It is often important to incorporate covariate information in the design of clinical trials. In literature there are many designs of using stratification and covariate-adaptive randomization to balance certain known c...It is often important to incorporate covariate information in the design of clinical trials. In literature there are many designs of using stratification and covariate-adaptive randomization to balance certain known covariate. Recently, some covariate-adjusted response-adaptive (CARA) designs have been proposed and their asymptotic properties have been studied (Ann. Statist. 2007). However, these CARA designs usually have high variabilities. In this paper, a new family of covariate-adjusted response-adaptive (CARA) designs is presented. It is shown that the new designs have less variables and therefore are more efficient.展开更多
Each place has its own peculiarities,determining that the resilience and adaptation to diverse types of risks will be different,requiring different time and methods for mitigation as well.The coexistence of several ri...Each place has its own peculiarities,determining that the resilience and adaptation to diverse types of risks will be different,requiring different time and methods for mitigation as well.The coexistence of several risks determines further resolution difficulties as commonly,since risks are sudden and unforeseen,there is a tendency to treat the last risk more carefully,neglecting the previous one even if it is just as important.Most of the methodologies used to analyse areas affected by different risks are aimed at focusing in particular on seismic risks without considering those relating to intangible aspects linked to the identity of the places or aspects related to urban health and liveability.And,more in general,in relation to design aspects,urban methodologies do not consider all the results of the analyses,maybe for the difficulty deriving from translating the complexity of collected data in project interventions.Starting from these premises,the objective of the article,elaborated within the SISMI and PRIN 2020 research projects is to propose an original methodology capable of analysing the places affected by multiple risks and planning its resilience attentive to its cultural resources and to its liveability.To this end,the proposed method will be aimed at creating flexible and adaptive places and the case-study of Cittaducale will be illustrated.Criticalities and qualities of this place affected by an earthquake in 2016 will be reported and project interventions to transform its risks into opportunities will be shown.展开更多
The strong approximations of a class of R^d-valued martingales are considered.The conditions usedin this paper are easier to check than those used in [3] and [9].As an application,the strong approximation ofa class of...The strong approximations of a class of R^d-valued martingales are considered.The conditions usedin this paper are easier to check than those used in [3] and [9].As an application,the strong approximation ofa class of non-homogenous Markov chains is established,and the asymptotic properties are established for themulti-treatment Markov chain adaptive designs in clinical trials.展开更多
The pyrotechnic control subsystem plays an important role in opening the solar array of a satellite. Assessing the reliability of the subsystem requires determining the level of a control factor that is needed to caus...The pyrotechnic control subsystem plays an important role in opening the solar array of a satellite. Assessing the reliability of the subsystem requires determining the level of a control factor that is needed to cause the desired response and energy output with high probability. A two-phase adaptive design to estimate the level of interest is proposed and studied. The convergence of the design is obtained. A simulation study shows that the estimate is very close to its population value and is robust to the initial guess of the design. As an application, the design is used to assess the reliability of a real pyrotechnic control subsystem.展开更多
This paper discusses the asymptotic properties of the SCAD(smoothing clipped absolute deviation)penalized quasi-likelihood estimator for generalized linear models with adaptive designs,which extend the related results...This paper discusses the asymptotic properties of the SCAD(smoothing clipped absolute deviation)penalized quasi-likelihood estimator for generalized linear models with adaptive designs,which extend the related results for independent observations to dependent observations.Under certain conditions,the authors proved that the SCAD penalized method correctly selects covariates with nonzero coefficients with probability converging to one,and the penalized quasi-likelihood estimators of non-zero coefficients have the same asymptotic distribution they would have if the zero coefficients were known in advance.That is,the SCAD estimator has consistency and oracle properties.At last,the results are illustrated by some simulations.展开更多
The core task of tracking control is to make the controlled plant track a desired trajectory.The traditional performance index used in previous studies cannot eliminate completely the tracking error as the number of t...The core task of tracking control is to make the controlled plant track a desired trajectory.The traditional performance index used in previous studies cannot eliminate completely the tracking error as the number of time steps increases.In this paper,a new cost function is introduced to develop the value-iteration-based adaptive critic framework to solve the tracking control problem.Unlike the regulator problem,the iterative value function of tracking control problem cannot be regarded as a Lyapunov function.A novel stability analysis method is developed to guarantee that the tracking error converges to zero.The discounted iterative scheme under the new cost function for the special case of linear systems is elaborated.Finally,the tracking performance of the present scheme is demonstrated by numerical results and compared with those of the traditional approaches.展开更多
