6,048 research outputs found

    2D Reconstruction of Small Intestine's Interior Wall

    Full text link
    Examining and interpreting of a large number of wireless endoscopic images from the gastrointestinal tract is a tiresome task for physicians. A practical solution is to automatically construct a two dimensional representation of the gastrointestinal tract for easy inspection. However, little has been done on wireless endoscopic image stitching, let alone systematic investigation. The proposed new wireless endoscopic image stitching method consists of two main steps to improve the accuracy and efficiency of image registration. First, the keypoints are extracted by Principle Component Analysis and Scale Invariant Feature Transform (PCA-SIFT) algorithm and refined with Maximum Likelihood Estimation SAmple Consensus (MLESAC) outlier removal to find the most reliable keypoints. Second, the optimal transformation parameters obtained from first step are fed to the Normalised Mutual Information (NMI) algorithm as an initial solution. With modified Marquardt-Levenberg search strategy in a multiscale framework, the NMI can find the optimal transformation parameters in the shortest time. The proposed methodology has been tested on two different datasets - one with real wireless endoscopic images and another with images obtained from Micro-Ball (a new wireless cubic endoscopy system with six image sensors). The results have demonstrated the accuracy and robustness of the proposed methodology both visually and quantitatively.Comment: Journal draf

    Fast DGT Based Receivers for GFDM in Broadband Channels

    Full text link
    Generalized frequency division multiplexing (GFDM) is a recent multicarrier 5G waveform candidate with flexibility of pulse shaping filters. However, the flexibility of choosing a pulse shaping filter may result in inter carrier interference (ICI) and inter symbol interference (ISI), which becomes more severe in a broadband channel. In order to eliminate the ISI and ICI, based on discrete Gabor transform (DGT), in this paper, a transmit GFDM signal is first treated as an inverse DGT (IDGT), and then a frequency-domain DGT is formulated to recover (as a receiver) the GFDM signal. Furthermore, to reduce the complexity, a suboptimal frequency-domain DGT called local DGT (LDGT) is developed. Some analyses are also given for the proposed DGT based receivers.Comment: 28 pages, 8 figure

    Up or Down? How Culture and Color Affect Judgments

    Get PDF
    The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.In the Mainland China stock market, an upmarket is represented by the color red, whereas a downmarket is represented by the color green. Elsewhere, including the Chinese Hong Kong stock market, the color representations are the opposite. Three studies were conducted to examine the red-upā€“green-down effect for Mainland Chinese as well as the green-upā€“red-down effect for Hong Kong people. Study 1 showed that Mainland Chinese tended to predict greater economic growth (study 1a) and higher growth in consumption trends (study 1b) when the experimental materials were presented in red than in green, whereas Hong Kong participants exhibited the opposite tendencies. Study 2 found that Mainland Chinese implicitly associated red and green with up and down, respectively; Hong Kong people, however, implicitly associated green and red with up and down, respectively. Study 3 further indicated that Mainland Chinese were more likely to predict good outcomes when scenarios were presented in red, whereas Hong Kong participants were more likely to predict good outcomes when scenarios were presented in green. These findings suggest that culturally specific environment cues could influence human prediction and judgment. Implications for judgment generally are discussed

    Optimal Entry and Consumption under Habit Formation

    Full text link
    This paper studies a composite problem involving the decision making of the optimal entry time and dynamic consumption afterwards. In stage-1, the investor has access to full market information subjecting to some information costs and needs to choose an optimal stopping time to initiate stage-2; in stage-2, the investor terminates the costly full information acquisition and starts dynamic investment and consumption under partial observations of free public stock prices. The habit formation preference is employed, in which the past consumption affects the investor's current decisions. By using the stochastic Perron's method, the value function of the composite problem is proved to be the unique viscosity solution of some variational inequalities.Comment: Final version, forthcoming in Advances in Applied Probabilit
    • ā€¦
    corecore