Zhang neural network and its application to Newton iteration for matrix square root estimation

A special class of recurrent neural networks (RNN) has recently been proposed by Zhang et al. for solving online time-varying matrix problems. Being different from conventional gradient-based neural networks (GNN), such RNN (termed specifically as Zhang neural networks, ZNN) are designed based on matrix-valued error functions, instead of scalar-valued norm-based energy functions. In this paper, we generalize and further investigate the ZNN model for time-varying matrix square root finding. For the purpose of possible hardware (e.g., digital circuit) realization, a discrete-time ZNN model is constructed and developed, which incorporates Newton iteration as a special case. Besides, to obtain an appropriate step-size value (in each iteration), a line-search algorithm is employed for the proposed discrete-time ZNN model. Computer-simulation results substantiate the effectiveness of the proposed ZNN model aided with a line-search algorithm, in addition to the connection and explanation to Newton iteration for matrix square root finding.     

Study of dynamic characteristics of resonators for MEMS resonant vibratory gyroscopes

Dynamic characteristics of resonators for MEMS resonant vibratory gyroscopes are studied in this paper. Firstly, a small parameter method is introduced to analyze the dynamic characteristic stability of the resonator. It is proved that geometrical parameters of the resonator have to be regulated to match corresponding stability analysis. In order to verify the rationality of the theoretical parameters design, static calibration experiment is built using a resonator sample. It is concluded from the calibrated result that the error between theory design and experiment is 0.03?%, which shows they have a good match, and the design of resonator is reasonable. Moreover, the method of small parameter perturbation is considered to analyze the input–output dynamic characteristic. Under some transformations, which make input angular velocity and output resonant frequency shift possess a good linear relationship. In order to verify the correctness of the theory analysis method, dynamic frequency output characteristic experiment is built using the resonant vibratory gyroscope sample. It is concluded from the dynamic measurement result that the correlation coefficient of output fitted curve is 99.95?%, the measured algorithm scale factor of the gyroscope sample is 0.2116, which prove theoretical analyzing approach is feasible.     

一种用于隐写测评的图像纹理复杂度估计方法

在评估图像隐写算法安全性及隐写分析性能时,隐写嵌入率等参数是重要的评价指标,而图像纹理差异对评价的影响很容易被忽略。为此,基于图像高维统计模型,提出一种新的针对隐写应用的图像纹理复杂度度量方法,用于衡量图像间的纹理差异。根据纹理复杂度对图像进行分类,单独在每一类不同纹理复杂度的图像集上评估隐写分析的检测性能。实验结果表明,该方法能有效地评价隐写的安 全性。     

Microstructure and mechanical properties of 8YSZ ceramics by liquid-phase sintering with CuO-TiO2 addition

The 8% (mass fraction) yttrium-partially-stabilized zirconia (8YSZ) ceramic was fabricated via liquid phase sintering at 1 200–1 400 °C by adding different mass ratios of CuO-16.7%TiO₂ (molar fraction) as sintering aid. Relative density, microstructure, Vickers hardness and bending strength as a function of sintering temperature and additive content were investigated. The experiment results show that liquid phase sintering at low temperature can be realized through adding CuO-16.7% TiO₂ to 8YSZ. The Vickers hardness and bending strength of samples with sintering aid are generally much higher than those of samples without sintering aid for all sintering temperatures, and increase with the increase of sintering temperature. When the addition content of CuO-16.7% TiO₂ is beyond 0.5%, the relative density, Vickers hardness and bending strength decrease with the increase of the mass ratio of sintering aid. Low additions of sintering aid are beneficial to aiding densification; high additions of sintering aid are detrimental to the sintered properties mainly due to greater amounts of pores generated by the volatilization of oxygen with the eutectic reaction between copper oxide and titanium dioxide. It is found that the fine grain size and high relative density are two main reasons of the high bending strength and Vickers hardness of the materials.     

Advanced run-out table cooling technology based on ultra fast cooling and laminar cooling in hot strip mill

In order to meet the severe requirements of market and reduce production costs of high quality steels, advanced run-out table cooling based on ultra fast cooling (UFC) and laminar cooling (LC) was proposed and applied to industrial production. Cooling mechanism of UFC and LC was introduced first, and then the control system and control models were described. By using UFC and LC, low-cost Q345B strips had been produced in a large scale, and industrial trials of producing low-cost dual phase strips were completed successfully. Application results show that the ultra fast cooling is uniform along the strip width and length, and does not affect the flatness of strips. The run-out table cooling system runs stably with a high precision, and makes it possible for the user to develop more high quality steels with low costs.     

Energy saving effect of building envelope in summer

To explore the energy saving effect of building envelope, the experiments were carried out through a comparison of basic cubicle in summer. Experiments show that if energy efficiency measures are applied only in the external walls and windows, the energy saving cubicles have an average energy efficiency ratio of 27.75% and 27.05% when the air change rates are 1.1 and 1.4 h⁻¹ in summer, with both values being over the standard target value by 25%. And the indoor air temperature of the energy saving cubicle is below that of the basic cubicle. The daily mean temperature difference between the interior surface of insulation wall and no insulation reaches 1.47 °C, and the mean temperature difference is up to 8.52 °C between the interior surface and exterior surface of insulating glass and single glass. The two cubicles were simulated for energy consumption using VisualDOE4.0 software under real weather conditions in summer. The results show that the mean deviation is 10.02% between experimental and simulated energy efficiency ratio. The correctness and validity of simulation results of the VisualDOE4.0 software are proved.     

传统内化、时代催生与域外视角——中国报告文学的文体演变

作为一种叙事文体的中国报告文学在其发展演化的过程q-受到了包括传统、时代以及域外资源的多重影响。史传与诗骚、经世致用思想以及传统纪游笔法孕育着报告文学的最初品格与形式。转型激荡时代的文化选择、报纸等现代传媒的繁荣以及知识分子的文化担当导引了报告文学在近现代转型时期的社会辐射。而域外新风借取尤其是左联时期大量的理论译介则促发了报告文学的现代化转进。     

高岭土原位合成ZSM-5中活性铝含量分析及影响

采用EDTA容量法,以PAN作为指示剂,准确分析不同温度下焙烧高岭土中的活性铝含量,滴定终点颜色变化明显.并讨论了活性硅、活性铝含量对原位晶化合成ZSM-5型分子筛的影响.750℃焙烧高岭土、外加铝源的950℃焙烧高岭土都难以合成出ZSM-5型分子筛.以950℃焙烧高岭土为载体和唯一铝源,外加硅源,适当调节碱、硅、水加入量,在150℃,高硅铝比条件下得到杂晶少、结晶度较高的产品.通过此方法可区分高岭土中载体铝和用于合成的活性铝.原位晶化合成中硅铝配比以活性铝、活性硅含量计算较为合理.     

Keccak算法非线性变换x的分析

x是keccak算法中唯一的非线性部件,本文研究了x变换的主要密码学性质,指出了x的非线性度为8,差分均匀度为8,代数次数为2,满足平衡性,可逆。计算出了x的逆变换的表达式,并分析了其密码学性质。基于x变换的设计思想,我们试图找到新的方法来构造分组密码中的S盒。