0000000000213400
AUTHOR
Werner Von Seelen
showing 6 related works from this author
Segmentierung dreidimensionaler Szenen mittels perspektiver Kartierungen
1988
Das Navigieren und Agieren von Lebewesen oder autonomen Maschinen in ihrer jeweiligen Umwelt erfordert neben der Koordination von Effektoren, vor allem die Perzeption von Ort und Bewegung fremder Objekte, bei Eigenbewegung des Beobachters. Die hier betrachtete Navigationsaufgabe wird wie folgt definiert: “Ein System bewege sich autonom, kollisionsfrei und zielgerichtet von A nach B, wobei die Wahl des Weges von den lokalen Gegebenheiten abhangt.”
Fourier optical approach to the extraction of morphological parameters from the diffraction pattern of biological cells.
1978
A new procedure for fast quantitative extraction of cell parameters from diffraction patterns was deduced from model calculations and applied to cervical gynecological material. Based on radial scans of the diffraction pattern, the technique permits simultaneous determination of the nuclear and cytoplasmic diameters by Fourier analysis of the radial scanning signals after compensation for the intensity falloff by an amplification proportional to the third power of the radial position in the diffraction plane. Illustrative examples of measurements on exfoliated cells of different types are presented.
Variations in acoustical beam properties of intracoronary Doppler catheters.
1993
The limitations of coronary angiography in assessing the functional significance of coronary obstructions is well known. While the critical variable of coronary blood flow cannot be readily measured, intraluminal Doppler sonography offers useful related functional information on blood flow velocity. In order to fully evaluate Doppler signals it is essential to have exact knowledge of the transducer transmission characteristics and of the ultrasound beam topology. In an experimental set-up, the transmitter-receiver characteristics of five commonly used Doppler catheters were investigated. In comparing the beam characteristics we found inhomogeneities in the lateral beam spread. At a penetrat…
Why Cortices? Neural Networks for Visual Information Processing
1989
Neural networks for the processing of sensory information show remarkable similarities between different species and across different sensory modalities. As an example, cortical organization found in the mamalian neopallium and in the optic tecta of most vertebrates appears to be equally appropriate as a substrate for visual, auditory, and somatosensory information processing. In this paper, we formulate three structural principles of the vertebrate visual cortex that allow to analyze structure and function of these neural networks on an intermediate level of complexity. Computational applications are taken from the field of early vision. The proposed principles are: (a) Average anatomy, i …
A Dichoptic Edge Effect Resulting from Binocular Contour Dominance
1980
If one eye sees a bright field on a dark surround while a homogeneous background is presented to the other eye, then a distinct dark zone appears at the outer borders of the field.If the surround is coloured, then the zone is of corresponding hue. The effect disappears if the edge of the field can be fused with a bar of appropriate contrast. The influence of parameters such as pattern contrast and size were studied quantitatively. A model is proposed relating the effect to receptive-field organisation and the fusion process.
Intraluminal Doppler-Sonography: Analysis and “in Vitro Test” of a New Device
1992
In treating patients with coronary heart disease it’ s necessary first to determine what influence the stenose has on the coronary blood flow. This is a prerequisite for any invasive treatment method. Coronary angiography explosures are only partially useful in attaining a functional evaluation of the haemodynamic stenoses.