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429 Research products, page 1 of 43

  • Canada
  • Publications
  • Research data
  • 2017-2021
  • Open Access
  • Transport Research

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  • Publication . Conference object . Part of book or chapter of book . 2017
    Open Access English
    Authors: 
    Yu Hao; Zhijie Xu; Jing Wang; Ying Liu; Jiulun Fan;
    Publisher: IEEE
    Country: United Kingdom

    With the purpose of automatic detection of crowd patterns including abrupt and abnormal changes, a novel approach for extracting motion “textures” from dynamic Spatio-Temporal Volume (STV) blocks formulated by live video streams has been proposed. This paper starts from introducing the common approach for STV construction and corresponding Spatio-Temporal Texture (STT) extraction techniques. Next the crowd motion information contained within the random STT slices are evaluated based on the information entropy theory to cull the static background and noises occupying most of the STV spaces. A preprocessing step using Gabor filtering for improving the STT sampling efficiency and motion fidelity has been devised and tested. The technique has been applied on benchmarking video databases for proof-of-concept and performance evaluation. Preliminary results have shown encouraging outcomes and promising potentials for its real-world crowd monitoring and control applications.

  • Open Access
    Authors: 
    Ashley Zachariah; Arno de Klerk;
    Publisher: American Chemical Society (ACS)

    Solvent deasphalting and visbreaking are two important technologies in the development of processes for partial upgrading of oilsands-derived bitumen to improve oil fluidity for pipeline transport. This work investigated the impact of the process sequence, solvent deasphalting followed by visbreaking (SDA-Vis) compared to visbreaking followed by solvent deasphalting (Vis-SDA). Thermal conversion during visbreaking was performed at 380 °C for 85 min, and solvent deasphalting was performed with n-pentane. Using this combination of processes in either sequence changed bitumen from a viscosity-limited fluid to a density-limited fluid with respect to pipeline specifications. The density and viscosity of the oil products from SDA-Vis and Vis-SDA were comparable. It was found that SDA-Vis achieved 2 wt % higher liquid yield than Vis-SDA. Conversely, Vis-SDA produced an oil product with higher hydrogen to carbon ratio compared to SDA-Vis. This difference could be explained in terms of hydrogen transfer during the...

  • Open Access English
    Authors: 
    Adrien Cervesato; E. Owen D. Waygood;
    Publisher: Transportation Research Board Commission on Sociotechnical Systems National Research Council National Academy of Sciences
    Country: Canada

    Children’s independent mobility (CIM) on school days (weekdays) and on the weekend are examined in this study. Previous studies have focused primarily on weekday trips, with a vast majority only examining trips to school. However, the types of trips and the available time differ between weekdays and weekends. Weekday trips are more regular and possibly more local, whereas on the weekend the children may have more free time (i.e., no school) to engage in activities. Parents (as a group) are also less likely to have work obligations, and thus potentially more time, on the weekend. Theoretically, each context for the weekend could facilitate more independent or active mode trips. Nonetheless, this may be linked to whether destinations are local, which is linked to the built environment. Using origin–destination data (2011) for the City of Québec, this paper will expand knowledge in the field of children’s travel by examining all trips during a weekday ( n = 979) and weekend ( n = 315) for children aged 9 to 11 across five built environment types. The findings show that weekend trips are rarely independent, and that the key explanatory factors for greater CIM are shorter distances, having an older sibling, and more urban environments. Other sociodemographic variables were not significant or were inconsistent between the two types of weekday.

