Pub Date : 2019-09-23DOI: 10.18757/EJTIR.2019.19.3.4383
M. Hueskes, J. Koppenjan, S. Verweij
In recent years, a considerable number of PhD-dissertations have appeared in the Netherland and Flanders (Belgium) on Public-Private Partnerships (PPPs) for the provision of public infrastructures such as transport infrastructure and public buildings. These PhD-theses provide valuable insights into how PPPs perform and especially into the conditions that influence their performance. We identified four clusters of relevant conditions: (1) public procurement procedures, (2) contract management, (3) transaction costs, and (4) democratic legitimacy and accountability. By discussing the theses in this article, their lessons learned become available for the international PPP-community. Our analysis of the PhD-theses shows that there are no definite arguments for or against the use of PPPs. The performance of PPP-arrangements depends on agency: on the skills and commitment of parties involved and on the way in which the arrangements are applied. The dissertations show that policymakers have to find ways to balance the need to reduce transaction costs through contract standardization with the need for tailor- made solutions in specific projects. Furthermore, the dissertations show that ‘soft’ contract management aspects, such as the quality of collaborative behavior and process management, are particularly important for the performance of PPPs. Finally, the theses bring to the fore the democratic issues involved in PPPs, showing their mixed results in terms of legitimacy and accountability.
{"title":"Public-private partnerships for infrastructure: Lessons learned from Dutch and Flemish PhD-theses","authors":"M. Hueskes, J. Koppenjan, S. Verweij","doi":"10.18757/EJTIR.2019.19.3.4383","DOIUrl":"https://doi.org/10.18757/EJTIR.2019.19.3.4383","url":null,"abstract":"\u0000 \u0000 \u0000In recent years, a considerable number of PhD-dissertations have appeared in the Netherland and Flanders (Belgium) on Public-Private Partnerships (PPPs) for the provision of public infrastructures such as transport infrastructure and public buildings. These PhD-theses provide valuable insights into how PPPs perform and especially into the conditions that influence their performance. We identified four clusters of relevant conditions: (1) public procurement procedures, (2) contract management, (3) transaction costs, and (4) democratic legitimacy and accountability. By discussing the theses in this article, their lessons learned become available for the international PPP-community. Our analysis of the PhD-theses shows that there are no definite arguments for or against the use of PPPs. The performance of PPP-arrangements depends on agency: on the skills and commitment of parties involved and on the way in which the arrangements are applied. The dissertations show that policymakers have to find ways to balance the need to reduce transaction costs through contract standardization with the need for tailor- made solutions in specific projects. Furthermore, the dissertations show that ‘soft’ contract management aspects, such as the quality of collaborative behavior and process management, are particularly important for the performance of PPPs. Finally, the theses bring to the fore the democratic issues involved in PPPs, showing their mixed results in terms of legitimacy and accountability. \u0000 \u0000 \u0000","PeriodicalId":46721,"journal":{"name":"European Journal of Transport and Infrastructure Research","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49568516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.34143/jtr.2019.26.3.1
Kim, Hui-yang, 송하영, 백호종, 윤지성
{"title":"항공사 운항 정시성 산정기준에 관한 연구: 출발지연을 중심으로","authors":"Kim, Hui-yang, 송하영, 백호종, 윤지성","doi":"10.34143/jtr.2019.26.3.1","DOIUrl":"https://doi.org/10.34143/jtr.2019.26.3.1","url":null,"abstract":"","PeriodicalId":46721,"journal":{"name":"European Journal of Transport and Infrastructure Research","volume":"37 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81906226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-09-01DOI: 10.34143/jtr.2019.26.3.13
임정은, 조성훈
{"title":"도시철도 개통이 통근·통학인구 변화에 미치는 영향 분석","authors":"임정은, 조성훈","doi":"10.34143/jtr.2019.26.3.13","DOIUrl":"https://doi.org/10.34143/jtr.2019.26.3.13","url":null,"abstract":"","PeriodicalId":46721,"journal":{"name":"European Journal of Transport and Infrastructure Research","volume":"55 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90838159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-24DOI: 10.3929/ETHZ-B-000354730
Daniel J. Reck, K. Axhausen
