广义Sylvester矩阵与循环分块矩阵

讨论了两个多项式矩阵右互质时其广义Sylvester矩阵的性质，指出了广义Sylvester矩阵与R-循环分块矩阵的联系，得到了R-循环分块矩阵可逆时的充要条件。     

在飞行模拟器中实现雪的实时模拟

基于粒子系统和空气动力学效应对下雪这一自然现象进行了实时仿真,建立了一个风的模型,把雪的运动看作风的运动和雪的自由落体的综合运动。根据雪粒子的自然属性和飞行模拟实际的视景需求,简化了数学计算,模拟了下雪这一特殊气象。最后对粒子间的碰撞做了简要介绍。     

Acceleration of Computation of Determinants and Characteristic Polynomials without Divisions

Algorithms are proposed that compute determinants and characteristic polynomials of n × n matrices without divisions in n^3+1/2 ring operations and adjoint matrices in three times more ring operations.     

A Sigma-Pi-Sigma Neural Network (SPSNN)

This letter presents a sigma-pi-sigma neural network (SPSNN) structure. The SPSNN can learn to implement static mapping that multilayer neural networks and radial basis function networks usually do. The output of the SPSNN has the sum of product-of-sum form , where x _j's are inputs, N _v is the number of inputs, f _nij() is a function to be generated through the network training, and K is the number of pi-sigma network (PSN) which is the basic building block for SPSNN. A linear memory array can be used to implement f _nij (). The function f _nij (x _j ) can be expressed as , where B _ijk() is a single-variable basis function, w _nijk's are weight values stored in memory, N _q is the quantized element number for x _j , and N _e is the number of basis functions in the neighborhood used for storing information for x _j. If all B _ijk()'s are Gaussian functions, the new neural network degenerates to a Gaussian function network. This paper focuses on the use of overlapped rectangular pulses as the basis functions. With such basis functions, will equal either zero or w _nijk, and the computation of f _nij (x _j) becomes a simple addition of retrieved w _nijk's. The new neural network structure demonstrates excellent learning convergence characteristics and requires small memory space. It has merits over multilayer neural networks, radial basis function networks and CMAC. This revised version was published online in June 2006 with corrections to the Cover Date.     

基于专用控制芯片的步进电机控制器

:介绍以专用控制芯片 PBD3 5 17、PBL3 770为核心构成的两相步进电机控制器的设计。主要涉及核心控制电路的构成、同步化的改进及驱动电路的并联使用。通过实验证明该控制器简单、实用     

关口电能表PT二次压降的改造

电能表ＰＴ二次压降影响电能计量的准确性,据调查,黑龙江省１９９７年其合格率仅为１２％,为贯彻实施厂网分开、竞价上网的政策,改造迫在眉睫。论述电能表ＰＴ二次压降的改造方法,采用电能表专用电压回路的措施,可以达到规程的要求,并在１９９８年黑龙江省关口电能自动计量系统工程中对发电厂部分予以实施,获得了巨大的经济效益。     

基于中国古典文学IP的文创产品转换路径探究

目的弘扬和传播中国传统文化,满足人们日益增长的精神需求,促进传统文化产业化发展,提高产品的附加值和竞争力。方法根据文创产品设计的三个层次和中国古典文学显性与隐性特征,由表及里地分析转换路径。首先,提取中国古典文学中具体的意象,选择具有广泛性和易解码的部分,结合时代特征,使产品易于理解且与时俱进。其次,针对同质化严重的现象,注重产品的创新与使用功能,基于古典文学IP,建立起产品与文化紧密又自然的联系。最后,深度理解中国古典文学的情感表现和价值观念的传达,完成文化内涵从文学到产品的创造性转化。结果指导中国古典文学IP向文创产品的创新性发展,使文创产品在新时代焕发活力,产生深远的经济效益、文化效益和社会效益。结论基于中国古典文学IP的文创产品设计应注重创新,从功能、审美、情感、价值观等方面将传统文化与新的时代特征相结合,以当代人的需求为中心,创造出广泛、实用、与时俱进的文创产品。     

基于阻抗特性多项式拟合的直驱风电机组次同步振荡稳定判据

近年来,阻抗分析法已成为分析新能源发电并网系统稳定性问题的一种主要研究方法。以直驱风电机组并网系统为例,分析了现有的奈奎斯特（Nyquist）稳定判据的特点和适用范围。为了弥补现有阻抗稳定判据的不足,提出了一种基于阻抗特性分式多项式函数拟合的量化稳定判据,采用分式多项式函数等效拟合理论推导或实测的风电机组端口阻抗特性,在拟合频段内分式多项式与原阻抗特性等价。通过求取拟合多项式零点获得了系统振荡频率和阻尼水平,量化分析了系统稳定特性,拓展了阻抗稳定判据的适用范围。最后,通过理论分析和时域仿真验证了分式多项式拟合判据的正确性和有效性。     

Uncertainty quantification of offshore anchoring systems in spatially variable soil using sparse polynomial chaos expansions

The trend toward deep water energy production has led to a growing use of plate anchors to moor floating production facilities. The effect on anchor uplift behaviour of the inherent spatial variability of soil deposits has so far been little considered, despite having important implications for anchor design. Spatial variability problems are commonly analysed by Monte Carlo simulation but it is difficult to establish the probabilities of failure that are of interest in practice. In this paper, sparse polynomial chaos expansions (SPCEs) are used for moment and reliability analysis of plate anchors in spatially variable undrained clay. A novel two-stage methodology is proposed: in the first stage, an SPCE is constructed to meet a target global error, allowing statistical moments of the uplift capacity to be obtained; in the second stage, an active learning method is used to refine the SPCE for reliability analysis. Anchor uplift capacity is obtained by a finite element method, which is coupled with a random field representation of spatial variability. The effect of embedment depth and the soil-anchor interface is investigated. The failure mechanism of the anchor is shown to have a significant effect on the statistical moments of the uplift capacity and the probability of failure in relation to current design guidelines. To inform future design, factors of safety are presented for a range of failure probabilities.     

Variance-based simplex stochastic collocation with model order reduction for high-dimensional systems

In this work, an adaptive simplex stochastic collocation method is introduced in which sample refinement is informed by variability in the solution of the system. The proposed method is based on the concept of multi-element stochastic collocation methods and is capable of dealing with very high-dimensional models whose solutions are expressed as a vector, a matrix, or a tensor. The method leverages random samples to create a multi-element polynomial chaos surrogate model that incorporates local anisotropy in the refinement, informed by the variance of the estimated solution. This feature makes it beneficial for strongly nonlinear and/or discontinuous problems with correlated non-Gaussian uncertainties. To solve large systems, a reduced-order model (ROM) of the high-dimensional response is identified using singular value decomposition (higher-order SVD for matrix/tensor solutions) and polynomial chaos is used to interpolate the ROM. The method is applied to several stochastic systems of varying type of response (scalar/vector/matrix) and it shows considerable improvement in performance compared to existing simplex stochastic collocation methods and adaptive sparse grid collocation methods.