Accurate estimation of the State of Charge(SOC),State of Health(SOH),and Terminal Resistance(TR)is crucial for the effective operation of Battery Management Systems(BMS)in lithium-ion batteries.This study conducts a c...Accurate estimation of the State of Charge(SOC),State of Health(SOH),and Terminal Resistance(TR)is crucial for the effective operation of Battery Management Systems(BMS)in lithium-ion batteries.This study conducts a comprehensive comparative analysis of four Kalman filter variants Extended Kalman Filter(EKF),Extended Kalman-Bucy Filter(EKBF),Unscented Kalman Filter(UKF),and Unscented Kalman-Bucy Filter(UKBF)under varying battery parameter conditions.These include temperature fluctuation,self-discharge,current direction,cell capacity,process noise,and measurement noise.Our findings reveal significant variations in the performance of SOC and SOH predictions across filters,emphasizing that UKF demonstrates superior robustness to noise,while EKF performs better under accurate system dynamics.The study underscores the need for adaptive filtering strategies that can dynamically adjust to evolving battery parameters,thereby enhancing BMS reliability and extending battery lifespan.展开更多
In recent years,three-dimensional reconstruction technologies that employ multiple cameras have continued to evolve significantly,enabling remote collaboration among users in extended Reality(XR)environments.In additi...In recent years,three-dimensional reconstruction technologies that employ multiple cameras have continued to evolve significantly,enabling remote collaboration among users in extended Reality(XR)environments.In addition,methods for deploying multiple cameras for motion capture of users(e.g.,performers)are widely used in computer graphics.As the need to minimize and optimize the number of cameras grows to reduce costs,various technologies and research approaches focused on Optimal Camera Placement(OCP)are continually being proposed.However,as most existing studies assume homogeneous camera setups,there is a growing demand for studies on heterogeneous camera setups.For instance,technical demands keep emerging in scenarios with minimal camera configurations,especially regarding cost factors,the physical placement of cameras given the spatial structure,and image capture strategies for heterogeneous cameras,such as high-resolution RGB cameras and depth cameras.In this study,we propose a pre-visualization and simulation method for the optimal placement of heterogeneous cameras in XR environments,accounting for both the specifications of heterogeneous cameras(e.g.,field of view)and the physical configuration(e.g.,wall configuration)in real-world spaces.The proposed method performs a visibility analysis of cameras by considering each camera’s field-of-view volume,resolution,and unique characteristics,along with physicalspace constraints.This approach enables the optimal position and rotation of each camera to be recommended,along with the minimum number of cameras required.In the results of our study conducted in heterogeneous camera combinations,the proposed method achieved 81.7%~82.7%coverage of the target visual information using only 2~3 cameras.In contrast,single(or homogeneous)-typed cameras were required to use 11 cameras for 81.6%coverage.Accordingly,we found that camera deployment resources can be reduced with the proposed approaches.展开更多
Understanding the fracture behavior of vertical cracks in piezoelectric semiconductor(PS)structures is vital due to their impacts on device reliability.This study establishes a model for a PS strip with a vertical cra...Understanding the fracture behavior of vertical cracks in piezoelectric semiconductor(PS)structures is vital due to their impacts on device reliability.This study establishes a model for a PS strip with a vertical crack under combined mechanical and electric loading,considering both central and edge cracks.Using Fourier transforms and dislocation density functions,the Mode-Ⅲproblem is converted to Cauchy-type singular integral equations.The crack surface fields,intensity factors,and energy release rate are derived.The accuracy of the proposed model is verified through the finite element(FE)simulation via COMSOL Multiphysics.The results for low electron concentrations align with those of the intrinsic piezoelectric materials,validating the correctness of the present model as well.The combined effects of crack position,applied electric loading,and initial carrier concentration on the crack propagation are analyzed.The normalized electric displacement factor shows heightened sensitivity to crack size,electromechanical loading,and carrier concentration.The crack position significantly influences the crack surface fields and normalized intensity factors due to the boundary proximity effect.展开更多
Molecular tailoring of self-assembled hole-transporting monolayers(SAMs)has been proven as an efficient approach for improving the device performance of inverted perovskite solar cells.Herein,a novel SAM with extended...Molecular tailoring of self-assembled hole-transporting monolayers(SAMs)has been proven as an efficient approach for improving the device performance of inverted perovskite solar cells.Herein,a novel SAM with extended conjugation is designed and synthesized,named NaPh-4PACz.Compared to Ph-4PACz,NaPh-4PACz exhibits a larger adsorption energy with the ITO substrate,enabling the formation of a more uniform and dense film,thereby preventing direct contact between the perovskite and ITO.Additionally,NaPh-4PACz also has a stronger interaction with the perovskite,which can reduce buried interface defects and suppress non-radiative recombination.Consequently,NaPh-4PACz-based devices achieved a power conversion efficiency of 25.48%due to their interfacial“adhesive”ability.Importantly,the stability of the NaPh-4PACz-based devices was significantly improved.展开更多
This paper investigates the adaptive optimal tracking control(AOTC)for underactuated surface vessels(USVs).Compared to the majority of existing studies,the control strategy in this paper innovatively combines an exten...This paper investigates the adaptive optimal tracking control(AOTC)for underactuated surface vessels(USVs).Compared to the majority of existing studies,the control strategy in this paper innovatively combines an extended state observer(ESO)with reinforcement learning(RL).The designed ESO has high estimation accuracy and robust disturbance rejection capabilities for the unmeasurable information for USVs.To obtain the AOTC,the actor–critic(AC)networks based on RL are constructed to solve the Hamilton–Jacobi–Bellman(HJB)equations.Due to the uncertainties,it is challenging to obtain the optimal controller by directly solving the HJB equations.To address this issue,this paper employs neural networks(NNs)to approximate the uncertainties and solves the optimal controller via AC-RL and ESO.In addition,the adaptive parameters of the optimal controller is trained in parallel with AC networks,which can ensure that the trained networks can further improve tracking performance.The boundedness of AOTC for USVs is shown by Lyapunov stability theorem.Finally,simulation results demonstrate the effectiveness of the proposed algorithm.展开更多
