The use of the Pearson’s correlation coefficients to identify mechanical-physical-chemical parameters controlling the tribocorrosion of metallic alloy

2021 ◽  
pp. 111-130
Author(s):  
Vincent Vignal ◽  
Halina Krawiec
2015 ◽  
Vol 116 (9/10) ◽  
pp. 564-577 ◽  
Author(s):  
RISHABH SHRIVASTAVA ◽  
Preeti Mahajan

Purpose – The purpose of this paper is twofold. First, the study aims to investigate the relationship between the altmetric indicators from ResearchGate (RG) and the bibliometric indicators from the Scopus database. Second, the study seeks to examine the relationship amongst the RG altmetric indicators themselves. RG is a rich source of altmetric indicators such as Citations, RGScore, Impact Points, Profile Views, Publication Views, etc. Design/methodology/approach – For establishing whether RG metrics showed the same results as the established sources of metrics, Pearson’s correlation coefficients were calculated between the metrics provided by RG and the metrics obtained from Scopus. Pearson’s correlation coefficients were also calculated for the metrics provided by RG. The data were collected by visiting the profile pages of all the members who had an account in RG under the Department of Physics, Panjab University, Chandigarh (India). Findings – The study showed that most of the RG metrics showed strong positive correlation with the Scopus metrics, except for RGScore (RG) and Citations (Scopus), which showed moderate positive correlation. It was also found that the RG metrics showed moderate to strong positive correlation amongst each other. Research limitations/implications – The limitation of this study is that more and more scientists and researchers may join RG in the future, therefore the data may change. The study focuses on the members who had an account in RG under the Department of Physics, Panjab University, Chandigarh (India). Perhaps further studies can be conducted by increasing the sample size and by taking a different sample size having different characteristics. Originality/value – Being an emerging field, not much has been conducted in the area of altmetrics. Very few studies have been conducted on the reach of academic social networks like RG and their validity as sources of altmetric indicators like RGScore, Impact Points, etc. The findings offer insights to the question whether RG can be used as an alternative to traditional sources of bibliometric indicators, especially with reference to a rapidly developing country such as India.


2020 ◽  
Vol 20 (2) ◽  
pp. 95-113
Author(s):  
Kamila Fałat

Abstract Research background: When a company changes a few separated information systems into one integrated information system there can appear the obligation of costing method change. It happens especially when the company is a part of an international manufacturing corporation. Purpose: The main goal of the paper is to compare two methods of manufacturing operating income calculation and data presentation when a company changes a costing method from normal costing to standard costing. Research methodology: In the paper for this research comparative analysis was used between two methods of manufacturing operating income calculation. In the first method manufacturing operating income is the difference between revenues from manufacturing operations and the costs of goods manufactured. In the second one manufacturing operating income is calculated as a sum of production variances, purchase price variances, currency variances and inventory adjustments. Pearson’s correlation coefficients for pairs of variables were calculated in both of the costing methods. A comparative analysis was done on the basis of a case study executed in a big international wholesaler. The company is a member of an international manufacturing corporation. Results: The same manufacturing operating incomes were obtained in both methods. The absolute values of Pearson’s correlation coefficients were similar in normal and standard costing, but they differ in directions. Novelty: In standard costing manufacturing operating income is calculated as a sum of various types of variances. They are calculated as deviations from standard costs. It enables the easier identification of impacting a company’s results factors.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yixin Gao ◽  
Jinhui Zhang ◽  
Huashuo Zhao ◽  
Fengjun Guan ◽  
Ping Zeng

BackgroundIn two-sample Mendelian randomization (MR) studies, sex instrumental heterogeneity is an important problem needed to address carefully, which however is often overlooked and may lead to misleading causal inference.MethodsWe first employed cross-trait linkage disequilibrium score regression (LDSC), Pearson’s correlation analysis, and the Cochran’s Q test to examine sex genetic similarity and heterogeneity in instrumental variables (IVs) of exposures. Simulation was further performed to explore the influence of sex instrumental heterogeneity on causal effect estimation in sex-specific two-sample MR analyses. Furthermore, we chose breast/prostate cancer as outcome and four anthropometric traits as exposures as an illustrative example to illustrate the importance of taking sex heterogeneity of instruments into account in MR studies.ResultsThe simulation definitively demonstrated that sex-combined IVs can lead to biased causal effect estimates in sex-specific two-sample MR studies. In our real applications, both LDSC and Pearson’s correlation analyses showed high genetic correlation between sex-combined and sex-specific IVs of the four anthropometric traits, while nearly all the correlation coefficients were larger than zero but less than one. The Cochran’s Q test also displayed sex heterogeneity for some instruments. When applying sex-specific instruments, significant discrepancies in the magnitude of estimated causal effects were detected for body mass index (BMI) on breast cancer (P = 1.63E-6), for hip circumference (HIP) on breast cancer (P = 1.25E-20), and for waist circumference (WC) on prostate cancer (P = 0.007) compared with those generated with sex-combined instruments.ConclusionOur study reveals that the sex instrumental heterogeneity has non-ignorable impact on sex-specific two-sample MR studies and the causal effects of anthropometric traits on breast/prostate cancer would be biased if sex-combined IVs are incorrectly employed.


2019 ◽  
Vol 21 (6) ◽  
pp. 640-652 ◽  
Author(s):  
Edouard Gerbaud ◽  
Giora Weisz ◽  
Atsushi Tanaka ◽  
Romain Luu ◽  
Hany Ahmed Salaheldin Hussein Osman ◽  
...  

