Statistics and parallaxes

1978 ◽  
Vol 48 ◽  
pp. 7-29
Author(s):  
T. E. Lutz
Keyword(s):  
Experimental Design ◽  
Statistical Methods ◽  
Review Paper ◽  
Systematic Errors ◽  
Past Experience ◽  
Random Errors ◽  
Trigonometric Parallaxes ◽  
Systematic And Random Errors

This review paper deals with the use of statistical methods to evaluate systematic and random errors associated with trigonometric parallaxes. First, systematic errors which arise when using trigonometric parallaxes to calibrate luminosity systems are discussed. Next, determination of the external errors of parallax measurement are reviewed. Observatory corrections are discussed. Schilt’s point, that as the causes of these systematic differences between observatories are not known the computed corrections can not be applied appropriately, is emphasized. However, modern parallax work is sufficiently accurate that it is necessary to determine observatory corrections if full use is to be made of the potential precision of the data. To this end, it is suggested that a prior experimental design is required. Past experience has shown that accidental overlap of observing programs will not suffice to determine observatory corrections which are meaningful.

scholarly journals The method for evaluation errors of automated measurements of base tangent length by three-axis indicator on five-axis CNC machine

2021 ◽  
pp. 35-43
Author(s):  
D. T. Safarov ◽  
◽  
A. G. Kondrashov ◽  
Keyword(s):  
Statistical Methods ◽  
Systematic Errors ◽  
Random Errors ◽  
Cnc Machine ◽  
Cnc Machines ◽  
Automated Measurements ◽  
Periodic Monitoring ◽  
End Mills ◽  
Systematic And Random Errors ◽  
Five Axis

The article provides an overview of studies of various errors in the process of measuring parts with three-coordinate probes on CNC machines. The paper considers a method for estimating systematic and random errors in the process of measuring the length of the base tangent using control maps and probabilistic and statistical methods for processing multiple repeated inputs of a three-coordinate indicator to the measured side surfaces of the wheel teeth. The method is designed to assess the acceptability of the measurement process by technologists and adjusters. The data of experimental estimation of random and systematic errors of measurement of the length of the base tangent on a five-coordinate CNC machine with a three-coordinate indicator of Mahr are presented. The obtained error values for the five-axis machine under study allow us to measure the length of the base tangent for the purposes of periodic monitoring and adjustment of the machine when processing oblique cylindrical wheels with universal disk or end mills

scholarly journals The calculation of errors and the choice of sampling times in the determination of irreversible disposal rates in vivo by isotope experiments

1975 ◽  
Vol 152 (2) ◽  
pp. 417-420 ◽  
Author(s):  
Dennis F. Heath ◽  
Vincent J. Cunningham
Keyword(s):  
Specific Radioactivity ◽  
Systematic Errors ◽  
British Library ◽  
Small Animals ◽  
Random Errors ◽  
Basic Language ◽  
Sampling Times ◽  
Label Time

In well-known methods of estimating rates of irreversible disposal (utilization) in vivo the rates are calculated from the areas to infinity under specific radioactivity–time (S–t) or quantity-of-label–time (q–t) curves obtained by measurements on samples of plasma after intravenous injection of labelled substrate. The errors in the calculated rates are mostly those of the estimates of the areas. These errors are of two kinds: random, caused by the variances of the values of S or q, and systematic, caused by differences between the curves used to interpolate between these values and the true curves. A rigorous method is given for calculating the random errors from the variances of the values of S or q, and is applied to choosing the best times to sample the plasma from small animals from which few plasma samples can be taken. A procedure for estimating systematic errors is also given. Programs in BASIC language to carry out the calculations are deposited as Supplementary Publication SUP 50058 (5 pages) at the British Library (Lending Division), Boston Spa, Wetherby, West Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms given in Biochem. J. (1975) 145, 5.