Anomaly detection is a vibrant research direction in controller area networks,which provides the fundamental real-time data transmission underpinning in-vehicle data interaction for the internet of vehicles.However,ex...Anomaly detection is a vibrant research direction in controller area networks,which provides the fundamental real-time data transmission underpinning in-vehicle data interaction for the internet of vehicles.However,existing unsupervised learning methods suffer from insufficient temporal and spatial constraints on shallow features,resulting in fragmented feature representations that compromise model stability and accuracy.To improve the extraction of valuable features,this paper investigates the influence of clustering constraints on shallow feature convergence paths at the model level and further proposes an end-to-end intrusion detection system based on efficient deep embedded subspace clustering(EDESC-IDS).Following the standard learning approach,continuous messages are encoded into two-dimensional data frames via a frame builder,which are then input into an extended convolutional autoencoder for extracting shallow features from high-dimensional data.On this basis,the dual constraints of these output features and the embedding clustering module facilitate end-to-end training of the EDESC-IDS in various attack scenarios.Extensive experimental results show that such a system exhibits significant detection performance on four types of attack datasets,including DoS,Gear,Fuzzy,and RPM,with precision,recall,and F1 scores consistently above 97.79%,while maintaining a false negative rate(FNR)and an error rate(ER)below 2.22%.展开更多
AIM:To compare the visual outcomes between bilateral implantation of Tecnis ZXR00 extended depth-of-focus(EDOF)intraocular lenses(IOLs)and mixed implantation of Tecnis ZXR00(EDOF)with Tecnis ZMB00(bifocal)IOLs.METHODS...AIM:To compare the visual outcomes between bilateral implantation of Tecnis ZXR00 extended depth-of-focus(EDOF)intraocular lenses(IOLs)and mixed implantation of Tecnis ZXR00(EDOF)with Tecnis ZMB00(bifocal)IOLs.METHODS:This postoperative cross-sectional study enrolled patients who underwent phacoemulsification combined with IOL implantation.Patients were divided into two groups:the bilateral ZXR00 group(ZXR00-only group)and the mixed IOL group(ZXR00+ZMB00 group).Primary outcome measures included uncorrected and corrected distance visual acuity(UDVA,CDVA),uncorrected and distance-corrected near visual acuity(UNVA,DCNVA),uncorrected and distance-corrected intermediate visual acuity(UIVA,DCIVA),and defocus curves.Secondary outcome measures were visual quality,spectacle independence,patient satisfaction,photic phenomena,and stereopsis.RESULTS:A total of 47 patients(94 eyes)were included,with 26 patients(11 males,15 females)in the ZXR00-only group(mean age:62.73±7.24y)and 21 patients(7 males,14 females)in the mixed group(mean age:65.71±9.16y).There was no statistically significant difference in age between the two groups(P=0.218).The mixed group showed significantly better binocular DCNVA compared to the ZXR00-only group(P=0.002).Defocus curve analysis revealed that the mixed group exhibited superior performance at−2.5 to−4.0 D but inferior performance at−0.5 and−1.5 D.Near stereoacuity was significantly poorer in the mixed group(Randot:5.589±0.744 vs 6.240±0.394 ln arcsec;Contour:4.966±0.973 vs 5.740±0.833 ln arcsec;both P<0.01).Both groups achieved high levels of spectacle independence and patient satisfaction,with no significant differences in photic phenomena or questionnaire scores.CONCLUSION:Mixed implantation of EDOF and bifocal IOLs improve near visual acuity but may compromise near stereopsis.This approach provides a viable option for patients prioritizing near vision;however,caution is recommended for individuals requiring fine stereoscopic vision for daily or professional tasks.展开更多
The Haicheng region,Liaoning,China,likely hosts a conjugate fault system comprising the NW-trending Haichenghe fault and NE-trending secondary faults.On February 4,1975,at 19:36 CST,an earthquake of M_(S)7.3 and inten...The Haicheng region,Liaoning,China,likely hosts a conjugate fault system comprising the NW-trending Haichenghe fault and NE-trending secondary faults.On February 4,1975,at 19:36 CST,an earthquake of M_(S)7.3 and intensity(MMI)IX hit the city of Haicheng,Liaoning,China.Although deep seismic profiling was previously conducted along the Haichenghe fault,the limited horizontal resolution in the shallow part prevented the recognition of kilometer-scale anomalies.The velocity structure characteristics of the Haichenghe fault and its NE-trending conjugate faults remain unclear.Using the extended range phase shift method,the high-resolution S-wave velocity structures are obtained by deploying a long,dense linear array of 55 short-period seismometers across the fault and NE-trending conjugate faults.The array length was 32 km and inter-station spacing was approximately 600 m,facilitating the collection of approximately 22 days of continuous waveform data.Employing the Extended Range Phase Shift(ERPS)method enabled the extraction of broadband 0.2–5 s Rayleigh wave phase velocity dispersion curves.The broadband dispersion data were used for inversion of the high-resolution S-wave velocity structure to a depth of 8 km from the surface.The velocity structure characteristics and seismicity of the Haichenghe fault and NE-trending conjugate faults were analyzed and compared with nearby fault gas measurements.Results show(1)shallow S-wave velocities show a low-high-low horizontal distribution,corresponding to basin-uplift-basin topography;(2)significant velocity contrasts occur across the Haichenghe fault:its SW segment(0–17 km)exhibits high velocities consistent with Paleoproterozoic crystalline basement(Pt_(1)),while the NE segment(17–32 km)shows low velocities related to Yanshanian intrusions(γ_(5))and Quaternary sediments.NE-trending conjugate faults display sharp velocity gradients marking fracture locations,with all faults being near-vertical to~8 km depth;(3)seismicity at 1–6 km depth mainly clusters in high-velocity zones;at 6–8 km depth,it concentrates beneath the Haichenghe fault in low-velocity areas and along NE-trending faults;(4)the seismic activity characteristics and fault zone width of the Haicheng he fault reflected by velocity imaging results are basically consistent with those obtained by the fault gas measurement method.展开更多
Slope failures,particularly in railway embankments during intense rainfall,are a major cause of economic damage and humanitarian loss.To forecast how shear cracks develop in slopes under heavy precipitation,we present...Slope failures,particularly in railway embankments during intense rainfall,are a major cause of economic damage and humanitarian loss.To forecast how shear cracks develop in slopes under heavy precipitation,we present a novel modeling framework:the Extended Cohesive Damage Element enhanced by soil moisture(SMECDE).The method first translates forecasted rainfall into soil moisture levels via an established correspondence.Then,recognizing that rainfall infiltration lowers soil cohesion—particularly at varying depths—we introduce a Soil Moisture Decoherence Model(SMDM)based on experimental data,which quantifies how cohesion degrades with moisture and how depth affects this process.By embedding SMDM within the ECDE technique,we investigate how shear fractures propagate under different moisture conditions throughout the slope profile.We apply SMECDE to a real railway embankment case to identify critical moisture thresholds and crack growth patterns.Validation is performed by comparing predictions against field measurements and weather station records,and further checked through simulations of large-scale plastic deformation in ABAQUS.展开更多
