1,291 research outputs found

    Accuracy of Author Names in Bibliographic Data Sources: An Italian Case Study

    Get PDF
    We investigate the accuracy of how author names are reported in bibliographic records excerpted from four prominent sources: WoS, Scopus, PubMed, and CrossRef. We take as a case study 44,549 publications stored in the internal database of Sapienza University of Rome, one of the largest universities in Europe. While our results indicate generally good accuracy for all bibliographic data sources considered, we highlight a number of issues that undermine the accuracy for certain classes of author names, including compound names and names with diacritics, which are common features to Italian and other Western languages

    Computing the shapley value in allocation problems: Approximations and bounds, with an application to the Italian VQR research assessment program

    Get PDF
    In allocation problems, a given set of goods are assigned to agents in such a way that the social welfare is maximized, that is, the largest possible global worth is achieved. When goods are indivisible, it is possible to use money compensation to perform a fair allocation taking into account the actual contribution of all agents to the social welfare. Coalitional games provide a formal mathematical framework to model such problems, in particular the Shapley value is a solution concept widely used for assigning worths to agents in a fair way. Unfortunately, computing this value is a #P-hard problem, so that applying this good theoretical notion is often quite difficult in real-world problems. In this paper, we first review the application of the Shapley value to an allocation problem that models the evaluation of the Italian research structures with a procedure known as VQR. For large universities, the problem involves thousands of agents and goods (here, researchers and their research products). We then describe some useful properties that allow us to greatly simplify many such large instances. Moreover, we propose new algorithms for computing lower bounds and upper bounds of the Shapley value, which in some cases provide the exact result and that can be combined with approximation algorithms. The proposed techniques have been tested on large real-world instances of the VQR research evaluation problem

    Max flow vitality in general and stst-planar graphs

    Full text link
    The \emph{vitality} of an arc/node of a graph with respect to the maximum flow between two fixed nodes ss and tt is defined as the reduction of the maximum flow caused by the removal of that arc/node. In this paper we address the issue of determining the vitality of arcs and/or nodes for the maximum flow problem. We show how to compute the vitality of all arcs in a general undirected graph by solving only 2(n−1)2(n-1) max flow instances and, In stst-planar graphs (directed or undirected) we show how to compute the vitality of all arcs and all nodes in O(n)O(n) worst-case time. Moreover, after determining the vitality of arcs and/or nodes, and given a planar embedding of the graph, we can determine the vitality of a `contiguous' set of arcs/nodes in time proportional to the size of the set.Comment: 12 pages, 3 figure

    Computing the Shapley value in allocation problems: approximations and bounds, with an application to the Italian VQR research assessment program

    Get PDF
    In allocation problems, a given set of goods are assigned to agents in such a way that the social welfare is maximised, that is, the largest possible global worth is achieved. When goods are indivisible, it is possible to use money compensation to perform a fair allocation taking into account the actual contribution of all agents to the social welfare. Coalitional games provide a formal mathematical framework to model such problems, in particular the Shapley value is a solution concept widely used for assigning worths to agents in a fair way. Unfortunately, computing this value is a #P-hard problem, so that applying this good theoretical notion is often quite difficult in real-world problems. We describe useful properties that allow us to greatly simplify the instances of allocation problems, without affecting the Shapley value of any player. Moreover, we propose algorithms for computing lower bounds and upper bounds of the Shapley value, which in some cases provide the exact result and that can be combined with approximation algorithms. The proposed techniques have been implemented and tested on a real-world application of allocation problems, namely, the Italian research assessment program known as VQR (Verifica della Qualità della Ricerca, or Research Quality Assessment)1. For the large university considered in the experiments, the problem involves thousands of agents and goods (here, researchers and their research products). The algorithms described in the paper are able to compute the Shapley value for most of those agents, and to get a good approximation of the Shapley value for all of the

    On the Shapley value and its application to the Italian VQR research assessment exercise

    Get PDF
    Research assessment exercises have now become common evaluation tools in a number of countries. These exercises have the goal of guiding merit-based public funds allocation, stimulating improvement of research productivity through competition and assessing the impact of adopted research support policies. One case in point is Italy's most recent research assessment effort, VQR 2011–2014 (Research Quality Evaluation), which, in addition to research institutions, also evaluated university departments, and individuals in some cases (i.e., recently hired research staff and members of PhD committees). However, the way an institution's score was divided, according to VQR rules, between its constituent departments or its staff members does not enjoy many desirable properties well known from coalitional game theory (e.g., budget balance, fairness, marginality). We propose, instead, an alternative score division rule that is based on the notion of Shapley value, a well known solution concept in coalitional game theory, which enjoys the desirable properties mentioned above. For a significant test case (namely, Sapienza University of Rome, the largest university in Italy), we present a detailed comparison of the scores obtained, for substructures and individuals, by applying the official VQR rules, with those resulting from Shapley value computations. We show that there are significant differences in the resulting scores, making room for improvements in the allocation rules used in research assessment exercises

