scholarly journals Detecting and Evaluating Defects in Beams by Correlation Coefficients

2021 ◽  
Vol 2021 ◽  
pp. 1-22
Author(s):  
Thanh Q. Nguyen ◽  
Hoang B. Nguyen
Keyword(s):  
Natural Frequency ◽  
Correlation Coefficient ◽  
Structural Changes ◽  
Correlation Coefficients ◽  
Positive Outcome ◽  
Damping Coefficient ◽  
Vibration Measurement ◽  
Linear Characteristic ◽  
Measurement Channels ◽  
And Shifts

This research proposes a correlation coefficient for detecting and evaluating defects in beams, which brings about a positive outcome in terms of accuracy and efficiency. This parameter surpasses other parameters, such as natural frequency and damping coefficient, thanks to its sensitivity to structural changes. Our results show that although the damping coefficient had more variation than the natural frequency value in the same experiment, its changes were insufficient and unstable at different levels of defects. In addition, the proposed correlation coefficient parameter has a linear characteristic and always changes significantly according to increasing levels of defects. The results outweigh damping coefficient and natural frequency values. Furthermore, this value is always sensitive to measurement channels, which could be an important factor in locating defects in beams. The testing index is statistically evaluated by a normal distribution of the amplitude value of vibration measurement signals. Changes and shifts in this distribution are the basis for evaluating beam defects. Thus, the suggested parameter is a reliable alternative for assessing the defects of a structure.

IMPROVEMENT OF SPRING DURUM WHEAT SELECTION METHODOLOGIES UNDER CLIMATE CHANGE CONDITIONS

1970 ◽  
pp. 33-36
Author(s):  
А. I. Grabovets ◽  
V. P. Kadushkina ◽  
S. А. Kovalenko
Keyword(s):  
Grain Yield ◽  
Durum Wheat ◽  
Correlation Coefficient ◽  
Harvest Index ◽  
Unit Area ◽  
Correlation Coefficients ◽  
Chemical Mutagenesis ◽  
Main Method ◽  
The Relationship ◽  
Selection Of

With the growing aridity of the climate on the Don, it became necessary to improve the methodology for conducting the  breeding of spring durum wheat. The main method of obtaining the source material remains intraspecific step hybridization. Crossings were performed between genetically distant forms, differing in origin and required traits and properties. The use of chemical mutagenesis was a productive way to change the heredity of genotypes in terms of drought tolerance. When breeding for productivity, both in dry years of research and in favorable years, the most objective markers were identified — the size of the aerial mass, the mass of grain per plant, spike, and harvest index. The magnitude of the correlation coefficients between the yield per unit area and the elements of its structure is established. It was most closely associated with them in dry years, while in wet years it decreased. Power the correlation of the characteristics of the pair - the grain yield per square meter - the aboveground biomass averaged r = 0.73, and in dry years it was higher (0.91) than in favorable ones (0.61 - 0.70) , between the harvest and the harvest index - r = 0.81 (on average). In dry years, the correlation coefficient increased to 0.92. Research data confirms the greatest importance of the mass of grain from one ear and the plant in the formation of grain yield per unit area in both dry and wet years. In dry years, the correlation coefficient between yield and grain mass per plant was on average r = 0.80; in favorable years, r = 0.69. The relationship between yield and grain mass from the ear was greater — r = 0.84 and r = 0.82, respectively. Consequently, the breeding significance of the aboveground mass and the productivity of the ear, as a criterion for the selection of the crop, especially increases in the dry years. They were basic in the selection.

scholarly journals Development and Relative Validity of a Semiquantitative Food Frequency Questionnaire to Estimate Dietary Intake among a Multi-Ethnic Population in the Malaysian Cohort Project

Nutrients ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 1163
Author(s):  
Suzana Shahar ◽  
Mohd Razif Shahril ◽  
Noraidatulakma Abdullah ◽  
Boekhtiar Borhanuddin ◽  
Mohd Arman Kamaruddin ◽  
...  
Keyword(s):  
Vitamin C ◽  
Correlation Coefficient ◽  
Food Frequency Questionnaire ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Weighted Kappa ◽  
Dietary Intakes ◽  
Food Frequency ◽  
Relative Validity ◽  
Spearman’S Correlation

