The growing prevalence of exercise-induced tibial stress fractures demands wearable sensors capable of monitoring dynamic musculoskeletal loads with medical-grade precision.While flexible pressure-sensing insoles show...The growing prevalence of exercise-induced tibial stress fractures demands wearable sensors capable of monitoring dynamic musculoskeletal loads with medical-grade precision.While flexible pressure-sensing insoles show clinical potential,their development has been hindered by the intrinsic trade-off between high sensitivity and full-range linearity(R^(2)>0.99 up to 1 MPa)in conventional designs.Inspired by the tactile sensing mechanism of human skin,where dermal stratification enables wide-range pressure adaptation and ion-channelregulated signaling maintains linear electrical responses,we developed a dual-mechanism flexible iontronic pressure sensor(FIPS).This innovative design synergistically combines two bioinspired components:interdigitated fabric microstructures enabling pressure-proportional contact area expansion(αP1/3)and iontronic film facilitating self-adaptive ion concentration modulation(αP^(2/3)),which together generate a linear capacitance-pressure response(CαP).The FIPS achieves breakthrough performance:242 kPa^(-1)sensitivity with 0.997linearity across 0-1 MPa,yielding a record linear sensing factor(LSF=242,000).The design is validated across various substrates and ionic materials,demonstrating its versatility.Finally,the FIPS-driven design enables a smart insole demonstrating 1.8%error in tibial load assessment during gait analysis,outperforming nonlinear counterparts(6.5%error)in early fracture-risk prediction.The biomimetic design framework establishes a universal approach for developing high-performance linear sensors,establishing generalized principles for medical-grade wearable devices.展开更多
The equivalent linearization method （ELM） is modified to investigate the nonlinear flut- ter system of an airfoil with a cubic damping. After obtaining the linearization quantity of the cubic nonlinearity by the ELM...The equivalent linearization method （ELM） is modified to investigate the nonlinear flut- ter system of an airfoil with a cubic damping. After obtaining the linearization quantity of the cubic nonlinearity by the ELM, an equivalent system can be deduced and then investigated by linear flut- ter analysis methods. Different from the routine procedures of the ELM, the frequency rather than the amplitude of limit cycle oscillation （LCO） is chosen as an active increment to produce bifurca- tion charts. Numerical examples show that this modification makes the ELM much more efficient. Meanwhile, the LCOs obtained by the ELM are in good agreement with numerical solutions. The nonlinear damping can delay the occurrence of secondary bifurcation. On the other hand, it has marginal influence on bifurcation characteristics or LCOs.展开更多
This paper investigates the magnetohydrodynamic （MHD） boundary layer flow of an incompressible upper-convected Maxwell （UCM） fluid over a porous stretching surface. Similarity transformations are used to reduce th...This paper investigates the magnetohydrodynamic （MHD） boundary layer flow of an incompressible upper-convected Maxwell （UCM） fluid over a porous stretching surface. Similarity transformations are used to reduce the governing partial differential equations into a kind of nonlinear ordinary differential equations. The nonlinear prob- lem is solved by using the successive Taylor series linearization method （STSLM）. The computations for velocity components are carried out for the emerging parameters. The numerical values of the skin friction coefficient are presented and analyzed for various parameters of interest in the problem.展开更多
Linearized equations of fluid dynamics of cell two phase flow for one dimensional case are proposed. Based on the equations, an analytic solution is derived, in which the frequency of wave is observed. The frequency f...Linearized equations of fluid dynamics of cell two phase flow for one dimensional case are proposed. Based on the equations, an analytic solution is derived, in which the frequency of wave is observed. The frequency formula consists of all important parameters of the fluid dynamics. In our observation, the group velocity and phase velocity of the motion of wave propagation are explicitly exhibited as well.展开更多
The aim of our work is to formulate and demonstrate the results of the normality, the Lipschitz continuity, of a nonlinear feedback system described by the monotone maximal operators and hemicontinuous, defined on rea...The aim of our work is to formulate and demonstrate the results of the normality, the Lipschitz continuity, of a nonlinear feedback system described by the monotone maximal operators and hemicontinuous, defined on real reflexive Banach spaces, as well as the approximation in a neighborhood of zero, of solutions of a feedback system [A,B] assumed to be non-linear, by solutions of another linear, This approximation allows us to obtain appropriate estimates of the solutions. These estimates have a significant effect on the study of the robust stability and sensitivity of such a