Eine Client/Server-Architektur für statistische Visualisierungen und Analyse von Finanzdaten

Statistische Visualisierungen bilden ein wichtiges Instrument der Daten-Analyse. In dieser Arbeit wird eine Client/Server-Architektur für die Ausgabe dieser vorgestellt. Die Architektur basiert auf drei Komponenten, wobei zwei Teile eine Grafikbibliothek für statistischen Visualisierungen enthalten. Es werden die Aufgaben jeder Komponente vorgestellt und deren Kommunikation miteinander erläutert. Der in dieser Arbeit vorgestellte Prototyp kann aufWebseiten, insbesondere im Bereich E-Learning, eingesetzt werden. Die Kommunikation erfolgt über die Middleware CORBA. Die Komponenten wurden in C++ und JAVA implementiert. Im zweiten Teil der Arbeit werden Modell zur Analyse von Finanzdaten basieren auf einer Studentschen Verteilung vorgestellt. Im Univariaten eine Studentsche Zeitreihe eingeführt. Im Multivariaten wird die Modellierung über Copulas vorgestellt. Es werden Copulas definiert, Schätzer und Simulationsalgorithmen angegeben. Besonders wird auf die Fragestellung: ”Welches ist die richtige Copula?“ eingegangen.Statistical visualizations form an important instrument of the data analysis. In this thesis a client/server-architecture for these visualizations is introduced. The architecture is based on the components, whereby two of them contain a graphic-library for statistical visualizations. The functions of each component are presented and their communication is described. The prototype introduced in this work can be used on web pages, in particular e-learning. The communication is made by the middleware CORBA. The components were implemented in C++ and JAVA. In the second part of the thesis models for analysis of finance data with student t-distributions, especially a timeseries, are introduced. In the multivariate case models depending on Copulas are presented. Copulas are defined, Estimators and simulationsalgorithms are given. Particularly the question ”Which copula is the right one?“is discussed

An illusion induced by an illusion -perceptual filling-in of coloured negative afterimages

Visual filling-in relates to a perceptual phenomenon in which a stimulus pattern apparently undergoes dynamic changes assuming an attribute such as colour, texture, or brightness from the surround. This perceptual completion effect has up to now been shown only for real images. Here, we present filling-in in negative afterimages, a phenomenon not yet reported. Using coloured disk-ring patterns for stimuli, we demonstrate that afterimage filling-in arises independently, and is not simply a replica of filling-in observed in real images. Such filling-in does not occur when the afterimage is elicited dichoptically, suggesting its emergence within the monocular visual pathway. In this way, our findings indicate that filling-in under certain conditions may derive from an active neural mechanism located at low levels of the visual pathway

Robust interactive cutting based on an adaptive octree simulation mesh

We present an adaptive octree based approach for interactive cutting of deformable objects. Our technique relies on efficient refine- and node split-operations. These are sufficient to robustly represent cuts in the mechanical simulation mesh. A high-resolution surface embedded into the octree is employed to represent a cut visually. Model modification is performed in the rest state of the object, which is accomplished by back-transformation of the blade geometry. This results in an improved robustness of our approach. Further, an efficient update of the correspondences between simulation elements and surface vertices is proposed. The robustness and efficiency of our approach is underlined in test examples as well as by integrating it into a prototype surgical simulato

Critical Field Strength in an Electroclinic Liquid Crystal Elastomer

We elucidate the polymer dynamics of a liquid crystal elastomer based on the time-dependent response of the pendent liquid crystal mesogens. The molecular tilt and switching time of mesogens are analyzed as a function of temperature and cross-linking density upon application of an electric field. We observe an unexpected maximum in the switching time of the liquid crystal mesogens at intermediate field strength. Analysis of the molecular tilt over multiple time regimes correlates the maximum response time with a transition to entangled polymer dynamics at a critical field strength.Comment: 4 pages, 3 figure

Identification of matrix metalloproteinase-2 and-9 activities within the intestinal mucosa of dogs with chronic enteropathies

