• Title/Summary/Keyword: linear fitting

검색결과 384건 처리시간 0.027초

The Confidence Regions for the Logistic Response Surface Model

  • Cho, Tae-Kyoung
    • 품질경영학회지
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    • 제25권2호
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    • pp.102-111
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    • 1997
  • In this paper I discuss a method of constructing the confidence region for the logistic response surface model. The construction involves a, pp.ication of a general fitting procedure because the log odds is linear in its parameters. Estimation of parameters of the logistic response surface model can be accomplished by maximum likelihood, although this requires iterative computational method. Using the asymptotic results, asymptotic covariance of the estimators can be obtained. This can be used in the construction of confidence regions for the parameters and for the logistic response surface model.

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Analysis of Complex Forced Raleigh Scattering Decay Profiles for the Diffusion of Methyl Yellow in Binary Solution

  • 박하선;성정문;이현정;장태현;Daniel R. Spiegal
    • Bulletin of the Korean Chemical Society
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    • 제18권9호
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    • pp.1006-1010
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    • 1997
  • The nature and analysis methods of complicated decay profiles found in forced Rayleigh scattering (FRS) have been investigated for the probe diffusion of methyl yellow in 2-propanol. The complementary shifted and ground state grating effect, which is known to be the origin of non-single exponential decays, was analyzed by non-linear regression fitting to a double exponential model function. We confirmed that the parameters were highly correlated so that it was difficult to extract a unique set of parameters in the presence of experimental noise. Nevertheless, a reasonable range of decay time constants could be estimated from the grating spacing dependence.

집락자료의 분할표에서 독립성검정 (Testing Independence in Contingency Tables with Clustered Data)

  • 정광모;이현영
    • 응용통계연구
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    • 제17권2호
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    • pp.337-346
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    • 2004
  • 랜덤표본에 관한 이원분할표의 독립성검정에는 통상 피어슨의 카이제곱적합도검정과 우도비검정을 사용한다. 그러나 랜덤표본이 아닌 집락자료에 관한 분할표의 경우에는 이들 검정법은 잘못된 결과를 나타낸다. 이러한 경우에는 공변량의 고정효과 외에 집락에 따른 변량효과를 함께 포함하는 일반화선형혼합모형을 고려함으로써 집락간의 이질성과 집락내의 종속성을 반영할 수 있다. 본 연구에서는 집락자료의 분할표에 대한 일반화선형혼합모형을 소개하고 실례를 통하여 이들 모형의 적합에 대해 논의한다.

Pulse pile-up correction by auto-regression on linear operations (ARLO) method: A comparison with integration-based algorithms

  • Mohammad-Reza Mohammadian-Behbahani
    • Nuclear Engineering and Technology
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    • 제56권9호
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    • pp.3904-3913
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    • 2024
  • Radiation detection at high count rate suffers from pulse pile-up, where the counting data and energy information of the system are affected by the overlapping of the system output pulses. There exist various pile-up correction strategies to recover the true information of the pulses, among which pulse-tail extrapolation is a well-known method focused on in this study. Present work aims to use a mono-exponential model for extrapolating the pileup-distorted trailing edge of a pulse, to provide a reference line for calculating the true amplitude of its subsequent overlapping pulse. To this goal, the auto-regression on linear operations (ARLO) method is examined and compared with two integration-based methods (the Foss and the Matheson methods), as well as the non-linear least squares (NLS) method. Despite a higher sensitivity to noise, the ARLO method was able to provide a simple, non-iterative solution with a performance over 400 times faster than the NLS algorithm, according to the analysis of a high count rate set of experimental pulses from a NaI(Tl) detection system. Foss and Matheson methods also provided solutions reasonably faster than NLS (but not surpassing ARLO), performing exactly the same as each other with results very close to NLS, benefiting from their non-iterative nature.

Analysis of Quasi-Likelihood Models using SAS/IML

  • Ha, Il-Do
    • Journal of the Korean Data and Information Science Society
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    • 제8권2호
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    • pp.247-260
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    • 1997
  • The quasi-likelihood models which greatly widened the scope of generalized linear models are widely used in data analysis where a likelihood is not available. Since a quasi-likelihood may not appear to be an ordinary likelihood for any known distribution in the natural exponential family, to fit the quasi-likelihood models the standard statistical packages such as GLIM, GENSTAT, S-PLUS and so on may not directly applied. SAS/IML is very useful for fitting of such models. In this paper, we present simple SAS/IML(version 6.11) program which helps to fit and analyze the quasi-likelihood models applied to the leaf-blotch data introduced by Wedderburn(1974), and the problem with deviance useful generally to model checking is pointed out, and then its solution method is mention through the data analysis based on this quasi-likelihood models checking.

