scholarly journals Intra-Oral 3D Scanning for the Digital Evaluation of Dental Arch Parameters

2018 ◽  
Vol 8 (10) ◽  
pp. 1838 ◽  
Author(s):  
Magdaléna Kašparová ◽  
Simona Halamová ◽  
Taťjana Dostálová ◽  
Aleš Procházka
Keyword(s):  
Three Dimensional ◽  
3D Models ◽  
Mean Value ◽  
Dental Arch ◽  
Three Dimensional Model ◽  
Digital Evaluation ◽  
Object Rotation ◽  
3D Printers ◽  
Examination Methods ◽  
The Mean

Intra-oral scanning technology has brought a completely new approach to examination methods in dentistry. In comparison to traditional plaster casts, it allows more precise digital analysis of dental arch components during the treatment of dental disorders. Data acquired can also be used for the creation of three-dimensional (3D) models using 3D printers. This paper describes a data acquisition system, the mathematical processing of resulting three-dimensional model, and the statistical analysis of selected parameters of the dental arch. The study aims at comparing the results achieved from 20 models of the same individual acquired by different specialists. The proposed methodology includes mathematical rotation of objects into the optimal plane defined by the teeth tops’ location to increase the accuracy of the resulting parameters. The mean evaluated distances between canines (3-3) and premolars (5-5) are 24.29 mm and 37.98 mm, respectively, for the lower dental arch. The proposed object rotation increased these distance by 0.9% and 1.4%, respectively, reducing the rotation error. Moreover, the variability of results decreased and the mean value of the coefficient of variation was lowered by 12%. Image registration was then used to evaluate changes of dental arch parameters. This paper presents the advantages of digital models for visualisation of the dental arch allowing its flexible rotation and evaluation of its parameters.

Integration of Safety Knowledge into Three-Dimensional Model Design and Construction Plan from the Perspective of Project Executors in Petrochemical Industry

2021 ◽  
Vol 11 (2) ◽  
pp. 185-192
Author(s):  
I-Jyh Wen ◽  
Chien Wei Liang
Keyword(s):  
Petrochemical Industry ◽  
Three Dimensional ◽  
3D Models ◽  
Model Design ◽  
Three Dimensional Model ◽  
3D Design ◽  
Safety And Health ◽  
Job Safety ◽  
Safety Knowledge ◽  
Design And Construction

In petrochemical industry, the execution of construction involves three main issues, namely, design planning, construction, and job safety. Three-dimensional (3D) models are increasingly applied to design and construction. However, the improper concept of 3D design has bred potential unsatisfactory behaviors and the lack of vigilance among workers. Besides, many employees are not fully aware of the safety in 3D design and construction planning. Therefore, our goal is to improve the safety and health of construction workers through design practices in the upstream of the construction phase, and verify the applicability of the combination of 3D models and safety knowledge. Specifically, a questionnaire survey was carried out among 124 employees in the construction-related fields of the petrochemical industry. The collected data were processed, and statically analyzed on SPSS. The results show that safety knowledge was acceptable in 3D model design from the perspective of project executors, and the integration of safety knowledge into the design helps to improve the safety environment of the construction site.

scholarly journals Creation of virtual 3D models of the existing architectonic structures using the web resources

Spatium ◽  
2016 ◽  
pp. 30-36 ◽  
Author(s):  
Petar Pejic ◽  
Sonja Krasic
Keyword(s):  
Laser Scanning ◽  
Three Dimensional ◽  
3D Models ◽  
Three Dimensional Model ◽  
Web Resources ◽  
Existing Structures ◽  
Software Packages ◽  
Physical Presence ◽  
The Creation ◽  
Three Dimensional Models

Digital three-dimensional models of the existing architectonic structures are created for the purpose of digitalization of the archive documents, presentation of buildings or an urban entity or for conducting various analyses and tests. Traditional methods for the creation of 3D models of the existing buildings assume manual measuring of their dimensions, using the photogrammetry method or laser scanning. Such approaches require considerable time spent in data acquisition or application of specific instruments and equipment. The goal of this paper is presentation of the procedure for the creation of 3D models of the existing structures using the globally available web resources and free software packages on standard PCs. This shortens the time of the production of a digital three-dimensional model of the structure considerably and excludes the physical presence at the location. In addition, precision of this method was tested and compared with the results acquired in a previous research.

