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EMPIRICAL LIKELIHOOD INFERENCE FOR LOGISTIC EQUATION WITH RANDOM PERTURBATION

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Journal of Systems Science & Complexity 2014年第2期27卷 350-359页

作者： hu Xuemei School of Mathematics and Statistics ChongQing Technology and Business University Academy of Mathematics and Systems Science Chinese Academy of Sciences

Empirical likelihood(EL) combined with estimating equations(EE) provides a modern semi-parametric alternative to classical estimation techniques such as maximum likelihood estimation(MLE). This paper not only uses closed form of conditional expectation and conditional variance of Logistic equation with random perturbation to perform maximum empirical likelihood estimation(MELE) for the model parameters, but also proposes an empirical likelihood ratio statistic(ELRS) for hypotheses concerning the interesting parameter. Monte Carlo simulation results show that MELE and ELRS provide competitive performance to parametric alternatives.

关键词： Empirical likelihood ratio statistic estimating equations logistic equation with randomperturbation maximum empirical likelihood estimations maximum likelihood estimation.

Steady-state responses of a belt-drive dynamical system under dual excitations

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Acta Mechanica Sinica 2016年第1期32卷 156-169页

作者： hu Ding Shanghai Institute of Applied Mathematics and Mechanics Shanghai Key Laboratory of Mechanics in Energy EngineeringShanghai UniversityShanghai 200072China

The stable steady-state periodic responses of a belt-drive system with a one-way clutch are studied. For the first time, the dynamical system is investigated under dual excitations. The system is simultaneously excited by the firing pulsations of the engine and the harmonic motion of the foundation. Nonlinear discrete-continuous equations are derived for coupling the transverse vibration of the belt spans and the rotations of the driving and driven pulleys and the accessory pulley. The nonlinear dynamics is studied under equal and multiple relations between the frequency of the fir- ing pulsations and the frequency of the foundation motion. Furthermore, translating belt spans are modeled as axially moving strings. A set of nonlinear piecewise ordinary differ- ential equations is achieved by using the Galerkin truncation. Under various relations between the excitation frequencies, the time histories of the dynamical system are numerically simulated based on the time discretization method. Further- more, the stable steady-state periodic response curves are calculated based on the frequency sweep. Moreover, the convergence of the Galerkin truncation is examined. Numer- ical results demonstrate that the one-way clutch reduces the resonance amplitude of the rotations of the driven pul- ley and the accessory pulley. On the other hand, numerical examples prove that the resonance areas of the belt spans are decreased by eliminating the torque-transmitting in the opposite direction. With the increasing amplitude of the foun- dation excitation, the damping effect of the one-way clutch will be reduced. Furthermore, as the amplitude of the firing pulsations of the engine increases, the jumping phenomena in steady-state response curves of the belt-drive system with or without a one-way clutch both occur.

关键词： Nonlinear vibration One-way clutch Dynamical system Steady-state responses Galerkinmethod

High Accuracy Gene Signature for Chemosensitivity Prediction in Breast Cancer

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Tsinghua Science and Technology 2015年第5期20卷 530-536页

作者： Wei hu Department of Computer Science Houghton College

Neoadjuvant chemotherapy for breast cancer patients with large tumor size is a necessary *** this treatment patients who achieve a pathologic Complete Response（p CR） usually have a favorable prognosis than those without. Therefore, p CR is now considered as the best prognosticator for patients with neoadjuvant chemotherapy. However, not all patients can benefit from this treatment. As a result, we need to find a way to predict what kind of patients can induce p CR. Various gene signatures of chemosensitivity in breast cancer have been identified, from which such predictors can be built. Nevertheless, many of them have their prediction accuracy around 80%. As such, identifying gene signatures that could be employed to build high accuracy predictors is a prerequisite for their clinical tests and applications. Furthermore, to elucidate the importance of each individual gene in a signature is another pressing need before such signature could be tested in clinical settings. In this study, Genetic Algorithm（GA） and Sparse Logistic Regression（SLR） along with t-test were employed to identify one signature. It had 28 probe sets selected by GA from the top 65 probe sets that were highly overexpressed between p CR and Residual Disease（RD） and was used to build an SLR predictor of p CR（SLR-28）. This predictor tested on a training set（n = 81） and validation set（n = 52） had very precise predictions measured by accuracy,specificity, sensitivity, positive predictive value, and negative predictive value with their corresponding P value all zero. Furthermore, this predictor discovered 12 important genes in the 28 probe set signature. Our findings also demonstrated that the most discriminative genes measured by SLR as a group selected by GA were not necessarily those with the smallest P values by t-test as individual genes, highlighting the ability of GA to capture the interacting genes in p CR prediction as multivariate techniques. Our gene signature produced superior per

关键词： genetic algorithm gene signature breast cancer sparse logistic regression predictor chemosensitivity

ESTIMATION IN A SEMI-VARYING COEFFICIENT MODEL FOR PANEL DATA WITH FIXED EFFECTS

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Journal of Systems Science & Complexity 2014年第3期27卷 594-604页

作者： hu Xuemei School of Mathematics and Statistics Chongqing Technology and Business University Academy of Mathematics and Systems Science Chinese Academy of Sciences

This paper considers a semi-varying coefficient model for panel data with fixed effects,proposes the profile-likelihood-based estimators for the parametric and nonparametric components,and establishes convergence rates and asymptotic normality properties for both *** results show that the proposed estimators behave well in finite sample cases.

关键词： Fixed effect profile likelihood semi-varying coefficient model for panel data.

