The work deals the monitoring of a single ancient landslide detected in the Vonace area,
southwards of Maierato (Calabria, Italy). A 18-hour-measurement campaign has been carried
out using the Ground-based Synthetic Aperture Radar (GBSAR) interferometry technique
carried between March, 25th and 26th. Displacement maps have been geolocated and overlaid
to a Digital Elevation Model of the scene. It has been observed that the Vonace area is almost
stable except two portions located at the foot of the ancient landslide and at the centre of the
town, respectively. In both cases, a maximum displacement of about 0.5 mm has been
measured. A further campaign is needed to confirm this displacement.
The modeling of various physical questions often leads to nonlinear boundary value problems involving a nonlocal operator, which depends on the unknown function in the entire domain, rather than at a single point. In order to answer an open question posed by J.R. Cannon and D.J. Galiffa, we study the numerical solution of a special class of nonlocal nonlinear boundary value problems, which involve the integral of the unknown solution over the integration domain. Starting from Cannon and Galiffa's results, we provide other sufficient conditions for the unique solvability and a more general convergence theorem. Moreover, we suggest different iterative procedures to handle the nonlocal nonlinearity of the discrete problem and show their performances by some numerical tests.
Fixed point theory
Integro-differential boundary value problems
M-matrices
Nonlinear problems
Nonlocal problems
Numerical iterative methods
We prove global existence and uniqueness of smooth solutions to a
nonlinear system of parabolic-elliptic equations, which describes the chemical aggression
of a permeable material, like calcium carbonate rocks, in presence of acid atmosphere.
This model applies when convective flows are not negligible, due to the high permeability of the material.
The global (in time) result is proven by using
a weak continuation principle for the local solutions.
reaction-diffusion
existence an
porous media
convective and diffusive flows
chemical reactions
carbonate rocks
Modeling Dry-Port-Based Freight Distribution Planning
Teodor Gabriel Crainic
;
Paolo Dell'Olmo
;
Nicoletta Ricciardi
;
Antonino Sgalambro
In this paper we review the dry port concept and its outfalls in terms of optimal design and management of freight distribution. Some optimization challenges arising from the presence of dry ports in intermodal freight transport systems are presented and discussed. Then we consider the tactical planning problem of defining the optimal routes and schedules for the fleet of vehicles providing transportation services between the terminals of a dry-port-based intermodal system. An original service network design model based on a mixed integer programming mathematical formulation is proposed to solve the considered problem. An experimental framework built upon realistic instances inspired by regional cases is described and the computational results of the model are presented and discussed.
Service network design; Dry port; Logistics; Optimization; Mixed integer programming
In this paper we propose a classification of crowd models in built environments based on the assumed pedestrian ability to foresee the movements of other walkers. At the same time, we introduce a new family of macroscopic models, which make it possible to tune the degree of predictiveness of the individuals. By means of these models we describe both the natural behavior of pedestrians, i.e., their expected behavior according to their real limited predictive ability, and a target behavior, i.e., a particularly efficient behavior one would like them to assume (for, e.g., logistic or safety reasons). Then we tackle a challenging shape optimization problem, which consists in controlling the environment in such a way that the natural behavior is as close as possible to the target one, thereby inducing pedestrians to behave more rationally than what they would naturally do. We present numerical tests which elucidate the role of rational/predictive abilities and show some promising results about the shape optimization problem.
Pedestrian dynamics
conservation laws
Hamilton-Jacobi-Bellman equations
minimum time problem
obstacles
shape optimization
The motion of a test particle in the gravitational field of a non-spherical source endowed
with both mass and mass quadrupole moment is investigated when a test
radiation field is also present. The background is described by the Erez-Rosen solution,
which is a static spacetime belonging to the Weyl class of solutions to the
vacuum Einstein's field equations, and reduces to the familiar Schwarzschild solution
when the quadrupole parameter vanishes. The radiation flux has a fixed but arbitrary
(non-zero) angular momentum. The interaction with the radiation field is assumed
to be Thomson-like, i.e., the particles absorb and re-emit radiation, thus suffering for
a friction-like drag force. Such an additional force is responsible for the PoyntingRobertson
effect, which is well established in the framework of Newtonian gravity and
has been recently extended to the general theory of relativity. The balance between
gravitational attraction, centrifugal force and radiation drag leads to the occurrence
of equilibrium circular orbits which are attractors for the surrounding matter for every
fixed value of the interaction strength. The presence of the quadrupolar structure
of the source introduces a further degree of freedom: there exists a whole family of
equilibrium orbits parametrized by the quadrupole parameter, generalizing previous
works. This scenario is expected to play a role in the context of accretion matter
around compact objects.
