SPECTRAL RADIUS,KRONECKER PRODUCTS AND STATIONARITY

Abstract. We provide a stochastic proof of the inequality ρ(A?A+B?B) ≥ρ(A?A), where ρ(M) denotes the spectral radius of any square matrix M, i.e. max{|eigenvalues| of M}, and M?N denotes the Kronecker product of any two matrices M and N. The inequality is then used to show that stationarity of the bilinear model will imply stationarity of the linear part, i.e. the linear ARMA model for r= 1 and q= 1. Furthermore, it is shown that stationarity of the subdiagonal model, i.e. the bilinear model with b_ij=0 for i< j, again implies stationarity of its linear part, provided that the stationarity condition given by Bhaskara Rao and his colleagues is met. Interestingly, the conclusion that stationarity of the subdiagonal models, implies that the linear component models cannot be extended to the general non-subdiagonal bilinear models. The last observation is demonstrated via a simple example with p=m= 1, r= 0 and q= 2.     

基于Newsvendor型产品特性的FJSP问题研究

针对新时代环境下Newsvendor型产品销售期短、期末未出售产品价值递减的产品特点,生产链要求位于上游的供应商必须快速加工出所需的工件,否则将面临着线性递增的拖期惩罚。在面对基于Newsvendor型产品的柔性作业车间调度问题时,设计了一种加入禁忌搜索的混合遗传算法,扩大了解的搜索范围,避免了传统遗传算法容易陷于局部最优的缺陷。最后利用混合遗传算法对一个仿真案例进行求解。     

三维虚拟仿真产品展示平台的应用与研究

随着网络的迅速发展,网上购物越来越受到人们的青睐。顾客希望能从网站上更详细地了解商品外观和体验功能,因此如何更好地向消费者展示商品是电子商务中吸引用户需要解决的问题。本文所讨论的三维虚拟仿真产品展示平台会给使用者提供一个虚拟仿真的环境,使用户“足不出户”就能有真实的体验,满足用户的浏览需求。     

Radiation-induced modification of polyurethane with hydroxyethyl methacrylate: blood compatibility

An attempt is made to develop the hydrophilic grafting of polyether urethane urea with hydroxyethyl methacrylate (hema) using⁶⁰Coγ-irradiation for achieving optimum hydrophilic/hydrophobic property needed towards blood compatibility. Contact angle method and platelet adhesion from calf’s blood are used to determine the suitability of these modified surfaces.     

人工神经网络技术在电工产品可靠性实验中的应用(理论部分)

本文简要介绍了人工神经网络，BP神经网络的结构、训练和学习规则以及人工神经网络非线性时间序列预测的应用概况。     

Remanufacturability and Assessment Method

WITH the development of surface engineering andlaws on environment protect,lots of companies have toconsider reclaim of the used products.In practice,theyrealized if the products adopt design forremanufacturing,the benefit of remanufacturing wouldbe increased obviously'1'.Some researcher haveentered into remanufacturability field and built relativeevaluating methods'2'.Based on researching resultabout design for remanufacturing,some concepts,remanufacturability system and assessment method ar…     

我国中厚板生产技术进步20年

综述了近 2 0年来我国中厚板生产技术的发展历程 ;并对其生产力、装备水平的提高 ,新工艺技术、自动控制系统的运用及产品开发等方面进行了较详细的分析和介绍     

论虚拟经营中"企业运行功能"的服务产品属性

知识经济、经济信息化的快速发展,使虚拟经济在我国经济发展中的重要地位更为突出,虚拟企业的运行,需要与其他企业进行"企业运行功能"的交换,对"企业运行功能"属性的研究,可以促进"企业运行功能"交换的顺利实现.在研究过程中,主要运用了定性分析方法,其中也贯穿了实证分析与规范研究的结合.作为商品,企业运行功能具有无形性、不可分离性、差异性、不可贮存性、缺乏所有权等服务产品的属性.但功能是一种特殊的服务产品,还有一些特殊的性质.     

不同牌号丁苯橡胶的耐低温性能研究

研究3种牌号丁苯橡胶(SKMS-10,SL-4525-0,SBR1502)的硫化特性、物理性能和耐低温性能。结果表明:SKMS-10具有优异的耐低温性能,生胶的玻璃化转变温度(T_g)为-73.3℃,硫化胶的T_g为-59.8℃,适于在极寒条件下使用;SL-4525-0胶料的F_max-FL较大,硫化胶的拉伸强度为19.3 MPa,撕裂强度为53 kN·m^-1,T_g为-48.6℃,具有优异的综合性能;SBR1502硫化胶的拉伸强度高达24.9 MPa,撕裂强度为49 kN·m^-1,但T_g为-38.4℃,耐低温性能较差,适用于载荷较大且耐低温性能要求不高的橡胶减振制品。     

Validation of a Gas Chromatography-Mass Spectrometry Method for the Measurement of the Redox State Metabolic Ratios Lactate/Pyruvate and β-Hydroxybutyrate/Acetoacetate in Biological Samples

The metabolic ratios lactate/pyruvate and β-hydroxybutyrate/acetoacetate are considered valuable tools to evaluate the in vivo redox cellular state by estimating the free NAD+/NADH in cytoplasm and mitochondria, respectively. The aim of the current study was to validate a gas-chromatography mass spectrometry method for simultaneous determination of the four metabolites in plasma and liver tissue. The procedure included an o-phenylenediamine microwave-assisted derivatization, followed by liquid-liquid extraction with ethyl acetate and silylation with bis(trimethylsilyl)trifluoroacetamide:trimethylchlorosilane 99:1. The calibration curves presented acceptable linearity, with a limit of quantification of 0.001 mM for pyruvate, β-hydroxybutyrate and acetoacetate and of 0.01 mM for lactate. The intra-day and inter-day accuracy and precision were within the European Medicines Agency’s Guideline specifications. No significant differences were observed in the slope coefficient of three-point standard metabolite-spiked curves in plasma or liver and water, and acceptable recoveries were obtained in the metabolite-spiked samples. Applicability of the method was tested in precision-cut liver rat slices and also in HepG2 cells incubated under different experimental conditions challenging the redox state. In conclusion, the validated method presented good sensitivity, specificity and reproducibility in the quantification of lactate/pyruvate and β-hydroxybutyrate/acetate metabolites and may be useful in the evaluation of in vivo redox states.