自适应广义线性回归拟似然估计渐近理论

研究自适应设计下的拟似然方程 ∑ni=1xi(yi- μ(x′iβ) ) =0 ,在一定的条件下证明了以概率 1此方程当n充分大时有解^βn,^βn 为β0 的强相合估计 ,且得出了 ^βn- β0的收敛速度 ;然后又在一定的条件下证明了 ^βn 的渐近正态性的一些结果     

连续时间Markov控制过程的平均代价最优鲁棒控制策略

在Markov性能势基础上 ,研究了一类转移速率不确定但受紧集约束的遍历连续时间Markov控制过程 (CTMCP)的鲁棒控制问题 .根据系统的遍历性 ,平均代价Poisson方程的解可被看作是性能势的一种定义 .在平均代价准则下 ,优化控制的目标是选择一个平稳策略使得系统在参数最坏取值下能获得最小无穷水平平均代价 ,据此论文给出了求解最优鲁棒控制策略的策略迭代 (PI)算法 ,并详细讨论了算法的收敛性 .     

关于Hurwitz Zeta函数的积分均值

设ζ(s,α)为HurwitzZeta函数.当Re(s)>1时,定义ζ(s,α)=∑∞n=01(n+α)s(实数α>0),ζ′(s,α)、ζ″(s,α)分别表示关于复变量s的一阶导数、二阶导数.利用解析方法及三角和估计给出了ζ(s,α)对参数α的积分均值的一些有趣的渐近公式.     

Exogenous carbon acquisition of photosynthesis in Porphyra haitanensis (Bangiales, Rhodophyta) under emersed state

The photosynthetic performances of Porphyra haitanensis thalli were investigated in order to understand its mechanisms for exogenous carbon acquisition during emersion at low tide. The emersed photosynthesis was studied by altering the pH value in the water film on the thalli surface, treating them with carbonic anhydarase inhibitors (acetazolamide and 6-ethoxyzolamide), adjusting the CO2 concentrations in the air, and comparing the theoretical maximum CO2 supply rates within the adherent water film with the observed photosynthetic CO2 uptake rates. It was found that the principal exogenous inorganic carbon source for the photosynthesis of P. haitanensis during emersion was atmospheric CO2. The driving force of CO2 flux across the water film was the CO2 concentration gradient within it. Carbonic anhydrase accelerated both extracellular and intracellular CO2 transport. The emersed photosynthesis of P. haitanensis was limited by the present atmospheric CO2 level, and would be enhanced by atmospheric CO2 rise that would trigger global warming.     

Difference schemes on non-uniform mesh and their application

High order accurate schemes are needed to simulate the multi-scale complex flow fields to get fine structures in simulation of the complex flows with large gradient of fluid parameters near the wall, and schemes on non-uniform mesh are desirable for many CFD (computational fluid dynamics) workers. The construction methods of difference approximations and several difference approximations on non-uniform mesh are presented. The accuracy of the methods and the influence of stretch ratio of the neighbor mesh increment on accuracy are discussed. Some comments on these methods are given, and comparison of the accuracy of the results obtained by schemes based on both non-uniform mesh and coordinate transformation is made, and some numerical examples with non-uniform mesh are presented.     

Early scale effect and hemisphere superiority on the visual spatial attention: From the electrophysiological evidence of ERP

The visual attention mechanism in the brain was studied among 16 young subjects through the precue-target visual search paradigm using the event-related potentials (ERPs) technique, with the attentive ranges cued with different scales of Chinese words. The results showed that the response time was shortened as the cue scale was reduced, while the amplitudes of the P1 and N1 components of the ERPs increased. These results not only provided the electrophysiological evidence supporting the spotlight theory, but also indicated that the spotlight effect occurred during the early period of the selected attention. Two kinds of separation in the P2 effect were observed. One separation was between the P1 effect and P2 effect, which meant that additional computation was needed when the spatial scale of attention was enlarged; the other was between the left and right hemisphere of the P2 effect, which indicates that the attentive processing of the cue range mainly occurred in the left hemisphere.     

Viola baoshanensis, a plant that hyperaccumulates cadmium

This paper reports upon the finding of Viola baoshanensis, a cadmium (Cd) hyperaccumulator through field survey and greenhouse experiments. Average Cd concentration in the shoots and roots of V. baoshanensis growing on Baoshan lead/zinc mine in Hunan Province, China, was 1168 and 981 mg/kg, respectively, varying from 456 to 2310mg/kg in the shoots, and from 233 to 1846 mg/kg in the roots.The ratio of Cd concentration in shoot to root (DW) and that in plant shoots to total concentration in surface soil was 1.32 and 2.38, respectively. Under nutrient solution culture, biomass (DW) of V. baoshanensis exposed to 0-30 mg/L Cd insolution increased with Cd supply increasing and reached a maximum at 30 mg/L Cd. Further increase of Cd concentration (40, 50 mg/L) in solution significantly reduced biomass.Cd concentration in the shoots was positively correlated with Cd concentration in the culture medium. Cd concentration in the shoots reached 4825 mg/kg at 50 mg/L Cd solution. Theratio of Cd concentration of shoots to roots in V. baoshanensis was greater than 1 at all Cd treatments, with an average of 1.67 (1.14-2.22). The results indicate that V. baoshanensis is a Cd hyperaccumulator plant.     

多Agent协作环境下的任务分配

对多Agent协作环境下的任务分配机制进行了论述。在合同网的分配机制基础上,提出了一种基于合同网的改进机制———任务列表分配机制。该任务分配机制针对多Agent协作工作时面临的突发性事件,能有效地提高系统的实时处理能力和工作效率。以多机器人系统为例,应用任务列表分配机制,解决突发事件下多机器人任务的再次分配问题,满足了多机器人协调工作的实时性要求。实验和理论证明了其机制的优越性。     

具有紧急消息的航电总线Petri网建模与性能分析

在航空电子综合化系统的设计过程中，总线系统的性能指标与整个航电系统的总体指标有着密切的关系。给出了一套完整的基于确定与随机Petri网的综合航电总线系统的性能评价的模型和算法。通过对总线系统的确定与随机Petri网模型的求解，给出了具有紧急消息的总线系统的两个重要性能指标总线负载、延迟时间，通过对性能曲线的分析，可以为综合航电系统的设计和完善提供重要的理论依据。     

多级缸起竖系统运动过程的建模与仿真

讨论了含多级油缸起竖液压系统的特点，运用多体系统动力学理论分析了起竖系统的多刚体模型，采用“分离-碰撞”两状态模型和非线性弹簧-阻尼力函数对活塞杆间的碰撞过程进行等效，建立了考虑碰撞的起竖多刚体系统动力学模型，对多级油缸的运动过程进行了仿真。仿真结果表明多级缸活塞杆运动过程中的碰撞是影响大型装置起竖过程平稳性的主要因素，模型和仿真结果可用于快速起竖系统的设计。