188 research outputs found
Measuring scientific performance without ties: is scientific leadership the solution?
No full text103-106For many decisions in science, evaluators have to select, assess, and rank authors based on their scientific achievements. However, the most diffused scientific performance bibliometric metric – the h index – produces many ties, precluding its use to define a full ranking of the authors. In turn, recently, Jorge Hirsch1 proposes the ha index (which measures the number of papers of the h core in which the author was the scientific leader) and the associated ra index(percentage of papers belonging to the h core in which the author was leader) to capture the concept of scientific leadership. We suggest using this last measure to break the ties of the h index. The method is extremely simple and provides a complete solution to this critical problem of the h index. To that end, we develop a two steps procedure, which is able to produce a more granulated ranking of the authors
Grasping cybersecurity: A set of essential mental models
No full textFor most people, cybersecurity is a hard to grasp notion. Traditionally, cybersecurity has been considered as a technical challenge and still many specialists view it equivalent with information security, with the notions of confidentiality, integrity and availability as starting points of thinking. And although others searched for a broader perspective, the complexity and ambiguity of the notion still thwarts a common understanding. While developing and executing a MSc cybersecurity program for professionals, the lack of a common understanding of what cybersecurity entails was again observed. Stimulated by this, we started to look for and define a new, transdisciplinary conceptualization of cybersecurity that everyone can agree upon. It resulted in two scientific papers published. This paper describes the outcomes of the continuation of our research journey. It turned out that the earlier introduced description of two key notions, namely that of cyberspace and that of cybersecurity, can still be considered as adequate starting points. Here, we describe a set of additional mental models that elaborates them and provides more detail to the meaning of the two key notions. In practice, it turned out that the additional mental models strongly support the description and analysis of existing and upcoming cybersecurity challenges and helps to understand how everybody, in his or her various roles, can or should contribute to reducing the related cyber risks to adequate levels. We further discovered that for certain cybersecurity challenges, especially those related to efficient cyber risk mitigation, we could not yet identify an adequate sub-set of mental models. This defines the agenda for near future cybersecurity research.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Information and Communication Technolog
Subsídio de desemprego: uma revisão da literatura teórica e empírica
No full textA vast theoretical and empirical literature has focused on the effects of unemployment insurance benefits on the decisions of the recipients and how these decisions influence their labor market outcomes. Three strands of literature are discussed in this paper: (i) the impact of unemployment insurance on the duration of unemployment spells; (ii) the impact of unemployment benefits on the quality of post unemployment jobs; and (iii) the mechanisms available to improve the effectiveness of unemployment insurance benefits
Fragility functions for tall URM buildings around early 20th century in Lisbon. Part 2: Application to different classes of buildings
No full textThis article describes the application of the procedure for the derivation of fragility functions presented in the companion article entitled Fragility functions for tall URM buildings around early 20th century in Lisbon. Part 1: methodology and application at building level. The procedure, based on the execution of non-linear analyses, was developed to be applied to unreinforced masonry buildings considering both the in-plane and out-of-plane response. Different sources of uncertainty, both epistemic and aleatory, affecting the behaviour of these unreinforced masonry buildings are discussed and treated with a probabilistic procedure. The fragility curves determined for the different classes of buildings are compared and then combined to define the final fragility curves for these unreinforced masonry buildings. The results put in evidence the high seismic vulnerability of these buildings and the urgent need for the structural intervention and for the design of retrofitting measures in order to reduce potential losses due to future earthquakes.The first author would like to acknowledge the financial support of Fundacao para a Ciencia e a Tecnologia (FCT, Ministerio da Educacao e Ciencia, Portugal) through the scholarship PD/BD/106076/2015 through the FCT Doctoral Program: Analysis and Mitigation of Risks in Infrastructures, INFRARISK (http://infrarisk.tecnico.ulisboa.pt)
Seismic assessment of nineteenth and twentieth centuries URM buildings in Lisbon: structural features and derivation of fragility curves
No full textThe article addresses the seismic vulnerability assessment of a typology of unreinforced masonry buildings constructed in Lisbon between the nineteenth and the twentieth centuries. The main architectural and structural features of these buildings are presented. This supported the identification of the main uncertainties affecting their seismic performance and the definition of classes of buildings representative of the typology. The seismic assessment includes the generation of fragility curves that combine the in-plane and out-of-plane response following different criteria and methods of analyses. The results put in evidence the seismic vulnerability of this class of buildings. Considering the earthquake-resistant code for Lisbon with a return period of 475 years, about 50% probability of having heavy damage and about 30% probability of collapse were estimated. The structural intervention on these buildings is urgent in order to reduce losses due to future earthquakes. Further studies for the assessment of similar buildings in Lisbon and elsewhere can be developed using the adopted procedure.The first author would like to acknowledge the financial support of Fundacao para a Ciencia e a Tecnologia (FCT, Ministerio da Educacao e Ciencia, Portugal) through the scholarship PD/BD/106076/2015 through the FCT Doctoral Program: Analysis and Mitigation of Risks in Infrastructures, INFRARISK-(http://infrarisk.tecnico.ulisboa.pt).The authors would also like to acknowledge the contribution from Bruno Silva (Instituto Superior Tecnico) and Nuno Mendes (University of Minho) regarding the ambient vibration tests
Publication Performance and Number of Authors – Evidence for World Top Economists
No full textIn social sciences the measurement of performance is usually done giving the full credit of each paper to all its authors. Aiming to analyze the impact of the number of authors on the performance results, we propose an adjustment to the h-index that is flexible enough to allow the consideration of distinct co-authorship weighting schemes. We then evaluate the publication performance of the members of the departments of economics of the top 10 world universities (472 authors; 15,243 papers). Our results show that the number of authors per paper is rapidly increasing and that this dimension measurably affects the final ranking of authors even in a scientific area in which the average number of authors is lower than in physical and life sciences
Publication Performance Through the Lens of the h‐index: How Can We Solve the Problem of the Ties?
No full textA Generic and Automatic Test Strategy for Compiler Testing
No full textDomain-specific Languages (DSLs) are languages specifically tailored for an application or expert domain. These can be implemented as compilers, which check the correctness of an input program and translates it to a target language. Manual testing of compilers is a time consuming and labor intensive task. This motivates the development of approaches to facilitate the quality assurance process. In this thesis we present an automatic and generic test strategy for the generation of test cases for Spoofax developed compilers. We use a program generator to generate large syntactically correct programs from Syntax Definition Formalism (SDF) grammars. Additionally, we improve the program generator with an expansion of our generation algorithm to use Name Binding Language (NaBL) modules to generate partial name correct programs. We also provide a DSL to define error fixes that are used to attempt the repair of static semantic errors reported after compilation. After program generation we use a partial oracle to automatically detect failures during the invocation of the compiler. Finally, we provide a heuristic to reduce the size of generated programs, whilst preserving their failure inducing behavior. This test strategy was used to generate test cases forWebDSL, a DSL targeting the domain of developing dynamic web applications with a rich data model. The generated test cases unveiled eleven unique faults in the analysis phase of compilation. These were reported together with the programs reduced by our program shrinking heuristic and they were positively received by the WebDSL development team.Computer ScienceSERGElectrical Engineering, Mathematics and Computer Scienc
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