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Energy-Efficient Target Channel Sequence Design for Spectrum Handoffs in Cognitive Radio Networks

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China Communications 2017年第5期14卷 207-217页

作者： xiaolong yang Xuezhi Tan Chongqing Key Lab of Mobile Communications Technology Chongqing University of Posts and TelecommunicationsChongqing 400065China Communication Research Centre.Harbin Institute of Technology Harbin 150080China

Cognitive radio is considered as an efficient way to improve the spectrum efficiency. As one of its key technologies,spectrum handoff can guarantee the transmission continuity of secondary users(SUs). In this paper,we address a new and more generalized spectrum handoff problem in cognitive radio networks(CRNs),by considering simultaneously energy efficiency,multiple spectrum handoffs and multiple channels. Furthermore,effects of the primary users'(PUs')arrival and service rate on the target channel sequence selection are also considered. In order to obtain the energy-efficient target channel sequence,we firstly analyze the energy consumption and the number of delivered bits per hertz in the spectrum handoff process,and formulate a ratio-type energy efficiency optimization problem,which can be transformed into a parametric problem by utilizing fractional programming. Then,we propose an algorithm combining dynamic programming with bisection(DPB)algorithm to solve the energy efficiency optimization problem. Our simulation results verify that the designed target channel sequence has better performance than the existing algorithms in terms of energy efficiency.

关键词： energy efficiency spectrum handoff: fractional programming cognitive radio networks

Estimation for Traffic Arrival Rate and Service Rate of Primary Users in Cognitive Radio Networks

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Journal of Harbin Institute of Technology(New Series) 2015年第5期22卷 61-68页

作者： xiaolong yang Xuezhi Tan Communication Research Center Harbin Institute of Technology

In order to estimate the traffic arrival rate and service rate parameters of primary users in cognitive radio networks,a hidden Markov model estimation algorithm( HMM-EA) is proposed,which can provide better estimation performance than the energy detection estimation algorithm( ED-EA). Firstly,spectrum usage behaviors of primary users are described by establishing a preemptive priority queue model,by which a real state transition probability matrix is derived. Secondly,cooperative detection is utilized to detect the real state of primary users and emission matrix is derived by considering both detection and false alarm probability. Then,a hidden Markov model is built based on the previous two steps,and evaluated through the forward-backward algorithm. Finally,the simulations results verify that the HMM-EA algorithm outperforms the ED-EA in terms of convergence performance,and therefore the secondary user is able to access the unused channel with the least busy probability in real time.

关键词： cognitive radio hidden Markov model cooperative detection

An adaptive path selection model for WSN multipath routing inspired by metabolism behaviors

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Science China(Information Sciences) 2015年第10期58卷 133-147页

作者： GONG WeiBing yang xiaolong ZHANG Min LONG KePing School of Computer & Communication Engineering University of Science and Technology Beijing

In multipath routing of wireless sensor network(WSN), greedy path selection is always prone to cause path oscillation(frequent path changes) between each couple of sensor and sink nodes. To alleviate the side effect, we propose an adaptive path selection model(called a WSN path selection model based on the adaptive response by attractor selection(ARAS) model(WARAS)) inspired by metabolism behaviors of Escherichia *** model consists of two main features. The first one is a new formula for a parameter called path-activity used to indicate adaptation goodness of multipath traffic transmission in dynamic network environments, which is inversely proportional to absolute value of difference between current path quality and best path *** second one is a novel attractor expression for attractors of multi-attractor equations to concretely specify stochastic effect of noise items in the equations on the path selection. Then, in an experimental WSN scenario composed of many source nodes and their shared neighbor nodes, we validate a dynamic-adaptive selection characteristic of the WARAS on distributing loads of the neighbor nodes. Subsequently, we design a path quality probe scheme in a multipath ad hoc on-demand distance vector routing(AODV) protocol. Compared with the greedy path selection through the path quality probe scheme, simulation results show the WARAS can perform better on reducing network delay and the path oscillation.

