379,535 research outputs found

    Probabilistic Model-Based Safety Analysis

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    Model-based safety analysis approaches aim at finding critical failure combinations by analysis of models of the whole system (i.e. software, hardware, failure modes and environment). The advantage of these methods compared to traditional approaches is that the analysis of the whole system gives more precise results. Only few model-based approaches have been applied to answer quantitative questions in safety analysis, often limited to analysis of specific failure propagation models, limited types of failure modes or without system dynamics and behavior, as direct quantitative analysis is uses large amounts of computing resources. New achievements in the domain of (probabilistic) model-checking now allow for overcoming this problem. This paper shows how functional models based on synchronous parallel semantics, which can be used for system design, implementation and qualitative safety analysis, can be directly re-used for (model-based) quantitative safety analysis. Accurate modeling of different types of probabilistic failure occurrence is shown as well as accurate interpretation of the results of the analysis. This allows for reliable and expressive assessment of the safety of a system in early design stages

    A synthesis of logic and bio-inspired techniques in the design of dependable systems

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    Much of the development of model-based design and dependability analysis in the design of dependable systems, including software intensive systems, can be attributed to the application of advances in formal logic and its application to fault forecasting and verification of systems. In parallel, work on bio-inspired technologies has shown potential for the evolutionary design of engineering systems via automated exploration of potentially large design spaces. We have not yet seen the emergence of a design paradigm that effectively combines these two techniques, schematically founded on the two pillars of formal logic and biology, from the early stages of, and throughout, the design lifecycle. Such a design paradigm would apply these techniques synergistically and systematically to enable optimal refinement of new designs which can be driven effectively by dependability requirements. The paper sketches such a model-centric paradigm for the design of dependable systems, presented in the scope of the HiP-HOPS tool and technique, that brings these technologies together to realise their combined potential benefits. The paper begins by identifying current challenges in model-based safety assessment and then overviews the use of meta-heuristics at various stages of the design lifecycle covering topics that span from allocation of dependability requirements, through dependability analysis, to multi-objective optimisation of system architectures and maintenance schedules

    Patient safety competencies in undergraduate nursing students: a rapid evidence assessment

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    Aims To identify patient safety competencies, and determine the clinical learning environments that facilitate the development of patient safety competencies in nursing students. Background Patient safety in nursing education is of key importance for health professional environments, settings, and care systems. To be effective, safe nursing practice requires a good integration between increasing knowledge and the different clinical practice settings. Nurse educators have the responsibility to develop effective learning processes and ensure patient safety. Design Rapid Evidence Assessment. Data Sources MEDLINE, CINAHL, SCOPUS, and ERIC were searched, yielding 500 citations published between 1 January 2004 - 30 September 2014. Review Methods Following the Rapid Evidence Assessment process, 17 studies were included in this review. Hawker's (2002) quality assessment tool was used to assess the quality of the selected studies. Results Undergraduate nursing students need to develop competencies to ensure patient safety. The quality of the pedagogical atmosphere in the clinical setting has an important impact on the students’ overall level of competence. Active student engagement in clinical processes stimulates their critical reasoning, improves interpersonal communication, and facilitates adequate supervision and feedback. Conclusion Few studies describe the nursing students’ patient safety competencies and exactly what they need to learn. In addition, studies describe only briefly which clinical learning environments facilitate the development of patient safety competencies in nursing students. Further research is needed to identify additional pedagogical strategies and the specific characteristics of the clinical learning environments that encourage the development of nursing students’ patient safety competencies

    Model-based dependability analysis : state-of-the-art, challenges and future outlook

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    Abstract: Over the past two decades, the study of model-based dependability analysis has gathered significant research interest. Different approaches have been developed to automate and address various limitations of classical dependability techniques to contend with the increasing complexity and challenges of modern safety-critical system. Two leading paradigms have emerged, one which constructs predictive system failure models from component failure models compositionally using the topology of the system. The other utilizes design models - typically state automata - to explore system behaviour through fault injection. This paper reviews a number of prominent techniques under these two paradigms, and provides an insight into their working mechanism, applicability, strengths and challenges, as well as recent developments within these fields. We also discuss the emerging trends on integrated approaches and advanced analysis capabilities. Lastly, we outline the future outlook for model-based dependability analysis

    Advancements in Road Safety Management Analysis

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    Road Safety Management (RSM) can be briefly defined as the tasks of preparing and implementing road safety policies. Many studies have been carried out on RSM, trying to identify success factors and reference best practice examples, but the complexity of the subject and the difficulty of quantitative data collection make it difficult a clear and comprehensive understanding. According to the EC-funded DACOTA research project, the weakest components of RSM systems in Europe are policy implementation and funding and the lack of knowledge-based road safety policy making. The main objective of the research, undertaken within the FERSI's working group on Road Safety Management (RSM), is to better investigate in several European countries those two RSM key functions: funding and research. Particularly the study aims at 1) exploring the existing structures, processes and factors affecting funding and research performances; 2) defining an assessment framework able to measure single country performances with reference to the efficiency and effectiveness of road safety funding and research, possibly shifting from a qualitative to a more quantitative approach. Based on the available knowledge on these two topics (research and funding), an assessment framework is defined and a set of qualitative and quantitative indicators for funding and research performance measurement is proposed. A desk analysis aiming at collecting available data useful to estimate the proposed indicators is conducted and a preliminary analysis with this subset of indicators is undertaken. A subset of research indicators (bibliometric) are used to estimate road safety research outputs performance of a country in terms of productivity and quality of research and international collaboration activities. Preliminary results show a positive correlation among them, even if the linear correlation turns to be not so strong. Countries are ranked on the basis of a composite index of all the three indicators

    Review of the strengths and weaknesses of risk matrices

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    Risk assessment and risk matrices are powered tools used in risk management and help guide in the process of decision-making in organisations. Nevertheless, risk matrices have their own weaknesses and strengths. This paper provides a critical overview of the development and use of risk matrices in different field with an example of the risk matrix used by the National Health Service (NHS) in England. Risk matrices are helpful tools for risk assessment as they use quantitative measures to ensure consistent method of determining risk but organisations should adjust the design and size of risk matrices to suit their needs
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