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Chinese Journal of Mechanical Engineering 2006年第1期19卷 67-71页

作者： LUE zhenzhou LIU Chengli fu Lin School of Aeronautics Northwestern Polytechnical University Xi＇ an 710072 China

An efficient importance sampling algorithm is presented to analyze reliability of complex structural system with multiple failure modes and fuzzy-random uncertainties in basic variables and failure modes. In order to improve the sampling efficiency, the simulated annealing algorithm is adopted to optimize the density center of the importance sampling for each failure mode, and results that the more significant contribution the points make to fuzzy failure probability, the higher occurrence possibility the points are sampled. For the system with multiple fuzzy failure modes, a weighted and mixed importance sampling function is constructed. The contribution of each fuzzy failure mode to the system failure probability is represented by the appropriate factors, and the efficiency of sampling is improved furthermore. The variances and the coefficients of variation are derived for the failure probability estimations. Two examples are introduced to illustrate the rationality of the present method. Comparing with the direct Monte-Carlo method, the improved efficiency and the precision of the method are verified by the examples.

关键词： Importance sampling Simulated annealing algorithm Randomness fuzziness

Nonlinear Control and Analysis of a Quadrotor with Sling Load in Path Tracking 36

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Nonlinear Control and Analysis of a Quadrotor with Sling Loa...

Modeling and Control of a New Multicopter 36

第36届中国控制会议

作者： Chaofan Wu zhenzhou fu Jia Yang Yiran Wei College of Engineering Bohai University

ISBN: (纸本)9781538629185

The structure of quadrotor with suspended load is widely used in many fields such as military and civilian.A wide range of research in this structure was implemented and have achieved a variety of *** the deeper of research,many problems are urged to be solved under the concern of *** example,the oscillation degree of the suspended *** first,this paper proposed a nonlinear dynamics model of quadrotor with a suspended ***,a proportional plus derivative controller is carried out to realize the trajectory tracking without consideration the vibration of the suspended ***,the simulation results show that the dynamics of the system and performance of path tracking.

关键词： Quadrotor slung load path tracking nonlinear model coupling

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Modeling and Control of a New Multicopter

A High-Performance Structural Aircraft:Modeling and Control 36

第36届中国控制会议

作者： zhenzhou fu Bing Xiao Jia Yang Chaofan Wu Yiran Wei College of Engineering Bohai University

ISBN: (纸本)9781538629185

This paper presents a new structure of multicopter with its propellers installed in three different *** aim is to achieve complete independent control of position and attitude of the *** can allow us to control the position with its desired attitude controlled *** such,this new multicopter can hover at any fixed point with its attitude changed *** can not be achieved for the existing *** key feature of this new design is that it provides the practical engineering area with a revelation,i.e.,it is actually not necessary to install robots on the aircraft to accomplish the planned aerial mission because this new multicopter is essentially a six degree-of-freedom aerial *** this novel design,the dynamic model is further established by using the Newton-Euler *** the basis of this,the work of controller design is also carried *** motion feature which the general multicopter can not be achieved is finally verified by numerical simulation.

关键词： multicopter PID control power allocation algorithm aerial manipulator

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A High-Performance Structural Aircraft:Modeling and Control

两种UDP-葡萄糖脱氢酶对透明质酸生物转化的影响

第36届中国控制会议

作者： Jia Yang Xing Huo Bing Xiao zhenzhou fu Chaofan Wu Yiran Wei College of Engineering Bohai University

ISBN: (纸本)9781538629185

The simple mechanical structure makes traditional quadrotor widely ***,some mechanical properties that hinders its further development,such as under-actuation and limited speed when moving *** these issues into account,a novel quadrotor is presented in this paper while its propellers are allowed to tilt about their *** a result,the drawback of the under-actuation of the quadrotor is *** this quadrotor,eight control inputs are provided for the six control *** except to system dynamics analysis and modeling,a PID controller is further developed to make the quadrotor available to flight in any *** applicability of the proposed design method is verified by simulation *** is demonstrated that the proposed high-performance structural aircraft has more superior performance than the traditional quadrotor.

