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Anticipative Stochastic Differential Equations with Non-smooth Diffusion Coefficient

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Acta Mathematica Sinica,English Series 2006年第5期22卷 1473-1480页

作者： Zong xia liang Department of Mathematical Sciences Tsinghua University Beijing 100084 P. R. China

In this paper we prove the existence and uniqueness of the solutions to the one-dimensional linear stochastic differential equation with Skorohod integral Xt（ω）=η（w）＋∫^t 0 asXs（ω）dWs＋∫^t 0 bsXs（ω）ds, t∈[0,1] where （Ws） is the canonical Wiener process defined on the standard Wiener space （W,H,u）, a is non-smooth and adapted, but η and b may be anticipating to the filtration generated by （Ws）. The intention of the paper is to eliminate the regularity of the diffusion coefficient a in the Malliavin sense, in the existing literature. The idea is to approach the non-smooth diffusion coefficient a by smooth ones.

关键词： Non-smooth and anticipative stochastic differential equations Skorohod integral Malliavin derivative

A biarc-based shape optimization approach to reduce stress concentration effects

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Acta Mechanica Sinica 2014年第3期30卷 370-382页

作者： liang Meng Wei-Hong Zhang Ji-Hong Zhu liang xia Engineering Simulation and Aerospace Computing (ESAC) Northwestern Polytechnical University

In order to avoid stress concentration, the shape boundary must be properly designed via shape optimiza- tion. Traditional shape optimization approach eliminates the stress concentration effect by using free-form curve to present the design boundaries without taking the machin- ability into consideration. In most numerical control （NC） machines, linear as well as circular interpolations are used to generate the tool path. Non-circular curves, such as non- uniform rotational B-spline （NURBS）, need other more ad- vanced interpolation functions to formulate the tool path. Forming the circular tool path by approximating the opti- mal free curve boundary with arcs or biarcs is another op- tion. However, these two approaches are both at a cost of sharp expansion of program code and long machining time consequently. Motivated by the success of recent researches on biarcs, a reliable shape optimization approach is pro- posed in this work to directly optimize the shape boundaries with biarcs while the efficiency and precision of traditional method are preserved. Finally, the approach is validated by several illustrative examples.

关键词： Structural shape optimization Biarc Curvefitting NURBS Stress concentration

Design and realization of digital audio equalizer based on MCU and FPAA

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仪器仪表学报 2008年第3期29卷 483-486页

作者： Zhou Ping Liu Zhuo xia liang Guilin University of Electronic Technology Guilin 541004 China Delft University of Technology Holand

In analog audio equalizer, the filters are constructed by op-amplifiers and discrete components. Being influenced by its discrete capabilities, audio equalizer has many disadvantages. Meanwhile, pure digital audio equalizer has got better performance and stability, but its cost and price are too high. So digital audio equalizer only has its application in upscale domain. A new design method for audio equalizer is proposed, which attempts to design and realize a high precision and high SNR (signal noise ratio) digital audio equalizer system based on field programmable analog array (FPAA) and micro-controller unit. This design confirms that design speed and performance will be greatly enhanced when FPAA technology is applied to analog design domain.

关键词：数字音频均衡器设计现场可编程模拟矩阵微程序控制器

An economic evaluation method of coalbed methane resources during the target selection phase of exploration

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Petroleum Science 2015年第4期12卷 705-711页

作者： Dong-Kun Luo liang-Yu xia School of Business Administration China University of Petroleum (Beijing)

Because forecasting a development program during the target selection phase of exploration for coalbed methane （CBM） is impossible, the conventional method that relies on a conceptual （or detailed） development pro- gram cannot be used during the economic evaluation of CBM resources. Hence, this study focuses on establishing an economic evaluation model based on the characteristics of the target selection phase. The discounted cashflow method is applied to the construction of the model with the assumption that there is a uniform distribution of produc- tion wells. The computational error generated by the assumption is corrected by introducing a correction factor based on the production profile of single CBM wells. The case study demonstrates that the blocks lacking economic value can be screened out, and the most advantageous targets can be found by computing the resource values in the best- and worst-case scenarios. This technique can help to reduce wasted investments and improve the quality of decision-making in selecting targets for exploration.

