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Deep Auto-Encoder Based Intelligent and Secure Time Synchronization Protocol(iSTSP)for Security-Critical Time-Sensitive WSNs
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作者 Ramadan Abdul-Rashid Mohd Amiruddin Abd Rahman Abdulaziz Yagoub Barnawi 《Computer Modeling in Engineering & Sciences》 2025年第9期3213-3250,共38页
Accurate time synchronization is fundamental to the correct and efficient operation of Wireless Sensor Networks(WSNs),especially in security-critical,time-sensitive applications.However,most existing protocols degrade... Accurate time synchronization is fundamental to the correct and efficient operation of Wireless Sensor Networks(WSNs),especially in security-critical,time-sensitive applications.However,most existing protocols degrade substantially under malicious interference.We introduce iSTSP,an Intelligent and Secure Time Synchronization Protocol that implements a four-stage defense pipeline to ensure robust,precise synchronization even in hostile environments:(1)trust preprocessing that filters node participation using behavioral trust scoring;(2)anomaly isolation employing a lightweight autoencoder to detect and excise malicious nodes in real time;(3)reliability-weighted consensus that prioritizes high-trust nodes during time aggregation;and(4)convergence-optimized synchronization that dynamically adjusts parameters using theoretical stability bounds.We provide rigorous convergence analysis including a closed-form expression for convergence time,and validate the protocol through both simulations and realworld experiments on a controlled 16-node testbed.Under Sybil attacks with five malicious nodes within this testbed,iSTSP maintains synchronization error increases under 12%and achieves a rapid convergence.Compared to state-ofthe-art protocols like TPSN,SE-FTSP,and MMAR-CTS,iSTSP offers 60%faster detection,broader threat coverage,and more than 7 times lower synchronization error,with a modest 9.3%energy overhead over 8 h.We argue this is an acceptable trade-off for mission-critical deployments requiring guaranteed security.These findings demonstrate iSTSP’s potential as a reliable solution for secure WSN synchronization and motivate future work on large-scale IoT deployments and integration with energy-efficient communication protocols. 展开更多
关键词 Time-sensitive wireless sensor networks(TS-WSNs) secure time synchronization protocol trust-based authentication autoencoder model deep learning malicious node detection Internet of Things energyefficient communication protocols
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Projective synchronization control and simulation of drive system and response network
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作者 LI De-kui 《兰州大学学报(自然科学版)》 北大核心 2025年第2期208-214,共7页
Projective synchronization problems of a drive system and a particular response network were investigated,where the drive system is an arbitrary system with n+1 dimensions;it may be a linear or nonlinear system,and ev... Projective synchronization problems of a drive system and a particular response network were investigated,where the drive system is an arbitrary system with n+1 dimensions;it may be a linear or nonlinear system,and even a chaotic or hyperchaotic system,the response network is complex system coupled by N nodes,and every node is showed by the approximately linear part of the drive system.Only controlling any one node of the response network by designed controller can achieve the projective synchronization.Some numerical examples were employed to verify the effectiveness and correctness of the designed controller. 展开更多
关键词 pinning control projective synchronization drive system response network
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Incorporating red blanket protocol within code crimson:Streamlining definitive trauma care amid the chaos
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作者 Sohil Pothiawala Savitha Bhagvan Andrew MacCormick 《World Journal of Critical Care Medicine》 2025年第1期14-19,共6页
The care of a patient involved in major trauma with exsanguinating haemorrhage is time-critical to achieve definitive haemorrhage control,and it requires coordinated multidisciplinary care.During initial resuscitation... The care of a patient involved in major trauma with exsanguinating haemorrhage is time-critical to achieve definitive haemorrhage control,and it requires coordinated multidisciplinary care.During initial resuscitation of a patient in the emergency department(ED),Code Crimson activation facilitates rapid decisionmaking by multi-disciplinary specialists for definitive haemorrhage control in operating theatre(OT)and/or interventional radiology(IR)suite.Once this decision has been made,there may still be various factors that lead to delay in transporting the patient from ED to OT/IR.Red Blanket protocol identifies and addresses these factors and processes which cause delay,and aims to facilitate rapid and safe transport of the haemodynamically unstable patient from ED to OT,while minimizing delay in resuscitation during the transfer.The two processes,Code Crimson and Red Blanket,complement each other.It would be ideal to merge the two processes into a single protocol rather than having two separate workflows.Introducing these quality improvement strategies and coor-dinated processes within the trauma framework of the hospitals/healthcare systems will help in further improving the multi-disciplinary care for the complex trauma patients requiring rapid and definitive haemorrhage control. 展开更多
