碳排放效率的库兹涅茨曲线及双收敛假说的检验

基于动态方向性距离函数对1980—2008年我国各地区碳排放效率进行了估算,发现考虑污染遗留问题的碳排放效率不同于传统的碳排放效率。在此基础上,利用动态面板协整方法研究有关碳排放效率的环境库兹涅茨曲线问题。结果表明:样本期内,我国碳排放效率有了改善;我国存在二氧化碳排放效率的环境库兹涅茨曲线;各地区不存在碳排放效率的双收敛现象。

双收敛因子策略下的改进灰狼优化算法

针对标准灰狼优化算法(GWO)的收敛速度慢、易陷入局部最优等缺点,提出一种在非线性双收敛因子策略下基于双头狼引领的改进灰狼优化(GWO-THW)算法。首先,利用混沌Cubic映射初始化种群,提升种群分布的均匀性和多样性,并通过平均适应度值将狼群分为捕猎狼和侦察狼,两类狼群采用不同的收敛因子,在各自的头狼带领下寻找和围捕猎物;其次,为提升搜索速度和精度,设计了一种位置更新的自适应权重因子;同时,为跳出局部最优,当一定时间内未发现猎物时,狼群采用莱维(Levy)飞行策略随机更新位置。在10个常用的基准测试函数上验证GWO-THW的有效性。实验结果表明,与标准GWO及相关变体相比,GWO-THW在8个基准测试函数上都取得了较高的寻优精度和收敛速度,尤其在多峰函数上,200次迭代内就能收敛到理想最优值,从而验证了GWO-THW具有更好的寻优性能。

一个新双参数矩形板元的构造及收敛性分析

利用"双参数法"构造了一个新的十二参矩形元,并对其收敛性进行了分析;同时计算了节点参数扰动量。与著名的ACM元比较,节点参数有8个是相同的。

双涵道S弯喷管内/外流场的温度分布研究

为了明晰基于真实排气混合器构型的双涵道S弯喷管的壁面温度分布及尾焰特征,数值模拟研究了双S弯收敛喷管内/外流场的温度分布特征。结果显示:排气混合器结构与S形圆转方构型共同影响着S弯喷管的壁面“热斑”分布及出口下游的尾焰特征。S弯喷管的壁面“热斑”呈带状分布,且主要存在于第二弯通道及出口区域的上、下壁面中间区域。喷管下壁面的温度峰值为867 K,相比喷管上壁面增加25.1%;但喷管下壁面的平均温度仅比上壁面高出7.1%。喷管出口截面的“鲸鱼尾形”高温核心区导致出口下游的高温核心区表现为2股较宽的高温喷流。由于流向涡的横向运动,尾焰核心区两侧出现温度较低的热流。

双S弯喷管的流固耦合特性研究

为了明晰S弯喷管的流固耦合特性,数值模拟了流固耦合作用下双S弯收敛喷管的结构变形特征及其内/外流特性。结果表明:S弯喷管的圆转方弯曲构型产生了非均匀的流场分布,并增强了结构的弹性特征,通过交换气动载荷与变形位移数据形成了S弯喷管流固耦合的作用机理。在气动载荷作用下,S弯喷管沿Y向的最大变形位移为25.3mm,位于喷管出口上壁面的中心位置。当喷管的结构变形稳定时,第二弯转弯处下壁面的气流加速至局部超声速,壁面静压大幅降低;第一弯下游上壁面附近形成了气流分离区;喷管出口喷流沿轴向向上偏转。流固耦合作用导致S弯喷管的流量系数减小0.6%,推力系数降低1.8%。

基于混合灰狼算法的阵元失效校正方法

针对经典灰狼算法在处理复杂非线性优化问题时存在搜索不均衡、易陷入局部最优而出现早熟、寻优精度低等缺点,提出一种基于非线性双收敛因子策略与局部跳出机制相结合的混合灰狼算法,用于解决阵元失效校正问题。首先,依据平均适应度值将种群分为侦察狼和捕猎狼,两类狼依据不同的非线性递减收敛因子寻优来平衡算法的全局勘探和局部挖掘能力;其次,引入一种基于Sine混沌函数的跳出机制,提高了头狼个体的局部抗停滞能力,提升了算法的种群多样性。算法在目标函数中设计增加公共激励约束条件来降低天线系统的维护成本、提高系统的稳定性。对比现有基于群智能算法的校正技术,在更为苛刻的约束条件下,算法综合所得公共激励占比由0分别上升至10.7%,且校正前后方向图的辐射特性有一定提升,证明了所述算法的有效性。

