• 제목/요약/키워드: Index of entropy

검색결과 146건 처리시간 0.034초

보건의료체계에 대한 전문가 인식 분석 (Analysis of Experts' Views on Health Care: A Survey)

  • 정영호;고숙자
    • 보건행정학회지
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    • 제16권4호
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    • pp.86-111
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    • 2006
  • Either ways of understanding health care as a commodity or public work are at opposite ends of health care spectrum. These two rival conceptions reflected by viewpoint(ideology) would lead to different directions in policy-making for health care reform. The purpose of this study is to access the value differences of experts' policy views about health care issues by analyzing the extent of consensus among experts in the field of health care. Using primary data obtained through a mail survey of 558 experts in the field of health care, we analyzed the differences of experts' opinions about characteristics of health care market, policy issues and values Gdeology). The study represents from 50-50 split analysis, entropy index, and factor analysis that the wide spread disagreements over health policy, which is a major barriers to effective policy-making, could be caused by the ideological perception differences among experts. This implies that, if values play an important role in policy-making, we should identify the differences in value and seek ways to balance among the diverse values such as efficiency, equity, freedom, and security. For this, the policy issues debated on differences in values should be reconciled for narrowing gaps of experts' perceptions through various ways.

사업 포트폴리오의 기술시너지 효과 : 50대 재벌의 패널자료분석

  • 김태유;박경민
    • 기술혁신연구
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    • 제5권1호
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    • pp.15-43
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    • 1997
  • This paper investigates empirically the relationship between various business portfolio properties (particularly technological properties) and chaebol's performance using data on the 50largest chaebols in Korea. In addition to the traditional indexes to measure diversification such as entropy index, we calculated inter-industry technological similarity using R'||'&'||'D expenditure data by industry and 1990 Input-output Table in korea, and obtained chaebol-level technological relatedness and internal transaction proportion from chaebols' business profile, inter-inustry technological similarity and 1990 input-output table. We applied factor analysis on 13 business portfolio property indexes and showed that they could be grouped into 3 dimensions. diversification scope, inter-business relatedness and degree of vertical integration. In this paper, using 50 largest chaebols' financial data (1989-1994), we analyzed empirically the effect of business portfolio properties on ROS(Return On Sales) which is conventional index for firm performance and on TFP(Total Factor Productivity) growth which is a pure measure of firm performance. To utilize the advantage of panel data, FEM(Fixed Effect Model) and REM(Random Effect Model) were used. The empirical result shows that the entropy index as a measurement of inter-business relatedness in not significant but technological relatedness index is significant. OLS estimates on pooled data were considerably different from FEM or REM estimates on panel data. By introducing interaction effect among the three variables for business portfolio properties, we obtained three findings. First, only VI(Vertical integration) has a significant positive correlation with ROS. Second, when using TFP growth as an dependent variable, both TR(Technological Relatedness) and VI are significant and positively related to the dependent variable. Third, the interaction term between TR and VI is significant and negatively affects TFP growth, meaning that TR and VI are substitutes. These results suggest strategic directions on restructuring business portfolio. As VI is increased, chaebols will get more profit. A higher level of either TR or VI will increase TFP growth rate, but increase in both TR and VI will have a negative effect on TFP growth. To summarize, certain business portfolio properties such as VI and TR can be considered "resources" themselves since they can affect profit rate and productivity growth. VI and TR have a synergy effect of change in profit rate and productivity growth. VI increases ROS and productivity growth, while TR increases productivity growth representing a technological synergy effect.t.

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Forest Fire Damage Assessment Using UAV Images: A Case Study on Goseong-Sokcho Forest Fire in 2019

  • Yeom, Junho;Han, Youkyung;Kim, Taeheon;Kim, Yongmin
    • 한국측량학회지
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    • 제37권5호
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    • pp.351-357
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    • 2019
  • UAV (Unmanned Aerial Vehicle) images can be exploited for rapid forest fire damage assessment by virtue of UAV systems' advantages. In 2019, catastrophic forest fire occurred in Goseong and Sokcho, Korea and burned 1,757 hectares of forests. We visited the town in Goseong where suffered the most severe damage and conducted UAV flights for forest fire damage assessment. In this study, economic and rapid damage assessment method for forest fire has been proposed using UAV systems equipped with only a RGB sensor. First, forest masking was performed using automatic elevation thresholding to extract forest area. Then ExG (Excess Green) vegetation index which can be calculated without near-infrared band was adopted to extract damaged forests. In addition, entropy filtering was applied to ExG for better differentiation between damaged and non-damaged forest. We could confirm that the proposed forest masking can screen out non-forest land covers such as bare soil, agriculture lands, and artificial objects. In addition, entropy filtering enhanced the ExG homogeneity difference between damaged and non-damaged forests. The automatically detected damaged forests of the proposed method showed high accuracy of 87%.

