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Resource Allocation for Cognitive Network Slicing in PD-SCMA System Based on Two-Way Deep Reinforcement Learning

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CHINA COMMUNICATIONS 2024年第6期21卷 1-16页

作者： zhang, zhenyu zhang, Yong Yuan, Siyu Cheng, Zhenjie Beijing Univ Posts & Telecommun Sch Elect Engn Beijing 100876 Peoples R China Beijing Univ Posts & Telecommun Beijing Key Lab Work Safety Intelligent Monitoring Beijing 100876 Peoples R China

In this paper, we propose the Two-way Deep Reinforcement Learning (DRL)-Based resource allocation algorithm, which solves the problem of resource allocation in the cognitive downlink network based on the underlay mode. Secondary users (SUs) in the cognitive network are multiplexed by a new Power Domain Sparse Code Multiple Access (PD-SCMA) scheme, and the physical resources of the cognitive base station are virtualized into two types of slices: enhanced mobile broadband (eMBB) slice and ultrareliable low latency communication (URLLC) slice. We design the Double Deep Q Network (DDQN) network output the optimal codebook assignment scheme and simultaneously use the Deep Deterministic Policy Gradient (DDPG) network output the optimal power allocation scheme. The objective is to jointly optimize the spectral efficiency of the system and the Quality of Service (QoS) of SUs. Simulation results show that the proposed algorithm outperforms the CNDDQN algorithm and modified JEERA algorithm in terms of spectral efficiency and QoS satisfaction. Additionally, compared with the Power Domain Non-orthogonal Multiple Access (PD-NOMA) slices and the Sparse Code Multiple Access (SCMA) slices, the PD-SCMA slices can dramatically enhance spectral efficiency and increase the number of accessible users.

关键词： cognitive radio deep reinforcement learn- ing network slicing Power-domain Non-orthogonal Multiple Access resource allocation NOMA DOWNLINK UPLINK

Riding on bifurcating Berry curvatures into reentrant quantum anomalous Hall states

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Science China(Physics,Mechanics & Astronomy) 2022年第4期65卷 125-126页

作者： zhenyu zhang International Center for Quantum Design of Functional Materials(ICQD) Hefei National Laboratory for Physical Sciences at MicroscaleUniversity of Science and Technology of ChinaHefei 230026China

When a sufficiently strong magnetic field is applied to a twodimensional electron gas,it will drive the electrons into quantized states,known as the Landau levels.The transport properties of such a system are best manifested by the emergence of the(integer)quantum Hall effect(QHE)[1],characterizing the system as a quantum Hall insulator,a close and proceeding analog of the quantum spin Hall insulator.

关键词： quantum system states

Mechanical responses of multi-layered ground due to shallow tunneling with arbitrary ground surface load

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Frontiers of Structural and Civil Engineering 2023年第5期17卷 745-762页

作者： Xuefei HONG Dingli zhang zhenyu SUN Key Laboratory for Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China

An analytical model based on complex variable theory is proposed to investigate ground responses due to shallow tunneling in multi-layered ground with an arbitrary ground surface load.The ground layers are assumed to be linear-elastic with full-stick contact between them.To solve the proposed multi-boundary problem,a series of analytic functions is introduced to accurately express the stresses and displacements contributed by different boundaries.Based on the principle of linear-elastic superposition,the multi-boundary problem is converted into a superposition of multiple single-boundary problems.The conformal mappings of different boundaries are independent of each other,which allows the stress and displacement fields to be obtained by the sum of components from each boundary.The analytical results are validated based on numerical and in situ monitoring results.The present model is superior to the classical model for analyzing ground responses of shallow tunneling in multi-layered ground;thus,it can be used with assurance to estimate the ground movement and surface building safety of shallow tunnel constructions beneath surface buildings.Moreover,the solution for the ground stress distribution can be used to estimate the safety of a single-layer composite ground.