连续型动态规划的新算法研究

提出了求解一维连续型动态规划问题的自创算法——离散近似迭代法,并结合双收敛方法求解多维连续型动态规划问题.该算法的基本思路为:在给定其它状态向量序列的基础上,每次对一个状态变量序列进行离散近似迭代,并找出该状态变量的最优序列,直到所有状态向量序列都检查完.当模型为非凸非凹动态规划时,证明了该算法的收敛性.当模型为凸动态规划时,证明了该算法的线性收敛性.最后,以一个具体算例验证了该模型和算法的有效性.

引入改进迭代局部搜索的灰狼算法及应用

针对标准灰狼算法(GWO)收敛速度慢,易陷入局部最优等缺点,提出一种引入改进迭代局部搜索的灰狼算法(IGWO)。首先,通过佳点集策略增强初始种群的均匀性与多样性;其次,采用双收敛因子,收敛因子基于种群位置非线性自适应更新,在种群寻优全期平衡全局勘探与局部开发能力;再次,在种群位置更新公式引入欧氏动态权重与莱维飞行策略,提升寻优精度,并帮助种群跳出局部最优值;最后,引入改进迭代局部搜索,使算法的搜索能力更加灵活,帮助算法加速收敛。通过10个基准测试函数的仿真分析及种群寻优平衡性对比,证明了IGWO具有更优的寻优精度、稳定性及收敛速度,随后将IGWO应用于工程优化问题中,相比GWO、GJO、WOA、HSSAHHO、SCHOA、NCPGWO、DSFGWO 7种算法,适应度分别优化了3.25%、27.2%、28.9%、3.15%、3.04%、0.23%、0.07%,证实了在工程应用中的可行性和有效性。

全卷积网络和条件随机场相结合的全极化SAR土地覆盖分类

针对经典全卷积网络(fully convolution network,FCN)分类精度低、效果差,以及传统的极化合成孔径雷达(PolSAR)土地覆盖分类方法未充分考虑地物散射特性的问题,提出了一种结合改进FCN和条件随机场(conditional random field,CRF)的全极化SAR土地覆盖分类算法。首先,利用Freeman分解和Pauli分解建模全极化SAR影像,同时提取各分解对应的散射特征,参考Freeman分解散射功率获取其主散射分量对应的主散射地物;同时,借鉴在图像分类领域中具有卓越表现的FCN-Vgg19-8s网络,考虑其高层卷积参数量大和低层卷积模型参数优化程度不足,通过在高层和中层分别构建多尺度卷积组和代价函数设计了FCN-MD-8s网络,保证对整体模型参数进行降维和优化;以Freeman分解散射机理特征为基准,采用级连式迁移学习结构,实现FCN-MD-8s网络的模型训练和测试;然后,根据主散射分量所对应的主散射地物,在各分量预测图中提取出主特征地物,得到分量地物分类结果,并将其进行叠加得到全局粗分类;最后,利用全连接CRF结合Pauli相干分解重建假彩色图,对全局粗分类进行全局像素类别转移获得细分类结果。通过对分类结果定性和定量分析,可知提出算法具有有效性和可行性。

双尺度收敛和拟线性抛物方程的均匀化

利用Ｆｏｕｒｉｅｒ分析的某些技巧，得到殆周期国数的一些新性质，在此基础上将均匀化理论中的双尺度收敛方法推广到殆周期振荡的情形．然后利用一些新技巧讨论了殆周期振荡的拟线性方程的均匀化问题，得到了相应的弱收敛和纠正子结果．

Strong Convergence Rates of Double Kernel Estimates of Conditional Desity Under Stationary Sequences

In the paper,we study the strong convergence rates of double kernel estimates of conditional density under stationary sequences.

