时滞系统的降维状态预测观测器及预测控制器设计

研究控制项含有时滞的线性系统的预测控制问题.利用被控对象的预测输出向量和系统的控制向量,设计了一种降维状态预测观测器,并将该状态观测器用于时滞控制系统的最优状态反馈控制中.利用该状态预测观测器可将闭环系统的时滞项移至系统闭环结构之外,从而最优控制规律完全可以按无时滞系统进行设计.由性能指标计算公式表明,该预测控制器关于二次型性能指标是次优的.     

基于单片机的单相SPWM变频器设计

介绍了基于单片机 80C196KB ,采用不对称规则采样法所实现的单相SPWM变频器。另外 ,给出了硬件电路与软件程序     

有限带宽网络多媒体传输的自适应QOS控制

介绍一种基于有限带宽网络的多媒体传输服务质量(QOS)解决方案。该方案采用增强的自适应QOS算法，可实现发送端与接收端速率的协调控制、多量化参数(QP)速率形成和自适应前向纠错(FEC)。基于标准MPEG-2编码解码方法进行比较实验，结果表明采取该算法不但可以令峰值信噪比(PSNR)减少抖动，而且平均性能提高0．5dB。     

发挥职教集团优势致力职教体制创新——试析浙江服装教育集团发展模式

阐述了浙江服装教育集团产生和发展的合理性和必然性;分析了浙江服装教育集团发展优势及特色;对浙江服装教育集团未来发展作了构想.     

生产函数的数据标准化和社会必要劳动

为了定量地解决社会必要劳动的概念及其对商品价值的决定问题，提出了生产函数的数据标准化方法，推导出标准化平均生产函数，并将实物量、劳动量和价值量3种统计总量联系起来进行统一分析。运用数学模型说明了最终决定商品交换价格的是其价值——社会必要劳动，商品效用和供求关系只是其催化剂。     

Properties of Magnetic Nanoparticles about Doped Rare Earth and Its Composites

The magnetic liquid was prepared with ferric salt by inorganic gel technology. The effect of the doped rare earth elements on the properties of magnetic particles was analyzed. The magnetic liquid was composed with clay mineral into magnetic mineral composites. The crystal structure and micro-morphology of the nanoparticles were studied by XRD and TEM. The results show that the crystal structure of the magnetic particles doped 0.5 % of lanthanum is more complete, and the magnetic response capability is higher with doping agent. At the same time, the possibility of the clay mineral magnetic composites as the carrier of target drug was probed.     

Three-dimensional porous composite framework assembled withCuO microspheres as anode current collector for lithium-ionbatteries

The surface structure and material composition of current collectors have significant effects on the electrochemical performances of lithium-ion batteries(LIBs). In this work, a three-dimensional(3D) porous composite framework is applied as the anode current collector in LIBs. This unique 3D skeleton is composed of conductive carbon fiber/Cu core/shell fibrous structure. With an oxidation treatment upon the copper shell, the porous framework is assembled with CuO microspheres. Using mesocarbon microbead(MCMB) graphite powders as the active material, the cell with this 3D porous composite current collector shows an improved reversible discharge-charge capacity of 415 mAh g~(–1) at a current rate of 0.1 C after 50 cycles, which is much higher than that of the cell with a flat Cu foil(127 mAh g~(–1)). It is demonstrated that this unique fibrous network of the 3D current collector coupled with the morphological effects of the CuO microspheres greatly improve the cell performance in terms of electrical conductivity, reversible capacity and cycling stability.     

基于元胞自动机的埃博拉药物配送系统设计

采用元胞自动机模型预测了西非36个地区埃博拉患者的未来人数,针对抗埃博拉病毒药物保质期较短的特点,根据所需药物数量设计出了该药物的二级配送系统,提出了最短时间配送系统、最低成本配送系统2种模型,并进一步阐述了运行效率更为高效的跨国界最低成本配送系统。更多还原     

基于直流电阻分析的电机温升初筛法

根据电阻法检测温升的原理,介绍了一种电机温升初筛的方法。利用实验室对直流电阻等参数测量经验的积累,通过对直流电阻的测量及其不确定度分析,结合具体型号电机的出厂合格区设置,快速排除出电机温升不合格产品,从而提高现场检验速度和质量。     

Evaluation of measurement uncertainty based on grey system theory for small samples from an unknown distribution

To evaluate measurement uncertainty for small sample size and measurement data from an unknown distribution, we propose a grey evaluation method of measurement uncertainty based on the grey relation coefficient. The uncertainty of measurement is analyzed using grey system theory, and the defects of the grey evaluation model of measurement uncertainty (GEMU) are studied. We then establish an improved grey evaluation model of measurement uncertainty (IGEMU). Simulations show that the precision of IGEMU is greater than that of GEMU, and that sample size has only a small effect on the precision of IGEVU. In particular, IGEMU is applied to evaluating measurement uncertainty for small sample size and measurement data from an unknown distribution. The measurement uncertainty of total profile deviation, which is measured by the CNC gear measuring center, can be evaluated by a combination of IGEMU and the Monte Carlo method.