51,587 research outputs found

    Universal attraction force-inspired freeform surface modeling for 3D sketching

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    This paper presents a novel freeform surface modeling method to construct a freeform surface from 3D sketch. The approach is inspired by Newton’s universal attraction force law to construct a surface model from rough boundary curves and unorganized interior characteristic curves which may cross the boundary curves or not. Based on these unorganized curves, an initial surface can be obtained for conceptual design and it can be improved later in a commercial package. The approach has been tested with examples and it is capable of dealing with unorganized design curves for surface modeling

    A simple construction method for sequentially tidying up 2D online freehand sketches

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    This paper presents a novel constructive approach to sequentially tidying up 2D online freehand sketches for further 3D interpretation in a conceptual design system. Upon receiving a sketch stroke, the system first identifies it as a 2D primitive and then automatically infers its 2D geometric constraints related to previous 2D geometry (if any). Based on recognized 2D constraints, the identified geometry will be modified accordingly to meet its constraints. The modification is realized in one or two sequent geometric constructions in consistence with its degrees of freedom. This method can produce 2D configurations without iterative procedures to solve constraint equations. It is simple and easy to use for a real-time application. Several examples are tested and discussed

    Sketch-based virtual human modelling and animation

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    Animated virtual humans created by skilled artists play a remarkable role in today’s public entertainment. However, ordinary users are still treated as audiences due to the lack of appropriate expertise, equipment, and computer skills. We developed a new method and a novel sketching interface, which enable anyone who can draw to “sketch-out” 3D virtual humans and animation. We devised a “Stick FigureFleshing-outSkin Mapping” graphical pipeline, which decomposes the complexity of figure drawing and considerably boosts the modelling and animation efficiency. We developed a gesture-based method for 3D pose reconstruction from 2D stick figure drawings. We investigated a “Creative Model-based Method”, which performs a human perception process to transfer users’ 2D freehand sketches into 3D human bodies of various body sizes, shapes and fat distributions. Our current system supports character animation in various forms including articulated figure animation, 3D mesh model animation, and 2D contour/NPR animation with personalised drawing styles. Moreover, this interface also supports sketch-based crowd animation and 2D storyboarding of 3D multiple character interactions. A preliminary user study was conducted to support the overall system design. Our system has been formally tested by various users on Tablet PC. After minimal training, even a beginner can create vivid virtual humans and animate them within minutes

    Sketching-out virtual humans: A smart interface for human modelling and animation

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    In this paper, we present a fast and intuitive interface for sketching out 3D virtual humans and animation. The user draws stick figure key frames first and chooses one for “fleshing-out” with freehand body contours. The system automatically constructs a plausible 3D skin surface from the rendered figure, and maps it onto the posed stick figures to produce the 3D character animation. A “creative model-based method” is developed, which performs a human perception process to generate 3D human bodies of various body sizes, shapes and fat distributions. In this approach, an anatomical 3D generic model has been created with three distinct layers: skeleton, fat tissue, and skin. It can be transformed sequentially through rigid morphing, fatness morphing, and surface fitting to match the original 2D sketch. An auto-beautification function is also offered to regularise the 3D asymmetrical bodies from users’ imperfect figure sketches. Our current system delivers character animation in various forms, including articulated figure animation, 3D mesh model animation, 2D contour figure animation, and even 2D NPR animation with personalised drawing styles. The system has been formally tested by various users on Tablet PC. After minimal training, even a beginner can create vivid virtual humans and animate them within minutes

    Sketching-out virtual humans: From 2d storyboarding to immediate 3d character animation

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    Virtual beings are playing a remarkable role in today’s public entertainment, while ordinary users are still treated as audiences due to the lack of appropriate expertise, equipment, and computer skills. In this paper, we present a fast and intuitive storyboarding interface, which enables users to sketch-out 3D virtual humans, 2D/3D animations, and character intercommunication. We devised an intuitive “stick figurefleshing-outskin mapping” graphical animation pipeline, which realises the whole process of key framing, 3D pose reconstruction, virtual human modelling, motion path/timing control, and the final animation synthesis by almost pure 2D sketching. A “creative model-based method” is developed, which emulates a human perception process, to generate the 3D human bodies of variational sizes, shapes, and fat distributions. Meanwhile, our current system also supports the sketch-based crowd animation and the storyboarding of the 3D multiple character intercommunication. This system has been formally tested by various users on Tablet PC. After minimal training, even a beginner can create vivid virtual humans and animate them within minutes

