scholarly journals Intrinsic alignments of BOSS LOWZ galaxies – II. Impact of shape measurement methods

2016 ◽  
Vol 457 (3) ◽  
pp. 2301-2317 ◽  
Author(s):  
Sukhdeep Singh ◽  
Rachel Mandelbaum
Keyword(s):  
Measurement Methods ◽  
Shape Measurement

scholarly journals Software package for testing three-dimensional shape measurement methods using structured lighting

2021 ◽  
Vol 2057 (1) ◽  
pp. 012087
Author(s):  
S V Dvoynishnikov ◽  
V O Zuev ◽  
I K Kabardin ◽  
D V Kulikov ◽  
V V Rahmanov
Keyword(s):  
Software Package ◽  
Three Dimensional ◽  
Measurement Methods ◽  
Shape Measurement ◽  
Structured Lighting ◽  
Lighting Conditions ◽  
Ambient Lighting ◽  
Dimensional Shape ◽  
Shadow Maps ◽  
Three Dimensional Shape

Abstract This work aims at creating a universal software package for the development and testing of triangulation methods using structured lighting for measuring the three-dimensional geometry of objects in difficult ambient lighting conditions. As a result, a software package meeting the stated requirements is created. Lighting is based on the Fong model. A method for preloading objects is implemented to optimize the operation of the software package. An accelerated method for creating shadow maps is proposed and implemented. The developed software package is shown to successfully perform all required functions.

scholarly journals The Methods and Experiments of Shape Measurement for Off-Axis Conic Aspheric Surface

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2101
Author(s):  
Shijie Li ◽  
Jin Zhang ◽  
Weiguo Liu ◽  
Haifeng Liang ◽  
Yi Xie ◽  
...  
Keyword(s):  
Measurement Methods ◽  
Optical Systems ◽  
Shape Measurement ◽  
Aspheric Surface ◽  
Mean Square ◽  
Optical Processing ◽  
Shape Accuracy ◽  
Shape Distribution ◽  
Auxiliary Component ◽  
Advantages And Disadvantages

The off-axis conic aspheric surface is widely used as a component in modern optical systems. It is critical for this kind of surface to obtain the real accuracy of the shape during optical processing. As is widely known, the null test is an effective method to measure the shape accuracy with high precision. Therefore, three shape measurement methods of null test including auto-collimation, single computer-generated hologram (CGH), and hybrid compensation are presented in detail in this research. Although the various methods have their own advantages and disadvantages, all methods need a special auxiliary component to accomplish the measurement. In the paper, an off-axis paraboloid (OAP) was chosen to be measured using the three methods along with auxiliary components of their own and it was shown that the experimental results involved in peak-to-valley (PV), root-mean-square (RMS), and shape distribution from three methods were consistent. As a result, the correctness and effectiveness of these three measurement methods were confirmed, which are very useful in engineering.

scholarly journals Fiber Bragg Gratings Sensors for Aircraft Wing Shape Measurement: Recent Applications and Technical Analysis

Sensors ◽  
2018 ◽  
Vol 19 (1) ◽  
pp. 55 ◽  
Author(s):  
Zhen Ma ◽  
Xiyuan Chen
Keyword(s):  
Electromagnetic Interference ◽  
Low Cost ◽  
Measurement Methods ◽  
Wing Shape ◽  
Shape Measurement ◽  
Aircraft Wing ◽  
Advantages And Disadvantages ◽  
Aerodynamic Loading ◽  
Sensing Technology ◽  
Bonding Technology

The safety monitoring and tracking of aircraft is becoming more and more important. Under aerodynamic loading, the aircraft wing will produce large bending and torsional deformation, which seriously affects the safety of aircraft. The variation of load on the aircraft wing directly affects the ground observation performance of the aircraft baseline. To compensate for baseline deformations caused by wing deformations, it is necessary to accurately obtain the deformation of the wing shape. The traditional aircraft wing shape measurement methods cannot meet the requirements of small size, light weight, low cost, anti-electromagnetic interference, and adapting to complex environment at the same time, the fiber optic sensing technology for aircraft wing shape measurement has been gradually proved to be a real time and online dynamic measurement method with many excellent characteristics. The principle technical characteristics and bonding technology of fiber Bragg grating sensors (FBGs) are reviewed in this paper. The advantages and disadvantages of other measurement methods are compared and analyzed and the application status of FBG sensing technology for aircraft wing shape measurement is emphatically analyzed. Finally, comprehensive suggestions for improving the accuracy of aircraft wing shape measurement based on FBG sensing technology is put forward.

A critical comparison of selected implicit measurement methods.

2018 ◽  
Vol 11 (4) ◽  
pp. 249-266 ◽  
Author(s):  
Judith Znanewitz ◽  
Lisa Braun ◽  
David Hensel ◽  
Claudia Fantapié Altobelli ◽  
Fabian Hattke
Keyword(s):  
Measurement Methods ◽  
Critical Comparison ◽  
Implicit Measurement

Calibration of a Lyophilized Pooled Plasma as Candidate Reference Plasma for Standardization of the Prothrombin Time Ratio

1993 ◽  
Vol 13 (02) ◽  
pp. 96-105 ◽  
Author(s):  
H. Beeser ◽  
U. Becker ◽  
H. J. Kolde ◽  
E. Spanuth ◽  
P. Witt ◽  
...  
Keyword(s):  
Prothrombin Time ◽  
International Study ◽  
International Normalized Ratio ◽  
Measurement Methods ◽  
Factor V ◽  
Diagnostic Instruments ◽  
Plasma Pool ◽  
Normal Plasma ◽  
German Association ◽  
Prothrombin Time Ratio

SummaryThe prothrombin time (PT), obtained from a fresh normal plasma pool (FPP), is the basis both for the establishment of the 100% activity (normal plasma) and for the ratio calculation used in the International Normalized Ratio (INR) according to the recommendations of the ICSH/ICTH (6). Today the PT of lyophilized normal plasma pools are successfully used as reference for the assessment of samples in proficiency studies. However, a lack of comparability is to be recognized. Therefore the Committee of Hematology of the German Association of Diagnostics’ and Diagnostic Instruments’ Manufacturers (VDGH) decided to produce a candidate reference plasma (VDGH Reference Plasma) which was calibrated against fresh normal plasma pools in an international study.The basic calibration was performed by using the same certified BCR thromboplastin (BCT/099) by all participants. The endpoint was determined manually and by using the coagulometer Schnitger-Gross. In additional testings each participant used his own routine thromboplastins and methods. Calculating the ratio [PT VDGH Reference Plasma (sec)/PT fresh normal plasma pool (sec)] the VDGH Reference Plasma showed a deviation from the average fresh normal plasma pool of 1.05 both with the BCT/099 and with all thromboplastins. There were obtained some statistical differences between “plain” and “combined’’ (added factor V and fibrinogen) thromboplastins. No statistical difference was found between the different endpoint measurement methods (manual, mechanical, optical).In spite of these statistical deviations the VDGH Reference Plasma can be used for the standardization of the PT-normal (100%) value with different ratios for plain (1.06) and combined (1.02) thromboplastins. The manufacturers will use this VDGH Reference Plasma for the calibration of their commercially available calibration plasmas, which allows the user of such a material to calculate a calibrated 100% PT value.

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