Chronic refractory w ounds are common and frequently-seen diseases in surgery.Due to their long course of disease and complex pathogeneses,chronic refractory w ounds arouse high attention in clinic.With the preliminar...Chronic refractory w ounds are common and frequently-seen diseases in surgery.Due to their long course of disease and complex pathogeneses,chronic refractory w ounds arouse high attention in clinic.With the preliminary results of clinical research of their pathogeneses and new treatments achieved,traditional Chinese medicine(TCM),w ith its unique concept,breaks the limitation commonly existing in the methods of w estern medicine,especially obtaining certain achievements in chronic refractory w ounds.This paper review ed the therapeutic effects of compound Baiyu pow der in the treatment of chronic refractory w ounds to prove to be effective,convenient to use and save medical costs.展开更多
This paper mainly investigates the security problem of a networked control system based on a Kalman filter.A false data injection attack scheme is proposed to only tamper the measurement output,and its stealthiness an...This paper mainly investigates the security problem of a networked control system based on a Kalman filter.A false data injection attack scheme is proposed to only tamper the measurement output,and its stealthiness and effects on system performance are analyzed under three cases of system knowledge held by an attacker and a defender.Firstly,it is derived that the proposed attack scheme is stealthy for a residual-based detector when the attacker and the defender hold the same accurate system knowledge.Secondly,it is proven that the proposed attack scheme is still stealthy even if the defender actively modifies the Kalman filter gain so as to make it different from that of the attacker.Thirdly,the stealthiness condition of the proposed attack scheme based on an inaccurate model is given.Furthermore,for each case,the instability conditions of the closed-loop system under attack are derived.Finally,simulation results are provided to test the proposed attack scheme.展开更多
In this paper, the data-based control problem is investigated for a class of networked nonlinear systems with measurement noise as well as packet dropouts in the feedback and forward channels. The measurement noise an...In this paper, the data-based control problem is investigated for a class of networked nonlinear systems with measurement noise as well as packet dropouts in the feedback and forward channels. The measurement noise and the number of consecutive packet dropouts in both channels are assumed to be random but bounded. A data-based networked predictive control method is proposed, in which a sequence of control increment predictions are calculated in the controller based on the measured output error, and based on the control increment predictions received by the actuator, a proper control action is obtained and applied to the plant according to the real-time number of consecutive packet dropouts at each sampling instant. Then the stability analysis is performed for the networked closedloop system. Finally, the effectiveness of the proposed method is illustrated by a numerical example.展开更多
This paper presents a novel observer-based predictive control method for networked systems where random network-induced delays,packet disorders and packet dropouts in both feedback and forward channels are considered....This paper presents a novel observer-based predictive control method for networked systems where random network-induced delays,packet disorders and packet dropouts in both feedback and forward channels are considered.The proposed method has three significant features:i)A concept of destination-based lumped(DBL)delay is introduced to represent the combined effects of random communication constraints in each channel;ii)in view of different natures of the random DBL delays in the feedback and forward channels,different compensation schemes are designed;and iii)it is actual control inputs rather than predicted ones that are employed to generate future control signals based on the latest system state estimate available in the controller.For the resulting closed-loop system,a necessary and sufficient stability condition is derived,which is less conservative and also independent of random communication constraints in both channels.Simulation results are provided to demonstrate the effectiveness of the proposed method.展开更多
This paper,from the view of a defender,addresses the security problem of cyber-physical systems(CPSs)subject to stealthy false data injection(FDI)attacks that cannot be detected by a residual-based anomaly detector wi...This paper,from the view of a defender,addresses the security problem of cyber-physical systems(CPSs)subject to stealthy false data injection(FDI)attacks that cannot be detected by a residual-based anomaly detector without other defensive measures.To detect such a class of FDI attacks,a stochastic coding scheme,which codes the sensor measurement with a Gaussian stochastic signal at the sensor side,is proposed to assist an anomaly detector to expose the FDI attack.In order to ensure the system performance in the normal operational context,a decoder is adopted to decode the coded sensor measurement when received at the controller side.With this detection scheme,the residual under the attack can be significantly different from that in the normal situation,and thus trigger an alarm.The design condition of the coding signal covariance is derived to meet the constraints of false alarm rate and attack detection rate.To minimize the trace of the coding signal covariance,the design problem of the coding signal is converted into a constraint non-convex optimization problem,and an estimation-optimization iteration algorithm is presented to obtain a numerical solution of the coding signal covariance.A numerical example is given to verify the effectiveness of the proposed scheme.展开更多
基金Jiangsu Province Natural Science Foundation Item(BK20161606)Special Fund for Improving Academic Ability of Nursing of Integrated Traditional Chinese and Western Medicine(TG20180003d)