잔향제거를 이용한 음성통신 시스템 성능 향상 (Performance Enhancement of Speech Communication System using Reverberation Rejection)

  • 김세영;강석엽;김기만
    • 한국정보통신학회논문지
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    • 제13권10호
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    • pp.2211-2217
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    • 2009
  • 본 논문에서는 잔향이 존재하는 환경에서 단일 마이크로폰을 사용한 음성 개선 방법을 제시한다. 스펙트럼 차감법(Spectral Subtraction)은 스펙트럼 상에서 잔향성분 및 잡음을 제거 할 수 있는 효과적인 방법이다. 스펙트럼 차감법은 음성과 비음성 구간의 정확한 구분을 필요로 하며 성능을 향상시키기 위해 본 논문에서는 엔트로피(Entropy) 기반의 음성 구간 검출법을 적용하였다. 제시된 방법을 기존의 에너지 검출 기반의 음성 검출법을 적용한 스펙트럼 차감법과 비교하여 성능 평가를 수행하였다. SNR 및 잔향시간에 따른 잔향 제거비율을 평가지표로 사용하였으며, 시뮬레이션 결과 기존의 스펙트럼 차감법과 비교하여 제시된 방법이 우수한 성능을 보였다.

정보통신산업 수출성과변화 및 R&D 역할에 대한 실증분석 (Empirical Analysis of Export Structure Change and the Role of R&D in the Field of Information Technology)

  • 조상섭;이중만
    • 한국콘텐츠학회논문지
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    • 제10권12호
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    • pp.300-308
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    • 2010
  • 본 연구에서 OECD 국가를 대상으로 우리나라 정보통신산업의 수출제품에 대한 구조변화를 1995년부터 2005년까지 분석하는 데 있다. 특히 단순한 수출구조변화지수인 RCA지수보다는 수출구조변화인 차별성의 위치 알 수 있는 국가간 엔트로피지수(우리나라 정보통신제품의 집중도)와 국내산업간에 수출차별성을 알 수 있는 국내 산업간 엔트로피지수(우리나라 수출제품의 다양화정도)로 측정하였다. 또한 수출차별성에 영향을 미치는 주요변수인 R&D활동의 연관관계를 추정하였다. 본 연구결과는 다음과 같다. 첫째, 정보통신관련 품목의 수출시장 집중도는 점차적으로 낮아지고 있다. 이러한 수출구조변화결과는 정보통신관련 제품시장이 독점적인 시장구조에서 보다 경쟁적인 시장구조로 변화되고 있다. 둘째, 기술집약적인 산업으로 정보통신산업과 바이오산업의 수출성과비교는 다른 OECD국가에 비하여 정보통신산업의 수출비중이 바이오산업의 수출비중보다 높게 나타나고 있다. 셋째, 우리나라 전체 수출의 경우에 엔트로피지수가 1995년부터 증가하다가 2000년도를 기점으로 점차적으로 감소하고 있으나, 분석대상기간동안에 정보통신산업제품의 수출차별화지수인 엔트로피지수는 조금씩 증가하고 있다. 마지막으로 정보통신산업에서 R&D활동이 정보통신산업의 수출구조변화에 미치는 영향관계는 정의 관계로 나타났다. 그러나 전반적으로 정보통신산업 R&D활동은 국내 산업 간에 정보통신산업제품의 수출차별성에 미치는 영향보다는 국제간에 정보통신산업제품의 수출차별성에 미치는 영향이 더 크게 나타났다. 이러한 연구결과는 정보통신 산업의 수출구조변화를 위한 R&D정책방향에 중요한 근거자료로 사용될 수 있다.

Dynamic Compressed Representation of Texts with Rank/Select

  • Lee, Sun-Ho;Park, Kun-Soo
    • Journal of Computing Science and Engineering
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    • 제3권1호
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    • pp.15-26
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    • 2009
  • Given an n-length text T over a $\sigma$-size alphabet, we present a compressed representation of T which supports retrieving queries of rank/select/access and updating queries of insert/delete. For a measure of compression, we use the empirical entropy H(T), which defines a lower bound nH(T) bits for any algorithm to compress T of n log $\sigma$ bits. Our representation takes this entropy bound of T, i.e., nH(T) $\leq$ n log $\sigma$ bits, and an additional bits less than the text size, i.e., o(n log $\sigma$) + O(n) bits. In compressed space of nH(T) + o(n log $\sigma$) + O(n) bits, our representation supports O(log n) time queries for a log n-size alphabet and its extension provides O(($1+\frac{{\log}\;{\sigma}}{{\log}\;{\log}\;n}$) log n) time queries for a $\sigma$-size alphabet.