    Creation and Growth of Components in a Random Hypergraph Process

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    Denote by an ℓ\ell-component a connected bb-uniform hypergraph with kk edges and k(b−1)−ℓk(b-1) - \ell vertices. We prove that the expected number of creations of ℓ\ell-component during a random hypergraph process tends to 1 as ℓ\ell and bb tend to ∞\infty with the total number of vertices nn such that ℓ=o(nb3)\ell = o(\sqrt[3]{\frac{n}{b}}). Under the same conditions, we also show that the expected number of vertices that ever belong to an ℓ\ell-component is approximately 121/3(b−1)1/3ℓ1/3n2/312^{1/3} (b-1)^{1/3} \ell^{1/3} n^{2/3}. As an immediate consequence, it follows that with high probability the largest ℓ\ell-component during the process is of size O((b−1)1/3ℓ1/3n2/3)O((b-1)^{1/3} \ell^{1/3} n^{2/3}). Our results give insight about the size of giant components inside the phase transition of random hypergraphs.Comment: R\'{e}sum\'{e} \'{e}tend

    The Panther Mountain circular structure, a possible buried meteorite crater

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    Panther Mountain, located near Phoenicia, New York, is part of the Catskill Mountains, which form the eastern end of the Allegheny Plateau in New York. It is a circular mass defined physiographically by an anomalous circular drainage pattern produced by Esopus Creek and its tributary Woodland Creek. The circular valley that rings the mountain is fracture-controlled; where bedrock is exposed, it shows a joint density 5 to 10 times greater than that on either side of the valley. Where obscured by alluvial valley fill, the bedrock's low seismic velocity suggests that this anomalous fracturing is continuous in the bedrock underlying the rim valley. North-south and east-west gravity and magnetic profiles were made across the structure. Terrane-corrected, residual gravity profiles show an 18-mgal negative anomaly, and very steep gradients indicate a near-surface source. Several possible explanations of the gravity data were modeled. We conclude that the Panther Mountain circular structure is probably a buried meteorite crater that formed contemporaneously with marine or fluvial sedimentation during Silurian or Devonian time. An examination of drill core and cuttings in the region is underway to search for ejecta deposits and possible seismic and tsunami effects in the sedimentary section. Success would result in both dating the impact and furnishing a chronostratigraphic marker horizon

    The pathway out of neoliberalism and the analysis of political ideology in the post-crisis world

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    Neoliberalism has not simply ‘survived’; it has failed to die, seemingly outlived the socio-economic conditions that gave rise to its existence. In this way, the non-death of neoliberalism raises some important questions about the nature of ideology, principally: its relationship to socio-economic determinants; how it exercises its grip over subjects and how this grip, or hold, can itself be exorcised. Seeking insights into these questions, this paper tells the story of the scholarly response to the non-death of neoliberalism over a ten year period of crisis: a pre-crisis era beginning with the Asian financial crisis (1997-2007) and a post-crisis era beginning with the global financial crisis to the present day (2008-2015). The paper considers key scholarly responses to the persistence of neoliberalism at three fundamental levels: (a) the trajectory of their analytical technique, or the key concepts that underpin their wider project; (b) their critique of neoliberalism, or how these concepts render the construction of core neoliberal ideals; and, (c) their ideological response to neoliberalism, or their recommendations regarding the pathway out of neoliberalism. On this basis, the paper engages in a discussion of the most plausible explanation for the non-death of neoliberalism and the most likely avenue along which the post-crisis world might build an escape

    Why should the German approach to health economic evaluation differ so markedly from approaches in other EU Member States?

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    The Efficiency Frontier is the method by which German policy makers establish the cost-effectiveness of new pharmaceutical technologies. In a new paper, Corinna Klingler, Sara Shah, Anthony Barron and John Wright argue that the development of the Efficiency Frontier can be associated with cultural reluctance to frame healthcare prioritization decisions around cost based valuations of human health and related doubts about the validity of metrics for human health gain. Using information gathered in interviews with key stakeholders, the authors contend that the Efficiency Frontier method responds to an environment characterized by a need to deny, or to ignore, the need to ration healthcare, and a deep aversion to describing the benefits of health gains in monetary terms
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