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Traffic signal coordination control for arterials with dedicated CAV lanes

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Journal of Intelligent and Connected Vehicles

Journal of Intelligent and Connected Vehicles 2022年第2期5卷 72-87页

作者： Liang Xu Sheng Jin Bolin Li Jiaming Wu Department of Beihang Hangzhou Innovation Institute Yuhang HangzhouChina College of Civil Engineering and Architecture Zhejiang UniversityHangzhouChina and Department of Alibaba-Zhejiang University Joint Research Institute of Frontier TechnologiesHangzhouChina Department of Architecture and Civil Engineering Chalmers University of TechnologyGothenburgSweden

Purpose–This study aims to make full use of the advantages of connected and autonomous vehicles(CAVs)and dedicated CAV lanes to ensure all CAVs can pass intersections without stopping.Design/methodology/approach–The authors developed a signal coordination model for arteries with dedicated CAV lanes by using mixed integer linear programming.CAV non-stop constraints are proposed to adapt to the characteristics of CAVs.As it is a continuous problem,various situations that CAVs arrive at intersections are analyzed.The rules are discovered to simplify the problem by discretization method.Findings–A case study is conducted via SUMO traffic simulation program.The results show that the efficiency of CAVs can be improved significantly both in high-volume scenario and medium-volume scenario with the plan optimized by the model proposed in this paper.At the same time,the progression efficiency of regular vehicles is not affected significantly.It is indicated that full-scale benefits of dedicated CAV lanes can only be achieved with signal coordination plans considering CAV characteristics.Originality/value–To the best of the authors’knowledge,this is the first research that develops a signal coordination model for arteries with dedicated CAV lanes.

关键词： Connected and automated vehicles Dedicated lane Arterial signal coordination

Modularized and Parametric Modeling Technology for Finite Element Simulations of Underground Engineering under Complicated Geological Conditions

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 621-645页

作者： Jiaqi wu Li Zhuo Jianliang Pei Yao Li Hongqiang Xie Jiaming Wu Huaizhong Liu State Key Laboratory of Hydraulics and Mountain River Engineering College of Water Resource and HydropowerSichuan UniversityChengdu610065China Research Institute of Testing and Inspection Sinohydro Bureau 7 Co.Ltd.Chengdu610213China

The surrounding geological conditions and supporting structures of underground engineering are often updated during construction,and these updates require repeated numerical modeling.To improve the numerical modeling efficiency of underground engineering,a modularized and parametric modeling cloud server is developed by using Python codes.The basic framework of the cloud server is as follows:input the modeling parameters into the web platform,implement Rhino software and FLAC3D software to model and run simulations in the cloud server,and return the simulation results to the web platform.The modeling program can automatically generate instructions that can run the modeling process in Rhino based on the input modeling parameters.The main modules of the modeling program include modeling the 3D geological structures,the underground engineering structures,and the supporting structures as well as meshing the geometric models.In particular,various cross-sections of underground caverns are crafted as parametricmodules in themodeling program.Themodularized and parametric modeling program is used for a finite element simulation of the underground powerhouse of the Shuangjiangkou Hydropower Station.This complicatedmodel is rapidly generated for the simulation,and the simulation results are reasonable.Thus,this modularized and parametric modeling program is applicable for three-dimensional finite element simulations and analyses.

关键词： Underground engineering modularized and parametric modeling finite element method complex geological structure cloud modeling

Intersection control with connected and automated vehicles:a review

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Journal of Intelligent and Connected Vehicles

Journal of Intelligent and Connected Vehicles 2022年第3期5卷 260-269页

作者： Jiaming Wu Xiaobo Qu Department of Architecture and Civil Engineering Chalmers University of TechnologyGothenburgSweden School of Vehicle and Mobility Tsinghua UniversityBeijingChina

Purpose–This paper aims to review the studies on intersection control with connected and automated vehicles(CAVs).Design/methodology/approach–The most seminal and recent research in this area is reviewed.This study specifically focuses on two categories:CAV trajectory planning and joint intersection and CAV control.Findings–It is found that there is a lack of widely recognized benchmarks in this area,which hinders the validation and demonstration of new studies.Originality/value–In this review,the authors focus on the methodological approaches taken to empower intersection control with CAVs.The authors hope the present review could shed light on the state-of-the-art methods,research gaps and future research directions.

