PADDLE: Proximal Algorithm for Dual Dictionaries LEarning

Recently, considerable research efforts have been devoted to the design of methods to learn from data overcomplete dictionaries for sparse coding. However, learned dictionaries require the solution of an optimization problem for coding new data. In order to overcome this drawback, we propose an algorithm aimed at learning both a dictionary and its dual: a linear mapping directly performing the coding. By leveraging on proximal methods, our algorithm jointly minimizes the reconstruction error of the dictionary and the coding error of its dual; the sparsity of the representation is induced by an $\ell_1$-based penalty on its coefficients. The results obtained on synthetic data and real images show that the algorithm is capable of recovering the expected dictionaries. Furthermore, on a benchmark dataset, we show that the image features obtained from the dual matrix yield state-of-the-art classification performance while being much less computational intensive

Unpacking the global/local nexus in world heritage sites : a pragmatic approach

This special panel session focuses on the critical interplay between global and local dynamics in heritage sites inscribed in the UNESCO’s World Heritage List. In fact, the management, planning and governance of these particular (and fragile) heritage sites of worldwide relevance is the result of a hybridization of standardized global principles and regulations, and local interpretation of heritage meanings and policy implementation. On the one hand, this session explores the role played by UNESCO and other heritage and non-heritage organisations in setting specific international goals, recommendations, policy guidelines and governance requirements. On the other, it discusses how the global/local nexus is affected by contemporary dynamics of change such as increasing touristification, marketing of local cultures, identities and landscapes for economic purposes, inconsiderate developments, and gentrification processes. Particular attention is paid to the (more or less explicit) conflicts generated by the friction between global and local heritage-based narratives, and between different priorities for local economic development (also through tourism promotion), conservation of heritage sites, and improvement of citizens’ quality of life. This panel discussion contributes to track 8 (Fragile Heritage Sites in a Globalizing World) by presenting a reflection based on (mostly European) case studies and an ever-growing literature on these topics. Key themes are: a) the global/local interplay in fragile World Heritage sites in historic urban environments, cultural landscapes and beyond; b) the suggestion of possible policy recommendations for a more sustainable planning practice in such contexts. The panel session consists in the following four contributions. Francesca Giliberto (University of Leeds, UK) examines the “heritage versus development dilemma” through the lens of a 21st century international approach to urban heritage conservation, management, and development. She highlights how, following the adoption of the 2030 Agenda for Sustainable Development by the United Nations (2015), UNESCO and ICOMOS – among others– have issued a series of ground-breaking documents to advocate for the importance of heritage for sustainable development, and have provided guidance on how to take concrete measures at the local level in that sense. She critically discusses the discrepancies between the global narratives and recommendations suggested in these documents and their local implementation focusing on the two World Heritage Cities (WHCs) of Florence (Italy) and Edinburgh (UK). She sheds light on effective practices and existing challenges by examining their management systems and urban regulatory frameworks in particular. Finally, she provides recommendations to rethink and reframe current urban heritage management practices for more sustainable WHCs, based on critical insights from“PRAXIS: Arts and Humanities for Global Development”, a research project led by the University of Leeds. Matteo Basso (Iuav University of Venice, Italy) challenges the dominant and essentially positive rural imagery conveyed by the successful inscription of the Prosecco Hills of Conegliano and Valdobbiadene (Italy) in the World Heritage List. Through a qualitative analysis based on planning documents and interviews with key actors, he emphasizes frictions and contradictions existing not only between global and local heritage-based narratives and initiatives, but also between different values and territorial aspirations. He underlines how the massive vineyard expansion generated by the Prosecco’s global demand has generated environmental impacts and health consequences triggered by the use of chemicals, and thus a growing discontent among locals. These challenges, together with the impacts of the vineyard expansion on the cultural landscape and a set of recommendations formulated by the World Heritage Centre, have resulted in diffused conflicts among different actors. In this context, Basso questions the role of ordinary planning tools in addressing more effectively the interactions between vineyards and urban settlements, as well as between heritage and development. Ilaria Rosetti (University of Antwerp, Belgium) focuses on participatory processes in managing WHCs, and their multiple roles with regard to sustainable urban development. International organisations acknowledge their relevance in official documents, promoting collaborative, inclusive, and equitable heritage processes at national and local levels. In turn, much research work has investigated the challenges and opportunities of implementing participatory heritage practices in WHCs. Different actors’ perspectives have been analysed, including local authorities and other organisations, practitioners as well as local communities, emphasising the role of governing bodies –especially elected ones– in decision-making processes. Still, although they play a key part in the identification and allocation of resources and in the prioritization of policies and actions, such actors’ perception of participatory heritage practices has been little explored. To address this gap, a mayors’ workshop was organized during the 2017 XIV World Congress of the Organization of WHCs, whose findings are discussed in Rosetti’s contribution. Beyond evident commonalities and differences, she analyses the challenges, both internal (weaknesses) and external (threats), that are perceived to hinder the implementation of participatory heritage practices in WHCs, as well as their implications for the quality of participation and sustainable heritage practices. Finally, Remi Wacogne (Iuav University of Venice, Italy) identifies key highlights emerged from the three previous contributions, i.e. that stakeholders involved in processes related to WH sites act according to sensibly different agendas and procedures. Drawing on the experience of the “support to the coordination of UNESCO sites of Veneto” carried out by a research group of Iuav with a formal agreement with the Veneto Region, his contribution presents an application of the actor-network theory (ANT) in this dynamic context. Through a renewed mapping of actors and agencies involved in processes related to WHS, further practical implications for planning and public policy at the local, regional, national and international levels, are highlighted

