By using the dynamic shift-share analysis, the industrial structure and competitive strength of 31 provincial districts except Taiwan, Hong Kong and Macao are studied by taking the GDP of the three industries as the r...By using the dynamic shift-share analysis, the industrial structure and competitive strength of 31 provincial districts except Taiwan, Hong Kong and Macao are studied by taking the GDP of the three industries as the research entrance and the whole nation as the reference district. The industrial structure and competitive strength of each provincial district is measured. Through the analysis of pertinence, the correlation degree of industrial structure and industrial competitive strength to economic growth is analyzed. The results show that the industrial competitive strength is closely related to the economic growth of the 31 provincial districts, but the contribution made by the industrial structure to economic growth is insufficient and the effect of industrial structure does not match with that of industrial competitive strength. According to industrial competitiveness and industrial structure effect, 31 provincial districts of the whole nation are divided into 4 types and the relevant countermeasures of the four types are put forward.展开更多
Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emp...Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emphasis on structural durability and monitoring is required.This study focuses on the mechanical vibrations that occur in rotary drilling systems,which have a substantial impact on the structural integrity of drilling equipment.The study specifically investigates axial,torsional,and lateral vibrations,which might lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency stick-slip.These events not only hinder the efficiency of drilling but also lead to exhaustion and harm to the system’s components since they are difficult to be detected and controlled in real time.The study investigates the dynamic interactions of these vibrations,specifically in their high-frequency modes,usingfield data obtained from measurement while drilling.Thefindings have demonstrated the effect of strong coupling between the high-frequency modes of these vibrations on drilling sys-tem performance.The obtained results highlight the importance of considering the interconnected impacts of these vibrations when designing and implementing robust control systems.Therefore,integrating these compo-nents can increase the durability of drill bits and drill strings,as well as improve the ability to monitor and detect damage.Moreover,by exploiting thesefindings,the assessment of structural resilience in rotary drilling systems can be enhanced.Furthermore,the study demonstrates the capacity of structural health monitoring to improve the quality,dependability,and efficiency of rotary drilling systems in the petroleum industry.展开更多
Chassis-by-wire technology has gained significant attention,with the scope of chassis domain control expanding from traditional two-dimensional plane motion control to encompass three-dimensional space motion control....Chassis-by-wire technology has gained significant attention,with the scope of chassis domain control expanding from traditional two-dimensional plane motion control to encompass three-dimensional space motion control.Modern chassis-by-wire systems manage an increasing number of heterogeneous chassis execution systems,including distributed drive,all-wheel drive(AWD),brake-by-wire(BBW),steer-by-wire(SBW),rear-wheel steering(RWS),active stabilizer bar(ASB)and active suspension system(ASS),greatly enhancing the controllable degrees of freedom compared to conventional chassis configurations.To advance research in chassis domain control,it is essential to understand how these heterogeneous execution systems influence vehicle dynamics.This paper focuses on the modeling and analysis of the lateral,longitudinal,and vertical chassis control and execution systems,-as well as their impact on vehicle lateral motion.Using a vehicle simulation platform,both the vehicle dynamics model and the individual dynamics models of each execution system were developed to analyze the influence of these systems on lateral dynamics.Additionally,a hierarchical control architecture was designed to control the vehicle’s lateral stability.The effectiveness of the proposed control scheme was demonstrated and validated through hardware-in-the-loop(HIL)tests and real-world vehicle testing.展开更多
Composite dams,due to their combination of advantages from multiple dam types,are widely used under complex topographic and geological conditions.The static and dynamic stability of their spillway sections is crucial ...Composite dams,due to their combination of advantages from multiple dam types,are widely used under complex topographic and geological conditions.The static and dynamic stability of their spillway sections is crucial for project safety.This paper takes a composite dam as the research object and uses finite difference software FLAC^(3D) to perform static and dynamic calculation analysis on its No.12 and No.13 spillway sections.The static conditions consider normal water level and dead water level,while the dynamic conditions are based on free-field boundary conditions and Rayleigh damping,with an input peak acceleration of 0.15g artificial synthetic seismic wave(duration 10s),analyzing dam displacement and stress distribution.Based on relevant national standards and specifications,the analysis results show:Under static conditions,the dam displacement and stress distribution conform to conventional patterns,with the maximum horizontal displacement at the dam crest being 3.43mm,meeting safety requirements;The tensile stress near the hinged beam area is relatively large,suggesting strengthened reinforcement,with no other hazardous areas.Under dynamic conditions,the maximum relative dynamic displacement at the dam crest is 5.51mm,which is safe and controllable;The tensile stress at the junction of the weir crest and gate pier exceeds the dynamic tensile strength of concrete,and the tensile stress near the hinged beam is relatively high,requiring strengthened reinforcement,with no other hazardous areas.The study indicates that the dam structure design generally meets safety requirements,but local high tensile stress areas need optimized reinforcement design.展开更多
Double-shaft-driven needle punching machine is a specialized equipment designed for processing C/C crucible preforms.Its main needle punching module is operated by two sets of reciprocating crank-slider mechanisms.The...Double-shaft-driven needle punching machine is a specialized equipment designed for processing C/C crucible preforms.Its main needle punching module is operated by two sets of reciprocating crank-slider mechanisms.The intense vibration during needle punching not only generates huge noise,but also substantially reduces the quality of the preform.It is imperative to perform a dynamic analysis and optimization of the entire needle punching machine.In this paper,the three-dimensional(3D)model of the entire double-shaft-driven needle punching machine for C/C crucible preforms is established.Based on the modal analysis theory,the modal characteristics of the needle punching machine under various operating conditions are analyzed and its natural frequencies and vibration modes are determined.The harmonic response analysis is then employed to obtain the amplitude of the needle plate at different frequencies,and the structural weak points of the needle punching machine are identified and improved.The feasibility of the optimized scheme is subsequently reevaluated and verified.The results indicate that the first six natural frequencies of the machine increase,and the maximum amplitude of the needle plate decreases by 70.3%.The enhanced dynamic characteristics of the machine significantly improve its performance,enabling more efficient needle punching of C/C crucible preforms.展开更多
