基于数据列变换的自回归预测方法的改善

证明了利用反双曲正弦函数变换能提高数据列的光滑程度,获得结论:设｛x_(k)｝为递增数据列,x_(1)>0,y(k)=ln(x_(k) (x_(k)~2 1)~(1/2)),则数据列｛y_(k)｝比数据列｛x_(k)｝光滑.给出了改善的自回归预测方法,并且举例加以论证.     

轮胎垂直方向刚性环模型

为研究轮胎在中等频率时的垂向力学特性,建立了垂直方向上的刚性环模型,对1/4车模型进行了振型分析,说明刚性环模型能反映中频时的振动。简单介绍了模型输入和轮胎动态特性试验,并将模型和试验结果进行了对比,表明垂直方向刚性环模型能较好反映轮胎在典型短波长不平路面上垂直方向上的力学特性。     

汽车轮胎内置加速度传感器信号的制动起始时刻自动判别

汽车制动失灵,即使在非高速状态下行驶也会影响生命安全。采用汽车轮胎内置传感器的事故防范技术正在兴起。文中通过轮胎内置MEMS电容加速度传感器来获取径向加速度,把制动时段的径向加速度信号向外传送,用作间接监测汽车制动性能的依据。文中提出了为解决制动起始点自动判定这个关键环节所采取的动态平滑去噪、斜率比较等实时处理方法,制动起始时刻自动判别的实验结果验证了该方法的可行性。     

Interaction of smooth muscle relaxant drugs with calmodulin and cyclic nucleotide phosphodiesterase

Summary Some smooth muscle relaxant drugs with an unknown mechanism of action have been tested for their interaction with calmodulin and with calmodulin-induced cyclic nucleotide phosphodiesterase (PDE) activity. The affinity of these drugs for calmodulin does not parallel their inhibitory effect on the calmodulin activation of PDE. The lack of parallelism could be due to a binding of the drugs to different sites on calmodulin; furthermore a binding of papaverine, octylonium bromide and felodipine to PDE molecule, might also be considered to explain their inhibitory effect on PDE basal activity. The myolytic effect of octylonium bromide and pinaverium bromide may be due to their interaction with calmodulin-dependent systems.     

APPROXIMATION OF ADDITIVE FUNCTIONALS OF THE SYMMETRIC HUNT PROCESSES AND ITS APPLICATION

Approximate theorem of positive continuous additive functionals is discussed and then used to give a d-dimensional analogue to the representation of additive functiouals of one-dimensional Brownian Motion with respect to local time.     

Forecasting interest rate swap spreads using domestic and international risk factors: evidence from linear and non‐linear models

This paper explores the ability of factor models to predict the dynamics of US and UK interest rate swap spreads within a linear and a non‐linear framework. We reject linearity for the US and UK swap spreads in favour of a regime‐switching smooth transition vector autoregressive (STVAR) model, where the switching between regimes is controlled by the slope of the US term structure of interest rates. We compare the ability of the STVAR model to predict swap spreads with that of a non‐linear nearest‐neighbours model as well as that of linear AR and VAR models. We find some evidence that the non‐linear models predict better than the linear ones. At short horizons, the nearest‐neighbours (NN) model predicts better than the STVAR model US swap spreads in periods of increasing risk conditions and UK swap spreads in periods of decreasing risk conditions. At long horizons, the STVAR model increases its forecasting ability over the linear models, whereas the NN model does not outperform the rest of the models. Copyright © 2007 John Wiley & Sons, Ltd.     

Simulation对一种测平小车控制系统的仿真

本文首先简要提出构造一辆测量路面平整度的方法,对其核心器件进行概述,然后应用MAT LAB中的仿真终端Simulation对此小车的控制系统进行仿真并给出相应的仿真结果,围绕此仿真结果对控制系统的各项性能指标进行了研究分析.     

一个边界振荡的台球模型

研究了一种边界周期振荡的台球模型，使台球场在半圆和略小于半圆之间周期转换，解析地导出了描述这个经典台球系统动力学行为的映象方程．对台球仅在半圆和略小于半圆的台球场内无耗散运动的2种极端情况进行了解析与数值分析，说明这2种情况下台球都呈现典型的保守系统特征．初步数值研究表明，边界周期振荡的模型会显示耗散的特征．     

汽车扭杆悬架及转向梯形运动学研究

本文针对某轻型客车前轮早期磨损问题对汽车扭杆弹簧双横臂前独立悬架及转向梯形机构进行了运动学分析。精确计算了转向轮在任意位置时的各项运动参数,编制了系统运动学特性分析程序,对某轻型客车进行了分析计算,指出其不合理之处,提出了修改意见。