基于圆和圆环点的摄像机线性标定

本文提出了一种基于圆和圆环点的线性自标定方法。该方法的平面模板要求圆内有3组两两正交的直径,从3个或多个不同的方位摄取平面圆模板的图像。根据射影几何调和共轭和交比不变的性质,求出6条直径灭点的坐标。由3组两两正交的直径和拉盖尔定理的推论解出圆环点的图像坐标。利用圆环点的性质得到关于内参数的约束方程,从而线性的求出摄像机的5个内参数。模拟和真实图像实验表明,该方法精确度较高,鲁棒性较强,有一定的实用性。     

基于A4纸的摄像机标定算法

摄像机标定技术是三维重建的第一步,文章结合三维重建对计算机标定精度要求不是很高的具体需求,在张正友提出的基于平面模板的标定方法基础上,提出了一种基于A4纸的摄像机标定算法。经实验验证,文章所采用的算法标定精度较高,鲁棒性较好。     

复杂背景下目标的快速识别方法

复杂背景下目标的识别是自动跟踪测量系统中的关键技术,识别算法的优劣直接影响了目标识别的精度与速度。针对空中目标成像,由于大气湍流等因素的影响,CCD图像中的光斑通常呈不规则形状,而传统的模板匹配法与圆拟合法在识别不规则光斑时存在不足。本文利用光斑在像平面上的空域分布特性,提出一种基于空域相关程度排序的识别算法,配合经过改进的高效图像处理方法,实现了多个不规则光斑的快速识别。实验结果表明该方法能够在混有多个假目标的图像中有效识别出真实目标并进行跟踪测量。     

一种基于主动视觉的非线性摄像机自标定

针对计算机视觉摄像机镜头畸变对精度的影响问题,提出了一种非线性摄像机标定方法。该方法是将非线性模型视为线性模型和畸变项的叠加,然后在主动视觉下利用线性模型下的正交运动的FOE(当物体或摄像机做纯平移运动时图像对应点连线的交点)点的关系,给出非线性模型参数的约束方程,从而实现非线性模型的摄像机自标定。模拟和真实图像实验均表明,该方法是有效的,具有一定的实用价值。     

基于主动视觉的摄像机线性自标定方法

为了解决传统摄像机标定方法的精确度差和使用不方便,本文提出了一种基于主动视觉的摄像机线性自标定方法,该方法通过控制摄像机做一次纯轴向运动来确定主点坐标,再做一次纯旋转运动利用单应性矩阵与旋转矩阵的关系确定摄像机的其他三个内参数。这种基于主动视觉的自标定方法原理简单、实现方便、可操作性强。实验结果表明,该方法能够比较准确地标定出摄像机的所有内参数。摄像机标定是计算机视觉中的一项基本任务。传统的标定方法是通过结构的物体(如标定块,标定板等)在图像中的投影计算摄像机的内参数。但是这种方法必须要有标定物,在很多实际应用中难以实现。为了解决传统摄像机标定方法的精确度差和使用不方便,     

一种高精度特征点检测和相机标定方法

针对特征点检测和相机标定精度问题,提出了一种亚像素级的角点检测和相机标定方法。该方法对角点的提取首先运用传统的方法得到初始值,并以此为初始值从棋盘格图像中搜索边缘,然后拟合边缘数据,并将拟合得到的曲线的交点作为角点的最终值,最后以这些角点作为标定相机的特征点对相机进行标定。实验结果表明,该方法提高了特征点提取的准确度和精度,以此提高了相机标定的精度。     

一种摄像机标定精度评估方法

摄像机标定系统的标定精度对于计算机视觉三维测量的精度至关重要,在Tsai的标定精度评估准则的基础上,给出了一种基于棋盘格的标定精度评估方法。该方法利用标定结果重构一组棋盘格长度,将该长度与实际的棋盘格长度进行比较,进而测量标定系统的精度。     

