Determination of correction function for reducing integral non-linearity of DSP-based event timer

2012 ◽  
Author(s):  
Yu. Artyukh ◽  
E. Boole ◽  
J. Bule
Keyword(s):  
Correction Function ◽  
Event Timer

New method for the determination of the correction function of a hemisperical electron analyser based on elastic electron images

2014 ◽  
Vol 197 ◽  
pp. 80-87 ◽  
Author(s):  
Mohamed Aymen Mahjoub ◽  
Guillaume Monier ◽  
Christine Robert-Goumet ◽  
Luc Bideux ◽  
Bernard Gruzza
Keyword(s):  
New Method ◽  
Correction Function ◽  
Elastic Electron

scholarly journals Determination of a setup correction function to obtain adsorption kinetic data at stagnation point flow conditions

2010 ◽  
Vol 346 (1) ◽  
pp. 208-215 ◽  
Author(s):  
Maria F. Mora ◽  
M. Reza Nejadnik ◽  
Javier L. Baylon-Cardiel ◽  
Carla E. Giacomelli ◽  
Carlos D. Garcia
Keyword(s):  
Stagnation Point ◽  
Kinetic Data ◽  
Adsorption Kinetic ◽  
Stagnation Point Flow ◽  
Correction Function ◽  
Flow Conditions

scholarly journals Application of the Correction Function to Improve the Quality of PM Measurements with Low-Cost Devices

2018 ◽  
Vol 57 ◽  
pp. 02009
Author(s):  
Mariusz Rogulski ◽  
Artur Badyda
Keyword(s):  
Low Cost ◽  
Correction Function ◽  
Reference Measuring ◽  
Comparative Tests ◽  
Measuring Devices ◽  
Reference Device ◽  
Accuracy Of Measurements ◽  
Measurement Results

Reliable information on the particulate matter (PM) concentration in the air is provided by professional, reference measuring devices. In recent times, however, measuring devices using low-cost PM sensors have been gaining more and more popularity. Low-cost PM sensors are not as accurate as professional devices and can under certain circumstances significantly distort results. Therefore comparative measurements with professional devices and the determination of the corrective function are necessary. The article presents the results of tests on the accuracy of measurements made with the use of such sensors after applying a correction function. The form of the correction function was determined based on several months of comparative tests low-cost sensors with reference device. Then, for a different set of low-cost sensors, a correction function was applied and again, during several months of research, the measurement results were compared with a reference device. This made it possible to determine the real measurement uncertainty of this type of equipment, as well as the need to support measurements using earlier comparative tests. Results showed, that for analysed low-cost PM sensors and correction function measurement error was about 15%.

Correction for counting losses in X-ray diffractometry

2005 ◽  
Vol 38 (3) ◽  
pp. 426-432 ◽  
Author(s):  
T. Ida ◽  
Y. Iwata
Keyword(s):  
Dead Time ◽  
Pulse Height ◽  
Approximate Model ◽  
Correction Function ◽  
Elementary Functions ◽  
Intermediate Model ◽  
Pulse Height Analyser ◽  
Maximum Relative Deviation ◽  
Experimental Errors

Non-extended and extended dead-time models, a pulse-height analyser (PHA) windowing model, and a model intermediate between the non-extended and extended models for losses in counting methods are compared. The validities of the methods are examined by application to the analysis of powder diffraction peak intensity profiles measured by a foil method. The intermediate model including parameters for the dead-time and degree of extension can reproduce both the non-extended and the extended models and also intermediate dependence between the two models. A convenient approximate formula for the intermediate model, the maximum relative deviation of which is 0.0003, is also proposed. The determination of the parameters and a correction for the measured intensities can easily be achieved by applying the approximate model, because it provides simple formulae for the correction function expressed as a combination of elementary functions. Experimental and analytical methods for precise evaluation of the parameters to specify the counting losses are also presented. Systematic deviations of the observed dependence from the non-extended and extended dead-time models have been detected by the precise analyses of experimental data, while the PHA windowing model, intermediate model and its approximation have reproduced the observed dependence within the experimental errors.

