Results 21 to 30 of about 52,646 (158)

Patient-Specific Pre-Treatment VMAT Plan Verification Using Gamma Passing Rates

Atom Indonesia, 2023
Continuous gantry motion, continuous beam modulation, and variable dose rate are used in volumetric modulated arc therapy (VMAT) to obtain highly conformal radiation therapy dose distributions.
M. Z. Arsalan, M. B. Kakakhel, M. Shamshad, T. A. Afridi   +3 more
doaj   +1 more source

Thermal Modal Analysis for Volumetric Error Characterization

, 2023
AbstractThe volumetric accuracy of machine tools is significantly impacted by thermal errors, making the evaluation of volumetric accuracy a significant challenge for the manufacturing industry. Several technical solutions have been implemented, both at the industrial and research level, to address this issue. However, considering thermal errors in the
Natalia Colinas-Armijo, Beñat Iñigo, Luis Norberto López de Lacalle, Gorka Aguirre   +3 more
openaire   +1 more source

Comparison of Two Machine Learning Models for Predicting Volumetric Errors From On-The-Fly R-Test Type Device Data and Virtual End Point Constraints

Journal of Machine Engineering
On-the-fly virtual end-point constraints consists in moving all five axes of the machine tool while nominally maintaining the coincidence of a sensing head centre point with a master ball centre attached to the workpiece table.
Min Zeng, J. R. R. Mayer, Miao Feng, Elie Bitar-Nehme, Xuan Truong Duong   +4 more
doaj   +1 more source

A Theoretical and Experimental Identification with Featured Structures for Crucial Position-Independent Geometric Errors in Ultra-Precision Machining

Machines, 2023
In ultra-precision machining (UPM), position-independent geometric errors (PIGEs), i.e., squareness errors, have a crucial impact upon the form accuracy of a machined surface.
Li Zhang, Shaojian Zhang
doaj   +1 more source

Measurement Method of Geometric Error of Coordinate Measuring Machine Using Laser Tracer

工程科学与技术, 2021
Geometric error is an important error source of coordinate measuring machine (CMM). The geometric error measurement methods currently used have the problems of low efficiency and low accuracy, which seriously deteriorate the further improvement of the ...
Lin HAN, Liang MI, Xingbao LIU, Qiang TENG, Qiang TANG, Yangqiu XIA   +5 more
doaj  

Multi-offset ground-penetrating radar imaging of a lab-scale infiltration test [PDF]

Hydrology and Earth System Sciences, 2012
A lab scale infiltration experiment was conducted in a sand tank to evaluate the use of time-lapse multi-offset ground-penetrating radar (GPR) data for monitoring dynamic hydrologic events in the vadose zone. Sets of 21 GPR traces at offsets between 0.44–
A. R. Mangel, S. M. J. Moysey, J. C. Ryan, J. A. Tarbutton   +3 more
doaj   +1 more source

Numerical modeling of ASR: an updated semi-empirical model

Revista IBRACON de Estruturas e Materiais, 2023
Alkali-silica reaction (ASR) is a deleterious expansion phenomenon affecting concrete structures worldwide. It occurs when a susceptible chemical composition of concrete components is present, and it is particularly rampant in inherently humid ...
Sandro Bezerra Torres, Sandro Marden Torres, André Jacomei Torii   +2 more
doaj   +1 more source

Principle and Method of Base Station Calibration Based on a Physical Standard for Multi-Station Laser Tracking Measurement

Machines
In the measurement of volumetric errors in CNC machine tools using multi-station laser tracking technology, the coordinate calibration accuracy of external measurement base stations is a key factor determining the system’s final accuracy.
Haitao Li, Yuanbiao Wang, Yawen Wang, Yunlong Yu, Zehao Wang, Weihao Su, Yehao Zhu, Lijun Yang, Chi Ma, Jie Li, Meng Zhang   +10 more
doaj   +1 more source

Evaluation of dosimetric effect caused by slowing with multi-leaf collimator (MLC) leaves for volumetric modulated arc therapy (VMAT)

Radiology and Oncology, 2016
This study is to report 1) the sensitivity of intensity modulated radiation therapy (IMRT) QA method for clinical volumetric modulated arc therapy (VMAT) plans with multi-leaf collimator (MLC) leaf errors that will not trigger MLC interlock during beam ...
Xu Zhengzheng, Wang Iris Z., Kumaraswamy Lalith K., Podgorsak Matthew B.   +3 more
doaj   +1 more source

Correlation of the gamma passing rates with the differences in the dose-volumetric parameters between the original VMAT plans and actual deliveries of the VMAT plans.

PLoS ONE, 2020
PurposeThe aim of this study was to investigate the correlations of the gamma passing rates (GPR) with the dose-volumetric parameter changes between the original volumetric modulated arc therapy (VMAT) plans and the actual deliveries of the VMAT plans ...
Jong Min Park, Chang Heon Choi, Hong-Gyun Wu, Jung-In Kim   +3 more
doaj   +1 more source