Interacting with Large Distributed Datasets using Sketch

We present Sketch, a distributed software infrastructure for building interactive tools for exploring large datasets, distributed across multiple machines. We have built three sophisticated applications using this framework: a billion-row spreadsheet, a distributed log browser, and a distributed- systems performance debugging tool. Sketch applications allow interactive and responsive exploration of complex distributed datasets, scaling gracefully to large system sizes. The conflicting constraints of large-scale data and small timescales required by human interaction are difficult to satisfy simultaneously. Sketch exploits a sweet spot in this trade-off by exploiting the observation that the precision of a data view is limited by the resolution of the user?s screen. The system pushes data reduction operations to the data sources. The core Sketch abstraction provides a narrow programming interface; Sketch clients construct a distributed application by stacking modular components with identical interfaces, each providing a useful feature: network transparency, concurrency, fault-tolerance, straggler avoidance, round-trip reduction, distributed aggregation

Using Visualizations to Enhance Users' Understanding of App Activities on Android Devices

The ever-increasing number of third-party applications developed for Android devices has resulted in a growing interest in the secondary activities that these applications perform and how they affect a user’s privacy. Unfortunately, users continue to install these applications without any concrete knowledge of the breadth of these activities; hence, they have little insight into the sensitive information and resources accessed by these applications. In this paper, we explore users’ perception and reaction when presented with a visual analysis of Android applications activities and their security implications. This study uses interactive visual schemas to communicate the effect of applications activities in order to support users with more understandable information about the risks they face from such applications. Through findings from a user-based experiment, we demonstrate that when visuals diagrams about application activities are presented to users, they became more aware and sensitive to the privacy intrusiveness of certain applications. This awareness and sensitivity stems from the fact that some of these applications were accessing a significant number of resources and sensitive information, and transferring data out of the devices, even when they arguably had little reason to do so

An algorithm and a tool for the automatic grading of MOOC learners from their contributions in the discussion forum

MOOCs (massive open online courses) have a built-in forum where learners can share experiences as well as ask questions and get answers. Nevertheless, the work of the learners in the MOOC forum is usually not taken into account when calculating their grade in the course, due to the difficulty of automating the calculation of that grade in a context with a very large number of learners. In some situations, discussion forums might even be the only available evidence to grade learners. In other situations, forum interactions could serve as a complement for calculating the grade in addition to traditional summative assessment activities. This paper proposes an algorithm to automatically calculate learners' grades in the MOOC forum, considering both the quantitative dimension and the relevance in their contributions. In addition, the algorithm has been implemented within a web application, providing instructors with a visual and a numerical representation of the grade for each learner. An exploratory analysis is carried out to assess the algorithm and the tool with a MOOC on programming, obtaining a moderate positive correlation between the forum grades provided by the algorithm and the grades obtained through the summative assessment activities. Nevertheless, the complementary analysis conducted indicates that this correlation may not be enough to use the forum grades as predictors of the grades obtained through summative assessment activities.This work was supported in part by the FEDER/Ministerio de Ciencia, Innovación y Universidades;Agencia Estatal de Investigación, through the Smartlet Project under Grant TIN2017-85179-C3-1-R, and in part by the Madrid Regional Government through the e-Madrid-CM Project under Grant S2018/TCS-4307, a project which is co-funded by the European Structural Funds (FSE and FEDER). Partial support has also been received from the European Commission through Erasmus+ Capacity Building in the Field of Higher Education projects, more specifically through projects LALA (586120-EPP-1-2017-1-ES-EPPKA2-CBHE-JP), InnovaT (598758-EPP-1-2018-1-AT-EPPKA2-CBHE-JP), and PROF-XXI (609767-EPP-1-2019-1-ES-EPPKA2-CBHE-JP)

Energy Efficiency

Energy efficiency is finally a common sense term. Nowadays almost everyone knows that using energy more efficiently saves money, reduces the emissions of greenhouse gasses and lowers dependence on imported fossil fuels. We are living in a fossil age at the peak of its strength. Competition for securing resources for fuelling economic development is increasing, price of fuels will increase while availability of would gradually decline. Small nations will be first to suffer if caught unprepared in the midst of the struggle for resources among the large players. Here it is where energy efficiency has a potential to lead toward the natural next step - transition away from imported fossil fuels! Someone said that the only thing more harmful then fossil fuel is fossilized thinking. It is our sincere hope that some of chapters in this book will influence you to take a fresh look at the transition to low carbon economy and the role that energy efficiency can play in that process