Journal of Transportation Systems Engineering and Information Technology, 2008
Urban transportation system is a complex system with multiple variables and nonlinear feedback lo... more Urban transportation system is a complex system with multiple variables and nonlinear feedback loops and influenced by transportation, social, economical, and environmental factors. Conventional transportation modeling approaches are unsuitable to simulate and evaluate its performance. This paper presents a system dynamics approach based on the cause-and-effect analysis and feedback loop structures. The proposed SD model comprises 7 submodels: population, economic development, number of vehicles, environmental influence, travel demand, transport supply, and traffic congestion. The model runs in Vensim PLE software using the data from Dalian, China. The coefficient of the intervention policy of vehicle ownership is chosen as the control variable for simulation, and the impacts of different policy scenarios on urban development and transportation system are analyzed. It suggests that Dalian should restrict the total number of vehicles to improve the sustainability of transportation system.
A method of reliability and economic analysis related to discrete transport systems with dispatch... more A method of reliability and economic analysis related to discrete transport systems with dispatcher is presented. The proposed analysis is based on modeling and simulating of the system behavior. The position of dispatcher is to mimic a function of real transport logistic. The Monte Carlo simulation is used for proper reliability and economic parameters calculation. No restriction on the system
6) effectiveness EF h In the paper methods of modelling nonlinear transportation systems have bee... more 6) effectiveness EF h In the paper methods of modelling nonlinear transportation systems have been presented basing on urban buses in aspect of considering processes connected with city-logistics. In chapter 1 deterministic nonlinear model of functioning of urban traffic transportation system has been formulated with distinction of elements dependent on vehicle operating systems. In the next chapter has been presented test method as well as investigations carried out together with the results obtained for the NEOPLAN N4020 bus. The investigations were carried out in Warsaw.
A Monte-Carlo code has been developed that can be used to optimally design vapor transport system... more A Monte-Carlo code has been developed that can be used to optimally design vapor transport systems for isotope-separator-on-line-based radioactive ion beam facilities in lieu of costly iterative trial and error design methods. The code provides a powerful means for delineating diffusion-release and effusive-flow (molecular-flow) processes, in combination, the delay times of which are principal intensity limiters of short-lived radioactive species at such facilities. The code provides time dependent particle evacuation, average distance traveled per particle, and particle/wall interaction information during particle transit through a given vapor-transport system under molecular-flow conditions, independent of the chemistry between particles of interest and the materials of which the transport system are constructed. In addition, the code provides powerful graphical insight via particle trajectories that serve as strong assets in arriving at a final design by identifying regions within the transport system where hold-up times are problematical. In this article, we compare simulation and experimental measurement results for transport of noble gases through selected vapor-transport systems using both cosine and isotropic particle re-emission distributions about the normal to the surface following adsorption (isotropic re-emission distributions are found to be in close agreement with experimental measurements) and describe a concept vapor-transport system that reduces transport times over those of conventional systems by >two orders of magnitude.
We present a new two-level numerical model describing the evolution of transportation network. Tw... more We present a new two-level numerical model describing the evolution of transportation network. Two separate but mutually interacting sub-systems are investigated: a "starving" environment and the network. We assume that the slow modes of the environment evolution can be modeled with classical cellular automata (CA) approach. We have coarse-grained the fast modes approximating the transportation network by the graph of cellular automata (GCA). This allows the simulation of transportation systems over larger spatio-temporal scales and scrutinizing global interactions between the network and the environment. We show that the model can mimic the realistic evolution of complex river systems. We also demonstrate how the model can simulate a reverse situation. We conclude that the paradigm of this model can be extended further to a general framework, approximating many realistic multiscale transportation systems in diverse fields such as geology, biology and medicine.
A number of modeling and simulation tools exist for studying transportation systems. The value of... more A number of modeling and simulation tools exist for studying transportation systems. The value of these tools would be significantly increased if they can be used in an integrated manner to investigate scenarios involving domain aspects modeled by different tools. This paper describes the design of an integrated traffic modeling and simulation framework using Semantic Web and workflow technology. The core component of the system is a domain ontology model which captures domain concepts and forms the common vocabulary for data and application integration. The proposed framework is designed to be modular and extensible, and to accommodate advanced visualization and human interaction together with data access and management capabilities. It hides the disparity of data formats, models and tools from domain experts and provides a single logical space for simulation design. We describe the technologies to achieve these goals and discuss the methodologies through representative use cases in studying transportation systems and control algorithms.
This tutorial describes the benefits of using simulation to evaluate the performance of transport... more This tutorial describes the benefits of using simulation to evaluate the performance of transportation facilities and systems.
... VISSIM Simulation Tool, http://www.itc-world.com/VISSIMinfo.htm ... of Large G=Freeway and Ar... more ... VISSIM Simulation Tool, http://www.itc-world.com/VISSIMinfo.htm ... of Large G=Freeway and Arterial Network with CORSIM, INTEGRATION, and WATSIM. Transportation Research Record ... The 2001Urban Mobility Report, Texas Transportation Institute, The Texas A&M University ...