数字摄影测量系统中非测量CCD相机标定算法

为了解决传统的相机标定方法,通常需要建立复杂三维标定块或高精度三维控制场这一实际问题,采用平面控制格网作为标定块,利用二维直接线性变换分解出相机的内外方位元素初值,然后采用改进的Hough变换算法检测标定图像中的格网直线并利用最小二乘法拟合出最佳直线,通过求直线的交点得到标定格网点的像坐标。最后利用自检校光线束法平差进行相机的精确标定。实际图像数据实验结果表明:主点和焦距的标定精度分别达到了0.2和0.3像素左右。可以满足高精度近景三维量测的要求。     

基于tsai方法的多项畸变模型单目摄像机标定

在基于tsai一阶径向畸变标定方式的基础上，提出了一种改进算法。算法结合传统标定原理首先线性求解摄像机模型内外参数，作为初值，应用于带有二阶径向畸变，偏心畸变和薄棱镜畸变的图像矫正模型，通过最小二乘法求解6项畸变尺度因子。充分利用OpenCV视觉函数库对图像分步校正，避免了重复计算并判断透镜非线性映射。实验结果表明，改进算法提高了系统标定精度，降低了计算时间复杂度，可以实现较高精度的单目视觉标定及立体视觉匹配的应用需求。     

基于数字图像处理的圆形孔径自动检测方法研究

目前广泛使用的圆形孔径自动检测方法有接触法和非接触法两种,但存在测量范围小、测量精度和分辨率低、效率低等问题,研制了基于数字图象处理的圆型孔径自动检测系统,它由CCD摄像机采集被测端面的显微图像,视频图像采集板将其数字化,计算机利用数字图象处理技术进行处理;本系统能取代传统的圆型孔径检测方法,简单迅速精度高。     

Development in Information and Communications Technology (ICT) Statistics at the Australian Bureau of Statistics

This paper outlines the ICT statistical developments that the ABS has undertaken over recent years. These developments have been on both the supply side (ICT industry) and the demand side (use of IT by sector). The content of ABS ICT surveys has changed significantly over the last few years and are expected to develop further in line with industry changes and emerging policy needs.
Recent developments in household collections have been the inclusion of IT use questions in the 2001 Census of Population and Housing and in various ABS social surveys such as Children's Participation in Culture and Leisure Activities. Annual business IT use surveys are now conducted and include topics such as Internet commerce and IT security. Biennial ICT industry surveys are conducted to provide data on ICT production, imports and exports, ICT industry employment, performance and structure information. An Internet activity survey is run every six months and provides regional Internet access details and infrastructure details on Internet service providers.
A major development for 2002–03 will be the compilation of an ICT satellite account. ABS intends to produce an ICT Information Development Plan to guide its future statistical development work in the ICT field.     

Value at Risk in the Suburbs: Eminent Domain and the Geographical Politics of the US Foreclosure Crisis

Several US counties and local governments have recently considered a novel solution to the foreclosure crisis. They plan to use eminent domain to compel the owners of mortgage debt—and specifically of private‐label mortgage‐backed securities—to sell the debt to the government at a price reflecting the loan's market value. The government would then restructure the debt and resell it to new investors. The plans are striking because—in contrast to both development‐driven eminent domain and the federal subprime bank bailout—they would force investors to assume asset devaluation and increased long‐term risk. Notably, the plans have emerged as an instance of financialization‐focused politics in suburbs and suburban cities of color, specifically majority‐black and ‐Latino/a suburbs. Local support for the plans, we argue, is rooted in the long‐term disinvestment of these ‘suburbs of exception', which became targets of subprime lending and eventually sites where the ‘financial exception' has been localized. But these demographic shifts, fragmentation and fiscal pressures have at the same time created a suburban political terrain in which the plans have gained their strongest political support.     

Towards a Theory of Serendipity: A Systematic Review and Conceptualization

Serendipity – the notion of making surprising and valuable discoveries – plays a major role in the success of individuals and organizations alike. Previous research has established the importance of serendipity and identified important individual- and organizational-level antecedents. However, the literature has been dispersed and the boundaries of the concept have been blurry, leading to a lack of conceptual clarity and structure, and thus limiting validity and managerial actionability. Based on a systematic literature review, I synthesize existing management-related research on serendipity and explicate the emergence and composition of serendipity in the organizational context. I first identify three necessary conditions that differentiate serendipity from related concepts such as luck or targeted innovation: agency, surprise, and value. Then, I draw from the literature on sensemaking, event-based theorizing, and quantum-based approaches to management to conceptualize the process of cultivating serendipity in the organizational context as a process of enabling potentiality and materialization, and develop a multi-level theory of (cultivating) serendipity. This conceptualization contributes to our collective understanding of how, why, and when (i.e., under what conditions) organizations can leverage the value in the unexpected, which opens up fruitful avenues for further research.     