Measuring dietary intakes in a multi-ethnic and multicultural setting, such as Malaysia, remains a challenge due to its diversity. This study aims to develop and evaluate the relative validity of an interviewer-administered food frequency questionnaire (FFQ) in assessing the habitual dietary exposure of The Malaysian Cohort (TMC) participants. We developed a nutrient database (with 203 items) based on various food consumption tables, and 803 participants were involved in this study. The output of the FFQ was then validated against three-day 24-h dietary recalls (n = 64). We assessed the relative validity and its agreement using various methods, such as Spearman’s correlation, weighed Kappa, intraclass correlation coefficient (ICC), and Bland–Altman analysis. Spearman’s correlation coefficient ranged from 0.24 (vitamin C) to 0.46 (carbohydrate), and almost all nutrients had correlation coefficients above 0.3, except for vitamin C and sodium. Intraclass correlation coefficients ranged from −0.01 (calcium) to 0.59 (carbohydrates), and weighted Kappa exceeded 0.4 for 50% of nutrients. In short, TMC’s FFQ appears to have good relative validity for the assessment of nutrient intake among its participants, as compared to the three-day 24-h dietary recalls. However, estimates for iron, vitamin A, and vitamin C should be interpreted with caution.

scholarly journals A Vibration-Based Structural Health Monitoring System for Transmission Line Towers

Electronics ◽  
2019 ◽  
Vol 8 (5) ◽  
pp. 515 ◽  
Author(s):  
Long Zhao ◽  
Xinbo Huang ◽  
Ye Zhang ◽  
Yi Tian ◽  
Yu Zhao
Keyword(s):  
Structural Health Monitoring ◽  
Transmission Line ◽  
Natural Frequency ◽  
Health Monitoring ◽  
Structural Changes ◽  
Natural Frequencies ◽  
Transmission Tower ◽  
Health Monitoring System ◽  
Wind Speeds ◽  
Before And After

In this paper, we present a vibration-based transmission tower structural health monitoring system consisting of two parts that identifies structural changes in towers. An accelerometer group realizes vibration response acquisition at different positions and reduces the risk of data loss by data compression technology. A solar cell provides the power supply. An analyser receives the data from the acceleration sensor group and calculates the transmission tower natural frequencies, and the change in the structure is determined based on natural frequencies. Then, the data are sent to the monitoring center. Furthermore, analysis of the vibration signal and the calculation method of natural frequencies are proposed. The response and natural frequencies of vibration at different wind speeds are analysed by time-domain signal, power spectral density (PSD), root mean square (RMS) and short-time Fouier transform (STFT). The natural frequency identification of the overall structure by the stochastic subspace identification (SSI) method reveals that the number of natural frequencies that can be calculated at different wind speeds is different, but the 2nd, 3rd and 4th natural frequencies can be excited. Finally, the system was tested on a 110 kV experimental transmission line. After 18 h of experimentation, the natural frequency of the overall structure of the transmission tower was determined before and after the tower leg was lifted. The results show that before and after the tower leg is lifted, the natural frequencies of each order exhibit obvious changes, and the differences in the average values can be used as the basis for judging the structural changes of the tower.

Comparison of visual (MUNSELL) and instrumental measures (CIELAB) of coloured textile standard samples

2019 ◽  
Vol 23 (4) ◽  
pp. 340-354
Author(s):  
Asim Kumar Roy Choudhury ◽  
Biswajit Naskar
Keyword(s):  
Correlation Coefficient ◽  
Design Methodology ◽  
Correlation Coefficients ◽  
Standard Samples ◽  
Content Type ◽  
Psychophysical Data ◽  
Physical Data ◽  
Hue Angle ◽  
Munsell Scale

Purpose This paper aims to compare visual (Munsell) and instrumental (CIELAB) attributes of SCOTDIC colour standards. Design/methodology/approach SCOTDIC cotton and polyester standards of defined hue, value and chroma were subjected to spectrophotometric assessment for finding the corresponding instrumental parameters. The visual and instrumental parameters were compared. Findings The correlation between SCOTDIC value and CIELAB lightness is quite high. Correlation coefficient between SCOTDIC hue and CIELAB hue angle and the correlation between SCOTDIC chroma and CIELAB chroma were only moderate because the CIELAB chroma varied widely at higher chroma. When the standards of SCOTDIC hues having erratic hue angles at two extremes are excluded, the Correlation coefficients between SCOTDIC hue and CIELAB hue angle become high. Research limitations/implications The psychophysical data (visual) are difficult to match with physical data (instrumental). Originality/value The object of the present research is to study and compare visual (Munsell) and instrumental (CIELAB) colorimetric parameters. Munsell scale is physically exemplified by SCOTDIC fabric samples available in two sets, namely, cotton and polyester sets.

