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132,590 result(s) for "CALIBRATION"
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P61 A comparative analysis of physical control alveolar volume data between a manual calibration syringe and a ventilated syringe
IntroductionRecent guidance suggests a daily physical control test should be performed using a 3L syringe (ARTP, 2020). In accordance, with supplier guidance this is performed locally with a syringe with integrated ventilation.The aim of this study was to assess if physical control readings for transfer factor could be performed with regular manual calibration syringe.MethodA TLCO verification (n=91) was performed using a 3L calibration (3LC) and a ventilated 3L syringe (3LV). The mean and difference was calculated between 3LC and 3LV. Local acceptable VA ranges for either syringe were set at (2.85 – 3.15L).A Bland-Altman analysis was conducted to assess the agreement between VA values obtained from the 3LC syringe and 3LV syringe, by evaluating the mean difference and the limits of agreement.ResultsThe median 3LC syringe VA value was 2.94 (IQR = 2.92–2.95), and the median 3LV syringe VA value was 2.92 (IQR = 2.89–2.97). The coefficient of variation (CV) for the 3LC VA was 0.90, compared to a CV for the 3LV of 1.83.The median 3LC VIN value was 2.99 (IQR = 2.98–3.01), and the median 3LV VIN value was 3.00 (IQR = 2.95–3.02). The CV for the 3LC syringe VIN was 1.04, compared to a CV for the 3LV syringe of 1.79.A Wilcoxon Signed Ranks test indicated no statistically significant differences in VA values between 3LC and 3LV (Z=-1.177, p = 0.239). (Figure 1)Abstract P61 Figure 1The figure shows Bland- Altman graph showing the difference between 3LC and 3LV syringes[Image Omitted. See PDF.]ConclusionThis data would suggest there is no significant difference between values for VA between either syringe. A non-vented calibration syringe can be used as an addition to a fan ventilated model for VA QC checks. Laboratories should set their own local tolerance levels when using different types of verification syringe.
Analysis of Abnormal Tank Volume Curve in Calibration Process of Horizontal Metal Tank Volume Comparison Method
This paper introduces the works, calibration process and data treating method of the horizontal metal tank system calibration by the volume comparison method. Nine typical abnormal tank volume curves are analyzed in this paper, which not only helps to improves the operating skills and work efficiency of the industry technicians, but also ensures the accuracy of the calibration results of the volume comparison method.
An overview of hand-eye calibration
Due to the increase in the difficulty and diversity of tasks performed by robots, robot “hand-eye” collaborative operation has attracted widespread attention. This technology is widely used in aerospace, medical, automotive, and industrial fields. Recently, hand-eye calibration technology is developing towards high precision and high intelligence. However, it has much work to be done in terms of identifying robot and camera parameters. This article introduces in detail the methods and theories involved in hand-eye calibration. According to the structure of the algorithm and the type of the optimization method, this paper summarizes the hand-eye calibration method into four steps: camera pose, mechanical claw pose, mathematical model, and error metrics. The well-known open problems about hand-eye calibration are finally stated, and some new research interests are also pointed out. The results of this review are useful for robot technicians to choose the correct parameter identification method and for researchers to determine further research areas.
Methods for Simultaneous Robot-World-Hand–Eye Calibration: A Comparative Study
In this paper, we propose two novel methods for robot-world-hand–eye calibration and provide a comparative analysis against six state-of-the-art methods. We examine the calibration problem from two alternative geometrical interpretations, called ‘hand–eye’ and ‘robot-world-hand–eye’, respectively. The study analyses the effects of specifying the objective function as pose error or reprojection error minimization problem. We provide three real and three simulated datasets with rendered images as part of the study. In addition, we propose a robotic arm error modeling approach to be used along with the simulated datasets for generating a realistic response. The tests on simulated data are performed in both ideal cases and with pseudo-realistic robotic arm pose and visual noise. Our methods show significant improvement and robustness on many metrics in various scenarios compared to state-of-the-art methods.
New Method and Portable Measurement Device for the Calibration of Industrial Robots
This paper presents an automated calibration method for industrial robots, based on the use of (1) a novel, low-cost, wireless, 3D measuring device mounted on the robot end-effector and (2) a portable 3D ball artifact fixed with respect to the robot base. The new device, called TriCal, is essentially a fixture holding three digital indicators (plunger style), the axes of which are orthogonal and intersect at one point, considered to be the robot tool center point (TCP). The artifact contains four 1-inch datum balls, each mounted on a stem, with precisely known relative positions measured on a Coordinate Measuring Machine (CMM). The measurement procedure with the TriCal is fully automated and consists of the robot moving its end-effector in such as a way as to perfectly align its TCP with the center of each of the four datum balls, with multiple end-effector orientations. The calibration method and hardware were tested on a six-axis industrial robot (KUKA KR6 R700 sixx). The calibration model included all kinematic and joint stiffness parameters, which were identified using the least-squares method. The efficiency of the new calibration system was validated by measuring the accuracy of the robot after calibration in 500 nearly random end-effector poses using a laser tracker. The same validation was performed after the robot was calibrated using measurements from the laser tracker only. Results show that both measurement methods lead to similar accuracy improvements, with the TriCal yielding maximum position errors of 0.624 mm and mean position errors of 0.326 mm.
