Concurrent transmission with minimal SR-pair interference in WiMAX mesh networks

Performance of wireless mesh networks can be greatly improved by spatial reuse (SR), therefore, lots of algorithms have been proposed to maximize the number of concurrent transmissions. However, most methods only considered the interference brought by the sender nodes. In this paper, we study the interference model in WiMAX mesh networks and propose a minimal SR-pair interference model to perform concurrent transmissions in both uplink and downlink directions. Simulation results show that our model is more efficient and stable, i.e., it increases the number of concurrent transmissions and its performance is constant and independent of transmission directions. Biography: XIONG Qing(1978–), male, Ph. D., research direction: wireless mesh networks.     

过滤性网渔具网囊网目扩张性能研究

依据渔具模型水槽试验，分析讨论影响网囊网目扩张性能的不同因素的影响机制。通过图像处理和数据分析，观测模型网的水阻力情况和不同情况下网囊网目的扩张情况；确定了不同改进措施下，网囊网目张开角度的变化情况和网囊不同位置网目张开角度的差异性，同时结合网囊水阻力的变化进行分析研究。     

有限单元法的非结构化网格及其自动生成

本文介绍了有限单元法非结构化网格的基本原理及其自动形成方法。由于有限元法是一种离散的数值求解方法，其近似求解方法的精确度，很大程度上取决于所形成网格的质量。另外，对于工程中一些形状复杂的问题，一般的网格生成方法很难对其进行离散。非结构化网格及其自动生成，使复杂形状的工程问题容易地进行离散，改善所形成网格的质量，提高近似计算的精确度，并且在有限元网格修正自适应分析中具有重要作用。     

环己烷氧化过程的模拟和优化

建立了多釜串联环隙内环流反应器中进行的环已烷贫氧化制作取环已醇、环已酮的反应器系统的数学模型．并以此为基础，从具体工业装置出发，进行操作变量调优．以提高目的产物的选择性，实行系统优化．通过计算机程序模拟计算，得到了预期效果．作者还提出了对于此模拟系统的优化问题的一种简捷、有效的算法．经实际算题验证，对于本模拟系统１３个变量的优化问题，较之于网格法，调用模拟系统的次数至少减少５００００倍．     

三方向网格上二元基插值的收敛性及误差估计

本文讨论了平面的三方向正则网格上二元箱样条的基插值及其导数问数,改进和推扩了 dc Boor 及 H(?)llig 等人的结果,然后给出了当“次数趋于无穷”时基插值的收敛性及误差估计。     

瞬态有自由面渗流分析的不动网格──高斯点有限元法

对于瞬态有自由面渗流问题，建立了一种简单、实用的不动网格─—高斯点有限 元法。该法与变网格法及已有的不动网格法相比，计算量小、格式简单。算例表明了 该法的有效性。     

单波谐波传动齿廓干涉的理论分析

齿廓干涉引起单波谐波传动失效的问题迄今没有精确的理论分析方法。该文运用旋量作为数学工具，根据３个基本旋量矩阵导出柔轮上啮合点的坐标方程。运用坐标方程和齿廓不干涉的条件，验算单波谐波传动齿廓的干涉。验算结果可判断设计参数的合理性，为改进设计提供理论依据。     

多天线多信道无线mesh网络的组播研究

在无线多跳mesh网络中，每个mesh节点可以配备多个天线。并利用不同的信道进行通讯，这给组播问题带来了新的挑战．针对这一问题，提出了一种基于组播树的多天线多信道无线mesh网络的组播方案，首次给出了转发信道冗余度的概念，并证明了发现转发信道冗余度最低的组播树是一个NP完全问题．同时给出了一个构造组播树的近似算法，以及基于组播树的抗干扰低延迟组播调度算法．模拟实验结果证明了该算法的有效性．     

多分辨率三角形表及其应用

一个网格模型的多分辨率表示由原模型信息与附加的多分辨率信息组成,由于两者独立存储,所以每次使用一个模型的多分辨率表示时,必须由原模型重新生成。给出了一种网格的多分辨率表示,支持模型渐渐简化、渐进细化及渐渐传输。还给出了这种多分辨率表示的构造方法,通过重新排序网格的三角形表与顶点表的元素,将所有多分辨率信息熔入三角形表之中(称为“多分辨率三角形表”)。由于没有增加任何额外变量,“多分辨率三角形表”仍是原网格的三角形表,一旦被生成后,可以被直接反复地使用。     

Parameterization for fitting triangular mesh

In recent years, with the development of 3D data acquisition equipments, the study on reverse engineering has become more and more important. However, the existing methods for parameterization can hardly ensure that the parametric domain is rectangular, and the parametric curve grid is regular. In order to overcome these limitations, we present a novel method for parameterization of triangular meshes in this paper. The basic idea is twofold: first, because the isotherms in the steady temperature do not intersect with each other, and are distributed uniformly, no singularity (fold-over) exists in the parameterization; second, a 3D harmonic equation is solved by the finite element method to obtain the steady temperature field on a 2D triangular mesh surface with four boundaries. Therefore, our proposed method avoids the embarrassment that it is impossible to solve the 2D quasi-harmonic equation on the 2D triangular mesh without the parametric values at mesh vertices. Furthermore, the isotherms on the temperature field are taken as a set of iso-parametric curves on the triangular mesh surface. The other set of iso-parametric curves can be obtained by connecting the points with the same chord-length on the isotherms sequentially. The obtained parametric curve grid is regular, and distributed uniformly, and can map the triangular mesh surface to the unit square domain with boundaries of mesh surface to boundaries of parametric domain, which ensures that the triangular mesh surface or point cloud can be fitted with the NURBS surface.