Web and wireless geographical information systems. 14th International Symposium, W2GIS 2015, Grenoble, France, May 21-22, 2015, Proceedings

This book constitutes the refereed conference proceedings of the 14th International Symposium, W2GIS 2015, held in Grenoble, France, in May 2015. The 12 revised full papers presented were carefully selected from 19 submissions. Selected papers cover hot topics related to W2GIS including spatiotemporal data collection, processing and visualization, mobile user generated content, semantic trajectories, locationbased Web search, Cloud computing and VGI approaches

Web and Wireless Geographical Information Systems: 14th International Symposium, W2GIS 2015, Grenoble, France, May 21-22, 2015, Proceedings

International audienc

A roadmap for the future of crowd safety research and practice: Introducing the Swiss Cheese Model of Crowd Safety and the imperative of a Vision Zero target

Crowds can be subject to intrinsic and extrinsic sources of risk, and previous records have shown that, in the absence of adequate safety measures, these sources of risk can jeopardise human lives. To mitigate these risks, we propose that implementation of multiple layers of safety measures for crowds—what we label The Swiss Cheese Model of Crowd Safety—should become the norm for crowd safety practice. Such system incorporates a multitude of safety protection layers including regulations and policymaking, planning and risk assessment, operational control, community preparedness, and incident response. The underlying premise of such model is that when one (or multiple) layer(s) of safety protection fail(s), the other layer(s) can still prevent an accident. In practice, such model requires a more effective implementation of technology, which can enable provision of real-time data, improved communication and coordination, and efficient incident response. Moreover, implementation of this model necessitates more attention to the overlooked role of public education, awareness raising, and promoting crowd safety culture at broad community levels, as one of last lines of defence against catastrophic outcomes for crowds. Widespread safety culture and awareness has the potential to empower individuals with the knowledge and skills that can prevent such outcomes or mitigate their impacts, when all other (exogenous) layers of protection (such as planning and operational control) fail. This requires safety campaigns and development of widespread educational programs. We conclude that, there is no panacea solution to the crowd safety problem, but a holistic multi-layered safety system that utilises active participation of all potential stakeholders can significantly reduce the likelihood of disastrous accidents. At a global level, we need to target a Vision Zero of Crowd Safety, i.e., set a global initiative of bringing deaths and severe injuries in crowded spaces to zero by a set year

L'AIS : une donnée pour l'analyse des activités en mer

4 pages, session "Mer et littoral"International audienceCette contribution présente des éléments méthodologiques pour la description des activités humaines en mer dans une perspective d'aide à la gestion. Différentes procédures, combinant l'exploitation de bases de données spatio-temporelles issue de données AIS archivées à des analyses spatiales au sein d'un SIG, sont testées afin de caractériser le transport maritime en Mer d'Iroise (Bretagne, France) sur les plans spatiaux, temporels et quantitatifs au cours d'une année

Real-Time Event Analysis and Spatial Information Extraction From Text Using Social Media Data

Since the advent of websites that enable users to participate and interact with each other by sharing content in different forms, a plethora of possibly relevant information is at scientists\u27 fingertips. Consequently, this thesis elaborates on two distinct approaches to extract valuable information from social media data and sketches out the potential joint use case in the domain of natural disasters

Empirically Measuring Salience of Objects for Use in Pedestrian Navigation

Humans usually refer to landmarks when they give route directions to pedestrians. One of the reasons why current mobile pedestrian navigation systems do not yet mimic this mode of communication is the lack of available data sources. The usefulness of a crowd-sourced data acquisition approach to overcome this problem has long been mooted. However, to date no empirically sound way of measuring the salience of objects by means of surveys exists. GOAL Given this background, this doctoral work has three goals: 1. To achieve a sound way of measuring salience and its subdimensions, i.e. visibility in advance, cognitive salience, prototypicality, structural salience, and visual salience based on taking dimensions revealed in earlier studies systematically and simultaneously into account. 2. To find subgroups of visual features among the large number of visual attributes known from the literature. 3. To find the most important subdimensions of salience by means of estimating two different structural equation models. Model I is based on assumptions of independence among subdimensions, whereas model II reflects hypotheses of mediation. Taken as a whole, achieving these goals will foster both, the advancement of theories of salience and landmark acquisition methods. METHODOLOGY A large scale, in-situ experiment was implemented, trying to overcome weaknesses of earlier attempts made to estimate salience. An appropriate sample size of buildings and non-buildings was calculated a priori (nobj = 360). Objects were randomly selected based on their geographical coordinates and randomly grouped into nr = 55 routes. Participants were required to rate objects by means of a survey. The questions were derived from empirical evidence found in earlier studies. Each route was walked by two different participants (n = 112), id est (i.e.) two ratings per object were collected for data analysis. FINDINGS Model I and model II were analyzed using PLS Path Modeling and consistent PLS Path Modeling, respectively. The measurement models proposed showed a good fit, although some weaknesses were identified for prototypicality and cognitive salience. Geometrical aspects as well as features like (visual) age turned out to have a stronger impact on visual salience than color. Model I did not yield reasonable structural model results based on consistent Partial Least Squares Path Modeling. Model II, however, showed that visual salience had a very high impact on visibility in advance which, in turn, heavily influenced structural salience. An analysis of the predictive capabilities of model II revealed important, but rather small effects. VALUE OF WORK This doctoral work adds to salience models as well as to its empirical, survey-based, in-situ measurement. The results of the mediation analysis as well as the predictive capabilities of model II suggest that important subdimensions of salience are missing in current theories. Emotional salience and familiarity are identified as two candidate constructs. The structural relationships found during the analysis of model II provide, in combination with the measurement model results, a sound basis to choose important features for surveys which are usable to gain crowd-sourced salience ratings. Furthermore, several important aspects for future studies are identified. These include heterogeneity analyses for different subgroups of users of pedestrian navigation systems as well as local environments different to the historic one used in this study