The Forgotten Ones? The Validity of Consideration and Initiating Structure in Leadership Research.

This study provided a meta-analysis of the relationship of the Ohio State leadership behaviors--Consideration and Initiating Structure--with leadership. Overall, 163 independent correlations for Consideration and 159 correlations for Initiating Structure were analyzed. Results revealed that both Consideration (.48) and Initiating Structure (.29) have moderately strong, nonzero relations with leadership outcomes. Consideration was more strongly related to follower satisfaction (leader satisfaction, job satisfaction), motivation, and leader effectiveness, and Initiating Structure was slightly more strongly related to leader job performance and group-organization performance. Validities did vary by leadership measure, but in most cases validities generalized regardless of the measure used. Overall, the results provide important support for the validity of Initiating Structure and Consideration in leadership research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于V/I转换电路的精密电流跟随器设计

设计了一种基于V/I转换电路的电流跟随器。对一种常见形式的V/I转换电路进行变形,得到一个存在一定系统误差的电流跟随器。通过对系统误差的分析,针对误差产生的主要因素提出了两种基于不同思想、不同形式的改进方案,得到两种改进型电路。理论推导、软件仿真及实际硬件电路测试都证明此方案合理可行。     

凹圆弧底直动从动件盘形凸轮机构设计的新方法

找出了凹圆弧底直动从动件盘形凸轮与原有凸轮之间的区别与联系,并统一了原有凸轮的设计方法.新方法实质上是内凸轮机构当滚子半径大于基圆半径时的一种特殊情况.     

直动滚子盘形凸轮弹流润滑分析

磨损是直动滚子盘形凸轮机构的主要失效形式之一,润滑形态是影响凸轮磨损的主要因素,利用弹流润滑理论,探讨直动滚子盘形凸轮机构的最小油膜厚度及其膜厚比的计算,为凸轮的摩擦学优.化设计提供参考.     

非完整移动机器人领航-跟随编队分布式控制

针对非完整移动机器人运动学模型的特点,并且考虑机器人之间的交互关系是局部的,提出了一种基于领航-跟随的非完整多移动机器人分布式编队控制方法。首先提出了一种分布式估计策略,为每个跟随机器人估计(虚拟)领航机器人的位置、方向、线速度等状态;接着利用每个跟随机器人的跟踪误差设计了编队控制算法;使用Lyapunov工具对算法进行了渐近稳定性和收敛性分析;最后,构建了多移动机器人视觉定位与控制实验平台,通过仿真和实验验证了所提算法的有效性。     

汽车方向预瞄式自适应PD控制算法

针对汽车动力学强非线性时变特性及驾驶员行为特性,基于预瞄跟随理论提出了汽车方向预瞄式自适应PD控制算法,并结合仿真计算和场地试验论证了算法的可行性和有效性。算法中建立了可近似描述汽车转向动力学特性的一阶线性参考模型,并实时在线地辨识了参考模型传递函数的参数;由此根据理想预瞄跟随器的结构,进行了PD控制器参数的自整定。该控制算法可较为精确地控制汽车跟随预期轨迹,且自适应控制算法的采用也提高了控制系统的鲁棒性和适应性,从而为智能汽车方向控制系统的研究提供了一条可行的研究途径。     

Electronically tunable low-component-count current-mode biquadratic filter using dual-output current followers

In this paper, a realization of a current-controlled three-input single-output current-mode universal biquadratic filter using dual-output current followers (DO-CFs) as active components is described. Based on the use of the current-controlled conveyor working as the DO-CF, the proposed circuit employs only two DO-CFs and two grounded capacitors that provide the advantage of an electronic tuning capability and is of special interest from the IC fabrication point of view. By suitably selecting three input signals, the filter can realize all of the standard biquadratic filtering functions, i.e., lowpass, bandpass, highpass, bandstop and allpass, all at a high impedance output which enables easy cascading in the current-mode operation. The natural angular frequency (ω _o ) and the bandwidth (BW) of the proposed circuit can be tuned independently and electronically over a wide range by adjusting the external bias currents. In addition, no critical component matching conditions are required for all the filter response realizations, and both active and passive sensitivities are low. PSPICE simulation results are used to confirm the characteristics of the proposed circuit.     

仅检测电感电流的AD/DC升压变换器非线性载波控制

非线性载波控制针对开关变换器固有的非线性在控制信号中引入非线性载波,能够达到高功率因数和输出电压快速调节的控制效果。针对仅检测电感电流实现非线性载波控制的目的,结合了目前研究的新进展,以升压变换器为控制对象研究了使用线性斜率跟随器简化控制器检测电路的电路实现,建立了控制器电流环路的小信号模型并进行了Matlab仿真。改进后的控制器不仅保留了非线性载波控制原有的优点,更简化了检测电路并易于在集成电路中实现。     

最小尺寸摆动从动杆移动凸轮机构的一种设计方法

对按许用压力角确定摆动从动杆移动凸轮的最小移动速度了分析,根据压力角表达式,作出该机构 的角速度图,利用图解原理和解析方法,给出了最小尺寸摆动从动杆移动凸轮机构的一种设计方法,     

Fault‐tolerant leader‐follower formation control of marine surface vessels with unknown dynamics and actuator faults

This paper concentrates on the leader‐follower formation control problem for marine surface vessels with unknown nonlinear dynamics and actuator faults. The unknown inertia matrix and multiplicative fault render the existing methods infeasible. To solve this problem, a low‐complexity prescribed performance controller is first proposed without the help of auxiliary neural/fuzzy systems or adaptive mechanisms. A modification technique is further adopted to relax the initial condition, such that global closed‐loop stability is guaranteed. Finally, simulation results illustrate the above theoretical results.