A New Approach to Parametric Identification of a Single-Link Flexible-Joint Manipulator

A new parametric observer for identifying the system parameters of a single-link flexible-joint manipulator is presented. The design achieves the desired goals provided two conditions are satisfied, i.e., the basis functions are linearly independent in terms of the steady-state trajectories and the parameter errors converge to some constants eventually. It can be incorporated with any a control scheme sustaining such steady-state trajectories. No acceleration signals are required. However, the motor inertia must be given a priori. Numerical study of the proposed scheme with a specific robust control law is undertaken to demonstrate its validity.     

Modeling the steady-state behavior of the Ca2+ -Mg2+ -ATPase pump of sarcoplasmic reticulum

A FORTRAN computer program capable of calculating the steady-state behavior of the Ca2+ -Mg2+-ATPase pump of skeletal sarcoplasmic reticulum under all conditions of reactant and product concentrations is described. The model describes the behavior of the enzyme in terms of occupation of three binding sites: (a) a translocator site which can bind Ca2+, K+, H+, or Mg2+, (b) an ATP/ADP binding site, and (c) a phosphorylation and phosphate binding site. The translocator site can move across the membrane in the Ca2+-laden and K+ + H+-laden form, thereby accomplishing Ca2+ for K+ + H+ countertransport. The rate constants for ion binding and the translocation reactions vary as a function of translocator orientation, ATP and ADP occupancy, phosphorylation, and phosphate binding. Rate constants for the binding and the reactant and product concentrations and association reactions and other transformations between states of the enzyme are entered and the computer program solves for the steady-state concentrations of all states of the enzyme and for the turnover number of the enzyme. The program contains a matrix of differential equations for creation and destruction of all states of the enzyme using the steady-state assumption together with the rule of conservation of the total enzyme. The matrix of equations and states is solved by Gaussian elimination. The program presents the distribution of enzyme states in histogram fashion and is capable of presenting the concentration of a particular state or the rate of turnover as a function of any of the reactant or product concentrations. Three demonstrations of the utility of the program and predictive power of the model are given.     

A BASIC program for the numerical solution of the transient kinetics of complex biochemical models

A highly optimized software for the kinetic analysis of complex chemical models is presented. The program is applied to the analysis of a vectorial biochemical reaction, where many species are linked by multiple equilibria of any order. The reaction stimulates the Ca2(+)-transport-linked ATPase reaction taking place in a suspension of vesicular fragments of isolated sarcoplasmic reticulum membranes, as described in many experimental reports. The model includes 12 reactants and intermediate chemical species, 14 kinetic constants, compartmentalization, and thermodynamic adjustment. The concentrations of all the model components, at any time, starting from a known initial condition, are calculated. The transient concentrations of the species are obtained by numerical integration of the appropriate differential equations, using an optimized version of the Runge-Kutta-Gill algorithm, with the aid of a Digital PDP11/23 computer and a standard BASIC-11 software, which could be fast and easily fitted to work with any microcomputer and/or alternative language or faster working compiled BASIC version. The errors of the calculations are evaluated.     

DerivFit:A Program for Rate Equation Parameter Fitting Using Derivatives

A C program for fitting parameters in enzymatic rate equations is presented. TheDerivFitprogram employs the reaction scheme in the form of ordinary differential equations (ODEs). The kinetic parameters are fitted to the experimental data by minimizing the sum of squared deviations of experimental points from theoretically predicted progress curves. In the minimization process we use the Gradient, Newton, and Marquardt algorithms. The gradients are calculated explicitly by solving a set of additional ODEs that are automatically attached by the program, taking advantage of a general formulation of the basic ODEs that determine the reaction's time course. The program is applied to simple enzymatic systems including slow tight-binding inhibition.     

包括隧道效应和曲率校正的单分子热反应速率常数的计算程序

介绍了个包括隧道效应和曲率校正的单分子热反应速率常数的计算程序，该程序以微正则速率常数为基础，通过积分的方法求得热速率常数。同时考虑量子力学隧道校正和垂直于反应途径的振动与沿ＩＲＣ的运动之间的耦合作用。     

Indistinguishability and identifiability of kinetic models for the MurC reaction in peptidoglycan biosynthesis

An important question in Systems Biology is the design of experiments that enable discrimination between two (or more) competing chemical pathway models or biological mechanisms. In this paper analysis is performed between two different models describing the kinetic mechanism of a three-substrate three-product reaction, namely the MurC reaction in the cytoplasmic phase of peptidoglycan biosynthesis. One model involves ordered substrate binding and ordered release of the three products; the competing model also assumes ordered substrate binding, but with fast release of the three products. The two versions are shown to be distinguishable; however, if standard quasi-steady-state assumptions are made distinguishability cannot be determined. Once model structure uniqueness is ensured the experimenter must determine if it is possible to successfully recover rate constant values given the experiment observations, a process known as structural identifiability. Structural identifiability analysis is carried out for both models to determine which of the unknown reaction parameters can be determined uniquely, or otherwise, from the ideal system outputs. This structural analysis forms an integrated step towards the modelling of the full pathway of the cytoplasmic phase of peptidoglycan biosynthesis.     

