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51.
高水头船闸常采用第二类输水系统以满足船闸闸室内水流条件的要求,但往往工程量大、施工复杂。根据船闸闸址处地形、地质条件,抬高闸底奠基高程以达到降低工程量并简化施工的目的,并在采取一定消能手段后,采用闸墙长廊道侧支孔输水形式。通过物理模型,对旁海航电枢纽输水系统进行布置及优化,证实采取加大闸室初始淹没水深、闸室两侧出水口加设连续消力坎、优化进出水口布置及进水口布置帷墙等措施可达到预期效果。 相似文献
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With the increasing prevalence of geo-enabled mobile phone applications, researchers can collect mobility data at a relatively high spatial and temporal resolution. Such data, however, lack semantic information such as the interaction of individuals with the transportation modes available. On the other hand, traditional mobility surveys provide detailed snapshots of the relation between socio-demographic characteristics and choice of transportation modes. Transportation mode detection is currently approached using features such as speed, acceleration and direction either on their own or in combination with GIS data. Combining such information with socio-demographic characteristics of travellers has the potential of offering a richer modelling framework that could facilitate better transportation mode detection using variables such as age and disability. In this paper, we explore the possibility to include both elements of the environment and individual characteristics of travellers in the task of transportation mode detection. Using dynamic Bayesian Networks, we model the transition matrix to account for such auxiliary data by using an informative Dirichlet prior constructed using data from traditional mobility surveys. Results have shown that it is possible to achieve comparable accuracy with the most widely used classification algorithms while having a rich modelling framework, even in the case of sparse mobility data. 相似文献
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This paper generalizes and extends classical traffic assignment models to characterize the statistical features of Origin-Destination (O-D) demands, link/path flow and link/path costs, all of which vary from day to day. The generalized statistical traffic assignment (GESTA) model has a clear multi-level variance structure. Flow variance is analytically decomposed into three sources, O-D demands, route choices and measurement errors. Consequently, optimal decisions on roadway design, maintenance, operations and planning can be made using estimated probability distributions of link/path flow and system performance. The statistical equilibrium in GESTA is mathematically defined. Its multi-level statistical structure well fits large-scale data mining techniques. The embedded route choice model is consistent with the settings of O-D demands considering link costs that vary from day to day. We propose a Method of Successive Averages (MSA) based solution algorithm to solve for GESTA. Its convergence and computational complexity are analyzed. Three example networks including a large-scale network are solved to provide insights for decision making and to demonstrate computational efficiency. 相似文献
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近年来盾构机越来越多地应用于各种隧道工程中,其中地铁应用的数量最多,约占80%。现代盾构已演变成为一种高度智能化的大型工程机械装备,对其控制的好坏将直接影响到整个工程的施工成本和企业的经营效益,而通过单机核算降低机械成本是降低施工成本、提高企业效益的有效手段,因此推行盾构法施工单机核算显得尤为重要。文章结合地铁2222标施工项目,重点介绍了盾构法单机核算管理模式及其在施工中的应用。 相似文献
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In this paper, we perform a rigorous analysis on a link-based day-to-day traffic assignment model recently proposed in He et al. (2010). Several properties, including the invariance set and the constrained stability, of this dynamical process are established. An extension of the model to the asymmetric case is investigated and the stability result is also established under slightly more restrictive assumptions. Numerical experiments are conducted to demonstrate the findings. 相似文献
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文章介绍了广西交通职业技术学院交通土建类工程造价专业工学结合人才培养模式的实践现状,分析了开展工学结合人才培养模式中出现的问题,提出了工学结合人才培养模式有效运行的措施。 相似文献
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陈静 《武汉船舶职业技术学院学报》2011,(5):79-80,87
语言是文化的载体,思维的载体,中西方不同的思维模式决定了中西方语言应用中形态的差异性。本文对汉语和英语思维特征进行了描述和比较,目的是为了让语言学习者更好地了解语言背后的文化内涵,并能依照不同民族的思维特点,组织合适的语言。 相似文献
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根据Biot饱和多孔连续介质波动方程,基于Bardet对准饱和土的假设,提出了准饱和土二相介质波动方程;运用Helmholtz矢量分解和传递、透射矩阵法(TRM)推导出准饱和土中层状半空间受竖向荷载作用下的动力响应表达式;利用Muki虚拟桩法,在层状半空间建立了桩和准饱和土相互作用的第二类Fredholm积分方程,通过离散的数值积分方法求解积分方程,讨论了准饱和土中单桩竖向动力响应问题.算例分析表明,准饱和土中桩顶竖向阻抗随饱和度的减少而增大,与饱和土地基相比,明显偏大;桩侧孔压随饱和度的减小而增大,并沿着桩长迅速衰减;桩顶位移幅值在频率较小时变化明显,饱和度越小,位移峰值越大,当频率较大时,饱和度的变化对振幅的影响不大. 相似文献