Distributed quantum election scheme

In an electronic voting protocol, a distributed scheme can be used for forbidding the malicious acts of the voting administrator and the counter during the election, but it cannot prevent them from collaborating to trace the ballots and destroy their privacy after the election. We present a distributed anonymous quantum key distribution scheme and further construct a distributed quantum election scheme with a voting administrator made up of more than one part. This quantum election scheme can resist the malicious acts of the voting administrator and the counter after the election and can work in a system with lossy and noisy quantum channels.Comment: 23 page

Probing the PP-wave charmonium decays of BcB_c meson

Motivated by the large number of $B_c$ meson decay modes observed recently by several detectors at the LHC, we present a detailed analysis of the $B_c$ meson decaying to the $P$-wave charmonium states and a light pseudoscalar($P$) or vector ($V$) meson within the framework of perturbative QCD factorization. The $P$-wave charmonium distribution amplitudes are extracted from the $n=2,l=1$ Schr$\ddot{o}$dinger states for a Coulomb potential,which can be taken as the universal nonperturbative objects to analyze the hard exclusive processes with $P$-wave charmonium production. It is found that these decays have large branching ratios of the order of $10^{-5}\sim 10^{-2}$, which seem to be in the reach of future experiments. We also provide predictions for the polarization fractions and relative phases of $B_c\rightarrow (\chi_{c1},\chi_{c2},h_c)V$ decays. It is expected that the longitudinal polarization amplitudes dominate the branching ratios according to the quark helicity analysis, and the magnitudes and phases of parallel polarization amplitude are approximately equal to the perpendicular ones. The obtained results are compared with available experimental data, our previous studies, and numbers from other approaches.Comment: 15 pages, 1 figure, 3 table

On the post-quantum security of encrypted key exchange protocols

We investigate the post-quantum security of the encrypted key exchange(EKE) protocols based on some basic physical parameters of ion-trap quantum computer, and show that the EKE protocol with a 40-bit password will be secure against a quantum adversary with several ion-trap quantum computers. We present a password encrypted no-key protocol to resist middle-man attack, and prove that it is also with the post-quantum security. The analysis presented here is probably of general meaning for the security evaluation of various hybrid cryptosystems.Comment: 14 page

Unitary operators in the orthogonal complement of a type I\mathrm{I} von Neumann algebra in a type II1\mathrm{II}^{}_{1} factor

It is well-known that the equality $$L^{}_{G}\ominus L^{}_{H}=\bar{\mathrm{span}\{L_{g}:g\in G-H\}^{\mathrm{SOT}}}$$ holds for $G$ an i.c.c. group and $H$ a subgroup in $G$, where $L^{}_{G}$ and $L^{}_{H}$ are the corresponding group von Neumann algebras and $L^{}_{G}\ominus L^{}_{H}$ is the set $\{x\in L^{}_{G}:E^{}_{L^{}_{H}}(x)=0\}$ with $E^{}_{L^{}_{H}}$ the conditional expectation defined from $L^{}_{G}$ onto $L^{}_{H}$. Inspired by this, it is natural to ask whether the equality N\ominus A=\bar{\mathrm{span}\{u: u\mbox{is unitary in}N\ominus A\}^{\mathrm{SOT}}} holds for $N$ a type \mbox{II}^{}_{1} factor and $A$ a von Neumann subalgebra of $N$. In this paper, we give an affirmative answer to this question for the case $A$ a type I von Neumann algebra.Comment: 11 page

Context-Constrained Accurate Contour Extraction for Occlusion Edge Detection

Occlusion edge detection requires both accurate locations and context constraints of the contour. Existing CNN-based pipeline does not utilize adaptive methods to filter the noise introduced by low-level features. To address this dilemma, we propose a novel Context-constrained accurate Contour Extraction Network (CCENet). Spatial details are retained and contour-sensitive context is augmented through two extraction blocks, respectively. Then, an elaborately designed fusion module is available to integrate features, which plays a complementary role to restore details and remove clutter. Weight response of attention mechanism is eventually utilized to enhance occluded contours and suppress noise. The proposed CCENet significantly surpasses state-of-the-art methods on PIOD and BSDS ownership dataset of object edge detection and occlusion orientation detection.Comment: To appear in ICME 201

SS-wave KπK\pi contributions to the hadronic charmonium BB decays in the perturbative QCD approach

We extend our recent works on the two-pion $S$-wave resonance contributions to the kaon-pion ones in the $B$ meson hadronic charmonium decay modes based on the perturbative QCD approach. The $S$-wave $K\pi$ time-like form factor in its distribution amplitudes is described by the LASS parametrization, which consists of the $K^*_0(1430)$ resonant state together with an effective range nonresonant component. The predictions for the decays $B\rightarrow J/\psi K\pi$ in this work agree well with the experimental results from $BABAR$ and Belle Collaborations. We also discuss theoretical uncertainties, indicating the results of this work, which can be tested by the LHCb and Belle-II experiments, are reasonably accurate.Comment: 8 pages,2 figures,2 table

