On a Model for Integrated Information

In this paper we give a thorough presentation of a model proposed by Tononi et al. for modeling \emph{integrated information}, i.e. how much information is generated in a system transitioning from one state to the next one by the causal interaction of its parts and \emph{above and beyond} the information given by the sum of its parts. We also provides a more general formulation of such a model, independent from the time chosen for the analysis and from the uniformity of the probability distribution at the initial time instant. Finally, we prove that integrated information is null for disconnected systems

Nearly Linear Time Minimum Spanning TreeMaintenance for Transient Node Failures

Given a 2-node connected, real weighted, and undirected graph $G=(V,E)$, with $n$ nodes and $m$ edges, and given a minimum spanning tree (MST) $T=(V,E_T)$ of $G$, we study the problem of finding, for every node $v \in V$, a set of replacement edges which can be used for constructing an MST of $G-v$ (i.e., the graph $G$ deprived of $v$ and all its incident edges). We show that this problem can be solved on a pointer machine in ${\cal O}(m \cdot \alpha(m,n))$ time and ${\cal O}(m)$ space, where $\alpha$ is the functional inverse of Ackermann's function. Our solution improves over the previously best known ${\cal O}(\min\{m \cdot \alpha(n,n), m + n \log n\})$ time bound, and allows us to close the gap existing with the fastest solution for the edge-removal version of the problem (i.e., that of finding, for every edge $e \in E_T$, a replacement edge which can be used for constructing an MST of $G-e=(V,E \backslash \{e\})$). Our algorithm finds immediate application in maintaining MST-based communication networks undergoing temporary node failures. Moreover, in a distributed environment in which nodes are managed by selfish agents, it can be used to design an efficient, truthful mechanism for building an MS

A pointer-free data structure for merging heaps and min-max heaps

AbstractIn this paper a data structure for the representation of mergeable heaps and min-max heaps without using pointers is introduced. The supported operations are: Insert, DeleteMax, DeleteMin, FindMax, FindMin, Merge, NewHeap, DeleteHeap. The structure is analyzed in terms of amortized time complexity, resulting in a O(1) amortized time for each operation except for Insert, for which a O(lg n) bound holds

Finding the most vital node of a shortest path

AbstractIn an undirected, 2-node connected graph G=(V,E) with positive real edge lengths, the distance between any two nodes r and s is the length of a shortest path between r and s in G. The removal of a node and its incident edges from G may increase the distance from r to s. A most vital node of a given shortest path from r to s is a node (other than r and s) whose removal from G results in the largest increase of the distance from r to s. In the past, the problem of finding a most vital node of a given shortest path has been studied because of its implications in network management, where it is important to know in advance which component failure will affect network efficiency the most. In this paper, we show that this problem can be solved in O(m+nlogn) time and O(m) space, where m and n denote the number of edges and the number of nodes in G

Work-related stress risk assessment: a critical review based on psychometric principles of an objective tool

Many approaches to work-related stress risk assessement suggest the integration between a phase where objective data are collected and analysed, and a phase where results of data collection and analysis are discussed and compared with information coming from the workers. On the other side, the use of self-report job stress measures has been criticized, due to their potential distortions, and stress researchers have repeatedly called for an approach based on the use of objective measures. The Italian law for work-related stress risk assessment, closer to the latter approach, prescribes a two-stage procedure: first a set of objective measures and then, conditionally to the outcome of the first stage, a set of subjective measures. We therefore describe and critically review, on the basis of psychometric principles, the tool used for the objective stage in the most adopted method in Italy. Such a tool is a checklist for which we discuss a number of issues suggesting it is not methodologically well founded. We conclude these weaknesses affect the practice of work-related stress risk assessment

UNA REPUBBLICA DA DIGITALIZZARE

Il lavoro analizza lo stato dell’arte della digitalizzazione in Italia, a partire dai dati che emergono dall'Indice DESI, per poi soffermarsi su una valutazione della strategia nazionale alla luce delle sfide della formazione digitale, nei diversi livelli del nostro sistema educativo (dalle scuole all'università ai programmi di formazione continua). Lo studio si conclude con una breve illustrazione del programma associato al Fondo per la Repubblica Digitale, recentemente istituito dai Ministeri delle Finanze e della Transizione Digitale in cooperazione con ACRI, l'Associazione delle Fondazioni di Risparmio e delle Casse di Risparmio

Abbiamo davvero bisogno del pensiero computazionale?

National audienceWe discuss if and to what extent we need the expression " computational thinking ". We argue that looking for a precise, operational definition could be misleading, and that this expression should not be used everywhere instead of " informatics ". " Computational thinking " , instead, is an instrumental expression which may help in suggesting that informatics is a new and distinct scientific discipline, and in motivating why it should be taught in the schools of any level.Esaminiamo in che misura sia necessaria l'espressione " pensiero computazionale " ed argomentiamo che può essere controproducente usarla in modo eccessivo insistendo a cercarne una definizione operativamente precisa. Questo termine dovrebbe servire, in modo strumentale, per spiegare sinteticamente perché l'informatica è una disciplina scientifica nuova e distinta dalle altre e perché dovrebbe essere insegnata a scuola a tutti i livelli

Computational Thinking in Italian Schools: Quantitative Data and Teachers' Sentiment Analysis after Two Years of "Programma il Futuro" Project

International audienceIn this paper the first two years of activities of "Programma il Futuro" project are described. Its goal is to disseminate among teachers in Italian primary and secondary schools a better awareness of informatics as the scientific basis of digital technologies. The project has adapted Code.org learning material and has introduced it to Italian schools with the support of a dedicated web site. Response has been enthusiastic in terms of participation: in two years more than one million students have been engaged and have completed a total of 10 million hours of informatics in schools. Almost all students found the material useful and were interested, teachers have reported. They have also declared to have experienced high satisfaction and a low level of difficulty. A detailed analysis of quantitative and qualitative data about the project is presented and areas for improvement are identified. One of the most interesting observations appears to corroborate the hypothesis that an exposure to informatics since the early age is important to attract students independently from their gender

Ionic Liquids as Working Fluids for Heat Storage Applications: Decomposition Behavior of N-Butyl-N-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate

Ionic liquids (ILs) represent promising working fluids to be used in thermal energy storage (TES) technologies thanks to their peculiar properties, such as low volatility, high chemical stability, and high heat capacity. Here, we studied the thermal stability of the IL N-butyl-N-methylpyrrolidinium tris(pentafluoroethyl)trifluorophosphate ([BmPyrr]FAP), a potential working fluid for TES applications. The IL was heated at 200 degrees C for up to 168 h either in the absence or in contact with steel, copper, and brass plates to simulate the conditions used in TES plants. High-resolution magic angle spinning nuclear magnetic resonance spectroscopy was found to be useful for the identification of the degradation products of both the cation and the anion, thanks to the acquisition of H-1, C-13, P-31, and F-19-based experiments. In addition, elemental analysis was performed on the thermally degraded samples by inductively coupled plasma optical emission spectroscopy and energy dispersive X-ray spectroscopy. Our analysis shows a significant degradation of the FAP anion upon heating for more than 4 h, even in the absence of the metal/alloy plates; on the other hand, the [BmPyrr] cation displays a remarkable stability also when heated in contact with steel and brass