Extended Jacobian elliptic function algorithm with symbolic computation to construct new doubly-periodic solutions of nonlinear differential equations

With the aid of computerized symbolic computation, the extended Jacobian elliptic function expansion method and its algorithm are presented by using some relations among ten Jacobian elliptic functions and are very powerful to construct more new exact doubly-periodic solutions of nonlinear differential equations in mathematical physics. The new (2+1)-dimensional complex nonlinear evolution equations is chosen to illustrate our algorithm such that sixteen families of new doubly-periodic solutions are obtained. When the modulus m→1 or 0, these doubly-periodic solutions degenerate as solitonic solutions including bright solitons, dark solitons, new solitons as well as trigonometric function solutions.     

Solitary wave solutions for a higher order nonlinear Schrödinger equation

We consider a higher order nonlinear Schrödinger equation with third- and fourth-order dispersions, cubic–quintic nonlinearities, self steepening, and self-frequency shift effects. This model governs the propagation of femtosecond light pulses in optical fibers. In this paper, we investigate general analytic solitary wave solutions and derive explicit bright and dark solitons for the considered model. The derived analytical dark and bright wave solutions are expressed in terms of the model coefficients. These exact solutions are useful to understand the mechanism of the complicated nonlinear physical phenomena which are related to wave propagation in a higher-order nonlinear and dispersive Schrödinger system.     

Dark matter origin and mass generation for Dirac particles

We present a new approach to dark matter identification and a new dynamical mechanism of mass generation for spinor particles. This approach is based on using a modified version of the massless Dirac equation with an analytic dependence of the wave function on a complex evolution parameter. It is shown that the spectrum of the theory contains massive, massless and tachyon modes. It is established that the presence of tachyons maintains a real addition to the mass of the quantum system, so the tachyon sector can be identified with dark matter in the Universe. We have also studied exact solutions of soliton type in this theory. It is shown that these quantum solitons possess nontrivial mass characteristics which have a dynamical nature.     

Efficient parallel implementation of the nonparaxial beam propagation method

An efficient parallel implementation of a nonparaxial beam propagation method for the numerical study of the nonlinear Helmholtz equation is presented. Our solution focuses on minimizing communication and computational demands of the method which are dependent on a nonparaxiality parameter. Performance tests carried out on different types of parallel systems behave according theoretical predictions and show that our proposal exhibits a better behavior than those solutions based on the use of conventional parallel fast Fourier transform implementations. The application of our design is illustrated in a particularly demanding scenario: the study of dark solitons at interfaces separating two defocusing Kerr media, where it is shown to play a key role.     

含外力项时变系数KdV方程与时变系数耦合KdV方程组的孤子解

应用孤子拟解法研究了含外力项时变系数KdV方程与一类时变系数耦合KdV方程组.首先将方程经过变量代换转换为齐次方程,然后将孤子解假设为双曲正割函数的形式带入方程或方程组,最后借助Maple软件完成复杂的计算来确定假设的孤子解的待定系数,从而得到孤子解存在的条件及其孤子解.结果显示:孤子拟解法计算简便且能得到方程的亮孤子解.     

Exact solutions of discrete complex cubic Ginzburg–Landau equation via extended tanh-function approach

In this paper, we obtained rich solutions for the discrete complex cubic Ginzburg–Landau equation by means of the extended tanh-function approach. These solutions include chirpless bright soliton, chirpless dark soliton, triangular function solutions and some solutions with alternating phases, and so on. Meanwhile, the range of parameters where some exact solution exists is given.     

一种亮暗小目标自适应检测方法*

在原始多级滤波检测小目标的方法基础上,改进了多级滤波器的结构,对其差分后的信号同时保留亮暗部分的信息.通过对感兴趣区域进行基于侧抑制的局对比度增强处理,有效地抑制了背景杂波,完整地增强了亮、暗目标,并且对目标边缘增强的定位准确,有利于目标特征的计算.实验结果表明,该算法能对亮、暗目标自适应检测,并且具有良好的检测性能.     