关键词 Red blanket protocol Code crimson HAEMORRHAGE Trauma
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SegInfer:Binary Network Protocol Segmentation Based on Probabilistic Inference
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作者 Guo Maohua Zhu Yuefei Fei Jinlong 《China Communications》 2025年第6期334-354,共21页
Protocol Reverse Engineering(PRE)is of great practical importance in Internet security-related fields such as intrusion detection,vulnerability mining,and protocol fuzzing.For unknown binary protocols having fixed-len... Protocol Reverse Engineering(PRE)is of great practical importance in Internet security-related fields such as intrusion detection,vulnerability mining,and protocol fuzzing.For unknown binary protocols having fixed-length fields,and the accurate identification of field boundaries has a great impact on the subsequent analysis and final performance.Hence,this paper proposes a new protocol segmentation method based on Information-theoretic statistical analysis for binary protocols by formulating the field segmentation of unsupervised binary protocols as a probabilistic inference problem and modeling its uncertainty.Specifically,we design four related constructions between entropy changes and protocol field segmentation,introduce random variables,and construct joint probability distributions with traffic sample observations.Probabilistic inference is then performed to identify the possible protocol segmentation points.Extensive trials on nine common public and industrial control protocols show that the proposed method yields higher-quality protocol segmentation results. 展开更多
关键词 binary protocol probabilistic inference protocol field segmentation protocol reverse engineering related construction
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Anticipating Lag Synchronization Based on Machine Learning
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作者 WU Yongqing BAO Xingxing 《数学理论与应用》 2025年第1期115-126,共12页
This paper propose a comprehensive data-driven prediction framework based on machine learning methods to investigate the lag synchronization phenomenon in coupled chaotic systems,particularly in cases where accurate m... This paper propose a comprehensive data-driven prediction framework based on machine learning methods to investigate the lag synchronization phenomenon in coupled chaotic systems,particularly in cases where accurate mathematical models are challenging to establish or where system equations remain unknown.The Long Short-Term Memory(LSTM)neural network is trained using time series acquired from the desynchronization system states,subsequently predicting the lag synchronization transition.In the experiments,we focus on the Lorenz system with time-varying delayed coupling,studying the effects of coupling coefficients and time delays on lag synchronization,respectively.The results indicate that with appropriate training,the machine learning model can adeptly predict the lag synchronization occurrence and transition.This study not only enhances our comprehension of complex network synchronization behaviors but also underscores the potential and practical applications of machine learning in exploring nonlinear dynamic systems. 展开更多
关键词 Coupled chaotic system LSTM neural network Anticipating synchronization Lag synchronization
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Machine Learning-Based Routing Protocol in Flying Ad Hoc Networks: A Review
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作者 Priyanka Manjit Kaur +2 位作者 Deepak Prashar Leo Mrsic Arfat Ahmad Khan 《Computers, Materials & Continua》 2025年第2期1615-1643,共29页
“Flying Ad Hoc Networks(FANETs)”,which use“Unmanned Aerial Vehicles(UAVs)”,are developing as a critical mechanism for numerous applications,such as military operations and civilian services.The dynamic nature of F... “Flying Ad Hoc Networks(FANETs)”,which use“Unmanned Aerial Vehicles(UAVs)”,are developing as a critical mechanism for numerous applications,such as military operations and civilian services.The dynamic nature of FANETs,with high mobility,quick node migration,and frequent topology changes,presents substantial hurdles for routing protocol development.Over the preceding few years,researchers have found that machine learning gives productive solutions in routing while preserving the nature of FANET,which is topology change and high mobility.This paper reviews current research on routing protocols and Machine Learning(ML)approaches applied to FANETs,emphasizing developments between 2021 and 2023.The research uses the PRISMA approach to sift through the literature,filtering results from the SCOPUS database to find 82 relevant publications.The research study uses machine learning-based routing algorithms to beat the issues of high mobility,dynamic topologies,and intermittent connection in FANETs.When compared with conventional routing,it gives an energy-efficient and fast decision-making solution in a real-time environment,with greater fault tolerance capabilities.These protocols aim to increase routing efficiency,flexibility,and network stability using ML’s predictive and adaptive capabilities.This comprehensive review seeks to integrate existing information,offer novel integration approaches,and recommend future research topics for improving routing efficiency and flexibility in FANETs.Moreover,the study highlights emerging trends in ML integration,discusses challenges faced during the review,and discusses overcoming these hurdles in future research. 展开更多
