scholarly journals Assessment of Laser Galvanometer Scanning System Accuracy Using Ball-Bar Standard

2021 ◽  
Vol 11 (19) ◽  
pp. 8929
Author(s):  
Konrad Kobiela ◽  
Michał Jedynak ◽  
Wiktor Harmatys ◽  
Marcin Krawczyk ◽  
Jerzy A. Sładek
Keyword(s):  
Measurement Errors ◽  
Scanning System ◽  
Reference Standard ◽  
Reference Element ◽  
Welded Structures ◽  
3D Objects ◽  
Laser Projector ◽  
Length Measurements ◽  
Ball Bar ◽  
Selection Of

The laser projector based on the laser galvanometer scanning system enables the projection of CAD-based laser images onto geometrical objects. Furthermore, the system can perform a scan of components in order to control proper positioning (e.g., welded structures). We decided to conduct research aimed at determining the suitability of such systems for length measurements and assess their accuracy. These systems are commonly calibrated with the use of flat calibration boards, although their capability of projecting and scanning 3D objects. For this reason, a new method based on ISO 10360 has been proposed. Analysis of the system’s ability to perform length measurements, selection of a reference standard, and the tested device accuracy were the main objectives of the study. A ball-bar with a nominal length of 3000 mm was chosen as a reference standard. Positions of the reference element in the workspace were determined, and three series of five measured deviations were performed in each setting. The obtained values of measurement errors prove that it is possible to use ball-bar standards to assess the accuracy of the described systems, which is defined by the equation MPE(E0) = ±0.5 mm. The proposed method could be adapted to perform more complex analyzes in this area.

scholarly journals Effective plots to assess bias and precision in method comparison studies

2016 ◽  
Vol 27 (6) ◽  
pp. 1650-1660 ◽  
Author(s):  
Patrick Taffé
Keyword(s):  
Measurement Errors ◽  
Regression Line ◽  
Latent Trait ◽  
Method Comparison ◽  
Estimation Procedure ◽  
New Method ◽  
Reference Standard ◽  
Limits Of Agreement ◽  
Modeling Framework ◽  
Methods Of Measurement

Bland and Altman’s limits of agreement have traditionally been used in clinical research to assess the agreement between different methods of measurement for quantitative variables. However, when the variances of the measurement errors of the two methods are different, Bland and Altman’s plot may be misleading; there are settings where the regression line shows an upward or a downward trend but there is no bias or a zero slope and there is a bias. Therefore, the goal of this paper is to clearly illustrate why and when does a bias arise, particularly when heteroscedastic measurement errors are expected, and propose two new plots, the “bias plot” and the “precision plot,” to help the investigator visually and clinically appraise the performance of the new method. These plots do not have the above-mentioned defect and still are easy to interpret, in the spirit of Bland and Altman’s limits of agreement. To achieve this goal, we rely on the modeling framework recently developed by Nawarathna and Choudhary, which allows the measurement errors to be heteroscedastic and depend on the underlying latent trait. Their estimation procedure, however, is complex and rather daunting to implement. We have, therefore, developed a new estimation procedure, which is much simpler to implement and, yet, performs very well, as illustrated by our simulations. The methodology requires several measurements with the reference standard and possibly only one with the new method for each individual.

scholarly journals A development of cloud top height retrieval using thermal infrared spectra observed with GOSAT and comparison with CALIPSO data

2016 ◽  
Vol 9 (5) ◽  
pp. 1981-1992 ◽  
Author(s):  
Yu Someya ◽  
Ryoichi Imasu ◽  
Naoko Saitoh ◽  
Yoshifumi Ota ◽  
Kei Shiomi
Keyword(s):  
Measurement Errors ◽  
Thermal Infrared ◽  
Atmospheric Conditions ◽  
Cloud Detection ◽  
Low Cloud ◽  
Atmospheric Profile ◽  
Slicing Method ◽  
Cloud Tops ◽  
Spectral Channels ◽  
Selection Of

Abstract. An algorithm based on CO2 slicing, which has been used for cirrus cloud detection using thermal infrared data, was developed for high-resolution radiance spectra from satellites. The channels were reconstructed based on sensitivity height information of the original spectral channels to reduce the effects of measurement errors. Selection of the reconstructed channel pairs was optimized for several atmospheric profile patterns using simultaneous studies assuming a cloudy sky. That algorithm was applied to data by the Greenhouse gases Observing SATellite (GOSAT). Results were compared with those obtained from the space-borne lidar instrument on-board Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO). Monthly mean cloud amounts from the slicing generally agreed with those from CALIPSO observations despite some differences caused by surface temperature biases, optically very thin cirrus, multilayer structures of clouds, extremely low cloud tops, and specific atmospheric conditions. Comparison of coincident data showed good agreement, except for some cases, and revealed that the improved slicing method is more accurate than the traditional slicing method. Results also imply that improved slicing can detect low-level clouds with cloud top heights as low as approximately 1.5 km.

