• 제목/요약/키워드: The Frequency of Occurrence

검색결과 1,407건 처리시간 0.031초

Invasion of Ambrosia artemisiifolia L. (Compositae) in the Ukrainian Carpathians Mts. and the Transcarpathian Plain (Central Europe)

  • Song, Jong-Suk;Prots, Bohdan
    • Animal cells and systems
    • /
    • 제2권2호
    • /
    • pp.209-216
    • /
    • 1998
  • The invasion of Ambrosia artemisiifolia in the Ukrainian Carpathians Mts. and the Transcarpathian Plain in Central Europe was reconstructed on the basis of floristic records. The first spontaneous occurrence was dated from the beginning of the 1940s. Within the next 55 year period, the distributional spread speed of the species was of 67.6 $km^2/y$ (by the average data). The occupied area by A. artemisiifolia in the range of the studied areas is about $3716.5km^2$ now. The features of behavior of the invader and the habitat preference were determined. The frequency of occurrence by sociologic-ecological classification was carried out. The generalized model of correlations among the gravitation, the active temperature sum and the disturbance gradients and the frequency of occurrence of the species was presented. The scheme of the invasion stages of A. artemisiifolia is reflected in the population status changes of the species during the areal dynamics.

  • PDF

대기 대순환 모헝과 해수면 온도 관측 자료를 이용한 태풍 활동의 계절 예측 가능성 (Seasonal Predictability of Typhoon Activity Using an Atmospheric General Circulation Model and Observed Sea Surface Temperature Data)

  • 한지영;백종진
    • 한국지구과학회지
    • /
    • 제27권6호
    • /
    • pp.653-658
    • /
    • 2006
  • 대기 대순환 모형인 GCPS를 이용하여 북서태평양에서의 태풍 활동의 계절 예측 가능성을 조사하였다. 1979년부터 2003년까지 각 해에 대해 해수면 온도 관측 자료를 사용하여 5개월간 초기 조건을 달리한 10개의 앙상블 멤버를 적분하였다. 모형은 발생 빈도의 평균적인 월변화 경향과 발생 분포를 관측과 유사하게 모의하였으나, 발생 빈도의 경년 변화는 신빙성 있게 예측하지 못하였다. 이는 관측과 모형간 태풍 발생 빈도와 ENSO의 상관성 차이에 인한 것으로 실제 태풍 발생 빈도와 ENSO가 뚜렷한 상관 관계를 갖지 않는 것과 달리, 모형에서는 엘니뇨 시기에 평년에 비해 많은 태풍이 발생하고 라니냐 시기에 평년에 비해 적은 태풍이 발생하는 경향을 보였기 때문이다. 반면에, 관측과 모형 모두 ENSO와의 상관 관계가 높게 나타난 태풍 발생 경도의 경우에는 모형이 발생 경도의 경년 변화를 관측과 유사하게 모의하였다.

Power-law exponents of runoff-drainage area relationships vary with flow occurrence frequency: Observations from Korean rivers

  • Kim, JongChun;Paik, Kyungrock
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2015년도 학술발표회
    • /
    • pp.246-246
    • /
    • 2015
  • Runoff at any given location along a stream can be expressed as a function of its upstream area. The runoff-drainage area relationship can be well expressed as power-law (Brush, 1961) with its exponent, ranging as high as unity (e.g., Stall and Fok, 1968) and as low as 0.5 in natural rivers. Here, we study the runoff-drainage area relationships for Han River and Nakdong River, Korea. We find that the relationships follow power-law and their exponents are highly related with occurrence frequency of flow. To support this, we analyze flow frequency with historical data measured over decades. Findings in this study can broaden our understanding on mechanisms behind the catchment response to runoff.

  • PDF

신경인성과 발달성 말더듬의 비유창성 발생 자리에 대한 연구 (A Comparative Study on the Occurrence Loci of Disfluency between Neurogenic and Developmental Stuttering)

  • 신명선;권도하;윤치연
    • 음성과학
    • /
    • 제13권3호
    • /
    • pp.185-195
    • /
    • 2006
  • This study aims to clarify disfluency loci in a neurogenic stuttering group and to examine how the characteristics are different from a developmental stuttering group. For the study, spoken language samples were collected from 11 adults with developmental stuttering and 11 adults with neurogenic stuttering in the course of speaking tasks including reading, monologue and conversation. Using the collected samples, disfluency characteristics of the two groups were to be investigated by analyzing adaptation effect, consistency effect and frequency of disfluency occurrence according to word position, which are related to the occurrence loci of disfluency. Results of this study were as follows: First, while the neurogenic stuttering group did not show any adaptation effect, the developmental stuttering group showed the adaptation effect that the percent of disfluency word reducing as they read the same materials repeatedly. Second, there was no meaningful difference of consistency effect between the two stuttering groups. Third, the neurogenic stuttering group showed more disfluency frequency in final sounds among the word position compared to the developmental stuttering group.

  • PDF

한국어 다음절 단어의 초성, 중성, 종성단위의 음절간 조건부 확률 (Conditional Probability of a 'Choseong', a 'Jungseong', and a 'Jongseong' Between Syllables in Multi-Syllable Korean Words)

  • 이재홍;이재학
    • 전자공학회논문지B
    • /
    • 제28B권9호
    • /
    • pp.692-703
    • /
    • 1991
  • A Korean word is composed of syllables. A Korean syllable is regarded as a random variable according to its probabilistic property in occurrence. A Korean syllable is divided into 'choseong', 'jungseong', and 'jongseong' which are regarded as random variables. We can consider teh conditional probatility of syllable as an index which represents the occurrence correlation between syllables in Korean words. Since the number of syllables is enormous, we use the conditional probability of a' choseong', a 'jungseong', and a 'jongseong' between syllables as an index which represents the occurrence correlation between syllables in Korean words. The length distribution of Korean woeds is computed according to frequency and to kind. Form the cumulative frequency of a Korean syllable computed from multi-syllable Korean woeds, all probabilities and conditiona probabilities are computed for the three random variables. The conditional probabilities of 'choseong'- 'choseong', 'jungseong'- 'jungseong', 'jongseong'-'jongseong', 'jongseong'-'choseong' between adjacent syllables in multi-syllable Korean woeds are computed.

