• 제목/요약/키워드: occurrence frequency distribution

검색결과 207건 처리시간 0.023초

공간통계와 GIS를 이용한 소나무림과 참나무류림의 분포패턴 (Distribution Pattern of Pinus densiflora and Quercus Spp. Stand in Korea Using Spatial Statistics and GIS)

  • 이종수;이우균;윤정호;송철철
    • 한국산림과학회지
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    • 제95권6호
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    • pp.663-671
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    • 2006
  • 본 연구는 소나무림과 참나무류림의 공간분포 패턴을 규명하기 위하여 수행하였다. 공간분석을 위한 기초 자료로 수치 임상도와 현존식생도를 활용하여 $100m{\times}100m$ 격자 단위로 전국 단위의 소나무림과 참나무류림 분포도를 제작하였다. 또한 $100m{\times}100m$ 래스터 격자 단위의 지형, 기후, 토양 관련 주제도를 제작하였다. 이상의 소나무림과 참나무류림의 분포도와 주제도간의 GIS 기반 공간 분석을 실시하여 지형, 기후, 토양 등의 환경 인자에 따른 소나무림과 참나무류림의 공간분포 특성을 분석하였으며, 이러한 공간분포 특성을 활용하여 소나무림과 참나무류림의 출현빈도모델을 제시하였다. 소나무림의 경우 참나무류림에 비하여 상대적으로 표고가 낮고 경사도가 완만하며 기온이 높은 지역에 많이 분포하고 있는 것으로 나타났다. 또한, 소나무림은 양토, 보통 이하의 얕은 토심지역이며 배수가 양호한 화성암 지역에 주로 분포한 반면, 참나무류림은 사양토, 보통 이하의 얕은 토심지역이며 배수가 양호한 변성암 지역에 주로 분포하고 있는 것으로 나타났다. 이상과 같은 지리형태학적 인자에 따른 소나무림과 참나무류림의 공간분포 패턴을 회귀식으로 도출한 결과 통계적 유의성이 매우 높게 나타났다. 본 연구 결과는 지형, 기후, 토양 등의 환경 요소를 고려한 소나무림과 참나무류림 임분의 합리적인 관리에 기여할 것으로 기대된다.

어휘의 동시 발생 빈도와 분포를 이용한 다중 주제 회의록 요약 (Multi-Topic Meeting Summarization using Lexical Co-occurrence Frequency and Distribution)

  • 이병수;이지형
    • 한국컴퓨터정보학회:학술대회논문집
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    • 한국컴퓨터정보학회 2015년도 제52차 하계학술대회논문집 23권2호
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    • pp.13-16
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    • 2015
  • 본 논문에서는 어휘의 동시 발생 (co-occurrence) 빈도와 분포를 이용한 회의록 요약방법을 제안한다. 회의록은 일반 문서와 달리 문서에 여러 세부적인 주제들이 나타나며, 잘못된 형식의 문장, 불필요한 잡담들을 포함하고 있기 때문에 이러한 특징들이 문서요약 과정에서 고려되어야 한다. 기존의 일반적인 문서요약 방법은 하나의 주제를 기반으로 문서 전체에서 가장 중요한 문장으로 요약하기 때문에 다중 주제 회의록 요약에는 적합하지 않다. 제안한 방법은 먼저 어휘의 동시 발생 (co-occurrence) 빈도를 이용하여 회의록 분할 (segmentation) 과정을 수행한다. 다음으로 주제의 구분에 따라 분할된 각 영역 (block)의 중요 단어 집합 생성, 중요 문장 추출 과정을 통해 회의록의 중요 문장들을 선별한다. 마지막으로 추출된 중요 문장들의 위치, 종속 관계를 고려하여 최종적으로 회의록을 요약한다. AMI meeting corpus를 대상으로 실험한 결과, 제안한 방법이 baseline 요약 방법들보다 요약 비율에 따른 평가 및 요약문의 세부 주제별 평가에서 우수한 요약 성능을 보임을 확인하였다.