The nonlinear Schrodinger equation(NLSE) is a key tool for modeling wave propagation in nonlinear and dispersive media. This study focuses on the complex cubic NLSE with δ-potential,explored through the Brownian proc...The nonlinear Schrodinger equation(NLSE) is a key tool for modeling wave propagation in nonlinear and dispersive media. This study focuses on the complex cubic NLSE with δ-potential,explored through the Brownian process. The investigation begins with the derivation of stochastic solitary wave solutions using the modified exp(-Ψ(ξ)) expansion method. To illustrate the noise effects, 3D and 2D visualizations are displayed for different non-negative values of noise parameter under suitable parameter values. Additionally, qualitative analysis of both perturbed and unperturbed dynamical systems is conducted using bifurcation and chaos theory. In bifurcation analysis, we analyze the detailed parameter analysis near fixed points of the unperturbed system. An external periodic force is applied to perturb the system, leading to an investigation of its chaotic behavior. Chaos detection tools are employed to predict the behavior of the perturbed dynamical system, with results validated through visual representations.Multistability analysis is conducted under varying initial conditions to identify multiple stable states in the perturbed dynamical system, contributing to chaotic behavior. Also, sensitivity analysis of the Hamiltonian system is performed for different initial conditions. The novelty of this work lies in the significance of the obtained results, which have not been previously explored for the considered equation. These findings offer noteworthy insights into the behavior of the complex cubic NLSE with δ-potential and its applications in fields such as nonlinear optics, quantum mechanics and Bose–Einstein condensates.展开更多
The 53rd issue of Financial Innovation(FIN),Volume 11,No.5(2025),features 21 papers that can be classified into four main themes:the Special Issue on The Anomie of Artificial Intelligence(AI)in Finance:Bridging the Ga...The 53rd issue of Financial Innovation(FIN),Volume 11,No.5(2025),features 21 papers that can be classified into four main themes:the Special Issue on The Anomie of Artificial Intelligence(AI)in Finance:Bridging the Gap Between Technical Power and Human Wisdom,and Financial Markets and Investments,Economic and Policy Analysis,Corporate Governance and Related Market Dynamics.展开更多
Assessing the benefits and costs of digitalization in the energy industry is a complex issue.Traditional cost-benefit analysis(CBA)might encounter problems in addressing uncertainties,dynamic stakeholder interactions,...Assessing the benefits and costs of digitalization in the energy industry is a complex issue.Traditional cost-benefit analysis(CBA)might encounter problems in addressing uncertainties,dynamic stakeholder interactions,and feedback loops arising out of the evolving nature of digitalization.This paper introduces a methodological framework to help address the intricate inter connections between digital applications and business models in the energy industry.The proposed framework leverages system dynamics to achieve two primary objectives.It investigates how digitalization generally influences the value proposi-tion,value capture,and value creation dimensions of business models.It also quantifies the financial and social impacts of digitalization from a dynamic perspective.The proposed dynamic CBA allows for a more precise quantification of the benefits and costs,associated with evidence-based decision-making.Findings from an illustrative case study challenge the static assumptions of conventional methods.These methods often presume continuous operation,neglecting reinvestment and operational feedback loops,and resulting in negative net present values.Conversely,the outcomes of the proposed method indicate positive net present values when accounting for factors such as reinvestment rates and the will-ingness to invest in digitalization projects.The principles outlined in this paper can enable a more accu-rate assessment of digitalization projects,thus catalyzing the development of new CBA applications and guidelines for digitalization.展开更多
During the construction of bank slopes involving pile driving,ensuring slope stability is crucial.This requires the design of appropriate support systems and a thorough evaluation of the failure mechanisms of pile str...During the construction of bank slopes involving pile driving,ensuring slope stability is crucial.This requires the design of appropriate support systems and a thorough evaluation of the failure mechanisms of pile structures under dynamic loading conditions.Based on the Huarong Coal Wharf project,various support schemes are analyzed using numerical simulation methods to calculate and compare slope stability coefficients.The optimal scheme is then identified.Under the selected support scheme,a numerical model of double-row suspended steel sheet piles is developed to investigate the dynamic response of the pile structures under pile driving loads.A time-history analysis is performed to assess the slope’s dynamic stability.The results show that the maximum displacements of the upper and lower steel sheet pile rows are 2.51 and 3.14 cm,respectively.The maximum principal stresses remain below 20 MPa in both rows,while the maximum von Mises stresses are 20.85 MPa for the upper row and 25.40 MPa for the lower row.The dominant frequencies of the steel sheet pile structures fall between 30 and 35 Hz,with a frequency bandwidth ranging from 0 to 500 Hz.The stability coefficient of the pile structures varies over time during the pile driving process,ultimately reaching a value of 1.26—exceeding the required safety threshold.This research provides practical guidance for designing support systems in wharf piling projects and offers a reliable basis for evaluating the safety performance of steel sheet piles in bank slopes.展开更多