The first/last mile is a long known deterrent to public transportation use, yet difficult to solve with fixed route transit. Many transit agencies are exploring partnerships with ridesourcing companies to offer subsidized feeder services. Ridership, however, has been surprisingly low. We explore two conceptual explanations. First, ridesourcing fares are found to exceed travel time savings for all distances below 1 mile and annual household incomes below USD 30,000 (i.e., the majority of US bus-using households). Subsidies are thus necessary, yet common schemes (flat fees, flat value or percentage discounts) are inequitable as they particularly benefit high-income households (thus miss their main target group). Second, the disutility of the additional transfer (‘transfer penalty’) and wait times exceed travel time savings assuming modest values for all distances below 0.45 miles. Subsidized ridesourcing for the first/last mile is thus not the panacea often portrayed, particularly not for short first/last miles. Where first/last miles are longer, investments in first/last mile services only might miss their purpose as the private car often remains the faster, more convenient and cheaper option. A much more holistic set of policy changes is hence required. Where transit agencies decide to proceed with first/last mile subsidies, they are advised to integrate them into existing fares (offering first/last mile rides for free) as this is the most equitable approach.
{"title":"Subsidized ridesourcing for the first/last mile: how valuable for whom?","authors":"Daniel J. Reck, K. Axhausen","doi":"10.3929/ETHZ-B-000354730","DOIUrl":"https://doi.org/10.3929/ETHZ-B-000354730","url":null,"abstract":"The first/last mile is a long known deterrent to public transportation use, yet difficult to solve with fixed route transit. Many transit agencies are exploring partnerships with ridesourcing companies to offer subsidized feeder services. Ridership, however, has been surprisingly low. We explore two conceptual explanations. First, ridesourcing fares are found to exceed travel time savings for all distances below 1 mile and annual household incomes below USD 30,000 (i.e., the majority of US bus-using households). Subsidies are thus necessary, yet common schemes (flat fees, flat value or percentage discounts) are inequitable as they particularly benefit high-income households (thus miss their main target group). Second, the disutility of the additional transfer (‘transfer penalty’) and wait times exceed travel time savings assuming modest values for all distances below 0.45 miles. Subsidized ridesourcing for the first/last mile is thus not the panacea often portrayed, particularly not for short first/last miles. Where first/last miles are longer, investments in first/last mile services only might miss their purpose as the private car often remains the faster, more convenient and cheaper option. A much more holistic set of policy changes is hence required. Where transit agencies decide to proceed with first/last mile subsidies, they are advised to integrate them into existing fares (offering first/last mile rides for free) as this is the most equitable approach.","PeriodicalId":46721,"journal":{"name":"European Journal of Transport and Infrastructure Research","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43681800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-12DOI: 10.18757/EJTIR.2019.19.2.4380
Zhaobin Liu, J. Guo, Lei Chen, Yun Wei, Wei Huang, Jinde Cao
Although Connected Vehicle technology is developing rapidly, connected vehicles (CV) are going to mix with the traditional vehicles (i.e., non-connected vehicles) for a long time. The effects of deploying CV on urban traffic systems are actually not clear. The main objective of this study is to evaluate the potential effects of route guidance under connected vehicle environment on an urban traffic network in terms of traffic mobility and safety. Microscopic simulation approach is used to conduct CV environment simulation and the rolling horizon approach is used for information updating among the connected vehicles. Meanwhile, driving behavior is modeled through aggressiveness and awareness of drivers. Traffic mobility for the road network was measured by average trip time and average vehicle trip speed. A surrogate measure, i.e., the time-to-collision involved incident rate for one kilometer driven, was used to assess the safety of the road network. Based on a real urban traffic network, the impacts of market penetration levels of connected vehicles and information updating intervals were studied. Simulation results showed that market penetration level of connected vehicles has little impact on the mobility and safety of road network. In addition, according to the simulation conducted in this paper, shorter updating interval is shown to be likely to lead to better mobility, while the safety of road network is likely to decline, under the assumptions embraced in the simulation. By contrast, the simulation also showed that longer updating interval is likely to lead to better safety and decreased mobility.
