Transportmetrica最新文献

{"title":"Correlation of levels of lactic acid and glucose in cerebrospinal fluid of cerebral hemorrhage patients with the occurrence of postoperative intracranial infection and clinical prognosis.","authors":"Lei Zhang, Yan Zhang, Xiaotian Wang, Yun Zhao","doi":"10.5937/jomb0-44058","DOIUrl":"10.5937/jomb0-44058","url":null,"abstract":"<p><strong>Background: </strong>Cerebral haemorrhage is a critical condition that often requires surgical treatment, and postoperative intracranial infection can significantly impact patient outcomes. The aim of the study was to examine the relationship between the levels of lactic acid and glucose in cerebrospinal fluid (CSF) of patients with cerebral haemorrhage and their postoperative intracranial infection and clinical prognosis.</p><p><strong>Methods: </strong>The study selected the clinical data of 324 patients with cerebral haemorrhage who underwent surgical treatment in our hospital from March 2020 to March 2022 for retrospective analysis and divided these patients into the intracranial infection group (Group A, n=22, leukocyte values in CSF>5×106/L) and the non-intracranial infection group (Group B, n=302, leukocyte values in CSF 5×106/L) according to the occurrence of postoperative intracranial infection in patients to detect the levels of lactic acid and glucose in CSF at different times in the two groups. Pearson method was adopted to analyze the correlation of the levels of lactic acid and glucose in CSF of patients with intracranial infection, and the Glasgow Outcome Scale (GOS) was used to assess the clinical prognosis of patients. According to their scores, these patients were divided into the good prognosis group (GPG, scores of 4-5 points, n=178) and the poor prognosis group (PPG, scores of 1-3 points, n=146). The levels of lactic acid and glucose in the CSF of patients in the two groups were measured, and the Pearson method was adopted to analyze the relationship between these levels and clinical prognosis.</p>","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"1 1","pages":"36-42"},"PeriodicalIF":2.5,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10943468/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82565044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Empirical study of the effects of physics-guided machine learning on freeway traffic flow modelling: model comparisons using field data","authors":"Zhao Zhang, Yun Yuan, Mingchen Li, Pan Lu, Xianfeng Terry Yang","doi":"10.1080/23249935.2023.2264949","DOIUrl":"https://doi.org/10.1080/23249935.2023.2264949","url":null,"abstract":"AbstractRecent studies have shown the successful implementation of classical model-based approaches (e.g. macroscopic traffic flow modelling) and data-driven approaches (e.g. machine learning – ML) to model freeway traffic patterns, while both have their limitations. Even though model-based approaches could depict real-world traffic dynamics, they could potentially lead to inaccurate estimations due to traffic fluctuations and uncertainties. In data-driven models, the acquisition of sufficient high-quality data is required to ensure the model performance. However, many transportation applications often suffer from data shortage and noises. To overcome those limitations, this study aims to introduce and evaluate a new model, named as physics-guided machine learning (PGML), that integrates the classical traffic flow model (TFM) with the machine learning technique. This PGML model leverages the output of a traffic flow model along with observational features to generate estimations using a neural network framework. More specifically, it applies physics-guided loss functions in the learning objective of neural networks to ensure that the model not only consists with the training set but also shows lower errors on the known physics of the unlabelled set. To illustrate the effectiveness of the PGML, this study implements empirical studies with a real-world dataset collected from a stretch of I-15 freeway in Utah. Experimental study results show that the proposed PGML model could outperform the other compatible methods, including calibrated traffic flow models, pure machine learning methods, and physics unguided machine learning (PUML).Keywords: Traffic state estimationphysics-guided machine learningmacroscopic traffic flow modellingneural networks AcknowledgmentsThe authors thank the Utah Department of Transportation (UDOT), for their valuable support and data provision.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis research is supported by the project ‘CMMI #2047268 CAREER: Physics Regularized Machine Learning Theory: Modeling Stochastic Traffic Flow Patterns for Smart Mobility Systems’ funded by the National Science Foundation (NSF) and the project ‘MPC-657 Knowledge-Based Machine Learning for Freeway COVID-19 Traffic Impact Analysis and Traffic Incident Management’ funded by the Mountain-Plains Consortium (MPC).","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135569703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applying an improved calibration method in the safety evaluation framework for the open tolling system","authors":"Seung-oh Son, Kyeongju Kwon, Juneyoung Park, Mohamed Abdel-Aty","doi":"10.1080/23249935.2023.2270759","DOIUrl":"https://doi.org/10.1080/23249935.2023.2270759","url":null,"abstract":"AbstractThis study proposed an improved calibration method in the safety evaluation framework and analysed the safety effect of installing the open road tolling (ORT) system. Although the ORT system in South Korea has recently installed in many tollgate sections, it is impossible to collect statistically significant crash data. Therefore, the safety benefits were estimated and compared by (1) applying the general calibration way suggested in the Highway Safety Manual, (2) the recent calibration research from Florida and (3) the improved calibration method suggested in this study. In the result, safety improvement effect of ORT installation was 43% to 51%. Additionally, the calibration function using the quadratic model showed the best performance. This study is meaningful in that the safety effectiveness was estimated using the calibration method when the sample size was insufficient, and it utilises new functions to predict nonlinear relationships that are difficult to calibrate with simple linear relationships.KEYWORDS: Calibration methodsafety effectshighway safety manualopen road tolling Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work is supported by the Korea Agency for Infrastructure Technology Advancement(KAIA) grant funded by the Ministry of Land, Infrastructure and Transport (Grant RS-2021-KA163182).","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"158 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135569995","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The optimal solution to the energy-efficient train control in a multi-trains system-part 1: the algorithm design","authors":"Yu Rao, Xiaoyun Feng, Qingyuan Wang, Pengfei Sun","doi":"10.1080/23249935.2023.2267685","DOIUrl":"https://doi.org/10.1080/23249935.2023.2267685","url":null,"abstract":"AbstractWhen a train travels in a multi-trains system, the power flow of other trains and the track grades make up the spatial–temporal area (STA) for the train. Finding the optimal solution for the energy-efficient train control problem in STA can help reduce the net energy consumption. This paper studies the analytic method to obtain the optimal solution. In Part 1, we propose an algorithm specifically designed for this problem. The underlying structure of the algorithm is the connection between three optimal states through the optimal feasible strategy. We propose an algebraic method to calculate the optimal feasible strategy and discuss how it intersects with the speed limit. In Part 2, we will discuss the optimality and uniqueness of the optimal feasible strategy. Case studies using data from a real freight railway line are given to demonstrate the effectiveness of the proposed algorithm.KEYWORDS: Optimal train controlenergy savingPontryagin’s maximum principlenet energy consumption Disclosure statementNo potential conflict of interest was reported by the author(s).CRediT authorship contribution statementYu Rao: Conceptualisation, Methodology, Software, Writing-original draft. Xiaoyun Feng: Methodology, Validation. Qingyuan Wang: Supervision, Visualisation. Pengfei Sun: Conceptualisation, Writing-review & editing.Data availability statementThe data that support the findings of this study are available from the corresponding author upon reasonable request.Additional informationFundingThis work was supported by the National Natural Science Foundation of China under grant 62003283 and the National Key Research and Development Program of China under grant 2021YFB2601500.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135883168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The optimal solution to the energy-efficient train control in a multi-trains system–Part 2: the optimality and the uniqueness","authors":"Yu Rao, Xiaoyun Feng, Qingyuan Wang, Pengfei Sun","doi":"10.1080/23249935.2023.2270330","DOIUrl":"https://doi.org/10.1080/23249935.2023.2270330","url":null,"abstract":"AbstractWhen a train travels in a multi-trains system, the power flow of other trains and the track grades make up the spatial–temporal area (STA) for the train. Finding the optimal solution for the energy-efficient train control (EETC) problem in STA can help reduce the net energy consumption. This paper studies the analytic method to obtain the optimal solution. In Part 1, the algorithm for the problem was designed. The underlying structure of the algorithm is the connection between three optimal states through optimal feasible strategy. In Part 2, the optimality of the optimal feasible strategy is verified through a generalised local energy functional, and its uniqueness is proved based on the variational method. Additionally, we discuss the influence of external power on the optimal solution of the classical EETC problem. Case studies using data for a real freight railway line are given to illustrate our results.KEYWORDS: Optimal train controlenergy savingPontryagin’s Maximum Principlenet energy consumption AcknowledgmentsThis work was supported by the National Natural Science Foundation of China under Grant 62003283 and the National Key Research and Development Program of China under Grant 2021YFB2601500.Disclosure statementNo potential conflict of interest was reported by the author(s).Data availability statementThe data that support the findings of this study are available from the corresponding author upon reasonable request.Authors’ contributionsYu Rao: Conceptualization, Methodology, Software, Writing-original draft. Xiaoyun Feng: Methodology, Validation. Qingyuan Wang: Supervision, Visualization. Pengfei Sun: Conceptualization, Writing-review & editing.