scholarly journals Influence of roundness deviation value on bearing vibration level

2018 ◽  
Vol 19 (12) ◽  
pp. 277-281 ◽  
Author(s):  
Bartłomiej Ambrożkiewicz ◽  
Krzysztof Przystupa ◽  
Sylwester Wnuk
Keyword(s):  
Linear Regression ◽  
Technological Process ◽  
Correlation Coefficients ◽  
Vibration Level ◽  
Pearson’S Correlation ◽  
Rolling Surface ◽  
Shape Errors ◽  
Pearson's Correlation ◽  
Roundness Deviation ◽  
Bearing Vibration

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.

Relationship amongst ResearchGate altmetric indicators and Scopus bibliometric indicators

2015 ◽  
Vol 116 (9/10) ◽  
pp. 564-577 ◽  
Author(s):  
RISHABH SHRIVASTAVA ◽  
Preeti Mahajan
Keyword(s):  
Sample Size ◽  
Correlation Coefficients ◽  
Strong Positive Correlation ◽  
Bibliometric Indicators ◽  
Pearson’S Correlation ◽  
Content Type ◽  
Positive Correlation ◽  
Pearson's Correlation ◽  
Different Characteristics ◽  
The Relationship

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.

scholarly journals Effects of Communicable Diseases on Life Expectancy in Low- and Lower-Middle-Income Countries

2021 ◽  
Vol 15 (8) ◽  
pp. 2329-2933
Author(s):  
Shariful Islam ◽  
Nazrul Islam Mondal ◽  
Rejaul Karim ◽  
Mohammad Rocky Khan Chowdhury ◽  
Aminur Rahman ◽  
...  
Keyword(s):  
Linear Regression ◽  
Life Expectancy ◽  
Hiv Infections ◽  
Communicable Diseases ◽  
Hbsag Prevalence ◽  
Pearson’S Correlation ◽  
Middle Income ◽  
Middle Income Countries ◽  
Pearson's Correlation ◽  
Children Under 5

Background: Life expectancy (LE) at birth is relatively poor in thelow- and lower-middle-income countries compared to the developed countries. There are many factors for this poor status of LE in these countries. Communicable disease in the human body is found to be one of the main causes. Aim: To determine the effects of communicable diseases on LE at birth in low- and lower-middle-income countries. Methods: Data of 82 low- and lower-middle-income countries were extracted from the World Health Statistics 2018. In this study, the dependent variable is LE at birth, and the communicable diseases such as new Human Immunodeficiency (HIV) infections, Tuberculosis (TB) incidences, Malaria incidences, and Hepatitis-B surface antigen (HBsAg) prevalence among children under 5 years are the independent variables. Descriptive statistics, Pearson’s correlation analysis, and Linear regression model were used to examine the data. Results: The lowest (52.90 years) and highest (76.30 years) LE at birth were observed in Lesotho and Viet Nam, respectively. Pearson’s correlation coefficients identified that new HIV infections, TB incidences, Malaria incidences, and HBsAg prevalence among children under 5 years are highly correlated with the LE at birth. The linear regression analysis reveals that all the selected variables are found to have significant negative effects on LE at birth in low and lowermiddleincome countries. Conclusions: The higher prevalence of communicable diseases contributes to reducing the LE at birth in low and lowermiddleincome countries. So, to raise the LE at birth of a country, the necessary steps should be taken to minimize the incidence and prevalence of communicable diseases. Keywords: Life expectancy; Communicable diseases;Low- and lower-middle-income countries

scholarly journals The Differences Between a Standard Costing and Normal Costing Method of Manufacturing Operating Income Calculation Caused by the Implementation of a New Integrated Information System

2020 ◽  
Vol 20 (2) ◽  
pp. 95-113
Author(s):  
Kamila Fałat
Keyword(s):  
Information System ◽  
Comparative Analysis ◽  
Correlation Coefficients ◽  
Pearson’S Correlation ◽  
Operating Income ◽  
Integrated Information System ◽  
Pearson's Correlation ◽  
The Difference ◽  
A Company ◽  
Integrated Information

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.

scholarly journals Evaluation of Impact of Happiness on Academic Performance among Medical Students of Rawalpindi Medical University, Pakistan

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Tayyab Mumtaz Khan ◽  
Sana Mansoor ◽  
Munazzah Kaleem ◽  
Muhammad Shahid Zafar ◽  
Anisa Shoail ◽  
...  
Keyword(s):  
Academic Performance ◽  
Medical Students ◽  
Linear Regression ◽  
Positive Association ◽  
Female Students ◽  
P Value ◽  
Pearson’S Correlation ◽  
Pearson's Correlation ◽  
Strong Positive Association ◽  
Medical University

