差分法

A kind of acoustic phased arc array transmitter was designed for azimuthal radiation. 3D Finite difference method was used to calculate acoustic field in borehole formation generated by the acoustic phased arc array transmitter in fluid-filled borehole.

设计一种具有方位辐射特性的声波测井相控圆弧阵声波辐射器，采用三维有限差分法对其在井旁地层中产生的声场进行了数值模拟。

An acoustic phased arc array transmitter with azimuth radiation was designed. The acoustic field generated by the acoustic phased arc array transmitter in the borehole formation was simulated using the 3D finite difference method.

设计了一种具有方位辐射特性的声波测井相控圆弧阵声波辐射器，采用三维有限差分法对其在井旁地层中产生的声场进行了数值模拟。

A mathematical model of the direct chill casting process for superlight Mg-Li alloy (LA141) slab has been developed using the finite differential method. Thermal boundary conditions including primary and secondary cooling conditions, have been selected based on knowledges of the physical process and the literatures. The variations of heat transfer coefficient between slab and dummy block interface resulting from the deformation of the slab have been considered.

中文摘要：运用有限差分法，对超轻Mg-Li合金（LA141）板坯直冷连铸过程温度场进行数值模拟，根据实际过程的物理现象以及文献资料确定包括一冷区、二冷区在内的边界条件，并且考虑底模与铸坯之间随着铸坯的变形而引起的换热系数的变化。

Fourth, systematic study on dynamic buckling of axial compression initial bending member through finite difference method, considered residual stress simultaneously, make some valuable conclusions.

然后，通过有限差分法对初始几何缺陷轴心受压构件的动力屈曲进行计算，并同时考虑残余应力作用，得到了一些有价值的结论。

To this end, a numerical approach combined by the finite element method for magnetic fields and the finite difference method for deflection of the microsensor is proposed to analyze quantitatively the deflection under magnetoelastic interaction.

为此，建立了由有限元方法分析磁场与有限差分法计算挠曲变形相结合来计算其结构在磁场中产生磁弹性变形的定量分析程序。

Science and Technology, Nanjing 210094, JiangsuAbstract : The carbon gradient of carburized case of parts can be predicted by using the finite difference method.

摘 要：零件渗碳后渗层的碳浓度分布可以用有限差分法预测，而碳浓度的高低决定了工件淬火后的硬度。

To investigate the detecting capability of GPR in the dispersive medium, we propose a Finite Difference Time Domain method to solve Maxwells equations. We give an iterative method for calculation of the electrical displacement and magnetic fields in the Debye medium, and a method to compute the electric field from electrical displacement.

为了研究地质雷达在频散介质中的探测能力，提出了频散介质中时间域有限差分法计算麦克斯韦方程的方法，给出了满足Debye关系的频散介质中的电位移和磁场的迭代算法，以及由电位移计算电场的算法。

Application and improvement of finit-difference time-domain algorithm in the analysis of optical waveguides.

时域有限差分法在光波导分析中的应用及改进。

ABSTRACT This thesis is a study of FDTD (Finite-Difference Time-Domain) method and its application to the problems of electromagnetic scatt...

本论文论述了时域有限差分法以及该方法应用于各向异性复合材料散射问题仿真的研究。

According to the function of distributed emulator, optical information processing and image multi-object tracking system, the following three aspects were emphasized in this dissertation. Firstly, a vast virtual terrain, ground radar models and canyons were created for the distributed emulator with modeling software Creator. The radars were driven to scan during emulating and the real time terrain code was sent to Radar module. Secondly, an optics channel simulating the optics camera of a virtual aircraft was implemented with simulating software Vega. The 2-D information got from the channel was translated and sent to multi-sensor information fusion system as an optics information source. Thirdly, the dissertation studied some motion estimation methods and analyzed the factors which influence the speed and the precision of the block matching algorithms. Then an improved block matching method was proposed for image multi-object tracking system and applied in the system combined with frame difference method.

论文根据多传感信息融合实验系统中的分布式飞行仿真系统、光学信号处理器和图像多目标跟踪系统三个子系统的功能要求，具体完成了以下三方面的工作：首先利用建模软件Creator创建分布式飞行仿真系统中的大面积地形、场景中的地面雷达模型和峡谷地形，并在仿真过程中实时驱动雷达模型的扫描，同时为后续雷达仿真模块提供实时地形编码；其次利用仿真软件Vega，在分布式仿真系统中为光学信号处理器设计实现了光学通道，模拟飞行器的光学摄像机的功能，并且对由此通道获得的目标二维光学信息进行转化处理，作为光学信息源发送给后续的多传感信息融合器；最后针对图像多目标跟踪系统，在研究图像分割运动估计算法的基础上，通过分析影响块匹配算法速度和精度的因素，改进了块匹配运动估计算法，结合差分法可应用到目标跟踪系统中。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。