Compression and reconstruction of speech signals based on compressed sensing

Based on the approximate sparseness of speech in wavelet basis,a compressed sensing theory is applied to compress and reconstruct speech signals.Compared with one-dimensional orthogonal wavelet transform(OWT),two-dimensional OWT combined with Dmeyer and biorthogonal wavelet is firstly proposed to raise running efficiency in speech frame processing,furthermore,the threshold is set to improve the sparseness.Then an adaptive subgradient projection method(ASPM)is adopted for speech reconstruction in compressed sensing.Meanwhile,mechanism which adaptively adjusts inflation parameter in different iterations has been designed for fast convergence.Theoretical analysis and simulation results conclude that this algorithm has fast convergence,and lower reconstruction error,and also exhibits higher robustness in different noise intensities.

Some Improvement on Hilbert's Inequality and Its Application

A new improvement of Hilbert's inequality for double series can be establishedby means of a strengthened Cauchy's inequality. As application, a quite sharp result onFejer-Riesz's inequality is obtained.

Anisotropic Biquadratic Finite Element with Some Natural Superconvergence Results

The paper studies the convergence and the superconvergence of the biquadratic finite element for Poisson＇ problem on anisotropic meshes. By detailed analysis, it shows that the biquadratic finite element is anisotropically superconvergent at four Gauss points in the element. Key words：

Post-Gaussian Effective Potential of Double sine-Gordon Field

In the framework of the functional integral formalism, we calculate the effective potential of the double sine-Gordon (DsG) model up to the second order with an optimized expansion and the Coleman's normal-ordering prescription. Within the range of convergence, we make a comparison among the classicaland the effective potential of the first and second order. The numerical analysis shows that the DsG post-Gaussian EP possesses some fine global properties and makes a substantial and a concordant quantum correction to the features of the classical potential.

渐近非扩张型映射的不动点迭代和△-收敛定理

研究了一致凸双曲度量空间中渐近非扩张型映射的三步迭代,这种迭代包括了Ishikawa型迭代和Krasnoselski-Mann迭代作为特例.作为应用还得到了迭代算法在CAT(0)空间中的△-收敛定理,得到的结论推广并加强了以前的许多已知结果.

一种多维连续型动态规划的新算法

在求解一维连续型动态规划问题的自创算法——离散近似迭代法的基础上,结合双收敛方法,对多维连续型动态规划问题进行计算.该算法的基本思路为:在给定其他状态向量序列的基础上,每次对一个状态变量序列进行离散近似迭代,并找出该状态变量的最优序列,直到所有状态向量序列都检查完.当模型为非凸非凹动态规划时,证明了该算法的收敛性;当模型为凸动态规划时,证明了该算法的线性收敛性.最后,通过具体算例验证了该模型和算法的有效性.

THE SUPERCONVERGENCE ANALYSIS OF AN ANISOTROPIC FINITE ELEMENT

This paper deals with the high accuracy analysis of bilinear finite element on the class of anisotropic rectangular meshes. The inverse inequalities on anisotropic meshes are established. The superclose and the superconvergence are obtained for the second order elliptic problem. A numerical test is given, which coincides with our theoretical analysis.

ＣＯＭＰＬＥＸＩＴＹ ＯＦ ＬＡＲＧＥ ＴＩＭＥ ＢＥＨＡＶＩＯＵＲ ＯＦＥＶＯＬＵＴＩＯＮ ＥＱＵＡＴＩＯＮＳ ＷＩＴＨ ＢＯＵＮＤＥＤ ＤＡＴＡ

The authors study the asymptotic behaviour of solutions of the heat equation and a number of evolution equations using scaling techniques. It is proved that in the framework of bounded data stabilization need not occur and the general asymptotic behaviour is complex. This behaviour reflects for large times, even on compact sets, the complexity of the initial data at infinity.

ON THE CONVERGENCE OF GODUNOV SCHEME FOR NONLINEAR HYPERBOLIC SYSTEMS

The authors consider systems of the form where the matrix A(u) is assumed to be strictly hyperbolic and with the property that the integral curves of the eigenvector fields are straight lines. For this class of systems one can define a natural Riemann solver, and hence a Godunov scheme, which generalize the standard Riemann solver and Godunov scheme for conservative systems. This paper shows convergence and L1 stability for this scheme when applied to data with small total variation. The main step in the proof is to estimate the increase in the total variation produced by the scheme due to quadratic coupling terms. Using Duhamel’s principle, the problem is reduced to the estimate of the product of two Green kernels, representing probability densities of discrete random walks. The total amount of coupling is then determined by the expected number of crossings between two random walks with strictly different average speeds. This provides a discrete analogue of the arguments developed in [3,9] in connection with continuous random processes.