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Slicing capacity-centered mode selection and resource optimization for network-assisted full-duplex cell-free distributed massive MIMO systems

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Science China(Information Sciences) 2024年第1期67卷 203-220页

作者： Jie WANG jiamin li Pengcheng ZHU Dongming WANG Hongbiao ZHANG Yue HAO Bin SHENG National Mobile Communications Research Laboratory Southeast University 2. Purple Mountain Laboratories China Mobile Research Institute

Network-assisted full-duplex(NAFD) cell-free distributed massive multiple-input multipleoutput(MIMO) systems enable uplink(UL) and downlink(DL) communications within the same timefrequency resources,which potentially reduce latency by avoiding the overhead of switching UL/DL modes.However,how to choose UL/DL modes remains an important factor affecting system performance.With the dramatic increase in the number of users and access points(APs),massive access brings significant overhead in the mode selection.Additionally,the different quality of service(QoS) among users also makes the effective utilization of resources difficult.As one of the most promising technologies in sixth-generation(6G),network slicing enables the adaptive configuration of limited UL/DL resources through the resource isolation assisted NAFD technique.Therefore,we propose a slicing capacity-centered scheme.Under this scheme,APs are motivated by slicing requirements and associated slices to form different subsystems.Collaborative mode selection and resource allocation are performed within each subsystem to reduce overhead and improve resource utilization.To implement this scheme efficiently,a double-layer deep reinforcement learning(DRL)mechanism is used to realize the joint optimization of mode selection and resource allocation.Simulation results show that the slicing capacity-centered scheme can effectively improve resource utilization and reduce overhead.

关键词： network-assisted full-duplex network slicing mode selection resource optimization deep reinforcement learning

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Peroxisome proliferator-activated receptors gama ameliorates liver fibrosis in non-alcoholic fatty liver disease by inhibiting TGF-β/Smad signaling activation

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Frigid Zone Medicine 2024年第1期4卷 12-22页

作者： Qingwei Zhang Wenjie Zhao Zeqi Sun Xinxin Dong liwei Zhu Zhen Zhang Ximing Chen Yingying Hu Menghan Du jiamin li Yong Zhang Department of Pharmacology College of Pharmacyand Department of Cardiologythe Second Affiliated HospitalHarbin Medical UniversityHarbin 150081China Department of Pharmacology College of PharmacyHarbin Medical UniversityHarbin 150081China The State Key Laboratory of Frigid Zone Cardiovascular Diseases(SKLFZCD) and the Key Laboratory of Cardiovascular Medicine ResearchMinistry of EducationHarbin 150081China Research Unit of Noninfectious Chronic Diseases in Frigid Zone Chinese Academy of Medical Sciences2019RU070Harbin 150081China

Background:Nonalcoholic fatty liver disease(NAFLD)is a chronic condition characterized by a progressive decline in liver function,leading to disruptions in liver integrity and metabolic function,resulting in lipid deposition and excessive accumulation of extracellular matrix(ECM).The pathogenesis of NAFLD is complex and not yet fully understood,contributing to the absence of specific therapeutic strategies.Peroxisome proliferator-activated receptor gamma(PPARγ)is a ligand-activated transcription factor pivotal in regulating lipid and glucose metabolism.However,the impacts of PPARγon NAFLD remains insufficiently explored.Thus,this study aimed to investigate the role of PPARγin NAFLD and its underlying molecular mechanisms.Methods:Chemical detection kits were utilized to quantify collagen content,alanine aminotransferase(ALT),and aspartate aminotransferase(AST)level variations.Quantitative real-time polymerase chain reaction(qRT-PCR)was employed to assess alterations in extracellular matrix-related genes and inflammatory response genes in liver tissue and HepG2 cells,while western blotting was conducted to analyze the levels of both PPARγand the TGF-β/Smad signaling pathway.Results:Our findings unveiled significantly reduced PPARγexpression in a rat model of NAFLD,leading to subsequent activation of the TGF-β/Smad signaling pathway.Furthermore,PPARγactivation effectively mitigated NAFLD progression by inhibiting inflammation and fibrosis-related gene expression and collagen production.On a cellular level,PPARγactivation was found to inhibit the expression of extracellular matrix-related genes such as matrix metalloproteinase 2(MMP2)and matrix metalloproteinase 9(MMP9),along with inflammatory response genes interleukin(IL)-1βand IL-6.Additionally,PPARγactivation led to a significant decrease in the levels of ALT and AST.At the molecular level,PPARγnotably down-regulated the TGF-β/Smad signaling pathway,which is known to promote liver fibrosis.Conclusion:These groundbreaking findings underscore PPARγactivation as a p

关键词： NAFLD PPARγ TGF-β/Smad liver fibrosis

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Triples of almost primes

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Science China Mathematics 2023年第12期66卷 2779-2794页

作者： jiamin li Jianya liu School of Mathematics Shandong UniversityJinan 250100China

The k-tuple conjecture of Hardy and little wood predicts that there are infinitely many primes p such that p+2 and p+6 are primes simultaneously.In this paper,we prove that there are infinitely many primes p such that Ω(p+2)≤3 and Ω(p+6)≤6,where Ω(n) denotes the total number of prime divisors of an integer n.We also prove a better conditional result,with the above Ω(p+6)≤6 replaced by Ω(p+6)≤3,under the Elliott-Halberstam conjecture.

