虚拟企业收益分配问题博弈研究

收益分配是虚拟企业的一个敏感而关键的问题，制订合理的收益分配方案对虚拟企业无疑是重要的。本分析了虚拟企业收益分配过程应考虑的因素，在此基础上应用博弈论建立了虚拟企业收益分配的博弈模型，并进行了相关分析，所得出的结论可用于虚拟企业的收益分配策略的制订，最后，论证了在虚拟企业中进行合作机制设计和应用的必要性。     

A polynomial time algorithm for a chance-constrained single machine scheduling problem

This paper gives an O(n√nlog³n) time algorithm for the chance-constrained sequencing problem on a single machine, where n is the number of jobs and the objective is to minimize the number of jobs which are early with probability not smaller than α (a given constant) against the common due time d.     

The Virtual Poincaré Polynomials of Homogeneous Spaces

We factor the virtual Poincaré polynomial of every homogeneous space G/H, where G is a complex connected linear algebraic group and H is an algebraic subgroup, as t^2u (t²–1)^r Q_G/H(t²) for a polynomial Q_G/H with nonnegative integer coefficients. Moreover, we show that Q_G/H(t²) divides the virtual Poincaré polynomial of every regular embedding of G/H, if H is connected.     

空间桁架结构的优化配置及振动控制研究

为抑制空间柔性桁架结构的低频振动,采用压电杆件进行优化配置实现桁架结构的振动主动控制。建立了空间桁架结构主动压电杆件的机电耦合模型,利用ANSYS前处理功能编制了压电桁架的机电耦合有限元程序。将可控性度量指标与逐步消减法相结合,实现了空间桁架结构主动杆件的优化配置。对结构进行初始位移扰动、正弦激励以及随机激励,并采用最优模态控制算法进行振动抑制仿真分析,对上述方法进行验证且建立振动控制评价指标进行评价。结果表明将可控性度量指标与逐步消减法相结合的方法可有效抑制空间柔性桁架结构的振动。     

基于PXI和RT-LAB的永磁同步电机快速控制原型设计

针对永磁同步电机控制器存在算法复杂、代码量大、开发周期长等问题,实现一种基于虚拟仪器的永磁同步电机快速控制原型系统。设计快速控制原型硬件平台,并对硬件设备进行选型,包括PXI虚拟仪器、功率驱动模块、电机对拖台架等;研究永磁同步电机转子磁场定向控制原理基础上,以一台3.1KW被测电机为被控对象,在RT-LAB实时仿真软件环境下,搭建永磁同步电机控制算法模型。实验结果表明,电机转速与定子电流均可无偏差跟踪参考给定值,系统控制性能良好,且该系统使电机控制器开发周期缩短、成本降低。     

基于DBN,SVM和BP神经网络的光谱分类比较

恒星的分类对了解恒星和星系形成与演化历史具有重要的研究价值。面对大型巡天计划及由此产生的海量数据,如何迅速准确地将天体自动分类显得尤为重要。通过对SDSS DR9的恒星光谱数据进行深度置信神经网络(DBN)、神经网络和支持向量机(SVM)等算法分类的对比,分析三种自动光谱分类方法在恒星分类上的适用性。首先利用上述三种方法对K,F恒星进行识别分类,然后再分别对K1,K3和K5次型和F2,F5,F9次型识别,最后基于SVM支持向量机的二次分类模型,利用K次型的数据,构建剔除不属于K次型的模型。结果表明:深度置信网络对K,F型恒星分类效果较好,但是对K,F次型的分类效果不佳;SVM支持向量机在K,F型恒星分类以及相应的次型分类都具有较好的识别率,对K,F型分类效果要好于K,F次型的分类效果;BP神经网络对K,F型恒星以及其次型的识别一般;在剔除不属于K次型实验中,剔除率高达100%,可知SVM能够对未知的光谱数据进行筛选与分类。     

基于虚拟仪器的装备ATS系统硬件平台设计与实现

在对现有维修检测设备存在不足分析的基础上,结合武器装备的维修技术保障需求,利用分块设计思想,采用虚拟仪器、人工智能、计算机通讯与控制等技术,搭建了基于虚拟仪器的装备自动测试系统硬件平台整体架构,在对系统各功能模块原理进行分析之后,对系统主控电路、电磁兼容性进行了设计。采用虚拟仪器的装备自动测试系统硬件平台,具有智能化、通用化、可视化的特点,通过试验结果分析,测试系统硬件平台能够实现装备的性能检测和故障诊断,测试数据符合任务要求,能满足各级修理机构维修测试需求。     

Identification of vehicle suspension shock absorber squeak and rattle noise based on wavelet packet transforms and a genetic algorithm-support vector machine

The squeak and rattle (S&R) noise of a vehicle’s suspension shock absorber substantially influences the psychological and physiological perception of passengers. In this paper, a state-of-the-art method, specifically, a genetic algorithm-optimized support vector machine (GA-SVM), which can select the most effective feature subsets and optimize the model’s free parameters, is proposed to identify this specific noise. A vehicular road test and a shock absorber rig test are conducted to investigate the relationship between these features, and then an approach for quantifying the shock absorber S&R noise is given. Pre-processed signals are decomposed through a wavelet packet transform (WPT), and two criteria, namely, the wavelet packet energy (WPE) and wavelet packet sample entropy (WPSE), are introduced as the feature extraction methods. Then, the two extracted feature sets are compared based on this genetic algorithm. Another advanced method, known as the genetic algorithm-optimized back propagation neural network (GA-BPNN), is introduced for comparison to illustrate the superiority of the newly developed GA-SVM model. The result shows that the WPSE can extract more useful features than the WPE and that the GA-SVM is more effective and efficient than the GA-BPNN. The proposed approach could be retrained and extended to address other fault identification problems.     

Tunable threading/dethreading efficiency of the pseudorotaxane by ether chain length

A series of axles containing the tetraethyl ester calix[4]arene derivative unit and 1,5-dioxynaphthalene (DNP) unit, with different lengths of ether chains, have been synthesized. Complexation of the axles and the cyclobis(paraquat-p-phenylene) (CBPQT⁴⁺) has been investigated by UV-vis and ¹H NMR spectra. The effect of the length of ether chain on the threading/dethreading processes has also been demonstrated, which indicated that the efficiency of threading/dethreading process decreases with the extension of ether chain.