239 research outputs found
Random series in Lp(X, Σ,μ) using unconditional basic sequences and lp stable sequences: A result on almost sure almost everywhere convergence
Here we study the almost sure almost everywhere convergence of random series of the form Σ∞ i=1αifi in the Lebesgue spaces L p(X, Σ,μ), where the ai's are centered random variables, and the fi's constitute an unconditional basic sequence or an lp stable sequence. We show that if one of these series converges in the norm topology almost surely, then it converges almost everywhere almost surely.Fil: Medina, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; ArgentinaFil: Cernuschi Frias, Bruno. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemática Alberto Calderón; Argentin
Brane-world localized gravity and the AdS/CFT correspondence
Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2018, Tutor: Jaume Garriga TorresIn this report, corrections to the gravitational potential of a massive point particle are computed for observers located in a brane-world scenario with intrinsic de Sitter (dS4) geometry embedded in an Anti de Sitter (AdS5) bulk. The results are compared, using the AdS/CFT correspondence, to a description in terms of four dimensional general relativity coupled to a conformal field theory
An open-source software-defined radio collection for GNSS receivers
The master's thesis has as a main objective to encompass the progress and efforts dedicated to the development and improvement of an open-source collection of Software-Defined Radios (SDR) for Global Navigation Satellite Systems (GNSS). Most of the efforts have focused in conducting an extensive test campaign for each implementation of the collection, with the aim of determining their characteristics at every stage in the positioning process, and make the required adjustments to achieve the defined performance. This document details the structure of the collection, the adjustments made to improve each code-base as well as the metrics considered to assess the obtained results.Outgoin
Customisable e-training programmes based on trainees profiles
Dissertation presented at Faculdade de Ciências e Tecnologia of Universidade Nova de Lisboa to obtain the Master degree in Electrical and Computer EngineeringOnline training (e-training) is a major driver to promote the development of competencies and knowledge in enterprises. A lack of customizable e-training programmes based on trainees‟ profiles and of continuous maintenance of the training materials prevents the sustainability of industrial training deployment. This dissertation presents a training strategy and a methodology for building training courses with the purpose to provide a trainee oriented industrial training development. The training strategy intends to facilitate the management of all the training components and tasks to be able to build a training structure focused in a specific planned objective. The methodology for building e-training courses proposes to create customizable training materials in an easier way, enabling various organizations to participate actively on its production.
Additionally a customisable training programme framework is presented. It is supported by a compliant ontology-based model able to support adaptable training contents, orchestration service, facilitating the efficiency and acceptance of the e-training programmes delivery
A convergence result for unconditional series in Lp(u)
We give sufficient conditions for the convergence almost everywhere of the expansion with respect to an unconditional basis forfunctions in Lp, p ≥ 2. This result extends the classical theorem ofMenchoff and Rademacher for orthogonal series in L2.Fil: Medina, Juan Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemáticas; Argentina;Fil: Cernuschi Frias, Bruno. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Saavedra 15. Instituto Argentino de Matemáticas; Argentina
Implementación de estrategias de gamificación y buenas practicas para el sitio web del Congreso Internacional de Ingeniería de la UPAO
La gamificación es un conjunto de técnicas de juego utilizadas en entornos no lúdicos,
como por ejemplo el ambiente laboral, selección de personal, sitios web. La
gamificación en un Sitio Web busca que los usuarios se vuelvan fieles al Sitio,
premiándolos por realizar acciones como comentar, publicar artículos, entre otras.
Para plantear todas estas acciones existen plataformas como “Captain Up”, la cual le
permite a los usuarios ganar puntos, medallas, subir de nivel (Principiante, Avanzado)
realizando algunas acciones como compartir información en sus perfiles sociales, ver
vídeos, twittear, dar Me Gusta, etc. A medida que los usuarios realicen una, dos, más
veces las acciones mencionadas, se volverán fieles al Sitio Web. Esta fidelidad se mide
a tráves de las visitas recurrentes que el Sitio recibe.
Existen muchas herramientas que permiten saber la cantidad de visitantes, clasificada
por país, ciudad, sistema operativo, navegador utilizado, redes sociales. La más usada y
recomendada es “Google Analytics”.