Many complex systems are frequently subject to the influence of uncertain disturbances,which can exert a profound effect on the critical transitions(CTs),potentially resulting in catastrophic consequences.Consequently...Many complex systems are frequently subject to the influence of uncertain disturbances,which can exert a profound effect on the critical transitions(CTs),potentially resulting in catastrophic consequences.Consequently,it is of uttermost importance to provide warnings for noise-induced CTs in various applications.Although capturing certain generic symptoms of transition behaviors from observational and simulated data poses a challenging problem,this work attempts to extract information regarding CTs from simulated data of a Gaussian white noise-induced tri-stable system.Using the extended dynamic mode decomposition(EDMD)algorithm,we initially obtain finite-dimensional approximations of both the stochastic Koopman operator and the generator.Subsequently,the drift parameters and the noise intensity within the system are identified from the simulated data.Utilizing the identified system,the parameter-dependent basin of the unsafe regime(PDBUR)is quantified,enabling data-driven early warning of Gaussian white noise-induced CTs.Finally,an error analysis is carried out to verify the effectiveness of the data-driven results.Our findings may serve as a paradigm for understanding and predicting noise-induced CTs in complex systems based on data.展开更多
In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypro...In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypropylene(PO)and oxyethylene(EO),octadecyl-(PO)_(m)-(EO)_(n)-sodium carboxylate(C_(18)PO_(m)EO_(n)C,m=5,10,15,n=5,10,15),were studied.The surface tension and contact angle of C_(18)PO_(m)EO_(n)C solution with different concentrations were measured,and the adhesion tension,PTFE-water interfacial tension,and adhesion work were calculated.It was found that the extended surfactant molecules adsorb on the surface of the solution and the PTFE-liquid interface simultaneously when the concentration is lower than the critical micelle concentration(cmc),and there was a linear relationship between surface tension and adhesion tension.The adsorption amount of C_(18)PO_(m)EO_(n)C at the PTFE-water interface was significantly lower than that on the surface of the solution.As the concentration increases above cmc,semi-micelle aggregates on the surface of PTFE are formed by C_(18)PO_(m)EO_(n)C molecules through hydrophobic interaction,and the hydrophilic group faces the solution to modify the surface of PTFE with high efficiency.展开更多
The concept of emissivity has been with the scientific and engineering world since Planck formulated his blackbody radiation law more than a century ago.Nevertheless,emissivity is an elusive concept even for ex⁃perts....The concept of emissivity has been with the scientific and engineering world since Planck formulated his blackbody radiation law more than a century ago.Nevertheless,emissivity is an elusive concept even for ex⁃perts.It is a vague and fuzzy concept for the wider community of engineers.The importance of remote sensing of temperature by measuring IR radiation has been recognized in a wide range of industrial,medical,and environ⁃mental uses.One of the major sources of errors in IR radiometry is the emissivity of the surface being measured.In real experiments,emissivity may be influenced by many factors:surface texture,spectral properties,oxida⁃tion,and aging of surfaces.While commercial blackbodies are prevalent,the much-needed grey bodies with a known emissivity,are unavailable.This study describes how to achieve a calibrated and stable emissivity with a blackbody,a perforated screen,and a reliable and linear novel IR thermal sensor,18 dubbed TMOS.The Digital TMOS is now a low-cost commercial product,it requires low power,and it has a small form factor.The method⁃ology is based on two-color measurements,with two different optical filters,with selected wavelengths conform⁃ing to the grey body definition of the use case under study.With a photochemically etched perforated screen,the effective emissivity of the screen is simply the hole density area of the surface area that emits according to the blackbody temperature radiation.The concept is illustrated with ray tracing simulations,which demonstrate the approach.Measured results are reported.展开更多
Soil moisture(SM)is a critical variable in terrestrial ecosystems,especially in arid and semi-arid areas where water sources are limited.Despite its importance,understanding the spatiotemporal variations and influenci...Soil moisture(SM)is a critical variable in terrestrial ecosystems,especially in arid and semi-arid areas where water sources are limited.Despite its importance,understanding the spatiotemporal variations and influencing factors of SM in these areas remains insufficient.This study investigated the spatiotemporal variations and influencing factors of SM in arid and semi-arid areas of China by utilizing the extended triple collation(ETC),Mann-Kendall test,Theil-Sen estimator,ridge regression analysis,and other relevant methods.The following findings were obtained:(1)at the pixel scale,the long-term monthly SM data from the European Space Agency Climate Change Initiative(ESA CCI)exhibited the highest correlation coefficient of 0.794 and the lowest root mean square error(RMSE)of 0.014 m^(3)/m^(3);(2)from 2000 to 2022,the study area experienced significant increase in annual average SM,with a rate of 0.408×10^(-3)m^(3)/(m^(3)•a).Moreover,higher altitudes showed a notable upward trend,with SM increasing rates at 0.210×10^(-3)m^(3)/(m^(3)•a)between 1000 and 2000 m,0.530×10^(-3)m^(3)/(m^(3)•a)between 2000 and 4000 m,and 0.760×10^(-3)m^(3)/(m^(3)•a)at altitudes above 4000 m;(3)land surface temperature(LST),root zone soil moisture(RSM)(10-40 cm depth),and normalized difference vegetation index(NDVI)were identified as the primary factors influencing annual average SM,which accounted for 34.37%,24.16%,and 22.64%relative contributions,respectively;and(4)absolute contribution of LST was more significant in subareas at higher altitudes,with average absolute contributions of 0.800×10^(-3)m^(3)/(m^(3)•a)between 2000 and 4000 m and 0.500×10^(-2) m^(3)/(m^(3)•a)above 4000 m.This study reveals the spatiotemporal variations and main influencing factors of SM in Chinese arid and semi-arid areas,highlighting the more pronounced absolute contribution of LST to SM in high-altitude areas,providing valuable insights for ecological research and water resource management in these areas.展开更多