Galactic orbits of stars

1966 ◽  
Vol 25 ◽  
pp. 93-97
Author(s):  
Richard Woolley
Keyword(s):  
Globular Cluster ◽  
Potential Field ◽  
High Velocity ◽  
Velocity Vector ◽  
Variable Stars ◽  
The Sun ◽  
Proper Motions ◽  
Rr Lyrae ◽  
The Galaxy

It is now possible to determine proper motions of high-velocity objects in such a way as to obtain with some accuracy the velocity vector relevant to the Sun. If a potential field of the Galaxy is assumed, one can compute an actual orbit. A determination of the velocity of the globular clusterωCentauri has recently been completed at Greenwich, and it is found that the orbit is strongly retrograde in the Galaxy. Similar calculations may be made, though with less certainty, in the case of RR Lyrae variable stars.

Distance to SN 1987A and the LMC

1999 ◽  
Vol 190 ◽  
pp. 549-554
Author(s):  
Nino Panagia
Keyword(s):  
Angular Size ◽  
Large Magellanic Cloud ◽  
Magellanic Cloud ◽  
Light Curves ◽  
Distance Modulus ◽  
Absolute Size ◽  
Sn 1987A

Using the new reductions of the IUE light curves by Sonneborn et al. (1997) and an extensive set of HST images of SN 1987A we have repeated and improved Panagia et al. (1991) analysis to obtain a better determination of the distance to the supernova. In this way we have derived an absolute size of the ringRabs= (6.23 ± 0.08) x 1017cm and an angular sizeR″ = 808 ± 17 mas, which give a distance to the supernovad(SN1987A) = 51.4 ± 1.2 kpc and a distance modulusm–M(SN1987A) = 18.55 ± 0.05. Allowing for a displacement of SN 1987A position relative to the LMC center, the distance to the barycenter of the Large Magellanic Cloud is also estimated to bed(LMC) = 52.0±1.3 kpc, which corresponds to a distance modulus ofm–M(LMC) = 18.58±0.05.

International determination of the total motion of the pole

1961 ◽  
Vol 13 ◽  
pp. 29-41
Author(s):  
Wm. Markowitz
Keyword(s):  
Secular Motion ◽  
The Future

A symposium on the future of the International Latitude Service (I. L. S.) is to be held in Helsinki in July 1960. My report for the symposium consists of two parts. Part I, denoded (Mk I) was published [1] earlier in 1960 under the title “Latitude and Longitude, and the Secular Motion of the Pole”. Part II is the present paper, denoded (Mk II).

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

Practical Realization of a Reference System for Earth Dynamics by Satellite Methods

1975 ◽  
Vol 26 ◽  
pp. 341-380 ◽  
Author(s):  
R. J. Anderle ◽  
M. C. Tanenbaum
Keyword(s):  
Reference Frame ◽  
Polar Motion ◽  
Pole Position ◽  
Control Points ◽  
Significant Information ◽  
Crustal Motion ◽  
Average Reference ◽  
Future Data ◽  
Existing Data

AbstractObservations of artificial earth satellites provide a means of establishing an.origin, orientation, scale and control points for a coordinate system. Neither existing data nor future data are likely to provide significant information on the .001 angle between the axis of angular momentum and axis of rotation. Existing data have provided data to about .01 accuracy on the pole position and to possibly a meter on the origin of the system and for control points. The longitude origin is essentially arbitrary. While these accuracies permit acquisition of useful data on tides and polar motion through dynamio analyses, they are inadequate for determination of crustal motion or significant improvement in polar motion. The limitations arise from gravity, drag and radiation forces on the satellites as well as from instrument errors. Improvements in laser equipment and the launch of the dense LAGEOS satellite in an orbit high enough to suppress significant gravity and drag errors will permit determination of crustal motion and more accurate, higher frequency, polar motion. However, the reference frame for the results is likely to be an average reference frame defined by the observing stations, resulting in significant corrections to be determined for effects of changes in station configuration and data losses.

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