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Komissarov, A. V., A. V. Remizov, M. M. Shlyakhova et K. K. Yambaev. « Handheld Laser Scanner Research ». Geodesy and Cartography 952, no 10 (20 novembre 2019) : 47–54. http://dx.doi.org/10.22389/0016-7126-2019-952-10-47-54.
Texte intégralRésumé :
The authors consider hand-held laser scanners, as a new photogrammetric tool for obtaining three-dimensional models of objects. The principle of their work and the newest optical systems based on various sensors measuring the depth of space are described in detail. The method of simultaneous navigation and mapping (SLAM) used for combining single scans into point cloud is outlined. The formulated tasks and methods for performing studies of the DotProduct (USA) hand-held laser scanner DPI?8X based on a test site survey are presented. The accuracy requirements for determining the coordinates of polygon points are given. The essence of the performed experimental research of the DPI?8X scanner is described, including scanning of a test object at various scanner distances, shooting a test polygon from various scanner positions and building point cloud, repeatedly shooting the same area of the polygon to check the stability of the scanner. The data on the assessment of accuracy and analysis of research results are given. Fields of applying hand-held laser scanners, their advantages and disadvantages are identified.
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Majstorović, Nemanja, Luka Čerče, Davorin Kramar, Mirko Soković, Branislav Glišić, Vidosav Majstorović et Srđan Živković. « Examination of Scanner Precision by Analysing Orthodontic Parameters ». Balkan Journal of Dental Medicine 21, no 1 (1 mars 2017) : 32–43. http://dx.doi.org/10.1515/bjdm-2017-0005.
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Summary Background: 3D modelling in orthodontics is becoming an increasingly widespread technique in practice. One of the significant questions already being asked is related to determining the precision of the scanner used for generating surfaces on a 3D model of the jaw. Materials and methods: This research was conducted by generating a set of identical 3D models on Atos optical 3D scanner and Lazak Scan laboratory scanner, which precision was established by measuring a set of orthodontic parameters (54 overall) in all three orthodontic planes. In this manner we explored their precision in space, since they are used for generating spatial models – 3D jaws. Results: There were significant differences between parameters scanned with Atos and Lazak Scan. The smallest difference was 0.017 mm, and the biggest 1.109 mm. Conclusion: This research reveals that both scanners (Atos and Lazak Scan), which belong to general purpose scanners, based on precision parameters can be used in orthodontics. Early analyses indicate that the reference scanner in terms of precision is Atos.
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Trojnacki, Maciej, Przemysław Dąbek et Piotr Jaroszek. « Analysis of the Influence of the Geometrical Parameters of the Body Scanner on the Accuracy of Reconstruction of the Human Figure Using the Photogrammetry Technique ». Sensors 22, no 23 (25 novembre 2022) : 9181. http://dx.doi.org/10.3390/s22239181.
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This article concerns the research of the HUBO full-body scanner, which includes the analysis and selection of the scanner’s geometrical parameters in order to obtain the highest possible accuracy of the reconstruction of a human figure. In the scanner version analyzed in this paper, smartphone cameras are used as sensors. In order to process the collected photos into a 3D model, the photogrammetry technique is applied. As part of the work, dependencies between the geometrical parameters of the scanner are derived, which allows to significantly reduce the number of degrees of freedom in the selection of its geometrical parameters. Based on these dependencies, a numerical analysis is carried out, as a result of which the initial values of the geometrical parameters are pre-selected and distribution of scanner cameras is visualized. As part of the experimental research, the influence of selected scanner parameters on the scanning accuracy is analyzed. For the experimental research, a specially prepared dummy was used instead of the participation of a real human, which allowed to ensure the constancy of the scanned object. The accuracy of the object reconstruction was assessed in relation to the reference 3D model obtained with a scanner of superior measurement uncertainty. On the basis of the conducted research, a method for the selection of the scanner’s geometrical parameters was finally verified, leading to the arrangement of cameras around a human, which guarantees high accuracy of the reconstruction. Additionally, to quantify the results, the quality rates were used, taking into account not only the obtained measurement uncertainty of the scanner, but also the processing time and the resulting efficiency.
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Jafri, Syed Riaz un Nabi, Sheraz Shamim, Sadia Muniza Faraz, Asif Ahmed, Syed Muhammad Yasir et Jamshed Iqbal. « Characterization and calibration of multiple 2D laser scanners ». PLOS ONE 17, no 7 (28 juillet 2022) : e0272063. http://dx.doi.org/10.1371/journal.pone.0272063.
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This paper presents the comparative evaluation of multiple compact and lightweight 2D laser scanners for their possible backpack based scanning and mapping applications. These scanners include Hokuyo URG-04LX, Slamtec RPLidar A1-M8 and Hokuyo UTM-30LX-EW scanners. Since the technical datasheets provide general information and limited working details, this research presents a thorough study on the performance of each scanner related explicitly to indoor mapping operations. A series of scanning experiments have been performed for the characterization of each scanner using statistical analysis. During the testing, all the scanning data has been recorded using Robot Operating System (ROS) and then computed in offline processing. In initial tests, each scanner’s drift effect on range measurements has been tested and presented in the relevant section of the paper. In continuation, the effect of various scanning distances on measurement accuracy has been evaluated and discussed. Later the impact of various materials typically found in indoor vicinities and their respective properties of color and smoothness have been tested and provided in the paper. Finally, a Kalman Filtering based mathematical formulation has been utilized to calibrate each scanner and to reduce the measuring uncertainties as observed in various tests for each scanner.
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Shelburne, Edward. « Producing High-Quality 3-D Models for Specimen Research with the Creaform 3-D Scanner at the Sternberg Museum of Natural History ». Biodiversity Information Science and Standards 2 (15 juin 2018) : e25908. http://dx.doi.org/10.3897/biss.2.25908.
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Digitization of natural history collections for specimen accessibility, research, and posterity has been a major push in museums over the past decade. One increasingly common form of specimen digitization is three-dimensional (3-D) surface scanning. There are numerous 3-D scanners on the market, including visible light and laser surface scanners. However, mobility of the scanning device, mesh resolution, and texture fidelity are among the most prominent issues facing regular implementation of 3-D scanning procedures for research purposes. Morphometrics research involving the digitization of Xiphactinus at the Sternberg Museum of Natural History (FHSM) using a Creaform Go!SCAN 50 visible light 3-D surface scanner has necessitated the development of a workflow using this 3-D scanner and the associated VXelements software. This workflow maximizes model quality with minimal loss of speed or efficiency when scanning numerous specimens. Major components of this workflow include proper use of positioning targets, appropriate merging of multiple specimen scans, and how to perform post-processing on models without sacrificing model resolution or texture. The primary benefit of the Creaform 3-D scanner is hardware mobility, allowing for use on large exhibited specimens or digitizing specimens during research trips. Shortcomings include relatively low mesh resolution, (bottoming out at 0.5 mm), difficulty scanning highly complex structures, and low texture fidelity of scanned models. However, texture fidelity can be improved through use of the free software, Meshlab, by overlaying high-quality stacked photographs onto the 3-D mesh. Incorporating Meshlab texture overlays into the workflow allows for the production of digital models with improved color and textural data – ideal for accurate visualization of specimens in 3-D viewers for educational outreach and online databases. While not perfect for all applications, the Creaform 3-D scanner allows for rapid digitization of specimens in an increasingly digital collections environment, and is sufficient for some research applications. The workflow established at the FHSM can serve as a framework for other institutions to use the Creaform 3-D scanner to best suit their digitization needs.
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Bucuresteanu, Anca, Dan Prodan et Adrian Motomancea. « Execution of Plastic Parts Using 3D Scanners and 3D Printers ». Materiale Plastice 55, no 2 (30 juin 2018) : 215–18. http://dx.doi.org/10.37358/mp.18.2.4998.
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In this paper, the authors show a part of research works performed on the use of 3D scanners and 3D printers to execute plastic parts with complex surfaces. 3D scanning allows copying of certain surfaces in our environment, based on existing models. Scanned models may represent various objects, made of a wide range of materials: metals, ceramics, fabrics, plastics, leather, organic materials etc. [1]. This paper shows the results achieved using a scanner and a common and affordable - low-price - printer. 3D scanners and printers allow execution of clones of certain parts with irregular surfaces.