文摘Chronic refractory w ounds are common and frequently-seen diseases in surgery.Due to their long course of disease and complex pathogeneses,chronic refractory w ounds arouse high attention in clinic.With the preliminary results of clinical research of their pathogeneses and new treatments achieved,traditional Chinese medicine(TCM),w ith its unique concept,breaks the limitation commonly existing in the methods of w estern medicine,especially obtaining certain achievements in chronic refractory w ounds.This paper review ed the therapeutic effects of compound Baiyu pow der in the treatment of chronic refractory w ounds to prove to be effective,convenient to use and save medical costs.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.62173002, 61925303, 62088101, U20B2073, and 61720106011the Beijing Natural Science Foundation under Grant No. 4222045
文摘This paper mainly investigates the security problem of a networked control system based on a Kalman filter.A false data injection attack scheme is proposed to only tamper the measurement output,and its stealthiness and effects on system performance are analyzed under three cases of system knowledge held by an attacker and a defender.Firstly,it is derived that the proposed attack scheme is stealthy for a residual-based detector when the attacker and the defender hold the same accurate system knowledge.Secondly,it is proven that the proposed attack scheme is still stealthy even if the defender actively modifies the Kalman filter gain so as to make it different from that of the attacker.Thirdly,the stealthiness condition of the proposed attack scheme based on an inaccurate model is given.Furthermore,for each case,the instability conditions of the closed-loop system under attack are derived.Finally,simulation results are provided to test the proposed attack scheme.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.61673023,61203230,61273104,61333003,61210012,and 61490701the Beijing Municipal Natural Science Foundation under Grant No.4152014+3 种基金the Great Wall Scholar Candidate Training Program of North China University of Technology(NCUT)the Excellent Youth Scholar Nurturing Program of NCUTthe Outstanding Young Scientist Award Foundation of Shandong Province of China under Grant No.BS2013DX015the Research Fund for the Taishan Scholar Project of Shandong Province of China
文摘In this paper, the data-based control problem is investigated for a class of networked nonlinear systems with measurement noise as well as packet dropouts in the feedback and forward channels. The measurement noise and the number of consecutive packet dropouts in both channels are assumed to be random but bounded. A data-based networked predictive control method is proposed, in which a sequence of control increment predictions are calculated in the controller based on the measured output error, and based on the control increment predictions received by the actuator, a proper control action is obtained and applied to the plant according to the real-time number of consecutive packet dropouts at each sampling instant. Then the stability analysis is performed for the networked closedloop system. Finally, the effectiveness of the proposed method is illustrated by a numerical example.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.61673023 and 61773144the Youth Talent Support Program of Beijing Municipality+2 种基金the NCUT Yujie Talent Training Programthe NCUT Science and Technology Innovation Projectthe BMEC Basic Scientific Research Foundation。
文摘This paper presents a novel observer-based predictive control method for networked systems where random network-induced delays,packet disorders and packet dropouts in both feedback and forward channels are considered.The proposed method has three significant features:i)A concept of destination-based lumped(DBL)delay is introduced to represent the combined effects of random communication constraints in each channel;ii)in view of different natures of the random DBL delays in the feedback and forward channels,different compensation schemes are designed;and iii)it is actual control inputs rather than predicted ones that are employed to generate future control signals based on the latest system state estimate available in the controller.For the resulting closed-loop system,a necessary and sufficient stability condition is derived,which is less conservative and also independent of random communication constraints in both channels.Simulation results are provided to demonstrate the effectiveness of the proposed method.
基金supported by the National Natural Science Foundation of China under Grant Nos.61925303,62088101,U20B2073,61720106011,and 62173002the National Key R&D Program of China under Grant No.2018YFB1700100the Beijing Natural Science Foundation under Grant No.4222045。
文摘This paper,from the view of a defender,addresses the security problem of cyber-physical systems(CPSs)subject to stealthy false data injection(FDI)attacks that cannot be detected by a residual-based anomaly detector without other defensive measures.To detect such a class of FDI attacks,a stochastic coding scheme,which codes the sensor measurement with a Gaussian stochastic signal at the sensor side,is proposed to assist an anomaly detector to expose the FDI attack.In order to ensure the system performance in the normal operational context,a decoder is adopted to decode the coded sensor measurement when received at the controller side.With this detection scheme,the residual under the attack can be significantly different from that in the normal situation,and thus trigger an alarm.The design condition of the coding signal covariance is derived to meet the constraints of false alarm rate and attack detection rate.To minimize the trace of the coding signal covariance,the design problem of the coding signal is converted into a constraint non-convex optimization problem,and an estimation-optimization iteration algorithm is presented to obtain a numerical solution of the coding signal covariance.A numerical example is given to verify the effectiveness of the proposed scheme.