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On Adaptation to Sparse Design in Bivariate Local Linear Regression

  • Hall, Peter;Seifert, Burkhardt;Turlach, Berwin A.
    • Journal of the Korean Statistical Society
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    • 제30권2호
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    • pp.231-246
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    • 2001
  • Local linear smoothing enjoys several excellent theoretical and numerical properties, an in a range of applications is the method most frequently chosen for fitting curves to noisy data. Nevertheless, it suffers numerical problems in places where the distribution of design points(often called predictors, or explanatory variables) is spares. In the case of univariate design, several remedies have been proposed for overcoming this problem, of which one involves adding additional ″pseudo″ design points in places where the orignal design points were too widely separated. This approach is particularly well suited to treating sparse bivariate design problem, and in fact attractive, elegant geometric analogues of unvariate imputation and interpolation rules are appropriate for that case. In the present paper we introduce and develop pseudo dta rules for bivariate design, and apply them to real data.

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영구자석 가동자를 갖는 직선형 왕복운동 전동기의 철손 특성 해석 (An Analysis on Core Loss Characteristics for Linear Oscillatory Motor with Permanent Magnet Mover)

  • 장석명;김관호;최장영;조한욱;정상섭;서진호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2011년도 제42회 하계학술대회
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    • pp.1023-1024
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    • 2011
  • This paper deals with an improved core loss calculation of Linear Oscillatory Motor from curve fitting method using modified Steinmetz equation considered anomalous loss. For an accurate calculation, magnetic field analyses in stator core considering, magnetic field analyses in stator core considering the time harmonics are performed. And using the nonlinear finite element analysis (FEM), we applied separated rotating and alternating magnetic filed to core loss calculation.

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The Estimation Method Comparison of Iron Loss Coefficients through the Iron Loss Calculation

  • Kim, Yong-Tae;Cho, Gyu-Won;Kim, Gyu-Tak
    • Journal of Electrical Engineering and Technology
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    • 제8권6호
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    • pp.1409-1414
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    • 2013
  • A new calculation method for iron loss coefficients is proposed by using the Steinmetz equation from Epstein data. The hysteresis loss must have linear characteristic according to the frequency. However, the existing iron loss coefficients are defined by formula of frequency. In this case, the hysteresis loss has non-linear characteristics by frequency. So, in this paper, the iron loss coefficients were defined by a function of the magnetic flux density, and the iron loss calculation is applied for Interior Permanent Magnet Synchronous Motor(IPMSM) of 600(W) and 200(W). The iron loss calculation results and the experimental results are compared according to the various materials.

Stochastic precipitation modeling based on Korean historical data

  • Kim, Yongku;Kim, Hyeonjeong
    • Journal of the Korean Data and Information Science Society
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    • 제23권6호
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    • pp.1309-1317
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    • 2012
  • Stochastic weather generators are commonly used to simulate time series of daily weather, especially precipitation amount. Recently, a generalized linear model (GLM) has been proposed as a convenient approach to fitting these weather generators. In this paper, a stochastic weather generator is considered to model the time series of daily precipitation at Seoul in South Korea. As a covariate, global temperature is introduced to relate long-term temporal scale predictor to short-term temporal predictands. One of the limitations of stochastic weather generators is a marked tendency to underestimate the observed interannual variance of monthly, seasonal, or annual total precipitation. To reduce this phenomenon, we incorporate time series of seasonal total precipitation in the GLM weather generator as covariates. It is veri ed that the addition of these covariates does not distort the performance of the weather generator in other respects.

Total Wood Volume Equations for Tectona Grandis Linn F. Stands in Gujarat, India

  • Tewari, Vindhya Prasad;Singh, Bilas
    • Journal of Forest and Environmental Science
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    • 제34권4호
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    • pp.313-320
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    • 2018
  • Tectona grandis (teak) is one of the most important timber species worldwide and India is one of the major teak growing countries. Though some volume equations were developed for teak in India but the models developed were neither evaluated using robust statistical criteria nor validated. Hence, the objective of this study was to develop statistically tested appropriate volume equation to predict total wood volume (over- and under-bark) for teak trees in Gujarat. A total of 41 trees with age varying from 15 to 33 years and diameter at breast height (dbh) from 7.3 to 30.8 cm were felled for the purpose. Linear and non-linear equations were used to model the relationship of the total wood volume with respect to dbh and total height. The equations tested mostly fitted well to the data. Model evaluation and validation indicated that models should be calibrated with local data for greater accuracy in the prediction.