Results 311 to 320 of about 1,723,588 (348)

Accuracy and reproducibility of 3-dimensional digital model measurements

American Journal of Orthodontics and Dentofacial Orthopedics, 2012
The purpose of this study was to evaluate the reliability of measurements made on 3-dimensional digital models obtained with a surface laser scanner (D-250; 3Shape, Copenhagen, Denmark).Twenty orthodontic dental casts of permanent dentitions were selected.
Guilherme Janson, Daniela Gamba Garib, Eliziane Cossetin Vasconcelos, Arnaldo Pinzan, Marines Vieira S. Sousa   +4 more
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Accuracy and traceability in dimensional measurements

SPIE Proceedings, 1998
While the importance of the concepts of measurement accuracy and measurement traceability has long been recognized, they have not always been applied in a consistent or rigorous manner. In 1993 the International Organization for Standards (ISO) published two documents which establish consistent definitions of these and other metrology terms and provide
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A Comparison Between the Accuracy of Two-Dimensional and Three-Dimensional Strain Measurements

Journal of Nondestructive Evaluation, Diagnostics and Prognostics of Engineering Systems, 2018
This investigation determined the effect of specimen out-of-plane movement on the accuracy of strain measurement made applying two-dimensional (2D) and three-dimensional (3D) measurement approaches using the representative, state-of-the-art digital image correlation (DIC)-based tool ARAMIS.
Niranjan Desai, Christos T. Georgakis, Gregor Fischer, Joel Poling   +3 more
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Dimensional measurement accuracy to health, quality of life and health related quality of life

Zbornik radova
Background: Health is only one dimension of quality of life, and quality of life is more than health status, clinical symptoms, or functional ability, however it might be challenging to distinguish between health-related quality of life (HRQoL) and both ...
Brunilda Subashi, F. Kamberi, Erlini Kokalla, Lejdi Fetahu, Stiliana Brokaj, Majlinda Rakipaj, Deona Taraj   +6 more
semanticscholar   +1 more source

Accuracy in integrated circuit dimensional measurements

SPIE Proceedings, 1994
The measurement of critical dimensions of features on integrated circuits and photomasks is modeled as the comparison of the images of the test object and of a standard object in a measuring device. A length measuring instrument is then a comparator. The calibration of the standard and the conditions necessary for a valid comparison are discussed.
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Present status of traceability and accuracy of dimensional measurement in Japan

Precision Engineering, 1981
Abstract The establishment and maintenance of the traceability of standards in Japan is rightly seen as an important task of the National Research Laboratory of Metrology. In this article, T. Katoh, M. Sawabe, K. Sakamoto and S. Seino outline the procedures and the results of three round robin measurements of gauge blocks by interferometry and by ...
S. Seino, T. Katoh, M. Sawabe, K. Sakamoto   +3 more
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Accuracy and Precision of In Vitro Volumetric Measurements by Three-Dimensional Sonography

Investigative Radiology, 1996
A radiologist often wishes to measure organ volume or monitor changes in internal lesion volume during treatment. If this can be determined via three-dimensional ultrasound, the relative simplicity of the procedure and the decreased cost and known risks to the patient would make this method an attractive alternative to other modalities.Three ...
Seibert Ja, Eugenio O. Gerscovich, Wong J, Michael S. Cronan   +3 more
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Accuracy of three-dimensional measurements using cone-beam CT

Dentomaxillofacial Radiology, 2006
Lesions causing intraosseous defects in the head and neck region are difficult to diagnose using two-dimensional radiography, and three-dimensional (3D) data provided by CT is useful but often difficult to obtain. Recently, cone-beam CT (CBCT) was made available, with the potential to become a practical tool in dentistry.
Kelly Misch, David P. Sarment, S. Dyda, R. W. Pinsky, Harold M. Pinsky   +4 more
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Accuracy of three-dimensional measurement using a single image

Optical Engineering, 1997
The accuracy of 3-D measurement using a single image of a four-point coplanar target of known size is studied. The factors that influence accuracy are analyzed and experimental techniques are used to establish their individual effect on accuracy. Experiments show that the four-point coplanar target has two solutions for real images and that mixing ...
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The measurement of pointing accuracy of two-dimensional scan mirror

SPIE Proceedings, 2015
Abstract The observation accuracy of space camera targ eted on ground objects is directly affected by th e pointing deviation of the two dimensional scan mirror. A plane model of the scan mirror’s normal trajectory is established when scan mirror is rotating along the rolling axis while the pitching axis remain s still.
Xing Hui, An Chao, Xuhua He, Song Junru
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