关键词： the k-tuple conjecture of Hardy and littlewood almost prime vector sieve weighted sieve

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Performance analysis of full-duplex densely distributed MIMO with wireless backhaul

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Science China(Information Sciences) 2023年第6期66卷 186-203页

作者： Ziqian WAN Qijun PAN jiamin li Pengcheng ZHU Dongming WANG National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories

In this paper, the spectral efficiency of a full-duplex(FD)densely distributed multi-input multioutput(MIMO)system with wireless backhaul is considered. In-band full-duplex(IBFD)backhauling, in which the backhaul and access transmissions take place on the same spectrum, is exploited for wireless backhauling to enable an efficient spectrum reuse. However, the severe cross-tier interference and crosslink interference reduce the gains of IBFD backhauling. To evaluate the achievable spectral efficiency with imperfect channel state information(CSI), we propose a two-phase channel estimation scheme to estimate the CSI for two wireless links, and the scheme estimates an effective interference CSI between access points(APs)based on beamforming training to perform interference cancelation at APs. Given the estimated CSI,the closed-form expressions of the uplink and downlink achievable rates with maximum ratio transmission beamforming and maximum ratio combining receivers, respectively, are derived with Gamma approximation.Numerical results verify the accuracy of the derived closed-form expressions and the effectiveness of the twophase channel estimation scheme for interference cancelation. Moreover, compared with half-duplex densely distributed MIMO systems, FD systems with interference cancelation have a better performance.

关键词： full-duplex wireless backhaul performance analysis beamforming training interference cancelation

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Polarization-entangled photon pairs with factorable spectra engineered by using an uneven four-stage nonlinear interferometer

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Chinese Optics Letters 2024年第5期22卷 106-110页

作者：崔亮陈浩然李嘉敏李小英 College of Precision Instrument and Opto-Electronics Engineering Key Laboratory of Opto-Electronics Information TechnologyMinistry of EducationTianjin UniversityTianjin 300072China School of Physics Taiyuan University of TechnologyTaiyuan 030000China

We report the generation of polarization-entangled photon pairs in the 1550 nm band by pumping an uneven nonlinear interferometer loop with two orthogonally polarized counterpropagating pump pulses.The uneven nonlinear interferometer,providing a more ideal interference pattern due to the elimination of secondary maxima,consists of four pieces of dispersion-shifted fibers sandwiched with three pieces of standard single-mode fibers,and the lengths of the nonlinear fibers follow the binomial distribution.The mode number of the photon pairs deduced from the measured joint spectrum is∼1.03.The collection efficiency of the photon pairs is found to be∼94%(after background noise correction).The directly measured visibility of two-photon interference of the polarization-entangled photon pairs is∼92%,while no interference is observed in the direct detection of either the signal or idler photons.

关键词： polarization-entangled photon pairs nonlinear interferometer quantum state engineering optical fiber

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Joint optimization of spectral efficiency and energy efficiency with low-precision ADCs in cell-free massive MIMO systems

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Science China(Information Sciences) 2022年第5期65卷 169-183页

作者： Han WANG Chang SUN jiamin li Pengcheng ZHU Dongming WANG Xiaohu YOU National Mobile Communications Research Laboratory Southeast University Purple Mountain Laboratories

In cell-free massive multiple-input multiple-output(MIMO) systems, it is beneficial to apply low-precision analog-to-digital converters(ADCs) to reduce power consumption, hardware cost, and the load on backhaul link. However, low-precision ADCs will result in serious degradation in spectral efficiency(SE). It is important to achieve a good tradeoff between SE and energy efficiency(EE) for cell-free massive MIMO systems with low-precision ADCs. In this paper, we first derive the closed-form expressions of uplink achievable rates with maximal ratio combining(MRC) receiver and zero-forcing(ZF) receiver in cell-free massive MIMO systems. Then we analyze the EE model of cell-free massive MIMO systems. Based on the above analysis, the tradeoff between SE and EE is studied. Moreover, we propose two quantization bit allocation algorithms to optimize the SE and EE jointly from the perspective of multi-objective optimization.One algorithm is based on the deep Q-network(DQN) and the other one is based on the non-dominated sorting genetic algorithm Ⅱ(NSGA-Ⅱ). The proposed algorithms provide more feasible solutions and achieve better system performance than equal quantization bit allocation algorithm. Numerical results verify the accuracy of the derived closed-form expressions and the effectiveness of the proposed optimization algorithms.