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135885205","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Artificial intelligence in automatic passenger counting: cost-efficient validation using the partitioned equivalence test","authors":"David Ellenberger, Michael Siebert","doi":"10.1080/23249935.2023.2267702","DOIUrl":"https://doi.org/10.1080/23249935.2023.2267702","url":null,"abstract":"In Automatic Passenger Counting (APC), the demand for very low errors has been fueled by applications like revenue sharing, which amounts to massive annual sums. As a consequence, APC validation costs are increasing and this work presents a solution to increase the efficiency of initial or recurrent, e.g. yearly, validations. The new approach, the partitioned equivalence test, guarantees the same bounded, low user risk while reducing efforts in comparison to established (equivalence) test procedures. This involves a pre-classification step, which selects the more informative bits of data (e.g. footage). Different use cases are evaluated: from entirely manual to algorithmic, artificial intelligence assisted workflows. Already for manual counts, the new approach can be used as a drop-in replacement to reduce validation costs, while savings in algorithmic use cases demonstrated that cost halving is possible. Due to the user risk being controlled no additional technical requirements are introduced.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"21 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135883160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessing transportation network redundancy by integrating route diversity and spare capacity","authors":"Zijian Wang, Xiangdong Xu, Yuchuan Du","doi":"10.1080/23249935.2023.2266508","DOIUrl":"https://doi.org/10.1080/23249935.2023.2266508","url":null,"abstract":"AbstractIn this paper, we develop a new transportation network redundancy measure by integrating the route diversity and spare capacity dimensions, which have been demonstrated as two complementary dimensions of redundancy and assessed separately in the literature. Instead of modelling redundancy as two separate measures with significantly different units and scales, an integrative measure is beneficial for comprehensive comparison and selection of redundancy enhancement schemes. Specifically, we represent the transportation network by adding a virtual link directly connecting each origin-destination (O-D) pair. The virtual link choice probability is affected by both the route diversity of the O-D pair and the spare capacity of these routes, which is used in the proposed measure. Numerical examples in the realistic Winnipeg network are conducted. The effectiveness of the proposed measure is further verified by applying it to identify the critical links in the Shanghai Expressway Network, where a severe traffic accident happened in 2016.KEYWORDS: Redundancyroute diversityspare capacitycritical link identification Disclosure statementNo potential conflict of interest was reported by the authors.Author contributionsZijian Wang: methodology, investigation, and writing – original draft preparation. Xiangdong Xu: conceptualisation, methodology, supervision, and writing – reviewing and editing. Yuchuan Du: conceptualisation and writing – reviewing and editing.Notes1 The free-flow travel time of a link is the travel time of the link when its volume is equal to 0, and the minimum free-flow travel time of an O-D pair is the minimum travel time of the O-D pair when the volume of all links in the network is equal to 0.2 In Section 3.1, a route is represented by the links traversed by it.Additional informationFundingThe work described in this paper was sponsored by the National Key Research and Development Program of China (2021YFB1600100), the National Natural Science Foundation of China (71971159), and Fundamental Research Funds for the Central Universities of China. These supports are gratefully acknowledged.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136211457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Joint operation planning of drivers and trucks for semi-autonomous truck platooning","authors":"Yilang Hao, Zhibin Chen, Jiangang Jin, Xiaotong Sun","doi":"10.1080/23249935.2023.2266041","DOIUrl":"https://doi.org/10.1080/23249935.2023.2266041","url":null,"abstract":"AbstractSemi-autonomous truck platooning, a futuristic and promising traveling mode of trucks on highways, has received extensive attention as autonomous driving gains more maturity. Under the semi-autonomous platooning mode, rather than requiring a human driver for each truck in the platoon, only one human driver is needed for the leading truck, and all following trucks can be controlled by autonomous driving and wireless communication technology. Therefore, in addition to saving energy, such a technology can help reduce labor costs by using fewer drivers to fulfill the same demand. Compared to traditional truck platooning, the schedules of drivers under semi-autonomous truck platooning may not be exactly the same as trucks, which are usually neglected in recent studies. Therefore, in this paper, we make the first attempt to develop a mathematical modeling framework to optimise the operation plan of drivers and trucks interdependently. To be mentioned, the truck fleet is equipped with the semi-autonomous platooning function and time windows. Specifically, the operation plan will dictate the number of drivers to be dispatched, and traveling routes and time schedules of drivers and trucks interdependently with the objective to minimise the total operation cost, including