An adaptive robust control algorithm for ship straight path control system in the presence of both modeling uncertainties and the bounded disturbances is proposed. Motivated by the backstepping approach, the algorithm...An adaptive robust control algorithm for ship straight path control system in the presence of both modeling uncertainties and the bounded disturbances is proposed. Motivated by the backstepping approach, the algorithm is developed by using the dissipation theory, such that the resulting dosed-loop system is both strictly dissipative and asymptotically adaptively stable for all admissible uncertainties. Also, it is able to steer an underactuated ship along a prescribed straight path with ultimate bounds under external disturbances induced by wave, wind and ocean current. When there are no disturbances, the straight path control can be implemented in a locally asymptotically stable manner. Simulation results on an ocean-going training ship ‘YULONG' are presented to validate the effectiveness of the algorithm.展开更多
This paper proposes a new kind of generalized Friendman's urn model,which with adaptive nonhomogeneous generating matrix.This model may be applied in sequential medical experiment.In this model some limit theorems...This paper proposes a new kind of generalized Friendman's urn model,which with adaptive nonhomogeneous generating matrix.This model may be applied in sequential medical experiment.In this model some limit theorems (strong consistency and asymptot- ical normality) have been obtained.展开更多
Objectives To explore the optimization method of vaccine clinical trial design based on immunological surrogate endpoint to improve the quality and efficiency of vaccine clinical research and development.Methods As to...Objectives To explore the optimization method of vaccine clinical trial design based on immunological surrogate endpoint to improve the quality and efficiency of vaccine clinical research and development.Methods As to the problems in the vaccine clinical research in China,the relevant guidelines and literatures of FDA and WHO were used to analyze and summarize the methods of optimizing the design of vaccine clinical trials.Results and Conclusion The adaptive design guidelines are established to guide clinical trial design,encourage the development and application of immunological surrogate endpoints,establish qualification process for drug development tools and information disclosure procedures to improve vaccine development efficiency.展开更多
With the price decreasing of the pneumatic proportional valve and the high performance micro controller, the simple structure and high tracking performance pneumatic servo system demonstrates more application potentia...With the price decreasing of the pneumatic proportional valve and the high performance micro controller, the simple structure and high tracking performance pneumatic servo system demonstrates more application potential in many fields. However, most existing control methods with high tracking performance need to know the model information and to use pressure sensor. This limits the application of the pneumatic servo system. An adaptive backstepping slide mode control method is proposed for pneumatic position servo system. The proposed method designs adaptive slide mode controller using backstepping design technique. The controller parameter adaptive law is derived from Lyapunov analysis to guarantee the stability of the system. A theorem is testified to show that the state of closed-loop system is uniformly bounded, and the closed-loop system is stable. The advantages of the proposed method include that system dynamic model parameters are not required for the controller design, uncertain parameters bounds are not need, and the bulk and expensive pressure sensor is not needed as well. Experimental performance, as compared with some existing methods. results show that the designed controller can achieve better tracking展开更多
This paper concerns a novel optimal self-learning battery sequential control scheme for smart home energy systems.The main idea is to use the adaptive dynamic programming(ADP) technique to obtain the optimal battery s...This paper concerns a novel optimal self-learning battery sequential control scheme for smart home energy systems.The main idea is to use the adaptive dynamic programming(ADP) technique to obtain the optimal battery sequential control iteratively. First, the battery energy management system model is established, where the power efficiency of the battery is considered. Next, considering the power constraints of the battery, a new non-quadratic form performance index function is established, which guarantees that the value of the iterative control law cannot exceed the maximum charging/discharging power of the battery to extend the service life of the battery.Then, the convergence properties of the iterative ADP algorithm are analyzed, which guarantees that the iterative value function and the iterative control law both reach the optimums. Finally,simulation and comparison results are given to illustrate the performance of the presented method.展开更多