关键词 FANET protocol machine learning
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Optimal synchronization of higher-order Kuramoto model on hypergraphs
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作者 Chong-Yang Wang Bi-Yun Ji Linyuan Lu 《Chinese Physics B》 2025年第7期231-238,共8页
Complex networks play a crucial role in the study of collective behavior,encompassing the analysis of dynamical properties and network topology.In real-world systems,higher-order interactions among multiple entities a... Complex networks play a crucial role in the study of collective behavior,encompassing the analysis of dynamical properties and network topology.In real-world systems,higher-order interactions among multiple entities are widespread and significantly influence collective dynamics.Here,we extend the synchronization alignment function framework to hypergraphs of arbitrary order by leveraging the multi-order Laplacian matrix to encode higher-order interactions.Our findings reveal that the upper bound of synchronous behavior is determined by the maximum eigenvalue of the multi-order Laplacian matrix.Furthermore,we decompose the contribution of each hyperedge to this eigenvalue and utilize it as a basis for designing an eigenvalue-based topology modification algorithm.This algorithm effectively enhances the upper bound of synchronous behavior without altering the total number of higher-order interactions.Our study provides new insights into dynamical optimization and topology tuning in hypergraphs,advancing the understanding of the interplay between higher-order interactions and collective dynamics. 展开更多
关键词 synchronization optimization HYPERGRAPH complex network
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Optimal Synchronization of Higher-Order Dynamical Networks
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作者 Guanrong CHEN 《Artificial Intelligence Science and Engineering》 2025年第1期31-36,共6页
This article briefly reviews the topic of complex network synchronization,with its graph-theoretic criterion,showing that the homogeneous and symmetrical network structures are essential for optimal synchronization.Fu... This article briefly reviews the topic of complex network synchronization,with its graph-theoretic criterion,showing that the homogeneous and symmetrical network structures are essential for optimal synchronization.Furthermore,it briefly reviews the notion of higher-order network topologies and shows their promising potential in application to evaluating the optimality of network synchronizability. 展开更多
关键词 complex network synchronization optimal synchronizability SIMPLEX higher-order topology
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Interacting Mathieu equation,synchronization dynamics and collision-induced velocity exchange in trapped ions
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作者 Asma Benbouza Xiaoshui Lin +1 位作者 Jin Ming Cui Ming Gong 《Communications in Theoretical Physics》 2025年第8期67-81,共15页
Recently,large-scale trapped ion systems have been realized in experiments for quantum simulation and quantum computation.They are the simplest systems for dynamical stability and parametric resonance.In this model,th... Recently,large-scale trapped ion systems have been realized in experiments for quantum simulation and quantum computation.They are the simplest systems for dynamical stability and parametric resonance.In this model,the Mathieu equation plays the most fundamental role for us to understand the stability and instability of a single ion.In this work,we investigate the dynamics of trapped ions with the Coulomb interaction based on the Hamiltonian equation.We show that the many-body interaction will not influence the phase diagram for instability.Then,the dynamics of this model in the large damping limit will also be analytically calculated using few trapped ions.Furthermore,we find that in the presence of modulation,synchronization dynamics can be observed,showing an exchange of velocities between distant ions on the left side and on the right side of the trap.These dynamics resemble that of the exchange of velocities in Newton's cradle for the collision of balls at the same time.These dynamics are independent of their initial conditions and the number of ions.As a unique feature of the interacting Mathieu equation,we hope this behavior,which leads to a quasi-periodic solution,can be measured in current experimental systems.Finally,we have also discussed the effect of anharmonic trapping potential,showing the desynchronization during the collision process.It is hoped that the dynamics in this many-body Mathieu equation with damping may find applications in quantum simulations.This model may also find interesting applications in dynamics systems as a pure mathematical problem,which may be beyond the results in the Floquet theorem. 展开更多
