scholarly journals Microphotometry-Computer Classification of Objective-Prism Spectra

1973 ◽  
Vol 50 ◽  
pp. 125-126
Author(s):  
K. M. Yoss
Keyword(s):  
Figure Of Merit ◽  
Three Dimensional ◽  
Absolute Magnitude ◽  
Calibration Data ◽  
Dimensional Classification ◽  
Straight Line ◽  
Objective Prism ◽  
Computer Classification ◽  
Right Ascension

Three-dimensional classification of late-type stars is obtained through computer-processed digitized microphotometer data. Plate transmissions are converted to relative intensity through spot-sensitometer calibration data. A pseudo-continuum consisting of several straight-line segments is formed by connecting high points in the spectrum. Absorption-line strengths and line ratios are then measured. The temperature-and-luminosity-sensitive ratios are relatively insensitive to seeing effects. For plates with a dispersion of 108 Å mm-1, preliminary results indicate an accuracy in derived absolute magnitude comparable to, and possibly better than, that of MK classification.The CN anomaly serves as the abundance index. The CN index was defined in a manner to give the largest figure of merit (the ratio of total range of the index to the mean error). The adopted method is the same as that of Yoss and Lutz (1971) and has a figure of merit over twice that of the index similar to that of Griffin and Redman (1960).For field stars, plate X and Y positions are converted to equatorial coordinates and printed out in order of increasing right ascension, making quick and easy identification of the Henry Draper numbers.

Preliminary thoughts on a taxonomy of value for sustainable computing

First Monday ◽  
2015 ◽  
Author(s):  
Kentaro Toyama
Keyword(s):  
Three Dimensional ◽  
The Novel ◽  
Technology Sector ◽  
Technology Industry ◽  
Dimensional Classification ◽  
Future Work ◽  
Great Danger

In anticipation of the various and imminent limits to global consumption-based growth, some quarters of the technology industry have begun to consider the novel use of computing to prevent, postpone, alleviate, or recover from a crisis in what could be called “sustainable computing.” There is, however, a great danger that certain inclinations of the technology sector will undermine the very goals of sustainability and resilience that such efforts claim to seek.This paper outlines a preliminary taxonomy of value for sustainable computing projects. The taxonomy suggests a three-dimensional classification of projects in terms of their impact on, intention toward, and effort required for sustainability. By making explicit an evaluative framework by which computing might and might not contribute to sustainability goals, the hope is that future work will tend toward projects that are genuinely helpful.

scholarly journals Photometric Classification of Stars in the Vilnius Observatory

1973 ◽  
Vol 50 ◽  
pp. 183-185 ◽  
Author(s):  
V. Straižys
Keyword(s):  
Spatial Distribution ◽  
Chemical Composition ◽  
Stellar Evolution ◽  
Three Dimensional ◽  
Point Of View ◽  
Photometric System ◽  
Intermediate Band ◽  
Dimensional Classification

The programs of three-dimensional classification of stars using eight-color intermediate band photometric system are described. They include (1) investigation of interstellar reddening and absorption in the direction of objects significant from point of view of stellar evolution, (2) investigation of spatial distribution of stars of different spectral classes, luminosities and chemical composition, (3) the detection of unique objects.

scholarly journals Three-Dimensional Classification of Thoracic Scoliotic Curves

Spine ◽  
2009 ◽  
Vol 34 (1) ◽  
pp. 91-99 ◽  
Author(s):  
Archana P. Sangole ◽  
Carl-Eric Aubin ◽  
Hubert Labelle ◽  
Ian A. F. Stokes ◽  
Lawrence G. Lenke ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dimensional Classification

scholarly journals On the Practical Application of the MK and Related Spectral-Classification Systems to Spectrograms of Various Resolutions

1979 ◽  
Vol 47 ◽  
pp. 389-413 ◽  
Author(s):  
A. Ardeberg
Keyword(s):  
Classification Systems ◽  
Spectral Intensity ◽  
Normal Observer ◽  
Practical Application ◽  
Standard Star ◽  
Quantitative Classification ◽  
Dimensional Classification ◽  
Objective Prism ◽  
Good Coverage

AbstractFor MK classification of program field stars the “normal” observer is confronted with a number of practical problems, rendering classification on the true MK system very difficult. These problems concern completeness of standard-star grid, spectrogram resolution, comparison of originals-reproductions, spectrogram density levels, spectrogram widening and emulsion. A new atlas of slit spectrograms at 74 Å mm−1 is presented, giving good coverage especially for high-luminosity stars. MK classification from spectral intensity tracings is discussed. Advantages include easy distribution and sharing of standards, relaxation of resolution requirements and wide acceptable density range. Apparent shortcomings of the method seem easy to overcome. An atlas of spectral intensity tracings is presented. Some problems regarding objective-prism classification are discussed for higher as well as lower resolution. Quantitative classification methods are commented. Work in progress is presented on systems for two-dimensional classification of low-resolution objective-prism spectrograms of stars with spectral types earlier than G0.

Investigation of quantitative classification methods for early-type stars

1966 ◽  
Vol 24 ◽  
pp. 91-92
Author(s):  
U. Sinnerstad
Keyword(s):  
Absolute Magnitude ◽  
Classification Methods ◽  
Early Type ◽  
Quantitative Classification ◽  
Spectrophotometric Methods ◽  
Spectral Class ◽  
Dimensional Classification ◽  
Objective Prism ◽  
Early Type Stars ◽  
Low Dispersion

As is well known the spectrophotometric methods as introduced by B. Lindblad and developed at the Stockholm and Uppsala Observatories aim at relatively faint stars. The two-dimensional classification in terms of spectral class and absolute magnitude is based on spectrophotometric measures on objective-prism spectrograms of low dispersion (about 200Å/mm). The measures pertain to average intensities in bands having widths of about 30Å.

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