269 research outputs found
High-Quality Visualization and Filtering
No full textDie meisten Renderingmethoden in der Visualisierung und Computergraphik konzentrieren sich entweder auf die Bildqualität; und generieren <i>korrekte</i> Bilder mit nicht mehr interaktiven Bildraten; oder opfern die Darstellungsqualität; um interaktive Performance zu erreichen. Andererseits erlaubt es die momentane Entwicklung im Bereich der Graphikhardware zunehmend; die Qualität von Offline Rendering-Ansätzen mit interaktiver Performance zu kombinieren. Um dies auch tatsächlich nutzen zu können; müssen neue und angepasste Algorithmen entwickelt werden; die die spezielle Architektur von Graphikhardware berücksichtigen. Das zentrale Thema dieser Arbeit ist; hohe Renderingqualität mit Echtzeitfähigkeit bei der Visualisierung von diskreten Volumendaten auf regulären dreidimensionalen Gittern zu kombinieren. Ein wesentlicher Teil beschäftigt sich mit dem generellen Filtern von Texturen unabhängig von deren Dimension. Mit Hilfe der Leistungsfähigkeit heutiger PC Graphikhardware werden Algorithmen demonstriert; die einen Qualitätsstandard erreichen; der bislang nur im Offline Rendering möglich war. Eine grundlegende Operation in der Visualisierung und Computergraphik ist die Rekonstruktion einer kontinuierlichen Funktion aus einer diskreten Darstellung mittels Filterung. Diese Arbeit stellt eine Methode zur Filterung mit Hilfe von Graphikhardware vor; die prinzipiell beliebige Faltungskerne auswerten kann. Die Hauptanwendung ist hierbei die Vergrösserung von Texturen direkt während dem Rendern. Darüber hinaus kann sie aber auch mit MIP-mapping zur Texturverkleinerung kombiniert werden. Im Bereich der Volumenvisualisierung stellt diese Arbeit weiters einen Ansatz zur Echtzeitdarstellung von segmentierten Daten vor. Segmentierte Volumendaten haben speziell in medizinischen Anwendungen hohe Bedeutung. Darüber hinaus stellt diese Arbeit Ansätze zum nicht-photorealistischen Rendern mit hoher Qualität vor; die sich besonders gut eignen; um die Aufmerksamkeit des Betrachters auf bestimmte Fokusbereiche zu lenken. Weiters werden Isoflächen mit Hilfe eines Deferred- Shading Ansatzes dargestellt; wobei differentialgeometrische Eigenschaften; wie beispielsweise die Krümmung der Oberfläche; in Echtzeit berechnet und für eine Vielzahl von Effekten verwendet werden können. Wir schliessen aus den erreichten Resultaten; dass es möglich ist; die Lücke zwischen Offline Rendering mit hoher Qualität auf der einen Seite; und Echtzeitrendering auf der anderen Seite; zu schliessen; ohne dabei notwendigerweise die Qualität zu beeinträchtigen. Besonders wichtig ist dies im Bereich des Renderings von Volumendaten; das sehr oft hohe Qualitätsansprüche hat; etwa bei der Darstellung von medizinischen Daten. - Most rendering methods in visualization and computer graphics are focusing either on image quality in order to produce<i> correct</i> images with non-interactive rendering times; or sacrifice quality in order to attain interactive or even real-time performance. However; the current evolution of graphics hardware increasingly allows to combine the quality of off-line rendering approaches with highly interactive performance. In order to do so; new and customized algorithms have to be developed that take the specific structure of graphics hardware architectures into account. The central theme of this thesis is combining high rendering quality with real-time performance in the visualization of sampled volume data given on regular three-dimensional grids. More generally; a large part of this work is concerned with high-quality filtering of texture maps; regardless of their dimension. Harnessing the computational power of consumer graphics hardware available in off-the-shelf personal computers; algorithms that attain a level of quality previously only possible in off-line rendering are introduced. A fundamental operation in visualization and computer graphics is the reconstruction of a continuous function from a sampled representation via filtering. This thesis presents a method for using completely arbitrary convolution filters for high-quality reconstruction exploiting graphics hardware; focusing on real-time magnification of textures during rendering. High-quality filtering in combination with MIP-mapping is also illustrated in order to deal with texture minification. Since texturing is a very fundamental operation in computer graphics and visualization; the resulting quality improvements have a wide variety of applications; including static texture-mapped objects; animated textures; and texture-based volume rendering. The combination of high-quality filtering and all major approaches to hardwareaccelerated volume rendering is demonstrated. In the context of volume rendering; this thesis introduces a framework for high-quality rendering of segmented