• 제목/요약/키워드: Goodness-of-Fit

검색결과 891건 처리시간 0.024초

Differences by Selection Method for Exposure Factor Input Distribution for Use in Probabilistic Consumer Exposure Assessment

  • Kang, Sohyun;Kim, Jinho;Lim, Miyoung;Lee, Kiyoung
    • 한국환경보건학회지
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    • 제48권5호
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    • pp.266-271
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    • 2022
  • Background: The selection of distributions of input parameters is an important component in probabilistic exposure assessment. Goodness-of-fit (GOF) methods are used to determine the distribution of exposure factors. However, there are no clear guidelines for choosing an appropriate GOF method. Objectives: The outcomes of probabilistic consumer exposure assessment were compared by using five different GOF methods for the selection of input distributions: chi-squared test, Kolmogorov-Smirnov test (K-S), Anderson-Darling test (A-D), Akaike information criterion (AIC) and Bayesian information criterion (BIC). Methods: Individual exposures were estimated based on product usage factor combinations from 10,000 respondents. The distribution of individual exposure was considered as the true value of population exposures. Results: Among the five GOF methods, probabilistic exposure distributions using the A-D and K-S methods were similar to individual exposure estimations. Comparing the 95th percentiles of the probabilistic distributions and the individual estimations for 10 CPs, there were 0.73 to 1.92 times differences for the A-D method, and 0.73 to 1.60 times differences (excluding tire-shine spray) for the K-S method. Conclusions: There were significant differences in exposure assessment results among the selection of the GOF methods. Therefore, the GOF methods for probabilistic consumer exposure assessment should be carefully selected.

연속적 분석법을 통한 어머니와 유아의 상호작용 연구 (A Sequential Analysis of Mother-Infant Interaction)

  • 최진경
    • 아동학회지
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    • 제6권1호
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    • pp.3-16
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    • 1985
  • The purpose of this study was the application of sequential analysis to mother-infant interaction data, with particular reference to goodness of fit. The subjects of this study were 22 7- to 16-month-old infants(12 girls and 10 boys) and their mothers. Each mother-infant dyad was videotaped in a 5-min free-play session in the playroom. The videotaped data was transcribed on the behavioral checklist every 3 seconds. The recorded raw data were lagged by one time interval (3 sec.). Transitional probabilities from behavior at time t-1 to behavior at time t were gathered. The statistical analysis of frequency data and transitional probabilities consisted of Z test, t test, and sign test. It was found that regarding 1) direction of effect: the transitional probability of infant vocalization following maternal vocalization was significantly higher than the reverse; the transitional probability of a 'Coacting State' following a 'Mother Active State' was significantly higher than the reverse; the probability of a 'Mother Active State' following 'Quiescent State' was significantly higher than that of a 'Coacting State' following an 'Infant Active State'; 2) sex differences: male infants' transitional probability from an 'Infant Active State' to a 'Quiescent State' was significantly higher than that of female infants; 3) age differences: more than younger infants older infants had higher transitional probabilities from a 'Mother Active State' to a 'Coacting State', from a 'Parallel State' to a 'Coacting State', and from a 'Quiescent State' to a 'Parallel State'. These showed goodness of fit for sex and age differences, particularily for direction of effect.

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교육행정공무원 상급자의 감성리더십, 임파워먼트, 직무만족 간의 구조 관계 (A Structural Relationship among Emotional Leadership of Educational Administrative Officials' Superiors, Empowerment, and Job Satisfaction)

  • 이기용
    • 수산해양교육연구
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    • 제28권4호
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    • pp.936-946
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    • 2016
  • The purpose of this study is to examine structural relations between the emotional leadership of educational administrative officials' superiors and subordinates' empowerment and job satisfaction. To attain the study goal, this researcher finally selected 368 educational administrative officials working in Gyeongsangbuk-do and conducted statistical analysis. Accordingly, this study has drawn the following detailed conclusions: First, there is statistically significant positive correlation among the subfactors of the emotional leadership of educational administrative officials' superiors and subordinates' empowerment and job satisfaction. Second, it has been found that the hypothetical path model to explain the emotional leadership of educational administrative officials' superiors and subordinates' empowerment and job satisfaction is appropriate. In other words, among the goodness-of-fit indexes of the final study model, ${\chi}^2=203.657$ (p<.001), RMR equals .030, RMSEA is .093, GFI equals .910, and AGFI is .900. About its relative goodness-of-fit indexes, TLI equals .930, NFI is .933, CFI equals .948, and IFI is .949; therefore, all indexes have been found to be allowable. Third, emotional leadership of educational administrative officials' superiors have had this influence directly on job satisfaction. But, the total influence of the emotional leadership of educational administrative officials' superiors on job satisfaction is smaller than that on job satisfaction with the mediation of subordinates' empowerment.

