scholarly journals Advocating a statistical definition for the BRDF

2022 ◽  
Vol 2149 (1) ◽  
pp. 012013
Author(s):  
P Chavel ◽  
Y Sortais ◽  
T Labardens ◽  
L Simonot ◽  
M Hébert ◽  
...  
Keyword(s):  
Angular Resolution ◽  
Spatial Coherence ◽  
Geometrical Optics ◽  
Optical Effect ◽  
Statistical Average ◽  
Stochastic Nature ◽  
Reflection Process ◽  
Diffraction Of Light ◽  
Definition Of ◽  
Statistical Definition

Abstract The definition of BRDF as a ratio of radiance to irradiance assumes that the geometrical optics framework applies, implicitly meaning that spatial coherence and diffraction of light have no significant effect in the reflection process. However, recent applications of BRDF push at increasing the angular resolution and thus at reducing the solid angles for illumination and collection. Therefore speckle, an optical effect inherent to the stochastic nature of scattering objects, becomes apparent. We suggest that BRDF should be redefined as the statistical average over that effect.

UNCERTAINTY BASED ROBUST OPTIMIZATION IN AERODYNAMICS

2009 ◽  
Vol 23 (03) ◽  
pp. 477-480 ◽  
Author(s):  
ZHILI TANG
Keyword(s):  
Nash Equilibrium ◽  
Robust Design ◽  
Single Point ◽  
Optimization Method ◽  
Equilibrium Solutions ◽  
Design Problems ◽  
Nash Equilibrium Solutions ◽  
Definition Of ◽  
Taguchi Robust Design ◽  
Statistical Definition

The Taguchi robust design concept is combined with the multi-objective deterministic optimization method to overcome single point design problems in Aerodynamics. Starting from a statistical definition of stability, the method finds, Nash equilibrium solutions for performance and its stability simultaneously.

A review and refinement of the concept of containment for the management of invasive plants

2020 ◽  
Vol 68 (8) ◽  
pp. 602
Author(s):  
A. C. Grice ◽  
H. T. Murphy ◽  
J. R. Clarkson ◽  
M. H. Friedel ◽  
C. S. Fletcher ◽  
...  
Keyword(s):  
Management Practice ◽  
Management Strategies ◽  
Plant Invasions ◽  
Research Literature ◽  
Stochastic Nature ◽  
Strategic Objective ◽  
Scientific Principles ◽  
Spatial Configurations ◽  
Frequent Failure ◽  
Definition Of

Containment is a frequently advocated strategic objective for countering plant invasions. It is commonly perceived that it is the valid fall-back option when eradication has failed or is deemed impossible with the available resources. We reviewed management and research literature on containment. The lack of a clear, universally accepted definition of containment is problematic and containment practice is not well aligned with the limited research literature. Vague and inconsistent use of the term, poorly developed relationships between management practice and the ecological drivers of invasion, and frequent failure to specify appropriately scaled spatial configurations in management strategies make it difficult to evaluate containment as a strategy, generally or in specific cases. Management strategies rarely provide the basis for effective and efficient containment programs and this may reflect a lack of under-pinning scientific principles. We recommend that containment be defined as ‘deliberate action taken to prevent establishment and reproduction of a species beyond a predefined area’ and suggest that containment efforts should focus on individual infestations or populations but simultaneously cover all infestations or populations that are separated from one another by habitat suitable for the species. Containment units should be rigorously defined but the inevitability of breaches of these containment units, due to the stochastic nature of dispersal, implies that containment generally requires a capacity for local eradication (extirpation). This means that many infestations are no more amenable to containment than to eradication. The measures we propose would improve assessment of the feasibility and success of containment strategies.

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