Matematica, Fisica ed Applicazioni
http://elea.unisa.it/xmlui/handle/10556/3005
2024-03-29T16:33:38ZDetailed study of the 2010-2014 Pollino (Italy) seismic sequence with absorption and scattering imaging of the surrounding area
http://elea.unisa.it/xmlui/handle/10556/6581
Detailed study of the 2010-2014 Pollino (Italy) seismic sequence with absorption and scattering imaging of the surrounding area
Napolitano, Ferdinando
A detailed study of the seismic sequence occurred in the western sector of the
Pollino Range (Southern Italy) between 2010 and 2014, and an imaging of the
surrounding area, have been performed in this thesis. The sequence, occurred in
this area considered as a seismic gap in the transition zone between the Calabrian Arc
and the Southern Apennines, developed as a seismic swarm, rather than an aftershock
sequence. The large number of small-to-medium earthquakes (mL < 5.0) recorded by
the seismic stations operated by different institutions in the area allowed to: 1) perform
high quality imaging and characterization of the seismogenic volume responsible for the
Pollino swarm using relative location technique; 2) characterize the properties of the
medium involved during the swarm and nearby, separating scattering and absorption
contribution to the total attenuation of coda waves; 3) assess site effects for seismic
risk mitigation purpose by applying HVSR technique and polarization analysis... [edited by the Author]
2018 - 2019
2020-02-04T00:00:00ZPolyhedral analysis and branch and cut algorithms for some NP-hard spanning subgraph problems
http://elea.unisa.it/xmlui/handle/10556/6466
Polyhedral analysis and branch and cut algorithms for some NP-hard spanning subgraph problems
Laureana, Federica
There is a widespread need to use a quantitative approach for the solution of decision problems that arise in many different areas of real life. The goal is to choose which decisions to take to manage a real system as efficiently as possible using mathematical tools. Operations Research provides a scientific basis to try to analyze and understand situations even with very complex structures and then use the gathered information to pre dict the behaviour of a system and improve the performance of the system
itself. The analysis of a real problem occurs in two phases: the representation of the problem through a mathematical model and the development of efficient mathematical methods to determine an optimal solution of the problem or a good approximation of it. Therefore, the Operations Research is the science that deals with giving a unitary context to mathematical and computer science concepts and that starting from theoretical bases arrives at the construction of concrete models and their solution. .. [edited by the Author]
2018 - 2019
2020-01-07T00:00:00ZA game theoretical approach to safe decision making system development for autonomous machines
http://elea.unisa.it/xmlui/handle/10556/6463
A game theoretical approach to safe decision making system development for autonomous machines
Negri, Gianpiero
One of the major technological and scientific challenges in developing autonomous
machines and robots is to ensure their ethical and safe behavior towards human beings. When dealing with autonomous machines the human operator is not present, so that the overall risk complexity has to be addressed to machine artificial intelligence and decision-making systems, which must be conceived and designed in order to ensure a safe and ethical behaviour. In this work a possible approach for the development of decision-making systems for autonomous machines will be proposed, based on the definition of general ethical criteria and principles. These principles concern the need to avoid or minimize the occurrence of harm for human beings, during the execution of the task the machine has been designed for.
Within this scope, four fundamental problems can be introduced:
1. First Problem: Machine Ethics Principles or Laws Identification
2. Second Problem: Incorporating Ethics in the Machine
3. Third Problem: Human-Machine Interaction Degree Definition
4. Fourth Problem: Machine Misdirection Avoidance.
This Ph.D. research activity has been mainly focused on First and Second
Problems, with specific reference to safety aspects. Regarding First Problem,
main scope of this work is on ensuring that an autonomous machine will act
in a safe way, that is:
• No harm is issued for surrounding human beings (non maleficence ethical
principle)
• In case a human being approaching a potential source of harm, the
machine must act in such a way to minimize such harm with the best
possible and available action (non-inaction ethical principle)
and, when possible and not conflicting with above principles:
• The machine must act in such a way to preserve its own integrity
(self-preservation).
Concerning Second Problem, the simplified version of some ethical principles
reported above has been used to build a mathematical model of a safe decision
system based on a game theoretical approach. When dealing just with safety
and not with general ethics, it is possible to adopt some well-defined criteria
in ensuring the machine behaviour is not issuing any harms towards human
beings, such as:
• Always ensure the machine is keeping a proper safety distance at a
certain operating velocity
• Always ensure that, within a certain range, the machine can detect the
distance between a human being and the location of a potential harm. [edited by Author]
2019 - 2020
2021-03-20T00:00:00ZMethodologies for environmental risks assessment related to the exploitation of energy geo-resources
http://elea.unisa.it/xmlui/handle/10556/6445
Methodologies for environmental risks assessment related to the exploitation of energy geo-resources
Battimelli, Elvira
The increasing exploitation of geo-energy resources to satisfy the needs of the world's
population has also led to a focus on the risks associated with this type of human activity.
It is in this context that this thesis is to be carried out with the purpose to study TechNa
(Technological Hazard Triggering Natural Disaster) and NaTech (Natural Hazard
Triggering Technological Disaster) events. The natural phenomenon that is a consequence
of an industrial activity or acts as a hazard for the industrial accident is considered to be an
earthquake. The entire thesis, carried out following a multidisciplinary approach, aims to
provide a contribution to the development of methodologies for the assessment of
environmental risks potentially related to the technological activities of geo-resources
exploitation.
Three case studies and different specific methodologies are considered to explore a broad
spectrum of analyses, i.e., the seismic characterization of an area, the statistical correlation
between the industrial and seismic activity, and finally a multi-hazard risk assessment.
The TechNa event considered is the induced seismicity that is studied in the offshore area
of Porto San Giorgio (Italy) and for the Cooper Basin geothermal site (Australia). In the first
case, a probabilistic approach (Lomax et al., 2000) is used to relocate the 1987 Porto San
Giorgio seismic sequence, which occurred in the Adriatic offshore near the Santa Maria a
Mare hydrocarbon field. The ambiguity on the mainshock depth, already known in the
literature, is solved by developing a technique that uses the macroseismic intensity field
data based on a grid-search of the magnitude-depth space. The results show that the seismic
sequence (about 30 events) developed in the first 15 km of the crust activating thrust faults
and the mainshock has depth of 5.7 km and local magnitude equal to 5. Subsequently, to
investigate whether there is a relationship between anthropogenic activity and seismicity, a
statistical correlation analysis is carried out using the binomial and Mann-Whitney tests. It
provides statistically significant values in correspondence with the 1987 Porto San Giorgio
seismic sequence.
The second study on induced seismicity carried out in this thesis concerns the
unconventional geothermal site of Cooper Basin. Unconventional techniques involve
creating fractures for the circulation of fluids, but sometimes they can reach pre-existing
faults by undesirable pathways, triggering strong earthquakes. In this work the relationship
between technological parameters and the potential for seismicity to build undesirable
pathways for fluid migration is investigated through a modern methodology (Lasocki &
Orlecka-Sikora, 2020). ... [edited by Author]
2019 - 2020
2021-10-05T00:00:00Z