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Review on strategies of space-based optical space situational awareness

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Journal of Systems Engineering and Electronics 2021年第5期32卷 1152-1166页

作者： HU Yunpeng LI Kebo liang yan’gang CHEN Lei College of Aerospace Science and Engineering National University of Defense TechnologyChangsha 410073China Unmanned Systems Research Center National Innovation Institute of Defense TechnologyBeijing 100071China

Space-based optical(SBO)space surveillance has attracted widespread interest in the last two decades due to its considerable value in space situation awareness(SSA).SBO observation strategy,which is related to the performance of space surveillance,is the top-level design in SSA missions *** recognized real programs about SBO SAA proposed by the institutions in the U.S.,Canada,Europe,etc.,are summarized firstly,from which an insight of the development trend of SBO SAA can be *** to the aim of the SBO SSA,the missions can be divided into general surveillance and space object ***,there are two major categories for SBO SSA *** general surveillance strategies for observing low earth orbit(LEO)objects and beyond-LEO objects are summarized and compared in terms of coverage rate,revisit time,visibility period,and image ***,the SBO space object tracking strategies,which has experienced from tracking an object with a single satellite to tracking an object with multiple satellites cooperatively,are also ***,this paper looks into the development trend in the future and points out several problems that challenges the SBO SSA.

关键词： space situation awareness(SSA) space-based space surveillance space-based optical(SBO)observation strategy general surveillance space object tracking

Seismic Fragility Analysis of Long-Span Bridge System with Durability Degradation

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Computer Modeling in Engineering & Sciences 2019年第10期121卷 177-214页

作者： yan liang Jialei yan Zhanqi Cheng Huai Chen Ruimin Mao College of Civil Engineering Zhengzhou UniversityZhengzhouChina

An offshore long-span continuous rigid-frame bridge is taken as an example to study the effect of degradation of bond-slip behavior on the seismic performance of bridges in an offshore environment during a service *** the basis of a numerical simulation analysis using the OpenSeeS platform,the influence of durability degradation of concrete carbonization,steel corrosion,and degradation of bond-slip performance is considered collectively using incremental dynamic analysis method to examine the time-varying seismic fragility of the offshore *** show that when bond slip is considered,the exceedance probability of the bridge components and the system increases significantly,and the durability degradation caused by concrete carbonization and chloride ion erosion in the whole life cycle increases the seismic response of the bridge *** results of the proposed time-varying seismic fragility analysis indicate that,considering the degradation of bond-slip behavior of reinforced concrete after the durability degradation of materials,the exceedance probability of the pier,bearing,abutment,and system increases with the extension of service period and the increase in seismic strength under earthquake *** addition,with the extension of service time,the effect of bond slip on the seismic fragility of components and system gradually decreases.

关键词： Bridge durability degradation bond slip seismic fragility

A Recipe Book for Culture Consumers： Yuan Mei and Suiyuan shidan

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Frontiers of History in China 2015年第4期10卷 547-570页

作者： yan liang Department of Modem Languages and Literatures & East Asian Studies Program Faculty Grand Valley State University Allendale M149401 USA

This article is a study of the writings on food, cooking, and dining by the eighteenth-century poet, essayist, and gourmet Yuan Mei （1716-98） as found in his recipe book Suiyuan shidan. Starting with an overview of the organization and content of Suiyuan shidan, the article offers an analysis of Yuan Mei＇s cultural attitudes reflected there and in his works in other genres. The value underlying Suiyuan shidan exemplifies Yuan＇s personal response to the Chinese intellectual environment at the end of the eighteenth century. Building a connection between the recipe book and Yuan Mei＇s controversial reputation in the literati community, the article explores the changing meaning of culture in eighteenth-century China and Yuan＇s way of surviving the intense competition for voice and influence among the cultural elites of the time.