  • Open Access English
    Authors: 
    Amirreza Poorfakhraei; Mehdi Narimani; Ali Emadi;
    Publisher: IEEE

    Traction inverter has been the subject of many studies due to its essential role in the proper performance of the drive system. With the recent trend in increasing the input voltage in battery-powered electric vehicles, multilevel inverters have been proposed in the literature as a promising substitute for conventional two-level traction inverters. A critical aspect of utilizing multilevel structures is employing proper control and modulation techniques. The control system structure must be capable of handling a number of key issues, like capacitor voltage balancing and equal power loss sharing, which arise in multilevel topologies. This paper presents a review of the present-day traction drive systems in the industry, control and modulation techniques for multilevel structures in the inverters, as well as the principal challenges that need to be addressed in the control stage of the multilevel traction inverter. A comparison has been made between different methods based on the most important criteria and requirements of the traction drive system. Finally, future trends in this application are presented and some suggestions have been made for the next generation of traction drives.

  • Open Access English
    Authors: 
    Geraldine J. Fuenmayor; John E Abraham; John Douglas Hunt;
    Publisher: University of Minnesota

    We applied the PECAS Framework, a spatial economic system for forecasting and policy analysis, to the region of Caracas, Venezuela. In this paper, we describe in 12 steps the elements developed for an Activity Allocation model in this region. A detailed inventory of built space and household characteristics was developed using a population synthesis technique. The model design and implementation reflected informal (slum) housing and social equity (with 20 residential space types), while accounting for the industrial mix of the region. Transport costs for economic interactions were calculated using a TRANUS travel demand model. We also describe the calibration of the model and the application to two policy scenarios: provision of public housing and increasing transit fares. The 12 steps can guide future researchers, specifically listing the data and processes that were applied in this context. The sensitivity tests showed how this type of model can be used to anticipate social equity effects due to policy. Based on the know-how gained, we provide valuable insights for other modelling teams, particularly for applications in developing economies.

  • Open Access English
    Authors: 
    Saad Nahi Saleh; Thamer J. Mohammed; Huda Kadhim Hassan; Shahzad Barghi;
    Publisher: Elsevier

    Abstract Transportation of heavy crude oil via pipelines possesses many technological issues that are inherently flow related. Accurate prediction of flow characteristics is an essential step for a reliable piping design of transporting the crude oil. A rheology-based Computational Fluid Dynamics (CFD) model of the Iraqi heavy crude oil flow through a horizontal pipe (1 m length of 3/4 in. inside diameter) was developed using the commercial software Ansys 15 Fluent. By using power law rheological model, the Iraqi heavy crude oil exhibits a non-Newtonian dilatant behavior over the examined shear rate range of 1–40 s−1. The proposed axi-symmetric CFD model identifies velocity profile and generates values of friction factor, which are validated with experimental measurements. Additionally, wall shear stress and entrance length were numerically predicted and compared with well-established correlations from the literature for Non-Newtonian flow. Detailed results of the CFD model exhibited a reliable prediction of the characteristics of heavy crude oil flow.

  • Open Access
    Authors: 
    Karim Sachedina; Atef Mohany;
    Publisher: The Pipeline Transport Institute

    THE SAFETY AND RELIABILITY of gas and oil pipeline systems are dependent upon the effectiveness of current monitoring and inspection techniques. This paper outlines the present methods used for constant, or on-line, monitoring of pipeline systems, including a discussion of their reliability, sensitivity, and response time for detecting system irregularities. Periodic inspection and monitoring systems are discussed to highlight the techniques used to supplement on-line monitoring techniques and the capabilities for accurately locating defects and degradation before pipeline failure occurs. Future technologies are then discussed to provide insights into the potential for overcoming the limitations of current systems.

