Airborne laser scanning is an applicable method to derive digital terrain models (DTMs) in wooded terrain. A considerable amount of the laser points are re°ections on the tree tops (vegetation points). Thus, special ¯ltering algorithms are required to obtain the ground surface. Earlier, we proposed to use iterative linear prediction. We review existing methods and compare them to our approach. ...

Continuity of stream playback is the crucial constraint in designing a continuous media server. From a distributed memory architectural model developed earlier, we found that there were many points where the stream capacity of the server could be improved. The stream capacity was usually limited by the storage bottlenecks. Serving streams from memory cache eliminates disk accesses and data tran...

There is no unique and defi nitive defi nition of phenomenology. It is rather a method and an experience always open and always renewing itself. Phenomenology involves a change in the “sense of the world”: everything acquires its sense and value only when it becomes the content of the lived experience of the subject correlated to his intentional acts. This is the main thesis of the phenomenolog...

Light interactions with matter is of remarkable complexity. An adequate modeling of global illumination is a vastly studied topic since the beginning of computer graphics, and still is an unsolved problem. The rendering equation for global illumination is based of refraction and re ection of light in interaction with matter within an environment. This physical process possesses a high computati...

A baroclinic shallow-water model is developed to investigate the e€ect of the orientation of the eastern ocean boundary on the behavior of equatorial Kelvin waves. The model is formulated in a spherical polar coordinate system and includes dissipation and nonlinear terms, e€ects which have not been previously included in analytical approaches to the problem. Both equatorial and middle latitude ...

We present a detailed study of spatially propagating waves in a discontinuous Galerkin scheme applied to a system of linear hyperbolic equations. We start with an eigensolution analysis of the semi-discrete system in one space dimension with uniform grids. It is found that, for any given order of the basis functions, there are at most two spatially propagating numerical wave modes for each phys...

The elastic behavior and the pressure-induced structural evolution of a natural nepheline (K0.54 Na3.24Ca0.03Al4Si4O16) were investigated by in-situ single-crystal X-ray diffraction up to 7.5 GPa with a diamond anvil cell under hydrostatic conditions. As observed in previous studies, at room conditions the diffraction pattern of nepheline includes satellite reß ections, whereas the structure re...

All visual sensors, biological and arti cial, are nite in resolution by necessity. This causes the e ective re ectance of surfaces in a scene to vary with magni cation. A reectance model for matte surfaces is described that captures the e ect of macroscopic surface undulations on image brightness. The model takes into account complex physical phenomena such as masking, shadowing and interre ect...

Starting from the waveguide model for plucked strings, a new digital signal processing model for the slapping technique on electric bassguitars is derived. The model includes amplitude limitations for the string at the frets and/or the ngerboard. These highly nonlinear elements are realized by conditional re ections which depend on the local string displacement. A model of the string dynamics f...

The useful environmental interaction of a mobile robot is completely dependent on the reliable extraction of information from its immediate surroundings A review of some of the most commonly used coaxial active sensing methods in robotics is presented A coaxial sensor results if the transmitter and receiver are geometri cally arranged in a coaxial manner Certain advantages of such con gurations...