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RCP 시나리오별 한반도 가뭄특성 분석 (Analysis of drought characteristics depending on RCP scenarios at Korea)

  • 김정호;김상단;주진걸
    • 한국수자원학회논문집
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    • 제49권4호
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    • pp.293-303
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    • 2016
  • 본 연구에서는 RCP 시나리오별 표준가뭄지수의 특성을 정량적인 측면과 공간적인 측면에서 상호비교 하였다. 이를 위해, 4개의 RCP 시나리오로부터 산정된 SPI를 기반으로 가뭄 특성을 정량적으로 비교하였고, 가뭄발생 횟수와 지속기간을 공간적으로 분석하였다. 결과적으로, RCP 시나리오별 SPI의 거동 특성은 매우 상이하고, 모든 상관계수가 0.08보다 낮은 것으로 나타났다. 또한 가뭄의 정도, 발생횟수, 그리고 지속기간에 대한 상이한 공간분포 경향을 확인할 수 있었다. RCP 시나리오별 상이한 가뭄발생전망 특성의 가장 큰 배경은 다른 온실가스 배출농도 시나리오 기반의 일 강수량을 들 수 있으나, 온실가스 배출농도 규모에 따른 영향은 명확하지 않았다. 아울러, 본 연구 결과를 통해 단일 RCP 시나리오 자료만 이용한 가뭄발생 전망에는 상당한 불확실성이 따를 것으로 판단된다.

기상자료의 통계처리방법이 원자력발전소의 가상 사고시 단기 대기확산인자에 미치는 영향 (Influence of Statistical Compilation of Meteorological Data on Short-Term Atmospheric Dispersion Factors in a Hypothetical Accidental Release of Nuclear Power Plants)

  • 황원태;김은한;정해선;정효준;한문희
    • Journal of Radiation Protection and Research
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    • 제37권3호
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    • pp.116-122
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    • 2012
  • 미국 원자력규제위원회(U. S. NRC)에서 개발한 PAVAN 프로그램을 사용하여 기상자료의 통계처리방법에 따른 원자력발전소의 수명기간 중 발생할 수 있는 가상 사고시 단기 대기확산인자 값의 영향을 분석하였다. 대기확산을 평가하기 위한 기본요소는 기상자료이며, PAVAN에서는 대기안정도에 대한 풍향과 풍속의 발생빈도를 나타내는 결합빈도분포자료를 사용하여 평가한다. 고리와 월성 원자력발전소 부지에서 2006~2010년까지 5년간 관측된 기상자료를 사용하여 풍속등급의 분류방법(U. S. NRC 권고와 균등발생빈도 분류방법)과 평가에 적용되는 기상자료의 통계처리기간(1년, 2년, 3년, 4년, 5년)에 따른 결합빈도분포자료를 작성하여 단기 대기확산인자를 평가하였다. 평가결과, 두 원자력발전소 부지 모두 풍속등급의 분류에 따른 단기 대기확산인자 값의 영향은 미미한 반면 평가에 적용되는 기상자료의 분석기간은 상대적으로 중요한 영향을 나타냈는데, 최대값과 최소값의 비는 1.5배 이상의 차이를 보였다.

Research Trends Analysis on ESG Using Unsupervised Learning

  • Woo-Ryeong YANG;Hoe-Chang YANG
    • 융합경영연구
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    • 제11권3호
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    • pp.47-66
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    • 2023
  • Purpose: The purpose of this study is to identify research trends related to ESG by domestic and overseas researchers so far, and to present research directions and clues for the possibility of applying ESG to Korean companies in the future and ESG practice through comparison of derived topics. Research design, data and methodology: In this study, as of October 20, 2022, after searching for the keyword 'ESG' in 'scienceON', 341 domestic papers with English abstracts and 1,173 overseas papers were extracted. For analysis, word frequency analysis, word co-occurrence frequency analysis, BERTopic, LDA, and OLS regression analysis were performed to confirm trends for each topic using Python 3.7. Results: As a result of word frequency analysis, It was found that words such as management, company, performance, and value were commonly used in both domestic and overseas papers. In domestic papers, words such as activity and responsibility, and in overseas papers, words such as sustainability, impact, and development were included in the top 20 words. As a result of analyzing the co-occurrence frequency of words, it was confirmed that domestic papers were related mainly to words such as company, management, and activity, and overseas papers were related to words such as investment, sustainability, and performance. As a result of topic modeling, 3 topics such as named ESG from the corporate perspective were derived for domestic papers, and a total of 7 topics such as named sustainable investment for overseas papers were derived. As a result of the annual trend analysis, each topic did not show a relatively increasing or decreasing tendency, confirming that all topics were neutral. Conclusions: The results of this study confirmed that although it is desirable that domestic papers have recently started research on consumers, the subject diversity is lower than that of overseas papers. Therefore, it is suggested that future research needs to approach various topics such as forecasting future risks related to ESG and corporate evaluation methods.

