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Ideally, a pervasive location‐based system should allow mobile users to go anywhere and benefit from personalized and pro‐active services tailored for their current activity. However, existing location‐based systems are still far from this vision, as they are either aimed at very specific activities or too generic to provide real value to specific user activities. The objective of this work is to identify and characterize the most fundamental challenges involved in the design of pervasive location‐based systems. The approach is based on the idea that such challenges will correspond to the key design tradeoffs for location‐based systems. Building on what is believed to be the high‐level requirements for a truly pervasive locationbased system, this paper proposes a design space with four design dimensions: functional scope, added‐value, pro‐activity, and adaptability. After analyzing a representative set of location‐based systems under that design space, the combinations between functional scope and any of the other dimensions are identified as the main contradictions in the design of such systems. The paper finally discusses the research challenges associated to the identified tradeoffs.

In recent years, increased awareness on global warming effects led to a renewed interest in all kinds of green technologies. Among them, some attention has been devoted to hybrid-electric aircraft – aircraft where the propulsion system contains power systems driven by electricity and power systems driven by hydrocarbon-based fuel. Examples of these systems include electric motors and gas turbines, respectively. Despite the fact that several research groups have tried to design such aircraft, in a way, it can actually save fuel with respect to conventional designs, the results hardly approach the required fuel savings to justify a new design. One possible path to improve these designs is to optimize the onboard energy management, in other words, when to use fuel and when to use stored electricity during a mission. The purpose of this paper is to address the topic of energy management applied to hybrid-electric aircraft, including its relevance for the conceptual design of aircraft and present a practical example of optimal energy management.

To address this problem the dynamic programming (DP) method for optimal control problems was used and, together with an aircraft performance model, an optimal energy management was obtained for a given aircraft flying a given trajectory.

The results show how the energy onboard a hybrid fuel-battery aircraft can be optimally managed during the mission. The optimal results were compared with non-optimal result, and small differences were found. A large sensitivity of the results to the battery charging efficiency was also found.

The novelty of this work comes from the application of DP for energy management to a variable weight system which includes energy recovery via a propeller.

This paper is an excerpt from a countrywide study entitled “Leisure in Brazil: representations and realizations of daily experiences”, which aims to investigate what Brazilians do in their leisure time, what they would like to do and why they do not do it.

Specifically, in this paper, the authors analyze data referring to the elderly population from southeastern Brazil. Sampling of the national survey comprised representative quotas of the population, considering region and state, and, in each state, quotas of sex, age, education level and family income, according to data obtained by IBGE in 2010. A total of 2,400 interviews were conducted in total. For the present study, the 91 interviews conducted with elderly subjects from the Southeast region of Brazil were considered.

The majority of participants understand leisure as a time for resting and fun and have physical/sports interests as their favorite leisure activity during the week. On weekends, social and tourism interests stand out, and idleness stands out in the preference of this public during the holiday period. Lack of time and financial resources are the main barriers to the access to and permanence in the desired leisure practices.

Having knowledge of the relationship between leisure and aging in Brazil is a way to contribute to the potential of this stage of life, based on the quality of life and continued learning provided by the content they enjoy.

We present a critical literature review debating Brazilian research on social and environmental accounting (SEA). The aim of this study is to understand the role of politics in the construction of hegemonies in SEA research in Brazil. In particular, we examine the role of hegemony in relation to the co-option of SEA literature and sustainability in the Brazilian context by the logic of development for economic growth in emerging economies. The methodological approach adopts a post-structural perspective that reflects Laclau and Mouffe’s discourse theory. The study employs a hermeneutical, rhetorical approach to understand and classify 352 Brazilian research articles on SEA. We employ Brown and Fraser’s (2006) categorizations of SEA literature to help in our analysis: the business case, the stakeholder–accountability approach, and the critical case. We argue that the business case is prominent in Brazilian studies. Second-stage analysis suggests that the major themes under discussion include measurement, consulting, and descriptive approach. We argue that these themes illustrate the degree of influence of the hegemonic politics relevant to emerging economics, as these themes predominantly concern economic growth and a capitalist context. This paper discusses trends and practices in the Brazilian literature on SEA and argues that the focus means that SEA avoids critical debates of the role of capitalist logics in an emerging economy concerning sustainability. We urge the Brazilian academy to understand the implications of its reifying agenda and engage, counter-hegemonically, in a social and political agenda beyond the hegemonic support of a particular set of capitalist interests.

This paper aims to present recently published resources on information literacy and library instruction providing an introductory overview and a selected annotated bibliography of publications covering all library types.

This paper introduces and annotates English-language periodical articles, monographs, dissertations and other materials on library instruction and information literacy published in 2016.

The paper provides information about each source, describes the characteristics of current scholarship and highlights sources that contain unique or significant scholarly contributions.

The information may be used by librarians and interested parties as a quick reference to literature on library instruction and information literacy.

The purpose of this study is to investigate international trade determinants, paying special attention to variables related to climate change and non-tariff measures (NTMs), as they shape more and more world trade flows, with particular incidence on globalised goods, such as wine.

Based on panel data of Port wine exports to 60 countries, between 2006 and 2018, a gravity model has been estimated through Poisson pseudo-maximum likelihood. Explanatory variables include NTMs, mean temperature, temperature anomaly, gross domestic product (GDP), exchange rate, ad valorem equivalent tariffs and home bias.

The findings show that exports are inversely related to both mean temperature and temperature anomaly in importing countries. Regarding NTMs, it is found that only part of them are trade deterrent. Additionally, purchasing power in importing countries is one of the main determinants of Port wine exports.

The results show that, besides traditional economic variables, policymakers and wineries should include in their exports' decisions the impact of variables related to climate change and NTMs.

The novelty of this paper is to incorporate the impact of climatic variability of importing countries as a determinant of international trade of wine. Most former studies inspired of the gravity model consider explanatory variables such as GDP and exchange rate, and more recent ones started to consider NTMs too, however, this study may be the first paper to include the impact of climate change (quantified by mean temperature and temperature anomaly in importing countries) on exports.