Radial rotating oscillating heat pipes(R-OHPs)have excellent thermal performance and great potential for application in the thermal management of rotatory machinery.However,the heat transport behavior and temperature ...Radial rotating oscillating heat pipes(R-OHPs)have excellent thermal performance and great potential for application in the thermal management of rotatory machinery.However,the heat transport behavior and temperature characteristics of R-OHPs are complex,and their understanding is still limited,hence necessitating further research.In this study,thanks to an experimental investigation involving a copper R-OHP running with acetone and water,its thermal performance is evaluated,and then the temperature characteristics are analyzed by nonlinear dynamic analysis.The study reveals that the effective heat transfer coefficient of R-OHPs undergoes a notable increase with rising rotational speed,exhibiting a peak at a threshold speed value.Such a peak is present irrespectively of the working fluid,and,after exceeding the threshold,higher rotational speeds lead to a lower thermal performance.Based on nonlinear dynamic analysis,the power spectrum density of the evaporator temperature indicates a lack of dominant frequency in temperature signals,suggesting a complex behavior characterized by random oscillations of vapor slugs and liquid plugs.In order to better understand how strong the chaotic behavior is,an autocorrelation analysis was carried out,the OHP at static state has a stronger chaos than R-OHPs.The correlation dimension analysis of the evaporator temperature provides values ranging from 1.2 to 1.6,which together with the Lyapunov exponent calculations,further support an evident chaotic nature of R-OHPs.展开更多
In this paper,a meshfree Jacobi point interpolation(MJPI)approach for the dynamic analysis of sandwich laminated conical and cylindrical shells with varying thickness is presented.The theoretical formulations for sand...In this paper,a meshfree Jacobi point interpolation(MJPI)approach for the dynamic analysis of sandwich laminated conical and cylindrical shells with varying thickness is presented.The theoretical formulations for sandwich laminated shells with varying thickness are established using the modified variational principle within the framework of first-order shear deformation theory(FSDT).The displacement components of the sandwich shell are expanded using the MJPI shape function and Fourier series in the meridional and circumferential directions,respectively.The accuracy and reliability of the proposed MJPI shape function are validated against numerical results from published literature and the commercial simulation tool Abaqus.Finally,the effects of different parameters such as thickness gradient,thickness power index and boundary condition on the free vibration and dynamic response of the sandwich laminated shell are investigated.展开更多
Kernel-based slow feature analysis(SFA)methods have been successfully applied in the industrial process fault detection field.However,kernel-based SFA methods have high computational complexity as dealing with nonline...Kernel-based slow feature analysis(SFA)methods have been successfully applied in the industrial process fault detection field.However,kernel-based SFA methods have high computational complexity as dealing with nonlinearity,leading to delays in detecting time-varying data features.Additionally,the uncertain kernel function and kernel parameters limit the ability of the extracted features to express process characteristics,resulting in poor fault detection performance.To alleviate the above problems,a novel randomized auto-regressive dynamic slow feature analysis(RRDSFA)method is proposed to simultaneously monitor the operating point deviations and process dynamic faults,enabling real-time monitoring of data features in industrial processes.Firstly,the proposed Random Fourier mappingbased method achieves more effective nonlinear transformation,contrasting with the current kernelbased RDSFA algorithm that may lead to significant computational complexity.Secondly,a randomized RDSFA model is developed to extract nonlinear dynamic slow features.Furthermore,a Bayesian inference-based overall fault monitoring model including all RRDSFA sub-models is developed to overcome the randomness of random Fourier mapping.Finally,the superiority and effectiveness of the proposed monitoring method are demonstrated through a numerical case and a simulation of continuous stirred tank reactor.展开更多
Data-driven process monitoring is an effective approach to assure safe operation of modern manufacturing and energy systems,such as thermal power plants being studied in this work.Industrial processes are inherently d...Data-driven process monitoring is an effective approach to assure safe operation of modern manufacturing and energy systems,such as thermal power plants being studied in this work.Industrial processes are inherently dynamic and need to be monitored using dynamic algorithms.Mainstream dynamic algorithms rely on concatenating current measurement with past data.This work proposes a new,alternative dynamic process monitoring algorithm,using dot product feature analysis(DPFA).DPFA computes the dot product of consecutive samples,thus naturally capturing the process dynamics through temporal correlation.At the same time,DPFA's online computational complexity is lower than not just existing dynamic algorithms,but also classical static algorithms(e.g.,principal component analysis and slow feature analysis).The detectability of the new algorithm is analyzed for three types of faults typically seen in process systems:sensor bias,process fault and gain change fault.Through experiments with a numerical example and real data from a thermal power plant,the DPFA algorithm is shown to be superior to the state-of-the-art methods,in terms of better monitoring performance(fault detection rate and false alarm rate)and lower computational complexity.展开更多
This paper presents a framework for constructing surrogate models for sensitivity analysis of structural dynamics behavior.Physical models involving deformation,such as collisions,vibrations,and penetration,are devel-...This paper presents a framework for constructing surrogate models for sensitivity analysis of structural dynamics behavior.Physical models involving deformation,such as collisions,vibrations,and penetration,are devel-oped using the material point method.To reduce the computational cost of Monte Carlo simulations,response surface models are created as surrogate models for the material point system to approximate its dynamic behavior.An adaptive randomized greedy algorithm is employed to construct a sparse polynomial chaos expansion model with a fixed order,effectively balancing the accuracy and computational efficiency of the surrogate model.Based on the sparse polynomial chaos expansion,sensitivity analysis is conducted using the global finite difference and Sobol methods.Several examples of structural dynamics are provided to demonstrate the effectiveness of the proposed method in addressing structural dynamics problems.展开更多
Ensuring software quality in open⁃source environments requires adaptive mechanisms to enhance scalability,optimize service provisioning,and improve reliability.This study presents the dynamic correlation analysis tech...Ensuring software quality in open⁃source environments requires adaptive mechanisms to enhance scalability,optimize service provisioning,and improve reliability.This study presents the dynamic correlation analysis technique to enhance software quality management in open⁃source environments by addressing dynamic scalability,adaptive service provisioning,and software reliability.The proposed methodology integrates a scalability metric,an optimized service provisioning model,and a weighted entropy⁃based reliability assessment to systematically improve key performance parameters.Experimental evaluation conducted on multiple open⁃source software(OSS)versions demonstrates significant improvements:scalability increased by 27.5%,service provisioning time reduced by 18.3%,and software reliability improved by 22.1%compared to baseline methods.A comparative analysis with prior works further highlights the effectiveness of this approach in ensuring adaptability,efficiency,and resilience in dynamic software ecosystems.Future work will focus on real⁃time monitoring and AI⁃driven adaptive provisioning to further enhance software quality management.展开更多
