License to chill!: how to empower users to cope with stress

There exists today a paucity of tools and devices that empower people to take control over their everyday behaviors and balance their stress levels. To overcome this deficit, we are creating a mobile service, Affective Health, where we aim to provide a holistic approach towards health by enabling users to make a connection between their daily activities and their own memories and subjective experiences. This construction is based upon values detected from certain bodily reactions that are then visualized on a mobile phone. Accomplishing this entailed figuring out how to provide real-time feedback without making the individual even more stressed, while also making certain that the representation empowered rather than controlled them. Useful design feedback was derived from testing two different visualizations on the mobile in a Wizard of Oz study. In short, we found that a successful design needs to: feel alive, allow for interpretative openness, include short-term history, and be updated in real-time. We also found that the interaction did not increase our participants stress reactions

Optimal monetary policy in a model of money and credit

The authors investigate the extent to which monetary policy can enhance the functioning of the private credit system. Specifically, they characterize the optimal return on money in the presence of credit arrangements. There is a dual role for credit: It allows buyers to trade without fiat money and also permits them to borrow against future income. However, not all traders have access to credit. As a result, there is a social role for fiat money because it allows agents to self-insure against the risk of not being able to use credit in some transactions. The authors consider a (nonlinear) monetary mechanism that is designed to enhance the credit system. An active monetary policy is sufficient for relaxing credit constraints. Finally, they characterize the optimal monetary policy and show that it necessarily entails a positive inflation rate, which is required to induce cooperation in the credit system.Monetary policy ; Money ; Credit

Optimal monetary policy in a model of money and credit

The authors study optimal monetary policy in a model in which fiat money and private debt coexist as a means of payment. The credit system is endogenous and allows buyers to relax their cash constraints. However, it is costly for agents to publicly report their trades, which is necessary for the enforcement of private liabilities. If it is too costly for the government to obtain information regarding private transactions, then it relies on the public information generated by the private credit system. If not all private transactions are publicly reported, the government has imperfect public information to implement monetary policy. In this case, the authors show that there is no incentive-feasible policy that can implement the socially efficient allocation. Finally, they characterize the optimal policy for an economy with a low record-keeping cost and a large number of public transactions, which results in a positive long-run inflation rate.Monetary policy ; Disclosure of information

Integrated Production and Distribution planning of perishable goods

Tese de doutoramento. Programa Doutoral em Engenharia Industrial e Gestão. Faculdade de Engenharia. Universidade do Porto. 201

Distributed Computing in a Cloud of Mobile Phones

For the past few years we have seen an exponential growth in the number of mobile devices and in their computation, storage and communication capabilities. We also have seen an increase in the amount of data generated by mobile devices while performing common tasks. Additionally, the ubiquity associated with these mobile devices, makes it more reasonable to start thinking in a different use for them, where they will begin to act as an important part in the computation of more demanding applications, rather than relying exclusively on external servers to do it. It is also possible to observe an increase in the number of resource demanding applications, whereas these resort to the use of services, offered by infrastructure Clouds. However, with the use of these Cloud services, many problems arise, such as: the considerable use of energy and bandwidth, high latency values, unavailability of connectivity infrastructures, due to the congestion or the non existence of it. Considering all the above, for some applications it starts to make sense to do part or all the computation locally in the mobile devices themselves. We propose a distributed computing framework, able to process a batch or a stream of data, which is being generated by a cloud composed of mobile devices, that does not require Internet services. Differently from the current state-of-the-art, where both computation and data are offloaded to mobile devices, our system intends to move the computation to where the data is, reducing significantly the amount of data exchanged between mobile devices. Based on the evaluation performed, both on a real and simulated environment, our framework has proved to support scalability, by benefiting significantly from the usage of several devices to handle computation, and by supporting multiple devices submitting computation requests while not having a significant increase in the latency of a request. It also proved that is able to deal with churn without being highly penalized by it

South–South cohesiveness versus South–South rhetoric: Brazil and Africa at the UN General Assembly

South–South relations have regained widespread interest in recent years, together with increasingly visible stances on international stages. Brazil’s interactions with the African continent, in particular, came to epitomise such a perception while sustaining an expectation of mutual alignment in several global issues. However, these assumptions still lack empirical corroboration. Drawing on United Nations General Assembly voting data for the 1991–2013 timeframe, this article questions a supposed South–South solidarity at the multilateral institution with the largest global representation and identifies key thematic axes that incite greater collective stances. The analysis further sheds light on whether or not a common South–South agenda has emerged over time.info:eu-repo/semantics/publishedVersio

Knowing Your Population: Privacy-Sensitive Mining of Massive Data

Location and mobility patterns of individuals are important to environmental planning, societal resilience, public health, and a host of commercial applications. Mining telecommunication traffic and transactions data for such purposes is controversial, in particular raising issues of privacy. However, our hypothesis is that privacy-sensitive uses are possible and often beneficial enough to warrant considerable research and development efforts. Our work contends that peoples behavior can yield patterns of both significant commercial, and research, value. For such purposes, methods and algorithms for mining telecommunication data to extract commonly used routes and locations, articulated through time-geographical constructs, are described in a case study within the area of transportation planning and analysis. From the outset, these were designed to balance the privacy of subscribers and the added value of mobility patterns derived from their mobile communication traffic and transactions data. Our work directly contrasts the current, commonly held notion that value can only be added to services by directly monitoring the behavior of individuals, such as in current attempts at location-based services. We position our work within relevant legal frameworks for privacy and data protection, and show that our methods comply with such requirements and also follow best-practice

Introduction: Crossing the Lines? Local actors’ responses to developmental challenges in Africa

info:eu-repo/semantics/publishedVersio

Avaliação de metais em pescado da região do Pontal da Barra, Laguna dos Patos, Pelotas-RS

Os metais pesados têm a capacidade de acumular-se em tecidos vivos ao longo da cadeia alimentar. Peixes podem se tornar a principal forma de transferir para a população esses elementos, uma vez que eles são capazes de bioacumulação e bioconcentração. Com o objetivo de investigar a bioacumulação nos peixes no Pontal da Barra-Laguna dos Patos, em Pelotas, foram escolhidas três espécies abundantes na região, Micropogonias furnieri (Corvina), Mugil platanus (Tainha) e Netuma barba (Bagre). Amostras da sua musculatura foram analisados para verificar o conteúdo de Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb e Zn. Amostras em quintuplicata sofreram digestão ácida HNO3/HCIO4, sendo os extratos analisados por plasma indutivamente acoplado - espectrometria de emissão óptica (ICP-OES). Os níveis de cromo encontrados nas três espécies estavam acima dos estabelecidos pela legislação brasileira (Decreto-Lei 55,871-65), que determinam como um nível máximo tolerado para o cromo 0,1 mg kg-1. Os 82,46 ± 4,69% mg kg-1 de zinco na espécie, Netuma barba, também excedeu o limite permitido. As concentrações de cádmio encontrada na espécie Micropogonias furnieri, 0,92 ± 8,16% mg kg-1 ficaram próximas ao limite permitido. Os demais analitos, encontraram-se em níveis inferiores aos estabelecidos pelo Ministério da Saúde e Anvisa