Measurement of tool wear using a non-contact method, using a laser measuring system

2021 ◽  
Vol 116 ◽  
pp. 15-20
Author(s):  
Bartłomiej Grzegorzewski ◽  
Patryk Król
Keyword(s):  
Tool Wear ◽  
Rotational Speed ◽  
Measuring System ◽  
Contact Method ◽  
Contactless Method ◽  
Laser Sensor ◽  
Laser Measurement ◽  
Pearson’S Correlation ◽  
Pearson's Correlation ◽  
Tool Diameter

Measurement of tool wear using a non-contact method, using a laser measuring system. This article examined the tools - straight cutters with a contactless method using a laser sensor. The first aspect of the research was to determine the influence of the spindle rotational speed on the accuracy of laser measurement. The second aspect of the research was to establish the correlation between the diameter of the tool measured with a laser micrometer and the wear of the tool measured with the microscope. A good (R2> 0.8) Pearson's correlation was found between the measured tool diameter and it’s wear.

scholarly journals Deep learning-based segmentation of the lung in MR-images acquired by a stack-of-spirals trajectory at ultra-short echo-times

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Andreas M. Weng ◽  
Julius F. Heidenreich ◽  
Corona Metz ◽  
Simon Veldhoen ◽  
Thorsten A. Bley ◽  
...  
Keyword(s):  
Image Segmentation ◽  
Deep Learning ◽  
Accurate Estimation ◽  
Dice Similarity Coefficient ◽  
Manual Segmentation ◽  
Pearson’S Correlation ◽  
Lung Volumes ◽  
Lung Segmentation ◽  
Pearson's Correlation ◽  
Lung Mri

Abstract Background Functional lung MRI techniques are usually associated with time-consuming post-processing, where manual lung segmentation represents the most cumbersome part. The aim of this study was to investigate whether deep learning-based segmentation of lung images which were scanned by a fast UTE sequence exploiting the stack-of-spirals trajectory can provide sufficiently good accuracy for the calculation of functional parameters. Methods In this study, lung images were acquired in 20 patients suffering from cystic fibrosis (CF) and 33 healthy volunteers, by a fast UTE sequence with a stack-of-spirals trajectory and a minimum echo-time of 0.05 ms. A convolutional neural network was then trained for semantic lung segmentation using 17,713 2D coronal slices, each paired with a label obtained from manual segmentation. Subsequently, the network was applied to 4920 independent 2D test images and results were compared to a manual segmentation using the Sørensen–Dice similarity coefficient (DSC) and the Hausdorff distance (HD). Obtained lung volumes and fractional ventilation values calculated from both segmentations were compared using Pearson’s correlation coefficient and Bland Altman analysis. To investigate generalizability to patients outside the CF collective, in particular to those exhibiting larger consolidations inside the lung, the network was additionally applied to UTE images from four patients with pneumonia and one with lung cancer. Results The overall DSC for lung tissue was 0.967 ± 0.076 (mean ± standard deviation) and HD was 4.1 ± 4.4 mm. Lung volumes derived from manual and deep learning based segmentations as well as values for fractional ventilation exhibited a high overall correlation (Pearson’s correlation coefficent = 0.99 and 1.00). For the additional cohort with unseen pathologies / consolidations, mean DSC was 0.930 ± 0.083, HD = 12.9 ± 16.2 mm and the mean difference in lung volume was 0.032 ± 0.048 L. Conclusions Deep learning-based image segmentation in stack-of-spirals based lung MRI allows for accurate estimation of lung volumes and fractional ventilation values and promises to replace the time-consuming step of manual image segmentation in the future.

scholarly journals Shoulder Related Temperature Thresholds in FSSW of Aluminium Alloys

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4375
Author(s):  
David G. Andrade ◽  
Sree Sabari ◽  
Carlos Leitão ◽  
Dulce M. Rodrigues
Keyword(s):  
Heat Generation ◽  
Process Parameters ◽  
Rotational Speed ◽  
Aluminium Alloys ◽  
Spot Welding ◽  
Base Material ◽  
Main Process ◽  
Welding Temperature ◽  
Friction Stir ◽  
Tool Diameter

