特征参数

Wide baseline correspondence problem was solved by rendering intermediate image.

算法采用合成中间图像的技术解决两图像特征点间的宽基线匹配问题，并应用扩展卡尔曼滤波器对参数估计结果进行平滑，以消除系统抖动现象。

The model takes into account the flow and physical property characteristics of the systems as well as geometric variables such as corrugation angle.

根据质量和动量守恒原理，考虑下降液膜和气相的相互作用、系统内气液两相流动、物性特征以及填料结构参数对压降的影响，提出了填料塔内规整填料的压降模型。

Based on the analysis for the dynamic characteristics of semi-rigid steel frames with simple or multiple degree-of-freedoms,effects of rotation stiffness of beam-to-column connections on the structure period,frequency,critical damping and mode of vibration are discussed.

通过对单自由度体系和多自由度体系半刚接钢框架的动力特征分析，初步探讨了梁柱连接转动刚度对结构自振周期、频率、临界阻尼以及振型等参数的影响。

All the local 3D world coordinates of the control points falling on two light stripe planes can be readily obtained by the invariance of the cross ratio.

利用构建的分别位于两个光平面上标定特征点，可以实现工作状态的十字结构光传感器参数的优化估计。

But due to the commonstructure characteristic of the segmented copolymers, the ratio of 〓 is still aneffective parameter to predict the crystallizability of the two segments in limitedenvironment.

虽然这个确切的比值对聚醚酯多嵌段共聚物不具有普遍意义，但是由于聚醚酯多嵌段共聚物共同的结构特征，软硬链段之间的相对长度仍是一个反映两种链段结晶能力的一个很有用的参数。

The paper simulates the mechanical behavior of plant stalk for cup equations are modified by experiments of corn stalk, was adopted to describe the rheological properties of the material.

为了搞清植物秸秆杯型容器成型过程中的力学变形特征和流动规律，确定模具参数对成型的影响，同时为模具设计和制造提供依据。

This algorithm changes the detect points on the target trajectory to the respective curve in parameter space, which takes full advantages of the target detect data in a certain period, and the trajectory characteristics can also be picked up even under low SNR.

该算法把航迹上的观测点变换为参数空间的对应曲线，充分利用一段时间内的目标观测数据，在低信噪比下也能从背景噪声中提取目标的航迹特征，提高了声呐的检测概率，且对部分信息和数据的缺失不敏感。

Detailed studies are made as follows: Searching the key internal factors which can affects slope stability. According to the geological data which was gained by exploration investigation, establishing a geological model which can reflect rock mass characteristics;With analyzing the internal and exterior factors synthetically, the deformation and possible failure mechanism and mode of the cut slopes was confirmed which combines with stereoic projection and other techniques;The stabilities of the 14 high slopes are estimated synthetically by applicable design codes and guidelines. With the estimate result and some other analysis methods, the rock mass mechanical parameters of slope are identified;As a results, 14 high slopes fall into 4 categories based on rockmass characteristics and discontinuities. The stability and deformation of some typical slopes was analyzed with distinct element method by UDEC;The safety factor of some dangerous slopes are calculated by rigid limiting equilibrium method for coMParison.

首先着重研究影响边坡稳定性的内在因素，主要是通过地质勘探、测量、现场观测等手段取得研究区地质体的基础地质资料，建立起能够反映地质体结构特征的地质模型；随后综合分析潜在的内外部影响因素，并结合赤平投影对边坡可能的失稳模式或破坏机制作出判断；运用已有岩体质量分类方法对沿线14个高陡边坡稳定性进行初步的评价，并结合试验研究、经验判断、工程类比等手段确定了坡体的岩体力学参数；根据稳定性初步评价结果将研究区14个高陡边坡按开挖方式分为4大类，并利用离散元程序UDEC对各类典型高陡边坡进行了稳定性计算分析；对潜在危险边坡利用刚体极限平衡法求出了不同工况下的安全系数。

The effect of tribology factors on bearing vibration is studied experimentally. AR model and WPT are used to processing the normal arid abnormal signals. The results are as follows:1. The vibration of ball bearings is caused by the tribology action of contact pairs of ball and ring races and has the essential of tribo-dynamics. Any factors affecting the tribology characteristics of contact pairs will affect vibration and noise of bearings consequently.2. Vibration characteristics of bearing keep almostly unchanged with the increasing of axial load expecting the increasing of nature frequencies. When radial load increasing with axial load unchanged, nature frequencies keep unchanged but some new vibration peaks appears in the spectrum.3. Vibration amplitudes are damped and nature frequency are enhanced with sufficient lubrication. Vibration and noise of bearings increase obviously and roar can happen and the contact surfaces scratch slightly under insufficient and unclean lubrication state. Bearing will be disabled in a few minutes without any lubrication.4. Bearing vibration is unstable under low speed. With the speed increasing, the vibration become stable and natural frequencies increase slightly but the amplitudes increase apparently.5. Bearing vibration can be excited only by some harmonics ofwaviness without lubrication and by all harmonics with lubrication based on the theoretical analysis.6. The nature frequencies of ball bearings decrease with the increasing sizes. When international clearance increasing, nature frequencies decrease in radial and increase in axial and angular and the amplitudes increase in radial and decrease in axial and angular. When the number of balls increasing, nature frequencies increase and amplitudes decrease. When the pitch diameter increasing, axial nature frequency increase and others nearly keep no change. When outer race groove curvature radius increasing, nature frequencies increase in radial and decrease in axial and angular and amplitudes keep no change in radial and increase in axial and angular. When inner race groove curvature radius increasing, nature frequencies decrease and amplitudes increase.7. The distortion in amplitude and frequency components of bearing vibration signals picked up by the present probe measurement method is founded and right conclusions cannot be achieved by the signals. When accelerometer is rigidly screwed with steel stud onto a flat outer surface of a ball bearing, vibration signal can be got without distortion and the reliability of research on bearing vibration is assured.8. AR model is suitable for large samples of bearing vibration signals, square root of length of samples can be used as the upper limitation of order determination and the FPE order selection criterion is effective. Many advantages of AR spectrum are founded over the classical based on FFT.9. Time-Frequency analysis is necessary for abnormal noise of ball bearings. WPT overcomes the principle shortcomings of STFT and proved to be a best tool to process the abnormal signals.

