1,720,970 research outputs found
Imparare ad imparare: Decostruire una storia per costruire la nostra storia
No full textDescriviamo una esperienza di avvio al pensiero computazionale attraverso attività di programmazione in ambiente Scratch realizzata in una classe seconda di scuola secondaria di I grado con insegnanti che stavano frequentando un corso di aggiornamento delle loro competenze digitali. Obiettivo di questa specifica esperienza è stato abituare alunni ed insegnanti ad imparare, da quello che già funziona, come risolvere i problemi che sorgono nella realizzazione di un nuovo progetto. Il modus operandi è decostruire una attività, nel caso in questione un programma realizzato in Scratch, andando ad individuare la soluzione ad un problema di interesse, astrarre questa soluzione e poi specializzarla a quanto interessa a noi realizzare. Così facendo ci uniamo a Dewey nel “...far conquistare agli allievi la pratica di scoprire come risolvere un problema da soli” [5] esercitando una forma dell’imparare ad imparare.
Si evidenzia come l’uso dell’ambiente Scratch faciliti l’individuazione, in particolare la verifica, della componente che in una attività funzionante può essere utile per una attività in costruzione.We describe an experience introducing computational thinking through programming using the Scratch environment. The activity has been carried out in a second grade middle school class with teachers who were undergoing a course for upgrading their digital skills. The objective of this specific experience was to get both students and teachers to learn how to solve the problems that arise in the implementation of a new project from programming activities already working. The modus operandi is to deconstruct an activity, in our case a Scratch program, in order to find in it the solution to a problem, then abstracting this solution and finally specializing again the abstraction into what interests us to have in the new project. By doing so, we join Dewey in "... making students learn the practice of finding out how to solve a problem on their own" [5] by exercising a form of learning to learn. We point out how using the Scratch environment facilitates the identification of the component that, in an already running activity, can be useful for another activity under implementation. In particular the Scratch environment simplifies verifying that the component works in the new context
On the Inapproximability of Finding Minimum Monitoring Edge-Geodetic Sets (short paper)
Full text linkGiven an undirected connected graph G = (V(G), E(G)) on n vertices, the minimum Monitoring Edge-Geodetic Set (MEG-set) problem asks to find a subset M subset of V(G) of minimum cardinality such that, for every edge e in E(G), there exist x, y in M for which all shortest paths between x and y in G traverse e. We show that, for any constant c < 1/2, no polynomial-time (c log n)-approximation algorithm for the minimum MEG-set problem exists, unless P = NP
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Supporting the construction of learning paths in a competency-based informatics curriculum
No full textThe design of learning activity and paths in informatics is made difficult on the one hand by the absence of a well-established tradition of teaching computer science and on the other by the fact that in many countries the official curricular recommendations are moving towards a competency-based model, increasing the responsibility of teachers. Motivated by the current state of informatics education in Italy, this work presents a system realized to support the research and classification of teaching activities in order to better select the most appropriate ones for the achievement of predetermined learning objectives. A wizard is also provided that allows teachers to use selected activities to design articulated learning paths. The system is designed to be used in the context of a community of practice involving teachers and experts in informatics education, in which innovative learning activities and paths are proposed, validated and shared
An algorithm composition scheme preserving monotonicity
No full textLet G=(V,E) be a graph modeling a network where each edge is owned by a selfish agent, which establishes the cost for using her edge by pursuing only her personal utility. In such a setting, several classic network optimization problems, like for instance many graph traversal problems, asks for solutions in which an edge of G can be used several times. In game-theoretic terms, these problems are known as one-parameter problems, but with a peculiarity: the workload of each agent is a natural number. In this paper we refine the classic notion of monotonicity of an algorithm so as to exactly capture this property, and we then provide a general technique to efficiently develop truthful mechanisms for this family of problems
Approximate Mechanisms for the Graphical TSP and Other Graph-Traversal Problems
No full textLet G = (V,E) be a graph modeling a network in which each edge is owned by a selfish agent, which establishes the cost for traversing its edge (i.e., assigns a weight to its edge) by pursuing only its personal utility. In such a setting, we aim at designing approximate truthful mechanisms for several NP-hard traversal problems on G, such as the graphical traveling salesman problem, the rural postman problem, and the mixed Chinese postman problem, each of which in general requires an edge of G to be used several times. Thus, in game-theoretic terms, these are one-parameter problems, but with a peculiarity: the workload of each agent is a natural number. In this paper we refine the classical notion of monotonicity of an algorithm so as to capture exactly this property, and we then provide a general mechanism-design technique that guarantees this monotonicity and that allows one to compute efficiently the corresponding payments. In this way, we show that the former two problems and the latter one admit a 3/2-and a 2-approximate truthful mechanism, respectively. Thus, for the first two problems we match the best known approximation ratios holding for their corresponding centralized versions, while for the third one we are only a 4/3-factor away from it
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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