5,030 research outputs found
Grain size characterization of modern and ancient dunes within a dune field along the Pisan coast (Tuscany, Italy)
In this paper, grain size analysis on a large number
of samples from a dune field within the Migliarino – San
Rossore – Massaciuccoli Regional Park has been carried out
in order to define the textural characterization of modern
and ancient dune ridges. More than 200 samples along five
transects have been collected from the backshore, the active
dunes and the steady dunes up to the last recognizable dune
ridge. The samples have been dry-sieved and the obtained data
have been processed electronically to achieve textural parameters
such as mean diameter and sorting. The results showed
similar trends of the transects throughout the entire dune field.
In particular, the grain size tends to decrease towards the most
ancient dune ridges, showing a significant drop at the transition
between active and inactive areas. The drastic decrease
might be related to a possible variation of River Arno sediment discharge occurred after the XVIII century
Anisotropic renormalized fluctuations in the microwave resistivity in YBCO
We discuss the excess conductivity above Tc due to renormalized
order-parameter fluctuations in YBCO at microwave frequencies. We calculate the
effects of the uniaxial anisotropy on the renormalized fluctuations in the
Hartree approximation, extending the isotropic theory developed by Dorsey
[Phys. Rev. B 43, 7575 (1991)]. Measurements of the real part of the microwave
resistivity at 24 and 48 GHz and of the dc resistivity are performed on
different YBCO films. The onset of the superconducting transition and the
deviation from the linear temperature behavior above Tc can be fully accounted
for by the extended theory. According to the theoretical calculation here
presented, a departure from gaussian toward renormalized fluctuations is
observed. Very consistent values of the fundamental parameters (critical
temperature, coherence lenghts, penetration depth) of the superconducting state
are obtained.Comment: RevTex, 8 pages with 5 figures included, to be published in Physical
Review
Report on the quality of the LHCb-Muon four-gap MWPC produced at LNF
The LNF-LHCb team produced 185 four-gap Multi-Wire Proportional Chambers (MWPC). In this note we report the summary of the results of the panel quality controls and of the measurements performed on the assembled detector
Disability, life satisfaction and social interaction in Italy
This paper will focus on the living conditions of disabled people with different degree of limitations as regards to daily activities. In a first step of analysis we focus on the predictors of four specific domains of life satisfaction. In a second step, we attempt to define the different well-being dimensions of disabled people by using the indicators available in the 2011 ISTAT Survey on social inclusion of people with disabilities and by comparing the well-being attainments with respect to the different levels of functional limitations. Given the relevance of social interaction in the life satisfaction of individuals, we focus on this dimension of well-being by analysing the effect of functional limitations on its development, measured by using the observable indicators on the satisfaction of interaction with friends and relatives, the extent of this interaction, and frequency and satisfaction on internet use
MONDO: A tracker for the characterization of secondary fast and ultrafast neutrons emitted in particle therapy
Household users cooperation to reduce cost in green mobile networks
The staggering mobile traffic growth is leading to a huge increase of operational costs for Mobile Operators (MOs) due to power supply. In a Smart Grid (SG) scenario, where Demand Response (DR) strategies are widely adopted to better balance the Demand-Supply mismatch, new opportunities arise for MOs, that can receive some monetary rewards for accomplishing the SG requests of periodically increasing or decreasing their energy consumption. This study considers a mobile network that exploits Renewable Energy (RE) to power the BSs and Resource on Demand (RoD) strategies to dynamically adapt the number of active radio resources to the varying traffic demand, in order to better react to the SG requests. On top of this, the purpose of this work is investigating the effects of the cooperation between Household Customers (HCs) engaged in the DR program and the mobile network. Based on a predefined agreement, HCs cooperate with the MO in order to increase its capability to accomplish the SG requests, receiving in return some benefits when stipulating the Internet provisioning contract with the MO. HCs can contribute to achieving the MO goals by means of two techniques. On the one hand, a fraction of the electric loads that are postponed by the HCs when the SG asks for a reduction of the energy consumption can be shifted on behalf of the mobile network, that will receive the corresponding monetary rewards (HC Trade - HCT). On the other hand, HCs can accept to handle some additional mobile traffic, that is moved to their own WiFi Access Points from the BSs, in order to reduce the energy load of the mobile network (WiFi Offloading - WO).Our results show that, although HCT alone provides limited saving in the energy bill due to the poor attitude of HCs to postpone their electric loads, up to 18% of cost saving can be achieved under full HCs cooperation when HCT is combined with WO. The effects of HCs cooperation can be further enhanced by installing larger sized RE generators, allowing to significantly reduce the energy bill up to more than 90%