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Hedges, Emily, Jenny Zinser, Mihail Dimitrov, Mathilde Antoniades, Lilla Porffy, Sara Pisani, Hannah Dickson, Philip McGuire et Matthew J. Kempton. « M154. INTRA- AND INTER-SCANNER RELIABILITY OF GRAY MATTER VOLUME AND CORTICAL THICKNESS ESTIMATES : IMPLICATIONS FOR MULTICENTRE IMAGING STUDIES IN PSYCHOSIS ». Schizophrenia Bulletin 46, Supplement_1 (avril 2020) : S194. http://dx.doi.org/10.1093/schbul/sbaa030.466.
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Abstract Background High-resolution structural MRI has been widely used in clinical research to detect and quantify subtle brain changes in patient populations. Findings from prospective, longitudinal studies show structural brain abnormalities as well as progressive gray matter changes over time in individuals at clinical high risk for psychosis compared to healthy subjects. In recent years, research in this field has seen an increase in multicentre neuroimaging projects, such as EU-GEI, PSYSCAN, PRONIA and NAPLS. Additional sources of variance, alongside known technological and biological factors, may be introduced when MRI images are acquired and combined from different sites. It is imperative for longitudinal multicentre studies to determine the accuracy of quantitative MRI measurements and account for systematic differences both between scanners and across scanning sessions. This is particularly true within psychosis research where morphometric changes as small as 3% or less are expected. Methods Six healthy participants were scanned on four separate occasions over a two-month period at King’s College London; twice on a GE SIGNA HDx 3T scanner used locally in the EU-GEI High Risk Study and twice on a GE MR750 3T scanner used locally in the PSYSCAN study. Both scanners implemented the ADNI-2 T1 protocol which is used globally across the EU-GEI and PSYSCAN consortia. Structural imaging data was segmented using the FreeSurfer 6.0 longitudinal pipeline. Intraclass correlation coefficients (ICCs) with a two-way mixed effects model of absolute agreement were calculated to assess intra- and inter-scanner reliability of brain morphometry. For volumetric studies, ICC values greater than 0.9 indicate ‘excellent’ reliability. Reliability analyses of key regions implicated in psychosis included gray matter volume estimates of the hippocampus, insula, lateral ventricle, orbitofrontal cortex and anterior cingulate cortex, and average cortical thickness measurements of the whole brain, parahippocampus and superior frontal cortex. Results Gray matter volume estimates of all structures yielded ‘excellent’ reliability for both intra-scanner (ICCs of 0.979 – 0.998) and inter-scanner analyses (ICCs of 0.976 – 0.999). Intra-scanner reliability for mean cortical thickness measurements was ‘excellent’ for right total cortex, resulting in an ICC of 0.901, but otherwise ‘good’ for left and total cortex, parahippocampus, superior frontal cortex (ICCs of 0.754 – 0.875). Inter-scanner reliability for mean cortical thickness estimates were most variable across the brain structures. Here, results demonstrated ‘excellent’ reliability for the parahippocampus and left total cortex (ICCs of 0.907 – 0.965), ‘good’ for total cortex (ICC of 0.835), ‘moderate’ for right total cortex, right and total superior frontal cortex (ICCs of 0.520 – 0.676), and ‘poor’ for the left superior frontal cortex which produced an ICC of 0.470. Overall, mean cortical thickness estimates of the superior frontal cortex from two different MR scanners showed the least reliability. Discussion Results confirmed highly reliable estimates for gray matter volumes in all brain structures, both from images acquired within the same scanner and across two different scanners. However, the findings indicated increased variability of mean cortical thickness estimates, particularly between scanners, which should be considered when interpreting study findings. Multicentre structural neuroimaging within the field of psychosis is becoming more common and it must be acknowledged that combining MRI data in multicentre studies will contribute additional sources of variance and potential bias with certain brain regions affected more than others.
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Li, Xin Wu. « Research on Color Control for Color Scanner ». Advanced Materials Research 121-122 (juin 2010) : 797–800. http://dx.doi.org/10.4028/www.scientific.net/amr.121-122.797.
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Color control for color Scanner is a key and difficult technique in Computer color image reproduction. After analyzing rendering principle of color scanner a new color control model based on subsectional fitting is preseed. First, The paper analyzes the color error source of scanner in theory; Then standard color target is taken for experimental sample to substitute color blocks in color shade district for complete color space to solve the difficulties of experimental color blocks selecting; Third the model for correcting color error is deduced; Finally the experimental results show that the model can improve scanner color control accuracy and can be used in scanner color control practically.
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Kedzierski, M., D. Wierzbickia, A. Fryskowska et B. Chlebowska. « ANALYSIS OF THE POSSIBILITIES OF USING LOW-COST SCANNING SYSTEM IN 3D MODELING ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B3 (9 juin 2016) : 261–67. http://dx.doi.org/10.5194/isprs-archives-xli-b3-261-2016.
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The laser scanning technique is still a very popular and fast growing method of obtaining information on modeling 3D objects. The use of low-cost miniature scanners creates new opportunities for small objects of 3D modeling based on point clouds acquired from the scan. The same, the development of accuracy and methods of automatic processing of this data type is noticeable. The article presents methods of collecting raw datasets in the form of a point-cloud using a low-cost ground-based laser scanner FabScan. As part of the research work 3D scanner from an open source FabLab project was constructed. In addition, the results for the analysis of the geometry of the point clouds obtained by using a low-cost laser scanner were presented. Also, some analysis of collecting data of different structures (made of various materials such as: glass, wood, paper, gum, plastic, plaster, ceramics, stoneware clay etc. and of different shapes: oval and similar to oval and prism shaped) have been done. The article presents two methods used for analysis: the first one - visual (general comparison between the 3D model and the real object) and the second one - comparative method (comparison between measurements on models and scanned objects using the mean error of a single sample of observations). The analysis showed, that the low-budget ground-based laser scanner FabScan has difficulties with collecting data of non-oval objects. Items built of glass painted black also caused problems for the scanner. In addition, the more details scanned object contains, the lower the accuracy of the collected point-cloud is. Nevertheless, the accuracy of collected data (using oval-straight shaped objects) is satisfactory. The accuracy, in this case, fluctuates between ± 0,4 mm and ± 1,0 mm whereas when using more detailed objects or a rectangular shaped prism the accuracy is much more lower, between 2,9 mm and ± 9,0 mm. Finally, the publication presents the possibility (for the future expansion of research) of modernization FabScan by the implementation of a larger amount of camera-laser units. This will enable spots the registration , that are less visible.
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Kedzierski, M., D. Wierzbickia, A. Fryskowska et B. Chlebowska. « ANALYSIS OF THE POSSIBILITIES OF USING LOW-COST SCANNING SYSTEM IN 3D MODELING ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLI-B3 (9 juin 2016) : 261–67. http://dx.doi.org/10.5194/isprsarchives-xli-b3-261-2016.
Texte intégralRésumé :
The laser scanning technique is still a very popular and fast growing method of obtaining information on modeling 3D objects. The use of low-cost miniature scanners creates new opportunities for small objects of 3D modeling based on point clouds acquired from the scan. The same, the development of accuracy and methods of automatic processing of this data type is noticeable. The article presents methods of collecting raw datasets in the form of a point-cloud using a low-cost ground-based laser scanner FabScan. As part of the research work 3D scanner from an open source FabLab project was constructed. In addition, the results for the analysis of the geometry of the point clouds obtained by using a low-cost laser scanner were presented. Also, some analysis of collecting data of different structures (made of various materials such as: glass, wood, paper, gum, plastic, plaster, ceramics, stoneware clay etc. and of different shapes: oval and similar to oval and prism shaped) have been done. The article presents two methods used for analysis: the first one - visual (general comparison between the 3D model and the real object) and the second one - comparative method (comparison between measurements on models and scanned objects using the mean error of a single sample of observations). The analysis showed, that the low-budget ground-based laser scanner FabScan has difficulties with collecting data of non-oval objects. Items built of glass painted black also caused problems for the scanner. In addition, the more details scanned object contains, the lower the accuracy of the collected point-cloud is. Nevertheless, the accuracy of collected data (using oval-straight shaped objects) is satisfactory. The accuracy, in this case, fluctuates between ± 0,4 mm and ± 1,0 mm whereas when using more detailed objects or a rectangular shaped prism the accuracy is much more lower, between 2,9 mm and ± 9,0 mm. Finally, the publication presents the possibility (for the future expansion of research) of modernization FabScan by the implementation of a larger amount of camera-laser units. This will enable spots the registration , that are less visible.
