Enhancing traffic efficiency and alleviating(even circumventing) traffic congestion with advanced traffic signal control(TSC) strategies are always the main issues to be addressed in urban transportation systems. Sinc...Enhancing traffic efficiency and alleviating(even circumventing) traffic congestion with advanced traffic signal control(TSC) strategies are always the main issues to be addressed in urban transportation systems. Since model predictive control(MPC) has a lot of advantages in modeling complex dynamic systems, it has been widely studied in traffic signal control over the past 20 years. There is a need for an in-depth understanding of MPC-based TSC methods for traffic networks. Therefore, this paper presents the motivation of using MPC for TSC and how MPC-based TSC approaches are implemented to manage and control the dynamics of traffic flows both in urban road networks and freeway networks. Meanwhile, typical performance evaluation metrics, solution methods, examples of simulations,and applications related to MPC-based TSC approaches are reported. More importantly, this paper summarizes the recent developments and the research trends in coordination and control of traffic networks with MPC-based TSC approaches. Remaining challenges and open issues are discussed towards the end of this paper to discover potential future research directions.展开更多
This paper deals with a comparative study on testing of concurrent programs based on different techniques. The various challenges in testing concurrent programming are: defining test coverage criteria based on control...This paper deals with a comparative study on testing of concurrent programs based on different techniques. The various challenges in testing concurrent programming are: defining test coverage criteria based on control flow, generating control flow graph of nondeterministic programs, investigating the applicability of sequential testing criteria to parallel program testing etc. For solving these issues, some existing techniques are discussed in this study. Various researchers use an intermediate graph called Event Inter Actions Graph (EIAG) to solve the problem of generating the control flow graph of nondeterministic programs. Some researches propose an intermediate graph called Interaction Sequence Testing Criteria (ISTC) approach based on sequence of interactions to solve the problem of test coverage criteria based on control and data flow. Another method to solve the problem of generating test coverage based on control flow graph of nondeterministic programs is constraint based approach. It needs constrained elements to generate test case which includes structural element and constraint. The selection of good test cases has been addressed by test data generation technique. The technique of concurrent path analysis approach is used to solve the problem of applicability of sequential testing criteria to parallel program testing. It reduces the number of combined concurrent test paths. The sequential test paths are combined to form concurrent test path. The Integration and System Test Automation (ISTA) approach is used to solve the problem of applicability of sequential testing criteria to parallel program testing. It is used for automated test case generation and execution by using high-level Petri net is a finite state test model.展开更多
基金supported in part by the National Natural Science Foundation of China(61603154,61773343,61621002,61703217)the Natural Science Foundation of Zhejiang Province(LY15F030021,LY19F030014)Open Research Project of the State Key Laboratory of Industrial Control Technology,Zhejiang University,China(ICT1800407)
文摘Enhancing traffic efficiency and alleviating(even circumventing) traffic congestion with advanced traffic signal control(TSC) strategies are always the main issues to be addressed in urban transportation systems. Since model predictive control(MPC) has a lot of advantages in modeling complex dynamic systems, it has been widely studied in traffic signal control over the past 20 years. There is a need for an in-depth understanding of MPC-based TSC methods for traffic networks. Therefore, this paper presents the motivation of using MPC for TSC and how MPC-based TSC approaches are implemented to manage and control the dynamics of traffic flows both in urban road networks and freeway networks. Meanwhile, typical performance evaluation metrics, solution methods, examples of simulations,and applications related to MPC-based TSC approaches are reported. More importantly, this paper summarizes the recent developments and the research trends in coordination and control of traffic networks with MPC-based TSC approaches. Remaining challenges and open issues are discussed towards the end of this paper to discover potential future research directions.
文摘This paper deals with a comparative study on testing of concurrent programs based on different techniques. The various challenges in testing concurrent programming are: defining test coverage criteria based on control flow, generating control flow graph of nondeterministic programs, investigating the applicability of sequential testing criteria to parallel program testing etc. For solving these issues, some existing techniques are discussed in this study. Various researchers use an intermediate graph called Event Inter Actions Graph (EIAG) to solve the problem of generating the control flow graph of nondeterministic programs. Some researches propose an intermediate graph called Interaction Sequence Testing Criteria (ISTC) approach based on sequence of interactions to solve the problem of test coverage criteria based on control and data flow. Another method to solve the problem of generating test coverage based on control flow graph of nondeterministic programs is constraint based approach. It needs constrained elements to generate test case which includes structural element and constraint. The selection of good test cases has been addressed by test data generation technique. The technique of concurrent path analysis approach is used to solve the problem of applicability of sequential testing criteria to parallel program testing. It reduces the number of combined concurrent test paths. The sequential test paths are combined to form concurrent test path. The Integration and System Test Automation (ISTA) approach is used to solve the problem of applicability of sequential testing criteria to parallel program testing. It is used for automated test case generation and execution by using high-level Petri net is a finite state test model.
