3,222 research outputs found

    Innovazione di business e adattamento al mercato: il caso Luxottica in Asia

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    Preliminary Study on Runway Pavement Friction Decay Using Data Mining

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    AbstractSurfaces of airport pavements are subject to the friction decay phenomenon. A recurrent problem for the runways is represented by the deposits of vulcanized rubber of aircraft tires. This happens mainly in the touch-down areas during landing operations, and the loss of grip compromises the safety of both take-off and landing operations. This study moves from the International Civil Aviation Organization and the Italian Civil Aviation Authority provisions concerning runway friction measurement and reporting to a better way to analyze friction data. Being data mining the computational process of discovering patterns in a large data sets, data mining techniques are very helpful to reach this target. Unsupervised and supervised classification methods to analyze friction data detected by Grip Tester Trailer were employed. First, K-means and Subtractive Clustering were applied to divide data into a certain number of clusters representing the different areas of consumption. In a second time two different Classification and Regression Trees models, CART and GCHAID, were employed to split the data points of the runway into nodes. At the end of the process scatterplots were built and better visualized through non-linear regressions. The decay curves obtained were of service to compare the results achieved using data mining techniques versus the International Civil Aviation Organization and the Italian Civil Aviation Authority provisions in order to find out the best way to analyze friction data. The final goals are to assure an optimum scheduling of the Airport Pavement Management System, as well as users safety

    Long-Term Results of Radiofrequency Energy Delivery for the Treatment of GERD: Results of a Prospective 48-Month Study

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    Since 2000, radiofrequency (RF) energy treatment has been increasingly offered as an alternative option to invasive surgical procedures for selected patients with gastroesophageal reflux disease (GERD). Out of 69 patients treated since June 2002 to December 2007 with the Stretta procedure, 56 of them reached by the end of 2010 a 48-month followup. RF treatment significantly improved heartburn scores, GERD-specific quality of life scores, and general quality of life scores at 24 and 48 months in 52 out of 56 patients (92,8%). At each control time both mean heartburn and GERD HRQL scores decreased (P = 0.001 and P = 0.003, resp.) and both mental SF-36 and physical SF-36 ameliorated (P = 0.001 and 0.05, resp.). At 48 months, 41 out of 56 patients (72,3%) were completely off PPIs. Morbidity was minimal, with only one relevant but transient complication. According to other literature data, this study shows that RF delivery to LES is safe and durably improves symptoms and quality of life in well-selected GERD patients

    Inter-services communication in child welfare: The interplay of age, work-group identification, trust and self efficacy

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    The present study involves 157 social workers employed in two public child welfare agencies of North-East Italy. Recent approaches (Pedrazza, Berlanda, 2017; Pedrazza, Sartori, Berlanda, 2017) show that social work in child welfare agencies requires communication skills and social competence, such as work-group identification and trust. These studies show that perceived self-efficacy represents an important element of inter-service communication. The aim of our study is to attempt to identify the role of age, work-group identification and trust in predicting social workers' self-efficacy in emotion regulation, procedural self-efficacy, self-efficacy in seeking support, and self-efficacy in professional communication. Assuming the causal relationship between variables, we propose multiple linear regression analysis in order to identify antecedents of self-efficacy

    Torsion Test vs. Other Methods to Obtain the Shear Strength of Elastic-Plastic Adhesives

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    Nowadays adhesive joints are more and more used; therefore, a precise and reliable shear strength measurement of these joints is necessary to design and predict a final components’ performance. This work aimed to assess the shear strength value of adhesively joined ceramics (SiC, Si3N4) and steel in the case of an elasto‐plastic (ductile) joining material (Loctite EA 9321 AERO) by an experimental campaign and associated analytical modelling. The joined samples were tested using a single lap offset test in compression (SLO), an asymmetrical 4‐point bending test (A4PB, ASTM C1469), and by torsion on fully joined hourglass shaped samples (THG). A simple model based on the elastic‐plastic response in shear was proposed to fit the torque‐rotation curve measured in the torsion tests. The results showed that, with the adopted test methods and conditions, and by using the model, consistent values of shear strength could be obtained by torsion tests
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