SHCal20 Southern Hemisphere Calibration, 0–55,000 Years cal BP
Early researchers of radiocarbon levels in Southern Hemisphere tree rings identified a variable North-South hemispheric offset, necessitating construction of a separate radiocarbon calibration curve for the South. We present here SHCal20, a revised calibration curve from 0–55,000 cal BP, based upon SHCal13 and fortified by the addition of 14 new tree-ring data sets in the 2140–0, 3520–3453, 3608–3590 and 13,140–11,375 cal BP time intervals. We detail the statistical approaches used for curve construction and present recommendations for the use of the Northern Hemisphere curve (IntCal20), the Southern Hemisphere curve (SHCal20) and suggest where application of an equal mixture of the curves might be more appropriate. Using our Bayesian spline with errors-in-variables methodology, and based upon a comparison of Southern Hemisphere tree-ring data compared with contemporaneous Northern Hemisphere data, we estimate the mean Southern Hemisphere offset to be 36 ± 27 14C yrs older.
Geometric Wide-Angle Camera Calibration: A Review and Comparative Study
Wide-angle cameras are widely used in photogrammetry and autonomous systems which rely on the accurate metric measurements derived from images. To find the geometric relationship between incoming rays and image pixels, geometric camera calibration (GCC) has been actively developed. Aiming to provide practical calibration guidelines, this work surveys the existing GCC tools and evaluates the representative ones for wide-angle cameras. The survey covers the camera models, calibration targets, and algorithms used in these tools, highlighting their properties and the trends in GCC development. The evaluation compares six target-based GCC tools, namely BabelCalib, Basalt, Camodocal, Kalibr, the MATLAB calibrator, and the OpenCV-based ROS calibrator, with simulated and real data for wide-angle cameras described by four parametric projection models. These tests reveal the strengths and weaknesses of these camera models, as well as the repeatability of these GCC tools. In view of the survey and evaluation, future research directions of wide-angle GCC are also discussed.
Study on Calibration Method of IC Aging Test Systems under Comprehensive Working Conditions
Domestic IC aging test systems are mostly designed with poor consideration of traceability, and self-calibration solutions, which lack systematic overall measurement. According to the comprehensive working conditions characteristics of IC aging test systems, a systematic overall calibration method of the IC aging test systems is presented in this paper.
The IntCal20 Northern Hemisphere Radiocarbon Age Calibration Curve (0–55 cal kBP)
Radiocarbon (14C) ages cannot provide absolutely dated chronologies for archaeological or paleoenvironmental studies directly but must be converted to calendar age equivalents using a calibration curve compensating for fluctuations in atmospheric 14C concentration. Although calibration curves are constructed from independently dated archives, they invariably require revision as new data become available and our understanding of the Earth system improves. In this volume the international 14C calibration curves for both the Northern and Southern Hemispheres, as well as for the ocean surface layer, have been updated to include a wealth of new data and extended to 55,000 cal BP. Based on tree rings, IntCal20 now extends as a fully atmospheric record to ca. 13,900 cal BP. For the older part of the timescale, IntCal20 comprises statistically integrated evidence from floating tree-ring chronologies, lacustrine and marine sediments, speleothems, and corals. We utilized improved evaluation of the timescales and location variable 14C offsets from the atmosphere (reservoir age, dead carbon fraction) for each dataset. New statistical methods have refined the structure of the calibration curves while maintaining a robust treatment of uncertainties in the 14C ages, the calendar ages and other corrections. The inclusion of modeled marine reservoir ages derived from a three-dimensional ocean circulation model has allowed us to apply more appropriate reservoir corrections to the marine 14C data rather than the previous use of constant regional offsets from the atmosphere. Here we provide an overview of the new and revised datasets and the associated methods used for the construction of the IntCal20 curve and explore potential regional offsets for tree-ring data. We discuss the main differences with respect to the previous calibration curve, IntCal13, and some of the implications for archaeology and geosciences ranging from the recent past to the time of the extinction of the Neanderthals.
99 PELOD-2: An Update of the Pediatric Logistic Organ Dysfunction Score
Background and aims Organ dysfunction scores, such as the PEdiatric Logistic Organ Dysfunction (PELOD) score developed in 1999, are primarily designed to describe the severity of organ dysfunction. This study was undertaken to update and improve the PELOD score, using a larger and more recent dataset. Methods We did a prospective, observational, multicentre cohort study in nine French-speaking multidisciplinary, tertiary-care PICUs of university-affiliated hospitals between June 2006 and October 2007. We collected data on variables considered for the PELOD-2 score at seven time-points after PICU admission: days 1, 2, 5, 8, 12, 16 and 18, plus PICU discharge. For each variable, the most abnormal value observed during each time point was collected. Identification of the best variable cutoffs was performed using bivariate, multivariate regressions and bootstrap process. The outcome was vital status at PICU discharge. We used area under receiver operating characteristic curve (AUC) to evaluate discrimination and Hosmer-Lemeshow goodness-of-fit test to evaluate calibration. Results We included 3671 consecutive patients (median age 15.5 months IQR 2.2–70.7). Mortality rate was 6.0% (222 deaths). Discrimination and calibration of the PELOD 2 score were 0.93 and 9.31 (p=0.317) respectively. Conclusion We developed and validated the PELOD-2 score, which allows assessment of the severity of cases of MODS in PICU with a continuous scale. The score will be in the public domain, which means that it can be freely used in clinical trials.