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Deriving a kinetic uncertainty relation for piecewise deterministic processes:from classical to quantum

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Communications in Theoretical Physics 2021年第12期73卷 149-158页

作者： Fei LIU School of Physics Beihang UniversityBeijing 100191China

From the perspective of Markovian piecewise deterministic processes(PDPs),we investigate the derivation of a kinetic uncertainty relation(KUR),which was originally proposed in Markovian open quantum systems.First,stationary distributions of classical PDPs are explicitly constructed.Then,a tilting method is used to derive a rate functional of large deviations.Finally,based on an improved approximation scheme,we recover the KUR.These classical results are directly extended to the open quantum systems.We use a driven two-level quantum system to exemplify the quantum results.

关键词： Nonequilibrium fluctuations kinetic uncertainty relations large deviation principle open quantum systems piecewise deterministic processes trajectory

On a tilted Liouville-master equation of open quantum systems

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Communications in Theoretical Physics 2021年第9期73卷 129-135页

作者： Fei LIU School of Physics Beihang UniversityBeijing 100191China

A tilted Liouville-master equation in Hilbert space is presented for Markovian open quantum systems.We demonstrate that it is the unraveling of the tilted quantum master equation.The latter is widely used in the analy... 详细信息

关键词： quantum stochastic thermodynamic tilted quantum master equation quantum trajectories Feynman-Kac formula stochastic heat Liouville-master equation

Estimation of the unfrozen water content of saturated sandstones by ultrasonic velocity

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International Journal of Mining Science and Technology 2023年第6期33卷 733-746页

作者： Shibing Huang Fei LIU Gang liu Shilin Yu School of Resources and Environmental Engineering Wuhan University of Science and TechnologyWuhan 430081China Hubei Key Laboratory for Efficient Utilization and Agglomeration of Metallurgic Mineral Resources Wuhan 430081China

The unfrozen water content(UWC)of rocks at low temperature is an important index for evaluating the stability of the rock engineering in cold regions and artificial freezing engineering.This study addresses a new method to estimate the UWC of saturated sandstones at low temperature by using the ultrasonic velocity.Ultrasonic velocity variations can be divided into the normal temperature stage(20 to 0℃),quick phase transition stage(0 to-5℃)and slow phase transition stage(-5 to-25℃).Most increment of ultrasonic velocity is completed in the quick phase transition stage and then turns to be almost a constant in the slow phase transition stage.In addition,the UWC is also measured by using nuclear magnetic resonance(NMR)technology.It is validated that the ultrasonic velocity and UWC have a similar change law against freezing and thawing temperatures.The WE(weighted equation)model is appropriate to estimate the UWC of saturated sandstones,in which the parameters have been accurately determined rather than by data fitting.In addition,a linear relationship between UWC and ultrasonic velocity is built based on pore ice crystallization theory.It is evidenced that this linear function can be adopted to estimate the UWC at any freezing temperature by using P-wave velocity,which is simple,practical,and accurate enough compared with the WE model.

关键词： Ultrasonic velocity Freeze-thaw cycles Unfrozen water content Prediction function Hysteresis effect

A fluctuation theorem for Floquet quantum master equations

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Communications in Theoretical Physics 2020年第9期72卷 127-131页

作者： Fei LIU School of Physics Beihang UniversityBeijing 100191China

We present a fluctuation theorem for Floquet quantum master equations. This is a detailed version of the famous Gallavotti–Cohen theorem. In contrast to the latter theorem, which involves the probability distribution of the total heat current, the former involves the joint probability distribution of positive and negative heat currents and can be used to derive the latter. A quantum two-level system driven by a periodic external field is used to verify this result.

关键词： Floquet quantum master equations Gallavotti–Cohen fluctuation theorem large deviation principle positive and negative heat currents

The Uniqueness of Knieper Measure on Non-compact Rank 1 Manifolds of Non-positive Curvature

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Acta Mathematica Sinica,English Series 2021年第8期37卷 1219-1228页

作者： Fei LIU Fang WANG College of Mathematics and Systems Science Shandong University of Science and TechnologyQingdao 266590P.R.China School of Mathematical Sciences Capital Normal UniversityBeijing 100048P.R.China

We study the Knieper measures of the geodesic flows on non-compact rank 1 manifolds of non-positive curvature.We construct the Busemann density on the ideal boundary,and prove that if there is a Knieper measure on T^(1)M with finite total mass,then the Knieper measure is unique,up to a scalar multiple.Our result partially extends Paulin-Pollicott-Shapira’s work on the uniqueness of finite Gibbs measure of geodesic flows on negatively curved non-compact manifolds to non-compact manifolds of non-positive curvature.

