Search results for "Correlation coefficient"

Country-specific correlations across Europe between modelled atmospheric cadmium and lead deposition and concentrations in mosses

2012

Previous analyses at the European scale have shown that cadmium and lead concentrations in mosses are primarily determined by the total deposition of these metals. Further analyses in the current study show that Spearman rank correlations between the concentration in mosses and the deposition modelled by the European Monitoring and Evaluation Programme (EMEP) are country and metal-specific. Significant positive correlations were found for about two thirds or more of the participating countries in 1990, 1995, 2000 and 2005 (except for Cd in 1990). Correlations were often not significant and sometimes negative in countries where mosses were only sampled in a relatively small number of EMEP gr…

Denoising AVIRIS-NG Data for Generation of New Chlorophyll Indices

2021

The availability of Airborne Visible and Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) data has enormous possibilities for quantification of Leaf Chlorophyll Content (LCC). The present study used the AVIRIS-NG campaign site of Western India for generation and validation of new chlorophyll indices by denoising the AVIRIS-NG data. For validation, concurrent to AVIRIS-NG flight overpass, field samplings were performed. The acquired AVIRIS-NG was subjected to Spectral Angle Mapper (SAM) classifier for discriminating the crop types. Three smoothing techniques i.e., Fast-Fourier Transform (FFT), Mean and Savitzky-Golay filters were evaluated for their denoising capability. Raw and fil…

Evaluation of Erythema Severity in Dermatoscopic Images of Canine Skin: Erythema Index Assessment and Image Sampling Reliability.

2021

The regular monitoring of erythema, one of the most important skin lesions in atopic (allergic) dogs, is essential for successful anti-allergic therapy. The smartphone-based dermatoscopy enables a convenient way to acquire quality images of erythematous skin. However, the image sampling to evaluate erythema severity is still done manually, introducing result variability. In this study, we investigated the correlation between the most popular erythema indices (EIs) and dermatologists’ erythema perception, and we measured intra- and inter-rater variability of the currently-used manual image-sampling methods (ISMs). We showed that the EIBRG, based on all three RGB (red, green, and blue) channe…

Neural network prediction of the AE index from the PC index

1999

Abstract It is shown that although the power spectra of the AE and PC data are quite similar they show differencies in structure function analysis. While the AE time series has a clear drop in the slope of the structure function (SF) after the first 2 hours, the slope of the SF of the PC data decreases gradually and at a little longer time scale. It is also shown by using 15-min averaged data, that both SFs are periodic with a clear diurnal variation. The PC time series seems to have a more pronounced periodicity, probably because it is measured at a single station at Thule. The AE index has been derived from the PC index for 7.5 minutes ahead by different methods. All these predictions gav…

2019

Aims To report corneal topometric and aberrometric values in mucopolysaccharidosis (MPS) and to investigate their correlation with biomechanical corneal parameters. Methods One randomly chosen eye of 20 MPS patients with no to moderate corneal clouding and one eye of 23 healthy controls with comparable age were prospectively included into this study. Corneal surface regularity was assessed by index of surface variance (ISV), -vertical asymmetry (IVA), -height asymmetry (IHA), -height decentration (IHD); keratoconus index (KI), central keratoconus index (CKI) and Zernike indices of anterior and posterior corneal surface using Scheimpflug imaging (Pentacam). Corneal resistance factor (CRF) an…

Non linear and linearized combination coefficients for modal pushover analysis

2017

Current design practice and seismic codes tend to assess seismic demand of buildings by Non linear Static Analysis (NSA), based on the evaluation of the pushover curve. Earlier non-linear static analysis procedure estimate the response peak value by evaluating the push-over curve adopting a distribution of invariant forces proportional to the fundamental vibration mode. In order to include the effect of higher modes several multimodal push-over analysis procedures were proposed in literature. In In the most famous of these, namely Modal Pushover Analysis (MPA), nodal response peak values are obtained by combination of "modal" responses by the traditional SRSS or CQC methods: the use of the …

Influence of image reconstruction parameters on cardiovascular risk reclassification by Computed Tomography Coronary Artery Calcium Score

2018

Objective: To investigate the influence of different CT reconstruction parameters on coronary artery calcium scoring (CACS) values and reclassification of predicted cardiovascular (CV) risk. Methods: CACS was evaluated in 113 patients undergoing ECG-gated 64-slice CT. Reference CACS protocol included standard kernel filter (B35f) with slice thickness/increment of 3/1.5 mm, and field-of-view (FOV) of 150–180 mm. Influence of different image reconstruction algorithms (reconstructed slice thickness/increment 2.0/1.0–1.5/0.8–3.0/2.0–3.0/3.0 mm; slice kernel B30f-B45f; FOV 200–250 mm) on Agatston score was assessed by Bland-Altman plots and concordance correlation coefficient (CCC) ana…

Prediction of the mesiodistal size of unerupted canines and premolars for a group of Romanian children: a comparative study

2013

Objectives The aim of the present study was to develop an optimization method of multiple linear regression equation (MLRE), using a genetic algorithm to determine a set of coefficients that minimize the prediction error for the sum of permanent premolars and canine dimensions in a group of young people from a central area of Romania represented by a city called Sibiu. Material and Methods To test the proposed method, we used a multiple linear regression equation derived from the estimation method proposed by Mojers, to which we adjusted regression coefficients using the Breeder genetic algorithm. A total of 92 children were selected with complete permanent teeth with no clinically visible …

Assessing Repeatability and Reproducibility of Anterior Active Rhinomanometry (AAR) in Children

2020

AbstractBackgroundRepeatability and reproducibility are essential for clinicians for several purposes. Although discouraged, use of the Coefficient of Variation (CV) for assessing repeatability and reproducibility, rather than the Intraclass Correlation Coefficient (ICC), is still widespread. The aim of the present study was to highlight how using inappropriate indices may lead to misleading results, and this is done by simulation study and using real data on Anterior Active Rhinomanometry (AAR) in both healthy children and ones with rhinitis.MethodsA simulation study was carried out to highlight how using inappropriate indices could be misleading. Then a comparison was made between CV and …

Reliability of Two Color Selection Devices in Matching and Measuring Tooth Color

2011

ABSTRACT Objective The objective of this study was to investigate the intra and interdevice reliability of two tooth color measurement devices: EasyShade (ES) and SpectroShade Micro (SSM). Materials and methods Tooth color was measured in six maxillary and mandibular. L*, a* and b* values and shade matches to VITA Classical and Vitapan 3D-Master shade guide systems were determined for all teeth. ÄE was assessed. Paired t-test and correlation coefficient (ICC) were used. Results Intradevices no significant differences (p > 0.05) were found between L*, a*, b*. Interdevice L* and b* were significantly higher for ES (p < 0.05), while a* was significantly higher for SSM (p < 0.05). ÄE s…