1,721,000 research outputs found
Influence of hydraulic and mechanical reliability on the overall reliability of water networks.
No full textInfluence of hydraulic and mechanical reliability on the overall reliability of water networks.
No full textFinancial Clustering in Presence of Dominant Markets
No full textClustering financial time series is a recent topic of statistical literature with important
fields of applications, in particular portfolio composition and risk evaluation. The
risk is generally linked to the volatility of the asset, but its level of predictability also
plays a basic role in investment decisions. In particular, the classification of a certain
asset could be linked to its dependence on the volatility of a dominant market:
movements in the volatility of the dominant market can provide similar movements
in the volatility of the asset and its predictability would depend on the strength of
this dependence. Working in a model based framework, we base the classification of
the volatility of an asset not only on its volatility level, but also on the presence of
spillover effects from a dominant market, such as the U.S. one, and on the similarity
of the dynamics of the asset and the dominant market. The method is carried out
using an extended version of the Multiplicative Error Model and is applied to a set
of European assets
Financial Clustering in Presence of Dominant Markets
No full textClustering financial time series is a recent topic of statistical literature with important
fields of applications, in particular portfolio composition and risk evaluation. The
risk is generally linked to the volatility of the asset, but its level of predictability also
plays a basic role in investment decisions. In particular, the classification of a certain
asset could be linked to its dependence on the volatility of a dominant market:
movements in the volatility of the dominant market can provide similar movements
in the volatility of the asset and its predictability would depend on the strength of
this dependence. Working in a model based framework, we base the classification of
the volatility of an asset not only on its volatility level, but also on the presence of
spillover effects from a dominant market, such as the U.S. one, and on the similarity
of the dynamics of the asset and the dominant market. The method is carried out
using an extended version of the Multiplicative Error Model and is applied to a set
of European assets
Incidenza dell’affidabilità meccanica sull’affidabilità complessiva delle reti di distribuzione idrica
No full textViene proposta una metodologia per la valutazione dell'affidabilità complessiva di una rete di distribuzione idrica, basata sulla stima contemporanea dell'affidabilità idraulica e dell'affidabilità meccanica del sistema. L'Affidabilità viene valutata con riferimento alla probabilità IA che un determinato indice di prestazione IP, pari al rapporto tra il volume giornaliero fornito all'utenza in una determinata condizione di funzionamento del sistema e quello richiesto, assuma valori superioori ad una soglia. L'Affidabilità complessiva IAC viene valutata effettuando una media pesata degli IA, dove il peso è dtao, per ciascun IA, dalla rispettiva probabilità che la rete si trovi a funzionare proprio nella condizione a cui esso si riferisce. Constatata l'impossibilità, dal punto di vista pratico, di valutare esattamente l'Affidabilità Complessiva, si propone, infine, un approccio semplificato, individuando una procedura e degli abachi per la valutazione dell'errore massimo che ne consegue
Reliability as a tool for hydraulic networks planning
No full textThis paper presents a methodology to evaluate the reliability of water distribution systems that
can be used in the design phase and for identifying repair works to be carried out on existing systems. The
methodology is based on the statistical analysis of dimensionless performance indices (hydraulic performance
indices) derived from a large number of simulations of various water system demand scenarios and/or operating
conditions. The hydraulic reliability index is assumed as the probability that, under a given operating condition,
the hydraulic performance index will be above a certain threshold. Finally, the system’s overall reliability (mechanical
1 hydraulic) is estimated using the overall reliability index, which is defined by the weighted mean of
the hydraulic performance indices obtained for the various operating conditions. A case study using this methodology
shows the concrete possibilities of applying this approach to a wide spectrum of cases, and the small
influence on overall system reliability normally exerted by such events as the failure of links, pipes, and valves
Closure to Reliability as Tool for Hydraulic Network Planning
Full text linkClosure to the discussion carried by prof. Kansal on the paper "Reliability as Tool for Hydraulic Network Planning
Almost all irritable bowel syndromes are post-infectious and respond to probiotics: consensus issues.
No full textSeveral reports have described post-infectious irritable bowel syndrome (Pi-IBS), while many animal and human studies have shown the presence of increased infiltration of inflammatory cells and hyperplasia of enterochromaffin cells in the intestinal mucosa after acute gastroenteritis. The potential value of probiotic bacteria in restoring normal gut function has been demonstrated by animal models of Pi-IBS. In humans, Pi-IBS can be prevented utilizing probiotics to reduce the duration of acute gastroenteritis, despite the variable efficacy shown in randomized control trials evaluating unspecified IBS. Here, advances in the pathophysiology supporting the post-infectious hypothesis are considered. In addition, the current role of probiotics in the management of Pi-IBS is discussed. 2007 S. Karger AG, Ba
Sul funzionamento degli scaricatori di piena con bacino di calma
No full textNella memoria viene analizzato, mediante un approccio sperimentale, il comportamento di uno scaricatore di piena dotato di bacino di calma
Un modello per la valutazione dell’affidabilità delle reti di distribuzione.
No full textVengono proposti una serie di indici per la valutazione dell'affidabilità idraulica e meccanica delle reti di distribuzione idrica, proponendo un approccio per la valutazione dell'affidabilità complessiva 8idraulica + meccanica) delle stesse
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