Search results for "cumulative"
showing 10 items of 299 documents
How the Covid-19 Pandemic Is Changing Online Food Shopping Human Behaviour in Italy
2020
The advent of the Internet has significantly changed consumption patterns and habits. Online grocery shopping is a way of purchasing food products using a web-based shopping service. The current COVID-19 pandemic is determining a rethinking of purchase choice elements and of consumers&rsquo
P2‐289: PREVALENCE AND CORRELATES OF SUBJECTIVE MEMORY IMPAIRMENT IN A RURAL ITALIAN POPULATION OF SUBJECTS AGED 50 YEARS AND OVER: DATA FROM THE ZAB…
2014
Background: Neuropathology related to dementia slowly accumulates over decades. Consequently, identifying persons at a higher risk of dementia could postpone or prevent dementia by timely targeting modifiable risk factors. In this light, mild cognitive impairment (MCI) has been identified as the transitional stage between normal aging and dementia. So far, the understanding of MCI in thegeneral population remains limited. Therefore,we investigated determinants, MRI-correlates, and prognosis of MCI within the populationbasedRotterdamStudy.Methods:A total of 4198 participants were included in this study. Firstly, we studied age, APOE4 carriership, waist circumference, hypertension, diabetes m…
Towards a cumulative tradition in e-Government Research: Going beyond the Gs and Cs
2007
Published version of a chapter published in Lecture Notes in Computer Science, 4656, 13-22. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-540-74444-3_2 The emerging research area of e-Government is gradually moving towards a level of maturity on the back of increasingly rigorous empirical research. Yet, there has been little theoretical progress and a cumulative tradition is not emerging. We argue that a principle reason for this is a lack of shared understanding about basic concepts and entities amongst scholars in the field. Specifically, the entities that form the bedrock of e-Government research, such as “Government” and “Citizen” are conceptualized at a very gen…
A comparative study of rainfall erosivity estimation for southern Italy and southeastern Australia
1999
Abstract In this paper, using Sicilian and Australian rainfall intensity data, a comparison between different estimators (modified Fournier index F, FF index) of the rainfall erosivity factor in the USLE was made. The relationship between the modified Fournier index and the mean annual rainfall, P, was theoretically derived. The K constant, linking the FF index and P, and its cumulative distribution function (CDF) were used to establish hydrological similitude among different geographical regions of southern Italy and southeastern Australia. To predict the erosion risk for an event of given average recurrence interval, the probability distribution of the annual value F a.j of the Arnoldus i…
On the Statistical Properties of Phase Crossings and Random FM Noise in Double Rayleigh Fading Channels
2016
In this paper, we study the statistics of phase processes and random frequency modulation (FM) noise encountered in double Rayleigh fading channels. The Rayleigh processes making up the double Rayleigh channel are assumed to be independent but not necessarily identically distributed. The Doppler power spectral densities of these processes are supposed to be symmetric about the carrier frequency. Under these fading conditions, we derive first an expression for the joint probability density function (jpdf) of the phase process and its rate of change. Capitalizing on this jpdf formula, we then investigate the probability density function (pdf) and cumulative distribution function (cdf) of rand…
Statistical Properties of Double Hoyt Fading With Applications to the Performance Analysis of Wireless Communication Systems
2018
In this paper, we investigate the statistical properties of double Hoyt fading channels, where the overall received signal is determined by the product of two statistically independent but not necessarily identically distributed single Hoyt processes. Finite-range integral expressions are first derived for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades of the envelope fading process. A closed-form approximate solution is also deduced for the LCR by making use of the Laplace approximation theorem. Applying the derived PDF of the double Hoyt channel, we then provide analytical expressions for the average…
On the Statistical Analysis of Equal Gain Combining over Multiple Double Rice Fading Channels in Cooperative Networks
2010
This article analyzes the statistical properties of narrowband mobile-to-mobile (M2M) fading channels with equal gain combining (EGC) under line-of-sight (LOS) propagation conditions. Here, we study a dual-hop amplify-and-forward (AF)relay network. It is assumed that there can exist LOS components in the transmission links between the source mobile station and the destination mobile station via K mobile relays. In order to cater for asymmetric fading conditions in the relay links, the received signal envelope at the output of the equal gain (EG) combiner is thus modeled as a sum of K double Rice processes. These processes are considered to be independent but not necessarily identically dist…
Exposure and cumulative risk assessment to non-persistent pesticides in Spanish children using biomonitoring.
2020
Abstract The main objective of the present research is to evaluate the exposure to pesticides in children (n = 568) from the Valencian Region (Spain). Six non-specific and 20 specific metabolites of organophosphate pesticides (OPs), herbicides (Herb), and pyrethroids (Pyr) were analyzed in urine samples. The biomarkers with the highest detection frequencies (>70%) were diethyl phosphate, p-nitrophenol, 3-phenoxybenzoic acid, and 3,5,6-trichloro-2-pyridinol, whose geometric mean concentrations (ng·ml-n1) were 1.53, 1.03, 1.51 and 1.19, respectively. Robust regression models showed that the province of residence and the recent consumption of vegetables, legumes and cereals were some of the mo…
Work-related upper limb musculoskeletal disorders in paediatric laparoscopic surgery. A multicenter survey.
2013
Abstract Background Surgeons are at risk for developing work-related musculoskeletal symptoms (WMS). The present study aims to examine the physical factors and their association with WMS among pediatric laparoscopic surgeons. Methods A questionnaire consisting of 21 questions was created and mailed to 25 pediatric laparoscopic surgeons (LG). 23/25 surgeons (92%) completed the survey. The questionnaire was analyzed and then split into 2 groups. Group 1 (LG1) included surgeons with greater laparoscopic experience, and group 2 (LG2) included surgeons with less important laparoscopic experience. In addition, we constructed and sent to the same surgeons a similar questionnaire focused on WMS aft…
Fluence Rate or Cumulative Dose? Vulnerability of Larval Northern Pike (Esox lucius) to Ultraviolet Radiation
2007
Newly hatched larvae of northern pike were exposed in the laboratory to four fluence rates of ultraviolet radiation (UVR; 290-400 nm) over three different time periods, resulting in total doses ranging from 3.0 +/- 0.2 to 63.0 +/- 4.4 kJ.m(-2). Mortality and behavior of the larvae were followed for 8-12 days, and growth measured at the end of the experiment. Also, the principle of reciprocity-that the UVR-induced mortality depends on the cumulative dose, independent of fluence rate-was tested. Fluence rates higher than 1480 +/- 150 mW.m(-2) caused mortality and growth retardation. The highest fluence rate (3040 +/- 210 mW.m(-2)) caused 100% mortality in 5 days. All fluence rates caused beha…