Adaptable design aims to extend the utilities of design and product. The specific methods are developed for practical applications of adaptable design in the design of mechanical structures, including adaptable platfo...Adaptable design aims to extend the utilities of design and product. The specific methods are developed for practical applications of adaptable design in the design of mechanical structures, including adaptable platform, interface and module designs. Adaptable redesign problems are formulated as adaptable platform design under adaptability bound constraints. Analysis tools are then suggested for the implementation of the redesign of machine tool structures, including variation techniques based sensitivity analysis, similarity-based commonality analysis, performance improvement, and adaptability measures. The specific measure of adaptability for machine tool structures is measured through the quantification of the structural similarity and performance improvement gained from adaptable design. The method provides designers with an approach that brings adaptability into the design process, with considering the cost and benefits of such adaptability. The redesign of CNC spiral bevel gear cutting machine structures has been included to illustrate these concepts and methods.展开更多
A policy iteration algorithm of adaptive dynamic programming(ADP) is developed to solve the optimal tracking control for a class of discrete-time chaotic systems. By system transformations, the optimal tracking prob...A policy iteration algorithm of adaptive dynamic programming(ADP) is developed to solve the optimal tracking control for a class of discrete-time chaotic systems. By system transformations, the optimal tracking problem is transformed into an optimal regulation one. The policy iteration algorithm for discrete-time chaotic systems is first described. Then,the convergence and admissibility properties of the developed policy iteration algorithm are presented, which show that the transformed chaotic system can be stabilized under an arbitrary iterative control law and the iterative performance index function simultaneously converges to the optimum. By implementing the policy iteration algorithm via neural networks,the developed optimal tracking control scheme for chaotic systems is verified by a simulation.展开更多
A newly emerging design pattern, named as adaptable design (AD), which aims at developing products that are adaptable from design to post-life cycle, is discussed. AD consists of four main phases: product modeling,...A newly emerging design pattern, named as adaptable design (AD), which aims at developing products that are adaptable from design to post-life cycle, is discussed. AD consists of four main phases: product modeling, design platform, specific design and product redesign. A new process-based design data model (PDDM) is presented which is organized according to the principles of convenient knowledge extraction, data representation, layout, sharing and reuse. Based on the PDDM, a universal design platform for product family development is established, which has characters of modularity, parameter-driven, variant design, etc. The framework of the platform is also proposed as a conceptual structure and overall logical organization for generating a family of products. AD methodology is successfully applied to develop a family of tunnel boring machine (TBM) for different engineering projects, with the efficiency of our developing team being greatly increased.展开更多
Today's manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for com...Today's manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for companies to achieve their objectives. Efforts to mass customisation should be made on two aspects: (1) To modularize products and make them as less differences as possible; (2) To design manufacturing resources and make them provide as many processes variations as possible. This paper reports our recent work on aspect (2), i.e. how to design a reconfignrable manufacturing system (RMS) so that it can be competent to accomplish various processes optimally; Reconfignrable robot system (RRS) is taken as an example. RMS design involves architecture design and configuration design, and configuration design is further divided in design analysis and design synthesis. Axiomatic design theory (ADT) is applied to architecture design, the features and issues of RRS configuration design are discussed, automatic modelling method is developed for design analysis, and concurrent design methodology is presented for design synthesis.展开更多
q-axis rotor flux can be chosen to form a model reference adaptive system(MRAS)updating rotor time constant online in induction motor drives.This paper presents a stability analysis of such a system with Popov’s hype...q-axis rotor flux can be chosen to form a model reference adaptive system(MRAS)updating rotor time constant online in induction motor drives.This paper presents a stability analysis of such a system with Popov’s hyperstability concept and small-signal linearization technique.At first,the stability of q-axis rotor flux based MRAS is proven with Popov’s Hyperstability theory.Then,to find out the guidelines for optimally designing the coefficients in the PI controller,acting as the adaption mechanism in the MRAS,small-signal model of the estimation system is developed.The obtained linearization model not only allows the stability to be verified further through Routh criterion,but also reveals the distribution of the characteristic roots,which leads to the clue to optimal PI gains.The theoretical analysis and the resultant design guidelines of the adaptation PI gains are verified through simulation and experiments.展开更多
In order to improve the system reliability and performance and to reduce the system cost, volume and weight, we have designed, fabricated and tested the multibus adapter system of a trimodular redundant fault tolerant...In order to improve the system reliability and performance and to reduce the system cost, volume and weight, we have designed, fabricated and tested the multibus adapter system of a trimodular redundant fault tolerant computer system on a single chip of 5000 gate CMOS gate array. The design, fabrication and test of this single chip system will be discussed..展开更多