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Fang, Shengbang, Ronnie A. Sebro et Matthew C. Stamm. « A Deep Learning Approach to MRI Scanner Manufacturer and Model Identification ». Electronic Imaging 2020, no 4 (26 janvier 2020) : 217–1. http://dx.doi.org/10.2352/issn.2470-1173.2020.4.mwsf-217.
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Forensics research has developed several techniques to identify the model and manufacturer of a digital image or videos source camera. However, to the best of our knowledge, no work has been performed to identify the manufacturer and model of the scanner that captured an MRI image. MRI source identification can have several important applications ranging from scientific fraud discovery, exposing issues around anonymity and privacy of medical records, protecting against malicious tampering of medical images, and validating AI-based diagnostic techniques whose performance varies on different MRI scanners. In this paper, we propose a new CNN-based approach to learn forensic traces left by an MRI scanner and use these traces to identify the manufacturer and model of the scanner that captured an MRI image. Additionally, we identify an issue called weight divergence that can occur when training CNNs using a constrained convolutional layer and propose three new correction functions to protect against this. Our experimental results show we can identify an MRI scanners manufacturer with 97.88% accuracy and its model with 91.07% accuracy. Additionally, we show that our proposed correction functions can noticeably improve our CNNs accuracy when performing scanner model identification.
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Мирзоева, Мария, Maria Mirzoeva, Сергей Жолудев et Sergey Zholudev. « COMPARATIVE CHARACTERISTICS OF THE FIT CERAMIC RESTORATIONS ― A PILOT STUDY ». Actual problems in dentistry 14, no 3 (23 octobre 2018) : 41–44. http://dx.doi.org/10.18481/2077-7566-2018-14-3-41-44.
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Importance. The development of digital dentistry allows the use of new technologies to create orthopedic structures. Scanners in orthopedic dentistry are becoming an integral part of quality prosthetics. To work with new scanners requires not only the ability to perform the scanning procedure itself, but also to understand how accurately the scanner reproduces the surface relief. To determine the contact density of all-ceramic inserts in the removed teeth, this study was carried out.
Objectives. Experimental comparison of the accuracy of the adhesion of all-ceramic inserts made using the VT Dental scanner (Russia).
Methods. The study was conducted at the Department of Orthopedic Dentistry of the State Pedagogical University in the UGMU, in the Urals Branch of the RAS of the Institute of Geology and Geochemistry. acad. A.N. Zavaritsky - in the laboratory of physical and chemical methods of research. Removed molars and premolars of the upper and lower jaws in an amount of 20 pcs. They were processed, prepared under the all-ceramic inserts on the occlusal surfaces. Scanners for registering the relief of cavities: VT Dental (Russia), D500 (3Shape, Denmark), InEos Blue (DentsplySirona, Germany). The device for milling: Wieland dental zenotec select hybrid. The material of the tabs is E.MAX Press (Ivoclar Vivadent, Germany). Cements for fixation: RelyX Ultimate (3M ESPE, USA), Multilink Automix (Ivoclar Vivadent, Germany), MaxCem Elite (Kerr, Italy). The made inserts were fixed in equal parts in the cavities of the removed teeth on the presented cements, longitudinal sections of the remote molars and premolars were created. The method of investigation is scanning electron microscopy. Statistical processing was carried out in Gretl software.
Results. As a result of the scanning electron microscopy of 20 sections in aggregate, data were obtained on the accuracy of the adherence of a ceramic insert made using a VT Dental scanner (Russia) that did not significantly differ from the data obtained with other scanners by 0.4, the scanning accuracy was 95% (CI 1.3-1.9). The results obtained do not exceed the permissible probable error (p≤0,05).
Conclusions. The density of adherence of all-curly inserts in the cavity that were scanned by the VT Dental scanner (Russia) tends to the maximum permissible taking into account the scanning error and in comparison with the world analogues of the scanning device.
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Kasimov, Ruslan M., Sergey P. Tuzhilin et Grisha Arumugam. « Possibilities of Using 3D Scanners in the Agro-Industrial Complex ». Elektrotekhnologii i elektrooborudovanie v APK 48, no 4 (décembre 2021) : 103–11. http://dx.doi.org/10.22314/2658-4859-2021-68-4-103-111.
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3D scanning finds more and more application every year in various fields of science, technology and production. 3D scanners are devices designed to scan physical objects with the possibility of modification and editing of the obtained models in specialized CAD systems. (Research purpose) The research purpose is to consider the possibilities of using 3D scanners in agriculture based on the analysis of existing models and the principles of their operation. (Materials and methods) There were used open information sources dedicated to the issues of 3D scanning. There have been studied the experience of using a 3D scanner based on FNAC VIM. The research was carried out using methods of collecting, studying and comparative analysis of information. (Results and discussion) With the use of a 3D scanner, it is possible to scan various physical objects, obtaining their three-dimensional digital models with high accuracy (the quality of the result depends on the selected scanner model and the scan processing used). The scanning method distinguishes between contact scanners, scanners using structured light, and laser scanners. Tomographs have been allocated to a separate group as a kind of 3D scanners, which make it possible to obtain models of objects with complex internal cavities. The most popular program is Geomagic Design X as a program that allows to obtain a solid-state model from a scan with subsequent editing in various CAD/CAM/CAE systems. The article presents the experiments conducted on the basis of FNAC VIM, showing the possibility of using 3D scanning to obtain a model of a ploughshare and analyze changes in its shape due to wear. (Conclusions) The use of 3D scanning in the agro-industrial complex is relevant as a means of controlling the geometric dimensions of parts at enterprises engaged in the manufacture and repair of agricultural machinery. 3D scanning serves as a convenient tool for conducting scientific research of a wide range.
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Tang, Phua Hwee, et Sameema Nisa. « IMG-06. Comparing between MR spectroscopy done at 1.5T and 3T ». Neuro-Oncology 24, Supplement_1 (1 juin 2022) : i77. http://dx.doi.org/10.1093/neuonc/noac079.282.
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Abstract INTRODUCTION: In hospitals with heavily utilised MRI scanners, it may not be possible to schedule the patient on 1 particular scanner for all scans and thus this project was carried out to determine if there is any significant difference in the spectroscopy profile between 1.5 T and 3T MRI scanners late year 2021. AIM: To describe the MR spectroscopy profile of normal brain tissue performed on 1.5T and 3T MRI scanners in KK Women’s and Children’s Hospital. METHODS: Three healthy adult volunteers with normal body mass index underwent MRI brain scans after informed consent in this Institute Review Board approved study. MRI brain scans were performed on 1.5T General Electric MRI scanner and 3T Siemens Skyra MRI scanner 1 week apart. NAA/Cr, Cho/Cr and Cho/ NAA values were obtained from the right and left cerebral hemispheres. RESULTS: Average NAA/Cr in the right cerebral hemisphere is 2.06+/-0.10 at 1.5T. Average NAA/Cr in the left cerebral hemisphere is 2.01+/-0.23 at 1.5T. Average NAA/Cr in the right cerebral hemisphere is 1.56+/-0.09 at 3T. Average NAA/Cr in the left cerebral hemisphere is 1.81+/-0.29 at 3T. Average Cho/Cr in the right cerebral hemisphere 1.06+/-0.14 at 1.5T. Average Cho/Cr in the left cerebral hemisphere is 1.11+/-0.22 at 1.5T. Average Cho/Cr in the right cerebral hemisphere is 0.90+/-0.05 at 3T. Average Cho/Cr in the left cerebral hemisphere is 0.95+/-0.27 at 3T. Average Cho/NAA in the right cerebral hemisphere is 0.51+/-0.06 at 1.5T. Average Cho/NAA in the left cerebral hemisphere is 0.58+/-0.00 at 1.5T. Average Cho/NAA in the right cerebral hemisphere is 0.55+/-0.05 at 3T. Average Cho/NAA in the left cerebral hemisphere is 0.52+/-0.07 at 3T. CONCLUSION: MR spectroscopy values obtained from 1.5T and 3T MRI scanners show no significant difference(P>0.05).
