Search results for "Correlation"
showing 10 items of 2282 documents
Experimental and numerical assessment of subsurface plastic deformation induced by OFHC copper machining
2015
Strain distributions in the machined surface and subsurface of OFHC copper workpieces were determined experimentally and through numerical simulations. An experimental setup, comprising a double frame camera and a pulsed laser, was developed to measure the displacement fields using the digital image correlation (DIC) technique; strain distributions were then calculated. A numerical orthogonal cutting model was also developed and applied in order to predict such distributions. Comparison between simulated and measured results enabled an understanding of the fundamental mechanisms of plastic deformation of the machined surface of OFHC copper.; International audience; Strain distributions in t…
OMA: From Research to Engineering Applications
2021
Ambient vibration modal identification, also known as Operational Modal Analysis (OMA), aims to identify the modal properties of a structure based on vibration data collected when the structure is under its operating conditions, i.e., when there is no initial excitation or known artificial excitation. This method for testing and/or monitoring historical buildings and civil structures, is particularly attractive for civil engineers concerned with the safety of complex historical structures. However, in practice, not only records of external force are missing, but uncertainties are involved to a significant extent. Hence, stochastic mechanics approaches are needed in combination with the iden…
Tests of Independence Based on Sign and Rank Covariances
2003
In this paper three different concepts of bivariate sign and rank, namely marginal sign and rank, spatial sign and rank and affine equivariant sign and rank, are considered. The aim is to see whether these different sign and rank covariances can be used to construct tests for the hypothesis of independence. In some cases (spatial sign, affine equivariant sign and rank) an additional assumption on the symmetry of marginal distribution is needed. Limiting distributions of test statistics under the null hypothesis as well as under interesting sequences of contiguous alternatives are derived. Asymptotic relative efficiencies with respect to the regular correlation test are calculated and compar…
Correlation Analysis between External Factors and Students’ Physics Learning Achievement
2018
Research was conducted to determine whether there is 1) the relationship between the state of the family of learning achievement, 2) the relationship between the state schools of learning achievement, 3) the relationship between communities of learning achievement, and 4) the relationship between the state of the family, school and community environment against learning achievement. This research is associative quantitative correlational analysis techniques. The results showed: 1) There is a positive relationship between the state of the family of learning achievement, the result of the calculation shows r table> count r ie 0.51 > 0.38, 2) There is a positive relationship between the …
Why benchmark-quality computations are needed to reproduce 1-adamantyl cation NMR chemical shifts accurately.
2011
While the experimental (1)H NMR chemical shiftsof the 1-adamantyl cation can be computed within reasonably small error bounds, the usual Hartree-Fock and density functional quantum-chemical computations, as well as those based on rather elaborate second-order Møller-Plesset perturbation theory, fail to reproduce its experimental (13)C NMR chemical shifts satisfactorily. This also is true even if the NMR shielding calculations treat electron correlation adequately by the coupled-cluster singles and doubles model augmented by a perturbative correction for triple excitations (i.e., at the CCSD(T) level) with quadruple-ζ basis sets. We demonstrate that good agreement can be achieved if highly a…
Fit-for-purpose chromatographic method for the determination of amikacin in human plasma for the dosage control of patients
2015
In this paper, a simple, rapid and sensitive method based on liquid chromatography with fluorimetric detection (HPLC-FLD) for the determination of amikacin (AMK) in human plasma is developed. Determination is performed by pre-column derivatization of AMK with ortho-phtalaldehyde (OPA) in presence of N-acetyl-L-cysteine (NAC) at pH 9.5 for 5 min at 80 °C. In our knowledge, this is the first time that NAC has been used in AMK derivatization. Derivatization conditions (pH, AMK/OPA/NAC molar ratios, temperature and reaction time) are optimized to obtain a single and stable, at room temperature, derivative. Separation of the derivative is achieved on a reversed phase LC column (Kromasil C18, 5 μ…
Cross-cultural adaptation and test-retest reliability of the spanish ROWAN foot pain assessment questionnaire (ROFPAQ-S)
2020
Background The ROWAN Foot Pain Assessment Questionnaire (ROFPAQ) may be considered as a self-reported health questionnaire with 45 items to measure foot health problems such as foot pain. To date, the ROFPAQ has only been validated into an English-language version. Objectives Therefore this study aim was to perform the cross-cultural adaptation and test-retest reliability of the Spanish ROFPAQ version (ROFPAQ-S). Study design A cross-sectional descriptive study. Settings Podiatry and physiotherapy clinical centers. Methods The recommended forward/backward translation protocol was applied for the procedure of translation and cross-cultural adaptation from United Kingdom to Spain. Results An …
Parental-caregiver perceptions of child oral health-related quality of life (P-CPQ): Psychometric properties for the peruvian spanish language.
2013
Objectives: The aim of the study was to cross-culturally adapt the Parental-Caregiver Perceptions Questionnaire (P-CPQ) to the Peruvian Spanish language and assess its reliability and validity. Study Design: To translate and cross-cultural adapt the instrument, 60 parents answered the P-CPQ in two pilot tests. The final version of the P-CPQ was evaluated in 200 parents of children aged 11 to 14 years, who were clini - cally examined for dental caries. The internal consistency was assessed by Cronbach's alpha coefficient while repeat administration of the P-CPQ on the same 200 children facilitated the test-retest reliability via intraclass correlation coefficient (ICC). Construct and discrim…
Vibrational dephasing of νs(OH) in 2,6-dichloro-4-nitrophenol
1988
Abstract A detailed analysis of the infrared bandshape of ν s (OH) in intramolecularly hydrogen-bonded 2,6-dichloro-4-nitrophenol in a series of solvents is presented. A distinct dependence of the bandshape and relaxation parameters on the polarity of solvent molecules has been found. The band shifts to lower wavenumbers, broadens and becomes more Gaussian with increasing solvent polarity; correspondingly, the correlation function decays faster and the correlation time decreases. The results are compared with those of previously studied systems. Factors determing the bandshape are discussed.
QSPR prediction of chromatographic retention times of pesticides: Partition and fractal indices
2014
The high-performance liquid-chromatographic retentions of red-wine pesticide residues are modeled by structure-property relationships. The effect of different types of features is analyzed: geometric, lipophilic, etc. The properties are fractal dimensions, partition coefficient, etc., in linear and nonlinear correlation models. Biological plastic evolution is an evolutionary perspective conjugating the effect of acquired characters and relations that emerge among the principles of evolutionary indeterminacy, morphological determination and natural selection. It is applied to design the co-ordination index that is used to characterize pesticide retentions. The parameters used to calculate th…