关键词： Yuan Mei Suiyuan shidan Chinese food culture literati culture eighteenth-century China Qing dynasty

Does Foreign Direct Investment Provide Desirable Development Finance? The Case of China

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China & World Economy 2007年第2期15卷 104-120页

作者： yan liang Simon＇s Rock College of Bard USA

Foreign direct investment （FDI） is ofen considered as a cost-effective and risk-reducing source for development finance. This paper, however, shows that FDI finance often entails underestimated risks and costs. FDI might react sensitively to business cycles and might not be as ＂permanent＂ as conventionally believed. FDI might also accelerate other forms of capital flow in times of financial difficulties and, hence, destabilize ftnancial order. In addition to the risks, compensations to FDI and the high import-dependency of FDI-related trade lead to a considerable drain on the balance of payments. Moreover, the reliance on foreign capital for development finance is equivalent to building a Ponzi financing scheme and, therefore, is unsustainable. Given the fact that FDI financing is risky and costly and China does not lack savings, it is suggested in the present paper that China ＇s efforts in attracting FDI should not aim at external capital provisioning.

关键词： development finance foreign direct investment portfolio investment

China and the Global Financial Crisis:Assessing the Impacts and Policy Responses

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China & World Economy 2010年第3期18卷 56-72页

作者： yan liang Assistant Professor Willamette University Salem OR USA

The present paper explores the role of China in the creation of the current global financial crisis and the impacts of the crisis on its economy. It argues against the view that the ＂saving glut＂ in China （along with other Asian emerging economies） played a significant causal role in the crisis. The global financial crisis did not engender much damage in China＇s financial structure, thanks to the relatively closed, bank-centered financial system. However, the impacts on the ＂real＂ side of the Chinese economy were hard felt. Growth and employment have fallen, largely due to the decline in exports and foreign direct investment. The crisis reveals the vulnerability of the export-dependent growth pattern. Policy responses of the Chinese Government, including monetary, fiscal and social policies, have helped to stem the downfall of the economy in the immediate term, but some of the policies have not addressed the structural problems of the Chinese economy and might well aggravate such problems over time. The present paper proposes a tentative reform blueprint to rebalance the economy and to sustain long-term growth.

关键词： export dependency financial crisis saving glut structural imbalances

A high-dexterity low-degree-of-freedom hybrid manipulator structure for robotic lion dance

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2010年第4期11卷 240-249页

作者： liang yan I-Ming CHEN Song-huat YEO yan CHEN Gui-lin yanG School of Automation Science and Electrical Engineering Beihang University Beijing 100191 China School of Mechanical and Aerospace Engineering Nanyang Technological University Nanyang 639798 Singapore Mechatronics Gnmp Singapore Institute of Mastrfacturing Technology Nanyang 638075 Singapore

Lion dance is a very popular and lively Chinese traditional art form.A robotic project in Singapore has been dedicated to the design and demonstration for similar traditional art forms using modern mechatronics *** paper deals with a novel six-degree-of-freedom (6-DOF) hybrid manipulator with high stiffness,high loading capability and high dexterity,mimicking the lion dancer's upper body motions along with the lion head *** design of the hybrid manipulator consists of a 2-DOF torso structure in serial configuration and a 4-DOF dual arm structure in parallel *** combined 6-DOF hybrid manipulator can support the weight and dynamics of the lion head during the lion dance *** kinematics of the manipulator has been formulated and visualized for design *** kinematics of the hybrid manipulator were analytically derived for real-time motion *** on the design and modeling,a complete hybrid manipulator has been fabricated,implemented into the robotic lion,and successfully demonstrated for real robotic lion dance performance.

