19,274 research outputs found

    FRAM for systemic accident analysis: a matrix representation of functional resonance

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    Due to the inherent complexity of nowadays Air Traffic Management (ATM) system, standard methods looking at an event as a linear sequence of failures might become inappropriate. For this purpose, adopting a systemic perspective, the Functional Resonance Analysis Method (FRAM) originally developed by Hollnagel, helps identifying non-linear combinations of events and interrelationships. This paper aims to enhance the strength of FRAM-based accident analyses, discussing the Resilience Analysis Matrix (RAM), a user-friendly tool that supports the analyst during the analysis, in order to reduce the complexity of representation of FRAM. The RAM offers a two dimensional representation which highlights systematically connections among couplings, and thus even highly connected group of couplings. As an illustrative case study, this paper develops a systemic accident analysis for the runway incursion happened in February 1991 at LAX airport, involving SkyWest Flight 5569 and USAir Flight 1493. FRAM confirms itself a powerful method to characterize the variability of the operational scenario, identifying the dynamic couplings with a critical role during the event and helping discussing the systemic effects of variability at different level of analysis

    A Survey on Compiler Autotuning using Machine Learning

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    Since the mid-1990s, researchers have been trying to use machine-learning based approaches to solve a number of different compiler optimization problems. These techniques primarily enhance the quality of the obtained results and, more importantly, make it feasible to tackle two main compiler optimization problems: optimization selection (choosing which optimizations to apply) and phase-ordering (choosing the order of applying optimizations). The compiler optimization space continues to grow due to the advancement of applications, increasing number of compiler optimizations, and new target architectures. Generic optimization passes in compilers cannot fully leverage newly introduced optimizations and, therefore, cannot keep up with the pace of increasing options. This survey summarizes and classifies the recent advances in using machine learning for the compiler optimization field, particularly on the two major problems of (1) selecting the best optimizations and (2) the phase-ordering of optimizations. The survey highlights the approaches taken so far, the obtained results, the fine-grain classification among different approaches and finally, the influential papers of the field.Comment: version 5.0 (updated on September 2018)- Preprint Version For our Accepted Journal @ ACM CSUR 2018 (42 pages) - This survey will be updated quarterly here (Send me your new published papers to be added in the subsequent version) History: Received November 2016; Revised August 2017; Revised February 2018; Accepted March 2018

    Exploring the Local Grammar of Evaluation: The Case of Adjectival Patterns in American and Italian Judicial Discourse

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    Based on a 2-million word bilingual comparable corpus of American and Italian judgments, this paper tests the applicability of a local grammar to study evaluative phraseology in judicial discourse in English and Italian. In particular, the study compares the use of two patterns: v-link + ADJ + that pattern / copula + ADJ + che and v-link + ADJ + to-infinitive pattern / copula + ADJ + verbo all’infinito in the disciplinary genre of criminal judgments delivered by the US Supreme Court and the Italian Corte Suprema di Cassazione. It is argued that these two patterns represent a viable and efficient diagnostic tool for retrieving instances of evaluative language and they represent an ideal starting point and a relevant unit of analysis for a cross-language analysis of evaluation in domainrestricted specialised discourse. Further, the findings provided shed light on important interactions occurring among major interactants involved in the judicial discourse

    Ethics and/or aesthetics? reflections on cosmetic surgery for adolescents

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    Cosmetic surgery entails various ethical issues, even more so in cases involving adolescent patients. Cosmetic surgeons need to take into account how modern societies consider physical appearance an essential component of everyday life, as well as the vulnerability of youths and adolescents. For that reason, it is imperative to thoroughly assess the psychological and emotional states, in addition to the motivations, of minor patients. That goal can be achieved through the use of the DAS-59, (the Derriford Appearance Scale)1 , an effective and dependable tool devised to evaluate the psychological difficulties and distress experienced by people living with problems of appearance. Prior to undergoing cosmetic surgery procedures, adolescents should be required to go through adequate counseling, over multiple sessions and extended to their family members as well, on account of the complex issues inherent in evaluating the risk-benefit ratio and a prospective patient's decision-making capability. A concerted effort on the part of surgeons, psychiatrists or psychologists is key in determining the real motivations behind a minor's decision to opt for cosmetic surgery in the first place. Possible psychiatric conditions may in fact prevent a minor from making a free, informed decision. From an ethical standpoint, cosmetic surgery procedures should be geared to serve the best interest of the minor patient, who may experience distress over his or her body image, from a health and psychological balance perspective and improve his or her social, affective and working life. Besides, cosmetic surgery should not be overly invasive compared to its potential benefits. Those procedures aimed at achieving ″ideal beauty″ are not desirable and ought to be banned. By virtue of such criteria, the authors have set out to evaluate the ethical admissibility of some aesthetic treatments. Thus, doctors should not consent to any request coming from their patients, but rather, intervene only in presence of an objective physical flaw or deformity, e.g. protruding ears, which have a potential to negatively affect social life and interactions

