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1. Generalized signed-rank estimation for regression models with non-ignorable missing responses

Author:
Bindele, Huybrechts F.; Nguelifack, Brice M.
Source:
Computational statistics & data analysis 2019 v.139 pp. 14-33
ISSN:
0167-9473
Subject:
least squares,   etc   ; models; statistical inference;     Show all 3 Subjects
Abstract:
... In regression modeling, it has become very common to deal with missing data, which render the statistical analysis more difficult. It is then of interest to develop robust methods toward statistical inference for the regression coefficients in the presence of missing data. From this, a generalized signed-rank estimator of the regression coefficients in a model with non-ignorable missing responses ...
DOI:
10.1016/j.csda.2019.04.014

2. Two-stage approaches to the analysis of occupancy data II. The heterogeneous model and conditional likelihood

Author:
Karavarsamis, N.; Huggins, R.M.
Source:
Computational statistics & data analysis 2019 v.133 pp. 195-207
ISSN:
0167-9473
Subject:
least squares,   etc   ; linear models; probability;     Show all 3 Subjects
Abstract:
... Occupancy models involve both the probability a site is occupied and the probability occupancy is detected. The homogeneous occupancy model, where the occupancy and detection probabilities are the same at each site, admits an orthogonal parameter transformation that yields a two-stage process to calculate the maximum likelihood estimates so that it is not necessary to simultaneously estimate the o ...
DOI:
10.1016/j.csda.2018.09.009

3. Modelling and estimation of nonlinear quantile regression with clustered data

Author:
Geraci, Marco
Source:
Computational statistics & data analysis 2019 v.136 pp. 30-46
ISSN:
0167-9473
Subject:
least squares,   etc   ; algorithms; growth curves; models; pharmacokinetics;     Show all 5 Subjects
Abstract:
... In regression applications, the presence of nonlinearity and correlation among observations offer computational challenges not only in traditional settings such as least squares regression, but also (and especially) when the objective function is nonsmooth as in the case of quantile regression. Methods are developed for the modelling and estimation of nonlinear conditional quantile functions when ...
DOI:
10.1016/j.csda.2018.12.005

4. The mixture problem in flake analysis: Allocating flake samples to segments of reduction using CLSR methods

Author:
Shott, Michael J.; Habtzghi, Desale
Source:
Journal of archaeological science 2019 v.103 pp. 46-56
ISSN:
0305-4403
Subject:
least squares,   etc   ; archaeology; basins; flaking; quarries;     Show all 5 Subjects
Abstract:
... Flake assemblages often are mixtures from knapping episodes that vary by reduction mode or stage. Stahle and Dunn (1982) developed a constrained least-squares regression (CLSR) method to allocate hypothetically mixed chert assemblages to successive biface-reduction stages, a partial solution to the mixing problem. ConReg is a recently developed alternative, validated against Stahle and Dunn's and ...
DOI:
10.1016/j.jas.2019.01.003

5. A multiscale kinetics model for the analysis of starch amylolysis

Author:
Bello-Perez, L.A.; Agama-Acevedo, E.; Garcia-Valle, D.E.; Alvarez-Ramirez, J.
Source:
International journal of biological macromolecules 2019 v.122 pp. 405-409
ISSN:
0141-8130
Subject:
least squares,   etc   ; digestion; enzymes; models; resistant starch;     Show all 5 Subjects
Abstract:
... Simple exponential decaying functions are commonly used for fitting the kinetics of starch digested by amylolytic enzymes. A common assumption is that a sole exponential function can account for the kinetics of the whole digestible starch. Recent studies using logarithm-of-slope (LOS) plots showed that digestion kinetics can exhibit multi-scale behavior, an effect reflecting starch fractions with ...
DOI:
10.1016/j.ijbiomac.2018.10.161

6. Feasible generalized least squares using support vector regression

Author:
Miller, Steve; Startz, Richard
Source:
Economics letters 2019 v.175 pp. 28-31
ISSN:
0165-1765
Subject:
least squares,   etc   ; confidence interval; economics; heteroskedasticity; variance;     Show all 5 Subjects
Abstract:
... We investigate semiparametric Feasible Generalized Least Squares using Support Vector Regression to estimate the conditional variance function. Monte Carlo results indicate the resulting estimator and an accompanying standard error correction offer substantially improved precision, nominal coverage rates, and shorter confidence intervals than Ordinary Least Squares with heteroskedasticity-consiste ...
DOI:
10.1016/j.econlet.2018.12.001

7. Threshold regression asymptotics: From the compound Poisson process to two-sided Brownian motion

Author:
Yu, Ping; Phillips, Peter C.B.
Source:
Economics letters 2018 v.172 pp. 123-126
ISSN:
0165-1765
Subject:
least squares,   etc   ; economics;     Show all 2 Subject
Abstract:
... The asymptotic distribution of the least squares estimator in threshold regression is expressed in terms of a compound Poisson process when the threshold effect is fixed and as a functional of two-sided Brownian motion when the threshold effect shrinks to zero. This paper explains the relationship between this dual limit theory by showing how the asymptotic forms are linked in terms of joint and s ...
DOI:
10.1016/j.econlet.2018.08.039

