This paper addresses the lane-keeping control problem for autonomous ground vehicles subject to input saturation and uncertain system parameters.An enhanced adaptive terminal sliding mode based prescribed performance ...This paper addresses the lane-keeping control problem for autonomous ground vehicles subject to input saturation and uncertain system parameters.An enhanced adaptive terminal sliding mode based prescribed performance control scheme is proposed,which enables the lateral position error of the vehicle to be kept within the prescribed performance boundaries all the time.This is achieved by firstly introducing an improved performance function into the controller design such that the stringent initial condition requirements can be relaxed,which further allows the global prescribed performance control result,and then,developing a multivariable adaptive terminal sliding mode based controller such that both input saturation and parameter uncertainties are handled effectively,which further ensures the robust lane-keeping control.Finally,the proposed control strategy is validated through numerical simulations,demonstrating its effectiveness.展开更多
The effect of high welding heat inputs in the range of 50–200 kJ/cm on the microstructural evolution,MX(M=Ti,Nb and V;X=N and C)precipitation and mechanical properties was investigated in the coarse-grained heat-affe...The effect of high welding heat inputs in the range of 50–200 kJ/cm on the microstructural evolution,MX(M=Ti,Nb and V;X=N and C)precipitation and mechanical properties was investigated in the coarse-grained heat-affected zone(CGHAZ)of a high-Nb(0.10 wt.%)structural steel.The results showed that the primary microconstituents varied from lath bainite(LB)to intragranular acicular ferrite(IAF)+intragranular polygonal ferrite(IPF),and the most content of IAF was acquired at 100 kJ/cm.Moreover,the submicron Ti-and Nb-rich MX precipitates not only pinned prior austenite grain boundaries but also facilitated IAF and IPF nucleation with the Kurdjumov–Sachs orientation relationship of[011]_(MX)//[111]_(Ferrite);the nanoscale V-rich MX precipitates hindered dislocation movement and followed the Baker–Nutting orientation relationship of[001]_(MX)//[001]_(Ferrite)with ferrite matrix,synergistically strengthening and toughening the CGHAZ.In addition,the−20℃impact absorbed energy firstly elevated from 93±5.2 J at 50 kJ/cm to 131±5.4 J at 100 kJ/cm and finally decreased to 59±3.0 J at 200 kJ/cm,being related to the IAF content,while the microhardness decreased from 312±26.1 to 269±12.9 HV0.1,because of the coarsened microstructure and the decreased content of LB and martensite.Compared to the CGHAZ properties with 0.05 wt.%Nb,a higher Nb content produced better low-temperature toughness,as more solid dissolved Nb atoms and precipitated Nb-rich MX particles in austenite limited prior austenite grain growth and promoted IAF formation.Furthermore,the welding process at 100 kJ/cm was most applicable for the high-Nb steel.展开更多
Objective To study the causal relationship between R&D investment and enterprise performance of domestic pharmaceutical enterprises.Methods Panel data model was adopted for empirical analysis.Results and Conclusio...Objective To study the causal relationship between R&D investment and enterprise performance of domestic pharmaceutical enterprises.Methods Panel data model was adopted for empirical analysis.Results and Conclusion Increasing the R&D investment intensity of pharmaceutical enterprises in the Yangtze River Delta and Zhejiang by 1%will increase their profit margins by 0.79%and 0.46%.On the contrary,if the profit margin increases by 1%,the R&D investment intensity will increase by 0.25%and 0.19%.If the profit margin of pharmaceutical enterprises in Beijing,Tianjin,Hebei,Chengdu,Chongqing and other regions increases by 1%,the R&D investment intensity will increase by 0.14%,0.07%and 0.1%,respectively,which are lower than those in the Yangtze River Delta and Zhejiang.The relationship between R&D investment and enterprise performance of pharmaceutical enterprises in the Yangtze River Delta and Zhejiang Province is Granger causality,showing a two-way positive effect.Profits and R&D investment of pharmaceutical enterprises in Beijing,Tianjin,Hebei,Chengdu,Chongqing and other regions are also Granger causality.But in the Pearl River Delta,profits and R&D investment have not passed the stability test,it is impossible to determine the causality between them.展开更多
In this paper, we mainly address the position control problem for one-degree of freedom(DOF) link manipulator despite uncertainties and the input saturation via the backstepping technique, active disturbance rejection...In this paper, we mainly address the position control problem for one-degree of freedom(DOF) link manipulator despite uncertainties and the input saturation via the backstepping technique, active disturbance rejection control(ADRC) as well as predefined tracking performance functions. The extended state observer(ESO) is employed to compensate uncertain dynamics and disturbances, and it does not rely on the accurate model of systems. The tracking differentiator(TD) is utilized to substitute the derivative of the virtual control signals, and the explosion of complexity caused by repeated differentiations of nonlinear functions is removed. The auxiliary system is used to deal with the control input limitation, and the tracking accuracy and speed are improved by predefined tracking performance functions.With the help of the input-to-state stability(ISS) and Lyapunov stability theories, it is proven that the tracking error can be gradually converged into arbitrarily small neighborhood of the origin, and the tracking error is adjusted by suitable choice of control parameters. The simulation results are presented for the verification of the theoretical claims.展开更多
In this paper, a laboratory study has been made to develop low cost high performance steel plates with superior HAZ toughness for large heat input welding. Simulated results show that the absorbed impact energy of hea...In this paper, a laboratory study has been made to develop low cost high performance steel plates with superior HAZ toughness for large heat input welding. Simulated results show that the absorbed impact energy of heat-affected zone (HAZ) at -20℃reaches above 200J when large heat inputs of 100 to 400kJ/cm were applied, suggestive of superior HAZ toughness for large heat input welding of developed steel plate. The microstructures in HAZ are transformed from mainly fine ferrite and bainite at 100kJ/cm, through an intermediate stage of ferrite, bainite and pearlite at 200 and 300kJ/cm, to nearly fine ferrite and pearlite at 400kJ/cm. The prior austenite grain size and ferrite grain size in HAZ are controlled to ～50 and ～20μm, respectively. The high HAZ toughness is due to the inhibition of prior austenite grain size at high temperatures and the formation of beneficial microstructures to HAZ toughness during continuous cooling.展开更多
