Call-taxi has seen tremendous growth during the past two decades and the smartphone app based call-taxi hiring for intra-city commuting has not only provided greater visibility to customers but also increased their expectations. Fleet sizing is an important decision to a call-taxi aggregator that strikes a balance between customer service in terms of call-taxi availability and the utilization of the fleet for a day’s forecasted demand. An optimization via simulation approach is developed for optimizing call-taxi fleet size. The simulation model embeds a Petri Net model of a call-taxi system where the customer requests and travel times are stochastic. Three optimization models are used to determine the fleet sizes, which are compared and inferences drawn. The developed approach can serve as a template for decision support tool for call-taxi service providers.
{"title":"Intra-City Call-Taxi Fleet Sizing using Petri Net Embedded Simulation Optimization","authors":"T. Godwin","doi":"10.48295/et.2022.89.9","DOIUrl":"https://doi.org/10.48295/et.2022.89.9","url":null,"abstract":"Call-taxi has seen tremendous growth during the past two decades and the smartphone app based call-taxi hiring for intra-city commuting has not only provided greater visibility to customers but also increased their expectations. Fleet sizing is an important decision to a call-taxi aggregator that strikes a balance between customer service in terms of call-taxi availability and the utilization of the fleet for a day’s forecasted demand. An optimization via simulation approach is developed for optimizing call-taxi fleet size. The simulation model embeds a Petri Net model of a call-taxi system where the customer requests and travel times are stochastic. Three optimization models are used to determine the fleet sizes, which are compared and inferences drawn. The developed approach can serve as a template for decision support tool for call-taxi service providers.","PeriodicalId":45410,"journal":{"name":"European Transport-Trasporti Europei","volume":"38 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76008002","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}
Pedestrians are important part of transportation system. Understanding pedestrian motion is a difficult task as it involves a lot of complexity at various level of studies. This study is based on pedestrian flow along the corridor highlighting the impact of geometric variations along the corridor. The impact of geometric variation (basic, symmetric, asymmetric) on pedestrian flow is studied in terms of lateral and longitudinal variations in densities and longitudinal variations in speed. The result shows (i) Corridor edges have a significant impact on the use of corridor (ii) Disturbance to pedestrian flow is significant in the case of narrowing (asymmetric) as compared to narrowing (symmetric) (iii) Effect of constriction is felt at both upstream and downstream side of the narrowed section. In a nutshell, the study provides a platform to understand pattern of pedestrian flow moving through an open corridor with and without constrictions.
{"title":"Studies on Pedestrian Flow through Open Corridors with Geometric Variations","authors":"U. Chattaraj","doi":"10.48295/et.2022.89.8","DOIUrl":"https://doi.org/10.48295/et.2022.89.8","url":null,"abstract":"Pedestrians are important part of transportation system. Understanding pedestrian motion is a difficult task as it involves a lot of complexity at various level of studies. This study is based on pedestrian flow along the corridor highlighting the impact of geometric variations along the corridor. The impact of geometric variation (basic, symmetric, asymmetric) on pedestrian flow is studied in terms of lateral and longitudinal variations in densities and longitudinal variations in speed. The result shows (i) Corridor edges have a significant impact on the use of corridor (ii) Disturbance to pedestrian flow is significant in the case of narrowing (asymmetric) as compared to narrowing (symmetric) (iii) Effect of constriction is felt at both upstream and downstream side of the narrowed section. In a nutshell, the study provides a platform to understand pattern of pedestrian flow moving through an open corridor with and without constrictions.","PeriodicalId":45410,"journal":{"name":"European Transport-Trasporti Europei","volume":"1 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90084272","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}
Object of this study is to predict the ‘Probability of Shift’ to the proposed metro corridor from two-wheeler, car, bus and suburban rail in Chennai. To achieve this, a Stated Preference survey questionnaire was prepared and survey was conducted among two-wheeler users; car users; bus users and suburban rail users through face-to-face interview method. The collected SP data were coded, analysed and mode-wise/ trip-based binary logit models were developed using Statistical Software Tools (SST) software. From the developed models, it is observed that irrespective of mode & trip purposes, the choice of metro is fully driven by the proposed metro fare. From the predicted Probability of Shift, it is observed that car users are more willing to switch to metro as well as relatively price sensitive when comparing with other mode users.
