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Set pair three-way overlapping community discovery algorithm for weighted social internet of things

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Digital Communications and Networks 2023年第1期9卷 3-13页

作者： Chunying Zhang Jing Ren Lu liu Shouyue liu Xiaoqi Li liya Wang College of Science North China University of Science and TechnologyTangshanHebeiChina Hebei Engineering Research Center for the Intelligentization of Iron Ore Optimization and Ironmaking Raw Materials Preparation Processes North China University of Science and TechnologyTangshanHebeiChina Hebei Key Laboratory of Data Science and Application North China University of Science and TechnologyTangshanHebeiChina The Key Laboratory of Engineering Computing in Tangshan City North China University of Science and TechnologyTangshanHebeiChina Tangshan Intelligent Industry and Image Processing Technology Innovation Center North China University of Science and TechnologyTangshanHebeiChina

There are many problems in Social Internet of Things(IoTs),such as complex topology information,different degree of association between nodes and overlapping communities.The idea of set pair information grain computing and clustering is introduced to solve the above problems so as to accurately describe the similarity between nodes and fully explore the multi-community structure.A Set Pair Three-Way Overlapping Community Discovery Algorithm for Weighted Social Internet of Things(WSIoT-SPTOCD)is proposed.In the local network structure,which fully considers the topological information between nodes,the set pair connection degree is used to analyze the identity,difference and reverse of neighbor nodes.The similarity degree of different neighbor nodes is defined from network edge weight and node degree,and the similarity measurement method of set pair between nodes based on the local information structure is proposed.According to the number of nodes'neighbors and the connection degree of adjacent edges,the clustering intensity of nodes is defined,and an improved algorithm for initial value selection of k-means is proposed.The nodes are allocated according to the set pair similarity between nodes and different communities.Three-way community structures composed of a positive domain,boundary domain and negative domain are generated iteratively.Next,the overlapping node set is generated according to the calculation results of community node membership.Finally,experiments are carried out on artificial networks and real networks.The results show that WSIoT-SPTOCD performs well in terms of standardized mutual information,overlapping community modularity and F1.

关键词： Social internet of things Set pair analysis K-means Local information structure Overlapping community

Low-cost all-iron flow battery with high performance towards long-duration energy storage

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Journal of Energy Chemistry 2022年第10期31卷 445-451,I0011页

作者： Xiaoqi Liu Tianyu li Zhizhang Yuan Xianfeng li Division of Energy Storage Dalian National Laboratory for Clean EnergyDalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023LiaoningChina University of Chinese Academy of Sciences Beijing 100049China

Long duration energy storage(LDES)technologies are vital for wide utilization of renewable energy sources and increasing the penetration of these technologies within energy infrastructures.Herein,we propose a low-cost alkaline all-iron flow battery by coupling ferri/ferro-cyanide redox couple with ferric/ferrous-gluconate complexes redox couple.The designed all-iron flow battery demonstrates a coulombic efficiency of above 99%and an energy efficiency of~83%at a current density of80 m A cm^(-2),which can continuously run for more than 950 cycles.Most importantly,the battery demonstrates a coulombic efficiency of more than 99.0%and an energy efficiency of~83%for a long duration(~12,16 and 20 h per cycle)charge/discharge process.Benefiting from the low cost of iron electrolytes,the overall cost of the all-iron flow battery system can be reached as low as$76.11 per k Wh based on a10 h system with a power of 9.9 k W.This work provides a new option for next-generation cost-effective flow batteries for long duration large scale energy storage.

关键词： Long-duration energy storage All-iron flow battery Iron-based complexes High performance Gluconate

Tensile properties of a composite–metal single-lap hybrid bonded/bolted joint

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Chinese Journal of Aeronautics 2021年第2期34卷 629-640页

作者： Xiaoqi Li Xiaoquan CHENG Yujia CHENG Zhiyong WANG Wenjun HUANG School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Istar-space Technology Co. Ltd.Tianjin 300304China AVIC China Helicopter Research ami Development Institute Jingdezhen 333001China

Hybrid bonded/bolted(HBB) joint has been widely used in engineering practice because it can overcome the potential weakness of pure bonded and pure bolted joints. However, studies on HBB joint are still at the initial stage. In this paper, tensile properties of a composite–metal singlelap HBB joint was investigated experimentally. And a detailed finite element model(FEM) was established to simulate the tensile behavior of the joint. The model was verified by the experimental results. Then the damage propagation and load transfer mechanism were explored based on the FEM. The results show that the HBB joint can provide multi-load transmission paths and resist damage propagation in the adhesive. The HBB joint has higher strength and energy absorption capacity than the pure bonded joint. And the HBB joint has greater initial damage load and tensile stiffness than pure bolted joint. Adhesive fillets can obviously improve the tensile performances of the HBB joint. Lateral stiffness of the joint boundary and testing machine show obvious effects on tensile performances of single-lap hybrid joints.