关键词： analytical model mechanical response multi-layered ground shallow tunneling ground surface load complex variable solution

Topological and superconducting properties of monolayered CoN and CoP:A first-principles comparative study

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Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 98-108页

作者： Jiaqing Gao zhenyu zhang Ping Cui International Center for Quantum Design of Functional Materials(ICQD) Hefei National Research Center for Physical Sciences at Microscale(HFNL)University of Science and Technology of ChinaHefei 230026China Hefei National Laboratory University of Science and Technology of ChinaHefei 230088China

Two-dimensional systems that simultaneously harbor superconductivity and nontrivial band topology may serve as appealing platforms for realizing topological superconductivity with promising applications in fault-tolerant quantum computing.Here,based on first-principles calculations,we show that monolayered Co N and Co P with the isovalent Fe Se-like structure are stable in freestanding form,even though their known bulk phases have no resemblance to layering.The two systems are further revealed to display intrinsic band inversions due to crystal field splitting,and such orderings are preserved with the inclusion of spin-orbit coupling(SOC),which otherwise is able to open a curved band gap,yielding a non-zero Z2 topological invariant in each case.Such a mechanism of topologicalization is distinctly contrasted with that identified recently for the closely related monolayers of CoX(X=As,Sb,Bi),where the SOC plays an indispensable role in causing a nontrivial band inversion.Next,we demonstrate that,by applying equi-biaxial tensile strain,the electron-phonon coupling strength in monolayered CoN can be significantly enhanced,yielding a superconducting transition temperature(Tc)up to 7-12 K for the Coulomb pseudopotential ofμ*=0.2-0.1,while the CoP monolayer shows very low Tc even under pronounced strain.Their different superconducting behaviors can be attributed to different variations in lattice softening and electronic density of states around the Fermi level upon pressuring.Our central findings enrich the understanding of different mechanisms of band inversions and topologicalization and offer platforms for achieving the coexistence of superconductivity and nontrivial band topology based on two-dimensional systems.

关键词： topological yielding otherwise

Fixed-Time Leader-Following Formation Control of Fully-Actuated Underwater Vehicles Without Velocity Measurements

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Journal of Systems Science & Complexity 2022年第2期35卷 559-585页

作者： GAO zhenyu zhang Yi GUO Ge School of Control Engineering Northeastern University at QinhuangdaoQinhuangdao 066004China

This paper is concerned with formation control of fully-actuated underwater vehicles(FUVs),focusing on improving system convergence speed and overcoming velocity measurement limitation.By employing the fixed-time control theory and command filtering technique,a full state feedback formation algorithm is proposed,which makes the follower track the leader in a given time with all signals in the system globally practically stabilized in fixed time.To avoid degraded control performance due to inaccurate velocity measurement,a fixed-time convergent observer is designed to estimate the velocity of FUVs.Then the authors give an observer-based fixed-time control method,with which acceptable formation performance can be achieved in fixed time without velocity measurement.The effectiveness and performance of the proposed method are demonstrated by numerical simulations.

关键词： Fixed-time control formation control fully-actuated underwater vehicles(FUVs) state feedback control velocity observer

Multiscale multiphysics modeling in geotechnical engineering

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2023年第1期24卷 1-5页

作者： zhenyu YIN Qi zhang Farid LAOUAFA Department of Civil and Environmental Engineering The Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina National Institute for Industrial Environment and Risks(INERIS) Verneuil-en-HalatteFrance

1 Introduction For geotechnical engineering,numerous applications involve multiscale and multiphysics processes,such as internal erosion,hydraulic fracturing,energy piles,municipal waste disposal,production from unconventional oil and gas reservoirs,heat stimulation and depressurization of natural gas hydrate formation,pavement subjected to heating-cooling cycles.

