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Distributed Game-Theoretical D2D-Enabled Task Offloading in Mobile Edge Computing

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Journal of Computer Science & Technology 2022年第4期37卷 919-941页

作者： En Wang Han Wang Peng-Min Dong yuan-bo xu Yong-Jian Yang Department of Computer Science and Technology Jilin UniversityChangchun 130012China Department of Software Jilin UniversityChangchun 130012China

Mobile Edge Computing(MEC)has been envisioned as a promising distributed computing paradigm where mobile users offload their tasks to edge nodes to decrease the cost of energy and ***,most of the existing studies only consider the congestion of wireless channels as a crucial factor affecting the strategy-making process,while ignoring the impact of offloading among edge *** addition,centralized task offloading strategies result in enormous computation complexity in center *** this line,we take both the congestion of wireless channels and the offloading among multiple edge nodes into consideration to enrich users'offloading strategies and propose the Parallel User Selection Algorithm(PUS)and Single User Selection Algorithm(SUS)to substantially accelerate the *** practically,we extend the users'offloading strategies to take into account idle devices and cloud services,which considers the potential computing resources at the ***,we construct a potential game in which each user selfishly seeks an optimal strategy to minimize its cost of latency and energy based on acceptable latency,and find the potential function to prove the existence of Nash equilibrium(NE).Additionally,we update PUS to accelerate its convergence and illustrate its performance through the experimental results of three real datasets,and the updated PUS effectively decreases the total cost and reaches Nash equilibrium.

关键词： computation offloading potential game Nash equilibrium device-to-device(D2D) acceptable latency

Variational quantum algorithms for scanning the complex spectrum of non-Hermitian systems

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Frontiers of physics 2024年第4期19卷 275-285页

作者： xu-Dan Xie Zheng-yuan xue Dan-bo Zhang Key Laboratory of Atomic and Subatomic Structure and Quantum Control(Ministry of Education) Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matterand School of PhysicsSouth China Normal UniversityGuangzhou 510006China Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials Guangdong–Hong Kong Joint Laboratory of Quantum Matterand Frontier Research Institute for PhysicsSouth China Normal UniversityGuangzhou 510006China

Solving non-Hermitian quantum many-body systems on a quantum computer by minimizing the variational energy is challenging as the energy can be ***,we propose a variational quantum algorithm for solving the non-Hermitian Hamiltonian by minimizing a type of energy variance,where zero variance can naturally determine the eigenvalues and the associated left and right ***,the energy is set as a parameter in the cost function and can be tuned to scan the whole spectrum efficiently by using a two-step optimization *** numerical simulations,we demonstrate the algorithm for preparing the left and right eigenstates,verifying the biorthogonal relations,as well as evaluating the *** also investigate the impact of quantum noise on our algorithm and show that its performance can be largely improved using error mitigation ***,our work suggests an avenue for solving non-Hermitian quantum many-body systems with variational quantum algorithms on near-term noisy quantum computers.

关键词： quantum algorithm non-Hermitian physics quantum manybody systems

Retrieval-and-alignment based large-scale indoor point cloud semantic segmentation

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Science China(Information Sciences) 2024年第4期67卷 164-180页

作者： Zongyi xu Xiaoshui HUANG bo yuan Yangfu WANG Qianni ZHANG Weisheng LI Xinbo GAO School of Computer Science and Technology Chongqing University of Posts and Telecommunications Shanghai Artificial Intelligence Laboratory School of Electronic Engineering and Computer Science Queen Mary University of London

Current methods for point cloud semantic segmentation depend on the extraction of descriptive features. However, unlike images, point clouds are irregular and often lack texture information, making it demanding to extract discriminative features. In addition, noise, outliers, and uneven point distribution are commonly present in point clouds, which further complicates the segmentation task. To address these problems, a novel architecture is proposed for direct and accurate large-scale point cloud segmentation based on point cloud retrieval and alignment. The proposed approach involves using a feature-based point cloud retrieval method for searching for reference point clouds with annotations from a dataset. In the following segmentation stage, an overlap-based point cloud registration method has been developed to align the target and reference point clouds. For accurate and robust alignment, an overlap region estimation module is trained to locate the optimal overlap region between two pieces of point clouds in a coarse-to-fine manner. In the detected overlap region, the global and local features of the points are extracted and combined for featuremetric registration to obtain accurate transformation parameters between the target and reference point clouds. After alignment, the annotated segmentation of the reference is transferred to the target point clouds to obtain accurate segmentation results. Extensive experiments are conducted to show that the developed method outperforms the state-of-the-art approaches in terms of both accuracy and robustness against noise and outliers.