Aimed at infinite horizon optimal control problems of discrete time-varying nonlinear systems,in this paper,a new iterative adaptive dynamic programming algorithm,which is the discrete-time time-varying policy iterati...Aimed at infinite horizon optimal control problems of discrete time-varying nonlinear systems,in this paper,a new iterative adaptive dynamic programming algorithm,which is the discrete-time time-varying policy iteration(DTTV)algorithm,is developed.The iterative control law is designed to update the iterative value function which approximates the index function of optimal performance.The admissibility of the iterative control law is analyzed.The results show that the iterative value function is non-increasingly convergent to the Bellman-equation optimal solution.To implement the algorithm,neural networks are employed and a new implementation structure is established,which avoids solving the generalized Bellman equation in each iteration.Finally,the optimal control laws for torsional pendulum and inverted pendulum systems are obtained by using the DTTV policy iteration algorithm,where the mass and pendulum bar length are permitted to be time-varying parameters.The effectiveness of the developed method is illustrated by numerical results and comparisons.展开更多
Patient-reported outcomes measures form the backbone of outcomes evaluation in orthopaedics,with most of the literature now relying on these scoring tools to measure change in patient health status.This patient-report...Patient-reported outcomes measures form the backbone of outcomes evaluation in orthopaedics,with most of the literature now relying on these scoring tools to measure change in patient health status.This patient-reported information is increasingly collected routinely by orthopaedic providers but use of the data is typically restricted to academic research.Developments in electronic data capture and the outcome tools themselves now allow use of this data as part of the clinical consultation.This review evaluates the role of patient reported outcomes data as a tool to enhance daily orthopaedic clinical practice,and documents how developments in electronic outcome measures,computer-adaptive questionnaire design and instant graphical display of questionnaire can facilitate enhanced patientclinician shared decision making.展开更多
SARISTU was a big cooperation project granted by the European Commission,7th Framework Programme,carried out between 2011 and 2015.It dealt with smart aeronautic structures,both morphing and sensored;its main target w...SARISTU was a big cooperation project granted by the European Commission,7th Framework Programme,carried out between 2011 and 2015.It dealt with smart aeronautic structures,both morphing and sensored;its main target was to demonstrate the feasibility of designing,manufacturing and operating in representative environment,instrumented structures.Till now,it represents the major effort carried out within the European Union on the development of adaptive architectures for air systems.Inside that big activity,the realization of an Adaptive Trailing Edge Device(ATED)for wing camber adaptations aimed at compensating the weight reduction following the fuel consumption during cruise was addressed.It made the core of investigations target variable geometry aircraft components together with two other analyses concerning the development of shape-changing winglet and droop nose.ATED activities were conducted by the Italian Aerospace Research Centre(CIRA)in tight cooperation with the University of Napoli,"Federico II",who coordinated a group of 12 different partners from 8 different nations(France,Germany,Greece,the Netherlands,Israel,Spain,Turkey,and Italy).In this paper,an integral synthesis of that work is reported,with a focus on the definition and realization of the components of the presented device.The publication is in fact meant as the first part of a series that is aimed at overviewing the whole adaptive trailing edge development,till wind tunnel tests execution.Such a concise report is a critical and harmonized review of what have been performed by many colleagues spread all over Europe,all of which are duly recalled in the reported bibliography where the reader may access more detailed information and descriptions.In detail,the paper starts with a general introduction of the concept and its aims,to move to the specs definition immediately after.Then,it deals with a short but comprehensive description of the main ATED components:structural skeleton,skin,actuation and sensing systems.It is worth remarking that the paragraph dedicated to the body frame includes some discussion about aeroelastic assessment and manufacture,seen as complementation for a complete assessment of the design constraints.展开更多
基金Partially supported by the National Natural Science Foundation of China (10771192)NSF Awards DMS-0349048 of USA
文摘It is often important to incorporate covariate information in the design of clinical trials. In literature there are many designs of using stratification and covariate-adaptive randomization to balance certain known covariate. Recently, some covariate-adjusted response-adaptive (CARA) designs have been proposed and their asymptotic properties have been studied (Ann. Statist. 2007). However, these CARA designs usually have high variabilities. In this paper, a new family of covariate-adjusted response-adaptive (CARA) designs is presented. It is shown that the new designs have less variables and therefore are more efficient.