  • Open Access
    Authors: 
    Yan Li; Peiwen Hao; Chaozhi Zhao; Junqiang Ling; Tao Wu; Dewen Li; Jingwen Liu; Bowei Sun;
    Publisher: Elsevier BV

    Abstract Asphalt pavement inevitably suffers rutting distress induced by repeated loads under high temperatures, which can be effectively alleviated by the modification of asphalt binders. This paper summarized the asphalt modifiers for enhancing the performance of asphalt pavement at high temperatures in terms of the modifier type, additive amount and improving effect. Then, the anti-rutting performance evaluation methods of asphalt binder were introduced with details, including the ring and ball (R&B) test, the dynamic viscosity test, the zero/low shear viscosity (ZSV/LSV) test, the dynamic shear rheometer (DSR) test, the repeated creep and recovery (RCR) test, and the multiple stress creep and recovery (MSCR) test. Furthermore, the sensitivity of the evaluation method to asphalt modifier was analyzed using the normalization method. It was found that the indicators from the MSCR test could clearly reveal the influence of asphalt modifiers on high temperature performance of asphalt binder. But it still had some limitations affecting the accuracy of evaluation results, such as the number of creep‐recovery cycles, the stress level and the recovery time. In addition, according to the rutting resistance improvement ratio (RRIR), the styrene-butadiene-styrene (SBS) modifier performed better in improving the rutting resistance of asphalt binder, compared with other modifiers when added within the usual dosage range.

  • Open Access
    Authors: 
    Mudasser Seraj; Tony Z. Qiu;
    Publisher: Hindawi Limited
    Project: NSERC

    Weaving sections are components of highway networks that introduce a heightened likelihood for bottlenecks and collisions. Automated vehicle technology could address this as it holds considerable promise for transportation mobility and safety improvements. However, the implications of combining automated vehicles (AuVs) with traditional human-driven vehicles (HuVs) in weaving freeway sections have not been quantitatively measured. To address this gap, this paper objectively experimented with bidirectional (i.e., longitudinal and lateral) motion dynamics in a microscopic modeling framework to measure the mobility and safety implications for mixed traffic movement in a freeway weaving section. Our research begins by establishing a multilane microscopic model for studied vehicle types (i.e., AuV and HuV) from model predictive control with the provision to form a CACC platoon of AuV vehicles. The proposed modeling framework was tested first with HuV only on a two-lane weaving section and validated using standardized macroscopic parameters from the Highway Capacity Manual. This model was then applied to incrementally expand the AuV share for varying inflow rates of traffic. Simulation results showed that the maximum flow rate through the weaving section was attained at a 65% AuV share. At the same time, steadiness in the average speed of traffic was experienced with increasing AuV share. The results also revealed that a 95% AuV share could reduce potential conflicts by 94.28%. Finally, the results of simulated scenarios were consolidated and scaled to report expected mobility and safety outcomes from the prevailing traffic state and the optimal AuV share for the current inflow rate in weaving sections.

  • Open Access English
    Authors: 
    Muntahith Mehadil Orvin; Daryus Ahmed; Mahmudur Rahman Fatmi; Gordon Lovegrove;
    Publisher: University of Minnesota

    This study develops vehicular and non-vehicular trip generation models for mid-rise, multi-family residential developments. A comparative analysis of observed and Instiutue of Transportation Engineers (ITE) trip rates suggests that ITE rates consistently overestimate. A latent segmentation-based negative binomial (LSNB) model is developed to improve the methodology for estimating vehicular and non-vehicular trips. One of the key features of an LSNB model is to capture heterogeneity. Segment allocation results for the vehicular and non-vehicular models suggest that one segment includes suburban developments, whereas the other includes urban developments. Results reveal that a higher number of dwelling units is likely to be associated with increased vehicle trips. For non-vehicular trips, a higher number of dwelling units and increased recreational opportunities are more likely to increase trip generation. The LSNB model confirms the existence of significant heterogeneity. For instance, higher land-use mix has a higher probability to deter vehicular trips in urban areas, whereas trips in the suburban areas are likely to continue increasing. Higher density of bus routes and sidewalks are likely to be associated with increased non-vehicular trips in urban areas, yet such trips are likely to decrease in suburban areas. An interesting finding is that higher bikeability in suburban areas is more likely to increase non-vehicular trips. The findings of this study are expected to assist engineers and planners to predict vehicular and non-vehicular trips with higher accuracy.

