177,525 research outputs found
Assessment of a vulnerability model against post-earthquake damage data: The case study of the historic city centre of L'Aquila in Italy
No full textThe quantitative measure of seismic vulnerability is a necessary requirement for prevention and for an optimal emergency management. Before L'Aquila's earthquake in 2009, the National Civil Protection, in collaboration with the University of L'Aquila, developed a model (Beolchini, "Definition of an indicator of urban vulnerability" (2003)) to evaluate the criticality seismic of urban centers by using a multidisciplinary approach. The study has led to the definition of an urban vulnerability index, that allows to identify the most critical urban centers and the problematic elements, in order to establish a hierarchy for preventative measures and for an efficient emergency management (Calvi et al. "Development of seismic vulnerability assessment methodologies over the past 30 years" (2006). One of the features of this evaluation is that it allows a simultaneous analysis of the multiple factors involved in risk assessment (Ferlito and Pizza "Modello di vulnerabilità di un centro urbano. Metodologia per la valutazione speditiva della vulnerabilità della viabilità d'emergenza" (2011); Ferlito et al. "Danger treblement de terre et mesure du risque à L'Aquila" (2010)). After the seismic event occurred, same tests have been done to verify the validity of the model on the part of buildings, by comparing the criticality evaluated and damage suffered by the buildings, taking into account the local effects resulting from operations of microzonation. The seismic vulnerability index is calculated as the weighted sum of same parameters, that represent a building feature which can affect the structural response under earthquake ground motion. Therefore, the influence of each parameter and their respective weights on the model have been analyzed. Sensitivity analyzes were performed to understand the model parameters that most affect structural vulnerability. Furthermore the aim of this work is to provide a correlation between the indicator of criticality proposed here and the possible damage to the buildings resulting from an earthquake, As for the test performed, the methodology has a good level of confidence in the modelling of the vulnerability of the buildings so it can be successfully used for seismic risk assessment, necessary for seismic safety and emergency management. © 2013 WIT Press
Validation and extension of a statistical usability model for unreinforced masonry buildings with different ground motion intensity measures
No full textPredicting the usability of a building, i.e. its condition of being occupiable after a seismic event, is relevant both in a post-emergency situation and within a risk-reduction policy. In the past an empirical model was proposed, involving the computation of a usability index based on macroseismic intensity and on seven building parameters, combined by means of regression coefficients and weights. The statistical model was calibrated on data of about 60,000 buildings affected by the 2009 L’Aquila earthquake in Italy. Therefore, it is useful to validate the model against data from the 2002 Molise earthquake in Italy. Good agreement between predicted and observed usability is shown, despite the fact that in 2002, macroseismic intensity was attributed to an entire municipality instead of a more limited area. Moreover, given the current availability of the shakemaps for the 2009 event, a novel model replacing conventional macroseismic intensity by an instrumental intensity measure is proposed. Three ground motion parameters are considered here: peak ground acceleration, peak ground velocity, and spectral pseudoacceleration at a period of vibration of 0.3 s. The model has been streamlined by reducing the building parameters from seven to five: building position within the structural aggregate, roof type, construction timespan, structural class, and pre-existing damage to structural elements. Peak ground acceleration and spectral pseudoacceleration are shown to be less effective than peak ground velocity in predicting observed usability. Therefore, usability probability matrices are computed in terms of peak ground velocity; the model is presented with all necessary coefficients and weights, and a worked-out example shows how to apply the procedure
Verification of a usability model for unreinforced masonry buildings with data from the 2002 Molise, southern Italy, earthquake
No full textIn this paper a methodology for assessing the usability of unreinforced masonry buildings, calibrated using the observed data collected after the 2009 L'Aquila, Southern Italy, Earthquake, is tested using data and performances surveyed after the 2002 Molise seismic event. The methodology is based on the computation of a Usability Index calculated as a weighted sum of seven parameters arranged in categories of decreasing usability. Each parameter represents a structural feature of the construction that may affect the building earthquake response. The Usability Index is correlated with the macroseismic intensity I MCS and Usability Probability Matrices, in terms of fully usable buildings, temporarily or partially unusable buildings, unusable buildings are derived. The application of the methodology on Molise data is rather successful especially with reference to the prediction of unusable buildings, despite the model was calibrated on a set of buildings belonging to a different region. The limited error can be at least partially explained in light of the differences in macroseismic intensity attribution
Typological damage fragility curves for unreinforced masonry buildings affected by the 2009 l'aquila, Italy earthquake
No full textBackground: Seismic risk mitigation has become a crucial issue due to the great number of casualties and large economic losses registered after recent earthquakes. In particular, unreinforced masonry constructions built before modern seismic codes, common in Italy and in other seismic-prone areas, are characterized by great vulnerability. In order to implement mitigation policies, analytical tools are necessary to generate scenario simulations. Methods: Therefore, data collected during inspections after the 2009 L’Aquila, Italy earthquake are used to derive novel fragility functions. Compared to previous studies, data are interpreted accounting for the presence of buildings not inspected due to those being undamaged. An innovative building damage state is proposed and is based on the response of different structural elements recorded in the survey form: vertical structures, horizontal structures, stairs, roof, and partition walls. In the suggested formulation, the combination of their performance is weighted based on typical reparation techniques and on the relative size of the structural elements, estimated from a database of complete geometrical surveys developed specifically for this study. Moreover, the proposed building damage state estimates earthquake-related damage by removing the preexisting damage reported in the inspection form. Results: Lognormal fragility curves, in terms of building damage state grade as a function of typological classes and peak ground acceleration, derived maximizing their likelihood and their merits compared with previous studies are highlighted. Conclusion: The correction of the database to account for uninspected buildings delivers curves that are less “stiff” and reach the median for lower peak ground acceleration values. The building feature that influences most the fragility is the masonry quality
Mucoepidermoid carcinoma of the larynx. A clinicopathological study of 11 cases with review of the literature
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Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Late occurrence of IgD myeloma in plasmacytoma of nasal cavity, cervical lymph node and larynx
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