OpenPTrack: Open Source Multi-Camera Calibration and People Tracking for RGB-D Camera Networks

OpenPTrack is an open source software for multi-camera calibration and people tracking in RGB-D camera networks. It allows to track people in big volumes at sensor frame rate and currently supports a heterogeneous set of 3D sensors. In this work, we describe its user-friendly calibration procedure, which consists of simple steps with real-time feedback that allow to obtain accurate results in estimating the camera poses that are then used for tracking people. On top of a calibration based on moving a checkerboard within the tracking space and on a global optimization of cameras and checkerboards poses, a novel procedure which aligns people detections coming from all sensors in a x-y-time space is used for refining camera poses. While people detection is executed locally, in the machines connected to each sensor, tracking is performed by a single node which takes into account detections from all over the network. Here we detail how a cascade of algorithms working on depth point clouds and color, infrared and disparity images is used to perform people detection from different types of sensors and in any indoor light condition. We present experiments showing that a considerable improvement can be obtained with the proposed calibration refinement procedure that exploits people detections and we compare Kinect v1, Kinect v2 and Mesa SR4500 performance for people tracking applications. OpenPTrack is based on the Robot Operating System and the Point Cloud Library and has already been adopted in networks composed of up to ten imagers for interactive arts, education, culture and human\u2013robot interaction applications

micro and macro modelling approaches for the evaluation of the carbon impacts of transportation

Abstract To quantify CO2 emissions from road transport, literature suggests the adoption of several alternative methods, based on transport modelling and carbon modules. Some of these methods are labelled as a micro approach and others as a macro approach. Their distinction is made according to the temporal and spatial horizons, the aim of the study and the degree of accuracy required. This paper presents these methods and discusses their appropriateness, whereby special focus is laid on the potential of the micro approach on ICT, based on a literature review of several European projects. We conclude that the adoption of the micro approach, is quite promising – mostly at the urban level, despite the computational efforts required and the technical difficulties to model driver behaviors. Thus, further research is required to overcome the numerous sources of scientific uncertainties

Venise aux prises avec le tourisme. « État d’urgence » et politiques d’intervention

Cet article propose une réflexion sur le rapport entre dynamiques touristiques et question du logement à Venise, à partir des conflictualités qui ont émergé dans le centre historique de la ville lagunaire. Les comités, les associations, et plus encore les groupes informels de citadins impliqués dans des formes diverses de mobilisations territoriales, se sont de fait multipliés, contribuant à l’émergence d’un réseau civique engagé à faire connaître, à dénoncer et à s’opposer aux processus de touristification en acte. Ces conflits sont des exemples intéressants de « contre-projectualité », qui mettent au centre du débat les valeurs de la résidentialité

Long-term cost-effectiveness of glass hybrid versus composite in permanent molars.

This original study was supported by a grant from the University of Zagreb (2015 and 2017)

Study of Innovative GO/PBI Composites as Possible Proton Conducting Membranes for Electrochemical Devices

The appeal of combining polybenzimidazole (PBI) and graphene oxide (GO) for the manufacturing of membranes is increasingly growing, due to their versatility. Nevertheless, GO has always been used only as a filler in the PBI matrix. In such context, this work proposes the design of a simple, safe, and reproducible procedure to prepare self-assembling GO/PBI composite membranes characterized by GO-to-PBI (X:Y) mass ratios of 1:3, 1:2, 1:1, 2:1, and 3:1. SEM and XRD suggested a homogenous reciprocal dispersion of GO and PBI, which established an alternated stacked structure by mutual π-π interactions among the benzimidazole rings of PBI and the aromatic domains of GO. TGA indicated a remarkable thermal stability of the composites. From mechanical tests, improved tensile strengths but worsened maximum strains were observed with respect to pure PBI. The preliminary evaluation of the suitability of the GO/PBI X:Y composites as proton exchange membranes was executed via IEC determination and EIS. GO/PBI 2:1 (IEC: 0.42 meq g−1; proton conductivity at 100 °C: 0.0464 S cm−1) and GO/PBI 3:1 (IEC: 0.80 meq g−1; proton conductivity at 100 °C: 0.0451 S cm−1) provided equivalent or superior performances with respect to similar PBI-based state-of-the-art materials

Tracking people within groups with rgb-d data

Abstract-This paper proposes a very fast and robust multi-people tracking algorithm suitable for mobile platforms equipped with a RGB-D sensor. Our approach features a novel depth-based sub-clustering method explicitly designed for detecting people within groups or near the background and a three-term joint likelihood for limiting drifts and ID switches. Moreover, an online learned appearance classifier is proposed, that robustly specializes on a track while using the other detections as negative examples. Tests have been performed with data acquired from a mobile robot in indoor environments and on a publicly available dataset acquired with three RGB-D sensors and results have been evaluated with the CLEAR MOT metrics. Our method reaches near state of the art performance and very high frame rates in our distributed ROS-based CPU implementation