Scaling and correlations in the dynamics of forest-fire occurrence

Forest-fire waiting times, defined as the time between successive events above a certain size in a given region, are calculated for Italy. The probability densities of the waiting times are found to verify a scaling law, despite that fact that the distribution of fire sizes is not a power law. The meaning of such behavior in terms of the possible self-similarity of the process in a nonstationary system is discussed. We find that the scaling law arises as a consequence of the stationarity of fire sizes and the existence of a non-trivial ``instantaneous'' scaling law, sustained by the correlations of the process.Comment: Not a long paper, but many figures (but no large size in kb

Big Earth Data for Cultural Heritage in the Copernicus Era

Digital data is stepping in its golden age characterized by an increasing growth of both classical and emerging big earth data along with trans- and multidisciplinary methodological approaches and services addressed to the study, preservation and sustainable exploitation of cultural heritage (CH). The availability of new digital technologies has opened new possibilities, unthinkable only a few years ago for cultural heritage. The currently available digital data, tools and services with particular reference to Copernicus initiatives make possible to characterize and understand the state of conservation of CH for preventive restoration and opened up a frontier of possibilities for the discovery of archaeological sites from above and also for supporting their excavation, monitoring and preservation. The different areas of intervention require the availability and integration of rigorous information from different sources for improving knowledge and interpretation, risk assessment and management in order to make more successful all the actions oriented to the preservation of cultural properties. One of the biggest challenges is to fully involve the citizen also from an emotional point of view connecting “pixels with people” and “bridging” remote sensing and social sensing

Hyperspectral image analysis techniques for the detection and classification of the early onset of plant disease and stress

This review explores how imaging techniques are being developed with a focus on deployment for crop monitoring methods. Imaging applications are discussed in relation to both field and glasshouse-based plants, and techniques are sectioned into ‘healthy and diseased plant classification’ with an emphasis on classification accuracy, early detection of stress, and disease severity. A central focus of the review is the use of hyperspectral imaging and how this is being utilised to find additional information about plant health, and the ability to predict onset of disease. A summary of techniques used to detect biotic and abiotic stress in plants is presented, including the level of accuracy associated with each method

Integrated and multi-scale NDT for the study of the architectural heritage

The restoration of artistic and architectural heritage represents a bench mark of the cultural development of a society. To this end it is necessary to develop a suitable methodology for the analysis of the material and building components which are usually brittle and in a poor state of conservation. The paper outlines the advantages and the drawbacks in the use of Non-Destructive Testing (NDT) techniques and the need to integrate them in order to obtain a reliable reconstruction of the internal characteristics of the building elements as well as the detection of defects. In the study case we used Ground Penetrating Radar (GPR), infrared thermography (IRT), sonic and ultrasonic tests to analyze a 13th century precious rose window in Southern Italy, affected by widespread decay and instability problems. The theoretical capabilities and limitations of NDT are strictly related to the frequency content of the signals used by the different techniques. Therefore, integrating several physical methods and using different frequency bands allowed as a comprehensive, multi-scale approach to the restoration problem. This revealed to be a proper strategy in order to get high-resolution information on the building characteristics and the state of decay which could support a careful structural restoration. © 2008 SPIE

Emergence of spatio-temporal patterns in forest-fire sequences

Temporal variation of spatial clustering in fire data recorded from 1997 to 2003 in Tuscany region, central Italy, has been investigated using the Voronoï polygon area, the Morishita index and the fractal dimension. Our findings reveal that the spatial clustering of fire events changes with time, showing an enhancement of the clustering degree before the largest events.</p

Packaged X-band T/R module for active phased array radar applications

In this article we describe a global design approach of an X-band Tx/Rx module which, by means of a Multi Chip Module (MCM) technique, includes in a single package the different microwave functions (4-bit phase-shifter, low-noise amplifier, power amplifier, switching control circuits), the thin film interconnections, the bias circuits, the driver circuits (Si ICs) and the switching MOS