65 research outputs found
Weak convergence to a class of two-parameter Gaussian processes from a Lévy sheet
In this paper, we show an approximation in law, in the space of the continuous functions on , of two-parameter Gaussian processes that can be represented as a Wiener type integral by processes constructed from processes that converge to the Brownian sheet. As an application, we obtain a sequence of processes constructed from a Lévy sheet that converges in law towards the fractional Brownian sheet
Weak convergence to a class of two-parameter Gaussian processes from a Lévy sheet
In this paper, we show an approximation in law, in the space of the continuous functions on , of two-parameter Gaussian processes that can be represented as a Wiener type integral by processes constructed from processes that converge to the Brownian sheet. As an application, we obtain a sequence of processes constructed from a Lévy sheet that converges in law towards the fractional Brownian sheet
On the strong convergence of multiple ordinary integrals to multiple Stratonovich integrals
Given , a sequence of approximations to a standard Brownian motion in such that converges almost surely to , we show that, under regular conditions on the approximations, the multiple ordinary integrals with respect to converge to the multiple Stratonovich integral. We are integrating functions of the type where for each has continuous derivatives in . We apply this result to approximations obtained from uniform transport processes
Strong approximations of Brownian sheet by uniform transport processes.
Many years ago, Griego, Heath and Ruiz-Moncayo proved that it is possible to define realizations of a sequence of uniform transport processes that converges almost surely to the standard Brownian motion, uniformly on the unit time interval. In this paper we extend their results to the multi parameter case. We begin constructing a family of processes, starting from a set of independent standard Poisson processes, that has realizations that converge almost surely to the Brownian sheet, uniformly on the unit square. At the end the extension to the d-parameter Wiener processes is presented
Coinfection in a stochastic model for bacteriophage systems
A system modeling bacteriophage treatments with coinfections in a noisy context is analysed. We prove that in a small noise regime, the system converges in the long term to a bacteria-free equilibrium. Moreover, we compare the treatment with coinfection with the treatment without coinfection, showing how coinfection affects the convergence to the bacteria-free equilibrium
Arthritis in acute febrile neutrophilic dermatosis (Sweet's Syndrome)
Sir: Acute febrile neutrophilic dermatosis
or Sweet's syndrome' is an uncommon condition
characterised by fever, polymorphonuclear
leucocytosis, painful erythematous
cutaneous plaques, and a dense dermal infiltrate
of neutrophils without vasculitis at the
site of the skin lesions. Although many
investigators suggest that acute febrile neutrophilic
dermatosis is a hypersensitivity reaction,2
no defmitive cause is known. The role
of the neutrophil as a cause or effect in this
syndrome has not been clarified. Acute febrile
neutrophilic dermatosis is histologically and
clinically mimicked by several disorders, and
the differential diagnosis with pyoderma gangrenosum3
and with some reactive erythemas
such as erythema multiforme2 is usually difficult
LEARN-SQL: herramienta de gestión de ejercicios de SQL con autocorrección
Algunas herramientas de autocorrección existen
ya en el ámbito de la docencia informática.
No obstante en asignaturas de bases de datos
el problema es especialmente complejo debido
a la gran variedad de tipos de ejercicios (los
sistemas existentes se limitan a consultas) y
a que éstos no tienen solución única. Nuestro
sistema tiene como objetivo corregir automáticamente
cualquier tipo de sentencia SQL (consultas,
actualizaciones, procedimientos, disparadores,
creación de índices, etc.) y discernir
si la respuesta aportada por el estudiante es o
no correcta con independencia de la solución
concreta que éste proponga. En esta comunicación
presentaremos específicamente el módulo
encargado de la gestión de ejercicios y todas
las tipologías de estos que estamos utilizando
en la actualidad.Peer Reviewe
Uso de LEARN-SQL en el aprendizaje cooperativo de bases de datos
En este artículo se describen los cambios
efectuados en algunas asignaturas del área de
bases de datos en dos vertientes: organizativa y tecnológica. En la primera, el objetivo principal ha sido la introducción de técnicas de aprendizaje
cooperativo. En la segunda, el objetivo ha sido potenciar el autoaprendizaje y el autoevaluación a través de la herramienta LEARN-SQL. Los cambios relacionados con las dos vertientes se han aplicado, hasta el momento, a asignaturas distintas. Para finalizar el artículo, se hace una valoración de los resultados obtenidos, y se trazan las líneas de futuros cambios orientados a la combinación de las dos vertientes.Peer ReviewedPostprint (author’s final draft
E-assessment of relational database skills by means of LearnSQL
LearnSQL is a software system that allows the automatic and efficient e-learning and e-assessment of relational database skills. It has been used at the Barcelona School of Informatics for 18 semesters with an average of 200 students per semester. This paper shows the functionalities of LearnSQL subsystems by means of specific and understandable examples.Peer ReviewedPostprint (published version
Integració i avaluació de la competència genèrica transversal actitud adequada davant el treball en assignatures de bases de dades
El canvi al nou Espai Europeu d'Educació Superior va portar a la Facultat d’Informàtica de Barcelona de la Universitat Politècnica de Catalunya a incorporar competències genèriques tranversals en els seus plans d’estudi. En aquest article es presenta com s’ha integrat la competència actitud adequada davant el treball en les assignatures de bases de dades del Grau en Enginyeria Informàtica en la especialitat d’Enginyeria del Software, el mètode d’avaluació utilitzat i es comenten els resultats obtinguts en els darrers tres anys.Peer ReviewedPostprint (published version
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