We propose a method to determine the light direction and diffuse reflectance property from two images with different light conditions. In our method, it is assumed that the shape of the target object is given. Using the relationships between light direction and diffuse reflectance, we can estimate both of them simultaneously from more than five points on two images. While speculars and shadows ...

This research investigates the performance of an active optical imaging radar system which is viewino a diffusely reflecting rough surface through the turbulent atmosphere. The mathematical formulation of this problem is not amenable to standard statistical techniques so that we examine a collection of related simplifications in order to evaluate the performance of this system. The results thus...

We propose a technique to modify colors in photographic images predicting the color appearance of objects in an image under different illuminations. Using the dichromatic surface reflectance model, we estimate the illumination spectrum and the spectrum of the diffuse surface reflectance via the color histogram and subspace analyses. With this estimated spectral information, and the spectrum of ...

We describe a method for the application of a highly reflectant, diffuse coating to the interior of light integration boxes. Simple box design considerations are presented in addition to techniques for dealing with a variety of problems which we have experienced. An analysis of the performance of a light integration box of 4 m 2 surface area is given. The overall box reflectivity is found to be...

We investigate the speed of approach to Maxwellian equilibrium for a collisionless gas enclosed in a vessel whose wall are kept at a uniform, constant temperature, assuming diffuse reflection of gas molecules on the vessel wall. We establish lower bounds for potential decay rates assuming uniform Lp bounds on the initial distribution function. We also obtain a decay estimate in the spherically ...

The analytical description of the volume reflection of the charged ultrarelativistic particles in bent single crystals is considered. The relation describing the angle of volume reflection as a function of the transversal energy is obtained. The different angle distributions of the scattered protons in the single crystals are found. Results of calculations for 400 GeV protons scattered by the s...

Recent studies have suggested that a two-photon Lyman alpha driven absorption mechanism in H2 or H + 2 is responsible for the diffuse interstellar absorption bands. This hypothesis differs radically from previous theories on the origin of the diffuse interstellar bands. In order to test the validity of the H+2 hypothesis, a study is undertaken to calculate the exact properties of the H+2 spectr...

We show that a generalized Landau theory for the smectic A and C phases exhibits a biaxiality induced AC tricritical point. Proximity to this tricritical point depends on the degree of orientational order in the system; for sufficiently large orientational order the AC transition is 3D XY like, while for sufficiently small orientational order, it is either tricritical or 1st order. We investiga...

The responsivity to diffuse radiation of a solar cell based pyranometer is studied. Diffuse measurements are made using a shade disk for a LiCor Pyranometer and an Eppley PSP pyranometer mounted side by side on an automatic tracker. The difference in the diffuse responsivity varies by 30 to 40% between cloudy conditions and clear skies. This difference is attributed to the spectral dependence o...

Structural disorder appears to relate to the useful physical properties of ferroelectrics and relaxors. One such material is PZN, PbZn1/3Nb2/3O3. To explore what aspects of the disorder are specific to the polarised state, the temperature dependence of diffuse scattering in PZN has been investigated. Data were collected using both neutron and X-ray single crystal experiments in a range of tempe...