From the perspective of wellbeing performance of ecological input,this paper constructs a low-carbon competitiveness evaluation model with wellbeing performance of carbon emissions as the measurement standard,and uses...From the perspective of wellbeing performance of ecological input,this paper constructs a low-carbon competitiveness evaluation model with wellbeing performance of carbon emissions as the measurement standard,and uses the LMDI factor decomposition method to decompose the total effect of low-carbon competitiveness changes into technology effect and service effect.And then it conducts positive analysis and comparison of the low-carbon competitiveness and its effect contribution of G20 countries from1990 to 2018.The results are as follows:Firstly,in 2018,the UK,France,Argentina,Brazil,and Germany had higher low-carbon competitiveness.From 1990 to 2018,the low-carbon competitiveness of the UK,Turkey,Germany,Italy,and Brazil increase rapidly.Secondly,from 1990 to 2018,the total effect of low-carbon competitiveness of G20 member states was all positive,that is to say,the overall wellbeing performance of carbon emissions increased,technology effect and service effect are positive in 17 countries and negative in 2 countries respectively.Thirdly,China's low-carbon competitiveness is low,lacking static and dynamic advantages,although the technology effect is the highest,but the service effect is the lowest,resulting in a low total effect,which indicates that the wellbeing performance of economic growth is the main bottleneck of China's low-carbon development.Finally,the policy recommendations for China's future low-carbon transition and sustainable development are put forward.展开更多
In this paper, an Independent Window-Access(IWA) scheme is proposed, and the performance of an input-buffered ATM switching fabric with the IWA scheme is analysed by means of a probability generating function approach...In this paper, an Independent Window-Access(IWA) scheme is proposed, and the performance of an input-buffered ATM switching fabric with the IWA scheme is analysed by means of a probability generating function approach, the closed formulas of the average cell delay and the maximum throughput are given, and results show that the IWA scheme makes the switching fabric have better performances than traditional window-access scheme. The computer simulation results are in good agreement with these analytical results.展开更多
This paper analyses the performance of the ATM switch fabric with Combined-Input/ Output Buffering(C-IOB) under two different service principles for the cells at the head of line (HOL) positions of input buffers: Firs...This paper analyses the performance of the ATM switch fabric with Combined-Input/ Output Buffering(C-IOB) under two different service principles for the cells at the head of line (HOL) positions of input buffers: First Come First Service (FCFS)/Random Service(RS) for the set of HOL cells addressed to a given output port with different/same "age" (the waiting time at the HOL position) and Pure Random Service(PRS) for all HOL cells addressed to a given output port regardless of their "ages" while the Queue Loss (QL) transfer scheme is adopted for interaction between input and output buffers in the ATM switch fabric. The results obtained show that the C-IOB ATM switch fabric with PRS service policy and the QL transfer scheme is better than other buffering ATM switch fabrics.展开更多
The high-performance computing paradigm needs high-speed switching fabrics to meet the heavy traffic generated by their applications.These switching fabrics are efficiently driven by the deployed scheduling algorithms...The high-performance computing paradigm needs high-speed switching fabrics to meet the heavy traffic generated by their applications.These switching fabrics are efficiently driven by the deployed scheduling algorithms.In this paper,we proposed two scheduling algorithms for input queued switches whose operations are based on ranking procedures.At first,we proposed a Simple 2-Bit(S2B)scheme which uses binary ranking procedure and queue size for scheduling the packets.Here,the Virtual Output Queue(VOQ)set with maximum number of empty queues receives higher rank than other VOQ’s.Through simulation,we showed S2B has better throughput performance than Highest Ranking First(HRF)arbitration under uniform,and non-uniform traffic patterns.To further improve the throughput-delay performance,an Enhanced 2-Bit(E2B)approach is proposed.This approach adopts an integer representation for rank,which is the number of empty queues in a VOQ set.The simulation result shows E2B outperforms S2B and HRF scheduling algorithms with maximum throughput-delay performance.Furthermore,the algorithms are simulated under hotspot traffic and E2B proves to be more efficient.展开更多
Micro-forging(MF)is a novel surface modification technology which is capable of smoothening and strengthening the workpiece surface simultaneously.Based on analysis of the mechanism and energy conversion of micro-forg...Micro-forging(MF)is a novel surface modification technology which is capable of smoothening and strengthening the workpiece surface simultaneously.Based on analysis of the mechanism and energy conversion of micro-forging process,an electromagnetically driven microforging system is developed.To further grasp the kinetic characteristic of the equipment,a simulation model is established and its accuracy is verified.With the help of simulation and experimental results,we propose an input voltage optimization method,which drives the micro-forging head moving in a uniform and stable way.In this study,the influence of MF on surface integrity of Ti-6 Al-4 V(TC4)is firstly reported.Experimental results show that MF treatment reduces surface roughness(Ra)and increases micro-hardness by 48%and 11.8%at most,respectively.Besides,a compressive stress layer with an amplitude of-1000 MPa and a depth of 0.8 mm is observed.This study analyzes the performance and reveals the potential of micro-forging technology,which lays a solid foundation for expanding its application in TC4 surface modification.展开更多
This study addresses the role of R&D leverage in SMEs’performance creation.The authors do so by considering SMEs’high resource dependence due to isomorphism.We propose that R&D leverage,with a presence of dy...This study addresses the role of R&D leverage in SMEs’performance creation.The authors do so by considering SMEs’high resource dependence due to isomorphism.We propose that R&D leverage,with a presence of dynamic capabilities,plays a moderating role in the relation between resource investments and performance.This study,which focused on Taiwan’s SMEs,conducts a questionnaire survey using the hierarchical sampling technique,across various industries and geographic areas in Taiwan.The empirical findings reveal that R&D leverage as an essential leveler in resource management enhances resource advantages.展开更多