Evaluation of IRD-WIM-5000 — a Canadian weigh-in-motion system

1990 ◽  
Vol 17 (4) ◽  
pp. 514-520 ◽  
Author(s):  
Satish C. Sharma ◽  
George Stamatinos ◽  
John Wyatt
Keyword(s):  
Systematic Errors ◽  
Study Data ◽  
Random Errors ◽  
Motion System ◽  
Planning And Design ◽  
Dynamic Weight ◽  
Weigh In Motion ◽  
Highway Planning ◽  
Systematic And Random Errors ◽  
Weight Data

The analysis presented in this paper deals with the accuracy of a weigh-in-motion (WIM) system installed on Trans-Canada Highway west of Regina. Spot speed data collected by the WIM system are compared with the measurements taken by a radar meter; the WIM data on axle spacing are compared with data obtained by manual measurements; and the dynamic weight data gathered by the WIM system are evaluated against static weights. The following conclusions can be made from this study: The WIM system under investigation provides accurate data for spot speed and axle spacing. The study data for 88 trucks indicate that the dynamic weights recorded by the WIM system may contain high magnitudes of both systematic and random errors. However, the results of analysis presented indicate that a proper calibration of the system can reduce the systematic errors to a large extent and produce results that may be satisfactory for a number of highway planning and design functions. Key words: axle spacing, dynamic weight, highways, static weight, traffic studies.

scholarly journals Spatially resolved measurements of the solar photospheric oxygen abundance

2020 ◽  
Vol 643 ◽  
pp. A142
Author(s):  
M. Cubas Armas ◽  
A. Asensio Ramos ◽  
H. Socas-Navarro
Keyword(s):  
Systematic Errors ◽  
Model Atmosphere ◽  
Nuisance Parameters ◽  
Hierarchical Bayesian Model ◽  
Random Errors ◽  
Vacuum Tower ◽  
Oxygen Abundance ◽  
Spatially Resolved ◽  
Good Agreement

Aims. We report the results of a novel determination of the solar oxygen abundance using spatially resolved observations and inversions. We seek to derive the photospheric solar oxygen abundance with a method that is robust against uncertainties in the model atmosphere. Methods. We use observations with spatial resolution obtained at the Vacuum Tower Telescope to derive the oxygen abundance at 40 different spatial positions in granules and intergranular lanes. We first obtain a model for each location by inverting the Fe I lines with the NICOLE inversion code. These models are then integrated into a hierarchical Bayesian model that is used to infer the most probable value for the oxygen abundance that is compatible with all the observations. The abundance is derived from the [O I] forbidden line at 6300 Å taking into consideration all possible nuisance parameters that can affect the abundance. Results. Our results show good agreement in the inferred oxygen abundance for all the pixels analyzed, demonstrating the robustness of the analysis against possible systematic errors in the model. We find a slightly higher oxygen abundance in granules than in intergranular lanes when treated separately (log(ϵO) = 8.83 ± 0.02 vs. log(ϵO) = 8.76 ± 0.02), which is a difference of approximately 2-σ. This tension suggests that some systematic errors in the model or the radiative transfer still exist but are small. When taking all pixels together, we obtain an oxygen abundance of log(ϵO) = 8.80 ± 0.03, which is compatible with both granules and lanes within 1-σ. The spread of results is due to both systematic and random errors.

scholarly journals 24. Commission des Parallaxes Stellaires et des Mouvements Propres

1936 ◽  
Vol 5 ◽  
pp. 144-155
Author(s):  
M. S. A. Mitchell ◽  
MM. Adams ◽  
Alden ◽  
Bianchi ◽  
Cecchini ◽  
...  
Keyword(s):  
Southern Hemisphere ◽  
Systematic Errors ◽  
Probable Error ◽  
Proper Motions ◽  
Astrophysical Journal ◽  
Trigonometric Parallaxes ◽  
Substantial Progress