system see <a href="#ref1">[1]</a> <a href="#ref2">[2]</a> <a href="#ref3">[3]</a>. We then consider a linear FS <img src="Edit_4629d4d0-bbb2-478d-adde-391efde3d1e0.bmp" alt="" />, and prove that, if <img src="Edit_435aae08-e821-4b4d-99d2-e2a2b47609c1.bmp" alt="" />;<img src="Edit_4fa030bc-1f97-4726-8257-ca8d00657aac.bmp" alt="" /> , with <img src="Edit_63ab4faa-ba40-45fe-8b8a-7a6caef91794.bmp" alt="" />the respective solutions of FS’s [A,B] and <img src="Edit_e78e2e6d-8934-4011-93eb-8b7eb52fa856.bmp" alt="" /> corresponding to the given (u,v) in <img src="Edit_0e18433c-8c7a-454f-8eec-6eb9fb69469a.bmp" alt="" /> . There exists,<img src="Edit_3dcd8afc-8cea-4c06-a920-e4148a5f793e.bmp" alt="" />, positive real constants such that, <img src="Edit_edb88446-3e39-4fe0-865a-114de701e78e.bmp" alt="" />. These results are the subject of theorems 3.1, <span style="font-size:10.0pt;font-family:;" "="">... </span>, 3.3. The proofs of these theorems are based on our lemmas 3.2, <span style="font-size:10.0pt;font-family:;" "="">... </span>, 3.5, devoted according to the hypotheses on A and B, to the existence of the inverse of the operator <em>I+BA</em> and <img src="Edit_2db1326b-cb5b-44cf-8d1f-df22bd6da45f.bmp" alt="" />. The results obtained and demonstrated along this document, present an extension in general Banach space of those in <a href="#ref4">[4]</a> on a Hilbert space <em>H</em> and those in <a href="#ref5">[5]</a> on a extended Hilbert space <img src="Edit_b70ce337-1812-4d4b-ae7d-a24da7e5b3cf.bmp" alt="" />.展开更多
The exact feedback linearization method implies an accurate knowledge of the model and its parameters.This assumption is an inherent limitation of the method,suffering from robustness issues.In general,the model struc...The exact feedback linearization method implies an accurate knowledge of the model and its parameters.This assumption is an inherent limitation of the method,suffering from robustness issues.In general,the model structure is only partially known and its parameters present uncertainties.The current paper extends the classical exact feedback linearization to the robust feedback linearization by adding an appropriatelydesigned robust control layer.This is then able to ensure robust stability and robust performance for the given uncertain system in a desired region of attraction.We consider the case of full relative degree input-affine nonlinear systems,which are of great practical importance in the literature.The inner loop contains the feedback linearization input for the nominal system and the resulting residual nonlinearities can always be characterized as inverse additive uncertainties.The constructive proofs provide exact representations of the uncertainty models in three considered scenarios:unmatched,fully-matched,and partially-matched uncertainties.The uncertainty model will be a descriptor system,which also represents one of the novelties of the paper.Our approach leads to a simplified control structure and a less conservative coverage of the uncertainty set compared to current alternatives.The end-to-end procedure is emphasized on an illustrative example,in two different hypotheses.展开更多
Judicious selection of landfill allocation is crucial since inappropriate dumping of wastes can negatively impact human health and degrade the ecosystem.Therefore,this survey presents an integration multi-criteria dec...Judicious selection of landfill allocation is crucial since inappropriate dumping of wastes can negatively impact human health and degrade the ecosystem.Therefore,this survey presents an integration multi-criteria decision approach with the geographic information system for re-evaluating the pending hazardous landfill in Jradou,Tunisia,considering the conflict with neighboring inhabitants.The study involved twelve constraints and eight factors relevant to environmental and socio-economic challenges based on international works,guidelines of the country’s legislation,and an assessment questionnaire on the landfill suitability map.The Analytic Hierarchy Process(AHP)apportioned weights to criteria,and a Weighted Linear Combination(WLC)approach generated landfill suitability maps(LSM).Afterward,the produced LSM revealed that 2%(8.46km²)of the land was classified as very high,followed by 48%(203.04km²)as high,25%(105.75km²)as moderate,10%(42.3km²)as low,and the remaining 15%(63.45km²)as very low suitable.Furthermore,the operating hazardous waste landfill of Jradou falls within unsuitable areas,inflicting severe harm on the neighboring.The pending hazardous landfill of Jradou should be closed,and a new site must be identified.Conversely,the highly suitable classes are further identified in(1)the Eastern part of the study area,near Ouled ben Amara,and(2)the Northern part of Zaghouan,at 2 km north of Smenja,for potential future hazardous waste landfills.Consequently,governments and relevant stakeholders should investigate these zones to locate new landfills.展开更多