8. On the generation of stream rating curves

Author:
Fenton, John D.
Source:
Journal of hydrology 2018 v.564 pp. 748-757
ISSN:
0022-1694
Subject:
least squares,   etc   ; hydrology; streams;     Show all 3 Subjects
Abstract:
... Traditional methods for the calculation of rating curves from measurements of water level and discharge are criticised as being limited and complicated to implement, such that manual methods are still often used. Two methods for automatic computation are developed using least-squares approximation, one based on polynomials and the other on piecewise-continuous splines. Computational problems are i ...
DOI:
10.1016/j.jhydrol.2018.07.025

9. Novel Least Mean Square Algorithm Using First order Al-Alaoui Digital Differentiator

Author:
Krishna, B. T.
Source:
National Academy science letters 2018 v.41 no.4 pp. 215-218
ISSN:
0250-541X
Subject:
least squares,   etc   ; algorithms; equations;     Show all 3 Subjects
Abstract:
... This paper proposes a Novel least mean square algorithm using First order Al-Alaoui differentiator.The performance of the proposed Algorithm is compared with existing algorithms by taking an example. The results prove the efficacy of the proposed Algorithm. ...
DOI:
10.1007/s40009-018-0652-z

10. A fully non-stationary linear coregionalization model for multivariate random fields

Author:
Fouedjio, Francky
Source:
Stochastic environmental research and risk assessment 2018 v.32 no.6 pp. 1699-1721
ISSN:
1436-3240
Subject:
least squares,   etc   ; models; prediction;     Show all 3 Subjects
Abstract:
... This paper introduces an extension of the traditional stationary linear coregionalization model to handle the lack of stationarity. Under the proposed model, coregionalization matrices are spatially dependent, and basic univariate spatial dependence structures are non-stationary. A parameter estimation procedure of the proposed non-stationary linear coregionalization model is developed under the l ...
DOI:
10.1007/s00477-017-1469-x

11. Improved crop forecasts for the Australian macadamia industry from ensemble models

Author:
Mayer, David G.; Chandra, Kerri A.; Burnett, Jolyon R.
Source:
Agricultural systems 2019 v.173 pp. 519-523
ISSN:
0308-521X
Subject:
least squares,   etc   ; Macadamia; climatic factors; horticulture; linear models; trees; Australia;     Show all 7 Subjects
Abstract:
... Annual forecasts for the Australian macadamia crop have been issued since 2001, with varying (and not always improving) degrees of accuracy. Regression models using climate variables have formed the basis for these forecasts, with general linear model (GLM) ensembles being adopted more recently. This has proven to be a challenging task, as there are only a small number of observations (18) combine ...
DOI:
10.1016/j.agsy.2019.03.018

12. On the structure of IV estimands

Author:
Andrews, Isaiah
Source:
Journal of econometrics 2019 v.211 no.1 pp. 294-307
ISSN:
0304-4076
Subject:
least squares,   etc   ; econometric models; economic analysis; economic theory; probability;     Show all 5 Subjects
Abstract:
... When the overidentifying restrictions of the constant-effect linear instrumental variables model fail, common IV estimators converge to different probability limits. I characterize the estimands of two stage least squares, two step GMM, and limited information maximum likelihood as functions of the single-instrument estimands from the just-identified IV regressions which consider each instrument s ...
DOI:
10.1016/j.jeconom.2018.12.017

13. Initial robust estimation in generalized linear models

Author:
Agostinelli, Claudio; Valdora, Marina; Yohai, Victor J.
Source:
Computational statistics & data analysis 2019 v.134 pp. 144-156
ISSN:
0167-9473
Subject:
least squares,   etc   ; Monte Carlo method; algorithms; linear models; methodology;     Show all 5 Subjects
Abstract:
... Generalized Linear Models are routinely used in data analysis. Classical estimators are based on the maximum likelihood principle and it is well known that the presence of outliers can have a large impact on them. Several robust procedures have been presented in the literature, being redescending M-estimators the most widely accepted. Based on non-convex loss functions, these estimators need a rob ...
DOI:
10.1016/j.csda.2018.12.010

14. Boundary modeling with moving least squares

Author:
Manchuk, John G.; Deutsch, Clayton V.
Source:
Computers & geosciences 2019 v.126 pp. 96-106
ISSN:
0098-3004
Subject:
least squares,   etc   ; computers; geometry; humans; kriging; models; uncertainty;     Show all 7 Subjects
Abstract:
... Modeling geological boundaries is an important step in geological modeling workflows that aim to quantify the location, volume, and uncertainty of a resource. Several well established explicit and implicit techniques can be used to identify the limits of an ore zone; however, most techniques are unable to account for uncertainty in a straightforward manner, where uncertainty originates from the sp ...
DOI:
10.1016/j.cageo.2019.02.006

15. Study of the hydrodynamic performance prediction method for a horizontal-axis tidal current turbine with coupled rotation and surging motion

