基于鲁棒性的空调自控系统设计

分析了空调自控系统的主要特性,并介绍了一种基于组合自校正控制策略的自适应控制算法,同时采取一些解决工程实际问题的辅助措施,以增强系统的抗干扰能力和对未建模动态、时变参数的鲁棒性.     

Liner ship route schedule design with port time windows

This paper examines a practical tactical liner ship route schedule design problem, which is the determination of the arrival and departure time at each port of call on the ship route. When designing the schedule, the availability of each port in a week, i.e., port time window, is incorporated. As a result, the designed schedule can be applied in practice without or with only minimum revisions. This problem is formulated as a mixed-integer nonlinear nonconvex optimization model. In view of the problem structure, an efficient holistic solution approach is proposed to obtain global optimal solution. The proposed solution method is applied to a trans-Atlantic ship route. The results demonstrate that the port time windows, port handling efficiency, bunker price and unit inventory cost all affect the total cost of a ship route, the optimal number of ships to deploy, and the optimal schedule.     

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。     

Measuring community reaction to urban transportation impacts using Von Neumann‐Morgenstern utility theory

This paper attempts to measure the impacts of urban transportation system improvements or changes on the community. The community's perceptions of the impacts are represented by its utilities (or disutilities) over various ranges of values of the multiple attributes representing these impacts. The utility technique used in the evaluation is based upon von Neumann‐Morgenstern (vN‐M, 1947) Utility Theory, and is applied using Raiffa's (1970) Fractile Method.

The paper specifically applies the technique to model the perceptions of five subgroups within a community to the impact of a new light rail transit system that is being incorporated in the transportation system of the City of Calgary.

Results of the modeling indicate explicitly how the community changes its perception over ranges of values of the attributes evaluated. Biases of various subgroups within the community over these attributes are also shown. Statistical tests indicate that aggregated utility perceptions can represent the utility perceptions of the individual subgroups quite reasonably.     

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.     

国产内燃机车排气阀焊修后焊接过热区的脆化及使用寿命分析

本文采用焊接热模拟和时效热处理等方法处理试件,通过金相分析和性能试验,研究了内燃机车排气阀焊修后焊接过热区的脆化及其使用寿命问题.     

中小型车站Smart2.0系统的方案与安全性分析

作者介绍了适合中小型车站Smart 2.0系统的一种可行方案,通过对该系统安全性的分析,该方案具有结构简单、安全可靠、节约投资等特点。     

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。