The long-term Mittag-Leffler stability of solutions to multi-term timefractional diffusion equations with constant coefficients was rigorously established,which demonstrated that the algebraic decay rate of the soluti...The long-term Mittag-Leffler stability of solutions to multi-term timefractional diffusion equations with constant coefficients was rigorously established,which demonstrated that the algebraic decay rate of the solution,characterized by||u_(n)||L^(2)(Ω)=O(t^(−αs)) as t→∞,is determined by the minimum order α_(s) of the time-fractional derivatives.Building on this foundational result,this article pursues two primary objectives.First,we introduce a strongly A-stable fractional linear multistep method and derive the numerical stability region for the governing equation.Second,we rigorously prove the long-term decay rate of the numerical solution through a detailed singularity analysis of its generating function.Notably,the numerical decay rate||u_(n)||L^(2)(Ω)=O(t_(n)^(−α_(s)) as t_(n)→∞aligns precisely with the continuous case.Theoretical findings are further validated through comprehensive numerical simulations,underscoring the robustness of our proposed method.展开更多
Ammonium level in body fluids serves as one of the critical biomarkers for healthcare,especially those relative to liver diseases.The continuous and real-time monitoring in both invasive and noninvasive manners is hig...Ammonium level in body fluids serves as one of the critical biomarkers for healthcare,especially those relative to liver diseases.The continuous and real-time monitoring in both invasive and noninvasive manners is highly desired,while the ammonium concentrations vary largely in different body fluids.Besides,the sensing reliability based on ion-selective biosensors can be significantly interfered by potassium ions.To tackle these challenges,a flexible and biocompatible sensing patch for wireless ammonium level sensing was reported with an ultrawide linear range for universal body fluids including blood,tears,saliva,sweat and urine.The as-prepared biocompatible sensors deliver a reliable sensitivity of 58.7 mV decade-1 in the range of 1-100 mM and a desirable selectivity coefficient of 0.11 in the interference of potassium ions,attributed to the cross-calibration within the sensors array.The sensor’s biocompatibility was validated by the cell growth on the sensor surface(>80%),hemolysis rates(<5%),negligible cellular inflammatory responses and weight changes of the mice with implanted sensors.Such biocompatible sensors with ultrawide linear range and desirable selectivity open up new possibility of highly compatible biomarker analysis via different body fluids in versatile approaches.展开更多
基金supported by the National Natural Science Foundation of China(NSFC 52175281,52475315)Youth Innovation Promotion Association of CAS(2021382)。
文摘The growing prevalence of exercise-induced tibial stress fractures demands wearable sensors capable of monitoring dynamic musculoskeletal loads with medical-grade precision.While flexible pressure-sensing insoles show clinical potential,their development has been hindered by the intrinsic trade-off between high sensitivity and full-range linearity(R^(2)>0.99 up to 1 MPa)in conventional designs.Inspired by the tactile sensing mechanism of human skin,where dermal stratification enables wide-range pressure adaptation and ion-channelregulated signaling maintains linear electrical responses,we developed a dual-mechanism flexible iontronic pressure sensor(FIPS).This innovative design synergistically combines two bioinspired components:interdigitated fabric microstructures enabling pressure-proportional contact area expansion(αP1/3)and iontronic film facilitating self-adaptive ion concentration modulation(αP^(2/3)),which together generate a linear capacitance-pressure response(CαP).The FIPS achieves breakthrough performance:242 kPa^(-1)sensitivity with 0.997linearity across 0-1 MPa,yielding a record linear sensing factor(LSF=242,000).The design is validated across various substrates and ionic materials,demonstrating its versatility.Finally,the FIPS-driven design enables a smart insole demonstrating 1.8%error in tibial load assessment during gait analysis,outperforming nonlinear counterparts(6.5%error)in early fracture-risk prediction.The biomimetic design framework establishes a universal approach for developing high-performance linear sensors,establishing generalized principles for medical-grade wearable devices.
基金supported by the National Natural Science Foundation of China (Nos.:11002088,11172333,11272361)
文摘The equivalent linearization method （ELM） is modified to investigate the nonlinear flut- ter system of an airfoil with a cubic damping. After obtaining the linearization quantity of the cubic nonlinearity by the ELM, an equivalent system can be deduced and then investigated by linear flut- ter analysis methods. Different from the routine procedures of the ELM, the frequency rather than the amplitude of limit cycle oscillation （LCO） is chosen as an active increment to produce bifurca- tion charts. Numerical examples show that this modification makes the ELM much more efficient. Meanwhile, the LCOs obtained by the ELM are in good agreement with numerical solutions. The nonlinear damping can delay the occurrence of secondary bifurcation. On the other hand, it has marginal influence on bifurcation characteristics or LCOs.