关键词： Experimental tests Failure mechanism Finite element model Hybrid(bonded/bolted)joint Tensile properties

Integral Real-time Locomotion Mode Recognition Based on GA-CNN for Lower limb Exoskeleton

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Journal of Bionic Engineering 2022年第5期19卷 1359-1373页

作者： Jiaqi Wang Dongmei Wu Yongzhuo Gao Xinrui Wang Xiaoqi Li Guoqiang Xu Wei Dong State Key Laboratory of Robotics and System Harbin Institute of TechnologyHarbin 150001China Weapon Equipment Research Institute China South Industries Group CorporationBeijing 102202China

The wearable lower limb exoskeleton is a typical human-in-loop human–robot coupled system,which conducts natural and close cooperation with the human by recognizing human locomotion timely.Requiring subject-specific training is the main challenge of the existing approaches,and most methods have the problem of insufficient recognition.This paper proposes an integral subject-adaptive real-time Locomotion Mode Recognition(LMR)method based on GA-CNN for a lower limb exoskeleton system.The LMR method is a combination of Convolutional Neural Networks(CNN)and Genetic Algorithm(GA)-based multi-sensor information selection.To improve network performance,the hyper-parameters are optimized by Bayesian optimization.An exoskeleton prototype system with multi-type sensors and novel sensing-shoes is used to verify the proposed method.Twelve locomotion modes,which composed an integral locomotion system for the daily application of the exoskeleton,can be recognized by the proposed method.According to a series of experiments,the recognizer shows strong comprehensive abilities including high accuracy,low delay,and sufficient adaption to different subjects.

关键词： Locomotion mode recognition Gait mode detection Lower limb exoskeleton Convolutional neural network Genetic algorithm Bionic design

Stable Transition of Quadruped Rhythmic Motion Using the Tracking Differentiator

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Journal of Harbin Institute of Technology(New Series) 2015年第5期22卷 9-16页

作者： Xiaoqi Li Wei Wang Jianqiang Yi Institute of Automation Chinese Academy of Sciences

Since the quadruped robot possesses predominant environmental adaptability,it is expected to be employed in nature environments. In some situations,such as ice surface and tight space,the quadruped robot is required to lower the height of center of gravity( COG) to enhance the stability and maneuverability. To properly handle these situations,a quadruped controller based on the central pattern generator( CPG) model,the discrete tracking differentiator( TD) and proportional-derivative( PD) sub-controllers is presented. The CPG is used to generate basic rhythmic motion for the quadruped robot. The discrete TD is not only creatively employed to implement the transition between two different rhythmic medium values of the CPG which results in the adjustment of the height of COG of the quadruped robot,but also modified to control the transition duration which enables the quadruped robot to achieve the stable transition. Additionally,two specific PD sub-controllers are constructed to adjust the oscillation amplitude of the CPG,so as to avoid the severe deviation in the transverse direction during transition locomotion. Finally,the controller is validated on a quadruped model. A tunnel with variable height is built for the quadruped model to travel through. The simulation demonstrates the severe deviation without the PD sub-controllers,and the reduced deviation with the PD sub-controllers.

关键词： quadruped robot center of gravity central pattern generator discrete tracking differentiator proportional-derivative sub-controller

Source and distribution of mercury in natural gas of major petroliferous basins in China

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Science China Earth Sciences 2020年第5期63卷 643-648页

作者： Quanyou liU Weilong PENG Jian li xiaoqi WU State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development Beijing 100083China Research Institute of Petroleum Exploration and Production SINOPECBeijing 100083China Research Institute of Petroleum Exploration and Development PetroChinaBeijing 100083China Research Center of Exploration and Development in Sichuan Basin Research Institute of Petroleum Exploration and ProductionSINOPECChengdu 610041China

Based on the analysis of the natural gas samples of 146 wells from four major petroliferous basins of China,the source and distribution of mercury in natural gas in major petroliferous basins of China were identified.Studies have shown that the mercury concentration of natural gas in petroliferous basins of China varies widely,ranging from 0.01 to 4050μg/m^3.The gas well with the highest mercury concentration is in the Xushen gas field in the Songliao Basin.The mercury concentration in the craton basin is relatively low,and the secondary gas reservoir in the Tarim Basin has the lowest mercury concentration.In the rift basin,due to the presence of deep faults which cut the basement and mixing effects of deep fluids,the mercury concentration in natural gas may be abnormally high,e.***.the Xushen gas field in the Songliao Basin.In relatively stable basins where deep and large faults do not develop,mercury is primarily of organic origin.In rift basins where deep fluids are mixed with gas reservoirs,mercury in natural gas may mainly come from the deep fluids and is characterized by abnormally high mercury concentration and R/Ra values.