In November 1934 the President circulated a letter to the members of the Commission as follows:Since the 1932 meeting the following projects have been completed, or are nearing completion:(1)The publication of many lists of trigonometric parallaxes.(2)The determination of the spectroscopic parallaxes of 4179 stars at Mt Wilson Observatory by Adams, Joy and Humason.(3)A discussion of systematic errors of trigonometric parallaxes by van Maanen and a re-discussion in the Astrophysical Journal of the same material by Mitchell and by Sterne.(4)The compilation of a second Yale Catalogue to include parallaxes completed before the end of 1934.(5)Substantial progress on the proper motions of 32,000 stars by Boss and his associates at the Dudley Observatory.(6)The publication at the Radcliffe Observatory of the proper motions of 32,000 stars from photographs on 115 Selected Areas.(7)The completion of the dynamical parallaxes of 2000 stars.(8)The completion of the proper motions of 18,000 stars derived from parallax plates at the Leander McCormick Observatory.(9)The publication at the Yale Observatory of the proper motions of 40,000 stars with a probable error less than 0”.010 determined from photographs by re-observing in zones the Astronomische Gesellschaft stars.(10)The determination of the proper motions of 50,000 stars in the Southern Hemisphere by Luyten from Harvard photographs.

Respirometry for determination of the influents SS-concentration

1996 ◽  
Vol 33 (1) ◽  
pp. 311-323 ◽  
Author(s):  
A. Witteborg ◽  
A. van der Last ◽  
R. Hamming ◽  
I. Hemmers
Keyword(s):  
Experimental Design ◽  
Activated Sludge ◽  
Substrate Concentration ◽  
Full Scale ◽  
Activated Sludge Process ◽  
Respiration Rates ◽  
On Line ◽  
Large Measurement ◽  
Set Up

A method is presented for determining influent readily biodegradable substrate concentration (SS). The method is based on three different respiration rates, which can be measured with a continuous respiration meter which is operated in a cyclic way. Within the respiration meter nitrification is inhibited through the addition of ATU. Simulations were used to develop the respirometry set-up and decide upon the experimental design. The method was tested as part of a large measurement programme executed at a full-scale plant. The proposed respirometry set-up has been shown to be suitable for a semi-on-line determination of an influent SS which is fully based on the IAWQ #1 vision of the activated sludge process. The YH and the KS play a major role in the principle, and should be measured directly from the process.

Optimum HPLC Conditions for Determination of Dibucaine HCL, Fluocortolone Pivalate and Fluocortolone Caproate by Using Experimental Design

2018 ◽  
Vol 15 (1) ◽  
pp. 32-38 ◽  
Author(s):  
Bürge Aşçı ◽  
Mesut Koç
Keyword(s):  
Experimental Design ◽  
Flow Rate ◽  
Mobile Phase ◽  
High Performance ◽  
Limit Of Detection ◽  
Pharmaceutical Preparations ◽  
Acid Mixture ◽  
Solution Stability ◽  
Uv Detector

Introduction:This paper presents the development and validation of a novel, fast, sensitive and accurate high performance liquid chromatography (HPLC) method for the simultaneous quantitative determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical preparations.Experiment:Development of the chromatographic method was based on an experimental design approach. A five-level-three-factor central composite design requiring 20 experiments in this optimization study was performed in order to evaluate the effects of three independent variances including mobile phase ratio, flow rate and amount of acid in the mobile phase.Conclusion:The optimum composition for mobile phase was found as a methanol:water:acetic acid mixture at 71.6 : 26.4 : 2 (v/v/v) ratio and optimum separation was acquired by isocratic elution with a flow rate of 1.3 mL/min. The analytes were detected using a UV detector at 240 nm. The developed method was validated in terms of linearity, precision, accuracy, limit of detection/quantitation and solution stability and successfully applied to the determination of dibucaine HCl, fluocortolone pivalate and fluocortolone caproate in pharmaceutical topical formulations such as suppositories and ointments.

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