关键词： point cloud semantic segmentation large-scale indoor point clouds point cloud alignment overlap estimation label transfer

Gluing Affine Vortices

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Acta Mathematica Sinica,English Series 2024年第1期40卷 250-312页

作者： Guang bo xu Department of Mathematics Rutgers UniversityHill Center-Busch Campus 110 Frelinghuysen RoadPiscatawayNJ 08854-8019USA

We provide an analytical construction of the gluing map for stable affine vortices over the upper half plane with the Lagrangian boundary *** result is a necessary ingredient in studies of the relation between gauged ... 详细信息

关键词： Affine vortices gauged linear sigma model adiabatic limit symplectic reduction

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Design and high-power testing of offline conditioning cavity for CiADS RFQ high-power coupler

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Nuclear Science and Techniques 2024年第9期35卷 18-27页

作者： Ruo-xu Wang yuan He Long-bo Shi Chen-Xing Li Zong-Heng xue Tian-Cai Jiang Xian-bo xu Lie-Peng Sun Zhou-Li Zhang Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Lanzhou University Lanzhou 730000China

To validate the design rationality of the power coupler for the RFQ cavity and minimize cavity contamination,we designed a low-loss offline conditioning cavity and conducted high-power *** offline cavity features two coupling ports and two tuners,operating at a frequency of 162.5 MHz with a tuning range of 3.2 *** the installation angle of the coupling ring and the insertion depth of the tuner helps minimize cavity *** performed electromagnetic structural and multiphysics simulations,revealing a minimal theoretical power loss of 4.3%.However,when the cavity frequency varied by110 kHz,theoretical power losses increased to10%,necessitating constant tuner adjustments during *** simulations indicated that increased cavity temperature did not affect frequency *** completion of the offline high-power conditioning platform,we measured the transmission performance,revealing a power loss of 6.3%,exceeding the theoretical *** utilized efficient automatic range scanning and standing wave resonant *** fully condition the power coupler,a 15°phase difference between two standing wave points in the condition-ing system was ***,the maximum continuous wave power surpassed 20 kW,exceeding the expected target.

关键词： RFQ cavity Power coupler Offline conditioning Resonant cavity

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boosting oxygen reduction activity and CO_(2) resistance on bismuth ferrite-based perovskite cathode for low-temperature solid oxide fuel cells below 600℃

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Journal of Energy Chemistry 2024年第3期90卷 600-609,I0013页

作者： Juntao Gao Zhiyun Wei Mengke yuan Zhe Wang Zhe Lü Qiang Li Lingling xu bo Wei School of Physics Harbin Institute of TechnologyHarbin 150001HeilongjiangChina Key Laboratory of Functional Inorganic Material Chemistry Ministry of EducationSchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin 150080HeilongjiangChina School of Physics and Electronic Engineering Harbin Normal UniversityHarbin 150025HeilongjiangChina

Developing efficient and stable cathodes for low-temperature solid oxide fuel cells(LT-SOFCs) is of great importance for the practical ***,we propose a series of Sm-modified Bi_(0.7-x)Sm_xSr_(0.3)FeO_(3-δ) perovskites as highly-active catalysts for *** doping can significantly enhance the electrocata lytic activity and chemical stability of *** 600℃,Bi_(0.675)Sm_(0.025)Sr_(0.3)FeO_(3-δ)(BSSF25) cathode has been found to be the optimum composition with a polarization resistance of 0.098 Ω cm^2,which is only around 22.8% of Bi_(0.7)Sr_(0.3)FeO_(3-δ)(BSF).A full cell utilizing BSSF25 displays an exceptional output density of 790 mW cm^(-2),which can operate continuously over100 h without obvious *** remarkable electrochemical performance observed can be attributed to the improved O_(2) transport kinetics,superior surface oxygen adsorption capacity,as well as O_(2)p band centers in close proximity to the Fermi ***,larger average bonding energy(ABE) and the presence of highly acidic Bi,Sm,and Fe ions restrict the adsorption of CO_(2) on the cathode surface,resulting in excellent CO_(2) *** work provides valuable guidance for systematic design of efficient and durable catalysts for LT-SOFCs.

