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Formation control for networked spacecraft in deep space:with or without communication delays and with switching topology

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science{1.(Information sciences) 2011年第3期54卷 469-481页

作者： wang Nan 1.{1. zhang TianWu {1.& XU JieQiong 1.1.{{1. of Aeronautic science and Engineering, Beijing university of Aeronautics and Astronautics, Beijing 1.01.1. china {1.Department of computer science and Engineering, Henan Institute of Engineering, Zhengzhou 451.91. china 1. school of Aeronautic {1. and Engineering Beijing University of Aeronautics and Astronautics Beijing 100191 China2. Department of Computer Science and Engineering Henan Institute of Engineering Zhengzhou 451191 China

In this paper, several formation controllers are developed with constant and variable connected communication topology for six-degree-of-freedom (6-DOF) networked spacecraft flying in deep space with constant and time-varying communication delays considered. In the control algorithm, any explicit leader does not exist in the formation team and it is required that each spacecraft communicate only with its neighbors and therefore the required communication loads of the whole formation is greatly reduced. The proposed control strategies allow that each spacecraft can track its desired position and attitude and simultaneously the whole group moves to the desired formation and obtain its desired relative attitudes with its neighbors. Simulation results demonstrate the effectiveness of the proposed controllers.

关键词： deep space graph theory formation control communication topology delays

Crowdsourcing intelligence for improving disaster forecasts

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The Innovation 2024年第4期5卷 13-14页

作者： Xiaohui wang Fuhai Dao Yatai Ji Sihang Qiu Xian Zhu Wenjie Dong Huizan wang Weimin {2. xiaolong Zheng College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410073China school of Atmospheric {1. Sun Yat-sen UniversityZhuhai 519082China College of Systems Engineering National University of Defense TechnologyChangsha 410073China The school of Artificial Intelligence University of Chinese Academy of SciencesBeijing 101408China The State Key Laboratory of Multimodal Artificial Intelligence Systems Institute of AutomationChinese Academy of SciencesBeijing 100190China

*** disasters,including floods,storms,and tsunamis,pose a great threat to human societies.A recent study highlighted this concern,revealing that billions of people globally were exposed to flood hazards.1.In 2.2.,Super Typhoon Doksuri caused devasting floods in Beijing and Hebei areas,resulting in massive casualties and huge economic ***,there is a need for a precise understanding of disaster processes,reliable forecasting of disaster effects,and timely warning of risks to prevent and mitigate major disasters.2.Numerical modeling stands as the predominant approach to meet these ***,the predictive accuracy of such numerical models could be degraded because of various factors:oversimplification of real processes,computational errors,fluctuations of complex environments(e.g.,terrains,precipitations,buildings,and plants),and the influence of human activities(e.g.,evacuation and rescue)during disasters.

关键词： disaster floods storm

Efficient expression of codon-adapted human acetaldehyde dehydrogenase 2.cDNA with 6×His tag in Pichia pastoris

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science{1.(Life sciences) 2009年第10期52卷 935-941页

作者： ZHAO YuFeng1,2. LEI MingKe2. WU YuanXin2. zhang ZiSheng3 & wang CunWen2.1 State key Laboratory of Agricultural Microbiology, College of Life {2. and technology, Huazhong Agriculture university, wuhan 430070, china 2.Key Laboratory for Green Chemical Processes of the Ministry of Education, hubei Key Lab of Novel Reactor & Green Chemical technology, school of Chemical Engineering and Pharmacy, wuhan Institute of technology, wuhan 430074, china 3 Department of Chemical Engineering, university of Ottawa, Ottawa, Canada K1N 6N5 1. State key Laboratory of Agricultural Microbiology College of Life Science and Technology Huazhong Agriculture University Wuhan 430070 China 2. Key Laboratory for Green Chemical Processes of the Ministry of Education Hubei Key Lab of Novel Reactor & Green Chemical Technology School of Chemical Engineering and Pharmacy Wuhan Institute of Technology Wuhan 430074 China 3. Department of Chemical Engineering University of Ottawa Ottawa Canada K1N 6N5

Human mitochondrial acetaldehyde dehydrogenase 2.(ALDH2. catalyzes the oxidation of acetaldehyde to acetic acid. Therefore, ALDH2.has therapeutic potential in detoxification of acetaldehyde. Further-more, ALDH2.catalyzes nitroglycerin to nitrate and 1. 2.glyceryldinitrate during therapy for angina pectoris, myocardial infarction, and heart failure. Large quantities of ALDH2.will be needed for potential clinical practice. In this study, Pichia pastoris was used as a platform for expression of human ALDH2. Based on the ALDH2.1.cDNA sequence, we designed ALDH2.cDNA by choosing the P. pastoris preferred codons and by decreasing the G + C content level. The sequence was synthesized using the overlap extension PCR method. The cDNA and 6×His tags were subcloned into the plasmid pPIC9K. The recombinant protein was expressed in P. pastoris GS1.5 and purified using Ni2.-Sepharose affinity chromatography. The amount of secreted protein in the culture was 80 mg/L in shake-flask cultivation and 2.0 mg/L in high-density bioreactor fermentation. Secreted ALDH2.was easily purified from the culture supernatant by using Ni2.-Sepharose affinity chromatography. After purification of the fermentation supernatant, the enzyme had a specific activity of 1.2.U/mg protein. The yield was about 1. mg/L in a shake flask culture of P. pastoris GS1.5 which contained the original human ALDH2.1.cDNA.

