The problems of airport landside capacity assessment are of industry-wide interest. Evaluation of landside capacity enables airport operators and airport designers to identify passenger and baggage flow bottlenecks, i...The problems of airport landside capacity assessment are of industry-wide interest. Evaluation of landside capacity enables airport operators and airport designers to identify passenger and baggage flow bottlenecks, identify the primary cause of bottlenecks formation and take measures mitigating the impact of bottlenecks on the airport terminal operation. Many studies dealing with the problems of airport landside capacity are focused mainly on the processing part of the airport terminal and consider the airport terminal to be an isolated system. Even the most of models of airport landside operations developed using various simulation （both generic and dedicated） software packages （e.g., PaxSim, SLAM, WITNESS, ARENA or EXTEND） are designed for simulating the passenger and baggage flows only between curb-side and apron. Although this approach provides valuable data concerning capacity, delays or processing bottlenecks, in some cases identified capacity constraints are only the symptoms of the actual problem. In order to discover the cause of the problem, it is necessary to consider the airport terminal as an integral part of much more complex regional, national or international transportation system. This article reflects the above mentioned requirements and introduces an innovative approach to passenger and baggage flow simulation based on the fact that airport terminal is considered as an integral part of air passenger door-to-door transportation process.展开更多
The PICOSEC Micromegas(MM)is a precise timing gaseous detector based on a Cherenkov radiator coupled with a semi-transparent photocathode and an MM amplifying structure.It features a two-stage amplification process th...The PICOSEC Micromegas(MM)is a precise timing gaseous detector based on a Cherenkov radiator coupled with a semi-transparent photocathode and an MM amplifying structure.It features a two-stage amplification process that leads to a significant deterioration of non-uniformity when scaling up to larger areas.Since the performance of gaseous detectors is highly dependent on the choice of working gas,optimizing the gas mixture offers a promising solution to improve the uniformity performance.This paper addresses these challenges through a combined approach of simulation based on Garfield++and experimental studies.The simulation investigates the properties of different mixing fractions of gas mixtures and their impact on detector performance,including gain uniformity and time resolution.To verify the simulation results,experimental tests were conducted using a multi-channel PICOSEC MM prototype with different gas mixtures.The experimental results are consistent with the findings of the simulation,indicating that a higher concentration of neon significantly improves the detector’s gain uniformity.Furthermore,the influence of gas mixtures on time resolution was explored as a critical performance indicator.The study presented in this paper offers valuable insights for improving uniformity in large-area PICOSEC MM detectors and optimizing overall performance.展开更多
正交时频空(Orthogonal Time and Frequency Space, OTFS)作为6G候选调制方案,旨在支持下一代无线通信系统在高速移动场景的异构性需求。为解决系统硬件成本高昂和功耗高的问题,构建了低精度量化OTFS系统,并推导了b-bit量化最小均方误差...正交时频空(Orthogonal Time and Frequency Space, OTFS)作为6G候选调制方案,旨在支持下一代无线通信系统在高速移动场景的异构性需求。为解决系统硬件成本高昂和功耗高的问题,构建了低精度量化OTFS系统,并推导了b-bit量化最小均方误差(Minimum Mean Square Error, MMSE)检测矩阵。通过加性量化噪声模型(Additive Quantization Noise Model, AQNM)推导系统输入-输出关系,并基于MMSE接收机评估系统误比特率(Bit Error Rate, BER)和可达速率性能。仿真结果表明,4-bit量化较全精度量化系统性能在BER=10^(-2)处损失约1 dB,可达速率减小约0.98%;8-bit量化与全精度量化的可达速率相当,验证了分析结果的有效性。展开更多