PROMETHEE를 이용한 도시 하수관거시스템 침수위험순위 평가 (Evaluation of Inundation Risk Ranking for Urban Sewer Systems using PROMETHEE)

  • 송양호;이정호
    • 한국콘텐츠학회논문지
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    • 제12권8호
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    • pp.388-398
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    • 2012
  • 본 연구에서는 도시 하수관거시스템의 침수위험순위 평가를 위하여 엔트로피(Entropy) 기법 및 다기준 의사결정기법의 하나인 프로메티(Preference Ranking Organization METHod for Enrichment Evaluations, PROMETHEE)를 적용하였다. 엔트로피와 프로메티를 이용한 침수위험순위 산정에 있어서 평가 대상이 되는 항목들은 두 가지의 접근방식으로 선정되었다. 먼저 침수발생 및 피해 규모에 영향을 미치는 인자로 지형 환경적 요인으로써 유역의 평균고도, 평균경사, 유역폭, 인구수 및 관밀도를 선정하였다. 또한 각 시스템별 침수가 가장 크게 발생하는 초과강우사상을 선정 및 적용하여 시스템내 월류발생량 및 발생지점 두 가지를 이용한 치수안전성 지수를 추가적으로 고려하였다. 본 논문에서 적용된 엔트로피기법과 프로메티에 의한 도시 하수관거시스템 침수위험순위 평가는 추후 하수관거 정비사업의 계획 및 추진에 있어서 각 시스템별 위험도에 따른 개량우선순위 결정 및 평가지표로서 활용될 수 있을 것이다.

RECURRENT PATTERNS IN DST TIME SERIES

  • Kim, Hee-Jeong;Lee, Dae-Young;Choe, Won-Gyu
    • Journal of Astronomy and Space Sciences
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    • 제20권2호
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    • pp.101-108
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    • 2003
  • This study reports one approach for the classification of magnetic storms into recurrent patterns. A storm event is defined as a local minimum of Dst index. The analysis of Dst index for the period of year 1957 through year 2000 has demonstrated that a large portion of the storm events can be classified into a set of recurrent patterns. In our approach, the classification is performed by seeking a categorization that minimizes thermodynamic free energy which is defined as the sum of classification errors and entropy. The error is calculated as the squared sum of the value differences between events. The classification depends on the noise parameter T that represents the strength of the intrinsic error in the observation and classification process. The classification results would be applicable in space weather forecasting.

The Calculation of Physical Properties of Amino Acids using Molecular Modeling Techniques

  • Ui-Rak Kim;Kyung-Sub Min;Bong-Jin Jeong
    • Bulletin of the Korean Chemical Society
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    • 제15권2호
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    • pp.106-112
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    • 1994
  • Six physical properties (molecular weight, heat capacity, side chain weight, side chain volume, standard entropy and partial molar volume) of amino acids, peptides and their derivatives were examined by molecular modeling techniques. The molecular connectivity index, Wiener distance index and ad hoc descriptor are employed as structural parameters to encode information about branching, size, cyclization, unsaturation, heteroatom content and polarizability. This paper examines the correlation of the molecular modeling techique's parameters and the physicochemical properties of amino acids and their derivatives. As a result, calculated values were in agreement with experimental data in the above six physical properties of amino acids, peptides and their derivatives and the molecular connectivity index was superior to the other indices in fitting the calculated data.

습공기선도 상에 20 종류의 상태 및 과정 값의 작도 (Drawing of Twenty Kinds of State and Process on Psychrometric Chart)

  • 김덕진
    • 대한설비공학회:학술대회논문집
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    • 대한설비공학회 2008년도 하계학술발표대회 논문집
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    • pp.1201-1206
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    • 2008
  • Psychrometric chart displays graphically the thermophysical properties of moist air, so it is very conveniently used in air-conditioning and refrigeration. On general psychrometric chart, there are dry bulb temperature, web bulb temperature, absolute humidity ratio, relative humidity, specific enthalpy, specific volume, sensible heat factor, and enthalpy-humidity difference ratio. However, various state and process values besides aboves can be plotted on psychrometric chart. In this study, we developed the software drawing twenty kinds of lines, that is vapor pressure, mole fraction ratio of vapor, dew point temperature, degree of saturation, density, specific entropy, specific exergy, contact or bypass factor, uncomfort index, discomposition index, predicted mean vote index, predicted percent dissatisfied, and so on. We wish to this software is a help to design, analysis and education.

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