AIM:To compare the clinical outcomes of extended depth-of-focus intraocular lenses(EDOF IOLs)using either micromonovision implantation or mixed implantation of EDOF and diffractive bifocal IOLs.METHODS:This retrospect...AIM:To compare the clinical outcomes of extended depth-of-focus intraocular lenses(EDOF IOLs)using either micromonovision implantation or mixed implantation of EDOF and diffractive bifocal IOLs.METHODS:This retrospective clinical trial included 130 patients(260 eyes),who were divided into two groups.Group RR comprised 70 patients(140 eyes)bilaterally implanted with ZXR00 IOLs(Tecnis ZXR00,where one target was-0.5 D to-0.75 D and the other was 0 to-0.25 D).Group RM comprised 60 patients(120 eyes)unilaterally implanted with both ZXR00 and ZMB00 IOLs(Tecnis ZMB00,0 to-0.25 D).Postoperative outcomes were compared after 3 mo,including visual acuity,defocus curves,stereoacuity,modulation transfer functions(MTFs),higher-order aberrations,and Visual Function-14(VF-14)questionnaire responses.RESULTS:Group RR had superior bilateral intermediate vision,while the group RM had superior bilateral near vision(both P<0.05).Group RM also exhibited superior MTFs and reduced higher-order aberrations(both P<0.05).Stereoacuity and VF-14 questionnaire results showed no statistically significant difference between groups(P>0.05).CONCLUSION:The implantation of micromonovision has significantly improved near vision.IOLs and their collocation can be customized according to individual patient needs to achieve precise treatment and provide cataract patients with high-quality vision.展开更多
With respect to oceanic fluid dynamics,certain models have appeared,e.g.,an extended time-dependent(3+1)-dimensional shallow water wave equation in an ocean or a river,which we investigate in this paper.Using symbolic...With respect to oceanic fluid dynamics,certain models have appeared,e.g.,an extended time-dependent(3+1)-dimensional shallow water wave equation in an ocean or a river,which we investigate in this paper.Using symbolic computation,we find out,on one hand,a set of bilinear auto-Backlund transformations,which could connect certain solutions of that equation with other solutions of that equation itself,and on the other hand,a set of similarity reductions,which could go from that equation to a known ordinary differential equation.The results in this paper depend on all the oceanic variable coefficients in that equation.展开更多
Phantom limb pain(PLP)is not only a physical pain experience but also poses a significant challenge to mental health and quality of life.Currently,the mechanism of PLP treatment is still unclear,and there are many met...Phantom limb pain(PLP)is not only a physical pain experience but also poses a significant challenge to mental health and quality of life.Currently,the mechanism of PLP treatment is still unclear,and there are many methods with varying effects.This article starts with the application research of extended reality technology in PLP treatment,through describing the application of its branch technologies(virtual reality,augmented reality,and mixed reality technology),to lay the foundation for subsequent research,in the hope of finding advanced and effective treatment methods,and providing a basis for future product transformation.展开更多
In this paper,an advanced satellite navigation filter design,referred to as the Variational Bayesian Maximum Correntropy Extended Kalman Filter(VBMCEKF),is introduced to enhance robustness and adaptability in scenario...In this paper,an advanced satellite navigation filter design,referred to as the Variational Bayesian Maximum Correntropy Extended Kalman Filter(VBMCEKF),is introduced to enhance robustness and adaptability in scenarios with non-Gaussian noise and heavy-tailed outliers.The proposed design modifies the extended Kalman filter(EKF)for the global navigation satellite system(GNSS),integrating the maximum correntropy criterion(MCC)and the variational Bayesian(VB)method.This adaptive algorithm effectively reduces non-line-of-sight(NLOS)reception contamination and improves estimation accuracy,particularly in time-varying GNSS measurements.Experimental results show that the proposed method significantly outperforms conventional approaches in estimation accuracy under heavy-tailed outliers and non-Gaussian noise.By combining MCC with VB approximation for real-time noise covariance estimation using fixed-point iteration,the VBMCEKF achieves superior filtering performance in challenging GNSS conditions.The method’s adaptability and precision make it ideal for improving satellite navigation performance in stochastic environments.展开更多
The output feedback active disturbance rejection control of a valve-controlled cylinder electro-hydraulic servo system is investigated in this paper.First,a comprehensive nonlinear mathematical model that encompasses ...The output feedback active disturbance rejection control of a valve-controlled cylinder electro-hydraulic servo system is investigated in this paper.First,a comprehensive nonlinear mathematical model that encompasses both matched and mismatched disturbances is formulated.Due to the fact that only position information can be measured,a linear Extended State Observer(ESO)is introduced to estimate unknown states and matched disturbances,while a dedicated disturbance observer is constructed to estimate mismatched disturbances.Different from the traditional observer results,the design of the disturbance observer used in this study is carried out under the constraint of output feedback.Furthermore,an output feedback nonlinear controller is proposed leveraging the aforementioned observers to achieve accurate trajectory tracking.To mitigate the inherent differential explosion problem of the traditional backstepping framework,a finite-time stable command filter is incorporated.Simultaneously,considering transient filtering errors,a set of error compensation signals are designed to counter their negative impact effectively.Theoretical analysis affirms that the proposed control strategy ensures the boundedness of all signals within the closed-loop system.Additionally,under the specific condition of only time-invariant disturbances in the system,the conclusion of asymptotic stability is established.Finally,the algorithm’s efficacy is validated through comparative experiments.展开更多
1Introduction To date,in model-based gait-planning methods,the dynamics of the center of mass(COM)of bipedal robots have been analyzed by establishing their linear inverted pendulum model(LIPM)or extended forms(Owaki ...1Introduction To date,in model-based gait-planning methods,the dynamics of the center of mass(COM)of bipedal robots have been analyzed by establishing their linear inverted pendulum model(LIPM)or extended forms(Owaki et al.,2010;Englsberger et al.,2015;Xie et al.,2020).With regard to model-based gait-generation methods for uphill and downhill terrain,Kuo(2007)simulated human gait using an inverted pendulum,which provided a circular trajectory for the COM rather than a horizontal trajectory.He found that a horizontal COM trajectory consumed more muscle energy.Massah et al.(2012)utilized a 3D LIPM and the concept of zero moment point(ZMP).They developed a trajectory planner using the semi-elliptical motion equations of an NAO humanoid robot and simulated walking on various sloped terrains using the Webots platform.展开更多
基金supported by the Royal Academy of Engineering,UK,in the scheme of Distinguished International Associate(DIA-2424-5-134).