This paper addresses the tracking control problem of a class of multiple-input–multiple-output nonlinear systems subject to actuator faults.Achieving a balance between input saturation and performance constraints,rat...This paper addresses the tracking control problem of a class of multiple-input–multiple-output nonlinear systems subject to actuator faults.Achieving a balance between input saturation and performance constraints,rather than conducting isolated analyses,especially in the presence of frequently encountered unknown actuator faults,becomes an interesting yet challenging problem.First,to enhance the tracking performance,Tunnel Prescribed Performance(TPP)is proposed to provide narrow tunnel-shape constraints instead of the common over-relaxed trumpet-shape performance constraints.A pair of non-negative signals produced by an auxiliary system is then integrated into TPP,resulting in Saturation-tolerant Prescribed Performance(SPP)with flexible performance boundaries that account for input saturation situations.Namely,SPP can appropriately relax TPP when needed and decrease the conservatism of control design.With the help of SPP,our developed Saturation-tolerant Prescribed Control(SPC)guarantees finite-time convergence while satisfying both input saturation and performance constraints,even under serious actuator faults.Simulations are conducted to illustrate the effectiveness of the proposed SPC.展开更多
New research and development(R&D)institutions are an important part of the national innovation system,playing an important role in promoting the transformation of scientific and technological achievements.In recen...New research and development(R&D)institutions are an important part of the national innovation system,playing an important role in promoting the transformation of scientific and technological achievements.In recent years,new R&D institutions have gradually become the driving force of innovation-driven development in China.Taking new R&D institutions in Zhejiang Province as the research object,this paper studies the internal talent training path and performance evaluation mechanism of new R&D institutions in Zhejiang Province by using the literature research method,comparison method,case verification method,and other methods.The investigation results show that there are problems such as lack of material and spiritual support and neglect of the absorption of local talents in the internal talent training,and there are problems such as unclear standards,insufficient data,and opaque processes in the performance evaluation mechanism,which greatly affect the establishment and improvement of the performance evaluation mechanism.Given the above problems,this paper puts forward a forward-looking,oriented,flexible,and compatible talent training path and performance evaluation mechanism,hoping to optimize the effective internal talent training path of new R&D institutions,improve the evaluation performance,and promote healthy development of new R&D institutions in Zhejiang Province.展开更多
An anti-saturation fault-tolerant adaptive torsional vibration control method with fixed-time prescribed performance for the rolling mill main drive system(RMMDS)was investigated,which is affected by control input sat...An anti-saturation fault-tolerant adaptive torsional vibration control method with fixed-time prescribed performance for the rolling mill main drive system(RMMDS)was investigated,which is affected by control input saturation,actuator faults,sensor measurement errors,and parameter perturbations.First,we gave a continuously differentiable saturation function to approximate the control input saturation characteristic of the RMMDS,translating the saturation characteristic into the matched uncertainty and unknown time-varying gain in the system.Then,an RMMDS mathematical model with unmatched uncertainty and unknown time-varying gain was developed,taking into account the presence of control input saturation,actuator faults,sensor measurement errors,and parameter perturbations.Based on the established mathematical model,an error transformation model of the roll speed tracking was constructed by the equivalent error transformation method.According to the error transformation model,a barrier Lyapunov function and a novel adaptive controller were studied to ensure that the roll speed tracking error always evolves inside a fixed-time asymmetric constraint.Finally,numerical simulations were performed in Matlab/Simulink to verify the effectiveness and superiority of the proposed control method in suppressing the RMMDS torsional vibration.展开更多
An optimal tracking control problem for a class of nonlinear systems with guaranteed performance and asymmetric input constraints is discussed in this paper.The control policy is implemented by adaptive dynamic progra...An optimal tracking control problem for a class of nonlinear systems with guaranteed performance and asymmetric input constraints is discussed in this paper.The control policy is implemented by adaptive dynamic programming(ADP)algorithm under two event-based triggering mechanisms.It is often challenging to design an optimal control law due to the system deviation caused by asymmetric input constraints.First,a prescribed performance control technique is employed to guarantee the tracking errors within predetermined boundaries.Subsequently,considering the asymmetric input constraints,a discounted non-quadratic cost function is introduced.Moreover,in order to reduce controller updates,an event-triggered control law is developed for ADP algorithm.After that,to further simplify the complexity of controller design,this work is extended to a self-triggered case for relaxing the need for continuous signal monitoring by hardware devices.By employing the Lyapunov method,the uniform ultimate boundedness of all signals is proved to be guaranteed.Finally,a simulation example on a mass–spring–damper system subject to asymmetric input constraints is provided to validate the effectiveness of the proposed control scheme.展开更多