关键词： New structural aircraft Tilt-rotor UAV Quadrotor

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生物工程学报 2014年第11期30卷 1691-1700页

作者：郭东会韩剑刘伟丰傅震洲朱启忠陶勇山东大学海洋学院山东威海264209 中国科学院微生物研究所北京100101

分别从大肠杆菌和化脓链球菌中扩增出编码UDP-葡萄糖脱氢酶基因ecohas B和spyhas B,并将其插入T7表达载体p RX2构建重组质粒p RXEB和p RXSB。在大肠杆菌BL21(DE3)中重组表达,并对经镍柱纯化后的UDP-葡萄糖脱氢酶的酶学性质进行分析。酶... 详细信息

分别从大肠杆菌和化脓链球菌中扩增出编码UDP-葡萄糖脱氢酶基因ecohas B和spyhas B,并将其插入T7表达载体p RX2构建重组质粒p RXEB和p RXSB。在大肠杆菌BL21(DE3)中重组表达,并对经镍柱纯化后的UDP-葡萄糖脱氢酶的酶学性质进行分析。酶学性质研究表明:spy Has B的最适反应温度是30℃,最适p H 10,最适条件下的比活力是12.2 U/mg;eco Has B的最适反应温度是30℃,最适p H 9,最适条件下的比活力是5.55 U/mg。从多杀巴氏杆菌扩增出的透明质酸合成酶基因pmuhas A分别与ecohas B和spyhas B构建共表达载体p BPAEB和p BPASB。将其转化到大肠杆菌BW25113中,经生物转化生产透明质酸(HA),并对转化条件进行了优化。结果表明:重组菌株进行透明质酸转化时,UDP-葡萄糖脱氢酶酶活力越高,稳定性越好,HA产量越高;转化条件优化后,p BPAEB/BW25113和p BPASB/BW25113在摇瓶中的产量分别是1.52和1.70 g/L,比之前报道的提高了2-3倍。

关键词： UDP-葡萄糖脱氢酶酶学性质透明质酸生物转化

Pre-judgment and Incomplete Allocation Approach for Query Result Cache

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Chinese Journal of Electronics 2016年第6期25卷 1101-1108页

作者： QIAN Libing JI zhenzhou fu Zhongchuan WU Qianqian SONG Guangjia School of Computer Science and Technology Harbin Institute of Technology

Query result caching is a crucial technique employed in search engines, reducing the response time and load of the search engines. As search engines continuously update their indexes, the query results in long-lived cache entries may become stale. It is important to provide the refresh mechanism to enhance the degree of freshness of cached results. We present a pre-judgment approach to improve the freshness of the result cache and design an incomplete allocation algorithm. We introduce the queryTime-to-live(TTL) and term-TTL structure to pre-judge the result cache. The query-TTL is used to pre-check the likelihood of a cache hit and term-TTL is applied to maintain all terms of the latest posting list. For the cache structure, we design a Queue-Hash structure and develop the corresponding incomplete allocation algorithm. The preliminary results demonstrate that our approaches can improve the freshness of cached results and decrease processing overhead compared with no pre-judgment approaches.

关键词： Time-to-live(TTL) Caching freshness Pre-judgment Result cache Cache structure

National Epidemiology and Evolutionary History of Four Hand, Foot and Mouth Disease-Related Enteroviruses in China from 2008 to 2016

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Virologica Sinica 2020年第1期35卷 21-33页

作者： Xuemin fu zhenzhou Wan Yanpeng Li Yihong Hu Xia Jin Chiyu Zhang Pathogen Discovery and Big Data Center CAS Key Laboratory of Molecular Virology and ImmunologyInstitut Pasteur of ShanghaiChinese Academy of SciencesUniversity of Chinese Academy of SciencesShanghai 200031China Medical Laboratory of Taizhou Fourth People’s Hospital Taizhou 225300China Viral Disease and Vaccine Translational Research Unit CAS Key Laboratory of Molecular Virology and ImmunologyInstitut Pasteur of ShanghaiChinese Academy of SciencesShanghai 200031China

Hand, foot and mouth disease(HFMD) is a major public health concern in China. The most predominant enteroviruses that cause HFMD have traditionally been attributed to enterovirus A71(EVA71) and coxsackievirus A16(CVA16). Since its first large outbreak in 2008, the dominant HFMD pathogens are constantly changing. In 2013 and 2015, CVA6 exceeded both EVA71 and CVA16 to become the leading cause of HFMD in some provinces. However, there still lacks a comprehensive overview on the molecular epidemiology and evolution of HFMD-related enteroviruses at the national level. In this study, we performed systematic epidemiological analyses of HFMD-related enteroviruses using the data of 64 published papers that met the inclusion criteria, and conducted phylogenetic analyses based on 12,080 partial VP1 sequences identified in China before 31 st June 2018. We found that EVA71 prevalence has decreased sharply but other enteroviruses have increased rapidly from 2008 to 2016 and that one subtype of each enterovirus is represented during the epidemic. In addition, four genotypes EVA71_C4, CVA16_B1, CVA6_D and CVA10_C are the most predominant enterovirus strains and collectively they cause over 90% of all HFMD cases in China according to the phylogenetic trees using representative partial VP1 sequences. These four major enterovirus genotypes have different geographical distributions, and they may cocirculate with other genotypes and serotypes. These results suggest that more molecular epidemiological studies should be performed on several enteroviruses simultaneously, and such information should have implications for virological surveillance, disease management, vaccine development and policy-making on the prevention and control of HFMD.

