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 Results from Three Dimensional Spectral Classification of Population II Stars Using the DDO Photometric System

1973 ◽  
Vol 50 ◽  
pp. 176-182
Author(s):  
W. Osborn
Keyword(s):  
Globular Clusters ◽  
Three Dimensional ◽  
Photometric System ◽  
Horizontal Branch ◽  
Intermediate Band ◽  
Theoretical Predictions ◽  
The Mean ◽  
Red Giant ◽  
The Masses

The David Dunlap Observatory (DDO) intermediate-band photometric system described in the previous paper has been used to observe a number of red giant branch, horizontal branch, and asymptotic branch members in each of the five globular clusters M3, M5, M10, M13, and M92. A calibration of the DDO system is described by which it was possible to determine the effective temperatures, surface gravities, [Fe/H] values, and masses of the observed stars. The mean [Fe/H] values for the clusters were found to be −1.01 for M3, −0.68 for M5, −1.44 for M10, −1.69 for M13, and −1.96 for M92. Evidence was found that the masses of the horizontal branch and asymptotic branch stars are systematically smaller than those of red giant branch members. Two stars were discovered to have CN bands that are anomalously strong for Population II objects. The observational results have been compared with the theoretical predictions of two detailed Population II evolutionary tracks and in general the agreement is good.

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 Globular Clusters in the Vilnius Photometric System

1988 ◽  
Vol 126 ◽  
pp. 515-516
Author(s):  
K. Zdanavičius
Keyword(s):  
Globular Clusters ◽  
Photometric System ◽  
Two Dimensional ◽  
Halo Stars ◽  
Dimensional Classification

The Vilnius photometric system was developed for photometric two-dimensional classification of stars and for the determination of interstellar reddening. The system consists of seven magnitudes U, P, X, Y, Z, V and S with mean wavelengths of 345, 375, 405, 466, 516, 544 and 655 nm and half-widths of the order 20 – 30 nm (Straižys 1977). Later on the system was successfully used for the determination of temperatures and the metallicities of halo stars (Bartkevičius and Sperauskas 1983).

scholarly journals Review of tetrahedrites from Bulgarian deposits in the light of changes in nomenclature and classification of these minerals taken in 2019

2020 ◽  
Vol 81 (1) ◽  
pp. 3-15
Author(s):  
Vladislav Kostov-Kytin
Keyword(s):  
Spatial Distribution ◽  
Chemical Composition ◽  
Electron Probe ◽  
Mineral Species ◽  
Published Data ◽  
Crystal Chemical ◽  
International Mineralogical Association ◽  
Mineralogical Association ◽  
Chemical Trends

The crystal-chemical peculiarities of the minerals in the tetrahedrite group are considered as a prerequisite for their role as indicators of the formation environment. Particular attention is paid to the silver-containing representatives because they comprise more than 60% of the Bulgarian tetrahedrites and because the recently adopted by the International Mineralogical Association changes in the nomenclature and classification within this group affect most sensitively them and their relation to a given series, mineral species or variety. The achievements of the Bulgarian mineralogical science in the study of tetrahedrites are briefly presented, and various aspects are considered, illustrating the efforts of the researchers to cover the diversity of these minerals as well as the opportunity to derive from this various crystal-chemical, geochemical and other mineralogical information. In the light of the adopted changes, already published data from 450 electron-probe microanalyses of samples from 45 localities distributed in three metallogenic zones in the country have been processed. The established crystal-chemical trends in the spatial distribution of tetrahedrites in Bulgaria generally confirm and extend the observations of previous researchers. It has been shown that, by their chemical composition, these minerals can be carriers of typomorphic characteristics, both for individual deposits and for metallogenic zones. The information and data provided may serve to: (i) correctly determine the mineral species of the newly investigated tetrahedrites and their affiliation to a given series; (ii) what compositions may be sought or expected according to the location of the investigated localities; (iii) comparing the new results to previous ones to confirm, correct or reject established models and trends.

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

Classification of Impossible Objects

Perception ◽  
1982 ◽  
Vol 11 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Kōkichi Sugihara
Keyword(s):  
Visual Perception ◽  
Three Dimensional ◽  
Point Of View ◽  
Psychological Problems ◽  
Human Visual Perception ◽  
Psychological Study ◽  
Mathematical Point ◽  
Solid Objects ◽  
Psychological Point

A mathematical scheme is proposed for the classification of impossible objects. Impossible objects are usually defined from a psychological point of view as mental images of ‘solid objects’ which cannot exist in a real three-dimensional world. From the mathematical point of view, however, various kinds of impossibility can be observed in such objects, and they are classified according to the kinds of impossibility they possess. Since impossible objects are treated in a purely mathematical way, the results afford a powerful basis for the psychological study of human visual perception of impossible objects. Several psychological problems arising from the present results are also discussed.

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.

Sign in / Sign up

Export Citation Format

Share Document