23 papers · ranked by Valyu relevance
Marilyn N. Martinez, Mary J. Bartholomew, Arlene McDowell, Neal Davies
'Neal Davies'] Typically, investigations are conducted with the goal of generating inferences about a population (humans or animal). Since it is not feasible to evaluate the entire population, the study is conducted using a randomly selected subset of that population. With the goal of using the results generated from…
Shaila Musharoff, Danny Park, Andy Dahl, Joshua Galanter + 6 more
Identifying the genetic and environmental factors underlying phenotypic differences between populations is fundamental to multiple research communities. To date, studies have focused on the relationship between population and phenotypic mean. Here we consider the relationship between population and phenotypic variance…
Sohaib Ahmad, Nitesh Kumar Adichwal, Muhammad Aamir, Javid Shabbir + 3 more
'Najwan Alsadat' 'Mohammed Elgarhy' 'Hijaz Ahmad'] In this article, we have suggested a new improved estimator for estimation of finite population variance under simple random sampling. We use two auxiliary variables to improve the efficiency of estimator. The numerical expressions for the bias and mean square error…
Ben O’Neill
suggestions to clear the cobwebs Authors: ['Ben O’Neill'] This paper gives a holistic overview of both the design-based and model-based paradigms for sampling theory. Both methods are presented within a unified framework with a simple consistent notation, and the differences in the two paradigms are explained within…
Sohaib Ahmad, Sardar Hussain, Kalim Ullah, Erum Zahid + 6 more
'Muhammad Aamir' 'Javid Shabbir' 'Zubair Ahmad' 'Huda M. Alshanbari' 'Wejdan Alajlan' 'Anoop Kumar'] In this article, we proposed an improved finite population variance estimator based on simple random sampling using dual auxiliary information. Mathematical expressions of the proposed and existing estimators are…
Jayant Singh, Viplav K. Singh, Sachin Malik, Rajesh Singh
This paper proposes a class of ratio type estimators of finite population variance, when the population variance of an auxiliary character is known. Asymptotic expression for mean square error (MSE) is derived and compared with the mean square errors of some existing estimators. An empirical study is carried out to…
Mohammed Ahmed Alomair, Syed Aflake Hussain Shah Gardazi
This study is completed for the estimation of unknown population variance for the variable of mean and variance of interest. To accomplish this task, a new generalized class of robust kind of variance estimators proposed utilizing known descriptives of auxiliary variable, for example, Mid-range, Hodges-Lehmann Mean…
Hal Caswell, Silke F. van Daalen
A heterogeneous population is a mixture of groups differing in vital rates. In such a population, some of the variance in demographic outcomes (e.g., longevity, lifetime reproduction) is due to heterogeneity and some is the result of stochastic demographic processes. Many studies have partitioned variance into its…
Viplav Kumar Singh, Rajesh Singh
In this paper we deal with the estimation of population variance of the study variable y using auxiliary information on variable x. A family of ratio and product-type estimators are proposed using suitable transformation on both random variable x(auxiliary variable) and y(study variable).Up to the first order of…
Robin S. Waples
In the 1950s, James Crow introduced two indices of reproductive success that depend on mean and variance (V_k_) in offspring per parent. The Index of Variability is the primary factor determining effective population size (N_e_). The Index of Total Selection (; aka Opportunity for Selection) is the variance in relative…
Joel P. Heath, Peter Borowski, Shu-Dong Zhang
Real quantities can undergo such a wide variety of dynamics that the mean is often a meaningless reference point for measuring variability. Despite their widespread application, techniques like the Coefficient of Variation are not truly proportional and exhibit pathological properties. The non-parametric measure…
Julien F. Ayroles, Sean M. Buchanan, Chelsea Jenney, Kyobi Skutt-Kakaria + 4 more
Variability is ubiquitous in nature and a fundamental feature of complex systems. Few studies, however, have investigated variance itself as a trait under genetic control. By focusing primarily on trait means and ignoring the effect of alternative alleles on trait variability, we may be missing an important axis of…
Charles W. Champ, Andrew V. Sills
if both Y1 and Y2 are continuous random variables. The subscript "Y1, Y2" is a more explicit way of indicating that the covariance is a parameter of the joint distribution of Y1 and Y2. If Y1 and/or Y2 is a discrete random variable, integration is replaced with summation. For convenience, we let Y = [Y1, Y2] T . We…
Ziyue Chen, Eloise Kaizar
Randomized controlled trials (RCTs) provide strong internal validity compared with observational studies. However, selection bias threatens the external validity of randomized trials. Thus, RCT results may not apply to either broad public policy populations or narrow populations, such as specific insurance pools. Some…
Alexis Habineza, Romanus Odhiambo Otieno, George Otieno Orwa, Nicholas Makumi + 1 more
'Nicholas Makumi' 'Saeed Mian Qaisar'] The primary focus of all sample surveys is on providing point estimates for the parameters of primary interest, and also estimating the variance associated with those point estimates to quantify the uncertainty. Larger samples and important measurement tools can help to reduce the…
Yvonne C.J. Wientjes, Piter Bijma, Jérémie Vandenplas, Mario P.L. Calus
Different methods are available to calculate multi-population genomic relationship matrices. Since those matrices differ in base population, it is anticipated that the method used to calculate the genomic relationship matrix affect the estimate of genetic variances, covariances and correlations. The aim of this paper…
Daniel J. Lawson
It is human nature to look for patterns in the natural world. One pattern is the grouping of individuals into populations based on observable features, be these anatomical, physiological, cultural, socio-economic, political or linguistic. Many of these groupings are for convenience – for example, we verbally group…
Shuichi Kitada, Reiichiro Nakamichi, Hirohisa Kishino
Populations are shaped by their history. It is crucial to interpret population structure in an evolutionary context. Pairwise F_ST_ measures population structure, whereas population-specific F_ST_ measures deviation from the ancestral population. To understand the current population structure and a population’s history…
Laval Jacquin, Walter Guerra, Mariusz Lewandowski, Andrea Patocchi + 5 more
This work introduces WISER (whitening and successive least squares estimation refinement), an innovative and efficient method designed to enhance phenotype estimation by addressing population structure. WISER outperforms traditional methods such as least squares (LS) means and best linear unbiased prediction (BLUP) in…
Authors not listed
People of color in the United States are disproportionately and unfairly exposed to air pollution. Equity-oriented scientific evaluations quantifying these disparities often use population-average exposure metrics to capture the overall inequality within a system. Utilizing these metrics involves choices about the…
Esther Heid, Charles J. McGill, Florence H. Vermeire, William H. Green
Characterizing uncertainty in machine learning models has recently gained interest in the context of machine learning reliability, robustness, safety, and active learning. Here, we separate the total uncertainty into contributions from noise in the data (aleatoric) and shortcomings of the model (epistemic), further…
Brianna Greenstein, Danielle Elsey, Geoffrey Hutchison
Genetic algorithms (GAs) are a powerful tool to search large chemical spaces for inverse molecular design. However, GAs have multiple hyperparameters that have not been thoroughly investigated for chemical space searches. In this work, we examine the general effects of a number of hyperparameters, such as population…
Charles W. Champ, Andrew V. Sills
A case is made that researchers are interested in studying processes. Often the inferences they are interested in making are about the process and its associated population. On other occasions, a researcher may be interested in making an inference about the collection of individuals the process has generated. We will…