{"title":"Effect of dynamic route guidance on urban traffic network under Connected Vehicle environment","authors":"Zhaobin Liu, J. Guo, Lei Chen, Yun Wei, Wei Huang, Jinde Cao","doi":"10.18757/EJTIR.2019.19.2.4380","DOIUrl":"https://doi.org/10.18757/EJTIR.2019.19.2.4380","url":null,"abstract":"\u0000 \u0000 \u0000Although Connected Vehicle technology is developing rapidly, connected vehicles (CV) are going to mix with the traditional vehicles (i.e., non-connected vehicles) for a long time. The effects of deploying CV on urban traffic systems are actually not clear. The main objective of this study is to evaluate the potential effects of route guidance under connected vehicle environment on an urban traffic network in terms of traffic mobility and safety. Microscopic simulation approach is used to conduct CV environment simulation and the rolling horizon approach is used for information updating among the connected vehicles. Meanwhile, driving behavior is modeled through aggressiveness and awareness of drivers. Traffic mobility for the road network was measured by average trip time and average vehicle trip speed. A surrogate measure, i.e., the time-to-collision involved incident rate for one kilometer driven, was used to assess the safety of the road network. Based on a real urban traffic network, the impacts of market penetration levels of connected vehicles and information updating intervals were studied. Simulation results showed that market penetration level of connected vehicles has little impact on the mobility and safety of road network. In addition, according to the simulation conducted in this paper, shorter updating interval is shown to be likely to lead to better mobility, while the safety of road network is likely to decline, under the assumptions embraced in the simulation. By contrast, the simulation also showed that longer updating interval is likely to lead to better safety and decreased mobility. \u0000 \u0000 \u0000","PeriodicalId":46721,"journal":{"name":"European Journal of Transport and Infrastructure Research","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42717510","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-12DOI: 10.18757/EJTIR.2019.19.2.4378
Carolina Liljenström, S. Toller, J. Åkerman, A. Björklund
By 2045, Sweden is to have zero net emissions of greenhouse gases. To reach this goal, stakeholders involved in planning and construction of Swedish transport infrastructure aim to half their climate impact by 2030. Planning for emission reduction measures require network level studies showing environmental impacts of the infrastructure network. Previous studies do not allow assessment of current hotspots in the infrastructure network, which limits their relevance for decision-support in this question. The aim of this paper is to assess the current annual climate impact and primary energy use of Swedish transport infrastructure by using a methodological approach based on life cycle assessment. The scope includes new construction and management (operation, maintenance, and reinvestment) of existing roads, railways, airports, ports, and fairway channels. The annual climate impact was estimated to 2.8 million tonnes carbon dioxide equivalents and the annual primary energy use was estimated to 27 terawatt hours. Mainly road and rail infrastructure contributed to these impacts. Environmental hotspots of the infrastructure network were management of the infrastructure stock (particularly reinvestment of road and rail infrastructure) and material production (particularly production of asphalt, steel, and concrete). If climate targets are to be met, these areas are particularly important to address. Additional research on impacts of small construction measures, the size of biogenic carbon emissions (in standing biomass as well as soil carbon), and the use and impacts of asphalt for road construction and management would further increase the understanding of impacts related to Swedish transport infrastructure at the network level. (Note: an Erratum has been published to this paper in volume 20(2))
