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A new 3D plastoelastohydrodynamic lubrication model for rough surfaces

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Friction 2024年第6期12卷 1176-1193页

作者： Shengyu YOU Jinyuan TANG Qiang WANG State Key Laboratory of Precision Manufacturing for Extreme service Performance Central South UniversityChangsha 410083China

Plastoelastohydrodynamic lubrication of rough surfaces(R-PEHL)is a cutting-edge area of research in interface fluid-structure coupling *** existing R-PEHL model calculates the elastic-plastic deformation of rough surface by the Love equation in a semi-infinite space smooth surface,which deviates from the actual ***,it is an innovative work to study the exact solution of elastic-plastic deformation of rough surface and its influence on the solution results of R-PEHL *** this paper,a new contact calculation model of plastoelastohydrodynamic lubrication(PEHL)with three-dimensional(3D)rough surface is proposed by integrating numerical method of EHL and finite element *** new model eliminates an original error introduced by the assumption of semi-infinite space in contact calculation,providing wide applicability and high *** the given rough surfaces and working conditions,the study reveals that:(1)the oil film pressure calculated by the new model is lower than that of the smooth surface in semi-infinite space by 200–800 MPa;(2)the Mises stress of the new model is 2.5%–26.6%higher than that of the smooth surface in semi-infinite space;(3)compared with the semi-infinite space assumption,the rough surface plastic deformation of the new model is increased by 71%–173%,and the local plastic deformation singularity may appear under the semi-infinite space assumption;(4)the plastic deformation caused by the first contact cycle on the rough surface of the new model accounts for 66.7%–92.9%of the total plastic deformation,and the plastic deformation of the semi-infinite space accounts for 50%–83.3%.This study resolves the contradiction between the smooth surface assumption and the rough surface in the existing R-PEHL model,establishing a solid logic foundation for the accurate solution of R-PEHL model.

关键词： rough surface plastoelastohydrodynamic lubrication(PEHL) asperity plastic deformation semi-infinite space

Neutrophil-to-lymphocyte ratio associated with renal function in type 2 diabetic patients

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World Journal of Clinical Cases 2024年第14期12卷 2308-2315页

作者： Jin-Li Gao Jue Shen Li-Ping Yang Li Liu Kai Zhao Xiao-Rong Pan Lei Li Ji-Ji Xu Department of Prevention and Health Care Community Health Service Center of Miaohang TownShanghai 200443China Department of Prevention and Health Care Community Health Service Center of Songnan TownShanghai 200434China Department of General Practice Community Health Service Center of Songnan TownShanghai 200434China Department of Administrative Community Health Service Center of Songnan TownShanghai 200434China

BACKGROUND Type 2 diabetes mellitus(T2DM)is a leading risk factor for the development and progression of chronic kidney disease(CKD).However,an accurate and con-venient marker for early detection and appropriate management of CKD in in-dividuals with T2DM is *** studies have demonstrated a strong correlation between the neutrophil-to-lymphocyte ratio(NLR)and ***-theless,the predictive value of NLR for renal damage in type 2 diabetic patients remains *** study included 1040 adults aged 65 or older with T2DM from Shanghai's Community Health service *** total number of neutrophils and lym-phocytes was detected,and NLR levels were *** was defined as an estimated glomerular filtration rate≤60 mL/min/1.73 m².Participants were di-vided into four groups based on NLR *** clinical data and biochemical characteristics were compared among groups.A multivariate logistic regression model was used to analyze the association between NLR levels and *** Significant differences were found in terms of sex,serum creatinine,blood urea nitrogen,total cholesterol,and low-density lipoprotein cholesterol among patients with T2DM in different NLR groups(P<0.0007).T2DM patients in the highest NLR quartile had a higher prevalence of CKD(P for trend=0.0011).Multivariate logistic regression analysis indicated that a high NLR was an independent risk factor for CKD in T2DM patients even after adjustment for important clinical and pathological parameters(P=0.0001,odds ratio=1.41,95%confidence intervals:1.18-1.68).CONCLUSION An elevated NLR in patients with T2DM is associated with higher prevalence of CKD,suggesting that it could be a marker for the detection and evaluation of diabetic kidney disease.