Author:
Wang, Shu-qi; Cui, Jie; Ye, Ren-chuan; Chen, Zhong-fei; Zhang, Liang
Source:
Renewable energy 2019 v.135 pp. 313-325
ISSN:
0960-1481
Subject:
least squares,   etc   ; hydrodynamics; prediction; renewable energy sources; tides; torque;     Show all 6 Subjects
Abstract:
... For the fast prediction of the hydrodynamic characteristics of a floating horizontal-axis tidal current turbine (HATT) with coupled rotation and surging motion, this study applies the CFD method to simulate the coupled rotation and surging motion, and obtains the axial force and axial torque coefficients at different current velocities. According to the CFD simulation data, the constant force, dam ...
DOI:
10.1016/j.renene.2018.12.020

16. Data fusion of electronic eye and electronic tongue signals to monitor grape ripening

Author:
Orlandi, Giorgia; Calvini, Rosalba; Foca, Giorgia; Pigani, Laura; Vasile Simone, Giuseppe; Ulrici, Alessandro
Source:
Talanta 2019 v.195 pp. 181-189
ISSN:
0039-9140
Subject:
least squares,   etc   ; electronic tongue; grapes; physicochemical properties; prediction; ripening;     Show all 6 Subjects
Abstract:
... Two separate artificial sensors, an electronic eye (EE) and an electronic tongue (ET), were recently developed to monitor grape ripening based on the analysis of must. The aim of this research is to exploit the complementary information obtained by means of EE and ET sensing systems using different data fusion strategies, in order to develop an integrated device able to quickly and easily quantify ...
DOI:
10.1016/j.talanta.2018.11.046

17. Attitudes and Motivations Toward Craft Beer Consumption: An Explanatory Study in Two Different Countries

Author:
Rivaroli, Sergio; Lindenmeier, Jörg; Spadoni, Roberta
Source:
Journal of food products marketing 2019 v.25 no.3 pp. 276-294
ISSN:
1540-4102
Subject:
least squares,   etc   ; attitudes and opinions; beers; models; motivation; Germany; Italy;     Show all 7 Subjects
Abstract:
... This study adopts a revised model of the Theory of Planned Behaviour incorporating self-identity and desire for unique consumer products to understand and predict consumers’ motivation to drink craft beer in Germany (N=210) and Italy (N=211). Data were analysed using Partial Least Squares modelling (PLS) approach. The findings provide support that the extended TPB model is a useful tool for unders ...
DOI:
10.1080/10454446.2018.1531802

18. Cloud Point Extraction and Simultaneous Spectrophotometric Determination of Allura Red and Carmoisine using Wavelet Orthogonal Signal Correction–Partial Least Squares Method

Author:
Ahmadreza Amraei,; Niazi, Ali; Alimoradi, Mohammad; Hosseini, Mohammad
Source:
Journal of analytical chemistry 2019 v.74 no.2 pp. 93-99
ISSN:
1061-9348
Subject:
least squares,   etc   ; azo dyes; detection limit; graphs; prediction; wavelet;     Show all 6 Subjects
Abstract:
... This study presents a simple, safe, cheap, and efficient cloud point extraction method for the simultaneous pre-concentration and determination of Allura Red (AR) and Carmoisine (CA) in food samples. Wavelet orthogonal signal correction was applied to denoise the spectrophotometric data and in combination with partial least squares regression was used to determine each compound simultaneously afte ...
DOI:
10.1134/S1061934819020023

19. Transmission Low-Frequency Raman Spectroscopy for Quantification of Crystalline Polymorphs in Pharmaceutical Tablets

Author:
Inoue, Motoki; Hisada, Hiroshi; Koide, Tatsuo; Fukami, Toshiro; Roy, Anjan; Carriere, James; Heyler, Randy
Source:
Analytical chemistry 2019 v.91 no.3 pp. 1997-2003
ISSN:
1520-6882
Subject:
least squares,   etc   ; Raman spectroscopy; active pharmaceutical ingredients; chemometrics; geometry; prediction;     Show all 6 Subjects
Abstract:
... The purpose of this study was to quantify polymorphs of active pharmaceutical ingredients in pharmaceutical tablets using a novel transmission low-frequency Raman spectroscopy method. We developed a novel transmission geometry for low-frequency Raman spectroscopy and compared quantitative ability in transmission mode versus backscattering mode using chemometrics. We prepared two series of tablets, ...
DOI:
10.1021/acs.analchem.8b04365

20. Comparison of residence time models for pharmaceutical twin-screw-extrusion processes

Author:
Wesholowski, Jens; Podhaisky, Helmut; Thommes, Markus
Source:
Powder technology 2019 v.341 pp. 85-93
ISSN:
0032-5910
Subject:
least squares,   etc   ; extrusion; mechanical stress; mixing; models; powders;     Show all 6 Subjects
Abstract:
... Twin-Screw-Extrusion is an emerging and focused method with several applications in the pharmaceutical field. With respect to the desired process conditions, three different types of extrusion can be utilized such as Hot-Melt-, Wet- or Cold-Extrusion. For all of them the residence time and the residence time distribution are crucial process parameters determining the duration of thermal and mechan ...
DOI:
10.1016/j.powtec.2018.02.054