40 research outputs found
Field trip to the Ischia resurgent caldera, a journey across an active volcano in the Gulf of Naples
Ischia is one of the most impressive examples of post-caldera resurgence in the world, with its almost 1,000 m of uplift in less than 30 ka. This three-days field trip will lead the participants through the geological and volcanological history of the island, illustrating the volcanic and related hazardous phenomena threatening about 50,000 inhabitants. Effusive and explosive eruptions, catastrophic earthquakes and huge debris-avalanches struck the island that, since Neolithic times, experienced a complex history of alternating human colonization and natural disasters. The field trip consists of three routes: 1) the circumnavigation of the island, aimed to outline its main volcanological, geomorphological and tectonic features and to observe the oldest volcanic rocks exposed, stimulating discussions about coastal evolution and the relationships between volcanism, volcano-tectonism and slope instability; 2) an onland excursion on peculiar aspects of the products related to Ischia more recent period of volcanic activity; 3) a route focusing on the Mt. Epomeo Green Tuff caldera forming eruptions (55-60 ka), encouraging a discussion on the dynamics of the intracalderic resurgence and the geomorphological evolution of the Mt. Epomeo slopes, with ongoing Mass Rock Creep (MRC) processes culminating in rockavalanche, debris-avalanche and lahar deposits
A fast robust optimization-based heuristic for the deployment of green virtual network functions
Network Function Virtualization (NFV) has attracted a lot of attention in the telecommunication field because it allows to virtualize core-business network functions on top of a NFV Infrastructure. Typically, virtual network functions (VNFs) can be represented as chains of Virtual Machines (VMs) or containers that exchange network traffic which are deployed inside datacenters on commodity hardware. In order to achieve cost efficiency, network operators aim at minimizing the power consumption of their NFV infrastructure. This can be achieved by using the minimum set of physical servers and networking equipment that are able to provide the quality of service required by the virtual functions in terms of computing, memory, disk and network related parameters. However, it is very difficult to predict precisely the resource demands required by the VNFs to execute their tasks. In this work, we apply the theory of robust optimization to deal with such parameter uncertainty. We model the problem of robust VNF placement and network embedding under resource demand uncertainty and network latency constraints using robust mixed integer optimization techniques. For online optimization, we develop fast solution heuristics. By using the virtualized Evolved Packet Core as use case, we perform a comprehensive evaluation in terms of performance, solution time and complexity and show that our heuristic can calculate robust solutions for large instances under one second.Peer ReviewedPostprint (author's final draft
Correlating Fluorescence and High-Resolution Scanning Electron Microscopy (HRSEM) for the study of GABAA receptor clustering induced by inhibitory synaptic plasticity
Both excitatory and inhibitory synaptic contacts display activity dependent
dynamic changes in their efficacy that are globally termed synaptic
plasticity. Although the molecular mechanisms underlying glutamatergic
synaptic plasticity have been extensively investigated and described, those
responsible for inhibitory synaptic plasticity are only beginning to be
unveiled. In this framework, the ultrastructural changes of the inhibitory
synapses during plasticity have been poorly investigated. Here we combined
confocal fluorescence microscopy (CFM) with high resolution scanning electron
microscopy (HRSEM) to characterize the fine structural rearrangements of post-
synaptic GABAA Receptors (GABAARs) at the nanometric scale during the
induction of inhibitory long-term potentiation (iLTP). Additional electron
tomography (ET) experiments on immunolabelled hippocampal neurons allowed the
visualization of synaptic contacts and confirmed the reorganization of post-
synaptic GABAAR clusters in response to chemical iLTP inducing protocol.
Altogether, these approaches revealed that, following the induction of
inhibitory synaptic potentiation, GABAAR clusters increase in size and number
at the post-synaptic membrane with no other major structural changes of the
pre- and post-synaptic elements
Reply to âComment on âThe 21 August 2017 Md 4.0 Casamicciola Earthquake: First Evidence of Coseismic Normal Surface Faulting at the Ischia Volcanic Islandâ by Nappi et al. (2018)â by V. De Novellis, S. Carlino, R. Castaldo, A. Tramelli, C. De Luca, N. A. Pino, S. Pepe, V. Convertito, I. Zinno, P. De Martino, M. Bonano, F. Giudicepietro, F. Casu, G. Macedonio, M. Manunta, M. Manzo, G. Solaro, P. Tizzani, G. Zeni, and R. Lanari
In this article, we show why the geological model of the 21 August
2017 earthquake proposed by Nappi et al. (2018) has less
uncertainty than the sourcemodel proposed by De Novellis et al.
(2018). As a matter of fact, the Nappi et al. (2018) model takes
into account all geophysical and geological information collected
soon after the earthquake. On the contrary, the model proposed
by DeNovellis et al. (2018) is based on a limited database, which
does not include (1) the available geological and macroseismic
information and (2) the extensive scientific literature concerning
the correlation between seismic source and surface faulting, also
in volcanic areas similar to Ischia.
Nevertheless, we are grateful for the comments from De Novellis
et al. (2018) because they give us the opportunity to consider
the epistemological landscape in which we should frame
the research for the best source model of the 21 August 2017
Casamicciola earthquake.Published316-3211T. Deformazione crostale attivaJCR Journa
The 21 August 2017 Md 4.0 Casamicciola Earthquake: First Evidence of Coseismic Normal Surface Faulting at the Ischia Volcanic Island
On 21 August 2017, a shallow earthquake of Md 4.0 struck the
CasamicciolaTerme village in the north of Ischia volcanic island
(Italy). It caused two fatalities and heavy damage in a restricted
area of a few square kilometers. Casamicciola Terme has been
recurrently destroyed in the last centuries by similar volcano-tectonic
earthquakes (1762, 1767, 1796, 1828, 1881, and 1883).