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Dědič, Martin. « 3D scanning and analysis of acquired data of historically and culturally significant objects referring to the work of Adalbert Stifter ». MATEC Web of Conferences 279 (2019) : 01014. http://dx.doi.org/10.1051/matecconf/201927901014.
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The aim of the paper is to bring new findings from ongoing specific university research. Within this project, the light scanner scanned historically and culturally significant objects referring to the work of Czech-Austrian writer Adalbert Stifter in South Bohemia and Lower Austria. It also analyzed the data obtained with the light 3D scanner. The data was generated as a cloud of points. With respect to object´s size, multiple parts of each object were scanned individually. By combining individual scans and removing unwanted points (noise), models - digital twins of objects - were developed. Created models are valuable for their use for virtual tours of historically and culturally significant places. The final models were modified for printing on a 3D printer, where they were subsequently printed.
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Balatska, V., et M. Shabatura. « EXPLORATION OF COMPUTER NETWORK BY VULNERABILITY SCANNER NESSUS ». Bulletin of Lviv State University of Life Safety 20 (22 janvier 2020) : 6–11. http://dx.doi.org/10.32447/20784643.20.2019.01.
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For today, computer networks are an integral part of our daily lives. As the analysis shows, the network is ex-tremely vulnerable, it can serve as a place of information leakage, changes of configuration of settings and modification of data by the attackers. There are many more threats, and the security of the network requires a great deal of attention to ensure the security of the network in order to maintain the confidentiality and integrity of the data. Organizations must regularly assess the vulnerability of the entire network to test the security level and strengthen the network. We use vulnerability scanners to find weaknesses, which are useful for detecting security vulnerabilities on a case-by-case basis and across the network as a whole. The purpose of the work is to explore the computer network for vulnerabilities using the Nessus Professional scanner. Research Methods – network scanning by Nessus Professional vulnerability scanner. The Nessus Professional vulnerability scanner from Tenable Network Security, which is freely available, was used for the research. The Nessus Professional scanner has been found to have better functionality and performance than other available scanners. The only downside to the scanner is its cost per year, as well as scanning a large number of hosts on the network at a time (over 100 hosts). After the scanner was successfully installed, carried out it was in-spected from the moment it was launched to the generation of host test reports. For the work, the Lviv State University of Life Safety network was tested. In the post-scan report, which is displayed in HTML format, you can see scan details for each host; the number and nature of vulnerabilities; the error correction dashboard. According to the results of testing, vulnerabilities of low, medium and high levels of hazards were identified, totaling 376. Vulnerabilities were ana-lyzed based on the obtained results, namely: a brief description and a way to solve the problem.
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Lenda, G., P. Lewińska et J. Siwiec. « Accuracy of Merging Point Clouds at the Maximum Range of a Scanner with Limited Possibilities of Target Placement ». Archives of Civil Engineering 65, no 4 (1 décembre 2019) : 229–48. http://dx.doi.org/10.2478/ace-2019-0057.
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AbstractThe research was aimed at analysing the factors that affect the accuracy of merging point clouds when scanning over longer distances. Research takes into account the limited possibilities of target placement occurring while scanning opposite benches of quarries or open-pit mines, embankments from opposite banks of rivers etc. In all these cases, there is an obstacle/void between the scanner and measured object that prevents the optimal location of targets and enlarging scanning distances. The accuracy factors for cloud merging are: the placement of targets relative to the scanner and measured object, the target type and instrument range. Tests demonstrated that for scanning of objects with lower accuracy requirements, over long distances, it is optimal to choose flat targets for registration. For objects with higher accuracy requirements, scanned from shorter distances, it is worth selecting spherical targets. Targets and scanned object should be on the same side of the void.
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Toś, Cezary. « The Possibilities of Using the Terrestrial Scanning Data for Classification of Rocks in Limestone Mine “Czatkowice” ». Reports on Geodesy and Geoinformatics 97, no 1 (3 février 2015) : 80–90. http://dx.doi.org/10.2478/rgg-2014-0013.
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AbstractThis paper presents results of a research of potential utilisation of the intensity of laser beam reflection recorded by ground-based lasers, for an initial classification of rock formations within the Czatkowice Limestone Quarry. As part of the research, spectrometric analysis in visible (VIS), near-infrared (NIR) and Short-wavelength infrared (SWIR) bands was carried out for rock samples typical for the Czatkowice Quarry. Moreover, the rock samples were scanned using equipment working within different wavelengths. The reflected intensity of the laser beam recorded for each rock sample with several different scanners were analysed to assess their potential use for rock classification. The results of this analysis were then compared with spectral curves of each sample. The relationship between the intensity of the laser beam reflection and the spectral curves can be used for selection of most suitable scanner for rock classification.
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Motomancea, Adrian, Anca Bucuresteanu et Dan Prodan. « Execution of Non-Metallic or Metallic Duplicates, Cast with 3D Scanners and 3D Printers ». Materiale Plastice 56, no 1 (30 mars 2019) : 6–10. http://dx.doi.org/10.37358/mp.19.1.5113.
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In this paper, the authors show a part of research works performed on the use of 3D scanners and 3D printers to execute the molds required for the cast of parts with complex surfaces. 3D scanning allows copying of certain surfaces in our environment, based on existing models. The finished parts may also be executed from metals that are relatively easy to cast (bronze, aluminum etc.). In order to execute the molds destined for the casting, various pieces may be scanned, with a volume size in the range of [150x150x200 mm3 ÷ 500x500x2000 mm3]. Plastic model printing is performed depending on the capacity of the 3D printer used. This paper shows the results achieved with general-purpose scanner and printer, valued at affordable prices.
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Shamdasani, Vijay, Unmin Bae, Siddhartha Sikdar, Yang Mo Yoo, Kerem Karadayi, Ravi Managuli et Yongmin Kim. « Research interface on a programmable ultrasound scanner ». Ultrasonics 48, no 3 (juillet 2008) : 159–68. http://dx.doi.org/10.1016/j.ultras.2007.11.009.
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Wei Li, Liew, et Khairul Hamimah Abas. « Three Dimension Scanning using Infrared Coded Light ». ELEKTRIKA- Journal of Electrical Engineering 19, no 2 (29 août 2020) : 46–52. http://dx.doi.org/10.11113/elektrika.v19n2.229.
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In this competitive market, reverse engineering is introduced to shorten a new product development time by digitizing an existing product for rapid redesign. In this project, a low cost and standalone 3D scanner is being developed to achieve this purpose. Research is done comparing advantages and limitation of different hardware and method for 3D scanning. Scanner is assisted by automated rotating and illumination scanning platform to improve its performance. Software is developed for scanning of object using a Red-Green-Blue-Depth (RGBD) camera. The scanned result is processed and refined using global and local registration method. Poisson surface reconstruction is performed on the processed point clouds for generating triangular mesh. This scanner able to scan the object with the accuracy up to 5mm with computational time around 25 minutes.
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Jang, Arum, Young K. Ju et Min Jae Park. « Structural Stability Evaluation of Existing Buildings by Reverse Engineering with 3D Laser Scanner ». Remote Sensing 14, no 10 (11 mai 2022) : 2325. http://dx.doi.org/10.3390/rs14102325.
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In the Fourth Industrial Revolution, research and development of application technologies that combine high-tech technologies have been actively conducted. Building information modeling (BIM) technology using advanced equipment is considered promising for future construction projects. In particular, using a 3D laser scanner, LIDAR is expected to be a solution for future building safety inspections. This work proposes a new method for evaluating building stability using a 3D laser scanner. In this study, an underground parking lot was analyzed using a 3D laser scanner. Further, structural analysis was performed using the finite element method (FEM) by applying the figure and geometry data acquired from the laser scan. This process includes surveying the modeled point cloud data of the scanned building, such as identifying the relative deflection of the floor slab, and the sectional shape and inclination of the column. Consequently, safety diagnosis was performed using the original evaluation criteria. This confirms that it is precise and efficient to use a 3D laser scanner for building stability assessment. This paper presents a digital point cloud-based approach using a 3D laser scanner to evaluate the stability of buildings.