Accountability of NGOs in Bangladesh A critical overview

NGOs in Bangladesh have been recognized as effective change agents in the socio-economic arena throughout the world. Their contributions in micro credit, non-formal education and primary health care are widely known. NGOs play a significant role in society. NGO accountability, as a result, has become a critical issue. NGO accountability in Bangladesh has been examined here in relation to patrons, clients and themselves. Of the three relationships only accountability to patrons is in a near satisfactory state. Accountability to clients is handicapped by lack of opportunities of beneficiaries to participate meaningfully in NGO policy making. Accountability to themselves is adversely affected due to the adherence to a strictly hierarchical system and the influence of founding and charismatic NGO leaders.     

Towards an Asian model of human resource management? A comparative analysis of China,Japan and South Korea

There has been much discussion regarding the possible decline and weakening of national systems of human resource management (HRM). Yet, culture and institutions are often cited as the major stumbling blocks to this outcome. Such constraints may dissipate in the analysis, particularly if ‘regional clusters’ are considered where geographic and cultural closeness and ‘openness’ to similar economic pressures exist. In such cases, it might be postulated that convergence in HRM will occur. We argue that China, Japan and South Korea represent such a cluster. This article examines these countries, to see if a degree of convergence is taking place and if it is towards an identifiable ‘Asian’ model of HRM. A model of change is presented that distinguishes between levels of occurrence and acceptance. Details of the development and practice of HRM in each country are then set out. The article ends with a discussion and implications section and a brief conclusion.     

The Creation of the Office for National Statistics

A new Office for National Statistics was created in the United Kingdom in 1996 following a series of developments designed to strengthen the relevance and integrity of statistics. This paper describes these fundamental changes and sets out a blueprint for future progress. It also sets current developments in the United Kingdom in an historical and international context.     

What helps? Women engineers' accounts of staying on

We have considerable understanding of the obstacles that women engineers encounter and the reasons that they leave the field, but we know less about what enables them to remain. Adopting an interpretivist approach, this article examines how a group of British women engineers in two FTSE 100 companies account for “staying on” in their male‐dominated work settings. We delineate four specific forms of help that facilitate women's retention in the field. We argue that exposure to help leads to women developing a habitus that enables them to continue working in engineering. To conclude, we draw on our findings to outline HR practices that will facilitate supportive relationships in the workplace and pave the way towards developing more positive organisational climates.     

论现代物流企业的发展观

物流业经过诸多年的发展目前已经成为最热门的行业之一,物流企业的注册数量也与日俱增,达到前所未有的规模。毋庸置疑,任何企业都希望自己迅速做强做大,并成为真正现代物流企业的典型代表,要实现这一目标一个首要问题就是要解决现代物流企业的发展观问题。     

浅谈大体积混凝土裂缝的控制

大体积混凝土的裂缝问题是实际工程中长期困扰工程技术人员的问题,其控制技术的研究是混凝土结构研究的热点问题,具有重大的学术价值和潜伏的工程背景。     

Supply Chain Strategies in the UK Fashion Industry—The Rhetoric of Partnership and Realities of Power

This paper focuses on the fashion industry, one characterised by issues such as dramatic shifts in the scale and power of major retail buyers in the market, the advent of retailer own brands, and the nature of sourcing and supply chain decisions, issues that are increasingly global in nature. The aim of this research is to explore the nature of relationships between UK high street multiple fashion retailers and their contracted suppliers, many of whom are entrepreneurial firms by most definitions of the term. Four core themes emerge from the literature and provide a framework for the research, namely, power, process, partnership, and people. The research approach was qualitative, and conducted over a period of twelve months. The paper ends with an agenda for future research.