Results 301 to 310 of about 4,651,873 (337)

Verification of Optical Distance Indicator Accuracy

Medical Dosimetry, 1991
The purpose of the optical distance indicator, or rangefinder, is to set the patient at a certain distance from the radiotherapy source when using either fixed SSD or an isocentric technique. If the distance that is set is not accurate, then the tumor dose calculated using this distance is also incorrect.
S, Burch, A M, Vann, J, Arazie
openaire   +2 more sources

Surface brightness fluctuations as primary and secondary distance indicators

, 2012
The surface brightness fluctuations (SBF) method measures the variance in a galaxy’s light distribution arising from fluctuations in the numbers and luminosities of individual stars per resolution element.
J. Blakeslee
semanticscholar   +1 more source

The Local Distance Network: A community consensus report on the measurement of the Hubble constant at ∼1% precision

Astronomy & Astrophysics
The direct empirical determination of the local value of the Hubble constant (̋cst) has markedly advanced thanks to improved instrumentation, measurement techniques, and distance estimators.
H0DN Collaboration Stefano Casertano, G. Anand, Richard I. Anderson, Rachael Beaton, Anupam Bhardwaj, John P. Blakeslee, Paula Boubel, L. Breuval, D. Brout, M. Cantiello, M. Reyes, G. Csornyei, T. D. Jaeger, S. Dhawan, E. D. Valentino, Lluís Galbany, H. Gil-Mar'in, D. Graczyk, Caroline Huang, Joseph B. Jensen, Pierre Kervella, B. Leibundgut, Bastian Lengen, Siyang Li, L. Macri, Emre Ozulker, D. Pesce, A. Riess, M. Romaniello, Khaled Said, N. Schoneberg, D. Scolnic, Teresa Sicignano, D. Skowron, S. A. Uddin, L. Verde, A. S. R. Institute, I. Physics, 'Ecole polytechnique f'ed'erale de Lausanne, Observatoire de Sauverny, Inter-University Centre for Astronomy, Astrophysics, NSF's NOIRLab, Research School of Astronomy Astrophysics, Australian National University, E. Agency, Esa Office, Space Telescope Science Institute, Boston University Departments of Astronomy, Physics, I. -. A. O. O. Abruzzo, Max-Planck Institute for Astrophysics, Garching, Sorbonne Universit'e, Cnrs, Laboratoire de Physique Nucl'eaire et des Hautes Energies, S. O. Physics, Astronomy, U. Birmingham, School of Applied Mathematical, P. Sciences, U. Sheffield, Institute of Space Sciences, I. D. E. D. Catalunya, Institut de Ci'encies del Cosmos, U. Barcelona, D. Astrof'isica, P. A. O. Sciences, N. A. Center, D. O. Astrophysics, Center for Astrophysics Harvard Smithsonian, D. Physics, Utah Valley University, Lira, Observatoire de Paris, Universit'e Psl, Universit'e de Paris Cit'e, French-Chilean Laboratory for Astronomy, Irl 3386, U. D. Chile, E. Observatory, D. O. Astronomy, J. University, D. O. Astronomy, U. California, Berkeley, College of Optical Sciences, University of Texas Rio Grande Valley, S. O. Mathematics, U. Queensland, University Observatory, F. O. Physics, Ludwig-Maximilians-Universitat, Excellence Cluster Origins, D. University, Scuola Superiore Meridionale, I. -. Capodimonte, Astronomical Observatory, U. Warsaw, American Public University System, C. F. Astronomy, S. Science, I. University, Bangladesh., I. C. D. R. I. E. Avanccats, I. S. S. Institute   +105 more
semanticscholar   +1 more source

Novae as Distance Indicators

2003
We review the status of Novae as distance indicators. We discuss the problem of the correct calibration of the life-luminosity relationship for Galactic novae on the basis of the properties of the M31 and LMC nova populations and show that linear regressions, normally used to interpolate the Galactic data, fit M31 and LMC only as a very rough first ...
Roberto Gilmozzi, Massimo Della Valle
openaire   +1 more source

Relation between Distance-Based Topological Indices

Journal of Chemical Information and Computer Sciences, 2000
The pi-index of the line graph of the molecular graph of an alkane is shown to be related to the pi, Harary, and reciprocal Wiener indices of that alkane. Thus a mathematical relation between several distance-based topological indices is obtained.
Ivan Gutman, Zeljko Tomoviç
openaire   +2 more sources

On metagalactic distance-indicators

Vistas in Astronomy, 1956
Abstract First, an historical outline is given of the “Island-Universe” conception ( Galilei , 1609), and of the development of our knowledge of the nebulae. The cosmological views of the eighteenth century are surveyed, and in particular the developments in England during the Restoration Period (1660–1700), the Augustan Age (1700–1745), and the era ...
openaire   +1 more source

Indicators of Genetic Distance

1974
In recent years, considerable attention has been devoted to measuring the genetic distance between populations, and several indices of distance have been proposed and used.
openaire   +1 more source

Distance Indicators: Beyond Distances — A Return to Astrophysics

1995
Continuing progress in the development, application, and physical understanding of distance indicators is likely to yield a generally accepted value for the Hubble constant during the VLT construction years. Thus, the VLT’s contribution to that highly visible subfield is unlikely to be pivotal.
openaire   +1 more source

Distance based indices in nanotubical graphs. II

2018
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Andova, Vesna, Knor, Martin, Škrekovski, Riste   +2 more
openaire   +2 more sources

Magellanic Clouds' Binaries as Distance Indicators

2001
Detached eclipsing binary systems of B-type stars in the Large and Small Magellanic Clouds have been observed in order to determine distances to these galaxies. We obtained high resolution spectra using the UVES spectrograph at the VLT, ESO. Analysis of the spectra with strongly overlapping spectral lines, which are heavily broadened by the Stark ...
Dominis, Dijana, Butler, Keith, Simon, Klaus, Clausen, J.V., Pritchard, J.   +4 more
openaire   +3 more sources