Analytical and simulation approaches to understand combined effects of transit signal priority and road-space priority measures

Transit signal priority (TSP) may be combined with road-space priority (RSP) measures to increase its effectiveness. Previous studies have investigated the combination of TSP and RSP measures, such as TSP with dedicated bus lanes (DBLs) and TSP with queue jump lanes (QJLs). However, in these studies, combined effects are usually not compared with separate effects of each measure. In addition, there is no comprehensive study dedicated to understanding combined effects of TSP and RSP measures. It remains unclear whether combining TSP and RSP measures creates an additive effect where the combined effect of TSP and RSP measures is equal to the sum of their separate effects. The existence of such an additive effect would suggest considerable benefits from combining TSP and RSP measures. This paper explores combined effects of TSP and RSP measures, including TSP with DBLs and TSP with QJLs. Analytical results based on time-space diagrams indicate that at an intersection level, the combined effect on bus delay savings is smaller than the additive effect if there is no nearside bus stop and the traffic condition in the base case is under-saturated or near-saturated. With a near-side bus stop, the combined effect on bus delay savings at an intersection level can be better than the additive effect (or over-additive effect), depending on dwell time, distance from the bus stop to the stop line, traffic demand, and cycle length. In addition, analytical results suggest that at an arterial level, the combined effect on bus delay savings can be the over-additive effect with suitable signal offsets. These results are confirmed by a micro-simulation case study. Combined effects on arterial and side-street traffic delays are also discussed.     

预抛高法处理桥头跳车问题

分析了桥头跳车的原因．介绍了解决这一问题的主要方法．深入探讨了预抛高法处理桥头跳车措施的原理．提出其抛高量的估算是该法的关键。     

桥头跳车问题研究综述

该文在查阅大量资料基础上,对桥头过渡段沉降控制指标、地基沉降控制方法、台背填料处理方法及桥台和桥头过渡段路基刚柔过渡的方法等桥头跳车问题进行分析,简要介绍了其研究现状,并提出了研究方法和方向。     

桥头跳车原因及防治对策

通过对桥头跳车产生原因的分析，进一步提出产生桥头跳车的相应防治对策。     

非线性横摇跳跃现象的预报方法

船舶在波浪中的大角度横摇运动、本质上是非线性振动问题。本文以非线性振动理论中的平均法为基础,推演了船模非线性横摇运动的幅频和相频曲线的计算公式,可预报其跳跃现象。与应用新型可控力矩式横摇激振装置的船模试验结果相比较,一致性较好。     

Mixing over the steep side of the Cycladic Plateau in the Aegean Sea

Intensive microstructure sampling over the southern slope of the Cycladic Plateau found very weak mixing in the pycnocline, centered on a thin minimum of diapycnal diffusivity with Kρ=1.5×¹⁰−6 m² s^− 1. Below the pycnocline, Kρ increased exponentially in the bottom 200 m, reaching 1 × 10^− 4 m² s^− 1 a few meters above the bottom. Near-bottom mixing was most intense where the bottom slope equaled the characteristic slope of the semi-diurnal internal tide. This suggests internal wave scattering and/or generation at the bottom, a conclusion supported by near-bottom dissipation rates increasing following rising winds and with intensifying internal waves. Several pinnacles on the slope were local mixing hotspots. Signatures included a vertical line of strong mixing in a pinnacle's wake, an hydraulic jump or lee wave over a downstream side of the summit, and a ‘beam’ sloping upward at the near-inertial characteristic slope. Because dissipation rate averages were dominated by strong turbulence, ?/νN² > 100, the effect on Kρ of alternate mixing efficiencies proposed for this range of turbulent intensity is explored.     

地聚合物注浆加固技术在“桥头跳车”病害治理中的应用

针对"桥头跳车"病害问题进行成因分析,对地聚合物注浆加固工艺的技术特点进行简介,通过实际工程案例的介绍对地聚合物注浆加固工艺在"桥头跳车"病害治理中的效果进行详细分析。采用地聚合物注浆加固工艺对浙江地区某桥梁台背填土进行注浆加固,增大台后路基的强度和承载力,并通过对路桥接顺段路面各位置的沉降监测,评价、分析注浆加固效果。通过地聚合物注浆加固工艺改善和延缓桥头台背因回填土方下沉和软土路基沉降形成的"桥头跳车"病害。     

公路涵洞两侧及桥头跳车的病害机理及预防措施

结合元磨高速公路某土建合同段涵洞两侧及桥头施工的实践,通过对公路涵洞两侧及桥头出现跳车的原因及机理的分析,提出了相应的预防措施。     

论高速公路桥(涵)台背"跳车"的原因分析及防治措施

通过时高速公路运行过程中桥头“跳车”的原因进行简要分析，并通过工程实践及研究，对这一问题的防治提出了新的处理方法：用粉喷桩和石灰桩加固桥（涵）台背，提高土体的整体强度和压实度，减少工后沉降，有效地减轻桥头跳车现象，保证行车的安全舒适。     

高铁定向天线同向辐射覆盖下的性能分析

通过理论分析和仿真发现,高铁移动通信网络在定向天线同向覆盖模式下,切换重叠区对于源基站是小区边缘,但对于目标基站却是信号最强的区域,即列车从弱信号区切换到强信号区不存在乒乓效应,可以提高车载台越区切换触发率.由于这种覆盖模式是同向辐射,列车在穿越切换区和基站时都不存在多普勒突跳,因此可降低移动通信系统的传输误码率.