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Guo, Zhiyuan. « The Principle and State-of-Art Facilities for PET ». Journal of Physics : Conference Series 2386, no 1 (1 décembre 2022) : 012062. http://dx.doi.org/10.1088/1742-6596/2386/1/012062.
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Abstract Since the late 20th century, Positron Emission Tomography (PET) scanners and their hybrid scanners (PET/CT and PET/MRI) offer a path to detect cancer. In this research, the PET scan will be introduced and discussed in multiple dimensions, mainly to explain the principle of PET scan, the state-of-art of PET scans, and the future of PET scans. According to the analysis, from the time that the PET scanner is invented, it not only had a better image quality but also had more functions. It is believed that an intelligent non-radioactive scanner will be achieved in the future due to the development of MRI and artificial intelligence. The main reason for conducting this research is to understand the mechanisms of PET as well as investigate the way to improve the technology itself to avoid the limitations it poses. Overall, these results shed light on guiding further exploration of the next generation of PET scans (e.g., Hybrid PET machines and machine learning).
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Aulia Putra, Handityo. « Exploring Air Properties for fMRI-Compatible Interaction Devices ». MATEC Web of Conferences 215 (2018) : 01001. http://dx.doi.org/10.1051/matecconf/201821501001.
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The strong magnetic field of functional magnetic resonance imaging (fMRI) and the supine position of participants in fMRI scanners severely limit how participants can interact during fMRI experiments. This paper explores the use of air properties to design interaction-device systems that allow various interaction styles inside a fMRI scanner. Airflow and air pressure are explored to design and develop the interaction system. A series of air-based devices are introduced and discussed to demonstrate the feasibility of an air-based approach. This includes soft tactile and conventional controls (e.g., button, slider, joystick, pedal). To achieve fMRI-compatibility, all parts used inside the scanner are built from non-ferromagnetic, off-the-shelf plastic, and/or 3D printed materials. The fMRI compatibility was evaluated on a 3.0 Tesla fMRI scanner. We conclude with example applications and thoughts on future avenues of research.
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Metawie, Mahmoud, et Mohamed Marzouk. « OPTIMIZING LASER SCANNING POSITIONS IN BUILDINGS EXTERIORS : HERITAGE BUILDING APPLICATION ». JOURNAL OF CIVIL ENGINEERING AND MANAGEMENT 26, no 3 (25 février 2020) : 304–14. http://dx.doi.org/10.3846/jcem.2020.12006.
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Digital documentation for heritage buildings is one of the methods of preserving them as it provides a current record for the buildings. Digital records of heritage buildings can be used for future building rehabilitation, or be presented to the public to raise the awareness, increase tourism and decrease vandalism. This paper focuses on scanning object geometry factor to increase the quality of heritage’s façade point cloud. It optimizes the scanner locations and the scanner field of view to increase the point cloud quality and shorten the scanning time while guaranteeing a set of quality constraints for the point cloud. The quality constraints are based on the incidence angle between the scanned surface and the laser beam, and the max spacing between points. Three different multi-objective optimization algorithms are utilized: 1) genetic algorithm, 2) Jaya algorithm, and 3) particle swarm optimization to increase the quality. Optimization performance measures are adopted to compare the outputs of the optimization algorithms. A multi-criteria decision-making technique (Weighed sum model) is used to choose the optimum solution between the Pareto frontier solutions. Optimization algorithms minimize point cloud density and scanning time while assuring a required point spacing and max incidence angle by changing distance between laser scanner and scanned Facade, horizontal and vertical scan repetitions, and scanner different resolutions. The Jaya algorithm generates the most diversifiable optimal solutions and it is the fastest of the three algorithms considered. This research focuses on vertical building façade and future research will include the all types of Heritage façade. Omar Tosson Palace in Egypt is considered as a case study to demonstrate the use of the developed methodology and to illustrate its essential features.
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Pantea, Mihaela, Robert Ciocoiu, Ana Maria Cristina Tancu, Daniela-Mădălina Nină, Alexandru Petre, Iulian Vasile Antoniac et Marina Melescanu-Imre. « Comparative Study on Two Methods Used in Obtaining 3D Printed Dental Models ». Materiale Plastice 56, no 4 (30 décembre 2019) : 812–16. http://dx.doi.org/10.37358/mp.19.4.5270.
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The purpose of this study was to assess the accuracy of two 3D printed dental models manufactured after intraoral/IO and extraoral/EO scanning. A dental study model (KaVo Dental GmbH/Germany) was used as a reference for this research; this model was scanned with an industrial scanner (XT H 225 ST/Industrial CT scan/Nikon Metrology Inc./U.S.A.) and a reference STL file was generated (coded M1). Two 3D printed models (Form2/FormLabs Inc./U.S.A.) were produced via IO scanning (TRIOS 3 Battery Cart/3 Shape/Denmark), respectively via EO scanning (Swing Dental Scanner/Dof Inc./South Korea) of the reference dental model. The 3D printed models obtained were scanned with the industrial scanner, resulting in other two STL files (coded M2, respectively M3). All the STL files obtained (reference M1; M2; M3) were compared in pairs, using a 3D analysis software. Good results were achieved in obtaining 3D printed dental models via IO or EO scanning, yet, the 3D printed dental model obtained via IO scanning (M3) showed slightly improved dimensional compatibility with the reference model (M1) in comparison with the 3D printed dental model manufactured via EO scanning (M2).
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Jiang, Hai Lin. « Precision Analysis of Reconstructed Aluminum Alloy Handle ». Advanced Materials Research 479-481 (février 2012) : 2226–30. http://dx.doi.org/10.4028/www.scientific.net/amr.479-481.2226.
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In order to carry out the error analyses of the aluminum alloy in reverse engineering, Mastercam was used to create three-dimensional (3D) parametric solid models and automatically generate NC program files. By using the generated NC program, a simulating is processed on a milling machine. The surface of the obtained product 1 was immediately scanned by a laser scanner. Using the obtained results from the laser scanner, the three-dimensional models were created in Geomagic Studio. Reanalysis of the three dimensional models, product 2 can be obtained. Finally, Error analysis was carried out by comparing the 3D scan data with the original design models. The current research demonstrates that error analysis by the present method is feasible. However, since aluminum was selected as the processing material, the scanned data is not satisfactory; contrast error is greater after reverse engineering.
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Haidekker, Mark A. « Building a 3D Computed Tomography Scanner From Surplus Parts ». Biomedical Instrumentation & ; Technology 48, no 2 (1 mars 2014) : 142–51. http://dx.doi.org/10.2345/0899-8205-48.2.142.
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Computed tomography (CT) scanners are expensive imaging devices, often out of reach for small research groups. Designing and building a CT scanner from modular components is possible, and this article demonstrates that realization of a CT scanner from components is surprisingly easy. However, the high costs of a modular X-ray source and detector limit the overall cost savings. In this article, the possibility of building a CT scanner with available surplus X-ray parts is discussed, and a practical device is described that incurred costs of less than $16,000. The image quality of this device is comparable with commercial devices. The disadvantage is that design constraints imposed by the available components lead to slow scan speeds and a resolution of 0.5 mm. Despite these limitations, a device such as this is attractive for imaging studies in the biological and biomedical sciences, as well as for advancing CT technology itself.
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Xu, Guo Ya, Jun Hua He, Fan Sen et Yuan Tao Zhu. « Research of a New All-Optical Solid-State Scanner Based on GaAs ». Advanced Materials Research 710 (juin 2013) : 269–72. http://dx.doi.org/10.4028/www.scientific.net/amr.710.269.
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Design an all-optical solid-state scanner chip, which can realize high speed light deflection in a very small space, instead of electron beam deflection scan image converter tube and opto-mechanical scanner, cancel the complicated mechanical components, use the all-optical scanning to realize the super fast phenomenon observation. The beam deflection system is based on semiconductor optical waveguide core layer carrier induced refractive index change effect to realize, its development work is mainly divided into semiconductor optical waveguide and saw prisms two parts. And through the experiment, we measured deflection angle of the scanner chip to 1053nm signal light.
