1,721,104 research outputs found
Building and Animating User-Specific Volumetric Face Rigs
No full textCurrently, the two main approaches to realistic facial animation are 1) blendshape models and 2) physics-based simulation. Blendshapes are fast and directly controllable, but it is not easy to incorporate features such as dynamics, collision resolution, or incompressibility of the flesh. Physics-based methods can deliver these effects automatically, but modeling of muscles, bones, and other anatomical features of the face is difficult, and direct control over the resulting shape is lost. We propose a method that combines the benefits of blendshapes with the advantages of physics-based simulation. We acquire 3D scans of a given actor with various facial expressions and compute a set of volumetric blendshapes that are compatible with physics-based simulation, while accurately matching the input scans. Furthermore, our volumetric blendshapes are driven by the same weights as traditional blendshapes, which many users are familiar with. Our final facial rig is capable of delivering physics-based effects such as dynamics and secondary motion, collision response, and volume preservation without the burden of detailed anatomical modeling. Eurographics/ ACM SIGGRAPH Symposium on Computer Animation Characters and Faces 107 117 Alexandru-Eugen Ichim, Ladislav Kavan, Merlin Nimier-David, and Mark Pauly Categories and Subject Descriptors (according to ACM CCS): I.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism-AnimationGC
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Study of Properties of Titanium Dioxide Nanoparticles
Full text linkCharles University in Prague Faculty of Science Department of Inorganic Chemistry STUDY OF PROPERTIES OF TITANIUM DIOXIDE NANOPARTICLES. PhD Thesis Abstract Jan Procházka Prague 2009 8. This PhD thesis is based on publications and patent applications (1-9) to which the author contributed considerably. The list of the publications is attached at the end of this text. Systematic research of the properties of TiO2 nanoparticles brought new pieces of knowledge into syntheses of titanium dioxide nanoparticles organized in the templated structures. When the structures were used in the solar cells, their solar efficiency significantly surpassed the performance of the conventional TiO2 films. The study was focused on the engineering and optimization of parameters of the nanostructures used as anodes in the dye sensitized solar cells (DSC). Several new technical solutions have been delivered during the work on variety of TiO2 structures. First, the factors with an impact on the proper function of the TiO2 multilayer film were determined 9. and then, the layer by layer deposition technique was perfected. Introduction of phosphorus into the templated mesoporous film synthesis protocol represented significant progress. The presence of phosphorus stabilized the TiO2 surface area at a high temperature and allowed a..
Inverse Anatomical Modeling and Simulation of Virtual Humans
No full textTitle: Inverse Anatomical Modeling and Simulation of Virtual Humans Author: RNDr. Petr Kadleček Department: Department of Software and Computer Science Education Supervisor: Mgr. Ladislav Kavan, Ph.D., Department of Software and Computer Science Education Abstract: In this dissertation, we focus on a mechanical aspect of a human body and face modeling. We leverage existing physics-based models of elasticity and use them as building blocks to create an animatable virtual human. We model different types of hard and soft tissues to enable our model to contract muscles, interact with an environment or realistically deform when subjected to external forces. In the first part of the work, we present a method to create personalized anatom- ical models of human body ready for physics-based animation, using only a set of 3D surface scans. We start by building a template anatomical model of an average male which supports deformations due to both 1) subject-specific vari- ations: shapes and sizes of bones, muscles, and adipose tissues and 2) skeletal poses. Next, we capture a set of 3D scans of an actor in various poses. Our key contribution is formulating and solving a large-scale optimization problem where we compute both subject-specific and pose-dependent parameters such that our resulting anatomical model..
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dynamika živých organismů
No full textThe computer animation of articulated figures is one of the most interesting and the most developing areas of the modern computer graphics. The goal of this thesis is to get the reader acquainted with the theory of constrained rigid body simulation, which is subsequently used to construct a generic rigid body simulator with constraints and friction and the figure library suitable for the animation of articulated human-like figures. Articulated figures are represented by sets of rigid bodies (segments) connected by joints and their motion is determined by the dynamics of the corresponding segments. Additional constraints, specifying e.g. desired angles at joints or the positions of selected sites on the surface of the figure segments, allow to control the figure motion. A rich set of interactive demonstration examples presents the features of the actual simulator and the capabilities of the figure library to process motion capture data (replay motion capture data, adapt the data to external influences, map the "raw" motion capture data to the motion of figure segments, etc)
Electrochemical Characterization of TiO2 Blocking Layers for Dye-Sensitized Solar Cells
No full textThin compact layers of TiO2 are grown by thermal oxidation of Ti, by spray pyrolysis, by electrochemical deposition, and by atomic layer deposition. These layers are used in dye-sensitized solar cells to prevent recombination of electrons from the substrate (FTO or Ti) with the hole-conducting medium at this interface. The quality of blocking is evaluated electrochemically by methylviologen, ferro/ferricyanide, and spiro-OMeTAD as the model redox probes. Two types of pinholes in the blocking layers are classified, and their effective area is quantified. Frequency-independent Mott–Schottky plots are fitted from electrochemical impedance spectroscopy. Certain films of the thicknesses of several nanometers allow distinguishing the depletion layer formation both in the TiO2 film and in the FTO substrate underneath the titania film. The excellent blocking function of thermally oxidized Ti, electrodeposited film (60 nm), and atomic-layer-deposited films (>6 nm) is documented by the relative pinhole area of less than 1%. However, the blocking behavior of electrodeposited and atomic-layer-deposited films is strongly reduced upon calcination at 500 °C. The blocking function of spray-pyrolyzed films is less good but also less sensitive to calcination. The thermally oxidized Ti is well blocking and insensitive to calcination
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