为改善应用于变参数振动钻削加工过程的仿真和参数优化的小波神经网络的逼近能力和泛化能力,提出一种小波神经网络结构和基于局部学习策略的共轭梯度(LCG:Local Con jugate G rad ient)算法,并利用灰色关联分析法对改进网络模型中的3个...为改善应用于变参数振动钻削加工过程的仿真和参数优化的小波神经网络的逼近能力和泛化能力,提出一种小波神经网络结构和基于局部学习策略的共轭梯度(LCG:Local Con jugate G rad ient)算法,并利用灰色关联分析法对改进网络模型中的3个输入权值进行选取,对网络权值、小波函数的平移因子和伸缩因子的初始值选取给出了原则。通过实验表明,该模型改善了网络性能和仿真效果。展开更多
伪随机数发生器(Pseudorandom Number Generator,PRNG)是密码学应用系统的一个重要组成部分.本文利用线性同余发生器(Linear Congruential Generator,LCG)、流密码算法RC4和密码学Hash函数,构造了一种基于软件实现的组合式伪随机数发生...伪随机数发生器(Pseudorandom Number Generator,PRNG)是密码学应用系统的一个重要组成部分.本文利用线性同余发生器(Linear Congruential Generator,LCG)、流密码算法RC4和密码学Hash函数,构造了一种基于软件实现的组合式伪随机数发生器.该伪随机数发生器可以快速生成伪随机数列并且从理论上证明了产生的数列具备不可预测性.同时,采用美国国家标准和技术研究院(National Institute of Standard Technology,NIST)发行的随机性测试包对该新构造的伪随机数发生器所产生的序列进行统计测试.实验结果显示,该新构造的伪随机数发生器产生的序列能够很好地通过各项测试,可以应用于信息安全领域.展开更多
An ionic liquid-polyaniline/tungsten disulfide(IL-PANI/WS_(2))composite was synthesized in 1-butyl-3-methylimidazole tetrafluoroborate(LB104)aqueous solution by in-situ polymerization and characterized by Fourier tran...An ionic liquid-polyaniline/tungsten disulfide(IL-PANI/WS_(2))composite was synthesized in 1-butyl-3-methylimidazole tetrafluoroborate(LB104)aqueous solution by in-situ polymerization and characterized by Fourier transform infrared spectroscopy.A current-carrying friction and wear tester was used to study the tribological properties of steel-steel and copper-copper friction pairs lubricated by an IL-PANI/WS_(2) lithium complex grease(LCG).After the experiment,scanning electron microscope was used to observe the surface morphology of the wear scar on the steel and copper plates,and X-ray photoelectron spectrometer was used to analyze the elemental composition of the wear scar surface.The results show that compared with greases containing IL-PANI and WS_(2),greases containing IL-PANI/WS_(2) exhibit better antiwear performance when lubricating steel-steel friction pairs and better tribological performance and electrical conductivity when lubricating copper-copper friction pairs.Therefore,it can be concluded that WS_(2) and IL-PANI have a synergistic effect.展开更多
A new method, referred to as the full-recurrent-decimal-sequences (FRDS) method, is proposed to generate the pseudorandom integer strings and the pseudorandom sequences. The pseudorandom integer strings properties and...A new method, referred to as the full-recurrent-decimal-sequences (FRDS) method, is proposed to generate the pseudorandom integer strings and the pseudorandom sequences. The pseudorandom integer strings properties and the run-length properties of the FRDS-sequences are investigated . By transformation, a new kind of pseudorandom sequences with optimal auto-correlation functions is suggested.展开更多
This paper presents a comprehensive overview of the element-wise locally conservative Galerkin(LCG)method.The LCG method was developed to find a method that had the advantages of the discontinuous Galerkin methods,wit...This paper presents a comprehensive overview of the element-wise locally conservative Galerkin(LCG)method.The LCG method was developed to find a method that had the advantages of the discontinuous Galerkin methods,without the large computational and memory requirements.The initial application of the method is discussed,to the simple scalar transient convection-diffusion equation,along with its extension to the Navier-Stokes equations utilising the Characteristic Based Split(CBS)scheme.The element-by-element solution approach removes the standard finite element assembly necessity,with an face flux providing continuity between these elemental subdomains.This face flux provides explicit local conservation and can be determined via a simple small post-processing calculation.The LCG method obtains a unique solution from the elemental contributions through the use of simple averaging.It is shown within this paper that the LCG method provides equivalent solutions to the continuous(global)Galerkin method for both steady state and transient solutions.Several numerical examples are provided to demonstrate the abilities of the LCG method.展开更多
