不均匀质量辊子固定支架结构优化方法

正一、引言现在市场竞争日趋剧烈,产品研发周期降低、产品研发成本降低,以及产品快速投放市场,已经是企业站稳市场的基石,这样就需要在产品研发阶段,使用强大的分析工具对产品的性能进行前期预测,对产品经济性进行评估和优化,从而避免不必要的浪费。DOE方法是一种对试验进行合理安排,以较少的试验次数、较短的试验周期及较低的试验成本,获得较理想的试验结果并得出合理的结论的方法。对于研发工程师来说,分析工具的易用性、计算精度是必要的前提,本文以ANSYS Workbench作为处理平台,使用ANSYS内核求解器进行求解,这种处理方式被广泛应用于各行各业的产品研发中。     

轮胎硫化过程的动态模拟

硫化过程是轮胎生产的最后阶段，胶料的硫化反应在这一阶段于硫化机中在升温升压的情况下发生。已开发了一个轮胎硫化过程模拟器，它执行建立在有限元方法上的数值算法，用于解管理不稳态传热和硫化反应的严密模型方程式。从简单的热传导问题到实际的轮胎硫化过程的广泛模拟已经完成，结果通过与分析解或者与热电偶测量比较而得到证实。模拟器成功地描述了轮胎在硫化过程期间温度和硫化状态的变化趋势，它也可作为正被开发的用于硫化过程的最优化算法的核心模块。     

面向多层次认知域教学目标的网络工程专业课程教学研究与设计

针对单向授课教学方式不能满足网络工程专业能力培养需求的实际情况,分析网络工程专业课程认知域教学目标的不同层次与能力培养的相互关系,以信息系统集成课程为例,提出采用布鲁姆分类法对认知域教学目标的知识点进行分类,运用BOPPPS模型设计核心知识点的教学过程。     

基于改进潜在语义分析算法的文本情感分类研究

针对文本挖掘过程中存在的搜索空间过大问题,介绍潜在语义分析的方法,指出该方法应用在文本情感分类中,具有空间占用小的优点,阐述潜在语义分析算法通过对词项和文档矩阵进行奇异值分解,能够有效降低文本情感分类的搜索空间并对词项在语义层面进行分析,解决一词多义的问题。     

卓越软件工程师的体验教学法

将卓越软件工程师的教育过程视作学生对软件工程理论和软件行业知识的体验过程,提出软件工程卓越工程师的体验教学法。分析体验教学模式、软件项目体验剧场模型并介绍教学法实施的5个成功要素。     

同时发生初次和二次成核且为聚结控制的沉淀过程多定态及稳定性分析

The possibility of multiplicity in an isothermal continuous mixed suspension-mixed product removal crystallizer is explored using the bifurcation theory.A process involving agglomeration controlled precipitation is considered in which secondary nucleation occurs simultaneously with primary nucleation.The determinant equations for the existence of multiple steady states are developed and the multiplicity boundaries dependent on the physical and kinetic properties and operational parameters of the process are obtained by resolving these determinant equations.The number of steady states in the precipitator for various multiplicity regions is determined and the linear stability of these steady states is analyzed by using the Routh criterion.     

Robust state estimation for uncertain linear systems with deterministic input signals

In this paper, we investigate state estimations of a dynamical system in which not only process and measurement noise, but also parameter uncertainties and deterministic input signals are involved. The sensitivity penalization based robust state estimation is extended to uncertain linear systems with deterministic input signals and parametric uncertainties which may nonlinearly affect a state-space plant model. The form of the derived robust estimator is similar to that of the well-known Kalman filter with a comparable computational complexity. Under a few weak assumptions, it is proved that though the derived state estimator is biased, the bound of estimation errors is finite and the covariance matrix of estimation errors is bounded. Numerical simulations show that the obtained robust filter has relatively nice estimation performances.     

Introducing robustness in model predictive control with multiple modelsand switching

Model predictive control is model-based. Therefore, the procedure is inherently not robust to modelling uncertainties. Further, a crucial design parameter is the prediction horizon. Only offline procedures to estimate an upper bound of the optimal value of this parameter are available. These procedures are computationally intensive and model-based. Besides, a single choice of this horizon is perhaps not the best option at all time instants. This is especially true when the control objective is to track desired trajectories. In this paper, we resolve the issue by a time-varying horizon achieved by switching between multiple model-predictive controllers. The stability of the overall system is discussed. In addition, an introduction of multiple models to handle modelling uncertainties makes the overall system robust. The improvement in performance is demonstrated through several examples.     

中国房地产业的国际竞争力研究

伴随着中国的经济开放程度逐步加深,一些本土房地产企业正开始走向国际化,但是与发达国家相比,还存在资本结构不够合理、发展受到本国经济增长方式制约等问题。本文甄选出衡量房地产国际竞争力的25个指标,使用因子分析法对其进行了成分划分,结果表明,中国房地产业的投机性需求过于膨胀,房地产企业在经营管理和盈利模式上存在问题,且较弱的产品创新能力降低了其国际竞争力;基于VAR模型、OLS估计、Johansen协整检验等计量方法对影响中国房地产业国际竞争力的重要因素进行了实证检验,结果表明,中国房地产企业过于重视经营安全能力,在公司治理、境外市场盈利能力等方面竞争力不强,人力资本发挥的作用则极其微弱。