Effect of Surface Roughness on Slip Resistance of Rubber

2011 ◽  
Vol 189-193 ◽  
pp. 1538-1542
Author(s):  
Li Xiao Jia ◽  
Yong Zhen Zhang ◽  
Yong Ping Niu ◽  
San Ming Du ◽  
Jian Li
Keyword(s):  
Surface Roughness ◽  
Correlation Coefficient ◽  
Correlation Coefficients ◽  
Roughness Parameters ◽  
Test Conditions ◽  
Slip Resistance ◽  
Materials Used ◽  
Almost All ◽  
Effect Of Surface

In order to decrease accidents of slips and falls, COFs of rubber samples with different surface roughness were measured by Brungraber Mark II. And the correlation coefficients between roughness parameters and COF were calculated. The rusults have shown that the COF increases with surface roughness and the correlation coefficient between Sq and COF is highest. In general, almost all the roughness parameters used in the study have high correlation with COF. Parameters had the highest correlation with COF depends on the materials used and test conditions.

scholarly journals Innovative Correlation Coefficient Measurement with Fuzzy Data

2016 ◽  
Vol 2016 ◽  
pp. 1-11
Author(s):  
Berlin Wu ◽  
Chin Feng Hung
Keyword(s):  
Mathematics Achievement ◽  
Correlation Coefficient ◽  
Empirical Studies ◽  
Correlation Coefficients ◽  
Interval Data ◽  
Fuzzy Data ◽  
Pearson’S Correlation Coefficient ◽  
Coefficient Measurement ◽  
The Relationship ◽  
Fuzzy Interval

Correlation coefficients are commonly found with crisp data. In this paper, we use Pearson’s correlation coefficient and propose a method for evaluating correlation coefficients for fuzzy interval data. Our empirical studies involve the relationship between mathematics achievement and other projects.

scholarly journals Psychometric Properties of the MyotonPRO in Dementia Patients with Paratonia

Gerontology ◽  
2017 ◽  
Vol 64 (4) ◽  
pp. 401-412 ◽  
Author(s):  
Hans Drenth ◽  
Sytse U. Zuidema ◽  
Wim P. Krijnen ◽  
Ivan Bautmans ◽  
Cees van der Schans ◽  
...  
Keyword(s):  
Psychometric Properties ◽  
Correlation Coefficient ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Functional Mobility ◽  
Future Research ◽  
Minimal Detectable Change ◽  
Muscle Properties ◽  
Dementia Patients ◽  
Longitudinal Outcome

Background: Paratonia is a distinctive form of hypertonia, causing loss of functional mobility in early stages of dementia to severe high muscle tone and pain in the late stages. For assessing and evaluating therapeutic interventions, objective instruments are required. Objective: Determine the psychometric properties of the MyotonPRO, a portable device that objectively measures muscle properties, in dementia patients with paratonia. Methods: Muscle properties were assessed with the MyotonPRO by 2 assessors within one session and repeated by the main researcher after 30 min and again after 6 months. Receiver operating characteristic curves were constructed for all MyotonPRO outcomes to discriminate between participants with (n = 70) and without paratonia (n = 82). In the participants with paratonia, correlation coefficients were established between the MyotonPRO outcomes and the Modified Ashworth Scale for paratonia (MAS-P) and muscle palpation. In participants with paratonia, reliability (intraclass correlation coefficient) and agreement values (standard error of measurement and minimal detectable change) were established. Longitudinal outcome from participants with paratonia throughout the study (n = 48) was used to establish the sensitivity for change (correlation coefficient) and responsiveness (minimal clinical important difference). Results: Included were 152 participants with dementia (mean [standard deviation] age of 83.5 [98.2]). The area under the curve ranged from 0.60 to 0.67 indicating the MyotonPRO is able to differentiate between participants with and without paratonia. The MyotonPRO explained 10-18% of the MAS-P score and 8-14% of the palpation score. Interclass correlation coefficients for interrater reliability ranged from 0.57 to 0.75 and from 0.54 to 0.71 for intrarater. The best agreement values were found for tone, elasticity, and stiffness. The change between baseline and 6 months in the MyotonPRO outcomes explained 8-13% of the change in the MAS-P scores. The minimal clinically important difference values were all smaller than the measurement error. Conclusion: The MyotonPRO is potentially applicable for cross-sectional studies between groups of paratonia patients and appears less suitable to measure intraindividual changes in paratonia. Because of the inherent variability in movement resistance in paratonia, the outcomes from the MyotonPRO should be interpreted with care; therefore, future research should focus on additional guidelines to increase the clinical interpretation and improving reproducibility.

