.3%) of epiphytes. According to the life form spectrum hemicryptophytes dominated high portions, which suggests Hallasan Natural Reserve has hemicryptophytic climate and similar to middle parts in the Korean Peninsular. The differences, however, were noticed by that it has more chamaephytes and less therophytes than that of the Peninsular and partially shows the characteristics of artic or subalpine climate.
        37.
        2007.10 KCI 등재 서비스 종료(열람 제한)
        여기에서는 제주도에 분포하는 임목유전자원에 대하여 앞으로의 개발과 보존전략 수립의 기초 자료로 활용하기 위하여 수행하였다. 제주도에 분포하는 목본식물은 62과 136속 279종 28변종 13품종으로 계 320 분류군이었다. 그 중 침엽수인 나자식물은 3과 5속 7종으로 전체의 2.2%였으며, 나머지인 59과 131속 272종 28변종 13품종 계 313 분류군이 활엽수였다. 활엽수 중 상록수는 31과 45속 72종 7변종 5품종으로 84 분류군으로 활엽수종의 26.8%이며, 낙엽수는 42과 93속 200종 21변종 8품종 계 229 분류군으로 73.2%였다. 이들은 교목 122 분류군(38.1%), 관목 177 분류군(55.1%), 만경 21 분류군(6.8%)으로 구성되어 있었다. 또한 휴면형, 번식형, 산포기관형 및 생육형에 의한 스펙트럼이 분석되었다. 제주도에 분포하는 목본식물 320 분류군 중 17과 21속 14종 16변종 30 분류군이 한국특산이었으며, 그 중 22 분류군은 제주특산이었다. 제주도에 분포하는 목본식물 중 식물구계학적 특정식물 종은 V 등급 10 분류군, IV 등급 24 분류군, III 등급 53 분류군이었다. 이 결과는 V 등급은 전국의 12%, IV 등급은 7.6%, III 등급은 17.2%에 해당하는 것이다.
        39.
        2006.10 KCI 등재 서비스 종료(열람 제한)
        주지역에 분포하고 있는 귀화식물의 분포 현황을 조사하고 분포특성을 분석하였다. 그 결과 제주지역의 외래식물은 47 과 161 속 248 종 6 변종으로 총 254 분류군이었다. 생육특성에 따른 구성은 일년생 초본이 107 분류군(42.13%)으로 가장 큰 비율을 차지하였으며, 생육형 구성은 직립형이 79 분류군으로서 전체의 31.1%를 차지하여 가장 높은 비율을 차지하였고, 번식형은 연결체가 없는 단위식물형이 203 분류군으로서 전체의 79.9%를 차지하였다. 생활형 분석결과 휴면형 구성은 일년생식물이 150 분류군으로 전체의 59%로서 대부분을 차지하였으며, 다음으로는 반지중식물이 53 분류군(20.9%), 지중식물이 26분류군(10.2%)의 순이었다. 원산지별 구성은 유럽이 115 분류군으로서 전체의 36.7%를 차지하여 가장 많았으며, 다음은 아시아가 69 분류군(22.0%), 북아메리카가 59 분류군(18.8%)의 순이었다. 도입배경은 사료 또는 곡물혼입이 가장 높은 비율을 차지하였다.
        40.
        2006.08 KCI 등재 서비스 종료(열람 제한)
        본 연구는 한라산의 대표적인 극지성 고산식물인 시로미의 현지내외 보존을 위한 기초 연구로서 증식체계를 마련하고 저지대에서 생장특성을 밝히고자 삽목조건 및 초기생육 특성 등을 알아보았다. 숙지삽시 식물호르몬의 처리나 상토의 조건에 따라 발근이나 생장 등이 다소 차이를 보였다. NAA 100 mg/l 또는 500 mg/l를 처리한 경우 생존율, 발근율 및 뿌리의 생장 등이 가장 양호할 뿐만 아니라 뿌리의 수도 많고 신초생장도 비교적 양호하여 시로미의 삽목증식을 위한 적정한 처리인 것으로 나타났다. 시로미 삽목묘를 노지에 옮겨서 키웠을 때에는 2개월 후부터 고사가 이루어지기 시작하여 7개월 후에는 26.7%가 고사한 것으로 나타났다. 이에 반해 차광처리를 하면 고사율이 낮아 91.1~94.4%가 생존하는 것으로 나타나 차광처리가 시로미의 생존율을 높이는데 효과적인 것으로 나타났다. 그리고 온실에서는 차광처리에 관계없이 생존율이 전체적으로 95.6~97.8%로 높게 나타났다. 그리고 생육장소 및 차광처리별 시로미의 평균 생장량은 노지와 온실에서 많은 차이를 보였다. 특히, 차광처리를 했을 때 상대적으로 높은 생장량을 보였는데 이는 차광처리가 상대습도를 높이고 광량을 낮추는 효과에 기인한 것으로 판단된다.
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