Telecontrol Engineering of Three-Dimensional Measurements from Two-Dimensional Digital Photogrammetry for Scene Reconstruction

2011 ◽  
Vol 271-273 ◽  
pp. 489-494
Author(s):  
Dai Qin Tao ◽  
Zhi Yong Yin ◽  
Sheng Xiong Liu ◽  
Li Jun Wang

It set up a quick and high accurate method of 3D measurements from the 2D digital photogrammetry to reconstruct the scene by teleprocessing. Three types of feature marks in the matrix arrayhave been projected. The calibrations of the camera with fixed focal length have been calculated and compared before and after revision. The cross-shaped feature was the most accurate mark. And the cone barrel with sharp apex was also more accurate than the traditional round dot. The real case practices have been engaged in to verify the practicability and efficiency of the projects. In less than 10m with 6 points, the maximal error has been reduced to 0.029%. In around 20m with 20 to 34 ponits, the maximal error has been reduced to 0.046%. And it was far more accurate than the counterpart research (0.44%).The measurements results of the more big areas have been found to be instability. So the lawful choice of the single photogrammetric image scope should be limited to 20m. In the proper image scope (<26m), the telecontrol 3D measurements are very accurate and highly active. It can be positively applied to the remote scene reconstruction as well as other engineering vistas.

2022 ◽  
Vol 12 (2) ◽  
pp. 588
Author(s):  
Jun Wang ◽  
Xuexing Li

Single circular targets are widely used as calibration objects during line-structured light three-dimensional (3D) measurements because they are versatile and easy to manufacture. This paper proposes a new calibration method for line-structured light 3D measurements based on a single circular target. First, the target is placed in several positions and illuminated by a light beam emitted from a laser projector. A camera captures the resulting images and extracts an elliptic fitting profile of the target and the laser stripe. Second, an elliptical cone equation defined by the elliptic fitting profile and optical center of the camera is established based on the projective geometry. By combining the obtained elliptical cone and the known diameter of the circular target, two possible positions and orientations of the circular target are determined and two groups of 3D intersection points between the light plane and the circular target are identified. Finally, the correct group of 3D intersection points is filtered and the light plane is progressively fitted. The accuracy and effectiveness of the proposed method are verified both theoretically and experimentally. The obtained results indicate that a calibration accuracy of 0.05 mm can be achieved for an 80 mm × 80 mm planar target.


2021 ◽  
Vol 45 (1) ◽  
pp. 58-65
Author(s):  
V.A. Knyaz ◽  
D.G. Stepanyants ◽  
O.Y. Tsareva

For non-contact 3D measurements in hydrodynamic tunnels by photogrammetry methods, it is necessary to refine the standard model of image formation in the camera by taking into account an effect of refraction of rays at the boundaries of optical media, namely, at an air-glass boundary and glass-working fluid boundary. The article presents a model of image formation for shooting in a working environment that includes various optical media and methods for calibrating an optical system for 3D measurements of the coordinates of scene objects, while taking into account the real boundaries of the optical media. Experimental results on calibrating the system of three-dimensional measurements when an object image is formed by rays passing through two optical boundaries are discussed.


Hand Surgery ◽  
2003 ◽  
Vol 08 (02) ◽  
pp. 157-161 ◽  
Author(s):  
Shoji Fukuda ◽  
Osamu Ishida ◽  
Mitsuo Kido ◽  
Fumihiro Suzumura ◽  
Yoshikazu Ikuta

To guide reconstruction of scaphoid non-union, we attempted to create full-scale models of the scaphoid by three-dimensional computed tomography (3D CT) of the healthy side. In this study, we obtained 3D scans of 51 cadaveric hands and studied the difference in morphology between genders and between the left and right sides. The major axis length on a fixed plane and Fourier transformation curve were examined. Ten scaphoid images were also obtained with 3D CT before and after removal from the cadaveric hands. Our findings suggest good correlation between models produced using 3D CT images of the scaphoid alone, and this could serve as an accurate model if the magnification is corrected using the regression line. However, the model using 3D CT images of the intact wrist joint has a large margin of error and its use will not be practical.


Author(s):  
Е.Б. Ганина ◽  
Ю.В. Червинец ◽  
Н.В. Грудинин ◽  
В.Г. Шестакова ◽  
В.М. Червинец ◽  
...  