텍스트 마이닝을 통한 상급종합병원의 미션, 비전, 핵심가치 분석 연구 (Analysis of Mission, Vision and Core values in Korean Tertiary General Hospitals Through Text Mining)

  • 이지훈
    • 한국병원경영학회지
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    • 제28권2호
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    • pp.32-43
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    • 2023
  • Purposes: This research is conducted to identify main features and trends of mission, vision and core values in Korean tertiary general hospitals by using text-mining. Methodology: For the study, 45 mission, 112 vision and 190 core values are collected from 45 tertiary general hospitals' homepages in 2022 and use word frequency analysis and Leyword co-occurrence analysis. Findings: In the tertiary general hospitals' mission, there are high frequency words such as 'health', 'humanity', 'medical treatment', 'education', 'research', 'happiness', 'love', 'best', 'spirit', and mission mainly includes the content of contributing humanity's health and happiness with these words. In case of vision, high frequency words are 'hospital', 'medical treatment', 'research', 'lead', 'trust', 'centered', 'patient', 'best', 'future'. By using these words in vision, it represents the definition and characteristics of vision such as ideal organizations in the future, goals and targets. As a result of the Leyword co-occurrence analysis, vision includes the content of 'high-tech medical treatment', 'special care for patients', 'leading education and research', 'the highest trust with customer', 'creative talents training'. -astly, the high frequency word-pairs in core values are 'social distribution', 'innovation pursuit', 'cooperation and harmony', and it defines standards of behavior for organizations. Practical Implication: To correct the problems of vision, mission and core values from findings, firstly, it needs for Korean tertiary general hospitals to use the words that can explain organization's identity and differentiate others in their mission. Secondly, considering strengthening the role of hospitals in their community and the importance of members in organizations, it is necessary to establish vision with considering community and members to activate vision effectively. Thirdly, because there are no specific guidelines of establishing mission, vision and core values for healthcare organizations, this research concepts and results could be utilized when other organizations establish mission, vision and core values.

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우리나라 무인도서의 귀화식물 분포에 대한 섬생물지리적 연구 (Island Biogeographic Study on Distribution Pattern of the Naturalized Plant Species on the Uninhabited Islands in Korea)

  • 정재민;홍경낙
    • Journal of Ecology and Environment
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    • 제29권6호
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    • pp.489-494
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    • 2006
  • 우리나라 남 서해안에 분포하는 261개의 무인도서에 대해, 생태계 보전과 귀화식물종의 효율적인 관리를 위하여, 섬생물 지리학적 방법론에 의한 귀화식물종의 분포와 확산 pattern 및 섬의 지리적 환경과의 상관성 분석을 수행하였다. 조사된 261개 도서 중 귀화식물 종은 229(87.7%)개 도서에서 총 106종이 관찰되었다. 도서 당 귀화식물 종수는 평균 4.6 $\pm$ 4.07)이었으며, 서해그룹보다 남해그룹에 속한 도서에서 많았다. 귀화식물 종당 관찰된 무인도서 수는 평균 12.9 $\pm$ 25.92)개였고, 100개 이상의 도서에서 관찰된 종은 귀화도(5등급)가 높은 소리쟁이(R. crispus L.; 153개)와 개망초(E. annuus Pers.; 130개), 망초(C. canadensis (L.) Cronquist; 121개)의 3종이었다. 106개 귀화식물 종의 출현 빈도에는 도서 면적과 육지와의 최단거리, 인간간섭 강도 및 위 경도 등이 모두 유의한 상관성을 나타냈으며, 면적(r=0.182)보다는 최단거리(r=-0.330)와의 상관성이 더욱 높은 것으로 나타났다. 경로분석 결과 귀화식물 종수는 도서의 면적이 증가할수록, 그리고 육지와의 거리가 가까울수록 종수가 증가하였으나, 인간 간섭 효과는 매우 낮았다. 회귀 분석 결과, 106종의 귀화식물 종의 분포는 육지와의 최단거리가 10.9%의 설명력으로 제일 높았으며, 면적을 추가했을 경우에는 회귀 직선으로 귀화종수 변화의 21.8 %까지 설명할 수 있었다. 본 연구의 결과는 무인도서에서 귀화식물의 관리와 생태계 보전을 위한 기초 자료로 이용될 수 있을 것으로 기대된다.