关键词： WSN multipath path selection metabolism behaviors of Escherichia Coli AODV

Real-Time Facial Pose Estimation and Tracking by Coarse-to-Fine Iterative Optimization

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Tsinghua Science and Technology 2020年第5期25卷 690-700页

作者： xiaolong yang Xiaohong Jia Mengke Yuan Dong-Ming Yan the Key Laboratory of Mathematics Mechanization Academy of Mathematics and Systems SciencesChinese Academy of SciencesBeijing 100190China the University of Chinese Academy of Sciences Beijing 100049China the National Laboratory of Pattern Recognition Institute of AutomationChinese Academy of SciencesBeijing 100190China

We present a novel and efficient method for real-time multiple facial poses estimation and tracking in a single frame or ***,we combine two standard convolutional neural network models for face detection and mean shape learning to generate initial estimations of alignment and ***,we design a bi-objective optimization strategy to iteratively refine the obtained *** strategy achieves faster speed and more accurate ***,we further apply algebraic filtering processing,including Gaussian filter for background removal and extended Kalman filter for target prediction,to maintain real-time tracking *** general RGB photos or videos are required,which are captured by a commodity monocular camera without any priori or *** demonstrate the advantages of our approach by comparing it with the most recent work in terms of performance and accuracy.

关键词： facial pose recognition facial pose estimation real-time tracking

Numerical and experimental study of magnetic fluid seal with large sealing gap and multiple magnetic sources

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Science China(Technological Sciences) 2013年第11期56卷 2865-2869页

作者： yang xiaolong ZHANG ZhiLi LI DeCai School of Mechanical Electronic and Control EngineeringBeijing Jiaotong University

To improve the pressure capability of magnetic fluid seal with more than a 0.25 mm single edge gap,a magnetic fluid sealing structure with multiple magnetic sources which has five permanent magnets was *** field distributions under the pole pieces of the magnetic fluid seal with single and multiple magnetic sources were simulated by finite element method and its sealing pressure difference could be calculated according to the theoretical formula of the magnetic fluid *** effects of sealing gap height and magnetic source amount on the sealing capability were investigated *** theoretical and experimental results were compared,analyzed and *** results demonstrated that the magnetic fluid seal with multiple magnetic sources was an effective method to improve the sealing capability for the rotary shaft with large *** theoretical results agreed well with the experimental results when the height of the single edge gap was equal to 0.4 ***,it was found that when the height of the single edge gap was larger than 0.4 mm,the difference between the theoretical values and experimental values increased with the gap height because part of magnetic source had less or even no effect on magnetic fluid sealing capability.

关键词： experimental study magnetic fluid multiple magnetic sources numerical simulation seals

Microstructure,Properties,and Grain Growth Kinetics of Mo-5Ta Refractory Sputtering Targets Prepared by SPS

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Journal of Wuhan University of Technology(Materials Science) 2023年第6期38卷 1248-1254页

作者： LIU Dawei yang xiaolong HUANG Lei PAN Yafei ZHANG Jiuxing School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China Engineering Research Center of High-Performance Copper Alloy Materials and Processing Ministry of EducationHefei University of TechnologyHefei 230009China

Mo-5Ta targets were prepared by the spark plasma sintering(SPS)technology under the sintering temperatures of 1400-1600℃,the holding times of 0-20 min,and the axial pressure of 30 *** microstructure,performance,and grain growth kinetics of Mo-5Ta sputtering targets were *** the increase of sintering temperatures and times,Ta can more dissolve in Mo and form a Mo(Ta)solid *** grain sizes of Mo-5Ta targets remain unchanged at low temperatures(1400-1500℃)while increasing significantly at high temperature(1600℃)with the extension of the holding *** addition,the densities and Vickers hardness(HV_(0.5))first ascend and then decrease with sintering *** thermal conductivity is positively correlated with the grain size and density,as a result of their joint *** on the comprehensive analysis,the grain growth is dominated by the combination of boundary diffusion and volume *** n=2,the activation energies of grain growth under holding times of 5,10,20 min are calculated as 762.70,617.86,and 616.52 kJ/mol,respectively.

关键词： SPS Mo-5Ta targets structure properties grain growth kinetics

Fabrication and integration of photonic devices for phase-change memory and neuromorphic computing

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International Journal of Extreme Manufacturing 2024年第2期6卷 2-27页

作者： Wen Zhou Xueyang Shen xiaolong yang Jiangjing Wang Wei Zhang Center for Alloy Innovation and Design(CAID) State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049People’s Republic of China

