均衡化特征匹配的非刚体细胞形态跟踪

提出利用均衡化特征匹配来进行非刚性细胞形体跟踪的方法。采用重启动的随机游走方法建立并求解特征匹配概率模型,利用双向均衡方法对匹配邻接矩阵进行均衡化处理,得到指定目标与待跟踪目标之间的精确匹配,以获得目标的定位跟踪结果。同时利用特征匹配结果进行目标的自动标定,并应用图像分割方法进行目标的精确轮廓跟踪。实验结果表明,将该方法应用于视频中动态背景下的运动细胞形态跟踪时,在背景相似度较高及目标迅速移动的条件下,表现出了良好的性能,与同类方法相比可获得较高的定位精度以及更为准确的目标轮廓。     

霍夫空间中多足球机器人协作目标定位算法

针对嵌入式仿人足球机器人提出一种霍夫空间中的多机器人协作目标定位算法。机器人利用实验场地中的标志物采用基于三角几何定位方法进行自定位,把机器人多连杆模型进行简化,通过坐标系位姿变换把图像坐标系转换到世界坐标系中,实现机器人目标定位;在多机器人之间建立ZigBee无线传感器网络进行通信,把多个机器人定位的坐标点进行霍夫变换,在霍夫空间中进行最小二乘法线性拟合,获取最优参数,然后融合改进后的粒子滤波实现对目标小球的跟踪;最后在21自由度的仿人足球机器人上进行仿真和实验。数据结果表明,这种多机器人协作的定位算法的精度提高了约48%,在满足实时性的前提下,对目标的跟踪效果也得到了改善。     

基于INS定位和WIFI指纹定位技术的无人机室内定位方法研究

针对无人机室内定位问题,提出了一种基于惯性导航系统（INS）和WIFI指纹定位技术的四旋翼无人机的室内定位方法。该方法首先利用WIFI模块测量的信号接收强度信息,根据WIFI指纹定位原理求出该定位时刻下的无人机位置;同时,利用惯性传感器信息计算出INS定位下的无人机位置,结合两种定位结果得出更为精确的位置。最后,通过实验验证了INS定位和WIFI指纹定位相结合的无人机室内定位方法的有效性,且该方法较两种单独定位方法的定位精度更高。     

图像中的文本定位技术研究综述

介绍了图像中文本定位技术的研究现状,依据定位所利用的特征进行分类,分析了其中几种典型算法,并对文本定位算法的性能评价标准进行了深入讨论。     

Elucidation of the Clustered Nano-Architecture of Radiation-Induced DNA Damage Sites and Surrounding Chromatin in Cancer Cells: A Single Molecule Localization Microscopy Approach

In cancer therapy, the application of (fractionated) harsh radiation treatment is state of the art for many types of tumors. However, ionizing radiation is a “double-edged sword”—it can kill the tumor but can also promote the selection of radioresistant tumor cell clones or even initiate carcinogenesis in the normal irradiated tissue. Individualized radiotherapy would reduce these risks and boost the treatment, but its development requires a deep understanding of DNA damage and repair processes and the corresponding control mechanisms. DNA double strand breaks (DSBs) and their repair play a critical role in the cellular response to radiation. In previous years, it has become apparent that, beyond genetic and epigenetic determinants, the structural aspects of damaged chromatin (i.e., not only of DSBs themselves but also of the whole damage-surrounding chromatin domains) form another layer of complex DSB regulation. In the present article, we summarize the application of super-resolution single molecule localization microscopy (SMLM) for investigations of these structural aspects with emphasis on the relationship between the nano-architecture of radiation-induced repair foci (IRIFs), represented here by γH2AX foci, and their chromatin environment. Using irradiated HeLa cell cultures as an example, we show repair-dependent rearrangements of damaged chromatin and analyze the architecture of γH2AX repair clusters according to topological similarities. Although HeLa cells are known to have highly aberrant genomes, the topological similarity of γH2AX was high, indicating a functional, presumptively genome type-independent relevance of structural aspects in DSB repair. Remarkably, nano-scaled chromatin rearrangements during repair depended both on the chromatin domain type and the treatment. Based on these results, we demonstrate how the nano-architecture and topology of IRIFs and chromatin can be determined, point to the methodological relevance of SMLM, and discuss the consequences of the observed phenomena for the DSB repair network regulation or, for instance, radiation treatment outcomes.     

Analysis of damage localization for ductile metal in process of shear band propagation

1 Introduction Shear localization is an important and often dominating deformation and failure mechanism for Ti and Ti alloy in dynamic loadings[1—10]. The eventual outcome of localized deformation is ductile rupture and material separation. Shear locali…     

基于并查集和边缘检测模板的非理想虹膜定位

非理想虹膜图像往往存在虹膜边缘模糊、灰度变化不均匀、位置偏移及光斑干扰等问题, 这些问题的存在会在一定程度上影响虹膜内、外边界定位的准确率. 针对这个问题, 本文提出采用并查集和边缘检测模板的方法来对非理想虹膜进行内、外边界定位. 内边界定位是首先采用并查集方法完成瞳孔区域粗定位, 然后采用Hough变换对瞳孔进行精确定位; 外边界定位是先利用一系列边缘检测模板大致确定外圆的位置, 然后再依据外边界附近圆环内边缘点的密度来最终完成外边界的精确定位. 实验结果表明, 对于非理想虹膜图像, 本文方法的定位正确率和定位速度均高于其他同类方法.     

Chemical properties of femoral gland secretions in the desert iguana,Dipsosaurus dorsalis

This study investigates the chemistry of femoral gland secretions in the desert iguana,Dipsosaurus dorsalis (Lacertilia: Iguanidae), and discusses their possible functional significance. Electrophoretic and proton NMR studies indicated that the secretions are composed of approximately 80 % protein and 20% lipid material. Individual differences in polyacrylamide gel banding patterns of femoral gland proteins were found. Reflectance spectroscopy revealed that the secretions strongly absorb longwave ultraviolet light, a feature that may be important in the localization of secretion deposits in the environment.     

一种基于SBL和APIT的混合定位算法

由于子区域分割粒度的限制,基于阶次序列的定位算法(Sequence-based localization,SBL)存在边缘区域节点定位误差较大和不能保证平均定位误差性能的问题。针对这些问题,提出了一种基于SBL和APIT的混合定位算法,利用APIT信标三角形切割SBL算法子区域,减小子区域面积,实现了分割粒度的细化。通过预先进行系统训练,优化了混合算法的加权系数,进一步提升了算法的定位精度。仿真结果表明,相比于原算法,所提出的混合算法有效地提升了边界区域节点的定位精度,其平均定位误差降低了17.9%,使基于阶次序列的定位算法的定位精度得到了有效改善。