scholarly journals Processing Three-Dimensional Models of Archaeological Artifacts

2021 ◽  
Vol 20 (7) ◽  
pp. 48-61
Author(s):  
Pavel V. Chistyakov ◽  
Ekaterina N. Bocharova ◽  
Ksenia A. Kolobova
Keyword(s):  
Three Dimensional ◽  
3D Models ◽  
International Standards ◽  
Post Processing ◽  
Three Dimensional Model ◽  
Scaled Model ◽  
Three Dimensional Modeling ◽  
Dimensional Modeling ◽  
Dimensional Models ◽  
Three Dimensional Models

This article provides a detailed account of the process of scanning, post-processing and further manipulation of three-dimensional models obtained with structured light scanners. Purpose. The purpose of the study is determined by the need for national archaeologists to learn the methods of three-dimensional modeling for the implementation of scientific research corresponding to international standards. Unfortunately, this direction in national archaeology began to develop in a relatively recent time and there is a lag in the application of three-dimensional modeling of national archaeology compared to the world level. Results. Any archaeological, experimental or ethnographic artifact can be used for three-dimensional scanning. To perform post-processing of three-dimensional models it is necessary to carry out primary scanning of an artifact by one of the existing algorithms. The algorithm for creating models, their positioning, simplification, saving in various formats and export is described. The main sequence of 3D models post-processing includes: processing of groups of scanned projections (their cleaning and alignment), creation of artifact model and processing/rectification of the resulting model using special software. Conclusion. As a result of correct implementation of the algorithm, the researcher receives a scaled model completely corresponding to the original artifact. Obtaining a scalable, texture-free three-dimensional model of the artifact, which fully corresponds to the original and exceeds a photograph in the quality of detail transfer, allows a scientist to conduct precise metric measurements and any procedures of non-invasive manipulation of the models. The ability to access a database of three-dimensional models of archaeological collections greatly simplifies the work of archaeologists, especially in situations when country borders are closed.

scholarly journals Methods building and printing 3D models historical architectural objects

2020 ◽  
Vol 75 ◽  
pp. 04016 ◽  
Author(s):  
Ihor Hevko ◽  
Olha Potapchuk ◽  
Iryna Lutsyk ◽  
Viktorya Yavorska ◽  
Viktoriia Tkachuk
Keyword(s):  
3D Printing ◽  
Complex Systems ◽  
Three Dimensional ◽  
3D Models ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Specialized Software ◽  
Bulk Data ◽  
Three Dimensional Models ◽  
Accuracy Speed

The authors present methods building and printing three-dimensional models for graphical reconstruction of historical architectural objects. Procedure sequence of the methods is exemplified through building the model of the Parochial Cathedral of St. Mary of the Perpetual Assistance of the 1950s. After analyzing and assessing the most popular specialized software means, the 3DS Max environment is chosen to build a three-dimensional model. Suggested software tools enable increased accuracy, speed and granularity of fixation of complex systems and expanded databases, providing efficient instruments to deal with bulk data and being relevant to new IT achievements. Sequence and content of operations for analytical and modeling cycles are substantiated. The cathedral model is built on the basis of archive photographs and drafts. The authors describe methods and the algorithm of procedures, principles of architectural and spacious modeling to recreate the architectural object. The three-dimensional model is built by applying a stereogram miniature of the destroyed Cathedral. Reconstruction of spacious configuration of the objects is based on parallax assessment of images. Stages of project implementation are determined. There are described methods of implementing modeling by 3DS Max tools and preparing the model for 3D printing in Cura.

