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Process modelling activity involves modelling a physical plant and external tasks imposed on the plant, and details of both aspects are discussed.


The land and facility are described, and the importance of certain elements of location, physical plant, and layout to the program model are discussed.


Also, aspects of the significance of the physical plant, the size of the residence, the role of psychotropic medication, and the management and staff attitudes toward regression are discussed.


The dynamics of a physical plant may be difficult to express as concise mathematical equations.


To accomplish this, those charged with the awesome task of education must know what to do and how to do it and have a physical plant adequate to do it in.

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 The acetaldehyde oxidation process is one of the important steps of acetic acid production. The reaction takes place in the multistage bubble column and the reaction mechanism is very complicate in which involves gasliquid mass transfer, hydrodynamics and other deciplines and a set of seriesparalled reaction. There is no doubt that the search for the optimun operating conditions of the bubble column reaction can be meaningful reliable and economical only on the basis of mathematical model for the reactor.... The acetaldehyde oxidation process is one of the important steps of acetic acid production. The reaction takes place in the multistage bubble column and the reaction mechanism is very complicate in which involves gasliquid mass transfer, hydrodynamics and other deciplines and a set of seriesparalled reaction. There is no doubt that the search for the optimun operating conditions of the bubble column reaction can be meaningful reliable and economical only on the basis of mathematical model for the reactor. Considering some features of the column and physical plant, for the convenience in obtaining the parameters of the modle and solving the model equations. We use the empirical correlations to ecaluate the parameters of the hydrodynamic model, and build up the multistage back flow model.According to the reaction kinetic equations, mass transfer and material balances, a set of nonlinear equations solved by iteration can be obtained. The ratio of acetaldehyde and oxygen and reaction temperature are the main variables which govern the oxidation reaction in bubble column. Studing the influence of thess two variables to the reaciton result. Comparing the simulation and the experimental data, the result is satisfied. This proves the feasibility of the modeling reactor. Through the treatment of simulation result, ws have obtained a simpliffied control model. It is useful to realize the optimal control.  本研究工作旨在为实现乙醛氧化塔的计算机优化控制而建立必需的过程数学模型。该塔是一种多层筛板并流鼓泡塔。本文考虑了乙醛氧化的动力学模型,传质过程及非理想流动等各主要因素,建立起工业氧化塔的数学模型。并提出了计算方法,进行模型仿真计算,与实际数据对照结果是满意的。最后,给出了氧化塔的最优操作条件,为优化控制策略的开发,打下了基础。  Polarization mode dispersion(PMD) is a serious limitation in modern optical communications systems,particularly with the advent of 10Gb/s and 40Gb/s systems.A new method with Optical Time Domain Reflectometry Technique for detecting PMD allows network operators to maximize the reuse of existing physical plant.  偏振模色散(PMD)对现代光纤通信系统是一个严重制约,特别是10Gb/s和40Gb/s系统的应用。本文介绍一种基于光时域反射技术的PMD测试新方法,可以保证网络运营商最大程度使用现有通信网络。  If simulation models are written based on first principles in a declarative equation based modeling language, such as Modelica, their simulation often consists in solving a system of differential algebraic equations(DAEs). For complex physical plants, the resultant DAE system is of very large dimension, so its numerical solution requires highly intensive computation. In this paper, techniques for the symbolic manipulation of general DAE systems are presented, and used for model reduction purpose, to support... If simulation models are written based on first principles in a declarative equation based modeling language, such as Modelica, their simulation often consists in solving a system of differential algebraic equations(DAEs). For complex physical plants, the resultant DAE system is of very large dimension, so its numerical solution requires highly intensive computation. In this paper, techniques for the symbolic manipulation of general DAE systems are presented, and used for model reduction purpose, to support efficient simulation of complex multidomain continuous systems. The specific problems addressed are canonical transformation of equations, efficient elimination of trivial equations by means of substitution to reduce the dimension of the DAE system, and partitioning the overall system into subsystems which can be solved in sequence. The result achieved by applying the discussed algorithms on an oscillator system is illustrated. The proposed strategies and algorithms have been successfully implemented in a modeling and simulation system, named EMWorks.  为解决复杂多领域连续系统的高效仿真问题,研究了陈述式基于方程仿真模型的约简策略.基于符号处理技术,提出了一种模型约简方法.该方法从方程的规范转换入手,通过消除特定形式方程缩减系统规模,将整个方程系统规划分解为一个可顺序求解的子系统序列.给出的实例表明文中约简方法效果显著.文中策略与算法已在多领域物理系统混合建模与仿真平台EMWorks中实现.  
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