检索结果-内蒙古大学图书馆

SSRN 2024年

作者： Yang, Lei Sun, Zhanbo Liu, Yafei Chen, Linbin School of Transportation and Logistics Southwest Jiaotong University Chengdu China National Engineering Laboratory of Integrated Transportation Big Data Application Technology Chengdu China

The paper presents a robust control method for effectively managing uncertainties and communication loss in a connected automated vehicle (CAV) platoon under the multiple-predecessor following (MPF) topology. The proposed approach incorporates uncertainties in vehicle dynamics, such as vehicle parameters and environmental resistances, into the closed-loop platoon system to enhance the robustness of the platoon controller. The impacts of communication loss are analyzed specifically for the MPF topology, considering potential disruptions in information flow among different numbers and locations of predecessors in a CAV platoon. A novel formulation of desired spacing, suitable for the CAV platoon with MPF topology under communication loss, is then developed based on the constant time headway (CTH) policy. Furthermore, the paper derives and proves the sufficient and necessary conditions for the local stability of the proposed robust platoon controller using Kharitonov's theorem. The sufficient conditions for string stability are also discussed through frequency-domain analysis. These conditions establish the stability region for the robust controller of a CAV platoon with varying locations and numbers of unconnected predecessors. Simulation experiments are conducted to demonstrate that the stability region of the controller diminishes as the number of unconnected predecessors increases, with the greatest impact observed when the communication with the nearest connected predecessor is lost. Additionally, the control performance is affected by uncertain dynamics and the range of time headway, resulting in a significant reduction in the stability region. The findings highlight the importance of fine-tuning control parameters within the stability region guided by the derived stability conditions to ensure both local and string stability of CAV platoons. © 2024, The Authors. All rights reserved.

关键词： Topology

来源：评论

学校读者我要写书评

暂无评论

Research on the Network Operation Mode of High-Speed Rail Express 5th

Research on the Network Operation Mode of High-Speed Rail Ex...

引用

5th International Conference on Smart Vehicular technology, transportation, Communication and applications, VTCA 2022

作者： Wang, Yongcheng Li, Yi Sun, Yunhao Chen, Tao Department of Transportation China Railway Beijing Group Co. Ltd Beijing100860 China School of Transportation and Logistics Southwest Jiaotong University Chengdu610031 China National and Local Joint Engineering Laboratory of Comprehensive Intelligent Transportation Southwest Jiaotong University Chengdu610031 China National Engineering Laboratory of Integrated Transportation Big Data Application Technology Chengdu China

ISBN: (纸本)9789819908479

Taking high-speed rail express as the research object, the research is carried out on the network operation mode of high-speed rail express. Taking the minimum cost of transportation enterprises as the optimization goal, the decision model of the network operation mode of high-speed rail express is constructed by taking the remaining capacity limit of the middle section of the high-speed rail express line network, the carrying capacity and operating cost restrictions corresponding to the high-speed rail express operating mode, and the overall transportation task limit as constraints. Taking the train operation map in the third quarter of 2021 as a reference, the decision-making model for the construction of the operation mode is verified, and the ARIMA model is used to calculate the OD of each city node in the prospect year, and the carrying capacity and operation cost of different operation modes are analyzed and calculated. The results show that: my country should adopt a high-speed rail express network operation mode combining direct transit. Transit transportation completes the collection and distribution of small batches of goods, improves the full load rate of high-speed rail freight trains, expands the scope of services, and completes long-distance transportation of large batches of goods through direct transportation, improving economies of scale. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Operating costs

来源：评论

学校读者我要写书评

暂无评论

Seasonal and Period Division Method for Dynamic Passenger Flow of High-Speed Railway 5th

Seasonal and Period Division Method for Dynamic Passenger Fl...

引用

5th International Conference on Smart Vehicular technology, transportation, Communication and applications, VTCA 2022

作者： Han, Hui Zou, Xinqian Gao, Yiyuan Guo, Xiuyun China Railway Beijing Group Co. Ltd. Beijing300010 China School of Transportation and Logistics Southwest Jiaotong University Chengdu610031 China National and Local Joint Engineering Laboratory of Comprehensive Intelligent Transportation Southwest JiaoTong University Chengdu610031 China National Engineering Laboratory of Integrated Transportation Big Data Application Technology Beijing China

