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J.W.C. Van Lint Serge P. Hoogendoorn 《Computer-Aided Civil and Infrastructure Engineering》2010,25(8):596-612
Abstract: Fusing freeway traffic data such as spot speeds and travel times from a variety of traffic sensors (loops, cameras, automated vehicle identification systems) into a coherent, consistent, and reliable picture of the prevailing traffic conditions (e.g., speeds, flows) is a critical task in any off‐ or online traffic management or data archival system. This task is challenging as such data differ in terms of spatial and temporal resolution, accuracy, reliability, and most importantly in terms of spatiotemporal semantics. In this article, we propose a data fusion algorithm (the extended generalized Treiber‐Helbing filter [the EGTF]) which, although heuristic in nature, uses basic notions from traffic flow theory and is generic in the sense that it does not impose any restrictions on the way the data are structured in a temporal or spatial way. This implies that the data can stem from any data source, given they provide a means to distinguish between free flowing and congested traffic. On the basis of (ground truth and sensor) data from a micro‐simulation tool, we demonstrate that the EGTF method results in accurate reconstructed traffic conditions and is robust to increasing degrees of data corruption. Further research should focus on validating the approach on real data. The method can be straightforwardly implemented in any traffic data archiving system or application which requires consistent and coherent traffic data from traffic sensors as inputs. 相似文献
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《Planning》2016,(4)
智能交通在当今社会的应用非常普遍,随着世界人口的急剧上升,交通堵塞问题也日益严重地影响着人们的生活。随着互联网技术的日益发展,大量的信息流入网络,将来也会是一个数据的时代,大数据技术在未来有着非常关键的作用,智能交通与大数据相结合也是必然趋势。文章将大数据分析平台Hadoop应用于智能交通,提出了Hadoop应用基站数据改善智能交通的方法,并分析、介绍了实现此应用需要的各个模块和实现方法,考虑到了现实情况中出现的问题和解决方案,高效地运用了之前难以利用和处理的大量数据资源,该应用的研究对智能交通系统的完善起着很大的作用,也有助于解决越来越严重的交通堵塞问题。 相似文献
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城镇地籍信息系统建库过程中的属性录入是一项工作量大且容易出错的工作,本文探讨了一种简便高效的录入方法。 相似文献
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本文以Cooke提出的摩擦桩荷载传递物理模型为基础,通过复合地基中单桩工作机理和沉降特性的分析,提出了一种计算柔性核单桩沉降的简化方法。 相似文献
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Ashish Bhaskar Edward Chung André‐Gilles Dumont 《Computer-Aided Civil and Infrastructure Engineering》2011,26(6):433-450
Abstract: This article presents a methodology that integrates cumulative plots with probe vehicle data for estimation of travel time statistics (average, quartile) on urban networks. The integration reduces relative deviation among the cumulative plots so that the classical analytical procedure of defining the area between the plots as the total travel time can be applied. For quartile estimation, a slicing technique is proposed. The methodology is validated with real data from Lucerne, Switzerland and it is concluded that the travel time estimates from the proposed methodology are statistically equivalent to the observed values. 相似文献
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《Planning》2015,(1)
近年,MOOC教育在国内外发展得如火如荼,为学生和教师开辟了一种全新的学习交流平台。MOOC凭借其本身海量的教育资源以及使用过程中积累的学习行为数据,成为大数据的显著代表。本文首先论述MOOC所体现的大数据"4V"特征。然后阐述面向MOOC的大数据辨析方法。最后结合MOOC大数据辨析,给出两点关于我国高等教育的启示及国外相关案例剖析。 相似文献
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《Planning》2022,(1)
8154型拖网渔船的螺旋桨导管腐蚀情况十分严重,使用寿命最短的只有1~2年。本文给出了一种简易的玻璃钢修复方法,可使导管的使用寿命递增一年。这种简易修复法的投入产出比,仅为1:10。 相似文献
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Eleni I. Vlahogianni Matthew G. Karlaftis & John C. Golias 《Computer-Aided Civil and Infrastructure Engineering》2008,23(7):536-548
