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11.
室外给排水设计是整个化工厂区室外管线设计的重要部分。本文介绍了石油化工企业给水排水管道工程设计中优化设计方案、管线综合规划、管线高程、管材选用、接口方式及管网附件、管道防腐、附属构筑物等方面的经验。  相似文献   
12.
潘永和 《中国水运》2007,5(7):13-14
在工程建设过程中,常常涉及到高程测量。本文结合工程实际,简要阐述新三角高程测量法。  相似文献   
13.
将GPS水准纳入到GPS定位与数据处理这个框架内进行研究分析,论述了高程拟合的具体方法和每种方法适用的范围,研究选用不同情况的已知点对最后拟合结果的影响.通过对每种方法解算的结果进行对比,得出关于高程拟合的几点结论.  相似文献   
14.
ObjectiveBicycle use for commuting is being encouraged not only to address physical inactivity, but also vehicular congestion, air pollution and climate change. The current study aimed to ascertain the urban environmental correlates and determinants of bicycle use for commuting (bicycle commuting) among the working or studying population in Barcelona, Spain.MethodsAdults (n = 769; 52% females) recruited whilst commuting within Barcelona (Spain) responded to a comprehensive telephone survey concerning their travel behaviour. Based upon responses collected from June 2011 to May 2012, participants were categorised into four groups: frequent bicyclists, infrequent bicyclists, willing non-bicyclists, and unwilling non-bicyclists. The determinants of frequency and willingness (propensity) to commute by bicycle were assessed by multinomial logistic regression models adjusted for potential confounders and covariates.ResultsThe number of public bicycle stations surrounding the home address and amount of greenness surrounding the work/study address were significant positive determinants of bicycle commuting propensity. On the other hand, the number of public transport stations surrounding the home address and elevation of the work/study address were significant negative determinants of bicycle commuting propensity. Individual age, education level, gender, nationality, physical activity level and commute distance significantly affected this propensity.ConclusionGreater availability of public bicycle stations and higher levels of urban greenness may increase bicycle use by adults commuting within a city such as Barcelona, Spain. Electrically-assisted public bicycles may address the challenge of elevation, making this system a more competitive mode against traditional motorised public transport.  相似文献   
15.
研究目的:分析正射影像图技术在铁路勘测中的实际应用及其发展前景。 研究结论:大规模地制作铁路航空或卫星数字正射影像图具有周期短、见效快、节省资金、降低对专门技术设备的需求等特点,能提高信息的现时性;在铁路规划、设计、征地、工务和土地管理中使用数字正射影像图能创造良好的经济效益和社会效益;利用高分辨率的卫星影像或航片制作的各类比例尺正射影像图,可为新线铁路勘测设计的各个设计阶段提供更加直观、信息量丰富、地理精度高等的设计所需信息;将设计区域的地面模型数据(DEM)和正射影像迭合在一起,加上设计的各类铁路设备模型,可以实现设计区域的三维影像图,再沿设计线路加上一条飞行路线,即可实现沿设计线路的三维真实景观图。  相似文献   
16.
Driving road identification is the key issue of a vehicle navigation system that supports various services of intelligent transportation systems. The method for driving road identification is also known as map matching (MM). In spite of the development of MM algorithms, limitations still exist in obtaining the positioning data and preparing candidate roads (CRs) that may result in mismatches in some special difficult road configurations such as flyovers and parallel roads. To overcome the limitations, an integrated trajectory-based MM (tbMM) system is proposed based on the trajectory similarity evaluation method. The system can fuse the information from global positioning systems (GPS) and inertial sensors to generate the vehicle trajectory that represents the vehicle continuous movement in three dimensions. The elevation data of vehicle and roads are involved to enhance the trajectory-based matching process. Also the method employs an optimized mechanism for generating and maintaining CRs. Using the mechanism, separated road segments in a digital map are reorganized in the form of possible driving roads and the topology among them is guaranteed. Moreover, the CRs are obtained considering all the possibilities in determining the driving road so that the valuable historical information can be effectively reserved to provide more reliable matches in ambiguous situations. The tbMM system was evaluated using a number of real-world vehicle-level test datasets in urban areas in Beijing. Also a comparison test was performed to evaluate the driving road identification accuracy against existing MM algorithms. The results show that the tbMM system can provide reliable matches with about 99% accuracy in all the difficult scenarios and outperforms the existing algorithms.  相似文献   
17.
针对矮塔斜拉桥的特点,结合惠青黄河大桥实际的工程经验,对矮塔斜拉桥的施工监控技术进行了研究。并对施工监控矮塔斜拉桥的关键技术进行重点介绍。  相似文献   
18.
针对西丰至开原高速公路高程控制数据处理过程中出现的各种计算方案进行了对比,从不同角度分析了各种计算方案的适用性与可行性,提出了最终解决方案,首次提出了水准点兼容性观点。  相似文献   
19.
高速铁路对线路的平顺性要求非常高。然而,处于自然界中的高铁桥梁结构受温度、混凝土收缩徐变和地基不均匀沉降等影响,不可避免地会发生沉降变化,直接影响到行车安全性和舒适性。针对高速铁路运营过程中产生的问题,对目前已有的调高技术进行全面分析,就目前调高支座只能单向调高和作业效率低下等问题,采用结构设计、试验验证及样品试制等方法,研发一种智能调高支座,详细介绍各系统的组成构件、功能以及安装维护要求,并对支座基本性能、自动调高功能、多台联动性能及安全可靠性能等进行试验。研究结果表明:该智能调高支座各项指标均达到了预期目标值,有效解决了现有调高支座被动、手工的操作模式。  相似文献   
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