Shift-share analysis has been confirmed a useful approach in the study of regional economics and many kinds of extended shift-share models have been advanced and put into practice in economic studies, but few have hit...Shift-share analysis has been confirmed a useful approach in the study of regional economics and many kinds of extended shift-share models have been advanced and put into practice in economic studies, but few have hitherto been introduced and applied to the tourism research in China. Moreover understanding the spatially competitive relationship is of paramount importance for marketers, developers, and planners involved in tourism strategy development. Based on international tourism receipts from 1995 to 2004, this study aims at probing into the spatial competitiveness of interna- tional tourism in Jiangsu Province in comparison with its neighbors by applying a spatially extended shift-share model and a modified dynamic shift-share model. The empirical results illustrate that exceptional years may exist in the ap- plication of dynamic shift-share models. To solve this issue, modifications to dynamic shift-share model are put forward. The analytical results are not only presented but also explained by the comparison of background conditions of tourism development between Jiangsu and its key competitors. The conclusions can be drawn that the growth of international tourism receipts in Jiangsu mainly attributes to the national component and the competitive component and Zhejiang is the most important rival to Jiangsu during the period of 1995-2004. In order to upgrade the tourism competitiveness, it is indispensable for Jiangsu to take proper positioning, promoting and marketing strategies and to cooperate and integrate with its main rivals.展开更多
With the background of severe rocky desertification in the west of China and the ohjective of ecological environment construction and poverty elimination, the management information system of rocky desertification was...With the background of severe rocky desertification in the west of China and the ohjective of ecological environment construction and poverty elimination, the management information system of rocky desertification was designed according to the natural and humane characteristics in Nanchuan of Sichuan Province. The system was composed of data management module, information query module for rocky desertification, spatial analysis module and dynamic monitoring module.展开更多
The particularity and practicality of harmony operations of close-coupling multiple helicopters indicate that the researches on it are urgent and necessary, Using the model that describes two hovering helicopters carr...The particularity and practicality of harmony operations of close-coupling multiple helicopters indicate that the researches on it are urgent and necessary, Using the model that describes two hovering helicopters carrying one heavy load, an inertia coordinate system and body coordinate systems of each sub-system are established. A nonlinear force model is established too. The equilibrium computation results can be regarded as the reference control inputs of the flight control system under hovering or low-speed flight condition. After the establishment of a translation kinematics model and a posture kinematics model, a coupling dynamics model of the multiple helicopter system is set up. The results can also be regarded as the base to analyze stabilization and design a controller for a close-coupling multiple helicopters harmony operation system.展开更多
In order to analyze the dynamic response of pavement on long-span steel bridge decks under random dynamic loads, the irregularities of the pavement surface is simulated with the power spectrum density function, and th...In order to analyze the dynamic response of pavement on long-span steel bridge decks under random dynamic loads, the irregularities of the pavement surface is simulated with the power spectrum density function, and the random load is calculated according to a vehicle vibration equation of vehicle model. The mechanical responses of three different cases are compared by using a transient dynamic analysis method, i. e., under random dynamic load, constant moving load and dead load respectively. The results indicate that the mid-span of two adjacent transversal diaphragms is the worst load position. The maximum vertical displacement and the maximum transversal tensile stress of the pavement are 1.33 times and 1.39 times as much as those when only considering the impact coefficients. This study not only provides a theoretical basis for the mixture design and structural design of pavement, but also puts forward higher demand on the construction and maintenance for steel deck pavement.展开更多
The analytical formulations of the velocity and the acceleration of a 2-DOF spherical parallel mechanism are derived by the screw theory. Based on building its dynamics model by the principle of virtual work and recip...The analytical formulations of the velocity and the acceleration of a 2-DOF spherical parallel mechanism are derived by the screw theory. Based on building its dynamics model by the principle of virtual work and reciprocal product of the screw, the equation of the motor moment is obtained. Through the transformation of dynamics model, the configuration space method of the dynamics equation and the corresponding coefficients are presented. Finally, the result of an example shows that the inertia moment and the gravity play a more important role than the coriolis and centrifugal moment, and the former is ten times of the latter in the magnitude. So, the latter can be neglected only when the velocity of mechanism is very slow.展开更多
文摘By using the dynamic shift-share analysis, the industrial structure and competitive strength of 31 provincial districts except Taiwan, Hong Kong and Macao are studied by taking the GDP of the three industries as the research entrance and the whole nation as the reference district. The industrial structure and competitive strength of each provincial district is measured. Through the analysis of pertinence, the correlation degree of industrial structure and industrial competitive strength to economic growth is analyzed. The results show that the industrial competitive strength is closely related to the economic growth of the 31 provincial districts, but the contribution made by the industrial structure to economic growth is insufficient and the effect of industrial structure does not match with that of industrial competitive strength. According to industrial competitiveness and industrial structure effect, 31 provincial districts of the whole nation are divided into 4 types and the relevant countermeasures of the four types are put forward.
