281 research outputs found
Emergence of classical trajectories in quantum systems: the cloud chamber problem in the analysis of Mott (1929)
No full textWe analyze the paper "The wave mechanics of {Mathematical expression}-ray tracks" Mott (Proc R Soc Lond A 126:79-84, 1929), published in 1929 by N. F. Mott. In particular, we discuss the theoretical context in which the paper appeared and give a detailed account of the approach used by the author and the main result attained. Moreover, we comment on the relevance of the work not only as far as foundations of Quantum Mechanics are concerned but also as the earliest pioneering contribution in decoherence theory. © 2012 Springer-Verlag Berlin Heidelberg
A Computational Approach to Poetic Structure, Rhythm and Rhyme
No full textIn this paper we present SPARSAR, a system for the automatic analysis of English and Italian poetry. The system can work on any type of poem and produces a set of parameters that are then used to compare poems with one another, of the same author or of different authors. In this paper, we will concentrate on the second module, which is a rule-based system to represent and analyze poetic devices. Evaluation of the system on the basis of a manually created dataset - including poets from Shakespeare's time down to T.S.Eliot and Sylvia Plath - has shown its high precision and accuracy approximating 90%
Machine Learning of a Density Functional for Anisotropic Patchy Particles
No full textIn dieser Arbeit untersuchen wir die homogene und inhomogene Struktur einer anisotropen assoziierenden Flüssigkeit, wie sie durch ein Kern--Frenkel-Potential realisiert wird. Wir verwenden hierfür Computersimulationen und
Dichtefunktionaltheorie (DFT). Die aktuellen Standard-Funktionale für diese Systeme basieren auf der fundamentalen Maßtheorie (fundamental measure theory) und Wertheims thermodynamischer Störungstheorie (thermodynamic perturbation theory). Diese sind in der Lage, recht genaue
Ergebnisse hinsichtlich der Zustandsgleichung und der inhomogenen Struktur zu liefern, wenn sie auf moderat hohe Temperaturen und „einfache“ externe Potentiale beschränkt sind.
Bei niedrigen Temperaturen jedoch erhöht sich die Bindungswahrscheinlichkeit der Teilchen in der assoziierenden Flüssigkeit, was zu einer starken orientierungsspezifischen Ordnung der Teilchen führt. Dies resultiert in
Ungenauigkeiten bei den Vorhersagen, die auf die isotrope Behandlung des Fluids zurückzuführen sind. Angesichts dieser Tatsache schlagen wir vor, die orientierungsabhängigen Freiheitsgrade der Teilchen explizit zu behandeln,
indem relevante Größen in Wigner-D-Matrizen entwickelt werden. Hierzu untersuchen wir, wie die Symmetrie des betrachteten Zweikörperpotentials die Entwicklungskoeffizienten beeinflusst und wie die numerische Behandlung durch
das Bestimmen invarianter Basisfunktionen vereinfacht werden kann.
Anschließend wird die Verteilungsfunktion der Orientierung für die inhomogene Flüssigkeit zwischen zwei harten Wänden und um ein sphärisches Tracer-Teilchen untersucht, welche eine relativ starke Ordnung aufzeigt. Um das System
mit dem DFT-Formalismus zu behandeln, leiten wir zunächst die notwendigen Gleichungen für den Fall eines anisotropen Fluids her. Danach wenden wir die beliebte Random-Phase-Approximation als Referenzpunkt für weitere Ansätze
an.
Wir beginnen mit dem Vorschlag eines Mean-Field Ansatzes, der die orientierungsabhängigen Momente der Dichteverteilung integriert. Die notwendigen Wechselwirkungspotentiale werden mithilfe maschinellen Lernens gefunden,
indem diese Potentiale durch differenzierbare Gewichte parametrisiert und anschließend mittels Vergleich zu Monte-Carlo-Simulationen optimiert werden, die bei verschiedenen Zustandspunkten gesammelt wurden. Ein Verfahren gewährleistet
die Selbstkonsistenz der resultierenden Euler--Lagrange-Gleichungen. Das endgültige Mean-Field-Funktional verbessert die Genauigkeit im Vergleich zu vorherigen Ansätzen, jedoch verschlechtert sich die numerische Stabilität
schnell, wenn man den Trainingsbereich verlässt.