Solitary wave families of NLPDES via reversible systems theory

The Ostrovsky equation is an important canonical model for the unidirectional propagation of weakly nonlinear long surface and internal waves in a rotating, inviscid and incompressible fluid. Since solitary wave solutions often play a central role in the long-time evolution of an initial disturbance, we consider such solutions here (via the normal form approach) within the framework of reversible systems theory. Besides confirming the existence of the known family of solitary waves and its reduction to the KdV limit, we find a second family of multihumped (or N-pulse) solutions, as well as a continuum of delocalized solitary waves (or homoclinics to small-amplitude periodic orbits). On isolated curves in the relevant parameter region, the delocalized waves reduce to genuine embedded solitons. The second and third families of solutions occur in regions of parameter space distinct from the known solitary wave solutions and are thus entirely new. Directions for future work, including on other NLPDEs, are also mentioned.     

Hidden solitons in the Zabusky–Kruskal experiment: Analysis using the periodic,inverse scattering transform

Recent numerical work on the Zabusky–Kruskal experiment has revealed, amongst other things, the existence of hidden solitons in the wave profile. Here, using Osborne’s nonlinear Fourier analysis, which is based on the periodic, inverse scattering transform, the hidden soliton hypothesis is corroborated, and the exact number of solitons, their amplitudes and their reference level is computed. Other “less nonlinear” oscillation modes, which are not solitons, are also found to have nontrivial energy contributions over certain ranges of the dispersion parameter. In addition, the reference level is found to be a non-monotone function of the dispersion parameter. Finally, in the case of large dispersion, we show that the one-term nonlinear Fourier series yields a very accurate approximate solution in terms of Jacobian elliptic functions.     

Reduction of permanent image sticking in ACPDPs using RF‐plasma pretreatment on MgO surface

Abstract— The characteristics of the MgO layer are known to be an important parameter that affects the permanent image sticking or lifetime of an ACPDP. In this paper, to reduce the permanent image sticking in ACPDPs, the effects of RF‐plasma pretreatments of the MgO layer on the permanent image sticking are investigated. The treatment was conducted by using several plasma‐forming gases, including Ar, Ar followed by O², and O² followed by Ar. Measurements of luminance, normalized luminance, V^t closed curve, haze, MgO hardness, and photoluminescence between the discharge and nondis‐charge regions under dark and bright backgrounds indicated that the plasma treatments of MgO using either Ar or Ar followed by O² gases reduce the permanent image sticking on dark and bright images in an ACPDP.     

Variants of the two-dimensional boussinesq equation with compactons,solitons, and periodic solutions

Variants of the two-dimensional Boussinesq equation with positive and negative exponents are studied. The sine-cosine ansatz is fruitfully used to carry out the analysis. Exact solutions of different physical structures: compactons, solitary patterns, solitons, and periodic solutions, are obtained. The quantitative change in the physical structure of the solutions is shown to depend mainly on the exponent of the wave function u(x, t) and on the ratio a/b of the derivatives of u(x, t).     

Parameter Settings and Representations in Pareto-Based Optimization for Job Shop Scheduling

A multiobjective optimization problem involves multiple objectives, often conflicting, to be met or optimized. A Pareto front provides a set of best solutions to determine the trade-offs between the various objectives. New evolutionary approaches demonstrated its ability to build well-delineated Pareto fronts in diverse multiobjective optimization problems, including multicriteria optimization in job shop scheduling with regular and nonregular objective functions. Good parameter settings and appropriate representations can enhance the behavior of an evolutionary algorithm. The present article shows a study of the influence of distinct parameter combinations as well as different chromosome representations. Details of implementation and results are discussed.     