关键词 trapped ions Mathieu equation Floquet theory synchronization many-body interactions
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Modified Fixed-Time Synchronization Criteria of Complex Networks with Time-Varying Delays via Continuous or Discontinuous Control
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作者 WU Huan WU Ailong ZHANG Jin'e 《Wuhan University Journal of Natural Sciences》 2025年第2期150-158,共9页
This paper investigates modified fixed-time synchronization(FxTS)of complex networks(CNs)with time-varying delays based on continuous and discontinuous controllers.First,for the sake of making the settling time(ST)of ... This paper investigates modified fixed-time synchronization(FxTS)of complex networks(CNs)with time-varying delays based on continuous and discontinuous controllers.First,for the sake of making the settling time(ST)of FxTS is independent of the initial values and parameters of the CNs,a modified fixed-time(FxT)stability theorem is proposed,where the ST is determined by an arbitrary positive number given in advance.Then,continuous controller and discontinuous controller are designed to realize the modified FxTS target of CNs.In addition,based on the designed controllers,CNs can achieve synchronization at any given time,or even earlier.And control strategies effectively solve the problem of ST related to the parameters of CNs.Finally,an appropriate simulation example is conducted to examine the effectiveness of the designed control strategies. 展开更多
关键词 complex networks settling time fixed-time synchronization controllers time-varying delays
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Deep Synchronization Control of Grid-Forming Converters:A Reinforcement Learning Approach
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作者 Zhuorui Wu Meng Zhang +2 位作者 Bo Fan Yang Shi Xiaohong Guan 《IEEE/CAA Journal of Automatica Sinica》 2025年第1期273-275,共3页
Dear Editor,This letter proposes a deep synchronization control(DSC) method to synchronize grid-forming converters with power grids. The method involves constructing a novel controller for grid-forming converters base... Dear Editor,This letter proposes a deep synchronization control(DSC) method to synchronize grid-forming converters with power grids. The method involves constructing a novel controller for grid-forming converters based on the stable deep dynamics model. To enhance the performance of the controller, the dynamics model is optimized within the deep reinforcement learning(DRL) framework. Simulation results verify that the proposed method can reduce frequency deviation and improve active power responses. 展开更多
关键词 reduce frequency deviation enhance performance stable deep dynamics model improve active power responses deep reinforcement learning drl dynamics model deep synchronization control dsc deep synchronization control
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Performance of digital filtering and synchronization method for APD communication receiver
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作者 Hui-Jun Zhang Peng Lin +4 位作者 Tong Wang Zi-Qi Zhang Bai-Qiu Zhao Wen-Fang Jiao Xiao-Nan Yu 《Journal of Electronic Science and Technology》 2025年第3期89-104,共16页
Optical wireless(OW)communication systems face significant challenges such as signal attenuation due to atmospheric absorption,scattering,and noise from hardware components,which degrade detection sensitivity.To addre... Optical wireless(OW)communication systems face significant challenges such as signal attenuation due to atmospheric absorption,scattering,and noise from hardware components,which degrade detection sensitivity.To address these challenges,we propose a digital processing algorithm that combines finite impulse response filtering with dynamic synchronization based on pulse addition and subtraction.Unlike conventional methods,which typically rely solely on hardware optimization or basic thresholding techniques,the proposed approach integrates filtering and synchronization to improve weak signal detection and reduce noise-induced errors.The proposed algorithm was implemented and verified using a field-programmable gate array.Experiments conducted in an indoor OW communication environment demonstrate that the proposed algorithm significantly improves detection sensitivity by approximately 6 dB and 5 dB at communication rates of 3.5 Mbps and 5.0 Mbps,respectively.Specifically,under darkroom conditions and a bit error rate of 1×10^(-7),the detection sensitivity was improved from-38.56 dBm to-44.77 dBm at 3.5 Mbps and from-37.12 dBm to-42.29 dBm at 5 Mbps.The proposed algorithm is crucial for future capture and tracking of signals at large dispersion angles and in underwater and long-distance communication scenarios. 展开更多
关键词 Detection sensitivity Digital filtering Optical wireless communication PHOTODETECTOR synchronization
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Tuning the Coefficients of Thermal Expansion of the Crystallized Cordierite Glasses by Thermal Treatment Protocols
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作者 DUAN Qiang KE Xuefei +1 位作者 QIAO Ang TAO Haizheng 《Journal of Wuhan University of Technology(Materials Science)》 2025年第5期1239-1243,共5页
