Search results for "Visualization"
showing 10 items of 449 documents
On the problem of visualizing point distributions in high dimensional spaces
1995
Abstract Exploring dynamical systems with the aid of computer graphics requires that the relevant structures can be seen and be noticed. This poses special problems if the system is multidimensional, and it has to be decided which kind of projection serves the purpose. I propose using the mathematical frame of categories and functors to describe the process of visualization. This allows detecting and analyzing possible sources of misinterpretation in a formal way. The distribution of distances of embedded electroencephalographic data from a fixed reference point is used as an example for discussing some aspects of the visualization process. The multidimensional p-norms are an example of a p…
Heuristics for the Constrained Incremental Graph Drawing Problem
2019
Abstract Visualization of information is a relevant topic in Computer Science, where graphs have become a standard representation model, and graph drawing is now a well-established area. Within this context, edge crossing minimization is a widely studied problem given its importance in obtaining readable representations of graphs. In this paper, we focus on the so-called incremental graph drawing problem, in which we try to preserve the user’s mental map when obtaining successive drawings of the same graph. In particular, we minimize the number of edge crossings while satisfying some constraints required to preserve the position of vertices with respect to previous drawings. We propose heur…
Visual data mining with self-organising maps for ventricular fibrillation analysis
2012
Detection of ventricular fibrillation (VF) at an early stage is being deeply studied in order to lower the risk of sudden death and allows the specialist to have greater reaction time to give the patient a good recovering therapy. Some works are focusing on detecting VF based on numerical analysis of time-frequency distributions, but in general the methods used do not provide insight into the problem. However, this study proposes a new methodology in order to obtain information about this problem. This work uses a supervised self-organising map (SOM) to obtain visually information among four important groups of patients: VF (ventricular fibrillation), VT (ventricular tachycardia), HP (healt…
Visualization of Large Terrain Using Non-restricted Quadtree Triangulations
2004
This paper presents a set of new techniques oriented towards the real-time visualization of large terrains. These techniques are mainly focused on semi-regular triangulations of non-restricted quadtree terrain representations. Despite the fact that the paper shows that triangulations based on non-restricted quadtrees are as simple and efficient as those based on restricted quadtrees, the new triangulations avoid discontinuity problems among the boundaries of different patches without the need for tree balancing and extra triangles addition. Another important feature of the proposed triangulation is that it incorporates an efficient method for building triangle strips and triangle fans for t…
UML Style Graphical Notation and Editor for OWL 2
2010
OWL is becoming the most widely used knowledge representation language. It has several textual notations but no standard graphical notation apart from verbose ODM UML. We propose an extension to UML class diagrams (heavyweight extension) that allows a compact OWL visualization. The compactness is achieved through the native power of UML class diagrams extended with optional Manchester encoding for class expressions thus largely eliminating the need for explicit anonymous class visualization. To use UML class diagram notation we had to modify its semantics to support Open World Assumption that is central to OWL. We have implemented the proposed compact visualization for OWL 2 in a UML style …
Correction of B-scan distortion for optimum ultrasonic imaging of backwalls with complex geometries
2020
Ultrasound undergoes refraction and reflection at interfaces between media of different acoustic refractive indices. The most common ultrasonic method (pulse-echo) monitors the reflected energy to infer the presence of flaws, whereas the lower amplitude of refracted signals is ignored. When the reflector is orientated normally with respect to the ultrasonic beam, the received echo signal shows the maximum amplitude. The pulse-echo method also relies on monitoring the amplitude of the backwall echo to identify or confirm the presence of defects. This works well for parts with constant thickness and with planar backwalls. Unfortunately, parts with complex backwalls are common to many industri…
A Cost-Effective 3D Acquisition and Visualization Framework for Cultural Heritage
2020
Museums and cultural institutions, in general, are in a constant challenge of adding more value to their collections. The attractiveness of assets is practically tightly related to their value obeying the offer and demand law. New digital visualization technologies are found to give more excitements, especially to the younger generation as it is proven by multiple studies. Nowadays, museums around the world are currently trying to promote their collections through new multimedia and digital technologies such as 3D modeling, virtual reality (VR), augmented reality (AR), and serious games. However, the difficulty and the resources required to implement such technologies present a real challen…
Joint Alignment and Modeling of Correlated Behavior Streams
2013
The Variable Time-Shift Hidden Markov Model (VTS- HMM) is proposed for learning and modeling pairs of cor- related streams. Unlike previous coupled models for time series, the VTS-HMM accounts for varying time shifts be- tween correlated events in pairs of streams having different properties. The VTS-HMM is learned on a set of pairs of unaligned streams and, thus, learning entails simultaneous estimation of the varying time shifts and of the parameters of the model. The formulation is demonstrated in the analysis of videos of dyadic social interactions between children and adults in the Multimodal Dyadic Behavior Dataset (MMDB). In dyadic social interactions, an agent starts an interaction …
Video Visualization of Predictors of Emotions Dynamically Expressed by Music
2013
Music is particularly appreciated for its capacity of evoking a large range of emotions. A growing area of research in music psychology and computer music endeavors to understand and model the role of the different constituents of music in its overall emotional impact. Whereas research so far has mainly focused on global musical and emotional descriptions, our project investigates more in detail the relationship between the dynamic evolution of musical content and the dynamic development of the resulting emotional reaction. We introduce a new method for predicting the dynamic appreciation of emotion based on audio and musical descriptions. We focus on one particular emotion: power. We propo…
Visiting the King of the World
2009
Apsilankymas pas Pasaulio karalių – tai tema, kuri bent paviršutiniškai supažindina su egzistuojančiais daugiau ar mažiau ezoteriniais pasakojimais, kartais net gana fantastiškais, kuriuose kalbama apie viršžmogiškosiomis galiomis apdovanotas būtybes, gyvenančias, atrodo, žemės gelmėse, Azijos žemių platybėse, Himalajų regione, Mongolijoje ar Tibete. „Pasaulio karalius“ – pavadinimas 1927 m. parašyto veikalo, kurio autorius René Guénonas – prancūzų ezoterikas ir mistikas, gimęs 1886 m. Blois, miręs 1951 m. Kaire. Iš literatūros kūrinių – ir kelionių aprašymų, ir fantastinių romanų – be Jules‘io „Kelionės į žemės centrą“ galima paminėti Ferdinando Ossendowskio knygą „Gyvuliai, žmonės ir diev…