scholarly journals AB0798 IS THERE A REPRODUCIBILITY OF THE HISTOGRAM AND GRAY SCALE IN ECOEXTRUCTURAL DAMAGES IN RHEUMATOTOLOGICAL DISEASES?

2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1423.2-1424
Author(s):  
J. A. Mendonça ◽  
I. Siste de Almeida Aoki ◽  
C. C. Cavuto ◽  
V. A. Leandro-Merhi ◽  
J. L. B. D. Aquino
Keyword(s):  
Correlation Coefficient ◽  
Intraclass Correlation Coefficient ◽  
Rheumatic Diseases ◽  
Femoral Condyle ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Concordance Correlation Coefficient ◽  
Image Method ◽  
Concordance Correlation ◽  
Gray Scale

Background:The gray scale (GS) in high resolution ultrasound is already well validated for use in rheumatological diseases, but the color map or the histogram, can be considered a new proposal, to better define and complement the echotextural damages detection1.Objectives:To calculate the lesions area measures reproducibility index in arthropathies, between 3 blind evaluators and correlate these measures using the GS and the histogram.Methods:Observational and retrospective study approved by the ethics committee of the Pontifical Catholic University of Campinas, with the opinion number: 1.526.307. A total of 29 patients have been assessed (31% males and 69% females) on period 2014 to 2019 in Rheumatology service. A MyLab 50 -Esaote equipment was used with frequency transducer that ranged between 6.0 and 18.0 MHz, 10 different area measures were performed from each recorded images previously, by the GS and the histogram. Statistical analysis: Spearman’s correlation coefficients, Lin’s concordance coefficient (CCC) and the intraclass correlation coefficient (ICC) and their respective 95% confidence intervals, with the SPSS software package for Windows v. 17.0 (SPSS Inc., Chicago, IL, USA).Results:Average age 43.5 ± 21.5 years of age; with disease duration that varied between ≤ 1 month (48.3%) and ≥36 months (24.1%); with the following diseases: juvenile idiopathic arthritis (17.24%); osteoarthritis (13.79%); psoriatic arthritis (13.79%); undifferentiated spondyloarthritis (3.44%); gout (20.68%); rheumatoid arthritis (27.58%) and reactive arthritis (3.44%). A total of 840 measures of exudative (27.58%), proliferative (27.58%) and snowstorm appearance (6.89%) synovitis were performed; femoral-condyle cartilage (3.44%); synovial cyst (3.44%); paratendinitis (6.89%); calcification (3.44%); nail enthesitis (3.44%); tenosynovitis (6.89%) and tophi (10.34%) (Figure 1). The concordance correlation coefficient showed values closer to 1; p <0.001, the intraclass correlation coefficients with excellent reproducibility (ICC ≥ 0.75); p <0.001, always in relation to the three evaluators (Table 1) and the Spearman correlation between the GS and the histogram ranged from rs = 0.665 to rs = 1,000; p <0.001.Conclusion:The histogram can be considered an image method to better identify echotextural damages.References:[1]Mendonça J, Provenza J, Guissa V, et al AB1059 2D Histogram Ultrasound and 3D Ultrasound Correlation in Rheumatic Diseases Annals of the Rheumatic Diseases 2015; 74:1253-1254.Table 1.Concordance Correlation Coefficient (CCC) and Intraclass Correlation Coefficient (ICC):EvaluatorsGS - CCC(IC 95%)p-valorHistogram (IC 95%)p-valor1 e 20,998(0,994-0,999)<0,0010,999(0,995-1,000)<0,0011 e 30,998(0,995-0,999)<0,0010,999(0,995-1,000)<0,0012 e 30,992(0,980-0,997)<0,010,996(0,979-0,999)<0,01Standard by US 2DICCp-valorGS0,997(0,992-0,999)<0,001Histogram0,998(0,992-0,999)<0,001Legends: Gray Scale (GS).Figure 1.Patient with gout: A and B: Tophi area measures (star) in right metatarsos and efusion (arrow) by GS (45 mm2) and histogram (39 mm2), respectively.Disclosure of Interests:José Alexandre Mendonça Speakers bureau: Novartis, Janssen, Bristol, UCB, Isabella Siste de Almeida Aoki: None declared, Caique Chagas Cavuto: None declared, Vânia Aparecida Leandro-Merhi: None declared, José Luis Braga de Aquino: None declared

scholarly journals A Quantitative Comparison of Multispectral Refraction Topography and Autorefractometer in Young Adults

