Rule-based update transformations and their application to model refactorings

A rule-based update transformation is a model transformation where a single model is transformed in place. A model refactoring is a model transformation that improves the design described in the model. A refactoring should only affect a previously chosen subset of the original model. In this paper, we discuss how to define and execute model refactorings as rule-based transformations in the context of the UML and MOF standards. We also present an experimental tool to execute this kind of transformation.     

超磁致伸缩作动器的率相关Hammerstein模型与H∞鲁棒跟踪控制

利用Hammerstein模型对超磁致伸缩作动器（Giant magnetostrictive actuators,GMA）的率相关迟滞非线性进行建模,分别以改进的 Prandtl-Ishlinskii（Modified Prandtl-Ishlinskii）模型和外因输入自回归模型（Autoregressive model with exogenous input,ARX）代表Hammerstein模型中的静态非线性部分和线性动态部分,并给出了模型的辨识方法. 此模型能在1～100Hz频率范围内较好地描述GMA的率相关迟滞非线性. 提出了带有逆补偿器和H∞鲁棒控制器的二自由度跟踪控制策略,实时跟踪控制实验结果证明了所提策略的有效性.     

线性不确定系统混合故障的可靠圆盘极点配置

针对一类不确定线性系统,利用更一般、更实际的执行器出现混合故障的模型,设计可靠控制器的同时将系统的极点配置到指定圆盘内问题,混合故障模型是指在一个系统中同时包含离散故障模型和连续故障模型,并给出系统将极点配置到指定圆盘上可靠控制的充分条件.通过求解LMI(线性矩阵不等式)完成状态反馈可靠控制器的设计.仿真验证本文提出的...     

Simulation of porous silicon structure formation

A model of porous silicon structure formation is considered. A computer implementation of this model is carried out, and a compact model of the silicon framework is created. A logical-probabilistic approach to simulating the porous silicon structure is described     

订货提前期对服务水平决策的影响研究

在服务水平的研究中,考虑了顾客面临缺货时的选择行为,引入顾客忍耐值,并度量了与顾客等待时间相关的损失,使建立的服务水平模型较传统模型更能真实地反映现实的购买行为.在该模型基础上,分析了订货提前期的变化对服务水平决策的影响,得出了有别于传统模型的结论,为企业在基于时间的竞争中作出恰当的服务水平决策提供了新的思路.算例分析进一步验证了该模型的有效性.     

Design of exact model matching systems and its applications to output tracking problems

This paper is concerned with the exact model matching problem described in the frequency domain, A systematic procedure to design a proper and lower order compensator with arbitrary pole position is proposed. In particular, the order of the compensator can be analytically found. Furthermore, the exact model matching problem in which the model satisfies output tracking is discussed. A compensator which includes an internal model of a reference signal generator is obtained as the solution of this exact model matching problem. A method which derives a robust compensator is also given.     

MIS软件开发过程的描述

本文用活动的概念来描述软件的开发过程，建立了软件过程的形式化描述模型，以此为基础，给出了MIS软件开发的过程描述。     

Partial shape recognition: a landmark-based approach

A method of recognizing partially occluded objects is presented in which each object is represented by a set of landmarks. Given a scene consisting of partially occluded objects, a model object in the scene is hypothesized by matching the landmarks of the model with those in the scene. A measure of similarity between two landmarks is needed to perform this matching. A local shape measure, sphericity, is introduced. It is shown that any invariant function under a similarity transformation is a function of the sphericity. To match landmarks between the model and the scene, a table of compatibility is constructed. A technique, known as hopping dynamic programming, is described to guide the landmark matching through the compatibility table. The location of the model in the scene is estimated with a least-squares fit among the matched landmarks. A heuristic measure is then computed to decide if the model is in the scene     

多Open-Shop生产线计划模型及简化

研究了一类带有限缓冲区的多open-shop生产线协调生产计划的模型问题,建立了上下游生产线的产品关联结构,给出了成本最低的生产计划模型。通常情况下,该模型的维数很大,为了便于求解,文中提出了不考虑主成品的模型简化方法。实例分析表明,这种方法可以大大减少模型规模,以提高求解速度。     

一种域增强的RBAC模型及其管理模型

在NISTRBAC模型的基础上扩展了域和客体类的概念,提出DE_RBAC模型,使其更适合在大型分层管理的系统中应用,减少了角色的定义和权限的分配。在此基础上提出一种新的管理模型,通过层层授权、分布式管理的方式建立分层的RBAC管理框架,并在系统运行中进行动态角色和权限管理。     