L 및 LH-모멘트법과 지역빈도분석에 의한 가뭄우량의 추정(I) - L-모멘트법을 중심으로 - (Estimation of Drought Rainfall by Regional Frequency Analysis using L and LH-Moments(I) - On the Method of L-Moments -)

  • 이순혁;윤성수;맹승진;류경식;주호길
    • 한국농공학회지
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    • 제45권5호
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    • pp.97-109
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    • 2003
  • This study is mainly conducted to derive the design drought rainfall by the consecutive duration using probability weighted moments with rainfall in the regional drought frequency analysis. It is anticipated to suggest optimal design drought rainfall of hydraulic structures for the water requirement and drought frequency of occurrence for the safety of water utilization through this study. Preferentially, this study was conducted to derive the optimal regionalization of the precipitation data that can be classified by the climatologically and geographically homogeneous regions all over the regions except Cheju and Ulreung islands in Korea. Five homogeneous regions in view of topographical and climatological aspects were accomplished by K-means clustering method. Using the L-moment ratio diagram and Kolmogorov-Smirnov test, generalized extreme value distribution was confirmed as the best fitting one among applied distributions. At-site and regional parameters of the generalized extreme value distribution were estimated by the method of L-moments. Design drought rainfalls using L-moments following the consecutive duration were derived by the at-site and regional analysis using the observed and simulated data resulted from Monte Carlo techniques. Relative root-mean-square error (RRMSE), relative bias (RBIAS) and relative reduction (RR) in RRMSE for the design drought rainfall derived by at-site and regional analysis in the observed an simulated data were computed and compared. In has shown that the regional frequency analysis procedure can substantially more reduce the RRMSE. RBIAS and RR in RRMSE than those of at-site analysis in the prediction of design drought rainfall. Consequently, optimal design drought rainfalls following the regions and consecutive durations were derived by the regional frequency analysis.

뇌졸중 환자의 발생특성에 관한 연구 (A study on the Occurrence of the Stroke Patients)

  • 김한수
    • The Journal of Korean Physical Therapy
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    • 제2권1호
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    • pp.21-33
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    • 1990
  • The purpose of this study is to investigated the occurrence properties of the cerebrovascular accidents. Clinical observations were done 252 cases, were carried from June, 1989 to May, 1990 at 4 general hospital in Taegu, Korea. The following results have been obtained ; 1. Among the 252 cases of cerebrovascular accidents, males was noted in $51.6\%$ and females in $48.4\%$. The ratio between males and females was 1.1 : 1 in whole groups of cerebrovascular accidents, and in aging distribution, it was showed variety distribution in age groups, fifties, sixties and forties were in order of frequency, particulary, more than half was shelved from 50 to 69. 2. Among the 252 cases of cerebrovascular accidents, cerebral hemorrhage was rioted in $64.3\%$, cerebral infarction in $25.8\%$, cerebral thrombosis in $6.3\%$, subarachnoid hemorrhage in $2.4\%$ and cerebral embolism in $1.2\%$. 3. In distribution of academic career, high school level was noted in $37.7\%$, elementary school level in $30.5\%$, middle school level in $17.1\%$, elementary school level in $30.5\%$, middle school level in $17.1\%$ arid college level in $14.7\%$. 4. In distribution of occupation, office worker was noted in $21.8\%$, housewife in $20.2\%$, the others in $19.1\%$, physical laborer in $18.3\%$ and inoccupation in $18.3\%$. 5. In seasonal distribution, spring was noted in $34.9\%$, winter in $32.5\%$, autumn in $20.3\%$ and summer in $12.3\%$. 6. Among the preceding diseases at the onset of cerebrovascular accidents, hypertension was noted in $51.6\%$, no preceding disease in $20.2\%$, other disease in $10.3\%$ and diabetes mellitus in $9.5\%$ and cardiovalvular disease in $6.0\%$. 7. In systolic blood pressure on admission, 160-199mmHg was noted in $32.2\%$, 200-239mmHg in $23.4\%$, 140-159mmHg in $19.4\%$, below 140mmHg in $16.3\%$, and above 240mmHg in $8.7\%$, While, in diastolic blood pressure, above 130mmHg noted in $24.6\%$, below 90 mmHg in $17.1\%$, 120-129mmHg in $13.1\%$ and was 90-99mmHg in $11.1\%$. 8. In major predisposing factors of patients, emotional stress was noted in $20.2\%$, physical action in $17.9\%$, rest in $16.9\%$, while sleeping in $10.7\%$, drinking in $9.9\%$ and defecation in $7.9\%$. 9. In distribution of affected side, left was noted in $48.4\%$, right in 42.1 and both $9.5\%$. 10. In rates of recurrent cases, first attach was noted in $79.0\%$, 1st recurrence in $17.0\%$, 2nd recurrence in $3.6\%$ and 3rd recurrence in $0.4\%$.