文摘This paper investigates the magnetohydrodynamic （MHD） boundary layer flow of an incompressible upper-convected Maxwell （UCM） fluid over a porous stretching surface. Similarity transformations are used to reduce the governing partial differential equations into a kind of nonlinear ordinary differential equations. The nonlinear prob- lem is solved by using the successive Taylor series linearization method （STSLM）. The computations for velocity components are carried out for the emerging parameters. The numerical values of the skin friction coefficient are presented and analyzed for various parameters of interest in the problem.
基金Supported by the National Natural Science Foundation of China(10672022)
文摘Linearized equations of fluid dynamics of cell two phase flow for one dimensional case are proposed. Based on the equations, an analytic solution is derived, in which the frequency of wave is observed. The frequency formula consists of all important parameters of the fluid dynamics. In our observation, the group velocity and phase velocity of the motion of wave propagation are explicitly exhibited as well.
文摘The aim of our work is to formulate and demonstrate the results of the normality, the Lipschitz continuity, of a nonlinear feedback system described by the monotone maximal operators and hemicontinuous, defined on real reflexive Banach spaces, as well as the approximation in a neighborhood of zero, of solutions of a feedback system [A,B] assumed to be non-linear, by solutions of another linear, This approximation allows us to obtain appropriate estimates of the solutions. These estimates have a significant effect on the study of the robust stability and sensitivity of such a system see <a href="#ref1">[1]</a> <a href="#ref2">[2]</a> <a href="#ref3">[3]</a>. We then consider a linear FS <img src="Edit_4629d4d0-bbb2-478d-adde-391efde3d1e0.bmp" alt="" />, and prove that, if <img src="Edit_435aae08-e821-4b4d-99d2-e2a2b47609c1.bmp" alt="" />;<img src="Edit_4fa030bc-1f97-4726-8257-ca8d00657aac.bmp" alt="" /> , with <img src="Edit_63ab4faa-ba40-45fe-8b8a-7a6caef91794.bmp" alt="" />the respective solutions of FS’s [A,B] and <img src="Edit_e78e2e6d-8934-4011-93eb-8b7eb52fa856.bmp" alt="" /> corresponding to the given (u,v) in <img src="Edit_0e18433c-8c7a-454f-8eec-6eb9fb69469a.bmp" alt="" /> . There exists,<img src="Edit_3dcd8afc-8cea-4c06-a920-e4148a5f793e.bmp" alt="" />, positive real constants such that, <img src="Edit_edb88446-3e39-4fe0-865a-114de701e78e.bmp" alt="" />. These results are the subject of theorems 3.1, <span style="font-size:10.0pt;font-family:;" "="">... </span>, 3.3. The proofs of these theorems are based on our lemmas 3.2, <span style="font-size:10.0pt;font-family:;" "="">... </span>, 3.5, devoted according to the hypotheses on A and B, to the existence of the inverse of the operator <em>I+BA</em> and <img src="Edit_2db1326b-cb5b-44cf-8d1f-df22bd6da45f.bmp" alt="" />. The results obtained and demonstrated along this document, present an extension in general Banach space of those in <a href="#ref4">[4]</a> on a Hilbert space <em>H</em> and those in <a href="#ref5">[5]</a> on a extended Hilbert space <img src="Edit_b70ce337-1812-4d4b-ae7d-a24da7e5b3cf.bmp" alt="" />.
基金funded by the project new smart and adaptive robotics solutions for personalized minimally invasive surgery in cancer treatment−ATHENA,European Union-NextGenerationEU and Romanian Government,under National Recovery and Resilience Plan for Romania(CF116/15.11.2022)through the Romanian Ministry of Research,Innovation and Digitalization(within Component 9,investment I8)。
文摘The exact feedback linearization method implies an accurate knowledge of the model and its parameters.This assumption is an inherent limitation of the method,suffering from robustness issues.In general,the model structure is only partially known and its parameters present uncertainties.The current paper extends the classical exact feedback linearization to the robust feedback linearization by adding an appropriatelydesigned robust control layer.This is then able to ensure robust stability and robust performance for the given uncertain system in a desired region of attraction.We consider the case of full relative degree input-affine nonlinear systems,which are of great practical importance in the literature.The inner loop contains the feedback linearization input for the nominal system and the resulting residual nonlinearities can always be characterized as inverse additive uncertainties.The constructive proofs provide exact representations of the uncertainty models in three considered scenarios:unmatched,fully-matched,and partially-matched uncertainties.The uncertainty model will be a descriptor system,which also represents one of the novelties of the paper.Our approach leads to a simplified control structure and a less conservative coverage of the uncertainty set compared to current alternatives.The end-to-end procedure is emphasized on an illustrative example,in two different hypotheses.
