986 research outputs found
KBERG: A MatLab toolbox for nonlinear kernel-based regularization and system identification
Abstract We present KBERG, a MatLab package for nonlinear Kernel-BasEd ReGularization and system identification. The toolbox provides a complete environment for running experiments on simulated and experimental data from both static and dynamical systems. The whole identification procedure is supported: (i) data generation, (ii) excitation signals design; (iii) kernel-based estimation and (iv) evaluation of the results. One of the main differences of the proposed package with respect to existing frameworks lies in the possibility to separately define experiments, algorithms and test, then combining them as desired by the user. Once these three quantities are defined, the user can simply run all the computations with only a command, waiting for results to be analyzed. As additional noticeable feature, the toolbox fully supports the manifold regularization rationale, in addition to the standard Tikhonov one, and the possibility to compute different (but equivalent) types of solutions other than the standard one
Spinoza: la verità utile
Come intendere la completa intelligibilità del reale affermata da Spinoza? Da un lato essa porta alla perdita di senso della nozione di miracolo, di cui si mostrano la contradditorietà e l'inutilità. Dall'altro lato essa espone però la verità stessa al rischio della propria dissoluzione all'interno di un Dio in cui tutte le idee sono vere. Il confronto con tale difficoltà porta ad indagare il ruolo positivo dell'immaginazione nella filosofia di Spinoza e ad ipotizzare nella nozione di vera religione un possibile esempio di "verità utile", capace di efficacia pratico-politica.Spinoza: the useful truth What does the full intelligibility of reality proposed by Spinoza mean? On the one hand, it turns the notion of miracle into a nonsense, both contradictory and useless. On the other hand, it seems that the truth itself could disappear into a God in which all ideas are true. The confrontation with this problem requires an analysis of Spinoza’s positive approach to imagination and brings to considers the notion of true religion as a possible example of “useful truth”, effective on a practical and political level
Mechatronics applications of condition monitoring using a statistical change detection method
Abstract In this paper, we propose the use of a change detection strategy to perform condition monitoring of mechanical components. The method looks for statistical changes in the distribution of features extracted from raw measurements, such as Root Mean Square or Crest Factor indicators. The proposed method works in a batch fashion, comparing data from one experiment to another. When these distributions differ by a specified amount, a degradation score is increased. The approach is tested on three experimental applications: (i) an ElectroMechanical Actuator (EMA) employed in flight applications, where the focus of the monitoring is on the ballscrew transmission; (ii) a CNC workbench, where the focus is on the vertical shaft bearing, (iii) an industrial EMA with focus on the ballscrew bearing. All components have undergone a severe experimental degradation process, that ultimately led to their failure. Results show how the proposed method is able to assess component degradation prior to their failure
Traffic-light control in urban environment exploiting drivers' reaction to the expected red lights duration
Traffic congestion in urban environment is one of the most critical issue for drivers and city
planners for both environment and efficiency reasons. Traffic lights are one of the main tools
used to regulate traffic by diverting the drivers between different paths. Rational drivers, in
turn, react to the traffic light duration by evaluating their options and, if necessary, by changing
direction in order to reach their destination quicker. In this paper, we introduce a macroscopic
traffic model for urban intersections that incorporates this rational behavior of the drivers.
Then, we exploit it to show that, by providing additional information about the expected redtime
duration to the drivers, one can decrease the amount of congestion in the network and the
overall length of the queues at the intersections. Additionally, we develop a control policy for
the traffic lights that exploits the reaction of the drivers in order to divert them to a different
route to further increase the performances. These claims are supported by extensive numerical
simulations
«La semiotica di Spinoza» di Lorenzo Vinciguerra
Recensione del recente studio di Lorenzo Vinciguerra sulla semiotica di Spinoz
Traffic-light control in urban environment exploiting drivers’ reaction to the expected red lights duration
Traffic congestion in urban environment is one of the most critical issue for drivers and city planners for both environment and efficiency reasons. Traffic lights are one of the main tools used to regulate traffic by diverting the drivers between different paths. Rational drivers, in turn, react to the traffic light duration by evaluating their options and, if necessary, by changing direction in order to reach their destination quicker. In this paper, we introduce a macroscopic traffic model for urban intersections that incorporates this rational behavior of the drivers. Then, we exploit it to show that, by providing additional information about the expected red-time duration to the drivers, one can decrease the amount of congestion in the network and the overall length of the queues at the intersections. Additionally, we develop a control policy for the traffic lights that exploits the reaction of the drivers in order to divert them to a different route to further increase the performances. These claims are supported by extensive numerical simulations
Immagini del «soggetto della conoscenza». Una nota a margine del saggio di Francesco Emmolo (31/01/13)
This note deals with Francesco Emmolo’s essay and aims to consider EnzoPaci’s philosophical proposal in the light of a question about the “knowing subject”. The history of philosophy has presented many images of it, which engage in a critical confrontation with the common understanding of the knowledgerelation.La nota entra in dialogo con il saggio di Francesco Emmolo e cerca di comprendere la proposta di Enzo Paci all’interno di una domanda sul “soggetto della conoscenza”. Di esso la storia della filosofia ha presentato molteplici immagini, che entrano in un confronto critico con la comprensione “quotidiana” della relazione conoscitiva
Seismic risk assessment of italian seaports: the case of Ancona (Italy)
A National research project was recently carried out to develop a robust methodology for the design and retrofit
of wharves structures located in areas of high to moderate seismicity. A detailed census of the Italian major
seaports was performed using purposely devised questionnaires and Ancona harbor was chosen for a detailed
investigation with the aim of providing risk assessment guidelines. This port has been selected as representative
of a moderate seismicity area (expected peak ground acceleration of 0.25 g with a return period of 475 yrs).
Ancona is the first harbor in the Adriatic sea, with more than a 1.500.000 passenger service and 150.000 trucks
transit. It is equipped with 30 wharfs, 25 of which built in 1965-1975.
To compute deterministic ground shaking scenarios, predictive empirical models have been used. At the same
time advanced numerical simulation have been carried out both at high (0.7-30 Hz) and low (0-1.3) frequency
ranges. The contributions of site effects and liquefaction have been also taken into account in damage estimation.
Standard risk assessment has been performed using the empirical curves implemented in HAZUS program
(NIBS, 2004), supported by recent studies (Lessloss, 2006, Del. 89) on damage observed after the 2003 event in
Lefkas (Greece)
Persistence of bubble outlets in soft, methane-generating sediments
Sediments submerged beneath many inland waterways and shallow oceans emit methane, a potent greenhouse gas, but the magnitude of the methane flux to the atmosphere remains poorly constrained. In many settings, the majority of methane is released through bubbling, and the spatiotemporal heterogeneity of this ebullition both presents challenges for measurement and impacts bubble dissolution and atmospheric emissions. Here we present laboratory-scale experiments of methane ebullition in a controlled incubation of reconstituted sediments from a eutrophic lake. Image analysis of a 0.14 m2 sediment surface area allowed identification of individual bubble outlets and resolved their location to ∼1 cm. While ebullition events were typically concentrated in bursts lasting ∼2 min, some major outlets showed persistent activity over the scale of days and even months. This persistence was surprising given the previously observed ephemerality of spatial structure at the field scale. This persistence suggests that, at the centimeter scale, conduits are reopened as a result of a drop in tensile strength due to deformation of sediments by the rising bubbles. The mechanistic insight from this work sheds light on the spatiotemporal distribution of methane venting from organic-rich sediments and has important implications for bubble survival in the water column and associated biogeochemical pathways of methane.National Science Foundation (U.S.) (1045193)United States. Department of Energy (DE-FE0013999
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