    Role of Fibre in Nutritional Management of Pancreatic Diseases

    Get PDF
    The role of fibre intake in the management of patients with pancreatic disease is still controversial. In acute pancreatitis, a prebiotic enriched diet is associated with low rates of pancreatic necrosis infection, hospital stay, systemic inflammatory response syndrome and multiorgan failure. This protective effect seems to be connected with the ability of fibre to stabilise the disturbed intestinal barrier homeostasis and to reduce the infection rate. On the other hand, in patients with exocrine pancreatic insufficiency, a high content fibre diet is associated with an increased wet fecal weight and fecal fat excretion because of the fibre inhibition of pancreatic enzymes. The mechanism by which dietary fibre reduces the pancreatic enzyme activity is still not clear. It seems likely that pancreatic enzymes are absorbed on the fibre surface or entrapped in pectin, a gel-like substance, and are likely inactivated by anti-nutrient compounds present in some foods. The aim of the present review is to highlight the current knowledge on the role of fibre in the nutritional management of patients with pancreatic disorders

    Are Italian research assessment exercises size-biased?

    Get PDF
    Research assessment exercises have enjoyed ever-increasing popularity in many countries in recent years, both as a method to guide public funds allocation and as a validation tool for adopted research support policies. Italy’s most recently completed evaluation effort (VQR 2011–14) required each university to submit to the Ministry for Education, University, and Research (MIUR) 2 research products per author (3 in the case of other research institutions), chosen in such a way that the same product is not assigned to two authors belonging to the same institution. This constraint suggests that larger institutions, where collaborations among colleagues may be more frequent, could suffer a size-related bias in their evaluation scores. To validate our claim, we investigate the outcome of artificially splitting Sapienza University of Rome, one of the largest universities in Europe, in a number of separate partitions, according to several criteria, noting significant score increases for several partitioning scenarios

    Gas Turbine Coatings Eddy-Current Quantitative and Qualitative Evaluation

    Get PDF
    Gas turbine blades (buckets) are among the most critical and expensive components of the engine. Buckets rely on protective coatings in order to withstand the harsh environment in which they operate. The thickness and the microstructure of coatings during the lifespan of a unit are fundamental to evaluate their fitness for service. A frequency scanning Eddy Current instrument can allow the measurement of the thickness and of physical properties of coatings in a Non-Destructive manner. The method employed relies on the acquisition of impedance spectra and on the inversion of the experimental data to derive the coating properties and structure using some assumptions. This article describes the experimental validation performed on several samples and real components in order to assess the performance of the instrument as a coating thickness gage. The application of the technique to support residual life assessment of serviced buckets is also presented

    Which Conference Is That? A Case Study in Computer Science

    Get PDF
    Conferences play a major role in some disciplines such as computer science and are often used in research quality evaluation exercises. Differently from journals and books, for which ISSN and ISBN codes provide unambiguous keys, recognizing the conference series in which a paper was published is a rather complex endeavor: There is no unique code assigned to conferences, and the way their names are written may greatly vary across years and catalogs. In this article, we propose a technique for the entity resolution of conferences based on the analysis of different semantic parts of their names. We present the results of an investigation of our technique on a dataset of 42,395 distinct computer science conference names excerpted from the DBLP computer science repository,1 which we automatically link to different authority files. With suitable data cleaning, the precision of our record linkage algorithm can be as high as 94%. A comparison with results obtainable using state-of-the-art general-purpose record linkage algorithms rounds off the article, showing that our ad hoc solution largely outperforms them in terms of the quality of the results

    The Hannover thermal noise experiment

    Get PDF
    To analyse the thermal noise of the pendulum mode of a suspended mirror, we interferometrically detect the differential movement of two mirrors suspended as multiple-stage pendulums. We present the set-up of this experiment and the current sensitivity, and also the different steps that we took in the past to increase the sensitivity, which include an auto alignment of the laser beam into the resonator eigenmode, changes of the seismic isolation system to more damping stages and higher moments of inertia and an intensive noise hunting
    • …
    corecore