S-wave ground state charmonium decays of BcB_c mesons in the perturbative QCD approach

We make a systematic investigation on the two-body nonleptonic decays $B_c\rightarrow J/\Psi(\eta_c),M$ by employing the perturbative QCD approach based on $k_T$ factorization, where $M$ is a light pseudoscalar or vector or a heavy charmed meson. We predict the branching ratios and direct CP asymmetries of these $B_c$ decays and also the transverse polarization fractions of $B_c\rightarrow J/\Psi V,J/\psi D^{*}_{(s)}$ decays. It is found that these decays have a large branching ratios of the order of $10^{-4} - 10^{-2}$ and could be measured by the future LHC-b experiment. Our predictions for the ratios of branching fractions $\frac{\mathcal {BR}(B_c^+\rightarrow J/\Psi D_s^+)} {\mathcal {BR}(B_c^+\rightarrow J/\Psi \pi^+)}$ ,$\frac{\mathcal {BR}(B_c^+\rightarrow J/\Psi D_s^{*+})} {\mathcal {BR}(B_c^+\rightarrow J/\Psi D_s^+)}$ and $\frac{\mathcal {BR}(B_c^+\rightarrow J/\Psi K^+)} {\mathcal {BR}(B_c^+\rightarrow J/\Psi \pi^+)}$ are in good agreement with the data. A large transverse polarization fraction which can reach $48\%$ is predicted in $B_c^+\rightarrow J/\Psi D_s^{*+}$ decay, which is consistent with the data. We find a possible direct CP violation in $B_c\rightarrow J/\psi D^{*}$ decays, which are helpful to test the CP violating effects in $B_c$ decays.Comment: 38 pages, 4 figures, 6 table

Newton Method for Sparse Logistic Regression: Quadratic Convergence and Extensive Simulations

Sparse logistic regression, {as an effective tool of classification,} has been developed tremendously in recent two decades, from its origination the $\ell_1$-regularized version to the sparsity constrained models. This paper is carried out on the sparsity constrained logistic regression by the Newton method. We begin with establishing its first-order optimality condition associated with a $\tau$-stationary point. This point can be equivalently interpreted as an equation system which is then efficiently solved by the Newton method. The method has a considerably low computational complexity and enjoys global and quadratic convergence properties. Numerical experiments on random and real data demonstrate its superior performance when against seven state-of-the-art solvers

A new condition for the uniform convergence of certain trigonometric series

The present paper proposes a new condition to replace both the ($O$-regularly varying) quasimonotone condition and a certain type of bounded variation condition, and shows the same conclusion for the uniform convergence of certain trigonometric series still holds.Comment: 10 page

Asymptotic behavior of the principal eigenvalue of a linear second order elliptic operator with small/large diffusion coefficient and its application

In this article, we are concerned with the following eigenvalue problem of a linear second order elliptic operator: \begin{equation} \nonumber -D\Delta \phi -2\alpha\nabla m(x)\cdot \nabla\phi+V(x)\phi=\lambda\phi\ \ \hbox{ in }\Omega, \end{equation} complemented by a general boundary condition including Dirichlet boundary condition and Robin boundary condition: $$\frac{\partial\phi}{\partial n}+\beta(x)\phi=0 \ \ \hbox{ on }\partial\Omega,$$ where $\beta\in C(\partial\Omega)$ allows to be positive, sign-changing or negative, and $n(x)$ is the unit exterior normal to $\partial\Omega$ at $x$. The domain $\Omega\subset\mathbb{R}^N$ is bounded and smooth, the constants $D>0$ and $\alpha>0$ are, respectively, the diffusive and advection coefficients, and $m\in C^2(\bar\Omega),\,V\in C(\bar\Omega)$ are given functions. We aim to investigate the asymptotic behavior of the principal eigenvalue of the above eigenvalue problem as the diffusive coefficient $D\to0$ or $D\to\infty$. Our results, together with those of \cite{CL2,DF,Fr} where the Nuemann boundary case (i.e., $\beta=0$ on $\partial\Omega$) and Dirichlet boundary case were studied, reveal the important effect of advection and boundary conditions on the asymptotic behavior of the principal eigenvalue. We also apply our results to a reaction-diffusion-advection equation which is used to describe the evolution of a single species living in a heterogeneous stream environment and show some interesting behaviors of the species persistence and extinction caused by the buffer zone and small/large diffusion rate