• Title/Summary/Keyword: 13세기 2

Search Result 277, Processing Time 0.028 seconds

한국의 기후학 반세기:회고와 전망

  • 이현영
    • Journal of the Korean Geographical Society
    • /
    • v.31 no.2
    • /
    • pp.128-137
    • /
    • 1996
  • 한국의 기후학 연구성과는 1958년 발표된 이후 약간의 기복은 있었으나 꾸준히 발 전하여 왔다. 연구성과를 하부 분야별로 보면 기후학 일반(43.5%)이 가장 많았고, 종관기후 학(34.7%), 기후변화(13.0%) 그리고 응용기후학(8.8%)으로 구성되어 있으나 근래에는 응용 기후학 분야에 대한 연구가 서서히 증가하고 있다. 1970년대 이전에는 주로 지상 기후요소 간의 기상자료를 사용하여 상관관계 출현빈도.시계열분석 등으로 전국 규모의 기후특성을 규명한 데 반하여 최근에는 시계열분석과 더불어 군집.주성분.인자분석 등 다변량 분석기 법 등의 통계기법이 많이 활용되고 있다. 초기에는 지상기상자료를 주로 연구에 사용하였는 데 점차 고층기상자료와 인공위성자료를 활용하면서 국지기후 연구와 더불어 기후예측 모델 의 구축단계까지 발달하였다. 그러나 한국기후학이 당면한 문제는 인적자원의 절대적인 빈 곤과 더불어 인접분야에 비하여 연구환경이 열악한 것이다. 즉, 대학에서는 비전공자에 의한 기후학 교육이 빈번하고, 국지기후 연구의 경우는 실측을 요하기도 하는데 자료의 생성 및 분석에 필요한 장비가 절대적으로 부족하다. 따라서 한국의 기후학의 발전을 도모하려면 기 후학자의 배출이 급선무이고, 기후학자는 물론, 대학 및 연구소간의 연구 및 자료 교류 등의 상호협조가 요청된다.

  • PDF

Study of the Flood Vulnerability Assessment on 5 River Basins in Korea under Climate Change (국내 5대강 유역의 기후변화에 의한 홍수 취약성 평가에 관한 연구)

  • Lee, Moon-Hwan;Lee, Byung-Ju;Jeong, Il-Won;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2010.05a
    • /
    • pp.47-51
    • /
    • 2010
  • 본 연구의 목적은 기후변화에 따른 홍수 취약성 평가 방법을 제안하고 미래 기후시나리오를 이용하여 국내 5대강 유역에 대해 홍수취약지역을 시 공간적으로 평가하는 데에 있다. 이에 현 기후상태의 홍수 취약성을 평가하고자 유역의 지형, 인문 사회 정보를 수집하였으며, 관측 기상, 수문자료와 수문모형 모의로부터 유역평균강수량 및 유역별 유출량을 산정하였다. 이상의 자료를 토대로 홍수와 관련된 취약성 지표를 선정 및 산정하여 현재 기후상태(1971~2000년)에서의 홍수취약성을 평가하였다. 또한 기후변화 영향을 고려하기 위해 3개의 온실가스배출시나리오를 기반으로 생산된 13GCMs 별 미래 기후시나리오 자료를 수집하였으며, 3개의 유출모형에 적용, 다수의 유출시나리오를 생산하여 현재 기후상태(1971~2000년) 대비 미래 세기간 S1(2011~2040년), S2(2041~2070년), S3(2071~2100년)의 홍수 취약성을 평가하였다. 현재 기후상태에 따른 홍수취약지역을 평가한 결과 대체로 한강 중 하류지역과 영 섬강 하류 지역에서 높게 나타났으며, 낙동강 중 상류유역은 상대적으로 낮은 것으로 나타났다. 또한 기후변화시나리오를 적용할 경우 취약지역의 공간적인 분포는 기준기간과 유사했으나, 대부분의 유역에서 심도는 증가할 것으로 나타났다. 특히 낙동강 권역에서 가장 크게 변할 것으로 분석되었는데 이는 하천의 적응능력이 작아 상대적으로 기상 수문지표의 변화에 더욱 민감하게 반응하는 것으로 판단된다.