针对受外部环境干扰和输入受限影响的欠驱动水面船舶的轨迹跟踪控制问题,设计了一种带有扰动观测器的复合控制方法。首先,设计了一种快速有限时间干扰观测器(finite time disturbance observer, FTDO),并通过Lyapunov稳定性分析证明其...针对受外部环境干扰和输入受限影响的欠驱动水面船舶的轨迹跟踪控制问题,设计了一种带有扰动观测器的复合控制方法。首先,设计了一种快速有限时间干扰观测器(finite time disturbance observer, FTDO),并通过Lyapunov稳定性分析证明其有效性。与普通的FTDO相比,新观测器即使初始误差远离原点,也能使估计误差快速收敛到零。然后,基于快速FTDO,利用反步法设计了一种新的轨迹跟踪复合控制器,实现了水面船舶控制系统轨迹跟踪误差在有限时间内趋于零点半径任意小的邻域内。最后,通过仿真将所设计的控制器与现有控制器进行比较,验证了所提方法的有效性。展开更多
文摘The problems of airport landside capacity assessment are of industry-wide interest. Evaluation of landside capacity enables airport operators and airport designers to identify passenger and baggage flow bottlenecks, identify the primary cause of bottlenecks formation and take measures mitigating the impact of bottlenecks on the airport terminal operation. Many studies dealing with the problems of airport landside capacity are focused mainly on the processing part of the airport terminal and consider the airport terminal to be an isolated system. Even the most of models of airport landside operations developed using various simulation （both generic and dedicated） software packages （e.g., PaxSim, SLAM, WITNESS, ARENA or EXTEND） are designed for simulating the passenger and baggage flows only between curb-side and apron. Although this approach provides valuable data concerning capacity, delays or processing bottlenecks, in some cases identified capacity constraints are only the symptoms of the actual problem. In order to discover the cause of the problem, it is necessary to consider the airport terminal as an integral part of much more complex regional, national or international transportation system. This article reflects the above mentioned requirements and introduces an innovative approach to passenger and baggage flow simulation based on the fact that airport terminal is considered as an integral part of air passenger door-to-door transportation process.
基金supported by the National Natural Science Foundation of China(12125505).
文摘The PICOSEC Micromegas(MM)is a precise timing gaseous detector based on a Cherenkov radiator coupled with a semi-transparent photocathode and an MM amplifying structure.It features a two-stage amplification process that leads to a significant deterioration of non-uniformity when scaling up to larger areas.Since the performance of gaseous detectors is highly dependent on the choice of working gas,optimizing the gas mixture offers a promising solution to improve the uniformity performance.This paper addresses these challenges through a combined approach of simulation based on Garfield++and experimental studies.The simulation investigates the properties of different mixing fractions of gas mixtures and their impact on detector performance,including gain uniformity and time resolution.To verify the simulation results,experimental tests were conducted using a multi-channel PICOSEC MM prototype with different gas mixtures.The experimental results are consistent with the findings of the simulation,indicating that a higher concentration of neon significantly improves the detector’s gain uniformity.Furthermore,the influence of gas mixtures on time resolution was explored as a critical performance indicator.The study presented in this paper offers valuable insights for improving uniformity in large-area PICOSEC MM detectors and optimizing overall performance.
文摘正交时频空(Orthogonal Time and Frequency Space, OTFS)作为6G候选调制方案,旨在支持下一代无线通信系统在高速移动场景的异构性需求。为解决系统硬件成本高昂和功耗高的问题,构建了低精度量化OTFS系统,并推导了b-bit量化最小均方误差(Minimum Mean Square Error, MMSE)检测矩阵。通过加性量化噪声模型(Additive Quantization Noise Model, AQNM)推导系统输入-输出关系,并基于MMSE接收机评估系统误比特率(Bit Error Rate, BER)和可达速率性能。仿真结果表明,4-bit量化较全精度量化系统性能在BER=10^(-2)处损失约1 dB,可达速率减小约0.98%;8-bit量化与全精度量化的可达速率相当,验证了分析结果的有效性。
文摘针对受外部环境干扰和输入受限影响的欠驱动水面船舶的轨迹跟踪控制问题,设计了一种带有扰动观测器的复合控制方法。首先,设计了一种快速有限时间干扰观测器(finite time disturbance observer, FTDO),并通过Lyapunov稳定性分析证明其有效性。与普通的FTDO相比,新观测器即使初始误差远离原点,也能使估计误差快速收敛到零。然后,基于快速FTDO,利用反步法设计了一种新的轨迹跟踪复合控制器,实现了水面船舶控制系统轨迹跟踪误差在有限时间内趋于零点半径任意小的邻域内。最后,通过仿真将所设计的控制器与现有控制器进行比较,验证了所提方法的有效性。
