1,721,060 research outputs found
Orthogonal stochastic duality from an algebraic point of view
No full textIn this dissertation I developed a theory for stochastic duality using
orthogonal polynomials as duality functions.
The results apply to a large class of Markov processes
with a common algebraic structure.
As we shall see, it is this mathematical structure that
is at the root of the orthogonal dualities. Moreover, I fitted these new
results into an algebraic approach to duality and self-duality.In questa tesi ho sviluppato una teoria per l'utilizzo della dualità stocastica attraverso
polinomi ortogonali come funzioni di dualità.
I risultati si applicano a una vasta classe di processi Markov
con una struttura algebrica comune.
Come vedremo, è questa struttura matematica che
è alla radice delle dualità ortogonali. Inoltre, ho inserito questi nuovi
risultati in un approccio algebrico alla dualità e all'auto-dualità
The Tradition of Change in Copies of the Santa Casa di Loreto: The Case of San Clemente in Venice
Full text linkWounds on Trial: Forensic Truth, Sanctity, and the Early Modern Visual Culture of Ritual Murder
Full text linkA splendid shrine for an ugly image : visual interactions in the Salviati Chapel at San Gregorio al Celio
Full text linkThis essay examines the history and decoration of the Salviati Chapel at San Gregorio al Celio in Rome as the repository of an image of the Virgin and in relation to two other chapels created by the same patron (Antonio Maria Salviati) in the church of San Giacomo in Augusta. In considering this dialogue among the chapels, I analyze the rationale behind the project at San Gregorio and its purpose to valorize antique images, reconstructing the particular design and function in the space of the now lost altarpiece with St. Gregory by Annibale Carracci. I also discuss more broadly th theme of the artistic experimentation and confrontation between "old" and "ruined" 'images' and "new" and "beautiful" 'works of art', that took place in Rome at the turn of the seventeenth century
Self-Duality of Markov Processes and Intertwining Functions
Full text linkWe present a theorem which elucidates the connection between self-duality of Markov processes and representation theory of Lie algebras. In particular, we identify sufficient conditions such that the intertwining function between two representations of a certain Lie algebra is the self-duality function of a (Markov) operator. In concrete terms, the two representations are associated to two operators in interwining relation. The self-dual operator, which arise from an appropriate symmetric linear combination of them, is the generator of a Markov process. The theorem is applied to a series of examples, including Markov processes with a discrete state space (e.g. interacting particle systems) and Markov processes with continuous state space (e.g. diffusion processes). In the examples we use explicit representations of Lie algebras that are unitarily equivalent. As a consequence, in the discrete setting self-duality functions are given by orthogonal polynomials whereas in the continuous context they are Bessel functions
Integrable heat conduction model
No full textWe consider a stochastic process of heat conduction where energy is redistributed along a chain between nearest neighbor sites via an improper beta distribution. Similar to the well-known Kipnis-Marchioro-Presutti (KMP) model, the finite chain is coupled at its ends with two reservoirs that break the conservation of energy when working at different temperatures. At variance with KMP, the model considered here is integrable and one can write in a closed form the -point correlation functions of the non-equilibrium steady state. As a consequence of the exact solution one can directly prove that the system is in a `local equilibrium' and described at the macro-scale by a product measure. Integrability manifests itself through the description of the model via the open Heisenberg chain with non-compact spins. The algebraic formulation of the model allows to interpret its duality relation with a purely absorbing particle system as a change of representation
A Joint Evaluation Methodology for Service Quality and User Privacy in Location Based Systems
Full text linkPervasive and ubiquitous applications provide novel and exciting services leveraging on a multitude of data obtained from people’s devices, adapting the computation to the context in which the user currently is. This improves the service quality of these applications, which can provide a more tailored configuration of the application itself depending on the user context and needs. In these scenarios privacy is of paramount importance, since users must be also be protected against the misuse of their personal data. Analyzing ubiquitous systems in terms of service quality and privacy issues is however a challenging task, due to the heterogeneity of the possible attacks, which makes it difficult to compare two applications. In this paper we propose a novel methodology to jointly evaluate the service quality and the privacy issues in ubiquitous applications in an extensible and comparable way, building on the data available in each part of the system to be analyzed, and defining service qualities and privacy issues so that they can be easily re-used in other analyses. Our evaluation on a candidate application highlights the benefits of our proposal, showing the dependency between privacy levels and service quality, and paving the way for a novel methodology for the definition of these scenarios
A new single red nodule on the abdomen of a woman with history of endometrial carcinoma: Noninvasive evaluation and histologic correlation
No full textAn 82-year-old woman was referred to our dermatology department from the oncology department with a new, well-demarcated, red papule on her abdomen (Fig 1). The patient had a history of endometrial carcinoma treated 3 years prior with extensive surgery and radiotherapy. She had been in complete remission for the past 2 years
- …