2021 ◽  
Vol 8 ◽  
Author(s):  
Yunru Liao ◽  
Zhenlan Yang ◽  
Zijing Li ◽  
Rui Zeng ◽  
Jing Wang ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Pearson Correlation ◽  
Intraclass Correlation ◽  
Correlation Coefficients ◽  
Cross Sectional Study ◽  
Cross Sectional ◽  
High Agreement ◽  
Intraclass Correlation Coefficients ◽  
Repeatability And Reproducibility ◽  
The Mean

Purpose: Purpose of this study is to evaluate the measuring consistency of central refraction between multispectral refraction topography (MRT) and autorefractometry.Methods: This was a descriptive cross-sectional study including subjects in Sun Yat-sen Memorial Hospital from September 1, 2020, to December 31, 2020, ages 20 to 35 years with a best corrected visual acuity of 20/20 or better. All patients underwent cycloplegia, and the refractive status was estimated with autorefractometer, experienced optometrist and MRT. We analyzed the central refraction of the autorefractometer and MRT. The repeatability and reproducibility of values measured using both devices were evaluated using intraclass correlation coefficients (ICCs).Results: A total of 145 subjects ages 20 to 35 (290 eyes) were enrolled. The mean central refraction of the autorefractometer was −4.69 ± 2.64 diopters (D) (range −9.50 to +4.75 D), while the mean central refraction of MRT was −4.49 ± 2.61 diopters (D) (range −8.79 to +5.02 D). Pearson correlation analysis revealed a high correlation between the two devices. The intraclass correlation coefficient (ICC) also showed high agreement. The intrarater and interrater ICC values of central refraction were more than 0.90 in both devices and conditions. At the same time, the mean central refraction of experienced optometrist was −4.74 ± 2.66 diopters (D) (range −9.50 to +4.75D). The intra-class correlation coefficient of central refraction measured by MRT and subjective refraction was 0.939.Conclusions: Results revealed that autorefractometry, experienced optometrist and MRT show high agreement in measuring central refraction. MRT could provide a potential objective method to assess peripheral refraction.

A selection of remarks on the measurement of correlations between variables of a panel data structure

2021 ◽  
Vol 66 (5) ◽  
pp. 7-25
Author(s):  
Mieczysław Kowerski ◽  
Jarosław Bielak
Keyword(s):  
Panel Data ◽  
Correlation Coefficient ◽  
Linear Correlation ◽  
Stock Exchange ◽  
Panel Data Analysis ◽  
Correlation Coefficients ◽  
Data Dependencies ◽  
Construction Companies ◽  
Advantages And Disadvantages ◽  
Warsaw Stock Exchange

Many articles featuring panel data modelling tend to begin their considerations with an introduction of the Pearson linear correlation coefficients matrix between the analysed variables. The aim of the article is to prove such an approach unsuitable in the analysis of panel data dependencies. Instead, an attempt has been made to propose a more appropriate measure – a correlation coefficient between the empirical and fitted values of the dependent variable of the estimated panel model (with fixed or random effects) in relation to the variable whose dependency towards the dependent variable is being studied. Pearson’s linear correlation coefficient does not reflect the basic advantage of panel data, which is the ability to provide information about the dependencies of the studied phenomena simultaneously in time and space. The fact that one observation relates to object i during period t and another to object j during period t + 1 is irrelevant for the calculation of the coefficient. Pearson’s coefficient, however, can be used when conducting sub-calculations in panel data analysis. The presented considerations have been illustrated by the calculations of the relationships between the structure of capital and the profitability and size of 17 construction companies listed on the Warsaw Stock Exchange in the years 2009–2018 (170 observations) which created a balanced panel. A specification of the advantages and disadvantages of the proposed solution was formulated on the basis of the calculations.

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