ISBN: (纸本)9789819908479

With the large-scale construction of China's high-speed railway network, the demand for passenger flow is growing and varies in different seasons. Therefore, refinement operational requirements are increasingly prominent. However, the passenger flow itself has time-varying characteristics, and the division of passenger flow seasons and periods is divided by manual methods and experience subjectively. As a result, it is difficult to adjust it dynamically with the passenger flow changing dynamically. There are few studies on the seasons and periods of the division about high-speed railway passenger flow at home and abroad. In this study, the seasonal and period division methods of high-speed railway passenger flow were studied, the dynamic characteristics of passenger flow were analyzed, and the annual passenger flow fluctuation was considered. Then, the high-speed railway passenger flow was divided into seasons by using the firefly affinity propagation algorithm. Meanwhile, the high-speed railway passenger flow was divided into periods by employing the orderly clustering algorithm with the consideration of the daily passenger flow fluctuation. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Clustering algorithms

来源：评论

学校读者我要写书评

暂无评论

Comprehensive recovery of W,V,and Ti from spent selective reduction catalysts

引用

Rare Metals 2023年第10期42卷 3518-3531页

作者： Li-Wen Ma Xiao-Li Xi Jia-Peng Chen Fan Guo Zi-Jie Yang Zuo-Ren Nie Key Laboratory of Advanced Functional Materials Ministry of EducationFaculty of Materials and ManufacturingBeijing University of TechnologyBeijing100124China Collaborative Innovation Center of Capital Resource-Recycling Material Technology Beijing University of TechnologyBeijing100124China National Engineering Laboratory for Industrial Big-Data Application Technology Beijing University of TechnologyBeijing100124China

In this study,spent WO_(3)/V_(2)O_(5)-TiO_(2) catalysts used for selective catalytic reduction were treated by a hydrometallurgical process to comprehensively recover valuable metallic elements,such as W,V,and *** and Si impurities were preferentially removed by selective micro wave-assisted alkali leaching.W and V were leached by enhanced high-pressure leaching with efficiencies estimated at 95% and 81%.The leaching of W and V followed the nuclear shrinkage model controlled by the combination of product layer diffusion and interfacial chemical reaction.A synergistic extraction was applied to separate W and V using an extractant mixture of di-(2-ethylhexyl)phosphoric acid P204 and the primary amine *** extraction efficiencies of V and W reached 86.5% and 6.3%,respectively,with a separation coefficient(V/W) of *** product was precipitated after extraction to yield ammonium paratung state(APT) and NH_(4)VO_(3).The TiO_(2)catalyst carrier residue meets commercial specifications for *** comprehensive recovery process with the characteristics of high-pressure leaching and synergistic extraction realizes the resourceful utilization of the spent catalysts.

关键词： Spent selective catalytic reduction(SCR)catalysts Microwaveleaching Pressure leaching Synergistic extraction Comprehensive recovery

来源：评论

学校读者我要写书评

暂无评论

Research on Optimization of Operation Organization of Transship Trains in Railway Hub 5th

Research on Optimization of Operation Organization of Transs...

引用

5th International Conference on Smart Vehicular technology, transportation, Communication and applications, VTCA 2022

作者： Song, Zongying Li, Yi Yue, Mengyuan Liu, Kun Lv, Miaomiao China Shenhua Energy Co. Ltd. Beijing10011 China School of Transportation and Logistics Southwest Jiaotong University Chengdu610031 China National and Local Joint Engineering Laboratory of Comprehensive Intelligent Transportation Southwest Jiaotong University Chengdu610031 China National Engineering Laboratory of Integrated Transportation Big Data Application Technology Chengdu China

ISBN: (纸本)9789819908479

Taking the transship trains of the railway hub as the research object, a study was carried out on the optimization of the operation organization of the transship trains in the hub. With the goal of minimizing the running cost of transship trains, an optimization model of the operation organization of transship trains in railway hubs is constructed under the condition that the trains can be picked up and delivered on time. At the same time, the railway hub case is selected, the model is used to analyze, the improved SA algorithm is designed to solve it, and the model and algorithm are verified. The results show that the constructed model and algorithm can make full use of resources such as dispatching vehicles on the premise of realizing the timely pickup and delivery of trains in the hub, and obtain a suitable operation plan for transship trains in the hub, so as to minimize the overall operating cost, so as to achieve the optimization of the operation organization of transship trains in railway hubs improves the efficiency of cargo transportation. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Railroads

