scholarly journals Comparison of Accuracy of Current Ten Intraoral Scanners

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Pokpong Amornvit ◽  
Dinesh Rokaya ◽  
Sasiwimol Sanohkan
Keyword(s):  
High Resolution ◽  
Measurement Data ◽  
Reference Points ◽  
San Jose ◽  
Control Precision ◽  
Dental Model ◽  
Kolmogorov Smirnov ◽  
Scan Pattern ◽  
Stereolithography Files ◽  
Smirnov Test

There have been various developments in intraoral 3D scanning technology. This study is aimed at investigating the accuracy of 10 scanners developed from 2015 to 2020. A maxillary dental model with reference points was printed from Form 2 (FormLabs, Somerville, MA, USA). The model was scanned 5 times with each intraoral scanner (IOS); Trios 3 (normal and high-resolution mode); Trios 4 (normal and high-resolution mode) (3Shape Trios A/S, Copenhagen, Denmark); iTero Element, iTero 2, and iTero 5D Element (Align Technologies, San Jose, California, USA); Dental Wings (Dental Wings, Montreal QC, Canada); Panda 2 (Pengtum Technologies, Shanghai, China); Medit i500 (Medit Corp. Seoul, South Korea); Planmeca Emerald™ (Planmeca, Helsinki, Finland); and Aoralscan (Shining 3D Tech. Co., Ltd., Hangzhou, China). After the scan, the 3D scanned stereolithography files were created. The various distances were measured five times in X , Y , Z , and X Y axes of various scans and with a vernier caliper (control) and from the Rhinoceros software. The data were analyzed using SPSS 18. Test for the normality of the various measurement data were done using Kolmogorov-Smirnov test. The trueness and precision of the measurements were compared among the various scans using the Kruskal-Wallis test. The significance was considered at P < 0.05 . The trueness of the intraoral scans was analyzed by comparing the measurements from the control. Precision was tested through the measurements of repeated scans. It showed that more the distance is less the accuracy for all scanners. In all studied scanners, the trueness varied but precision was favorably similar. Diagonal scanning showed less accuracy for all the scanners. Hence, when scanning the full arch, the dentist needs to take more caution and good scan pattern. Trios series showed the best scan results compared to other scanners.

scholarly journals An assessment of the climatological representativeness of IAGOS-CARIBIC trace gas measurements using EMAC model simulations

2017 ◽  
Vol 17 (4) ◽  
pp. 2775-2794 ◽  
Author(s):  
Johannes Eckstein ◽  
Roland Ruhnke ◽  
Andreas Zahn ◽  
Marco Neumaier ◽  
Ole Kirner ◽  
...  
Keyword(s):  
Climate Model ◽  
Trace Gases ◽  
Measurement Data ◽  
Final Analysis ◽  
Trace Gas ◽  
Measurement Variability ◽  
Statistical Measures ◽  
Kolmogorov Smirnov ◽  
Relative Differences ◽  
Smirnov Test

Abstract. Measurement data from the long-term passenger aircraft project IAGOS-CARIBIC are often used to derive climatologies of trace gases in the upper troposphere and lower stratosphere (UTLS). We investigate to what extent such climatologies are representative of the true state of the atmosphere. Climatologies are considered relative to the tropopause in mid-latitudes (35 to 75° N) for trace gases with different atmospheric lifetimes. Using the chemistry–climate model EMAC, we sample the modeled trace gases along CARIBIC flight tracks. Representativeness is then assessed by comparing the CARIBIC sampled model data to the full climatological model state. Three statistical methods are applied for the investigation of representativeness: the Kolmogorov–Smirnov test and two scores based on the variability and relative differences. Two requirements for any score describing representativeness are essential: representativeness is expected to increase (i) with the number of samples and (ii) with decreasing variability of the species considered. Based on these two requirements, we investigate the suitability of the different statistical measures for investigating representativeness. The Kolmogorov–Smirnov test is very strict and does not identify any trace-gas climatology as representative – not even of long-lived trace gases. In contrast, the two scores based on either variability or relative differences show the expected behavior and thus appear applicable for investigating representativeness. For the final analysis of climatological representativeness, we use the relative difference score and calculate a representativeness uncertainty for each trace gas in percent. In order to justify the transfer of conclusions about representativeness of individual trace gases from the model to measurements, we compare the trace gas variability between model and measurements. We find that the model reaches 50–100 % of the measurement variability. The tendency of the model to underestimate the variability is caused by the relatively coarse spatial and temporal model resolution. In conclusion, we provide representativeness uncertainties for several species for tropopause-referenced climatologies. Long-lived species like CO2 have low uncertainties ( ≤ 0.4 %), while shorter-lived species like O3 have larger uncertainties (10–15 %). Finally, we translate the representativeness score into a number of flights that are necessary to achieve a certain degree of representativeness. For example, increasing the number of flights from 334 to 1000 would reduce the uncertainty in CO to a mere 1 %, while the uncertainty for shorter-lived species like NO would drop from 80 to 10 %.