{"title":"Trip-based Modal Shift Behaviour of Mode Users along the Proposed Extension Metro Corridor in Chennai (India)","authors":"Siddi Ramulu D.","doi":"10.48295/et.2022.89.6","DOIUrl":"https://doi.org/10.48295/et.2022.89.6","url":null,"abstract":"Object of this study is to predict the ‘Probability of Shift’ to the proposed metro corridor from two-wheeler, car, bus and suburban rail in Chennai. To achieve this, a Stated Preference survey questionnaire was prepared and survey was conducted among two-wheeler users; car users; bus users and suburban rail users through face-to-face interview method. The collected SP data were coded, analysed and mode-wise/ trip-based binary logit models were developed using Statistical Software Tools (SST) software. From the developed models, it is observed that irrespective of mode & trip purposes, the choice of metro is fully driven by the proposed metro fare. From the predicted Probability of Shift, it is observed that car users are more willing to switch to metro as well as relatively price sensitive when comparing with other mode users.","PeriodicalId":45410,"journal":{"name":"European Transport-Trasporti Europei","volume":"14 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78306502","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}
In recent times, there has been a growing demand for e-shopping as compared to in-store shopping due to rapid changes in technology as well as extensive usage of the internet. E-shopping has changed people's shopping and travel behaviour. Due to the increase in internet usage, there is a tremendous change in people's shopping choices and it further impacts the travel patterns in urban communities. In this context, the proposed study evaluates people’s shopping choice behaviour in an urban scenario. To fulfil the proposed objective, a questionnaire survey has been conducted in order to understand consumer behaviour about their shopping choices as well as the number of online orders that have been made by the user during the specified duration of time (viz., during the last one month). To analyse the collected data, a principal component based logistic regression analysis has been adopted to estimate the significant contributing factors affecting consumer shopping choices. The results show that motivational factors (viz., saving in travel time and better prices) have a significant positive impact on online shopping; however, there are concerns such as delivery time as well as care required during online payment. The frequency of using online shopping mode and recently made purchases has had a significant positive impact on online shopping. Further, it has been concluded that higher income levels and higher occupation levels negatively impact e-shopping choice. The results are useful for transport planners to predict the transformation in people's travel behaviour with respect to shopping trips in present and future scenarios.
{"title":"Explore the Factors Contributing to Online Versus Store Shopping in Transportation Perspective: Evidence from India","authors":"Vishnu Abbagani","doi":"10.48295/et.2022.89.2","DOIUrl":"https://doi.org/10.48295/et.2022.89.2","url":null,"abstract":"In recent times, there has been a growing demand for e-shopping as compared to in-store shopping due to rapid changes in technology as well as extensive usage of the internet. E-shopping has changed people's shopping and travel behaviour. Due to the increase in internet usage, there is a tremendous change in people's shopping choices and it further impacts the travel patterns in urban communities. In this context, the proposed study evaluates people’s shopping choice behaviour in an urban scenario. To fulfil the proposed objective, a questionnaire survey has been conducted in order to understand consumer behaviour about their shopping choices as well as the number of online orders that have been made by the user during the specified duration of time (viz., during the last one month). To analyse the collected data, a principal component based logistic regression analysis has been adopted to estimate the significant contributing factors affecting consumer shopping choices. The results show that motivational factors (viz., saving in travel time and better prices) have a significant positive impact on online shopping; however, there are concerns such as delivery time as well as care required during online payment. The frequency of using online shopping mode and recently made purchases has had a significant positive impact on online shopping. Further, it has been concluded that higher income levels and higher occupation levels negatively impact e-shopping choice. The results are useful for transport planners to predict the transformation in people's travel behaviour with respect to shopping trips in present and future scenarios.","PeriodicalId":45410,"journal":{"name":"European Transport-Trasporti Europei","volume":"82 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84400976","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}
The performance of signalized intersections is usually evaluated by measuring delay occurring to vehicles which are passing through the signalized intersections. The field delay under heterogeneous traffic condition will be influenced by many parameters such as cycle time, traffic volume, degree of saturation, percentage of different vehicle categories especially the bunching of motorized two wheelers. In the present research work, the delay is estimated from the field using Indian Highway Capacity Manual (Indo HCM) (2017) procedure and the bunching effect of motorised two wheelers is studied on delay at signalized intersections under heterogeneous traffic conditions. Also, a linear delay model is developed for control delay estimation considering heterogeneous traffic conditions. From the field data, it was observed that, the percentage of motorised two wheelers in a bunch is varying from 37% to 57% whereas the total average delay occurred to vehicles which are passing the approach is varying from 106 s to 163 s respectively.