Цель исследования - охарактеризовать микробиологическую картину стоматита до и после его лечения высокоактивными культурами лактобацилл, дать оценку эффективности их применения при экспериментальном стоматите. Методика. Опыты проводились на 32 самках беспородных белых крыс массой 230 г. Моделирование стоматита включало 2 этапа: моделирование травматического стоматита и воспроизведение бактериального стоматита на базе травматического. У крыс контрольной и опытных серий на всех этапах эксперимента брали мазки с поверхности десен для характеристики микробиоценоза ротовой полости. Результаты. После обработки слизистой оболочки полости рта (СОПР) культурой патогенного штамма Staphylococcus aureus существенно снизились частота встречаемости и количество условно-патогенных микроорганизмов. Лечение стоматита у крыс культурами лактобацилл ( Lactobacillus 11 зв., Lactobacillus 2 п.рта, Lactobacillus 24 д.ст.) и их комбинацией приводило к снижению распространенности S. aureus вплоть до его исчезновения, а также к нормализации количества условно-патогенной микробиоты. Заключение. Исследования показали эффективность использования отдельных высокоактивных штаммов лактобацилл или их комбинации при лечении заболеваний СОПР, в частности бактериального стоматита. Aim. To characterize the microbiological picture of stomatitis in intact rats before and after the treatment with highly active cultured lactobacilli and to evaluate the effectiveness of this treatment in experiments on white rats. Methods. Experiments were carried out on 32 mongrel female white rats weighing 230 g. Smears were taken from the gum surface of control and experimental rats at all stages of the experiment to characterize the oral cavity microbiocenosis. Results. After treatment of the oral cavity with cultured Staphylococcus aureus , the occurrence and quantity of opportunistic microorganisms significantly decreased. The treatment of stomatitis in rats with cultured lactobacillus ( Lactobacillus 11 zv., Lactobacillus 2 p.r., Lactobacillus 24 d.st. and their combination) led to a decrease in S. aureus prevalence up to its extinction and to normalization of the quantitative composition of opportunistic microbiota. Conclusions. The study showed the effieacy of highly active lactobacillus strains individually or their combinations in the treatment of oral diseases, in particular, bacterial stomatitis.


Author(s):  
Yuan Gao ◽  
Xiaoguang Duan ◽  
Bin Li ◽  
Qianqian Jia ◽  
Yang Li ◽  
...  

Persulfate-based advanced oxidation processes are promising technologies to solve water pollution. In this work, single iron atoms are anchored in three-dimensional N-doped carbon nanosheets by a chemical vapor deposition (CVD)...


2021 ◽  
Vol 22 (5) ◽  
pp. 2491
Author(s):  
Yujin Park ◽  
Kang Moo Huh ◽  
Sun-Woong Kang

The process of evaluating the efficacy and toxicity of drugs is important in the production of new drugs to treat diseases. Testing in humans is the most accurate method, but there are technical and ethical limitations. To overcome these limitations, various models have been developed in which responses to various external stimuli can be observed to help guide future trials. In particular, three-dimensional (3D) cell culture has a great advantage in simulating the physical and biological functions of tissues in the human body. This article reviews the biomaterials currently used to improve cellular functions in 3D culture and the contributions of 3D culture to cancer research, stem cell culture and drug and toxicity screening.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Javier Caviedes-Bucheli ◽  
Nestor Rios-Osorio ◽  
Diana Usme ◽  
Cristian Jimenez ◽  
Adriana Pinzon ◽  
...  

Abstract Background The purpose of this study was to evaluate the changes in canal volume after root canal preparation in vivo with 3 different single-file techniques (Reciproc-Blue®, WaveOne-Gold® and XP-EndoShaper®), with a new method using CBCT and 3D reconstruction. Methods In this prospective study, thirty human lower premolars from healthy patients were used, in which extraction was indicated for orthodontic reasons. All the teeth used were caries- and restoration-free with complete root development, without signs of periodontal disease or traumatic occlusion, and with only one straight canal (up to 25º curvature). Teeth were randomly divided into three different groups: Reciproc-Blue, WaveOne-Gold and XP-EndoShaper. CBCT scans before root canal preparation were used to create a 3D reconstruction with RHINOCEROS 5.0 software to assess the initial canal volume, and then compared with 3D reconstructions after canal preparation to measure the increase in canal volume. Student’s t test for paired data were used to determine statistically significant differences between the before and after canal volumes. Anova test was used to determine statistically significant differences in the percentage of canal volume increase between the groups and Tukey's post-hoc test were used to paired comparison. Results Reciproc-Blue showed the higher increase in canal volume, followed by WaveOne-Gold and XP-EndoShaper (p = 0.003). XP-EndoShaper did not show a statistically significant increase in canal volume after root canal preparation (p = 0.06). Conclusion With this model, Reciproc-Blue showed higher increase in root canal volume, followed by WaveOne-Gold, while XP-EndoShaper did not significantly increase root canal volume during preparation.


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