关键词： Geodesic flows Patterson-Sullivan measure Knieper measure

Foundation Treatment in Urban Underground Engineering Using Big Data Analysis for Smart City Applications

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Computer Modeling in Engineering & Sciences 2022年第7期131卷 153-172页

作者： Fei LIU Yunkai Zhang Jian Zhang School of Civil and Transportation Engineering Beijing University of Civil Engineering and ArchitectureBeijing102616China Beijing Advanced Innovation Center for Future Urban Design Beijing102616China School of Science Beijing University of Civil Engineering and ArchitectureBeijing102616China

A core element of the sustainable approach to global living quality improvement can now become the intensive and organized usage of underground space.There is a growing interest in underground building and growth worldwide.The reduced consumption of electricity,effective preservation of green land,sustainable wastewater and sewage treatment,efficient reverse degradation of the urban environment,and reliable critical infrastructure management can improve the quality of life.At the same time,technological innovations such as artificial intelligence(AI),cloud computing(CC),the internet of things(IoT),and big data analytics(BDA)play a significant role in improved quality of life.Hence,this study aims to integrate the technological innovations in urban underground engineering to ensure a high quality of life.Thus,this study uses big data analytics to carry out the status quo of foundation treatment and proposes a conceptual framework named the BDA with IoT on urban underground engineering(BI0T-UUE).This framework connects hidden features with various high-level sensing sources and practical predictive model characterization to lower building costs,productive infrastructure management,preparedness for disasters,and modern community smart services.The IoT integration gives an optimum opportunity to work towards the functionality of‘‘digital doubles’’of secret infrastructure,both economical and scalable,with the increasing sophistication and tooling of the underworld.The simulation analysis ensures the highest efficiency and cost-effectiveness of the underground engineering with a value of 96.54%and 97.46%.

关键词： Underground engineering internet of things big data analytics status quo economic and social smart city

Bayesian Filtering for High-Dimensional State-Space Models With State Partition and Error Compensation

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1239-1249页

作者： Ke Li Shunyi Zhao Biao Huang Fei LIU Key Laboratory of Advanced Process Control for Light Industry(Ministry of Education) Institute of AutomationJiangnan UniversityWuxi 214122China Department of Chemical and Materials Engineering University of AlbertaEdmonton AB T6G 2G6Canada

In the era of exponential growth of data availability,the architecture of systems has a trend toward high dimensionality,and directly exploiting holistic information for state inference is not always computationally affordable.This paper proposes a novel Bayesian filtering algorithm that considers algorithmic computational cost and estimation accuracy for high-dimensional linear systems.The high-dimensional state vector is divided into several blocks to save computation resources by avoiding the calculation of error covariance with immense dimensions.After that,two sequential states are estimated simultaneously by introducing an auxiliary variable in the new probability space,mitigating the performance degradation caused by state segmentation.Moreover,the computational cost and error covariance of the proposed algorithm are analyzed analytically to show its distinct features compared with several existing methods.Simulation results illustrate that the proposed Bayesian filtering can maintain a higher estimation accuracy with reasonable computational cost when applied to high-dimensional linear systems.

关键词： filtering estimation error

Robust Control of Manned Submersible Vehicle With Nonlinear MPC and Disturbance Observer

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IEEE/CAA Journal of Automatica Sinica 2023年第5期10卷 1349-1351页

作者： Qiuxin Zhong Xing Fang Zhengtao Ding Fei LIU the Key Laboratory of Advanced Process Control for Light Industry of the Ministry of Education Jiangnan UniversityWuxi 214122China the Department of Electrical and Electronic Engineering University of ManchesterManchester M139PLUK

Dear Editor,This letter focuses on the trajectory tracking of 7000 m JIAOLONG manned submersible vehicle(MSV)with disturbances.The robust controller is realized by a composite control law,where an analytical nonlinear... 详细信息

关键词： Nonlinear letter law

A Fusion Kalman Filter and UFIR Estimator Using the Influence Function Method

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IEEE/CAA Journal of Automatica Sinica 2022年第4期9卷 709-718页

作者： Wei Xue Xiaoli Luan Shunyi Zhao Fei LIU IEEE the Key Laboratory of Advanced Process Control for Light Industry(Ministry of Education) Institute of AutomationJiangnan University

In this paper,the Kalman filter(KF)and the unbiased finite impulse response(UFIR)filter are fused in the discrete-time state-space to improve robustness against uncertainties.To avoid the problem where fusion filters may give up some advantages of UFIR filters by fusing based on noise statistics,we attempt to find a way to fuse without using noise statistics.The fusion filtering algorithm is derived using the influence function that provides a quantified measure for disturbances on the resulting filtering outputs and is termed as an influence finite impulse response(IFIR)filter.The main advantage of the proposed method is that the noise statistics of process noise and measurement noise are no longer required in the fusion process,showing that a critical feature of the UFIR filter is inherited.One numerical example and a practice-oriented case are given to illustrate the effectiveness of the proposed method.It is shown that the IFIR filter has adaptive performance and can automatically switch from the Kalman estimate to the UFIR estimates according to operating conditions.Moreover,the proposed method can reduce the effects of optimal horizon length on the UFIR estimate and can give the state estimates of best accuracy among all the compared methods.

关键词： Fusion filter influence function Kalman filter(KF) robustness unbiased finite impulse response(FIR)