Search results for "computer graphic"

2021

Abstract Reliable patient-specific ventricular repolarization times (RTs) can identify regions of functional block or afterdepolarizations, indicating arrhythmogenic cardiac tissue and the risk of sudden cardiac death. Unipolar electrograms (UEs) record electric potentials, and the Wyatt method has been shown to be accurate for estimating RT from a UE. High-pass filtering is an important step in processing UEs, however, it is known to distort the T-wave phase of the UE, which may compromise the accuracy of the Wyatt method. The aim of this study was to examine the effects of high-pass filtering, and improve RT estimates derived from filtered UEs. We first generated a comprehensive set of UE…

Saliency Features for 3D CAD-Data in the Context of Sampling-Based Motion Planning

2021

In this paper, we consider disassembly scenarios for real-world 3D CAD-data, where each component is defined by a triangle mesh. For a fast construction of collision-free disassembly paths, common approaches use sampling-based rigid body motion planning which is well studied in the literature. One fact that has so far received little attention is that in industrial disassembly scenarios components are often attached to each other with flexible fastening elements like clips. In the planning process, the fastening elements show the following characteristics: 1) They can cause complex non-linear disassembly paths. 2) They are often deformable. 3) They are usually modeled in a relaxed state and…

Compression of binary images based on covering

1995

The paper describes a new technique to compress binary images based on an image covering algorithm. The idea is that binary images can be always covered by rectangles, univocally described by a vertex and two adjacent edges (L-shape). Some optimisations are necessary to consider degenerate configurations. The method has been tested on several images representing drawings and typed texts. The comparison with existing image file compression techniques shows a good performance of our approach. Further optimisations are under development.

Improving structural similarity based virtual screening using background knowledge

2013

Background Virtual screening in the form of similarity rankings is often applied in the early drug discovery process to rank and prioritize compounds from a database. This similarity ranking can be achieved with structural similarity measures. However, their general nature can lead to insufficient performance in some application cases. In this paper, we provide a link between ranking-based virtual screening and fragment-based data mining methods. The inclusion of binding-relevant background knowledge into a structural similarity measure improves the quality of the similarity rankings. This background knowledge in the form of binding relevant substructures can either be derived by hand selec…

Reversing arrows: Duality

2021

What do you get reversing all arrows? The drawing ‘Duality’ is an homage to mirrors, classical art themes, and abstract mathematics.I’m looking for beauty in the arts and beauty in science. It’s a ...

A comic page for the first isomorphism theorem

2022

Given a homomorphism between algebras, there exists an isomorphism between the quotient of the domain by its kernel and the subalgebra in the codomain given by its image. This theorem, commonly known as the first isomorphism theorem, is a fundamental algebraic result. Different problems have been identified in its instruction, mainly related to the abstraction inherent to its content and to the lack of conceptual models to improve its understanding. In response to this situation, in this paper, we present an illustration that explores the narrative and graphical resources of comics with the aim of describing the set-theoretic elements that are involved in the proof of this theorem.

Visualizing Confidence in Cluster-based Ensemble Weather Forecast Analyses

2020

In meteorology, cluster analysis is frequently used to determine representative trends in ensemble weather predictions in a selected spatio-temporal region, e.g., to reduce a set of ensemble members to simplify and improve their analysis. Identified clusters (i.e., groups of similar members), however, can be very sensitive to small changes of the selected region, so that clustering results can be misleading and bias subsequent analyses. In this article, we — a team of visualization scientists and meteorologists-deliver visual analytics solutions to analyze the sensitivity of clustering results with respect to changes of a selected region. We propose an interactive visual interface that enab…

A Visual Introduction to Cubic Surfaces Using the Computer Software Spicy

2003

At the end of the 19th century geometers like Clebsch, Klein and Rodenberg constructed plaster models in order to get a visual impression of their surfaces, which are so beautiful from an abstract point of view. But these were static visualizations. Using the computer program Spicy 1, which was written by the second author, one can now draw algebraic curves and surfaces depending on parameters interactively.

Fillets:Cues for connections in Focus+Context views of graph-like diagrams

2003

We apply fillets-smoothing of sharp angles at the joints-between the connections and nodes of graph-like diagrams. In situations where the graph layout is constrained, e.g. Focus+Context views or views where the coordinates of the nodes are informative, fillets can clarify the relationships considerably without altering the layout. A visual search experiment supports our hypothesis that with fillets it is considerably easier to perceive node-connection structures. We discuss algorithms with different tradeoffs for flexibility and performance for rendering these connections in a single pass using OpenGL.

La holografía como recurso didáctico para la enseñanza de contenidos de geometría en primaria

2021

En el presente artículo se analizarán los usos y beneficios que reportaría trabajar con hologramas como material didáctico, como así demuestran los estudios de Ghuloum, Escrivà y Orcos. A través de estas propuestas didácticas se refuerza la idea de que el uso de la técnica de representación en tres dimensiones puede beneficiar al alumnado en la adquisición de los contenidos geométricos presentes en el currículum oficial. El ámbito de la geometría ofrece una amplia gama de contenidos que posibilitan trabajar mediante técnicas de representación gráfica. Cabe destacar, por otra parte, que ahora los estudiantes de educación primaria están socializados en el acceso y uso de imágenes de todo tipo…