955 resultados para Dirichlet character
Resumo:
by Adam Smith, LL.D., fellow of the royal societies of London and Edinburgh, one of the commissioners of his majesty's customs in Scotland, and formerly professor of moral philosophy in the University of Glasgow
Resumo:
We completely determine the spectra of composition operators induced by linear fractional self-maps of the unit disc acting on weighted Dirichlet spaces; extending earlier results by Higdon [8] and answering the open questions in this context.
Resumo:
Acknowledgements We acknowledge the support of the PRACSS Joint Industry Project at University of Aberdeen, funded by BG Group, BP, DONG, RWE Dea, Petrochina, Statoil and Tullow Oil. We also acknowledge the entire crew of the Urania Research vessel which was used to acquire the CHIRP lines, bathymetric data and gravity cores from the Tyrrhenian Sea, Italy. Our colleagues Michal Janocko and Mike Mayall are thanked for the discussions and comments. Our colleagues Pan Li, Amanda Santa Catharina, Guilherme Bozetti and Matheus Silveira Sobiesiak are thanked for their assistance during field work where some of the ideas in this paper were synthesized. Finally we thank one anonymous reviewer and Brian Romans for their invaluable feedback which made some of the ideas introduced in this review much more succinct.
Resumo:
Peer reviewed
Resumo:
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
Resumo:
Testing for differences within data sets is an important issue across various applications. Our work is primarily motivated by the analysis of microbiomial composition, which has been increasingly relevant and important with the rise of DNA sequencing. We first review classical frequentist tests that are commonly used in tackling such problems. We then propose a Bayesian Dirichlet-multinomial framework for modeling the metagenomic data and for testing underlying differences between the samples. A parametric Dirichlet-multinomial model uses an intuitive hierarchical structure that allows for flexibility in characterizing both the within-group variation and the cross-group difference and provides very interpretable parameters. A computational method for evaluating the marginal likelihoods under the null and alternative hypotheses is also given. Through simulations, we show that our Bayesian model performs competitively against frequentist counterparts. We illustrate the method through analyzing metagenomic applications using the Human Microbiome Project data.
Resumo:
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
Resumo:
We study the Dirichlet to Neumann operator for the Riemannian wave equation on a compact Riemannian manifold. If the Riemannian manifold is modelled as an elastic medium, this operator represents the data available to an observer on the boundary of the manifold when the manifold is set into motion through boundary vibrations. We study the Dirichlet to Neumann operator when vibrations are imposed and data recorded on disjoint sets, a useful setting for applications. We prove that this operator determines the Dirichlet to Neumann operator where sources and observations are on the same set, provided a spectral condition on the Laplace-Beltrami operator for the manifold is satisfied. We prove this by providing an implementable procedure for determining a portion of the Riemannian manifold near the area where sources are applied. Drawing on established results, an immediate corollary is that a compact Riemannian manifold can be reconstructed from the Dirichlet to Neumann operator where sources and observations are on disjoint sets.
Resumo:
We study the Dirichlet to Neumann operator for the Riemannian wave equation on a compact Riemannian manifold. If the Riemannian manifold is modelled as an elastic medium, this operator represents the data available to an observer on the boundary of the manifold when the manifold is set into motion through boundary vibrations. We study the Dirichlet to Neumann operator when vibrations are imposed and data recorded on disjoint sets, a useful setting for applications. We prove that this operator determines the Dirichlet to Neumann operator where sources and observations are on the same set, provided a spectral condition on the Laplace-Beltrami operator for the manifold is satisfied. We prove this by providing an implementable procedure for determining a portion of the Riemannian manifold near the area where sources are applied. Drawing on established results, an immediate corollary is that a compact Riemannian manifold can be reconstructed from the Dirichlet to Neumann operator where sources and observations are on disjoint sets.