  • PDF

Smart Paradox: An Effect of Mobile Instant Messengers (스마트 패러독스: 모바일 인스턴트 메신저의 영향에 관한 연구)

  • Yim, Myung-Seong
    • Journal of the Korea Convergence Society
    • /
    • v.3 no.4
    • /
    • pp.7-13
    • /
    • 2012
  • The mobile instant messengers could change the lives of average citizens as much as did the telephone in the early part of the 20th century and television in the 1950s and 1960s. Researchers are debating whether the mobile instant messengers are improving or harming participation in community life and social relationships. For this study, 155 participants in two universities completed questionnaires pertaining to their own mobile instant messengers use and feelings of loneliness. We used survey data to examine the effects of the mobile instant messengers on social involvement and psychological well-being. In this sample, the mobile instant messengers were used extensively for communication. Results suggest that greater use of the mobile instant messengers were associated with declines in participants' communication with the people around which in turn increases their loneliness. These findings have implications for research and for the design of technology.

Etiology and Clinical Features of Viral Lower-respiratory Tract Infections in Children in Winter, 2003 (2003년 겨울철 소아의 바이러스성 하기도 감염증에 대한 원인 및 바이러스별 임상양상)

  • Yun, Byung Ho;Lee, Hee Chul;Chun, Jung Mi;Yoon, So Young;Lee, Woo Gill;Shin, Son Moon
    • Clinical and Experimental Pediatrics
    • /
    • v.48 no.7
    • /
    • pp.723-730
    • /
    • 2005
  • Purpose : This study was performed to characterize the etiology and clinical features of acute viral lower-respiratory tract infections(LRI). Methods : Etiologic agents and clinical features of acute viral LRI were studied from October. 2003 through March. 2004 in hospitalized children with LRI(253 cases) at Samsung Cheil Hospital. The viruses were identified by indirect immunofluorescent method. Medical records of patients with proven viral LRI were reviewed retrospectively. Results : Ninety two cases(36.4%) were confirmed as viral infections. The identified pathogens were respiratory syncytial virus(RSV, 76.0%), adenovirus(ADV, 12.0%), influenza virus type A(INFA, 9.8 %), influenza virus type B(INFB, 1.1%) and parainfluenza virus(PIV, 1.1%). Eight four point eight% of patients were younger than 2 years of age. Clinical diagnosis of LRI were pneumonia(56.5%), bronchiolitis(35.9%), tracheobronchitis(4.3%) and croup(3.3%). The clinical symptoms and signs were cough(98.8%), rhinorrhea(82.6%), fever(70.7%), rale(67.4%), wheezing(29.3%), chest retraction(28.3%) and cyanosis(4.3%). The severe respiratory symptoms and signs were more common in RSV-infected patients, even cyanosis could be observed. Seventeen point four percent of patient had fever of $38.5^{\circ}C$ or higher and their most common etiologic agent was INFA(66.7%). Twenty three point nine percent had fever more than 5 days and common etiologic agent was INFA(77.8%). The elevated WBC count($>14{\times}10^3/{\mu}L$) was in 14.1%, and common etiologic agents were INFA(22.2%) and ADV(18.2%). C-reactive protein(CRP >4.0 mg/dL) was increased in 13.0%, and common in ADV(63.6 %). Increased aspartate aminotransferase(AST)/alanine aminotransferase(ALT) was detected in 10.9%, and the most common etiologic agent was RSV(12.9%). Conclusion : The common agents of acute viral LRI were RSV, ADV and INF, respectively. Because the etiologic agents present variable clinical features, it may be helpful to treat and to evaluate acute viral LRI that we should understand their etiologic variability.

A Study on the Publication and Composition of JujaDaejeon Anthologies in the Joseon dynasty (조선시대 『주자대전』 선집서의 간행과 구성에 관한 연구)