关键词： Type 2 diabetes mellitus Neutrophil-to-lymphocyte ratio Chronic kidney disease Logistic regression Diabetes mellitus

Analysis of a Typical Case of Meteorological service in Tangpu Reservoir

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Meteorological and Environmental Research 2024年第2期15卷 44-47页

作者： Quan SHAN Yuxin DING Tingting GU Jinxin WANG Kai TANG Zhejiang Meteorological service Center Hangzhou 310017China

The continuous rainy precipitation process from February to March in 2019 was selected to analyze the effect of meteorological service in Tangpu Reservoir basin,so as to sum up service experience and then lay a better foundation for subsequent *** response to the rainy weather from December 2018 to early 2019,three rounds of flood discharge were carried out in Tangpu *** February-March in 2019,the hit rate of short-term area rainfall forecast for Tangpu Reservoir was 80.0%.Compared with the median of forecast interval,the average absolute error was 7.6 mm,and the relative error was 32.7%.The large deviation in the forecast from March 27 to 28 was deeply analyzed,and it is found that the main reasons were excessive reliance on and trust in a single model,insufficient correction of the actual situation,and insufficient judgment of the nature of *** the future reservoir meteorological service,three aspects of thinking were put forward,such as further strengthening the sharing of hydrological and meteorological information,improving the forecasting ability,and deepening the research of runoff forecast models.

关键词： Tangpu Reservoir Meteorological service Continuous rain Analysis of a typical case

A Cloud-Fog Enabled and Privacy-Preserving IoT Data Market Platform Based on Blockchain

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Computer Modeling in Engineering & Sciences 2024年第5期139卷 2237-2260页

作者： Yurong Luo Wei You Chao Shang Xiongpeng Ren Jin Cao Hui Li School of Cyber Engineering State Key Laboratory of Integrated Service NetworkXidian UniversityXi’an710126China

The dynamic landscape of the Internet of Things(IoT)is set to revolutionize the pace of interaction among entities,ushering in a proliferation of applications characterized by heightened quality and *** the pivotal applications within the realm of IoT,as a significant example,the Smart Grid(SG)evolves into intricate networks of energy deployment marked by data *** evolution concurrently entails data interchange with other IoT ***,there are also several challenges including data-sharing overheads and the intricate establishment of trusted centers in the IoT *** this paper,we introduce a hierarchical secure data-sharing platform empowered by cloud-fog ***,we propose a novel non-interactive zero-knowledge proof-based group authentication and key agreement protocol that supports one-to-many sharing sets of IoT data,especially SG *** security formal verification tool shows that the proposed scheme can achieve mutual authentication and secure data sharing while protecting the privacy of data *** with previous IoT data sharing schemes,the proposed scheme has advantages in both computational and transmission efficiency,and has more superiority with the increasing volume of shared data or increasing number of participants.

关键词： IoT data sharing zero-knowledge proof authentication privacy preserving blockchain

Conversion of a single-layer ANN to photonic SNN for pattern recognition

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Science China(Information Sciences) 2024年第1期67卷 261-270页

作者： Yanan HAN Shuiying XIANG Tianrui ZHANG Yahui ZHANG Xingxing GUO Yuechun SHI State Key Laboratory of Integrated service Networks State Key Discipline Laboratory of Wide Bandgap Semiconductor TechnologyXidian University Yongjiang Laboratory

This work presents a complete conversion scheme for photonic spiking neural networks(SNNs).We verified that the output of an artificial neural network(ANN) trained with the simulated optical activation function can be directly converted into the spike rate of a photonic spiking neuron *** reveal the feasibility of hardware implementation,we considered the effects of different bit precisions of data and weight,noise level,and bias current mismatch on the converted *** proposed scheme was evaluated using the Deterding vowel,IRIS,TIDIGITS,and MNIST datasets for pattern recognition,and achieved mean accuracies of 95.80%,98.67%,96.19%,and 92.33%,*** proposed scheme can convert an ANN into a photonic SNN with almost no precision loss,and the performance was comparable to that of an ANN trained with the rectified linear unit *** proposed scheme can enable the high-performance implementation of photonic SNNs.