Abstract: Recognizing temporal patterns in traffic flow has been an important consideration in short-term traffic forecasting research. However, little work has been conducted on identifying and associating traffic pattern occurrence with prevailing traffic conditions. We propose a multilayer strategy that first identifies patterns of traffic based on their structure and evolution in time and then clusters the pattern-based evolution of traffic flow with respect to prevailing traffic flow conditions. Temporal pattern identification is based on the statistical treatment of the recurrent behavior of jointly considered volume and occupancy series; clustering is done via a two-level neural network approach. Results on urban signalized arterial 90-second traffic volume and occupancy data indicate that traffic pattern propagation exhibits variability with respect to its statistical characteristics such as deterministic structure and nonlinear evolution. Further, traffic pattern clustering uncovers four distinct classes of traffic pattern evolution, whereas transitional traffic conditions can be straightforwardly identified . 相似文献
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围护结构冷负荷是建筑冷负荷的重要组成部分。传统的建筑围护结构冷负荷计算方法需要大量详细的建筑信息。城市规划阶段通过控制性详细规划只能获得建筑功能、建筑高度、容积率等有限的信息,限制了传统方法的应用。本文结合城市规划阶段特点,依据建筑体形系数及窗墙比的不同取值,将公共建筑划分为24类,提出了公共建筑围护结构冷负荷的简单计算方法。以北京地区为例,对每一类建筑进行了不同底面边长及高度条件时的建筑围护结构冷负荷计算,提出了适用于北京地区的简单估算公式,并分析了建筑围护结构冷负荷与建筑底面边长、建筑高度及建筑体形系数的关系。 相似文献
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A Generic Approach to Estimate Freeway Traffic Time Using Vehicle ID‐Matching Technologies
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Pengfei Li Reginald R. Souleyrette 《Computer-Aided Civil and Infrastructure Engineering》2016,31(5):351-365
New technologies have emerged to estimate the travel time on freeways by matching certain unique identifications of passing vehicles at different locations. These types of technologies share many similarities despite having different mechanisms. In this article, a generic method is presented to estimate freeway travel times using vehicle ID‐matching technologies. In particular, the new method addresses two long‐standing challenges: outlier screening and travel time estimation. Innovations include (1) using both statistical methods and traffic flow theory to screen outliers; and (2) accounting for mechanisms of various equipment measurement errors. The effectiveness of the proposed method is demonstrated using simulation and shown to be more accurate and responsive to travel time changes than methods based on the use of traditional inductive loops. 相似文献
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尹树林 《地下空间与工程学报》2018,14(3):579-584
城市核心区的地下空间开发已经进入快速发展期,建设城市地下交通环廊是改善区域交通与环境的重要措施, 多应用于商务区、公共服务核心区等交通压力大、慢行环境品质要求较高的区域,是用于连接各地块地下车库并直接与城市道路相衔接。目前相关研究及规范对地下交通环廊功能定位、规划设计中应重点考虑因素的论证尚不成熟,且受政策、管理、规划设计、宣传等影响,已运营的地下交通环廊普遍存在运营效率不高等问题。本文重点从规划设计层面分析了环廊利用效率不高的原因,结合既有工程运营实践分析了既有设计规范的不合理点,并提出了规划设计新思路与新标准,并应用于西咸新区能源金贸区地下环廊规划设计实践,供行业实践及规范进一步修编参考。 相似文献
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讨论了目前连续变化钢筋尺寸翻样的几种方法,介绍了利用Autocad进行翻样的优势,并用lisp语言实现翻样的自动化,最后结合某桥墩实例详细的描述了利用lisp语言实现连续变化钢筋尺寸快速翻样的一般步骤。 相似文献
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There is an abundance of evidence supporting a cross-sectional association between poor housing and poor health, but relatively few studies have examined the relationship between housing and health over time. Using contemporary longitudinal data from seven yearly waves (1996–2002) of the British Household Panel Survey, summary statistics and multivariate first-differences regression models, this study provides robust evidence of a dynamic relationship between housing conditions and health. Worsening housing conditions, measured in three domains, are independently associated with deterioration in health, especially the number of reported health problems in women. These findings add to the longitudinal evidence of the effect of housing conditions. It is concluded that improvements in housing conditions produce health benefits and the findings are important for proposed housing interventions to maximise health benefits and prioritise areas of housing investment. 相似文献
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为经济便捷地对膨胀型饰面防火涂料进行防火性能检测,设计了1种简易的防火性能测试装置.在一些简化假设的基础上,针对该测试方法,提出了1个包含6个关键变量的传热数学模型.研究发现:6个关键变量中,反映外炭化层隔热能力以及热源综合影响的参数i值对防火涂料防火保护时间的影响最为关键.利用曲线拟合,获得i值的计算公式,并通过测试起始涂覆厚度不同的1组透明饰面型防火涂料样品,估算出了该防火涂料的i值. 相似文献