• 제목/요약/키워드: Coefficient of determination

검색결과 1,957건 처리시간 0.036초

바닥재의 확산계수 및 분배계수 산정 (The Determination of Diffusion and Partition Coefficients of Indoor Bottom Finishing Materials)

  • 박진수;;김신도;윤중섭
    • 한국환경보건학회지
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    • 제34권3호
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    • pp.219-225
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    • 2008
  • Many building materials may contain high concentrations of volatile organic compounds (VOCs) and other hazardous pollutants(HAPs). Specifically, VOCs discharged by indoor building material may cause "new house" syndrome, atopic dermatitis etc. The diffusion coefficient and initially contained total VOC quantity were determined using microbalance experiments and small chamber tests. Interactions between volatile organic compounds (VOCs) and vinyl flooring (VF), a relatively homogenous, diffusion-controlled building material, were characterized. Rapid determination of the material/air partition coefficient (K) and the material-phase diffusion coefficient (D) for each VOC was achieved by placing thin VF slabs in a dynamic microbalance and subjecting them to controlled sorption/desorption cycles. K and D are shown to be independent of concentration for all of the VOCs and water vapor. This approach can be applied to other diffusion-controlled materials and should facilitate the prediction of their source/sink behavior using physically-based models.

광학적 방법에 의한 이산화티타늄 박막의 굴절율, 소광계수 결정 및 증착 방법에 따 른 조밀도 변화 (Determination of refractive index, extinction coefficient of TiO2 thin films using optical methods and packing density variation with growth technique)

  • 김현종;방현용;김상열
    • 한국광학회:학술대회논문집
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    • 한국광학회 1996년도 Advance Program of 13th optics andquantum Electronics conference, 1996제13 회 광학 및 양자전자 학술 발표회 논문 요약집
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    • pp.4-4
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    • 1996
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Graphical Descriptions for Hierarchical Log Linear Models

  • Hyun Jip Choi;Chong Sun Hong
    • Communications for Statistical Applications and Methods
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    • 제2권2호
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    • pp.310-319
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    • 1995
  • We represent graphically the relationship of hierachical log linear models by regarding the values of the likelihood ratio statistics as the squared norm of the corresponding vectors. Right angled triangles, tetrahedrons, and modified polyhedrons are used for graphical description. We find that the angle between the two vectors depends on the coefficient of determination and the partial coefficent of determination. Thess graphical descriptions could be applied to the model selection method.

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Mechanically Immobilized Copper Hexacyanoferrate Modified Electrode for Electrocatalysis Amperometric Determination of Glutathione

  • D. Davi Shankaran;S. Sriman Narayanan
    • Bulletin of the Korean Chemical Society
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    • 제22권8호
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    • pp.816-820
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    • 2001
  • A new copper hexacyanoferrate modified electrode was constructed by mechanical immobilization. The modified electrode was characterised by cyclic voltammetric experiments. Electrocatalytic oxidation of glutathione was effective at the modified electrode at a significantly reduced overpotential and at broader pH range. The modified electrode shows a stable and linear response in the concentration range of 9 ${\times}$10-5 to 9.9 ${\times}$10-4M with a correlation coefficient of 0.9995. The modified electrode exhibits excellent stability, reproducibility and rapid response and can be used in flow injection analysis for the determination of glutathione.

수정 결정계수를 사용한 로지스틱 회귀모형에서의 변수선택법 (Variable Selection for Logistic Regression Model Using Adjusted Coefficients of Determination)

  • 홍종선;함주형;김호일
    • 응용통계연구
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    • 제18권2호
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    • pp.435-443
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    • 2005
  • 로지스틱 회귀모형에서 결정계수는 선형 회귀모형보다 다양하게 정의되며 그 값들도 매우 작아 로지스틱 회귀모형 평가기준으로 사용되는 통계량이 라고 할 수 없다. Liao와 McGee(2003)는 부적절한 설명변수의 추가 또는 표본크기의 변화에 민감하지 않은 두 종류의 수정 결정계수를 제안하였다. 본 연구에서는 실제자료에 적용한 로지스틱 회귀모형에서 수정 결정계수를 포함한 네 종류의 결정계수들을 변수선택의 기준으로 사용하여 기존의 변수선택 방법인 전진선택, 후진제거, 단계적 선택방법, AIC 통계량 등을 사용한 방법들과 비교하여 그 적절함과 효율성을 토론한다.