Searching for dominant high-level features for music information retrieval
Music Information Retrieval systems are often based on the analysis of a large number of low-level audio features. When dealing with problems of musical genre description and visualization, however, it would be desirable to work with a very limited number of highly informative and discriminant macro-descriptors. In this paper we focus on a specific class of training-based descriptors, which are obtained as the loglikelihood of a Gaussian Mixture Model trained with short musical excerpts that selectively exhibit a certain semantic homogeneity. As these descriptors are critically dependent on the training sets, we approach the problem of how to automatically generate suitable training sets and optimize the associated macro-features in terms of discriminant power and informative impact. We then show the application of a set of three identified macro-features to genre visualization, tracking and classification
Motion estimation and signaling techniques for 2D+t scalable video coding
We describe a fully scalable wavelet-based 2D+t (in-band) video coding architecture. We propose new coding tools specifically designed for this framework aimed at two goals: reduce the computational complexity at the encoder without sacrificing compression; improve the coding efficiency, especially at low bitrates. To this end, we focus our attention on motion estimation and motion vector encoding. We propose a fast motion estimation algorithm that works in the wavelet domain and exploits the geometrical properties of the wavelet subbands. We show that the computational complexity grows linearly with the size of the search window, yet approaching the performance of a full search strategy. We extend the proposed motion estimation algorithm to work with blocks of variable sizes, in order to better capture local motion characteristics, thus improving in terms of rate-distortion behavior. Given this motion field representation, we propose a motion vector coding algorithm that allows to adaptively scale the motion bit budget according to the target bitrate, improving the coding efficiency at low bitrates. Finally, we show how to optimally scale the motion field when the sequence is decoded at reduced spatial resolution. Experimental results illustrate the advantages of each individual coding tool presented in this paper. Based on these simulations, we define the best configuration of coding parameters and we compare the proposed codec with MC-EZBC, a widely used reference codec implementing the t+2D framework
Adapted Physical Activity Can Increase Life Appreciation in Patients with Parkinson's Disease
Objectives: This study aimed to measure the effect of a treatment of adapted physical activity (APA) on motor symptoms and on positive psychological resources in a group of patients with PD. Methods: 37 patients with PD (M age = 71.5; 70.3% male) completed measures of disability level, motor performance, distress, well-being, and quality of life before and after participating in a program of APA (duration: 7 months). Analysis of variance - repeated measures was performed to evaluate the effect of APA on disability, distress, and well-being. Results: After intervention, patients reported significant improvements in their motor autonomy, disability level, psychological distress, and in life appreciation. Discussion: A brief physical activity program was beneficial not only to patients’ motor functioning, but also to their mental health, by reducing distress and promoting life appreciation
Litho-sedimentological and morphodynamic characterization of the Pisa Province coastal area (northern Tuscany, Italy)
In this paper litho-sedimentological and morphodynamic maps of the coastal sector belonging to the Pisa Province are presented as an example of how increasing the accessibility to data on lithology, sedimentology, and morphodynamics may lead to a better approach to coastal management. The database used to build the maps includes an original rendering of remote sensing data (aerial imagery) and new field data (geologic survey), as well as data retrieved from the scientific literature (grain-size and past coastline positions). The maps show that the geometry of beach ridges is an indication of the evolution of the Arno River delta in the last 3000 years, highlighting the relationships between geological aspects and morphodynamic features. The maps represent the synthesis of different data available in the database, and they may be a useful support to coastal management as they are more easily understandable and straightforward than the database from which are created
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