文摘Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emphasis on structural durability and monitoring is required.This study focuses on the mechanical vibrations that occur in rotary drilling systems,which have a substantial impact on the structural integrity of drilling equipment.The study specifically investigates axial,torsional,and lateral vibrations,which might lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency stick-slip.These events not only hinder the efficiency of drilling but also lead to exhaustion and harm to the system’s components since they are difficult to be detected and controlled in real time.The study investigates the dynamic interactions of these vibrations,specifically in their high-frequency modes,usingfield data obtained from measurement while drilling.Thefindings have demonstrated the effect of strong coupling between the high-frequency modes of these vibrations on drilling sys-tem performance.The obtained results highlight the importance of considering the interconnected impacts of these vibrations when designing and implementing robust control systems.Therefore,integrating these compo-nents can increase the durability of drill bits and drill strings,as well as improve the ability to monitor and detect damage.Moreover,by exploiting thesefindings,the assessment of structural resilience in rotary drilling systems can be enhanced.Furthermore,the study demonstrates the capacity of structural health monitoring to improve the quality,dependability,and efficiency of rotary drilling systems in the petroleum industry.
基金Supported by National Nature Science Foundation of China(Grant Nos.52325212,52372394)National Key Research and Development Program of China(Grant Nos.2022YFE0117100,2021YFB2501201)+1 种基金Industry-University-Research Innovation Fund for Chinese Universities(Grand No.2024HT010)Fundamental Research Funds for the Central Universities.
文摘Chassis-by-wire technology has gained significant attention,with the scope of chassis domain control expanding from traditional two-dimensional plane motion control to encompass three-dimensional space motion control.Modern chassis-by-wire systems manage an increasing number of heterogeneous chassis execution systems,including distributed drive,all-wheel drive(AWD),brake-by-wire(BBW),steer-by-wire(SBW),rear-wheel steering(RWS),active stabilizer bar(ASB)and active suspension system(ASS),greatly enhancing the controllable degrees of freedom compared to conventional chassis configurations.To advance research in chassis domain control,it is essential to understand how these heterogeneous execution systems influence vehicle dynamics.This paper focuses on the modeling and analysis of the lateral,longitudinal,and vertical chassis control and execution systems,-as well as their impact on vehicle lateral motion.Using a vehicle simulation platform,both the vehicle dynamics model and the individual dynamics models of each execution system were developed to analyze the influence of these systems on lateral dynamics.Additionally,a hierarchical control architecture was designed to control the vehicle’s lateral stability.The effectiveness of the proposed control scheme was demonstrated and validated through hardware-in-the-loop(HIL)tests and real-world vehicle testing.
文摘Composite dams,due to their combination of advantages from multiple dam types,are widely used under complex topographic and geological conditions.The static and dynamic stability of their spillway sections is crucial for project safety.This paper takes a composite dam as the research object and uses finite difference software FLAC^(3D) to perform static and dynamic calculation analysis on its No.12 and No.13 spillway sections.The static conditions consider normal water level and dead water level,while the dynamic conditions are based on free-field boundary conditions and Rayleigh damping,with an input peak acceleration of 0.15g artificial synthetic seismic wave(duration 10s),analyzing dam displacement and stress distribution.Based on relevant national standards and specifications,the analysis results show:Under static conditions,the dam displacement and stress distribution conform to conventional patterns,with the maximum horizontal displacement at the dam crest being 3.43mm,meeting safety requirements;The tensile stress near the hinged beam area is relatively large,suggesting strengthened reinforcement,with no other hazardous areas.Under dynamic conditions,the maximum relative dynamic displacement at the dam crest is 5.51mm,which is safe and controllable;The tensile stress at the junction of the weir crest and gate pier exceeds the dynamic tensile strength of concrete,and the tensile stress near the hinged beam is relatively high,requiring strengthened reinforcement,with no other hazardous areas.The study indicates that the dam structure design generally meets safety requirements,but local high tensile stress areas need optimized reinforcement design.
