Scalable analysis of movement data for extracting and exploring significant places

Place-oriented analysis of movement data, i.e., recorded tracks of moving objects, includes finding places of interest in which certain types of movement events occur repeatedly and investigating the temporal distribution of event occurrences in these places and, possibly, other characteristics of the places and links between them. For this class of problems, we propose a visual analytics procedure consisting of four major steps: 1) event extraction from trajectories; 2) extraction of relevant places based on event clustering; 3) spatiotemporal aggregation of events or trajectories; 4) analysis of the aggregated data. All steps can be fulfilled in a scalable way with respect to the amount of the data under analysis; therefore, the procedure is not limited by the size of the computer's RAM and can be applied to very large data sets. We demonstrate the use of the procedure by example of two real-world problems requiring analysis at different spatial scales

Partners' Empathy Increases Pain Ratings: Effects of Perceived Empathy and Attachment Style on Pain Report and Display

Pain can be influenced by its social context. We aimed to examine under controlled experimental conditions how empathy from a partner and personal attachment style affect pain report, tolerance, and facial expressions of pain. Fifty-four participants, divided into secure, anxious, and avoidant attachment style groups, underwent a cold pressor task with their partners present. We manipulated how much empathy the participants perceived that their partners had for them. We observed a significant main effect of perceived empathy on pain report, with greater pain reported in the high perceived empathy condition. No such effects were found for pain tolerance or facial display. We also found a significant interaction of empathy with attachment style group, with the avoidant group reporting and displaying less pain than the secure and the anxious groups in the high perceived empathy condition. No such findings were observed in the low empathy condition. These results suggest that empathy from one's partner may influence pain report beyond behavioral reactions. In addition, the amount of pain report and expression that people show in high empathy conditions depends on their attachment style. Perspective: Believing that one's partner feels high empathy for one's pain may lead individuals to rate the intensity of pain as higher. Individual differences in attachment style moderate this empathy effect

A systems design approach to appropriate, smart technology in a youth agriculture initiative

Abstract: A transformative research paradigm is rooted in knowledge mobilization processes involving close collaboration between researchers and the community. The research presents the development of an integrated, connected food ecosystem that, because of its fundamental design and use of appropriate, smart technology, which tends to naturally create inclusion and prosperity opportunities for many and not simply for the few. The research relies on multistakeholder participation to develop appropriate technologies to enhance economic activity amongst unemployed youths in Johannesburg, South Africa. A humancentered, systems engineering approach to develop a pilot project that promotes integrated, online, technologically supported food system is presented. The research is also concerned with how to measure the impact of the intervention the on food resilience as a result of urban farming. This paper presents the systems analysis of the current local food network and the proposed integrated solutions for a pilot project to establish a minimal viable project that can be tested. The research describes the planning and implementation of a pilot project as a minimal viable product to test in the market

Peacock Bundles: Bundle Coloring for Graphs with Globality-Locality Trade-off

Bundling of graph edges (node-to-node connections) is a common technique to enhance visibility of overall trends in the edge structure of a large graph layout, and a large variety of bundling algorithms have been proposed. However, with strong bundling, it becomes hard to identify origins and destinations of individual edges. We propose a solution: we optimize edge coloring to differentiate bundled edges. We quantify strength of bundling in a flexible pairwise fashion between edges, and among bundled edges, we quantify how dissimilar their colors should be by dissimilarity of their origins and destinations. We solve the resulting nonlinear optimization, which is also interpretable as a novel dimensionality reduction task. In large graphs the necessary compromise is whether to differentiate colors sharply between locally occurring strongly bundled edges ("local bundles"), or also between the weakly bundled edges occurring globally over the graph ("global bundles"); we allow a user-set global-local tradeoff. We call the technique "peacock bundles". Experiments show the coloring clearly enhances comprehensibility of graph layouts with edge bundling.Comment: Appears in the Proceedings of the 24th International Symposium on Graph Drawing and Network Visualization (GD 2016

Broadening access to problem-based learning : design of the shell eco-marathon car-in-a-box concept