Als zweiten Ansatz schlagen wir vor, die Funktionsform des isotropen Funktionals beizubehalten, aber verbesserte Gewichtsfunktionen zu lernen, die über die gewichteten Dichten eingehen. Obwohl wir mit diesem Ansatz keine Vorhersagen über die
orientierungsabhängigen Freiheitsgrade des Systems treffen können, gewinnen wir an numerischer Stabilität durch die Beibehaltung der bekannten Funktionsform des Referenz-Funktionals. Neben genaueren Dichteprofilen lässt sich beobachten, dass die Korrelationsfunktion aus diesem Ansatz und dem Trainingsverfahren viel näher am tatsächlichen Wert liegt.In this work we investigate the homogeneous and inhomogeneous structure
of an anisotropic associating liquid, as realized by a Kern--Frenkel potential, through means of computer
simulations and density functional theory (DFT). Current state-of-the-art
functionals for these systems are based on fundamental measure theory
and Wertheim's thermodynamic perturbation theory. They are
able to achieve rather accurate results regarding the equation of state and the inhomogeneous structure
when restricted to moderately high temperatures and ``simple'' external potentials.
At low temperatures however, the bonding probability of the particles in the associating liquid
increases, leading to a strong orientational ordering of the particles.
This results in inaccuracies in the predictions,
that can be attributed to the isotropic treatment of the fluid.
Motivated by this fact, we propose the explicit treatment of the orientational degrees
of freedom of the particles using an expansion of the relevant quantities in Wigner D-matrices.
To this end, we examine how the symmetry of the
investigated two-body potential influences the expansion coefficients and how
the numerical treatment can be simplified by finding invariant basis functions.
After this, the orientation distribution function of the inhomogeneous liquid between two
hard walls and around a spherical tracer particle is examined, showing a relatively
strong order. In order to treat the system with the DFT formalism we first derive the
necessary equations for the case of an anisotropic liquid. Then we
apply the popular random phase approximation as a reference for further approaches.
We start by proposing a mean-field ansatz incorporating the orientational moments
of the density distribution. The necessary interaction potentials are found
using a machine-learning based approach, by parametrizing the potentials using
differentiable weights. These are then optimized using Monte Carlo simulation data, collected
at different state points and a procedure that guarantees the self-consistency of
the resulting Euler--Lagrange equations. The final mean-field functional improves
on the performance of previous treatments, however numerical stability quickly
degrades when stepping outside the training region.
As a second approach, we propose keeping the functional form of the isotropic functional but learning
improved weight functions that enter through the weighted densities. While in this case we cannot make
predictions about the orientational degrees of freedom of the system, we gain improved numerical stability through keeping the known functional
form of the reference functional. Apart from more accurate density profiles, we can also observe
that the correlation function resulting from this ansatz and training procedure is much closer to its real value
The use of life cycle assessment (LCA) to analyse environmental impacts produced by solid waste management systems
No full text2008-2009Nowadays, the qualitative and quantitative assessment of environmental
impacts produced by every human activity is a topical field of research.
As a matter of fact, all over the world there is an increasing attention
about the environmental issues and influences exerted by productive and
management sectors. In particular, the management of waste is a crucial
sector involving important aspects of our life as well as it produces
several environmental impacts that have to be adequately monitored and
managed in a sustainable development perspective.
In the first part, this study was focused on the evaluation of the positive
and negative impacts caused on different environmental components by
several municipal solid waste management systems defined at provincial
scale. This assessment was performed by means of two different Life
Cycle Assessment (LCA) procedures called WISARD and SimaPro,
respectively. The LCA procedures were able to calculate the
consequences produced by the whole system as well as by each phase.
While, in the second part, the study was focused on the collection and
transport of materials to determine environmental and economic effects
for ten municipalities from 1000 to 10,000 inhabitants.
The performed analysis taken into account a kerbside collection system
of all recyclables, glass excepted, with a percentage of separate collection
varying in the range of 35% – 80% and transport to composting of
putrescibles, RDF pressed balls production and incineration, final
landfilling. There are other two scenarios, for 80% separate collection,
that consider different alternatives of treatment for residues as dry
residue sorting and final landfilling or direct disposal in landfill.
The obtained results pointed out that the increasing of the percentage
separated collection involves an environmental performances’
improvement of management system and an environmental benefits’
increase. For high percentage of waste separated collection incineration
doesn’t weighed upon impact’s results respectful to dry residue sorting.