文摘Accurate estimation of the State of Charge(SOC),State of Health(SOH),and Terminal Resistance(TR)is crucial for the effective operation of Battery Management Systems(BMS)in lithium-ion batteries.This study conducts a comprehensive comparative analysis of four Kalman filter variants Extended Kalman Filter(EKF),Extended Kalman-Bucy Filter(EKBF),Unscented Kalman Filter(UKF),and Unscented Kalman-Bucy Filter(UKBF)under varying battery parameter conditions.These include temperature fluctuation,self-discharge,current direction,cell capacity,process noise,and measurement noise.Our findings reveal significant variations in the performance of SOC and SOH predictions across filters,emphasizing that UKF demonstrates superior robustness to noise,while EKF performs better under accurate system dynamics.The study underscores the need for adaptive filtering strategies that can dynamically adjust to evolving battery parameters,thereby enhancing BMS reliability and extending battery lifespan.
基金supported by the 2024 Research Fund of University of Ulsan.
文摘In recent years,three-dimensional reconstruction technologies that employ multiple cameras have continued to evolve significantly,enabling remote collaboration among users in extended Reality(XR)environments.In addition,methods for deploying multiple cameras for motion capture of users(e.g.,performers)are widely used in computer graphics.As the need to minimize and optimize the number of cameras grows to reduce costs,various technologies and research approaches focused on Optimal Camera Placement(OCP)are continually being proposed.However,as most existing studies assume homogeneous camera setups,there is a growing demand for studies on heterogeneous camera setups.For instance,technical demands keep emerging in scenarios with minimal camera configurations,especially regarding cost factors,the physical placement of cameras given the spatial structure,and image capture strategies for heterogeneous cameras,such as high-resolution RGB cameras and depth cameras.In this study,we propose a pre-visualization and simulation method for the optimal placement of heterogeneous cameras in XR environments,accounting for both the specifications of heterogeneous cameras(e.g.,field of view)and the physical configuration(e.g.,wall configuration)in real-world spaces.The proposed method performs a visibility analysis of cameras by considering each camera’s field-of-view volume,resolution,and unique characteristics,along with physicalspace constraints.This approach enables the optimal position and rotation of each camera to be recommended,along with the minimum number of cameras required.In the results of our study conducted in heterogeneous camera combinations,the proposed method achieved 81.7%~82.7%coverage of the target visual information using only 2~3 cameras.In contrast,single(or homogeneous)-typed cameras were required to use 11 cameras for 81.6%coverage.Accordingly,we found that camera deployment resources can be reduced with the proposed approaches.
基金Project supported by the Guangdong Basic and Applied Basic Research Foundation of China(Nos.2022B1515020099 and 2024A1515240026)the National Natural Science Foundation of China(No.12372147)the Fundamental Research Funds for the Central Universities of China(No.HIT.OCEF.2024019)。
文摘Understanding the fracture behavior of vertical cracks in piezoelectric semiconductor(PS)structures is vital due to their impacts on device reliability.This study establishes a model for a PS strip with a vertical crack under combined mechanical and electric loading,considering both central and edge cracks.Using Fourier transforms and dislocation density functions,the Mode-Ⅲproblem is converted to Cauchy-type singular integral equations.The crack surface fields,intensity factors,and energy release rate are derived.The accuracy of the proposed model is verified through the finite element(FE)simulation via COMSOL Multiphysics.The results for low electron concentrations align with those of the intrinsic piezoelectric materials,validating the correctness of the present model as well.The combined effects of crack position,applied electric loading,and initial carrier concentration on the crack propagation are analyzed.The normalized electric displacement factor shows heightened sensitivity to crack size,electromechanical loading,and carrier concentration.The crack position significantly influences the crack surface fields and normalized intensity factors due to the boundary proximity effect.
基金supported by the National Natural Science Foundation of China(61904053,22279033)the National Key Research and Development Program of China(2023YFB4204502)+2 种基金the 111 Project(B16016)the Fundamental Research Funds for the Central Universities(2025MS043)the Special Foundation for Carbon Peak Carbon Neutralization Technology Innovation Program of Jiangsu Province(BE2022026).
文摘Molecular tailoring of self-assembled hole-transporting monolayers(SAMs)has been proven as an efficient approach for improving the device performance of inverted perovskite solar cells.Herein,a novel SAM with extended conjugation is designed and synthesized,named NaPh-4PACz.Compared to Ph-4PACz,NaPh-4PACz exhibits a larger adsorption energy with the ITO substrate,enabling the formation of a more uniform and dense film,thereby preventing direct contact between the perovskite and ITO.Additionally,NaPh-4PACz also has a stronger interaction with the perovskite,which can reduce buried interface defects and suppress non-radiative recombination.Consequently,NaPh-4PACz-based devices achieved a power conversion efficiency of 25.48%due to their interfacial“adhesive”ability.Importantly,the stability of the NaPh-4PACz-based devices was significantly improved.
基金supported by the National Natural Science Foundation of China under Grants 62203338,62173259 and U1913602Zhejiang Provincial Natural Science Foundation of China under Grant LZ24F0390006the Postdoctoral Science Foundation of China under Grant 2022M722485.