네트워크 부하 조건의 변화가 채널 상태 정보에 미치는 영향을 고려한 옥내 전력선 통신 채널의 채널 용량 분석 (Channel Capacity Analysis for Indoor PLC Networks with Considering the Effect of Loading conditions of Networks on Channel State Information)

  • 신재영;정지채
    • 전기학회논문지
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    • 제60권2호
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    • pp.252-256
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    • 2011
  • We analyze the channel capacity with considering the effect of the loading conditions of indoor PLC networks on channel state information. We consider various numbers of load for two kinds of the networks with regular length branches and a deployed network of indoor PLC. For calculating the channel capacity degradation, two noise scenarios and impedances are considered. From the simulation results, we suggest the robust regression lines for modeling the channel capacity degradation. In the cases of 0 $\Omega$ and $Z_0$ loads, natural log and linear function curve show the best goodness of fit, respectively. For the deployed indoor PLC network with 0 $\Omega$ loads, compared with the networks with regular length branches, the goodness of fit decreases by the amount of 0.12 and 0.15 for low noise and high noise scenarios, respectively. Using the regression lines, we can estimate the channel capacity degradation without measurement.

Probabilistic analysis of spectral displacement by NSA and NDA

  • Devandiran, P.;Kamatchi, P.;Rao, K. Balaji;Ravisankar, K.;Iyer, Nagesh R.
    • Earthquakes and Structures
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    • 제5권4호
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    • pp.439-459
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    • 2013
  • Main objective of the present study is to determine the statistical properties and suitable probability distribution functions of spectral displacements from nonlinear static and nonlinear dynamic analysis within the frame work of Monte Carlo simulation for typical low rise and high rise RC framed buildings located in zone III and zone V and designed as per Indian seismic codes. Probabilistic analysis of spectral displacement is useful for strength assessment and loss estimation. To the author's knowledge, no study is reported in literature on comparison of spectral displacement including the uncertainties in capacity and demand in Indian context. In the present study, uncertainties in capacity of the building is modeled by choosing cross sectional dimensions of beams and columns, density and compressive strength of concrete, yield strength and elastic modulus of steel and, live load as random variables. Uncertainty in demand is modeled by choosing peak ground acceleration (PGA) as a random variable. Nonlinear static analysis (NSA) and nonlinear dynamic analysis (NDA) are carried out for typical low rise and high rise reinforced concrete framed buildings using IDARC 2D computer program with the random sample input parameters. Statistical properties are obtained for spectral displacements corresponding to performance point from NSA and maximum absolute roof displacement from NDA and suitable probability distribution functions viz., normal, Weibull, lognormal are examined for goodness-of-fit. From the hypothesis test for goodness-of-fit, lognormal function is found to be suitable to represent the statistical variation of spectral displacement obtained from NSA and NDA.

Negative Exponential Disparity Based Deviance and Goodness-of-fit Tests for Continuous Models: Distributions, Efficiency and Robustness

  • Jeong, Dong-Bin;Sahadeb Sarkar
    • Journal of the Korean Statistical Society
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    • 제30권1호
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    • pp.41-61
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    • 2001
  • The minimum negative exponential disparity estimator(MNEDE), introduced by Lindsay(1994), is an excellenet competitor to the minimum Hellinger distance estimator(Beran 1977) as a robust and yet efficient alternative to the maximum likelihood estimator in parametric models. In this paper we define the negative exponential deviance test(NEDT) as an analog of the likelihood ratio test(LRT), and show that the NEDT is asymptotically equivalent to he LRT at the model and under a sequence of contiguous alternatives. We establish that the asymptotic strong breakdown point for a class of minimum disparity estimators, containing the MNEDE, is at least 1/2 in continuous models. This result leads us to anticipate robustness of the NEDT under data contamination, and we demonstrate it empirically. In fact, in the simulation settings considered here the empirical level of the NEDT show more stability than the Hellinger deviance test(Simpson 1989). The NEDT is illustrated through an example data set. We also define a goodness-of-fit statistic to assess adequacy of a specified parametric model, and establish its asymptotic normality under the null hypothesis.