  • PDF

공공데이터를 이용한 습도 및 온도와 실화 발생 간의 관계분석 (An Relational Analysis between Humidity, Temperature and Fire Occurrence using Public Data)

  • 송동우;김기성;이수경
    • 한국화재소방학회논문지
    • /
    • 제28권2호
    • /
    • pp.82-90
    • /
    • 2014
  • 최근 공공정보의 개방과 공유를 위한 정부 3.0 운영 패러다임에 따라 기상청과 소방방재청의 데이터를 활용하여 습도 및 온도와 화재 발생과의 관계를 분석하였다. 습도 및 온도와 화재 발생의 관계를 분석하기 위하여 습도 및 온도범위대비 시간당 화재 발생 빈도의 개념을 분석방법으로 제안하였다. 이를 통해 습도 및 온도에 따른 화재 발생 빈도의 경향을 파악해 보았으며, 세부속성에 대한 특성을 통계적으로 확인할 수 있었다. 지역별로 습도범위를 나누어 시간당 화재발생 빈도를 구한 결과, 모든 지역에서 습도가 낮을수록 빈도가 높아지는 비슷한 경향을 보였다. 온도범위에 따른 시간당 화재 발생 빈도도 지역별로 유사한 경향을 확인하였다. 또한, 화재유형, 발화열원, 최초 착화물, 발화요인 등 대상속성별 특성을 분석하였고, 특징적인 경향을 제시하였다. 본 논문에서 제안된 방법은, 국가화재정보시스템의 화재통계현황에서 범주별로 빈도 제시할 때 실용적으로 활용할 수 있을 것이다.

부산지역 기단성 뇌우 발생일의 대기안정도지수 특성 (Characteristics of Atmospheric Stability Index of Airmass thunderstorm day at Busan)

  • 전병일
    • 한국습지학회지
    • /
    • 제5권1호
    • /
    • pp.29-40
    • /
    • 2003
  • This study was performed to research the relation between airmass thunderstorm and stability index with 12 years meteorological data(1990~2001) at Busan. Also We used the analysed stability indices from University of Wyoming to consider airmass thunderstorm. The frequency of thunderstorm occurrence during 12 years was 156 days(annual mean 13days). The airmass thunderstorm frequency was 14 days, most of those occurrence were summertime(59%). And occurrence hour of airmass thunderstorm was distributed from 1300LST to 2100LST broadly. The highest forecast index for airmass thunderstorm at Busan was K index, the lowest forecast index was SWEAT index. The forecasting of thunderstorms is based primary on the concepts of conditional instability, convective instability, and forced lifting of air near the surface. Instability is a critical factor in severe weather development. Severe weather stability indices can be a useful tool when applied correctly to a given convective weather situation.

  • PDF

Design-Build Change Order Impacts in Highway Projects

  • Ryu, Kyeong Rok;Choi, Kunhee;Ryoo, Boong Yeol;Kang, Julian H.
    • 국제학술발표논문집
    • /
    • The 6th International Conference on Construction Engineering and Project Management
    • /
    • pp.371-375
    • /
    • 2015
  • Design-Build (DB) has gained in popularity in roadway projects due to its defining advantage to improve communication and fast-track project delivery. However, very little is known about the impact of change order frequency and occurrence timing pertaining to DB projects. The study analyzes their impacts on project time and cost performance by conducting a rigorous numerical analysis drawing on 530 3R (rehabilitation, reconstruction, and resurfacing) projects completed between 2002 and 2011 in Florida by using a multiple linear regression. The results indicate that DB outperformed Design-Bid-Build in project cost as well as time. Critically, the regression analysis signifies that earlier change order occurrence caused more unfavorable impacts on schedule and cost. The proposed analyses and models will lead to the improved ability of agencies to quickly and more reliably estimate the potential change order impacts on schedule and cost.

  • PDF

다중빈도 키워드 가시화에 관한 연구 (A Study on Multi-frequency Keyword Visualization based on Co-occurrence)

  • 이현창;신성윤
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2018년도 춘계학술대회
    • /
    • pp.103-104
    • /
    • 2018
  • Recently, interest in data analysis has increased as the importance of big data becomes more important. Particularly, as social media data and academic research communities become more active and important, analysis becomes more important. In this study, co-word analysis was conducted through altmetrics articles collected from 2012 to 2017. In this way, the co-occurrence network map is derived from the keyword and the emphasized keyword is extracted.

  • PDF

다중빈도 키워드 가시화에 관한 연구 (A Study on Multi-frequency Keyword Visualization based on Co-occurrence)

  • 이현창;신성윤
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국정보통신학회 2018년도 춘계학술대회
    • /
    • pp.424-425
    • /
    • 2018
  • Recently, interest in data analysis has increased as the importance of big data becomes more important. Particularly, as social media data and academic research communities become more active and important, analysis becomes more important. In this study, co-word analysis was conducted through altmetrics articles collected from 2012 to 2017. In this way, the co-occurrence network map is derived from the keyword and the emphasized keyword is extracted.

  • PDF