文摘This paper investigates the adaptive optimal tracking control(AOTC)for underactuated surface vessels(USVs).Compared to the majority of existing studies,the control strategy in this paper innovatively combines an extended state observer(ESO)with reinforcement learning(RL).The designed ESO has high estimation accuracy and robust disturbance rejection capabilities for the unmeasurable information for USVs.To obtain the AOTC,the actor–critic(AC)networks based on RL are constructed to solve the Hamilton–Jacobi–Bellman(HJB)equations.Due to the uncertainties,it is challenging to obtain the optimal controller by directly solving the HJB equations.To address this issue,this paper employs neural networks(NNs)to approximate the uncertainties and solves the optimal controller via AC-RL and ESO.In addition,the adaptive parameters of the optimal controller is trained in parallel with AC networks,which can ensure that the trained networks can further improve tracking performance.The boundedness of AOTC for USVs is shown by Lyapunov stability theorem.Finally,simulation results demonstrate the effectiveness of the proposed algorithm.
基金supported by the National Natural Science Foundation of China(Grant No.62172292).
文摘Anomaly detection is a vibrant research direction in controller area networks,which provides the fundamental real-time data transmission underpinning in-vehicle data interaction for the internet of vehicles.However,existing unsupervised learning methods suffer from insufficient temporal and spatial constraints on shallow features,resulting in fragmented feature representations that compromise model stability and accuracy.To improve the extraction of valuable features,this paper investigates the influence of clustering constraints on shallow feature convergence paths at the model level and further proposes an end-to-end intrusion detection system based on efficient deep embedded subspace clustering(EDESC-IDS).Following the standard learning approach,continuous messages are encoded into two-dimensional data frames via a frame builder,which are then input into an extended convolutional autoencoder for extracting shallow features from high-dimensional data.On this basis,the dual constraints of these output features and the embedding clustering module facilitate end-to-end training of the EDESC-IDS in various attack scenarios.Extensive experimental results show that such a system exhibits significant detection performance on four types of attack datasets,including DoS,Gear,Fuzzy,and RPM,with precision,recall,and F1 scores consistently above 97.79%,while maintaining a false negative rate(FNR)and an error rate(ER)below 2.22%.
文摘AIM:To compare the visual outcomes between bilateral implantation of Tecnis ZXR00 extended depth-of-focus(EDOF)intraocular lenses(IOLs)and mixed implantation of Tecnis ZXR00(EDOF)with Tecnis ZMB00(bifocal)IOLs.METHODS:This postoperative cross-sectional study enrolled patients who underwent phacoemulsification combined with IOL implantation.Patients were divided into two groups:the bilateral ZXR00 group(ZXR00-only group)and the mixed IOL group(ZXR00+ZMB00 group).Primary outcome measures included uncorrected and corrected distance visual acuity(UDVA,CDVA),uncorrected and distance-corrected near visual acuity(UNVA,DCNVA),uncorrected and distance-corrected intermediate visual acuity(UIVA,DCIVA),and defocus curves.Secondary outcome measures were visual quality,spectacle independence,patient satisfaction,photic phenomena,and stereopsis.RESULTS:A total of 47 patients(94 eyes)were included,with 26 patients(11 males,15 females)in the ZXR00-only group(mean age:62.73±7.24y)and 21 patients(7 males,14 females)in the mixed group(mean age:65.71±9.16y).There was no statistically significant difference in age between the two groups(P=0.218).The mixed group showed significantly better binocular DCNVA compared to the ZXR00-only group(P=0.002).Defocus curve analysis revealed that the mixed group exhibited superior performance at−2.5 to−4.0 D but inferior performance at−0.5 and−1.5 D.Near stereoacuity was significantly poorer in the mixed group(Randot:5.589±0.744 vs 6.240±0.394 ln arcsec;Contour:4.966±0.973 vs 5.740±0.833 ln arcsec;both P<0.01).Both groups achieved high levels of spectacle independence and patient satisfaction,with no significant differences in photic phenomena or questionnaire scores.CONCLUSION:Mixed implantation of EDOF and bifocal IOLs improve near visual acuity but may compromise near stereopsis.This approach provides a viable option for patients prioritizing near vision;however,caution is recommended for individuals requiring fine stereoscopic vision for daily or professional tasks.
基金supported by the Special Fund of the Institute of Geophysics,China Earthquake Administration,(No.DQJB21B34).
文摘The Haicheng region,Liaoning,China,likely hosts a conjugate fault system comprising the NW-trending Haichenghe fault and NE-trending secondary faults.On February 4,1975,at 19:36 CST,an earthquake of M_(S)7.3 and intensity(MMI)IX hit the city of Haicheng,Liaoning,China.Although deep seismic profiling was previously conducted along the Haichenghe fault,the limited horizontal resolution in the shallow part prevented the recognition of kilometer-scale anomalies.The velocity structure characteristics of the Haichenghe fault and its NE-trending conjugate faults remain unclear.Using the extended range phase shift method,the high-resolution S-wave velocity structures are obtained by deploying a long,dense linear array of 55 short-period seismometers across the fault and NE-trending conjugate faults.The array length was 32 km and inter-station spacing was approximately 600 m,facilitating the collection of approximately 22 days of continuous waveform data.Employing the Extended Range Phase Shift(ERPS)method enabled the extraction of broadband 0.2–5 s Rayleigh wave phase velocity dispersion curves.The broadband dispersion data were used for inversion of the high-resolution S-wave velocity structure to a depth of 8 km from the surface.The velocity structure characteristics and seismicity of the Haichenghe fault and NE-trending conjugate faults were analyzed and compared with nearby fault gas measurements.Results show(1)shallow S-wave velocities show a low-high-low horizontal distribution,corresponding to basin-uplift-basin topography;(2)significant velocity contrasts occur across the Haichenghe fault:its SW segment(0–17 km)exhibits high velocities consistent with Paleoproterozoic crystalline basement(Pt_(1)),while the NE segment(17–32 km)shows low velocities related to Yanshanian intrusions(γ_(5))and Quaternary sediments.NE-trending conjugate faults display sharp velocity gradients marking fracture locations,with all faults being near-vertical to~8 km depth;(3)seismicity at 1–6 km depth mainly clusters in high-velocity zones;at 6–8 km depth,it concentrates beneath the Haichenghe fault in low-velocity areas and along NE-trending faults;(4)the seismic activity characteristics and fault zone width of the Haicheng he fault reflected by velocity imaging results are basically consistent with those obtained by the fault gas measurement method.