文摘为改善应用于变参数振动钻削加工过程的仿真和参数优化的小波神经网络的逼近能力和泛化能力,提出一种小波神经网络结构和基于局部学习策略的共轭梯度(LCG:Local Con jugate G rad ient)算法,并利用灰色关联分析法对改进网络模型中的3个输入权值进行选取,对网络权值、小波函数的平移因子和伸缩因子的初始值选取给出了原则。通过实验表明,该模型改善了网络性能和仿真效果。
文摘伪随机数发生器(Pseudorandom Number Generator,PRNG)是密码学应用系统的一个重要组成部分.本文利用线性同余发生器(Linear Congruential Generator,LCG)、流密码算法RC4和密码学Hash函数,构造了一种基于软件实现的组合式伪随机数发生器.该伪随机数发生器可以快速生成伪随机数列并且从理论上证明了产生的数列具备不可预测性.同时,采用美国国家标准和技术研究院(National Institute of Standard Technology,NIST)发行的随机性测试包对该新构造的伪随机数发生器所产生的序列进行统计测试.实验结果显示,该新构造的伪随机数发生器产生的序列能够很好地通过各项测试,可以应用于信息安全领域.
文摘An ionic liquid-polyaniline/tungsten disulfide(IL-PANI/WS_(2))composite was synthesized in 1-butyl-3-methylimidazole tetrafluoroborate(LB104)aqueous solution by in-situ polymerization and characterized by Fourier transform infrared spectroscopy.A current-carrying friction and wear tester was used to study the tribological properties of steel-steel and copper-copper friction pairs lubricated by an IL-PANI/WS_(2) lithium complex grease(LCG).After the experiment,scanning electron microscope was used to observe the surface morphology of the wear scar on the steel and copper plates,and X-ray photoelectron spectrometer was used to analyze the elemental composition of the wear scar surface.The results show that compared with greases containing IL-PANI and WS_(2),greases containing IL-PANI/WS_(2) exhibit better antiwear performance when lubricating steel-steel friction pairs and better tribological performance and electrical conductivity when lubricating copper-copper friction pairs.Therefore,it can be concluded that WS_(2) and IL-PANI have a synergistic effect.
文摘A new method, referred to as the full-recurrent-decimal-sequences (FRDS) method, is proposed to generate the pseudorandom integer strings and the pseudorandom sequences. The pseudorandom integer strings properties and the run-length properties of the FRDS-sequences are investigated . By transformation, a new kind of pseudorandom sequences with optimal auto-correlation functions is suggested.
文摘This paper presents a comprehensive overview of the element-wise locally conservative Galerkin(LCG)method.The LCG method was developed to find a method that had the advantages of the discontinuous Galerkin methods,without the large computational and memory requirements.The initial application of the method is discussed,to the simple scalar transient convection-diffusion equation,along with its extension to the Navier-Stokes equations utilising the Characteristic Based Split(CBS)scheme.The element-by-element solution approach removes the standard finite element assembly necessity,with an face flux providing continuity between these elemental subdomains.This face flux provides explicit local conservation and can be determined via a simple small post-processing calculation.The LCG method obtains a unique solution from the elemental contributions through the use of simple averaging.It is shown within this paper that the LCG method provides equivalent solutions to the continuous(global)Galerkin method for both steady state and transient solutions.Several numerical examples are provided to demonstrate the abilities of the LCG method.