Focusing on the ultralow expansion functionality of the crystalized glass containing the cordierite crystal phase with the molar composition 20.7MgO·20.7Al_(2)O_(3)·51.6SiO_(2)·7.0TiO_(2),we systematica... Focusing on the ultralow expansion functionality of the crystalized glass containing the cordierite crystal phase with the molar composition 20.7MgO·20.7Al_(2)O_(3)·51.6SiO_(2)·7.0TiO_(2),we systematically investigated impacts of thermal treatment protocols on T dependence of coefficients of thermal expansion(CTE).Except for the phase compositions,morphology is identified as another important factor to control the T dependence of CTE.By using X-ray diffraction and scanning electron microscope,various modes of T dependence of CTE for crystallized glasses are ascribed to their different phase compositions and microstructure with finely dispersed nanoparticles.These understanding contributes to the further modification of CTE of the crystalized glass by altering their thermal treatment scenarios. 展开更多
关键词 coefficients of thermal expansion crystalized glass CORDIERITE thermal treatment protocols
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Effects of noise on synchronization in simplicial complexes
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作者 Linying Xiang Shuwei Yao +2 位作者 Yining Chen Ruitong Yan Ruya Xia 《Chinese Physics B》 2025年第7期240-251,共12页
This paper explores the synchronization of stochastic simplicial complexes with noise,modeled by stochastic differential equations of It?type.It establishes the relationship between synchronization and individual dyna... This paper explores the synchronization of stochastic simplicial complexes with noise,modeled by stochastic differential equations of It?type.It establishes the relationship between synchronization and individual dynamics,higher-order structures,coupling strengths,and noise.In particular,this study delves into the role of multi-body interactions,particularly focusing on the influence of higher-order simplicial structures on the overall synchronization behavior.Furthermore,the effects of noise on synchronizability in the stochastic simplicial complex are thoroughly examined.The obtained results indicate that the effects of noise on the synchronizability vary with the manner in which noise propagates.The presence of noise can regulate the synchronization pattern of the simplicial complex,transforming the unstable state into a stable state,and vice versa.These findings offer valuable insights and a theoretical foundation for improving the performance of real-world networks,such as communication networks,biological systems,and social networks,where noise is often inevitable. 展开更多
关键词 simplical complex higher-order network synchronization noise stochastic differential equation
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Improving nursing care protocols for diabetic patients through a systematic review and meta-analysis of recent years
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作者 Mónica Grande-Alonso María Barbado García +2 位作者 Soledad Cristóbal-Aguado Soledad Aguado-Henche Rafael Moreno-Gómez-Toledano 《World Journal of Diabetes》 2025年第2期257-269,共13页
BACKGROUND Diabetes mellitus has become one of the major pandemics of the 21st century.In this scenario,nursing interventions are essential for improving self-care and quality of life in patients with type 2 diabetes ... BACKGROUND Diabetes mellitus has become one of the major pandemics of the 21st century.In this scenario,nursing interventions are essential for improving self-care and quality of life in patients with type 2 diabetes mellitus.Nursing interventions are crucial for managing the disease and preventing complications.AIM To analyse nursing interventions in recent years through a systematic review and meta-analysis and to propose improvements in care plans.METHODS This study conducted a systematic review and meta-analysis of the impact of nursing interventions on quantitative glycaemic variables,such as glycated haemoglobin and fasting plasma glucose.RESULTS After confirming that the combined effect of all studies from the past 5 years positively impacts quantitative variables,a descriptive analysis of the studies with the most significant changes was conducted.Based on this,an improvement in diabetic patient care protocols has been proposed through follow-up plans tailored to the patient’s technological skills.CONCLUSION The combined results obtained and the proposal for improvement developed in this manuscript could help to improve the quality of life of many people around the world. 展开更多
关键词 Diabetes mellitus Nursing interventions Systematic review META-ANALYSIS protocol enhancement proposal
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Synchronization Characterization of DC Microgrid Converter Output Voltage and Improved Adaptive Synchronization Control Methods
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作者 Wei Chen Xin Gao +2 位作者 Zhanhong Wei Xusheng Yang Zhao Li 《Energy Engineering》 2025年第2期805-821,共17页
