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Solving the Perspective-Three-Point Problem Using Comprehensive Grobner Systems

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Journal of Systems Science & Complexity 2016年第5期29卷 1446-1471页

作者： zhou jie WANG Dingkang Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China.

A complete solution classification of the perspective-three-point(P3P) problem is given by using the Gr?bner basis method. The structure of the solution space of the polynomial system deduced by the P3P problem can be obtained by computing a comprehensive Gr?bner system. Combining with properties of the generalized discriminant sequences, the authors give the explicit conditions to determine the number of distinct real positive solutions of the P3P problem. Several examples are provided to illustrate the effectiveness of the proposed conditions.

关键词： Comprehensive GrSbner system parametric polynomials perspective-three-point prob-lem real solutions.

More Efficient Estimators for Marginal Additive Hazards Model in Case-cohort Studies with Multiple Outcomes

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Acta Mathematica Sinica,English Series 2016年第3期32卷 351-362页

作者： Jin WANG jie zhou School of Statistics and Management Shanghai University of Finance and Economics School of Mathematics Capital Normal University

Case-cohort study designs are widely used to reduce the cost of large cohort studies. When several diseases are of interest, we can use the same subcohort. In this paper, we will study the casecohort design of marginal additive hazards model for multiple outcomes by a more efficient version. Instead of analyzing each disease separately, ignoring the additional exposure measurements collected on subjects with other diseases, we propose a new weighted estimating equation approach to improve the efficiency by utilizing as much information collected as possible. The consistency and asymptotic normality of the resulting estimator are established. Simulation studies are conducted to examine the finite sample performance of the proposed estimator, which confirm the efficiency gains.

关键词： Case-cohort study multivariate failure times marginal additive hazards model efficient estimator

Improved smoothed L0 reconstruction algorithm for ISI sparse channel estimation

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The Journal of China Universities of Posts and Telecommunications 2014年第2期21卷 40-47页

作者： LIU Ting zhou jie Department of Communications Nanjing University of Information Science and Technology Department of Electronic and Electrical Engineering Niigata University

In this paper, the problem of inter symbol interference （ISI） sparse channel estimation in wireless communication with the application of compressed sensing is investigated. However, smoothed L0 norm algorithm （SL0） has ＇notched effect＇ due to the negative iterative gradient direction. Moreover, the property of continuous function in SL0 is not steep enough, which results in inaccurate estimations and low convergence. Afterwards, we propose the Lagrange multipliers as well as Newton method to optimize SL0 algorithm in order to obtain a more rapid and efficient signal reconstruction algorithm, improved smoothed L0 （ISL0）. ISI channel estimation will have a direct effect on the performance of ISI equalizer at the receiver. So, we design a pre-filter model which with no considerable loss of optimality and do analyses of the equalization methods of the sparse multi-path channel. Real-time simulation results clearly show that the ISL0 algorithm can estimate the ISI sparse channel much better in both signal noise ratio （SNR） and compression levels. In the same channel conditions, ISL0 algorithm has been greatly improved when compared with the SL0 algorithm and other compressed-sensing algorithms.

关键词： compressed-sensing channel model ISI improved SLO algorithm sparse channel estimation MIMO system

Monte Carlo Likelihood Estimation of Mixed-Effects State Space Models with Application to HIV Dynamics

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Journal of Systems Science & Complexity 2016年第4期29卷 1160-1176页

作者： zhou jie TANG Aiping FENG Hailin Department of Statistics Xidian University

The statistical inference for generalized mixed-effects state space models （MESSM） are investigated when the random effects are unknown. Two filtering algorithms are designed both of which are based on mixture Kalman filter. These algorithms are particularly useful when the longitudinal ts are sparse. The authors also propose a globally convergent algorithm for parameter estimation of MESSM which can be used to locate the initial value of parameters for local while more efficient algorithms. Simulation examples are carried out which validate the efficacy of the proposed approaches. A data set from the clinical trial is investigated and a smaller mean square error is achieved compared to the existing results in literatures.

关键词： Mixed-effects mixture Kalman filter state estimation state space model.

Statistical Diagnosis for HIV Dynamics Based on Mean Shift Outlier Model

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Journal of Systems Science & Complexity 2015年第3期28卷 592-605页

作者： WU Ting LIU Sanyang zhou jie School of Mathematics and Statistics Xidian University

Ordinary differential equation(ODE) are widely used for quantifying HIV viral *** is interesting but challenging to estimate ODE parameters from noisy data, especially when the data have some outliers. In this study, the authors use the Mean Shift Outlier Model(MSOM) to detect outliers in HIV model based on the two-step estimation of ODE. Approximate formula for shift parameter is derived. Furthermore, a score test statistic is constructed and its approximating distribution is established. The simulation results show that: 1) The boundary points have more impact on the parameter estimation relative to interior points. 2) The proposed procedure can detect the outliers effectively. The authors illustrate the proposed approach using an application example from an HIV clinical trial and find similar pattern to the simulation studies.