基金the Italian Ministry of University and Research(MUR)in the framework of the Project PRIN2020#20209F3A37 is gratefully acknowledged.
文摘Each place has its own peculiarities,determining that the resilience and adaptation to diverse types of risks will be different,requiring different time and methods for mitigation as well.The coexistence of several risks determines further resolution difficulties as commonly,since risks are sudden and unforeseen,there is a tendency to treat the last risk more carefully,neglecting the previous one even if it is just as important.Most of the methodologies used to analyse areas affected by different risks are aimed at focusing in particular on seismic risks without considering those relating to intangible aspects linked to the identity of the places or aspects related to urban health and liveability.And,more in general,in relation to design aspects,urban methodologies do not consider all the results of the analyses,maybe for the difficulty deriving from translating the complexity of collected data in project interventions.Starting from these premises,the objective of the article,elaborated within the SISMI and PRIN 2020 research projects is to propose an original methodology capable of analysing the places affected by multiple risks and planning its resilience attentive to its cultural resources and to its liveability.To this end,the proposed method will be aimed at creating flexible and adaptive places and the case-study of Cittaducale will be illustrated.Criticalities and qualities of this place affected by an earthquake in 2016 will be reported and project interventions to transform its risks into opportunities will be shown.
基金Supported by The National Natural Science Foundation of China (No.10071072)
文摘The strong approximations of a class of R^d-valued martingales are considered.The conditions usedin this paper are easier to check than those used in [3] and [9].As an application,the strong approximation ofa class of non-homogenous Markov chains is established,and the asymptotic properties are established for themulti-treatment Markov chain adaptive designs in clinical trials.
基金Supported by the National Natural Science Foundation of China(No.10971012)
文摘The pyrotechnic control subsystem plays an important role in opening the solar array of a satellite. Assessing the reliability of the subsystem requires determining the level of a control factor that is needed to cause the desired response and energy output with high probability. A two-phase adaptive design to estimate the level of interest is proposed and studied. The convergence of the design is obtained. A simulation study shows that the estimate is very close to its population value and is robust to the initial guess of the design. As an application, the design is used to assess the reliability of a real pyrotechnic control subsystem.
基金the National Social Science Foundation of China under Grant No.18BTJ040。
文摘This paper discusses the asymptotic properties of the SCAD(smoothing clipped absolute deviation)penalized quasi-likelihood estimator for generalized linear models with adaptive designs,which extend the related results for independent observations to dependent observations.Under certain conditions,the authors proved that the SCAD penalized method correctly selects covariates with nonzero coefficients with probability converging to one,and the penalized quasi-likelihood estimators of non-zero coefficients have the same asymptotic distribution they would have if the zero coefficients were known in advance.That is,the SCAD estimator has consistency and oracle properties.At last,the results are illustrated by some simulations.
基金This work was supported in part by Beijing Natural Science Foundation(JQ19013)the National Key Research and Development Program of China(2021ZD0112302)the National Natural Science Foundation of China(61773373).
