基于椭圆曲线的盲签署系统

介绍了椭圆曲线的基本概念与其特性 ,以椭圆曲线密码理论为依据 ,给出基于椭圆曲线的盲签署算法 ,并给出实际例子 ,评估了算法的安全性 ,给出算法性能分析 .研究结果表明基于椭圆曲线的盲签署算法是安全的 ,高效的 .它将在诸多领域中得到广泛的应用 ,现在已经成为信息安全研究的热点之一 .     

Characterization of PdAg/Al2O3 composite membrane by electroless co-deposition

In this work, PdAg/Al₂O₃ composite membranes prepared by electroless co-deposition technique have been studied. Effects of plating time, Ag composition and total concentration of metal ions on surface morphologies, composition and microstructure of the resulting layers were investigated. Scanning electron microscope, energy dispersive spectrometer and nitrogen permeation technique were used to characterize the as-prepared composite membranes. From the experimental results, it shows that the surface morphology of the deposited PdAg layer is strongly affected by the Ag content of the plating bath. Since large differences of deposition rates and growth modes are observed between Pd and Ag grains, the PdAg layer exhibits the dendritic structure. As the Ag content is approximately 50%, the dendritic structured PdAg layer reveals the largest nitrogen permeability with the smallest size of residual pores. Furthermore, a comprehensive electrochemical analysis is proposed to interpret the composition and structure of the PdAg layer. Eventually, the experimental results are quite consistent with those predicted from the electrochemical analysis.     

Generalized Deformation Curve for High-Strength Steel over a Wide Range of Strain Rates

Test results for different high-strength steel specimens in static and impact tension and compression over a wide range of strain rates were summarized. These data were used to calculate the generalized deformation curve. The calculations based on this curve were compared with the experimental data on impact indentation with the conical indenter to evaluate the applicability of this method for studying the behavior of metals at high strain rates.     

复杂配电系统的可靠性评估

采用故障模式与后果分析法(FMEA)结合网络等值的原理对带有分支子馈线的复杂配电系统进行了可靠性评估,并提出了一种简单配电系统的等效逻辑模型。该算法通过网络等值原理将复杂配电系统逐步等值为只有一条馈线的简单配电系统,进而结合等效逻辑模型和FMEA法评估系统的各项可靠性指标,这样就比直接利用FMEA法大大提高了效率。     

四连杆直线导引机构的瞬时极点综合方法

提出了直线导引机构的一种综合方法。该方法通过分析连杆点的运动轨迹与瞬时极点的关系，找到带直线段轨迹的连杆点位置的求解方法。以电子图谱的形式给出的结果，为机构综合提供了直观而可靠的依据。     

Structured Latent Curve Models for the Study of Change in Multivariate Repeated Measures.

This article considers a structured latent curve model for multiple repeated measures. In a structured latent curve model, a smooth nonlinear function characterizes the mean response. A first-order Taylor polynomial taken with regard to the mean function defines elements of a restricted factor matrix that may include parameters that enter nonlinearly. Similar to factor scores, random coefficients are combined with the factor matrix to produce individual latent curves that need not follow the same form as the mean curve. Here the associations between change characteristics in multiple repeated measures are studied. A factor analysis model for covariates is included as a means of relating latent covariates to the factors characterizing change in different repeated measures. An example is provided. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

也谈高强度公钥密码体制的研究

文章对刊载于《计算机工程与应用》2003年第3期、题名为“基于双密钥的高强度公钥密码体制的研究”的文章进行了分析,指出该文提出的将RSA和Elgamal串起来用的公钥密码体制不能增加安全强度。同时,文章阐述了目前公钥密码体制的安全现状和今后的研究方向。     

A novel two-phase Hilbert-scan-based search algorithm for block motion estimation using CTF data structure

Motion estimation is one of the kernel issues in MPEG series. In this correspondence, a novel two-phase Hilbert-scan-based search algorithm for block motion estimation is presented. First in the intra-phase, a segmentation of the Hilbert curve is applied to the current block, then a novel coarse-to-fine data structure is developed to eliminate the impossible reference blocks in the search window of the reference frame. In the inter-phase, a new prediction scheme for estimating the initial motion vector of the current block is presented. Experimental results reveal that when compared to the GAPD algorithm, our proposed algorithm has better execution time and estimation accuracy performance. Under the same estimation accuracy, our proposed algorithm has better execution time performance when compared to the FS algorithm. In addition, when comparing with the TSS algorithm, our proposed algorithm has better estimation accuracy performance, but has worse execution time performance.     

研磨加工层对高碳铬轴承钢超长寿命疲劳行为的影响

为了阐明磨石研磨加工层对高碳铬轴承钢JIS SUJ2超长寿命疲劳行为的影响,分别使用经砂纸研磨和电解研磨的砂漏形试样,在室温空气环境下进行旋转弯曲疲劳试验.砂纸研磨试样被除去部分磨石研磨层,电解研磨试样被除去了全部的磨石研磨层.结果表明,两种试样的S-N曲线由位于短寿命区的表面破坏模式和位于长寿命区的内部破坏模式的两条组成,表面破坏模式的S-N曲线受表面粗糙度和表面压缩残余应力的影响.内部破坏模式的S-N曲线不受表面条件的影响,是材料固有的特性.砂纸研磨试样表面破坏模式的疲劳极限最高,是电解研磨试样1.11倍和磨石研磨的1.20倍.表面压缩残余应力对表面破坏模式疲劳极限的影响可以用修正Goodman图表示.还讨论裂纹的萌生和扩展条件,推定超长寿命的疲劳极限.     

一种新型并联运动振动筛及其运动学研究与研制

提出了并联运动振动筛的新概念,设计了一种新型空间二自由度并联机构,固结于该机构运动平台的筛箱能产生一个独立的铅垂运动和两个转动(其中一个为独立转动,一个为衍生转动),筛面轨迹为空间复杂曲线,适合于高效物料筛分运动;建立了该机构运动学正逆解数学模型,根据振动筛分工艺要求,设计了杆件长度,并进行了相应的三维实体运动仿真;还导出了上平台各点运动轨迹方程,用MATLAB绘出了相应的轨迹曲线,为该机构工艺参数的进一步优化设计奠定了基础;最后研制了样机.