scholarly journals An assessment of the climatological representativeness of IAGOS-CARIBIC trace gas measurements using EMAC model simulations

2016 ◽  
Author(s):  
Johannes Eckstein ◽  
Roland Ruhnke ◽  
Andreas Zahn ◽  
Marco Neumaier ◽  
Ole Kirner ◽  
...  
Keyword(s):  
Climate Model ◽  
Trace Gases ◽  
Measurement Data ◽  
Trace Gas ◽  
Statistical Measures ◽  
Kolmogorov Smirnov ◽  
Gas Measurements ◽  
Passenger Aircraft ◽  
Relative Differences ◽  
Smirnov Test

Abstract. Measurement data from the long-term passenger aircraft project IAGOS-CARIBIC is often used to derive trace gas climatologies. We investigate to what extent such derived climatologies can be assumed to be representative for the true state of the atmosphere. Using the chemistry-climate model EMAC we sample the modelled trace gases along CARIBIC flight tracks. Different trace gases are considered and climatologies relative to the mid-latitude tropopause are calculated. Representativeness can now be assessed by comparing the CARIBIC sampled model data to the true climatological model state. Three statistical methods are applied for this purpose: the Kolomogorov-Smirnov test, and scores based on the variability and relative differences. Generally, representativeness is expected to decrease with increasing variability and to increase with the number of available samples. Based on this assumption, we investigate the suitability of the different statistical measures for our problem. The Kolmogorov-Smirnov test seems too strict and does not identify any climatology as representative – not even long lived well observed trace gases. In contrast, the variability based scores pass the general requirements for representativeness formulated above. In addition, even the simplest metric (relative differences) seems applicable for investigating representativeness. Using the relative differences score we investigate the representativeness of a large number of different trace gases. For our final consideration we assume that the EMAC model is a reasonable representation of the real world and that representativeness in the model world can be translated to representativeness for CARIBIC measurements. This assumption is justified by comparing the model variability to the variability of CARIBIC measurements. Finally, we show how the representativeness score can be translated into a number of flights necessary to achieve a certain degree of representativeness.

scholarly journals Data-Driven Intelligent 3D Surface Measurement in Smart Manufacturing: Review and Outlook

Machines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 13
Author(s):  
Yuhang Yang ◽  
Zhiqiao Dong ◽  
Yuquan Meng ◽  
Chenhui Shao
Keyword(s):  
High Resolution ◽  
High Performance ◽  
Sampling Design ◽  
Three Dimensional ◽  
Measurement Data ◽  
Data Driven ◽  
Surface Measurement ◽  
Smart Manufacturing ◽  
Future Research ◽  
3D Surface