  • Choi, Kyunghun
    • Journal of the Korean Society for Library and Information Science
    • /
    • v.54 no.2
    • /
    • pp.435-455
    • /
    • 2020
  • The purpose of this study is to examine the publication, composition, method of composition, and acceptance patterns of JujaDaejeon anthologies edited by Joseon scholars in the Joseon dynasty. When a large amount of JujaDaejeon was published in the 16th century, anthologies of JujajaDaejeon was compiled, published and learned as a way to understand it. A total of 13 kinds of JujajaDaejeon anthologies were published, including six kinds in the early Joseon period and seven kinds in the late Joseon period. And the composition of main anthologies showed a trend that was supplemented by Jeong Gyeong-se's Jumunjakhae from Lee Hwang's Jujaseojeolyo, and aggregated into Song Si-yeol's Jeoljaktongpyeon(boyu). JujaDaejeon consists of total 3,645 works except for poems. Among them, 1,734 works were selected by 13 anthologies. The theme of a work with a high cumulative number of selections is the virtue and attitude of the king, policy proposals, the appointment of talent, the duty of subjects, criteria for evaluating historical figures, opposition to harmony with Jin and territorial restoration, and academic discussions. This study is expected to be meaningful in the field of the research on the acceptance of the foreign books and acceptance of the Zhu Xi's works in the Joseon dynasty.

Ghost Vaccine Prepared from Strong Virulent Salmonella typhimurium Does not Improve Immune Responses of BALB/c Mice (독력이 강한 S. typhimurium으로부터 유도된 고스트 백신으로 면역응답 개선에 관한 연구)

  • Ha, Yeon Jo;Kim, Tae Wan;Kim, Seung Tae;Gal, Sang Wan;Kim, Sam Woong
    • Journal of Life Science
    • /
    • v.24 no.1
    • /
    • pp.39-45
    • /
    • 2014
  • Salmonella typhimurium MMP13 and S. typhimurium ${\chi}8554$ were derived from weak JOL401 and strong ${\chi}3339$ virulent strains. Heat-labile subunit B (LT-B) was used as an adjuvant to increase the effectiveness of the vaccine. Plasmid pMMP184 carrying a ghost cassette was transformed into MMP13 and ${\chi}8554$ to produce the ghost, and the prepared ghost cells were administered into the muscles of BALB/c mice. In the absence of the adjuvant, the total IgG content showed a tendency to increase contrary to the original virulent strength. In contrast, in the presence of the adjuvant, the strain that originated from the strong virulent showed a tendency to promote the immune more than that of weak virulent strain. However, the final concentration of total IgG was similar between the compared groups, indicating that the originated virulent strength does not affect a specific immune. Other elements of the immunoglobulins IgG1, IgG2a, and sIgAs did not show a specific trend. The results of Salmonella challenge showed a similar tendency to regardless of the originated virulence. Taken together, the results suggest that the Salmonella ghost cells promoted the immune system of BALB/c mice, irrespective of the virulence applied to create the ghost cells.

Study on electron beam treatment on $Cu_2Se$ thin films by DC sputtering method (DC sputter방식으로 제조된 $Cu_2Se$ 박막의 전자빔 처리에 따른 특성 연구)

  • Kwon, Hyuk;Kim, ChaeWoong;Jung, SeungChul;Kim, DongJin;Park, InSun;Jeong, ChaeHwan
    • 한국신재생에너지학회:학술대회논문집
    • /
    • 2011.11a
    • /
    • pp.53.1-53.1
    • /
    • 2011
  • 현재 태양전지시장에서 비중이 많은 실리콘 태양전지는 높은 효율에 비해 제조 단가가 비싸다는 단점을 가지고 있다. 이에 비해 칼코파라이트 구조의 $CuInSe_2$ (CIS)계 화합물은 직접 천이형 반도체로서 높은 광흡수 계수($1{\times}105cm-{\acute{e}1$)와 밴드갭 조절의 용이성 및 열적 안정성 등으로 인해 고효율 박막 태양전지용 광흡수층 재료로 많은 관심을 끌고 있다. CIS 계 물질에 속하는 Cu(InGa)$Se_2$ (CIGS) 태양전지의 경우 양산화에 sputtering방식사용하고 Showa Shell에서는 대면적 CIGS 모듈 효율 13.4%를 달성한 바 있다. 현재 CIGS는 열처리하는 방법으로 selenization 공정을 사용하는데 이 공정은 유독한 $H_2Se$ gas를 이용해야 한다는 점과 긴 시간 동안 열처리를 해야 하는 단점을 가지고 있다. 따라서 이러한 단점을 보완하기 위해 본 연구에서는 전자빔을 사용하여 후속 공정을 실시하였다. 전자빔을 사용할 경우 낮은 온도에서 precursor를 처리하며 짧은 시간에 공정이 끝난다는 장점이 있다. 본 연구에서는 sodalime glass위에 조성비(Cu 60.87% Se 38.66%)인 Cu_2Se$ target(4.002"${\times}0.123$") 을 DC sputter를 이용하여 DC power를 50W,100W를 주고 Working pressure를 20,15,10,5,3,1mtorr로 조절하여 증착하였다. 전자빔의 세기 조건을 3Kv, Rf power 200W, Ar 7sccm로 전자빔 조사 시간을 1,2,3,4,5min으로 늘려가며 최적화 실험 하였고 최적화된 조건으로 $Cu_2Se$ target에 조사 하였다. 박막의 특성평가는 전자빔 조사 전/후에 대해 XRD, SEM, XRF, Hall measurement, UV-VIS을 이용하여 분석평가를 하였다. 이 실험은 $Cu_2Se$상이 자라는 특성과 표면 상태에 따라 CIGS박막을 증착하였을 때 나타나는 효율 변화를 알아 보기위한 초기 공정 실험이다.