来源：评论

学校读者我要写书评

暂无评论

Analysis of the impact of heterogeneous platoon for mixed traffic flow: control strategy, fuel consumption and emissions

arXiv

引用

arXiv 2024年

作者： Wu, Yunxia Li, Le Yao, Zhihong Wang, Yi Li, Gen Jiang, Yangsheng School of Transportation and Logistics National Engineering Laboratory of Integrated Transportation Big Data Application Technology Southwest Jiaotong University Sichuan Chengdu611756 China School of Transportation and Logistics National Engineering Laboratory of Integrated Transportation Big Data Application Technology National United Engineering Laboratory of Integrated and Intelligent Transportation Southwest Jiaotong University Sichuan Chengdu611756 China School of Automobile and Traffic Engineering Nanjing Forestry University Jiangsu Nanjing210037 China

Compared with traditional vehicle longitudinal spacing control strategies, the combination spacing strategy can integrate the advantages of different spacing control strategies. However, the impact mechanism of different combination spacing control strategies on mixed traffic flow has not been analyzed yet. Therefore, this paper proposes various combination spacing control strategies for connected automated vehicles (CAVs). First, a mixed traffic flow model was developed to analyze the characteristics of CAV platoons. On this basis, a probability model of vehicle distribution was derived, and its effectiveness was verified through simulation. Then, multiple spacing combination strategies are proposed based on four spacing control strategies. Finally, numerical experiments were conducted to calculate the average fuel consumption and pollutant emissions of mixed traffic flow under different spacing control strategies, and the impact of platoon spacing control strategies on traffic flow fuel consumption and pollutant emissions was further analyzed. Results show that: (1) the differences in average fuel consumption and pollutant emissions of traffic flow are relatively small under different platoon spacing control strategies under low traffic density (i.e., 15 veh/km);(2) at medium to high traffic densities (i.e., 55-95 veh/km), when the penetration rate of CAVs exceeds 80%, VTG1-CS, VTG2-CS, and CTG-CS strategies can effectively ensure traffic flow stability and safety, and significantly reduce fuel consumption and pollutant emissions. © 2024, CC BY.

关键词： Antiknock compounds

来源：评论

学校读者我要写书评

暂无评论

A Study of Optimization of Dynamic Freight Train Diagrams Based on Market-Orientation 5th

A Study of Optimization of Dynamic Freight Train Diagrams Ba...

引用

5th International Conference on Smart Vehicular technology, transportation, Communication and applications, VTCA 2022

作者： Wang, Meng Shi, Fangyu Dong, Ziqi Lu, Hongxia Southwest Jiaotong University Sichuan Chengdu610031 China China National Energy Group Railway Equipment Company Beijing100000 China National and Local Joint Engineering Laboratory of Comprehensive Intelligent Transportation Southwest Jiaotong University Chengdu610031 China National Engineering Laboratory of Integrated Transportation Big Data Application Technology Sichuan Chengdu610031 China

ISBN: (纸本)9789819908479

The dynamic freight train diagram is the key link to realize the whole-process integrated transportation of goods and the key to realize the "According to the Timetable". This paper studies the optimization of freight train diagram based on the basic diagram for dynamic route selection with market orientation as the core. Firstly, considering the quality of freight service and the satisfaction of cargo owners, taking the minimum transportation time consumption of each freight train as the optimization goal, starting from the characteristics of dynamic traffic flow, considering the connection time of traffic flow with the train at the station and the arrival period of the loaded goods, the dynamic route selection optimization model based on the basic diagram of the train diagram is established, and the solution strategy of the improved particle swarm algorithm based on binary coding is designed. Finally, a small road network case is constructed to verify the feasibility of the model and algorithm. © 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Freight transportation

来源：评论

学校读者我要写书评

暂无评论

An end-to-end repair-based joint training framework for weakly supervised pavement crack segmentation

引用

Multimedia Tools and applications 2024年 1-19页

作者： Zhou, Hui Tao, Huanjie Duan, Qianyue Hu, Zhenwu Deng, Yishi School of Computer Science Northwestern Polytechnical University Xi’an710129 China School of Cyberspace Security Northwestern Polytechnical University Xi’an710129 China Engineering Research Center of Embedded System Integration Ministry of Education Xi’an710129 China National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology Xi’an710129 China