关键词： cell-free massive MIMO low-precision ADC spectral efficiency energy efficiency multi-objective optimization

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Anomaly monitoring and early warning of electric moped charging device with infrared image

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Optoelectronics Letters 2024年

作者： li jiamin Han Bo Jiang Mingshun School of Control Science and Engineering Shandong University

Potential high-temperature risks exist in heat-prone components of electric moped charging devices， such as sockets， interfaces， and controllers. Traditional detection methods have limitations in terms of real-time performance and monitoring scope. To address this， a temperature detection method based on infrared image processing has been proposed: utilizing the median filtering algorithm to denoise the original infrared image， then applying an image segmentation algorithm to divide the image. After trimming the image boundaries， the corner detection algorithm is used to extract corner information from the image， acquiring the position of the rectangular selection area that includes all corners. Finally， the block partitioning algorithm is used for temperature detection of the selected area and to determine the type of fault in the charging device based on the threshold. Based on this method， an electric moped charging device monitoring and warning system using infrared images has been designed. Experimental results demonstrate that this monitoring system can effectively detect the location and temperature of the test area， display and transmit warning information in real time via software， and has a high accuracy rate. This system holds promise as a crucial tool for enhancing the safety of electric moped charging devices.

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Joint utility optimization for wireless sensor networks with energy harvesting and cooperation

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Science China(Information Sciences) 2020年第2期63卷 146-159页

作者： Pengcheng ZHU Bingqian XU jiamin li Dongming WANG National Mobile Communications Research Laboratory Southeast University

In wireless sensor networks(WSNs), the limited battery capacity restricts the lifetime of the sensor nodes and thus degrades the system performance. The energy harvesting and cooperation techniques are promising solutions to prolonging the battery life, by collecting energy from ambient environment and exchanging energy among sensor nodes. This paper studies the joint utility maximization problem for WSNs in consideration of energy harvesting and cooperation. We first derive an upper bound on the Lyapunov drift for the network stability, and then formulate the optimization as a stochastic optimization problem. Furthermore, we propose an energy harvesting and energy transfer, data transmission, power control, routing and scheduling(EDPR) online algorithm by combining Lyapunov optimization technique with drift-plus-penalty method and perturbation technique. It contributes to optimal utility in a distributed manner along with a balanced trade-off between network utility and queue backlog, with no need for any statistical information about dynamic systems and no concern of curse of dimensionality under large queue backlog. Simulation results also show the practicality of the proposed algorithm in real implementation since data transmission has a linear relationship with battery life.

关键词： drift-plus-penalty energy management Lyapunov analysis utility optimization WSNs

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Trans-synaptic Neural Circuit-Tracing with Neurotropic Viruses

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Neuroscience Bulletin 2019年第5期35卷 909-920页

作者： jiamin li Taian liu Yun Dong Kunio Kondoh Zhonghua Lu Guangdong Provincial Key Laboratory of Brain Connectome and Behavior The Brain Cognition and Brain Disease Institute Shenzhen Institutes of Advanced Technology Chinese Academy of Sciences Shenzhen 518055 China University of Chinese Academy of Sciences Beijing 100049 China Division of Endocrinology and Metabolism Department of Homeostatic Regulation National Institute for Physiological Sciences National Institute of Natural Sciences Myodaiji Okazaki Aichi 444-8585 Japan Japan Science and Technology Agency PRESTO Myodaiji Okazaki Aichi 444-8585 Japan

A central objective in deciphering the nervous system in health and disease is to define the connections of neurons. The propensity of neurotropic viruses to spread among synaptically-linked neurons makes them ideal for mapping neural circuits. So far, several classes of viral neuronal tracers have become available and provide a powerful toolbox for delineating neural networks. In this paper, we review the recent developments of neurotropic viral tracers and highlight their unique properties in revealing patterns of neuronal connections.

关键词： Neurotropic virus Central nervous system Neural circuit Trans-synaptic tracer Retrograde tracing Anterograde tracing

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Impacts of practical channel impairments on the downlink spectral efficiency of large-scale distributed antenna systems

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Science China(Information Sciences) 2019年第2期62卷 146-159页

作者： jiamin li Dongming WANG Pengcheng ZHU Xiaohu YOU National Mobile Communications Research Laboratory Southeast University

Channel impairments are major limiting factors in the performance of large-scale antenna systems. In this paper, we analyze the impacts of practical channel impairments caused by pilot contamination,Doppler shift, and phase noise on the downlink spectral efficiency of large-scale distributed antenna systems(L-DASs) with maximum ratio transmission(MRT) and zero-forcing(ZF) beamforming, in which per user power normalization is considered. Using a joint channel model that allows study of the simultaneous impacts of these channel impairments, we derive accurate and tractable closed-form approximations for the ergodic achievable downlink rate, thereby enabling spectral efficiency analysis of L-DASs and an efficient evaluation of the impacts of the channel impairments. It is shown that channel impairments reduce the downlink spectral efficiency and have a significant impact on ZF beamforming. The asymptotic user rate limit is also determined, from which we analyze the asymptotic performance of L-DASs with channel impairments. The analytical results show that MRT and ZF beamforming achieve the same asymptotic performance limit even with channel impairments. It is also found that the use of a large-scale antenna array at the base station sides can weaken the impacts of channel impairments.

关键词： Doppler shift phase noise large-scale distributed antenna systems spectral efficiency pilot contamination

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