切比雪夫多项式拟合卫星轨道与钟差的精度分析

利用切比雪夫多项式拟合卫星轨道,用经验统计法确定轨道不同弧段数据的满足精度要求的拟合阶数区间,发现非最佳拟合阶数会引入较大的拟合噪声,因此在精密计算时应选择最佳拟合阶数。本文用此多项式拟合卫星钟差,能达到内插钟差同等的精度,而且与拉格朗日滑动内插相比,拟合残差序列分布更好,计算效率更高;提出利用残差自相关进行精度评定的方法,当精度变化微小时相比一般的精度评定方法具有明显优势。     

GNSS电磁环境信息管理技术研究

随着我国北斗系统的建成和投入使用,全球卫星导航系统(GNSS)受电磁环境影响的问题也日益凸显。详细调研分析了国外在此领域已经开展的各项工作,国内在此领域已经具备的基础条件,提出了我国的GNSS电磁环境信息管理技术方法,并以此为基础编写完成了初步的演示验证软件。     

Virtual geographic environment-based integrated rockfall risk simulation method for canyon bridges

Bridges located in mountainous areas are vulnerable to rockfall accidents, posing a threat to bridge engineering construction and operation safety in these regions. Under the coupling effect of complex environments and engineering disturbances, integrated rockfall risk simulation has become increasingly important for canyon bridge structural protection in long-term construction and operation phases. One of the main scientific challenges in rockfall risk simulation is studying the interaction between rockfalls and the topography and engineering environments during consecutive contacts. To systematically simulate the integrated bridge rockfall risk, an integrated construction of multivariable elements coupled with rockfall risk environments and scenarios is required. In this article, we proposed a VGE-based integrated rockfall scenario simulation method that uses the “associated representation—integrated modelling—interactional simulation” core strategy. Our method constructs a virtual rockfall risk environment by fusing multisource data to represent rockfall factors that induce rockfall disasters, hazard-forming environments, and elements at risk. We design rockfall scenarios under different bridge engineering construction conditions and extreme environmental conditions to analyze the interactional rockfall risks. The results demonstrate that our method enables a systematic analysis of the potential integrated rockfall risk, providing realistic reference value for the timely and effective disposal of emergencies, and reducing the harm and losses caused by such emergencies.     

EVKG: An interlinked and interoperable electric vehicle knowledge graph for smart transportation system

Over the past decade, the electric vehicle (EV) industry has experienced unprecedented growth and diversification, resulting in a complex ecosystem. To effectively manage this multifaceted field, we present an EV-centric knowledge graph (EVKG) as a comprehensive, cross-domain, extensible, and open geospatial knowledge management system. The EVKG encapsulates essential EV-related knowledge, including EV adoption, EV supply equipment, and electricity transmission network, to support decision-making related to EV technology development, infrastructure planning, and policy-making by providing timely and accurate information and analysis. To enrich and contextualize the EVKG, we integrate the developed EV-relevant ontology modules from existing well-known knowledge graphs and ontologies. This integration enables interoperability with other knowledge graphs in the Linked Data Open Cloud, enhancing the EVKG's value as a knowledge hub for EV decision-making. Using six competency questions, we demonstrate how the EVKG can be used to answer various types of EV-related questions, providing critical insights into the EV ecosystem. Our EVKG provides an efficient and effective approach for managing the complex and diverse EV industry. By consolidating critical EV-related knowledge into a single, easily accessible resource, the EVKG supports decision-makers in making informed choices about EV technology development, infrastructure planning, and policy-making. As a flexible and extensible platform, the EVKG is capable of accommodating a wide range of data sources, enabling it to evolve alongside the rapidly changing EV landscape.     

美国内政部四轮战略规划的发展趋势及特点分析

美国内政部的战略规划是该部施政纲领的集中体现。四轮战略规划的目标从2003年强调资源保护、利用与休闲娱乐的平衡,到2007年增加全球经济、环境、政治和其他因素对内政部战略规划的影响,直至2014年强调资源的娱乐、人文观赏价值,并重视培养下一代的管理责任。内政部战略定位逐渐清晰。资源保护、经济发展、休闲娱乐的相对关系发生变化,从强调三者平衡到强调资源的休闲、文化等景观价值。     

建设工程基础验线与竣工规划测量的研究

基础验线与竣工规划测量是城市规划管理的重要环节,其成果是规划过程监督管理与竣工验收审核的重要依据。无锡市自2012年1月1日起正式实施建设工程基础验线与竣工规划测量工作。本文介绍了无锡市建设工程基础验线与竣工规划测量的作业依据与资料准备、工作内容及提交的成果,并结合工程实例对成果进行分析,为今后工作提供参考。     

Scale-oriented temporal analysis of movement data: A series-based approach

The ubiquity of movement data has led to new research interest in aspects of temporal scale. Few of the approaches analyzing movement data have been developed specifically for scale-oriented temporal analysis. To overcome this limitation, this article proposes a series-based approach to perform scale-oriented temporal analysis of movement data. Key to the proposed approach is the construction of four types of series (one type of identical-scale series and three types of cross-scale series) based on the continuous triangular model (CTM). Two distinct research goals are derived from this: to investigate the changes in motion attributes of moving individuals across different temporal scales, and to detect the time intervals during which active events might have occurred. The results based on real football movement data show that finer changes in motion attributes can be found and more accurate time intervals can be detected through the proposed approach.     

顾及用户体验的三维城市模型自适应组织方法

传统基于“图层付象”的组织方法,没有考虑三维城市模型的不同内容以及不同细节层次的粒度差异,导致在网络环境下的传输效率低,难以满足多用户并发访问的流畅可视化。深入分析了大范围漫游与小范围聚焦的用户体验特点,通过元数据统筹管理和对象离散化,即时响应用户请求,减少无效数据传输,保证了多用户并发环境下的高效调度和浏览。针对模型LoI)和分解的对象,设计了结构统一的对象ID,隐式存储关联关系并支持分布式模型存储管理。以分布式数据库MongoDB为平台进行实验,验证了本文方法的可行性和有效性。     

基于SMVF的高频雷达自适应多目标检测

针对高频雷达强海杂波和干扰环境下的多目标检测问题,结合S-method时频分布和Vitcrbi算法提出了一种多分量线性调频信号瞬时频率估计方法—SMVF法(S-method viterbi fitting),然后根据所提取的瞬时频率的直线拟合性能,提出了一种自适应多目标检测算法。实测数据的处理结果,表明了该算法在低信噪比时,与WDM法(wigncr distribution maxima) , WDV法( wigncr distribution vitcrbi)相比,估计精度提高约2000,验证了该算法的可行性和有效性。     

面向道路网络地图示意化的线形简化方法

针对当前示意网络地图线形状简化方法中存在需要人工干预或地图认知度低的问题,本文提出自动化程度高并能保证良好地图认知的线形状简化方法.该方法通过合理设定线形状简化中所需的阈值以避免人工干预,提高了线形状简化过程的自动化程度,并通过在简化过程中应用平滑算法,以减少示意结果中线对象在方向上的转折数,从而提高了简化度和清晰度.试验表明该方法不仅可以生成清晰的示意结果,并且能够保证良好的地图认知度.