Teste Repositóri
2014-01-01
Resultados de pesquisa
Foram encontrados 852 registos.
This thesis presents a series of analytical models, based on the Generalized Beam
Theory (GBT), to describe the buckling and post-buckling behaviour of thin-walled prismatic
cold-formed steel structural members under compression and/or bending. GBT has a unique
feature of enabling an theoretical significance to the structural analysis of these members,
which can not be achieved by any other known method.
Initially, a review of the current state of the art in GBT is carried out, together with a
review on the most recent bibliography of alternative methods for post-buckling analysis of
thin-walled structures, allowing to define the specific goal of the present work – the setting up
of a consistent GBT-based methodology for post-buckling analysis. Next, a consistent
formulation based on the concept of Total Potential Energy in the framewo...
It is a well-known fact that most of the computing power spread over the Internet
simply goes unused, with CPU and other resources sitting idle most of the
time: on average less than 5% of the CPU time is effectively used. Desktop grids
are software infrastructures that aim to exploit the otherwise idle processing power,
making it available to users that require computational resources to solve longrunning
applications. The outcome of some efforts to harness idle machines can
be seen in public projects such as SETI@home and Folding@home that boost impressive
performance figures, in the order of several hundreds of TFLOPS each. At
the same time, many institutions, both academic and corporate, run their own desktop
grid platforms. However, while desktop grids provide free computing power,
they need to face important issues like fault tol...
Tese de doutoramento em Engenharia Civil, apresentada à Faculdade de Ciências e Tecnologia da Universidade de Coimbra
Web-based applications play an important role for the business of many enterprises. Numbers recently published, in the Internet Retailer Magazine, reveal the vibrancy of these businesses: in 2012 the volume of online sales grew about 19% in Latin America reaching $15.42 billion, grew 16% in US reaching $225.54 billion, grew 16% in Europe reaching $302.20 billion and grew 32% in Asia reaching $256.50 billion. Supporting this growth, there exist applications that are becoming increasingly complex in terms of functionalities and management. Such complexity can lead to scenarios of service unavailability or performance loss, damaging the revenue and the company’s reputation. According to Joshua Bixby, the president of Strangeloop Corporation, “one second of performance loss could cost $2.5 million in sales per year for a site that typicall...
A IBM publicou em 2001 um manifesto sobre a complexidade do software como obstáculo principal para o progresso da indústria de Tecnologias de Informação. Este manifesto levou a indústria e o meio académico a explorar novos paradigmas de desenvolvimento, manutenção e gestão de software. O paradigma de Computação Autónoma foi proposto pela IBM como uma solução para este problema, através do desenvolvimento de sistemas computacionais capazes de se gerir autonomamente a partir de objectivos de alto nível definidos pelos administradores. A auto-reparação é o aspeto da Computação Autónoma responsável pela deteção, diagnóstico e reparação autónoma de problemas resultantes de defeitos de software e hardware.
O conceito de auto-reparação tem uma utilidade muito importante nos serviços de streaming de vídeo. Estes serviços impõem requisitos de t...
Mestrado em Engenharia Zootécnica - Produção Animal - Instituto Superior de Agronomia
Mestrado em Ensino da Educação Física nos Ensinos Básico e Secundário
Mestrado em Desenvolvimento e Cooperação Internacional
Both Oporto and the North Region of Portugal definitions of tourism have evolved significantly during the past decade. In this journey it is relevant to highlight the contribution of the arrival of Low Cost Carriers (LCCs) at Francisco Sá Carneiro Airport, thus contributing to a rapid expansion of this region as a tourism destination.
Hence, this work project aims to understand the touristic and economic impact motivated by the entry of LCCs in Oporto and in the North Region of Portugal and tries to understand if this event was in fact an asset in the development of the aforementioned tourism destinations.