A model of the distribution and metabolism of corticotropin-releasing factor

1988 ◽  
Vol 254 (1) ◽  
pp. E104-E112
Author(s):  
B. Candas ◽  
J. Lalonde ◽  
M. Normand
Keyword(s):  
Measurement Errors ◽  
Compartment Model ◽  
Corticotropin Releasing Factor ◽  
Data Sets ◽  
Data Set ◽  
Rapid Injection ◽  
Three Compartment Model ◽  
Rival Models ◽  
Sampling Schedule ◽  
Selection Of

The aim of this study is the selection of the number of compartments required for a model to represent the distribution and metabolism of corticotropin-releasing factor (CRF) in rats. The dynamics of labeled rat CRF were measured in plasma for seven rats after a rapid injection. The sampling schedule resulted from the combination of the two D-optimal sampling sets of times corresponding to both rival models. This protocol improved the numerical identifiability of the parameters and consequently facilitated the selection of the relevant model. A three-compartment model fits adequately to the seven individual dynamics and better represents four of them compared with the lower-order model. It was demonstrated, using simulations in which the measurement errors and the interindividual variability of the parameters are included, that his four-to-seven ratio of data sets is consistent with the relevance of the three-compartment model for every individual kinetic data set. Kinetic and metabolic parameters were then derived for each individual rat, their values being consistent with the prolonged effects of CRF on pituitary-adrenocortical secretion.

scholarly journals Biasplot: A Package to Effective Plots to Assess Bias and Precision in Method Comparison Studies

2017 ◽  
Vol 17 (1) ◽  
pp. 208-221 ◽  
Author(s):  
Patrick Taffé ◽  
Mingkai Peng ◽  
Vicki Stagg ◽  
Tyler Williamson
Keyword(s):  
Measurement Errors ◽  
Measurement Method ◽  
Quantitative Characteristic ◽  
Method Comparison ◽  
Simulated Data ◽  
Worked Examples ◽  
Measurement Methods ◽  
Reference Standard ◽  
Statistical Methodology ◽  
Limits Of Agreement

Bland and Altman's (1986, Lancet 327: 307–310) limits of agreement have been used in many clinical research settings to assess agreement between two methods of measuring a quantitative characteristic. However, when the variances of the measurement errors of the two methods differ, limits of agreement can be misleading. biasplot implements a new statistical methodology that Taffé (Forthcoming, Statistical Methods in Medical Research) recently developed to circumvent this issue and assess bias and precision of the two measurement methods (one is the reference standard, and the other is the new measurement method to be evaluated). biasplot produces three new plots introduced by Taffé: the “bias plot”, “precision plot”, and “comparison plot”. These help the investigator visually evaluate the performance of the new measurement method. In this article, we introduce the user-written command biasplot and present worked examples using simulated data included with the package. Note that the Taffé method assumes there are several measurements from the reference standard and possibly as few as one measurement from the new method for each individual.

Assessment of the Robustness of Gas Turbine Diagnostics Tools Based on Neural Networks

2006 ◽  
Author(s):  
R. Bettocchi ◽  
M. Pinelli ◽  
P. R. Spina ◽  
M. Venturini ◽  
G. A. Zanetta
Keyword(s):  
Neural Networks ◽  
Gas Turbine ◽  
Measurement Errors ◽  
Health State ◽  
Artificial Intelligence Technique ◽  
Boundary Load ◽  
Set Up ◽  
Operating Points ◽  
Range Of Variation ◽  
Selection Of

The paper deals with the set-up and the application of an Artificial Intelligence technique based on Neural Networks (NNs) to gas turbine diagnostics, in order to evaluate its capabilities and its robustness. The data used for both training and testing the NNs were generated by means of a Cycle Program, calibrated on a Siemens V94.3A gas turbine. Such data are representative of operating points characterized by different boundary, load and health state conditions. The analyses carried out are aimed at the selection of the most appropriate NN structure for gas turbine diagnostics, by evaluating NN robustness with respect to: • interpolation capability and accuracy in the presence of data affected by measurement errors; • extrapolation capability in the presence of data lying outside the range of variation adopted for NN training; • accuracy in the presence of input data corrupted by bias errors; • accuracy when one input is not available. This situation is simulated by replacing the value of the unavailable input with its nominal value.

The Selection of Thermistors for the Temperature Measurement Gear

1970 ◽  
Vol 111 (5) ◽  
pp. 59-62
Author(s):  
J. Leskauskaite ◽  
A. Dumcius
Keyword(s):  
Temperature Measurement ◽  
Measurement Errors ◽  
Numerical Data ◽  
Optimum Selection ◽  
Selection Of

The parameters represented on manufacturer datasheet are usually insufficient for the optimum selection of thermistors. Some manufacturers give generalized numerical data of R(T) dependences. Using this data it is possible to select successfully the most suitable thermistor and equation for describing of T(R) dependence. It is shown that by selecting four points in the generalized characteristic it is possible to calculate the coefficients of the approximation equation. By the application of these coefficients in the calculations the temperature measurement errors can be decreased by an order. The results of calculations and experiment are given. Ill. 4, bibl. 8, tabl. 5 (in English; abstracts in English and Lithuanian).http://dx.doi.org/10.5755/j01.eee.111.5.357

