• 제목/요약/키워드: Shannon index

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Shannon의 정보이론과 문헌정보 (Shannon's Information Theory and Document Indexing)

  • 정영미
    • 한국문헌정보학회지
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    • 제6권
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    • pp.87-103
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    • 1979
  • Information storage and retrieval is a part of general communication process. In the Shannon's information theory, information contained in a message is a measure of -uncertainty about information source and the amount of information is measured by entropy. Indexing is a process of reducing entropy of information source since document collection is divided into many smaller groups according to the subjects documents deal with. Significant concepts contained in every document are mapped into the set of all sets of index terms. Thus index itself is formed by paired sets of index terms and documents. Without indexing the entropy of document collection consisting of N documents is $log_2\;N$, whereas the average entropy of smaller groups $(W_1,\;W_2,...W_m)$ is as small $(as\;(\sum\limits^m_{i=1}\;H(W_i))/m$. Retrieval efficiency is a measure of information system's performance, which is largely affected by goodness of index. If all and only documents evaluated relevant to user's query can be retrieved, the information system is said $100\%$ efficient. Document file W may be potentially classified into two sets of relevant documents and non-relevant documents to a specific query. After retrieval, the document file W' is reclassified into four sets of relevant-retrieved, relevant-not retrieved, non-relevant-retrieved and non-relevant-not retrieved. It is shown in the paper that the difference in two entropies of document file Wand document file W' is a proper measure of retrieval efficiency.

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시설재배지(施設栽培地)(P.E. 하우스, P.E. 턴넬, P.E. 멀칭)에서의 잡초발생특성(雜草發生特性) (Characterization of Weed Occurrence in Protected Culture(P.E. house, P.E. tunnel, P.E. mulching))

  • 우인식;변종영
    • 한국잡초학회지
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    • 제8권3호
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    • pp.317-323
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    • 1988
  • 본(本) 연구(硏究)는 시설재배(施設栽培)에서 잡초방제(雜草防除)의 기초자료(基礎資料)를 얻고자 대전시(大田市) 유성지역(儒城地域)에서 1985년(年) 2월(月)부터 6월(月)까지 15일(日) 간격(間隔)으로 여러 시설재배조건(施設栽培條件)에서 잡초수(雜草數), 건물중(乾物重), 발생잡초(發生雜草)의 종생태적(種生態的) 및 사회적(社會的) 특성분석(特性分析)과 우점도(優占度)를 조사(調査)하였다. 1. 시설재배(施設栽培)에서 노지(露地)의 경우, 명아주, 여뀌, 쇠비름, 바랭이가 우점(優占)하였으며, PE 하우스는 냉이, 명아주, 바랭이, 쇠비름이 우점(優占)하였고 발생잡초(發生雜草) 본수(本數)는 무멀칭에 비해 멀칭과 턴넬내 멀칭에서는 많이 발생(發生)했으며 건물중(乾物重)은 이와는 반대로 무멀칭에서 무거웠다. 노지(露地)에서는 여름 광엽잡초(廣葉雜草)와 여름 화본과잡초(禾本科雜草)가 많이 발생(發生)했으나 PE 하우스내에서는 무멀칭에서 월동광엽잡초(越冬廣葉雜草)가 우점(優占)했으며 멀칭에서는 초기(初期)에 월동화본과잡초(越冬禾本科雜草)와 월동광엽잡초(越冬廣葉雜草)가 많이 발생(發生)했으나 후기(後期)에는 여름 화본과잡초(禾本科雜草)와 여름 광엽잡초(廣葉雜草)가 많이 발생(發生)하였다. 2. 시설내(施設內)에서 PE 하우스는 시설(施設)을 하므로 Simpson 지수(指數)가 높아 몇 초종(草種)이 우점(優占)하고 있는 군락(群落)을 이루었고 종다양도(種多樣度), 최대종다양도(最大種多樣度)가 안정도(安定度)에 비해 낮았고 또한 무피복보다 멀칭, 턴넬내 멀칭에서 높았으며 노지(露地)는 종다양도(種多樣度), 최대종다양도(最大種多樣度)가 멀칭, 턴넬을 하므로써 높아졌고 Simpson지수(指數)는 무멀칭에서 높고 오히려 시설(施設)을 하므로 낮아졌으며, PE 하우스, 노지(露地) 공(共)히 종간경쟁(種間競爭)이 종내경쟁(種內競爭)보다 높았던 것으로 생각된다.

