87 research outputs found

    A new approach for diagnosability analysis of Petri nets using Verifier Nets

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    In this paper, we analyze the diagnosability properties of labeled Petri nets. We consider the standard notion of diagnosability of languages, requiring that every occurrence of an unobservable fault event be eventually detected, as well as the stronger notion of diagnosability in K steps, where the detection must occur within a fixed bound of K event occurrences after the fault. We give necessary and sufficient conditions for these two notions of diagnosability for both bounded and unbounded Petri nets and then present an algorithmic technique for testing the conditions based on linear programming. Our approach is novel and based on the analysis of the reachability/coverability graph of a special Petri net, called Verifier Net, that is built from the Petri net model of the given system. In the case of systems that are diagnosable in K steps, we give a procedure to compute the bound K. To the best of our knowledge, this is the first time that necessary and sufficient conditions for diagnosability and diagnosability in K steps of labeled unbounded Petri nets are presented

    Adaptation of communication assessment tool for community pharmacists in medication adherence and minor diseases management

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    Aim: To develop two versions of the Communication Assessment Tool (CAT) skilled for the setting of community pharmacy and to pilot test it on a selected sample. Materials: Development of two versions of CAT-tool for community pharmacists. Validity and reliability assessments were required to determine the psychometric properties of developed tool versions. To investigate the construct validity of each adapted tool item, confirmatory factor analysis was performed. Reliability was assessed with the Cronbach’s Alpha evaluation, internal validity by submitting tool versions to patients of eleven pharmacies from North, Center, and South of Italy for pilot testing. Results: Two CAT versions were developed and tested: CAT-Pharm-community Adherence to therapy and Minor Disease Management versions. First to evaluate pharmacist-patient communication following the dispensing of a prescription drug, second a consultation for minor disease management. Conclusion: Communication tools are useful to implement optimal management of chronic diseases to minimize non-adherence and patients’ negative health outcomes

    Industrial air pollution and mortality in the Taranto area, Southern Italy: A difference-in-differences approach.

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    Background: A large steel plant close to the urban area of Taranto (Italy) has been operating since the sixties. Several studies conducted in the past reported an excess of mortality and morbidity from various diseases at the town level, possibly due to air pollution from the plant. However, the relationship between air pollutants emitted from the industry and adverse health outcomes has been controversial. We applied a variant of the "difference-in-differences" (DID) approach to examine the relationship between temporal changes in exposure to industrial PM10 from the plant and changes in cause-specific mortality rates at area unit level. Methods: We examined a dynamic cohort of all subjects (321,356 individuals) resident in the Taranto area in 1998–2010 and followed them up for mortality till 2014. In this work, we included only deaths occurring on 2008–2014. We observed a total of 15,303 natural deaths in the cohort and age-specific annual death rates were computed for each area unit (11 areas in total). PM10 and NO2 concentrations measured at air quality monitoring stations and the results of a dispersion model were used to estimate annual average population weighted exposures to PM10 of industrial origin for each year, area unit and age class. Changes in exposures and in mortality were analyzed using Poisson regression. Results: We estimated an increased risk in natural mortality (1.86%, 95% confidence interval [CI]: −0.06, 3.83%) per 1 μg/m3 annual change of industrial PM10, mainly driven by respiratory causes (8.74%, 95% CI: 1.50, 16.51%). The associations were statistically significant only in the elderly (65+ years). Conclusions: The DID approach is intuitively simple and reduces confounding by design. Under the multiple assumptions of this approach, the study indicates an effect of industrial PM10 on natural mortality, especially in the elderly population. Keywords: Air pollution, Mortality, PM10, Steel industry, Confounding, Difference-in-difference

    Phenol composition and antioxidant capacity of red wines produced in Central Italy changes after one-year storage

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    Much interest is currently concentrated on phenol compounds and antioxidants of wine. The aim of this study was to characterize and evaluate controlled designation of origin (CDO) and typical geographical indications (TGI) red wines from Central Italy and to evaluate possible modifications after one year of storage. The total phenol content and antioxidant activity by ORAC method were determined, while phenolic qualitative and quantitative profiles were evaluated by HRGC-FID or HPLC-DAD. All wines showed a good content of total phenols and an obvious antioxidant effect. After a one-year storage in the bottle, a significant decrease (P<0.05) of the ORAC values was observed for TGI wines. Interesting correlations between phenol and ORAC values for CDO wines were found. It can be confirmed that one-year storage in the bottle has not significantly affected the quality of the wines analyzed, in particular the CDO category

    Petri Net Languages and Infinite Subsets of Nm

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    AbstractFamilies of Petri net languages are usually defined by varying the type of transition labeling and the class of subsets of Nm to be used as sets of final markings (m is the number of places). So far three main classes of subsets have been studied: the trivial class containing as single element Nm, the class of finite subsets of Nm, and the class of ideals (or covering subsets) of Nm. In this paper we extend the known hierarchy of Petri net languages by considering the classes of semi-cylindrical, star-free, recognizable, rational (or semilinear) subsets of Nm. We compare the related Petri net languages. For arbitrarily labeled and for λ-free labeled Petri net languages, the above hierarchy collapses: one does not increase the generality by considering semilinear accepting sets instead of the usual finite ones. However, for free-labeled and for deterministic Petri net languages, we show that one gets new distinct subclasses of languages, for which several decidability problems become solvable. We establish as intermediate results some properties of star-free subsets of general monoids
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