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991.
Baker S. Sim T. Kanade T. 《IEEE transactions on pattern analysis and machine intelligence》2003,25(1):100-109
The complete set of measurements that could ever be used by a passive 3D vision algorithm is the plenoptic function or light-field. We give a concise characterization of when the light-field of a Lambertian scene uniquely determines its shape and, conversely, when the shape is inherently ambiguous. In particular, we show that stereo computed from the light-field is ambiguous if and only if the scene is radiating light of a constant intensity (and color, etc.) over an extended region. 相似文献
992.
Neogi A. Everitt H. Morkoc H. Kuroda T. Tackeuchi A. 《Nanotechnology, IEEE Transactions on》2003,2(1):10-14
Self-assembled GaN quantum dots (QDs), grown on AlN by molecular beam epitaxy, were investigated by time-resolved photoluminescence spectroscopy. We investigate the emission mechanism in GaN QDs by comparing the carrier recombination dynamics in single and multiple period QDs. At 100 K, the PL decay time in single period QD structures is considerably shorter than in stacked QDs. Compared to single period QDs, the room temperature PL efficiency is considerably enhanced in 20 period QDs due to the reduction in nonradiative recombination processes. 相似文献
993.
994.
995.
P. T. Tsilingiris 《国际能源研究杂志》1991,15(9):723-730
The paper describes the calculation of the beam solar radiation transmission across the uniform salinity upper convecting zone (UCZ) and the salinity stratified gradient zone (GZ), when the extinction coefficient is not only wavelength but also salinity-concentration dependent, assuming that the effect of scattering to be negligible. The results are useful in determining the effects of dissolved salt ions on pure water transmission, at least according to the existing measured data in the literature. 相似文献
996.
An Arctangent Unwrapping Technique of Photoelasticity Using Linearly Polarized Light at Three Wavelengths 总被引:2,自引:0,他引:2
Abstract: In the automatic measurements of the principal stress directions ψ and the total relative phase retardation ρ tol , ψ and ρ tol can be easily obtained by the phase unwrapping method using the arctangent function. However, only some published works exist on the measurements of ψ and ρ tol by photoelastic techniques using a linearly polarised incident light source. This paper presents the technique of applying an unwrapping by means of the arctangent function to photoelasticity. The technique overcomes the error associated with the quarter-wave plate by using an incident light of different wavelength and does not need an interpolation for the determination of ψ . The technique is validated by determining ψ and ρ tol for the well-known circular disk subjected to a diametral compressive load model. 相似文献
997.
998.
A numerical model based on the finite-element method for solving the nonlinear diffusion equation of ion-exchange in glasses is presented. The model is applied to the calculation of the concentration profile for a Ag+-Na+ ion-exchanged channel waveguide. The calculated concentration profile is in good agreement with a measured refractive-index profile of a waveguide fabricated with the same parameters as used in the calculations 相似文献
999.
Phase-change read-and-write memory (PRAM) is a promising memory that can solve the problems of conventional memory—scalability, read/write speed, and reliability. We will review the opportunities and technical challenges of PRAM. The most important challenge of PRAM is the reduction of the writing current. Various approaches to reduce the writing current will be reviewed and the prospects of PRAM are discussed. 相似文献
1000.
YoungJu Choie Dougherty S.T. Haesuk Kim 《IEEE transactions on information theory / Professional Technical Group on Information Theory》2003,49(5):1275-1282
We define the complete joint weight enumerator in genus g for codes over /spl Zopf//sub 2k/ and use it to study self-dual codes and their shadows. These weight enumerators are related to the theta series of the associated lattices and Siegel and Jacobi forms are formed from these series. 相似文献