关键词： Natural gas Mercury concentration Petroliferous basin Xushen gas field Deep fluids

Spatial-Spectral Joint Network for Cholangiocarcinoma Microscopic Hyperspectral Image Classification

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Journal of Beijing Institute of Technology 2023年第5期32卷 586-599页

作者： xiaoqi Huang Xueyu Zhang Mengmeng Zhang Meng Lyu Wei li School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China

Accurate histopathology classification is a crucial factor in the diagnosis and treatment of Cholangiocarcinoma(CCA).Hyperspectral images(HSI)provide rich spectral information than ordinary RGB images,making them more useful for medical diagnosis.The Convolutional Neural Network(CNN)is commonly employed in hyperspectral image classification due to its remarkable capacity for feature extraction and image classification.However,many existing CNN-based HSI classification methods tend to ignore the importance of image spatial context information and the interdependence between spectral channels,leading to unsatisfied classification performance.Thus,to address these issues,this paper proposes a Spatial-Spectral Joint Network(SSJN)model for hyperspectral image classification that utilizes spatial self-attention and spectral feature extraction.The SSJN model is derived from the ResNet18 network and implemented with the non-local and Coordinate Attention(CA)modules,which extract long-range dependencies on image space and enhance spatial features through the Branch Attention(BA)module to emphasize the region of interest.Furthermore,the SSJN model employs Conv-LSTM modules to extract long-range depen-dencies in the image spectral domain.This addresses the gradient disappearance/explosion phenom-ena and enhances the model classification accuracy.The experimental results show that the pro-posed SSJN model is more efficient in leveraging the spatial and spectral information of hyperspec-tral images on multidimensional microspectral datasets of CCA,leading to higher classification accuracy,and may have useful references for medical diagnosis of CCA.

关键词： self-attention microscopic hyperspectral images image classification Conv-LSTM

Clinical features and risk factors for viral pneumonia complicated with invasive pulmonary aspergillosis in adult patients

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Chinese Medical Journal 2023年第11期136卷 1361-1363页

作者： lijuan li Chuan Wang Yali Ren Jiangbo liu Feifei liu xiaoqi Zhang Department of Pulmonary and Critical Care Medicine National Centre for Clinical Research on Respiratory DiseasesChina-Japan Friendship HospitalBeijing 100029China Department of Pulmonary and Critical Care Medicine First Hospital of ShijiazhuangShijiazhuangHebei 050011China Department of Pulmonary and Critical Care Medicine Second Hospital of Hebei Medical UniversityShijiazhuangHebei 050000China Department of Pulmonary and Critical Care Medicine Tianjin First Central HospitalTianjin 300192China Department of Respiratory and Critical Care Medicine First Hospital of Qin Huang DaoQinhuangdaoHebei 066000China Department of Pulmonary and Critical Care Medicine Second People’s Hospital of WeifangWeifangShandong 261041China

Viral pneumonia has recently been defined as a risk factor for invasive pulmonary aspergillosis(IPA).Wauters et al[1]reported that 23%of critically ill patients who were admitted to the intensive care unit(ICU)with swine-origin influenza A(H1N1)viral infection had developed invasive aspergillosis.IPA was diagnosed in 83 of 432(19%)patients who were admitted with influenza;for patients with influenza who were immunocompromised,the incidence of IPA reached up to 32%(38 of 117 patients).

关键词： patients admitted pneumonia

An Algorithm Based on Markov Chain to Improve Edge Cache Hit Ratio for Blockchain-Enabled IoT

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China Communications 2020年第9期17卷 66-76页

作者： Hongman Wang Yingxue li xiaoqi Zhao Fangchun Yang Institute of Network Technology Beijing University of Posts and TelecommunicationsBeijing 100876China Engineering Research Center of Information Network Ministry of EducationBeijing 100876China

Reasonable allocation of storage and computing resources is the basis of building big data system.With the development of IoT(Internet of Things),more data will be brought.A three-layer architecture includes smart devices layer,edge cloud layer and blockchain-based distributed cloud layer.Blockchain is used in IoT for building a distributed decentralize P2P architecture to deal with the secure issue while edge computing deals with increasing volume of data.Edge caching is one of the important application scenarios.In order to allocate edge cache resources reasonably,to improve the quality of service and to reduce the waste of bandwidth resources,this paper proposes a content selection algorithm of edge cache nodes.The algorithm adopts markov chain model,improves the utilization of cache space and reduces the content transmission delay.The hierarchical caching strategy is adopted and the secondary cache stores slides of contents to expand the coverage of cached content and to reduce user waiting time.Regional node cooperation is adopted to expand the cache space and to support the regional preference of cache content.Compared with the classical substitution algorithm,simulation results show that the algorithm in this paper has higher cache hit ratio and higher space utilization.

关键词： cache resource allocation blockchain-enabled iot edge computing Markov chain hierarchical caching technique