Weakly supervised pavement crack segmentation aims to assign each pixel of pavement surface images a category label (crack or non-crack) using limited annotation information. Most existing methods adopt the multi-stage approach based on the class activation map (CAM), which outputs from a pre-trained crack classification model, to generate the pixel-level pseudo labels, and then train a segmentation model using these pseudo labels. However, these methods have two notable drawbacks: (i) CAM focuses primarily on the most discriminative regions of the image, potentially resulting in an incomplete estimation of crack regions, and (ii) the process of obtaining pixel-level pseudo labels from CAM is complex and may introduce noise. To avoid these issues, we propose an end-to-end repair-based joint training framework for weakly supervised pavement crack segmentation. Specifically, to better guide the model to pay more attention to the repair process of crack regions, we introduce the segmentation loss, which assigns different weights for crack regions and background regions, through the Residual Project Network. Additionally, to alleviate the impact of the domain gap between synthetic and real datasets, we introduce the consistency loss through the joint training paradigm of unpaired data that incorporates both crack and non-crack images into the training process simultaneously. Furthermore, to enable the model to effectively extract local features and reduce the model's computational complexity, we introduce the Lightweight Multi-head Self-attention module. The experiment results on the CRACK500 dataset, the CFD dataset, and the AEL dataset demonstrate that our model achieves better performance than some existing weakly supervised pavement segmentation methods. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2024.

关键词： Repair

来源：评论

学校读者我要写书评

暂无评论

integrated Optimization of Traffic Signals and Vehicle Trajectories for Mixed Traffic at Signalized Intersections: A Two-Level Hierarchical Control Framework

SSRN

引用

SSRN 2024年

作者： Zou, Yangang Zheng, Fangfang Liu, Can Liu, Xiaobo School of Transportation and Logistics National Engineering Laboratory of Integrated Transportation Big Data Application Technology National United Engineering Laboratory of Integrated and Intelligent Transportation Southwest Jiaotong University Western Hi-tech Zone Sichuan Chengdu611756 China

With the rapid advancement of connected and automated vehicle (CAV) technology, the integrated optimization of traffic signals and vehicle trajectories has emerged as a promising approach to enhance intersection performance. However, the complexity of this integrated optimization problem requires substantial computational resources, rendering existing methods impractical for real-time applications. To address this challenge, this paper presents a two-level hierarchical control framework for mixed traffic, which provides a computationally efficient solution to the integrated optimization problem of traffic signals and vehicle trajectories, while maintaining high performance. At the upper level, instead of considering individual vehicles, this study introduces a platoon-based mixed integer linear programming (PMILP) model to jointly optimize signal timing and desired arrival times, with the main objective of minimizing traffic delay. Building upon the optimized desired arrival times, a Nash-based distributed model predictive control (DMPC) method is developed at the lower level to optimize CAV trajectories for eco-driving. Numerical experiments are conducted to assess the performance of the proposed method. The results demonstrate that the integrated optimization approach significantly reduces traffic delay, fuel consumption, and idling time, while simultaneously enhancing driving comfort. Notably, the proposed method achieves these improvements with a high level of computational efficiency. © 2024, The Authors. All rights reserved.

关键词： Traffic signals

来源：评论

学校读者我要写书评

暂无评论

A Revisit of Landsat-Observed Macroalgal Blooms in the Yellow Sea and East China Sea Before 2008

引用

Journal of Ocean University of China 2025年第2期24卷 525-531页

作者： YUAN Chao HUANG Juan WU Lingjuan XIAO Jie ZHANG Xuelei GAO Song LI Yifei XU Jiangling WANG Zongling Shandong Key Laboratory of Marine Ecological Environment and Disaster Prevention and Mitigation North China Sea Marine Forecasting and Hazard Mitigation CenterMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Ecology and Environmental Science Qingdao Marine Science and Technology CenterQingdao 266061China First Institute of Oceanography Ministry of Natural ResourcesQingdao 266061China National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology Xi’an 710129China

Harmful macroalgal blooms caused by Ulva prolifera and Sargassum horneri are increasing in the Yellow Sea and East China ***,our understanding of macroalgal blooms before 2008 is fragmented and *** time-series Landsat imagery from 1984 to 2008,we examined macroalgal bloom events and their evolutionary *** results suggest that no macroalgal blooms were observed before *** blooms could be traced back to 1999 and occurred on a small scale in 2000,2004 and 2005,before escalating into large green tides in 2007 and ***,these Ulva blooms were confined to the southern Yellow Sea from May to *** comparison,Sargassum blooms were first detected in the East China Sea in March 2000 and occurred almost every year thereafter,although the size of the blooms showed significant interannual *** distribution areas generally moved northwards from March until the bloom dissipated in May or June,suggesting the influence of the monsoon and *** investigation provided some insight into the bloom history of these two harmful macroalgal blooms in the Yellow Sea and East China Sea.

关键词： macroalgal bloom green tide golden tide remote sensing Landsat Yellow Sea East China Sea

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：