106,137 research outputs found
William F. Chambers
No full textChambers, William.pdf - Funeral program for William F. Chambers. Service held in Fremont, Ohio.https://digitalcommons.georgiasouthern.edu/willowhillheritage-obituaries/8369/thumbnail.jp
Small Area Estimation with Skewed Data
No full textIn business surveys, data typically are skewed and the standard approach for small area estimation based on linear mixed models lead to inefficient estimates. In this paper, we discuss small area estimation techniques for skewed data that are linear following a suitable transformation. In this context, implementation of the empirical best linear unbiased prediction (EBLUP) approach under transformation to a linear mixed model is complicated. However, this is not the case with the model-based direct (MBD) approach (Chambers and Chandra, 2006), which is based on weighted linear estimators. We extend the MBD approach to skewed data using sample weights derived via model calibration based on a log transform model with random area effects. Our results show this estimator is both efficient and robust with respect to the distribution of these random effects. An application to real data demonstrates the satisfactory performance of the method
Chambers, F D, VX21359
No full textThis record was harvested from a previous catalogue system and will be withdrawn in 2025. Information in this record may be superseded or incomplete. Visit this record in UMA's new catalogue at: https://archives.library.unimelb.edu.au/nodes/view/376585Surname: CHAMBERS
Given Name(s) or Initials: F D
Military Service Number or Last Known Location: VX21359
Missing, Wounded and Prisoner of War Enquiry Card Index Number: 7041189573
Item: [2016.0049.08890] "Chambers, F D, VX21359
Imputation vs. Estimation of Finite Population Distributions
No full textEstimates of the distribution of hourly wage rates for employees are an important output for a national statistics agency. However, many employees are not paid by the hour and so their hourly wage rate data are effectively missing in a survey that attempts to collect this information. A standard approach in this situation is to impute these missing values using derived measures of this wage rate based on salary and hours worked data also collected in the survey. This paper contrasts this imputation approach with direct estimation of the wage rate distribution using the derived wage rate variable as an auxiliary. In particular, we focus on data obtained in the 2002 UK New Earnings Survey and use simulation based on actual and derived hourly wage rate data collected in this survey to compare two imputation approaches, one based on substituting the derived wage rate values for the missing actual values, the other using nearest neighbour imputation based on the derived wage rate, with two estimation approaches that use this variable as an auxiliary. The first of these is a semi-parametric extension of the Chambers and Dunstan (1986) estimator of the finite population distribution function, the other is a calibrated spline-based estimator of this function recently suggested by Harms and Duchesne (2004). Our conclusion is that an approach based on the semi-parametric estimator is best for these data. However, confidence interval estimation remains an open problem
M-Quantile Models for Small Area Estimation
No full textSmall area estimation techniques are employed when sample data are insufficient for acceptably precise direct estimation in domains of interest. These techniques typically rely on regression models that use both covariates and random effects to explain variation between domains. However, such models also depend on strong distributional assumptions, require a formal specification of the random part of the model and do not easily allow for outlier robust inference. We describe a new approach to small area estimation that is based on modelling quantile-like parameters of the conditional distribution of the target variable given the covariates. This avoids the problems associated with specification of random effects, allowing inter-domain differences to be characterized by the variation of area-specific M-quantile coefficients. The proposed approach is easily made robust against outlying data values and can be adapted for estimation of a wide range of area specific parameters, including that of the quantiles of the distribution of the target variable in the different small areas. Results from two simulation studies comparing the performance of the M-quantile modelling approach with more traditional mixed model approaches are also provided
A simple analytical model to study and control azimuthal instabilities in annular combustion chambers
No full textThis study describes a simple analytical method to compute the azimuthal
modes appearing in annular combustion chambers and help analyzing experimental, acoustic and LES (Large Eddy Simulation) data obtained in these
combustion chambers. It is based on a one-dimensional zero Mach number
formulation where N burners are connected to a single annular chamber. A
manipulation of the corresponding acoustic equations in this configuration
leads to a simple dispersion relation which can be solved by hand when the
interaction indices of the flame transfer function are small and numerically
when they are not. This simple tool is applied to multiple cases: (1) a single
burner connected to an annular chamber (N = 1), (2) two burners connected
to the chamber (N = 2), (3) four burners (N = 4). In this case, the tool
also allows to study passive control methods where two different types of
burners are mixed to control the azimuthal mode. Finally, a complete helicopter chamber (N = 15) is studied. For all cases, the analytical results
are compared to the predictions of a full three-dimensional Helmholtz solver
and a very good agreement is found. These results show that building very
simple analytical tools to study azimuthal modes in annular chambers is an
interesting path to control them
Austin Papers: Series IV, 1830
No full textCopy of transcript for a letter from T. Jefferson Chambers to Stephen F. Austin, in which Chambers informs Austin that the real estate business is improving and the natives are buying large tracts of land. Chambers also asks Austin's opinion on including descriptions of water courses on the land titles
The role of logistic constraints on termite construction of chambers and tunnels
No full textIn previous models of the building behaviour of termites, physical and logistic constraints that limit the movement of termites andpheromones have been neglected. Here, we present an individual-based mo del of termite construction that includes idealized constraints on the diffusion of pheromones, the movement of termites, and the integrity of the architecture that they construct. The model allows us to explore the extent to which the results of previous idealized models (typically realised in one or two dimensions via a set of coupled partial differential equations) generalize to a physical, 3-D environment. Moreover we are able to investigate new processes and architectures that rely upon these features. We explore the role of stigmergic recruitment in pillar formation, wall building, and the construction of royal chambers, tunnels and intersections. In addition, for the first time, we demonstrate the way in which the physicality of partially built structures can help termites to achieve efficient tunnel structures and to establish and maintain entrances in royal chambers. As such we show that, in at least some cases, logistic constraints can be important or even necessary in order for termites to achieve efficient, effective constructions
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Reflections on Chambers’ odyssey
No full textThis is a series of critical reflections on the contribution of Raymond J. Chambers to accounting thought, education and practice. It was stimulated by the recent publication of Accounting Thought and Practice Reform: Ray Chambers’ Odyssey, by Frank Clarke, Graeme Dean and Martin Persson, and draws extensively on the material presented in that book. It represents the author’s personal reflections on the material in The Odyssey rather than a comprehensive survey of the extensive literature surrounding Chambers’ work
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