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On Two-stage Estimate Based on Independent Estimate of Covariance Matrix

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Acta Mathematica Sinica,English Series 2006年第1期22卷 283-288页

作者： Su Ju yin Song gui WANG College of Applied Sciences Beijing University of Technology Beijing 100022 P. R. China

When an independent estimate of covariance matrix is available, we often prefer two-stage estimate （TSE）. Expressions of exact covarianee matrix of the TSE obtained by using all and some covariables in eovariance adjustment approach are given, and a necessary and sufficient condition for the TSE to be superior to the least square estimate and related large sample test is also established. Furthermore the TSE, by using some covariables, is expressed as weighted least square estimate. Basing on this fact, a necessary and sufficient condition for the TSE by using some covariables to be superior to the TSE by using all eovariables is obtained. These results give us some insight into the selection of covariables in the TSE and its application.

关键词： two-stage estimate covariance adjusted estimate canonical correlation coefficients

Diverse and variable sex determination mechanisms in vertebrates

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Science China(Life Sciences) 2018年第12期61卷 1503-1514页

作者： Xi-yin Li Jian-Fang gui State Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology College of Modern Agriculture Sciences University of Chinese Academy of Sciences The Innovative Academy of Seed Design Chinese Academy of Sciences

Sex is prevalent in nature and sex determination is one of the most fundamental biological processes, while the way of initiating female and male development exhibits remarkable diversity and variability across vertebrates. The knowledge on why and how sex determination mechanisms evolve unusual plasticity remains limited. Here, we summarize sex determination systems,master sex-determining genes and gene-regulatory networks among vertebrates. Recent research advancements on sex determination system transition are also introduced and discussed in some non-model animals with multiple sex determination mechanisms. This review will provide insights into the origin, transition and evolutionary adaption of different sex determination strategies in vertebrates, as well as clues for future perspectives in this field.

关键词： sex determination sex-determining gene sex chromosome sex transition sex differentiation sex control breeding

TZ Lyrae:an Algol-type Eclipsing Binary with Mass Transfer

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Chinese Journal of Astronomy and Astrophysics 2007年第2期7卷 258-264页

作者： Yuan-gui Yang Xin-Guo yin Physics Department of Huaibei Coal Industry Teachers College Huaibei 235000

We present a detailed investigation of the Algol-type binary TZ Lyrae, based on 55 light minimum timings spanning 90 years. It is found that the orbital period shows a long-term increase with a cyclic variation superimposed. The rate of the secular increase is dP/dt = ＋7.18 × 10^-8d yr^-1, indicating that a mass transfer from the less massive component to the more massive one at a rate of dra = ＋2.21 × 10^-8M⊙ yr^-1. The cyclic component, with a period of P3 = 45.5 yr and an amplitude of A = 0.^d0040, may be interpreted as either the light-time effect in the presence of a third body or magnetic activity cycles in the components. Using the latest version Wilson-Devinney code, a revised photometric solution was deduced from B and V observations. The results show that TZ Lyr is an Algol-type eclipsing binary with a mass ratio of q = 0.297±0.003）. The semidetached configuration with a lobe-filling secondary suggests a mass transfer from the secondary to the primary, which is in agreement with the long-term period increase of the binary system.

关键词： stars binaries close - stars binaries eclipsing - stars individual TZ Lyrae

An approach to estimate tree height using PolInSAR data constructed by the Sentinel-1 dual-pol SAR data and RVoG model

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Journal of Electronic Science and Technology 2024年第3期22卷 69-79页

作者： yin Zhang ding-Feng Duan School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu611731China

We estimate tree heights using polarimetric interferometric synthetic aperture radar(PolInSAR)data constructed by the dual-polarization(dual-pol)SAR data and random volume over the ground(RVoG)*** the Sentinel-1 SAR dual-pol(SVV,vertically transmitted and vertically received and SVH,vertically transmitted and horizontally received)configuration,one notes that S_(HH),the horizontally transmitted and horizontally received scattering element,is *** S_(HH)data were constructed using the SVH data,and polarimetric SAR(PolSAR)data were *** proposed approach was first verified in simulation with satisfactory *** was next applied to construct PolInSAR data by a pair of dual-pol Sentinel-1A data at Duke Forest,North Carolina,*** to local observations and forest descriptions,the range of estimated tree heights was overall *** the heights with the ICESat-2 tree heights at 23 sampling locations,relative errors of 5 points were within±30%.Errors of 8 points ranged from 30%to 40%,but errors of the remaining 10 points were>40%.The results should be encouraged as error reduction is *** instance,the construction of PolSAR data should not be limited to using SVH,and a combination of SVH and SVV should be ***,an ensemble of tree heights derived from multiple PolInSAR data can be considered since tree heights do not vary much with time frame in months or one season.