关键词： acetaldehyde dehydrogenase codon optimization overlap extension PCR Pichia pastoris.

Stability analysis of cellular neural networks with time-varying delay

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Journal of Systems Engineering and Electronics 2009年第2期20卷 266-273页

作者： wang Xingang1,4, zhang Dongmei2.& Liu Jun3 1. Coll. of Information Engineering, Zhejiang Univ. of {2., Hangzhou 310032. P. R. china 2. Coll. of science, Zhejiang Univ. of {2., Hangzhou 310032. P. R. china 3. Coll. of science, Beihua Univ., Jilin 132.00, P. R. china 4. school of computer Engineering and science, Shanghai Univ., Shanghai 2.0072. P. R. china Coll. of Information Engineering Zhejiang Univ. of Technology Hangzhou 310032 P. R. China school of {1. Engineering and {2. Shanghai Univ. Shanghai 200072 P. R. China Coll. of science Zhejiang Univ. of Technology Hangzhou 310032 P. R. China Coll. of science Beihua Univ. Jilin 132000 P. R. China

The global asymptotic stability of cellular neural networks with delays is investigated. Three kinds of time delays have been considered. New delay-dependent stability criteria are proposed and are formulated as the feasibility of some linear matrix inequalities, which can be checked easily by resorting to the recently developed interior-point algorithms. Based on the Finsler Lemma, it is theoretically proved that the proposed stability criteria are less conservative than some existing results.

关键词： cellular neural networks time-varying delay integral inequality

Aeroservoelastic model based active control for large civil aircraft

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science{1.(Technological sciences) 2010年第4期53卷 1126-1137页

作者： FAN Yong1.ZHU JiHong1.HU ChunHua2.MENG XianYu1.{1. XiangYang2.& GE AiXue1.1.Department of computer {2. and technology,Tsinghua university,Beijing 1.0084,china 2.school of Astronautics and Aeronautics,Tsinghua university,Beijing 1.0084,china 1. Department of computer {1. and {2. Tsinghua University Beijing 100084 China2. School of Astronautics and Aeronautics Tsinghua University Beijing 100084 China

A modeling and control approach for an advanced configured large civil aircraft with aeroservoelasticity via the LQG method and control allocation is *** models and implementation issues for the multi-input/multi-output(MIMO) aeroservoelastic system simulation developed for a flexible wing with multi control surfaces are described.A fuzzy logic based optimization approach is employed to solve the constrained control allocation problem via intelligently adjusting the components of output vector and find a proper vector in the attainable moment set(AMS) *** basic idea is to minimize the L{1.norm of error between the desired moment and achievable moment using the designing freedom provided by redundantly allocated actuators and control *** the constraints of control surfaces,in order to obtain acceptable performance of aircraft such as stability and maneuverability,the fuzzy weights are updated by the learning algorithm,which makes the closed-loop system ***,an application example of flight control designing for the advanced civil aircraft is discussed as a *** studies we have performed showed that the advanced configured large civil aircraft has good performance with the proper designed control law designed via the proposed *** gust alleviation and flutter suppression are applied with the synergetic effects of elevator,ailerons,equivalent rudders and *** results show good closed loop performance and meet the requirement of constraint of control surfaces.

关键词： modeling active control aeroelastic flutter suppression control allocation

Path-partitioned encoding supports wildcard-awareness twig queries

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Journal of Shanghai university(English Edition) 2009年第5期13卷 363-374页

作者：徐小双冯玉才王锋 school of {1. Huazhong University of Science and Technology school of {1. Huanggang Normal University Technic Pre-research Department Dameng Database Company Limited

Finding all occurrences of a twig query in an XML database is a core operation for efficient evaluation of XML queries. It is important to effiectively handle twig queries with wildcards. In this paper, a novel path-partitioned encoding scheme is proposed for XML documents to capture paths of all elements, and a twig query is modeled as an XPattern extended from tree pattern. After definition, simplification, normalization, verification and initialization of the XPattern, both work sets and a join plan are generated. According to these measures, an effiective algorithm to answer for a twig query, called DMTwig, is designed without unnecessary elements and invalid structural joins. The algorithm can adaptively deal with twig queries with branch ([ ]), child edge (/), descendant edge (//), and wildcard (*) synthetically. We show that path-partitioned encoding scheme and XPattern guarantee the I/O and CPU optimality for twig queries. Experiments on representative data set indicate that the proposed solution performs significantly.