  • PDF

History of ICM (ICM의 초기역사 -태동기부터 제5차 ICM까지를 중심으로-)

  • Khang, Mee-Kyung;Kim, Sung-Sook
    • Journal for History of Mathematics
    • /
    • v.25 no.2
    • /
    • pp.23-34
    • /
    • 2012
  • The International Congress of Mathematicians (ICM) will next be held in Seoul, Korea from August 13th to 21st 2014. The ICM, currently hosted by the International Mathematical Union, has a history spanning a period of one hundred years and is traditionally held every four years. Felix Klein has often been credited with formulating the concept of the ICM, however George Cantor not only initially propagated the idea of forming a mathematical society in Germany, but also proposed organizing an international mathematical union. This study has endeavored to investigate the early period of development of the ICM. Specifically, this paper has studied the development of early 20th century mathematics through changes in the formulaic language of the ICM, the number of participants, the number of presentations, the nationality of plenary speakers, and the changes in sessions.

Automatic Change Detection of MODIS NDVI using Artificial Neural Networks (신경망을 이용한 MODIS NDVI의 자동화 변화탐지 기법)

  • Jung, Myung-Hee
    • Journal of the Institute of Electronics Engineers of Korea CI
    • /
    • v.49 no.2
    • /
    • pp.83-89
    • /
    • 2012
  • Natural Vegetation cover, which is very important earth resource, has been significantly altered by humans in some manner. Since this has currently resulted in a significant effect on global climate, various studies on vegetation environment including forest have been performed and the results are utilized in policy decision making. Remotely sensed data can detect, identify and map vegetation cover change based on the analysis of spectral characteristics and thus are vigorously utilized for monitoring vegetation resources. Among various vegetation indices extracted from spectral reponses of remotely sensed data, NDVI is the most popular index which provides a measure of how much photosynthetically active vegetation is present in the scene. In this study, for change detection in vegetation cover, a Multi-layer Perceptron Network (MLPN) as a nonparametric approach has been designed and applied to MODIS/Aqua vegetation indices 16-day L3 global 250m SIN Grid(v005) (MYD13Q1) data. The feature vector for change detection is constructed with the direct NDVI diffenrence at a pixel as well as the differences in some subset of NDVI series data. The research covered 5 years (2006-20110) over Korean peninsular.

Energy Transfer and Cross-Relaxation in $Tb^{3+}$-doped Borosilicate Glasses ($Tb^{3+}$를 첨가한 Borosilicate 유리속에서 일어나는 에너지 전달과 Cross-Relaxation)

  • 김중환;문병기;오학태;김학수;윤수인;서효진;설정식
    • Korean Journal of Optics and Photonics
    • /
    • v.1 no.2
    • /
    • pp.149-154
    • /
    • 1990
  • Energy transfer in $Tb^{3+}$-doped borosilicate glasses has been studied by the analysis of fluorescence intensities and lifetimes of $^5D_3$ and $^5D_4$ states as a function of Tb3+ concentration. It is shown that as the $Tb^{3+}$ concentration is increased the cross-relaxation produces high population of the $^5D_4$ state at the expense of $^5D_3$. It is also found that this interaction is predominantly dipole-dipole transition with critical distance of 13 A. The critical distance for energy transfer $^5D_4$$^5D_4$ which is responsible for the quenching of 5D4 emission at high concentratron of Tb3+ ions is 4.5 A.

  • PDF