Global ETD Search

1	Echtzeitfähige modellbasierte Bilderkennung zur visuomotorischen Kontrolle bewegter Objekte Bunk, Michael 20 October 2017 (has links) Autonome Roboter müssen sich in einer dynamischen Umwelt zurechtfinden können und zeitnah auf Ereignisse reagieren. Der echtzeitfähigen Verarbeitung visueller Information kommt dabei eine Schlüsselrolle zu. Am Beispiel zweier spezieller Roboter wird die Gewinnung steuerungsrelevanter Daten aus einer Bildsequenz demonstriert. Dazu werden in Form von Modellen umfassende Voraussetzungen aufgestellt von dem, was gesehen werden soll und kann. Es wird ein Erkennungssystem entworfen und implementiert, welches die Extraktion der gesuchten Daten aus den Bilddaten u.a. mittels Bildkorrelation im Frequenzraum und Hough-Transformation durchführt. Die gewonnenen Daten werden zur Steuerung eines der Roboter verwendet. info:eu-repo/classification/ddc/000 ddc:000
2	Investigation of the biophysical basis for cell organelle morphology Mayer, Jürgen 09 February 2010 (has links) (PDF) It is known that fission yeast Schizosaccharomyces pombe maintains its nuclear envelope during mitosis and it undergoes an interesting shape change during cell division - from a spherical via an ellipsoidal and a peanut-like to a dumb-bell shape. However, the biomechanical system behind this amazing transformation is still not understood. What we know is, that the shape must change due to forces acting on the membrane surrounding the nucleus and the microtubule based mitotic spindle is thought to play a key role. To estimate the locations and directions of the forces, the shape of the nucleus was recorded by confocal light microscopy. But such data is often inhomogeneously labeled with gaps in the boundary, making classical segmentation impractical. In order to accurately determine the shape we developed a global parametric shape description method, based on a Fourier coordinate expansion. The method implicitly assumes a closed and smooth surface. We will calculate the geometrical properties of the 2-dimensional shape and extend it to 3-dimensional properties, assuming rotational symmetry. Using a mechanical model for the lipid bilayer and the so called Helfrich-Canham free energy we want to calculate the minimum energy shape while respecting system-specific constraints to the surface and the enclosed volume. Comparing it with the observed shape leads to the forces. This provides the needed research tools to study forces based on images. morphology nucleus shape energy bending energy shape analysis Fourier series Fourier coordinate expansion data reduction elliptic approximation harmonic truncation pareto optimality Helfrich-Canham free energy fission yeast microtubules Schizosaccharomyces pombe mitosis confocal microscopy image analysis Morphologie Zellkern Konturenergie Biegeenergie Formanalyse Fourier-Serien Koordinatenweise Fourier-Entwicklung Datenreduktion elliptische Näherung harmonische Analyse pareto-Optimierung freie Energie nach Helfrich und Canham Mikrotubuli Mitose konfokale Mikroskopie Bildanalyse ddc:570 rvk:WD 2300 rvk:WC 7000 rvk:WE 5300
3	Investigation of the biophysical basis for cell organelle morphology Mayer, Jürgen 12 February 2008 (has links) It is known that fission yeast Schizosaccharomyces pombe maintains its nuclear envelope during mitosis and it undergoes an interesting shape change during cell division - from a spherical via an ellipsoidal and a peanut-like to a dumb-bell shape. However, the biomechanical system behind this amazing transformation is still not understood. What we know is, that the shape must change due to forces acting on the membrane surrounding the nucleus and the microtubule based mitotic spindle is thought to play a key role. To estimate the locations and directions of the forces, the shape of the nucleus was recorded by confocal light microscopy. But such data is often inhomogeneously labeled with gaps in the boundary, making classical segmentation impractical. In order to accurately determine the shape we developed a global parametric shape description method, based on a Fourier coordinate expansion. The method implicitly assumes a closed and smooth surface. We will calculate the geometrical properties of the 2-dimensional shape and extend it to 3-dimensional properties, assuming rotational symmetry. Using a mechanical model for the lipid bilayer and the so called Helfrich-Canham free energy we want to calculate the minimum energy shape while respecting system-specific constraints to the surface and the enclosed volume. Comparing it with the observed shape leads to the forces. This provides the needed research tools to study forces based on images. info:eu-repo/classification/ddc/570 ddc:570

1

Page generated in 0.1005 seconds