This paper is based on the fundamental loading model of pure bending and the analytical model of a circular beam element with arbitrary initial deflection. The L.W. Guo solution is modified and generalized according t...This paper is based on the fundamental loading model of pure bending and the analytical model of a circular beam element with arbitrary initial deflection. The L.W. Guo solution is modified and generalized according to the elastic theory, and the analytical solution for the stress of the beam element with arbitrary initial deflection under pure bending is derived. Using yield theory of edge strength, an expression for the safety margin of one point in the arbitrary curved beam under pure bending （ACPB） is built. This paper modifies the model for weak points of service structures and establishes a foundation for safe design and inspection of imperfect structures. Also, according to the theory of the method of advanced first-order second-moment（AFOSM） , this paper derives an expression for the reliability index of one point in ACPB. Lastly, it modifies the solution for weak points by solving the minimal reliability index.展开更多
Based on the basic content of advanced technology,safety and reliability, and economic reasonability and the definition of mine ventilation system, 16 assessment indexes of ventilation system are put forward from the ...Based on the basic content of advanced technology,safety and reliability, and economic reasonability and the definition of mine ventilation system, 16 assessment indexes of ventilation system are put forward from the point of 8 aspects such as mine ventilation power, ventilation network, ventilation equipments, ventilation quality, ventilation monitoring, capacity of preventing and fighting disaster, ventilation consumption of power, and the capacity of ventila- tion system. A new assessment index system is put forward and has a good effect after being applied in coal mines.展开更多
This paper investigates the comparison problem of the reliability index between a parallel and a cold-standby system,both of which are consisting of two identical units.On the contrary to the general intuitive result,...This paper investigates the comparison problem of the reliability index between a parallel and a cold-standby system,both of which are consisting of two identical units.On the contrary to the general intuitive result,we proved that,under the condition that the system is shocked by a Poisson stream,the life time of the parallel system is longer than that of the cold-standby one in the sense of probability.展开更多
Travel time reliability(TTR)is an important measure which has been widely used to represent the traffic conditions on freeways.The objective of this study is to develop a systematic approach to analyzing TTR on roadwa...Travel time reliability(TTR)is an important measure which has been widely used to represent the traffic conditions on freeways.The objective of this study is to develop a systematic approach to analyzing TTR on roadway segments along a corridor.A case study is conducted to illustrate the TTR patterns using vehicle probe data collected on a freeway corridor in Charlotte,North Carolina.A number of influential factors are considered when analyzing TTR,which include,but are not limited to,time of day,day of week,year,and segment location.A time series model is developed and used to predict the TTR.Numerical results clearly indicate the uniqueness of TTR patterns under each case and under different days of week and weather conditions.The research results can provide insightful and objective information on the traffic conditions along freeway segments,and the developed data-driven models can be used to objectively predict the future TTRs,and thus to help transportation planners make informed decisions.展开更多
基金Supported by Commission of Science Technology and Industry for National Defence Foundation (NO.z192001A001)
文摘This paper is based on the fundamental loading model of pure bending and the analytical model of a circular beam element with arbitrary initial deflection. The L.W. Guo solution is modified and generalized according to the elastic theory, and the analytical solution for the stress of the beam element with arbitrary initial deflection under pure bending is derived. Using yield theory of edge strength, an expression for the safety margin of one point in the arbitrary curved beam under pure bending （ACPB） is built. This paper modifies the model for weak points of service structures and establishes a foundation for safe design and inspection of imperfect structures. Also, according to the theory of the method of advanced first-order second-moment（AFOSM） , this paper derives an expression for the reliability index of one point in ACPB. Lastly, it modifies the solution for weak points by solving the minimal reliability index.
基金Project 0424220161 supported by Science and Technology Foundation of Education Bureau of Henan Province
文摘Based on the basic content of advanced technology,safety and reliability, and economic reasonability and the definition of mine ventilation system, 16 assessment indexes of ventilation system are put forward from the point of 8 aspects such as mine ventilation power, ventilation network, ventilation equipments, ventilation quality, ventilation monitoring, capacity of preventing and fighting disaster, ventilation consumption of power, and the capacity of ventila- tion system. A new assessment index system is put forward and has a good effect after being applied in coal mines.
文摘This paper investigates the comparison problem of the reliability index between a parallel and a cold-standby system,both of which are consisting of two identical units.On the contrary to the general intuitive result,we proved that,under the condition that the system is shocked by a Poisson stream,the life time of the parallel system is longer than that of the cold-standby one in the sense of probability.
基金the financial support by the United States Department of Transportation, University Transportation Center through the Center for Advanced Multimodal Mobility Solutions and Education (CAMMSE) at The University of North Carolina at Charlotte (Grant Number: 69A3551747133)
文摘Travel time reliability(TTR)is an important measure which has been widely used to represent the traffic conditions on freeways.The objective of this study is to develop a systematic approach to analyzing TTR on roadway segments along a corridor.A case study is conducted to illustrate the TTR patterns using vehicle probe data collected on a freeway corridor in Charlotte,North Carolina.A number of influential factors are considered when analyzing TTR,which include,but are not limited to,time of day,day of week,year,and segment location.A time series model is developed and used to predict the TTR.Numerical results clearly indicate the uniqueness of TTR patterns under each case and under different days of week and weather conditions.The research results can provide insightful and objective information on the traffic conditions along freeway segments,and the developed data-driven models can be used to objectively predict the future TTRs,and thus to help transportation planners make informed decisions.