基金Open Project of Shanghai Key Laboratory of Lightweight Composite,China(No.2232021A4-04)。
文摘Double-shaft-driven needle punching machine is a specialized equipment designed for processing C/C crucible preforms.Its main needle punching module is operated by two sets of reciprocating crank-slider mechanisms.The intense vibration during needle punching not only generates huge noise,but also substantially reduces the quality of the preform.It is imperative to perform a dynamic analysis and optimization of the entire needle punching machine.In this paper,the three-dimensional(3D)model of the entire double-shaft-driven needle punching machine for C/C crucible preforms is established.Based on the modal analysis theory,the modal characteristics of the needle punching machine under various operating conditions are analyzed and its natural frequencies and vibration modes are determined.The harmonic response analysis is then employed to obtain the amplitude of the needle plate at different frequencies,and the structural weak points of the needle punching machine are identified and improved.The feasibility of the optimized scheme is subsequently reevaluated and verified.The results indicate that the first six natural frequencies of the machine increase,and the maximum amplitude of the needle plate decreases by 70.3%.The enhanced dynamic characteristics of the machine significantly improve its performance,enabling more efficient needle punching of C/C crucible preforms.
基金Supporting Project under Grant No.RSP2025R472,King Saud University,Riyadh,Saudi Arabia。
文摘The nonlinear Schrodinger equation(NLSE) is a key tool for modeling wave propagation in nonlinear and dispersive media. This study focuses on the complex cubic NLSE with δ-potential,explored through the Brownian process. The investigation begins with the derivation of stochastic solitary wave solutions using the modified exp(-Ψ(ξ)) expansion method. To illustrate the noise effects, 3D and 2D visualizations are displayed for different non-negative values of noise parameter under suitable parameter values. Additionally, qualitative analysis of both perturbed and unperturbed dynamical systems is conducted using bifurcation and chaos theory. In bifurcation analysis, we analyze the detailed parameter analysis near fixed points of the unperturbed system. An external periodic force is applied to perturb the system, leading to an investigation of its chaotic behavior. Chaos detection tools are employed to predict the behavior of the perturbed dynamical system, with results validated through visual representations.Multistability analysis is conducted under varying initial conditions to identify multiple stable states in the perturbed dynamical system, contributing to chaotic behavior. Also, sensitivity analysis of the Hamiltonian system is performed for different initial conditions. The novelty of this work lies in the significance of the obtained results, which have not been previously explored for the considered equation. These findings offer noteworthy insights into the behavior of the complex cubic NLSE with δ-potential and its applications in fields such as nonlinear optics, quantum mechanics and Bose–Einstein condensates.
文摘The 53rd issue of Financial Innovation(FIN),Volume 11,No.5(2025),features 21 papers that can be classified into four main themes:the Special Issue on The Anomie of Artificial Intelligence(AI)in Finance:Bridging the Gap Between Technical Power and Human Wisdom,and Financial Markets and Investments,Economic and Policy Analysis,Corporate Governance and Related Market Dynamics.
基金conducted as part of the project Innovative Tools for Cyber-Physical Energy Systems(InnoCyPES)received funding from the European Union’s Horizon 2020 research and innovation pro-gram under the Marie Skłodowska-Curie(956433).
文摘Assessing the benefits and costs of digitalization in the energy industry is a complex issue.Traditional cost-benefit analysis(CBA)might encounter problems in addressing uncertainties,dynamic stakeholder interactions,and feedback loops arising out of the evolving nature of digitalization.This paper introduces a methodological framework to help address the intricate inter connections between digital applications and business models in the energy industry.The proposed framework leverages system dynamics to achieve two primary objectives.It investigates how digitalization generally influences the value proposi-tion,value capture,and value creation dimensions of business models.It also quantifies the financial and social impacts of digitalization from a dynamic perspective.The proposed dynamic CBA allows for a more precise quantification of the benefits and costs,associated with evidence-based decision-making.Findings from an illustrative case study challenge the static assumptions of conventional methods.These methods often presume continuous operation,neglecting reinvestment and operational feedback loops,and resulting in negative net present values.Conversely,the outcomes of the proposed method indicate positive net present values when accounting for factors such as reinvestment rates and the will-ingness to invest in digitalization projects.The principles outlined in this paper can enable a more accu-rate assessment of digitalization projects,thus catalyzing the development of new CBA applications and guidelines for digitalization.
基金sponsored by Natural Science Research Project of Anhui Educational Committee(GrantNo.2022AH050810),NationalNatural Science Foundation of China(GrantNos.42402276,41972286,42072309,42102329)State Key Laboratory of Precision Blasting and Hubei Key Laboratory of Blasting Engineering,Jianghan University(No.PBSKL2023A1)the Open Fund of National Center for International Research on Deep Earth Drilling and Resource Development(No.DEDRD-2023-02).
文摘During the construction of bank slopes involving pile driving,ensuring slope stability is crucial.This requires the design of appropriate support systems and a thorough evaluation of the failure mechanisms of pile structures under dynamic loading conditions.Based on the Huarong Coal Wharf project,various support schemes are analyzed using numerical simulation methods to calculate and compare slope stability coefficients.The optimal scheme is then identified.Under the selected support scheme,a numerical model of double-row suspended steel sheet piles is developed to investigate the dynamic response of the pile structures under pile driving loads.A time-history analysis is performed to assess the slope’s dynamic stability.The results show that the maximum displacements of the upper and lower steel sheet pile rows are 2.51 and 3.14 cm,respectively.The maximum principal stresses remain below 20 MPa in both rows,while the maximum von Mises stresses are 20.85 MPa for the upper row and 25.40 MPa for the lower row.The dominant frequencies of the steel sheet pile structures fall between 30 and 35 Hz,with a frequency bandwidth ranging from 0 to 500 Hz.The stability coefficient of the pile structures varies over time during the pile driving process,ultimately reaching a value of 1.26—exceeding the required safety threshold.This research provides practical guidance for designing support systems in wharf piling projects and offers a reliable basis for evaluating the safety performance of steel sheet piles in bank slopes.