In the past decade,there has been tremendous progress in integrating chalcogenide phase-change materials(PCMs)on the silicon photonic platform for non-volatile memory to neuromorphic in-memory computing *** particular,these non von Neumann computational elements and systems benefit from mass manufacturing of silicon photonic integrated circuits(PICs)on 8-inch wafers using a 130 nm complementary metal-oxide semiconductor *** manufacturing based on deep-ultraviolet lithography and electron-beam lithography enables rapid prototyping of PICs,which can be integrated with high-quality PCMs based on the wafer-scale sputtering technique as a back-end-of-line *** this article,we present an overview of recent advances in waveguide integrated PCM memory cells,functional devices,and neuromorphic systems,with an emphasis on fabrication and integration processes to attain state-of-the-art device *** a short overview of PCM based photonic devices,we discuss the materials properties of the functional layer as well as the progress on the light guiding layer,namely,the silicon and germanium waveguide ***,we discuss the cleanroom fabrication flow of waveguide devices integrated with thin films and nanowires,silicon waveguides and plasmonic microheaters for the electrothermal switching of PCMs and mixed-mode ***,the fabrication of photonic and photonic–electronic neuromorphic computing systems is *** systems consist of arrays of PCM memory elements for associative learning,matrix-vector multiplication,and pattern *** large-scale integration,the neuromorphic photonic computing paradigm holds the promise to outperform digital electronic accelerators by taking the advantages of ultra-high bandwidth,high speed,and energy-efficient operation in running machine learning algorithms.

关键词： nanofabrication silicon photonics phase-change materials non-volatile photonic memory neuromorphic photonic computing

An Adaptive Traffic Distribution Scheme for CMT based on Lotka-Volterra Model in Multihomed Networks

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China Communications 2017年第2期14卷 79-89页

作者： Weibing Gong xiaolong yang Min Zhang Keping Long School of Computer & Communication Engineering University of Science and Technology Beijing China

CMT(concurrent multipath transfer) can increase throughput and transmission efficiency in multihomed networks. However, it is still an important challenge about distributing traffic adaptively into multiple access networks. Based on LV(***) model, we propose an adaptive traffic distribution scheme. In the scheme, two competition modes are concluded, multiple S.D(***) streams competition for bandwidth of one path and multipath competition for traffic between each multihomed S.D host pair. Actually, each access network can establish a path for S.D pairs. So, in the first mode, each path is analogous to a predator, and overall traffic in a multihomed host is analogous to prey. Then, each path has to compete for the traffic by path information, e.g., bandwidth and congestion level. In the other one, if several S.D pairs pass through a shared path simultaneously, they will compete for bandwidth of the path. Here, each S.D pair is analogous to a predator, and the bandwidth of the common path is analogous to the prey. At last, compared with other three schemes, uniform traffic distribution, greedy path selection, random path selection in OPNET simulator, the proposed scheme can perform better onreducing file transmission time and increasing network throughput in FTP service.

关键词： multihomed networks lotka-volterra cmt multipath bio-inspired

Sustainable Investment Forecasting of Power Grids Based on theDeep Restricted Boltzmann Machine Optimized by the Lion Algorithm

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Computer Modeling in Engineering & Sciences 2022年第1期130卷 269-286页

作者： Qian Wang xiaolong yang Di Pu Yingying Fan School of Economics andManagement Jilin Institute of Chemical TechnologyJilin132022China School of Economics andManagement Northeast Electric Power UniversityJilin132012China Digital Grid Research Institute China Southern Power GridGuangzhou510000China School of Art Hebei GEO UniversityShijiazhuang050031China

This paper proposes a new power grid investment prediction model based on the deep restricted Boltzmann machine(DRBM)optimized by the Lion algorithm(LA).Firstly,two factors including transmission and distribution price reform(TDPR)and 5G station construction were comprehensively incorporated into the consideration of influencing factors,and the fuzzy threshold method was used to screen out critical influencing ***,the LA was used to optimize the parameters of the DRBM model to improve the model’s prediction accuracy,and the model was trained with the selected influencing factors and ***,the LA-DRBM model was used to predict the investment of a power grid enterprise,and the final prediction result was obtained by modifying the initial result with the modifying *** LA-DRBMmodel compensates for the deficiency of the singlemodel,and greatly improves the investment prediction accuracy of the power *** this study,a power grid enterprise was taken as an example to carry out an empirical analysis to prove the validity of the model,and a comparison with the RBM,support vector machine(SVM),back propagation neural network(BPNN),and regression model was conducted to verify the superiority of the *** conclusion indicates that the proposed model has a strong generalization ability and good robustness,is able to abstract the combination of low-level features into high-level features,and can improve the efficiency of the model’s calculations for investment prediction of power grid enterprises.

关键词： Lion algorithm deep restricted boltzmann machine fuzzy threshold method power grid investment forecasting