反应时和动态视野测量研究

以动态视野的测量为例,分析了反应时、简单反应时的关系,指出传统动态视野测量中由于简单反应时的影响而不能准确评价人的动态视野.通过减除反应时中包含的简单反应时,重新定义了动态视野.通过简单反应时实验和动态视野测量,表明了这种新定义的正确性.巧妙的实验程序设计思路和自行研发的测量装置,都是反应时和动态视野测量准确性的保证.     

Semiglobal finite‐time synchronization of complex networks with stochastic disturbance via intermittent control

This paper focuses on the problem of semiglobal finite‐time synchronization of stochastic complex networks via an intermittent control strategy. By establishing a finite‐time criterion condition and a novel finite‐time ‐operator differential inequality, combined with convex techniques, some sufficient conditions are obtained to ensure finite‐time synchronization for stochastic complex networks with time delays. An effective controller is given to guarantee inner finite‐time synchronization, especially for a nondelayed dynamic system. This paper provides a simple controller. Finally, a numerical simulation is given to demonstrate the effectiveness of our results.     

Finite‐time fault tolerant control for stochastic parameter systems with intermittent fault under stochastic communication protocol

In this article, the finite‐time fault tolerant control problem is investigated for a class of discrete‐time stochastic parameter systems subject to censored measurements. For the sake of relieving the communication burden, a stochastic communication protocol governed by a Markov chain is employed to determine which actuator has the access to the network at each transmission instant. Moreover, an improved performance index dependent on the predetermined censored threshold is constructed to evaluate the disturbance rejection level of the fault tolerant controller in the simultaneous presence of both external disturbances and censoring effects. The main aim of the addressed problem is to design a fault tolerant controller such that the closed‐loop system satisfies both the stochastically finite‐time boundedness and H_∞ performance requirements. In light of the Lyapunov theory combined with matrix inequalities, some sufficient conditions are derived skillfully, and the desired controller gains are calculated by solving a set of linear matrix inequalities. Finally, two simulation examples are utilized to demonstrate the effectiveness of the developed controller design method.     

Consensus for linear multi-agent system with intermittent information transmissions using the time-scale theory

This paper investigates the consensus problem for linear multi-agent system with fixed communication topology in the presence of intermittent communication using the time-scale theory. Since each agent can only obtain relative local information intermittently, the proposed consensus algorithm is based on a discontinuous local interaction rule. The interaction among agents happens at a disjoint set of continuous-time intervals. The closed-loop multi-agent system can be represented using mixed linear continuous-time and linear discrete-time models due to intermittent information transmissions. The time-scale theory provides a powerful tool to combine continuous-time and discrete-time cases and study the consensus protocol under a unified framework. Using this theory, some conditions are derived to achieve exponential consensus under intermittent information transmissions. Simulations are performed to validate the theoretical results.     

浓度-时间比法确定反应级数和计算速率常数

介绍了浓度-时间比法确定反应级数的原理以及数据处理的计算机实现过程。应用该方法时首先计算出反应物在不同时刻的转化率和按浓度-时间比计算式计算对应的时间比,然后通过计算机用全局寻优搜索算法求出反应级数和反应速率常数。方法对一级、二级和分数级反应的实验测定数据分析,结果表明,利用浓度-时间比法确定的反应级数与常规方法能很好地吻合。在数据处理过程中,为高效、快速确定反应级数,文中列出了浓度-时间比法的开放式Matlab程序。     

用Visual Basic实现测控软件中的实时曲线和历史曲线

本文介绍了如何用VB实现测控软件中的实时曲线和历史曲线,总结了在不同的系统要求下该曲线的设计思路和实现要点,对于用VB开发测控软件有一定的指导意义。     

Measuring the impact of Lean tools on the cost–time investment of a product using cost–time profiles

Traditional costing systems consider the accumulation of costs, but not their timing. Value stream mapping presents a good picture of the time consumed and operations performed for the production of a product within a manufacturing facility, but it does not track the accumulation of costs. The cost–time profile (CTP) is a tool that follows the accumulation of cost in the manufacturing of a product through time; and it finds the cost–time investment (CTI), which is an indicator of the use of resources in the manufacturing of a product through quantities and timing. In this paper, the expected impact of Lean implementations on the CTP and CTI is discussed. The CTP is proposed as a useful tool for the evaluation of the improvements achieved by the implementation of Lean tools and techniques.