High-fidelity characterization and effective monitoring of spatial and spatiotemporal processes are crucial for high-performance quality control of many manufacturing processes and systems in the era of smart manufacturing. Although the recent development in measurement technologies has made it possible to acquire high-resolution three-dimensional (3D) surface measurement data, it is generally expensive and time-consuming to use such technologies in real-world production settings. Data-driven approaches that stem from statistics and machine learning can potentially enable intelligent, cost-effective surface measurement and thus allow manufacturers to use high-resolution surface data for better decision-making without introducing substantial production cost induced by data acquisition. Among these methods, spatial and spatiotemporal interpolation techniques can draw inferences about unmeasured locations on a surface using the measurement of other locations, thus decreasing the measurement cost and time. However, interpolation methods are very sensitive to the availability of measurement data, and their performances largely depend on the measurement scheme or the sampling design, i.e., how to allocate measurement efforts. As such, sampling design is considered to be another important field that enables intelligent surface measurement. This paper reviews and summarizes the state-of-the-art research in interpolation and sampling design for surface measurement in varied manufacturing applications. Research gaps and future research directions are also identified and can serve as a fundamental guideline to industrial practitioners and researchers for future studies in these areas.

Age dependency of the diabetes effects on the iris recognition systems performance evaluation results

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Mohammadreza Azimi ◽  
Seyed Ahmad Rasoulinejad ◽  
Andrzej Pacut
Keyword(s):  
Iris Recognition ◽  
Recognition Task ◽  
Aging Effect ◽  
Recognition System ◽  
Health Condition ◽  
Age Dependency ◽  
Biometric Systems ◽  
Kolmogorov Smirnov ◽  
Recognition Systems ◽  
Smirnov Test

AbstractIn this paper, we attempt to answer the questions whether iris recognition task under the influence of diabetes would be more difficult and whether the effects of diabetes and individuals’ age are uncorrelated. We hypothesized that the health condition of volunteers plays an important role in the performance of the iris recognition system. To confirm the obtained results, we reported the distribution of usable area in each subgroup to have a more comprehensive analysis of diabetes effects. There is no conducted study to investigate for which age group (young or old) the diabetes effect is more acute on the biometric results. For this purpose, we created a new database containing 1,906 samples from 509 eyes. We applied the weighted adaptive Hough ellipsopolar transform technique and contrast-adjusted Hough transform for segmentation of iris texture, along with three different encoding algorithms. To test the hypothesis related to physiological aging effect, Welches’s t-test and Kolmogorov–Smirnov test have been used to study the age-dependency of diabetes mellitus influence on the reliability of our chosen iris recognition system. Our results give some general hints related to age effect on performance of biometric systems for people with diabetes.

Multifractal characterization of mechanical vibration signals through improved empirical mode decomposition-based detrended fluctuation analysis

2016 ◽  
Vol 231 (22) ◽  
pp. 4139-4149 ◽  
Author(s):  
Du Wenliao ◽  
Guo Zhiqiang ◽  
Gong Xiaoyun ◽  
Xie Guizhong ◽  
Wang Liangwen ◽  
...  
Keyword(s):  
Empirical Mode Decomposition ◽  
Detrended Fluctuation Analysis ◽  
Fluctuation Analysis ◽  
Intrinsic Mode Functions ◽  
Vibration Signals ◽  
Multifractal Detrended Fluctuation Analysis ◽  
Mode Decomposition ◽  
Kolmogorov Smirnov ◽  
Detrended Fluctuation ◽  
Smirnov Test

A novel multifractal detrended fluctuation analysis based on improved empirical mode decomposition for the non-linear and non-stationary vibration signal of machinery is proposed. As the intrinsic mode functions selection and Kolmogorov–Smirnov test are utilized in the detrending procedure, the present approach is quite available for contaminated data sets. The intrinsic mode functions selection is employed to deal with the undesired intrinsic mode functions named pseudocomponents, and the two-sample Kolmogorov–Smirnov test works on each intrinsic mode function and Gaussian noise to detect the noise-like intrinsic mode functions. The proposed method is adaptive to the signal and weakens the effect of noise, which makes this approach work well for vibration signals collected from poor working conditions. We assess the performance of the proposed procedure through the classic multiplicative cascading process. For the pure simulation signal, our results agree with the theoretical results, and for the contaminated time series, the proposed method outperforms the traditional multifractal detrended fluctuation analysis methods. In addition, we analyze the vibration signals of rolling bearing with different fault types, and the presence of multifractality is confirmed.

