交叉口处现代有轨电车与其他机动车的平衡感应信号控制方法

介绍了现代有轨电车与机动车在交叉口的平衡感应信号控制方法,通过对现代有轨电车交叉口各入口排队车辆数的监测,实时改变信号配时,从而平衡各入口车辆排队长度;通过赋予现代有轨电车更高的排队权重,使现代有轨电车与同向机动车流减少停车时间,获得更多的通行时间,从而在保证其他机动车辆通行效率的同时,间接地实现现代有轨电车优先通行权。运用交通仿真软件对比分析各入口车辆平均排队长度、最大排队长度、总停车次数、平均延误与平均排队时长,确定各信号相位近似最优的最大感应绿灯信号时长。仿真结果表明,在排队长度与车辆延误方面,感应信号配时远优于定时信号配时;相比单纯的公共交通信号优先,感应信号控制更注重现代有轨电车和机动车每个乘客的通行权利。     

地基承载力的常用提法及其工程应用

地基承载力有多种提法,如容许承载力、极限承载力、承载力特征值、根据地基的荷载条件与土性指标计算的承载力、勘察单位在工程设计前提供的承载力等;明确各种地基承载力的工程意义,对应用是重要的.文章分析了获得各种常用承载力计算方法的前提条件,提出工程应用中应当注意的问题.对地基在垂直、水平荷载共同作用下的情况,给出了地基承载力的计算公式.为正确的应用各种提法的地基承载力提出了建议.     

关于CASS工艺在设计过程中值得优化问题的探讨

循环式活性污泥法CASS工艺在设计过程中的经验参数较多,而规范中仅对部分参数的取值范围进行了限定,故不同设计人员的计算结果可能会有很大出入。该文结合该工艺目前在国内的使用情况,对该工艺的适用条件、部分关键参数的取值及设计过程中值得优化的问题进行了总结,以期在类似工程中可结合各工程自身特点予以应用。     

Railway wheel-flat and rail surface defect modelling and analysis by time–frequency techniques

Damage to the surface of railway wheels and rails commonly occurs in most railways. If not detected, it can result in the rapid deterioration and possible failure of rolling stock and infrastructure components causing higher maintenance costs. This paper presents an investigation into the modelling and simulation of wheel-flat and rail surface defects. A simplified mathematical model was developed and a series of experiments were carried out on a roller rig. The time–frequency analysis is a useful tool for identifying the content of a signal in the frequency domain without losing information about its time domain characteristics. Because of this, it is widely used for dynamic system analysis and condition monitoring and has been used in this paper for the detection of wheel flats and rail surface defects. Three commonly used time–frequency analysis techniques: Short-Time Fourier Transform, Wigner–Ville transform and wavelet transform were investigated in this work.     

DEADBEAT COVARIANCE CONTROLLER DESIGN FOR SAMPLED-DATA SYSTEMS

ＭＰＬＥＤ－ＤＡＴＡ ＳＹＳＴＥＭＳTX＠霍沛军＠王子栋ＩｎｔｒｏｄｕｃｔｉｏｎＳａｍｐｌｅｄ－ｄａｔａｆｅｅｄｂａｃｋｃｏｎｔｒｏｌｈａｓｒｅｃｅｉｖｅｄｍｕｃｈａｔｅｎｔｉｏｎｉｎｔｈｅａｒｅａｏｆｃｏｎｔｒｏｌｓｙｓｔｅｍｄｅ－ｓｉｇｎｂｅｃａｕｓｅｏ...     

螺旋桨噪声的Wigner谱研究

就信号处理中的Ｗｉｇｎｅｒ方法及其螺旋桨噪声试验中的应用问题作了初步探讨。简要地介绍了Ｗｉｇｎｅｒ分布的基本概念及其物理意义，结合模型试验和数值计算给出了螺旋桨噪声的时－频联合分布及其在时域和频域中的能量分布。结果表明：Ｗｉｇｎｅｒ谱对于螺旋桨噪声的时域分布、线谱和非定常噪声的测试分析是十分有效的。     

浅析无碴轨道条件下客运专线的天窗时间

本文通过无碴轨道条件下客运专线维修内容、维修组织和维修时间的分析,得出了客运专线综合维修的控制因素和控制时间;合理确定了无碴轨道条件下客运专线矩形天窗时间,并提出了合理利用客运专线运行图三角区缩短天窗时间,使之与衔接普速铁路的天窗时间协调,组织＂夕发朝至＂列车的思路。     

泵站厂房中吊车竖向荷载下吊车梁最大内力值及作用面的计算方法

在厂房中设有吊车来起吊大构件,运行时吊车在吊车梁上移动,对梁产生的最大内力值及作用面在变化;而吊车梁等自重产生的内力值则随截面位置的不同而变化。该文推导用公式一次即能准确计算出吊车梁的最大内力值及作用位置,以便设计吊车梁。     

从坞容率的变化，分析中国修船能力预期和对策

文章根据国内修船坞容量的不完全统计数据，从船舶修理坞容率变化的观点，分析了中国修船能力的预期和建议及采取的对策，同时还介绍了新加坡的船舶修理和改装的情况，可供同行参考。     

Forecasting container throughput based on wavelet transforms within a decomposition-ensemble methodology: a case study of China

To improve predictive accuracy, new hybrid models are proposed for container throughput forecasting based on wavelet transforms and data characteristic analysis (DCA) within a decomposition-ensemble methodology. Because of the complexity and nonlinearity of the time series of container throughputs at ports, the methodology decomposes the original time series into several components, which are rather simpler sub-sequences. Consequently, difficult forecasting tasks are simplified into a number of relatively easier subtasks. In this way, the proposed hybrid models can improve the accuracy of forecasting significantly. In the methodology, four main steps are involved: data decomposition, component reconstruction based on the DCA, individual prediction for each reconstructed component, and ensemble prediction as the final output. An empirical analysis was conducted for illustration and verification purposes by using time series of container throughputs at three main ports in Bohai Rim, China. The results suggest that the proposed hybrid models are able to forecast better than do other benchmark models. Forecasting may facilitate effective real-time decision making for strategic management and policy drafting. Predictions of container throughput can help port managers make tactical and operational decisions, such as operations planning in ports, the scheduling of port equipment, and route optimization.