{"title":"Annual climate impact and primary energy use of Swedish transport infrastructure","authors":"Carolina Liljenström, S. Toller, J. Åkerman, A. Björklund","doi":"10.18757/EJTIR.2019.19.2.4378","DOIUrl":"https://doi.org/10.18757/EJTIR.2019.19.2.4378","url":null,"abstract":"\u0000 \u0000 \u0000By 2045, Sweden is to have zero net emissions of greenhouse gases. To reach this goal, stakeholders involved in planning and construction of Swedish transport infrastructure aim to half their climate impact by 2030. Planning for emission reduction measures require network level studies showing environmental impacts of the infrastructure network. Previous studies do not allow assessment of current hotspots in the infrastructure network, which limits their relevance for decision-support in this question. The aim of this paper is to assess the current annual climate impact and primary energy use of Swedish transport infrastructure by using a methodological approach based on life cycle assessment. The scope includes new construction and management (operation, maintenance, and reinvestment) of existing roads, railways, airports, ports, and fairway channels. The annual climate impact was estimated to 2.8 million tonnes carbon dioxide equivalents and the annual primary energy use was estimated to 27 terawatt hours. Mainly road and rail infrastructure contributed to these impacts. Environmental hotspots of the infrastructure network were management of the infrastructure stock (particularly reinvestment of road and rail infrastructure) and material production (particularly production of asphalt, steel, and concrete). If climate targets are to be met, these areas are particularly important to address. Additional research on impacts of small construction measures, the size of biogenic carbon emissions (in standing biomass as well as soil carbon), and the use and impacts of asphalt for road construction and management would further increase the understanding of impacts related to Swedish transport infrastructure at the network level. \u0000(Note: an Erratum has been published to this paper in volume 20(2)) \u0000 \u0000 \u0000","PeriodicalId":46721,"journal":{"name":"European Journal of Transport and Infrastructure Research","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47363938","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-07-12DOI: 10.18757/EJTIR.2019.19.2.4379
R. Kucharski, A. Drabicki, Klaudia Żyłka, A. Szarata
The objective of this paper is to propose a method to analyse and describe cyclists’ behaviour at signalized intersections with specific focus on the multichannel (multi-lane) queue phenomenon. As we observed, cyclists form queues without a fixed-lane and FIFO discipline, for which the classical, car-oriented analytical approach becomes insufficient. Cyclists’ multichannel queueing behaviour is common and characterized by substantial degree of variability, especially in case of shorter queues which emerge regularly at cycle crossings. Although cyclist behaviour has been widely studied by transportation research community, their queueing behaviour picture is still incomplete. Namely, there is no method addressed to analyse the full scope of these phenomena and to quantify their impact on the cyclist queue performance. To bridge this gap, we introduce the technique to observe multichannel queues and report relevant observations, which we then complement with a methodological framework to analyse obtained results and provide a complete multichannel queue description. We video-record cyclists as they enqueue to one of multiple channels, form the queue and smoothly merge into a single lane again as the queue discharges. We apply the method to analyse results from a pilot study of 160 cyclists forming 50 queues in the city of Krakow, Poland. The proposed method allows us to analyse and quantify the observed queue performance and its characteristics: the number of channels, their emergence process, channel and queue lengths, discharge process with FIFO violations, starting and discharging times. Findings from pilot study reveal that both queue length and discharge times strongly depend on queue formation process. The contribution of this paper is the method to describe multichannel cyclist queueing behaviour, enriching current picture of bicycle flow and cyclists’ behaviour. Since the method has been developed on relatively short queues (up to 10 cyclists), findings included in this paper primarily refer to such queue sizes. Nonetheless, the method is formulated in a generic way, applicable also for longer bicycle queues. Possible practical implications are new estimates for queue lengths and discharge times - useful for bicycle infrastructure design and traffic engineering purposes.
