The remain passenger problem at subway station platform was defined initially,and the period variation of remain passenger queues at platform was investigated through arriving and boarding analyses.Taking remain passe...The remain passenger problem at subway station platform was defined initially,and the period variation of remain passenger queues at platform was investigated through arriving and boarding analyses.Taking remain passenger queues at platform as dynamic stochastic process,a new probabilistic queuing method was developed based on probabilistic theory and discrete time Markov chain theory.This model can calculate remain passenger queues while considering different directions.Considering the stable or variable train arriving period and different platform crossing types,a series of model deformation research was carried out.The probabilistic approach allows to capture the cyclic behavior of queues,measures the uncertainty of a queue state prediction by computing the evolution of its probability in time,and gives any temporal distribution of the arrivals.Compared with the actual data,the deviation of experimental results is less than 20%,which shows the efficiency of probabilistic approach clearly.展开更多
文摘目的:探讨兔骨质疏松症(osteoporosis,OP)发生过程中骨髓代谢的变化特点。方法:通过兔双侧卵巢切除术(ovariectomy,OVX)制作兔OP模型模拟绝经期妇女的OP过程。双能X线吸收测量法测量骨密度(bone mineraldensity,BMD)的变化。通过活体磁共振氢质子波谱(proton magnetic resonance spectroscopy,1H-MRS)和离体液相色谱结合质谱(LC-MS/MS)分析等多种方法对骨髓进行代谢组学分析。OVX组和假手术组(Sham组)的取样分析节点均分别设定在术前、术后2个月和术后5个月。结果:随着时间的发展,术后5个月OVX组的BMD值较Sham组明显减低(2个月,P<0.05;5个月,P<0.01)。1H-MRS扫描分析表明,与Sham组相比,OVX组骨髓中的乳酸和脂类含量在术后2个月和5个月时均明显增加。OVX组骨髓中的胆碱、肌酸、谷氨酰胺、羟脯氨酸却较Sham组减少。在术后2个月时,进行离体骨髓代谢组学分析,也得到了上述相似的骨髓代谢变化结果。此外,1H-MRS扫描分析发现,OVX组的氨基酸、酰基肉碱、核苷酸和神经酰胺发生了显著变化。相关分析发现,BMD值与乳酸值之间呈明显负相关(r=-0.842,P<0.01),BMD与胆碱、肌酸、谷氨酰胺和羟脯氨酸呈显著正相关。结论:本研究发现随着OP进展,骨髓代谢会发生一系列复杂变化。利用1H-MRS对活体进行骨代谢变化扫描分析可能是评价OP的一种潜在无创方法。
基金Project(2011BAG01B01) supported by the Major State Basic Research and Development Program of ChinaProject(RCS2012ZZ002) supported by the State Key Lab of Rail Traffic Control and Safety,China
文摘The remain passenger problem at subway station platform was defined initially,and the period variation of remain passenger queues at platform was investigated through arriving and boarding analyses.Taking remain passenger queues at platform as dynamic stochastic process,a new probabilistic queuing method was developed based on probabilistic theory and discrete time Markov chain theory.This model can calculate remain passenger queues while considering different directions.Considering the stable or variable train arriving period and different platform crossing types,a series of model deformation research was carried out.The probabilistic approach allows to capture the cyclic behavior of queues,measures the uncertainty of a queue state prediction by computing the evolution of its probability in time,and gives any temporal distribution of the arrivals.Compared with the actual data,the deviation of experimental results is less than 20%,which shows the efficiency of probabilistic approach clearly.
