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31.
本文提出了大卫星定位通信系统中采用四相扩频(Q-SS)技术,并沿用瑞士人给出的卫星转发器功率放大器的数学模型,推导了Q-SS信号通过卫星转发器后输出的表示式;通过进一步分析发现了采用Q-SS技术可以在信号解扩后完全消除三阶和五阶的互调干扰。  相似文献   
32.
介绍了一种用于铁路机车车辆油压减振器试验台的微机测控系统,提出了一套完整的从信号采集到数据处理的软、硬件设计方案,并详细介绍了系统控制原理及硬件和软件的设计与实现。  相似文献   
33.
One of the main causes of mortality worldwide is air pollution. To tackle this problem, local, regional and national governments have implemented policies to reduce emissions from industrial and on-road sources. However, when these policies are being designed, shipping emissions are often overlooked. There has been a drastic increase in the demand for cruises and its economic relevance is also growing in port-cities. Barcelona is Europe’s leading cruise port, and it is located near the centre of the city. In this context, this paper analyses the impact of cruise ships in the air quality of the entire city of Barcelona using a dataset with information about pollutants and the number of cruises arriving to the port. We show that there is a direct impact between cruises staying at the port and city pollution. Additionally, the size and age of the cruise also affect air quality. The larger (or newer) the cruise is, the higher the emission generated. Moreover, our simulations show that the whole city is affected by these emissions.  相似文献   
34.
Since 2006, Beijing lowered its public transit fares as a way to improve air quality. However, Beijing increased public transportation fare prices from December 28, 2014, and commuters pay for the distance they traveled rather than a flat fare. This paper explores the effect of Beijing public transit fares increase on air quality. We collect daily data of air pollution and weather variables and use synthetic control method of Abadie and Gardeazabal (2003) to select control units. We then estimate a difference-in-differences model and assess the effect of the policy on air quality index (AQI). We find a 16.28% increase in air pollution in short run. However, we find no longer-run effect on air quality.  相似文献   
35.
Most previous work in addressing the adaptive routing problem in stochastic and time-dependent (STD) network has been focusing on developing parametric models to reflect the network dynamics and designing efficient algorithms to solve these models. However, strong assumptions need to be made in the models and some algorithms also suffer from the curse of dimensionality. In this paper, we examine the application of Reinforcement Learning as a non-parametric model-free method to solve the problem. Both the online Q learning method for discrete state space and the offline fitted Q iteration algorithm for continuous state space are discussed. With a small case study on a mid-sized network, we demonstrate the significant advantages of using Reinforcement Learning to solve for the optimal routing policy over traditional stochastic dynamic programming method. And the fitted Q iteration algorithm combined with tree-based function approximation is shown to outperform other methods especially during peak demand periods.  相似文献   
36.
采用80C196KC的直流电机数字控制调速系统   总被引:1,自引:0,他引:1  
介绍了一种用80C196KC单片机和多功能芯片PSD311构成的直流电机数字控制调速系统,简述了系统的结构,并对系统的两个组成部分——调速控制系统和远程控制器的工作原理进行了较详细的阐述  相似文献   
37.
本文介绍了由混合信号处理器C8051F040和电机驱动芯片L298N构成的直流电机调速系统。并对相关寄存器设置及工作方式作了详细的说明,给出了系统硬件设计原理框图以及C语言控制程序。  相似文献   
38.
为改善交叉口排队长度管理,避免交叉口某个方向排队长度过长,采用强化学习理论建立了以平均排队长度差最小为优化目标的在线Q学习模型.针对控制性能指标相对于邻近的配时方案不敏感的特点,提出了以平均排队长度差作为基本单位重新构造奖励函数,目的是拉大各行为对应的Q值差距,提高模型的收敛速度和鲁棒性.集成Excel VBA,Vissim,Matlab建立了在线仿真平台,作为计算环境对算例进行了计算.算例中利用GPS数据对Vissim软件中车辆加减速度曲线进行了标定.计算结果表明以平均排队长度差作为优化目标能够提高各个方向排队长度的平衡性,优化整个交叉口的时空资源;建立的在线Q模型具有学习能力和较快的计算速度,模型能否收敛受到周期取值和可选行为数量的影响.  相似文献   
39.
Conducting hydrodynamic and physical motion simulation tests using a large-scale self-propelled model under actual wave conditions is an important means for researching environmental adaptability of ships. During the navigation test of the self-propelled model, the complex environment including various port facilities, navigation facilities, and the ships nearby must be considered carefully, because in this dense environment the impact of sea waves and winds on the model is particularly significant. In order to improve the security of the self-propelled model, this paper introduces the Q learning based on reinforcement learning combined with chaotic ideas for the model's collision avoidance, in order to improve the reliability of the local path planning. Simulation and sea test results show that this algorithm is a better solution for collision avoidance of the self navigation model under the interference of sea winds and waves with good adaptability.  相似文献   
40.
Conducting hydrodynamic and physical motion simulation tests using a large-scale self-propelled model under actual wave conditions is an important means for researching environmental adaptability of ships. During the navigation test of the self-propelled model, the complex environment including various port facilities, navigation facilities, and the ships nearby must be considered carefully, because in this dense environment the impact of sea waves and winds on the model is particularly significant. In order to improve the security of the self-propelled model, this paper introduces the Q learning based on reinforcement learning combined with chaotic ideas for the model's collision avoidance, in order to improve the reliability of the local path planning. Simulation and sea test results show that this algorithm is a better solution for collision avoidance of the self navigation model under the interference of sea winds and waves with good adaptability.  相似文献   
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