关键词： Constructed polarimetric SAR data Dual polarization Sentinel-1 SAR data Polarimetric interferometric SAR Random volume over the ground model Tree height estimation

Effect of printing parameters on properties of 3D printing sand samples

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China Foundry 2023年第6期20卷 553-562页

作者： De-quan Shi yin-yu Hou gui-li Gao School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China School of Mechanical and Energy Engineering Shanghai Technical Institute of Electronics and InformationShanghai 201411China

Three-dimensional sand printing(3DSP)is widely applied in sand mold *** this study,the effects of printing parameters including the resolution of printehead holes,activator content,layer thickness,and recoating speed on the tensile and bending strengths,gas evolution,and loss-on-ignition(LOI)of 3DSP samples were investigated by changing single parameter,and the dimension deviation was also *** the resolution increases,the tensile strength,bending strength,gas evolution,LOI,and deviations at X-and Y-axis directions decrease gradually while the deviation at Z-axis direction firstly increases and then *** gas evolution and LOI drops by 13.02%and 8.13%respectively,but the strength only reduces by 2.2% when the resolution increases from 0.08 mm to 0.09 *** strengths of samples rise at first and then decline while the gas evolution and LOI rise gradually with the increasing activator content or recoating *** activator content is found to have little effect on the gas evolution as the activator increases from 0.14%to 0.34%,the gas evolution is increased by 7.3%which is far less than the LOI increment of 24.1%.As the layer thickness increases,the tensile and bending strengths firstly rise and then drop while gas evolution and LOI *** the optimal printing parameters of 0.09 mm resolution,0.18%activator,0.28 mm layer thickness and 160 mm·s^(-1) recoating speed,the tensile strengths for X-sample and Y-sample are 1.48 MPa and 1.37 MPa,the bending strengths are 1.84 MPa and 1.75 MPa,the gas evolution and LOI are 9.62 mL·g^(-1) and 1.92%,respectively.

关键词： three-dimensional sand printing printing parameters mechanical properties LOI

An epigenetic regulatory switch controlling temperature-dependent sex determination in vertebrates

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Science China(Life Sciences) 2018年第8期61卷 996-998页

作者： Xi-yin Li Jian-Fang gui State Key Laboratory of Freshwater Ecology and Biotechnology Institute of Hydrobiology The Innovative Academy of Seed Design Chinese Academy of Sciences Wuhan 430072 China University of Chinese Academy of sciences Beijing 100049 China

Most vertebrates present two sexes, and females and males are determined via two diverse strategies including geno-typic sex determination （GSD） and environmental sex de-termination （ESD）（Mei and gui, 2015; Ma et al., 2016）. The most common form of ESD is temperature-dependent sex determination （TSD）. Although several master sex-de-termining genes and their molecular pathways have been elucidated in vertebrates with GSD, the molecular mechan-ism underlying TSD remains unclear （Bachtrog et al., 2014; Capel, 2017）.

关键词：脊椎动物温度依赖开关控制性别规章环境性 gui ESD

Borel Equivalence Relations between l_1and l_p

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Acta Mathematica Sinica,English Series 2013年第12期29卷 2391-2396页

作者： Long Yun ding Zhi yin School of Mathematical Sciences and LPMC Nankai University

In this paper, we show that, for each p 〉 1, there are continuum many Borel equivalence relations between Rω/l1 and Rω/p ordered by ≤B which are pairwise Borel incomparable.

关键词： Borel equivalence relation Borel reducibility

Iterative subspace matching pursuit for joint sparse recovery

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The Journal of China Universities of Posts and Telecommunications 2023年第2期30卷 26-35页

作者： Shu Feng Zhang Linghua ding yin School of Communications and Information Engineering Nanjing University of Posts and TelecommunicationsNanjing 210003China

Joint sparse recovery(JSR)in compressed sensing(CS)is to simultaneously recover multiple jointly sparse vectors from their incomplete measurements that are conducted based on a common sensing *** this study,the focus is placed on the rank defective case where the number of measurements is limited or the signals are significantly correlated with each ***,an iterative atom refinement process is adopted to estimate part of the atoms of the support ***,the above atoms along with the measurements are used to estimate the remaining *** estimation criteria for atoms are based on the principle of minimum subspace *** numerical experiments were performed in noiseless and noisy scenarios,and results reveal that iterative subspace matching pursuit(ISMP)outperforms other existing algorithms for JSR.

关键词： joint sparse recovery(JSR) multiple measurement vector(MMV) support set estimation compressed sensing(CS)

A multiscale differential-algebraic neural network-based method for learning dynamical systems

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International Journal of Mechanical System Dynamics 2024年第1期4卷 77-87页

作者： yin Huang Jieyu ding College of Computer Science&Technology Qingdao UniversityQingdaoChina School of Mathematics and Statistics Qingdao UniversityQingdaoChina Center for Computational Mechanics and Engineering Simulation Qingdao UniversityQingdaoChina

The objective of dynamical system learning tasks is to forecast the future behavior of a system by leveraging observed ***,such systems can sometimes exhibit rigidity due to significant variations in component parameters or the presence of slow and fast variables,leading to challenges in *** overcome this limitation,we propose a multiscale differential-algebraic neural network(MDANN)method that utilizes Lagrangian mechanics and incorporates multiscale information for dynamical system *** MDANN method consists of two main components:the Lagrangian mechanics module and the multiscale *** Lagrangian mechanics module embeds the system in Cartesian coordinates,adopts a differential-algebraic equation format,and uses Lagrange multipliers to impose constraints explicitly,simplifying the learning *** multiscale module converts high-frequency components into low-frequency components using radial scaling to learn subprocesses with large differences in *** results demonstrate that the proposed MDANN method effectively improves the learning of dynamical systems under rigid conditions.

关键词： dynamical systems learning multibody system dynamics differential-algebraic equation neural networks multiscale structures