The results are similar for both Life Cycle Assessment procedures in
qualitative terms.
xviii
With regard phase of collection and transport for communities results
show how impacts rise such as community’s size; opposite management
costs in term of Euro/inhabitant/year increase for the little communities
but don’t depend by the number of inhabitants for the communities with
a population major of 5000 inhabitants.
The multi-criteria analysis was developed giving the same importance to
both economic and environmental variables. The principal result
obtained was that the municipalities up to 4000 inhabitants must get
together to optimize both environmental and management costs. [edited by Author]VIII n.s
The pathology and pathobiology of bicuspid aortic valve: State of the art and novel research perspectives†
No full textAbstract Bicuspid aortic valve is the most prevalent cardiac valvular malformation. It is associated with a high rate of long‐term morbidity including development of calcific aortic valve disease, aortic regurgitation and concomitant thoracic aortic aneurysm and dissection. Recently, basic and translational studies have identified some key processes involved in the development of bicuspid aortic valve and its morbidity. The development of aortic valve disease and thoracic aortic aneurysm and dissection is the result of complex interactions between genotypes, environmental risk factors and specific haemodynamic conditions created by bicuspid aortic valve anatomy. Herein, we review the pathobiology of bicuspid aortic valve with a special emphasis on translational aspects of these basic findings. Important but unresolved problems in the pathology of bicuspid aortic valve and thoracic aortic aneurysm and dissection are discussed, along with the molecular processes involved.Version of Recor
Erratum to “Systematic versus on-demand early palliative care: A randomised clinical trial assessing quality of care and treatment aggressiveness near the end of life” [Eur J Cancer (2016) 69 (110–118)] (S095980491632487X)(10.1016/j.ejca.2016.10.004)
No full textThe publisher regrets that the collaborators for this paper were not listed as such within the author details of the published paper. The collaborators were published in the Acknowledgements and are as follows: Alberto Farolfi, Silvia Ruscelli, Martina Valgiusti, Sara Pini, Marina Faedi, Department of Medical Oncology, IRST IRCCS, Meldola; Angela Ragazzini, Unit of Biostatistics and Clinical Trials, IRST IRCCS, Meldola; Cristina Pittureri and Elena Amaducci, Palliative Care and Hospice Unit, AUSL Romagna, Cesena; Irene Guglieri, Psychooncology Service, Veneto Institute of Oncology IOV – IRCCS, Padua; Francesca Bergamo, Sara Lonardi, Department of Clinical and Experimental Oncology, Medical Oncology 1, Veneto Institute of Oncology IOV – IRCCS, Padua; Camilla Di Nunzio, Medical Oncology Unit, Oncology–Hematology Department, Guglielmo da Saliceto Hospital, Piacenza; Monica Bosco, Palliative Care Unit, Oncology–Hematology Department, Guglielmo da Saliceto Hospital, Piacenza; Barbara Bocci, Medical Oncology Unit, San Paolo Hospital, Milan; Alfina Bramanti and Chiara Gandini, Oncology Unit, Fondazione IRCCS Policlinico San Matteo, Pavia; Angela Buonadonna, Medical Oncology Unit, Aviano National Cancer Institute, Aviano; Alessandro Comandone, Medical Oncology Unit, Presidio Humanitas Gradenigo, Turin; Sonia Zoccali, Coordinamento Cure Palliative (supported by F.I.L.E., Leniterapia Italian Foundatio), Florence; Maria Simona Pino, Medical Oncology Unit, Oncology Department, S. Maria Annunziata Hospital, Florence; Davide Dalu, Palliative Care Unit, Oncology Department, L. Sacco Hospital, Milan; Pietro Sozzi, Oncology Unit, Ospedale degli Infermi, Ponderano; Alberto Gozza, Medical Oncology, Department of Medicine, E.O. Galliera Hospitals, Genoa; Monica Giordano and Carla Longhi, Oncology Unit, Sant'Anna Hospital, Como; Cristina Autelitano, Palliative Care Unit, Arcispedale S. Maria Nuova – IRCCS, Reggio Emilia; Teresa Gamucci, Oncology Unit, SS Trinità Hospital Sora, ASL Frosinone, Frosinone; Cataldo Mastromauro, Oncology Unit, ULSS 12 Veneziana, Venice; Rodolfo Scognamiglio, Hospice Nazareth, Mestre; Daniela Degiovanni, Palliative Care Unit, Casale Monferrato, ASL Alessandria; Federica Negri, Medical Oncology Unit, Istituti Ospitalieri, Cremona; Augusto Caraceni, Palliative Care, Pain Therapy and Rehabilitation Department, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan; and Luigi Montanari, Palliative Care Unit Ravenna, AUSL Romagna, Italy. The publisher would like to apologise for any inconvenience caused
Mass and energy transfers in soeil - vegetation - atmosphere system
No full text2009 - 2010Knowledge of hydrological processes acting in the water balance is
determinant for a rational water resources management plan. Among
these, the water losses as vapour, in the form of evapotranspiration, play
an important role in the water balance and the heat transfers between the
land surface and the atmosphere. Mass and energy interactions between
soil, atmosphere and vegetation, in fact, influence all hydrological
processes modificating rainfall interception, infiltration,
evapotraspiration, surface runoff and groundwater recharge.
