2,552 research outputs found

    Ball-path inference based on a combination of audio and video clues in tennis video sequences

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    Tennis-sports analysis is attracting much attention in content-analysis research and professional applications.This paper presents a scheme for sports analysis employing an automatic tennis ball-path inference driven by a combination of auditory and visual information. The ball-path inference is implemented for tactics analysis.Since ball tracking remains to be a challenging issue in practice, we use a non-tracking approach for ball-path inference. We propose an effective serving-player detection for achieving an accurate match between a sequence of racket-hit moments and the position of the hitting player in the corresponding video frames. Experimental results have shown that the proposed system can reliably detect the serving-player and classify into different categories, such as left-court/right-court service and frontcourt/ back-court service. Therefore, our system can be utilized for an effective and automatic extraction of various tennis events, performance and tactics analysis with high reliability

    Fast detection and modeling of human-body parts from monocular video

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    This paper presents a novel and fast scheme to detect different body parts in human motion. Using monocular video sequences, trajectory estimation and body modeling of moving humans are combined in a co-operating processing architecture. More specifically, for every individual person, features of body ratio, silhouette and appearance are integrated into a hybrid model to detect body parts. The conventional assumption of upright body posture is not required. We also present a new algorithm for accurately finding the center point of the human body. The body configuration is finally described by a skeleton model. The feasibility and accuracy of the proposed scheme are analyzed by evaluating its performance for various sequences with different subjects and motion types (walking, pointing, kicking, leaping and falling). Our detection system achieves nearly real-time performance (around 10 frames/second)

    Low adherence coating

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    Self-replenishing low-adherence coatings

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    Low-adherence coatings are widely used today since their water/oil repellency makes them easily cleanable (a well-known example is PTFE). The low surface tension is provided by fluorine- or silicon-containing species that are present at the film surface. Low adherence coatings have already been developed via surface segregation of fluorinated species. However, it has been shown that the fluorine-enriched layer is very thin, and the coating may not sustain low adherence upon mechanical abrasion. An approach to develop self-replenishing low surface energy coatings is to distribute long perfluoroalkyl-end-capped chains relatively homogeneously in a coating network. In case of surface damage that leads to the loss of the top layers of the coating, fluorinated tails from sub-layers will be able to reorient themselves to minimize the air/film interfacial energy. In order to study the self-replenishing behavior, model polyester precursors with controlled functionality were synthesized via controlled ring-opening polymerization of e-caprolactone using perfluoroalkyl alcohol or polyol as initiators. The as-prepared precursors were cured with polyisocyanate crosslinker to obtain films with low surface energy. The fluorine depth profile and the self-replenishing behavior have been investigated. The influence of the mobility of polymer spacer and network, as well as temperature, on the self-replenishing behavior will be discussed

    Low adherence coating containing polymers with low surface energy

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    A low adherence coating comprises: (a) a crosslinked polymeric network (N), based on a first polymer (P), (b) a low-surface-energy group (E), coupled to the network via (c) a polymeric spacer (S), having the following relationship between the native surface energies of P, E, and S (resp. sp, se, and ss,, in mN/m): se <ss <sp. The coatings have a low adherence towards different types of contaminants. A coating contained a polycaprolactone terminated with perfluorooctyl ethanol. [on SciFinder (R)

    Low adherence coating

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    The invention relates to a coating having a low adherence towards different types of contaminants. Such a coating comprises a crosslinked polymeric network provided with an end-functionalized dangling chain, as a result of which the surface maintains its low surface energy
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