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Generalized Stochastic Subdivision
 ACM Transactions on Graphics
, 1987
"... This paper describes the basis for techniques such as stochastic subdivision in the theory of random processes and estimation theory. The popular stochastic subdivision construction is then generalized to provide control of the autocorrelation and spectral properties of the synthesized random functi ..."
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Cited by 37 (2 self)
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This paper describes the basis for techniques such as stochastic subdivision in the theory of random processes and estimation theory. The popular stochastic subdivision construction is then generalized to provide control of the autocorrelation and spectral properties of the synthesized random functions. The generalized construction is suitable for generating a variety of perceptually distinct highquality random functions, including those with nonfractal spectra and directional or oscillatory characteristics. It is argued that a spectral modeling approach provides a more powerful and somewhat more intuitive perceptual characterization of random processes than does the fractal model. Synthetic textures and terrains are presented as a means of visually evaluating the generalized subdivision technique. Categories and Subject Descriptors: I.3.3 [Computer Graphics]: Picture/Image Generation; I.3.7 [Computer Graphics]: Three Dimensional Graphics and Realism <F11.
Continuum Field Model of Street Canyon: Numerical Examples, Engineering Transactions
, 1999
"... A general proecological urban road traffic control idea for the street canyon is proposed with emphasis placed on development of advanced continuum field gasdynamical (hydrodynamical) control model of the street canyon. The continuum field model of optimal control of street canyon is studied. The ma ..."
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Cited by 5 (5 self)
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A general proecological urban road traffic control idea for the street canyon is proposed with emphasis placed on development of advanced continuum field gasdynamical (hydrodynamical) control model of the street canyon. The continuum field model of optimal control of street canyon is studied. The mathematical physics ’ approach (Eulerian approach) to vehicular movement, to pollutants ’ emission, and to pollutants’ dynamics is used. The rigorous mathematical model is presented, using gasdynamical (hydrodynamical) theory for both air constituents and vehicles, including many types of vehicles and many types of pollutant (exhaust gases) emitted from vehicles. The six optimal control problems are formulated. 1 Description of the model. In the present article we develop a continuum field model of the street canyon. In the next article we will deal with numerical examples [1]. The vehicular flow in the canyon is multilane bidirectional onelevel rectilinear, and it is considered with two coordinated signalized junctions [2, 3, 4]. The vehicles belong to different vehicular classes: passenger
Ray Tracing in NonConstant Media
 In Proc. Eurographics Workshop on Rendering
, 1996
"... . In this paper, we explore the theory of optical deformations due to continuous variations of the refractive index of the air, and present several efficient implementations. We introduce the basic equations from geometrical optics, outlining a general method of solution. Further, we model the fluct ..."
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. In this paper, we explore the theory of optical deformations due to continuous variations of the refractive index of the air, and present several efficient implementations. We introduce the basic equations from geometrical optics, outlining a general method of solution. Further, we model the fluctuations of the index of refraction both as a superposition of blobs and as a stochastic function. Using a well known perturbation technique from geometrical optics, we compute linear approximations to the deformed rays. We employ this approximation and the blob representation to efficiently ray trace non linear rays through multiple environments. In addition we present a stochastic model for the ray deviations derived from an empirical model of air turbulence. We use this stochastic model to precompute deformation maps. 1
Prepared for the Federal Aviation Administration,
, 1988
"... This document is available to the public through the National Technical Information Service, Springfield, VA 22161This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its ..."
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This document is available to the public through the National Technical Information Service, Springfield, VA 22161This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. 2List of Errors: pg.5 Definitions concerning equation {2) are incorrect. 7 (ratio of specific heats is written as "g". T is written as "t '. pg.6 Definitions concerning c9uation (~~) are incorrect. Units 011 Da are wrong. Air density p is written as "r '. pg.8 Equation (7) should read 1\1/2 instcad of D il The following sentence should rea.d "... comparing Eqs. (:3) and (5)... " rather than "...(3) and (4)...". U de is inversely proportional to V. The text states that fa is directly proportional to V 4 / 3 • In fact, it is (~/3 that is inversely proportional to V 4 / 3 • In the following paragraph, the text should read " whereas f)a l / 2 will be ratIler tI lan "...D 1/3 " a •.. • pg.22 Second paragraph: Text should read "(seeF'igure 2 and Table 4)", not "...
An EOF study of the Earth's ozone field
"... In a previous paper we discussed the spectral properties of the Earth's ozone layer, obtained using Empirical Orthogonal Function decomposition of the Total Ozone Mapping Spectrometer (TOMS) database. Here we present other aspects of the analysis, including the EOF method adapted for incomplete data ..."
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In a previous paper we discussed the spectral properties of the Earth's ozone layer, obtained using Empirical Orthogonal Function decomposition of the Total Ozone Mapping Spectrometer (TOMS) database. Here we present other aspects of the analysis, including the EOF method adapted for incomplete datasets, analysis of spatial structure and temporal variation of first several eigenfunctions, and an extended study of smallscale properties of ozone concentration fields. Geophysical datasets collected by satellitebased devices currently provide a wealth of information which needs to be assimilated and interpreted. In this paper we analyze the global ozone concentration fields measured by Total Mapping Ozone Spectrometer [1]. The interest in atmospheric ozone is due to both its environmental role (ozone hole phenomenon [2, 3]), and the fact that it can be regarded as a passive tracer, thus providing an additional insight in the properties of atmospheric circulation. This is an extended version of a previous paper [4], where the principal attention was paid to the spectral properties of the ozone concentration fields.
unknown title
, 2012
"... Review of earthviewing methods for inflight assessment of modulation transfer function and noise of optical spaceborne sensors A review of earthviewing methods for inflight assessment of modulation transfer function and noise of optical spaceborne sensors ..."
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Review of earthviewing methods for inflight assessment of modulation transfer function and noise of optical spaceborne sensors A review of earthviewing methods for inflight assessment of modulation transfer function and noise of optical spaceborne sensors
L 864 JOURNAL OF PHYSICAL OCEANOGRAPHY Volurrle I I Satellite Determination of the Mesoscale Variabitity of the Sea Surface Temperature
, 1980
"... centre deTélédétection et d'Analyse des Milieux Nalurels, Ecole Nationale supérieure des Mines cle paris,06560valbonne, France ..."
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centre deTélédétection et d'Analyse des Milieux Nalurels, Ecole Nationale supérieure des Mines cle paris,06560valbonne, France
Some Examples of the Use of Structure Functions in the Analysis of Satellite lmages of the Ocean
"... ABsrRAcr: This paper deals with the use of the structure function, also called a variogram, to analyze satellite images of the ocean. The sJructure function is a powerful tool for the description of twoldimensional'random fields."Its characteristics are used in two different examples. First, the beh ..."
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ABsrRAcr: This paper deals with the use of the structure function, also called a variogram, to analyze satellite images of the ocean. The sJructure function is a powerful tool for the description of twoldimensional'random fields."Its characteristics are used in two different examples. First, the behavior of ihe structure function close to its origin gives the variance of salt and pepper noise within an image. Such a method has been applied to various spaceborne sensors. Second, fitting the experimental structure function by a power law demonstratei ihe way the turbùlent energy at the surface of the ocean is transferred from scales to scales.