186,882 research outputs found
Comparison of hyperbolic and constant width simultaneous confidence bands in multiple linear regression under MVCS criterion
No full textA simultaneous confidence band provides useful information on the plausible range of the unknown regression model, and different confidence bands can often be constructed for the same regression model. For a simple regression line, Liu and Hayter (2007) propose use of the area of the confidence set corresponding to a confidence band as an optimality criterion in comparison of confidence bands; the smaller the area of the confidence set, the better the corresponding confidence band. This minimum area confidence set (MACS) criterion can begeneralized to a minimum volume confidence set (MVCS) criterion in the study of confidence bands for a multiple linear regression model. In this paper hyperbolic and constant width confidence bands for a multiple linear regression model over a particular ellipsoidal region of the predictor variables are compared under the MVCS criterion. It is observed that whether one band is better than the other depends on the magnitude of one particular angle that determines the size of the predictor variable region. When the angle and so the size of the predictor variable region is small, the constant width band is better than the hyperbolic band but only marginally. When the angle and so the size of the predictor variable region is large the hyperbolic band can be substantially better than the constant width band
Comparison of hyperbolic and constant width simultaneous confidence bands in multiple linear regression under MVCS criterion
No full textA simultaneous confidence band provides useful information on the plausible range of the unknown regression model, and different confidence bands can often be constructed for the same regression model. For a simple regression line, Liu and Hayter [W. Liu, A.J. Hayter, Minimum area confidence set optimality for confidence bands in simple linear regression, J. Amer. Statist. Assoc. 102 (477) (2007) pp. 181–190] proposed the use of the area of the confidence set corresponding to a confidence band as an optimality criterion in comparison of confidence bands; the smaller the area of the confidence set, the better the corresponding confidence band. This minimum area confidence set (MACS) criterion can be generalized to a minimum volume confidence set (MVCS) criterion in the study of confidence bands for a multiple linear regression model. In this paper hyperbolic and constant width confidence bands for a multiple linear regression model over a particular ellipsoidal region of the predictor variables are compared under the MVCS criterion. It is observed that whether one band is better than the other depends on the magnitude of one particular angle that determines the size of the predictor variable region. When the angle and hence the size of the predictor variable region is small, the constant width band is better than the hyperbolic band but only marginally. When the angle and hence the size of the predictor variable region is large the hyperbolic band can be substantially better than the constant width band
Exact simultaneous confidence intervals for a finite set of contrasts of three, four or five generally correlated normal means
No full textThe construction of a set of simultaneous confidence intervals for any finite number of contrasts of pp generally correlated normal means is considered. It is shown that the simultaneous confidence level can be expressed as a (p?2)(p?2)-dimensional integral for a general p?3p?3. This expression allows one to compute quickly and accurately, by using numerical quadrature, the required critical constants and multiplicity adjusted pp-values for at least p=3p=3, 4 and 5, involving only one-, two- and three-dimensional integrals, respectively. Real data examples from a drug stability study and a dose response study are used to illustrate the metho
A ray method of confidence band construction for multiple linear regression models
No full textThis paper addresses the problem of confidence band construction for a standard multiple linear regression model. A “ray” method of construction is developed which generalizes the method of Graybill and Bowden [1967. Linear segment confidence bands for simple linear regression models. J. Amer. Statist. Assoc. 62, 403–408] for a simple linear regression model to a multiple linear regression model. By choosing suitable directions for the rays this method requires only critical points from t-distributions so that the confidence bands are easy to construct. Both one-sided and two-sided confidence bands can be constructed using this method. An illustration of the new method is provided
Notes sur quatre documents d'ecclésiologie byzantine
No full textREB 37 1979 France p. 249-258
Patricia Karlin-Hayter, Notes sur quatre documents d'ecclésiologie byzantine. — A propos d'un ouvrage de J. Darrouzès (Documents inédits d'ecclésiologie byzantine, Paris 1966), l'auteur fait quelques remarques sur les élections épiscopales à Byzance. Ces observations portent sur les écrits respectifs d'Euthyme de Sardes sur les élections épiscopales, d'un anonyme sur les prérogatives des métropolites, de Nicétas d'Amasée à propos d'une querelle survenue au patriarcat à cause des votes d'élection, de Nicétas d'Ancyre sur les élections.Karlin-Hayter Patricia. Notes sur quatre documents d'ecclésiologie byzantine. In: Revue des études byzantines, tome 37, 1979. pp. 249-258
The Fightback of the Traditional Right in the Labour Party 1979 to 1987
No full textPhDThe Labour Party, having lost the General Election in 1979 after the Winter of
Discontent,d escendedin to internalt urmoil, ast he Left-dominatedN ational Executive
Committee( NEC) and conferences oughtr evengeo n the centre-rightP arliamentary
Labour Party (PLP) for its alleged failures in government. In 1981, the Social
Democratic Party (SDP) split from Labour, leaving the Labour Party facing possible
electoral extinction. However, the trade unions - founders of the Labour Party - came
to its rescue,le d by a small groupo f dedicatedg enerals ecretariesa nd staff, who set out
to regaint he NEC for the moderatesa, ndt o return the Labour Partyt o what they termed
"sanity" and electability,b y expellingM ilitant, safeguardingth e position of Deputy
LeaderD enis HealeyM P whenc hallengedb y Tony Benn MP, andd eliveringf or Neil
Kinnock MP (the Leader they helped install after the 1983 election) an NEC committed
to supporting him in changing the party.