{"title":"Bunching Effect of Motorised Two Wheelers on Delay at Signalized Intersections under Heterogeneous Traffic Conditions","authors":"R. Sushmitha","doi":"10.48295/et.2022.89.5","DOIUrl":"https://doi.org/10.48295/et.2022.89.5","url":null,"abstract":"The performance of signalized intersections is usually evaluated by measuring delay occurring to vehicles which are passing through the signalized intersections. The field delay under heterogeneous traffic condition will be influenced by many parameters such as cycle time, traffic volume, degree of saturation, percentage of different vehicle categories especially the bunching of motorized two wheelers. In the present research work, the delay is estimated from the field using Indian Highway Capacity Manual (Indo HCM) (2017) procedure and the bunching effect of motorised two wheelers is studied on delay at signalized intersections under heterogeneous traffic conditions. Also, a linear delay model is developed for control delay estimation considering heterogeneous traffic conditions. From the field data, it was observed that, the percentage of motorised two wheelers in a bunch is varying from 37% to 57% whereas the total average delay occurred to vehicles which are passing the approach is varying from 106 s to 163 s respectively.","PeriodicalId":45410,"journal":{"name":"European Transport-Trasporti Europei","volume":"91 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80403088","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}
Motorised Two-Wheeler (MTW) ownership has increased worldwide, especially in emerging countries. The growing usage of MTW vehicles has resulted in several issues, one of the most serious of which is an increase in fatality rates. Therefore, it is essential to understand the MTW rider behaviour for a safe operation and minimise crash likelihood. Motorised two-wheeler Rider Behaviour Questionnaire (MRBQ) is one such survey instrument used for this purpose. In previous decades, many researchers have attempted to examine numerous factors related to the MRBQ survey in various countries. This study aims to review research papers that have examined various factors used in MRBQ studies from various nations and highlight state-of-the-art conclusions. In addition, the study emphasises the research gaps that are critical for factors related to rider behaviour that can be incorporated in the MRBQ survey. This review will benefit the researchers working in the area of MTW safety and MRBQ studies, as well as be useful to decision makers for analysis and policy implementation.