关键词： Connected and automated vehicles Intersection control Trajectory planning Optimization

Are shared electric scooters energy efficient?

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Communications in Transportation Research 2021年第1期1卷 182-192页

作者： Yuxuan Wang Jiaming Wu Kequan Chen Pan Liu Jiangsu Key Laboratory of Urban ITS School of TransportationSoutheast UniversitySi Pai Lou#2Nanjing210096China Department of Architecture and Civil Engineering Chalmers University of TechnologyGothenburgSE41296Sweden

Shared electric scooters(e-scooter)are booming across the world and widely regarded as a sustainable mobility service.An increasing number of studies have investigated the e-scooter trip patterns,safety risks,and environmental impacts,but few considered the energy efficiency of e-scooters.In this research,we collected the operational data of e-scooters from a major provider in Gothenburg to shed light on the energy efficiency performance of e-scooters in real cases.We first develop a multiple logarithmic regression model to examine the energy consumption of single trips and influencing factors.With the regression model,a Monte Carlo simulation framework is proposed to estimate the fleet energy consumption in various scenarios,taking into account both trip-related energy usage and energy loss in idle status.The results indicate that 40%of e-scooter battery energy was wasted in idle status in the current practice,mainly due to the relatively low usage rate(0.83)of e-scooters.If the average usage rate drops below 0.5,the wasted energy could reach up to 53%.In the end,we present a field example to showcase how to optimally integrate public transport with e-scooters from the perspective of energy efficiency.We hope the findings of this study could help understand and resolve the current and future challenges regarding the ever-growing e-scooter services.

关键词： E-scooters Shared mobility Sustainable transportation Monte Carlo simulation

Future connected vehicles:Communications demands,privacy and cyber-security

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Communications in Transportation Research 2022年第1期2卷 39-41页

作者： Tomas Olovsson Tommy Svensson Jiaming Wu Department of Computer Science and Engineering Chalmers University of TechnologyGothenburgSE41296Sweden Department of Electrical Engineering Chalmers University of TechnologyGothenburgSE41296Sweden Department of Architecture and Civil Engineering Chalmers University of TechnologyGothenburgSE41296Sweden

1.Introduction With the advance of data collection,data processing,telecommunication and vehicular technologies,connected vehicles(CVs)have been emerging as a crucial branch of smart mobility(Olia et al.,2015;Li et al.,2021).Its basic idea is to realize real-time exchanges and processing of essential information,such as positions and destinations,among surrounding vehicles and infrastructures.

关键词： connected branch destination

Distributed coordinated control scheme of UAV swarm based on heterogeneous roles

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Chinese Journal of Aeronautics 2022年第1期35卷 81-97页

作者： Jiang ZHAO jiaming SUN Zhihao CAI Yingxun WANG Kun wu School of Automation Science and Electrical Engineering Beihang UniversityBeijing 100083China Flying College Beihang UniversityBeijing 100083China

This paper proposes a new distributed coordinated control scheme based on heterogeneous roles for Unmanned Aerial Vehicle(UAV)swarm to achieve formation control.First,the framework of the distributed coordinated control scheme is designed on the basis of Distributed Model Predictive Control(DMPC).Then,the effect of heterogeneous roles including leader,coordinator and follower is discussed,and the role-based cost functions are developed to improve the performance of coordinated control for UAV swarm.Furthermore,a group of coordination strategies are proposed for UAVs with different roles to achieve swarm conflict resolution.Numerical simulations demonstrate that the presented distributed coordinated control scheme is effective to formulate and maintain the desired formation for the UAV swarm.

