Integral barrier Lyapunov function-based adaptive fuzzy output feedback control for nonlinear delayed systems with time-varying full-state constraints

In this article, an adaptive fuzzy output feedback control method is presented for nonlinear time-delay systems with time-varying full state constraints and input saturation. To overcome the problem of time-varying constraints, the integral barrier Lyapunov functions (IBLFs) integrating with dynamic surface control (DSC) are applied for the first time to keep the state from violating constraints. The effects of unknown time delays can be removed by using designed Lyapunov-Krasovskii functions (LKFs). An auxiliary design system is introduced to solve the problem of input saturation. The unknown nonlinear functions are approximated by the fuzzy logic systems (FLS), and the unmeasured states are estimated by a designed fuzzy observer. The novel controller can guarantee that all signals remain semiglobally uniformly ultimately bounded and satisfactory tracking performance is achieved. Finally, two simulation examples illustrate the effectiveness of the presented control methods.     

中小学校的电气设计探讨

随着政府对教育的投入比重逐年提高．近年来新建改建的学校也越来越多．虽然学校的电气设计并不复杂。但变配电系统、照明及配电装置、弱电、防雷及接地等均有其一定的特殊性。其设计的深度直接影响到学生的学习环境和学校的经济利益。     

基于锁相同步检测的数字化阻抗测试方法

介绍了一种数字化阻抗测试方法，它采用锁相同步采样、数字化矢量电压电流比法及校准技术测试元器件或线路阻抗。同时介绍了相应实验电路原理，并结合线路接口，进行了通信电缆的线路阻抗测试实验。     

竹/玻璃钢复合建筑材料的研制及性能分析

竹/玻璃钢复合建筑材料是一种新型三维复合材料.本文对其进行了结构设计的研究,并通过大量试验对其力学性能进行了分析,结果证明竹/玻璃钢复合建筑材料确实是一种重量轻、性能好、工艺简单、价格便宜的材料,具有广阔的应用前景.     

LoVis: Local Pattern Visualization for Model Refinement

Linear models are commonly used to identify trends in data. While it is an easy task to build linear models using pre‐selected variables, it is challenging to select the best variables from a large number of alternatives. Most metrics for selecting variables are global in nature, and thus not useful for identifying local patterns. In this work, we present an integrated framework with visual representations that allows the user to incrementally build and verify models in three model spaces that support local pattern discovery and summarization: model complementarity, model diversity, and model representivity. Visual representations are designed and implemented for each of the model spaces. Our visualizations enable the discovery of complementary variables, i.e., those that perform well in modeling different subsets of data points. They also support the isolation of local models based on a diversity measure. Furthermore, the system integrates a hierarchical representation to identify the outlier local trends and the local trends that share similar directions in the model space. A case study on financial risk analysis is discussed, followed by a user study.     

Synthesis of calcium silicate hydrate based on steel slag with various alkalinities

This study aimed to improve the hydraulic potential properties of the slag. Therefore, a method of dynamic hydrothermal synthesis was applied to synthesize calcium silicate hydrate. The phases and nanostructures were characterized by XRD, FTIR, TEM, and BET nitrogen adsorption. The infl uence of alkalinity of steel slag on its structures and properties was discussed. The experimental results show that, the main product is amorphous calcium silicate hydrate gel with fl occulent or fi brous pattern with a BET specifi c surface area up to 77 m2/g and pore volume of 0.34 mL/g. Compared with low alkalinity steel slag, calcium silicate hydrate synthesized from higher alkalinity steel slag is prone to transform to tobermorite structure.     

制粉工艺对贮氢合金电化学性能的影响研究

研究了干法、湿法和湿法加添加剂三种制粉工艺对贮氢合金电化学性能的影响 ,结果表明 :制粉工艺对合金粉末的表面形貌、粒度分布、氧含量均存在很大的影响 ,并影响到其电化学性能。当采用湿法制粉工艺时 ,贮氢合金电极的活化性能较干法制粉明显改善 ,若加入一定量的添加剂 ,活化性能进一步提高 ,第一次放电容量即达到2 78mAh·g-1,第二次放电容量达到合金电极的稳定容量 32 2mAh·g-1。湿法制粉对贮氢合金电极的循环稳定性能有一定的负面影响 ,这可能与贮氢合金粉末表面的氧化和细粉相对含量较多有关 ,然而 ,当加入一定量的添加剂以后 ,贮氢合金电极的氧含量得到有效的控制 ,3C充放循环稳定寿命达到 5 0 0次 ,与干法制粉工艺接近。     

并联机器人安全保护系统的研究

以6-UHU并联机器人为研究模型,提出了一种新的并联机器人的工作空间姿态描述方法.提出一种"虚拟限位"的保护策略:将并联机器人的安全问题看作是受限变量的限位问题,通过计算受限变量对杆长向量的偏导预测将要发生的干涉,根据导数智能的决策采取的限位、规划操作.从关节空间对并联机器人的约束直接进行检验,避免传统上查询整个工作空间带来的运算量大等问题,大大减少了运算量.最后阐述了安全保护系统结构.设计了整个并联机器人安全保护实时多任务系统,在实际并联机器人中得到了应用.     

更新观念,加强企业内部管理之我见

企业要适应市场、摆脱亏损局面,必须更新观念,加强内部管理:要牢固树立“用户第一、销售第二、生产第三”的观念;狠抓管理,苦练内功,增强企业竞争力。     

基于Δ-Σ技术和FPGA的数据采集系统

为了改善传统数据采集系统运算能力差、分辨率低、可靠性低等缺点,结合Δ-Σ技术和FPGA,设计了一种多通道、高分辨率、宽动态范围的新型数据采集系统。提出了一种由Δ-ΣA/D转换芯片、高性能FPGA和DSP组成的数据采集系统方案及其硬件电路实现方法。系统利用A/D器件对信号进行滤波、放大、差分转换和模数转换,利用FPGA设计内部模块和时钟信号进行电路控制及实现数据缓存、数据传递等功能,由高速DSP芯片核心控制,对采样数据进行实时处理。系统能实现24位高分辨率、宽动态范围的信号数据采集与高速实时处理,可用于电压、电流、温度等参量的采集系统中。