volume data; i.e.; data with object membership information such as segmented medical data sets. High-quality shading with per-object optical properties such as rendering modes and transfer functions is made possible; while maintaining real-time performance. The presented method is able to filter the boundaries between different objects on-the-fly; which is non-trivial when more than two objects are present; but important for high-quality rendering. Finally; several approaches to high-quality non-photorealistic volume rendering are introduced; a concept that is especially powerful in combination with segmented volume data in order to focus a viewer s attention and separate focus from context regions. High-quality renderings of isosurfaces are obtained from volumetric representations; utilizing the concept of deferred shading and deferred computation of high-quality differential implicit surface properties. These properties include the gradient; the Hessian matrix; and principal curvature magnitudes as well as directions. They allow high-quality shading and a variety of nonphotorealistic effects building on implicit surface curvature. We conclude that it is possible to bridge the gap between traditional high-quality off- line rendering and real-time performance without necessarily sacrificing quality. In an area such as volume rendering that can be very demanding with respect to quality; e.g.; in medical imaging; but whose usefulness increases significantly with higher interactivity; combining both high quality and high performance is especially important.EG Graphics Dissertation Onlin
Hadwiger Number and the Cartesian Product Operation on Graphs
No full textThe Hadwiger number is defined as the largest integer for which the complete graph on nodes . Hadwiger conjectured that for any ,where is the chromatic number of . In this thesis, we investigate the Hadwiger number with respect to the cartesian product operation on Graphs. As the main result of this thesis, we show that for any two graphs !"# $ %&(' )*' +&-,. . (Since isomorphic to / 0 , we can assume without loss of generality that 12 ). This lower bound is the best possible (up to a small constant factor), since if 3 5 6 7 !8:9 ,.' . We also show that ! are bounded whereas ;7 !8 grows with the number of nodes. (The problem of studying the Hadwiger number with respect to the cartesian product operation was posed by Z.Miller in 1978.) As consequences of our main result, we show the following: be a connected graph. Let the (unique) prime factorization of be given by !/ = C,EDGF.H3DGFIH3 KJ LM L"M is a constant. This improves the ,EDGFIH3 NJPO bound given in [2]
A quantitative program for Hadwiger's covering conjecture
No full textIn 1957, Hadwiger made a conjecture that every n-dimensional convex body can be covered by 2(n) translates of its interior. Up to now, this conjecture is still open for all n >= 3. In 1933, Borsuk made a conjecture that every n-dimensional bounded set can be divided into n + 1 subsets of smaller diameters. Up to now, this conjecture is open for 4 <= n <= 297. In this article we encode the two conjectures into continuous functions defined on the spaces of convex bodies, propose a four-step program to attack them, and obtain some partial results.Mathematics, AppliedMathematicsSCI(E)2ARTICLE92551-25605
Case Study of Physiotherapy Treatment of a Patient with total knee replacement
No full textAuthor: Jiří Hadwiger Title: The case study of physioterapeutical treatment of a patient with total knee replacement diagnosis Objective: The objective of this thesis is processing of the case study of the physioterapeutic care of a patient with total knee replacement diagnosis during an internship at ORFM department at ÚVN hospital. Comprehensive theoretical introduction to this subject is also a part of this thesis. Summary: This thesis is divaded into two parts. The first part consists of the theoretical knowledge of the anatomy, kinesiology and biomechanics of the knee joint. Following is the gonarthrosis chapter as the most common indication for the total knee replacement, its ethiology and choices of treatement. At last to present is total knee replacement, its history, surgical procedure and following postoperative rehabilitation. Second part is a case study of the real patient with total knee replacement diagnosis lasting 8 therapeutical units. In the end of the study is comparison of the paatients condition before and after rehabilitation and evaluation of the effect. Key words: knee joint, total knee replacement, gonarthrosis, physical therapy, case stud
Topology of the Grünbaum-Hadwiger-Ramos problem for mass assignments
No full textIn this paper, motivated by recent work of Schnider and Axelrod-Freed and Soberón, we study an extension of the
classical Grünbaum-Hadwiger-Ramos mass partition problem to mass assignments.