In recent years, China has promulgated many laws and regulations of environmental protection, gradually forming an environmental regulation system, and most enterprises are under the dual pressure of environmental pro...In recent years, China has promulgated many laws and regulations of environmental protection, gradually forming an environmental regulation system, and most enterprises are under the dual pressure of environmental protection and business performance. It would be a significant way that enterprises undertake R&D activities for a change. This paper is based on the Shanghai and Shenzhen A-share listed heavy pollution enterprises in 2011-2016, which is based on the review and summary of research results of former researchers, combining with current environmental regulation situation of our country, raising the relevant hypothesis between environmental regulations, R&D investment and business performance against heavy pollution industry. Adopting the method of empirical research, it also built the linear regression model which employs the relevant financial data of heavy-polluting enterprises in China as the statistical research sample. The relationship for heavy-polluting enterprises affected by environmental regulations between environmental protection R&D investment and enterprise business performance was tested. The results show that there is a positive influence on the environmental R&D investment and business performance, and a lag effect upon the R&D investment of enterprises to business performance. Finally, the research results were used to evaluates problems existing in the R&D investment on pollution industry in China as well as business performance and we put forward some suggestions on improving environmental regulation standards and technology innovation consciousness as well as optimizing the structure of R&D investment.展开更多
Objective To improve the creativity and enthusiasm of R&D personnel in R Company.Methods The status quo of the performance assessment of R&D personnel in R Company was studied through questionnaire and intervi...Objective To improve the creativity and enthusiasm of R&D personnel in R Company.Methods The status quo of the performance assessment of R&D personnel in R Company was studied through questionnaire and interview survey.Factor analysis and multiple linear regression method were used to find out the core factors affecting the expectation of employee performance optimization,and the regression equation of employee performance optimization was established.Results and Conclusion R&D personnel in R Company have low satisfaction with the current performance appraisal and strong self-actualization needs,so they expect to optimize the performance appraisal.The objectives and key results(OKR),a management goal-setting system,can make up the deficiencies of R&D personnel’s current performance assessment in R Company,which meets their self-realization needs to a greater extent,thus stimulating their productivity.展开更多
Objective To explore the influence of new drug R&D investment and sales expense on the performance of biomedical enterprises.Methods The financial statements of 76 listed biomedical enterprises for 5 consecutive y...Objective To explore the influence of new drug R&D investment and sales expense on the performance of biomedical enterprises.Methods The financial statements of 76 listed biomedical enterprises for 5 consecutive years were selected,and the data were modeled to study the effect of R&D investment and sales expense on the performance of biomedical enterprises by using financial indicators as tools and statistical methods of multiple linear regression.Results and Conclusion Under the premise that the weak related factors such as enterprise scale,life cycle and asset-liability ratio are set as unrelated variables,the R&D investment intensity of biomedical enterprises is negatively correlated with the current performance,which also shows that the R&D of biomedical enterprises has the characteristics of high risk.Besides,the influence of early R&D investment is delayed.However,the sales expense of leading biomedical enterprises with large scales have higher proportion.Meanwhile the greater sales expense of the same enterprise in different periods,the better the enterprise performance is.Biomedical enterprises should consider their own development stage to develop more patented drugs.Besides,they must formulate plans for allocating reasonable sales personnel and cost expense to ensure that enterprises can obtain better benefits.展开更多
Objective To study the impact of independent R&D and collaborative innovation on economic performance in the pharmaceutical industry.Methods A panel regression model was established by selecting the panel data of ...Objective To study the impact of independent R&D and collaborative innovation on economic performance in the pharmaceutical industry.Methods A panel regression model was established by selecting the panel data of China’s pharmaceutical industry from 2009 to 2019.Results and Conclusion Independent R&D and collaborative innovation of the pharmaceutical industry in eastern,central and western regions of China had a positive effect on economic performance.Besides,the promotion effect of independent R&D was greater than that of collaborative innovation.The positive driving effect of economic performance is the largest among the three regions,followed by the central and western regions.The collaborative innovation has the greatest positive effect on economic performance in the central region,followed by the eastern and western regions.展开更多
Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge in...Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge increasing demand for bandwidth. Several different technologies have been developed for optical packet switching such as space switches, broadcast-and-select, input buffered switches and output buffered switches. These architectures vary based on several parameters such as the way of optical buffering, the placement of optical buffers, the way of solving the external blocking inherited from switching technologies in general and the components used to implement the WDM. This study surveys most of the exiting optical packet switching architectures. A simulation-based comparison of input buffered and output buffered architectures is presented. The performance analysis of the selected two architectures is derived using simulation program and compared at different scenarios. We found that the output buffered architectures give better performance than input buffered architectures. The simulation results show that the-broadcast-and-select architecture is attractive in terms that it has lees number of components compared to other switches.展开更多
基金supported in part by the National Key Research and Development Program of China under Grant 2023YFA1011803in part by Natural Science Foundation of Chongqing,China under Grant CSTB2023NSCQ-MSX0588+2 种基金in part by the Fundamental Research Funds for the Central Universities,China under Grant 2023CDJKYJH047in part by the National Natural Science Foundation of China under Grant 62273064,Grant 61991400,Grant 61991403,Grant 61933012,Grant 62250710167,Grant 62203078in part by Innovation Support Program for International Students Returning to China under Grant cx2022016.
