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81.
Brian Whited Gioacchino Noris Maryann Simmons Robert W. Sumner Markus Gross Jarek Rossignac 《Computer Graphics Forum》2010,29(2):605-614
The generation of inbetween frames that interpolate a given set of key frames is a major component in the production of a 2D feature animation. Our objective is to considerably reduce the cost of the inbetweening phase by offering an intuitive and effective interactive environment that automates inbetweening when possible while allowing the artist to guide, complement, or override the results. Tight inbetweens, which interpolate similar key frames, are particularly time‐consuming and tedious to draw. Therefore, we focus on automating these high‐precision and expensive portions of the process. We have designed a set of user‐guided semi‐automatic techniques that fit well with current practice and minimize the number of required artist‐gestures. We present a novel technique for stroke interpolation from only two keys which combines a stroke motion constructed from logarithmic spiral vertex trajectories with a stroke deformation based on curvature averaging and twisting warps. We discuss our system in the context of a feature animation production environment and evaluate our approach with real production data. 相似文献
82.
We present a new approach for an average-case analysis of algorithms and data structures that supports a non-uniform distribution of the inputs and is based on the maximum likelihood training of stochastic grammars. The approach is exemplified by an analysis of the expected size of binary tries as well as by three sorting algorithms and it is compared to the known results that were obtained by traditional techniques. Investigating traditional settings like the random permutation model, we rediscover well-known results formerly derived by pure analytic methods; changing to biased data yields original results. All but one step of our analysis can be automated on top of a computer-algebra system. Thus our new approach can reduce the effort required for an average-case analysis, allowing for the consideration of realistic input distributions with unknown distribution functions at the same time. As a by-product, our approach yields an easy way to generate random combinatorial objects according to various probability distributions. 相似文献
83.
84.
Tobias Müller Volker Piotter Klaus Plewa Markus Guttmann Hans-Joachim Ritzhaupt-Kleissl Juergen Hausselt 《Microsystem Technologies》2010,16(8-9):1419-1423
Powder injection molding is a preferred technology for the production of micro parts or microstructured parts. Derived from the well known thermoplastic injection molding technique it is suitable for a large-scale production of ceramic and metallic parts without final machining. To achieve good surface quality and control the part size and distortions is an important goal to allow mass production. This means that all process steps like part design adjusted for MIM/CIM-technology, appropriate choice of powder and binder components and injection molding simulation to design the sprue are required. Concerning the injection molding itself high quality mold inserts, high-precision injection molding with suitable molding machines like Battenfeld Microsystem50 or standard machine with special equipment like variotherm or evacuation of the molding tool and an adjusted debinding and sintering process have to be available. Results of producing micro parts by powder injection molding of ceramic feedstock will be presented. 相似文献
85.
Steinicke Frank Bruder Gerd Jerald Jason Frenz Harald Lappe Markus 《IEEE transactions on visualization and computer graphics》2010,16(1):17-27
In immersive virtual environments (IVEs), users can control their virtual viewpoint by moving their tracked head and walking through the real world. Usually, movements in the real world are mapped one-to-one to virtual camera motions. With redirection techniques, the virtual camera is manipulated by applying gains to user motion so that the virtual world moves differently than the real world. Thus, users can walk through large-scale IVEs while physically remaining in a reasonably small workspace. In psychophysical experiments with a two-alternative forced-choice task, we have quantified how much humans can unknowingly be redirected on physical paths that are different from the visually perceived paths. We tested 12 subjects in three different experiments: (E1) discrimination between virtual and physical rotations, (E2) discrimination between virtual and physical straightforward movements, and (E3) discrimination of path curvature. In experiment E1, subjects performed rotations with different gains, and then had to choose whether the visually perceived rotation was smaller or greater than the physical rotation. In experiment E2, subjects chose whether the physical walk was shorter or longer than the visually perceived scaled travel distance. In experiment E3, subjects estimate the path curvature when walking a curved path in the real world while the visual display shows a straight path in the virtual world. Our results show that users can be turned physically about 49 percent more or 20 percent less than the perceived virtual rotation, distances can be downscaled by 14 percent and upscaled by 26 percent, and users can be redirected on a circular arc with a radius greater than 22 m while they believe that they are walking straight. 相似文献
86.
