1,829 research outputs found
Monitoring post-fire forest recovery using multi-temporal Digital Surface Models generated from different platforms
Wildfires can greatly affect forest dynamics. Given the alteration of fire regimes foreseen globally due to climate and land use changes, greater attention should be devoted to prevention and restoration activities. Concerning in particular post-fire restoration actions, it is fundamental, together with a better understanding of ecological processes resulting from the disturbance, to define techniques and protocols for long-term monitoring of burned areas. This paper presents the results of a study conducted within an area affected by a stand-replacing crown fire (Verrayes, Aosta (AO), Italy) in 2005, which is part of a long-term monitoring research on post-fire restoration dynamics.
We performed a change detection analysis through a time sequence (2008-2015) of DSMs (Digital Surface Models) obtained from LiDAR (ALS - Airborne Laser Scanner) and digital images (UAV - Unmanned Aerial Vehicle flight) to test the ability of the systems (platform + sensor) to identify the ongoing processes. New technologies providing high-resolution information and new devices (i.e. UAV) able to acquire geographic data “on demand” demonstrated great potential for monitoring post disturbance recovery dynamics of vegetation
Airborne and Terrestrial Laser Scanning Data for the Assessment of Standing and Lying Deadwood: Current Situation and New Perspectives
LiDAR technology is finding uses in the forest sector, not only for surveys in producing forests but also as a tool to gain a deeper understanding of the importance of the three-dimensional component of forest environments. Developments of platforms and sensors in the last decades have highlighted the capacity of this technology to catch relevant details, even at finer scales. This drives its usage towards more ecological topics and applications for forest management. In recent years, nature protection policies have been focusing on deadwood as a key element for the health of forest ecosystems and wide-scale assessments are necessary for the planning process on a landscape scale. Initial studies showed promising results in the identification of bigger deadwood components (e.g., snags, logs, stumps), employing data not specifically collected for the purpose. Nevertheless, many efforts should still be made to transfer the available methodologies to an operational level. Newly available platforms (e.g., Mobile Laser Scanner) and sensors (e.g., Multispectral Laser Scanner) might provide new opportunities for this field of study in the near future
Residual entropy and critical behavior of two interacting boson species in a double well
Motivated by the importance of entanglement and correlation indicators in the
analysis of quantum systems, we study the equilibrium and the bipartite
residual entropy in a two-species Bose Hubbard dimer when the spatial phase
separation of the two species takes place. We consider both the zero and
non-zero-temperature regime. We present different kinds of residual entropies
(each one associated to a different way of partitioning the system), and we
show that they strictly depend on the specific quantum phase characterizing the
two species (supermixed, mixed or demixed) even at finite temperature. To
provide a deeper physical insight into the zero-temperature scenario, we apply
the fully-analytical variational approach based on su(2) coherent states and
provide a considerably good approximation of the entanglement entropy. Finally,
we show that the effectiveness of bipartite residual entropy as a critical
indicator at non-zero temperature is unchanged when considering a restricted
combination of energy eigenstates.Comment: 18 pages, 9 figure
Archaeological site monitoring: UAV photogrammetry can be an answer
During archaeological excavations it is important to monitor the new excavated areas and findings day by day in order to be able to plan future excavation activities. At present, this daily activity is usually performed by using total stations, which survey the changes of the archaeological site: the surveyors are asked to produce day by day draft plans and sections which allow archaeologists to plan their future activities. The survey is realized during the excavations or just at the end of every working day and drawings have to be produced as soon as possible in order to allow the comprehension of the work done and to plan the activities for the following day. By using this technique, all the measurements, even those not necessary for the day after, have to be acquired in order to avoid a ‘loss of memory'. A possible alternative to this traditional approach is aerial photogrammetry, if the images can be acquired quickly and at a taken distance able to guarantee the necessary accuracy of a few centimeters. Today the use of UAVs (Unmanned Aerial Vehicles) can be considered a proven technology able to acquire images at distances ranging from 4 m up to 20 m: and therefore as a possible monitoring system to provide the necessary information to the archaeologists day by day. The control network, usually present at each archaeological site, can give the stable control points useful for orienting a photogrammetric block acquired by using an UAV equipped with a calibrated digital camera and a navigation control system able to drive the aircraft following a pre-planned flight scheme. Modern digital photogrammetric software can solve for the block orientation and generate a DSM automatically, allowing rapid orthophoto generation and the possibility of producing sections and plans. The present paper describes a low cost UAV system realized by the research group of the Politecnico di Torino and tested on a Roman villa archaeological site located in Aquileia (Italy), a well-known UNESCO WHL site. The results of automatic orientation and orthophoto production are described in terms of their accuracy and the completeness of information guaranteed for archaeological site excavation managemen
Thermometry of bosonic mixtures in Optical Lattices via Demixing
Motivated by recent experiments and theoretical investigations on binary
mixtures, we investigate the miscible-immiscible transition at finite
temperature by means of Quantum Monte Carlo. Based on the observation that the
segregated phase is strongly affected by temperature, we propose to use the
degree of demixing for thermometry of a binary bosonic mixture trapped in an
optical lattice. We show that the proposed method is especially sensitive at
low temperatures, of the order of the tunnelling amplitude, and therefore is
particularly suitable in the regime where quantum magnetism is expected.Comment: 10 pages, 6 figures, Supplemental Materia
A topological signature of multipartite entanglement
In this manuscript, we present a proposal to relate topological structure of
worldline configurations to multipartite entanglement. Configurations result
from the path-integral formulation of the density matrix in the limit of zero
temperature. We consider hard-core bosons for which configurations, i.e.
collections of particle paths, can be seen as geometric braids with a certain
topological structure. We propose that properties of worldline configurations
may realize a comprehensive deciphering of multipartite entanglement. By means
of Monte Carlo calculations, we study checkerboard, stripe, valence-bond
solids, topologically ordered spin liquid, and superfluid phase.
We find that each ground-state is characterized by a certain `topological
spectrum' which can be used to differentiate among different ground-states.Comment: 6 pages, 3 figures and supplemental material. Version 2 focuses on
the discussion of topological signatures of multipartite entanglement in the
ground-state expansion, with added results. The study of phase transitions
and permutation cycles in version 1 has been moved to a new manuscript:
arXiv:1912.00080. Version 3 corrected some typos and reference
Newly designed single-ion conducting polymer electrolytes enabling advanced Li-metal solid-state batteries
L'abstract è presente nell'allegato / the abstract is in the attachmen
The Law Governing Arbitration Agreements in International Trade
This paper on the law applicable to arbitration agreements will start with an examination of the provisions adopted in international conventions on arbitration. The reason for this approach lies in the fact that, when national statutes contain choic of law rules specifically applicable to arbitration agreements, such rules tend to conform to those adopted by the conventions. However, problems of incompatibility between national choice of law provisions and the interpretation of international conventions may arise in the case of those countries which extend their general choice of law rules regarding contracts to rules concerning international arbitration agreements. Finally, this paper is intended to provide indications to arbitrators of solutions generally relied on in the international legal community. It does not merely seek to describe the way national courts have dealt with the law governing international arbitration agreements
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