DSpace Kolekce:
http://hdl.handle.net/11025/803
2024-03-19T04:21:11ZFinding direction of intersection curve in critical cases of surface-surface intersection
http://hdl.handle.net/11025/855
Název: Finding direction of intersection curve in critical cases of surface-surface intersection
Autoři: Oh, Min-jae; Hur, Seok; Kim, Tae-wan
Editoři: Skala, Václav
Abstrakt: Determining the topology of intersection curves is one of the important issues of surface-surface intersection
problem used in Computer Aided Geometric Design and Computer Graphics. To compute the intersection
curves, we first need to determine the topology of the curves. Thomas A. Grandine[Gr97] presented an
algorithm to determine topology using partial derivatives of surface intersection equations. When the two
surfaces meet tangentially, the differential values of the parameters of the surfaces are not determined in the
intersection equations. These cases are called critical cases. In [Ye99] a method of finding the values of the
differentials is presented for the case of the contact of order 1. We present general methods for the case of the
contact of higher order ≥ 1 using perturbation method. With these results, we can decide starting or ending of the
critical boundary point.2007-01-01T00:00:00ZOh, Min-jaeHur, SeokKim, Tae-wanDuct tracking in 3D medical data
http://hdl.handle.net/11025/854
Název: Duct tracking in 3D medical data
Autoři: Petříček, Martin; Pelikán, Josef; Horák, Martin
Editoři: Skala, Václav
Abstrakt: Implementing duct tracking of bronchi and blood vessels in 3D medical data can significantly help in examining
these body structures and reduce time needed for correct diagnosis. Nature of the problem involved may require
some operator interaction when selecting duct branches of interest or correcting possible mistakes in duct path
segmentation. Noise, badly discernible duct walls, branching or extreme duct curvatures, that can be found in
computer tomography data, make the segmentation challenging. There are more ways to display segmented ducts,
as overlay over original data or unrolled to planar tube, allowing easier measurements of length, width or observation
of tube anomalies.2007-01-01T00:00:00ZPetříček, MartinPelikán, JosefHorák, MartinDesign patterns for multithreaded software pipelines in real time applications
http://hdl.handle.net/11025/853
Název: Design patterns for multithreaded software pipelines in real time applications
Autoři: Preuss, Stefan; Schmitt, Alfred A.
Editoři: Skala, Václav
Abstrakt: This paper presents design patterns that will help in the task of parallelizing graphical real time algorithms,
according to the example of a visual real time 3D reconstruction algorithm. These algorithms can often be
designed as a dataflow graph, so they can be coarsely granular parallelized in a pipeline pattern. With these
patterns, the design process of the parallelization is detached from the design of the graphical algorithm. The
advantages and drawbacks of these patterns are discussed with regard to speed, but also to handling and errorproneness
and the demanded robustness of real time applications, due to the varying workload of the different
steps or data loss or obsoleteness during processing.2007-01-01T00:00:00ZPreuss, StefanSchmitt, Alfred A.Implementation of NURBS curve derivatives in engineering practice
http://hdl.handle.net/11025/852
Název: Implementation of NURBS curve derivatives in engineering practice
Autoři: Procházková, Jana; Procházka, David
Editoři: Skala, Václav
Abstrakt: Derivatives are a very important tool of computations in an engineering practice on the graphics structures. B-Spline functions
are defined recursively, so the direct computation is very difficult. In this article new direct proof of the formula used for simpler
direct computation is shown. The paper also presents own method of programming derivatives of NURBS curves by means of
the proven formula which is implemented in German engineering software RFEM 3D.2007-01-01T00:00:00ZProcházková, JanaProcházka, David