关键词： Coalbed methane Exploration targetselection Economic evaluation Scenario analysis

The Spectral Gap for Quasi-birth and Death Processes

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Acta Mathematica Sinica,English Series 2012年第5期28卷 1075-1090页

作者： Yong Hua MAO liang Hui xia School of Mathematical Sciences LMCSMinistry of EducationBeijing Normal University Department of Mathematics Ji'nan University

For a reversible quasi-birth and death process, we generalize and refine the decomposition method, by constructing a birth-death process and a sequence of restriction processes. The spectral gap for the quasi-birth and death process is estimated in terms of the spectral gaps for these processes, and in some special cases, the estimation is sharp. With the aid of the symmetrization procedure, the result is also applied to two queueing models： M/M/1 in random environment and MIMIc with synchronous vacation.

关键词： Quasi-birth and death process spectral gap birth-death process M/M/1 in random environment MIMIc with synchronous vacation

Spectral Gap for Open Jackson Networks

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Acta Mathematica Sinica,English Series 2015年第12期31卷 1879-1894页

作者： Yong Hua MAO liang Hui xia School of Mathematical Sciences LMCSMinistry of Education Beijing Normal University Department of Mathematics Ji'nan University

We generalize the decomposition method of the finite Markov chains for Poincare inequality in Jerrum et al.（***.,14,1741-1765（2004）） to the reversible continuous-time Markov *** inductively,we give the lower bound of spectral gap for the ergodic open Jackson network by the decomposition method and the symmetrization *** upper bound of the spectral gap is also presented.

关键词： Jackson networks reversibility decomposition of Markov chain spectral gap symmetrization

Error-detected N-photon cluster state generation based on the controlled-phase gate using a quantum dot in an optical microcavity

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Frontiers of physics 2020年第2期15卷 1-11页

作者： Lei-xia liang Yan-Yan Zheng Yuan-xia Zhang Mei Zhang Department of Physics Applied Optics Beijing Area Major LaboratoryBeijing Normal UniversityBeijing 100875China School of Physics and Electronic Information Yan’an UniversityYan’an 716000China

We propose a scheme for error-detected generation of an AT-photon cluster state with a quantum dot(QD)embedded in a single-sided optical niicrocavity(QD-cavity system).The basic structure of this scheme is an error-detected controlled-phase(C-phase)gate on the hybrid electron-photon *** this scheme,the fidelity of N-photon cluster state generation can be reached imity even if low-Q cavity and cavity leakage are *** using error detecting,the generation of an AT-photon cluster state can be performed by repeating until success,which also leads to a high success probability,compared with other schemes assisted by the QD-cavity *** error-detected generation of an N-photon cluster state in the highly controllable way may benefit on the quantum network in the future.

关键词： controlled-phase gate cluster state error-detected QD-cavity system

1D/2D material-based photodetectors driven by ferroelectrics

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Science China(Physics,Mechanics & Astronomy) 2017年第3期60卷 89-90页

作者： Feng-xia liang Lin-Bao Luo School of Electronic Science and Applied Physics Hefei University of Technology Hefei 230009 China

One-dimensional （1D） and two-dimensional （2D） materials, such as nanowires, graphene, and transition metal dichalcogenides （TMDs）, have received emerging research study in the past ten years [1-3]. They have demonstrated to be idea building blocks for fabricating high-performance photodetector devices owing to their unique electrical and optical properties [4-6].

关键词：光电探测器二维材料铁电材料一维过渡金属硫化物驱动 TMDS 光学性质

DISJOINT SUPERCYCLIC WEIGHTED PSEUDO-SHIFTS ON BANACH SEQUENCE SPACES

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Acta Mathematica Scientia 2019年第4期39卷 1089-1102页

作者： Ya WANG Yu-xia liang Department of Mathematics Tianjin University of Finance and Economics Tianjin 300222 China School of Mathematical Sciences Tianjin Normal University Tianjin 300387 China

In this article, we present several equivalent conditions ensuring the disjoint supercyclicity of finite weighted pseudo-shifts acting on an arbitrary Banach sequence *** disjoint supercyclic properties of weighted translations on locally compact discrete groups,the direct sums of finite classical weighted backward shifts, and the bilateral backward operator weighted shifts can be viewed as special cases of our main results. Furthermore, we exhibit an interesting fact that any finite bilateral weighted backward shifts on the space ?~2(Z) never satisfy the d-Supercyclicity Criterion by a simple proof.

关键词： Disjoint supercyclicity weighted pseudo-shifts disjoint Blow-up/collapse Property