关键词： photonic SNN conversion optical computing pattern recognition artificial neural network

Biomimetic soft robotic wrist with 3-DOF motion and stiffness tunability based on ring-reinforced pneumatic actuators and a particle jamming joint

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Science China(Technological Sciences) 2024年第3期67卷 774-790页

作者： HU TeTe LU XinJiang YI Jian WANG YuHui XU Du State Key Laboratory of Precision Manufacturing for Extreme service Performance School of Mechanical and Electrical EngineeringCentral South UniversityChangsha 410083China

The human wrist, a complex articulation of skeletal muscles and two-carpal rows, substantially contributes to improvements in maneuverability by agilely performing three-degree-of-freedom(3-DOF) orienting tasks and regulating stiffness according to variations in interaction forces. However, few soft robotic wrists simultaneously demonstrate dexterous 3-DOF motion and variable stiffness;in addition, they do not fully consider a soft-rigid hybrid structure of integrated muscles and two carpal *** this study, we developed a soft-rigid hybrid structure to design a biomimetic soft robotic wrist(BSRW) that is capable of rotating in the x and y directions, twisting around the z-axis, and possessing stiffness-tunable capacity. To actuate the BSRW, a lightweight soft-ring-reinforced bellows-type pneumatic actuator(SRBPA) with large axial, linear deformation(η_(lcmax)=70.6%,η_(lemax)=54.3%) and small radial expansion(η_(demax)=3.7%) is designed to mimic the motion of skeletal muscles. To represent the function of two-carpal rows, a compact particle-jamming joint(PJJ) that combines particles with a membrane-covered ballsocket mechanism is developed to achieve various 3-DOF motions and high axial load-carrying capacity(>60 N). By varying the jamming pressure, the stiffness of the PJJ can be adjusted. Finally, a centrally positioned PJJ and six independently actuated SRBPAs, which are in an inclined and antagonistic arrangement, are sandwiched between two rigid plates to form a flexible,stable, and compact BSRW. Such a structure enables the BSRW to have a dexterous 3-DOF motion, high load-carrying ability,and stiffness tunability. Experimental analysis verify 3-DOF motion of BSRW, producing force of 29.6 N and 36 N and torque of2.2 Nm in corresponding rotations. Moreover, the range of rotational angle and stiffness-tuning properties of BSRW are studied by applying jamming pressure to the PJJ. Finally, a system combining a BSRW and a soft enclosing gripper is proposed to demo

关键词： pneumatic soft actuators particle jamming robotic wrist soft robotics stiffness-tunable

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Effective Identity Authentication Based on Multiattribute Centers for Secure Government Data Sharing

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Tsinghua Science and Technology 2024年第3期29卷 736-752页

作者： Meiquan Wang Junhua Wu Tongdui Zhang Junhao Wu Guangshun Li School of Computer Science Qufu Normal UniversityRizhao 276800China Science and Technology Innovation service Institution of Rizhao Rizhao 276800China

As one of the essential steps to secure government data sharing,Identity Authentication(IA)plays a vital role in the processing of large ***,the centralized IA scheme based on a trusted third party presents problems of information leakage and single point of failure,and those related to key ***,herein,an effective IA model based on multiattribute centers is ***,a private key of each attribute of a data requester is generated by the attribute authorization *** obtaining the private key of attribute,the data requester generates a personal private ***,a dynamic key generation algorithm is proposed,which combines blockchain and smart contracts to periodically update the key of a data requester to prevent theft by external attackers,ensure the traceability of IA,and reduce the risk of privacy ***,the combination of blockchain and interplanetary file systems is used to store attribute field information of the data requester to further reduce the cost of blockchain information storage and improve the effectiveness of information *** results show that the proposed model ensures the privacy and security of identity information and outperforms similar authentication models in terms of computational and communication costs.