Using the Fadell-Husseini index theory we prove that for a given family of mass assignments
on the Grassmann manifold
and a given
integer there exist a linear subspace and
affine hyperplanes in that equipart the masses
assigned to the subspace , provided that
Josef Willomitzer (1849 - 1900). Life and Work of German Writing Author from Bohemia.
No full textJosef Willomitzer (1849 - 1900). Life and Work of German Writing Author from Bohemia. The bachelor theses deals with life and work of german writing author from Bohemia, Josef Willomitzer. The work describes as a introduction the social and culture situation in Prague in the end of 19. century. The following chapters concern Willomitzers life and work in context of the historical and political development of Bohemia. The work is based on information available from ressources such as lexicons, newspaper articles and archive ressources. Apart from his life is in this work described also his journalistic activity. In the last part is summarized Willomitzers literary work. The analysis of chosen works which correspond to certain historical topics is also involved. The purpose of this work is to draw up a compact biography of Josef Willomitzer and a summary of his work. Keywords: Josef Willomitzer, humoresque, journalism, Bohemia, German Prague in the end of 19. centur
Josef Willomitzer (1849 - 1900). Life and Work of German Writing Author from Bohemia.
No full textJosef Willomitzer (1849 - 1900). Life and Work of German Writing Author from Bohemia. The bachelor theses deals with life and work of german writing author from Bohemia, Josef Willomitzer. The work describes as a introduction the social and culture situation in Prague in the end of 19. century. The following chapters concern Willomitzers life and work in context of the historical and political development of Bohemia. The work is based on information available from ressources such as lexicons, newspaper articles and archive ressources. Apart from his life is in this work described also his journalistic activity. In the last part is summarized Willomitzers literary work. The analysis of chosen works which correspond to certain historical topics is also involved. The purpose of this work is to draw up a compact biography of Josef Willomitzer and a summary of his work. Keywords: Josef Willomitzer, humoresque, journalism, Bohemia, German Prague in the end of 19. centur
Cytokine exposure mediates transcriptional activation of the orphan nuclear receptor Nur77 in hematopoietic cells
No full textThe orphan nuclear receptor Nur77 is an immediate-early response gene that based on tissue and cell context is implicated in a plethora of cellular processes, including proliferation, differentiation, apoptosis, metabolism, and inflammation. Nur77 has a ligand-binding pocket that is obstructed by hydrophobic side groups. Naturally occurring, cell-endogenous ligands have not been identified, and Nur77 transcriptional activity is thought to be regulated through posttranslational modification and modulation of protein levels. To determine whether Nur77 is transcriptionally active in hematopoietic cells in vivo, we used an upstream activating sequence (UAS)-GFP transgenic reporter. We found that Nur77 is transcriptionally inactive in vivo in hematopoietic cells under basal conditions, but that activation occurs following cytokine exposure by G-CSF or IL-3. We also identified a series of serine residues required for cytokine-dependent transactivation of Nur77. Moreover, a kinase inhibitor library screen and proximity labeling-based mass spectrometry identified overlapping kinase pathways that physically interacted with Nur77 and whose inhibition abrogated cytokine-induced activation of Nur77. We determined that transcriptional activation of Nur77 by G-CSF or IL-3 requires functional JAK and mTor signaling since their inhibition leads to Nur77 transcriptional inactivation. Thus, intracellular cytokine signaling networks appear to regulate Nur77 transcriptional activity in mouse hematopoietic cells
Minimal determinants and lattice inequalities
No full textSome results of P. McMullen on determinants of sublattices of Z d induced by rational subspaces are generalized to arbitrary lattices. As an application, we obtain an equality for the minimal determinants introduced by J. M. Wills, namely Dt(L) = Dd(L)Dd_((L*). Using an inequality of Lagarias, Lenstra and Schnorr, we generalize two isoperimetric inequalities with lattice constraints by Bokowski, Hadwiger and Wills, and Hadwiger, respectively, to arbitrary lattices. 1
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