理论分析和试验研究表明： 1球轴承振动是钢球—滚道接触副中的各种摩擦学作用引起的，具有摩擦动力学的本质，任何对接触副的摩擦学特性有影响的因素都将对球轴承的振动和噪声特性产生影响； 2中心轴向载荷作用下，载荷增大使球轴承的固有振动频率升高，载荷越大同样的载荷增幅引起的频率升幅减小，足够大的中心轴向载荷作用下载荷的变化对球轴承振动的频率特性不会产生明显的影响； 3轴向和径向联合载荷作用下，径向载荷不大时球轴承振动的固有频率基本不变，但是可能引起变刚度激励的非线性振动，出现新的频峰，过大的径向载荷将使部分钢球脱离接触，使球轴承的振动和噪声呈现不稳定状态； 4润滑对球轴承的振动和噪声特性有重要的影响，良好的润滑对振动有明显的抑制作用，润滑不充分时，振动和噪声的水平会有明显增高，一定条件下还会激发接触副中的谐振，发出啸声，造成接触表面的伤害，无润滑干接触时，短时的运转就会损伤接触副表面，使振动和噪声迅速增大，并随时可能引发严重的磨损和卡滞失效；接触副润滑良好时，油膜的"刚化效应"使球轴承振动的固有频率有所提高，润滑剂中含有弥散性污浊时，振动的幅度总体升高，但弥散性污浊不会改变球轴承振动的频率特性；浙江大学博士学位论文：球轴承振动的研究 5低速时，球轴承振动的基本特征呈现不稳定状态，随着转速的提高，球轴承振动的频率特性趋于稳定，固有频率频峰升高； 6理论分析表明，干接触时钢球和滚道表面波纹度的某些谐波分量能激励球轴承的振动，振动的幅值与谐波幅值成正比，实际球轴承中钢球的分布不可能完全均匀，波纹度的激励作用会随时发生；润滑接触的分析表明，波纹度的任意谐波分量均能激励球轴承的振动； 7球轴承的几何和结构参数分析表明，球轴承尺寸越大，径向、轴向和角振动的固有频率越低；钢球中心圆直径增大，球轴承的径向和轴向振动的固有频率基本不变，角振动的固有频率有所上升，振动的幅频特性基本不变；径向游隙加大使球轴承的径向振动固有频率降低，轴向和角振动的固有频率有所升高，径向振动幅频特性的幅值升高，而轴向和角向降低；钢球的数量增多使球轴承振动的固有频率上升，幅频特性的幅值下降，径向振动的幅值下降最为明显；外圈沟曲率半径系数增大使球轴承径向振动的固有频率升高，轴向和角振动的固有频率降低，径向幅频特性基本不变，轴向和角向幅频特性幅值升高；内圈沟曲率半径系数增大使径向、轴向和角振动固有频率均下降，振动幅频特性的幅值均有升高； 8试验对比表明，传感器采用探针式安装时，由于探针接触副接触特性的影响，钡(量得到的球轴承振动信号有失真，采用专门设计和制作的试验球轴承，以固定式安装加速度计，首次测量得到了球轴承振动的真实信号，通过对振动信号的分析，验证了球轴承振动的理论模型； 9)基于时间序列分析的AR模型适用于大样本球轴承振动信号的分析，以样本长度的均方根值作定阶上界，FPE做判阶准则，给出的AR谱光滑，频率分辨率高，是球轴承振动分析的简便而可靠的手段； 10以时频域分析的小波包变换分析球轴承异音信号能够比较好地定位和聚焦异音发生的时间，时间间隔，频率范围，同样是球轴承振动分析的可靠的手段，可用作球轴承故障诊断技术。

By means of the frequency analysis, the characteristic dynamic response for short and long times were given, respectively, and proved that the otolith sys- tem was a second-order forced damping system with mass, dashpot, and spring.

通过对于系统频率特性的分析，分别得到了耳石层在初始阶段以及最终阶段的系统特征频率响应参数，并证明了耳石系统是一个由内淋巴液和胶质层共同作用的二阶受迫振荡动力学系统。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。