Background: Matrix metalloproteinases (MMPs) 2 and 9 are zinc-and calcium-dependent endopeptidases involved in the breakdown and reconstitution of extracellular matrix under both physiological and pathological conditions. Mucosal MMP-2 and -9 activities have been reported to be upregulated in the intestine of humans with inflammatory bowel disease (IBD), and in animal models of IBD. However, their involvement in the pathogenesis of canine chronic enteropathies (CE) is unknown. This study investigated mucosal pro-and active MMP-2 and -9 activities in dogs with CE and healthy dogs using gelatin zymography, and also to determine the association of their activities in dogs with CE with the canine IBD activity index (CIBDAI), histopathologic findings, the clinical outcome, and hypoalbuminemia. Intestinal mucosal samples from duodenum, ileum, colon, and cecum were collected from 40 dogs with CE and 18 healthy Beagle dogs. Results: In dogs with CE, the number of samples positive for mucosal pro-and active MMP-2 was significantly higher in the duodenum (P <0.0001 and P = 0.011, respectively), ileum (P = 0.002 and P = 0.018, respectively), and colon (P <0.0001 and P = 0.002, respectively), compared with healthy controls. Mucosal pro-MMP-9-positive samples in the duodenum and colon were significantly more frequent in dogs with CE than in healthy dogs (P = 0.0004 and P = 0.001, respectively). Despite the presence of mucosal samples positive for active MMP-9 in the intestinal segments of dogs with CE, the difference compared to healthy controls did not reach statistical significance. None of the intestinal mucosal samples in healthy dogs showed gelatinolytic activity corresponding to the control bands of active MMP-2 and -9. Mucosal active MMP-9 activities displayed a significant positive association with the severity of neutrophil infiltration in the duodenum (P = 00.040), eosinophils in the cecum (P = 00.037), and the CIBDAI score for ileum samples (P = 0.023). There was no significant association of pro-and active MMP-2 and -9 levels with the clinical outcome or hypoalbuminemia. Conclusions: This study is the first to demonstrate upregulation of mucosal pro-and active MMP-2 and pro-MMP-9 in the intestine of dogs with CE compared to healthy dogs. The results provide supporting evidence for the possible involvement of MMP-2 and -9 in the pathogenesis of canine CE.Peer reviewe

The role of back muscle endurance, maximum force, balance and trunk rotation control regarding lifting capacity

Evaluation of lifting capacity is widely used as a reliable instrument in order to evaluate maximal and safe lifting capacity. This is of importance in regard to planning rehabilitation programs and determining working ability. The aim of this study was to investigate the influence of basic functions on the lifting capacity measured by the progressive isoinertial lifting evaluation (PILE) and the functional capacity evaluation (FCE) tests in a lower (floor to waist) and an upper (waist to shoulder) setting and compare the two test constructs. Seventy-four female subjects without acute low back pain underwent an examination of their lifting capacities and the following basic functions: (1) strength and endurance of trunk muscles, (2) cardiovascular endurance, (3) trunk mobility and (4) coordination ability. A linear regression model was used to predict lifting capacity by means of the above-mentioned basic functions, where the F statistics of the variables had to be significant at the 0.05 level to remain in the model. Maximal force in flexion showed significant influence on the lifting capacity in both the PILE and the FCE in the lower, as well as in the upper, lifting task. Furthermore, there was a significant influence of cardiovascular endurance on the lower PILE and also of endurance in trunk flexion on the lower FCE. Additional inclusion of individual factors (age, height, weight, body mass index) into the regression model showed a highly significant association between body height and all lifting tasks. The r 2 of the original model used was 0.19/0.18 in the lower/upper FCE and 0.35/0.26 in the lower/upper PILE. The model r 2 increased after inclusion of these individual factors to between 0.3 and 0.4. The fact that only a limited part of the variance in the lifting capacities can be explained by the basic functions analyzed in this study confirms the assumption that factors not related to the basic functions studied, such as lifting technique and motor control, may have a strong influence on lifting capacity. These results give evidence to suggest the inclusion of an evaluation of lifting capacity in clinical practice. Furthermore, they raise questions about the predictive value of strength and endurance tests in regard to lifting capacity and work abilit