974 resultados para supersymmetry and duality


Relevância:

30.00% 30.00%

Publicador:

Resumo:

In this paper we discuss the relationship and characterization of stochastic comparability, duality, and Feller–Reuter–Riley transition functions which are closely linked with each other for continuous time Markov chains. A necessary and sufficient condition for two Feller minimal transition functions to be stochastically comparable is given in terms of their density q-matrices only. Moreover, a necessary and sufficient condition under which a transition function is a dual for some stochastically monotone q-function is given in terms of, again, its density q-matrix. Finally, for a class of q-matrices, the necessary and sufficient condition for a transition function to be a Feller–Reuter–Riley transition function is also given.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The key problems in discussing duality and monotonicity for continuous-time Markov chains are to find conditions for existence and uniqueness and then to construct corresponding processes in terms of infinitesimal characteristics, i.e., q-matrices. Such problems are solved in this paper under the assumption that the given q-matrix is conservative. Some general properties of stochastically monotone Q-process ( Q is not necessarily conservative) are also discussed.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The European Skynet Radiometers network (EuroSkyRad or ESR) has been recently established as a research network of European PREDE sun-sky radiometers. Moreover, ESR is federated with SKYNET, an international network of PREDE sun-sky radiometers mostly present in East Asia. In contrast to SKYNET, the European network also integrates users of the CIMEL CE318 sky–sun photometer. Keeping instrumental duality in mind, a set of open source algorithms has been developed consisting of two modules for (1) the retrieval of direct sun products (aerosol optical depth, wavelength exponent and water vapor) from the sun extinction measurements; and (2) the inversion of the sky radiance to derive other aerosol optical properties such as size distribution, single scattering albedo or refractive index. In this study we evaluate the ESR direct sun products in comparison with the AERosol RObotic NETwork (AERONET) products. Specifically, we have applied the ESR algorithm to a CIMEL CE318 and PREDE POM simultaneously for a 4-yr database measured at the Burjassot site (Valencia, Spain), and compared the resultant products with the AERONET direct sun measurements obtained with the same CIMEL CE318 sky–sun photometer. The comparison shows that aerosol optical depth differences are mostly within the nominal uncertainty of 0.003 for a standard calibration instrument, and fall within the nominal AERONET uncertainty of 0.01–0.02 for a field instrument in the spectral range 340 to 1020 nm. In the cases of the Ångström exponent and the columnar water vapor, the differences are lower than 0.02 and 0.15 cm, respectively. Therefore, we present an open source code program that can be used with both CIMEL and PREDE sky radiometers and whose results are equivalent to AERONET and SKYNET retrievals.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The housing dimension in Kolkata has been changing in recent years. Since 1991, the city has initiated housing reform that has taken many forms and manifestations characterized by the reduction in social allocation, cutbacks in public funding and promotion of a real estate culture in close partnership between the state and private actors. There has been increasing concern about the housing condition of the poor in the deserted slums and bustee settlements amidst the evident ‘poor blindness’ in housing and investment policies. Against this background the paper discusses self-help housing in Kolkata. It seeks to answer a simple question – why the concept of self-help has not been recognised as a viable policy option for a city with widespread slums and bustee settlements by visiting the complex urban context of Kolkata set within the city's politics, poverty and policies. The paper concludes that there is a need to recognise the existing structural duality in the city and support self-help housing as a parallel housing approach.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

The human respiratory tract contains a highly adapted microbiota including commensal and opportunistic pathogens. Noncapsulated or nontypable Haemophilus influenzae (NTHi) is a human-restricted member of the normal airway microbiota in healthy carriers and an opportunistic pathogen in immunocompromised individuals. The duality of NTHi as a colonizer and as a symptomatic infectious agent is closely related to its adaptation to the host, which in turn greatly relies on the genetic plasticity of the bacterium and is facilitated by its condition as a natural competent. The variable genotype of NTHi accounts for its heterogeneous gene expression and variable phenotype, leading to differential host-pathogen interplay among isolates. Here we review our current knowledge of NTHi diversity in terms of genotype, gene expression, antigenic variation, and the phenotypes associated with colonization and pathogenesis. The potential benefits of NTHi diversity studies discussed herein include the unraveling of pathogenicity clues, the generation of tools to predict virulence from genomic data, and the exploitation of a unique natural system for the continuous monitoring of long-term bacterial evolution in human airways exposed to noxious agents. Finally, we highlight the challenge of monitoring both the pathogen and the host in longitudinal studies, and of applying comparative genomics to clarify the meaning of the vast NTHi genetic diversity and its translation to virulence phenotypes.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Concepts such as righteousness, equality, tolerance and freedom are nowadays considered fundamental issues that should prevail in any society. Balance and righteousness thrive however on a very thin layer. We are, in fact, living in an era of duality and antithetical paradigms. This essay approaches two Renaissance authors who dealt with the same matters in their works, at a very different time and through different ways of reflection: Thomas More and Sir Walter Raleigh.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