Journal of Transportation Systems Engineering and Information Technology, 2008
Urban transportation system is a complex system with multiple variables and nonlinear feedback lo... more Urban transportation system is a complex system with multiple variables and nonlinear feedback loops and influenced by transportation, social, economical, and environmental factors. Conventional transportation modeling approaches are unsuitable to simulate and evaluate its performance. This paper presents a system dynamics approach based on the cause-and-effect analysis and feedback loop structures. The proposed SD model comprises 7 submodels: population, economic development, number of vehicles, environmental influence, travel demand, transport supply, and traffic congestion. The model runs in Vensim PLE software using the data from Dalian, China. The coefficient of the intervention policy of vehicle ownership is chosen as the control variable for simulation, and the impacts of different policy scenarios on urban development and transportation system are analyzed. It suggests that Dalian should restrict the total number of vehicles to improve the sustainability of transportation system.
A method of reliability and economic analysis related to discrete transport systems with dispatch... more A method of reliability and economic analysis related to discrete transport systems with dispatcher is presented. The proposed analysis is based on modeling and simulating of the system behavior. The position of dispatcher is to mimic a function of real transport logistic. The Monte Carlo simulation is used for proper reliability and economic parameters calculation. No restriction on the system
6) effectiveness EF h In the paper methods of modelling nonlinear transportation systems have bee... more 6) effectiveness EF h In the paper methods of modelling nonlinear transportation systems have been presented basing on urban buses in aspect of considering processes connected with city-logistics. In chapter 1 deterministic nonlinear model of functioning of urban traffic transportation system has been formulated with distinction of elements dependent on vehicle operating systems. In the next chapter has been presented test method as well as investigations carried out together with the results obtained for the NEOPLAN N4020 bus. The investigations were carried out in Warsaw.
A Monte-Carlo code has been developed that can be used to optimally design vapor transport system... more A Monte-Carlo code has been developed that can be used to optimally design vapor transport systems for isotope-separator-on-line-based radioactive ion beam facilities in lieu of costly iterative trial and error design methods. The code provides a powerful means for delineating diffusion-release and effusive-flow (molecular-flow) processes, in combination, the delay times of which are principal intensity limiters of short-lived radioactive species at such facilities. The code provides time dependent particle evacuation, average distance traveled per particle, and particle/wall interaction information during particle transit through a given vapor-transport system under molecular-flow conditions, independent of the chemistry between particles of interest and the materials of which the transport system are constructed. In addition, the code provides powerful graphical insight via particle trajectories that serve as strong assets in arriving at a final design by identifying regions within the transport system where hold-up times are problematical. In this article, we compare simulation and experimental measurement results for transport of noble gases through selected vapor-transport systems using both cosine and isotropic particle re-emission distributions about the normal to the surface following adsorption (isotropic re-emission distributions are found to be in close agreement with experimental measurements) and describe a concept vapor-transport system that reduces transport times over those of conventional systems by >two orders of magnitude.
We present a new two-level numerical model describing the evolution of transportation network. Tw... more We present a new two-level numerical model describing the evolution of transportation network. Two separate but mutually interacting sub-systems are investigated: a "starving" environment and the network. We assume that the slow modes of the environment evolution can be modeled with classical cellular automata (CA) approach. We have coarse-grained the fast modes approximating the transportation network by the graph of cellular automata (GCA). This allows the simulation of transportation systems over larger spatio-temporal scales and scrutinizing global interactions between the network and the environment. We show that the model can mimic the realistic evolution of complex river systems. We also demonstrate how the model can simulate a reverse situation. We conclude that the paradigm of this model can be extended further to a general framework, approximating many realistic multiscale transportation systems in diverse fields such as geology, biology and medicine.
A number of modeling and simulation tools exist for studying transportation systems. The value of... more A number of modeling and simulation tools exist for studying transportation systems. The value of these tools would be significantly increased if they can be used in an integrated manner to investigate scenarios involving domain aspects modeled by different tools. This paper describes the design of an integrated traffic modeling and simulation framework using Semantic Web and workflow technology. The core component of the system is a domain ontology model which captures domain concepts and forms the common vocabulary for data and application integration. The proposed framework is designed to be modular and extensible, and to accommodate advanced visualization and human interaction together with data access and management capabilities. It hides the disparity of data formats, models and tools from domain experts and provides a single logical space for simulation design. We describe the technologies to achieve these goals and discuss the methodologies through representative use cases in studying transportation systems and control algorithms.
This tutorial describes the benefits of using simulation to evaluate the performance of transport... more This tutorial describes the benefits of using simulation to evaluate the performance of transportation facilities and systems.
... VISSIM Simulation Tool, http://www.itc-world.com/VISSIMinfo.htm ... of Large G=Freeway and Ar... more ... VISSIM Simulation Tool, http://www.itc-world.com/VISSIMinfo.htm ... of Large G=Freeway and Arterial Network with CORSIM, INTEGRATION, and WATSIM. Transportation Research Record ... The 2001Urban Mobility Report, Texas Transportation Institute, The Texas A&M University ...
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