Friction Stir Spot Welding (FSSW) is assumed as an environment-friendly technique, suitable for the spot welding of several materials. Nevertheless, it is consensual that the temperature control during the process is not feasible, since the exact heat generation mechanisms are still unknown. In current work, the heat generation in FSSW of aluminium alloys, was assessed by producing bead-on-plate spot welds using pinless tools. Coated and uncoated tools, with varied diameters and rotational speeds, were tested. Heat treatable (AA2017, AA6082 and AA7075) and non-heat treatable (AA5083) aluminium alloys were welded to assess any possible influence of the base material properties on heat generation. A parametric analysis enabled to establish a relationship between the process parameters and the heat generation. It was found that for rotational speeds higher than 600 rpm, the main process parameter governing the heat generation is the tool diameter. For each tool diameter, a threshold in the welding temperature was identified, which is independent of the rotational speed and of the aluminium alloy being welded. It is demonstrated that, for aluminium alloys, the temperature in FSSW may be controlled using a suitable combination of rotational speed and tool dimensions. The temperature evolution with process parameters was modelled and the model predictions were found to fit satisfactorily the experimental results.

scholarly journals Case Study of Anaerobic Digestion Process Stability Detected by Dissolved Hydrogen Concentration

Processes ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 106
Author(s):  
Daniela Platošová ◽  
Jiří Rusín ◽  
Jan Platoš ◽  
Kateřina Smutná ◽  
Roman Buryjan
Keyword(s):  
Anaerobic Digestion ◽  
Correlation Coefficient ◽  
Hydrogen Concentration ◽  
Pearson’S Correlation ◽  
Pearson’S Correlation Coefficient ◽  
Digestion Process ◽  
Short Service Life ◽  
Pearson's Correlation ◽  
Dissolved Hydrogen ◽  
Pearson's Correlation Coefficient

The paper presents the results of a laboratory experiment of mesophilic single-stage anaerobic digestion performed to verify the possibility of early detection of process instability and reactor overload by evaluating the course of dissolved hydrogen concentration of the main intermediate. The digestion process was run in a Terrafors IS rotary drum bioreactor for 230 days. The substrate dosed on weekdays was food leftovers from the university canteen. At an average temperature of 37 °C, an organic loading of volatiles of 0.858 kg m−3 day−1 and a theoretical retention time of 259 days, biogas production of 0.617 Nm3 kg VS−1 was achieved with a CH4 content of 51.7 vol. %. The values of the established FOS/TAC stability indicator ranged from 0.26 to 11.4. The highest value was reached when the reactor was overloaded. The dissolved hydrogen concentration measured by the amperometric microsensor ranged from 0.039–0.425 mg dm−3. Data were statistically processed using Pearson’s correlation coefficient. The correlation of the hydrogen concentration with other parameters such as the concentration of organic acids was evaluated. The value of Pearson’s correlation coefficient was 0.331 and corresponded to a p-value of 0. The results confirmed a very low limit of the hydrogen concentration at which the microbial culture, especially methanogens, was already overloaded. The amperometric microsensor proved to be rather unsuitable for operational applications due to insufficient sensitivity and short service life. The newly designed ratio of dissolved hydrogen concentration to neutralizing capacity was tested but did not work significantly better than the established FOS/TAC stability indicator.

scholarly journals Remote administration of the symbol digit modalities test to individuals with multiple sclerosis is reliable: A short report

2021 ◽  
Vol 7 (1) ◽  
pp. 205521732199485
Author(s):  
Tehila Eilam-Stock ◽  
Michael T Shaw ◽  
Kathleen Sherman ◽  
Lauren B Krupp ◽  
Leigh E Charvet
Keyword(s):  
Multiple Sclerosis ◽  
Correlation Analysis ◽  
Gold Standard ◽  
Short Report ◽  
Strongly Correlated ◽  
Cognitive Screening ◽  
Pearson’S Correlation ◽  
Screening Approach ◽  
Pearson's Correlation ◽  
Pearson’S Correlation Analysis

Background The Symbol Digit Modalities Test (SDMT) is the gold standard for cognitive screening in multiple sclerosis (MS). Objective Due to the recent COVID-19 pandemic and the increased need for virtual clinical visits, we examined the reliability of remote administration of the SDMT vs. standard in-person administration to individuals with MS. Methods Pearson’s correlation analysis was performed between SDMT scores on the in-person and remote administrations. Results For n = 132 participants, remote and in-person SDMT scores were strongly correlated (r = .80, p = .000). Conclusion Remote administration of the SDMT is a reliable cognitive screening approach in MS.