关键词： Coordination strategy Distributed control Heterogeneous roles Swarm intelligence Unmanned Aerial Vehicles(UAV)

Flow Control Effect of Spanwise Distributed Pulsed Arc Discharge Plasma Actuation on Supersonic Compressor Cascade Flow

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Journal of Thermal Science 2022年第5期31卷 1723-1733页

作者： SHENG jiaming wu Yun ZHANG Haideng WANG Yizhou TANG Mengxiao Science and Technology on Plasma Dynamic Laboratory Air Force Engineering UniversityXi’an710038China Institute of Aero-engine School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an710049China

To achieve efficient control of supersonic compressor cascade flow,a type of spanwise distributed pulsed arc discharge plasma actuation(PADPA)was designed.To simulate the influences of PADPA on the flow field,a phenomenological model was established.Then,the flow control effects of PADPA on supersonic compressor cascade flow were researched numerically.The results show that under low static pressure ratio condition,the compressive wave induced by PADPA reduced the intensity of the passage shock wave,which eventually reduced shock wave loss.It was also found that PADPA produced an adverse pressure gradient(pre-compression effect)around the actuation location,which reduced the strength of the high adverse pressure gradient induced by the passage shock wave.The airflow on both sides of the actuation location was accelerated by PADPA owing to the spanwise distributed layout.Thus,it improved the ability of the boundary layer to resist the effect of the adverse pressure gradient and reduced the separation zone.Consequently,the total pressure loss was reduced by 6.8%.Under high pressure ratio condition,the effect of PADPA on the suction side controlling the large separation of the boundary layer was insignificant.The total pressure loss also increased slightly.

关键词： plasma flow control supersonic cascade shock wave/boundary layer interaction numerical simulation

Fabrication of wear-resistant PA6 composites with superior thermal conductivity and mechanical properties via constructing highly oriented hybrid network of SiC-packed BN platelets

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Journal of Materials Science & Technology 2023年第15期146卷 200-210页

作者： Jing Chen jiaming Zhu Yang Pan Hong wu Shaoyun Guo Jianhui Qiu The State Key Laboratory of Polymer Materials Engineering Sichuan Provincial Engineering Laboratory of PlasticRubber Complex Processing TechnologyPolymer Research Institute of Sichuan UniversityChengdu 610065China Jiangsu Industrial Technology Research Institute of Advanced Polymer Materials Nanjing 211899China Department of Mechanical Engineering Faculty of Systems Science and TechnologyAkita Prefectural UniversityAkita 015-0055Japan

Herein,a strong extensional and shearing field was introduced to construct highly oriented hybrid networks of silicon carbide(SiC)-packed boron nitride(BN)platelets to fabricate high-performance wearresistant PA6 composites.Results show that in-plane and through-plane thermal conductivity(TC)of the prepared PA6 composites with a total filler loading of 20 wt.%reached 1.31 and 0.35 W/(m K),352%and 25%higher than those of pure PA6,respectively.It is attributed to the highly oriented hybrid network that facilitates the formation of efficient thermal conductivity pathways.Temperature monitoring results during friction confirm that high TC favors the friction heat dissipation performance.Meanwhile,the yield strength of PA6 composites increased by 39.1%and they still have excellent ductility with an elongation at break of 207.1%.Finally,the wear rate of PA6 composites decreased sharply by 92.5%.This method can be used to manufacture advanced linear bearing and guideway parts,etc。

关键词： Polymer-matrix composites(PMCs) Hybrid Wear Thermal properties

Effects of probiotics and its fermented milk on constipation: a systematic review

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Food Science and Human Wellness 2023年第6期12卷 2124-2134页

作者： jiaming Yan Meiling wu Wei Zhao Lai-Yu Kwok Wenyi Zhang Key Laboratory of Dairy Biotechnology and Engineering Ministry of EducationInner Mongolia Agricultural UniversityHohhot 010018China Key Laboratory of Dairy Products Processing Ministry of AgricultureInner Mongolia Agricultural UniversityHohhot 010018China

This study reviewed clinical evidence of probiotics-mediated effects on constipation.Four databases were used in the literature searches,namely Cochrane Library,Embase,Pubmed,and Web of Science.The last retrieval time was March 2021.Collected data were analyzed by Review Manager(version 5.3)and Stata(version 14).The primary search retrieved 8418 articles after removing duplicates.Eventually,26 studies were included in the meta-analysis.Administration of probiotics signifi cantly increased stool frequency(MD:1.15 times/week;95%CI:0.59 to 1.70;Pothers(tablets,powder)>fermented milk.

关键词： Constipation Probiotics Fermented milk Meta-analysis Dosage form