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暴雨의 時間的 分布에 關한 硏究 (Studies on the Time Distribution of Heavy Storms)

  • 이근후
    • 한국농공학회지
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    • 제26권2호
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    • pp.69-84
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    • 1984
  • This study was carried out to investigate the time distribution of single storms and to establish the model of storm patterns in korea. Rainfall recording charts collected from 42 metheorological stations covering the Korean peninsula were analyzed. A single storm was defined as a rain period seperated from preceding and succeeding rainfall by 6 hours and more. Among the defined single storms, 1199 storms exceeding total rainfall of 80 mm were qualified for the study. Storm patterns were cklassified by quartile classification method and the relationship between cummulative percent of rainfalls and cummulative storm time was established for each quartile storm group. Time distribution models for each stations were prepared through the various analytical and inferential procedures. Obtained results are summarized as follows: 1. The percentile frequency of quartile storms for the first to the fourth quartile were 22.0%, 26.5%, 28.9% and 22.6%, respectively. The large variation of percentile frequency was show between the same quartile storms. The advanced type storm pattern was predominant in the west coastal type storm patterns predominantly when compared to the single storms with small total rainfalls. 3. The single storms with long storm durations tended to show delayed type storm patterns predominantly when compared to the single storms with short storm durations. 4. The percentile time distribution of quartile storms for 42 rin gaging stations was estimated. Large variations were observed between the percentiles of time distributions of different stations. 5. No significant differences were generally found between the time distribution of rainfalls with greater total rainfall and with less total rainfall. This fact suggests that the size of the total rainfall of single storms was not the main factor affecting the time distribution of heavy storms. 6. Also, no significant difference were found between the time distribution of rainfalls with long duration and with short duration. The fact indicates that the storm duration was no the main factor affecting the time distribution of heavy storms. 7. In Korea, among all single storms, 39.0% show 80 to 100mm of total rainfall which stands for the mode of the frequency distribution of total rainfalls. The median value of rainfalls for all single storms from the 42 stations was 108mm. The shape of the frequency distribution of total rainfalls showed right skewed features. No significant differences were shown in the shape of distribution histograms for total rainfall of quartile storms. The mode of rainfalls for the advanced type quartile storms was 80~100mm and their frequencies were 39~43% for respective quartiles. For the delayed type quartile storms, the mode was 80~100mm and their frequencies were 36!38%. 8. In Korea, 29% of all single storms show 720 to 1080 minutes of storm durations which was the highest frequency in the frequency distribution of storm durations. The median of the storm duration for all single storms form 42 stations was 1026 minutes. The shape of the frequency distribution was right skewed feature. For the advanced type storms, the higher frequency of occurrence was shown by the single storms with short durations, whereas for the delayed type quartile storms, the higher frequency was shown gy the long duration single storms. 9. The total rainfall of single storms was positively correlated to storm durations in all the stations throughout the nation. This fact was also true for most of the quartile storms. 10. The third order polynomial regression models were established for estimating the time distribution of quartile storms at different stations. The model test by relative error method resulted good agreements between estimated and observed values with the relative error of less than 0.10 in average.

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