参考点自适应调整下评价指标驱动的高维多目标进化算法

在具有不同Pareto前沿形状的优化问题上, 基于参考点的高维多目标进化算法表现出较差的通用性. 为了解决这个问题, 提出参考点自适应调整下评价指标驱动的高维多目标进化算法(Many-objective evolutionary algorithm driven by evaluation indicator under adaptive reference point adjustment, MaOEA-IAR). MaOEA-IAR提出Pareto前沿形状监测基础上的参考点自适应策略, 利用该策略选择一组候选解作为初始参考点; 然后通过曲线参数对参考点位置进行调整; 将最终得到的能够适应不同Pareto前沿的参考点用于计算增强的反世代距离指标, 基于指标值设计适应度函数作为选择标准. 实验证明提出的算法在处理各种Pareto前沿形状的优化问题时能获得较好的性能, 算法通用性高.     

QuickBird spots flamingos off Nalabana Island,Chilika Lake,India

High‐resolution QuickBird data on 3 January 2005 identified flamingo congregation areas around Nalaban Island, a protected area for conservation of migratory birds in Chilika Lake, India. The bright pixels against the dark water bodies represented bird signatures observed in the northwestern rim of Nalabana Island. Some of the locations provided relative bright areas, indicating the disturbance created by the bird congregating in the area and flashing of the water created during their flying.     

Shifted robust multi-objective test problems

In 2013 Gaspar-Cunha et al. proposed a set of novel robust multi-objective benchmark functions to increase the difficulty of the current test problems and effectively mimic the characteristics of real search spaces. Despite the merits of the proposed benchmark problems, it is observed that the robust Pareto optimal fronts are located on the boundaries of the search space, which may result in the infeasibility of solutions obtained in case of perturbations along the negative side of the second parameter. This paper modifies the proposed test functions by Gaspar-Cunha et al. to mimic real problems better and allow the parameters to be fluctuated by any degree of perturbations. In fact, the robust fronts are shifted to the centre of the search space, so that any degree of uncertainties can be considered. The paper considers theoretical and experimental analysis of both set of test functions as well.     

结合暗原色图像参考的单幅图像去雾*

针对在暗原色先验理论下对天空区域的透射率估计总是过于偏小的问题,提出了一种基于暗原色图像的透射率纠正方法。以暗原色图像为参考,提取其天空等明亮区域的灰度归一化值替换生成新的透射率图。该方式提高了天空区域的透射率值,使其更接近于真实值。实验结果表明,对于各类雾化图像,在无需调整各参数值的情况下,该算法均能很好地避免天空区域出现色差失真问题;同时对于不含天空区域的图像,去雾仍然有效。此外,算法执行时无需进行复杂的天空区域识别及提取等操作。算法在实际去雾应用中实现了无参化,自动化程度高;对于分辨率为640?480彩色图像,速度可达1.5帧/s。     

Special types of the nonlinear dispersive Zakharov–Kuznetsov equation with compactons,solitons, and periodic solutions

In this article, we study nonlinear dispersive special types of the Zakharov–Kuznetsov equation with positive and negative exponents. The approach depends mainly on the sine–cosine algorithm. Compactons, solitary patterns, solitons, and periodic solutions are formally derived.     

一种基于视觉注意的小目标检测方法

为了方便而快速地在图像中标出目标,提出了一种基于视觉注意的小目标检测方法。该方法对Itti通用视觉注意计算模型作了改进,将目标检测过程分为亮目标检测和暗目标检测。其中亮目标检测采用了简化的Itti模型,暗目标检测主要采用侧抑制网络模型,将亮目标检测与暗目标检测各自生成的显著图合成得到最终的显著图。通过设定一阈值得到图像的预注意区域,采用模糊C-均值算法进行图像分割,以便相对完整地标出每个目标。结果表明,算法能够有效地检测待检测目标。     

基于暗通道先验的比值重估透射率去雾算法

针对暗原色先验去雾算法中雾霾图像明亮区域透射率估计过小,造成图像色彩失真的问题,提出一种新的基于比值重估透射率去雾算法。设定暗通道图与大气光强的差值阈值,利用预估透射率和全局透射率的比值重新估计透射率,从而改善明亮区域过小的透射率。实验结果表明,比值重估透射率去雾算法跟暗通道和容差机制去雾算法相比,该算法恢复的图像更接近于真实图像。