费马原理

In this thesis, sound wave path equation is derived from Fermat's theorem and the calculus of variations, and then the temperature field is reconstructed by the combination least-square method and the modified sound wave path.

本文通过求解由费马定理和变积分原理确定的声波路径方程，结合最小二乘法实现了声波路径的修正。

Fermat's principle is not so much a computational device as it is a concise way of thinking about the propagation of light.

费马原理更多的是对光的传播的一种简明看法，而不是一种计算工具。

A numerical ray-tracing algorithm is provided based on Fermat＇s principle.

并基于费马原理，提出了记录光路的光线追迹数值算法。

The path which a seismic ray takes according to Fermat's principle.

最短时程：满足费马原理的地震射线路径。

Based on Fermat's principle and light path function, it gets the spectral distribution of the incident rays, and it can get the ray tracing map through a matrix method.

在费马原理的基础上利用光程函数法得到入射光通过光栅后的光谱分布情况，再使用传输矩阵的计算方法构造出光谱的点列图。

Fermat's principle ; ray tracing ; spline function ; gradient method ; target method

费马原理；射线追踪；样条函数；梯度法；打靶法

Based on Fermat's principle, the paper uses full-path iterative algorithm to realize 3-D VSP two-point ray tracing in volume element model.

本文基于费马原理，利用全路径迭代算法实现体元模型中的三维VSP两点射线追踪。

First,using cubic spline function to describe the geologic model in detail,then using fermat's principle to introduce deferential form for a set of raypath equations.

首先利用三次样条函数详细描述地质模型，根据费马原理导出微分形式的射线路径方程组。

Fermat's principle: The raypath which seismic energy will follow between two points is that for which the first order variation with all neighboring paths is zero.

费马原理：两点之间地震波传播的射线路径，它与相邻路径的一阶差分为零。

In the modeling of recording optics, the main contents of this thesis are: deriving the fourth-order analytical model for the recording optics with auxiliary spherical mirrors and auxiliary uniform-line-spacing plane gratings, providing the numerical ray-tracing models based on Fermat's principle and local search, and analyzing the expansion errors of analytical models.

本文在记录光路建模方面的主要工作是：针对使用辅助球面镜与辅助等间距平面光栅的两种记录光路，推导了四阶解析模型，给出了基于费马原理与局部搜索的光线追迹数值模型，并分析了解析模型的展开误差。

On the other hand, the more important thing is because the urban housing is a kind of heterogeneity products.

另一方面，更重要的是由于城市住房是一种异质性产品。

Climate histogram is the fall that collects place measure calm value, cent serves as cross axle for a few equal interval, the area that the frequency that the value appears according to place is accumulated and becomes will be determined inside each interval, discharge the graph that rise with post, also be called histogram.

气候直方图是将所收集的降水量测定值，分为几个相等的区间作为横轴，并将各区间内所测定值依所出现的次数累积而成的面积，用柱子排起来的图形，也叫做柱状图。