61,223 research outputs found

    Multi-Parented End-Effectors in Optimization-Based Prediction of Posture and Anthropometry

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    Improving motion capture processing onto a virtual model is an important research area. Although there has been significant research in this field, little work has been done to determine posture and anthropometry simultaneously with the intent of visualizing the data on virtual models. Many existing techniques are less accurate when applying processed data to a virtual model for biomechanical analysis. This paper presents a novel approach that estimates posture and anthropometry using optimization-based posture prediction to determine joint angles and link-lengths of a virtual model. By including anthropometric design variables, this approach introduces flexible handling of innate variance in subject-model measurements without need for pre- or post-processing. This produces a more realistic motion and exhibits anthropometric measurements closer to those of the original subject, resulting in a new level of biomechanical accuracy that allows for analysis of a processed motion with a higher degree of confidence

    Visualizing the motion of graphene nanodrums

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    Membranes of suspended two-dimensional materials show a large variability in mechanical properties, in part due to static and dynamic wrinkles. As a consequence, experiments typically show a multitude of nanomechanical resonance peaks, which makes an unambiguous identification of the vibrational modes difficult. Here, we probe the motion of graphene nanodrum resonators with spatial resolution using a phase-sensitive interferometer. By simultaneously visualizing the local phase and amplitude of the driven motion, we show that unexplained spectral features represent split degenerate modes. When taking these into account, the resonance frequencies up to the eighth vibrational mode agree with theory. The corresponding displacement profiles however, are remarkably different from theory, as small imperfections increasingly deform the nodal lines for the higher modes. The Brownian motion, which is used to calibrate the local displacement, exhibits a similar mode pattern. The experiments clarify the complicated dynamic behaviour of suspended two-dimensional materials, which is crucial for reproducible fabrication and applications

    Visualization of the Phosphoproteomic Data from AfCS with the Google Motion Chart Gadget

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    Results from multivariate molecular biological experiments become increasingly complex. Hence, the challenge of projecting high-dimensional data onto few dimensions for effective data visualization is becoming increasingly important in Systems Biology. Effective data visualization can summarize the activity of many variables over time as well as display relationships between variables. Dynamic interactive visualization tools can provide scientists with ways of visually identifying relationship and patterns, and improve communication of results on the web and in presentations. For this, interactive systems with animation have great potential since they add dimensions to static images limited to two dimensions. Interactivity and animation is particularly useful for showing time-series trends in multi-dimensional data. The Flash-based Motion Chart Google Gadget available through GoogleDocs is a recent advance in multi-dimensional data visualization. The Motion Chart Gadget is a component of the Trendalyzer software, which was developed for web-based animation of statistical results. Here we demonstrate the use of this Gadget to visualize molecular biological data, the phosphoproteomics results published on the Data Center of the Signaling Gateway web-site

    Application of serious games to sport, health and exercise

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    Use of interactive entertainment has been exponentially expanded since the last decade. Throughout this 10+ year evolution there has been a concern about turning entertainment properties into serious applications, a.k.a "Serious Games". In this article we present two set of Serious Game applications, an Environment Visualising game which focuses solely on applying serious games to elite Olympic sport and another set of serious games that incorporate an in house developed proprietary input system that can detect most of the human movements which focuses on applying serious games to health and exercise

    Visualizing sound emission of elephant vocalizations: evidence for two rumble production types

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    Recent comparative data reveal that formant frequencies are cues to body size in animals, due to a close relationship between formant frequency spacing, vocal tract length and overall body size. Accordingly, intriguing morphological adaptations to elongate the vocal tract in order to lower formants occur in several species, with the size exaggeration hypothesis being proposed to justify most of these observations. While the elephant trunk is strongly implicated to account for the low formants of elephant rumbles, it is unknown whether elephants emit these vocalizations exclusively through the trunk, or whether the mouth is also involved in rumble production. In this study we used a sound visualization method (an acoustic camera) to record rumbles of five captive African elephants during spatial separation and subsequent bonding situations. Our results showed that the female elephants in our analysis produced two distinct types of rumble vocalizations based on vocal path differences: a nasally- and an orally-emitted rumble. Interestingly, nasal rumbles predominated during contact calling, whereas oral rumbles were mainly produced in bonding situations. In addition, nasal and oral rumbles varied considerably in their acoustic structure. In particular, the values of the first two formants reflected the estimated lengths of the vocal paths, corresponding to a vocal tract length of around 2 meters for nasal, and around 0.7 meters for oral rumbles. These results suggest that African elephants may be switching vocal paths to actively vary vocal tract length (with considerable variation in formants) according to context, and call for further research investigating the function of formant modulation in elephant vocalizations. Furthermore, by confirming the use of the elephant trunk in long distance rumble production, our findings provide an explanation for the extremely low formants in these calls, and may also indicate that formant lowering functions to increase call propagation distances in this species'

    Uncertainty in phylogenetic tree estimates

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    Estimating phylogenetic trees is an important problem in evolutionary biology, environmental policy and medicine. Although trees are estimated, their uncertainties are discarded by mathematicians working in tree space. Here we explicitly model the multivariate uncertainty of tree estimates. We consider both the cases where uncertainty information arises extrinsically (through covariate information) and intrinsically (through the tree estimates themselves). The importance of accounting for tree uncertainty in tree space is demonstrated in two case studies. In the first instance, differences between gene trees are small relative to their uncertainties, while in the second, the differences are relatively large. Our main goal is visualization of tree uncertainty, and we demonstrate advantages of our method with respect to reproducibility, speed and preservation of topological differences compared to visualization based on multidimensional scaling. The proposal highlights that phylogenetic trees are estimated in an extremely high-dimensional space, resulting in uncertainty information that cannot be discarded. Most importantly, it is a method that allows biologists to diagnose whether differences between gene trees are biologically meaningful, or due to uncertainty in estimation.Comment: Final version accepted to Journal of Computational and Graphical Statistic
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