scholarly journals Site-specific estimation of peak-streamflow frequency using generalized least-squares regression for natural basins in Texas

1999 ◽  
Author(s):  
Simone Persiano ◽  
Jose Luis Salinas ◽  
Jery Russell Stedinger ◽  
William H. Farmer ◽  
David Lun ◽  
...  

2011 ◽  
Vol 49 (3) ◽  
pp. 301-321 ◽  
Author(s):  
Daniel M. Maggin ◽  
Hariharan Swaminathan ◽  
Helen J. Rogers ◽  
Breda V. O'Keeffe ◽  
George Sugai ◽  
...  

2020 ◽  
Author(s):  
James G. Saulsbury

AbstractThe analysis of patterns in comparative data has come to be dominated by least-squares regression, mainly as implemented in phylogenetic generalized least-squares (PGLS). This approach has two main drawbacks: it makes relatively restrictive assumptions about distributions and can only address questions about the conditional mean of one variable as a function of other variables. Here I introduce two new non-parametric constructs for the analysis of a broader range of comparative questions: phylogenetic permutation tests, based on cyclic permutations and permutations conserving phylogenetic signal. The cyclic permutation test, an extension of the restricted permutation test that performs exchanges by rotating nodes on the phylogeny, performs well within and outside the bounds where PGLS is applicable but can only be used for balanced trees. The signal-based permutation test has identical statistical properties and works with all trees. The statistical performance of these tests compares favorably with independent contrasts and surpasses that of a previously developed permutation test that exchanges closely related pairs of observations more frequently. Three case studies illustrate the use of phylogenetic permutations for quantile regression with non-normal and heteroscedastic data, testing hypotheses about morphospace occupation, and comparative problems in which the data points are not tips in the phylogeny.


2021 ◽  
Vol 13 (15) ◽  
pp. 8599
Author(s):  
Luo Jing ◽  
Joonho Moon

The aim of this research is to explore the determinants of airline CSR. Stakeholder theory is the theoretical underpinning. Chief executive officers (CEOs) are the research target, which is theoretically underpinned by upper echelon theory. For data collection, this study used data from COMPUSTAT, EXECUCOMP, KLD MSCI, LinkedIn, and the Bureau of Economic Analysis. Standard industry classification code 4512 was employed to obtain information on airline companies. Moreover, the number of observations was 154, the number of firms was 15, and the study period was 1999–2016. CSR domains include employment, the environment, and the product. The explanatory attributes are the CEO’s age, tenure, education, share ownership, stock option, and duality. Ordinary least squares and feasible generalized least squares regression analyses were executed for hypothesis testing. Regarding the results, employment CSR was positively affected by CEO age. This study found an inverted U-shaped relationship between CEO tenure and environmental CSR. Environmental CSR was also negatively influenced by stock options. Product CSR was positively associated with CEO age, whereas it was negatively associated with CEO duality.


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