INTRA-RATER AND INTER-RATER RELIABILITY STUDY OF A MEASUREMENT METHOD FOR THE PATHWAY OF THE SUPRASPINATUS INTRAMUSCULAR TENDON BY 3.0 TESLA MRI IMAGES: THE SHEAR FORCE ANGLE ANTERIOR POSTERIOR

2018 ◽  
Vol 21 (02) ◽  
pp. 1850009
Author(s):  
Yohei Kanno ◽  
Hajime Toda ◽  
Tsutomu Horiuchi ◽  
Masaki Katayose
Keyword(s):  
Shear Force ◽  
Measurement Method ◽  
Intraclass Correlation ◽  
Three Dimensional ◽  
3D Models ◽  
Minimal Detectable Change ◽  
3.0 Tesla ◽  
Rater Reliability ◽  
The Mean ◽  
Anterior Posterior

Objective: The aim of this study was to establish intra-rater and inter-rater reliability of a measurement method for the pathway of the supraspinatus intramuscular tendon by 3.0 tesla MRI images. Methods: The scapula and intramuscular tendon extraction DICOM data was made to extract only a scapula domain and intramuscular tendon domain. The shear force angle anterior posterior (SFA-AP) was measured as the pathway of supraspinatus intramuscular tendon with respect to the glenoid plane on three-dimensional (3D) models of the bone and intramuscular tendon. SFA-AP of supraspinatus was measured on 3D models of the bone and intramuscular tendon. The mean and standard deviation of SFA-AP of supraspinatus was calculated. Intra-rater reliability and inter-rater reliability were evaluated by the intraclass correlation coefficient (ICC), the standard error of the mean (SEM) and the minimal detectable change (MDC). Inter-rater reliability was evaluated by three raters. Results: As for intra-rater reliability, SFA-AP of supraspinatus measured averaged [Formula: see text], with ICC (1,1) of 0.978, with ICC (1,3) of 0.993, with SEM of 0.53, with MDC of 1.46[Formula: see text]. As for inter-rater reliability, SFA-AP of supraspinatus measured averaged [Formula: see text] (rater1), SFA-AP measured averaged [Formula: see text] (rater2), SFA-AP measured averaged [Formula: see text] (rater3), with ICC (2,1) of 0.896, with ICC (2,3) of 0.963, with SEM of 1.11, with MDC of 3.09[Formula: see text]. Conclusions: 3D models of the bone and intramuscular tendon were evaluated as intra-rater and inter-rater reliabilities. SFA-AP of supraspinatus is guaranteed by one measurement.

Sand bars in tidal channels. Part 1. Free bars

2001 ◽  
Vol 440 ◽  
pp. 49-74 ◽  
Author(s):  
G. SEMINARA ◽  
M. TUBINO
Keyword(s):  
Three Dimensional ◽  
Basic Mechanism ◽  
Critical Value ◽  
Suspended Load ◽  
Tidal Channels ◽  
Three Dimensional Model ◽  
Mean Values ◽  
Depth Ratio ◽  
Mean Width ◽  
The Mean

We investigate the basic mechanism whereby bars form in tidal channels or estuaries. The channel is assumed to be long enough to allow neglect of the effects of end conditions on the process of bar formation. In this respect, the object of the present analysis differs from that of Schuttelaars & de Swart (1999) who considered bars of length scaling with the finite length of the tidal channel. The channel bottom is assumed to be cohesionless and consisting of uniform sediments. Bars are shown to arise from a mechanism of instability of the erodible bed subject to the propagation of a tidal wave. Sediment is assumed to be transported both as bedload and as suspended load. A fully three-dimensional model is employed both for the hydrodynamics and for sediment transport. At the leading order of approximation considered, the effects of channel convergence, local inertia and Coriolis forces on bar instability are shown to be negligible. Unlike fluvial free bars, in the absence of mean currents tidal free bars are found to be non-migrating features (in the mean). Instability arises for large enough values of the mean width to depth ratio of the channel, for given mean values of the Shields parameter and of the relative channel roughness. The role of suspended load is such as to stabilize bars in the large-wavenumber range and destabilize them for small wavenumbers. Hence, for large values of the mean Shields stress, it turns out that the first critical mode (the alternate bar mode) is characterized by a very small value of the critical width to depth ratio. Furthermore, the order-m mode being characterized by a critical value of the width to depth ratio equal to m times the critical value for the first mode, it follows that for large values of the mean Shields stress several unstable modes are simultaneously excited for relatively low values of the aspect ratio. This suggests that the actual bar pattern observed in nature may arise from an interesting nonlinear competition among different unstable modes.