Improving the dynamic response of neural network controllers usingvelocity reference feedback

A neural network controller designed solely based on the desired response of the dynamics to realize a maximum acceptable steady-state error may not be the best one in terms of the transient responses. It may have an excessive overshoot and larger risetime. Similarly, a controller having a very good transient response may not have the desired steady-state characteristics. The effectiveness of using a velocity reference feedback for improving the dynamic response of the neural network controllers is investigated. Using the direct control scheme, on an underwater vehicle with nonlinear dynamics, it is shown that specific improvements in overshoot, risetime, and settling time can be achieved using this method.     

A non-linear regression program in BASIC for estimating Km and Vmax

This paper gives a program in BASIC for calculating the kinetic parameters Km and Vmax for an enzyme reaction from a set of paired values of reaction velocity at given substrate concentrations. An initial estimate of the two parameters is made using a weighted linear regression, these values are then used in an iterative process to fit the data to the Michaelis-Menten equation and give final values of Km and Vmax with their associated standard errors.     

REACTKIN—a program for modelling the chemical reactions in electrolytes solutions

In this paper, REACTKIN, the new computer program for modelling the kinetics of complex homogeneous chemical reactions in electrolyte and non-electrolyte solutions has been presented. This program makes possible the creation of a model of a reaction in the convenient form of a graph as well as simulating the course of a reaction on the basis of the model created. REACTKIN allows the determination of the rate constants of elementary reactions using experimental kinetic data concerning the influence of the ionic strength of the solution. The program REACTKIN can be of importance in the studies of multi-step chemical reactions in electrolyte solutions as well as in chemistry education.     

Leader-follower finite-time formation control of multiple quadrotors with prescribed performance

This paper investigates the leader-follower formation problem for a group of quadrotors. Finite-time control scheme and prescribed performance control method, which are regarded as two highlights, are introduced in this paper. First, a control scheme with prescribed performance is used to control the translational movements to ensure the quadrotors obtain a relative gentle transient process and an adjustable steady-state error bound. Then, the desired orientations for the rotation subsystem provided by translational movements part are stabilised by a fixed-time control law. Finally, by designing a finite-time formation controller, followers can track the desired position and heading angle in finite time, which is important for the practical application. Several simulation results are given to show the effectiveness of the designed control strategy.     

计算机曲线拟合求解析氢反应的动力学参数

应用电化学稳态极化方法,研究1M NaOH电解液中镍硫合金电极表面析氢反应电催化活性与沉积层中含硫量之间的关系.根据析氢反应机理,用理论电化学极化方程拟合实验稳态极化曲线,得到不同含硫量的镍硫合金电极表面氢原子吸附和脱附反应的速率常数、反应对称系数等动力学参数.     

Terminal synthesis of orbital orientation for a spacecraft

This paper presents an algorithm for the terminal synthesis of the orbital orientation for a spacecraft. The algorithm is based on solving the following problems: the analytical determination of the program values for the angular velocity vector components in an orbital coordinate system and the stabilization of the program values for the turn rate vector components and the desired terminal angular position of a spacecraft. The program values of the angular velocity vector components are determined analytically using the method previously proposed by the authors for solving a boundary value problem based on the parameter identification of a discrete model with the use of modal control. The simulation results demonstrating the effectiveness of the proposed algorithm, as well as the high accuracy level of the steady-state control, are presented.     

