Experimental constraints on fluid-rock reactions during incipient serpentinization of harzburgite
Klein, Frieder
2014-10-20
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An increasing number of researchers is trying to define models of biochemical pathways via theoretical and technological tools, allowing biologists to simulate reactions before doing them in vitro. The advantages are obvious: a computation normally requires less time then a real experiment, simulation of reactions is cheaper than doing them ectively, and so on.
Il paper sintetizza alcuni lavori di ricerca e alcuni interventi a convegni realizzati negli ultimi anni da parte degli autori. In particolare, il paper riprende i risultati di una ricerca sulla formazione superiore in campo non profit, realizata in Italia, Francia, Belgio e Paesi Scandinavi nell'ambito di un progetto finanziato dalla Commissione Europea attraverso il "Programma Leonardo 1998".
Advances in stochastic system analysis have opened the way to a reconsideration of the processes through which behaviors spread in a population of individuals or organizations. One peculiar phenomenon affecting diffusion is information contagion (Arthur and Lane 1994). When agents have to choose on the basis of other people’s experience, rather than relying on their own direct observations, information externalities arise that drive towards the emergence of the arbitrary, stable dominance of one product over the competing one. We reproduced in controlled laboratory conditions the process of information contagion. The experiments show that when agents can only resort to the observation of other people’s experience in choosing between competing alternatives, the choice process generates some peculiar features: - information contagion amo...
In questo lavoro si presenta una rassegna dei principali contributi che riguardano il rischio sistemico apparsi in letteratura negli ultimi vent’anni, periodo nel quale si è assistito ad una fiorente attività causa anche il manifestarsi di varie crisi economiche e finanziarie. Lo scopo principale che ci siamo posti è quello di individuare una chiave di lettura organica per i vari filoni di indagine. Questi sono stati classificati in base al “luogo” dove si origina l’evento che fa iniziare la crisi: sistema dei pagamenti, sistema finanziario e sistema bancario. Abbiamo inoltre evidenziato i meccanismi di trasmissione delle crisi all’interno dei vari sistemi, mostrando i legami che si vengono a creare tra variabili economiche e finanziarie. Nelle conclusioni indichiamo una possibile direzione di indagine per i lavori futuri.
We propose an automatic translation of UML specifications made up of sequence and state diagrams into pi-calculus processes. The central point of the proposed translation is the coherence of the two types of diagrams. An implicit result of the paper is also the definition of a formal semantics for UML sequence diagrams.
The available experimental evidence suggests that even two-person normal form games with an elementary action space present substantial degrees of cognitive difficulty. We submit that the relational structure of the players' preferences is a source of complexity of a game. We provide a formal classication of order structures in two-person normal form games, based on the two properties of monotonicity and projectivity, and present an experiment on individual ability to construct a representation of bi-ordered sets isomorphic to the preference structure of paradigmatic normal form games. Experimental results support the hypothesis that relational complexity matters. In particular, they support Schelling's intuition that `mixed motive games' are harder to represent than `pure motive' ones. In addition, the experiment shows that most subje...
Over the past decade, goal models have been used in Computer Science in order to represent software requirements, business objectives and design qualities. Such models extend traditional AI planning techniques for representing goals by allowing for partially defined and possibly inconsistent goals. This paper presents a formal framework for reasoning with such goal models. In particular, the paper proposes a qualitative and a numerical axiomatization for goal modeling primitives and introduces label propagation algorithms that are shown to be sound and complete with respect to their respective axiomatizations. In addition, the paper reports on preliminary experimental results on the label propagation algorithms applied to a goal model for a North America car manufacturer.
A system for a regular updating of land-cover maps is proposed that is based on the use of multitemporal remote-sensing images. Such a system is able to face the updating problem under the realistic but critical constraint that, for the image to be classified (i.e., the most recent of the considered multitemporal data set), no ground truth information is available. The system is composed of an ensemble of partially unsupervised classifiers integrated in a multiple classifier architecture. Each classifier of the ensemble exhibits the following novel peculiarities: i) it is developed in the framework of the cascade-classification approach to exploit the temporal correlation existing between images acquired at different times in the considered area; ii) it is based on a partially unsupervised methodology capable to accomplish the classifi...
We present a set of SAT-based decision procedures for various classical modal logics. By SAT-based, we mean built on top of a SAT solver. We show how the SAT-based approach allows for a modular implementation for these logics. For some of the logics we deal with, we are not aware of any other implementation. For the others, we define a testing methodology which generalizes the 3CNFK methodology by Giunchiglia and Sebastiani. The experimental evaluation shows that our decision procedures perform better than or as well as other state-of-the-art decision procedures.
Many real-world problems require the ability of reasoning efficiently on formulae which are boolean combinations of boolean and unquantified mathematical propositions. This task requires a fruitful combination of efficient boolean reasoning and mathematical solving capabilities. SAT tools and mathematical reasoners are respectively very effective on one of these activities each, but not on both. In this paper we present a formal framework, a generalized algorithm and architecture for integrating boolean reasoners and mathematical solvers so that they can efficiently solve boolean combinations of boolean and unquantified mathematical propositions. We describe many techniques to optimize this integration, and highlight the main requirements for SAT tools and mathematicalsolvers to maximize the benefits of their integration.
