Smart Antenna for Indoor Millimeter Wave Communication

The following paper introduces a smart antenna system with MUSIC algorithm for indoor millimeter wave communication. The smart antenna system separates main transmission paths towards receiver by antenna array. Maximal-ratio combination (MRC) of the separated transmission paths provides nearly optimal performance of receiver. Multipath distortion and noise can be greatly reduced by the system.     

应变异质外延生长中的自组织纳米结构

具有纳米尺度的三维岛的阵列能在有应变的外延生长薄膜上自组织生长，包括反量子点和量子分子在内的其他结构在合适的生长或退火条件下也被观测到。讨论了有关这些纳米结构自组织生长的动力学蒙特卡罗模拟计算中的最新进展。     

双光栅衍射消色散成像实验图像的处理

针对双光栅衍射消色散成像实验现有图像处理程序要求图像对称造成的实验操作难、测量误差大的问题,通过分析图像数据在计算机中的存储情况,提出了改进算法,该算法可实现非对称实验图像的处理,降低了实验操作难度,提高了实验测量精度。     

Besov类上的贪婪算法

我们讨论了Besov类MBpr,θ上的相应于张量积小波词典Wd的最佳m-项 逼近问题,证明了其最佳m-项逼近的阶可以通过简单的贪婪算法得到.     

球形阵列自适应网格分层定位算法

刚性球形传声器阵列可以在无空间模糊的条件下进行球谐域数据处理,基于球形阵列的可控波束形成器导向响应功率(SRP)算法定位精度高,但是计算量大,计算效率低。通过将球面致密的全局网格搜索替换为分层搜索策略可以有效减小SRP算法的计算量。提出MRE-SRP算法保持球形阵列SRP定位精度的同时降低计算量,首先通过球谐域MUSIC(SH-MUSIC)算法判断入射声源的数量减小搜索区域;其次将相对熵模型引入球谐域SRP(SH-SRP)定位算法中,提取网格分层前后的信息增益,设计自适应网格选择判据,实现分层多分辨率网格的精准再细分,从而降低计算量。实验验证了所提出算法的性能,结果显示在单双声源定位中,该算法可以实现较高的定位精度,精准选择分层网格,计算量减少75%以上。     

Near field imaging of small isotropic and extended anisotropic scatterers

In this paper, we consider two time-harmonic inverse scattering problems of reconstructing penetrable inhomogeneous obstacles from near field measurements. First, we appeal to the Born approximation for reconstructing small isotropic scatterers via the MUSIC algorithm. Some numerical reconstructions using the MUSIC algorithm are provided for reconstructing the scatterer and piecewise constant refractive index using a Bayesian method. We then consider the reconstruction of an anisotropic extended scatterer by a modified linear sampling method and the factorization method applied to the near field operator. This provides a rigorous characterization of the support of the anisotropic obstacle in terms of a range test derived from the measured data. Under appropriate assumptions on the material parameters, the derived factorization can be used to determine the support of the medium without a priori knowledge of the material properties.     

激光微加工制作的微光纤珐-珀加速度传感器

将157nm激光微加工制作的微光纤珐-珀腔贴于悬臂梁结构构成加速度传感器。通过设计特定的悬臂梁结构和FFT方法,该加速度传感器的分辨率约为1．13mg／HZ1/2。通过采用MUSIC算法处理信号,信噪比可提高45dB,系统分辨率约为3．56×10^-2μg／Hz1/2。该微光纤珐一珀传感器具有可批量制作、成本低、抗高温、量程灵活等优点,有望应用于石油勘探、地震测量等领域中。     

基于Group Lasso的多重信号分类声源 定位优化算法*

多重信号分类算法因其抑制噪声能力强、计算速度快等优点,在声源定位领域得到广泛应用。但该算法在中低频段分辨率及聚焦性能较差。针对该问题,提出一种基于Group Lasso的多重信号分类优化算法。该算法将多重信号分类算法输出值作为初始值,并在Group Lasso算法组间计算时对目标信号进行稀疏、在组内计算时对该组信号进行平滑及阈值截断。仿真结果表明:该优化算法在中低频段可明显提高多重信号分类算法分辨率,同时改善因扫描位置与声源面位置不重合引起的聚焦性能下降问题。     

Music algorithm for locating point-like scatterers contained in a sample on flat substrate

In this paper, we consider a MUSIC algorithm for locating point-like scatterers contained in a sample on flat substrate. Based on an asymptotic expansion of the scattering amplitude proposed by Ammari et al., the reconstruction problem can be reduced to a calculation of Green function corresponding to the background medium. In addition, we use an explicit formulation of Green function in the MUSIC algorithm to simplify the calculation when the cross-section of sample is a half-disc. Numerical experiments are included to demonstrate the feasibility of this method.     

有限平面点集强可见点对的O(n~2logn)算法

1引言计算机图形可见性问题是离散计算几何、计算机图形学、模式识别等研究与应用领域中的一个重要问题~[1-2],关于有限平面点集强可见点对的几何结构以及结构以及应用在文献[3]中有较