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showing 10 items of 2078 documents
Cultural institutions as agents of urban and community regeneration in the (post-)pandemic city. The case of the «Laboratorio Zen Insieme» in Palermo
2022
Although all cities in the world have been affected by the COVID-19 pandemic, its impacts on the territories, yet to be understood, are unevenly distributed, revealing extremely varied imbalances depending on the places. However, it is clear that the virus and its variants have aggravated pre-existing socio-spatial inequalities, creating new ones and bringing attention back to those implications between space, planning, public health and citizenship that are at the origins of contemporary urbanism. In a reference framework in which the crisis is globalized but unequal and in the absence of a welfare system capable of responding to the urgencies of the most marginalized social contexts and g…
Opportunities and pitfalls related to e-commerce strategies in small-medium firms: A system dynamics approach
2002
E-commerce is often perceived as a powerful lever to foster growth of SMEs. However, both the literature and empirical evidence have shown the perils hidden in superficial decision making by SME entrepreneurs. A system dynamics (SD) approach is used in this article to demonstrate how managing processes of accumulation and depletion of strategic assets, detecting inertial effects of decisions made in the past, and selectively acting on policy levers are likely to help entrepreneurs in understanding opportunities and pitfalls related to e-commerce strategies. A feedback analysis of three case studies selected from the literature and the main findings from a survey conducted by the authors on …
IOWA Operators and Its Application to Image Retrieval
2014
This paper presents a relevance feedback procedure based on logistic regression analysis. Since, the dimension of the feature vector associated to each image is typically larger than the number of evaluated images by the user, different logistic regression models have to be fitted separately. Each fitted model provides us with a relevance probability and a confidence interval for that probability. In order to aggregate these set of probabilities and confidence intervals we use an IOWA operator. The results will show the success of our algorithm and that OWA operators are an efficient and natural way of dealing with this kind of fusion problems.
Bidirectional laser cavity solitons
2007
Cavity solitons in optical systems have been studied for two decades in a large variety of optical systems. In principle, bidirectional lasers can emit only unidirectionally in steady state, as the two-mode solution (non null steady state in the two possible emission directions) is an unstable solution (winner-takes-all competition prevents the bidirectional cw emission). But for a wide aperture cavity this is not necessarily true as, in different regions of the transverse (with respect to the propagation axis) direction, emission in different propagation directions could occur if the fronts separating these domains are stable. In fact this is exactly what happens when the cavity losses for…
Simultaneous remote extraction of multiple speech sources and heart beats from secondary speckles pattern
2009
The ability of dynamic extraction of remote sounds is very appealing. In this manuscript we propose an optical approach allowing the extraction and the separation of remote sound sources. The approach is very modular and it does not apply any constraints regarding the relative position of the sound sources and the detection device. The optical setup doing the detection is very simple and versatile. The principle is to observe the movement of the secondary speckle patterns that are generated on top of the target when it is illuminated by a spot of laser beam. Proper adaption of the imaging optics allows following the temporal trajectories of those speckles and extracting the sound signals ou…
Implementation to Back-Projection Techniques of Resistivity Data
2005
In order to obtain well contrasted images by back-projection of resistivity data some modifications to the back-projection algorithm as well as the use of filtering techniques for the sensitivity matrix were proposed (Kotre 1994; Cosentino et al. 1998). To further improve the back-projection algorithm a new implementation is here suggested. Besides a subsequent filtering algorithm of the sensitivity coefficient matrix is proposed. It is aimed to increase resistivity contrasts and to reduce smoothness in tomographic final representation. Finally the proposed technique is tested on synthetic data.
Backscatter and Transmission through a Lead Shield Used in Surface and Interstitial HDR Brachytherapy
2014
Optimal design of complex passive-damping systems for vibration control of large structures: An energy-to-peak approach
2014
Published version of an article in the journal: Abstract and Applied Analysis. Also available from the publisher at: http://dx.doi.org/10.1155/2014/510236 Open Access We present a new design strategy that makes it possible to synthesize decentralized output-feedback controllers by solving two successive optimization problems with linear matrix inequality (LMI) constraints. In the initial LMI optimization problem, two auxiliary elements are computed: a standard state-feedback controller, which can be taken as a reference in the performance assessment, and a matrix that facilitates a proper definition of the main LMI optimization problem. Next, by solving the second optimization problem, the …
Correlation, hierarchies, and networks in financial markets
2010
We discuss some methods to quantitatively investigate the properties of correlation matrices. Correlation matrices play an important role in portfolio optimization and in several other quantitative descriptions of asset price dynamics in financial markets. Specifically, we discuss how to define and obtain hierarchical trees, correlation based trees and networks from a correlation matrix. The hierarchical clustering and other procedures performed on the correlation matrix to detect statistically reliable aspects of the correlation matrix are seen as filtering procedures of the correlation matrix. We also discuss a method to associate a hierarchically nested factor model to a hierarchical tre…
LES VARIATIONS DU NIVEAU MARIN SUR LE BASSIN DE PARIS AU BATHONIEN-CALLOVIEN. IMPACTS SUR LES COMMUNAUTÉS BENTHIQUES ET SUR L'ÉVOLUTION DES ORNITHELL…
1992
The study deals with the biological impacts of sea-Ievel changes on evolution of a Jurassic benthic fossil group (Ornithellida, Brachiopoda). The different time and scale at which the shifts in marine environments occur leads to the recognition of three interacting dynamic systems: environmental, communities, populations dynamics. The analysis is thus divided into a three steps hierarchy: sequence stratigraphy, analysis of the diversity of brachiopod assemblages, and analysis of morphological variations within omithellid populations. Sequence stratigraphy of the Dogger marly and carbonate successions in the Paris basin provides accurate correlations of depositional environments from shallow…