查询词典 spherical geometry

This thesis contributes to geometry compression in the following aspects: Proposes a method of progressive spherical mesh parameterization based on local parameterization by directly projecting the deleted vertices to its neighborhood. Based on spherical mesh paramterization, an adaptive subdivision remeshing method by progressivly redistributing of sampling points is proposed, by this means, the main geometry information of the original mesh can be captured with only a small amount of samples, it can also be used in mesh simplification. By regarding attributes binded on mesh vertices as geometry signals and transferring them onto a uint sphere by means of spherical mesh parameterization, meshes with different attributes are compressed with spherical wavelet successfully with high compression rate. As a kind of lossy geometry compression technique, two mesh simplification algorthimes are also presented in this thesis.

归纳起来，本文的主要贡献有：提出了以直接投影局部参数化方法为基础的网格累进球面参数化方法；在网格球面参数化方法的基础之上，提出了一种基于累进优化布点方案的网格细分采样方法，该方法可以用很少的采样点就可以捕获到网格的主要特征，因此我们也将其用于后面的网格简化工作当中；通过将网格顶点上定义的各种属性看成几何信号，并以网格球面参数化为手段将几何信号迁移到单位球面上，从而成功地实现了用球面小波对各种几何信号的压缩；作为一种有损压缩方法，本文还提出了基于统一距离的网格简化算法和基于重采样的网格简化算法。

Then we re-sampling all signals defined on the surface of the original triangle mesh at the vertices of the spherical subdivision mesh and get a set of discrete geometry signals with subdivision topology which can be compressed by using spherical wavelet.

于是，在参数域内位于细分网格顶点处对定义在参数网格表面上的各种几何信号进行重采样，可得到新的具有细分结构的几何信号近似表示原始几何信号，以此满足球面细分小波对处理对象的细分结构要求，从而使得用球面细分小波对几何信号进行压缩得以实现。

The basic principle is based on spherical astronomy and elementary geometry of the trajectory mapping method based on the observation of a celestial body zenith distance, then the ship is located in order to sing the next point as the center of this satellite zenith distance of the ship's position as the radius of the circle, observing the same two objects, or objects at different times of the two observations, we can get two ship's position round, then the ship must have been a point of intersection of two ship's position on the circle.

其基本原理是建立在球面天文学和初等几何中的轨迹作图法基础上的，观测一个天体的天顶距，则航船就位于以星下点为圆心，此星天顶距为半径的船位圆上，观测两个天体或者不同时间同一天体的两个观测值，就可以得到两个船位圆，则航船一定在两个船位圆的一个交点上。

It thinks that Complete Principle of Measurement inherited the Writing Style of Elements. Secondly, it is taken out five key parts——plane geometry, solid geometry, conic, spherical trigonometry and spherical astronomy part——to comprehend. The main contents of mathematics and astronomy involved in Complete Principle of Measurement have been set up respectively in accordance with the characteristics of their subject.

其次，又按照学科分布从中抽出平面几何、立体几何、圆锥曲线、球面三角和球面天文等五部分内容进行重点解读，认为《测量全义》中所涉及到的主要数学和天文学内容已经按照学科特点分别形成和建立起来，为后来西学的进一步传播做出了贡献。

Microsphere material was about 10 μm in diamerter and had good spherical geometry, high monodispersity with nanometer size holes on the surface.

结果 扫描电镜观察示复合材料微球直径约10 μm，单个分散存在，微球表面存在纳米级孔洞。

The annulus model captures the key features of rotating convection in full spherical geometry and has been widely employed to study convection, magnetoconvection and dynamos in planetary systems, usually in connection with the small-gap approximation neglecting the effect of azimuthal curvature of the annulus.

圆环模型被广泛用来研究行星系统的对流，磁对流和发电机。通常在这些研究中用到了小间隙的近似，忽略了圆环的环向曲率效应。我们这一工作用数值模拟方法解完全的非线性对流方程组来研究有限间隙的旋转圆环中的非线性对流。

The solarterrestrial transit process of three successive CMEs during November 4-5, 1998 has been investigated numerically in onedimensional spherical geometry. These CMEs interact with each other while they are propagating in interplanetary space and finally form a "Complex Ejecta".

在一维球坐标系下模拟了1998年11月4日至5日3个连续日冕物质抛射在行星际空间的传播和相互作用并最终形成"复杂抛射"的日地传输过程。

GuoShouJing his ancestors in the Yuan Dynasty in China are well-known astronomer, mathematician, hydraulic engineering experts, he advanced mathematics, spherical geometry, triangulation has become highly literate, living in the home environment such郭伯of jade, from the favorite Math, especially for simpler and quicker abacus, but also aroused the interest of his research, he studies at abacus are enormous achievements, the Qing Dynasty famous mathematician Mei-ting in the "ancient Yan count slightly," Chu said plate of law, began in the early Ming郭伯jade, jade郭伯abacus at laws on the tremendous contribution to the world people have been referred to as "beads set of laws," the creators

他的先辈郭守敬是我国元代著名的天文学家、数学家、水利工程学家，他对高等数学、球面几何、三角都有很高的造诣，生活在这种家庭环境中的郭伯玉，从小就喜爱数学，尤其对简便、快捷的珠算，更引起他研究的兴趣，他在珠算研究上的成就是巨大的，清代著名数学家梅文鼎在《古算衍略》中说珠盘之法，始于明初郭伯玉，郭伯玉在珠算之法上的巨大贡献，被世人人称为"珠盘之法"的创制者

In order to simulate the global characteristics of wave propagation in solar chromosphere-corona, by employing a 2-dimensional MHD simulation subjected to a self-consistent non-isothermal, non-uniform initial state in spherical geometry, we study numerically the global propagation process of disturbances initiated by a pressure pulse implemented at the bottom of chromosphere.

在球坐标中一自洽的非等温非均匀等离子体初态下，应用二维理想磁流体动力学全球模拟，对色球底部压力脉冲引起扰动传播的全球问题进行了数值研究。

It is necessary to find the effects of spherical geometry on surface wave; Based on normal modal summation, the synthetic seismograms corresponding to the fundamental and few higher modes are calculated; Based on surface waveform scattering theory, the scattering surface wave are calculated for three dimensional laterally varying medium.

基于球地球模型计算面波波形，考虑到地球的圆球率，比平地球模型更接近实际；根据简正振型叠加原理计算出基阶和高阶直达面波；用面波散射理论计算出三维非均匀弹性地球模型的散射面波，包含振型转换，与实际更吻合。

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。