Para que la experiencia del usuario sea la mejor, el Sitio Web debe contar con un
Diseño Interactivo. Las tecnologías que permiten realizar este tipo de Diseño son:
HTML5, CSS3, jQuery, Bootstrap, Responsive Web Design.The gamification is a set of playing techniques in not used in recreational environments,
for example work environment, recruitment, website. The gamification on a website
seeks to become loyal users to the Site, by rewarding them do things like comment,
publish articles, among others.
To put all these actions are platforms like ""Captain Up"", which allows users to earn
points, medals, level up (Beginner, Advanced) performing some actions as sharing
information on their social profiles, watch videos, tweet, give like, etc. As users perform
one, two, most times the above actions, faithful to the Web site will become. This
loyalty is measured through the recurring visits the site receives.
There are many tools that let you know the number of visitors, classified by country,
city, operating system, browser used, social networks. The most used and recommended
is ""Google Analytics"".
So the user experience is the best, the Web site must have an interactive design. The
technologies that allow this type of design are: HTML5, CSS3, jQuery, Bootstrap,
Responsive Web Design.Tesi
Validez pronóstica de índice de fibrosis - 4 para la mortalidad en pacientes con enfermedad hepática crónica
Objetivo: Hallar la validez pronóstica de índice de fibrosis-4 para la mortalidad en pacientes con enfermedad hepática crónica
Materiales y método: se realizó un estudio analítico transversal, cohorte retrospectiva a partir de historias clínicas, se usó el programa STATA versión 15.2; se analizó la normalidad de la variable cuantitativa, para la asociación entre la puntuación del FIB-4 y la presencia de mortalidad se usó regresión logística en modelos crudos y ajustados con las variables intervinientes en mortalidad.
Resultados: Se revisaron las historias clínicas de 320 pacientes, de las cuales se incluyeron 313 debido a los criterios de selección. Se realizó un modelo de supervivencia, se encontró que los pacientes con un tiempo de enfermedad mayor tenían menor probabilidad a morir durante el tiempo de hospitalización actual. Se encontró una sensibilidad del 56,25% para la escala MELD a comparación del 92,54% de Fib-4, mientras que una especificidad mayor para la escala MELD a comparación que su contraparte para la mortalidad general. El área bajo la curva ROC según la mortalidad general para FIB 4 fue de un valor de 0.8477 mientras que para MELD resultó en 0.8649.
Conclusiones: la escala FIB-4 y MELD son válidas para la predicción de mortalidad en los pacientes con enfermedad hepática crónicaObjective: To find the prognostic validity of fibrosis index-4 for mortality in patients with chronic liver disease.
Materials and method: a cross-sectional analytical study was carried out, a retrospective cohort from medical records, using the STATA program version 15.2; the normality of the quantitative variable was analyzed, for the association between the FIB-4 score and the presence of mortality, logistic regression was used in crude models and adjusted with the variables intervening in mortality.
Results: The medical records of 320 patients were reviewed, of which 313 were included due to the selection criteria. A survival model was carried out, it was found that patients with a longer illness time were less likely to die during the current hospitalization time. A sensitivity of 56.25% was found for the MELD scale compared to 92.54% for Fib-4, while a higher specificity for the MELD scale compared to its counterpart for general mortality. The area under the ROC curve according to general mortality for FIB 4 was 0.8477 while for MELD it was 0.8649.
Conclusions: the FIB-4 and MELD scale are valid for the prediction of mortality in patients with chronic liver disease.Tesi
Challenges and opportunities of mobile payments innovations
Innovation in financial services is a major trend on the sector and the payments industry is no
exception to that. New ways of paying, as mobile payments, are emerging and changing the
payments market. Non-financial institutions are entering the market through the provision of
mobile payments, threatening the dominant position banks hold in the industry. This thesis aim
is to analyze mobile payments as a service innovation, primarily through the spectrum of banks
as old incumbents in this market. To understand the traits and main characteristics of these
products, as well as how innovation in mobile payments is changing or even creating a new
market.
