Search results for "Errors"
showing 10 items of 279 documents
What to Expect and What to Focus on in SQL Query Teaching
2019
In the process of learning a new computer language, writing erroneous statements is part of the learning experience. However, some errors persist throughout the query writing process and are never corrected. Structured Query Language (SQL) consists of a number of different concepts such as expressions, joins, grouping and ordering, all of which by nature invite different possible errors in the query writing process. Furthermore, some of these errors are relatively easy for a student to fix when compared to others. Using a data set from three student cohorts with the total of 744 students, we set out to explore which types of errors are persistent, i.e., more likely to be left uncorrected by…
Selection of the Best Subset of Variables in Regression and Time Series Models
2009
The problem of variable selection is one of the most pervasive model selection problems in statistical applications. Often referred to as the problem of subset selection, it arises when one wants to model the relationship between a variable of interest and a subset of potential explanatory variables or predictors, but there is uncertainty about which subset to use. Several papers have dealt with various aspects of the problem but it appears that the typical regression user has not benefited appreciably. One reason for the lack of resolution of the problem is the fact that it is has not been well defined. Indeed, it is apparent that there is not a single problem, but rather several problems …
Individual measurements and nested designs in aquaculture experiments: a simulation study
1998
Simple and nested models for analysis of variance (ANOVA) in aquaculture experiments were compared with the help of computer simulations. Simple models for analysing variables that are based on tank means, such as final weight and growth rate, were found to be sensitive to differences in the number of individual observations in each tank. In comparison to nested models that take into account individual measurements, the simple models were found to overestimate the F ratio and increase the risk of committing type I error, i.e., accepting a false alternative hypothesis. Further, nested models permit greater flexibility in experimental design, and allow more economical solutions within a given…
Numerical scheme influence on Pseudo Dynamic tests results
2008
Advances in Strain Gauge Measurement on Composite Materials
2010
This article gives an overview on the application of strain gauge techniques to the analysis of the strains in composite materials. The orthotropic behaviour of the composite influences the performance of strain gauges that are calibrated for use on isotropic materials. The article considers therefore the typical topics of the strain gauge technology applied to composites with particular reference to the compensation of thermal output, the measurement of the coefficients of thermal expansion, the determination of the strain and stress state, the influence of the misalignment error, the reinforcement effect, the determination of the stress intensification factor, the analysis of residual str…
Rateless Codes Performance Analysis in Correlated Channel Model for GEO Free Space Optics Downlinks
2012
Testi arabi di Sicilia. Un esempio di disputa linguistica
2021
Il mio contributo si propone di illustrare un testo esemplare dei rapporti culturali tra la Sicilia e la civiltà islamica. Il testo si intitola Taṯqīf al-lisān wa talqīḥ al-ǧanān di Abū Ḥafṣ ῾Umar Ibn Ḫalaf Ibn Makkī al-Ḥamīrī al-Māzirī al-Ṣiqillī, grammatico e linguista ed è un esempio della lingua araba parlata in Sicilia nel X secolo , quando l'isola era un emirato sotto il dominio islamico. Il Taṯqīf al-lisān, composto da cinquanta capitoli, il trattato elenca gli errori grammaticali commessi dai siciliani sia persone comuni (al-'amma) che dotti (al-muḫaṣṣiṣūn). Ogni errore elencato è seguito dalla sua forma corretta. Il grammatico classifica gli errori secondo alcune categorie: paradig…
eNOS Activation by HDL Is Impaired in Genetic CETP Deficiency.
2014
Mutations in the CETP gene resulting in defective CETP activity have been shown to cause remarkable elevations of plasma HDL-C levels, with the accumulation in plasma of large, buoyant HDL particles enriched in apolipoprotein E. Genetic CETP deficiency thus represents a unique tool to evaluate how structural alterations of HDL impact on HDL atheroprotective functions. Aim of the present study was to assess the ability of HDL obtained from CETP-deficient subjects to protect endothelial cells from the development of endothelial dysfunction. HDL isolated from one homozygous and seven heterozygous carriers of CETP null mutations were evaluated for their ability to down-regulate cytokine-induced…
WEIGHTS AND IMPUTATIONS
2019
This chapter provides a description of the weighting and imputation strategies used to address problems of unit nonresponse, sample attrition and item nonresponse in the seventh wave of SHARE.