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Yan, Heng Feng, et Ji Min Chen. « Laser Scanner System Correction Research Based on Image Recognition ». Applied Mechanics and Materials 678 (octobre 2014) : 185–88. http://dx.doi.org/10.4028/www.scientific.net/amm.678.185.
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This paper introduces a new correction method for laser scanner system. Based on image recognition, the laser marking result which includes a crossed matrix is grabbed as matching pattern. A algorithm is presented to locate all crosses and measure their positions , and a correction data is generated automatically for laser scanner system. This method makes the correcting process be much faster and more accurate than conventional manual measurement way.
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Nikoohemat, S., M. Peter, S. Oude Elberink et G. Vosselman. « EXPLOITING INDOOR MOBILE LASER SCANNER TRAJECTORIES FOR SEMANTIC INTERPRETATION OF POINT CLOUDS ». ISPRS Annals of Photogrammetry, Remote Sensing and Spatial Information Sciences IV-2/W4 (14 septembre 2017) : 355–62. http://dx.doi.org/10.5194/isprs-annals-iv-2-w4-355-2017.
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The use of Indoor Mobile Laser Scanners (IMLS) for data collection in indoor environments has been increasing in the recent years. These systems, unlike Terrestrial Laser Scanners (TLS), collect data along a trajectory instead of at discrete scanner positions. In this research, we propose several methods to exploit the trajectories of IMLS systems for the interpretation of point clouds. By means of occlusion reasoning and use of trajectory as a set of scanner positions, we are capable of detecting openings in cluttered indoor environments. In order to provide information about both the partitioning of the space and the navigable space, we use the voxel concept for point clouds. Furthermore, to reconstruct walls, floor and ceiling we exploit the indoor topology and plane primitives. The results show that the trajectory is a valuable source of data for feature detection and understanding of indoor MLS point clouds.
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Jin Yadong, 金亚东, 闫爱民 Yan Aimin, 胡志娟 Hu Zhijuan, 张浩 Zhang Hao et 吕聪玲 Lü Congling. « Research Progress of Optical Waveguide Phased Array Scanner ». Laser & ; Optoelectronics Progress 51, no 8 (2014) : 080002. http://dx.doi.org/10.3788/lop51.080002.
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Sinkula, James M. « Status of company usage of scanner based research ». Journal of the Academy of Marketing Science 14, no 1 (mars 1986) : 63–71. http://dx.doi.org/10.1007/bf02722114.
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Mourik, Jurgen EM, Mark Lubberink, Floris HP van Velden, Reina W. Kloet, Bart NM van Berckel, Adriaan A. Lammertsma et Ronald Boellaard. « In vivo Validation of Reconstruction-Based Resolution Recovery for Human Brain Studies ». Journal of Cerebral Blood Flow & ; Metabolism 30, no 2 (21 octobre 2009) : 381–89. http://dx.doi.org/10.1038/jcbfm.2009.225.
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The aim of this study was to validate in vivo the accuracy of a reconstruction-based partial volume correction (PVC), which takes into account the point spread function of the imaging system. The NEMA NU2 Image Quality phantom and five healthy volunteers (using [11C]flumazenil) were scanned on both HR+ and high-resolution research tomograph (HRRT) scanners. HR+ data were reconstructed using normalization and attenuation-weighted ordered subsets expectation maximization (NAW-OSEM) and a PVC algorithm (PVC-NAW-OSEM). HRRT data were reconstructed using 3D ordinary Poisson OSEM (OP-OSEM) and a PVC algorithm (PVC-OP-OSEM). For clinical studies, parametric volume of distribution ( VT) images were generated. For phantom data, good recovery was found for both OP-OSEM (0.84 to 0.97) and PVC-OP-OSEM (0.91 to 0.98) HRRT reconstructions. In addition, for the HR+, good recovery was found for PVC-NAW-OSEM (0.84 to 0.94), corresponding well with OP-OSEM. Finally, for clinical data, good correspondence was found between PVC-NAW-OSEM and OP-OSEM-derived VT values (slope: 1.02±0.08). This study showed that HR+ image resolution using PVC-NAW-OSEM was comparable to that of the HRRT scanner. As the HRRT has a higher intrinsic resolution, this agreement validates reconstruction-based PVC as a means of improving the spatial resolution of the HR+ scanner and thereby improving the quantitative accuracy of positron emission tomography.
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Reiazi, Reza, Colin Arrowsmith, Mattea Welch, Farnoosh Abbas-Aghababazadeh, Christopher Eeles, Tony Tadic, Andrew J. Hope, Scott V. Bratman et Benjamin Haibe-Kains. « Prediction of Human Papillomavirus (HPV) Association of Oropharyngeal Cancer (OPC) Using Radiomics : The Impact of the Variation of CT Scanner ». Cancers 13, no 9 (8 mai 2021) : 2269. http://dx.doi.org/10.3390/cancers13092269.
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Studies have shown that radiomic features are sensitive to the variability of imaging parameters (e.g., scanner models), and one of the major challenges in these studies lies in improving the robustness of quantitative features against the variations in imaging datasets from multi-center studies. Here, we assess the impact of scanner choice on computed tomography (CT)-derived radiomic features to predict the association of oropharyngeal squamous cell carcinoma with human papillomavirus (HPV). This experiment was performed on CT image datasets acquired from two different scanner manufacturers. We demonstrate strong scanner dependency by developing a machine learning model to classify HPV status from radiological images. These experiments reveal the effect of scanner manufacturer on the robustness of radiomic features, and the extent of this dependency is reflected in the performance of HPV prediction models. The results of this study highlight the importance of implementing an appropriate approach to reducing the impact of imaging parameters on radiomic features and consequently on the machine learning models, without removing features which are deemed non-robust but may contain learning information.
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Pinkel, Sheila. « Refractive Fingerprints of Lenses : Explorations in Light Transformations ». Leonardo 51, no 2 (avril 2018) : 118–23. http://dx.doi.org/10.1162/leon_a_01264.
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Searching for an apt visual metaphor for multiculturalism to form the cover of an exhibition catalogue in 2011, the author scanned a Canon lens using a flatbed scanner and found that the whole visible color spectrum was included in the resulting image. This serendipitous discovery led to an ongoing research project on the unique refractions of all manner of lenses.
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Kofman, Rianne, Anna M. Beekman, Cornelis H. Emmelot, Jan H. B. Geertzen et Pieter U. Dijkstra. « Measurement properties and usability of non-contact scanners for measuring transtibial residual limb volume ». Prosthetics and Orthotics International 42, no 3 (8 novembre 2017) : 280–87. http://dx.doi.org/10.1177/0309364617736088.
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Background: Non-contact scanners may have potential for measurement of residual limb volume. Different non-contact scanners have been introduced during the last decades. Reliability and usability (practicality and user friendliness) should be assessed before introducing these systems in clinical practice. Objectives: The aim of this study was to analyze the measurement properties and usability of four non-contact scanners (TT Design, Omega Scanner, BioSculptor Bioscanner, and Rodin4D Scanner). Study design: Quasi experimental. Methods: Nine (geometric and residual limb) models were measured on two occasions, each consisting of two sessions, thus in total 4 sessions. In each session, four observers used the four systems for volume measurement. Mean for each model, repeatability coefficients for each system, variance components, and their two-way interactions of measurement conditions were calculated. User satisfaction was evaluated with the Post-Study System Usability Questionnaire. Results: Systematic differences between the systems were found in volume measurements. Most of the variances were explained by the model (97%), while error variance was 3%. Measurement system and the interaction between system and model explained 44% of the error variance. Repeatability coefficient of the systems ranged from 0.101 (Omega Scanner) to 0.131 L (Rodin4D). Differences in Post-Study System Usability Questionnaire scores between the systems were small and not significant. Conclusion: The systems were reliable in determining residual limb volume. Measurement systems and the interaction between system and residual limb model explained most of the error variances. The differences in repeatability coefficient and usability between the four CAD/CAM systems were small. Clinical relevance If accurate measurements of residual limb volume are required (in case of research), modern non-contact scanners should be taken in consideration nowadays.