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Ecological Attributes of Species Composition by Topographical Positions in the Natural Deciduous Forest

  • Kim, Ji-Hong;Lee, Hye-Seon;Hwang, Gwang-Mo
    • Journal of Forest and Environmental Science
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    • 제27권1호
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    • pp.17-22
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    • 2011
  • Based upon the vegetation data of woody plants by plot sampling method in the natural deciduous forest of Mt. Jeombong, the study was carried out to examine importance value, rank abundance curve, and species abundance curve, and comparatively evaluate seven different species diversity indices for Shannon-Wiener index, Simpson index, McIntosh index, Log series, Margalef index, Berger-Parker index, and species richness, according to topographic positions. The minimal area which meant only few more species were increased was 3.48 ha in total. The dominant species of valley were Carpinus cordata, Acer pseudo-sieboldianum, Quercus mongolica, Acer mono, and Abies holophylla, and the dominant species of mid-slope were Quercus mongolica, Acer pseudo-sieboldianum, Carpinus cordata, Tilia amurensis, and Fraxinus rhynchophylla. Moreover, the dominant species of ridge were Quercus mongolica, Acer pseudo-sieboldianum, Tilia amurensis, Fraxinus rhynchophylla, and Acer mono. According to rank abundance curve and species abundance curve, species evenness was also low. All of Log series, species richness, Margalef, and Shannon-Wiener index discriminated that valley had the highest diversity, and ridge had the lowest diversity; but, Simpson index, McIntosh index, and Berger-Parker index represented that mid-slope had the highest diversity, and ridge had the lowest diversity. Uniquely, in Berger-Parker index, mid-slope was the higher value than total.

Comparison of Plant Diversity of Natural Forest and Plantations of Rema-Kalenga Wildlife Sanctuary of Bangladesh

  • Sobuj, Norul-Alam;Rahman, Mizanur
    • Journal of Forest and Environmental Science
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    • 제27권3호
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    • pp.127-134
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    • 2011
  • The purpose of the study was to assess and compare the diversity of plant species (trees, shrubs, herbs) of natural forest and plantations. A total of 52 plant species were recorded in the natural forest, of which 16 were trees, 15 were shrubs and 21 were herbs. On the contrary, 31 species of plants including 11 trees, 8 shrubs and 12 herbs were identified in plantation forest. Shannon-Wiener diversity index were 2.70, 2.72 and 3.12 for trees, shrubs and herbs respectively in the natural forest. However, it was 2.35 for tree species, 2.31 for shrub species and 2.81 for herb species in the plantation forest. Jaccard's similarity index showed that 71% species of trees, 44% species of shrubs and 43% species of herbs were same in plantations and natural forest.

정보계측기법을 이용한 생태조사자료의 종다양도 분석 (Species Diversity Analysis of Ecosystem Survey Data Using Total Information)

  • 정남수;이정재;박승기;김웅
    • 농촌계획
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    • 제13권2호
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    • pp.1-5
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    • 2007
  • Shannon and Simpson indexes are used for species diversity analysis of ecosystem. In species diversity analysis of ecosystem, not only frequency of each species but also survey size have to be considered. In this study, total information composed with knowledge and ignorance was suggested as a species diversity analysis method for ecosystem survey. To apply developed method, flora in the Sangachun river valley was sampled with 19 sites and 198 species. In applying results, Shannon index shows more reasonable results than Simpson index by the variance of sample size but has difficulties of determining the relation of surveying species number and sample site number. Suggested total information can overcome this difficulty by the relation of knowledge and ignorance.

공간스케일 변화에 따른 생물다양성 평가 -강원도 백두대간 보호구역을 대상으로- (Evaluation of Biodiversity Based on Changes of Spatial Scale -A Case Study of Baekdudaegan Area in Kangwondo-)

  • 심우담;박진우;이정수
    • Journal of Forest and Environmental Science
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    • 제30권1호
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    • pp.91-100
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    • 2014
  • This research was conducted on the conservation area of Baekdudaegan, Kangwondo under the purpose of evaluating bio-diversity according to the changes of spatial scale, using GIS data and spatial filtering method. The diversity index was calculated based on the information of species of The $5^{th}$ forest type map using Shannon-weaver index (H'), evenness index ($E_i$) and richness index ($R_i$). The diversity index was analyzed and compared according to the changes of 12 spatial scales from Kernel size $3{\times}3$ to $73{\times}73$ and basin unit. As for H' and $R_i$, spatial scale increased as diversity index decreased, while $E_i$ decreases gradually. H' and $R_i$ was highest; each 1.1 and 0.6, when the Kernel size was $73{\times}73$, while $E_i$ was 0.2, the lowest. When you look at according to the basin unit, for large basin unit, 'YeongDong' region shows higher diversity index than 'YeongSeo' region. For middle basin unit, 'Gangneung Namdaecheon' region, and for small basin unit, 'Gangneung Namdaecheon' and 'Gangneung Ohbongdaem' region shows high diversity index. When you look at the relationship between diversity index and Geographic factors, H' shows positive relation to curvature and sunshine factor while shows negative to elevation, slope, hillshade, and wetness index. Also $E_i$ was similar to the relationship between H' and Geographic factor. Meanwhile, $R_i$ shows positive relationship to curvature and sunshine factor, while negative to elevation, slope, hillshade, and wetness index. macro unit diversity index evaluation was possible through the GIS data and spatial filtering, and it can be a good source for local biosphere conservation policy making.

