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关键词： Image steganography   Multimedia   Arnold scrambling   Sub-matrix generation   Laplacian pyramid   Histogram shifting   Redundant integer wavelet transform   Deep learning  

摘要： Nowadays, highly sensitive medical images are vulnerable to data threats and privacy attacks. They must be kept secure while transmitting them across insecure channels precisely for this purpose. The robust image steganography is focused on this work by exploiting Redundant Integer Wavelet Transform (RIWT), Laplacian Pyramid, Arnold scrambling and Histogram shifting algorithm to facilitate secure communication of secret images in the context. Stego images thus generated are subjected to a deep learning approach to assess if it can be classified as a cover or not. If not, the HS parameter is modified to generate stego images in such a way to classify it as a cover image. Thus it is difficult to suspect the existence of a secret image by the Human Visual System (HVS). The efficiency of our method is analyzed by comparing it with related methods present in the literature. Average NCC values between the original secret image and the extracted secret image are 0.8917 which is higher than the schemes in the literature. Average PSNR values of the stego image are 36.375 even when the embedding rate is increased to 4 bits per pixel. The analysis was done on security and robustness also reveals better results. From the experimental analysis, it is proved that the proposed method is superior to the related methods of the literature.

关键词： Internal circulation   Cooler   Hydrodynamics   Fluidized bed   CFD  

摘要： Annular catalyst cooler (ACC) can intensify the bed-to-wall heat transfer compared with traditional base catalyst cooler (BCC). Although the intensified mechanism has been investigated, it is necessary to clearly understand information on hydrodynamics and internal circulation characteristics in the whole cooler. Euler-Euler model with modified Gidaspow drag model is employed to simulate the hydrodynamics and internal circulation characteristics. The results show that the hydrodynamics difference between two coolers is positioned at their downer region, where the solids volume fraction in the ACC is bigger than those in the upper region of dense bed and in the whole BCC. The internal circulation of particles in the ACC is also located in the downer region of dense bed, which is verified by profiles of axial and radial velocities at different positions. In order to quantify this internal circulation flow, both internal cir-culation height and flux are proposed and determined respectively by radial velocity of particles and by their flux below heat tube. The height increases and the flux decreases with increasing gas velocity from center distributor. Those results indicate that the heat transfer intensified effect is mainly influenced by internal circulation height, which is agreement with the effect of gas velocity on heat transfer intensified height. (c) 2021 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.

关键词： Dunkl-Laplace operator   Poisson kernel   Green function   Dirichlet problem   Spherical harmonics   Newton kernel   Primary   Secondary  

摘要： Let Delta(k)be the Dunkl Laplacian relative to a fixed root system R in R-d, d >= 2, and to a nonnegative multiplicity functionkon R. Our first purpose in this paper is to solve the Delta(k)-Dirichlet problem for annular regions. Secondly, we introduce and study the Delta(k)-Green function of the annulus and we prove that it can be expressed by means of Delta(k)-spherical harmonics. As applications, we obtain a Poisson-Jensen formula for Delta(k)-subharmonic functions and we study positive continuous solutions for a Delta(k)-semilinear problem.

关键词： Photochemotherapy   Antimicrobial resistance   TONS504   Methylene blue   Singlet oxygen  

摘要： TONS504 (C51H58O5I2) is a chlorin derivative that exhibits a photodynamic antimicrobial effect (PAE) on various infectious keratitis pathogens. However, the molecular characteristics of TONS504 are not well understood. This study aimed to investigate the molecular characteristics of TONS504 by comparing its singlet oxygen (1O2) quantum yields and PAE with those of methylene blue (MB). To measure the 1O2 quantum yields, TONS504 and MB were dissolved in phosphate-buffered saline and phosphate-buffered saline containing 1% Triton X-100. The solutions were then activated by a Nd:YAG laser with an average output power of 8 mW. Near-infrared 1O2 luminescence was detected as an indicator of the 1O2 quantum yields. To evaluate the PAE, TONS504 and MB were activated by a light-emitting diode with a total light energy of 30 J/cm2. We compared the minimum molar concentration of each photosensitizer to show apparent PAEs on Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans. TONS504 exhibited higher 1O2 quantum yields than MB in PBS/Triton X-100 but not in PBS. S. aureus and C. albicans were reduced by TONS504 at lower concentrations than by MB, but this was not the case for P. aeruginosa. Our results provide insight on the molecular characteristics of TONS504 and suggest that TONS504 has excellent 1O2 quantum yields and PAE. Compared with MB, TONS504 in PBS has stronger efficacy toward some infectious keratitis pathogens but not others.