Italian version of the cornell musculoskeletal discomfort questionnaire (CMDQ-I): Translation, cultural adaptation and validation

Work ◽  
2021 ◽  
pp. 1-7
Author(s):  
F. Magnifica ◽  
F. Colagrossi ◽  
A. Aloisi ◽  
S. Politi ◽  
A. Peretti ◽  
...  
Keyword(s):  
Correlation Coefficient ◽  
Cultural Adaptation ◽  
Italian Version ◽  
Cronbach’S Alpha ◽  
Musculoskeletal Discomfort ◽  
Pearson’S Correlation ◽  
Pearson’S Correlation Coefficient ◽  
Cronbach's Alpha ◽  
Pearson's Correlation ◽  
Pearson's Correlation Coefficient

BACKGROUND: Almost 25%of workers in the European Union suffer from back pain, and 23%complain of muscle pain. Sixty-two percent of workers carry out repetitive operations with their hands or arms, 46%work in painful or tired positions and 35%carry or handle loads. OBJECTIVE: This study aimed to translate, culturally adapt and validate the Italian version of the Cornell Musculoskeletal Discomfort Questionnaire (CMDQ-I). METHODS: Translation and cultural adaptation procedures followed international guidelines. Participants were recruited from among the personnel components of the Italian Air Force, who were between 18 and 65 years old. Cronbach’s alpha and the intraclass correlation coefficient (ICC) were calculated to assess internal consistency and stability, respectively. The CDMQ-I was administered together with the Visual Analogic Scale (VAS), and the validity was evaluated using Pearson’s correlation coefficient. RESULTS: All CDMQ-I items were either identical or similar in meaning to the original version’s items. The scale was administered twice with a retest after seven to 10 days to 66 participants. Cronbach’s alpha was higher than 0.761, and the ICC ranged between 0.737 and 0.952. Pearson’s correlation coefficient showed positive and significant correlations (p >  0.01). CONCLUSIONS: The study produced an Italian version of the CMDQ with good reliability and validity. This scale is a useful tool to investigate the frequency and intensity of musculoskeletal disorders in various categories of workers.

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 Do height and weight play an important role in block and attack efficiency in high-level men's volleyball?

2017 ◽  
Vol 26 (1) ◽  
pp. 64 ◽  
Author(s):  
Raini Stamm ◽  
Meelis Stamm ◽  
Aleksander Jairus ◽  
Reino Toop ◽  
Reeda Tuula ◽  
...  
Keyword(s):  
Correlation Analysis ◽  
Pearson’S Correlation ◽  
Anthropometric Characteristics ◽  
Pearson's Correlation ◽  
Pearson’S Correlation Analysis ◽  
Standard Deviations ◽  
High Level

The research objective was to study the relationships of players’ efficiency in attack and block with their anthropometric characteristics. Data on men’s weight and height and their proficiency in the game were used. The subjects were the members of the Estonian, Italian, French and Croatian national volleyball teams who participated in Pool B of the European Championship. Data are given on men’s height, weight, age, total number of spikes, attack errors, attacks won, efficiency of attack, total number of blocks, block errors, blocks won, and efficiency of block. In addition, the number of points won by men and their positions in the game are given. Minimums, maximums, standard deviations and means were calculated. To find correlations, Pearson’s correlation analysis (p<0.05) was used. In our study, taller and heavier players proved to be more efficient at attack. Comparison of positions showed that middle blockers were taller and performed more blocks, setters were shorter and performed the least of attacks, and outside attackers and opposite attackers were of medium height and carried the greatest load of attack. As a conclusion, it was found that, in professional volleyball, height correlated with the efficiency of attack (r= 0.534; p<0.05), and weight also correlated with the efficiency of attack (r= 0.518; p<0.05). There was no correlation between the anthropometric characteristics and block in volleyball at the professional level in our study. In volleyball, the greatest load at attack is carried by outside attackers and opposite attackers, while middle blockers have the greatest load at block. Setters perform the smallest number of attacks.

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