关键词： Enterovirus Hand,foot and mouth disease(HFMD) Molecular epidemiology Evolution Genotype

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基于线抽样的可靠性灵敏度分析方法

力学学报 2007年第4期39卷 564-570页

作者：宋述芳吕震宙傅霖西北工业大学航空学院西安710072

提出了一种基于线抽样的可靠性灵敏度分析方法．线抽样可靠性分析中,结构失效概率P_f是由每个抽样样本对应的失效概率P_(fj)的算术平均值来计算的。由此可知P_f对基本变量分布参数θ的灵敏度P_f/θ可以表示为P_(fj)对θ的偏导数P_... 详细信息

提出了一种基于线抽样的可靠性灵敏度分析方法．线抽样可靠性分析中,结构失效概率P_f是由每个抽样样本对应的失效概率P_(fj)的算术平均值来计算的。由此可知P_f对基本变量分布参数θ的灵敏度P_f/θ可以表示为P_(fj)对θ的偏导数P_(fj)/θ的算术平均值,而P_(fj)/θ则可以很容易地由P_(fj)与基本变量分布参数θ的解析关系求得．P_(fj)/θ和P_f/θ的计算公式被详细推导．可靠性灵敏度分析的线抽样方法继承了线抽样法的优点,诸如精度高、收敛快且适用于高维及多模式情况等．这些优点由算例证实．

关键词：可靠性灵敏度线抽样重要方向失效概率分布参数

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粉末冶金涡轮盘低周疲劳寿命可靠性敏度分析

西北工业大学学报 2007年第2期25卷 290-294页

作者：傅霖吕震宙袁修开西北工业大学航空学院陕西西安710072

对于在0-起飞-0循环载荷作用下的某型粉末冶金涡轮盘,利用可靠性分析的要求寿命-实际寿命干涉模型,建立了给定寿命要求下的涡轮盘低周疲劳寿命非线性极限状态方程。在此基础上,分别采用改进一次二阶矩法、Monte-Carlo模拟法和马尔可夫... 详细信息

对于在0-起飞-0循环载荷作用下的某型粉末冶金涡轮盘,利用可靠性分析的要求寿命-实际寿命干涉模型,建立了给定寿命要求下的涡轮盘低周疲劳寿命非线性极限状态方程。在此基础上,分别采用改进一次二阶矩法、Monte-Carlo模拟法和马尔可夫链模拟方法,对涡轮盘进行了低周疲劳寿命可靠性灵敏度分析。通过对分布参数可靠性灵敏度作无量纲归一化处理,得到了影响涡轮盘低周疲劳寿命失效概率的分布参数排序,其中起飞状态应变的均值对失效概率的影响最大。研究了涡轮盘寿命可靠性灵敏度随基本变量变异系数变化的趋势,分析了变化趋势对设计的影响。同时,通过3种可靠性灵敏度方法结果的对照分析,得出了各种方法的适用范围。

关键词：可靠性灵敏度分析改进一次二阶矩 Monte-Carlo模拟马尔可夫链模拟低周疲劳寿命粉末冶金涡轮盘

基于重要抽样马尔可夫链模拟的可靠性参数灵敏度分析方法

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西北工业大学学报 2007年第1期25卷 51-55页

作者：马超吕震宙傅霖西北工业大学航空学院陕西西安710072

针对重要抽样法求解失效概率的问题,提出了一种基于重要抽样马尔可夫链模拟的快速可靠性参数灵敏度分析方法。该方法首先采用Metropolis准则和马尔可夫链模拟,将重要抽样法抽取的落入失效域中的样本点转化为条件样本点,这些条件样本点... 详细信息

针对重要抽样法求解失效概率的问题,提出了一种基于重要抽样马尔可夫链模拟的快速可靠性参数灵敏度分析方法。该方法首先采用Metropolis准则和马尔可夫链模拟,将重要抽样法抽取的落入失效域中的样本点转化为条件样本点,这些条件样本点是落在失效域中的基本变量的实现,它们服从失效域条件下基本变量的概率分布,利用这些样本点替代Monte Carlo法抽取的条件样本点,可以通过加权回归分析快速得到隐式极限状态方程的近似,进而得到可靠性灵敏度。所提方法的显著优点是效率高,它只要在重要抽样法计算失效概率的结果中增加非常小的工作量,即可以快速得到可靠性参数灵敏度,算例结果充分说明所提方法的效率和合理性。

关键词：可靠性灵敏度分析马尔可夫链模拟重要抽样