A Manœuvre Criterion

1964 ◽  
Vol 17 (4) ◽  
pp. 358-363
Author(s):  
J. B. Parker
Keyword(s):  
Statistical Treatment ◽  
Technical Committee ◽  
Main Stream ◽  
Random Errors ◽  
Different Types ◽  
Observational Errors ◽  
Systematic And Random Errors

The consideration of the effect of observational errors on the problem of manoeuvring ships at sea has, surprisingly enough, only recently become the object of attention by contributors to this Journal, though the basic background was provided many years ago by Sadler. The discussion at the Technical Committee of the Institute emphasized the importance of a statistical treatment of the problem and this led first to a brief note by myself in which systematic and random errors in range and bearing were discussed, and later to a full survey by Hollingdale in which it was shown that the total time to the instant of closest approach should be divided between observing time and manoeuvring time. An article by Proctor, though rather out of the main stream of the ideas pursued by the above mentioned contributors, breaks new ground in the sense that comparisons are made between different types of manœuvre on a probabilistic basis.

The Effect of Observational Errors on the Avoidance of Collision at Sea

1964 ◽  
Vol 17 (4) ◽  
pp. 345-357
Author(s):  
S. H. Hollingdale
Keyword(s):  
Relative Velocity ◽  
Velocity Vector ◽  
Technical Committee ◽  
Near Miss ◽  
Graphical Form ◽  
Random Errors ◽  
Collision Problem ◽  
Previous Discussion ◽  
Observational Errors ◽  
Definition Of

At a meeting of the Technical Committee of the Institute held on 9 January 1963 it was suggested that recent theoretical treatments of the collision problem could usefully be extended to include a discussion of the near-miss situation and the effect of observational errors. The basic mathematical relations for near-miss encounters have been set out in this Journal on several occasions, notably by Sadler and Morrell, and in graphical form by Wylie. The recent paper by Parker deals with the effects of both systematic and random errors of radar observations of relative range and bearing.My previous discussion of the collision problem was presented in terms of the idealized situation where two ships are on an actual collision course, in which case the sight line is in the same direction as the relative velocity vector (the relative track). To extend the results to a near-miss situation, one has only to redefine the angle α (see p. 24s of ref. 3) as the angle through which the relative velocity vector rotates when one or both ships manœuvre. I have pointed this out on a previous occasion: ‘The two craft need not be on a collision course; this definition of α applies equally well to a “miss” situation provided that no reference is made to the sight line.

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 Evaluation of the SteamVR Motion Tracking System with a Custom-Made Tracker

2021 ◽  
Vol 11 (14) ◽  
pp. 6390
Author(s):  
Marcin Maciejewski
Keyword(s):  
Motion Tracking ◽  
Tracking System ◽  
Training System ◽  
Random Errors ◽  
Operational Conditions ◽  
Custom Made ◽  
Systematic And Random Errors ◽  
Position And Orientation ◽  
Motion Tracking System ◽  
System Operating

The paper presents the research of the SteamVR tracker developed for a man-portable air-defence training system. The tests were carried out in laboratory conditions, with the tracker placed on the launcher model along with elements ensuring the faithful reproduction of operational conditions. During the measurements, the static tracker was moved and rotated in a working area. The range of translations and rotations corresponded to the typical requirements of a shooting simulator application. The results containing the registered position and orientation values were plotted on 3D charts which showed the tracker’s operation. Further analyses determined the values of the systematic and random errors for measurements of the SteamVR system operating with a custom-made tracker. The obtained results with random errors of 0.15 mm and 0.008° for position and orientation, respectively, proved the high precision of the measurements.

scholarly journals Quantifying and minimising systematic and random errors in X-ray micro-tomography based volume measurements

2015 ◽  
Vol 77 ◽  
pp. 1-7 ◽  
Author(s):  
Q. Lin ◽  
S.J. Neethling ◽  
K.J. Dobson ◽  
L. Courtois ◽  
P.D. Lee
Keyword(s):  
Random Errors ◽  
X Ray ◽  
Volume Measurements ◽  
Systematic And Random Errors ◽  
Micro Tomography

scholarly journals A Matrix-Variate t Model for Networks

2021 ◽  
Vol 4 ◽  
Author(s):  
Monica Billio ◽  
Roberto Casarin ◽  
Michele Costola ◽  
Matteo Iacopini
Keyword(s):  
Network Analysis ◽  
Measurement Errors ◽  
Statistical Treatment ◽  
Centrality Measures ◽  
Random Errors ◽  
Inference Procedure ◽  
Financial Firms ◽  
The Matrix ◽  
Different Sources ◽  
Flexible Model

Networks represent a useful tool to describe relationships among financial firms and network analysis has been extensively used in recent years to study financial connectedness. An aspect, which is often neglected, is that network observations come with errors from different sources, such as estimation and measurement errors, thus a proper statistical treatment of the data is needed before network analysis can be performed. We show that node centrality measures can be heavily affected by random errors and propose a flexible model based on the matrix-variate t distribution and a Bayesian inference procedure to de-noise the data. We provide an application to a network among European financial institutions.

scholarly journals Systematic and random errors between collocated satellite ice water path observations

2013 ◽  
Vol 118 (6) ◽  
pp. 2629-2642 ◽  
Author(s):  
S. Eliasson ◽  
G. Holl ◽  
S. A. Buehler ◽  
T. Kuhn ◽  
M. Stengel ◽  
...  
Keyword(s):  
Random Errors ◽  
Water Path ◽  
Ice Water Path ◽  
Systematic And Random Errors ◽  
Ice Water

TWO WAVELENGTHS METHODS FOR DETERMINATION LEVEL OF CONTAMINATION OF SOIL WITH CRUDE OIL HYDROCARBONS USING REFLECTION SPECTRUM OF VEGETATION

2019 ◽  
pp. 56-60
Author(s):  
L. Dj. Abdullayeva
Keyword(s):  
Crude Oil ◽  
Reflection Spectrum ◽  
Dynamic Range ◽  
Stressed Condition ◽  
Random Errors ◽  
Close Link ◽  
Oil Hydrocarbons ◽  
Different Types ◽  
Light Oil

The questions on determination level of contamination of soil with crude oil hydrocarbons using vegetations reflection spectrum are considered. The close link between concentration of pigments in vegetation and its reflection properties make it possible to use the reflection spectroscopy as an indicator to predict the vegetation stress occur due to spill of different types of crude oil. The reason is that light types of oil have a more effect on vegetation in comparison with heavy ones. The heavy types of oil have a predominant high molecular heavy components which are hardly transported and distributed within vegetation. The light oil is less viscose’s and well filtered through soil and roots of vegetation. The stressed condition occurred due to effect of oil is mainly reasoned by its such toxic components as aromatic compounds. The carried out analysis of reflection spectrums reveals the double polarity of differences of spectral signals formed by subtraction of reflection spectrums of oil of light and heavy types from controlled reflection spectrum. It causes uncertainty in estimation of contamination of oil using single wavelength method. The question on utilization in practices the inverse type interrelations for diminishing errors of measurements inherent for single wavelength method by transition to two wavelength regime of measurements. It is shown that presence of above said inverse interrelations allows to reach following prevalence’s upon use of two wavelength measurements. 1. Incrtease of dynamic range of measurements; 2. Decrease of random errors. Two variants of two wavelengths methods allowing to determine the level of contamination of soil with crude oil hydrocarbons are developed. The general methodic for determination of level of soil pollution with oil is suggested.

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