1,720,976 research outputs found
Investigação e desenho de uma rede pan-académica para Angola
Full text linkNuma constante tentativa de replicar localmente os casos de sucesso das sociedades mais avançadas, as sociedades modernas de tudo têm feito para melhorar a qualidade de vida das suas comunidades. A par desta circunstância, o mundo educacional tudo tem feito com o objetivo de manter linear o acesso a informação, independentemente do local ou do horário, e para isso, têm sido colocados muitos recursos na disponibilização do acesso à Internet. A dissertação apresentada centra-se na investigação e desenho da extensão da rede académica angolana ao serviço Eduroam, por esta ser uma rede de dimensão mundial que contribui fortemente para a mobilidade e melhoria da qualidade de vida das comunidades académicas. O levantamento do estado da rede académica angolana, o estudo e definição de um mapa que promova a instalação de uma rede pan-académica, bem como os mecanismos para a ligação da mesma na rede Eduroam foram tidos em conta. Os servidores RADIUS são o padrão da implementação do serviço Eduroam, pois, a GÉANT como equipa gestora líder deste serviço, mantém uma hierarquia de servidores RADIUS para o funcionamento adequado do serviço, permitindo o encaminhamento e resposta de solicitações por via desta hierarquia quando os utilizadores do serviço estão em mobilidade. No caso desta dissertação, optou-se por usar o FreeRADIUS, uma plataforma que é compatível com RADIUS e também usada em vários pontos da rede Eduroam, por ser opensource e flexível na configuração. A disponibilização do serviço para utilizadores internos com a autenticação no servidor Identity Provider local, bem como, o acesso a rede por parte de utilizadores externos via servidor proxy, foram testados e validados, de modo a garantir acesso à rede a quando da mobilidade dos mesmos.In a constant attempt to replicate at a local level the cases of success of more advanced societies, modern societies have excelled in attempts to improve the quality of life of their communities. Accompanying these efforts, academia has also gone the length to keep the access to information in an effortless manner, regardless of time and place, and for this, a significant amount of resources have been committed to provide access to the Internet. This dissertation is focused on the research and design of the extension of the academic network of Angola to the Eduroam service, as this is a world-wide network that strongly contributes to the mobility of the academia and to the increase of the quality of life of its members. The identification of the status of the Angolan academic network, the study and definition of a roadmap that promotes the connection of the Angolan academic network to Eduroam, as well the study of all the required mechanisms were taken into consideration. RADIUS servers are the standard for Eduroam, as the management team of this service, GÉANT, maintains a hierarchy of RADIUS servers to support the routing and response of solicitations from users that are in mobility. In the case of this research, the FreeRADIUS software was used, because this is compatible with RADIUS, it’s used in several points of the Eduroam network and it’s open source and very flexible in its configuration. The availability of the service in the deployed testbed, both to internal and mobility users was achieved. The internal users were authenticated via the local Identity Provider server, while the mobility users were authenticated via the proxy server. Conclusions are presented to deploy the Eduroam service in the academic network in Angola
SocialBike:Quantified-Self Data as Social Cue in Physical Activity
No full textQuantified-self application is widely used in sports and health management; the type and amount of data that can be fed back to the user are growing rapidly. However, only a few studies discussed the social attributes of quantified-self data, especially in the context of cycling. In this study, we present “SocialBike,” a digital augmented bicycle that aims to increase cyclists’ motivation and social relatedness in physical activity by showing their quantified-self data to each other. To evaluate the concept through a rigorous control experiment, we built a cycling simulation system to simulate a realistic cycling experience with SocialBike. A within-subjects experiment was conducted through the cycling simulation system with 20 participants. Quantitative data were collected with the Intrinsic Motivation Inventory (IMI) and data recorded by the simulation system; qualitative data were collected through user interviews. The result showed that SocialBike increase cyclists’ intrinsic motivation, perceived competence, and social relatedness in physical activity.</p
Development and Evaluation of Methodology for Personal Recommendations Applicable in Connected Health.
No full textIn this paper, a personal recommendation system of outdoor physical activities using solely user’s history data and without application of collaborative filtering algorithms is proposed and evaluated. The methodology proposed contains four phases: data fuzzyfication, activity usefulness calculation, estimation of most useful activities, activities classification. In the process of classification several data mining techniques were compared such as: decision trees algorithms, decision rules algorithm, Bayes algorithm and support vector machines. The pro-posed algorithm has been experimentally validated using real dataset collected in a certain period of time from a community of 1000 active users. Recommendations generated by the system were related to weight loss. The results show that our generated recommendations have high accuracy, up to 95%
Evaluation of Pareto/D/1/k Queue by Simulation
Full text linkThe finding that Pareto distributions are adequate to model Internet packet interarrival times has
motivated the proposal of methods to evaluate steady-state performance measures of Pareto/D/1/k queues.
Some limited analytical derivation for queue models has been proposed in the literature, but their solutions are
often of a great mathematical challenge. To overcome such limitations, simulation tools that can deal with general
queueing system must be developed. Despite certain limitations, simulation algorithms provide a mechanism to
obtain insight and good numerical approximation to parameters of queues. In this work, we give an overview of
some of these methods and compare them with our simulation approach, which are suited to solve queues with
Generalized-Pareto interarrival time distributions. The paper discusses the properties and use of the Pareto
distribution. We propose a real time trace simulation model for estimating the steady-state probability showing the
tail-raising effect, loss probability, delay of the Pareto/D/1/k queue and make a comparison with M/D/1/k. The
background on Internet traffic will help to do the evaluation correctly. This model can be used to study the long-
tailed queueing systems. We close the paper with some general comments and offer thoughts about future work
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
General Assisted Living System Architecture Model
No full textNovel information and communication technologies create possibilities to change the future of health care and support. Ambient Assisted Living (AAL) is seen as a promising alternative to the current care models so a number of researchers have developed AAL systems with promising results. The main goal of AAL solutions is to apply ambient intelligence technologies to enable people with specific needs to continue to live in their preferred environments. In this paper, we are presenting a general architecture of system for assisted living that supports most of the use cases for such system
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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