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Javaid, Mohd, Abid Haleem, Shahbaz Khan et Sunil Luthra. « Different Flexibilities of 3D Scanners and Their Impact on Distinctive Applications ». International Journal of Business Analytics 7, no 1 (janvier 2020) : 37–53. http://dx.doi.org/10.4018/ijban.2020010103.
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3D scanners are supporting technology which offers a higher level of flexibility to create designs for ergonomic tooling, biocompatible surgical guides, and realistic prototypes and parts. Flexibility helps to reduce lead time, weight, cost, and product development time. Scanning technologies are in tandem with support software that helps a designer to (re)design products at a cheaper and faster rate. There is a need to understand different types of flexibilities and associated application of 3D scanner. In this article, we have conducted an extensive review of the available literature for identifying various flexibilities of 3D scanners and its applications. This research categorises 3D scanner flexibility and applications into five major types. From design to final quality inspection, these flexibilities play a significant role in industries and sectors to achieve optimum performance. Ranking of these flexibilities and their impact on different applications are accomplished using the analytical hierarchical process (AHP) with the help of expert opinion. The ranking of five significant flexibilities by using 3D scanners, undertaken through the AHP technique shows that scanning provides object flexibility at a higher level. The impacts of different flexibilities on applications are also weighted, and it shows that all flexibilities are enough to achieve application individually. This digital technology is helpful to create the customised product which is also helpful to achieve goals of Industry 4.0. It facilitates the customisation and has a significant impact on the design applications. This study provides an understanding of the 3D scanner in the context of flexibilities by identifying the different flexibilities it offers when used for different applications. Findings may assist developing a decision support system for the selection of 3D scanners for the different applications.
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Probst, Jannis, Konstantinos Dritsas, Demetrios Halazonetis, Yijin Ren, Christos Katsaros et Nikolaos Gkantidis. « Precision of a Hand-Held 3D Surface Scanner in Dry and Wet Skeletal Surfaces : An Ex Vivo Study ». Diagnostics 12, no 9 (18 septembre 2022) : 2251. http://dx.doi.org/10.3390/diagnostics12092251.
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Three-dimensional surface scans of skeletal structures have various clinical and research applications in medicine, anthropology, and other relevant fields. The aim of this study was to test the precision of a widely used hand-held surface scanner and the associated software’s 3D model generation-error in both dry and wet skeletal surfaces. Ten human dry skulls and ten mandibles (dry and wet conditions) were scanned twice with an industrial scanner (Artec Space Spider) by one operator. Following a best-fit superimposition of corresponding surface model pairs, the mean absolute distance (MAD) between them was calculated on ten anatomical regions on the skulls and six on the mandibles. The software’s 3D model generation process was repeated for the same scan of four dry skulls and four mandibles (wet and dry conditions), and the results were compared in a similar manner. The median scanner precision was 31 μm for the skulls and 25 μm for the mandibles in dry conditions, whereas in wet conditions it was slightly lower at 40 μm for the mandibles. The 3D model generation-error was negligible (range: 5–10 μm). The Artec Space Spider scanner exhibits very high precision in the scanning of dry and wet skeletal surfaces.
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Suchocki, Czesław, Jacek Katzer, Marzena Damięcka-Suchocka, Elżbieta Kuźmińska et Jacek Rapiński. « Harnessing Terrestrial Laser Scanning for Monitoring of Saturation of Buildings ». Bulletin of the Military University of Technology 66, no 4 (31 décembre 2017) : 165–77. http://dx.doi.org/10.5604/01.3001.0010.8232.
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A type of scanned surface (its physico-chemical properties) significantly influences the power of the returning laser signal in terrestrial laser scanner technique. The influence of different colour and rough-ness of a scanned surface on absorption and scattering was proven by multiple researchers. Water is characterized by high absorption coefficient of a laser signal. Keeping this fact in mind authors prepared a research programme focused on the influence of moisture movement in building wall on the value of the intensity in TLS. An impulse TLS scanner ScanStation C10 produced by Leica was used during the research programme in an indoor environment. The measurements were conducted targeting specially formed walls made of cellular concrete and ceramic hollow blocks. Test objects were placed in a special plastic container with water. The level of the water in the container was kept constant using an autonomous hydraulic pressure system. The porous dry wall was sucking water and the level of saturation was rising. The differences in values of intensity point cloud from scan were of special interest. In addition, tests have been carried out to the building object in an outdoors environment. Achieved results have shown that the intensity of the reflected laser beam from the wet building materials is much lower than that of dry materials. This dependency can be used for the measurement of TLS in the geodetic monitoring. Apart from determining the geometry of a building wall, it is possible to determine changes its humidity. Keywords: terrestrial laser scanner, intensity, humidity, geodetic monitoring
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Moyano, Juan, Elena Cabrera-Revuelta, Juan E. Nieto-Julián, María Fernández-Alconchel et Pedro Fernández-Valderrama. « Evaluation of Geometric Data Registration of Small Objects from Non-Invasive Techniques : Applicability to the HBIM Field ». Sensors 23, no 3 (3 février 2023) : 1730. http://dx.doi.org/10.3390/s23031730.
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Reverse engineering and the creation of digital twins are advantageous for documenting, cataloging, and maintenance control tracking in the cultural heritage field. Digital copies of the objects into Building Information Models (BIM) add cultural interest to every artistic work. Low-cost 3D sensors, particularly structured-light scanners, have evolved towards multiple uses in the entertainment market but also as data acquisition and processing techniques for research purposes. Nowadays, with the development of structured-light data capture technologies, the geometry of objects can be recorded in high-resolution 3D datasets at a very low cost. On this basis, this research addresses a small artifact with geometric singularities that is representative of small museum objects. For this, the precision of two structured-light scanners is compared with that of the photogrammetric technique based on short-range image capture: a high-cost Artec Spider 3D scanner, and the low-cost Revopoint POP 3D scanner. Data capture accuracy is evaluated through a mathematical algorithm and point set segmentation to verify the spatial resolution. In addition, the precision of the 3D model is studied through a vector analysis in a BIM environment, an unprecedented analysis until now. The work evaluates the accuracy of the devices through algorithms and the study of point density at the submillimeter scale. Although the results of the 3D geometry may vary in a morphometric analysis depending on the device records, the results demonstrate similar accuracies in that submillimeter range. Photogrammetry achieved an accuracy of 0.70 mm versus the Artec Spider and 0.57 mm against the Revopoint POP 3D scanner.
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Kulynych, Jennifer J. « The Regulation of MR Neuroimaging Research : Disentangling the Gordian Knot ». American Journal of Law & ; Medicine 33, no 2-3 (juin 2007) : 295–317. http://dx.doi.org/10.1177/009885880703300207.
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In a typical magnetic resonance imaging (“MRI”) study of the brain, subjects are screened for contraindications before being placed in the bore of a large machine, the MRI scanner, which contains a powerful magnet. The scanner produces cross-sectional images of brain tissue as the subjects undergo a series of brief electromagnetic pulses, perceptible only as noise and vibration. If the protocol involves functional MRI (“fMRI”), a popular research technique for obtaining indirect measurements of brain activity, equipment might be used to present stimuli (sounds or pictures) during the scan, but generally the study involves no invasive procedures, no physical discomfort, and no ionizing radiation. Upon completion of the scan, MRI data is transferred to an investigator's computer for further analysis, often in combination with behavioral test results and clinical information obtained from subjects or their medical records.This procedure sounds benign, and usually is. But an MRI scanner is a powerful medical device, capable of causing serious injury or death if operated carelessly.
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Delgado, Carlos Alberto, Roberto Shimabuku, Erika Alarcón, Luis Huicho et Augusto Cesar Ferreira De Moraes. « Reliability of unconventional torso anthropometry using a three-dimensional scanner in Peruvian children and adolescents ». F1000Research 7 (2 mars 2018) : 259. http://dx.doi.org/10.12688/f1000research.13936.1.
