排序方式: 共有13条查询结果,搜索用时 15 毫秒
1.
贾玉林 《中小企业管理与科技》2020,(6):185-186
目前,倾斜摄影测量作为一种新技术,经过不断的探索、应用和发展,已开始在测绘行业中大显身手,并取得了不小的成绩。通过三维模型进行的矢量数据采集,其矢量精度完全依赖于三维模型精度。论文以实践经验为基础,定性地分析了在航空摄影、像控测量、模型生产三阶段中,影响模型精度的因素,希望对三维模型的生产起到一定的指导作用。 相似文献
2.
塔脚板是铁塔的关键部位,某些荷载大的塔脚板采用加劲板四周围焊成一圈,以目前的放样软件还不能解决该加劲板的放样,只能采用三维绘图解决,不能实现柔性设计,效率低。针对此问题,本文通过点坐标法推导出计算公式,节省放样时间,缩短加工周期。 相似文献
3.
4.
斜流沉淀池具有占地面积小,沉淀效率高的优点,但由于存在排泥较困难,不耐冲击负荷等弱点,制约了其在废水处理中的应用,本文结合铅锌冶炼废水治理的工程实例,对造成上述问题的原因进行了分析,提出了改进的办法,取得了良好的效果。 相似文献
5.
贵州省县域经济的综合评价 总被引:6,自引:0,他引:6
运用因子分析法可对贵州省2003年县域经济的综合指标进行评价.其过程是:通过SPSS统计软件进行计算和分析,以斜交旋转后的综合因子得分作为县域经济综合实力的度量,给出贵州省2003年各区县的综合实力排序以及等级划分情况并做出相应的评价. 相似文献
6.
Wim Rogmans Mark Rosenberg 《International journal of injury control and safety promotion》2013,20(1):1-2
Youth violence continues to be a serious and too prevalent problem in the United States. There is increasingly compelling evidence that the exceptionally high levels of mortality are linked to access to guns by youth. There is also evidence that youth violence occurs in multiple forms and that these differing forms call for different prevention strategies. Some youth violence is situational, some is best understood within its relationship context, some occurs as part of a predatory criminal activity, and some seems to be the result of serious psychopathology. This paper provides a review of the current understanding of the epidemiology of youth violence in the United States, applies a developmental-ecological perspective to risk, reviews the empirical support for differing prevention approaches, and suggests practice, research, and policy implications of this knowledge base. 相似文献
7.
Martina Hančová 《Metrika》2008,67(3):265-276
The method of “natural” estimation of variances in a general (orthogonal or nonorthogonal) finite discrete spectrum linear
regression model of time series is suggested. Using geometrical language of the theory of projectors a form and properties
of the estimators are investigated. Obtained results show that in describing the first and second moment properties of the
new estimators the central role plays a matrix known in linear algebra as the Schur complement. Illustrative examples with
particular regressors demonstrate direct applications of the results. 相似文献
8.
We analyze the evolution of culture when parents socialize children to the cultural variants that maximize child lifetime utility. Parents invest in cultural transmission by taking into account that children are also influenced by peers. We model the influence of peers by assuming that children observe different cultural variants in their peer group, assign merit to them and adopt one variant, following a probabilistic adoption rule. We show that cultural diversity is sustainable even if all parents strive to transmit the same variant. We also show that a parental demand for cultural pluralism does not guarantee cultural diversity. 相似文献
9.
在利用直角三角形法图解一般位置直线与投影面倾角方法的研究中,揭示了图解一般位置直线与投影面的垂直面倾角的规律,并由此给出了广义直角三角形法,该法拓宽了原直角三角形法只局限于图解一般位置直线与投影面倾角的范围,为图解空间角度问题提供了1种新的简便方法。 相似文献
10.
袁国强 《国土与自然资源研究》2006,(4):38-39
依据信阳茶叶生产发展的特点水平及我国茶叶生产发展的趋向,提出河南省信阳茶叶进一步发展对策:实施产业化;鼓励绿色无公害茶产品的发展;加强信阳茶叶生产的标准化研究推广;加强对外经济技术联系协作;加强茶叶科技信息网络建设。 相似文献