Motivated by the picture of a thin accretion disc around a black hole, radiating mainly in the direction perpendicular to its plane, we study the motion of test particles interacting with a test geodesic radiation flux propagating perpendicular to the equatorial plane in a Schwarzschild space-time. We assume that the interaction (kind of Poynting-Robertson effect) is modelled by an effective term corresponding to a Thomson-type radiation drag. After approximating the individual photon trajectories in quite an accurate way, we solve the continuity equation (up to linear order in M) in order to find a consistent radiation-flux density, prescribing a certain plausible equatorial profile. The combined effect of gravitation and radiation is illustrated on several figures; they confirm that the particles are generically strongly influenced by the flux, in particular, they are both collimated and accelerated in the direction perpendicular to the disc, but the acceleration received in this manner is not enough to explain highly relativistic outflows emanating from some black-hole-disc sources. Main improvement needed is a more realistic description of the radiation-particle interaction, allowing for Compton-type frequency-dependent effect and particle heating/cooling.
In a recent paper we proposed a numerical method to solve a non-standard non-linear second order integro-differential boundary value problem. Here, we answer two questions remained open: we state the order of convergence of this method and provide some sufficient conditions for the uniqueness of the solution both of the discrete and the continuous problem. Finally, we compare the performances of the method for different choices of the iteration procedure to solve the non-standard nonlinearity.
Numerical solution of boundary value problems; Non-linear non-standard integro-differential equations; Half-line; Order of convergence; Uniqueness
Satellite Earth observation data to identify anthropogenic pressures in selected protected areas
Nagendra H
;
Mairota P
;
Marangi C
;
Lucas R
;
Dimopoulos P
;
Honrado JP
;
Niphadkar M
;
Mücher CA
;
Tomaselli V
;
Panitsa M
;
Tarantino M
;
Manakos I
;
Blonda P
tProtected areas are experiencing increased levels of human pressure. To enable appropriate conserva-tion action, it is critical to map and monitor changes in the type and extent of land cover/use and habitatclasses, which can be related to human pressures over time. Satellite Earth observation (EO) data andtechniques offer the opportunity to detect such changes. Yet association with field information and expertinterpretation by ecologists is required to interpret, qualify and link these changes to human pressure.There is thus an urgent need to harmonize the technical background of experts in the field of EO dataanalysis with the terminology of ecologists, protected area management authorities and policy makers inorder to provide meaningful, context-specific value-added EO products. This paper builds on the DPSIRframework, providing a terminology to relate the concepts of state, pressures, and drivers with the appli-cation of EO analysis. The type of pressure can be inferred through the detection of changes in state (i.e.changes in land cover and/or habitat type and/or condition). Four broad categories of changes in stateare identified, i.e. land cover/habitat conversion, land cover/habitat modification, habitat fragmentationand changes in landscape connectivity, and changes in plant community structure. These categories ofchange in state can be mapped through EO analyses, with the goal of using expert judgement to relatechanges in state to causal direct anthropogenic pressures. Drawing on expert knowledge, a set of pro-tected areas located in diverse socio-ecological contexts and subject to a variety of pressures are analysedto (a) link the four categories of changes in state of land cover/habitats to the drivers (anthropogenic pres-sure), as relevant to specific target land cover and habitat classes; (b) identify (for pressure mapping) themost appropriate spatial and temporal EO data sources as well as interpretations from ecologists andfield data useful in connection with EO data analysis. We provide detailed examples for two protectedareas, demonstrating the use of EO data for detection of land cover/habitat change, coupled with expertinterpretation to relate such change to specific anthropogenic pressures. We conclude with a discussionof the limitations and feasibility of using EO data and techniques to identify anthropogenic pressures,suggesting additional research efforts required in this direction
It is known that symplectic algorithms do not necessarily conserve energy even for the harmonic oscillator. However, for separable Hamiltonian systems, splitting and composition schemes have the advantage to be explicit and can be constructed to preserve energy. In this paper we describe and test an integrator built on a one-parameter family of symplectic symmetric splitting methods, where the parameter is chosen at each time step so as to minimize the energy error. For second-degree polynomial Hamiltonian functions as the one describing the linear oscillator, we build up second and fourth order symmetric methods which are symplectic, energy-preserving and explicit. For non-linear examples, it is possible to construct schemes with minimum error on energy conservation. The methods are semi-explicit in the sense that they require, as additional computational effort, the search for a zero of a scalar function with respect to a scalar variable. Therefore, our approach may represent an effective alternative to energy-preserving implicit methods whenever multi-dimensional problems are dealt with as is the case of many applications of interest.
A patient with PMP22-related hereditary neuropathy and DBH-gene-related dysautonomia
BartolettiStella A
;
Chiaro G
;
CalandraBuonaura G
;
Contin M
;
Scaglione C
;
Barletta G
;
Cecere A
;
Garagnani P
;
Tieri P
;
Ferrarini A
;
Piras S
;
Franceschi C
;
Delledonne M
;
Cortelli P
;
Capellari S
Recurrent focal neuropathy with liability to pressure palsies is a relatively frequent autosomal-dominant demyelinating neuropathy linked to peripheral myelin protein 22 (PMP22) gene deletions. The combination of PMP22 gene mutations with other genetic variants is known to cause a more severe phenotype than expected. We present the case of a patient with severe orthostatic hypotension since 12 years of age, who inherited a PMP22 gene deletion from his father. Genetic double trouble was suspected because of selective sympathetic autonomic disturbances. Through exome-sequencing analysis, we identified two novel mutations in the dopamine beta hydroxylase gene. Moreover, with interactome analysis, we excluded a further influence on the origin of the disease by variants in other genes. This case increases the number of unique patients presenting with dopamine-?-hydroxylase deficiency and of cases with genetically proven double trouble. Finding the right, complete diagnosis is crucial to obtain adequate medical care and appropriate genetic counseling.
