scholarly journals Virtual time reference system: a unifying scheduling framework for scalable support of guaranteed services

2000 ◽  
Vol 18 (12) ◽  
pp. 2684-2695 ◽  
Author(s):  
Z.-L. Zhang ◽  
Z. Duan ◽  
Y.T. Hou
Keyword(s):  
Reference System ◽  
System A ◽  
Virtual Time ◽  
Guaranteed Services

May Fast Screen-Film Combinations be used for Cephalometry?

1978 ◽  
Vol 5 (4) ◽  
pp. 189-192 ◽  
Author(s):  
Agnar Halse ◽  
Måns Hedin
Keyword(s):  
Rare Earth ◽  
Reference System ◽  
Rare Earth Metals ◽  
High Definition ◽  
Film Density ◽  
System A ◽  
Linear Distance ◽  
Cephalometric Measurements ◽  
Phantom Head

Five fast screen-film combinations were tested and compared with a conventional high-definition system. A phantom head was radiographed using different tube voltages. One linear distance and four angles were measured on films with the same density. All the combinations were subjectively judged to be qualitatively inferior to the reference system. The loss in definition had little influence on the reliability of the cephalometric measurements as estimated from duplicate readings on identical films. The exposure required to obtain adequate film density was low, especially for the systems based on salts of rare earth metals.

scholarly journals Local Geometric and Gravimetric Datum and Its Relation to the Global Terrestrial Reference System

1980 ◽  
Vol 56 ◽  
pp. 225-228
Author(s):  
R. Kelm
Keyword(s):  
Gravity Field ◽  
Reference System ◽  
Earth Surface ◽  
System A ◽  
Surface Displacements ◽  
Active Tectonic ◽  
Tectonic Zones ◽  
Gravity Disturbances ◽  
Terrestrial Reference System ◽  
Relative Gravity

AbstractIn active tectonic zones relative earth surface displacements of mm-order and, relative gravity disturbances of 0.1 mgal size may be expected between two survey epochs. To monitor and separate these small effects significantly special local free networks have to be designed which are measured by relative observations of highest accuracy (mm-and ygal-level). For the connection of the local nets to a global terrestrial reference system a suitable local datum for point coordinates (geometric datum) and gravity field parameters (gravimetric datum) has to be defined within the terrestrial reference system.

Brain SPECT imaging within the Talairach reference system: a simple registration algorithm

1998 ◽  
Author(s):  
Jean Meunier ◽  
Bernard Imbert ◽  
Christian Janicki ◽  
Jean-Paul Soucy
Keyword(s):  
Reference System ◽  
Brain Spect ◽  
Spect Imaging ◽  
Registration Algorithm ◽  
System A

Viewpoint - Semiotics: A Winning Formula?

2009 ◽  
Vol 51 (3) ◽  
pp. 1-4
Author(s):  
Chris Arning
Keyword(s):  
Reference System ◽  
Short Term ◽  
Brand Valuation ◽  
System A ◽  
Investment Value ◽  
Industry Standards ◽  
Consistent Performance ◽  
Compare And Contrast ◽  
Benchmarking System ◽  
Over Time

The article discusses semiotics and argues that it is widely misunderstood by researchers, because it lacks a convincing means of assuring quality and guarantees of consistent performance. Industry standards need to be created for semiotics. In the short term this could be done by creating a benchmarking system: a ‘semiotic value index, or SVI for short: ‘Semiotic’ because it attempts to measure units of symbolic investment; ‘value’ because it would quantify this figure; ‘index’ both because this has resonances of a reference system and gives the means to compare and contrast brands and track them over time. Successful examples of this approach in other areas are reviewed. A process for achieving SVI is proposed: a committee of practitioners to decide criteria and how to gather them, next a step-by-step formulaic calculation. The Interbrand model of brand valuation shows how this could work in practice.

New Design for a Differentially Pumped Hydration Chamber for a Siemens IA

1971 ◽  
Vol 29 ◽  
pp. 44-45
Author(s):  
R. C. Moretz ◽  
G. G. Hausner ◽  
D. F. Parsons
Keyword(s):  
Electron Microscopy ◽  
Water Vapor ◽  
Electron Diffraction ◽  
Water Vapor Pressure ◽  
Biological Materials ◽  
Thin Membrane ◽  
Reliable System ◽  
System A ◽  
Water Films ◽  
Aperture Opening

Electron microscopy and diffraction of biological materials in the hydrated state requires the construction of a chamber in which the water vapor pressure can be maintained at saturation for a given specimen temperature, while minimally affecting the normal vacuum of the remainder of the microscope column. Initial studies with chambers closed by thin membrane windows showed that at the film thicknesses required for electron diffraction at 100 KV the window failure rate was too high to give a reliable system. A single stage, differentially pumped specimen hydration chamber was constructed, consisting of two apertures (70-100μ), which eliminated the necessity of thin membrane windows. This system was used to obtain electron diffraction and electron microscopy of water droplets and thin water films. However, a period of dehydration occurred during initial pumping of the microscope column. Although rehydration occurred within five minutes, biological materials were irreversibly damaged. Another limitation of this system was that the specimen grid was clamped between the apertures, thus limiting the yield of view to the aperture opening.

High-resolution electron microscopy of Cu2O surfaces

1986 ◽  
Vol 44 ◽  
pp. 396-397
Author(s):  
V. Castano ◽  
W. Krakow
Keyword(s):  
High Resolution ◽  
Natural Extension ◽  
High Resolution Electron Microscopy ◽  
Point Of View ◽  
Initial Oxidation ◽  
System A ◽  
Resolution Electron ◽  
Surface Reconstructions ◽  
Atomic Surface ◽  
Au Thin Films

In non-UHV microscope environments atomic surface structure has been observed for flat-on for various orientations of Au thin films and edge-on for columns of atoms in small particles. The problem of oxidation of surfaces has only recently been reported from the point of view of high resolution microscopy revealing surface reconstructions for the Ag2O system. A natural extension of these initial oxidation studies is to explore other materials areas which are technologically more significant such as that of Cu2O, which will now be described.

Twin boundary structure of a Y-Ba-Cu-O superconductor

1989 ◽  
Vol 47 ◽  
pp. 168-169
Author(s):  
Yimei Zhu ◽  
Masaki Suenaga ◽  
R. L. Sabatini ◽  
Youwen Xu
Keyword(s):  
Twin Boundary ◽  
Fine Particles ◽  
Imaging Techniques ◽  
Fine Powder ◽  
Orthorhombic Phase ◽  
Boundary Structure ◽  
Crystallographic Axis ◽  
System A ◽  
High Resolution Structure ◽  
Electron Microscopes

The (110) twin structure of YBa2Cu3O7 superconductor oxide, which is formed to reduce the strain energy of the tetragonal to orthorhombic phase transformation by alternating the a-b crystallographic axis across the boundary, was extensively investigated. Up to now the structure of the twin boundary still remained unclear. In order to gain insight into the nature of the twin boundary in Y-Ba-Cu-O system, a study using electron diffraction techniques including optical and computed diffractograms, as well as high resolution structure imaging techniques with corresponding computer simulation and processing was initiated.Bulk samples of Y-Ba-Cu-O oxide were prepared as described elsewhere. TEM specimens were produced by crushing bulk samples into a fine powder, dispersing the powder in acetone, and suspending the fine particles on a holey carbon grid. The electron microscopy during this study was performed on both a JEOL 2000EX and 2000FX electron microscopes operated at 200 kV.

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