{"title":"Motorised two-wheeler Rider Behaviour Questionnaire: State of the Art","authors":"Madurai Krishnakishore","doi":"10.48295/et.2022.89.4","DOIUrl":"https://doi.org/10.48295/et.2022.89.4","url":null,"abstract":"Motorised Two-Wheeler (MTW) ownership has increased worldwide, especially in emerging countries. The growing usage of MTW vehicles has resulted in several issues, one of the most serious of which is an increase in fatality rates. Therefore, it is essential to understand the MTW rider behaviour for a safe operation and minimise crash likelihood. Motorised two-wheeler Rider Behaviour Questionnaire (MRBQ) is one such survey instrument used for this purpose. In previous decades, many researchers have attempted to examine numerous factors related to the MRBQ survey in various countries. This study aims to review research papers that have examined various factors used in MRBQ studies from various nations and highlight state-of-the-art conclusions. In addition, the study emphasises the research gaps that are critical for factors related to rider behaviour that can be incorporated in the MRBQ survey. This review will benefit the researchers working in the area of MTW safety and MRBQ studies, as well as be useful to decision makers for analysis and policy implementation.","PeriodicalId":45410,"journal":{"name":"European Transport-Trasporti Europei","volume":"146 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74873644","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}
This research investigates and models the level of service for urban roads based on travelers’ perceptions. A video-based perception survey is utilized to collect the required perception data, in which the survey participants assessed the quality of operating conditions illustrated in the given video clips. The ratings stated by the study participants were statistically related to the corresponding traffic parameters associated with the video clips using a random-effects ordered probit modeling approach. The primary findings confirm that level of service was primarily dependent on average travel speed, as indicated by the significance of the measure of effectiveness known as the percent free-flow speed. Subsequently, a comprehensive exploratory analysis revealed that other traffic characteristics such as control delay, extra lanes, and proper medians also influenced the perception of service levels. Specific traveler characteristics like age, income and usage of particular vehicle classes also influenced the perception of the level of service on urban roads.
{"title":"Modeling Level of Service of Urban Roads Based on Travelers’ Perceptions","authors":"Jithin Raj","doi":"10.48295/et.2022.89.1","DOIUrl":"https://doi.org/10.48295/et.2022.89.1","url":null,"abstract":"This research investigates and models the level of service for urban roads based on travelers’ perceptions. A video-based perception survey is utilized to collect the required perception data, in which the survey participants assessed the quality of operating conditions illustrated in the given video clips. The ratings stated by the study participants were statistically related to the corresponding traffic parameters associated with the video clips using a random-effects ordered probit modeling approach. The primary findings confirm that level of service was primarily dependent on average travel speed, as indicated by the significance of the measure of effectiveness known as the percent free-flow speed. Subsequently, a comprehensive exploratory analysis revealed that other traffic characteristics such as control delay, extra lanes, and proper medians also influenced the perception of service levels. Specific traveler characteristics like age, income and usage of particular vehicle classes also influenced the perception of the level of service on urban roads.","PeriodicalId":45410,"journal":{"name":"European Transport-Trasporti Europei","volume":"29 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91321869","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}
In developing nations like India, due to non-homogeneity in traffic streams, the flow of motorized three-wheelers gets clogged. While studying the literature, researchers do not find any significant Level of Service (LOS) models for forecasting motorized three-wheelers' service quality at uncontrolled un-signalized intersections under heterogeneous traffic conditions. This study brings to an AI-based Three-Wheeler Level of Service (3WhLOS) model to evaluate the service quality offered by un-signalized intersections operating under mixed traffic conditions. Data are collected from 21 uncontrolled intersections located at 7 different cities of India. Spearman's correlation analysis is performed to fathom the influence of service parameters towards perceived 3WhLOS score. Bayesian Regularized Artificial Neural Network (BRANN) is adopted for the prediction of 3WhLOS scores. Sensitivity Analysis is also executed to determine the relative importance of each parameter and help the transport authorities to identify the issues and improvise them for the betterment of the users.
