237 research outputs found

    A Modified Uniformization Method for the Solution of the Chemical Master Equation

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    The chemical master equation is considered an accurate description of general chemical systems, and especially so for modeling cell cycle and gene regulatory networks. This paper proposes an efficient way of solving the chemical master equation for some prototypical problems in systems biology. A comparison between this new approach and some traditional approaches is also given

    COMPARATIVE RESEARCH ON THE STROKE RHYTHM OF MEN AND WOMEN KAYAKERS IN THE INTERNATIONAL COMPETITION

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    The text studied the stroke rate and rhythm of men and women kayakers in the world cup competition on the base of defined division of time phase for each stroke. It is found that the time proportion of the pull and air-work phase in the two sides of men kayakers are both 65% to 35%, while the time proportion of the same phase in the right-side of women kayakers is 66% to 34%, and that in the lefl-side is 69% to 31%; the power time proportion in the right-side of men kayakers is 40% and in the left-side is 41 %, while that in the right-side of women kayakers is 39% and in the lefl-side is 41 %. Men kayakers command a better symmetry and consistency between the left and right side in stroke rhythm than women kayakers. Men kayakers increase the stroke rate mainly accompanied with shortening the air-work time proportion while womenkayakers mainly with shortening the pull time proportion

    Singlino-dominated dark matter in general NMSSM

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    The general Next-to-Minimal Supersymmetric Standard Model (NMSSM) describes the singlino-dominated dark-matter (DM) property by four independent parameters: singlet-doublet Higgs coupling coefficient λ\lambda, Higgsino mass μtot\mu_{tot}, DM mass mχ~10m_{\tilde{\chi}_1^0}, and singlet Higgs self-coupling coefficient κ\kappa. The first three parameters strongly influence the DM-nucleon scattering rate, while κ\kappa usually affects the scattering only slightly. This characteristic implies that singlet-dominated particles may form a secluded DM sector. Under such a theoretical structure, the DM achieves the correct abundance by annihilating into a pair of singlet-dominated Higgs bosons by adjusting κ\kappa's value. Its scattering with nucleons is suppressed when λv/μtot\lambda v/\mu_{tot} is small. This speculation is verified by sophisticated scanning of the theory's parameter space with various experiment constraints considered. In addition, the Bayesian evidence of the general NMSSM and that of Z3Z_3-NMSSM is computed. It is found that, at the cost of introducing one additional parameter, the former is approximately 3.3×1033.3 \times 10^3 times the latter. This result corresponds to Jeffrey's scale of 8.05 and implies that the considered experiments strongly prefer the general NMSSM to the Z3Z_3-NMSSM.Comment: 29 pages, 9 figure

    Optical flow-based vascular respiratory motion compensation

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    This paper develops a new vascular respiratory motion compensation algorithm, Motion-Related Compensation (MRC), to conduct vascular respiratory motion compensation by extrapolating the correlation between invisible vascular and visible non-vascular. Robot-assisted vascular intervention can significantly reduce the radiation exposure of surgeons. In robot-assisted image-guided intervention, blood vessels are constantly moving/deforming due to respiration, and they are invisible in the X-ray images unless contrast agents are injected. The vascular respiratory motion compensation technique predicts 2D vascular roadmaps in live X-ray images. When blood vessels are visible after contrast agents injection, vascular respiratory motion compensation is conducted based on the sparse Lucas-Kanade feature tracker. An MRC model is trained to learn the correlation between vascular and non-vascular motions. During the intervention, the invisible blood vessels are predicted with visible tissues and the trained MRC model. Moreover, a Gaussian-based outlier filter is adopted for refinement. Experiments on in-vivo data sets show that the proposed method can yield vascular respiratory motion compensation in 0.032 sec, with an average error 1.086 mm. Our real-time and accurate vascular respiratory motion compensation approach contributes to modern vascular intervention and surgical robots.Comment: This manuscript has been accepted by IEEE Robotics and Automation Letter
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