置换DCT域中频系数的盲水印嵌入算法研究

介绍了一种基于离散余弦变换域(DCT)中频系数置换的盲水印算法,用该算法对数字水印进行了自适应嵌入方法研究.该算法突破了数字水印的加性算法、乘性算法等传统的水印嵌入方法;解决了被提取水印中含有原始图像DCT系数从而影响水印检测准确性的问题.该算法使用人类视觉模型对水印图像进行自适应嵌入,使嵌入的数字水印从根本上不可逆.实验证明该算法对数字水印的滤波、剪切、噪声等攻击有很强的鲁棒性.     

浅析涤纶生产中结晶系统的改进

通过对结晶系统工作情况的分析,对其进行设备改造,同时运用变频器进行运行控制方式的改进,起到改善工作状况、节约能耗的作用。     

直接求解P-Ⅲ型分布函数的水文频率计算

皮尔逊Ⅲ型(P-Ⅲ型)频率曲线作为中国规定的水文频率线型,其累计频率的计算一般是借助查"P-Ⅲ型频率曲线离均系数Φ值表"进行的。介绍不使用Φ值表的水文频率计算方式:用程序直接求解P-Ⅲ型频率分布函数的水文频率计算。该计算方法可以对P-Ⅲ型频率曲线的3个统计参数进行优化计算。阐述了利用IMSL FORTRAN程序库编写该程序的要点。     

低含水W/O乳化液电脱水实验研究

针对低含水W/O型乳化液,通过高压脉冲电脱水实验,对影响脱水过程的关键因素进行了实验研究,绘制了不同电场参数下的电流曲线与脱水效率曲线。实验是在直径80 cm的圆筒脱水器中进行的。实验结果显示了与高含水时不同的电流特征。作为辅助手段,通过三目显微镜与成像系统对电场中微小水滴的运动进行了观察,还观察和分析了电极附近水滴在电泳力作用下的运动。     

基于实时预测的传感器信号倍频算法

可穿戴助力机器人是一种能够根据传感器获得的力信号和位置信号进行自主控制的装置,其助力效果与传感器信号的响应频率密切相关.为了改善机器人助力效果,提出了一种提高传感器信号响应频率的算法.该算法首先利用MWQAR预测修正算法获得预测信号,然后利用三样条插值法,在真实信号与预测信号之间插入补偿信号.该算法在保证系统实时性的前...     

变频技术在铝电解厂烟气净化系统节能改造中的应用

介绍了采用ABB ACS1000和西门子PLC相结合的变频控制方案在实现铝电解厂烟气净化系统的节能降耗目标中的应用情况,重点描述了软件功能与设计,Profibus通讯设计等关键内容.实际运行表明,该方案运行稳定、可靠,节能效果显著,具有良好的应用前景.     

Analysis of an automatic phase adjustment system for the output signal of a quantum group frequency and time keeper

An phase locked loop (PLL) system for the output signal of a quantum group frequency and time keeper is studied. A mathematical model of an PLL system is constructed and recommendations are provided for optimizing its parameters. __________ Translated from Izmeritel’naya Tekhnika, No. 3. pp. 21–26, March, 2008.     

Estimating the total error for a distributed group standard for time and frequency

Studies have been made on the systematic and random errors in the group frequency and time scale for a distributed group standard for the units of time and frequency. A new approach has been devised for calculating the total error of secondary standards. __________ Translated from Izmeritel’naya Tekhnika, No. 6, pp. 24–26, June, 2008.     

Analysis of the informativeness of piezoelectric presure transducers by means of a generalized performance index

A comparison of piezoelectric pressure transducers produced by different Russian and foreign firms is carried out using a generalized performance index. __________ Translated from Izmeritel’naya Tekhnika, No. 6, pp. 27–29, June, 2008.     

The choice of the optimum frequency band for correlation measurements of the time delay of steady signals

Algorithms for choosing the optimum frequency band for the correlation processing of steady signals are proposed and specific examples are considered. The particular features of the problem of filtering received signals for optimum and nonparametric detection algorithms are considered. Translated from Izmeritel'naya Tekhnika, No. 11, pp. 55–61, November, 2008.