This paper deeply introduces a brand-new research method for the synchronous characteristics of DC microgrid bus voltage and an improved synchronous control strategy.This method mainly targets the problem of bus volta... This paper deeply introduces a brand-new research method for the synchronous characteristics of DC microgrid bus voltage and an improved synchronous control strategy.This method mainly targets the problem of bus voltage oscillation caused by the bifurcation behavior of DC microgrid converters.Firstly,the article elaborately establishes a mathematical model of a single distributed power source with hierarchical control.On this basis,a smallworld network model that can better adapt to the topology structure of DC microgrids is further constructed.Then,a voltage synchronization analysis method based on the main stability function is proposed,and the synchronous characteristics of DC bus voltage are deeply studied by analyzing the size of the minimum non-zero eigenvalue.In view of the situation that the line coupling strength between distributed power sources is insufficient to achieve bus voltage synchronization,this paper innovatively proposes a new improved adaptive controller to effectively control voltage synchronization.And the convergence of the designed controller is strictly proved by using Lyapunov’s stability theorem.Finally,the effectiveness and feasibility of the designed controller in this paper are fully verified through detailed simulation experiments.After comparative analysis with the traditional adaptive controller,it is found that the newly designed controller can make the bus voltages of each distributed power source achieve synchronization more quickly,and is significantly superior to the traditional adaptive controller in terms of anti-interference performance. 展开更多
关键词 DC microgrid BIFURCATION small-world network voltage synchronization improved adaptive control
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Effect of alpha-tocopherol and OTR-4131 on muscle degeneration after rotator cuff tear in rats:An experimental protocol
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作者 Stavros Stamiris Angeliki Cheva +7 位作者 Michael Potoupnis Elissavet Anestiadou Dimitrios Stamiris Chryssa Bekiari Antonia Loukousia Papavasiliou Kyriakos Eleftherios Tsiridis Ioannis Sarris 《World Journal of Methodology》 2025年第4期287-298,共12页
BACKGROUND Massive rotator cuff tears(RCTs)result in impaired shoulder function and quality of life.These tears lead to structural changes in the rotator cuff muscles,which compromise recovery after repair and increas... BACKGROUND Massive rotator cuff tears(RCTs)result in impaired shoulder function and quality of life.These tears lead to structural changes in the rotator cuff muscles,which compromise recovery after repair and increase re-tear rates.AIM To investigate the potential inhibitory effects of alpha-tocopherol(vitamin E)and OTR-4131 on muscle atrophy,fatty infiltration,and fibrosis in rotator cuff muscles following a massive RCT using a Wistar rat model,and establish a standardized methodology for evaluating potential therapeutic agents.METHODS This protocol outlines a controlled animal study using 40 male Wistar rats,randomized into five groups.The experimental groups will receive either systemic administration of alpha-tocopherol or local administration of OTR-4131 via intramuscular injection into the supraspinatus and infraspinatus muscles.Two sham groups will receive systemic and local saline injections respectively,while a control group will undergo no intervention.The interventions will be administered after surgical transection of the supraspinatus and infraspinatus tendons.Outcomes will be assessed via wet muscle weight measurements,muscle fiber diameter,fatty infiltration percentage,and fibrosis evaluation using histological methods.RESULTS The study anticipates that alpha-tocopherol and OTR-4131 will reduce muscle atrophy,fatty infiltration,and fibrosis compared to control and sham groups,supporting their potential protective role in rotator cuff muscle degeneration.CONCLUSION The results are expected to improve the understanding on the role of alpha-tocopherol and OTR-4131 in rotator cuff muscle protection after massive RCT and may serve as a foundation for further preclinical and clinical research aimed at improving rotator cuff repair outcomes. 展开更多
关键词 Alpha-tocopherol OTR-4131 Rotator cuff tears Experimental protocol Muscle atrophy Fatty infiltration
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Adaptive Time Synchronization in Time Sensitive-Wireless Sensor Networks Based on Stochastic Gradient Algorithms Framework
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作者 Ramadan Abdul-Rashid Mohd Amiruddin Abd Rahman +1 位作者 Kar Tim Chan Arun Kumar Sangaiah 《Computer Modeling in Engineering & Sciences》 2025年第3期2585-2616,共32页