search
Include:
The following results are related to Canada. Are you interested to view more results? Visit OpenAIRE - Explore.
429 Research products, page 1 of 43
  • Publication . Conference object . Part of book or chapter of book . 2017
    Open Access English
    Authors: 
    Yu Hao; Zhijie Xu; Jing Wang; Ying Liu; Jiulun Fan;
    Publisher: IEEE
    Country: United Kingdom

    With the purpose of automatic detection of crowd patterns including abrupt and abnormal changes, a novel approach for extracting motion “textures” from dynamic Spatio-Temporal Volume (STV) blocks formulated by live video streams has been proposed. This paper starts from introducing the common approach for STV construction and corresponding Spatio-Temporal Texture (STT) extraction techniques. Next the crowd motion information contained within the random STT slices are evaluated based on the information entropy theory to cull the static background and noises occupying most of the STV spaces. A preprocessing step using Gabor filtering for improving the STT sampling efficiency and motion fidelity has been devised and tested. The technique has been applied on benchmarking video databases for proof-of-concept and performance evaluation. Preliminary results have shown encouraging outcomes and promising potentials for its real-world crowd monitoring and control applications.

  • Open Access
    Authors: 
    Ashley Zachariah; Arno de Klerk;
    Publisher: American Chemical Society (ACS)

    Solvent deasphalting and visbreaking are two important technologies in the development of processes for partial upgrading of oilsands-derived bitumen to improve oil fluidity for pipeline transport. This work investigated the impact of the process sequence, solvent deasphalting followed by visbreaking (SDA-Vis) compared to visbreaking followed by solvent deasphalting (Vis-SDA). Thermal conversion during visbreaking was performed at 380 °C for 85 min, and solvent deasphalting was performed with n-pentane. Using this combination of processes in either sequence changed bitumen from a viscosity-limited fluid to a density-limited fluid with respect to pipeline specifications. The density and viscosity of the oil products from SDA-Vis and Vis-SDA were comparable. It was found that SDA-Vis achieved 2 wt % higher liquid yield than Vis-SDA. Conversely, Vis-SDA produced an oil product with higher hydrogen to carbon ratio compared to SDA-Vis. This difference could be explained in terms of hydrogen transfer during the...

  • Open Access English
    Authors: 
    Adrien Cervesato; E. Owen D. Waygood;
    Publisher: Transportation Research Board Commission on Sociotechnical Systems National Research Council National Academy of Sciences
    Country: Canada

    Children’s independent mobility (CIM) on school days (weekdays) and on the weekend are examined in this study. Previous studies have focused primarily on weekday trips, with a vast majority only examining trips to school. However, the types of trips and the available time differ between weekdays and weekends. Weekday trips are more regular and possibly more local, whereas on the weekend the children may have more free time (i.e., no school) to engage in activities. Parents (as a group) are also less likely to have work obligations, and thus potentially more time, on the weekend. Theoretically, each context for the weekend could facilitate more independent or active mode trips. Nonetheless, this may be linked to whether destinations are local, which is linked to the built environment. Using origin–destination data (2011) for the City of Québec, this paper will expand knowledge in the field of children’s travel by examining all trips during a weekday ( n = 979) and weekend ( n = 315) for children aged 9 to 11 across five built environment types. The findings show that weekend trips are rarely independent, and that the key explanatory factors for greater CIM are shorter distances, having an older sibling, and more urban environments. Other sociodemographic variables were not significant or were inconsistent between the two types of weekday.

