Search results for "Statistica"

Level-crossing rate and average duration of fades of non-stationary multipath fading channels

2017

The level-crossing rate (LCR) and average duration of fades (ADF) are important statistical quantities describing the fading behaviour of mobile radio channels. To date, these quantities have only been analysed under the assumption that the mobile radio channel is wide-sense stationary, which is generally not the case in practice. In this paper, we propose a concept for the analysis of the LCR and ADF of non-stationary channels. Rice's standard formula for the derivation of the LCR of wide-sense stationary processes is extended to a more general formula enabling the computation of the instantaneous LCR of non-stationary processes. The application of the new concept results in closed-form ex…

Tourism Statistics for Destination Management: The Trips/Arrivals Model

2014

Simply counting the number of tourists in a destination is not as simple as one might initially think. The present work intends to formalize a conceptual model by decomposing tourism nights, trips, and average duration of visit in a given destination, in terms of quantities and parameters that only for a small part could be derived from official tourism statistics. On the other hand, most of the quantities and parameters required for determining the number of tourists in a given destination are in general unknown, and need to be (directly or indirectly) estimated. Empirical evidences resulting from a survey on incoming tourism in Sicily are provided, showing the biases affecting supply-side…

Il rinvio della fecondità in Italia e Ungheria: analogie e differenze

2008

S-Detect characterization of focal solid breast lesions: a prospective analysis of inter-reader agreement for US BI-RADS descriptors

2020

Background: To assess inter-reader agreement for US BI-RADS descriptors using S-Detect: a computer-guided decision-making software assisting in US morphologic analysis. Methods: 73 solid focal breast lesions (FBLs) (mean size: 15.9 mm) in 73 consecutive women (mean age: 51 years) detected at US were randomly and independently assessed according to the BI-RADS US lexicon, without and with S-Detect, by five independent reviewers. US-guided core-biopsy and 24-month follow-up were considered as standard of reference. Kappa statistics were calculated to assess inter-operator agreement, between the baseline and after S-Detect evaluation. Agreement was graded as poor (≤ 0.20), moderate (0.21–0.40)…

Probabilities of conditionals and previsions of iterated conditionals

2019

Abstract We analyze selected iterated conditionals in the framework of conditional random quantities. We point out that it is instructive to examine Lewis's triviality result, which shows the conditions a conditional must satisfy for its probability to be the conditional probability. In our approach, however, we avoid triviality because the import-export principle is invalid. We then analyze an example of reasoning under partial knowledge where, given a conditional if A then C as information, the probability of A should intuitively increase. We explain this intuition by making some implicit background information explicit. We consider several (generalized) iterated conditionals, which allow…

Mortality and demographic recovery in early post-black death epidemics: Role of recent emigrants in medieval Dijon

2020

International audience; Objective and methodsWe analyze the influence of population movement on susceptibility to death and resilience during two epidemics occurring in Dijon soon after the Black Death. Using a specific program designed to propose links between entries in annual tax registers, we define tentative heads of household, the elapsed time since their first registration and their ties with other persons within the city.ResultsDuring the 1400 epidemic heads of household who were registered for 1–3 years die in large numbers, whereas during years without epidemics, their death rate is lower than that of heads of household who were registered longer. Recent registration is an epidemi…

Association between passive tobacco exposure and caries in children and adolescents. A systematic review and meta-analysis.

2017

To examine the available evidence on the association between exposure to tobacco use in the womb and in infancy and the presence of caries in primary and permanent dentition in children and adolescents. A systematic review was conducted through searches in 4 data bases (Pubmed, Scopus, Embase and Web of Science), complemented by hand-searching. Of the 559 articles identified, 400 were duplicates. Finally, 28 articles were included in the qualitative review and 21 in the meta-analysis. Their quality was assessed using the Newcastle-Ottawa scale. The quality was medium in 44% of the articles included and high in 56%. The overall meta-analysis gave a significant odds ratio (OR = 1.53, 95% conf…

La misurazione della performance dei distretti turistici: una proposta

2014

Il presente lavoro si propone di affrontare il tema della valutazione di impatto territoriale dell'esperienza distrettuale.

The territories of tourism: a reflection about the experience of the Tourist Districts (Local Tourism Systems) in Sicily

2013

The tourist district is an important tool for territorial governance of regional tourism. The district is a type of Local System which is characterized by its multidimensionality, as well as the spatial contiguity of traders who belong to it. The territory is a space transformed by social interactions and relations of production: it is therefore the indispensable reference for measuring the impact of tourism. A bottom up approach in the process of identification of the districts is therefore vital. A Balance Score Card-approach is desirable to correctly manage this process. This study is a preliminary analysis derived from direct experience of the Sicilian tourist districts, recently formed…

A statistical model for predicting the inter-annual variability of birch pollen abundance in Northern and North-Eastern Europe

2018

The paper suggests a methodology for predicting next-year seasonal pollen index (SPI, a sum of daily-mean pollen concentrations) over large regions and demonstrates its performance for birch in Northern and North-Eastern Europe. A statistical model is constructed using meteorological, geophysical and biological characteristics of the previous year). A cluster analysis of multi-annual data of European Aeroallergen Network (EAN) revealed several large regions in Europe, where the observed SPI exhibits similar patterns of the multi-annual variability. We built the model for the northern cluster of stations, which covers Finland, Sweden, Baltic States, part of Belarus, and, probably, Russia and…