Abstract
In this article we survey the historical background and development of information and data visualization, and an overview of the intersection of data visualization with storytelling applied to the field of data journalism, where it finds its most widespread use in narrative visualizations. We start by explaining why the mere act of visualization can be highly useful to readers, helping them discover patterns and comprehend information. Backed by historical references, we will describe how some of the first data visualizations were used to explain facts, understand certain events, and determine courses of action. We will then outline how storytelling and narrative techniques are being currently used with data visualization to leverage the power of visual expression. Our goal is to characterize storytelling with data as a vibrant and interesting field that current journalism practices employ to help readers understand and form opinions on complex facts. By presenting concepts like storytelling with data and data stories, we aim to spark interest in further research in the applications of data visualization and narrative. © 2015 ACM.

Abstract
We describe GPU implementations of the matrix recommender algorithms CCD++ and ALS. We compare the processing time and predictive ability of the GPU implementations with existing multi- core versions of the same algorithms. Results on the GPU are better than the results of the multi- core versions (maximum speedup of 14.8).

Abstract
The IEEE 802.11 standard has been evolving over the past decade, introducing a set of new mechanisms at the MAC layer to improve the Quality of Service (QoS) provided to the communication. Among such improvements, we highlight the evolution from earlier DCF and PCF, until more recent EDCA and HCCA MAC layer mechanisms. In this paper we perform a simulation assessment of these four MAC mechanisms, evaluating their ability to support real-time (RT) communication. More specifically, we assess their ability to handle RT traffic in open communication environments composed of RT and non-RT stations operating in the same frequency channel and coverage area. The target of this paper is to highlight and understand the limitations of each mechanism when supporting RT communication. We show that for most of the situations, including less demanding scenarios, these mechanisms are not adequate to support RT traffic.

Abstract

Abstract
This paper presents a framework for management of flexible energy loads in the context of the Internet of Things and the Smart Grid. The framework takes place in the European project Arrowhead, and aims at taking advantage of the flexibility (in time and power) of energy production and consumption offered by sets of devices, appliances or buildings, to help at solving the issue of fluctuating energy production of renewable energies. The underlying concepts are explained, the actors involved in the framework, their incentives and interactions are detailed, and a technical overview is provided. An implementation of the framework is presented, as well as the expected results of the pilots.

Abstract
We present a new type system combining refinement types and the expressiveness of intersection type discipline. The use of such features makes it possible to derive more precise types than in the original refinement system. We have been able to prove several interesting properties for our system (including subject reduction) and developed an inference algorithm, which we proved to be sound.