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851.
基于Web的铁路施工方案管理信息系统研究 总被引:2,自引:1,他引:1
介绍了基于计算机网络的铁路施工方案管理信息系统,系统目标,系统特点,系统功能和网络结构,论述了基于Web的PowerBuilder8可视化开发工具下系统实现的关键技术. 相似文献
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853.
本文主要通过对岩石洞室地基的破坏失稳模式,以及洞室的破坏模式的分析,简单地提出了洞室地基稳定性判据和洞室地基失稳的影响因素。 相似文献
854.
This paper utilizes socio-psychometric survey data to investigate the influence of attitudes, affective appraisal and habit formation on commuting mode choice. The data-set was collected in 2009–2010 in Edmonton, Alberta. In addition to conventional socio-economic, demographic and modal attributes, the survey gathered psychological information regarding habitual behaviour, affective appraisal and personal attitudes. Different psychometric tools were used to capture psychological factors affecting mode choice. Habitual behaviour was measured using Verplanken's response-frequency questionnaire. Affective appraisal was indirectly estimated using the Osgood's semantic differential. Five-point Likert scales were used to measure attitude. The structural equation modelling (SEM) approach was used to investigate the effects of psychological factors on mode choice behaviour. SEM captures the latent nature of psychological factors and uses path diagrams to identify the directionality as well as intensity of the relationships. The investigation reveals that passengers have positive emotions towards their chosen mode. Further, evidence of the superiority of the car as a travel alternative was established in terms of strong habit towards it, such that passengers would use the car for almost every single trip. 相似文献
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856.
朱俊 《船舶标准化工程师》2021,54(2):96-98
为避免船舶电气设计过程中因人数较多、多方沟通等情况导致沟通混乱、影响设计质量和进度,介绍一种以SBAR模式为依托建立的标准化的高效沟通模式,用以规范电气设计内部沟通模式,提高沟通效率,可作为设计内部修改的成本分析的数据支撑. 相似文献
857.
杨娥 《广州航海高等专科学校学报》2011,19(1):33-36
沥青路面性能衰减规律的预测模型是进行路面预防性养护管理的重要内容,通过采用经验法预测模型对性能指标IRI、PCI进行分析,来预测路面的使用性能,总结出经验法预测模型的建模程序和使用特点. 相似文献
858.
For route planning and tracking, it is sometimes necessary to know if the user is walking or using some other mode of transport. In most cases, the GPS data can be acquired from the user device. It is possible to estimate user’s transportation mode based on a GPS trace at a sampling rate of once per minute. There has been little prior work on the selection of a set of features from a large number of proposed features, especially for sparse GPS data. This article considers characteristics of distribution, auto- and cross-correlations, and spectral features of speed and acceleration as possible features, and presents an approach to selecting the most significant, non-correlating features from among those. Both speed and acceleration are inferred from changes in location and time between data points. Using GPS traces of buses in the city of Tampere, and of walking, biking and driving from the OpenStreetMap and Microsoft GeoLife projects, spectral bins were found to be among the most significant non-correlating features for differentiating between walking, bicycle, bus and driving, and were used to train classifiers with a fair accuracy. Auto- and cross-correlations, kurtoses and skewnesses were found to be of no use in the classification task. Useful features were found to have a fairly large (>0.4) correlation with each other. 相似文献
859.
Jonathan Levine Moira Zellner María Arquero de Alarcón Yoram Shiftan Dean Massey 《运输规划与技术》2018,41(5):463-480
This article reports on an integrated modeling exercise, conducted on behalf of the US Federal Highway Administration, on the potential for frequent automated transit shuttles (‘community transit’), in conjunction with improvements to the walking and cycling environment, to overcome the last-mile problem of regional rail transit and thereby divert travelers away from car use. A set of interlocking investigations was undertaken, including development of urban visualizations, distribution of a home-based survey supporting a stated-preference model of mode choice, development of an agent-based model, and alignment of the mode-choice and agent-based models. The investigations were designed to produce best-case estimates of the impact of community transit and ancillary improvements in reducing car use. The models in combination suggested significant potential to divert drivers, especially in areas that were relatively transit-poor to begin with. 相似文献
860.
针对欠驱动无人艇(USV)自主回收的需求,提出一种基于动态规划制导的跟踪控制方法。
在运动学层面,将平行接近制导(CB)与动态窗口算法(DWA)相结合,引导USV实现目标跟踪与动态避障;在动力学层面,针对模型参数及回收环境的不确定性,采用径向基函数神经网络(RBFNN)设计动力学滑模控制器,实现对制导输出的跟踪控制。随后,采用Lyapunov理论对系统的稳定性进行分析。
仿真结果表明,所提方法使USV具备了稳定跟踪性能,可有效规避回收过程中的动态障碍,并能自适应估计模型中的不确定因素和未知的环境干扰。
所提方法展现出较强的鲁棒性与灵活性,可为USV在动态环境下的回收进行制导与目标跟踪提供参考。