Abstract: Problem-based learning has proven to develop teamwork, problem solving skills, communication and critical thinking skills amongst learners. Due to these advantages, secondary schools in South Africa engage with problem-based events to promote the participation of learners in Science, Technology, Engineering and Mathematics (STEM). However, many schools face lack of time, lack of available funds and lack of the required technical skill set, which limits them from participating in these events. The Car-In-a-Box concept was developed to broaden access to a STEM problem-based learning event, called the Shell Eco-Marathon. The Car-In-A-Box concept addresses the three challenges that would normally prevent a school from entering the Shell Eco-Marathon, disenabling learners to harness the advantages of problem-based learning. The impact of the Car-In-A-Box concept for broadening access to problem-based learning is discussed

Bundled Crossings Revisited

An effective way to reduce clutter in a graph drawing that has (many) crossings is to group edges that travel in parallel into \emph{bundles}. Each edge can participate in many such bundles. Any crossing in this bundled graph occurs between two bundles, i.e., as a \emph{bundled crossing}. We consider the problem of bundled crossing minimization: A graph is given and the goal is to find a bundled drawing with at most $k$ bundled crossings. We show that the problem is NP-hard when we require a simple drawing. Our main result is an FPT algorithm (in $k$) when we require a simple circular layout. These results make use of the connection between bundled crossings and graph genus.Comment: Appears in the Proceedings of the 27th International Symposium on Graph Drawing and Network Visualization (GD 2019

Bilan et perspectives de la Recherche en Agriculture Bio-dynamique

L’Agriculture Biodynamique (BD) a été l’objet de nombreux efforts de recherches durant les dernières décennies, bien qu’une partie de la communauté scientifique regarde les méthodes biodynamiques avec scepticisme et les considère comme dogmatiques. Néanmoins, comme cela est montré dans cet article de synthèse, une part non négligeable des résultats présentés dans des revues scientifiques à comité de lecture et issus d’expérimentations contrôlées de plein champ, ou d’étude de cas, montrent des effets des préparations biodynamiques sur le rendement, la qualité du sol et la biodiversité. De plus, les préparations biodynamiques ont un impact environnemental positif en termes d’utilisation et d’efficacité énergétique. Cependant, le mode d’action mécanique des préparations biodynamique est toujours en cours d’investigation en sciences naturelles. Par ailleurs, les méthodes d’évaluations de la qualité basées sur des approches globales (holistiques) sont de plus en plus étudiées et reconnues. L’agriculture BD s’efforce également, comme cela est montré dans plusieurs publications, d’influencer positivement le paysage culturel. La synthèse des données montre le besoin de poursuivre les recherches dans le domaine de la qualité des aliments, de la sécurité alimentaire, des performances environnementales (par ex. l’empreinte écologique), et sur l’influences des pratiques BD sur les animaux d’élevage

Visualization of Frequent Itemsets with Nested Circular Layout and Bundling Algorithm

International audienceFrequent itemset mining is one of the major data mining issues. Once generated by algorithms, the itemsets can be automatically processed, for instance to extract association rules. They can also be explored with visual tools, in order to analyze the emerging patterns. Graphical itemsets representation is a convenient way to obtain an overview of the global interaction structure. However, when the complexity of the database increases, the network may become unreadable. In this paper, we propose to display itemsets on concentric circles, each one being organized to lower the intricacy of the graph through an optimization process. Thanks to a graph bundling algorithm, we finally obtain a compact representation of a large set of itemsets that is easier to exploit. Colors accumulation and interaction operators facilitate the exploration of the new bundle graph and to illustrate how much an itemset is supported by the data

A Review of Temporal Data Visualizations Based on Space-Time Cube Operations

International audienceWe review a range of temporal data visualization techniques through a new lens, by describing them as series of op- erations performed on a conceptual space-time cube. These operations include extracting subparts of a space-time cube, flattening it across space or time, or transforming the cube's geometry or content. We introduce a taxonomy of elementary space-time cube operations, and explain how they can be combined to turn a three-dimensional space-time cube into an easily-readable two-dimensional visualization. Our model captures most visualizations showing two or more data dimensions in addition to time, such as geotemporal visualizations, dynamic networks, time-evolving scatterplots, or videos. We finally review interactive systems that support a range of operations. By introducing this conceptual framework we hope to facilitate the description, criticism and comparison of existing temporal data visualizations, as well as encourage the exploration of new techniques and systems