  • Open Access English
    Authors: 
    Amirreza Poorfakhraei; Mehdi Narimani; Ali Emadi;
    Publisher: IEEE

    Traction inverter has been the subject of many studies due to its essential role in the proper performance of the drive system. With the recent trend in increasing the input voltage in battery-powered electric vehicles, multilevel inverters have been proposed in the literature as a promising substitute for conventional two-level traction inverters. A critical aspect of utilizing multilevel structures is employing proper control and modulation techniques. The control system structure must be capable of handling a number of key issues, like capacitor voltage balancing and equal power loss sharing, which arise in multilevel topologies. This paper presents a review of the present-day traction drive systems in the industry, control and modulation techniques for multilevel structures in the inverters, as well as the principal challenges that need to be addressed in the control stage of the multilevel traction inverter. A comparison has been made between different methods based on the most important criteria and requirements of the traction drive system. Finally, future trends in this application are presented and some suggestions have been made for the next generation of traction drives.

  • Open Access English
    Authors: 
    Geraldine J. Fuenmayor; John E Abraham; John Douglas Hunt;
    Publisher: University of Minnesota

    We applied the PECAS Framework, a spatial economic system for forecasting and policy analysis, to the region of Caracas, Venezuela. In this paper, we describe in 12 steps the elements developed for an Activity Allocation model in this region. A detailed inventory of built space and household characteristics was developed using a population synthesis technique. The model design and implementation reflected informal (slum) housing and social equity (with 20 residential space types), while accounting for the industrial mix of the region. Transport costs for economic interactions were calculated using a TRANUS travel demand model. We also describe the calibration of the model and the application to two policy scenarios: provision of public housing and increasing transit fares. The 12 steps can guide future researchers, specifically listing the data and processes that were applied in this context. The sensitivity tests showed how this type of model can be used to anticipate social equity effects due to policy. Based on the know-how gained, we provide valuable insights for other modelling teams, particularly for applications in developing economies.

  • Open Access English
    Authors: 
    Saad Nahi Saleh; Thamer J. Mohammed; Huda Kadhim Hassan; Shahzad Barghi;
    Publisher: Elsevier

    Abstract Transportation of heavy crude oil via pipelines possesses many technological issues that are inherently flow related. Accurate prediction of flow characteristics is an essential step for a reliable piping design of transporting the crude oil. A rheology-based Computational Fluid Dynamics (CFD) model of the Iraqi heavy crude oil flow through a horizontal pipe (1 m length of 3/4 in. inside diameter) was developed using the commercial software Ansys 15 Fluent. By using power law rheological model, the Iraqi heavy crude oil exhibits a non-Newtonian dilatant behavior over the examined shear rate range of 1–40 s−1. The proposed axi-symmetric CFD model identifies velocity profile and generates values of friction factor, which are validated with experimental measurements. Additionally, wall shear stress and entrance length were numerically predicted and compared with well-established correlations from the literature for Non-Newtonian flow. Detailed results of the CFD model exhibited a reliable prediction of the characteristics of heavy crude oil flow.

  • Open Access
    Authors: 
    Karim Sachedina; Atef Mohany;
    Publisher: The Pipeline Transport Institute

    THE SAFETY AND RELIABILITY of gas and oil pipeline systems are dependent upon the effectiveness of current monitoring and inspection techniques. This paper outlines the present methods used for constant, or on-line, monitoring of pipeline systems, including a discussion of their reliability, sensitivity, and response time for detecting system irregularities. Periodic inspection and monitoring systems are discussed to highlight the techniques used to supplement on-line monitoring techniques and the capabilities for accurately locating defects and degradation before pipeline failure occurs. Future technologies are then discussed to provide insights into the potential for overcoming the limitations of current systems.

