共查询到20条相似文献,搜索用时 46 毫秒
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高速列车要实现安全平稳地高速行驶,轨道必须具有高平顺性,作为铁路轨道铺设和运营维护的测量基准——轨道控制网(CPⅢ)必须精确可靠。CPⅢ网跨度大、网形结构复杂,其观测数据误差、平差基准的原始数据误差和分段衔接误差等因素会影响控制点的精度和可靠性,最终会影响到轨道的高平顺性建设和评判。在现有的技术规范基础上,以轨道平顺性控制为目标,进一步提高轨道控制网测量数据精度和可靠性,完善高速铁路测量数据质量过程控制的理论和技术体系,确保高速铁路高标准建设和列车高速、平稳、安全运行,是高速铁路测量理论领域值得探索研究的课题。论文借鉴大系统控制理论和多元质量控制与诊断理论的思想,构建起轨道控制网全局式数据质量控制体系(global data quality control system of CPⅢ,GDQCS-CPⅢ),主要成果如下。 相似文献
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J. Gazdzicki 《Journal of Geodesy》1976,50(4):363-376
In strength analysis of horizontal geodetic networks it is appropriate to use pairs of functions which involve the relative
position of two points and relative position of three points. Using properly chosen pairs of functions, formulae are given
which allow the computation of precision criteria for the orientation and scale of the network as well as its shape. To illustrate
the presentation of results, new types of errors ellipses are introduced. Analogies and correlations existing among the adopted
functions are introduced by using the concept of orthogonal networks which are defined in the paper. 相似文献
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HONGFan ZHUXian XINGGuanglin 《地球空间信息科学学报》2005,8(2):138-143
Access control in multi-domain environments is one of the important questions of building coalition between domains. On the basis of RBAC access control model, the concepts of role delegation and role mapping are proposed, which support the third-party authorization. Then, a distributed RBAC model is presented. Finally the implementation issues are discussed. 相似文献
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GPS Solutions - Reliability is an important indicator of GNSS performance, especially for the safety-critical applications. Carrier phase-based GNSS positioning can achieve high precision, but its... 相似文献
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Access control in multi-domain environments is one of the important questions of building coalition between domains. On the basis of RBAC access control model, the concepts of role delegation and role mapping are proposed, which support the third-party authorization. Then, a distributed RBAC model is presented. Finally the implementation issues are discussed. 相似文献
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