{"title":"Multichannel queueing behaviour in urban bicycle traffic","authors":"R. Kucharski, A. Drabicki, Klaudia Żyłka, A. Szarata","doi":"10.18757/EJTIR.2019.19.2.4379","DOIUrl":"https://doi.org/10.18757/EJTIR.2019.19.2.4379","url":null,"abstract":"\u0000 \u0000 \u0000The objective of this paper is to propose a method to analyse and describe cyclists’ behaviour at signalized intersections with specific focus on the multichannel (multi-lane) queue phenomenon. As we observed, cyclists form queues without a fixed-lane and FIFO discipline, for which the classical, car-oriented analytical approach becomes insufficient. Cyclists’ multichannel queueing behaviour is common and characterized by substantial degree of variability, especially in case of shorter queues which emerge regularly at cycle crossings. Although cyclist behaviour has been widely studied by transportation research community, their queueing behaviour picture is still incomplete. Namely, there is no method addressed to analyse the full scope of these phenomena and to quantify their impact on the cyclist queue performance. \u0000To bridge this gap, we introduce the technique to observe multichannel queues and report relevant observations, which we then complement with a methodological framework to analyse obtained results and provide a complete multichannel queue description. We video-record cyclists as they enqueue to one of multiple channels, form the queue and smoothly merge into a single lane again as the queue discharges. We apply the method to analyse results from a pilot study of 160 cyclists forming 50 queues in the city of Krakow, Poland. The proposed method allows us to analyse and quantify the observed queue performance and its characteristics: the number of channels, their emergence process, channel and queue lengths, discharge process with FIFO violations, starting and discharging times. Findings from pilot study reveal that both queue length and discharge times strongly depend on queue formation process. \u0000The contribution of this paper is the method to describe multichannel cyclist queueing behaviour, enriching current picture of bicycle flow and cyclists’ behaviour. Since the method has been developed on relatively short queues (up to 10 cyclists), findings included in this paper primarily refer to such queue sizes. Nonetheless, the method is formulated in a generic way, applicable also for longer bicycle queues. Possible practical implications are new estimates for queue lengths and discharge times - useful for bicycle infrastructure design and traffic engineering purposes. \u0000 \u0000 \u0000","PeriodicalId":46721,"journal":{"name":"European Journal of Transport and Infrastructure Research","volume":" ","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-07-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45683255","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-01DOI: 10.34143/jtr.2019.26.2.35
Cho, Hong Nam, 박형준, Jeong Woong Sohn
{"title":"정책갈등프레임워크(PCF)를 활용한 신공항 입지갈등 분석 : 제주 제2공항 사례를 중심으로","authors":"Cho, Hong Nam, 박형준, Jeong Woong Sohn","doi":"10.34143/jtr.2019.26.2.35","DOIUrl":"https://doi.org/10.34143/jtr.2019.26.2.35","url":null,"abstract":"","PeriodicalId":46721,"journal":{"name":"European Journal of Transport and Infrastructure Research","volume":"8 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87169483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-01DOI: 10.34143/jtr.2019.26.2.19
Jaemin Jang, Lee, Byung-Ho
{"title":"근로자의 특성과 통근권역 선택: 경기도 거주자를 중심으로","authors":"Jaemin Jang, Lee, Byung-Ho","doi":"10.34143/jtr.2019.26.2.19","DOIUrl":"https://doi.org/10.34143/jtr.2019.26.2.19","url":null,"abstract":"","PeriodicalId":46721,"journal":{"name":"European Journal of Transport and Infrastructure Research","volume":"4 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82450543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-06-01DOI: 10.34143/jtr.2019.26.2.71
Choi, Ji-Eun, Kim, Shi-Han, Lee, Jung-Won, 배명환
{"title":"자율협력주행 도로시스템의 종합성능평가 방법론 개발","authors":"Choi, Ji-Eun, Kim, Shi-Han, Lee, Jung-Won, 배명환","doi":"10.34143/jtr.2019.26.2.71","DOIUrl":"https://doi.org/10.34143/jtr.2019.26.2.71","url":null,"abstract":"","PeriodicalId":46721,"journal":{"name":"European Journal of Transport and Infrastructure Research","volume":"39 1","pages":""},"PeriodicalIF":1.7,"publicationDate":"2019-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90943289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","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：