SELECTION OF AN ASTRINGENCY REFERENCE STANDARD FOR THE SENSORY EVALUATION OF BLACK TEA

2004 ◽  
Vol 19 (2) ◽  
pp. 119-132 ◽  
Author(s):  
ZUZANA DROBNA ◽  
WENDY V. WISMER ◽  
LAKSIRI A. GOONEWARDENE
Keyword(s):  
Sensory Evaluation ◽  
Black Tea ◽  
Reference Standard ◽  
Selection Of

Evaluation of the economic impacts of length and diameter measurement error on mechanical harvesters and processors operating in pine stands

2006 ◽  
Vol 36 (7) ◽  
pp. 1661-1673 ◽  
Author(s):  
Hamish D Marshall ◽  
Glen E Murphy ◽  
Kevin Boston
Keyword(s):  
Measurement Error ◽  
Simulation Model ◽  
Measurement Errors ◽  
Economic Impacts ◽  
Error Rates ◽  
Potential Value ◽  
Value Recovery ◽  
The World ◽  
Length Measurements ◽  
Value Loss

Value recovery studies from around the world have shown that on average mechanical log-making systems lose 18% of the potential value compared to 11% for motor manual systems. One of the potential reasons for their poor value recovery performance is the level of accuracy of their stem diameter and length measurements. Numerous studies have looked at the level of error in both the diameter and length measurements made by mechanical harvesters and processors; however, few have looked at the economic impacts of these errors. The paper investigates the economic impacts in terms of value loss of six different harvesting operations in three different pine species. The accuracy and precision of the measurements recorded in this study were similar to those of other studies from around the world. A simulation model was developed to estimate the value loss caused by these errors. The results of the simulation model showed that the operations were losing between 3% and 23% of the potential value because of measurement errors. Further analysis showed that the industry should concentrate on increasing the precision of the length and diameter measurements to optimize gains from reducing the measurement error rates.

scholarly journals On content, migration and concentration of heavy metals in oils (by the example of the Dnieper-Donets Depression)

2019 ◽  
Vol 4 (181) ◽  
pp. 96-103
Author(s):  
Artem YEROFIEIEV ◽  
Ihor BEREZOVSKY
Keyword(s):  
Heavy Metals ◽  
Measurement Errors ◽  
Oil And Gas ◽  
Geological Structure ◽  
X Ray ◽  
Physical Conditions ◽  
Sediment Formation ◽  
Abnormal Accumulation ◽  
Ore Mineralization ◽  
Selection Of

Literature review and analysis of previous studies of the problem was carried. The main scientific works on the research topic, as well as the main directions and stages of the study are indicated. Similar studies that were conducted on the territory of Ukraine are considered. The results of the study of heavy metals in oil samples taken from a large oil and gas region from more than thirty deposits of Ukraine are presented. All current and non-working fields are considered. The geological structure of the oil and gas province, as well as the main geochemical features of the formation of mineral deposits are considered. The main forms of finding target metals, as well as possible ways of transferring these elements in the earth’s crust are given. Samples were investigated using x-ray fluorescence and neutron activation analysis. The obtained research data in the framework of two selected methods are combined for analysis. The results obtained within the same geological structure are compared with each other to determine the effect of the physical conditions of sediment formation on the microcomponent composition of crude oil. They also compared the effect of physical conditions on the properties of oil and their ability to accumulate heavy metals. Possible causes of the abnormal accumulation of heavy metals due to the close occurrence of oil and formation water are noted. According to the results obtained, a graph is constructed of the dependence of the mineralization of oil on its depth. An exponential graphical approximation is presented to display the general trend of dependence. Possible sources and ways of migration and accumulation of heavy metals in hydrocarbons are analyzed. The concept of the migration of heavy metals in oil is proposed in conjunction with the ore mineralization of adjacent and adjacent deposits. Possible causes of differences in the concentrations of heavy metals in oil of various geological structures are indicated, as well as the main possible causes of measurement errors and complications in the selection of each of the analysis methods are specified.

scholarly journals The strength of welded structures at low climatic temperatures

2018 ◽  
Vol 245 ◽  
pp. 08001
Author(s):  
Sergey Sokolov ◽  
Ivan Vasilyev ◽  
Konstantin Manzhula
Keyword(s):  
Metal Structure ◽  
Welded Structures ◽  
Metal Structures ◽  
Steel 09G2s ◽  
Normative Documents ◽  
Selection Of

Methods for the selection of steels for metal structures were analyzed in accordance with the normative documents GOST 32578-2013, ISO 20332-2015 and F.E.M.1.001. As the example the choice of steel 09G2S was confirmed for a metal structure of a crane, operated at a temperature of minus 55° C. To confirm the correctness of the choice of steel for this design and justify the allowable size of defects, welded samples were tested at temperatures from plus 20 to minus 60° C.

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