After the catastrophic 1883 Casamicciola event (2343 casualties),
this is the first heavy damaging earthquake at Ischia that
provides, for the first time, the opportunity of integrating historical
seismicity, macroseismic observations, instrumental information,
and detailed mapping of coseismic geological effects.
Soon after the 2017 mainshock we surveyed the epicentral area
to collect data on the coseismic ground effects, recording more
than 100 geological field observations. Mapped effects define
a belt which closely follows the trace of the Casamicciola
EâW-trending normal fault system, bounding the northern
slope of Mt. Epomeo, previously known as a Latest Pleistocene
to Holocene normal fault with a slip rate of âŒ3:0 cm=yr. We
found significant evidence for coseismic surface faulting, testified
by a main alignment of ruptures for a 2 km end-to-end length
and normal dip-slip displacement of 1â3 cm. The geometry and
regularity of the structural pattern, together with constant kinematics
of the coseismic ruptures with the north side down,
strongly suggest a primary tectonic origin for the mapped ruptures
and strongly supports an EâW normal-faulting focal
mechanism for the 2017 Casamicciola earthquake.Macroseismic
information supports the notion that previous historical events
also had a similar style of faulting.Published1323-13343T. Sorgente sismicaJCR Journa
Preliminary analysis of site effects in the Ischia island: new insights from md 4.0 earthquake of 21 august 2017 and seismic noise data
On August 21, 2017, at 18:57 UTC, an earthquake of MD 4.0 occurred in Casamicciola, district of Ischia island. The damage caused by the earthquake was massive, with two victims and several buildings collapsed, and circumscribed to the areas of uptown Casamicciola, particularly in the Piazza Maio-La Rita area, and in a small area, called Fango, in Lacco Ameno. Medium and minor damages occurred in Piazza Bagni, in the area around
the town hall of Casamicciola and in the Sentinella area. Even assuming the poor quality constructions and/or not in compliance with the anti-seismic regulations, such a level of damage has induced the scientific community to analyse the effects of local site amplifications, that usually are not negligible in volcanic areas. As a matter of fact the seismic station IOCA, located very close to the high damage areas, recorded a peak ground acceleration (PGA) of 2.6 m/s2. This paper is aimed to study the possible site amplification in the areas heavily affected by the August 21 earthquake in order to better understand the causes of these macroseismic effects and high damage levels already observed in the past.PublishedCentro Congressi della Stazione Marittima, Trieste, Italy6V. PericolositĂ vulcanica e contributi alla stima del rischi
Analysis of tourism in Campania as a tool for the development of high-quality cultural services for sightseers: The âReale Osservatorio Vesuvianoâ case history
The purpose of this work is to identify the guidelines for the development and diversification of the cultural touristic offer achievable at the Reale Osservatorio Vesuviano (ROV). Founded in 1841, it is the oldest volcano observatory in the world and it has always had the vocation for scientific-naturalistic and formative tourism. The present study investigates the connections between the sociology of tourism and the ROVâs sustainability and competitiveness as a tourist destination. Here it is performed a study of the tourist flow, based on the sociology of tourism and on the correct processing of data sets, distinguishing the ''statistical information on tourism" from "tourism statistics", as such a study is the basis of a proper market strategy in different sectors. Tourism remains, in fact, an important phenomenon in world economy: despite the economic crisis of recent years, international tourist arrivals show a positive development of the trend in all the major sub-areas into which the large international areas are traditionally divided. The principles for a future marketing plan were outlined after collecting all the relevant information. The plan was designed to enhance the overall touristic offer of the ROV, never ceasing to consider the integration of natural- scientific aspects and cultural events to be offered within the observatory itself.Published64-872TM. Divulgazione Scientifica6TM. Poli Museali1VV. AltroN/A or not JC
Gruppo Operativo Emersito++ Evento Sismico Ischia 2017: Campagne Di Misure Geofisiche, Rapporto N°1
Rapporto Tecnico n°1 della task force operativa EMERSITO++ (INGV) che descrive le campagne sismiche ed elettromagnetiche condotte nei comuni di Casamicciola Terme e di Lacco Ameno a seguito del terremoto di Ischia del 21 Agosto 2017.INGVPublished4T. Sismologia, geofisica e geologia per l'ingegneria sismica1SR. TERREMOTI - Servizi e ricerca per la Società N/A or not JC
On the energy cost of robustness for green virtual network function placement in 5G virtualized infrastructures
Next generation 5G networks will rely on virtualized Data Centers (vDC) to host virtualized network functions on commodity servers. Such Network Function Virtualization (NFV) will lead to significant savings in terms of infrastructure cost and reduced management complexity. However, green strategies for networking and computing inside data centers, such as server consolidation or energy aware routing, should not negatively impact the quality and service level agreements expected from network operators. In this paper, we study how robust strategies that place virtual network functions (VNF) inside vDC impact the energy savings and the protection level against resource demand uncertainty. We propose novel optimization models that allow the minimization of the energy of the computing and network infrastructure which is hosting a set of service chains that implement the VNFs. The model explicitly provides for robustness to unknown or imprecisely formulated resource demand variations, powers down unused routers, switch ports and servers, and calculates the energy optimal VNF placement and network embedding also considering latency constraints on the service chains. We propose both exact and heuristic methods. Our experiments were carried out using the virtualized Evolved Packet Core (vEPC), which allows us to quantitatively assess the trade-off between energy cost, robustness and the protection level of the solutions against demand uncertainty. Our heuristic is able to converge to a good solution in a very short time, in comparison to the exact solver, which is not able to output better results in a longer run as demonstrated by our numerical evaluation. We also study the degree of robustness of a solution for a given protection level and the cost of additional energy needed because of the usage of more computing and network elements.HIT