Shannon의 함수

  • 이범준
    • 한국해양학회지
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    • 제14권1호
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    • pp.32-38
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    • 1979
  • 생태학에서의 다양성(diversity) 문제는 일반적으로 통용되고 있는 다양성=안정성 (diversity=stability)의 개념과 연관되어 항상 생태학자들의 관심대상이 되어 있다. (Watt 1966). 처음으로 군집(community)의 diversity에 대한 개념을 시도한 것은 Gleason(1922)이며 diversity index의 측정은 Fisher(1943)로부터 시작한다.(in Travers 1979, Hurlbert 1971, Gallucci 1973).

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안면도 먹넌출 집단의 유전다양성과 공간적 유전구조 (Genetic Diversity and Spatial Genetic Structure of Berchemia racemosa var. magna in Anmyeon Island)

  • 송정호;임효인;장경환;홍경낙;한진규
    • 원예과학기술지
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    • 제32권1호
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    • pp.84-90
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    • 2014
  • 우리나라에서 먹넌출은 안면도 지역에서만 소나무 숲에서 제한적으로 분포하는 덩굴성 식물이다. 본 연구는 먹넌출 집단의 분포형태와 특성, 유전다양성 및 공간분포에 따른 유전구조를 파악하는데 있다. 선발된 8개 I-SSR primer에서 총 50개의 I-SSR 증폭산물을 얻었으며 37개의 단형성 증폭산물을 제외한 13개의 다형적 증폭산물을 분석에 이용하였다. 공간적 자기상관 분석을 위한 조사구 $90m{\times}70m$내에 총 39개체의 먹넌출이 자생하고 있었으며, 군집지수(aggregation index)는 0.706으로 집중분포(clumped distribution)하는 공간분포를 나타냈다. I-SSR 표지자 분석 결과 39개체 중 유전자형이 서로 다른 21개의 유성생식체(genet)가 식별되었으며, 유전자형 비율(G/N)은 53.8%, 유전자형 다양성(D)은 0.966, 유전자형 균등도(E)는 0.946으로 각각 나타났다. Shannon의 다양성지수(I = 0.598)는 적은 개체수와 제한적 분포에도 불구하고 다른 수종들에 비해 비교적 높은 유전다양성을 나타냈다. Tanimoto distance를 이용한 공간적 자기상관 분석 결과 안면도 먹넌출의 현지외 보존을 위한 표본 추출 전략은 6m 이상의 간격을 두고 개체를 선발하는 것이 타당한 것으로 나타났다.

경북지역 복숭아과원에 분포하는 식물기생성 선충의 조사 (Survey on Plant-Parasitic Nematodes in Peach Orchards in Gyeongbuk Province)

  • 권태영;김동근;최충돈;윤재탁
    • 한국응용곤충학회지
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    • 제43권1호
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    • pp.81-84
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    • 2004
  • 복숭아의 주요 식물기생성선충 종류를 밝히기 위하여 2000년부터 2002년까지 3년간 경북지역의 124개 복숭아 과원 토양으로부터 선충을 분리하고 선충의 종류, 밀도, 빈도(Frequency), 우점도(Simpson's index), 다양성지수(Shannon and Wiener index), 중요도(Prominence value)를 분석하였다. 식물기생성 선충은 총 124지점 중 97지점에서 발견되었으며 우점도는 0.717-0.881, 다양성지수는 0.221-0.286로 복숭아는 다양한 종류의 식물기생성선충에 의하여 피해를 받기보다는 몇몇 우점하고 있는 식물기생성선충에 의하여 피해를 받고 있었다 복숭아과원에서 중요한 식물기생성선충은 Tylenchorhynchus nudus, Criconemoides informis, Paratylenchus elachistus, Pratylenchus vulnus, Helicotylenchus digonichus 순이었고, 그 외 Aphelenchus sp., Tylenchus sp., Heterodera sp., Scutellonema sp. 등이 검출은 되었으나 중요종은 아니었다. 이번 조사에서 특히 국내 복숭아과원 토양에는 Paratylenchus elachistus가 널리 분포하고 있었으며, 반면 외국에서 심각한 문제가 되고 있는 뿌리혹선충류는 발견되지 많았다.

Relationship between Tree Species Diversity and Carbon Stock Density in Moist Deciduous Forest of Western Himalayas, India

  • Shahid, Mohommad;Joshi, Shambhu Prasad
    • Journal of Forest and Environmental Science
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    • 제33권1호
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    • pp.39-48
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    • 2017
  • With the growing global concern about climate change, relationship between carbon stock density and tree species has become important for international climate change mitigation programmes. In this study, 150 Quadrats were laid down to assess the diversity, biomass and carbon stocks in each of the forest ranges (Barkot Range, Lachchiwala Range and Thano Range) of Dehra Dun Forest Division in Doon Valley, Western Himalaya, India. Community level carbon stock density was analyzed using Two Way Indicator Species Analysis. Species Richness and Shannon Weiner index was correlated with the carbon stocks of Doon Valley. Positive and weak relationship was found between the carbon stock density and Shannon Weiner Index, and between carbon stock density and Species Richness.