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1 – 10 of 363Hanyu Yang, Jing Zhao and Meng Wang
This study aims to propose a centralized optimal control model for automated left-turn platoon at contraflow left-turn lane (CLL) intersections.
Abstract
Purpose
This study aims to propose a centralized optimal control model for automated left-turn platoon at contraflow left-turn lane (CLL) intersections.
Design/methodology/approach
The lateral lane change control and the longitudinal acceleration in the control horizon are optimized simultaneously with the objective of maximizing traffic efficiency and smoothness. The proposed model is cast into a mixed-integer linear programming problem and then solved by the branch-and-bound technique.
Findings
The proposed model has a promising control effect under different geometric controlled conditions. Moreover, the proposed model performs robustly under various safety time headways, lengths of the CLL and green times of the main signal.
Originality/value
This study proposed a centralized optimal control model for automated left-turn platoon at CLL intersections. The lateral lane change control and the longitudinal acceleration in the control horizon are optimized simultaneously with the objective of maximizing traffic efficiency and smoothness
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Keywords
Liang Xu, Sheng Jin, Bolin Li and Jiaming Wu
This study aims to make full use of the advantages of connected and autonomous vehicles (CAVs) and dedicated CAV lanes to ensure all CAVs can pass intersections without stopping.
Abstract
Purpose
This study aims to make full use of the advantages of connected and autonomous vehicles (CAVs) and dedicated CAV lanes to ensure all CAVs can pass intersections without stopping.
Design/methodology/approach
The authors developed a signal coordination model for arteries with dedicated CAV lanes by using mixed integer linear programming. CAV non-stop constraints are proposed to adapt to the characteristics of CAVs. As it is a continuous problem, various situations that CAVs arrive at intersections are analyzed. The rules are discovered to simplify the problem by discretization method.
Findings
A case study is conducted via SUMO traffic simulation program. The results show that the efficiency of CAVs can be improved significantly both in high-volume scenario and medium-volume scenario with the plan optimized by the model proposed in this paper. At the same time, the progression efficiency of regular vehicles is not affected significantly. It is indicated that full-scale benefits of dedicated CAV lanes can only be achieved with signal coordination plans considering CAV characteristics.
Originality/value
To the best of the authors’ knowledge, this is the first research that develops a signal coordination model for arteries with dedicated CAV lanes.
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Keywords
Doctors' labour and medicines are special necessities for human survival and evolution. Since China launched the healthcare reform, the theoretical circles' discussions have not…
Abstract
Purpose
Doctors' labour and medicines are special necessities for human survival and evolution. Since China launched the healthcare reform, the theoretical circles' discussions have not yet clarified the respective special properties of doctors' labour and medicines as goods and the internal relations between doctors' labour and medicines at the level of the theoretical basis.
Design/methodology/approach
Health is a prerequisite for people's all-round development, a precondition for economic and social development and the people's common aspiration. The all-round moderately prosperous society could not be achieved without people's all-round health.
Findings
The authors believe the socialist relation between doctors' labour and medicines with Chinese characteristics should be one that is people-oriented, and the corporatization of hospitals or the capitalization of doctors' labour should be avoided.
Originality/value
In this paper, the authors explore the particularity of doctors' labour, particularity of medicine production, circulation, consumption and the internal relations between doctors' labour and medicines by using the analytical approach of Marxist political economy while considering the special roles of doctor's labour and medicines in the reproduction of labour power and put forward the theoretical basis for the segregation of doctor's labour and medicines.
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