234 research outputs found

    Structural Change and the Income Distribution: a Post-Keynesian disequilibrium model

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    This paper extends the out-of-equilibrium literature to analyse a structural transition characterized by the emergence of a new sector that satisfies a want lower in the hierarchical scale. In particular, the dynamic interaction demand-supply can be a source of multiple long-run outcomes if both preferences and the technology evolve endogenously. It will be shown that a successful transition to a two-sector economy is ensured by a balanced distribution of innovative rents. Moreover, the full-employment region lies between two regions of classical and Keynesian unemployment, in contrast with the standard view of a negative relationship between real wages and employment. Finally, demand shortages, due to an unbalanced distribution, can bring about a long-run slump.Structural Change, Income Distribution, Unemployment, Innovation, Habit formation

    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

    An analytic framework to assess organizational resilience

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    Background: Resilience Engineering is a paradigm for safety management that focuses on coping with complexity to achieve success, even considering several conflicting goals. Modern socio-technical systems have to be resilient to comply with the variability of everyday activities, the tight-coupled and underspecified nature of work and the nonlinear interactions among agents. At organizational level, resilience can be described as a combination of four cornerstones: monitoring, responding, learning and anticipating. Methods: Starting from these four categories, this paper aims at defining a semi-quantitative analytic framework to measure organizational resilience in complex socio-technical systems, combining the Resilience Analysis Grid (RAG) and the Analytic Hierarchy Process (AHP). Results: This paper presents an approach for defining resilience abilities of an organization, creating a structured domain-dependent framework to define a resilience profile at different levels of abstraction, to identify weaknesses and strengths of the system and thus potential actions to increase system’s adaptive capacity. An illustrative example in an anaesthesia department clarifies the outcomes of the approach. Conclusions: The outcome of the RAG, i.e. a weighted set of probing questions, can be used in different domains, as a support tool in a wider Safety-II oriented managerial action to bring safety management into the core business of the organization

    A monte carlo evolution of the functional resonance analysis method (FRAM) to assess performance variability in complex systems

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    Modern trends of socio-technical systems analysis suggest the development of an integrated view on technological, human and organizational system components. The Air Traffic Management (ATM) system can be taken as an example of one of the most critical socio-technical system, deserving particular attention in managing operational risks and safety. In the ATM system environment, the traditional techniques of risk and safety assessment may become ineffective as they miss in identifying the interactions and couplings between the various functional aspects of the system itself: going over the technical analysis, it is necessary to consider the influences between human factors and organizational structure both in everyday work and in abnormal situations. One of the newly introduced methods for understanding these relations is the Functional Resonance Analysis Method (FRAM) which aims to define the couplings among functions in a dynamic way. This paper evolves the traditional FRAM, proposing an innovative semi-quantitative framework based on Monte Carlo simulation. Highlighting critical functions and critical links between functions, this contribution aims to facilitate the safety analysis, taking account of the system response to different operating conditions and different risk state. The paper presents a walk-through section with a general application to an ATM process

    Condition-based maintenance—an extensive literature review

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    This paper presents an extensive literature review on the field of condition-based maintenance (CBM). The paper encompasses over 4000 contributions, analysed through bibliometric indicators and meta-analysis techniques. The review adopts Factor Analysis as a dimensionality reduction, concerning the metric of the co-citations of the papers. Four main research areas have been identified, able to delineate the research field synthetically, from theoretical foundations of CBM; (i) towards more specific implementation strategies (ii) and then specifically focusing on operational aspects related to (iii) inspection and replacement and (iv) prognosis. The data-driven bibliometric results have been combined with an interpretative research to extract both core and detailed concepts related to CBM. This combined analysis allows a critical reflection on the field and the extraction of potential future research directions

    Thinking in systems, sifting through simulations: a way ahead for cyber resilience assessment