    Topological invariants of eigenvalue intersections and decrease of Wannier functions in graphene

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    We investigate the asymptotic decrease of the Wannier functions for the valence and conduction band of graphene, both in the monolayer and the multilayer case. Since the decrease of the Wannier functions is characterised by the structure of the Bloch eigenspaces around the Dirac points, we introduce a geometric invariant of the family of eigenspaces, baptised eigenspace vorticity. We compare it with the pseudospin winding number. For every value nZn \in Z of the eigenspace vorticity, we exhibit a canonical model for the local topology of the eigenspaces. With the help of these canonical models, we show that the single band Wannier function ww satisfies w(x)constx2|w(x)| \leq \mathrm{const} |x|^{- 2} as x|x| \rightarrow \infty, both in monolayer and bilayer graphene.Comment: 54 pages, 4 figures. Version 2: Section 1.0 added; improved results on the decay rate of Wannier functions in graphene (Th. 4.3 and Prop. 4.6). Version 3: final version, to appear in JSP. New in V3: previous Sections 3.1 and 3.2 are now Section 2.2; Lemma 2.4 modified (previous statement was not correct); major modifications to Section 2.3; Assumption 4.1(v) on the Hamiltonian change

    The Bostrichidae of the Maltese Islands (Coleoptera)

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    The Bostrichidae of the Maltese Islands are reviewed. Ten species are recorded with certainty from this Archipelago, of which 6 namely, Trogoxylon impressum (Comolli, 1837), Amphicerus bimaculatus (A.G. Olivier, 1790), Heterobostrychus aequalis (Waterhouse, 1884), Sinoxylon unidentatum (Fabricius, 1801), Xyloperthella picea (A.G. Olivier, 1790) and Apate monachus Fabricius, 1775 are recorded for the first time. Two of the mentioned species (H. aequalis and S. unidentatum) are alien and recorded only on the basis of single captures and the possible establishment of these species is discussed. Earlier records of Scobicia pustulata (Fabricius, 1801) from Malta are incorrect and should be attributed to S. chevrieri (A. Villa & J.B. Villa, 1835). A zoogeographical analysis and an updated checklist of the 12 species of Bostrichidae recorded from the Maltese Islands and neighbouring Sicilian islands (Pantelleria, Linosa and Lampedusa) are also provided. Rhizopertha dominica (Fabricius, 1792) form granulipennis Lesne in Beeson & Bhatia, 1937 from Uttarakhand (northern India) was overlooked by almost all subsequent authors. Its history is summarized and the following new synonymy is established: Rhizopertha dominica (Fabricius, 1792) form granulipennis Lesne in Beeson & Bhatia, 1937 = Rhyzopertha dominica (Fabricius, 1792), syn. n. Finally, records of Amphicerus bimaculatus from Azerbaijan, of Bostrichus capucinus (Linnaeus, 1758) from Jordan and Syria, of Scobicia chevrieri from Jordan and Italy, of Xyloperthella picea from Italy, and of Apate monachus from Corsica (France) and Italy, are also provided.peer-reviewe

    On rank 2 vector bundles on Fano manifolds

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    In this work we deal with vector bundles of rank two on a Fano manifold XX with b2=b4=1b_2=b_4=1. We study the nef and pseudoeffective cones of the corresponding projectivizations and how these cones are related to the decomposability of the vector bundle. As consequences, we obtain the complete list of P1\mathbb{P}^1-bundles over XX that have a second P1\mathbb{P}^1-bundle structure, classify all the uniform rank two vector bundles on this class of Fano manifolds and show the stability of indecomposable Fano bundles (with one exception on P2\mathbb{P}^2).Comment: Updated version with an issue correcte

    Conference on Corporate Governance: Search for the Advanced Practices

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    The purpose of the article is to examine the role of the board of directors in corporate law in Jordan
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