drivers' fixed dispatch cost, on-road labor cost, and energy consumption cost while fulfilling all delivery demands. To tackle the large-scale problem in a timely manner, a tailored Lagrangian Relaxation approach is proposed to solve the model. Numerical experiments are conducted to demonstrate the performance of the proposed modeling framework and validate the feasibility and efficiency of the proposed solution algorithm.Keywords: Semi-autonomous truck platooningvehicle routing and schedulingdriver dispatchinglabor and energy costlagrangian relaxation Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was partially supported by the National Natural Science Foundation of China (72101153, 72061127003, 72001021), Shanghai Chenguang Program (21CGA72), Shanghai Eastern Scholar Program (QD2020057), the Preparation Fund of Shanghai Key Laboratory of Urban Design and Urban Science (Grant No. 10407_Key Lab_Preparation Fund), the NYU Shanghai Boost Fund, and the NYU Shanghai Doctoral Fellowships.","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"48 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135141513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Convexity and global optimisation of lane-based fixed-time signal model for delay minimisation at an isolated intersection","authors":"Haiming Hao, Hui Jin","doi":"10.1080/23249935.2023.2259014","DOIUrl":"https://doi.org/10.1080/23249935.2023.2259014","url":null,"abstract":"AbstractLane-based fixed-time signal is basic to various signal control strategies. It performs well in maximizing road capacity, but is faced with significant challenge in minimizing traffic delay. This study validates the convexity of lane-based fixed-time signal model for delay minimization, when lane markings are determined as well as flow factors. Thus Breadth first search algorithm is developed to enumerate the feasible lane markings, which are then screened with flow factors. Cutting plane algorithm is applied to the CMINLP for each feasible lane markings, where the non-linear delay function is converted to a series of linear ones, until the relaxed delay converges to the actual delay. Branch pruning strategy is established for efficiency, to eliminate the lane markings with uncompetitive delay. Numerical analyses follow to validate the proposed algorithm. This research promotes the redesign of lane-based fixed-time signal control.KEYWORDS: Lane-based fixed-time signaldelay minimisationconvexitycutting planebranch pruning Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work has been funded by the National Natural Science Foundation of China [NO. 52002261] and by the Key Laboratory of Road and Traffic Engineering of the Ministry of Education of Tongji University [NO. K202105] and China Postdoctoral Science Foundation [NO. 2020M671581].","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136341945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mapping the spatial organisation of air transport network by WENA-MLST analysis","authors":"Chengliang Liu, Bangjuan Wang, Hong Zhang","doi":"10.1080/23249935.2023.2261044","DOIUrl":"https://doi.org/10.1080/23249935.2023.2261044","url":null,"abstract":"AbstractDue to the airline hubs’ organisation such as linkage, hierarchical structure, and hub-and-spoke remains a mystery at a global scale. Thereby, the research aims to unravel the spatial organisation of airline hubs in the air transport network (ATN) by using weighted ego network analysis (WENA), Ht-index, and maximum leaf spanning tree (MLST) at multi-scales. The findings provide valuable insights into the status of different regional cities in the ATN and the critical relationship between hubs and their associated spokes. The result shows that the ATN is a legibly hierarchical network, and three types of airline hubs, i.e. global, international, and regional hubs have been identified. Additionally, the study reveals that the ATN is made up of several regional hub-and-spoke systems, where hubs dominate their subgraphs, with range and geographical proximity effects are observed. Finally, the role of airline hubs as international gateways and domestic hubs is also noted.KEYWORDS: Airline hubshierarchical structurehub-and-spoke system Disclosure statementNo potential conflict of interest was reported by the author(s).Notes1 MAR is defined as a cluster of two or more major commercial airports in a metropolitan area (O'Connor and Fuellhart Citation2016; Wong et al. Citation2019).2 https://www.lboro.ac.uk/gawc/world2018t.html3 This article refers to Alpha-rated cities in the GAWC, which are also known as world's first-tier cities.4 Single hub-and-spoke means that the hub is the only interacting node directly connected to other nodes, double-hub network means that there are two competing hubs in the system and have a strong airline connection between them, and multiple-hub network means that there are more than two hubs in the system, and the presence of multiple paths provides more choice and convenience for passengers, and hierarchical hub-and-spoke means that there is a hierarchy between the hubs of the spoke system (Chou Citation1990).Additional informationFundingThis work was supported by the National Natural Science Foundation of China (Grant No.42171179; 42171420), and the Shanghai Natural Science Foundation of China (Grant No.21ZR1419600).","PeriodicalId":49416,"journal":{"name":"Transportmetrica","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136060128","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}