DEVELOPMENT AND COMPARISON OF THE METHODS OF AUTOMATICAL SEARCHING OF PEAKS IN γ–SPECTRA

Mapping Intimacies ◽

10.46813/2019-121-124 ◽

2019 ◽

pp. 124-128

Author(s):

A.Yu. Berezhnoy ◽

Yu.V. Lyashko

Keyword(s):

Statistical Methods ◽

Sufficient Accuracy ◽

Spectra Processing ◽

New Algorithms ◽

Program Version

We elaborated the program of γ-spectra processing called ”GAMMAPEAKS” which approximates peaks in specters by gauss functions. We included two new algorithms which mark peaks in spectra to the new program version. The peaks marking algorithms are based on statistical methods of searching of extremes in functions. The algorithms developed are possible to mark peaks in spectra with suﬃcient accuracy.

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Investigation of the influence of gear milling modes of cylindrical gears on the quality parameters of tooth surfaces

MATEC Web of Conferences ◽

10.1051/matecconf/202031705002 ◽

2020 ◽

Vol 317 ◽

pp. 05002

Author(s):

Mark Kane ◽

Valery Sheleg ◽

Marina Kravchuk ◽

Pavel Kot

Keyword(s):

Residual Stresses ◽

Statistical Methods ◽

Roughness Parameter ◽

Cutting Speed ◽

Quality Parameters ◽

Sufficient Accuracy ◽

Cylindrical Gears ◽

Current State ◽

Tooth Surfaces ◽

Research Objects

Summary. The current state of the problem of studying the influence of gear milling modes of cylindrical gears on the quality parameters of the tooth surfaces is considered. Insufficient study of this problem and inconsistency of the available results is shown. The relevance and possible areas of application of this research are shown. The research objects are described (the effect of the cutting speed V and feed S during hobbing of cylindrical gears on the roughness parameter Ra, microhardness Hμ, residual stresses 1 and 2, σ1 and σ2 in the tooth surfaces), the accepted methods of planning experiments and presenting results. The results obtained are presented. It is established that the considered relationships can be modeled with sufficient accuracy by statistical methods and can be described by polynomials of the first or second degree. Shows the nature of the change Ra, Hμ, σ1 and σ2, with changes of V and S. Given are calculated according to Ra, Hμ, σ1 and σ2 from V and S.

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Statistics and parallaxes

International Astronomical Union Colloquium ◽

10.1017/s0252921100073875 ◽

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.

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Defocus ramp correction in spot-scan imaging

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100121053 ◽

1992 ◽

Vol 50 (1) ◽

pp. 130-131

Author(s):

Kenneth H. Downing

Keyword(s):

Computer Control ◽

Three Dimensional ◽

Sufficient Accuracy ◽

Objective Lens ◽

Electron Crystallography ◽

Contrast Transfer Function ◽

Tilt Axis ◽

Specimen Height ◽

The Difference ◽

Envelope Functions

Three-dimensional structures of a number of samples have been determined by electron crystallography. The procedures used in this work include recording images of fairly large areas of a specimen at high tilt angles. There is then a large defocus ramp across the image, and parts of the image are far out of focus. In the regions where the defocus is large, the contrast transfer function (CTF) varies rapidly across the image, especially at high resolution. Not only is the CTF then difficult to determine with sufficient accuracy to correct properly, but the image contrast is reduced by envelope functions which tend toward a low value at high defocus.We have combined computer control of the electron microscope with spot-scan imaging in order to eliminate most of the defocus ramp and its effects in the images of tilted specimens. In recording the spot-scan image, the beam is scanned along rows that are parallel to the tilt axis, so that along each row of spots the focus is constant. Between scan rows, the objective lens current is changed to correct for the difference in specimen height from one scan to the next.

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