http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
인버터 기반 신재생 에너지 발전 시스템의 계통 지원 운전을 위한 계통 전압 검출 방법
안현철(Ahn, Hyun-Chul),송승호(Song, Seung-Ho) 한국신재생에너지학회 2013 신재생에너지 Vol.9 No.2
The Grid code is being strengthen as increase of renewable energy ratio. Especially, the grid connection regulations are continuously being updated for stable operation of power grids. Static grid support and Dynamic grid support must make an accurate measure at Grid connected point because they needs control algorithm individually. It has to exactly measure voltage including switching ripple at the output of the inverter generating system. In addition, it is necessary to have an accurate voltage measurement when the situation rapidly changing the grid impedance is caused by the input of serial impedance of transformer and line impedance as well as Grid Fault Device. In this paper, We propose a new detection method of grid voltage to calculate accurately the r.m.s voltage of the grid connection point along the standard required by the low voltage regulation. We verified performance through simulation grid fault device.
안현철(Hyun chul Ahn),이형용(Hyoung Yong Lee) 한국IT서비스학회 2015 한국IT서비스학회지 Vol.14 No.1
Currently, Social Commerces have increasingly gained popularity with the growth of Social Network Services (SNS). As the applications of smartphones are being applied in widespread areas, social commerces in the smartphone environment have entered a new chapter. The applications of social commerces on smartphones are widely used, which has increased the market share of social commerces exponentially. Thus, we tried to find out factors which may affect the user acceptance of social commerces in the smartphone environment. We develop a research model to examine how social commerces in the smartphone environment are accepted by users based on the academic factors-switch costs, trend-seeking tendency, richness in media. The theoretical model is validated through an survey of social commerce users in the smartphone environment from the undergraduates and the graduates in Seoul, Korea. The structural equation analysis is conducted based on the partial least square (PLS) approach. The results reveal that the switch cost will have positive mediating influences to the intention to use social commerce in the smartphone environment. We also find that the perceived usefulness of the smartphone is affected by the media richness. The results also suggest that the trend-seeking tendency has no influences to the users of social commerces in the smartphone environment. Also, theoretical and practical implications are discussed. The findings are believed to increase our understanding an interesting mobile phenomenon, as well as making contributions.
백두대간의 구룡령에서 약수산 마루금의 식생구조특성에관한 연구1a
안현철 ( Hyun Chul An ),추갑철 ( Gab Chul Choo ),박삼봉 ( Sam Bong Park ),조현서 ( Hyun Seo Cho ),안종빈 ( Jong Bin An ),박정근 ( Jeong Geun Park ),하현우 ( Hyoun Woo Ha ),김진중 ( Jin Joong Kim ),김봉규 ( Bong Gyu Kim ) 한국환경생태학회 2014 한국환경생태학회지 Vol.28 No.6
백두대간 구룡령-약수산 마루금에 22개의 방형구(100㎡)를 설정하여 식생을 조사하였다. 식생군집을 분석한 결과 신갈나무-까치박달나무-당단풍나무군집, 신갈나무군집, 층층나무-신갈나무군집 등 3개의 군집으로 분류되었다. 백두대간 구룡령-약수산 마루금은 대부분 신갈나무가 우점하고 있었으며, 일부지역에서 까치박달나무와 층층나무 등이 혼효하고 있었다. 수종간의 상관관계에서 신갈나무와 노린재나무, 철쭉; 피나무와 찰피나무, 노린재나무; 찰피나무와 노린재나무, 철쭉; 거제수나무와 고로쇠나무; 노린재나무와 철쭉 등의 수종 간에는 높은 정의 상관이 인정되었다. 당단풍나무와 노린재나무, 철쭉 등의 수종 간에는 높은 부의 상관이 인정되었다. 조사지의 군집별 종다양성 지수는 0.8170~1.1446범위로 백두대간에 위치한 국립공원들의 능선부 식생구조 보다는 약간 낮게 나타났다. To investigate the vegetation structure of mountain ridge from Guryongryeong to Mt. Yaksu, 22 plots (100 ㎡) installed with random sampling method were surveyed. Three groups of Quercus mongolica-Acer pseudosieboldianum community, Q. mongolica community, Cornus controversa-Q. mongolica community were classified by cluster analysis. Q. mongolica was a major woody plant species in the ridge area from Guryongryeong to Yaksusan and Carpinus cordata and C. controversa was partly occupied in some area. High positive correlations showed between Q. mongolica and Symplocos chinensis for. pilosa, Rhododendron schlippenbachii; Tilia amurensis and Tilia mandshurica, Symplocos chinensis for. pilosa; Tilia mandshurica and S. chinensis for. pilosa, R. schlippenbachii; Betula costata and Acer mono; Symplocos chinensis for. pilosa and Rhododendron schlippenbachii, and relatively high negative correlations showed between A. pseudosieboldianum and S. chinensis for. pilosa, R. schlippenbachii. Species diversity(H`) of investigated groups were ranged 0.8170~1.1446 and it was lower compared to those of the ridge area of the national parks in Baekdudaegan.