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Background: Three-dimensional (3D) scanners have made it possible to measure and display body surface and shape with high precision. These are fast measurements with minimum discomfort, which is especially useful when children are involved. The objective was to assess the reliability and validity of a 3D-scanner for measuring unconventional torso parameters in children and adolescents. Methods: This is a sub-sample of the SAYCARE study, an observational multicentre research effort being conducted in six South American countries, aimed at developing methods to collect data on cardiovascular health biomarkers, lifestyles, and environmental, social and family risk factors. Images were captured using a portable scanner (iSense, Cubify, USA) attached to a Tablet 128Gb with OSX (Ipad-Air Apple, USA). Images were reshaped to exclude head, hair, arms and legs; area and volume were measured using 3D design software ((Rhinoceros for OSX, v5.02, USA). Results: The sub-sample for our study comprised 54 girls and 46 boys, aged 6 to 17 years old, from two private schools in Lima, Peru. Out of 100 participants, 82 were scanned twice. There was strong reliability (rho_c> 0.80) between first and second measurements of area and volume in boys of every age group. In girls, the reliability coefficient was moderate (rho_c> 0.70) only for area comparison in adolescents older than 10 years of age. The mean torso area was 0.55 m2 (SD 0.08) in girls and 0.63 m2 (SD 0.13) in boys. The overall mean torso volume was 24.4 l (SD 5.33) in girls and 31.47 l (SD 10.14) in boys. Area under ROC curve oscillates between 0.5707 and 0.6383 when volume/area ratio was compared to the selected “gold standard” (waist to height ratio > 0.5). Conclusion: Use of portable and low cost 3D-scanners provides a reliable but inaccurate alternative for area and volume torso measurements in children and adolescents.
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Maria, Putut Son, et Elva Susianti. « Uji Kinerja Surface Scanner 3D Menggunakan Sensor VL53L0X dan Mikrokontroler ATMEGA8535 ». Jurnal Teknik Elektro 11, no 1 (20 juin 2019) : 1–8. http://dx.doi.org/10.15294/jte.v11i1.18821.
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Digital data recording of the geometry of 3-dimensional objects require a 3D scanner tool which are mostly using an imagery sensor. However there is hardly used information of scanned result, named color. Imagery sensor requires high spesification processing unit as capable as a personal computer for data acquisition processing. This research aims to build a 3D surface scanner using a time of flight laser ranging sensor and to develop its simple function to become more valuable device. Using point to point displacement method, the sensor measures the distance between the outermost point of the object and the sensor surface perpendicularly, once when one measurement is done then the object to be rotated along with the rotary table. The prototype was built using the VL53L0X sensor and ATMEGA8535 microcontroller as a motor controller for rotary table and vertical axis. Scanned data is sent from the microcontroller to the computer to be visualized in real time. The results show that the VL53L0X sensor is suitable for scanning convex objects but it is not capable to handle objects with multiple cavities.
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Milde, Jan, et František Jurina. « Comparison of Selected Thermoplastic Materials in the Fused Deposition Modeling Process and their Influence on the Dimensional Accuracy of an Orthodontic Upper Teeth Model ». Materials Science Forum 952 (avril 2019) : 143–52. http://dx.doi.org/10.4028/www.scientific.net/msf.952.143.
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The article focuses on the research of selected thermoplastic materials processed by the Fused Deposition Modeling (FDM) additive manufacturing method and dimensional accuracy of parts in particular. The selected thermoplastic materials were ABS, PLA and HIPS. The digital model of the object (upper teeth) was obtained by the intraoral 3D scanner of 3Shape TRIOS used in dentistry. Based on the 3D (Three Dimensional) scanned digital model, the manufacturing of the upper teeth was performed on the Zortrax M200 FDM 3D printer. Parameters of the manufactured parts were as follows: Layer thickness 0.09 mm, infill 20% and model orientation 0°. The manufactured parts were digitized by the GOM ATOS Triple Scan optical 3D scanner with the measuring volume of MV 170. The dimensional accuracy of the parts was evaluated in the GOM Inspect software.
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Alencar, Herlen, Umar Mahmood, Yoshihiro Kawano, Tadashi Hirata et Ralph Weissleder. « Novel Multiwavelength Microscopic Scanner for Mouse Imaging ». Neoplasia 7, no 11 (novembre 2005) : 977–83. http://dx.doi.org/10.1593/neo.05376.
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Saed, M., A. Sadremomtaz et H. Mahani. « Design and optimization of a breast-dedicated SPECT scanner with multi-lofthole collimation ». Journal of Instrumentation 17, no 01 (1 janvier 2022) : P01006. http://dx.doi.org/10.1088/1748-0221/17/01/p01006.
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Abstract Background: the need for simultaneous high-sensitivity and high-resolution breast SPECT imaging mandates to design and optimize dedicated scanners. Therefore, this work aims to design and optimize a novel breast-dedicated SPECT system with multi-lofthole collimator. Materials and Methods: in this research, a novel breast-dedicated scanner is designed and then optimized. The scanner is equipped with a single full-ring multi-lofthole collimation long with modular NaI(Tl) detectors. The step-and-shoot data acquisition was considered with two steps. Then, an analytic optimization was conducted to balance the existing sensitivity-resolution tradeoff. To do so, several scanner geometries were investigated. The optimal configuration maximized the system sensitivity at a given system resolution. Furthermore, the scanner was also modeled within the GATE simulator. Then, detector energy resolution, septal penetration and scattering, and system sensitivity were calculated. Analytic findings were also compared with the simulated ones. Results: the results showed that high sensitivity of about 2 cps/kBq can be obtained for a diameter of lofthole 3.05 mm with a 75° opening angle. Results of GATE simulations showed clinically acceptable performance of the system offering 9% energy resolution for a point source. The septal penetration and scattering were approximately 0.5% and 0.2%, respectively, for cylindrical water phantom and tungsten as collimator material. Conclusion: the designed SPECT scanner provides promising results in terms of sensitivity and spatial resolution and therefore outperforms the traditional multi-pinhole collimation by a much higher sensitivity at a given system resolution.
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Li, Jianxiong, Qian Zhou, Xinghui Li, Ruiming Chen et Kai Ni. « An Improved Low-Noise Processing Methodology Combined with PCL for Industry Inspection Based on Laser Line Scanner ». Sensors 19, no 15 (2 août 2019) : 3398. http://dx.doi.org/10.3390/s19153398.
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This paper introduces a three-dimensional (3D) point cloud data obtained method based on a laser line scanner and data processing technology via a PCL open project. This paper also provides a systematical analysis of the error types of laser line scanner and common error reducing solutions and calibration of the laser line scanner. The laser line scanner is combined with a precision motorized stage to obtain the 3D information of a measurand, and the format of point cloud data is converted via the set of x, y, and z coordinates. The original signal is processed according to the noise signal types of the raw point cloud data. This paper introduced a denoise process step by step combining various segmentation methods and a more optimized three-dimensional data model is obtained. A novel method for industry inspection based on the numerous point cloud for the dimensions evaluation via feature extraction and the deviation of complex surface between scanned point cloud and designed point cloud via registration algorithm is proposed. Measurement results demonstrate the good performance of the proposed methods. An obtained point cloud precision of ±10 μm is achieved, and the precision of dimension evaluation is less than ±40 μm. The results shown in the research demonstrated that the proposed method allows a higher precision and relative efficiency in measurement of dimensions and deviation of complex surfaces in industrial inspection.
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Havlik, Radek, Alena Gottwaldova et Jan Vavruška. « Application of 3D Scanner for Transportation a CNC Machine Tools ». Applied Mechanics and Materials 693 (décembre 2014) : 213–18. http://dx.doi.org/10.4028/www.scientific.net/amm.693.213.
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This paper deals with research in area 3D digitalization of large objects. Application of 3D scanners for transportation is not common. Digitalized area is a final placement for new machines. Final location and transport way for machines is in very a low ceiling room. Using the 3D data we can determine an optimal way for transport. In next step we define optimal final placement for CNC machine tools. If we have 3D model from 3D scanner we can measure the height between the floor and ceiling.
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Takahashi, Nanao, Masako Nakagome, Keiichi Machida et Shigemitsu Izumi. « 444. Research of Xray-Tube Life for CT-scanner ». Japanese Journal of Radiological Technology 46, no 8 (1990) : 1415. http://dx.doi.org/10.6009/jjrt.kj00003322566.
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