A numbers of methods have been developed in scientific literature for
modelling evapotranspiration. They can be divided in three main groups:
i) traditional meteorological models, ii) energy fluxes balance models,
considering interaction between vegetation and the atmosphere, and iii)
remote sensing based models.
The present analysis preliminary performs a study of fluxes directions
and an evaluation of energy balance closure in a typical Mediterranean
short vegetation area, using data series recorded from an eddy covariance
station, located in the Campania region, Southern Italy. The analysis was
performed on different seasons of the year with the aim to assess
climatic forcing features impact on fluxes balance, to evaluate the smaller
imbalance and to highlight influencing factors and sampling errors on
balance closure. The present study also concerns evapotranspiration
fluxes assessment at the point scale. Evapotranspiration is evaluated both
from empirical relationships (Penmann-Montheit, Penmann FAO,
Prestley&Taylor) calibrated with measured energy fluxes at mentioned
experimental site, and from measured latent heat data scaled by the latent
heat of vaporization. These results are compared with traditional and
reliable well known models at the plot scale (Coutagne, Turc,
Thorthwaite). [edited by Author]IX n.s
Gli effetti indotti sul costruito da frane a cinematica lenta
No full text2008 - 2009Landslides - alone or in combination with other natural disasters such as earthquakes, volcanic
eruptions, floods etc. - Represent a major cause of casualties and property damage in terms of direct
and indirect costs.
For this reason, it’s interesting, either for the scientific community and for that technique, to
study aimed at the prediction of the effects associated with the action of landslides on the elements
at risk and, therefore, the estimation of their vulnerability.
As for this, the extreme complexity of the problem has, in fact, contributed to the practical
absence of standardized procedures.
The research carried out as part of this thesis aims to make a contribution in this direction with
specific reference to aspects concerning the estimation of physical vulnerability, or of the
consequences, in terms of expected damage, are predictable structures that interact with the bodies
of landslides kinematics active or slow, if quiescent, occasionally reactivated.
Additional reasons for the research are to be found in extreme dissemination of these
phenomena on the Italian territory, as it was recently revealed by the studies undertaken in the
context of the preparation of plans for the hydrogeological Excerpt (PSAI) and Landslide Project (
Inventory of Landslide in Italy), and the consequences that may result from the research in terms of
land management.
For the estimation of the vulnerability, it is necessary to study, analysis and interpretate the
interaction between the landslide and the vulnerable elements (in terms of single element exposed
or sets of elements) according to the following logic flow of operations (Varnes, 1984; Cruden and
Fell, 1997; Cascini 2005; Pisciotta, 2008): characterization of landslides or potential; estimate of its
intensity; identification of the exposed element or set of elements exposed; vulnerability
assessment.
As part of this methodological approach, the research activities were focused, at first on the
definition of the parameters useful to estimate the intensity of landslides and on the identification of
the most appropriate criteria for the identification of the elements at risk two different scales of
territorial representation (average and detail).
So, the real definition of physical vulnerability has been specializing in a different way
depending on the assumptions made at the two scales of work.