基于BP神经网络的模糊参数辨识

提出一种与TSK模糊模型相似的模糊模型—M-2模型,证明了M-2模型与一个4层前向神经网络是等价的,在此基础上提出基于BP神经网络的模糊模型参数辨别算法,即通过BP神经网络对样本数据的学习,直接从样本数据获取模型参数,建立M-2模糊模型,通过仿真实例验证了该算法的有效性。     

离散不确定系统的鲁棒预测控制

对预测控制中模型不确定性的处理一直是预测控制算法亟待解决的问题.考虑一类包含模型不确定性的控制对象模型,提出一种极大极小预测控制器设计方法.在滚动优化的每一步,考虑了状态变量不完全可测的情况,引入动态输出反馈的思想得到一个最坏条件下的性能指标的最优解,以最坏条件下的性能指标为求解优化问题的上界,通过线性矩阵不等式的方法求解凸优化问题.并从理论上证明了所设计的鲁棒预测控制器对不确定模型是稳定的.通过仿真算例的分析,证明了极大极小鲁棒预测控制器设计的有效性.     

一种新的DSS模型描述方法

模型管理系统是（群体）决策支持系统的重要研究领域，文中认为决策中使用的数学模型由属性数据，操作和知识组成，并由此给出了种嵌入知识的面向对象模型描述方法ＯＯＭＤＥＫ。文中探讨了知识在模型管理系统中的作用；从模型组合的角度，提取出３种模型类的继承关系，做了相应的讨论，并给出了基于ＯＯＭＤＥＫ的模型管理系统的实现方法。     

非线性多变量零阶接近有界系统的多模型自适应控制

针对一类多变量非线性离散时间系统,提出一种新的基于神经网络的多模型自适应控制方法.为了将非线性系统的高阶非线性项的限制条件放宽到零阶接近有界,该方法引入了一种新的非线性模型.该模型在传统线性回归模型基础上增加了非线性补偿项,使模型的估计误差有界.一个神经网络模型与非线性模型同时被用来对系统进行辨识.基于性能指标的切换机构选择性能较好的模型对应的控制器 对系统进行控制. 理论分析证明了零阶接近有界多模型自适应控制系统的有界输 入和有界输出稳定性. 仿真实验说明了提出的多模型自适应控制方法的有效性.     

一种基于立方单元体的三维模型的构造方法及算法分析

本文主要提出一种基于立方单元体的三维模型的构造方法及其数学模型，并详细介绍基于此数学模型来构造三维模型的程序算法分析，该种算法在设计制作“三维模型与三视图”的CAI课件有一定的参考价值。     

基于BSP的并行事务处理模型

BSP模型独立于并行体系结构,既可作为并行计算模型,又可作为并行程序设计模型。提出了基于BSP模型的H－V事务模型,适用于长、短事务和长短事务混杂的情况。给出了在无共享结构下实现并行事务处理的进程结构。该结构不仅实现了事务内及事务间并行性,而且使人有可用性（availability）和可扩充性（scalability）,而后给出了适用于该模型的基于时间戳的多版本并发控制协议,最后描述了事务在超步结构下的运行过程。性能测试表明,使用该模型进行事务处理时可获得良好的事务响应时间和加速比。     

Identification and prediction propagation of uncertainty in models with bounded noise

The identification of measurement, parametric, and structural model uncertainty is considered for models from observations with bounded noise. A min-max estimate for the upper bound of the structural model uncertainty is presented. The propa- gation of the parametric and structural model uncertainty, as a result of the obser- vation uncertainty bounds to the model prediction error, is examined. A simple water quality model is used to illustrate the different steps.     

Selecting a job mix for running a benchmark by using an integer programming model

A brief review of computer selection methods indicates that benchmark testing is the most common technique for computer selection. A model for selecting a set of programs comprising a benchmark is then constructed step-by-step up to a “basic model”. The “basic” model is altered and expanded up to a “global” model. The paper summarizes advantages of the model and cites some experimental results.     

Evaluation of markov program models in virtual memory systems

A first order Markov model of program behaviour is developed from FORTRAN program instruction data. The program model is evaluated by using it to generate page references for input into a simple virtual memory operating system (VMOS) simulation model. The actual trace data are also used to drive the VMOS model. In both cases the fault probability is obtained for different replacement rules, memory sizes and page sizes. A comparison of fault probabilities is used to determine the effectiveness of the Markov program model.     

Shape optimization for noise radiation problems

A shape design model that reduces the amount of noise radiated from aircraft turbofan engines is studied in this paper. The model is formulated as shape control of the Helmholtz equation with radiation boundary conditions on part of the boundary and incoming waves specified as the source. Existence of optimal shape is proved to show that the model is appropriately established. A numerical experiment is conducted to demonstrate the efficiency of the model.