Development of hydraulically driven shaking table for damping experiments on shock absorbers

The hydraulically driven shaking table has been developed for damping characteristic experiments on shock absorbers in this paper. The damping characteristics and corresponding experiments on the double-tube hydraulic absorber are analyzed firstly, and its damping force model is also built. Then the working principle is introduced, and the structure and components of the physical shaking table are described, especially the hydraulic actuator, composed of servo valve controlled asymmetric cylinder with damping load, is analyzed. Considering parameter uncertainty, nonlinearity, asymmetry and time-variation of such hydraulic system, as well as repeatability of desired trajectory, an open-closed-loop ILC scheme is designed to solve the challenging control issue. The simulation and experiments are developed to verify the feasibility of working principle and the superiority of proposed control method. The hydraulically driven shaking table developed by discussed electro-hydraulic control technology has been applied in actual damping characteristic experiments for a serial of shock absorbers, and achieved satisfactory testing performance.     

GF(p)上q元旋转对称弹性函数的一个等价刻画

基于旋转对称弹性函数l值支撑矩阵的性质,给出了GF(p)上q变元旋转对称弹性函数的一个等价刻画,证明了GF(p)上q变元旋转对称一阶弹性函数的构造问题等价于一个方程组的求解问题,并且利用方程组的所有解给出这类函数计数结果的一个表示。     

网络上元素周期表的资源评价研究*

元素周期表是学生研究化学问题的重要工具。除了教材提供的元素周期表,网络上提供的各类元素周期表有潜力提高学生对化学元素和化学基本概念的理解。本文汇总了网络上多种形式的元素周期表的来源,并对其网站进行介绍,为教学提供素材和资源。同时,针对提供较多物理化学数据的元素周期表以《物理化学手册》为标准,对教材中常出现的4种元素碳、氧、铁、氯进行数据评估,为使用者提供有效参考。     

Zeros in Tables of Characters for the Groups <Emphasis Type="Italic">S</Emphasis><Subscript>n</Subscript> and <Emphasis Type="Italic">A</Emphasis><Subscript>n</Subscript>. II

Let P(n) be the set of all partitions of a natural number n. In the representation theory of symmetric groups, for every partition α ∈ P(n), the partition h(α) ∈ P(n) is defined so as to produce a certain set of zeros in the character table for S_n. Previously, the analog f(α) of h(α) was obtained pointing out an extra set of zeros in the table mentioned. Namely, h(α) is greatest (under the lexicographic ordering ≤) of the partitions β of n such that χ^α(g_β) ≠ 0, and f(α) is greatest of the partitions γ of n that are opposite in sign to h(α) and are such that χ^α(g_γ) ≠ 0, where χ^α is an irreducible character of S_n, indexed by α, and g_β is an element in the conjugacy class of S_n, indexed by β. For α ∈ P(n), under some natural restrictions, here, we construct new partitions h′(α) and f′(α) of n possessing the following properties. (A) Let α ∈ P(n) and n ⩾ 3. Then h′(α) is identical is sign to h(α), χ^α(g_h′(α)) ≠ 0, but χ^α(g_γ) = 0 for all γ ∈ P(n) such that the sign of γ coincides with one of h(α), and h′(α) < γ < h(α). (B) Let α ∈ P(n), α ≠ α′, and n ⩾ 4. Then f′(α) is identical in sign to f(α), χ^α(g_f′(α)) ≠ 0, but χ^α(g_γ) = 0 for all γ ∈ P(n) such that the sign of γ coincides with one of f(α), and f′(α) < γ < f(α). The results obtained are then applied to study pairs of semiproportional irreducible characters in A_n. Supported by RFBR grant No. 04-01-00463. __________ Translated from Algebra i Logika, Vol. 44, No. 6, pp. 643–663, November–December, 2005.     

正交Hermite—Pade表中的恒等式

在正规性的条件下，在S维正交Hermite-Pade表中以显示方式、递推地构造表中所存在的恒等关系，并给出相应的余项估计式．     

图像处理中Gamma校正的研究和实现

对图像处理中的GAMMA校正进行了详细分析,从CRT(阴极射线管)显示器和人类视觉特性两方面分析了GAMMA校正的必要性,给出了RGB三原色的非线性编码,并对GAMMA校正给出了基于帧缓存颜色查找表的实现方法。     

有线电视HFC双向网络同轴分配网的设计方案

为使小区用户收看数字电视节目，并可实现交互式服务功能，须对同轴分配网络进行设计．论述了上行通道设计指标在整个分配网设计过程中的重要性。     

Critical points at infinity and blow up of solutions of autonomous polynomial differential systems via compactification

Critical points at infinity for autonomous differential systems are defined and used as an essential tool. Rn is mapped onto the unit ball by various mappings and the boundary points of the ball are used to distinguish between different directions at infinity. These mappings are special cases of compactifications. It is proved that the definition of the critical points at infinity is independent of the choice of the mapping to the unit ball.We study the rate of blow up of solutions in autonomous polynomial differential systems of equations via compactification methods. To this end we represent each solution as a quotient of a vector valued function (which is a solution of an associated autonomous system) by a scalar function (which is a solution of a related scalar equation).     

一种用于可控震源数据采集的接力式网络结构

将以太网技术应用于可控震源地震数据采集系统,以解决可控震源地震数据采集中的数据传输瓶颈,并针对可控震源地震数据采集系统的特点,提出了一种接力式的网络拓扑结构,给出了基于该拓扑结构的网络协议设计要点,着重讨论了其中IP的动态分配和路由表的建立方法.     

超标量处理器的转移预测方案研究

随着高性能超标量处理器的流水线深度和发射度的增加,为挖掘宽发射、深度流水线处理器的潜在性能,设计一个杰出的转移预测器已变得越来越重要.常规的两级转移预测器是根据局部转移历史信息或全局转移历史信息来预测转移的结果,文章给出了一种新的转移预测方案,称为LGshare,它同时使用全局和局部转移历史信息来改进超标量微处理器的转移预测准确度.当模式历史表（PHT）的大小固定时,与常规的两级预测器相比,LGshare能获得更高的转移预测准确度.