Des nouvelles courbes de polarisation et de radiances en fonction de l’angle de diffusion sont étudiées à _ = 632,8 nm et 543,5 nm en utilisant des instruments PROGRA2 (Propriétés Optiques des GRains Astronomiques et Atmosphériques) pour différents types d'échantillons de suie et de noir de carbone en lévitation dans l’air et déposés sur une surface. Les échantillons de suie sont produits dans des conditions de combustion différentes, affectant ainsi leurs propriétés morphologiques. Un générateur de suie a été également utilisé pour étudier des suies ‘jeunes’ émises par la combustion du propane. Une comparaison des propriétés optiques entre les suies en lévitation et déposées sur une surface a été discutée. Enfin, ces courbes sont comparées à celles produites par différents types de sable. Les amplitudes de polarisation produites par la suie diffèrent en fonction du diamètre des particules primaires et de la distribution en taille. Ces courbes seules sont donc insuffisantes pour estimer la nature des agglomérats solides qui pourraient être détectés par des mesures à distance dans la stratosphère. D'autre part les courbes de radiance produites par ces échantillons montrent un comportement différent de celles produites par les échantillons de sable et par la poussière interplanétaire. Il est donc important lors de l'interprétation des mesures stratosphériques de combiner les courbes de radiances avec les courbes de polarisation pour déterminer la nature des agglomérats et de fournir des informations sur la nature de suie détectée telle que la taille des particules primaires ainsi que la distribution en taille. / New polarization and brightness curves as function of scattering angle are studied at _= 632.8 nm and 543.5 nm using PROGRA2 instruments (Propriétés Optiques des Grains Astronomiques et Atmosphériques) for different kinds of soot samples and carbon-black samples levitating in a cloud and deposited on a surface. The soot samples are generated under different combustion conditions, thus affecting their optical properties. A soot generator was also used to study fresh samples issued from propane combustion. A comparison between soot levitating on a cloud and deposited on surface was discussed. Finally these curves are compared to those produced by different kind of sand. The amplitudes of polarization produced by soot differ significantly depending on the primary particle diameter and on size distribution. These curves alone are then not sufficient to estimate the nature of the solid agglomerates that could be detected by remote measurements in the stratosphere. On the other hand the curves of brightness produced by these samples show a behavior different from those produced by the sand samples and that produced by interplanetary dust. It is therefore important in the interpretation of stratospheric measurements to combine the brightness with the polarization curves to identify the nature of the agglomerates and to provide information on the nature of soot detected as the primary particle diameter and size distribution.

No description available.

Thesis (Ph. D.)--University of Oregon, 2000. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 94-96). Also available for download via the World Wide Web; free to University of Oregon users.

No description available.

No description available.

No description available.

Brightness judgments are a key part of the primate brain's visual analysis of the environment. There is general consensus that the perceived brightness of an image region is based not only on its actual luminance, but also on the photometric structure of its neighborhood. However, it is unclear precisely how a region's context influences its perceived brightness. Recent research has suggested that brightness estimation may be based on a sophisticated analysis of scene layout in terms of transparency, illumination and shadows. This work has called into question the role of low-level mechanisms, such as lateral inhibition, as explanations for brightness phenomena. Here we describe experiments with displays for which low-level and high-level analyses make qualitatively different predictions, and with which we can quantitatively assess the trade-offs between low-level and high-level factors. We find that brightness percepts in these displays are governed by low-level stimulus properties, even when these percepts are inconsistent with higher-level interpretations of scene layout. These results point to the important role of low-level mechanisms in determining brightness percepts.

The public security and working safety are the most important issue for technical engineers operated in nuclear power plant, to face the works with the equipment in nuclear power plant. An Ergonomics Knowledge and Intelligent DEsign System¡]EKIDES¡^ was developed by Munich University of Technology, Germany. EKIDES is a set of ergonomic project software, which has been applied to some institution, such as BMW, AUDI and RWE Essen. This thesis is mainly based on EKIDES, which is introduced to the ergonomic training as well as aids for staffs survey the operation of nuclear power plant. First, EKIDES has been translated to a Chinese version, which includes the existing task analysis, such as environmental factors, technical components, service manual and operating instructions, referring the data of body size, forces and motions, for the most basic requirement of ergonomics. Second, the customer information about the nuclear energy is added into the database, including basic rules and laws of nuclear power plant. Third, a remote function is linked into EKIDES. By utilizing a web-cam, one can have the convenience for monitoring security and a training for operating nuclear power plant. Finally, an assessment interface is developed by Visual Basic for testing the comfortableness of the panel color of instrument. From this program one has a questionnaire test for comfortable color. Through analysis, a distribution of comfortable color has been found out referring to the panel design for the future. This work can also be used for training new employees of nuclear power plant. This study has performed for testing some engineers in the Third Nuclear Power Plant of Taipower Co. in PingTung, Taiwan. A comfortable panel color and brightness distribution has been analyzed from color scale of red, orange, yellow, green, blue, indigo, purple, black and white. In accordance with the result, the comfortable color of background is in the range of blue, indigo and green, and the comfortable brightness of background is between 14 to 20 Lux.

No description available.

No description available.