关键词： blockchain identity authentication distribution dynamic key generation

Experimental demonstration of a photonic spiking neuron based on a DFB laser subject to side-mode optical pulse injection

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Science China(Information Sciences) 2024年第3期67卷 271-280页

作者： Shuiying XIANG Shuang GAO Yuechun SHI Yuna ZHANG Ziwei SONG Xingxing GUO Yahui ZHANG Yuxin MA Xiangfei CHEN State Key Laboratory of Integrated service Networks Xidian University Yongjiang Laboratory 3. College of Engineering and Applied Sciences Nanjing University

We proposed and experimentally demonstrated a simple and novel photonic spiking neuron based on a distributed feedback(DFB) laser subject to side-mode optical pulse injection(SMOPI). The DFB laser chip is designed and fabricated based on asymmetric equivalent π phase shift(π-EPS) with the reconstruction-equivalent-chirp(REC) technique. Under side-mode continuous-wave(CW) optical injection,excitability pulse was experimentally observed during the dominant mode switching process due to the injection-locked effect. Based on the transition between the excitability regime and the side-mode injection locking effect, the controllable and repeatable neuron-like spiking response can be realized when external stimulus pulses are electro-optically modulated on the CW optical carrier. The experimental results show that the spike threshold, temporal integration, and refractory period, which are important spike processing mechanisms in biological neurons, can all be achieved in the optically-injected DFB laser. The experimental findings are also verified numerically with a rate equation model that considers the SMOPI. To the best of our knowledge, this is the first experimental demonstration of a photonic spiking neuron based on a DFB laser subject to SMOPI, which holds promise for realizing large-scale photonic spiking neuron arrays for hardware photonic spiking neural network chips.

关键词： neuromorphic photonics photonic spiking neuron DFB laser side-mode optical pulse injections

Chaotic CS Encryption:An Efficient Image Encryption Algorithm Based on Chebyshev Chaotic System and Compressive Sensing

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Computers, Materials & Continua 2024年第5期79卷 2625-2646页

作者： Mingliang Sun Jie Yuan Xiaoyong Li Dongxiao Liu Key Laboratory of Trustworthy Distributed Computing and service(BUPT) Ministry of EducationBeijing University of Posts and TelecommunicationsBeijing100876China

Images are the most important carrier of human information. Moreover, how to safely transmit digital imagesthrough public channels has become an urgent problem. In this paper, we propose a novel image encryptionalgorithm, called chaotic compressive sensing (CS) encryption (CCSE), which can not only improve the efficiencyof image transmission but also introduce the high security of the chaotic system. Specifically, the proposed CCSEcan fully leverage the advantages of the Chebyshev chaotic system and CS, enabling it to withstand various attacks,such as differential attacks, and exhibit robustness. First, we use a sparse trans-form to sparse the plaintext imageand then use theArnold transformto perturb the image pixels. After that,we elaborate aChebyshev Toeplitz chaoticsensing matrix for CCSE. By using this Toeplitz matrix, the perturbed image is compressed and sampled to reducethe transmission bandwidth and the amount of data. Finally, a bilateral diffusion operator and a chaotic encryptionoperator are used to perturb and expand the image pixels to change the pixel position and value of the compressedimage, and ultimately obtain an encrypted image. Experimental results show that our method can be resistant tovarious attacks, such as the statistical attack and noise attack, and can outperform its current competitors.

关键词： Image encryption chaotic system compressive sensing arnold transform