Study on the separation of 100 TeV γ-rays from cosmic rays for the Tibet ASγ experiment

A γ/hadron separation analysis is described for the observed air shower events with primary energy above 100 TeV based on the Tibet AST detector configuration. The shower age and size parameters are fitted from the measured lateral density distribution and used as discrimination variables. According to the MC simulation while taking into account the systematic uncertainty estimated from data and MC comparison,it is found that 70% of the cosmic ray (CR) background can be rejected while more than 78% of the γ-rays can be retained. Sensitivity for 100 TeV γ-rays observation can thus be improved by at least 40%.     

Simplification of I-Vector Extraction for Speaker Identification

The identity vector (i-vector) approach has been the state-of-the-art for text-independent speaker recognition,both identification and verification in recent years.An i-vector is a low-dimensional vector in the socalled total variability space represented with a thin and tall rectangular matrix.This paper introduces a novel algorithm to improve the computational and memory requirements for the application.In our method,the series of symmetric matrices can be represented by diagonal expression,sharing the same dictionary,which to some extent is analogous to eigen decomposition,and we name this algorithm Eigen decomposition like factorization (EDLF).Similar algorithms are listed for comparison,in the same condition,our method shows no disadvantages in identification accuracy.     

视觉传感网络中身份特征自适应识别算法改进

在对视觉传感网络中身份特征进行识别时,容易受到人脸表情、光照条件及遮挡等干扰,降低了身份特征识别精度.提出了一种基于改进最小灰度差树的身份特征自适应识别算法.对待识别图像进行灰度处理后,利用最小灰度差数增强待识别图像的质量;定义基于灰度的代价函数,获取待识别人脸图像和指定人脸图像对应的各灰度对的匹配代价,建立最小灰度差树模型,计算两幅图像相似度后,直接采用最近邻匹配算法获取和视觉传感网络注册图库中最小匹配代价对应的图像身份,将其看作待识别身份,实现视觉传感网络中身份特征自适应识别.仿真实验结果表明,所提算法具有很高的身份识别精度.     

基于图像处理的二维条码技术的应用

本文针对陕西省边防检查机关验放旅客由人工处理信息的现状,提出了基于二维条码技术的自动识别与传输方案,设计并实现了条码技术在出入境人员申报系统中的应用。本系统极大地简化了边检工作流程、提升了服务水平,是实现电子政务建设的一次有力推动。     

Characterising indoor positioning estimation using experimental data from an active RFID-based real-time location system

Indoor positioning has attracted much research effort due to many potential applications such as human or object tracking and inventory management. Whilst there are a number of indoor positioning techniques and algorithms developed to improve positioning estimation, there is still no systematic way to characterise the estimation. In this paper, we propose a method comprising of three characteristics to characterise indoor positioning estimation. We conducted experiments on an active radio frequency identification (RFID)-based real-time location system in different environmental conditions. We used both a human and a robot to traverse two experimental areas and collected positioning results at different fixed points along the traversal path. Using this basic positioning data, we were able to characterise positioning estimation using three characterisations: position accuracy, centroid consistency and angular distribution. We demonstrate the use of these characteristics for examining different points in a travelling path and different measurements.     

网格环境下信任机制的研究

本文介绍了网格环境下信任机制的重要性,给出了信任的定义、特性和分类,并重点描述了行为信任机制的研究方法。文章最后给出了行为信任机制在网格环境下的典型应用场景。     

一种面向Deep Web数据源的重复记录识别模型

重复记录是指描述现实世界中同一实体的不同的记录信息。由于从同一个领域的不同Deep Web数据源中抽取的记录信息通常存在许多重复记录,本文针对半结构化的重复记录的识别进行研究。在已知全局模式和全局模式与各Deep Web数据源查询接口映射关系的基础上,提出了一种重复记录识别模型。 基于从Deep Web中抽取出的半结构化的数据,采用查询探测方法确定所抽取数据所匹配的属性,通过分析抽取的实例数据确定属性重要度,结合多种相似度估算器和多种算法计算记录间的相似度,进而识别重复记录。实验表明,该重复记录识别模型在Deep Web环境下是可行且有效的。     

基于参数估计的降晰函数辨识及图像复原算法

成像系统的点扩展函数(PSF)以及观测噪声,在一般应用过程中是未知信息,因此,点扩展函数的辨识是一个具有挑战性的世界难题.为解决实际工作中遇到的在已知降晰类型情况下的降晰函数辨识和降晰图像复原问题,提出了基于参数估计的降晰函数辨识及降晰图像复原算法.首先,由初始猜测给定降晰函数参数的变化范围和参数的增量步长;然后,最小化降晰图像和由相应点扩展函数及降晰图像得到的实验观测图像的差的Frobenius范数,以确定点扩展函数的参数,进而确定降晰图像的点扩展函数并对降晰图像进行复原.应用基于Wiener滤波的频域循环边界算法对降晰图像进行复原.实验结果表明:在降晰图像信噪比较高的情况下,降晰函数的辨识结果是可靠和准确的,有较好的复原效果.     

单兵识别系统的现状与发展

阐述了发展单兵识别系统的必要性,对比分析了国外单兵识别系统的优劣和目前主要的单兵识别手段,提出了采用毫米波体制的单兵识别系统的思路,以及设计该系统必须突破的关键技术,以期能对从事该系统研究的相关人员提供参考.     

生物识别技术及其军事应用前景

生物识别代表身份识别技术的未来方向,近年来发展迅速。文中对生物识别技术本身仅作简单介绍,文章侧重于生物识别技术在军事领域的应用前景,以及近年来生物识别技术在外军的一些重要研发及装备动态,最后提出了生物识别技术的一些未来研究方向。