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Search Results: 1 - 10 of 3464 matches for " Federico Lucchi "
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Long-period seismic events with strikingly regular temporal patterns on Katla volcano's south flank (Iceland)
Giulia Sgattoni,Zeinab Jeddi,ólafur Guemundsson,Páll Einarsson,Ari Tryggvason,Bj?rn Lund,Federico Lucchi
Physics , 2015,
Abstract: Katla is a threatening volcano in Iceland, partly covered by the M\'yrdalsj\"okull ice cap. The volcano has a large caldera with several active geothermal areas. A peculiar cluster of long-period seismic events started on Katla's south flank in July 2011, during an unrest episode in the caldera that culminated in a glacier outburst. The seismic events were tightly clustered at shallow depth in the Gvendarfell area, 4 km south of the caldera, under a small glacier stream on the southern margin of M\'yrdalsj\"okull. No seismic events were known to have occurred in this area before. The most striking feature of this seismic cluster is its temporal pattern, characterized by regular intervals between repeating seismic events, modulated by a seasonal variation. Remarkable is also the stability of both the time and waveform features over a long time period, around 3.5 years. No comparable examples have been found in the literature. Both volcanic and glacial processes can produce similar waveforms and therefore have to be considered as potential seismic sources. Discerning between these two causes is critical for monitoring glacier-clad volcanoes and has been controversial at Katla. For this new seismic cluster on the south flank we regard volcano-related processes as more likely than glacial ones for the following reasons: 1) the seismic activity started during an unrest episode involving sudden melting of the glacier and a j\"okulhlaup; 2) the glacier stream is small and stagnant; 3) the seismicity remains regular and stable for years; 4) there is no apparent correlation with short-term weather changes, such as rain storms. We suggest that a small, shallow hydrothermal system was activated on Katla's south flank in 2011, either by a minor magmatic injection or by changes of permeability in a local crack system.
Formalizing Mobility in Service Oriented Computing
Claudio Guidi,Roberto Lucchi
Journal of Software , 2007, DOI: 10.4304/jsw.2.1.1-13
Abstract: The usual scenario of service oriented systems is characterized by several services offering the same functionalities, by new services that are continuosly deployed and by other ones that are removed. In this context it can be useful to dynamically discover and compose services at runtime. Orchestration languages provide a mean to deal with service composition, while the problem of fulfilling at runtime the information about the involved services is usually referred to as open-endedness. When designing service-based applications both composition and open endedness play a central role. Such issues are strongly related to mobility mechanisms which make it possible to design applications that acquire, during the execution, the information which are necessary to invoke services. In this paper we discuss the forms of mobility for the service oriented computing paradigm. To this end we model a service by means of the notions of interface, location, internal process and internal state, then we formalize a calculus supporting the mobility of each element listed above. We conclude by tracing a comparison between the proposed calculus and the mobility mechanisms supported by the Web Services technology.
A General Purpose Analysis Package  [PDF]
Stefano Federico
Atmospheric and Climate Sciences (ACS) , 2012, DOI: 10.4236/acs.2012.22022
Abstract: This paper presents a general-purpose analysis package able to solve two- and three- dimensional analysis problems. The system can use the following methods of solution: Successive Approximation (SA), Optimal Interpolation (OI), and 3D-Var. Analyses are given for the following parameters: zonal and meridional wind components, temperature, relative humidity, and geopotential height. The analysis package was applied to produce analyses at 6 h time interval for the period 1-11 August 2008. The period was selected for data availability and forty-one analyses were collected. The results show the validity of the different solutions, which can be chosen depending on the physical problem to solve and on the computational resources available. In particular, assuming the observations as the reference, all solutions show a decrease of the RMSE compared to the background. The decrease is consistent with the particular setting of the analysis system used in this paper. The comparison between different solutions shows that the SA converges to OI in few iterations, and that the SA solution with ten iteration is, in practice, equal to OI. Moreover, the 3D-Var method shows its potential to improve the analysis, once the horizontal and vertical length-scales and the background and observational errors are set optimally, because its solution may be sizeably different from two-dimensional methods.
Emerging Trends and Old Habits in Higher Education Management: Focus on the Public vs. Private Funding Debate  [PDF]
Federico Barnabè
Creative Education (CE) , 2012, DOI: 10.4236/ce.2012.326152
Abstract: This work takes into consideration the wide reform process that is impacting on Universities all over the world, especially focusing on the public versus private funding debate for Higher Education Institutions. In this regard, the paper provides some considerations on possible funding sources, discusses data related to the relevance of public funding and presents the features of the main models of public funding across many countries, particularly focusing on Europe.
Preliminary Results of a Data Assimilation System  [PDF]
Stefano Federico
Atmospheric and Climate Sciences (ACS) , 2013, DOI: 10.4236/acs.2013.31009
Abstract:

A data assimilation system combines all available information on the atmospheric state in a given time-window to produce an estimate of atmospheric conditions valid at a prescribed analysis time. Nowadays, increased computing power coupled with greater access to real-time asynoptic data is paving the way toward a new generation of high-resolution (i.e. on the order of 10 km) operational mesoscale analyses and forecasting systems. Moreover, better initial conditions are increasingly considered of the utmost importance for Numerical Weather Prediction (NWP) at the short range (0 - 12 h). This paper presents a general-purpose data assimilation system, which is coupled with the Regional Atmospheric Modelling System (RAMS) to give the analyses for: zonal and meridional wind components, temperature, relative humidity, and geopotential height. In order to show its potential, the data assimilation systems applied to produce analyses over Central Europe. For this application the background field is given by a short-range forecast (12 h) of the RAMS and analyses are produced by 2D-Var with 0.25? horizontal resolution. Results show the validity of the analyses because they are closer to the observations, consistently with the settings of the data assimilation system. To quantify the impact of improved initial conditions on the forecast, the analyses are then used as initial conditions of a short-range (6 h) forecast of the RAMS model. The results show that the RMSE is effectively reduced for the one- and two hours forecast, with some improvement for the three-hours forecast.

Photovoltaic Prickle Pear Harvesting Tool  [PDF]
Federico Hahn
Natural Resources (NR) , 2013, DOI: 10.4236/nr.2013.43033
Abstract:

Mexico is the largest cactus exporter of the world and 40% of the production cost is provided from the harvest operation. Many workers are required to operate daily and suffer wrist pain after two weeks of collecting pears with mechanical pruners. A motor driven tool supplied from a photovoltaic system was employed for harvesting; different blades were tested at different cutting speeds. It was found that toothed blades sliced the pears with efficiencies over 90%. Abrasive blades were finally selected as the current required per cut was minimum, permitting a longer battery lifetime before requiring recharging.

One Dimensional Relativistic Particle in a Quadratic Dissipative Medium Subjected to a Force That Depends on the Position  [PDF]
Federico Petrovich
Journal of Modern Physics (JMP) , 2015, DOI: 10.4236/jmp.2015.69122
Abstract: We will find a constant of motion with energy units for a relativistic particle moving in a quadratic dissipative medium subjected to a force which depends on the position. Then, we will find the Lagrangian and the Hamiltonian of the equation of motion in a time interval such that the velocity does not change its sign. Finally, we will see that the Lagrangian and Hamiltonian have some problems.
A New Formulation of Classical Mechanics—Part 1  [PDF]
Federico Petrovich
Journal of Applied Mathematics and Physics (JAMP) , 2016, DOI: 10.4236/jamp.2016.42048
Abstract: This paper has two parts, in this occasion we will present the first one. Until today, there are two formulations of classical mechanics. The first one is based on the Newton’s laws and the second one is based on the principle of least action. In this paper, we will find a third formulation that is totally different and has some advantages in comparison with the other two formulations.
A New Formulation of Classical Mechanics—Part 2  [PDF]
Federico Petrovich
Journal of Applied Mathematics and Physics (JAMP) , 2016, DOI: 10.4236/jamp.2016.45103
Abstract: In the first part of this paper, we found a more convenient algorithm for solving the equation of motion of a system of n bodies. This algorithm consists in solving first the trajectory equation and then the temporal equation. In this occasion, we will introduce a new way to solve the temporal equation by curving the horizontal axis (the time axis). In this way, we will be able to see the period of some periodic systems as the length of a certain curve and this will allow us to approximate the period in a different way. We will also be able to solve some problems like the pendulum one without using elliptic integrals. Finally, we will solve Kepler’s problem using all the formalism.
Outside camp settings
Alena Koscalova,Elena Lucchi,Sabine Kampmüller
Forced Migration Review , 2010,
Abstract: Current assessment tools and intervention strategies are based mainly on experience of camp-like situations; what is needed are innovative responses to address problems specific to open settings.
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