关键词： Schrodinger-Kirchhoff-type equation   nonlocal term   constrained various method  

摘要： In this paper, we are interested in the existence of ground state nodal solutions for the following Schrodinger-Kirchhoff-type Laplacian problems: -M(integral(R3) vertical bar del u vertical bar(2)dx)Delta u + V(x)u = vertical bar u vertical bar(4) u + kf(u), x is an element of R-3, where M(t) = a+bt(gamma) with 0 < gamma < 2, a, b > 0 and the nonlinear function f is an element of C(R, R). By the nodal Nehari manifold method, for each b > 0, we obtain a least energy nodal solution u(b) and a ground state solution v(b) of this problems when k >> 1. Our results improve and extend the known results of the usual case gamma = 1 in the sense that a more wider range of gamma is covered.

关键词： Logarithmic Laplacian   Symmetry and monotonicity   The direct method of moving planes  

摘要： In this paper, a direct method of moving planes for the Logarithmic Laplacian is developed. Some key concepts of the method such as Maximum principle for anti-symmetric functions, Narrow region principle and Decay at infinity are discussed. As an application of the direct method of moving planes, the symmetry and monotonicity of the positive solutions of two nonlinear equations involving Logarithmic Laplacian are obtained. (C) 2021 Elsevier Ltd. All rights reserved.

关键词： Particle and Nuclear Physics   Classical and Quantum Gravitation   Relativity Theory   Elementary Particles   Quantum Field Theory   Solid State Physics  

摘要： The dynamics of time evolution of quantum oscillator excitation by electromagnetic pulses is investigated theoretically for an arbitrary field amplitude in a pulse. We consider a harmonic oscillator without damping and excitation between stationary states. The general formula for the excitation of quantum states as a function of time is derived in terms of instantaneous energy of an associated classical oscillator in the field of an electromagnetic pulse. The derived expression is used in detailed analysis of the time dependence of the quantum oscillator excitation probability beyond the range of perturbation theory for various pulse parameters including total excitation from the ground state, excitation from excited states, and excitation spectra.

关键词： inverse problem   Kelvin-Voigt equations   p-Laplacian   damping term   existence   uniqeness  

摘要： In this paper, we consider the nonlinear inverse problem for generalized Kelvin-Voigt equations with the p-Laplace diffusion and damping term, describing the motion of incompressible viscous fluids. We assume that the damping term in the momentum equation depends on whether its signal is positive or negative, which may realizes the presence of a source or a sink within the system. The investigated inverse problem consists of finding a coefficient f(t) of the right-hand side of the momentum equation, a vector of velocity field v, and a pressure pi. An additional information on a solution of the inverse problem is given as integral overdetermination condition. Under several assumptions on the exponents p, m, the coefficients mu, kappa, gamma, the dimension of the space d, and specified initial data, we prove the existence and uniqueness of the weak solution of the problem.

关键词： Eigenvalue estimates   Weighted p-Laplacian   Bakry-Emery manifolds   and modulus of continuity   Gradient comparison theorem  

摘要： We establish sharp lower bounds for the first nonzero eigenvalue of the weighted p-Laplacian with 1 < p < infinity on a compact Bakry-Emery manifold (M-n, g, f) satisfying Ric + del(2)f >= kappa g, provided that either 1 < p <= 2 or kappa <= 0. For 1 < p <= 2, we provide a simple proof via the modulus of continuity estimates. The proof for the kappa <= 0 case is based on a sharp gradient comparison theorem for the eigenfunction together with a careful analysis of the underlying one-dimensional model equation.

摘要： We consider the quantum electrodynamic corrections to the two-stream instability. We find these corrections vanish at first order unless a guiding magnetic field B-0 is considered. With respect to the classical version of the instability, quantum electrodynamic effects reduce the most unstable wave vector and its growth rate by a factor root 1+xi, with xi = alpha/9 pi (B-0/B-cr)(2), where alpha is the fine-structure constant and B-cr the Schwinger critical magnetic field. Although derived for a cold system, these results are valid for the kinetic case. The results are valid in the range xi << 1 and, actually, up to linear corrections in xi. Copyright (C) 2021 EPLA