Dopamine-?-hydroxylase deficiency
Exome sequencing
dysautonomia
Recurrent focal neuropathy with liability to pressure palsies
Stable, predictive biomarkers and interpretable disease signatures are seen as a signi cant step towards personalized medicine. In this per- spective, integration of multi-omic data com- ing from genomics, transcriptomics, glycomics, proteomics, metabolomics is a powerful strat- egy to reconstruct and analyse complex mul- ti-dimensional interactions, enabling deeper mechanistic and medical insight.
At the same time, there is a rising concern that much of such different omic data -although often publicly and freely available- lie in data- bases and repositories underutilised or not used at all. Issues coming from lack of stand- ardisation and shared biological identities are also well-known.
From these considerations, a novel, pressing
request arises from the life sciences to design methodologies and approaches that allow for these data to be interpreted as a whole, i.e. as inter- twined molecular signatures containing genes, proteins, mRNAs and miRNAs, able to capture
inter-layers connections and complexity.
Papers discuss data integration approaches and methods of several types and extents, their application in understanding the pathogenesis of speci c diseases or in identifying candidate biomarkers to exploit the full bene t of multi-omic datasets and their intrinsic information content.
Topics of interest include, but are not limited to:
o Methods for the integration of layered data, including, but not limited to, genomics, transcrip- tomics, glycomics, proteomics, metabolomics;
o Application of multi-omic data integration approaches for diagnostic biomarker discovery in any eld of the life sciences;
o Innovative approaches for the analysis and the visualization of multi-omic datasets;
o Methods and applications for systematic measurements from single/undivided samples (com-
prising genomic, transcriptomic, proteomic, metabolomic measurements, among others);
o Multi-scale approaches for integrated dynamic modelling and simulation;
o Implementation of applications, computational resources and repositories devoted to data
integration including, but not limited to, data warehousing, database federation, semantic
integration, service-oriented and/or wiki integration;
o Issues related to the de nition and implementation of standards, shared identities and seman-
tics, with particular focus on the integration problem.
multi-omics
multi-omic data integration
integration
systems biology
network analysis
MUSCL extensions (Monotone Upstream-centered Schemes for Conservation Laws) of the Godunov numerical scheme for scalar conservation laws are shown to admit a rather simple reformulation when recast in the formalism of the Haar multi-resolution analysis of L<sup>2</sup>(R). By pursuing this wavelet reformulation, a seemingly new MUSCL-WB scheme is derived for advection-reaction equations which is stable for a Courant number up to 1 (instead of roughly 1/2 ). However these highorder reconstructions aren't likely to improve the handling of delicate nonlinear wave interactions in the involved case of systems of Conservation/Balance laws.
An elementary model of (1 + 1)-dimensional general relativity, known as "R = T " and mainly developed by Mann and coworkers in the early 1990s, is set up in various contexts. Its formulation, mostly in isothermal coordinates, is derived and a relativistic Euler system of selfgravitating gas coupled to a Liouville equation for the metric's conformal factor is deduced. First, external field approximations are carried out: both a Klein-Gordon equation is studied along with its corresponding density, and a Dirac one inside a hydrostatic gravitational field induced by a static, piecewise constant mass repartition. Finally, the coupled Euler-Liouville system is simulated, by means of a locally inertial Godunov scheme: the gravitational collapse of a static random initial distribution of density is displayed. Well-balanced discretizations rely on the treatment of source terms at each interface of the computational grid, hence the metric remains flat in every computational cell.
1+1 general relativity
Dirac and Klein-Gordon equations
Intrinsic finite differences
Locally inertial scheme
Relativistic hydrodynamics
Schemes
Structure-preserving and well-balanced
This monograph presents, in an attractive and self-contained form, techniques based on the L1 stability theory derived at the end of the 1990s by A. Bressan, T.-P. Liu and T. Yang that yield original error estimates for so-called well-balanced numerical schemes solving 1D hyperbolic systems of balance laws. Rigorous error estimates are presented for both scalar balance laws and a position-dependent relaxation system, in inertial approximation. Such estimates shed light on why those algorithms based on source terms handled like "local scatterers" can outperform other, more standard, numerical schemes. Two-dimensional Riemann problems for the linear wave equation are also solved, with discussion of the issues raised relating to the treatment of 2D balance laws. All of the material provided in this book is highly relevant for the understanding of well-balanced schemes and will contribute to future improvements.
analytical and numerical aspects of 1D hyperbolic balance laws
accuracy of well-balanced numerical schemes
wavefront tracking
2D Riemann problems