基于二元模糊匹配的编程题智能评分方法

针对传统编程题自动评分方法不能准确衡量学生程序与参考答案之间的接近程度等问题,提出了一种基于二元模糊匹配的编程题智能评分方法。第一元为结构匹配,检测学生程序在变量声明、数据输入、函数调用、控制结构等方面与参考答案的相似程度,目的是快速判断学生程序中是否存在关键的采分点。第二元为词语匹配,首先进行词频统计,以确定每个词的权重。然后,分别构造学生程序与参考答案的向量空间模型,并计算两者的余弦相似度,来作为评判词语相似的依据。最终的分数由结构相似度和词语相似度的加权分数计算得出。由于该二元匹配方法不关心程序中结构/词语的先后顺序和是否为精确表达,因此被称为是模糊的。仿真实验表明,该方法具有不错的评分准确性,尽管与人工评分相比还存在一定的差距,但当试题规模较大时,可以作为人工评分的替代手段。     

一种高效能的机器人模糊控制方案

本文提出一种高效能的模糊控制方案,来提高机器人当存在摩擦力和负载等不确定因素 时以及动力学参数变化时的系统响应特性.该控制方案是由一个模糊逻辑(FL)控制器(主 控制器)和一个传统的微分(D)控制器(辅助控制器)所构成.FL控制器用来提高系统的瞬 态特性和稳态精度,D控制器用来保证系统的稳定性.在这一控制方案基础上,获得理想控 制特性的主要思想是研究和调整语言变量的隶属度函数.模拟结果表明了这一控制方案的 有效性和鲁棒性.此外,这一控制方案具有结构简单且易于实现的优点.     

An evolutionary algorithm for multi-criteria inverse optimal value problems using a bilevel optimization model

Given a linear program, a desired optimal objective value, and a set of feasible cost vectors, one needs to determine a cost vector of the linear program such that the corresponding optimal objective value is closest to the desired value. The problem is always known as a standard inverse optimal value problem. When multiple criteria are adopted to determine cost vectors, a multi-criteria inverse optimal value problem arises, which is more general than the standard case. This paper focuses on the algorithmic approach for this class of problems, and develops an evolutionary algorithm based on a dynamic weighted aggregation method. First, the original problem is converted into a bilevel program with multiple upper level objectives, in which the lower level problem is a linear program for each fixed cost vector. In addition, the potential bases of the lower level program are encoded as chromosomes, and the weighted sum of the upper level objectives is taken as a new optimization function, by which some potential nondominated solutions can be generated. In the design of the evolutionary algorithm some specified characteristics of the problem are well utilized, such as the optimality conditions. Some preliminary computational experiments are reported, which demonstrates that the proposed algorithm is efficient and robust.     

The statistical dynamics of activity-led reactions

For any chemical reaction we construct a non-linear stochastic process in continuous or discrete time in which the concentrations obey a kinetic law, where the rates are proportional to the products of the activities. The main microscopic assumption can be interpreted as expressing the hypothesis of a collective effect related to saturation. The theory is unable to shed light on the problem of absolute rates. In the final section we suggest how the hypotheses of the model might be tested experimentally.     

连续反应动力学的计算及过程的计算机模拟

在连续反应中,速率系数的比值很大程度上决定了中间产物浓度的走向,并由此引出了一个重要的方法：稳态近似法。微软公司推出的可视化编程语言Visual Basic提供了强大的计算与绘图功能,作者利用它研制了一级连续反应动力学的模拟程序。该程序能够计算出参与反应的各个物质的浓度,并且能够生动和直观地演示出各个物质的浓度随着反应的进行而发生的变化,从而使初学者进一步深刻理解一级连续反应和掌握稳态近似法的理论来源。     

Flows in micro fluidic networks: From theory to experiment

When complex flow structures are designed, such as in DNA computing, it is essential to be able to predict the flow pattern of the solutions in the fluidic network. A model based on the resistance of the channels and flow velocities of the inlets can eliminated re-iterative design steps. We have constructed a symbolic model using Mathematica ® to determine the desired flow pattern based on the equations of Ohm and Kirchoff. The values from this simulation were used in a flow simulation program and then tested in a microflow network. Results show that the simulation and calculation match very well, while the experiments in the fluidic network show a flow pattern as predicted by the model.     

连续反应动力学过程模拟程序的研究

连续一级反应动力学过程,实质是一阶常微分方程组的求解过程.本文用四阶龙格-库塔法求解,开发连续反应动力学Visual Basic 6.0模拟程序并提供源代码,其功能根据设定的参数计算出参与反应的各反应物浓度随时间推移的变化,可直观反应动力学曲线,以及输出计算结果和图形.     

高校区域大学生微博身份的精确识别方法

对高校大学生微博身份进行精确识别有利于尽早的定位大学生网络谣言、高校舆情事件的起源,为高校辅导员及相关管理部门采取线下补救措施、及时处理突发事件争取时间.以学校提供的学生信息资料为背景,让挖掘到的大学生微博信息尽可能地去匹配已有的背景信息,从而识别高校区域大学生微博帐号.分别采用3种阈值进行实验分析,证明这种循环匹配的方法可以获得较好的识别效果.