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311.
论浅水多波束测量质量保证措施 总被引:1,自引:1,他引:1
在对影响多波束测量精度、质量的关键因素进行分析的基础上,提出了保证测量质量的措施。 相似文献
312.
通过DCC型灌包机称量过程的分析,阐述影响称量精度和称量速度的主要因素是粗、细加料门关闭产生的机械振动和加料流变化的冲击力。指出DCC型灌包机是机电一体化产品,在优化机械结构的同时,引进新的控制、检测方式——时间禁止比较法及二次检测法,从而在保证称量精度的条件下,提高灌包机的称量速度。 相似文献
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314.
探地雷达检测公路面层厚度的准确性研究 总被引:1,自引:0,他引:1
在简述探地雷达基本原理和工作方法的基础上,对用探地雷达检测道路面层厚度的可靠性、准确性进行了分析,并通过试验予以验证。试验结果表明:探地雷达对于每一点厚度测量比较精确,而对于某一段的厚度测量则是非常精确,说明探地雷达完全具备替代现行钻孔取芯的条件。 相似文献
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316.
Tracking daily travel; Assessing discrepancies between GPS-derived and self-reported travel patterns
Global Positioning Systems (GPS) technologies have been used in conjunction with traditional one- or two-day travel diaries to audit respondent reporting patterns, but we used GPS-based monitoring to conduct the first assessment to our knowledge of travel reporting patterns using a seven-day travel log instrument, which could reduce response burden and provide multiple-day, policy-relevant information for evaluation studies. We found substantial agreement between participant-reported daily travel patterns and GPS-derived patterns among 116 adult residents of a largely low-income and non-white transportation corridor in urbanized Los Angeles in 2011–2013. For all modes, the average difference between daily GPS- and log-derived trip counts was only about 0.39 trips and the average difference between daily GPS- and log-derived walking duration was about −11.8 min. We found that the probability that a day would be associated with agreement or discrepancies between these measurement tools varied by travel mode and participant socio-demographic characteristics. Future research is needed to investigate the potential and limitations of this and other self-report instruments for a larger sample and a wider range of population groups and travel patterns. 相似文献
317.
The scheduling operations of many paratransit agencies in the United States are undertaken manually. Those customers who are eligible to travel call in their requests the day before the trip is needed. As the trip requests are received, they are entered into a list of unscheduled trips. In order to schedule these trips, the scheduler must first determine the number of drivers and shuttle buses that are available as well as the time of availability of each. The scheduler must then try to match the rides that are in “similar” areas around the “same” time to place together on the driver's schedule. As new trip requests are made, the schedulers must adjust the trips that are already scheduled to try and schedule as many trips as possible in the most efficient way. By developing a system that would improve the scheduling system operations of, in this case, DART (Delaware Administration for Regional Transit) First State Paratransit, customers can expect to receive better service that will improve their ability to travel throughout the community. Some devices that could also improve the operations of paratransit agencies are described in this paper, such as satellite‐based Global Positioning System (GPS), radio communication systems, mobile computers, radio frequency‐based data communication systems, internet web pages, automated paratransit information systems, and card‐based data storage and transfer media. However, because paratransit systems are difficult to operate cost‐efficiently, the optimum and most cost‐efficient device must be selected. The system chosen for DART First State Paratransit includes the use of a relational database management system (RDMS) and a transportation Geographic Information System (GIS). RDMS keeps track of the database information as well as the scheduled trips and the GIS is ideal for analyzing both geographic and temporal data. This system is shown to be superior to the manual system. 相似文献
318.
本文详细地介绍了使用双点法对DSS—80型镗头回转精度的现场测试;讨论了主轴径向误差运动园图象的分析处理和评定方法。测试系统简单,实验操作方便,数据可靠。这对高精度轴系的园度误差和表面粗糙度测试具有现实意 相似文献
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320.
赵耀忠 《武汉船舶职业技术学院学报》2010,9(3):27-29
针对经济型数控车床位置精度问题,提出了编程法、参数修正输入、机构调整、采用误差修正软件、合理调配工艺流程等误差补偿修正方法,使数控车床位置精度得到了有效控制,达到了提高经济数控车床加工精度的目的。 相似文献