基金Supported by National Natural Science Foundation of China(Grant No.52205476)Jiangsu Provincial Natural Science Foundation(Grant No.BK20242040)+2 种基金Fundamental Research Funds for the Central Universities(Grant No.NG2024008)the Youth Talent Support Project of CASTthe Fund of Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology(Grant No.1005-ZAA20003-14)。
文摘Radial rotating oscillating heat pipes(R-OHPs)have excellent thermal performance and great potential for application in the thermal management of rotatory machinery.However,the heat transport behavior and temperature characteristics of R-OHPs are complex,and their understanding is still limited,hence necessitating further research.In this study,thanks to an experimental investigation involving a copper R-OHP running with acetone and water,its thermal performance is evaluated,and then the temperature characteristics are analyzed by nonlinear dynamic analysis.The study reveals that the effective heat transfer coefficient of R-OHPs undergoes a notable increase with rising rotational speed,exhibiting a peak at a threshold speed value.Such a peak is present irrespectively of the working fluid,and,after exceeding the threshold,higher rotational speeds lead to a lower thermal performance.Based on nonlinear dynamic analysis,the power spectrum density of the evaporator temperature indicates a lack of dominant frequency in temperature signals,suggesting a complex behavior characterized by random oscillations of vapor slugs and liquid plugs.In order to better understand how strong the chaotic behavior is,an autocorrelation analysis was carried out,the OHP at static state has a stronger chaos than R-OHPs.The correlation dimension analysis of the evaporator temperature provides values ranging from 1.2 to 1.6,which together with the Lyapunov exponent calculations,further support an evident chaotic nature of R-OHPs.
文摘In this paper,a meshfree Jacobi point interpolation(MJPI)approach for the dynamic analysis of sandwich laminated conical and cylindrical shells with varying thickness is presented.The theoretical formulations for sandwich laminated shells with varying thickness are established using the modified variational principle within the framework of first-order shear deformation theory(FSDT).The displacement components of the sandwich shell are expanded using the MJPI shape function and Fourier series in the meridional and circumferential directions,respectively.The accuracy and reliability of the proposed MJPI shape function are validated against numerical results from published literature and the commercial simulation tool Abaqus.Finally,the effects of different parameters such as thickness gradient,thickness power index and boundary condition on the free vibration and dynamic response of the sandwich laminated shell are investigated.
基金supported by the Program of National Natural Science Foundation of China(U23A20329,62163036)Youth Academic and Technical Leaders Reserve Talent Training project(202105AC160094)Industrial Innovation Talent Special Project of Xingdian Talent Support Program(XDYC-CYCX-2022-0010).
文摘Kernel-based slow feature analysis(SFA)methods have been successfully applied in the industrial process fault detection field.However,kernel-based SFA methods have high computational complexity as dealing with nonlinearity,leading to delays in detecting time-varying data features.Additionally,the uncertain kernel function and kernel parameters limit the ability of the extracted features to express process characteristics,resulting in poor fault detection performance.To alleviate the above problems,a novel randomized auto-regressive dynamic slow feature analysis(RRDSFA)method is proposed to simultaneously monitor the operating point deviations and process dynamic faults,enabling real-time monitoring of data features in industrial processes.Firstly,the proposed Random Fourier mappingbased method achieves more effective nonlinear transformation,contrasting with the current kernelbased RDSFA algorithm that may lead to significant computational complexity.Secondly,a randomized RDSFA model is developed to extract nonlinear dynamic slow features.Furthermore,a Bayesian inference-based overall fault monitoring model including all RRDSFA sub-models is developed to overcome the randomness of random Fourier mapping.Finally,the superiority and effectiveness of the proposed monitoring method are demonstrated through a numerical case and a simulation of continuous stirred tank reactor.
基金supported in part by the National Science Fund for Distinguished Young Scholars of China(62225303)the National Natural Science Fundation of China(62303039,62433004)+2 种基金the China Postdoctoral Science Foundation(BX20230034,2023M730190)the Fundamental Research Funds for the Central Universities(buctrc202201,QNTD2023-01)the High Performance Computing Platform,College of Information Science and Technology,Beijing University of Chemical Technology
文摘Data-driven process monitoring is an effective approach to assure safe operation of modern manufacturing and energy systems,such as thermal power plants being studied in this work.Industrial processes are inherently dynamic and need to be monitored using dynamic algorithms.Mainstream dynamic algorithms rely on concatenating current measurement with past data.This work proposes a new,alternative dynamic process monitoring algorithm,using dot product feature analysis(DPFA).DPFA computes the dot product of consecutive samples,thus naturally capturing the process dynamics through temporal correlation.At the same time,DPFA's online computational complexity is lower than not just existing dynamic algorithms,but also classical static algorithms(e.g.,principal component analysis and slow feature analysis).The detectability of the new algorithm is analyzed for three types of faults typically seen in process systems:sensor bias,process fault and gain change fault.Through experiments with a numerical example and real data from a thermal power plant,the DPFA algorithm is shown to be superior to the state-of-the-art methods,in terms of better monitoring performance(fault detection rate and false alarm rate)and lower computational complexity.
基金support from the National Natural Science Foundation of China(Grant Nos.52174123&52274222).