文摘Slope failures,particularly in railway embankments during intense rainfall,are a major cause of economic damage and humanitarian loss.To forecast how shear cracks develop in slopes under heavy precipitation,we present a novel modeling framework:the Extended Cohesive Damage Element enhanced by soil moisture(SMECDE).The method first translates forecasted rainfall into soil moisture levels via an established correspondence.Then,recognizing that rainfall infiltration lowers soil cohesion—particularly at varying depths—we introduce a Soil Moisture Decoherence Model(SMDM)based on experimental data,which quantifies how cohesion degrades with moisture and how depth affects this process.By embedding SMDM within the ECDE technique,we investigate how shear fractures propagate under different moisture conditions throughout the slope profile.We apply SMECDE to a real railway embankment case to identify critical moisture thresholds and crack growth patterns.Validation is performed by comparing predictions against field measurements and weather station records,and further checked through simulations of large-scale plastic deformation in ABAQUS.
基金Project supported by the National Natural Science Foundation of China(No.12402033)the National Natural Science Foundation for Distinguished Young Scholars of China(No.52225211)。
文摘Many complex systems are frequently subject to the influence of uncertain disturbances,which can exert a profound effect on the critical transitions(CTs),potentially resulting in catastrophic consequences.Consequently,it is of uttermost importance to provide warnings for noise-induced CTs in various applications.Although capturing certain generic symptoms of transition behaviors from observational and simulated data poses a challenging problem,this work attempts to extract information regarding CTs from simulated data of a Gaussian white noise-induced tri-stable system.Using the extended dynamic mode decomposition(EDMD)algorithm,we initially obtain finite-dimensional approximations of both the stochastic Koopman operator and the generator.Subsequently,the drift parameters and the noise intensity within the system are identified from the simulated data.Utilizing the identified system,the parameter-dependent basin of the unsafe regime(PDBUR)is quantified,enabling data-driven early warning of Gaussian white noise-induced CTs.Finally,an error analysis is carried out to verify the effectiveness of the data-driven results.Our findings may serve as a paradigm for understanding and predicting noise-induced CTs in complex systems based on data.
文摘In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypropylene(PO)and oxyethylene(EO),octadecyl-(PO)_(m)-(EO)_(n)-sodium carboxylate(C_(18)PO_(m)EO_(n)C,m=5,10,15,n=5,10,15),were studied.The surface tension and contact angle of C_(18)PO_(m)EO_(n)C solution with different concentrations were measured,and the adhesion tension,PTFE-water interfacial tension,and adhesion work were calculated.It was found that the extended surfactant molecules adsorb on the surface of the solution and the PTFE-liquid interface simultaneously when the concentration is lower than the critical micelle concentration(cmc),and there was a linear relationship between surface tension and adhesion tension.The adsorption amount of C_(18)PO_(m)EO_(n)C at the PTFE-water interface was significantly lower than that on the surface of the solution.As the concentration increases above cmc,semi-micelle aggregates on the surface of PTFE are formed by C_(18)PO_(m)EO_(n)C molecules through hydrophobic interaction,and the hydrophilic group faces the solution to modify the surface of PTFE with high efficiency.
文摘The concept of emissivity has been with the scientific and engineering world since Planck formulated his blackbody radiation law more than a century ago.Nevertheless,emissivity is an elusive concept even for ex⁃perts.It is a vague and fuzzy concept for the wider community of engineers.The importance of remote sensing of temperature by measuring IR radiation has been recognized in a wide range of industrial,medical,and environ⁃mental uses.One of the major sources of errors in IR radiometry is the emissivity of the surface being measured.In real experiments,emissivity may be influenced by many factors:surface texture,spectral properties,oxida⁃tion,and aging of surfaces.While commercial blackbodies are prevalent,the much-needed grey bodies with a known emissivity,are unavailable.This study describes how to achieve a calibrated and stable emissivity with a blackbody,a perforated screen,and a reliable and linear novel IR thermal sensor,18 dubbed TMOS.The Digital TMOS is now a low-cost commercial product,it requires low power,and it has a small form factor.The method⁃ology is based on two-color measurements,with two different optical filters,with selected wavelengths conform⁃ing to the grey body definition of the use case under study.With a photochemically etched perforated screen,the effective emissivity of the screen is simply the hole density area of the surface area that emits according to the blackbody temperature radiation.The concept is illustrated with ray tracing simulations,which demonstrate the approach.Measured results are reported.
基金supported by the Natural Science Foundation of Henan Province(252300421290)the National Natural Science Foundation of China(41771438)+1 种基金the Program for Innovative Research Team(in Science and Technology)of Henan University(22IRTSTHN010)the Postgraduate Education Reform and Quality Improvement Project of Henan Province(HNYJS2020JD14).
文摘Soil moisture(SM)is a critical variable in terrestrial ecosystems,especially in arid and semi-arid areas where water sources are limited.Despite its importance,understanding the spatiotemporal variations and influencing factors of SM in these areas remains insufficient.This study investigated the spatiotemporal variations and influencing factors of SM in arid and semi-arid areas of China by utilizing the extended triple collation(ETC),Mann-Kendall test,Theil-Sen estimator,ridge regression analysis,and other relevant methods.The following findings were obtained:(1)at the pixel scale,the long-term monthly SM data from the European Space Agency Climate Change Initiative(ESA CCI)exhibited the highest correlation coefficient of 0.794 and the lowest root mean square error(RMSE)of 0.014 m^(3)/m^(3);(2)from 2000 to 2022,the study area experienced significant increase in annual average SM,with a rate of 0.408×10^(-3)m^(3)/(m^(3)•a).Moreover,higher altitudes showed a notable upward trend,with SM increasing rates at 0.210×10^(-3)m^(3)/(m^(3)•a)between 1000 and 2000 m,0.530×10^(-3)m^(3)/(m^(3)•a)between 2000 and 4000 m,and 0.760×10^(-3)m^(3)/(m^(3)•a)at altitudes above 4000 m;(3)land surface temperature(LST),root zone soil moisture(RSM)(10-40 cm depth),and normalized difference vegetation index(NDVI)were identified as the primary factors influencing annual average SM,which accounted for 34.37%,24.16%,and 22.64%relative contributions,respectively;and(4)absolute contribution of LST was more significant in subareas at higher altitudes,with average absolute contributions of 0.800×10^(-3)m^(3)/(m^(3)•a)between 2000 and 4000 m and 0.500×10^(-2) m^(3)/(m^(3)•a)above 4000 m.This study reveals the spatiotemporal variations and main influencing factors of SM in Chinese arid and semi-arid areas,highlighting the more pronounced absolute contribution of LST to SM in high-altitude areas,providing valuable insights for ecological research and water resource management in these areas.