Having established the general criteria which determine the approach adopted, the activities
were aimed at the development of innovative procedures, based on the so-called "model of the
consequences", for the estimation of physical vulnerability... [edited by Author]VIII n.s
A Vision of Collaborative Verification-Driven Engineering of Hybrid Systems
No full textHybrid systems with both discrete and continuous dynamics are an important model for real-world physical systems. The key challenge is how to ensure their correct functioning w.r.t. safety requirements. Promising techniques to ensure safety seem to be model-driven engineering to develop hybrid systems in a well-defined and traceable manner, and formal verification to prove their correctness. Their combination forms the vision of verification-driven engineering. Despite the remarkable progress in automating formal verification of hybrid systems, the construction of proofs of complex systems often requires significant human guidance, since hybrid systems verification tools solve undecidable problems. It is thus not uncommon for verification teams to consist of many players with diverse expertise. This paper introduces a verification-driven engineering toolset that extends our previous work on hybrid and arithmetic verification with tools for (i) modeling hybrid systems, (ii) exchanging and comparing models and proofs, and (iii) managing verification tasks. This toolset makes it easier to tackle large-scale verification tasks
Satellite remote sensing for surface soil water content estimation
No full text2008 - 2009Satellite remote sensing is a useful source of observations of land surface
hydrologic variables and processes and could be a practical substitution
of conventional in-situ monitoring. Most of hydrological dynamic
processes change not only throughout the years but also within weeks or
months and their monitoring requires frequent observations. The most
prominent advantage of the remote sensing technologies is that they
offer a synoptic view of the dynamics and spatial distribution of
phenomena and parameters, often difficult to monitor with traditional
ground survey, with a frequent temporal coverage. Many of the variables
in the land surface water balance can now be observed with satellite
techniques thanks to an extensive development over the last decades.
Often the problem connected to the use of remotely sensed data is their
accuracy that, according to the sensor used and to the application
considered, can ranges from moderate to excellent.
The objective of this thesis has been to evaluate the use of satellite
remote sensing techniques for the monitoring of two variables useful for
hydrology applications: water body extension and soil moisture
monitoring.
The capability to map water surface is important in many hydrological
applications, in particular accurate information on the extent of water
boundary is essential for flood monitoring and water reservoir
management. Often, this information is difficult to retrieve using
traditional survey techniques because water boundaries can be fast
moving as in floods or may be inaccessible. In this PhD thesis, an
artificial basin for which in-situ information about the water extension
are available is used as case study. The area extension recorded daily by
the dam owner is compared to the one retrieved by using satellite images
acquired from SAR and TM/ETM+ sensors. The outcomes of the
analysis show that satellite images are able to map water body surfaces
with a good accuracy. The analysis also highlighted the factor to be taken
into account while using types of sensors.
Soil moisture is recognized as a key variable in different hydrological and
ecological processes as it controls the exchange of water and heat energy
between land surface and the atmosphere. Despite the high spatial
variability of this parameter it has been demonstrated that many satellite
sensors are able to retrieve soil moisture information of the surface layer
at catchment scale. Among other sensors, the Scatterometer is very
useful for climatic studies and modelling analysis thanks, respectively, to
the temporal frequency, global coverage and to the long time series
availability. Even though the ERS Scatterometer has been designed to
measure the wind over the ocean surface, in recent years it has been
pointed out that backscattering measurements have high potentiality for
soil moisture retrieval.
The second task of this PhD thesis, concerning the use of satellite data
for soil moisture monitoring, has been developed at Serco S.p.A. in the
framework of the Advanced Scatterometer Processing System (ASPS)
project developed by ESA (European Space Agency) to reprocess the
entire ERS Scatterometer mission. Since the beginning of the ERS-1
Scatterometer mission in 1991 a long dataset of C-band backscattering
signal from the Earth surface is available for studies and researches. This
is a very consistent dataset, but in particular for climatology studies it is
important to have high quality and homogeneous long term observation
as also stated in the key guidelines included in the Global Climate
Observing System (GCOS) from the World Meteorological Organization
(WMO).
The main goal of this task has been the generation of the new
Scatterometer ASPS products with improved data quality and spatial
resolution. This achievement required a long preparation activity but
represents an important contribution to the C-band Scatterometer
dataset available to the scientific community. In order to evaluate the
usage of the re-processed Scatterometer data for soil moisture
estimation, the backscattering measurements derived in the new ASPS
products have been then compared to in-situ volumetric soil moisture
data and the relationship between radar backscattering and soil moisture
measurements has been investigated under different conditions: angle of
incidence, angle of azimuth, data measurements resolution, season of the
year.
Analysis results show that a relationship between the C-band
backscattering coefficient and the in-situ volumetric soil moisture exists
and takes into account the incidence and azimuth angles and the
vegetation cover. [edited by Author]VIII n. s
- …