关键词： XML tree pattern structural join encoding scheme twig query

A Hybrid of Theorems of Goldbach and Piatetski-Shapiro

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Chinese Annals of Mathematics,Series B 2006年第3期27卷 341-352页

作者： Xianmeng MENG Mingqiang wang {1. of {2. science and technology, Shandong university, Jinan 2.01.0, china Department of Statistics and Mathematics, Shandong Finance Institute, Jinan 2.001., china. {1. of {2. science and technology, Shandong university, Jinan 2.01.0, china Department of Mathematics, Qufu Normal university, Qufu 2.31.5, Shandong, china. school of {1. {2. and technology Shandong University Jinan 250100 China Department of Statistics and Mathematics Shandong Finance Institute Jinan 250014 China Department of Mathematics Qufu Normal University Qufu 273165 Shandong China

It is proved that for almost all sufficiently large even integers n, the prime variable equation n = p1.＋ p2. p1.∈ Pγ is solvable, with 1./1. 〈γ≤ 1. where Pγ = {p ｜p = [m^1.γ], for integer m and prime p} is t... 详细信息

关键词： Circle method Sieve method Goldbach problem

A novel model-free approach for reconstruction of time-delayed gene regulatory networks

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中国科学：生命科学英文版 2006年第2期49卷 190-200页

作者： JIANG Wei1,2. LI Xia1,2.3,4, GUO Zheng1,2.3, LI Chuanxing1, wang Lihong1 & RAO Shaoqi1,5 1. Department of Bioinformatics, Harbin Medical university, Harbin 150086,{2. 2. Department of computer science, Harbin Institute of technology, Harbin 150080,{2. 3. school of Life science and technology, Tongji university, Shanghai 2.0092.{2. 4. Biomedical Engineering Institute, Capital university of Medical sciences, Beijing 100054,{2. 5. Departments of Cardiovascular Medicine and Molecular Cardiology, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA Department of Bioinformatics Harbin Medical University Harbin 150086 China Department of computer {1. Harbin Institute of Technology Harbin 150080 China school of Life {1. technology Tongji University Shanghai 200092 China Biomedical Engineering Institute Capital University of Medical Sciences Beijing 100054 China Departments of Cardiovascular Medicine Molecular Cardiology Cleveland Clinic Foundation Cleveland Ohio 44195 USA

Reconstruction of genetic networks is one of the key scientific challenges in functional genomics. This paper describes a novel approach for addressing the regulatory dependencies be-tween genes whose activities can be delayed by multiple units of time. The aim of the proposed ap-proach termed TdGRN (time-delayed gene regulatory networking) is to reversely engineer the dy-namic mechanisms of gene regulations, which is realized by identifying the time-delayed gene regu-lations through supervised decision-tree analysis of the newly designed time-delayed gene expres-sion matrix, derived from the original time-series microarray data. A permutation technique is used to determine the statistical classification threshold of a tree, from which a gene regulatory rule(s) is ex-tracted. The proposed TdGRN is a model-free approach that attempts to learn the underlying regula-tory rules without relying on any model assumptions. Compared with model-based approaches, it has several significant advantages: it requires neither any arbitrary threshold for discretization of gene transcriptional values nor the definition of the number of regulators (k). We have applied this novel method to the publicly available data for budding yeast cell cycling. The numerical results demonstrate that most of the identified time-delayed gene regulations have current biological knowledge supports.

关键词： gene regulatory networks, time delayed, decision tree.

A Trusted Environment Construction Method for Security-Sensitive Software

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wuhan {1. Journal of Natural {2.s 2011年第5期16卷 383-390页

作者： LI Jing1,2.zhang Huanguo1,2.ZHAO Bo1,2.FANG Lingling1,2.1.school of {2.,wuhan university,wuhan 430072.hubei,china 2.Key Laboratory of Aerospace Information Security and Trust Computing,Ministry of Education,wuhan 430072.hubei,china school of {1. Wuhan University Wuhan Hubei China Key Laboratory of Aerospace Information Security and Trust Computing Ministry of Education Wuhan Hubei China

This paper presents a trusted-environment construction method based on the underlying hardware. This method aims at protecting the security-sensitive software in the aspects of software loading, running, and storing in the general operating system. It extends the trust chain of the traditional trusted computing technology to reach the target software, ensuring trusted loading. The extended memory management mechanism effectively pre- vents memory dumping and memory tampering for the high-sensitivity data. The file monitoring mechanism protects files from vicious operation made by attackers. Flexible-expanded storage environment provides the target software with static storing protection. Experimental system verifies that the method is suitable for general operating system and can effectively protect security-sensitive software with low overhead.

关键词： information security trusted computing securitysensitive software trusted environment