‘Mean Contrast’ Texture Feature Model of Nature Environmental Protection Fabric

2010 ◽  
Vol 113-116 ◽  
pp. 943-946
Author(s):  
Zhe Liu
Keyword(s):  
Three Dimensional ◽  
Texture Feature ◽  
Feature Model ◽  
Quality Inspection ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Numerical Convergence ◽  
Texture Characteristics ◽  
The Mean ◽  
Contrast Feature

Aiming at lack of mature texture feature model of natural green fabric image, this paper presents a new “Mean Contrast” texture feature model, which can express better on the type of collecting and narrow-long and some irregular defects. First, three-dimensional model of texture characteristics is established, various natural green fabrics are tested in experiments using the contrast feature, and then “Mean Contrast” feature is proposed, so that characteristic value of fabric texture can be converged. Finally, experimental results show that the “mean contrast” feature is so simple and effective that better show a variety of fabric texture variation, and has the numerical convergence. So it provides a contrasting texture feature model for continue related to fabric quality inspection.

scholarly journals On the zeroth law of turbulence for the stochastically forced Navier-Stokes equations

2021 ◽  
Vol 0 (0) ◽  
pp. 0
Author(s):  
Yat Tin Chow ◽  
Ali Pakzad
Keyword(s):  
Stokes Equations ◽  
Three Dimensional ◽  
Energy Dissipation Rate ◽  
Mean Value ◽  
Navier Stokes ◽  
Navier Stokes Equations ◽  
Additional Hypothesis ◽  
The Mean ◽  
Deterministic Force ◽  
Martingale Solutions

<p style='text-indent:20px;'>We consider the three-dimensional stochastically forced Navier–Stokes equations subjected to white-in-time (colored-in-space) forcing in the absence of boundaries. Upper bounds of the mean value of the time-averaged energy dissipation rate are derived directly from the equations for weak (martingale) solutions. This estimate is consistent with the Kolmogorov dissipation law. Moreover, an additional hypothesis of energy balance implies the zeroth law of turbulence in the absence of a deterministic force.</p>

scholarly journals Wits Appraisal of a Qatari Male Population: A Comparative Study. Part II

2020 ◽  
Vol 2 (6) ◽  
Author(s):  
Hayder A. Hashim ◽  
Najat Al-Sayed ◽  
Ayah AL-Qaisi
Keyword(s):  
Three Dimensional ◽  
Mean Value ◽  
Cone Beam ◽  
Facial Appearance ◽  
Male Population ◽  
Significant Difference ◽  
The Mean ◽  
Age Range ◽  
Relationship Of ◽  
Gender Specific

Introduction: Cephalometric analysis aims to determine skeletal and dental relationships. The ANB angle, initially suggested by Rediel and applied by Steiner. is the most used angle in establishing the anteroposterior relationship of the mandible to the maxilla. However, limitations to the accuracy of the ANB angle for this purpose have been reported. To avoid these potential sources of inaccuracy a diagnostic tool was introduced by Jenkins and later modified by Jacobson and became known as the “Wits appraisal”. Aims: The aim of this study was to establish the Wits appraisal value in a sample of Qatari males, a group which had not previously been studied in this context, and to compare the findings with those from racially and ethnically differing groups as reported in the literature. Materials and Methods: The sample consisted of 28 lateral cephalometric radiographs of Qatari males with an age range of 15 to 32 years, presenting with a well-balanced facial appearance and an acceptable profile. Results: The mean value of the Wits appraisal for Qatari males in the present study was 0.50 ± 2.96. This differed at a statistically significant level from the mean value in the Jacobson study with no gender significant difference noted. On the other hand, significant differences were found when compared with previous reports on different races. Conclusion: The Wits appraisal value for the Qatari male population studied was 0.5±2.96, a result which is significantly higher than that reported in Jacobson’s study. This study revealed that the Wits appraisal is not ethnicity or gender-specific, and therefore cannot be used to differentiate between different ethnic groups. However, it can find application as an alternative to the ANB angle in the treatment of borderline cases. The application of cone beam computed tomography (CBCT) will enhance the diagnosis and treatment of cases by yielding three-dimensional views.

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