10,660 research outputs found
New Negentropy Optimization Schemes for Blind Signal Extraction of Complex Valued Sources
Blind signal extraction, a hot issue in the field of communication signal processing, aims to retrieve the sources through the optimization of contrast functions. Many contrasts based on higher-order statistics such as kurtosis, usually behave sensitive to outliers. Thus, to achieve robust results, nonlinear functions are utilized as contrasts to approximate the negentropy criterion, which is also a classical metric for non-Gaussianity. However, existing methods generally have a high computational cost, hence leading us to address the problem of efficient optimization of contrast function. More precisely, we design a novel “reference-based” contrast function based on negentropy approximations, and then propose a new family of algorithms (Alg.1 and Alg.2) to maximize it. Simulations confirm the convergence of our method to a separating solution, which is also analyzed in theory. We also validate the theoretic complexity analysis that Alg.2 has a much lower computational cost than Alg.1 and existing optimization methods based on negentropy criterion. Finally, experiments for the separation of single sideband signals illustrate that our method has good prospects in real-world applications
Transport Coefficients for Holographic Hydrodynamics at Finite Energy Scale
We investigate the relations between black hole thermodynamics and
holographic transport coefficients in this paper. The formulae for DC
conductivity and diffusion coefficient are verified for electrically
single-charged black holes. We examine the correctness of the proposed
expressions by taking charged dilatonic and single-charged STU black holes as
two concrete examples, and compute the flows of conductivity and diffusion
coefficient by solving the linear order perturbation equations. We then check
the consistence by evaluating the Brown-York tensor at a finite radial
position. Finally, we find that the retarded Green functions for the shear
modes can be expressed easily in terms of black hole thermodynamic quantities
and transport coefficients.Comment: 33 pages,4 figures,to appear in Advances in High Energy Physic
Convertible bond announcement effects: why is Japan different?
U.S. and Japanese firms dominate global convertible bond issuance. Previous research documents more favorable convertible bond announcement effects in Japan than in the U.S. and other developed countries. Using a global sample of convertible bonds issued from 1982 to 2012, we find that the more favorable announcement effects of Japanese convertibles are driven by their stated uses of proceeds. Japanese convertibles more often include capital expenditure as an intended use, while U.S. firms tend to mention general purposes to motivate their offering. Our findings illustrate the value to firms of being more explicit when disclosing the intended use of proceeds of security offerings
Study on radiative decays of and into by means of LFQM
The observed resonance peak around 2.86 GeV has been carefully reexamined by
the LHCb collaboration and it is found that under the peak there reside two
states and which are considered as
and with slightly different masses and
total widths. Thus, the earlier assumption that the resonance
was a state should not be right. We suggest to measure the partial widths
of radiative decays of and to confirm their
quantum numbers. We would consider as or a pure
state, or their mixture and respectively calculate the corresponding
branching ratios as well as those of . The future precise
measurement would provide us information to help identifying the structures of
those resonances .Comment: 8 pages, 4 figures, 1 tabl
Induction of MET Receptor Tyrosine Kinase Down-Regulation through Antibody-Mediated Receptor Clustering
The proto-oncoprotein MET is a receptor tyrosine kinase that plays a key role in cancer cell growth and invasion. We have used fluorescence-tagged antibodies to activate MET in live serum-starved glioblastoma cells and monitor the fate of antibody-bound MET receptor in single cell-based assays. We found that the antibodies induced rapid and transient formation of highly polarized MET clusters on the plasma membrane and promoted the activation of MET, resembling the initial effects of binding to its ligand, HGF. However, the antibody-induced clustering and activation of MET led to the rapid removal of the receptor from cell surface and altered its intracellular processing, resulted in rapid degradation of the receptor. Consequently, while cells pre-treated with HGF remain competent to respond to further HGF stimulation, cells pre-treated with antibodies are refractory to further HGF stimulation due to antibody-mediated MET depletion. Removal of MET by sustained treatment of antibodies blocked cancer cell migration and invasion. Our studies reveal a novel mechanism to alter the recycling process of MET in glioblastoma cancer cells by promoting the receptor degradation through a proteasome-sensitive and lysosome-dependent pathway through the ligand-independent activation of MET using anti-MET antibodies
- …