Due to the fact that there is no protected signal phase for right turns at most signalized intersections, the conflict between pedestrians and right-turning vehicles is one of the most common conflict types for pedest...Due to the fact that there is no protected signal phase for right turns at most signalized intersections, the conflict between pedestrians and right-turning vehicles is one of the most common conflict types for pedestrians. A pedestrian safety analysis of the common right-turn mode at four-phase signalized intersections is presented. Relative risk is used as a measure of the effect of behaviors. The analysis mainly includes five pedestrian factors that affect the conflict process between pedestrians and right-turning vehicles. Pedestrians tend to have a higher risk of being involved in conflicts in the following six situations: crossing with others, running over the crossing, entering the intersection, being near the exit lane, crossing in the middle or at the end of a green light when the right-turn lane is shared, crossing at the beginning of a green light or red period when the right-turn lane is exclusive. It is easier for pedestrians to get priority when crossing the street in the following situations: running over a crossing, entering the intersection, being near the entrance lane, and not using the crosswalk. However, pedestrians are more inclined to yield to right-turning vehicles when pedestrians are crossing in the middle of the green light time. Some measures to alleviate the conflict are put forward according to the conclusion. Video observations also indicate that a clear pedestrian waiting area must be marked for both pedestrian safety and right-turning vehicle efficiency at major flat intersections, particularly when the arms cover the lateral dividing strips.展开更多
A novel network control method based on trophaUaxis mechanism is applied to the formation flight problem for multiple un- manned aerial vehicles (UAVs). Firstly, the multiple UAVs formation flight system based on tr...A novel network control method based on trophaUaxis mechanism is applied to the formation flight problem for multiple un- manned aerial vehicles (UAVs). Firstly, the multiple UAVs formation flight system based on trophallaxis network control is given. Then, the model of leader-follower formation flight with a virtual leader based on trophallaxis network control is pre- sented, and the influence of time delays on the network performance is analyzed. A particle swarm optimization (PSO)-based formation controller is proposed for solving the leader-follower formation flight system. The proposed method is applied to five UAVs for achieving a 'V' formation, and a series of experimental results show its feasibility and validity. The proposed control algorithm is also a promising control strategy for formation flight of multiple unmanned underwater vehicles (UUVs), unmanned ground vehicles (UGVs), missiles and satellites.展开更多
Objective: To analyze the crash and injury data in forensic medicine for years of 2004-2007. Methods: A sample of over 567 accident cases (9 pedestrians, 116 bicyclists, and 442 motor vehicle occupants) was consi...Objective: To analyze the crash and injury data in forensic medicine for years of 2004-2007. Methods: A sample of over 567 accident cases (9 pedestrians, 116 bicyclists, and 442 motor vehicle occupants) was considered from the Department of Forensic Medicine, Shahid Bahonar University of Kerman, involving drivers of all ages and covering a four-year period. Results: The male fatality rates were significantly higher than female ones. The groups at 15-30 years old and at 30-55 years old had the first and second highest numbers of deaths (40% and 34%, respectively). There were substantial differences in distribution of injuries in motor vehicle occupants and pedestrians and bicyclists. Among motor vehicle occupants, there were more head injuries, such as skull fracture, brain contusion, subdural haemorrhage, and epidural haemorrhage. Nearly 77% of fatalities occurred during 08:00-22:00 in Sirjan. Internal bleeding was also higher in motor vehicle occupants. Pedestrians and bicyclists also had head injuries frequently. Conclusions: In spite of reduction of road traffic fatalities in Sirjan in 2007, it is still one of the cities with high road traffic fatality in the world. These results underline the importance of preventive strategies in transportation, suggesting that different methods are necessary to reduce fatalities of various traffic participants.展开更多
基金The National Natural Science Foundation of China(No.51278220)
文摘Due to the fact that there is no protected signal phase for right turns at most signalized intersections, the conflict between pedestrians and right-turning vehicles is one of the most common conflict types for pedestrians. A pedestrian safety analysis of the common right-turn mode at four-phase signalized intersections is presented. Relative risk is used as a measure of the effect of behaviors. The analysis mainly includes five pedestrian factors that affect the conflict process between pedestrians and right-turning vehicles. Pedestrians tend to have a higher risk of being involved in conflicts in the following six situations: crossing with others, running over the crossing, entering the intersection, being near the exit lane, crossing in the middle or at the end of a green light when the right-turn lane is shared, crossing at the beginning of a green light or red period when the right-turn lane is exclusive. It is easier for pedestrians to get priority when crossing the street in the following situations: running over a crossing, entering the intersection, being near the entrance lane, and not using the crosswalk. However, pedestrians are more inclined to yield to right-turning vehicles when pedestrians are crossing in the middle of the green light time. Some measures to alleviate the conflict are put forward according to the conclusion. Video observations also indicate that a clear pedestrian waiting area must be marked for both pedestrian safety and right-turning vehicle efficiency at major flat intersections, particularly when the arms cover the lateral dividing strips.
基金supported by the National Natural Science Foundation of China(Grant Nos.61273054,60975072 and 60604009)the National Basic Research Program of China("973"Project)(Grant No.2013CB035503)+1 种基金the Program for New Century Excellent Talents in University of China(Grant No.NCET-10-0021)the Aeronautical Foundation of China(Grant No.20115151019)
文摘A novel network control method based on trophaUaxis mechanism is applied to the formation flight problem for multiple un- manned aerial vehicles (UAVs). Firstly, the multiple UAVs formation flight system based on trophallaxis network control is given. Then, the model of leader-follower formation flight with a virtual leader based on trophallaxis network control is pre- sented, and the influence of time delays on the network performance is analyzed. A particle swarm optimization (PSO)-based formation controller is proposed for solving the leader-follower formation flight system. The proposed method is applied to five UAVs for achieving a 'V' formation, and a series of experimental results show its feasibility and validity. The proposed control algorithm is also a promising control strategy for formation flight of multiple unmanned underwater vehicles (UUVs), unmanned ground vehicles (UGVs), missiles and satellites.
文摘Objective: To analyze the crash and injury data in forensic medicine for years of 2004-2007. Methods: A sample of over 567 accident cases (9 pedestrians, 116 bicyclists, and 442 motor vehicle occupants) was considered from the Department of Forensic Medicine, Shahid Bahonar University of Kerman, involving drivers of all ages and covering a four-year period. Results: The male fatality rates were significantly higher than female ones. The groups at 15-30 years old and at 30-55 years old had the first and second highest numbers of deaths (40% and 34%, respectively). There were substantial differences in distribution of injuries in motor vehicle occupants and pedestrians and bicyclists. Among motor vehicle occupants, there were more head injuries, such as skull fracture, brain contusion, subdural haemorrhage, and epidural haemorrhage. Nearly 77% of fatalities occurred during 08:00-22:00 in Sirjan. Internal bleeding was also higher in motor vehicle occupants. Pedestrians and bicyclists also had head injuries frequently. Conclusions: In spite of reduction of road traffic fatalities in Sirjan in 2007, it is still one of the cities with high road traffic fatality in the world. These results underline the importance of preventive strategies in transportation, suggesting that different methods are necessary to reduce fatalities of various traffic participants.