文摘This paper presents a framework for constructing surrogate models for sensitivity analysis of structural dynamics behavior.Physical models involving deformation,such as collisions,vibrations,and penetration,are devel-oped using the material point method.To reduce the computational cost of Monte Carlo simulations,response surface models are created as surrogate models for the material point system to approximate its dynamic behavior.An adaptive randomized greedy algorithm is employed to construct a sparse polynomial chaos expansion model with a fixed order,effectively balancing the accuracy and computational efficiency of the surrogate model.Based on the sparse polynomial chaos expansion,sensitivity analysis is conducted using the global finite difference and Sobol methods.Several examples of structural dynamics are provided to demonstrate the effectiveness of the proposed method in addressing structural dynamics problems.
文摘Ensuring software quality in open⁃source environments requires adaptive mechanisms to enhance scalability,optimize service provisioning,and improve reliability.This study presents the dynamic correlation analysis technique to enhance software quality management in open⁃source environments by addressing dynamic scalability,adaptive service provisioning,and software reliability.The proposed methodology integrates a scalability metric,an optimized service provisioning model,and a weighted entropy⁃based reliability assessment to systematically improve key performance parameters.Experimental evaluation conducted on multiple open⁃source software(OSS)versions demonstrates significant improvements:scalability increased by 27.5%,service provisioning time reduced by 18.3%,and software reliability improved by 22.1%compared to baseline methods.A comparative analysis with prior works further highlights the effectiveness of this approach in ensuring adaptability,efficiency,and resilience in dynamic software ecosystems.Future work will focus on real⁃time monitoring and AI⁃driven adaptive provisioning to further enhance software quality management.
基金Under the auspices of the National Natural Science Foundation of China (No. 40371030)
文摘Shift-share analysis has been confirmed a useful approach in the study of regional economics and many kinds of extended shift-share models have been advanced and put into practice in economic studies, but few have hitherto been introduced and applied to the tourism research in China. Moreover understanding the spatially competitive relationship is of paramount importance for marketers, developers, and planners involved in tourism strategy development. Based on international tourism receipts from 1995 to 2004, this study aims at probing into the spatial competitiveness of interna- tional tourism in Jiangsu Province in comparison with its neighbors by applying a spatially extended shift-share model and a modified dynamic shift-share model. The empirical results illustrate that exceptional years may exist in the ap- plication of dynamic shift-share models. To solve this issue, modifications to dynamic shift-share model are put forward. The analytical results are not only presented but also explained by the comparison of background conditions of tourism development between Jiangsu and its key competitors. The conclusions can be drawn that the growth of international tourism receipts in Jiangsu mainly attributes to the national component and the competitive component and Zhejiang is the most important rival to Jiangsu during the period of 1995-2004. In order to upgrade the tourism competitiveness, it is indispensable for Jiangsu to take proper positioning, promoting and marketing strategies and to cooperate and integrate with its main rivals.
基金the National Science and Technology Key Project (2006BAC01A16)Program of Chongqing Science Committee (2004-8258)~~
文摘With the background of severe rocky desertification in the west of China and the ohjective of ecological environment construction and poverty elimination, the management information system of rocky desertification was designed according to the natural and humane characteristics in Nanchuan of Sichuan Province. The system was composed of data management module, information query module for rocky desertification, spatial analysis module and dynamic monitoring module.
基金National Natural Science Foundation of China(60475039)
文摘The particularity and practicality of harmony operations of close-coupling multiple helicopters indicate that the researches on it are urgent and necessary, Using the model that describes two hovering helicopters carrying one heavy load, an inertia coordinate system and body coordinate systems of each sub-system are established. A nonlinear force model is established too. The equilibrium computation results can be regarded as the reference control inputs of the flight control system under hovering or low-speed flight condition. After the establishment of a translation kinematics model and a posture kinematics model, a coupling dynamics model of the multiple helicopter system is set up. The results can also be regarded as the base to analyze stabilization and design a controller for a close-coupling multiple helicopters harmony operation system.
基金The National Natural Science Foundation of China(No.50578038)the Ph.D.Programs Foundation of Ministry of Education of China(No.20050286008)
文摘In order to analyze the dynamic response of pavement on long-span steel bridge decks under random dynamic loads, the irregularities of the pavement surface is simulated with the power spectrum density function, and the random load is calculated according to a vehicle vibration equation of vehicle model. The mechanical responses of three different cases are compared by using a transient dynamic analysis method, i. e., under random dynamic load, constant moving load and dead load respectively. The results indicate that the mid-span of two adjacent transversal diaphragms is the worst load position. The maximum vertical displacement and the maximum transversal tensile stress of the pavement are 1.33 times and 1.39 times as much as those when only considering the impact coefficients. This study not only provides a theoretical basis for the mixture design and structural design of pavement, but also puts forward higher demand on the construction and maintenance for steel deck pavement.
基金Supported by the National Natural Science Foundation of China (50375071)the Jiangsu Province Key Lab on Digital Manufacture Project (HGDML-0604)~~
文摘The analytical formulations of the velocity and the acceleration of a 2-DOF spherical parallel mechanism are derived by the screw theory. Based on building its dynamics model by the principle of virtual work and reciprocal product of the screw, the equation of the motor moment is obtained. Through the transformation of dynamics model, the configuration space method of the dynamics equation and the corresponding coefficients are presented. Finally, the result of an example shows that the inertia moment and the gravity play a more important role than the coriolis and centrifugal moment, and the former is ten times of the latter in the magnitude. So, the latter can be neglected only when the velocity of mechanism is very slow.