{"title":"Service level modelling of motorized three-wheelers at un-signalized intersections under heterogeneous traffic conditions","authors":"Abhijnan Maji","doi":"10.48295/et.2022.88.2","DOIUrl":"https://doi.org/10.48295/et.2022.88.2","url":null,"abstract":"In developing nations like India, due to non-homogeneity in traffic streams, the flow of motorized three-wheelers gets clogged. While studying the literature, researchers do not find any significant Level of Service (LOS) models for forecasting motorized three-wheelers' service quality at uncontrolled un-signalized intersections under heterogeneous traffic conditions. This study brings to an AI-based Three-Wheeler Level of Service (3WhLOS) model to evaluate the service quality offered by un-signalized intersections operating under mixed traffic conditions. Data are collected from 21 uncontrolled intersections located at 7 different cities of India. Spearman's correlation analysis is performed to fathom the influence of service parameters towards perceived 3WhLOS score. Bayesian Regularized Artificial Neural Network (BRANN) is adopted for the prediction of 3WhLOS scores. Sensitivity Analysis is also executed to determine the relative importance of each parameter and help the transport authorities to identify the issues and improvise them for the betterment of the users.","PeriodicalId":45410,"journal":{"name":"European Transport-Trasporti Europei","volume":"96 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79058250","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}
The goal of this study is to quantify and analyse the costs of road-intermodal freight transportation in Pakistan. For the design of the problem, a performance model is utilised, which provides calculations of the costs incurred in road and intermodal freight transports. Our research shows a big cost difference between road and road-rail freight transport. The results show that the cost of road freight transport is 1.48 million Pkr/day and the cost of intermodal freight transport is 1.26 million Pkr/day for the delivery of 220 tonnes of cargo to the consumers. The quantitative analysis of real-life data from one of Asia's leading paper and board businesses used in this study demonstrates operational benefits of more than 60% cost reductions when switching from road to intermodal freight (road-rail) transport. Sensitivity analysis is also presented to assist decision-makers in selecting the most efficient and cost-effective mode of transportation.
{"title":"Economic Impact, Design, and Significance of Intermodal Freight Distribution in Pakistan","authors":"Rizwan Shoukat","doi":"10.48295/et.2022.88.6","DOIUrl":"https://doi.org/10.48295/et.2022.88.6","url":null,"abstract":"The goal of this study is to quantify and analyse the costs of road-intermodal freight transportation in Pakistan. For the design of the problem, a performance model is utilised, which provides calculations of the costs incurred in road and intermodal freight transports. Our research shows a big cost difference between road and road-rail freight transport. The results show that the cost of road freight transport is 1.48 million Pkr/day and the cost of intermodal freight transport is 1.26 million Pkr/day for the delivery of 220 tonnes of cargo to the consumers. The quantitative analysis of real-life data from one of Asia's leading paper and board businesses used in this study demonstrates operational benefits of more than 60% cost reductions when switching from road to intermodal freight (road-rail) transport. Sensitivity analysis is also presented to assist decision-makers in selecting the most efficient and cost-effective mode of transportation.","PeriodicalId":45410,"journal":{"name":"European Transport-Trasporti Europei","volume":"12 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85043751","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}
Although Greek coastal shipping is a very important shipping industry, there are not a lot of scientific efforts calculating economies of scale and minimum optimal firm size in the past. In our opinion, Stigler’s survivor technique is the best-fitted method for researching these issues. It examines the configuration of companies’ sizes over time and argues that only the companies with the lowest long-term average costs will survive in a market. Methodologically, we divided coastal companies into size classes regarding the number of employees per company and the contribution of companies per size class to gross production value, gross added value, and revenue without vat. Then we checked the statistical significance of changes in market share distribution. The analysis led to the conclusion that economies of scale exist in Greek coastal shipping and the minimum firm size pertains to the employment of 20-49 employees or the operation of two ships per shipping company.
{"title":"Economies of scale in Greek coastal shipping. A survivor analysis","authors":"I. Sitzimis","doi":"10.48295/et.2022.88.7","DOIUrl":"https://doi.org/10.48295/et.2022.88.7","url":null,"abstract":"Although Greek coastal shipping is a very important shipping industry, there are not a lot of scientific efforts calculating economies of scale and minimum optimal firm size in the past. In our opinion, Stigler’s survivor technique is the best-fitted method for researching these issues. It examines the configuration of companies’ sizes over time and argues that only the companies with the lowest long-term average costs will survive in a market. Methodologically, we divided coastal companies into size classes regarding the number of employees per company and the contribution of companies per size class to gross production value, gross added value, and revenue without vat. Then we checked the statistical significance of changes in market share distribution. The analysis led to the conclusion that economies of scale exist in Greek coastal shipping and the minimum firm size pertains to the employment of 20-49 employees or the operation of two ships per shipping company.","PeriodicalId":45410,"journal":{"name":"European Transport-Trasporti Europei","volume":"61 1","pages":""},"PeriodicalIF":0.7,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88524367","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：