  • Open Access
    Authors: 
    Yan Li; Peiwen Hao; Chaozhi Zhao; Junqiang Ling; Tao Wu; Dewen Li; Jingwen Liu; Bowei Sun;
    Publisher: Elsevier BV

    Abstract Asphalt pavement inevitably suffers rutting distress induced by repeated loads under high temperatures, which can be effectively alleviated by the modification of asphalt binders. This paper summarized the asphalt modifiers for enhancing the performance of asphalt pavement at high temperatures in terms of the modifier type, additive amount and improving effect. Then, the anti-rutting performance evaluation methods of asphalt binder were introduced with details, including the ring and ball (R&B) test, the dynamic viscosity test, the zero/low shear viscosity (ZSV/LSV) test, the dynamic shear rheometer (DSR) test, the repeated creep and recovery (RCR) test, and the multiple stress creep and recovery (MSCR) test. Furthermore, the sensitivity of the evaluation method to asphalt modifier was analyzed using the normalization method. It was found that the indicators from the MSCR test could clearly reveal the influence of asphalt modifiers on high temperature performance of asphalt binder. But it still had some limitations affecting the accuracy of evaluation results, such as the number of creep‐recovery cycles, the stress level and the recovery time. In addition, according to the rutting resistance improvement ratio (RRIR), the styrene-butadiene-styrene (SBS) modifier performed better in improving the rutting resistance of asphalt binder, compared with other modifiers when added within the usual dosage range.

  • Open Access
    Authors: 
    Mudasser Seraj; Tony Z. Qiu;
    Publisher: Hindawi Limited
    Project: NSERC

    Weaving sections are components of highway networks that introduce a heightened likelihood for bottlenecks and collisions. Automated vehicle technology could address this as it holds considerable promise for transportation mobility and safety improvements. However, the implications of combining automated vehicles (AuVs) with traditional human-driven vehicles (HuVs) in weaving freeway sections have not been quantitatively measured. To address this gap, this paper objectively experimented with bidirectional (i.e., longitudinal and lateral) motion dynamics in a microscopic modeling framework to measure the mobility and safety implications for mixed traffic movement in a freeway weaving section. Our research begins by establishing a multilane microscopic model for studied vehicle types (i.e., AuV and HuV) from model predictive control with the provision to form a CACC platoon of AuV vehicles. The proposed modeling framework was tested first with HuV only on a two-lane weaving section and validated using standardized macroscopic parameters from the Highway Capacity Manual. This model was then applied to incrementally expand the AuV share for varying inflow rates of traffic. Simulation results showed that the maximum flow rate through the weaving section was attained at a 65% AuV share. At the same time, steadiness in the average speed of traffic was experienced with increasing AuV share. The results also revealed that a 95% AuV share could reduce potential conflicts by 94.28%. Finally, the results of simulated scenarios were consolidated and scaled to report expected mobility and safety outcomes from the prevailing traffic state and the optimal AuV share for the current inflow rate in weaving sections.

  • Open Access English
    Authors: 
    Muntahith Mehadil Orvin; Daryus Ahmed; Mahmudur Rahman Fatmi; Gordon Lovegrove;
    Publisher: University of Minnesota

    This study develops vehicular and non-vehicular trip generation models for mid-rise, multi-family residential developments. A comparative analysis of observed and Instiutue of Transportation Engineers (ITE) trip rates suggests that ITE rates consistently overestimate. A latent segmentation-based negative binomial (LSNB) model is developed to improve the methodology for estimating vehicular and non-vehicular trips. One of the key features of an LSNB model is to capture heterogeneity. Segment allocation results for the vehicular and non-vehicular models suggest that one segment includes suburban developments, whereas the other includes urban developments. Results reveal that a higher number of dwelling units is likely to be associated with increased vehicle trips. For non-vehicular trips, a higher number of dwelling units and increased recreational opportunities are more likely to increase trip generation. The LSNB model confirms the existence of significant heterogeneity. For instance, higher land-use mix has a higher probability to deter vehicular trips in urban areas, whereas trips in the suburban areas are likely to continue increasing. Higher density of bus routes and sidewalks are likely to be associated with increased non-vehicular trips in urban areas, yet such trips are likely to decrease in suburban areas. An interesting finding is that higher bikeability in suburban areas is more likely to increase non-vehicular trips. The findings of this study are expected to assist engineers and planners to predict vehicular and non-vehicular trips with higher accuracy.