The results of the study suggest that we are facing a radical innovation, according to the Gallouj
and Weinstein (1997) modes and models of innovation, as there is a completely new system
behind mobile payments services. This innovation is assuming different forms and is still hard
to infer if mobile payments are creating a new market, as these kind of services are still majorly
seen by experts in the area, who were interviewed for this study, as a complement to other ways
of paying, regardless of being a complete new system with different competences needed for
operating. With regard to the new and different providers of these services operating in the
market, it was found that they can be segmented into three clusters with different characteristics:
Banks, which are the traditional incumbents of this market; Mobile Network Operators &
Manufacturers, which are extremely focused on technology and data; Others, which include
companies from other sectors, fintechs or other startups, characterized by being very innovative
and flexible. These new services come with new market dynamics involving companies that
traditionally were not associated with the provision of financial services, and threatening the
relevance banks used to have in the payments industry.A inovação nos serviços financeiros é uma tendência geral do sector e a área dos pagamentos
não é exceção. A área financeira dos pagamentos tem sofrido enormes mudanças, o que está a
ter implicações nos mercados financeiros, e em particular nos serviços de pagamentos. Várias
instituições não financeiras estão a entrar no mercado através da criação de novos serviços de
pagamentos móveis, ameaçando a posição dominante que os bancos possuíam na área. Esta tese
tem como objetivo analisar os pagamentos móveis enquanto uma inovação em serviços,
focando principalmente a perspetiva dos bancos que tradicionalmente possuíam uma posição
dominante neste mercado. A tese pretende entender e discutir as principais características destes
produtos inovadores de pagamentos móveis, bem como se estes novos serviços estão a mudar
ou mesmo a criar um novo mercado. Os resultados deste estudo sugerem que estamos perante uma inovação radical, pois de acordo com os modos e modelos de inovação de Gallouj e Weinstein (1997), os serviços de pagamentos móveis são um novo sistema de pagamentos. Esta inovação tem assumido diferentes formas, havendo ainda um elevado grau de ambiguidade quanto à sua capacidade de geração de um novo mercado, já que este tipo de serviços são considerados por especialistas da área, que foram entrevistados no âmbito deste estudo, como um complemento a outros métodos de pagamento. Isto, apesar de se tratar de um sistema novo com diferentes competências necessárias à sua execução e utilização. O estudo conclui que os fornecedores destes serviços podem ser segmentados em três clusters com diferentes características: Bancos, os tradicionais incumbentes deste mercado; Fabricantes e Operadores de redes móveis, que são extremamente focados em tecnologia e data; Outros, incluindo empresas de outros sectores, fintechs e outras start-ups, caracterizados por serem extremamente inovadores e flexíveis. O estudo evidência que estes novos serviços de pagamentos trazem novas dinâmicas ao mercado envolvendo empresas que tradicionalmente não estariam associados à prestação de serviços financeiros, o que ameaça a relevância dos bancos no sector dos pagamentos
From mobile phone data to the spatial structure of cities
Pervasive infrastructures, such as cell phone networks, enable to capture
large amounts of human behavioral data but also provide information about the
structure of cities and their dynamical properties. In this article, we focus
on these last aspects by studying phone data recorded during 55 days in 31
Spanish metropolitan areas. We first define an urban dilatation index which
measures how the average distance between individuals evolves during the day,
allowing us to highlight different types of city structure. We then focus on
hotspots, the most crowded places in the city. We propose a parameter free
method to detect them and to test the robustness of our results. The number of
these hotspots scales sublinearly with the population size, a result in
agreement with previous theoretical arguments and measures on employment
datasets. We study the lifetime of these hotspots and show in particular that
the hierarchy of permanent ones, which constitute the "heart" of the city, is
very stable whatever the size of the city. The spatial structure of these
hotspots is also of interest and allows us to distinguish different categories
of cities, from monocentric and "segregated" where the spatial distribution is
very dependent on land use, to polycentric where the spatial mixing between
land uses is much more important. These results point towards the possibility
of a new, quantitative classification of cities using high resolution
spatio-temporal data.Comment: 14 pages, 15 figure
Uncovering the spatial structure of mobility networks
The extraction of a clear and simple footprint of the structure of large,
weighted and directed networks is a general problem that has many applications.
An important example is given by origin-destination matrices which contain the
complete information on commuting flows, but are difficult to analyze and
compare. We propose here a versatile method which extracts a coarse-grained
signature of mobility networks, under the form of a matrix that
separates the flows into four categories. We apply this method to
origin-destination matrices extracted from mobile phone data recorded in
thirty-one Spanish cities. We show that these cities essentially differ by
their proportion of two types of flows: integrated (between residential and
employment hotspots) and random flows, whose importance increases with city
size. Finally the method allows to determine categories of networks, and in the
mobility case to classify cities according to their commuting structure.Comment: 10 pages, 5 figures +Supplementary informatio
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