灰度人脸识别形态学相关的一般理论研究

提出一般形态学相关概念,并提出一种小型联合变换相关器的硬件设计以实现一般形态学相关.提出两种改进的一般形态学相关算法,灰度图像按某种分解方法分解成一系列二值图像片.在第一种算法中,每片二值联合图像片的边缘被检测,其功率谱求和.在第二种算法中,一种情况是每片的联合变换功率谱被二值化或细化再求和;另一种情况是这些片的联合变换功率谱的总和被二值化或细化.计算机模拟结果表明,改进后的算法能改善高相似度灰度人脸图像识别的鉴别率.     

空地激光通信系统中捕获子系统仿真

针对空地激光通信系统,推导了复合光栅螺旋扫描捕获方法所需的最大捕获时间、平均捕获时间和捕获概率的计算公式,建立了捕获性能仿真模型,分析了捕获时间和捕获概率的关系,以及空中平台的相对速度对捕获系统的影响和抑制方法.仿真结果表明,当通信终端的捕获不确定区域为50mrad,扫描重叠因子为0.12时,捕获探测器的信噪比大于6时,空地激光通信系统总的捕获概率优于95%,最大捕获时间约为36s,平均捕获时间约为12s.     

方位远探测声波测井仪数据采集控制软件设计*

方位远探测声波测井技术在近年来得到了快速发展,数据采集控制软件是测井仪器系统的重要功能模块,其主要功能是完成地面采集控制平台与井下仪器的实时命令控制与数据传输。方位远探测声波测井仪数据采集控制软件模块以仪器库的形式挂接到成像测井系统,软件主要由仪器初始化、数据采集、数据分析及处理、仪器参数设置、下发命令封装、文件操作、实时波形绘图显示、实时波形处理、数据回放、帮助系统等部分组成。在程序设计中采用了多线程编程技术,提高与测井主控平台进行交互的时效性以及程序的响应速度。实验室及现场测试表明,方位远探测声波测井仪数据采集控制软件的总体及各个功能模块运行稳定,能够完成现场应用过程中对仪器的控制、数据读取、数据分析及处理、文件记录以及与现场测井采集控制平台的数据接口等需求,为仪器的进一步功能优化升级和现场应用提供了基础。     

Optimized projections for compressed sensing via rank-constrained nearest correlation matrix

Optimizing the acquisition matrix is useful for compressed sensing of signals that are sparse in overcomplete dictionaries, because the acquisition matrix can be adapted to the particular correlations of the dictionary atoms. In this paper a novel formulation of the optimization problem is proposed, in the form of a rank-constrained nearest correlation matrix problem. Furthermore, improvements for three existing optimization algorithms are introduced, which are shown to be particular instances of the proposed formulation. Simulation results show notable improvements and superior robustness in sparse signal recovery.     

空间光束实时捕获、跟踪实验与分析

提出一种空间光束捕获、跟踪设计方案,在实验室条件下实现其主要功能,并对其定位精度和实时性进行了分析,结果表明：信标光定位处理的时间为25 ms,角度测量的相对误差为1.3％,显示出良好性能.同时,为由理论分析到实际星载PAT系统提供试验依据.     

连续值域信息系统的规则提取与知识约简

研究连续值域信息系统的规则提取和知识约简，给出规则提取的完整方法和2种新的知识约简的概念，讨论各种协调集之间的关系，探讨系统允许误差变化对规则提取的影响。     

基于单相机-双棱镜的小型三维指纹获取系统

提出了一种小型非接触式三维指纹获取系统.该系统采用单个CCD相机作为图像传感器,利用相机镜头结合双棱镜的成像装置在单帧CCD图像上获得立体图像对,再基于立体视觉原理重建三维指纹.整个系统封装后尺寸为12 mm×12 mm×10 mm.基于该系统进行了指纹获取实验,测量的均方根误差为0.022 mm.该系统操作简单且结构紧凑,为三维指纹的获取提供了一种小型化方案.     

Acquiring new use of multiplication through classroom teaching: an exploratory study

This article analyzes the process in which pupils acquire new uses of multiplication to measure area. Behaviors of five 4th-grade pupils in a series of lessons on areas were studied in depth by qualitative case-study methodology. Their use of multiplication changed as the lesson evolved, characterized conceptually as “using multiplication as a label,” “using it positively to approach problems which have not been solved before,” and “using it effectively to achieve the goal of measuring areas.” These three phases show the pupils’ understanding of multiplication in the context of measuring areas from a secondary accompaniment to a powerful tool of thinking. The phases observed and the students’ progress between the phases differs noticeably among the pupils. Factors that foster learners’ progress are investigated by comparing their behaviors.     

Optimal acquisition and production policy in a hybrid manufacturing/remanufacturing system with core acquisition at different quality levels

We study the acquisition and production planning problem for a hybrid manufacturing/remanufacturing system with core acquisition at two (high and low) quality conditions. We model the problem as a stochastic dynamic programming, derive the optimal dynamic acquisition pricing and production policy, and analyze the influences of system parameters on the acquisition prices and production quantities. The production cost differences among remanufacturing high- and low-quality cores and manufacturing new products are found to be critical for the optimal production and acquisition pricing policy: the acquisition price of high-quality cores is increasing in manufacturing and remanufacturing cost differences, while the acquisition price of low-quality cores is decreasing in the remanufacturing cost difference between high- and low-quality cores and increasing in manufacturing and remanufacturing cost differences; the optimal remanufacturing/manufacturing policy follows a base-on-stock pattern, which is characterized by some crucial parameters dependent on these cost differences.     

Diffusion tensor encoding schemes optimized for white matter fibers with selected orientations

A method to produce gradient encoding schemes that minimize the noise of diffusion tensor imaging (DTI) indices for selected fiber orientations has been developed. The accuracy of DTI measurements depends on the gradient encoding scheme used. Most current acquisition schemes contain diffusion directions uniformly distributed in 3D space in order to provide equal noise levels for fibers in any orientation. However, when considering specific fiber bundles such as the corticospinal tract (CST) or parts of fiber bundles, the range of fiber orientations of interest may be limited. We hypothesized that, when studying fiber tracts with a limited range of orientations, measuring diffusion in directions that are uniformly distributed in 3D space may be suboptimal for the noise levels of various DTI indices. Therefore, we first used simulations to determine six diffusion directions that minimize the noise of DTI measurements for selected fiber orientations. The resulting optimized set of directions was then tested on the right CST of a healthy human subject, and its performance was compared with that of conventional acquisition strategies. Both the simulations and the experiments on the human subject demonstrated that the new scheme significantly reduced the standard deviation of DTI indices for tensors with primary eigenvectors within a selected range of orientations.