文摘The core task of tracking control is to make the controlled plant track a desired trajectory.The traditional performance index used in previous studies cannot eliminate completely the tracking error as the number of time steps increases.In this paper,a new cost function is introduced to develop the value-iteration-based adaptive critic framework to solve the tracking control problem.Unlike the regulator problem,the iterative value function of tracking control problem cannot be regarded as a Lyapunov function.A novel stability analysis method is developed to guarantee that the tracking error converges to zero.The discounted iterative scheme under the new cost function for the special case of linear systems is elaborated.Finally,the tracking performance of the present scheme is demonstrated by numerical results and compared with those of the traditional approaches.
文摘An adaptive robust control algorithm for ship straight path control system in the presence of both modeling uncertainties and the bounded disturbances is proposed. Motivated by the backstepping approach, the algorithm is developed by using the dissipation theory, such that the resulting dosed-loop system is both strictly dissipative and asymptotically adaptively stable for all admissible uncertainties. Also, it is able to steer an underactuated ship along a prescribed straight path with ultimate bounds under external disturbances induced by wave, wind and ocean current. When there are no disturbances, the straight path control can be implemented in a locally asymptotically stable manner. Simulation results on an ocean-going training ship ‘YULONG' are presented to validate the effectiveness of the algorithm.
基金This work is supported by a grant of National University of Singapore(RP 3972712)by partially National Science Foundation of
文摘This paper proposes a new kind of generalized Friendman's urn model,which with adaptive nonhomogeneous generating matrix.This model may be applied in sequential medical experiment.In this model some limit theorems (strong consistency and asymptot- ical normality) have been obtained.
文摘Objectives To explore the optimization method of vaccine clinical trial design based on immunological surrogate endpoint to improve the quality and efficiency of vaccine clinical research and development.Methods As to the problems in the vaccine clinical research in China,the relevant guidelines and literatures of FDA and WHO were used to analyze and summarize the methods of optimizing the design of vaccine clinical trials.Results and Conclusion The adaptive design guidelines are established to guide clinical trial design,encourage the development and application of immunological surrogate endpoints,establish qualification process for drug development tools and information disclosure procedures to improve vaccine development efficiency.
基金Supported by National Key Scientific and Technological Project(Grant No.2010ZX04001-051-031)Key Program of National Natural Science Foundation of China((Grant No.61533014)the Innovative Research Team of Shaanxi Province,China(Grant No.2013KCT-04)
文摘With the price decreasing of the pneumatic proportional valve and the high performance micro controller, the simple structure and high tracking performance pneumatic servo system demonstrates more application potential in many fields. However, most existing control methods with high tracking performance need to know the model information and to use pressure sensor. This limits the application of the pneumatic servo system. An adaptive backstepping slide mode control method is proposed for pneumatic position servo system. The proposed method designs adaptive slide mode controller using backstepping design technique. The controller parameter adaptive law is derived from Lyapunov analysis to guarantee the stability of the system. A theorem is testified to show that the state of closed-loop system is uniformly bounded, and the closed-loop system is stable. The advantages of the proposed method include that system dynamic model parameters are not required for the controller design, uncertain parameters bounds are not need, and the bulk and expensive pressure sensor is not needed as well. Experimental performance, as compared with some existing methods. results show that the designed controller can achieve better tracking
基金supported in part by National Natural Science Foundation of China(61533017,61273140,61304079,61374105,61379099,61233001)Fundamental Research Funds for the Central Universities(FRF-TP-15-056A3)the Open Research Project from SKLMCCS(20150104)
文摘This paper concerns a novel optimal self-learning battery sequential control scheme for smart home energy systems.The main idea is to use the adaptive dynamic programming(ADP) technique to obtain the optimal battery sequential control iteratively. First, the battery energy management system model is established, where the power efficiency of the battery is considered. Next, considering the power constraints of the battery, a new non-quadratic form performance index function is established, which guarantees that the value of the iterative control law cannot exceed the maximum charging/discharging power of the battery to extend the service life of the battery.Then, the convergence properties of the iterative ADP algorithm are analyzed, which guarantees that the iterative value function and the iterative control law both reach the optimums. Finally,simulation and comparison results are given to illustrate the performance of the presented method.