This study proposes a novel time-synchronization protocol inspired by stochastic gradient algorithms.The clock model of each network node in this synchronizer is configured as a generic adaptive filter where different... This study proposes a novel time-synchronization protocol inspired by stochastic gradient algorithms.The clock model of each network node in this synchronizer is configured as a generic adaptive filter where different stochastic gradient algorithms can be adopted for adaptive clock frequency adjustments.The study analyzes the pairwise synchronization behavior of the protocol and proves the generalized convergence of the synchronization error and clock frequency.A novel closed-form expression is also derived for a generalized asymptotic error variance steady state.Steady and convergence analyses are then presented for the synchronization,with frequency adaptations done using least mean square(LMS),the Newton search,the gradient descent(GraDes),the normalized LMS(N-LMS),and the Sign-Data LMS algorithms.Results obtained from real-time experiments showed a better performance of our protocols as compared to the Average Proportional-Integral Synchronization Protocol(AvgPISync)regarding the impact of quantization error on synchronization accuracy,precision,and convergence time.This generalized approach to time synchronization allows flexibility in selecting a suitable protocol for different wireless sensor network applications. 展开更多
关键词 Wireless sensor network time synchronization stochastic gradient algorithm MULTI-HOP
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Brief Discussion on the Enlightenment of FDA’s Comparability Protocol to the Post-Approval Change Management of New Drugs in China
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作者 Lu Xiaoling Tian Lijuan 《Asian Journal of Social Pharmacy》 2025年第2期126-133,共8页
Objective To discuss the flexible supervision and communication mode in the post-approval change(PAC)of drugs,to explore how to ensure the quality and availability of drugs during the changes,and to provide some sugge... Objective To discuss the flexible supervision and communication mode in the post-approval change(PAC)of drugs,to explore how to ensure the quality and availability of drugs during the changes,and to provide some suggestions and reference for promoting the timely marketing of drugs.Methods Based on the comparability protocol guidelines issued by the US FDA in October 2022,the regulatory status quo of PAC between China and the US was compared to explore the feasibility of implementing comparability protocols in China.Results and Conclusion According to the specific situation of post-approval of drug change supervision,some suggestions were put forward to optimize the PAC management procedure,such as establishing the communication pathways between holders and health authorities,publishing relevant guidance and strengthening training,so as to provide reference for the implementation of comparability protocols in China. 展开更多
关键词 post-approval change quality risk management risk assessment comparability protocol pharmaceutical quality system
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Efficient One-Way Time Synchronization for VANET withMLE-Based Multi-Stage Update
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作者 Hyeontae Joo Sangmin Lee +1 位作者 Kiseok Kim Hwangnam Kim 《Computers, Materials & Continua》 2025年第8期2789-2804,共16页
As vehicular networks become increasingly pervasive,enhancing connectivity and reliability has emerged as a critical objective.Among the enabling technologies for advanced wireless communication,particularly those tar... As vehicular networks become increasingly pervasive,enhancing connectivity and reliability has emerged as a critical objective.Among the enabling technologies for advanced wireless communication,particularly those targeting low latency and high reliability,time synchronization is critical,especially in vehicular networks.However,due to the inherent mobility of vehicular environments,consistently exchanging synchronization packets with a fixed base station or access point is challenging.This issue is further exacerbated in signal shadowed areas such as urban canyons,tunnels,or large-scale indoor hallswhere other technologies,such as global navigation satellite system(GNSS),are unavailable.One-way synchronization techniques offer a feasible approach under such transient connectivity conditions.One-way schemes still suffer from long convergence times to reach the required synchronization accuracy in these circumstances.In this paper,we propose a WLAN-based multi-stage clock synchronization scheme(WMC)tailored for vehicular networks.The proposed method comprises an initial hard update stage to rapidly achieve synchronization,followed by a high-precision stable stage based on Maximum Likelihood Estimation(MLE).By implementing the scheme directly at the network driver,we address key limitations of hard update mechanisms.Our approach significantly reduces the initial period to collect high-quality samples and offset estimation time to reach sub-50μs accuracy,and subsequently transitions to a refined MLE-based synchronization stage,achieving stable accuracy at approximately 30μs.The windowed moving average stabilized(reaching 90%of the baseline)in approximately 35 s,which corresponds to just 5.1%of the baseline time accuracy.Finally,the impact of synchronization performance on the localization model was validated using the Simulation of Urban Mobility(SUMO).The results demonstrate that more accurate conditions for position estimation can be supported,with an improvement about 38.5%in the mean error. 展开更多
关键词 One-way time synchronization maximum likelihood estimation hybrid clock update
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