Aspects of Statistical Inference

Welsh, Andrew

doi:10.1002/9781118165423

Cited by 86 publications

(51 citation statements)

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“…One can in this respect distinguish between the frequentist's and the subjectivist's (or Bayesian) interpretation of the probability concept (Welsh, 1996). The former interprets the probability as the measured frequency that a variable is in a specific state.…”

Section: Probabilistic Safety Assessmentmentioning

confidence: 99%

The Use of Bayesian Belief Nets in Safety Assessment of Software Based Systems

Dahll¹,

Gran²

2000

International Journal of General Systems

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The paper describes an investigation of methods to perform a reliability and safety assessment of the software in programmable safety relevant systems. It emphasises in particular how disparate information sources and different quantitative and qualitative methods should be combined in such an assessment. It starts with a general discussion of rule based, probabilistic and expert judgement methods and heir applicability on software reliability. Then a method for combining different evidences in a reliability and safety assessment is pinpointed, viz. the Bayesian Belief Net (BBN) methodology. It is also illustrated how this method may be applied for safety assessment of software.

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Section: Probabilistic Safety Assessmentmentioning

confidence: 99%

The Use of Bayesian Belief Nets in Safety Assessment of Software Based Systems

Dahll¹,

Gran²

2000

International Journal of General Systems

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“…Despite the importance of the mass-loss process in terminating the AGB stellar evolutionary phase and in replenishing the ISM with newly-produced elements, the nature of the wind driving mechanism is still not well understood (e.g. Woitke 2006). Recent CO and scattered light observations of AGB objects show that winds from late-type stars are far from being smooth (e.g.…”

Section: Introductionmentioning

confidence: 99%

The variable mass loss of the AGB star WX Piscium as traced by the CO J = 1-0 through 7-6 lines and the dust emission

Decin

Hony

Koter

et al. 2007

A&A

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Context. Low and intermediate mass stars lose a significant fraction of their mass through a dust-driven wind during the Asymptotic Giant Branch (AGB) phase. Recent studies show that winds from late-type stars are far from being smooth. Mass-loss variations occur on different time scales, from years to tens of thousands of years. The variations appear to be particularly prominent towards the end of the AGB evolution. The occurrence, amplitude and time scale of these variations are still not well understood. Aims. The goal of our study is to gain insight into the structure of the circumstellar envelope (CSE) of WX Psc and map the possible variability of the late-AGB mass-loss phenomenon. Methods. We have performed an in-depth analysis of the extreme infrared AGB star WX Psc by modeling (1) the CO J = 1−0 through 7−6 rotational line profiles and the full spectral energy distribution (SED) ranging from 0.7 to 1300 µm. We hence are able to trace a geometrically extended region of the CSE. Results. Both mass-loss diagnostics bear evidence of the occurrence of mass-loss modulations during the last ∼2000 yr. In particular, WX Psc went through a high mass-loss phase (Ṁ ∼ 5 × 10 −5 M /yr) some 800 yr ago. This phase lasted about 600 yr and was followed by a long period of low mass loss (Ṁ ∼ 5 × 10 −8 M /yr). The present day mass-loss rate is estimated to be ∼6 × 10 −6 M /yr. Conclusions. The AGB star WX Psc has undergone strong mass-loss rate variability on a time scale of several hundred years during the last few thousand years. These variations are traced in the strength and profile of the CO rotational lines and in the SED. We have consistently simulated the behaviour of both tracers using radiative transfer codes that allow for non-constant mass-loss rates.

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“…Recall that the PQL method is based on a relatively coarse Taylor series expansion, which is a factor to be taken into consideration next to the numerical stability. The estimates for intraclass correlations displayed in Table 2 were obtained from Equation (2) and their standard errors were calculated using the delta method [32]. Details on the calculation are presented in Appendix 2.…”

Section: Inheritance Study Of Trichomes Density In Tomatomentioning

confidence: 99%

Negative variance components for non-negative hierarchical data with correlation, over-, and/or underdispersion

Oliveira

Molenberghs

Verbeke

et al. 2016

Journal of Applied Statistics

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The concept of negative variance components in linear mixed-effects models, while confusing at first sight, has received considerable attention in the literature, for well over half a century, following the early work of Chernoff [7] and Nelder [21]. Broadly, negative variance components in linear mixed models are allowable if inferences are restricted to the implied marginal model. When a hierarchical view-point is adopted, in the sense that outcomes are specified conditionally upon random effects, the variance-covariance matrix of the random effects must be positive-definite (positive-semi-definite is also possible, but raises issues of degenerate distributions). Many contemporary software packages allow for this distinction. Less work has been done for generalized linear mixed models. Here, we study such models, with extension to allow for overdispersion, for nonnegative outcomes (counts). Using a study of trichomes counts on tomato plants, it is illustrated how such negative variance components play a natural role in modeling both the correlation between repeated measures on the same experimental unit and over-or underdispersion. ARTICLE HISTORY

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Aspects of Statistical Inference

Cited by 86 publications

References 0 publications

The Use of Bayesian Belief Nets in Safety Assessment of Software Based Systems

The Use of Bayesian Belief Nets in Safety Assessment of Software Based Systems

The variable mass loss of the AGB star WX Piscium as traced by the CO J = 1-0 through 7-6 lines and the dust emission

Negative variance components for non-negative hierarchical data with correlation, over-, and/or underdispersion

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