Search results for "STATISTICS"
showing 10 items of 7671 documents
Cognitive and neuropsychological profiles of the elderly
1993
Testing the cognitive functions of the elderly is often eclectic and atheoretical. We take a theoretical model, simultaneous and successive processing, and the tests derived from it to describe the cognitive functions of the elderly. Subsequently, the performance of an elderly sample on a battery of neuropsychological tests is examined and also understood in relation to the two processing modes. Subjects were 81 individuals, 75 years old, from a population of nearly 300 persons participating in a Finnish research project on aging. They were administered tests of simultaneous and successive processing as well as an extensive battery of neuropsychological tasks. Multivariate and univariate an…
La inteligencia de los niños
2005
Partial results of an investigation are presented whose primary objective is to adapt and to standardize the neurocognitive assessment battery C.A.S. of Das and Naglieri (1997) in a child sample. The test is an operationalization of a non traditional intelligence model (PASS) that considers the intelligent behaviors as a group of four cognitive basic processes (planning, attention, simultaneous and successive processing). The objectives of this work are to obtain the psychometric properties of the instrument and also, to analyze if differences exist according to sex and age. The study type is crosswise - transactional. It was administered the CAS to 150 children residents in Buenos Aires am…
Estimating Polling Accuracy in Multiparty Elections Using Surveybias
2016
Any rigorous discussion of bias in opinion surveys requires a scalar measure of survey accuracy. Martin, Traugott, and Kennedy (2005, Public Opinion Quarterly 69: 342-369) propose such a measure A for the two-party case, and Arzheimer and Evans (2014, Political Analysis 22: 31-44) demonstrate how measures A'i, B, and Bw for the more common multiparty case can be derived. We describe the commands surveybias, surveybiasi, and surveybiasseries, which enable the fast computation of these binomial and multinomial measures of bias in opinion surveys. While the examples are based on pre-election surveys, the methodology applies to any multinomial variable whose true distribution in the population…
Testing international dental maturation scoring system and population-specific Demirjian versions on Saudi sub-population
2013
Objectives: The purpose of this study was to test the applicability of the Demirjian method and revised versions for estimating chronological age (CA) from dental age (DA) in a sample of children. Study Design: A sample of 252 individuals of known age (4 to 14 yrs), sex (males: 125, females: 127), and ethnicity (Saudi) was collected. Each individual was aged using the original Demirjian method and revised versions, including Saudi, Kuwaiti, Belgian, and revised international curves. The differences between dental age and chronological age were analyzed using paired sample t-tests with Bonferroni corrections and multinomial regression tests at the 0.05 level of significance. Results: The res…
Validation of the F-DBQ: A short (and accurate) risky driving behavior questionnaire for long-haul professional drivers
2021
Abstract Although the Driving Behavior Questionnaire (DBQ) remains the most known tool for assessing risky road behaviors among motor vehicle drivers, recent studies have raised several concerns on the specificity of both driving task conditions and behavioral repertory of certain segments of the driving population. Among them, long-haul (cargo) professional drivers constitute one of the “intensive driving” groups for which the existing adapted behavioral research tools are still very scarce. Purpose The aim of the present study was to test and validate the F-DBQ (or “Freight Driving Behavior Questionnaire”), a short version of the DBQ adapted to the occupational driving conditions and typi…
Validation of the Multidimensional Driving Style Inventory (MDSI) in professional drivers: How does it work in transportation workers?
2019
Abstract The Multidimensional Driving Style Inventory or MDSI constitutes, perhaps, the most relevant tool for measuring driving styles. Since its releasing in 2004, it has been applied worldwide to different samples of drivers, showing an important value and utility for road safety. However, empirical studies using the MDSI on professional drivers are scarce and, to the date, there is no validated version of the instrument in this workforce yet. Objectives: This study had two aims. First, to describe in detail the validation of the Taubman-Ben-Ari’s MDSI among professional drivers and, second, to test its convergent validity with other key relevant factors present in the work environment o…
An analysis of the bias of variation operators of estimation of distribution programming
2018
Estimation of distribution programming (EDP) replaces standard GP variation operators with sampling from a learned probability model. To ensure a minimum amount of variation in a population, EDP adds random noise to the probabilities of random variables. This paper studies the bias of EDP's variation operator by performing random walks. The results indicate that the complexity of the EDP model is high since the model is overfitting the parent solutions when no additional noise is being used. Adding only a low amount of noise leads to a strong bias towards small trees. The bias gets stronger with an increased amount of noise. Our findings do not support the hypothesis that sampling drift is …
The Tax Justice Network-Africa v Cabinet Secretary for National Treasury & 2 Others: A Big Win for Tax Justice Activism?
2019
This paper develops an optimization model for selecting a large subsample that improves the representativeness of a simple random sample previously obtained from a population larger than the population of interest. The problem formulation involves convex mixed-integer nonlinear programming (convex MINLP) and is therefore NP-hard. However, the solution is found by maximizing the “constant of proportionality” – in other words, maximizing the size of the subsample taken from a stratified random sample with proportional allocation – and restricting it to a p-value high enough to achieve a good fit to the population of interest using Pearson’s chi-square goodness-of-fit test. The beauty of the m…
Call admission control scheme using borrowable guard channels and prioritizing fresh calls retrials in small cell networks
2014
International audience; Recent trends in mobile cellular networks turn towards deployment of Small Cell Networks (SCNs), where, the cell size gets smaller, and thus the number of subscribers served in a cell will be relatively smaller, such that traffic models with a finite source of subscribers should be considered. Smaller cells cause the mobile subscribers to cross several cells during an ongoing conversation resulting in frequent handovers. Most of works dealing with Call Admission Control (CAC) problems based on guard channels scheme in cellular mobile networks consider models without retrials (reapeted calls phenomenon). However, almost all existing works which take into account retri…
Analysis of radionuclide concentration in air released through the stack of a radiopharmaceutical production facility based on a medical cyclotron
2015
Abstract Positron emitting radionuclides are increasingly used in medical diagnostics and the number of radiopharmaceutical production facilities have been estimated to be growing worldwide. During the process of production and/or patient administration of radiopharmaceuticals, an amount of these radionuclides might become airborne and escape into the environment. Therefore, the analysis of radionuclide concentration in the air released to the stack is a very important issue to evaluate the dose to the population living around the plant. To this end, sampling and measurement of radionuclide concentration in air released through the stack of a Nuclear Medicine Center (NMC), provided with a c…