12,493 research outputs found

    Serious interface design for dental health: Wiimote-based tangible interaction for school children

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    This paper describes a camera-based approach towards creating a tangible interface for serious games. We introduce our game for dental health targeted at school children which implements the Nintendo WiiMote as infrared camera. Paired with a gesture-recognition system, this combination allows us to apply real-world items as input devices. Thereby, the game tries to address different aspects of dental hygiene along with the improvement of children's motor skills. In our focus group test, we found that tangible interfaces offer great potential for educational purposes and can be used to engage kids in a playful learning process by addressing their childlike curiosity and fostering implicit learning

    gamma-ray DBSCAN: a clustering algorithm applied to Fermi-LAT gamma-ray data. I. Detection performances with real and simulated data

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    The Density Based Spatial Clustering of Applications with Noise (DBSCAN) is a topometric algorithm used to cluster spatial data that are affected by background noise. For the first time, we propose the use of this method for the detection of sources in gamma-ray astrophysical images obtained from the Fermi-LAT data, where each point corresponds to the arrival direction of a photon. We investigate the detection performance of the gamma-ray DBSCAN in terms of detection efficiency and rejection of spurious clusters, using a parametric approach, and exploring a large volume of the gamma-ray DBSCAN parameter space. By means of simulated data we statistically characterize the gamma-ray DBSCAN, finding signatures that differentiate purely random fields, from fields with sources. We define a significance level for the detected clusters, and we successfully test this significance with our simulated data. We apply the method to real data, and we find an excellent agreement with the results obtained with simulated data. We find that the gamma-ray DBSCAN can be successfully used in the detection of clusters in gamma-ray data. The significance returned by our algorithm is strongly correlated with that provided by the Maximum Likelihood analysis with standard Fermi-LAT software, and can be used to safely remove spurious clusters. The positional accuracy of the reconstructed cluster centroid compares to that returned by standard Maximum Likelihood analysis, allowing to look for astrophysical counterparts in narrow regions, minimizing the chance probability in the counterpart association. We find that gamma-ray DBSCAN is a powerful tool in the detection of clusters in gamma-ray data, this method can be used both to look for point-like sources, and extended sources, and can be potentially applied to any astrophysical field related with detection of clusters in data.Comment: Accepted for publication in A&

    Learning an Interactive Segmentation System

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    Many successful applications of computer vision to image or video manipulation are interactive by nature. However, parameters of such systems are often trained neglecting the user. Traditionally, interactive systems have been treated in the same manner as their fully automatic counterparts. Their performance is evaluated by computing the accuracy of their solutions under some fixed set of user interactions. This paper proposes a new evaluation and learning method which brings the user in the loop. It is based on the use of an active robot user - a simulated model of a human user. We show how this approach can be used to evaluate and learn parameters of state-of-the-art interactive segmentation systems. We also show how simulated user models can be integrated into the popular max-margin method for parameter learning and propose an algorithm to solve the resulting optimisation problem.Comment: 11 pages, 7 figures, 4 table

    Characterizing and Improving Stability in Neural Style Transfer

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    Recent progress in style transfer on images has focused on improving the quality of stylized images and speed of methods. However, real-time methods are highly unstable resulting in visible flickering when applied to videos. In this work we characterize the instability of these methods by examining the solution set of the style transfer objective. We show that the trace of the Gram matrix representing style is inversely related to the stability of the method. Then, we present a recurrent convolutional network for real-time video style transfer which incorporates a temporal consistency loss and overcomes the instability of prior methods. Our networks can be applied at any resolution, do not re- quire optical flow at test time, and produce high quality, temporally consistent stylized videos in real-time

    Molecular simulation of 2-dimensional microphase separation of single-component homopolymers grafted onto a planar substrate

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    The structural phase behavior of polymer brushes, single-component linear homopolymers grafted onto a planar substrate, is studied using the molecular Monte Carlo method in 3 dimensions. When simulation parameters of the system are set in regions of macrophase separation of solution for the corresponding non-grafted homopolymers, the grafted polymers also prefer segregation. However, macrophase separation is disallowed due to the spatially-fixed grafting points of the polymers. Such constraints on the grafting are similar to connecting points between blocks of non-grafted diblock copolymers at the microphase separation in the melt state. This results in "microphase separation" of the homopolymer brush in the lateral direction of the substrate. Here we extensively search the parameter space and reveal various lateral domain patterns that are similar to those found in diblock copolymer melts at microphase separation.Comment: 6 pages, 5 figures, accepted for publication in EP

    CLD-shaped Brushstrokes in Non-Photorealistic Rendering

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    Rendering techniques based on a random grid can be improved by adapting brushstrokes to the shape of different areas of the original picture. In this paper, the concept of Coherence Length Diagram is applied to determine the adaptive brushstrokes, in order to simulate an impressionist painting. Some examples are provided to instance the proposed algorithm.Comment: Keywords: Image processing, Non-photorealistic processing, Image-based rendering Coherence Length Diagra

    Models of MOS and SOS devices

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    Quarterly report describes progress in three programs: dc sputtering machine for aluminum and aluminum alloys; two dimensional computer modeling of MOS transistors; and development of computer techniques for calculating redistribution diffusion of dopants in silicon on sapphire films
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