scholarly journals Relationship between oral habits and spirometry maneuvers, in children

Revista CEFAC ◽  
2018 ◽  
Vol 20 (1) ◽  
pp. 37-43
Author(s):  
Rafaela Coelho Minsky ◽  
Tayná Castilho ◽  
Roseane Rebelo Silva Meira ◽  
Tatiana Godoy Bobbio ◽  
Camila Isabel Santos Schivinski
Keyword(s):  
Healthy Children ◽  
Chi Square ◽  
Cross Sectional ◽  
Public And Private ◽  
Oral Habits ◽  
Qualitative Variables ◽  
Chi Square Test ◽  
Kolmogorov Smirnov ◽  
Thumb Sucking ◽  
Smirnov Test

ABSTRACT Purpose: to analyze whether deleterious oral habits can influence the number of attempts of forced spirometry maneuvers performed by healthy children. Methods: this observational and cross-sectional analytical study included 149 healthy children aged 6-12 years attending public and private schools in Florianópolis, SC, Brazil. A validated protocol was applied for the analysis of deleterious oral habits. The children were grouped according to the number of spirometry maneuvers needed to achieve successful spirometry results, as follows: G1) children who needed 3 maneuvers; G2) 4 maneuvers; G3) 5-8 maneuvers. Data were analyzed with the Kolmogorov-Smirnov test and the Kruskal-Wallis test was applied to compare quantitative variables between the groups. The Chi-square test was used to assess the association between the groups and qualitative variables. Results: there was no association between the number of attempts and the qualitative variables evaluated by the protocol. There was also no difference between the groups regarding quantitative variables for breastfeeding time, breastfeeding occurrence, use of pacifiers, and thumb sucking. Conclusion: the presence of DOH did not influence the number of forced spirometry maneuvers, performed by the healthy children in this study.

Investigation of The Nutritional Approaches of Student Athletes During The Covid-19 Epidemic

2021 ◽  
Vol 15 (7) ◽  
pp. 1940-1944
Author(s):  
Sevcan Altun ◽  
Aykut Aksu ◽  
Osman Imamoglu ◽  
Murat Erdogdu ◽  
Kursat Karacabey
Keyword(s):  
Student Athletes ◽  
Eating Habits ◽  
T Test ◽  
Outbreak Period ◽  
Significant Difference ◽  
Package Program ◽  
Kolmogorov Smirnov ◽  
The Subject ◽  
The University ◽  
Smirnov Test

The aim of this study is to investigate the nutritional approaches of student athletes studying at the university during the coronavirus outbreak period. Participants consisted of students studying and doing sports at the University. 446 students, 246 males and 200 females, participated in the study. Besides the personal form, students were filled the questionnaire testing questionnaire. Students voluntarily participated. The surveys were done on social media. Nutritional habits questionnaire consists of 12 questions. In the preparation of the survey questions, the questions proved validity of the researches which have been done on the subject before have been used. SPSS 23.00 package program was used in statistical analyses. Kolmogorov-Smirnov test was performed to test whether the data was normally distributed and it was determined that the data showed normal distribution. Independent t-test, paired t-test, unidirectional variance analysis and LSD tests were used in statistical operations. There was no significant difference in students' nutrition approaches by gender, both in the pre-outbreak period and in the outbreak period points (p> 0.05). Nutrition scores were significantly increased during the outbreak period (p <0.001). A significant difference was found between the students who felt bad before the epidemic and those who felt well before the epidemic and their nutritional scores according to the levels they felt (p <0.05). A significant difference was found between the pre-outbreak period and post-epidemic nutrition scores of the sports faculty students (p <0.05). During the coronavirus epidemic, university student athletes have either increased their nutritional opportunities or have changed their eating habits positively to keep their immune systems strong or both. The fact that sports faculty students have better nutrition compared to other faculty students can be attributed to their taking courses in nutrition, health and similar. It is recommended to give lectures or seminars on nutrition to athlete students. Keywords: Student, Nutrition, Sports Nutrition, Nutritional Approach, Covid-19

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