A Molecular Quasi-Hydrodynamic Free-Space Model for Melocular Rotational Relaxation in Liquids

1981 ◽  
Vol 85 (24) ◽  
pp. 3734-3734
Author(s):  
Janis L. Dote ◽  
Daniel Kivelson ◽  
Robert N. Schwartz
Keyword(s):  
Free Space ◽  
Rotational Relaxation ◽  
Space Model

A molecular quasi-hydrodynamic free-space model for molecular rotational relaxation in liquids

1981 ◽  
Vol 85 (15) ◽  
pp. 2169-2180 ◽  
Author(s):  
Janis L. Dote ◽  
Daniel Kivelson ◽  
Robert N. Schwartz
Keyword(s):  
Free Space ◽  
Rotational Relaxation ◽  
Space Model

Multivalue coding: application to autonomous robots

Robotica ◽  
1992 ◽  
Vol 10 (2) ◽  
pp. 125-133 ◽  
Author(s):  
A. Pruski
Keyword(s):  
Path Planning ◽  
Free Space ◽  
Autonomous Robots ◽  
Switching Function ◽  
Numerical Comparison ◽  
Robot Path Planning ◽  
Space Model ◽  
Space Modeling ◽  
Operating Method ◽  
Robot Path

SUMMARYThe paper describes a free space modeling method by multivalue coding. Each code defines some numerical values representing a set of cells from a grid. The idea consists in using the grid as a Karnaugh board whose rows and columns are binary coded rather than Gray coded. This operating method allows to define, for each code, its grid location and allows numerical comparison in order to locate a code relatively to another. This aspect is helpful for path planning. The free space model is represented by a switching function or a tree to which boolean algebra rules and mathematic operations are applied. We describe an application to mobile robot path planning.

Dielectric permittivity and resistivity mapping using high‐frequency, helicopter‐borne EM data

Geophysics ◽  
2002 ◽  
Vol 67 (3) ◽  
pp. 727-738 ◽  
Author(s):  
Haoping Huang ◽  
Douglas C. Fraser
Keyword(s):  
Dielectric Permittivity ◽  
Half Space ◽  
High Frequency ◽  
Free Space ◽  
Apparent Resistivity ◽  
Phase Component ◽  
High Frequencies ◽  
Space Model ◽  
Homogeneous Half Space ◽  
Displacement Currents

The interpretation of helicopter‐borne electromagnetic (EM) data is commonly based on the transformation of the data to the apparent resistivity under the assumption that the dielectric permittivity is that of free space and so displacement currents may be ignored. While this is an acceptable approach for many applications, it may not yield a reliable value for the apparent resistivity in resistive areas at the high frequencies now available commercially for some helicopter EM systems. We analyze the feasibility of mapping spatial variations in the dielectric permittivity and resistivity using a high‐frequency helicopter‐borne EM system. The effect of the dielectric permittivity on the EM data is to decrease the in‐phase component and increase the quadrature component. This results in an unwarranted increase in the apparent resistivity (when permittivity is neglected) for the pseudolayer half‐space model, or a decrease in the apparent resistivity for the homogeneous half‐space model. To avoid this problem, we use the in‐phase and quadrature responses at the highest frequency to estimate the apparent dielectric permittivity because this maximizes the response of displacement currents. Having an estimate of the apparent dielectric permittivity then allows the apparent resistivity to be computed for all frequencies. A field example shows that the permittivity can be well resolved in a resistive environment when using high‐frequency helicopter EM data.

scholarly journals Photon storage inΛ-type optically dense atomic media. II. Free-space model

2007 ◽  
Vol 76 (3) ◽  
Author(s):  
Alexey V. Gorshkov ◽  
Axel André ◽  
Mikhail D. Lukin ◽  
Anders S. Sørensen
Keyword(s):  
Free Space ◽  
Space Model ◽  
Atomic Media

Mapping of the resistivity, susceptibility, and permittivity of the earth using a helicopter‐borne electromagnetic system

Geophysics ◽  
2001 ◽  
Vol 66 (1) ◽  
pp. 148-157 ◽  
Author(s):  
Haoping Huang ◽  
Douglas C. Fraser
Keyword(s):  
Dielectric Properties ◽  
Dielectric Permittivity ◽  
Half Space ◽  
Magnetic Permeability ◽  
Free Space ◽  
Electromagnetic System ◽  
Space Model ◽  
The Earth

Interpretation of helicopter‐borne electromagnetic (EM) data is commonly based on the mapping of resistivity (or conductivity) under the assumption that the magnetic permeability is that of free space and dielectric permittivity can be ignored. However, the data obtained from a multifrequency EM system may contain information about the magnetic permeability and dielectric permittivity as well as the conductivity. Our previous work has shown how helicopter EM data may be transformed to yield the resistivity and magnetic permeability or, alternatively, the resistivity and dielectric permittivity. A method has now been developed to recover the resistivity, magnetic permeability, and dielectric permittivity together from the transformation of helicopter EM data based on a half‐space model. A field example is presented from an area which exhibits both permeable and dielectric properties. This example shows that the mapping of resistivity, magnetic permeability, and dielectric permittivity together yields more credible results than if the permeability or permittivity is ignored.

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