工程建设施工现场中3G视频监控系统的研究与实现

随着建筑行业的飞速发展,施工现场的安全问题一直是工地管理工作的重中之重。网络技术的发展,使得视频监控系统运用到各行各业中。通过运用远程视频监控技术,实时对分布在各地的多个施工现场进行监管,既减轻了管理人员的工作量,又加强了建设行政主管部门以及施工和安全质量监督管理部门的监管力度。安全管理是建筑工地的重要管理环节,考虑到工地实际需求,本文针对传统视频监控系统实时性差、传输效率低、图像质量不稳定等缺点,对基于3G网络的工程建设施工现场远程视频监控系统进行研究和实现。文中介绍了3G网络的无线视频技术的优势及远程视频监控系统的功能特点,对施工现场3G远程视频监控系统的方案进行研究设计,并在某施工单位几个重点施工现场进行了试点安装,达到了预期效果,实现对施工现场实时监控。     

Optimality conditions¶and bubbles in sequential economies¶and bounded relative risk-aversion

We provide specific qualifications in order that Kuhn–Tucker type Euler equations and transversality conditions at infinity hold in stochastic equilibrium models with heterogeneous agents and where assets are traded in sequential markets. It is not assumed that uncertainty is modeled as an event-tree structure or that preferences are necessarily bounded. We also describe an important class of preferences based on bounded relative risk aversion which yields relevant simplifications. Our results are used to establish conditions that rule out asset pricing bubbles. Specific examples of economies with bubbles are also discussed. Received: 28 January 2002 / Accepted: 19 July 2002 We are grateful to the editor and an anonymous referee for their valuable comments. This research was partially supported by MURST (Italy), National Group on “Nonlinear Dynamics and Stochastic Models in Economics and Finance”.     

A note on the projection properties of Hadamard matrices obtained by the first Payley construction

We show that the projections on four factors of an arbitrary orthogonal array of strength 2 allow the estimation of main effects and two-factor interactions when all other effects are assumed to be zero, if those projections satisfy the bounds given by Weils theorem. The only exceptions are the Hadamard matrices of orders 16 and 24. A consequence is again the estimability of main effects and two-factor interactions for the projections on four factors of the first Payley construction for arbitrary run size.     

3自由度并联机器人的研究现状和应用前景

3自由度并联机器人具有结构相对简单、高刚度、低惯性力、大载荷和高速能力的特点,在工业生产及其他领域有着广阔的应用前景,引起了越来越多的学者的广泛兴趣。     

基于三线流模型的垂直裂缝井采油指数研究

针对低渗透地层垂直裂缝井的渗流过程,考虑了启动压力梯度和介质变形系数的影响,建立了三线流模型。根据此模型可得到不同地层及裂缝参数条件下油井采油指数变化规律。计算结果表明：在相同的生产压差条件下,采油指数随着变形系数的增大而减小,随着启动压力梯度的增大而减小,随着裂缝半长增大而增大。     

长洲水利枢纽三线四线船闸建设征地移民安置初步规划

文章根据调查的实物指标,结合征地区的情况,在分析安置区的环境容量后提出符合当地情况的移民安置规划,并对移民安置静态投资作出了估算。     

武汉市三维数字地图系统建设及其应用

武汉市是国内较早开展三维数字城市建设的城市之一,武汉市三维数字地图系统建设是武汉市三维数字城市建设的核心内客,该项目历时三年基本建成.本文全面总结了该项目建设的主要内容、建设策略和成果应用,对下一步工作提出了展望,相信对国内三维数字城市建设及规划界利用三维技术提高规划编制管理技术水平有借鉴意义.     

Tax-benefit systems and differences in aggregate labour force participation: Comparative evidence from the Czech Republic and Hungary

This paper investigates the extent to which cross-country differences in aggregate participation rates can be explained by differences in tax-benefit systems. We take the example of two countries, the Czech Republic and Hungary, which – despite a lot of similarities – differ markedly in labour force participation rates. Using comparable individual-level labour supply estimates, we simulate how the aggregate participation rate would change in one country if the other country’s tax and social welfare system were adopted. The estimation results for the two countries are quite similar, suggesting that individual preferences are essentially identical in the two countries. The simulation results show that about one-third of the difference in the participation rates of the 15–74 year-old population and more than two-thirds of the participation of the prime-age population can be explained by differences in the tax-benefit systems.     

‘Get out of Traian Square!’: Roma Stigmatization as a Mobilizing Tool for the Far Right in Timişoara,Romania

Post‐communist Central and Eastern Europe has seen far right movements and parties gain considerable ground by drawing on nativist and ethnic claims to call for a return to an imagined past. In Romania, far right groups have been able to capitalize on a sense of injustice while also playing on historically negative feelings towards the Roma community. These patterns have been observed in Timi?oara, where the group Noua Dreapt? (New Right) has established a foothold over the past decade by emphasizing claims that blame the Roma for loss of built heritage and corruption in the administration of property restitution. The aims of this article are to examine the emergence of Noua Dreapt? and its use of Roma stigmatization, and to consider the ways in which extreme views are normalized by appealing to beliefs and perceptions. The findings of the article show that pre‐existing prejudices can be a powerful force that not only targets marginalized communities, but also challenges administrative practices and builds organizational support. At the level of the city, it is possible to identify the way in which these claims can be more precisely calibrated to draw on concerns that circulate within the community.     

Volatilidad en los ingresos y en el mercado de trabajo de los jóvenes en Europa

Los autores ofrecen nuevos datos empíricos sobre la volatilidad en los ingresos y en el mercado de trabajo (incluyendo entradas y salidas del empleo) de los jóvenes en Europa durante la Gran Recesión. Los datos de EU‐SILC para el periodo 2004–2013 revelan grandes disparidades al respecto entre los países europeos. La Gran Recesión incrementó la volatilidad entre los jóvenes. Mediante un ejercicio de descomposición de la varianza se observa una mayor rotación laboral en el sur de Europa. Según un modelo de efectos fijos, un mayor nivel de prestaciones de desempleo y de protección del empleo se asocia con una reducción de la volatilidad.