基金National Natural Science Foundation of China(No.50575084,No.50675126)Tianjin Municipal Science Technology Development Key Project,China(No.06YFGZGX00200)National Hi-tech Research Development Program of China(863 Program,No.2006AA04Z107)
文摘Adaptable design aims to extend the utilities of design and product. The specific methods are developed for practical applications of adaptable design in the design of mechanical structures, including adaptable platform, interface and module designs. Adaptable redesign problems are formulated as adaptable platform design under adaptability bound constraints. Analysis tools are then suggested for the implementation of the redesign of machine tool structures, including variation techniques based sensitivity analysis, similarity-based commonality analysis, performance improvement, and adaptability measures. The specific measure of adaptability for machine tool structures is measured through the quantification of the structural similarity and performance improvement gained from adaptable design. The method provides designers with an approach that brings adaptability into the design process, with considering the cost and benefits of such adaptability. The redesign of CNC spiral bevel gear cutting machine structures has been included to illustrate these concepts and methods.
基金supported by the National Natural Science Foundation of China(Grant Nos.61034002,61233001,61273140,61304086,and 61374105)the Beijing Natural Science Foundation,China(Grant No.4132078)
文摘A policy iteration algorithm of adaptive dynamic programming(ADP) is developed to solve the optimal tracking control for a class of discrete-time chaotic systems. By system transformations, the optimal tracking problem is transformed into an optimal regulation one. The policy iteration algorithm for discrete-time chaotic systems is first described. Then,the convergence and admissibility properties of the developed policy iteration algorithm are presented, which show that the transformed chaotic system can be stabilized under an arbitrary iterative control law and the iterative performance index function simultaneously converges to the optimum. By implementing the policy iteration algorithm via neural networks,the developed optimal tracking control scheme for chaotic systems is verified by a simulation.
文摘A newly emerging design pattern, named as adaptable design (AD), which aims at developing products that are adaptable from design to post-life cycle, is discussed. AD consists of four main phases: product modeling, design platform, specific design and product redesign. A new process-based design data model (PDDM) is presented which is organized according to the principles of convenient knowledge extraction, data representation, layout, sharing and reuse. Based on the PDDM, a universal design platform for product family development is established, which has characters of modularity, parameter-driven, variant design, etc. The framework of the platform is also proposed as a conceptual structure and overall logical organization for generating a family of products. AD methodology is successfully applied to develop a family of tunnel boring machine (TBM) for different engineering projects, with the efficiency of our developing team being greatly increased.
文摘Today's manufacturing cnvironmem forces manufacturing companies to make as many product variations as possible at affordable costs within a short time. Mass customisation is one of most important technologies for companies to achieve their objectives. Efforts to mass customisation should be made on two aspects: (1) To modularize products and make them as less differences as possible; (2) To design manufacturing resources and make them provide as many processes variations as possible. This paper reports our recent work on aspect (2), i.e. how to design a reconfignrable manufacturing system (RMS) so that it can be competent to accomplish various processes optimally; Reconfignrable robot system (RRS) is taken as an example. RMS design involves architecture design and configuration design, and configuration design is further divided in design analysis and design synthesis. Axiomatic design theory (ADT) is applied to architecture design, the features and issues of RRS configuration design are discussed, automatic modelling method is developed for design analysis, and concurrent design methodology is presented for design synthesis.
文摘q-axis rotor flux can be chosen to form a model reference adaptive system(MRAS)updating rotor time constant online in induction motor drives.This paper presents a stability analysis of such a system with Popov’s hyperstability concept and small-signal linearization technique.At first,the stability of q-axis rotor flux based MRAS is proven with Popov’s Hyperstability theory.Then,to find out the guidelines for optimally designing the coefficients in the PI controller,acting as the adaption mechanism in the MRAS,small-signal model of the estimation system is developed.The obtained linearization model not only allows the stability to be verified further through Routh criterion,but also reveals the distribution of the characteristic roots,which leads to the clue to optimal PI gains.The theoretical analysis and the resultant design guidelines of the adaptation PI gains are verified through simulation and experiments.
