近红外耳穴信号的超低频成份提取与分析

血氧超慢信号与脑神经递质的超慢振荡特点具有平行性与同源性。应用940 nm单波长近红外对管,检测识别耳颞穴的透射信息,可以帮助理解脑神经血管耦合的机制,同时发现新信号的特征以支持脑认知研究。具体工作包括:①基于输出能量的最大值寻优探头传感角度;②基于软件SPSS11.0统计描述谎实数据差异显著性的P分数;③利用Agilent54624A型示波器内嵌的FFT功能,提取近红外透射信息中0~100 mHz的超低频特征,以便显示谎和实的差异性。研究工作进一步细化了专用的近红外耳穴信息识别系统,为整机的SoC化奠定了基础。     

温度效应造成的半球谐振陀螺振幅和测角误差因素分析

在半球谐振陀螺工作的过程中,环境温度的变化是不可避免的。温度的变化影响谐振子尺寸变化,导致陀螺产生热漂移。根据振幅检测原理,推导温度效应误差的数学表达式,分析它对测量结果的影响,这对选择合适的补偿算法以消除温度效应误差有一定的指导意义。     

新型转炉系统整体结构三维有限元分析

为考察大型转炉系统应力和变形对生产安全和结构优化设计的影响,采用三维有限元方法,建立新型转炉的整体结构装配体模型,计算该转炉系统在不同倾动角工况及重力载荷下的应力和位移. 通过详细分析各零部件的应力、变形和位移情况,研究应力和位移随倾动角的变化规律,提出改进设计方案. 结果可为转炉系统的设计和应用提供计算依据.     

低速永磁直线同步电动机的失步预防控制策略研究

永磁直线同步电动机在运行过程中是否失步是决定其稳定运行的关键。通过对永磁直线同步电动机的力角特性分析,文章提出了一种改变电压和改变压频比相结合的电动机失步预防控制策略,即运用双模态模糊控制器实现电动机的失步预防控制。仿真结果表明,该策略具有算法简单、控制品质好等优点,可以有效地避免永磁直线同步电动机失步的发生,具有较高的应用价值。     

Moving‐picture response time (MPRT) of LCDs for the oblique viewing direction

Abstract— The dynamic performance of displays is an important characteristic for multimedia applications. Motion‐picture response time (MPRT) has been used as an indicator of the dynamic performance of LCDs. This paper describes a comprehensive method of MPRT evaluation for the oblique viewing direction. By using a tilted camera configuration, the angular dependency of MPRT is investigated for the condition that the horizontally scrolling patterns are observed from the vertical direction. For each gray‐to‐gray transition, distinct changes in MPRT and the luminance profile of blur are observed.     

Design and stability discussion of an hybrid intelligent controller for an unordinary system

In this paper, the pitch angle control of a lab model helicopter is discussed. This problem has some specific features. As a major unusual feature, it is observed that the steady state control command is completely dependent on the setpoint, and for different setpoints, different steady state control commands are needed to keep the error around zero. Moreover, the system is one with highly oscillating dynamics. In order to solve this control problem, two controllers are designed: an artificial neural network (ANN), whose input is the setpoint, is used to provide steady state control command, and a fuzzy inference system (FIS), whose input is error, is used to provide transient control command. The total control command is the sum of the two aforementioned control commands. It is proven that both ANN and FIS are boundary‐input boundary‐output (BIBO) systems. Using this fact and considering two experimental assumptions, the closed‐loop stability is also proven. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society     

从社会管理角度来看设计——在现代设计史里去找答案

长期以来,有很多学者都对设计做了很多重要的研究,并得到了丰富的理论成果。但是设计是一个很难说得明明白白的词,其内在的含义却需要不断的挖掘,如其内在所含的管理属性就需要我们去做一个探究,本文从历史的、客观的角度对设计的管理层面进行了探讨。     

流道缩扩比对半波纹微通道流动和传热特性的影响

为探究流道缩扩比对半波纹微通道流动和传热特性的影响,设计了5种不同缩扩比的半波纹微通道模型,并对各通道内的层流流动(200＜Re＜1000,Re为雷诺数)和传热进行了数值模拟研究。结果表明,半波纹微通道的压降和努塞尔数随着流道缩扩比的减小而增大;与光滑微通道相比,半波纹微通道具有更优的传热性能但压降损失也更高;引入η作为综合性能指标,发现减小流道缩扩比是提高半波纹微通道综合换热能力的有效方式,且当Re＞490时,其综合换热能力均优于光滑微通道。     

Data-driven dual-rate cascade control and application to pitch angle control of UAV

A data-driven design method for a cascade control system is proposed. The cascade control system consists of inner and outer loops, where the control interval of the outer loop is an integer multiple of the inner loop; hence, the system is a dual-rate system. In the proposed method, controllers in the inner and outer loops are designed based on one-shot data. In such a dual-rate cascade system, since the controllers are designed using different data-rate signals, the lifting technique is applied to align the dual-rate data. To show its effectiveness, the proposed method is compared with a conventional single-rate cascade control method, and numerical simulations and experiments are presented to examine servo and regulation performance.     

Investigation of process parameters influence in abrasive water jet cutting of D2 steel

In the present experimental study, abrasive water jet (AWJ) cutting tests were conducted on D2 steel by different jet impingement angles and abrasive mesh sizes. The experimental data was statistically analyzed using the simos–grey relational method and ANOVA test. In addition, the outcome of influencing cutting parameters, namely jet pressure, jet impingement angle, and abrasive mesh size on the different response parameters, namely, the jet penetration, material removal rate, taper ratio, roughness, and topography, were studied. Micro-hardness test and surface morphology analysis were employed to examine the D2 cut surfaces at different AWJ cutting conditions. The chemical element study was performed to determine the abrasive particle contamination in the AWJ kerf wall cut surfaces. The ANOVA test result indicated the jet pressure and jet impingement angle as the influencing process parameters affecting the various performance characteristics of AWJ cutting. The overall AWJ cutting performance of the D2 steel has been improved through proper identification of the optimal process parameter settings, namely jet pressure 225?MPa, abrasive mesh size #100, and jet impingement angle 70° by the simos–grey relational analysis.