Non-parametric lactation curves

ABSTRACTLactation curves are fitted to data as a preliminary to estimating summary statistics. Two widely quoted curves are atbe-ct (Wood, 1967) and a(1 - e-bt) - ct (Cobby and Le Du, 1978), each of which has three parameters. Restriction to either of these curves imposes limitations on the fit to the data and can result in biased estimation of summary statistics. Alternatively, lactation curves can be generated by the use of a non-parametric method which requires only weak assumptions about the signs of derivatives of the curves. Because the non-parametric curves are more flexible, estimates of summary statistics are less likely to be biased than those based on parametric models. Use of the non-parametric curves is particularly advantageous around the time of peak yield, where the curves of Wood and Cobby and Le Du are known to fit data poorly.

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Comparison of Three Statistical Classification Techniques for Maser Identification

Publications of the Astronomical Society of Australia ◽

10.1017/pasa.2016.13 ◽

2016 ◽

Vol 33 ◽

Cited By ~ 1

Author(s):

Ellen M. Manning ◽

Barbara R. Holland ◽

Simon P. Ellingsen ◽

Shari L. Breen ◽

Xi Chen ◽

...

Keyword(s):

Logistic Regression ◽

Random Forests ◽

Parametric Method ◽

Parametric Models ◽

Critical Parameters ◽

Parametric Methods ◽

Statistical Classification ◽

Classification Techniques ◽

Linear Discriminant ◽

Non Parametric

AbstractWe applied three statistical classification techniques—linear discriminant analysis (LDA), logistic regression, and random forests—to three astronomical datasets associated with searches for interstellar masers. We compared the performance of these methods in identifying whether specific mid-infrared or millimetre continuum sources are likely to have associated interstellar masers. We also discuss the interpretability of the results of each classification technique. Non-parametric methods have the potential to make accurate predictions when there are complex relationships between critical parameters. We found that for the small datasets the parametric methods logistic regression and LDA performed best, for the largest dataset the non-parametric method of random forests performed with comparable accuracy to parametric techniques, rather than any significant improvement. This suggests that at least for the specific examples investigated here accuracy of the predictions obtained is not being limited by the use of parametric models. We also found that for LDA, transformation of the data to match a normal distribution led to a significant improvement in accuracy. The different classification techniques had significant overlap in their predictions; further astronomical observations will enable the accuracy of these predictions to be tested.

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Non-parametric method for estimating the species richness of a nekton community during fall in the southern waters of Shandong Peninsula

Journal of Fishery Sciences of China ◽

10.3724/sp.j.1118.2018.17199 ◽

2018 ◽

Vol 25 (2) ◽

pp. 436

Author(s):

Xiuxia MOU ◽

Binduo XU ◽

Ying XUE ◽

Yiping REN ◽

Chongliang ZHANG

Keyword(s):

Species Richness ◽

Parametric Method ◽

Shandong Peninsula ◽

Nekton Community ◽

Non Parametric

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Circulant Singular Spectrum Analysis to Monitor the State of the Economy in Real Time

Mathematics ◽

10.3390/math9111169 ◽

2021 ◽

Vol 9 (11) ◽

pp. 1169

Author(s):

Juan Bógalo ◽

Pilar Poncela ◽

Eva Senra

Keyword(s):

Business Cycles ◽

Real Time ◽

Parametric Method ◽

Singular Spectrum Analysis ◽

The State ◽

Signal Extraction ◽

Alternative Procedure ◽

State Of The Economy ◽

Regular Patterns ◽

Non Parametric

Real-time monitoring of the economy is based on activity indicators that show regular patterns such as trends, seasonality and business cycles. However, parametric and non-parametric methods for signal extraction produce revisions at the end of the sample, and the arrival of new data makes it difficult to assess the state of the economy. In this paper, we compare two signal extraction procedures: Circulant Singular Spectral Analysis, CiSSA, a non-parametric technique in which we can extract components associated with desired frequencies, and a parametric method based on ARIMA modelling. Through a set of simulations, we show that the magnitude of the revisions produced by CiSSA converges to zero quicker, and it is smaller than that of the alternative procedure.

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Modeling Post-Liberalized European Gas Market Concentration—A Game Theory Perspective

Forecasting ◽

10.3390/forecast3010001 ◽

2020 ◽

Vol 3 (1) ◽

pp. 1-16

Author(s):

Hassan Hamie ◽

Anis Hoayek ◽

Hans Auer

Keyword(s):

Game Theory ◽

Statistical Tests ◽

Parametric Method ◽

Linear Complementarity Problems ◽

Market Concentration ◽

Cournot Equilibrium ◽

Gas Markets ◽

Gas Market ◽

Equilibrium Test ◽

Non Parametric

The question of whether the liberalization of the gas industry has led to less concentrated markets has attracted much interest among the scientific community. Classical mathematical regression tools, statistical tests, and optimization equilibrium problems, more precisely non-linear complementarity problems, were used to model European gas markets and their effect on prices. In this research, the parametric and nonparametric game theory methods are employed to study the effect of the market concentration on gas prices. The parametric method takes into account the classical Cournot equilibrium test, with assumptions on cost and demand functions. However, the non-parametric method does not make any prior assumptions, a factor that allows greater freedom in modeling. The results of the parametric method demonstrate that the gas suppliers’ behavior in Austria and The Netherlands gas markets follows the Nash–Cournot equilibrium, where companies act rationally to maximize their payoffs. The non-parametric approach validates the fact that suppliers in both markets follow the same behavior even though one market is more liquid than the other. Interestingly, our findings also suggest that some of the gas suppliers maximize their ‘utility function’ not by only relying on profit, but also on some type of non-profit objective, and possibly collusive behavior.

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A Non Parametric Model for Magneto Rheological Dampers

Volume 7B: 17th Biennial Conference on Mechanical Vibration and Noise ◽

10.1115/detc99/vib-8017 ◽

1999 ◽

Author(s):

Mehdi Ahmadian ◽

Xubin Song

Keyword(s):

Test Data ◽

Mr Damper ◽

Parametric Model ◽

Parametric Models ◽

Magnetic Saturation ◽

Mr Dampers ◽

Electro Magnetic ◽

Magneto Rheological ◽

Force Characteristics ◽

Non Parametric

Abstract A non-parametric model for magneto-rheological (MR) dampers is presented. After discussing the merits of parametric and non-parametric models for MR dampers, the test data for a MR damper is used to develop a non-parametric model. The results of the model are compared with the test data to illustrate the accuracy of the model. The comparison shows that the non-parametric model is able to accurately predict the damper force characteristics, including the damper non-linearity and electro-magnetic saturation. It is further shown that the parametric model can be numerically solved more efficiently than the parametric models.

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