196,717 research outputs found
Concurrency for graph grammars (in a Petri net shell)
No full textM. Bauderon and A. Corradini, eds., Elsevier
Solving 1D non‐linear magneto quasi‐static Maxwell's equations using neural networks
No full textAbstract Electromagnetics (EM) can be described, together with the constitutive laws, by four PDEs, called Maxwell's equations. “Quasi‐static” approximations emerge from neglecting particular couplings of electric and magnetic field related quantities. In case of slowly time varying fields, if inductive and resistive effects have to be considered, whereas capacitive effects can be neglected, the magneto quasi‐static (MQS) approximation applies. The solution of the MQS Maxwell's equations, traditionally obtained with finite differences and elements methods, is crucial in modelling EM devices. In this paper, the applicability of an unsupervised deep learning model is studied in order to solve MQS Maxwell's equations, in both frequency and time domain. In this framework, a straightforward way to model hysteretic and anhysteretic non‐linearity is shown. The introduced technique is used for the field analysis in the place of the classical finite elements in two applications: on the one hand, the B–H curve inverse determination of AISI 4140, on the other, the simulation of an induction heating process. Finally, since many of the commercial FEM packages do not allow modelling hysteresis, it is shown how the present approach could be further adopted for the inverse magnetic properties identification of new magnetic flux concentrators for induction applications
Verifying a Behavioural Logic for Graph Transformation Systems
No full textCoMeta'03, F. Honsell, M. Lenisa, M. Miculan ed., Elsevier
Partializing Stone Spaces using SFP domains (Extended Abstract)
No full text) F. Alessi, P. Baldan, F. Honsell Dipartimento di Matematica ed Informatica via delle Scienze 208, 33100 Udine, Italy falessi, baldan, [email protected] Abstract. In this paper we investigate the problem of "partializing" Stone spaces by "Sequence of Finite Posets" (SFP) domains. More specifically, we introduce a suitable subcategory SFP m of SFP which is naturally related to the special category of Stone spaces 2-Stone by the functor MAX, which associates to each object of SFP m the space of its maximal elements. The category SFP m is closed under limits as well as many domain constructors, such as lifting, sum, product and Plotkin powerdomain. The functor MAX preserves limits and commutes with these constructors. Thus, SFP domains which "partialize" solutions of a vast class of domain equations in 2-Stone, can be obtained by solving the corresponding equations in SFP m . Furthermore, we compare two classical partializations of the space of Milner's Synchronization Tre..
Comparing Metabolic Pathways through Potential Fluxes: a Selective Opening Approach
No full textIn our previous work we developed CoMeta, a tool for
comparing metabolic pathways of different organisms, using the KEGG database as data source.
The similarity measure adopted combines homology of
reactions and functional aspects of the pathways. The latter are captured by T-invariants in the Petri net representation, which correspond to potential fluxes in the pathways.
A Petri net can model a metabolic pathway of an organism either in isolation, focussing on its internal behaviour (isolated net), or as an interactive subsystem of the full metabolic network (open net).
Modelling a pathway as an isolated net normally works fine for comparison purposes, but unsatisfactory results can arise as it supplies a partial view on internal fluxes.
A representation as an open net makes additional information
available, but the choice of the interactions of the pathway with the environment is non-trivial.
Considering all possible interactions with the environment (an
information automatically retrieved from KEGG) is not appropriate. Some interactions may add noise to the model, the size of invariants bases grows up to an order of magnitude and the comparison results might be less precise than with the isolated representation.
Here we propose an extension of CoMeta which allows the user to select which metabolites should be considered as interactions of interest, discriminating between input and output metabolites.
We illustrate some experiments which show the advantages of this more flexible approach. Our experience suggests that in general a good choice is to take as open metabolites those which are the input and output compounds for the pathway
Discovering Pareto-Optimal Magnetic-Design Solutions via a Generative Adversarial Network
No full textIn the framework of induction hardening, the coil design task is particularly suitable to be formulated as a multi-objective optimization problem. In fact, the Pareto front estimation raises the issue of guaranteeing a satisfactory diversity and number of non-dominated solutions to be provided to the decision maker (DM). In this article, a generative adversarial network (GAN) and a forward neural network (FNN), which is cascade connected to the GAN generator, produce additional Pareto optimal solutions starting from the results of a genetic algorithm [non-dominated sorting genetic algorithm (NSGA II)] used as a training set. The FNN ensures an accurate prediction of the objectives of the added solutions, removing the need for further field analyses. This method is first tested against two analytical problems and subsequently validated on a three-objective coil design task to illustrate its utility for a real-world case
Functorial and Non-Functorial Solution of Metric Domain Equations
No full textMFPS'95. S. Brookes, M. Main, A. Melton, M. Mislove eds., Elsevier
Mate desertion affects offspring survival, development and physiology in a songbird with multiple parental strategies
No full textAuthor Contributions
Alejandro Cantarero, Matteo Griggio, Jenny Q Ouyang, Andrea Pilastro and Davide Baldan conceived the ideas and designed the methodology; Alejandro Cantarero, Matteo Beccardi, Manuel Fuertes-Recuero, Matteo Schiavinato, Lia Zampa and Davide Baldan collected the data; Valentina Alaasam, Alejandro Corregidor-Castro and Alessandro Grapputo analysed the data; and Valentina Alaasam, Jenny Q Ouyang and Davide Baldan led the writing of the manuscript. All authors contributed critically to the drafts and gave final approval for publication.Sexual conflict affects the amount and duration of offspring care each parent invests, resulting in multiple parental care strategies sometimes coexisting within a single population. Understanding the persistence of multiple parental care strategies requires a precise estimate of the benefits and costs associated with parental decisions. Even though the benefits of brood desertion are well known, the reproductive costs of desertion (i.e., nestlings' physiological conditions and survival), are less explored.
