改进差分进化算法在非线性模型预测控制中的应用

为了解决非线性模型预测控制在实际工程系统应用时,传统方法求解非凸的非线性规划问题容易陷入局部极小,计算量随着问题维数的增加呈几何级数增长的问题,对传统的差分进化算法进行了改进.通过动态调节差分进化算法的主要参数加快差分进化算法的收敛速度,同时采用多种突变策略增加种群的多样性,有效克服了传统差分进化算法容易陷入局部极小的缺点.在简单三容液位系统上的仿真实验结果证明了该算法的有效性和可行性,在工业应用中具有较好的应用前景.     

多氯联苯（PCBS）分配系数的估算和预测

基于烷烃分子距边矢量,将以原子为基准的距离－边数 量扩展为以基团为基准的距离－边数矢量。研究发现新分子距边矢量与多氯联苯正辛醇／水分配系数的对数有很好的线性关系：ｌｏｇＫｏｗ＝４．１０８８４＋０．５２４２３７ｕ１－０．０９２９０６２ｕ２ｎ＝３７,ｒ＝０．０９９０８,Ｓ＝０．１７７５,ＥＶ＝０．９８１１,Ｆ＝１８６８。     

基于ASM的元模型形式化语义的研究*

提出一种在模型驱动开发过程中的形式化语义描述方法。该方法利用元建模技术,形式化地描述了元模型及其语义间的映射关系,以提供精确的语义描述,从而为模型驱动开发提供有力的支持。将描述框架用于模型转换规则的定义以及元模型的分析与验证,并以简单Petri网为例,说明该方法可以有效地支持模型转换和代码生成。     

Optimal design of catalytic distillation columns: A case study on synthesis of TAEE

The design of catalytic distillation (CD) columns is a challenging task because of the superposition of chemical reaction and distillation in one apparatus. In this work, a method to design a cost-optimal CD column for chemical systems with large number of components and chemical reactions is presented. The method is based on the following steps: (1) estimation of the number of theoretical stages and catalyst volume by the decomposition of the CD column into a sequence of chemical reactors and non-reactive distillation columns, (2) estimation of the column diameter and operating conditions using an equilibrium stage model, and (3) design of the column applying an optimisation algorithm and using a rigorous non-equilibrium stage model to represent the CD process. The method is applied to determine the optimal column configuration and operating conditions for the synthesis of tert-amyl ethyl ether from ethanol and isoamylenes. Eight components and four chemical reactions were selected to represent the chemical system in the simulations.     

Modeling real-time communication systems: Practices and experiences in Motorola

Visual modeling languages and techniques have been increasingly adopted for software specification, design, development, and testing. With the major improvements of UML 2.0 and tools support, visual modeling technologies have significant potential for simplifying design, facilitating collaborations, and reducing development cost. In this paper, we describe our practices and experiences of applying visual modeling techniques to the design and development of real-time wireless communication systems within Motorola. A model-driven engineering approach of integrating visual modeling with development and validation is described. Results, issues, and our viewpoints are also discussed.     

A neural differential evolution identification approach to nonlinear systems and modelling of shape memory alloy actuator

This paper proposes a hybrid modified differential evolution plus back‐propagation (MDE‐BP) algorithm to optimize the weights of the neural network model. In implementing the proposed training algorithm, the mutation phase of the differential evolution (DE) is modified by combining two mutation strategies rand/1 and best/1 to create trial vectors instead of only using one mutation operator or rand/1 or best/1 as the standard DE. The modification aims to balance the global exploration and local exploitation capacities of the algorithm in order to find potential global optimum solutions. Then the local searching ability of the back‐propagation (BP) algorithm is applied in that region so as to swiftly converge to the optimum solution. The performance and efficiency of the proposed method is tested by identifying some benchmark nonlinear systems and modeling the shape memory alloy actuator. The proposed training algorithm is compared with the other algorithms, such as the traditional DE and BP algorithm. As a result, the proposed method can improve the accuracy of the identification process.     

An MDE-based method for bridging different design notations

Different communities have developed plenty of design notations for software engineering in support of practical (via UML) and rigorous (via formal methods) approaches. Hence the problem of bridging these notations rises. Model-driven engineering (MDE) is a new paradigm in software engineering, which treats models and model transformations as first class citizens. Furthermore, it is seen as a promising method for bridging heterogeneous platforms. In this paper, we provide an MDE-based approach to build bridges between informal, semi-formal and formal notations: Firstly, different notations are viewed as different domain specification languages (DSLs) and introduced into MDE, especially into the ATLAS Model Management Architecture (AMMA) platform, by metamodeling. Then, ATL transformation rules are built for semantics mapping. At last, TCS-based model-to-text syntax rules are developed, allowing one to map models to programs. Consequently, different design notations in both graphical style and grammatical style are bridged. A case study of bridging OMG SysML™ to LOTOS is also illustrated showing the validity and practicability of our approach.     

多氯联苯(PCB_S)分配系数的估算和预测

基于烷烃分子距边矢量 ,将以原子为基准的距离 边数矢量扩展为以基团为基准的距离 边数矢量。研究发现新分子距边矢量与多氯联苯正辛醇 /水分配系数的对数有很好的线性关系 :logKow =4 1 0 884 0 52 4 2 37μ1 - 0 0 92 90 6 2 μ2 .n =37,r =0 990 8,S =0 1 775,EV=0 981 1 ,F =1 86 8.     

Tuned reactive power dispatch through modified differential evolution technique

This paper explores the capability of modified differential evolution (MDE) technique for solving the reactive power dispatch (RPD) problem. The proposed method is based on the basic differential evolution (DE) technique with a few modifications made into it. DE is one of the strongest optimization techniques though it suffers from the problem of slow convergence while global minima appear. The proposed modifications are tried to resolve the problem. The RPD problem mainly defines loss minimization with stable voltage profile. To solve the RPD problem, the generator bus voltage, transformer tap setting and shunt capacitor placements are controlled by the MDE approach. In this paper, IEEE 14-bus and IEEE 30-bus systems are chosen for MDE implementation. The applied modification show much improved result in comparison to normal DE technique. Comparative study with other soft-computing technique including DE validates the effectiveness of the proposed method.