文摘This paper addresses the lane-keeping control problem for autonomous ground vehicles subject to input saturation and uncertain system parameters.An enhanced adaptive terminal sliding mode based prescribed performance control scheme is proposed,which enables the lateral position error of the vehicle to be kept within the prescribed performance boundaries all the time.This is achieved by firstly introducing an improved performance function into the controller design such that the stringent initial condition requirements can be relaxed,which further allows the global prescribed performance control result,and then,developing a multivariable adaptive terminal sliding mode based controller such that both input saturation and parameter uncertainties are handled effectively,which further ensures the robust lane-keeping control.Finally,the proposed control strategy is validated through numerical simulations,demonstrating its effectiveness.
基金financially supported by the National Natural Science Foundation of China(Grant No.52104333)the Natural Science Foundation of Inner Mongolia(Grant No.2024MS05029)+1 种基金the Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(Grant No.NJYT24070)the Research Project of Carbon Peak and Carbon Neutrality in Universities of Inner Mongolia Autonomous Region(Grant No.STZX202316).
文摘The effect of high welding heat inputs in the range of 50–200 kJ/cm on the microstructural evolution,MX(M=Ti,Nb and V;X=N and C)precipitation and mechanical properties was investigated in the coarse-grained heat-affected zone(CGHAZ)of a high-Nb(0.10 wt.%)structural steel.The results showed that the primary microconstituents varied from lath bainite(LB)to intragranular acicular ferrite(IAF)+intragranular polygonal ferrite(IPF),and the most content of IAF was acquired at 100 kJ/cm.Moreover,the submicron Ti-and Nb-rich MX precipitates not only pinned prior austenite grain boundaries but also facilitated IAF and IPF nucleation with the Kurdjumov–Sachs orientation relationship of[011]_(MX)//[111]_(Ferrite);the nanoscale V-rich MX precipitates hindered dislocation movement and followed the Baker–Nutting orientation relationship of[001]_(MX)//[001]_(Ferrite)with ferrite matrix,synergistically strengthening and toughening the CGHAZ.In addition,the−20℃impact absorbed energy firstly elevated from 93±5.2 J at 50 kJ/cm to 131±5.4 J at 100 kJ/cm and finally decreased to 59±3.0 J at 200 kJ/cm,being related to the IAF content,while the microhardness decreased from 312±26.1 to 269±12.9 HV0.1,because of the coarsened microstructure and the decreased content of LB and martensite.Compared to the CGHAZ properties with 0.05 wt.%Nb,a higher Nb content produced better low-temperature toughness,as more solid dissolved Nb atoms and precipitated Nb-rich MX particles in austenite limited prior austenite grain growth and promoted IAF formation.Furthermore,the welding process at 100 kJ/cm was most applicable for the high-Nb steel.
基金Shenyang Pharmaceutical University Young and Middle aged Teacher Career Development Support PlanPublic Welfare Research Fund for Scientific Undertakings of Liaoning Province in 2022(Soft Science Research Plan)(No.2022JH4/10100040).
文摘Objective To study the causal relationship between R&D investment and enterprise performance of domestic pharmaceutical enterprises.Methods Panel data model was adopted for empirical analysis.Results and Conclusion Increasing the R&D investment intensity of pharmaceutical enterprises in the Yangtze River Delta and Zhejiang by 1%will increase their profit margins by 0.79%and 0.46%.On the contrary,if the profit margin increases by 1%,the R&D investment intensity will increase by 0.25%and 0.19%.If the profit margin of pharmaceutical enterprises in Beijing,Tianjin,Hebei,Chengdu,Chongqing and other regions increases by 1%,the R&D investment intensity will increase by 0.14%,0.07%and 0.1%,respectively,which are lower than those in the Yangtze River Delta and Zhejiang.The relationship between R&D investment and enterprise performance of pharmaceutical enterprises in the Yangtze River Delta and Zhejiang Province is Granger causality,showing a two-way positive effect.Profits and R&D investment of pharmaceutical enterprises in Beijing,Tianjin,Hebei,Chengdu,Chongqing and other regions are also Granger causality.But in the Pearl River Delta,profits and R&D investment have not passed the stability test,it is impossible to determine the causality between them.