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복소 라플라시안 확률 밀도 함수에 기반한 음성 향상 기법 (Noisy Speech Enhancement Based on Complex Laplacian Probability Density Function)

  • 박윤식;조규행;장준혁
    • 대한전자공학회논문지SP
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    • 제44권6호
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    • pp.111-117
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    • 2007
  • 본 논문에서는 복소 라플라시안 확률밀도함수 (PDF, Probability Density Function)에 기반한 새로운 음성 향상 기법을 제시한다. 적용된 복소 라플라시안 PDF가 기존의 가우시안 PDF보다 오염된 음성 분포를 정확하게 표현한다는 것을 Goodness-of-Fit (GOF) 테스트로 확인하였고, 음성 향상 알고리즘의 음성부재확률을 위해 우도비 (LR, Likelihood Ratio)를 적용하였다. 제시된 알고리즘의 성능은 객관적 테스트에 의해 평가하였고 기존의 가우시안 PDF보다 개선된 음성 향상 결과를 나타내었다.

평균과 분산의 동시모형에 따른 회귀진단법에 관한 연구 (Regression Diagnostics on Joint Modelling of Mean and Dispersion)

  • 강위창;이영조;송문섭
    • 응용통계연구
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    • 제13권2호
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    • pp.407-414
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    • 2000
  • Carroll과 Ruppert(1988)는 준가능도(quasi-likelihood)를 이용하여 에스트라제 측정자료를 회귀분석하였다. Jung과 Lee(1997)는 준가능도을 이용한 회귀분석모형의 적합도정통계량을 제안하였으며 검정 별과 기각되지 않아 본 분석모형이 타당하다고 주장하였다. 그러나 Lee와 Nelder(1998)의 잔차그림을 검토한 결과, 상기 모형으로는 평균증가에 따른 분산증가를 충분히 반영할 수 없었다. 본 논문에서는 Lee와 Nelder(1998)의 평균과 분산의 동시모형으로 에스트라제 자료를 재분석하고 잔차그림을 이용하여 모형의 타당성을 재평가하였다. 또한 분산에서 산포모형에 대한 적합도검정에는 Lee와 Nelder(1998)의 제한가능도(restricted likelihood)에 근거한 검정법이 보다 적절함을 제시하였다.

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세장비가 큰 사각케이스 성형 공정에서의 인공신경망을 적용한 초기 블랭크 형상 최적설계 모델 개발 (A Development of Optimal Design Model for Initial Blank Shape Using Artificial Neural Network in Rectangular Case Forming with Large Aspect Ratio)

  • 곽민준;박지우;박근태;강범수
    • 소성∙가공
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    • 제29권5호
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    • pp.272-281
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    • 2020
  • As the thickness of mobile communication devices is getting thinner, the size of the internal parts is also getting smaller. Among them, the battery case requires a high-level deep drawing technique because it has a rectangular shape with a large aspect ratio. In this study, the initial blank shape was optimized to minimize earing in a multi-stage deep drawing process using an artificial neural network(ANN). There has been no reported case of applying artificial neural network technology to the initial blank optimal design for a square case with large aspect ratio. The training data for ANN were obtained though simulation, and the model reliability was verified by performing comparative study with regression model using random sample test and goodness-of-fit test. Finally, the optimal design of the initial blank shape was performed through the verified ANN model.

승용차 보유대수와 차종선택에 대한 네스티드로짓모형의 추정 (A Nested Logit Model of Auto Ownership and Vehicle Type Choices)

  • 박상준;김성수
    • 대한교통학회지
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    • 제25권1호
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    • pp.133-141
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    • 2007
  • 승용차 부문의 에너지수요 또는 대기오염물 배출에 대해 영향을 미치는 정책의 효과를 정확히 예측하기 위해서는 소비자의 승용차 보유 및 이용행태에 대한 분석 및 예측이 선행되어야 한다. 이를 위해 본 연구는 네스티드로짓모형 을 활용한 가계의 자동차 보유대수 및 차종선택에 대한 연구로서 2003년 에너지경제연구원에서 수행한 에너지간이 조사 자료를 이용하여 추정을 시도하였다. 모형의 추정결과를 요약하면 모형의 적합도(goodness of fit)를 나타내는 ${\rho}^2$ 값과 포괄값이 모두 통계적으로 유의한 범위 내에 있어 네스티드로짓모형을 활용한 방법이 더 우수하다고 할 수 있다. 또한 운행비용의 탄력성이 1보다 커서 가구의 차량보유대수 및 차종선택은 운행비용에 대해 매우 민감하다는 것과 소득계층별로는 저소득 계층이 고소득 계층보다 더 민감하게 반응한다는 것을 알 수 있었다.