半捷联惯性测量系统多路采集数据对齐方法

半捷联惯性测量系统能实时精确测量弹体的各种飞行参数,为常规弹药精确制导提供可能,半捷联惯性测量系统包含两块采集数据的采存模块,当系统运行时,由于两个采存模块采集不同步以及取点不统一导致采集的数据不是实时同步,从而无法对系统测得的数据进行解算,本文提出一个实时对齐方法,利用数据相关性,求出差的平方和的最小值即为最接近的值,实现数据对齐,为后续精确解算奠定基础.     

Ferroelectric liquid crystals: Excellent tool for modern displays and photonics

The ferroelectric liquid crystals, because of their fast electro‐optical response, are one of the most important classes of liquid crystals. Here, in this review, we have summarized the different electro‐optical modes for ferroelectric liquid crystals. Clark–Lagerwall effect (surface stabilized ferroelectric liquid crystal), deformed helix ferroelectric (DHF) effect, electrically suppressed helix (ESH) mode, DHF orientational Kerr effect, and ESH diffraction modes have been discussed. All of the crucial features, that is, optics, electro‐optics, dynamics, and their dependence on material parameters, operational regime, and applications, have been reviewed.     

基于贝叶斯估计的水下机器人罗盘故障检测

以电子磁通门罗盘为例对自主水下机器人(Autonomous Underwater Vehicles,AUVs)传感器故障检测方法展开研究.针对电子罗盘极易受到周围磁场的影响而产生时对时错的数据这一问题,首先联立AUV的运动学和动力学方程得到AUV的全状态非线性模型;然后分析了电子罗盘的误差来源,建立了误差的模型;在此基础上,提出了基于贝叶斯估计的故障检测方法并给出了该方法离散形式的递推迭代公式;最后参照实际使用的电子罗盘的参数和AUV的机动能力,设计了仿真实验和外场试验,通过实验验证了该方法的正确性和有效性.     

Service-Oriented Security Architecture and its Implications for Security Department Organization Structures

ABSTRACT

Cyber-crime and malware has evolved so drastically over the last two years that it is a challenge for an IT professional to stay on top of recent malware trends and technological advances in cyber-security. This paper provides a look from inside the antivirus laboratory at current malware attacks and technology developments for effective defenses.     

IT-Business Alignment: A Two-Level Analysis

Abstract

In this paper, we identify processes associated with “Tactical IT-Business Alignment”, illustrate four types of alignment states resulting from “strategic” and “tactical” alignment levels, and propose alignment-related managerial actions appropriate for each type. Our results are based on about 45 hours of interviews with about 30 senior, middle and junior managers from IS and other functions, and from company records, in an investigation of four organizations.     

EM-GPA: Generalized Procrustes analysis with hidden variables for 3D shape modeling

Aligning shapes is essential in many computer vision problems and generalized Procrustes analysis (GPA) is one of the most popular algorithms to align shapes. However, if some of the shape data are missing, GPA cannot be applied. In this paper, we propose EM-GPA, which extends GPA to handle shapes with hidden (missing) variables by using the expectation-maximization (EM) algorithm. For example, 2D shapes can be considered as 3D shapes with missing depth information due to the projection of 3D shapes into the image plane. For a set of 2D shapes, EM-GPA finds scales, rotations and 3D shapes along with their mean and covariance matrix for 3D shape modeling. A distinctive characteristic of EM-GPA is that it does not enforce any rank constraint often appeared in other work and instead uses GPA constraints to resolve the ambiguity in finding scales, rotations, and 3D shapes. The experimental results show that EM-GPA can recover depth information accurately even when the noise level is high and there are a large number of missing variables. By using the images from the FRGC database, we show that EM-GPA can successfully align 2D shapes by taking the missing information into consideration. We also demonstrate that the 3D mean shape and its covariance matrix are accurately estimated. As an application of EM-GPA, we construct a 2D + 3D AAM (active appearance model) using the 3D shapes obtained by EM-GPA, and it gives a similar success rate in model fitting compared to the method using real 3D shapes. EM-GPA is not limited to the case of missing depth information, but it can be easily extended to more general cases.     

基于金属氧化物气体传感器的气味罗盘的实验分析研究

设计一种由TGS2620金属氧化物气体传感器构建的气味罗盘系统。研制了气味罗盘的信号采样系统及辅助电路。在点气源及平流环境下对该系统进行了360°静态气源定位实验,提取传感器阻值响应比为特征量,并论证了该特征量与罗盘偏转角度α的对应关系。实验表明气味罗盘对相差30°方向的气源据有较大的响应差,以响应比值为特征量进行分析能够排除同类型传感器个体差异对分析结果的影响。     

噪声对基于不同梯度算子的ICG算法的影响

反向合成梯度算法是一种基于局部指向性的反向合成图像对齐算法,能有效克服光照变化对匹配结果准确性的影响。局部指向性的计算在本质上是梯度的计算,可以用不同的梯度算子求解。该文采用4种梯度算子计算局部指向性,通过给输入图像和模板图像中加入噪声模拟实际图像,研究了噪声对基于4种梯度算子的反向合成梯度算法的影响。     

基于英汉平行语料库术语词典的自动抽取

该文提出了一种从英汉平行语料库中自动抽取术语词典的算法。采用的是已对齐好的双语语料,中文经过了分词处理。利用英文和中文词性标注工具对英文语料和中文语料分辨进行词性标注。统计双语语料库中的名词和名词短语生成候选术集。然后对每个英文候选术语计算与其相关的中文翻译间的翻译概率。再通过设定阈值过滤掉一些与该英文候选词无关的中文翻译,最后通过贪心算法选取概率最大的词作为该英文候选词的中文翻译。     

光学透射头盔显示器标定综述

光学透射头盔显示器(OSTHMD)标定是增强现实技术研究中一个具有挑战性的关键技术问题.文中详细阐述了OSTHMD的标定技术,包括标定要求、标定计算模型、标定方法、标定评估、发展趋势和应用前景等,重点介绍了比较实用的基于单点主动对准法和基于图像的标定方法.