基金supported in part by the National Natural Science Foundation of China (61873130,61533010,61503194,61633016)the Natural Science Foundation of Jiangsu Province (BK20140877)+2 种基金the Research and Development Program of Jiangsu (BE2016184)the Jiangsu Government Scholarship for Overseas Studies (2017-037)1311 Talent Project of Nanjing University of Posts and Telecommunications
文摘In this paper, we mainly address the position control problem for one-degree of freedom(DOF) link manipulator despite uncertainties and the input saturation via the backstepping technique, active disturbance rejection control(ADRC) as well as predefined tracking performance functions. The extended state observer(ESO) is employed to compensate uncertain dynamics and disturbances, and it does not rely on the accurate model of systems. The tracking differentiator(TD) is utilized to substitute the derivative of the virtual control signals, and the explosion of complexity caused by repeated differentiations of nonlinear functions is removed. The auxiliary system is used to deal with the control input limitation, and the tracking accuracy and speed are improved by predefined tracking performance functions.With the help of the input-to-state stability(ISS) and Lyapunov stability theories, it is proven that the tracking error can be gradually converged into arbitrarily small neighborhood of the origin, and the tracking error is adjusted by suitable choice of control parameters. The simulation results are presented for the verification of the theoretical claims.
文摘In this paper, a laboratory study has been made to develop low cost high performance steel plates with superior HAZ toughness for large heat input welding. Simulated results show that the absorbed impact energy of heat-affected zone (HAZ) at -20℃reaches above 200J when large heat inputs of 100 to 400kJ/cm were applied, suggestive of superior HAZ toughness for large heat input welding of developed steel plate. The microstructures in HAZ are transformed from mainly fine ferrite and bainite at 100kJ/cm, through an intermediate stage of ferrite, bainite and pearlite at 200 and 300kJ/cm, to nearly fine ferrite and pearlite at 400kJ/cm. The prior austenite grain size and ferrite grain size in HAZ are controlled to ～50 and ～20μm, respectively. The high HAZ toughness is due to the inhibition of prior austenite grain size at high temperatures and the formation of beneficial microstructures to HAZ toughness during continuous cooling.
文摘From the perspective of wellbeing performance of ecological input,this paper constructs a low-carbon competitiveness evaluation model with wellbeing performance of carbon emissions as the measurement standard,and uses the LMDI factor decomposition method to decompose the total effect of low-carbon competitiveness changes into technology effect and service effect.And then it conducts positive analysis and comparison of the low-carbon competitiveness and its effect contribution of G20 countries from1990 to 2018.The results are as follows:Firstly,in 2018,the UK,France,Argentina,Brazil,and Germany had higher low-carbon competitiveness.From 1990 to 2018,the low-carbon competitiveness of the UK,Turkey,Germany,Italy,and Brazil increase rapidly.Secondly,from 1990 to 2018,the total effect of low-carbon competitiveness of G20 member states was all positive,that is to say,the overall wellbeing performance of carbon emissions increased,technology effect and service effect are positive in 17 countries and negative in 2 countries respectively.Thirdly,China's low-carbon competitiveness is low,lacking static and dynamic advantages,although the technology effect is the highest,but the service effect is the lowest,resulting in a low total effect,which indicates that the wellbeing performance of economic growth is the main bottleneck of China's low-carbon development.Finally,the policy recommendations for China's future low-carbon transition and sustainable development are put forward.
文摘In this paper, an Independent Window-Access(IWA) scheme is proposed, and the performance of an input-buffered ATM switching fabric with the IWA scheme is analysed by means of a probability generating function approach, the closed formulas of the average cell delay and the maximum throughput are given, and results show that the IWA scheme makes the switching fabric have better performances than traditional window-access scheme. The computer simulation results are in good agreement with these analytical results.
文摘This paper analyses the performance of the ATM switch fabric with Combined-Input/ Output Buffering(C-IOB) under two different service principles for the cells at the head of line (HOL) positions of input buffers: First Come First Service (FCFS)/Random Service(RS) for the set of HOL cells addressed to a given output port with different/same "age" (the waiting time at the HOL position) and Pure Random Service(PRS) for all HOL cells addressed to a given output port regardless of their "ages" while the Queue Loss (QL) transfer scheme is adopted for interaction between input and output buffers in the ATM switch fabric. The results obtained show that the C-IOB ATM switch fabric with PRS service policy and the QL transfer scheme is better than other buffering ATM switch fabrics.
文摘The high-performance computing paradigm needs high-speed switching fabrics to meet the heavy traffic generated by their applications.These switching fabrics are efficiently driven by the deployed scheduling algorithms.In this paper,we proposed two scheduling algorithms for input queued switches whose operations are based on ranking procedures.At first,we proposed a Simple 2-Bit(S2B)scheme which uses binary ranking procedure and queue size for scheduling the packets.Here,the Virtual Output Queue(VOQ)set with maximum number of empty queues receives higher rank than other VOQ’s.Through simulation,we showed S2B has better throughput performance than Highest Ranking First(HRF)arbitration under uniform,and non-uniform traffic patterns.To further improve the throughput-delay performance,an Enhanced 2-Bit(E2B)approach is proposed.This approach adopts an integer representation for rank,which is the number of empty queues in a VOQ set.The simulation result shows E2B outperforms S2B and HRF scheduling algorithms with maximum throughput-delay performance.Furthermore,the algorithms are simulated under hotspot traffic and E2B proves to be more efficient.