The Grad-Shafranov reconstruction in twenty years: 1996–2016

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Science China Earth Sciences 2017年第8期60卷 1466-1494页

作者： hu Qiang Department of Space Science and CSPAR University of Alabama in Huntsville

We review and summarize the applications of the Grad-Shafranov(GS) reconstruction technique to space plasma structures in the Earth's magnetosphere and in the interplanetary space. We organize our presentations following the branches of the "academic family tree" rooted on Prof. Bengt U. ? Sonnerup, the inventor of the GS method. Special attentions are paid to validations of the GS reconstruction results via(1) the direct validation by co-spatial in-situ measurements among multiple spacecraft, and(2) indirect validation by implications and interpretations of the physical connection between the structures reconstructed and other related processes. For the latter, the inter-comparison and interconnection between the large-scale magnetic flux ropes(i.e., Magnetic Clouds) in the solar wind and their solar source properties are presented. In addition, we also summarize various GS-type(or-like) reconstruction and an extension of the GS technique to toroidal geometry. In particular,we point to a possible advancement with added complexity of "helical symmetry" and mixed helicity, in the hope of stimulating interest in future development. We close by offering some thoughts on appreciating the scientific merit of GS reconstruction in general.

关键词： Grad-Shafranov equation Magnetohydrodynamics Magnetic clouds Magnetic flux ropes Magnetopause Current sheets Flux transfer events Plasmoids Solar flare Coronal mass ejections

Identifying the genes of unconventional high temperature superconductors

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Science Bulletin 2016年第7期61卷 561-569页

作者： Jiangping hu Beijing National Laboratory for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100190 China Collaborative Innovation Center of Quantum Matter Beijing 100190 China

We elucidate a recently emergent framework in unifying the two families of high temperature （high To） superconductors, cuprates and iron-based superconductors. The unification suggests that the latter is simply the counterpart of the former to realize robust extended s-wave pairing symmetries in a square lattice. The unification identifies that the key ingredients （gene） of high Tc superconductors is a quasi two dimensional electronic environment in which the d-orbitals of cations that partic- ipate in strong in-plane couplings to the p-orbitals of anions are isolated near Fermi energy. With this gene, the superexchange magnetic interactions mediated by anions could maximize their contributions to superconductivity. Creating the gene requires special arrangements between local electronic structures and crystal lattice structures. The speciality explains why high Tc superconductors are so rare. An explicit prediction is made to realize high Tc superconductivity in Co/Ni-based materials with a quasi two dimensional hexagonal lattice structure formed by trigonal bipyramidal complexes.

关键词： Cuprates Iron-based superconductors Unconventional high Tc superconducotors Superexchange

Degenerate cascade fluorescence: Optical spectral-line narrowing via a single microwave cavity

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Chinese Physics B 2021年第6期30卷 346-358页

作者： Liang hu Xiang-Ming hu Qing-Ping hu College of Physical Science and Technology Central China Normal UniversityWuhan 430079China

For a three-level atom, two nondegenerate(even microwave and optical) electric dipole transitions are usually allowed;for either of these, the fluorescence spectra are well-described in terms of spontaneous transitions from a triplet of dressed sublevels to an adjacent lower-lying triplet. When the three dressed sublevels are equally spaced from each other, a remarkable feature known as degenerate cascade fluorescence takes place, which displays a five-peaked structure. We show that a single cavity can make all the spectral lines extremely narrow, whether they arise from cavity-coupled or cavity-free transitions. This effect is based on intrinsic cascade lasing feedback and makes it possible to use a single microwave cavity(even a bad cavity) to narrow the spectral lines in the optical frequency regime.

关键词： resonance fluorescence narrow spectral lines microwave cavity

Double-bosonization and Majid's conjecture(IV): Type-crossings from A to BCD

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Science China Mathematics 2016年第6期59卷 1061-1080页

作者： hu HongMei hu NaiHong Department of Mathematics SKLPMMP East China Normal University

Both in Majid's double-bosonization theory and in Rosso's quantum shuffle theory, the rankinductive and type-crossing construction for U_q(g)'s is still a remaining open question. In this paper, working in Majid's framework, based on the generalized double-bosonization theorem we proved before, we further describe explicitly the type-crossing construction of U_q(g)'s for(BCD)_n series directly from type An-1via adding a pair of dual braided groups determined by a pair of(R, R′)-matrices of type A derived from the respective suitably chosen representations. Combining with our results of the first three papers of this series, this solves Majid's conjecture, i.e., any quantum group U_q(g) associated to a simple Lie algebra g can be grown out of U_q(sl_2)recursively by a series of suitably chosen double-bosonization procedures.

关键词： double-bosonization braided category braided groups type-crossing construction normalizedR-matrix representations

Polymer Features in Crystallization

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Chinese Journal of Polymer Science 2022年第6期40卷 545-555页

作者： Wen-Bing hu State Key Lab of Coordination Chemistry School of Chemistry and Chemical EngineeringNanjing UniversityNanjing 210023China

This review firstly gives an overview on the importance of crystallization in natural and synthetic polymers/*** it introduces the typical features that have been raised by chain-like macromolecules in crystallization,including anisotropic interactions in the thermodynamic driving forces,chain folding in the crystal morphologies,chemical confinement in the copolymer crystallization,and mechanical enhancement in the stretching *** features separately cover the thermodynamics and the kinetics of polymer crystallization,as well as the crystallinity and the mechanical properties of semicrystalline *** review ends up with how these features enhance specific functions of crystalline polymers,which demonstrates polymer crystallization as a challenging yet promising field in the future.

关键词： Crystallization Macromolecules Property Function