We use rock sparrows, Petronia petronia, a species in which both uniparental and biparental care occur in the same population, to investigate the costs of brood desertion. Specifically, we continuously monitored breeding attempts to explore the behavioural mechanisms (desertion decision and compensatory responses) and the reproductive and physiological consequences (offspring corticosterone concentrations, oxidative stress, telomere attrition) of parental care strategies.
We show that male desertion was not related to the initial value of the brood (clutch size, brood size) but was associated with a reduction in the survival probability of the nestlings. Females caring alone increased their per capita feeding rate, partially compensating for the lack of male care. Nestlings deserted earlier also experienced higher oxidative stress and had higher corticosterone concentrations during the early stages of development, but these effects did not persist to fledging, and there were no differences in telomere attrition.
Our findings indicate combined reproductive and physiological costs associated with brood desertion. Considering these costs is essential to understand the evolution and persistence of polymorphic patterns of care.National Biodiversity Future CenterMinisterio de Ciencia, Innovación y Universidades (España)Università degli Studi di PadovaDepto. de FisiologíaFac. de VeterinariaTRUEpu
Le procedure assistenziali applicate dall’ostetrica al parto fisiologico: effetti sul benessere fetali e neonatale. Revisione della letteratura e risultati di un’indagine conoscitiva su un campione di 48 ostetriche e di 105 puerpere
No full textL’OMS dichiara che lo scopo dell’assistenza al parto fisiologico è quello di “raggiungere l'obiettivo di madre e figlio in buona salute con il livello minore di intervento compatibile con la sicurezza. Questo approccio implica che nel parto fisiologico deve esistere una valida motivazione per interferire con l’evoluzione naturale”.
Ogni procedura assistenziale, che l’ostetrica applica durante il travaglio di parto, dovrebbe essere, quindi, accuratamente vagliata, non solo per i rischi e i benefici che essa può comportare, ma anche per il vissuto che può lasciare sull’esperienza del parto sia della madre che del bambino e sul loro primo incontro.
Viene svolta in questo lavoro un’indagine conoscitiva, in tre ospedali milanesi, su un campione di puerpere che hanno partorito spontaneamente dopo un travaglio fisiologico, per valutare il decorso del loro travaglio e per conoscere la loro opinione e il loro pensiero su come queste procedure possano influenzare il benessere del loro bambino.
In parallelo viene svolta un’altra indagine conoscitiva, che permetta di capire come le ostetriche, che lavorano nelle sale parto degli stessi ospedali, valutino le pratiche assistenziali che utilizzano durante il travaglio di parto fisiologico, oltre che per apprendere le loro opinioni e le loro conoscenze in merito a questo argomento
Con questa ricerca si ha la possibilità di comprendere quale deve essere il reale ruolo dell’ostetrica nell’accompagnare la donna e il suo bambino nel percorso della nascita, evidenziando anche l’importanza di piccoli gesti che, pur non richiedendo maggior tempo o maggior impegno, possono diventare fondamentali strumenti di supporto ad una nuova vita che già sta compiendo uno sforzo enorme per adattarsi ad un mondo così diverso da quello che ha sempre conosciuto.
Il travaglio di parto è un processo fisiologico che va rispettato: l’ostetrica deve essere in grado di tenere in considerazione ed accettare le scelte della donna e i tempi del bambino, mettendoli in condizione di portare a termine ciò che sono in grado di fare. Al feto deve essere offerta la possibilità di sfruttare tutto ciò che la natura gli ha donato per meglio adattarsi al mondo che lo accoglierà: dalla forza di gravità in travaglio al supporto del cordone ombelicale dopo la nascita. L’ostetrica dovrebbe quindi evitare di intervenire accelerando i tempi del parto, perchè una nascita più veloce non significa minor sofferenza per la donna e per il bambino
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