基金the National Major Science and Technology Projects of China(No.2018ZX04005001-002)State Administration for Science,Technology and Industry for National Defense of China(No.DE0904)Shanghai Academy of Spaceflight Technology of China(No.SAST2018-055)。
文摘Micro-forging(MF)is a novel surface modification technology which is capable of smoothening and strengthening the workpiece surface simultaneously.Based on analysis of the mechanism and energy conversion of micro-forging process,an electromagnetically driven microforging system is developed.To further grasp the kinetic characteristic of the equipment,a simulation model is established and its accuracy is verified.With the help of simulation and experimental results,we propose an input voltage optimization method,which drives the micro-forging head moving in a uniform and stable way.In this study,the influence of MF on surface integrity of Ti-6 Al-4 V(TC4)is firstly reported.Experimental results show that MF treatment reduces surface roughness(Ra)and increases micro-hardness by 48%and 11.8%at most,respectively.Besides,a compressive stress layer with an amplitude of-1000 MPa and a depth of 0.8 mm is observed.This study analyzes the performance and reveals the potential of micro-forging technology,which lays a solid foundation for expanding its application in TC4 surface modification.
文摘This study addresses the role of R&D leverage in SMEs’performance creation.The authors do so by considering SMEs’high resource dependence due to isomorphism.We propose that R&D leverage,with a presence of dynamic capabilities,plays a moderating role in the relation between resource investments and performance.This study,which focused on Taiwan’s SMEs,conducts a questionnaire survey using the hierarchical sampling technique,across various industries and geographic areas in Taiwan.The empirical findings reveal that R&D leverage as an essential leveler in resource management enhances resource advantages.
基金supported by the National Research Foundation Singapore under its AI Singapore Programme(Award Number:[AISG2-GC-2023-007]).
文摘This paper addresses the tracking control problem of a class of multiple-input–multiple-output nonlinear systems subject to actuator faults.Achieving a balance between input saturation and performance constraints,rather than conducting isolated analyses,especially in the presence of frequently encountered unknown actuator faults,becomes an interesting yet challenging problem.First,to enhance the tracking performance,Tunnel Prescribed Performance(TPP)is proposed to provide narrow tunnel-shape constraints instead of the common over-relaxed trumpet-shape performance constraints.A pair of non-negative signals produced by an auxiliary system is then integrated into TPP,resulting in Saturation-tolerant Prescribed Performance(SPP)with flexible performance boundaries that account for input saturation situations.Namely,SPP can appropriately relax TPP when needed and decrease the conservatism of control design.With the help of SPP,our developed Saturation-tolerant Prescribed Control(SPC)guarantees finite-time convergence while satisfying both input saturation and performance constraints,even under serious actuator faults.Simulations are conducted to illustrate the effectiveness of the proposed SPC.
文摘New research and development(R&D)institutions are an important part of the national innovation system,playing an important role in promoting the transformation of scientific and technological achievements.In recent years,new R&D institutions have gradually become the driving force of innovation-driven development in China.Taking new R&D institutions in Zhejiang Province as the research object,this paper studies the internal talent training path and performance evaluation mechanism of new R&D institutions in Zhejiang Province by using the literature research method,comparison method,case verification method,and other methods.The investigation results show that there are problems such as lack of material and spiritual support and neglect of the absorption of local talents in the internal talent training,and there are problems such as unclear standards,insufficient data,and opaque processes in the performance evaluation mechanism,which greatly affect the establishment and improvement of the performance evaluation mechanism.Given the above problems,this paper puts forward a forward-looking,oriented,flexible,and compatible talent training path and performance evaluation mechanism,hoping to optimize the effective internal talent training path of new R&D institutions,improve the evaluation performance,and promote healthy development of new R&D institutions in Zhejiang Province.
基金supported by Central Government to Guide local scientific and Technological Development of Hebei Province(No.216Z1902G)Major Program of National Natural Science Foundation of China(U20A20332)+1 种基金Natural Science Foundation of Hebei Province(A2022203024)Provincial Key Laboratory Performance Subsidy Project(22567612H).
文摘An anti-saturation fault-tolerant adaptive torsional vibration control method with fixed-time prescribed performance for the rolling mill main drive system(RMMDS)was investigated,which is affected by control input saturation,actuator faults,sensor measurement errors,and parameter perturbations.First,we gave a continuously differentiable saturation function to approximate the control input saturation characteristic of the RMMDS,translating the saturation characteristic into the matched uncertainty and unknown time-varying gain in the system.Then,an RMMDS mathematical model with unmatched uncertainty and unknown time-varying gain was developed,taking into account the presence of control input saturation,actuator faults,sensor measurement errors,and parameter perturbations.Based on the established mathematical model,an error transformation model of the roll speed tracking was constructed by the equivalent error transformation method.According to the error transformation model,a barrier Lyapunov function and a novel adaptive controller were studied to ensure that the roll speed tracking error always evolves inside a fixed-time asymmetric constraint.Finally,numerical simulations were performed in Matlab/Simulink to verify the effectiveness and superiority of the proposed control method in suppressing the RMMDS torsional vibration.
基金supported in part by the National Natural Science Foundation of China(62033003,62003093,62373113,U23A20341,U21A20522)the Natural Science Foundation of Guangdong Province,China(2023A1515011527,2022A1515011506).