Happiness is a collection of various kinds of emotions including positive and negative because of satisfaction in life. Happiness affects almost every aspect of life, however, among students, its most important impact is on their academic performance. Academic performance is positively affected by happiness and subsequently their performance as a physician. Therefore, our current study is set to assess the impact of happiness on academic performance among final-year medical students of Rawalpindi Medical University Pakistan. This may provide us a new way to bring improvement in academic performance of medical students. This descriptive cross-sectional study was carried out among final-year medical students of Rawalpindi Medical University in January 2020. Collection of data was accomplished with the help of two questionnaires including Oxford Happiness Questionnaire for happiness assessment and self-structured questionnaire which was developed to obtain required data about demographic details and marks in last professional examination. Students who had diagnosed any physical and mental illness were excluded. From total of 223 students who were enrolled at the beginning of study, only 186 returned correctly filled questionnaires so final sample size became 186. Data analysis was completed through SPSS v.25.0. Different statistical tests including Independent sample t-test, Chi-square test, Pearson’s correlation, and linear regression were used to assess the study variables. Statistically significant and strong positive association was noted between happiness and academic performance of students (p = 0.000). To evaluate the direction and strength of association between happiness and academic performance, Pearson’s correlation coefficient was calculated, and it was 0.809 with p-value 0.000). Difference in happiness score between male students and female students (p=0.015) and between boarder students and non-boarder students (p=0.000) was statistically significant. Likewise, the difference in academic performance that was assessed through marks in last professional examination was also statistically significant between male student and female students (p=0.001) and between boarder students and non-boarder students (p=0.000) was also statistically significant. With p-value of 0.000 for F test, simple linear regression model was valid. Value of unstandardized regression Coefficient (B) was 61.40. R² was 0.655 (65.5%). Our study overall shows higher happiness score and better academic performance among female and non-boarder students relative to male and boarder students. This current study also indicates statistically significant and strong positive association between happiness and academic performance, which means that increase in happiness increases the academic performance of students and vice versa. So, with the implementation of appropriate measures for the increase in happiness we can bring enhancement in academic performance of medical students.

scholarly journals Instrumental Heterogeneity in Sex-Specific Two-Sample Mendelian Randomization: Empirical Results From the Relationship Between Anthropometric Traits and Breast/Prostate Cancer

2021 ◽  
Vol 12 ◽  
Author(s):  
Yixin Gao ◽  
Jinhui Zhang ◽  
Huashuo Zhao ◽  
Fengjun Guan ◽  
Ping Zeng
Keyword(s):  
Breast Cancer ◽  
Prostate Cancer ◽  
Mendelian Randomization ◽  
Causal Effect ◽  
Correlation Coefficients ◽  
Causal Effects ◽  
Mr Studies ◽  
Pearson’S Correlation ◽  
Pearson's Correlation ◽  
Effect Estimation

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.

scholarly journals Plaque burden can be assessed using intravascular optical coherence tomography and a dedicated automated processing algorithm: a comparison study with intravascular ultrasound

2019 ◽  
Vol 21 (6) ◽  
pp. 640-652 ◽  
Author(s):  
Edouard Gerbaud ◽  
Giora Weisz ◽  
Atsushi Tanaka ◽  
Romain Luu ◽  
Hany Ahmed Salaheldin Hussein Osman ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Intravascular Ultrasound ◽  
Correlation Coefficients ◽  
Processing Algorithm ◽  
Plaque Burden ◽  
Optical Coherence ◽  
Pearson’S Correlation ◽  
Pearson's Correlation ◽  
Intravascular Optical Coherence Tomography ◽  
Enhancement Algorithm

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.

scholarly journals Linear relationships between cherry tomato traits

2017 ◽  
Vol 47 (3) ◽  
Author(s):  
Bruno Giacomini Sari ◽  
◽  
Alessandro Dal'Col Lúcio ◽  
Cinthya Souza Santana ◽  
Sidinei José Lopes ◽  
...  
Keyword(s):  
Correlation Coefficients ◽  
Fruit Weight ◽  
Variable Number ◽  
Cherry Tomato ◽  
Pearson’S Correlation ◽  
Effect Relationship ◽  
Cause And Effect ◽  
Tomato Yield ◽  
Linear Relationships ◽  
Pearson's Correlation

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.

scholarly journals Factors influencing bearing vibration level

2018 ◽  
Vol 19 (12) ◽  
pp. 273-276 ◽  
Author(s):  
Bartłomiej Ambrożkiewicz ◽  
Krzysztof Przystupa ◽  
Sylwester Wnuk
Keyword(s):  
Vibration Level ◽  
Research Experience ◽  
Durability Test ◽  
Technical Literature ◽  
Factors Affecting ◽  
Term Operation ◽  
Factors Influencing ◽  
Shape Errors ◽  
Bearing Vibration

This article presents the problem of factors influencing bearing vibration level, which is a comprehensive parameter providing information about bearing condition. Basing on technical literature and research experience, factors affecting bearing vibration level will be defined, both originating from shape errors, as well as those that may have occurred during long-term operation. Additionally, the methodology is described in accordance with ISO-15242 standard, concerning bearing vibration level tests performance. Experiment considered bearing vibration level measurements for bearing 6208C3, for post-production parts and those that have passed durability test. Comparative analysis included a compilation of numerical values and finding a correlation between level of bearing wear and mentioned parameter.

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