지리산(智異山) 물박달나무림(林)의 식생구조(植生構造)와 동태(動態)
안현철,이정환,Ahn, Hyun-Chul,Lee, Jeong-Hwan 한국산림과학회 1998 한국산림과학회지 Vol.87 No.3
본 연구는 지리산 국립공원 오봉리 지역에서 집단적으로 분포하는 물박달나무림의 식생구조와 동태를 분석하여 물박달나무림의 경영과 분포지에 대한 정보를 제공하기 위하여 수행되었다. 그 결과 물박달나무림의 구조는 교목층(18종류), 아교목층(29종류), 관목층(43수종) 그리고 초본층(68종류)으로 구성되어 있다. 층위별 중요치는 교목층에서 물박달나무가 129.97%로 가장 높고 다음으로 물오리나무(49.04%), 밤나무(25.58%), 졸참나무(25.02%), 노각나무(14.49%), 아교목층에서 물박달나무(70.81%), 졸참나무(37.47%), 물푸레나무(25.35%), 비목나무(24.52%) 및 노각나무(18.86%)가 높은 우점을 보였고, 관목층에서는 조릿대(28.28%), 비목(24.94%), 개윷나무(20.42%), 국수나무(19.90%), 그리고 초본층에서는 오미자(18.51%), 참취(12.26%), 애기나리(10.63%)로 우점하고 있었다. 30개 조사방형구에서 전층을 대상으로 출현 비출현에 의한 17수종에 대한 $x^2$ 검정결과 굴참나무-상수리나무, 노각나무-검노린재나무, 당단풍-신갈나무간에는 고도의 유의성이 인정되었다. 또 밀도에 의한 Pearson 상관에서는 $x^2$ 검정에서 보다, 많은 7개 쌍의 유의성이 인정되었고, Spearman 상관에서는 모두 18개의 상관이 있는 쌍이 인정되었다. 물박달나무림에 대한 직경급의 분포는 물박달나무림의 지속이 계속될 것으로 예상되지만 치수 발생량이 거의 없어 앞으로 졸참나무, 노각나무 등 교목층과 아교목층을 형성하고 있는 활엽수종과 경쟁에 의하여 천이가 있을 것으로 사료된다. The present study focused on the vegetation structure and dynamics of Betula davurica forest were to provide the information for management, distribution and utilization of B. davurica forest in Mt. Chiri national park, southern Korea. The layer structure of B. davurica forest were consist of tree layer(18 species), middle layer(29 species), shrub layer(43 species) and herb layer(68 species). According to the importance value of stratification of layers, In tree layer, B. davurica dominant the highest value of 123.97%, Alnus hirsuta 49.04., Castanea crenata 25.58%, Quercus serrata 25.02%, Stewartia koreana 14.49%, in middle layer were B. davurica 70.81%, Q. serrata 37.74%, Fraxinus rhynchophylla 25.35% Lindera erythrocarpa 24.52%, S. koreana 18.86%, shrub layer were Sasa borealis 28.28%, L. erythrocarpa 24.94%, Rhus trichocarpa, 20.42%, Stephanandra incisa 19.90% and herb layer Schizandra chinensis 18.51%, Aster scaber 12.26%. Disporum smilacinum 10.63% etc, respectively. Results of chi-square test statistics based on presence-absence parameters, the positively associated species pair were Quercus variablis - Q. acutissima, Stewartia koreana - Symplocos paniculata, Acer pseudo-sieboldianum - Quercus mongolica. And covariation was calculated based on quantitative measure of density. The results showed that the association and covariation values among species not agreed with each other. The frequency distribution of DBH Betula davurica species showed reverse J-shaped, therefore it's seems to retrain as a dominant species. When predicting succession in Betula davurica forest, it is seedling and saplings were not richness, succession was governed by competition of hardwood species of subtree and tree layer.
안현철,이정환 ( Hyun Chul Ahn,Jeong Hwan Lee ) 한국산림과학회 1998 한국산림과학회지 Vol.87 No.3
The present study focused on the vegetation structure and dynamics of Betula davurica forest were to provide the information for management, distribution and utilization of B. davurica forest in Mt. Chiri national park, southern Korea. The layer structure of B. davurica forest were consist of tree layer(18 species), middle layer(29 species), shrub layer(43 species) and herb layer(68 species). According to the importance value of stratification of layers, In tree layer, B. davurica dominant the highest value of 123.97%, Alnus hirsuta 49.04., Castanea crenata 25.58%, Quercus serrata 25.02%, Stewartia koreana 14.49%, in middle layer were B. davurica 70.81%, Q. serrata 37.74%, Fraxinus rhynchophylla 25.35% Lindera erythrocarpa 24.52% , S. koreana 18.86%, shrub layer were Sasa borealis 28.28%, L. erythrocarpa 24.94% . Rhus trichocarpa, 20.42%, Stephanandra incisa 19.90% and herb layer Schazandra chinensis 18.51%, Aster scaber 12.26%. Disporum smilacinum 10.63% etc, respectively. Results of chi-square test statistics based on presence-absence parameters, the positively associated species pair were Quercus variablis - Q. acutissima, Stewartia koreana - Symplocos paniculata, Acer pseudo-sieboldianum - Quercus mongolica. And covariation was calculated baste on quantitative measure of density. The results showed that the association and covariation values among species not agreed with each other. The frequency distribution of DBH Betula davurica species showed reverse J-shaped, therefore it`s seems to retrain as a dominant species. When predicting succession in Betula davurica forest, it is seedling and saplings were not richness, succession was governed by competition of hardwood species of subtree and tree layer.