Markus Kaufmann Dan Zenkert Per Wennhage 《Structural and Multidisciplinary Optimization》2010,41(2):325-334
A methodology for a combined cost/weight optimization of aircraft components is proposed. The objective function is formed
by a simplified form of direct operating cost, i.e. by a weighted sum of the manufacturing cost and the component weight.
Hence, the structural engineer can perform the evaluation of a design solution based on economical values rather than pure
cost or weight targets. The parameter that governs the balance between manufacturing cost and weight is called weight penalty
and incorporates the effect of fuel burn, environmental impact or contractual penalties due to overweight. Unlike previous
work, the analytical cost model and structural models are replaced by commercially available software packages that allow
a more realistic model of the manufacturing costs; further, arbitrary constraints for the structural analysis can be implemented.
By means of parametric studies it is shown that the design solution strongly depends on the magnitude of the weight penalty. 相似文献
87.
Dennis Heinson York Yannikos Frederik Franke Christian Winter Markus Schneider 《Datenschutz und Datensicherheit - DuD》2010,34(2):75-79
Der Einsatz von Informationstechnologie (IT) in Organisationen bietet viele M?glichkeiten des Missbrauchs. Besch?ftigte k?nnen
sich die besonderen Eigenschaften der IT zunutze machen, um sich etwa in gesch?ftssch?digender Weise Vorteile zu verschaffen.
Gleichzeitig erm?glicht IT aber auch, verbotene Handlungen aufzuspüren und zu belegen (IT-Forensik). Der Beitrag beschreibt
die technische Praxis von IT-forensischen Analysen und geht auf damit verbundene rechtliche Fragestellungen ein. 相似文献
88.
We investigate the decidability of the operation problem for T0L languages and subclasses. Fix an operation on formal languages. Given languages from the family considered (0L languages, T0L languages, or their propagating variants), is the application of this operation to the given languages still a language that belongs to the same language family? Observe, that all the Lindenmayer language families in question are anti-AFLs, that is, they are not closed under homomorphisms, inverse homomorphisms, intersection with regular languages, union, concatenation, and Kleene closure. Besides these classical operations we also consider intersection and substitution, since the language families under consideration are not closed under these operations, too. We show that for all of the above mentioned language operations, except for the Kleene closure, the corresponding operation problems of 0L and T0L languages and their propagating variants are not even semidecidable. The situation changes for unary 0L languages. In this case we prove that the operation problems with respect to Kleene star, complementation, and intersection with regular sets are decidable. 相似文献
89.
Markus Haas Stefan Mittnik Marc S. Paolella 《Computational statistics & data analysis》2009,53(6):2129-2154
An asymmetric multivariate generalization of the recently proposed class of normal mixture GARCH models is developed. Issues of parametrization and estimation are discussed. Conditions for covariance stationarity and the existence of the fourth moment are derived, and expressions for the dynamic correlation structure of the process are provided. In an application to stock market returns, it is shown that the disaggregation of the conditional (co)variance process generated by the model provides substantial intuition. Moreover, the model exhibits a strong performance in calculating out-of-sample Value-at-Risk measures. 相似文献
90.
Rule cubes for causal investigations 总被引:1,自引:1,他引:0
Axel Blumenstock Franz Schweiggert Markus Müller Carsten Lanquillon 《Knowledge and Information Systems》2009,18(1):109-132
With the complexity of modern vehicles tremendously increasing, quality engineers play a key role within today’s automotive
industry. Field data analysis supports corrective actions in development, production and after sales support. We decompose
the requirements and show that association rules, being a popular approach to generating explanative models, still exhibit
shortcomings. Interactive rule cubes, which have been proposed recently, are a promising alternative. We extend this work
by introducing a way of intuitively visualizing and meaningfully ranking them. Moreover, we present methods to interactively
factorize a problem and validate hypotheses by ranking patterns based on expectations, and by browsing a cube-based network
of related influences. All this is currently in use as an interactive tool for warranty data analysis in the automotive industry.
A real-world case study shows how engineers successfully use it in identifying root causes of quality issues.
相似文献
Axel BlumenstockEmail: |