关键词： Parallel mechanism Hybrid manipulator Kinematics analysis

High-performance compensation scheme for frequency-dependent IQ imbalances in OFDM transmitter and receiver

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Journal of Systems Engineering and Electronics 2013年第2期24卷 204-208页

作者： yan liang Feng Shu Yijin Zhang Junhui Zhao School of Electronic Engineering and Optoelectronic Technology Nanjing University of Science and Technology College of Telecommunications & Information Engineering Nanjing University of Posts and Telecommunications National Mobile Communications Research Laboratory Southeast University School of Electronic and Information Engineering Beijing Jiaotong University

An efficient compensation scheme combining a timedomain Gaussian elimination（GE） channel estimator and a frequency-domain GE equalizer is proposed for orthogonal frequency division multiplexing（OFDM） systems with frequencydependent in-phase and quadrature-phase（IQ） imbalances at both transmitter and *** with the traditional least square and least mean square compensation schemes,the proposed compensation scheme achieves the same bit error rate as the ideal IQ branches by using only two training OFDM symbols instead of about 20 OFDM symbols.

关键词： in-phase and quadrature-phase(IQ) imbalance time domain frequency domain least square least mean square Gaussian elimination(GE).

Nonadiabatic holonomic quantum computation and its optimal control

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Science China(Information Sciences) 2023年第8期66卷 23-44页

作者： yan liang Pu SHEN Tao CHEN Zheng-Yuan XUE Key Laboratory of Atomic and Subatomic Structure and Quantum Control (Ministry of Education) School of Physics South China Normal University Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials Guangdong-Hong Kong Joint Laboratory of Quantum Matter Frontier Research Institute for PhysicsSouth China Normal University Hefei National Laboratory

The geometric phase has the intrinsic property of being resistant to some types of local noises as it only depends on global properties of the evolution path. Meanwhile, the non-Abelian geometric phase is in the matrix form, and thus can naturally be used to implement high performance quantum gates,i.e., the so-called holonomic quantum computation. This article reviews recent advances in nonadiabatic holonomic quantum computation, and focuses on various optimal control approaches that can improve the gate performance, in terms of gate fidelity and robustness. Besides, we also pay special attention to its possible physical realizations and some concrete examples of experimental realizations. Finally, with all these efforts, within state-of-the-art technology, the performance of the implemented holonomic quantum gates can outperform the conventional dynamical ones, under certain conditions.

关键词： quantum computation geometric phases quantum gates optimal control

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Fine-grained grid computing model for Wi-Fi indoor localization in complex environments

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Journal of Electronic Science and Technology 2024年第1期22卷 42-52页

作者： yan liang Song Chen Xin Dong Tu Liu School of Computer Engineering Chengdu Technological UniversityChengdu611730China HAN Networks Corporation Limited Beijing100094China

The fingerprinting-based approach using the wireless local area network(WLAN)is widely used for indoor ***,the construction of the fingerprint database is quite *** when the position of the access point(AP)or wall changes,updating the fingerprint database in real-time is *** appropriate indoor localization approach,which has a low implementation cost,excellent real-time performance,and high localization accuracy and fully considers complex indoor environment factors,is preferred in location-based services(LBSs)*** this paper,we proposed a fine-grained grid computing(FGGC)model to achieve decimeter-level localization *** points(RPs)are generated in the grid by the FGGC ***,the received signal strength(RSS)values at each RP are calculated with the attenuation factors,such as the frequency band,three-dimensional propagation distance,and walls in complex *** a result,the fingerprint database can be established automatically without manual measurement,and the efficiency and cost that the FGGC model takes for the fingerprint database are superior to previous *** proposed indoor localization approach,which estimates the position step by step from the approximate grid location to the fine-grained location,can achieve higher real-time performance and localization accuracy *** mean error of the proposed model is 0.36 m,far lower than that of previous ***,the proposed model is feasible to improve the efficiency and accuracy of Wi-Fi indoor *** also shows high-accuracy performance with a fast running speed even under a large-size *** results indicate that the proposed method can also be suitable for precise marketing,indoor navigation,and emergency rescue.

关键词： Fine-grained grid computing (FGGC) Indoor localization Path loss Random forest Reference points(RPs)