文摘In order to improve the system reliability and performance and to reduce the system cost, volume and weight, we have designed, fabricated and tested the multibus adapter system of a trimodular redundant fault tolerant computer system on a single chip of 5000 gate CMOS gate array. The design, fabrication and test of this single chip system will be discussed..
基金supported in part by Fundamental Research Funds for the Central Universities(2022JBZX024)in part by the National Natural Science Foundation of China(61872037,61273167)。
文摘Aimed at infinite horizon optimal control problems of discrete time-varying nonlinear systems,in this paper,a new iterative adaptive dynamic programming algorithm,which is the discrete-time time-varying policy iteration(DTTV)algorithm,is developed.The iterative control law is designed to update the iterative value function which approximates the index function of optimal performance.The admissibility of the iterative control law is analyzed.The results show that the iterative value function is non-increasingly convergent to the Bellman-equation optimal solution.To implement the algorithm,neural networks are employed and a new implementation structure is established,which avoids solving the generalized Bellman equation in each iteration.Finally,the optimal control laws for torsional pendulum and inverted pendulum systems are obtained by using the DTTV policy iteration algorithm,where the mass and pendulum bar length are permitted to be time-varying parameters.The effectiveness of the developed method is illustrated by numerical results and comparisons.
文摘Patient-reported outcomes measures form the backbone of outcomes evaluation in orthopaedics,with most of the literature now relying on these scoring tools to measure change in patient health status.This patient-reported information is increasingly collected routinely by orthopaedic providers but use of the data is typically restricted to academic research.Developments in electronic data capture and the outcome tools themselves now allow use of this data as part of the clinical consultation.This review evaluates the role of patient reported outcomes data as a tool to enhance daily orthopaedic clinical practice,and documents how developments in electronic outcome measures,computer-adaptive questionnaire design and instant graphical display of questionnaire can facilitate enhanced patientclinician shared decision making.
基金The research herein reported did gratefully receive funding from Seventh Framework Programme of the European Union(FP7/2007-2013)under Grant Agreement N.284562,SARISTUThe project was prodigiously and effectively coordinated by Piet Christof Woelcken(Airbus)with the support of Michael Papadopoulos(EASN–European Aeronautic Science Network).
文摘SARISTU was a big cooperation project granted by the European Commission,7th Framework Programme,carried out between 2011 and 2015.It dealt with smart aeronautic structures,both morphing and sensored;its main target was to demonstrate the feasibility of designing,manufacturing and operating in representative environment,instrumented structures.Till now,it represents the major effort carried out within the European Union on the development of adaptive architectures for air systems.Inside that big activity,the realization of an Adaptive Trailing Edge Device(ATED)for wing camber adaptations aimed at compensating the weight reduction following the fuel consumption during cruise was addressed.It made the core of investigations target variable geometry aircraft components together with two other analyses concerning the development of shape-changing winglet and droop nose.ATED activities were conducted by the Italian Aerospace Research Centre(CIRA)in tight cooperation with the University of Napoli,"Federico II",who coordinated a group of 12 different partners from 8 different nations(France,Germany,Greece,the Netherlands,Israel,Spain,Turkey,and Italy).In this paper,an integral synthesis of that work is reported,with a focus on the definition and realization of the components of the presented device.The publication is in fact meant as the first part of a series that is aimed at overviewing the whole adaptive trailing edge development,till wind tunnel tests execution.Such a concise report is a critical and harmonized review of what have been performed by many colleagues spread all over Europe,all of which are duly recalled in the reported bibliography where the reader may access more detailed information and descriptions.In detail,the paper starts with a general introduction of the concept and its aims,to move to the specs definition immediately after.Then,it deals with a short but comprehensive description of the main ATED components:structural skeleton,skin,actuation and sensing systems.It is worth remarking that the paragraph dedicated to the body frame includes some discussion about aeroelastic assessment and manufacture,seen as complementation for a complete assessment of the design constraints.