Abstract Aims Plaque burden (PB) measurement using intravascular optical coherence tomography (IVOCT) is currently thought to be inferior to intravascular ultrasound (IVUS). We developed an automated IVOCT image processing algorithm to enhance the external elastic lamina (EEL) contour. Thus, we investigated the accuracies of standard IVOCT and an IVOCT enhancement algorithm for measuring PB using IVUS as the reference standard. Methods and results The EEL-enhancement algorithm combined adaptive attenuation compensation, exponentiation, angular registration, and image averaging using three sequential frames. In two different laboratories with intravascular imaging expertise, PB was quantified on 200 randomized, matched IVOCT and IVUS images by four independent observers. Fibroatheroma, fibrocalcific plaque, fibrous plaque, pathological intimal thickening (PIT), and mixed plaque were included in each set. Pearson’s correlation coefficients between IVUS and standard IVOCT measurements of PB were 0.61, 0.67, 0.76, 0.78, and 0.87 for fibroatheromas, mixed plaques, fibrocalcific plaques, fibrous plaques, and PIT plaques, respectively. Pearson’s correlation coefficients increased to 0.81, 0.83, 0.83, 0.84, and 0.90 when using the EEL-enhanced images (P = 0.003, P = 0.004, P = 0.08, P = 0.12, and P = 0.23, respectively). EEL-enhanced IVOCT analysis was associated with a lower EEL-area measurement absolute error for fibroatheromas, mixed plaques, and all pooled plaques (P = 0.006, P = 0.02, and P < 0.001, respectively). Compared with standard IVOCT, the EEL-enhanced IVOCT images had a higher sensitivity (79% vs. 28%, P < 0.001) and specificity (98% vs. 85%, P = 0.03) for plaques with an IVUS PB ≥70%. Conclusion EEL-enhanced IVOCT can be used to reliably measure PB in all types of coronary atherosclerotic lesions, including fibroatheromas and mixed plaques.


2018 ◽  
Vol 19 (12) ◽  
pp. 277-281 ◽  
Author(s):  
Bartłomiej Ambrożkiewicz ◽  
Krzysztof Przystupa ◽  
Sylwester Wnuk

This article investigates the influence of roundness value on vibration level generated by bearing. One of the shape errors playing a key role in bearing’s operation is roundness deviation. Its value directly influence on vibration level generated by bearing. In the paper, the significance and methodology of roundness measurements in reference to profile of rolling surface received in technological process. Experiment consisted of inner rings matching of bearing 6009C3 with variable roundness deviation with outer rings characterized with little variability of mentioned deviation. In the next step bearing vibration level was examined. In the end, obtained results were combined with values of roundness deviation and basing on them, models of linear regression were obtained, also Pearson’s correlation coefficients were calculated.


2017 ◽  
Vol 47 (3) ◽  
Author(s):  
Bruno Giacomini Sari ◽  
◽  
Alessandro Dal'Col Lúcio ◽  
Cinthya Souza Santana ◽  
Sidinei José Lopes ◽  
...  

ABSTRACT: The objective of this study was to identify the linear relationship between cherry tomato yield components. Two uniformity trials, without treatments, were conducted on Lilli cherry tomato plants in a plastic greenhouse during the 2014 spring/summer season, with the plants in two stems. Variables observed for each plant were mean fruit length, mean fruit width, mean fruit weight, number of bunches, number of fruits per bunch, total number of fruits, and total fruit weight; a Pearson's correlation matrix was used to estimate the relationship between the variables. Path analysis was then performed considering total fruit weight as the main variable and the remaining variables as explanatory. Due to the severe multicollinearity, the variable 'number of fruits per bunch' was eliminated. Pearson's correlation coefficients were significant between explanatory and main variables. Mean fruit weight has a low cause-and-effect relationship with the total weight of fruits produced. A low cause-and-effect relationship was also observed between number of fruits and number of bunches. Cherry tomato productivity is directly related to the number of fruits per plant.


Nutrients ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1998 ◽  
Author(s):  
Marjolein Visser ◽  
Liset E. M. Elstgeest ◽  
Laura H. H. Winkens ◽  
Ingeborg A. Brouwer ◽  
Mary Nicolaou

The aim of this study was to determine the relative validity of the HEalthy LIfe in an Urban Setting (HELIUS) food frequency questionnaire (FFQ) in assessing the dietary intake of energy, nutrients, and food groups of Dutch older men and women. In 2014–2015, 88 participants of the Longitudinal Aging Study Amsterdam aged 71.9 (SD 8.6) years completed the 238-item HELIUS FFQ and three 24-hour dietary recalls. The mean group-level bias in the intakes of energy, nutrients, and food groups between the two methods was assessed, as well as Pearson’s correlation coefficients and level of agreement using quintile distribution. For the intakes of energy and macronutrients, the group-level bias was ≤5%, Pearson’s correlation coefficients were moderate to good (ranging from 0.26 for total fat to 0.72 for alcohol), and agreement was moderate to high (classification in same or adjacent quintile ranging from 63% for energy, protein, and carbohydrate to 91% for alcohol). For most micronutrients and food groups, the relative validity was moderate (Pearson’s correlation coefficients between 0.3 and 0.5), with the lowest correlations for β-carotene (0.08), vitamin B1 (0.19), fish (0.14), and grains (0.24). In conclusion, for energy and macronutrients, most micronutrients, and most food groups, the relative validity of the HELIUS FFQ to assess dietary intake in Dutch older adults was acceptable to good.


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