文摘An optimal tracking control problem for a class of nonlinear systems with guaranteed performance and asymmetric input constraints is discussed in this paper.The control policy is implemented by adaptive dynamic programming(ADP)algorithm under two event-based triggering mechanisms.It is often challenging to design an optimal control law due to the system deviation caused by asymmetric input constraints.First,a prescribed performance control technique is employed to guarantee the tracking errors within predetermined boundaries.Subsequently,considering the asymmetric input constraints,a discounted non-quadratic cost function is introduced.Moreover,in order to reduce controller updates,an event-triggered control law is developed for ADP algorithm.After that,to further simplify the complexity of controller design,this work is extended to a self-triggered case for relaxing the need for continuous signal monitoring by hardware devices.By employing the Lyapunov method,the uniform ultimate boundedness of all signals is proved to be guaranteed.Finally,a simulation example on a mass–spring–damper system subject to asymmetric input constraints is provided to validate the effectiveness of the proposed control scheme.
基金supported by Jiangsu University Philosophical and Social Science Research Projects (Grant No. 2014SJB4442014)
文摘In recent years, China has promulgated many laws and regulations of environmental protection, gradually forming an environmental regulation system, and most enterprises are under the dual pressure of environmental protection and business performance. It would be a significant way that enterprises undertake R&D activities for a change. This paper is based on the Shanghai and Shenzhen A-share listed heavy pollution enterprises in 2011-2016, which is based on the review and summary of research results of former researchers, combining with current environmental regulation situation of our country, raising the relevant hypothesis between environmental regulations, R&D investment and business performance against heavy pollution industry. Adopting the method of empirical research, it also built the linear regression model which employs the relevant financial data of heavy-polluting enterprises in China as the statistical research sample. The relationship for heavy-polluting enterprises affected by environmental regulations between environmental protection R&D investment and enterprise business performance was tested. The results show that there is a positive influence on the environmental R&D investment and business performance, and a lag effect upon the R&D investment of enterprises to business performance. Finally, the research results were used to evaluates problems existing in the R&D investment on pollution industry in China as well as business performance and we put forward some suggestions on improving environmental regulation standards and technology innovation consciousness as well as optimizing the structure of R&D investment.
文摘Objective To improve the creativity and enthusiasm of R&D personnel in R Company.Methods The status quo of the performance assessment of R&D personnel in R Company was studied through questionnaire and interview survey.Factor analysis and multiple linear regression method were used to find out the core factors affecting the expectation of employee performance optimization,and the regression equation of employee performance optimization was established.Results and Conclusion R&D personnel in R Company have low satisfaction with the current performance appraisal and strong self-actualization needs,so they expect to optimize the performance appraisal.The objectives and key results(OKR),a management goal-setting system,can make up the deficiencies of R&D personnel’s current performance assessment in R Company,which meets their self-realization needs to a greater extent,thus stimulating their productivity.
文摘Objective To explore the influence of new drug R&D investment and sales expense on the performance of biomedical enterprises.Methods The financial statements of 76 listed biomedical enterprises for 5 consecutive years were selected,and the data were modeled to study the effect of R&D investment and sales expense on the performance of biomedical enterprises by using financial indicators as tools and statistical methods of multiple linear regression.Results and Conclusion Under the premise that the weak related factors such as enterprise scale,life cycle and asset-liability ratio are set as unrelated variables,the R&D investment intensity of biomedical enterprises is negatively correlated with the current performance,which also shows that the R&D of biomedical enterprises has the characteristics of high risk.Besides,the influence of early R&D investment is delayed.However,the sales expense of leading biomedical enterprises with large scales have higher proportion.Meanwhile the greater sales expense of the same enterprise in different periods,the better the enterprise performance is.Biomedical enterprises should consider their own development stage to develop more patented drugs.Besides,they must formulate plans for allocating reasonable sales personnel and cost expense to ensure that enterprises can obtain better benefits.
基金Research on the Innovation and Development Strategy of the Pharmaceutical Industry in Liaoning Province(No.2020lslktyb-095).
文摘Objective To study the impact of independent R&D and collaborative innovation on economic performance in the pharmaceutical industry.Methods A panel regression model was established by selecting the panel data of China’s pharmaceutical industry from 2009 to 2019.Results and Conclusion Independent R&D and collaborative innovation of the pharmaceutical industry in eastern,central and western regions of China had a positive effect on economic performance.Besides,the promotion effect of independent R&D was greater than that of collaborative innovation.The positive driving effect of economic performance is the largest among the three regions,followed by the central and western regions.The collaborative innovation has the greatest positive effect on economic performance in the central region,followed by the eastern and western regions.
文摘Optical Packet Switching (OPS) and transmission networks based on Wavelength Division Multiplexing (WDM) have been increasingly deployed in the Internet infrastructure over the last decade in order to meet the huge increasing demand for bandwidth. Several different technologies have been developed for optical packet switching such as space switches, broadcast-and-select, input buffered switches and output buffered switches. These architectures vary based on several parameters such as the way of optical buffering, the placement of optical buffers, the way of solving the external blocking inherited from switching technologies in general and the components used to implement the WDM. This study surveys most of the exiting optical packet switching architectures. A simulation-based comparison of input buffered and output buffered architectures is presented. The performance analysis of the selected two architectures is derived using simulation program and compared at different scenarios. We found that the output buffered architectures give better performance than input buffered architectures. The simulation results show that the-broadcast-and-select architecture is attractive in terms that it has lees number of components compared to other switches.