关键词： reservoirs disposal municipal

A promising new route toward materialization of high-temperature topological superconductors

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Science Bulletin 2017年第10期62卷 671-672页

作者： zhenyu zhang International Center for Quantum Design of Functional Materials (ICQD) Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Centerof Quantum Information and Quantum Physics University of Science and Technology of China Hefei 230026 China

Topologically non-trivial superconductivity,or more succinctly known as chiral superconductivity,is a new property of quantum matter actively chased after by today’s condensed matter community.The motivations for such research efforts are mainly twofold.For one,it is naturally intriguing to integrate superconductivity and topology,respectively among the most fundamental and stimulating concepts in physics and mathematics.For the other,prop-

关键词：超导体拓扑学凝聚态物质物化高温量子计算超导性物理学

Stochastic Joint Replenishment Optimization under Joint Inbound Operational Cost

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Journal of Systems Science and Systems Engineering 2023年第5期32卷 531-552页

作者： Xiaotian Zhuang zhenyu Gao Yuli zhang Qian zhang Shengnan Wu Department of Intelligent Supply Chain JD LogisticsBeijing100076China School of Management and Economics Beijing Institute of TechnologyBeijing100081China Yangtze Delta Region Academy of Beijing Institute of Technology JiaxingZhejiang314019China

With e-commerce concentrating retailers and customers onto one platform,logistics companies(e.g.,JD Logistics)have launched integrated supply chain solutions for corporate customers(e.g.,online retailers)with warehousing,transportation,last-mile delivery,and other value-added services.The platform’s concentration of business flows leads to the consolidation of logistics resources,which allows us to coordinate supply chain operations across different corporate customers.This paper studies the stochastic joint replenishment problem of coordinating multiple suppliers and multiple products to gain the economies of scale of the replenishment setup cost and the warehouse inbound operational cost.To this end,we develop stochastic joint replenishment models based on the general-integer policy(SJRM-GIP)for the multi-supplier and multi-product problems and further reformulate the resulted nonlinear optimization models into equivalent mixed integer second-order conic programs(MISOCPs)when the inbound operational cost takes the square-root form.Then,we propose generalized Benders decomposition(GBD)algorithms to solve the MISOCPs by exploiting the Lagrangian duality,convexity,and submodularity of the sub-problems.To reduce the computational burden of the SJRM-GIP,we further propose an SJRM based on the power-of-two policy and extend the proposed GBD algorithms.Extensive numerical experiments based on practical datasets show that the stochastic joint replenishment across multiple suppliers and multiple products would deliver 13∼20%cost savings compared to the independent replenishment benchmark,and on average the proposed GBD algorithm based on the enhanced gradient cut can achieve more than 90%computational time reduction for large-size problem instances compared to the Gurobi solver.The power-of-two policy is capable of providing high-quality solutions with high computational efficiency.

关键词： Stochastic joint replenishment stochastic demand inbound warehouse cost benders decomposition power-of-two policy

Scientific problems and research proposals for Sichuan–Tibet railway tunnel construction

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Underground Space 2022年第3期7卷 419-439页

作者： Dingli zhang zhenyu Sun Qian Fang Sichuan–Tibet Railway Research Institute Beijing Jiaotong UniversityBeijing 100044China Key Laboratory for Urban Underground Engineering of Ministry of Education Beijing Jiaotong UniversityBeijing 100044China

The Sichuan–Tibet railway construction has received significant attention from both China and abroad.The new section from Ya’an to Nyingchi is about 1018.6 km long,including 69 tunnels with a total length of 841.7 km.The longest tunnel(Yigong tunnel)is 42.4 km long.The successful construction of the Sichuan–Tibet railway depends largely on tunnel construction.Due to the complex conditions,tunnel construction for the Sichuan–Tibet railway poses great challenges to the research community.This paper aims to illustrate the necessity of interdisciplinary and joint research to solve problems associated with tunnel construction that will be encountered in the immediate future and facilitate the communication and exchange of ideas between disciplines.To this end,based on a systematic analysis of the available data related to Sichuan–Tibet railway tunnels,six major aspects of the geology,environment,and engineering conditions are identified.Next,based on the engineering responses from the Sichuan–Tibet railway tunnels,potential technical problems and risk characteristics are predicted and evaluated.Further,six key scientific issues are identified and discussed based on a coupled multi-layer analysis of essential tunnel engineering issues.Finally,research directions,technical ideas,and research methods that should be carried out for this project are proposed.

关键词： Sichuan–Tibet railway tunnels Key scientific problems Complex stress environment Deformation mechanism of surrounding rock Dynamic response