基金This research was supported by Researchers Supporting Project number(RSP2025R425),King Saud University,Riyadh,Saudi Arabia.
文摘Judicious selection of landfill allocation is crucial since inappropriate dumping of wastes can negatively impact human health and degrade the ecosystem.Therefore,this survey presents an integration multi-criteria decision approach with the geographic information system for re-evaluating the pending hazardous landfill in Jradou,Tunisia,considering the conflict with neighboring inhabitants.The study involved twelve constraints and eight factors relevant to environmental and socio-economic challenges based on international works,guidelines of the country’s legislation,and an assessment questionnaire on the landfill suitability map.The Analytic Hierarchy Process(AHP)apportioned weights to criteria,and a Weighted Linear Combination(WLC)approach generated landfill suitability maps(LSM).Afterward,the produced LSM revealed that 2%(8.46km²)of the land was classified as very high,followed by 48%(203.04km²)as high,25%(105.75km²)as moderate,10%(42.3km²)as low,and the remaining 15%(63.45km²)as very low suitable.Furthermore,the operating hazardous waste landfill of Jradou falls within unsuitable areas,inflicting severe harm on the neighboring.The pending hazardous landfill of Jradou should be closed,and a new site must be identified.Conversely,the highly suitable classes are further identified in(1)the Eastern part of the study area,near Ouled ben Amara,and(2)the Northern part of Zaghouan,at 2 km north of Smenja,for potential future hazardous waste landfills.Consequently,governments and relevant stakeholders should investigate these zones to locate new landfills.
文摘The long-term Mittag-Leffler stability of solutions to multi-term timefractional diffusion equations with constant coefficients was rigorously established,which demonstrated that the algebraic decay rate of the solution,characterized by||u_(n)||L^(2)(Ω)=O(t^(−αs)) as t→∞,is determined by the minimum order α_(s) of the time-fractional derivatives.Building on this foundational result,this article pursues two primary objectives.First,we introduce a strongly A-stable fractional linear multistep method and derive the numerical stability region for the governing equation.Second,we rigorously prove the long-term decay rate of the numerical solution through a detailed singularity analysis of its generating function.Notably,the numerical decay rate||u_(n)||L^(2)(Ω)=O(t_(n)^(−α_(s)) as t_(n)→∞aligns precisely with the continuous case.Theoretical findings are further validated through comprehensive numerical simulations,underscoring the robustness of our proposed method.
基金supported by the National Natural Science Foundation of China(62201243)Natural Science Foundation of Guangdong Province(2022A1515011928)+2 种基金Shenzhen Science and Technology Program(Grant No.RCYX20231211090432060,JSGGZD20220822095600001)Postgraduate Scientific Research Innovation Project of Hunan Province(CX20231306)the technical support from the Southern University of Science and Technology Core Research Facilities(SUSTech CRF)。
文摘Ammonium level in body fluids serves as one of the critical biomarkers for healthcare,especially those relative to liver diseases.The continuous and real-time monitoring in both invasive and noninvasive manners is highly desired,while the ammonium concentrations vary largely in different body fluids.Besides,the sensing reliability based on ion-selective biosensors can be significantly interfered by potassium ions.To tackle these challenges,a flexible and biocompatible sensing patch for wireless ammonium level sensing was reported with an ultrawide linear range for universal body fluids including blood,tears,saliva,sweat and urine.The as-prepared biocompatible sensors deliver a reliable sensitivity of 58.7 mV decade-1 in the range of 1-100 mM and a desirable selectivity coefficient of 0.11 in the interference of potassium ions,attributed to the cross-calibration within the sensors array.The sensor’s biocompatibility was validated by the cell growth on the sensor surface(>80%),hemolysis rates(<5%),negligible cellular inflammatory responses and weight changes of the mice with implanted sensors.Such biocompatible sensors with ultrawide linear range and desirable selectivity open up new possibility of highly compatible biomarker analysis via different body fluids in versatile approaches.