Resumo:
The Dirichlet distribution is a multivariate generalization of the Beta distribution. It is an important multivariate continuous distribution in probability and statistics. In this report, we review the Dirichlet distribution and study its properties, including statistical and information-theoretic quantities involving this distribution. Also, relationships between the Dirichlet distribution and other distributions are discussed. There are some different ways to think about generating random variables with a Dirichlet distribution. The stick-breaking approach and the Pólya urn method are discussed. In Bayesian statistics, the Dirichlet distribution and the generalized Dirichlet distribution can both be a conjugate prior for the Multinomial distribution. The Dirichlet distribution has many applications in different fields. We focus on the unsupervised learning of a finite mixture model based on the Dirichlet distribution. The Initialization Algorithm and Dirichlet Mixture Estimation Algorithm are both reviewed for estimating the parameters of a Dirichlet mixture. Three experimental results are shown for the estimation of artificial histograms, summarization of image databases and human skin detection.
Resumo:
We consider a parametric semilinear Dirichlet problem driven by the Laplacian plus an indefinite unbounded potential and with a reaction of superdifissive type. Using variational and truncation techniques, we show that there exists a critical parameter value λ_{∗}>0 such that for all λ> λ_{∗} the problem has least two positive solutions, for λ= λ_{∗} the problem has at least one positive solutions, and no positive solutions exist when λ∈(0,λ_{∗}). Also, we show that for λ≥ λ_{∗} the problem has a smallest positive solution.
Resumo:
This article introduces a theoretical framework for the analysis of the player character (PC) in offline computer role-playing games (cRPGs). It derives from the assumption that the character constitutes the focal point of the game, around which all the other elements revolve. This underlying observation became the foundation of the Player Character Grid and its constituent Pivot Player Character Model, a conceptual framework illustrating the experience of gameplay as perceived through the PC’s eyes. Although video game characters have been scrutinised from many different perspectives, a systematic framework has not been introduced yet. This study aims to fill that void by proposing a model replicable across the cRPG genre. It has been largely inspired by Anne Ubersfeld’s semiological dramatic character research implemented in Reading Theatre I (1999) and is demonstrated with reference to The Witcher (CD Projekt RED 2007).
Resumo:
By considering the spatial character of sensor-based interactive systems, this paper investigates how discussions of seams and seamlessness in ubiquitous computing neglect the complex spatial character that is constructed as a side-effect of deploying sensor technology within a space. Through a study of a torch (`flashlight') based interface, we develop a framework for analysing this spatial character generated by sensor technology. This framework is then used to analyse and compare a range of other systems in which sensor technology is used, in order to develop a design spectrum that contrasts the revealing and hiding of a system's structure to users. Finally, we discuss the implications for interfaces situated in public spaces and consider the benefits of hiding structure from users.
Resumo:
Changes in the television industry with regards to the development of new media technologies are having a significant impact on audience engagement with television drama. This article explores how the internet is being used to extend audience engagement onto platforms other than the television set to the point where television drama should increasingly be reconsidered as trans-media drama. However audience engagement with the various elements of a trans-media drama text is complex. By exploring audience attitudes towards character in the British television series Spooks and its associated online games, this article argues that in an increasingly converged media landscape audiences transfer values between platforms. Consequently the audience's perception of control in relation to their engagement with a trans-media drama text such as Spooks becomes complicated with values associated with television proving key to their engagement with the same fictional world in the form of games.
Resumo:
This paper considers recent attempts to introduce managerial reform in higher education. In exploring the issues the paper draws on an interviewing programme conducted with female and male academics in Sweden and England responsible for delivering change: heads of department, heads of division and principal lecturers. The aim is to examine the implications for the day-to-day work of academics arising from the reforms and to consider the gender implications. The paper conceptualises the areas of academic responsibility along the following dimensions identified by the academics themselves: dog work, tough work, care work, real work and nice work. In bringing into sharper focus the harsher realities of academe, and exploring the overlap and connectivity between gender and academic labour, it is argued that intellectual labour is hard work indeed, particularly for women.