间歇式沥青拌和站冷料供给系统流量的标定方法

以实例介绍间歇式沥青拌和冷料供给系统流量的标定方法和步骤，以确保冷料供给器按目标配合比准确供料，使沥青混合料的生产配比更加接近目标配比，保证拌和成品料的质量。     

沥青混凝土转运车对提高道路施工质量的试验研究

对道路摊铺过程中采用摊铺机直接摊铺作业和采用徐工AT1000A型转运车与摊铺机联合施工作业的试验路面效果进行了对比,分析了摊铺温度场和骨料摊铺效果.结果证明使用沥青混凝土转运车是提高道路施工质量的有效手段.     

特种弹药铁路运输可调式定位装置研究

概述了特种弹药铁路运输可调试定位装置的主要功能、技术要求、主要战技术指标，介绍了特种弹药铁路运输采用的从箱体顶部固定方式，并进行了相应的可调式定位装置研究，将装置分为整体固定和单点独立固定两种，用于固定弹箱在敞车内的位置，确保弹体运输安全。     

舱口盖强度计算方法

在某集装箱舱口盖结构强度的有限元计算中，对舱口盖周围水平限位器和支撑块处的约束以及顶部压紧器处的关联程度进行了模拟，分别讨论了在垂向设计载荷的情况下，水平限位器、支撑块处的不同约束以及顶部压紧器的不同关联程度对舱口盖应力分布的影响，得出更符合实际情况的舱口盖结构强度计算方法。     

基于DSP的船舶电力推进系统滤波装置控制器设计

小型船舶电力系统中非线性负载多、谐波污染严重.针对这一情况,本文设计一款基于DSP的电力系统滤波装置控制器,该控制器结构简单,稳定性好,实验证明该控制器能有效降低谐波污染,具有一定实用价值.     

城市轨道交通钢轨电位和新型回流装置研究

以成都地铁为例,基于钢轨绝缘节的老化和单向导通装置频繁导通问题,将车辆段及停车场等效为小电阻接地支路进行仿真。仿真结果表明,小电阻接地支路可使正线钢轨电位最大提升27.2 V,威胁了正线的安全运营。据此提出一种应用于车辆段与停车场的新型钢轨回流装置,并介绍其控制方法。该新型钢轨回流装置具有辅助列车安全通过绝缘节遏制车辆段与停车场内杂散电流、评估钢轨绝缘节绝缘性能和测量出入段线钢轨过渡电阻的功能。     

STX4型驮背多功能运输车车体制造工艺

介绍了STX4型驮背多功能运输车的主要结构特点,分析了车体制造过程中的控制要点和难点,同时对制造难点提出了应对措施,有效保证了STX4型驮背多功能运输车的制造质量。     

某型汽轮机超速脱扣试验浅析

某型汽轮机的超速保护装置采用脱扣结构,文章针对该汽轮机的超速脱扣结构进行分析,总结此种超速脱扣装置的装配要求和试验方法,以利于该型汽轮机的生产。     

Validation of an extended discrete first-order model with variable speed limits

This paper validates the prediction model embedded in a model predictive controller (MPC) of variable speed limits (VSLs). The MPC controller was designed based on an extended discrete first-order model with a triangular fundamental diagram. In our previous work, the extended discrete first-order model was designed to reproduce the capacity drop and the propagation of jam waves, and it was validated with reasonable accuracy without the presence of VSLs. As VSLs influence traffic dynamics, the dynamics including VSLs needs to be validated, before it can be applied as a prediction model in MPC. For conceptual illustrations, we use two synthetic examples to show how the model reproduces the key mechanisms of VSLs that are applied by existing VSL control approaches. Furthermore, the model is calibrated by use of real traffic data from Dutch freeway A12, where the field test of a speed limit control algorithm (SPECIALIST) was conducted. In the calibration, the original model is extended by using a quadrangular fundamental diagram which keeps the linear feature of the model and represents traffic states at the under-critical branch more accurately. The resulting model is validated using various traffic data sets. The accuracy of the model is compared with a second-order traffic flow model. The performance of two models is comparable: both models reproduce accurate results matching with real data. Flow errors of the calibration and validation are around 10%. The extended discrete first-order model-based MPC controller has been demonstrated to resolve freeway jam waves efficiently by synthetic cases. It has a higher computation speed comparing to the second-order model-based MPC.     

A methodology for evaluating the performance of model-based traffic prediction systems

Model-based traffic prediction systems (mbTPS) are a central component of the decision support and ICM (integrated corridor management) systems currently used in several large urban traffic management centers. These models are intended to generate real-time predictions of the system’s response to candidate operational interventions. They must therefore be kept calibrated and trustworthy. The methodologies currently available for tracking the validity of a mbTPS have been adapted from approaches originally designed for off-line operational planning models. These approaches are insensitive to the complexity of the network and to the amount and quality of the data available. They also require significant human intervention and are therefore not suitable for real-time monitoring. This paper outlines a set of criteria for designing tests that are appropriate for the mbTPS task. It also proposes a test that meets the criteria. The test compares the predictions of the mbTPS in question to those of a model-less alternative. A t-test is used to determine whether the predictions of the mbTPS are superior to those of the model-less predictor. The approach is applied to two different systems using data from the I-210 freeway in Southern California.