文摘AIM:To compare the clinical outcomes of extended depth-of-focus intraocular lenses(EDOF IOLs)using either micromonovision implantation or mixed implantation of EDOF and diffractive bifocal IOLs.METHODS:This retrospective clinical trial included 130 patients(260 eyes),who were divided into two groups.Group RR comprised 70 patients(140 eyes)bilaterally implanted with ZXR00 IOLs(Tecnis ZXR00,where one target was-0.5 D to-0.75 D and the other was 0 to-0.25 D).Group RM comprised 60 patients(120 eyes)unilaterally implanted with both ZXR00 and ZMB00 IOLs(Tecnis ZMB00,0 to-0.25 D).Postoperative outcomes were compared after 3 mo,including visual acuity,defocus curves,stereoacuity,modulation transfer functions(MTFs),higher-order aberrations,and Visual Function-14(VF-14)questionnaire responses.RESULTS:Group RR had superior bilateral intermediate vision,while the group RM had superior bilateral near vision(both P<0.05).Group RM also exhibited superior MTFs and reduced higher-order aberrations(both P<0.05).Stereoacuity and VF-14 questionnaire results showed no statistically significant difference between groups(P>0.05).CONCLUSION:The implantation of micromonovision has significantly improved near vision.IOLs and their collocation can be customized according to individual patient needs to achieve precise treatment and provide cataract patients with high-quality vision.
基金financially supported by the Scientific Research Foundation of North China University of Technology(Grant Nos.11005136024XN147-87 and 110051360024XN151-86).
文摘With respect to oceanic fluid dynamics,certain models have appeared,e.g.,an extended time-dependent(3+1)-dimensional shallow water wave equation in an ocean or a river,which we investigate in this paper.Using symbolic computation,we find out,on one hand,a set of bilinear auto-Backlund transformations,which could connect certain solutions of that equation with other solutions of that equation itself,and on the other hand,a set of similarity reductions,which could go from that equation to a known ordinary differential equation.The results in this paper depend on all the oceanic variable coefficients in that equation.
文摘Phantom limb pain(PLP)is not only a physical pain experience but also poses a significant challenge to mental health and quality of life.Currently,the mechanism of PLP treatment is still unclear,and there are many methods with varying effects.This article starts with the application research of extended reality technology in PLP treatment,through describing the application of its branch technologies(virtual reality,augmented reality,and mixed reality technology),to lay the foundation for subsequent research,in the hope of finding advanced and effective treatment methods,and providing a basis for future product transformation.
基金supported by the National Science and Technology Council,Taiwan under grants NSTC 111-2221-E-019-047 and NSTC 112-2221-E-019-030.
文摘In this paper,an advanced satellite navigation filter design,referred to as the Variational Bayesian Maximum Correntropy Extended Kalman Filter(VBMCEKF),is introduced to enhance robustness and adaptability in scenarios with non-Gaussian noise and heavy-tailed outliers.The proposed design modifies the extended Kalman filter(EKF)for the global navigation satellite system(GNSS),integrating the maximum correntropy criterion(MCC)and the variational Bayesian(VB)method.This adaptive algorithm effectively reduces non-line-of-sight(NLOS)reception contamination and improves estimation accuracy,particularly in time-varying GNSS measurements.Experimental results show that the proposed method significantly outperforms conventional approaches in estimation accuracy under heavy-tailed outliers and non-Gaussian noise.By combining MCC with VB approximation for real-time noise covariance estimation using fixed-point iteration,the VBMCEKF achieves superior filtering performance in challenging GNSS conditions.The method’s adaptability and precision make it ideal for improving satellite navigation performance in stochastic environments.
基金supported by the National Key R&D Program of China(No.2021YFB2011300)the Special Funds Project for the Transformation of Scientific and Technological Achievements of Jiangsu Province,China(No.BA2023039)+1 种基金the National Natural Science Foundation of China(No.52075262)the Fundamental Research Funds for the Central Universities,China(No.30922010706).
文摘The output feedback active disturbance rejection control of a valve-controlled cylinder electro-hydraulic servo system is investigated in this paper.First,a comprehensive nonlinear mathematical model that encompasses both matched and mismatched disturbances is formulated.Due to the fact that only position information can be measured,a linear Extended State Observer(ESO)is introduced to estimate unknown states and matched disturbances,while a dedicated disturbance observer is constructed to estimate mismatched disturbances.Different from the traditional observer results,the design of the disturbance observer used in this study is carried out under the constraint of output feedback.Furthermore,an output feedback nonlinear controller is proposed leveraging the aforementioned observers to achieve accurate trajectory tracking.To mitigate the inherent differential explosion problem of the traditional backstepping framework,a finite-time stable command filter is incorporated.Simultaneously,considering transient filtering errors,a set of error compensation signals are designed to counter their negative impact effectively.Theoretical analysis affirms that the proposed control strategy ensures the boundedness of all signals within the closed-loop system.Additionally,under the specific condition of only time-invariant disturbances in the system,the conclusion of asymptotic stability is established.Finally,the algorithm’s efficacy is validated through comparative experiments.
基金supported by the National Natural Science Foundation of China(No.12332023)the Zhejiang Provincial Natural Science Foundation of China(No.LY23E050010).
文摘1Introduction To date,in model-based gait-planning methods,the dynamics of the center of mass(COM)of bipedal robots have been analyzed by establishing their linear inverted pendulum model(LIPM)or extended forms(Owaki et al.,2010;Englsberger et al.,2015;Xie et al.,2020).With regard to model-based gait-generation methods for uphill and downhill terrain,Kuo(2007)simulated human gait using an inverted pendulum,which provided a circular trajectory for the COM rather than a horizontal trajectory.He found that a horizontal COM trajectory consumed more muscle energy.Massah et al.(2012)utilized a 3D LIPM and the concept of zero moment point(ZMP).They developed a trajectory planner using the semi-elliptical motion equations of an NAO humanoid robot and simulated walking on various sloped terrains using the Webots platform.
