Galerkin method for a Stefan-type problem in one space dimension

Based on a Landau-type transformation, both continuous and discrete in time L²-Galerkin methods are applied to a single-phase Stefan-type problem in one space dimension. Optimal rates of convergence in L^ℵ, L^∞, and H¹-norms are derived and computational results are presented. © 1997 John Wiley & Sons, Inc. Numer Methods Partial Differential Eq 13: 393–416, 1997     

一类弱整体维数为2的局部环上的Bass-Quillen问题Ⅱ

设R是U2环,即(R,m)是局部GCD整环,且存在u∈m-m2,使得R/(u)是赋值环,且Ru是Bézout整环.本文证明了若R是带有正规元素为u的U2环,且dim(R/(u))=1,则每个有限生成投射R[X1,...,Xn]模是自由模.由此得到了若R是广义伞环,则每个有限生成投射R[X1,...,Xn]模是自由模.     

Lip_J-扩张域和一致域(英文)

本文证明了如下两个结果:(1)域D(?)R~n是一致域当且仅当D是Lip_J-扩张域;(2)Jordan域D(?)R~2是拟圆当且仅当对在D上满足|f′(z)|≤d(z,(?)D)~(-1)的任意的解析函数f恒有f∈Lip_J(D),其中J(x_1,x_2)=1/2 log(1+|x_1-x_2|/d(x_1,(?)D))(1+|x_1-x_2|/d(x_2,(?)D)),x_1,x_2∈D.     

Optimization design of RIS-assisted high-capacity visible light communications based on HDMA

In this paper, a new non-orthogonal multiple access (NOMA) scheme is proposed for the reconfigurable intelligent surface (RIS) assisted high-capacity visible light communication (VLC) system, which is named hybrid domain multiple access (HDMA). HDMA enjoys the benefit of hybrid-domain signals, including the power domain, code domain, and frequency domain, where the message passing algorithm (MPA) and successive interference cancellation (SIC) detectors are jointly used at the HDMA receiver. Furthermore, to achieve a higher communication capacity for the VLC system, we proposed an optimization model by jointly optimizing the power allocation ratio and RIS reflection units. The simulation results verified the proposed scheme. By comparing the system capacity of different RIS allocation schemes and multiple access methods, the VLC system based on HDMA proposed in this paper can significantly improve its communication capacity.     

The frequency-domain method reveals the dimeric structure of Na,K-ATPase

Lucifer yellow and lissamine rhodamine sulfonyl hydrazine were used as the donor and the receptor, respectively, for Förster energy transfer measurements to determine the location of the subunit in the native Na,K-ATPase from pig kidney. It was found that (1) the subunits are located in one functional complex, i.e., the dimer ()₂ appears to be the functional complex of Na,K-ATPase, and (2) the subunits in the functional enzyme complex in the membrane are not located next to each other but are rather well separated. The distance between fluorophores covalently attached to the subunits was found to be 5.3 nm.     

关于Fejer点上的一种复有理型插值的一致逼近阶

设D是一个Jordan,Г为其边界，并设Г满足Aльпер条件。本文得到了一种基于Fejer点的有理型插值算子对于f(z)∈C（Г）的一致逼近阶。     

光频域喇曼反射光纤温度传感器的频域参量设计

研究了功率调制型光频域反射技术空间采样函数的基本特征,得到了频域测量参量对测量距离和空间分辨率的基本限制;用数值计算模拟了功率调制型光频域光纤温度传感器的测量过程,通过比较模拟测量得到的喇曼反射强度空间分布因子对实际喇曼反射强度空间分布因子的再现程度,研究了调制频率范围、频率采样间隔以及起始调制频率对测量结果的影响,得出技术可行的最佳频域测量方案.     

An improved partial SPIHT with classified weighted rate-distortion optimization for interferential multispectral image compression

Based on the property analysis of interferential multispectral images, a novel compression algorithm of partial set partitioning in hierarchical trees (SPIHT) with classified weighted rate-distortion optimization is presented.After wavelet decomposition, partial SPIHT is applied to each zero tree independently by adaptively selecting one of three coding modes according to the probability of the significant coefficients in each bitplane.Meanwhile the interferential multispectral image is partitioned into two kinds of regions in terms of luminous intensity, and the rate-distortion slopes of zero trees are then lifted with classified weights according to their distortion contribution to the constructed spectrum.Finally a global ratedistortion optimization truncation is performed.Compared with the conventional methods, the proposed algorithm not only improves the performance in spatial domain but also reduces the distortion in spectral domain.     

用神经网络鉴别退化图像的模糊类型

提出了一种用神经网络鉴别退化图像的模糊类型的方法。由于采用不同降质方法得到退化图像的频谱差异较大,以此作为判别依据,用概率神经网络实现了对四种模糊类型:离焦,矩形,运动和高斯模糊的鉴别。根据神经网络的鉴别结果决定点扩散函数的初始估计值,可大大地提高盲解恢复算法的复原质量和系统点扩散函数的估计精度,扩大了算法的实用范围。     

一种三环并联Rayleigh后向散射式光纤转动传感器

以单环后向Rayleigh散射式光纤转动传感器原理为基础,提出了一种三环形腔并联Rayleigh后向散射式光纤转动传感器新结构.利用三个2×2单模光纤耦合器,建立了并联三环形腔Rayleigh后向散射式光纤转动传感器的理论模型,给出了用光时域反射计（OTDR）探测到的信号强度表达式.通过计算机仿真优化了参量,选择三环的长度分别为1 500 m、1 078 m和680 m.三个2×2光纤耦合器的耦合系数分别为95.23%、94.88%和95.26%构建了测试系统,对不同转速所探测到的后向Rayleigh散射信号进行测量,得到与理论相一致的实验结果.三环的采用,增加了测试的有效数据,使其更有利于识别,提高了测量转速的准确度.