It is generally challenging to determine end-to-end delays of applications for maximizing the aggregate system utility subject to timing constraints. Many practical approaches suggest the use of intermediate deadline of tasks in order to control and upper-bound their end-to-end delays. This paper proposes a unified framework for different time-sensitive, global optimization problems, and solves them in a distributed manner using Lagrangian duality. The framework uses global viewpoints to assign intermediate deadlines, taking resource contention among tasks into consideration. For soft real-time tasks, the proposed framework effectively addresses the deadline assignment problem while maximizing the aggregate quality of service. For hard real-time tasks, we show that existing heuristic solutions to the deadline assignment problem can be incorporated into the proposed framework, enriching their mathematical interpretation.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Dissertação apresentada para obtenção do grau de Doutor em Biologia Celular pelo Instituto de Tecnologia Química e Biológica da Universidade Nova de Lisboa

Relevância:

30.00% 30.00%

Publicador:

Resumo:

Abstract: Nietzsche's Will-to-Power Ontology: An Interpretation of Beyond Good and Evil § 36 By: Mark Minuk Will-to-power is the central component of Nietzsche's philosophy, and passage 36 of Beyond Good and Evil is essential to coming to an understanding of it. 1 argue for and defend the thesis that will-to-power constitutes Nietzsche's ontology, and offer a new understanding of what that means. Nietzsche's ontology can be talked about as though it were a traditional substance ontology (i.e., a world made up of forces; a duality of conflicting forces described as 'towards which' and 'away from which'). However, 1 argue that what defines this ontology is an understanding of valuation as ontologically fundamental—^the basis of interpretation, and from which a substance ontology emerges. In the second chapter, I explain Nietzsche's ontology, as reflected in this passage, through a discussion of Heidegger's two ontological categories in Being and Time (readiness-to-hand, and present-at-hand). In a nutshell, it means that the world of our desires and passions (the most basic of which is for power) is ontologically more fundamental than the material world, or any other interpretation, which is to say, the material world emerges out of a world of our desires and passions. In the first chapter, I address the problematic form of the passage reflected in the first sentence. The passage is in a hypothetical style makes no claim to positive knowledge or truth, and, superficially, looks like Schopenhaurian position for the metaphysics of the will, which Nietzsche rejects. 1 argue that the hypothetical form of the passage is a matter of style, namely, the style of a free-spirit for whom the question of truth is reframed as a question of values. In the third and final chapter, 1 address the charge that Nietzsche's interpretation is a conscious anthropomorphic projection. 1 suggest that the charge rests on a distinction (between nature and man) that Nietzsche rejects. I also address the problem of the causality of the will for Nietzsche, by suggesting that an alternative, perspectival form of causality is possible.

Relevância:

30.00% 30.00%

Publicador:

Resumo:

La version intégrale de ce[te] mémoire [thèse] est disponible uniquement pour consultation individuelle à la Bibliothèque de musique de l’Université de Montréal (http://www.bib.umontreal.ca/MU).

Relevância:

30.00% 30.00%

Publicador:

Resumo:

In the first half of this memoir we explore the interrelationships between the abstract theory of limit operators (see e.g. the recent monographs of Rabinovich, Roch and Silbermann (2004) and Lindner (2006)) and the concepts and results of the generalised collectively compact operator theory introduced by Chandler-Wilde and Zhang (2002). We build up to results obtained by applying this generalised collectively compact operator theory to the set of limit operators of an operator (its operator spectrum). In the second half of this memoir we study bounded linear operators on the generalised sequence space , where and is some complex Banach space. We make what seems to be a more complete study than hitherto of the connections between Fredholmness, invertibility, invertibility at infinity, and invertibility or injectivity of the set of limit operators, with some emphasis on the case when the operator is a locally compact perturbation of the identity. Especially, we obtain stronger results than previously known for the subtle limiting cases of and . Our tools in this study are the results from the first half of the memoir and an exploitation of the partial duality between and and its implications for bounded linear operators which are also continuous with respect to the weaker topology (the strict topology) introduced in the first half of the memoir. Results in this second half of the memoir include a new proof that injectivity of all limit operators (the classic Favard condition) implies invertibility for a general class of almost periodic operators, and characterisations of invertibility at infinity and Fredholmness for operators in the so-called Wiener algebra. In two final chapters our results are illustrated by and applied to concrete examples. Firstly, we study the spectra and essential spectra of discrete Schrödinger operators (both self-adjoint and non-self-adjoint), including operators with almost periodic and random potentials. In the final chapter we apply our results to integral operators on .

Relevância:

30.00% 30.00%

Publicador:

Resumo:

We present an explicit description, in terms of central simple algebras, of a cup product map which occurs in the statement of local Tate duality for Galois modules of prime cardinality p. Given cocycles f and g, we construct a central simple algebra of dimension p^2 whose class in the Brauer group gives the cup product f\cup g. This algebra is as small as possible.