关键词： HIV dynamics local polynomial smoothing mean shift outlier model nonparametric regression.

Ultrasonic vibration assisted tungsten inert gas welding of dissimilar magnesium alloys

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Journal of Materials Science & Technology 2018年第12期34卷 2240-2245页

作者： Fangzhou Yang jie zhou Rongrong Ding College of Materials Science and Engineering Chongqing University The School of Robot Engineering and Mechanical-Electrical Engineering Chongqing University of Arts and Sciences

The effects of ultrasonic vibration assisted（UVA） treatment on the microstructures and mechanical properties of MB3/AZ31 dissimilar magnesium（Mg） alloy joints were studied by microstructural characterization, micro-hardness testing and tensile testing. Results indicate that the welding pores are eliminated and coarse a-Mg grains of fusion zone are refined to 26 μm, owing to the acoustic streaming effect and cavitation effect induced by the UVA treatment with an optimal ultrasonic power of 1.0 *** addition, Mg;Al;precipitation phases are fine and uniformly distributed in the whole fusion zone of weldment. Micro-hardness of fusion zone of the Mg alloy joints increases to 53.5 HV after UVA process,and the maximum tensile strength with optimized UVA treatment increases to 263 MPa, which leads to fracture occurrence in the Mg alloy base plate. Eventually, it is experimentally demonstrated that robust MB3/AZ31 Mg alloy joints can be obtained by UVA process.

关键词： Ultrasonic vibration assist Magnesium alloy TIG welding Microstructure Mechanical property

An Adaptive JPEG Steganographic Scheme Based on Run-Length Statistical Complexity

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Chinese Journal of Electronics 2018年第1期27卷 52-59页

作者： WEN Juan ZHANG jie zhou jie LI Yan XUE Yiming College of Information and Electrical Engineering China Agricultural University College of Science China Agricultural University

This paper presents a novel adaptive JPEG steganographic scheme in Discrete cosine transform(DCT)domain using Run-length statistical complexity(RSC). Unlike the traditional complexity measurements, RSC considers the change randomness of DCT coefficients in image blocks. The distortion functions in both side-informed and non-side-informed schemes are derived by RSC and minimized by Syndrome trellis coding(STC). Experimental results show superior performance of our scheme over a wide range of embedding rates at different image quality factors compared with previous three common steganographic schemes.

关键词： Steganography Distortion function Runlength Complexity

Engineering cyanobacteria for fuels and chemicals production

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Protein & Cell 2010年第3期1卷 207-210页

作者： jie zhou Yin Li Institute of Microbiology Chinese Academy of SciencesBeijing 100101China

The world’s energy and global warming crises call for sustainable,renewable,carbon-neutral alternatives to replace fossil fuel ***,most biofuels are produced from agricultural crops and residues,which lead to concerns about food security and land *** to the current biofuel production system,cyanobacteria,as autotrophic prokaryotes,do not require arable land and can grow to high densities by efficiently using solar energy,CO2,water,and inorganic ***,powerful genetic techniques of cyanobacteria have been *** these reasons,cyanobacteria,which carry out oxygenic photosynthesis,are attractive hosts for production of fuels and ***,several chemicals including ethanol,isobutanol and isoprene have been produced by engineered cyanobacteria directly using solar energy,CO2,and *** is therefore a potential novel cell factory for fuels and chemicals production to address global energy security and climate change issues.

关键词： chemicals attractive crops

Multi-user cognitive radio network resource allocation based on the adaptive niche immune genetic algorithm

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Chinese Physics B 2012年第1期21卷 558-565页

作者： Zu Yun-Xiao zhou jie School of Electronic Engineering Beijing University of Posts and TelecommunicationsBeijing 100876China

Multi-user cognitive radio network resource allocation based on the adaptive niche immune genetic algorithm is proposed, and a fitness function is provided. Simulations are conducted using the adaptive niche immune genetic algo- rithm, the simulated annealing algorithm, the quantum genetic algorithm and the simple genetic algorithm, respectively. The results show that the adaptive niche immune genetic algorithm performs better than the other three algorithms in terms of the multi-user cognitive radio network resource allocation, and has quick convergence speed and strong global searching capability, which effectively reduces the system power consumption and bit error rate.

关键词： cognitive radio networks niche genetic algorithm King map resource allocation