The variance of intensity of stellar scintillation has been measured as a function of wavelength using photon counting and on-line digital analysis techniques. The experimental data are consistent with that predicted by the theory of Tatarski. Measurements of the temporal correlation function of intensity and the higher moments of the probability density function of scintillation are also descr...

This paper introduces a recursive temporal algebra based on temporal semantics for querying time-varying data. The algebra, called < , is based on a temporal relational data model in which a temporal database is modeled as a collection of time-varying relations. Each time-varying relation is a collection of ordinary relations indexed by moments in time. In < , recur-sive queries (such as the tr...

A statistically stationary and nearly homogeneous turbulent shear flow is established by an additional volume forcing in combination with stress-free boundary conditions in the shear direction. Both turbulent energy and enstrophy are stationary to a much better approximation than in previous simulations that use remeshing. The temporal fluctuations decrease with increasing Reynolds number. Ener...

Exact relations between Tk , the kth temporal moments of the nucleation flux, and the derivative of its Laplace transform ~LT! are established and applied to available asymptotic expressions for the LT, generalizing earlier results by Shneidman and Weinberg @J. Chem. Phys. 95, 9148 ~1991!; 97, 3629 ~1992!# on the time-lag T0 . For any k>2 the moments Tk are expressed through simple algebraic co...

This paper addresses the inverse problem of time-resolved (fluorescence) diffuse optical tomography from temporal moments of the measurements. A methodology that enables one to provide fairly comparable reconstructions is presented. The proposed reconstruction methodology is applied to infinite medium synthetic phantoms in the transmission geometry. Reconstructions are performed for moment orde...

In this study, we derive a fast, novel time-domain algorithm to compute the nth-order moment of the power spectral density of the photoelectric current as measured in laser-Doppler flowmetry (LDF). It is well established that in the LDF literature these moments are closely related to fundamental physiological parameters, i.e. concentration of moving erythrocytes and blood flow. In particular, w...

We introduce a new micro-macro decomposition of collisional kinetic equations in the specific case of the diffusion limit, which naturally incorporates the incoming boundary conditions. The idea is to write the distribution function f in all its domain as the sum of an equilibrium adapted to the boundary (which is not the usual equilibrium associated with f) and a remaining kinetic part. This e...

A number of interventions and technique changes have been proposed to attempt to improve performance and reduce the number of running related injuries. Running shoes, barefoot running and alterations in spatio-temporal parameters (stride frequency and stride length) have been associated with significant kinematic and kinetic changes, which may have implications for performance and injury preven...

A simple scheme is presented for modifying geometric moments to use geodesic distances. This provides a set of global shape descriptors that are invariant to bending as well as rotation, translation and scale.

Abstract. This paper considers the timeand space-dependent linear Boltzmann equation with general boundary conditions in the case of inelastic (granular) collisions. First, in the (angular) cut-off case, mild L1-solutions are constructed as limits of the iterate functions and boundedness of higher velocity moments are discussed in the case of inverse power collisions forces. Then the problem of...