关键词： Low-temperature solid oxide fuel cell Perovskite cathode DFT calculations CO_(2) tolerance

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Toward tunable shape memory effect of NiTi alloy by grain size engineering:A phase field study

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Journal of Materials Science & Technology 2024年第1期168卷 276-289页

作者： bo xu Chong Wang Qingyuan Wang Failure Mechanics and Engineering Disaster Prevention Key Laboratory of Sichuan ProvinceSichuan UniversityChengdu 610065China Department of Mechanical Science and Engineering College of Architecture and EnvironmentSichuan UniversityChengdu 610065China Key Laboratory of Deep Underground Science and Engineering (Sichuan University)Ministry of EducationChengdu 610065China

The inelastic deformations of shape memory alloys(SMAs)always show poor controllability due to the avalanche-like martensite transformation,and the effective control for the deformation of precision de-vices has been not yet *** this work,the phase field method was used to investigate the shape memory effects(SMEs)of NiTi SMAs undergoing grain size(GS)engineering,to obtain tunable one-way and stress-assisted two-way SMEs(OWSME and SATWSME).The OWSME and SATWSME of the systems with various gradient-nanograin structures and bimodal grain structure,as well as that with geometric gradients were *** simulated results indicate that due to the GS dependences of martensite transformation and reorientation,the occurrence and expansion of martensite reorientation,martensite transformation and its reverse can be efficaciously controlled via the GS *** combining the GS engineering and geometric gradient design,since the effects of GS and stress gradient can be su-perimposed or competing,and the responses of martensite reorientation,martensite transformation and its reverse to this are different,the OWSME and SATWSME of the geometrically graded systems with various nanograin structures can exhibit different improvements in *** short,the reorienta-tion hardening modulus during OWSME is increased and the transformation temperature window during SATWSME is widened by GS engineering,indicating the improved controllability of *** optimal GS engineering schemes revealed in this work provide the basic reference and guidance for designing tun-able SMEs and producing NiTi-based driving devices catering to desired functional performance in various engineering fields.

关键词： Phase field NiTi Shape memory effect Grain size engineering Geometric gradient

An Accelerated Stochastic Mirror Descent Method

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Journal of the Operations Research Society of China 2024年第3期12卷 549-571页

作者： bo-Ou Jiang Ya-Xiang yuan LSEC ICMSECAMSSChinese Academy of SciencesBeijing100190China Department of Mathematics University of Chinese Academy of SciencesBeijing100049China

Driven by large-scale optimization problems arising from machine learning,the development of stochastic optimization methods has witnessed a huge *** types of methods have been developed based on vanilla stochastic gradient descent ***,for most algorithms,convergence rate in stochastic setting cannot simply match that in deterministic *** understanding the gap between deterministic and stochastic optimization is the main goal of this ***,we are interested in Nesterov acceleration of gradient-based *** our study,we focus on acceleration of stochastic mirror descent method with implicit regularization *** that the problem objective is smooth and convex or strongly convex,our analysis prescribes the method parameters which ensure fast convergence of the estimation error and satisfied numerical performance.

关键词： Large-scale optimization Variance reduction Mirror descent Acceleration Independent sampling Importance sampling

Tunable single emitter-cavity coupling strength through waveguide-assisted energy quantum transfer

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Light(Science & Applications) 2024年第9期13卷 1779-1788页

作者： yuan Liu Hongwei Zhou Linhan Lin Hong-bo Sun Department of Precision Instrument State Key Laboratory of Precision Measurement Technology and InstrumentsTsinghua UniversityBeijing 100084China State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin UniversityChangchun 130012China

The emitter-cavity strong coupling manifests crucial significance for exploiting quantum technology,especially in the scale of individual ***,due to the small light-matter interaction cross-section,the single emitter-cavity strong coupling has been limited by its harsh requirement on the quality factor of the cavity and the local density of optical ***,we present a strategy termed waveguide-assisted energy quantum transfer(WEQT)to improve the single emitter-cavity coupling strength by extending the interaction *** ancillary emitters are optically linked by a waveguide,providing an indirect coupling channel to transfer the energy quantum between target emitter and *** enhancement factor of coupling strength eg=g>10 can be easily achieved,which dramatically release the rigorous design of *** an extension of concept,we further show that the ancillae can be used as controlling bits for a photon gate,opening up new degrees of freedom in quantum manipulation.

关键词： quantum coupling transfer