The thesis documents the organisation of the Right within the PLP before 1981 (the
Manifesto Group and Labour First). It then covers the internal party groupings which
organised the Fightback of the party's traditional right (the St Ermins Group of trade
union leaders, Labour Solidarity Campaign and Forward Labour). It details their role in
the leadership and deputy leadership elections, in changing the NEC's political
composition and its workings, in the expulsion of Militant, in campaigning for One
Member One Vote, and in helping keep Moderate members within the party.
Contrary to some academic writings, this thesis shows how this was initially undertaken
without the supporto f the Leader,a nd it detailst he amounto f organisationawl ork
neededto achievec hangea nd assisti n Labour's re-emergencea s an electablep arty.
The researchd rawso n extensivep rivatep apersa nd archives,t ogetherw ith over 70
interviews with key players
Lake Erie's sport fish community
No full textTitle from PDF p. 1 (viewed on Apr. 8, 2010).; "Created: 4/16/2004 ...; Modified: 4/19/2006 ..."--Document properties screen.; Harvested from the web on 4/8/10Verso: Understanding Lake Erie's "dead zones" / developed by Ohio Sea Grant College Program, the Ohio State University ; Cindy Hayter Allison ... [et al.
Teresa Hayter, French aid T. Soper, P. Williams, A. Krassowski, British Development Policies Yonah Alexander, International Technical Assistance Experts
No full textChapuis Philippe. Teresa Hayter, French aid T. Soper, P. Williams, A. Krassowski, British Development Policies Yonah Alexander, International Technical Assistance Experts. In: Tiers-Monde, tome 8, n°29, 1967. Blocages et freinages de la croissance et du développement (2) pp. 171-174
Soft X-ray absorption spectroscopy of catalysts and related materials
No full textAn in situ investigation has been performed on a series of oxide based desulfurization absorbents and sulfur poisoned heterogeneous catalysts using the technique of sulfur K-edge Extended X-ray Absorption Fine Structure (EXAFS). The work has been complemented by the characterisation of standard sulfur containing materials using EXAFS, X-ray Photoelectron Spectroscopy (XPS) and Powder X-ray Diffraction (XRD).Using a model reactor, a zinc oxide based commercial absorbent (ICI 32-4) was treated with hydrogen sulfide at 370°C for several hours. Characterisation of these ex situ treated materials using powder XRD revealed two crystalline phases for each sample consisting of zinc oxide (wurtzite) and zinc sulfide (wurtzite) as well as a trace of calcium carbonate (aragonite). XPS analysis of the same series of samples confirmed the presence of sulfide. Analysis of the peak areas, after deconvolution of the oxygen 1s peak indicated a detectable sulfur profile which was maximum just after the midpoint of the reactor. Zinc K-edge EXAFS analysis of the materials yielded spectra similar to zinc oxide (wurtzite) but with additional peaks in the Fourier transform which were modelled to sulfur at 2.31 Å and 3.93 Å. Refinement of sulfur K-edge EXAFS confirmed the sulfide phase.In situ sulfur K-edge X-ray Absorption Spectroscopy (XAS) observations on the reaction of zinc oxide with hydrogen sulfide, using a specially constructed environmental cell, revealed a change in the local environment surrounding the sulfur atom as the reaction progressed. Analysis of the sulfur X-ray Absorption Near Edge Structure (XANES) region indicated a smooth transition occurred from chemisorbed hydrogen sulfide to zinc sulfide as the reaction progressed. Data obtained on the reaction was consistent with a mechanism of formation involving surface 2-dimensional islands of zinc sulfide which grow from a small number of zinc nucleating centres, to form 3-dimensional areas of bulk zinc sulfide.Nickel oxide and cobalt oxide were found to react with hydrogen sulfide by a similar mechanism forming the sulfides Ni3S2 and CoS, which was then further oxidized to cobalt sulfate.</p
Confidence bands for regression: the independence point method
No full textIn some circumstances for a linear model with ? parameters ? regression in Rd of the form ? one can find special points ? for which the usual least squares estimators ? of the expected response ? are uncorrelated, independent in the Gaussian case. Following Wynn (Biometrika, 1984) we use this to set up simple piecewise linear confidence bands in the case ?, namely the additive main effect model in multiple regression and some other cases.(this abstract contains LaTex markup that cannot be reproduced here; see the original paper for details)<br/
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