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    The interaction between the physical world and information technologies creates advantages and novel emerging threats. Cyber-physical systems (CPSs) result vulnerable to cyber-related disruptive scenarios, and, for some critical systems, cyber failures may have fallouts on society and environment. Traditional risk analysis in no more sufficient to deal with these problems. New techniques are gaining increasing consensus, especially those based on systems theory. In this context, the System-Theoretic Process Analysis for Security (STPA-Sec) extends the Systems-Theoretic Accident Modelling and Processes (STAMP) model considering cyber threats, and identifying unsafe and unsecure controls throughout a cyber socio-technical system. Despite its large usage as a descriptive tool, there is still limited use of STPA-Sec in (semi-)quantitative terms. This article presents System-Theoretic Process Analysis for Security with Simulations (STPA-Sec/S), a methodological interface between STPA-Sec and quantitative resilience assessment based on simulation models. The methodology is instantiated in a demonstrative case study of a water treatment plant, and its critical CPSs which may impact both community health, and environment. The obtained results show how STPA-Sec/S foster systems understanding, allow a systematic identification of its major criticalities, and the respective quantification

    Exploring forest infrastructures equipment through multivariate analysis: complementarities, gaps and overlaps in the Mediterranean basin

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    The countries of the Mediterranean basin face several challenges regarding the sustainability of forest ecosystems and the delivery of crucial goods and services that they provide in a context of rapid global changes. Advancing scientific knowledge and foresting innovation is essential to ensure the sustainable management of Mediterranean forests and maximize the potential role of their unique goods and services in building a knowledge-based bioeconomy in the region. In this context, the European project FORESTERRA ("Enhancing FOrest RESearch in the MediTERRAnean through improved coordination and integration”) aims at reinforcing the scientific cooperation on Mediterranean forests through an ambitious transnational framework in order to reduce the existing research fragmentation and maximize the effectiveness of forest research activities. Within the FORESTERRA project framework, this work analyzed the infrastructures equipment of the Mediterranean countries belonging to the project Consortium. According to the European Commission, research infrastructures are facilities, resources and services that are used by the scientific communities to conduct research and foster innovation. To the best of our knowledge, the equipment and availability of infrastructures, in terms of experimental sites, research facilities and databases, have only rarely been explored. The aim of this paper was hence to identify complementarities, gaps and overlaps among the different forest research institutes in order to create a scientific network, optimize the resources and trigger collaborations

    Refractory and 17p-deleted chronic lymphocytic leukemia: improving survival with pathway inhibitors and allogeneic stem cell transplantation.

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    ABSTRACT Refractory/early relapsed and 17p deletion/p53 mutation (del(17p)/TP53mut)-positive chronic lymphocytic leukemia (CLL) has been conventionally considered a high-risk disease, potentially eligible for treatment with allogeneic stem cell transplantation (alloSCT). In this multicenter retrospective analysis of 157 patients, we compared the outcomes of patients with high-risk CLL treated with alloSCT, a B-cell receptor pathway inhibitor (BCRi), and both. Seventy-one patients were treated with BCRis, 67 patients underwent reduced-intensity conditioning alloSCT, and 19 received alloSCT with a BCRi before and/or after transplantation. Inverse probability of treatment weighting analyses were performed to compare the alloSCT and no-alloSCT groups; in the 2 groups, 5-year OS, PFS, and cumulative incidence of nonrelapse mortality (NRM) and relapse were 40% versus 60% (P = .096), 34% versus 17% (P = .638), 28% versus 5% (P = .016), and 38% versus 83% (P = .005), respectively. Patients treated with alloSCT plus BCRi had a 3-year OS of 83%. The 3-year OS and NRM by year of alloSCT, including patients treated with BCRi, were 53% and 17% in 2000 to 2007, 55% and 30% in 2008 to 2012, and 72% and 18% in 2013 to 2018. In conclusion, the combination of pathway inhibitors and alloSCT is feasible and may further improve the outcome of high-risk CLL patients
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