The delay-dependent absolute stability for a class of Lurie systems with interval time-varying delay is studied. By employing an augmented Lyapunov functional and combining a free-weighting matrix approach and the rec...The delay-dependent absolute stability for a class of Lurie systems with interval time-varying delay is studied. By employing an augmented Lyapunov functional and combining a free-weighting matrix approach and the reciprocal convex technique, an improved stability condition is derived in terms of linear matrix inequalities （LMIs）. By retaining some useful terms that are usually ignored in the derivative of the Lyapunov function, the proposed sufficient condition depends not only on the lower and upper bounds of both the delay and its derivative, but it also depends on their differences, which has wider application fields than those of present results. Moreover, a new type of equality expression is developed to handle the sector bounds of the nonlinear function, which achieves fewer LMIs in the derived condition, compared with those based on the convex representation. Therefore, the proposed method is less conservative than the existing ones. Simulation examples are given to demonstrate the validity of the approach.展开更多
In order to study the stability of desert climate, the instability of climate in Minqin desert in response to global warming during 1961-2013 was analyzed by sliding standard deviation and a linear trend line. The res...In order to study the stability of desert climate, the instability of climate in Minqin desert in response to global warming during 1961-2013 was analyzed by sliding standard deviation and a linear trend line. The results show that the instabili- ty of average temperature in January and April increased, and the isothermal date in February was 10.36 d earlier from 1961 to 2013. The instability of extreme maxi- mum temperature in December and January improved. The instability of extreme minimum temperature in July instability also increased. The coefficient of variation of extreme minimum temperature in May was up to 287.3%. It is concluded that the instability of desert climate of Minqin County increased with global warming. The stability of climate is more worthy of attention.展开更多
基金The National Natural Science Foundation of China(No.60835001,60875035,60905009,61004032,61004064,11071001)China Postdoctoral Science Foundation(No.201003546)+2 种基金the Ph.D.Programs Foundation of Ministry of Education of China(No.20093401110001)the Major Program of Higher Education of Anhui Province(No.KJ2010ZD02)the Natural Science Research Project of Higher Education of Anhui Province(No.KJ2011A020)
文摘The delay-dependent absolute stability for a class of Lurie systems with interval time-varying delay is studied. By employing an augmented Lyapunov functional and combining a free-weighting matrix approach and the reciprocal convex technique, an improved stability condition is derived in terms of linear matrix inequalities （LMIs）. By retaining some useful terms that are usually ignored in the derivative of the Lyapunov function, the proposed sufficient condition depends not only on the lower and upper bounds of both the delay and its derivative, but it also depends on their differences, which has wider application fields than those of present results. Moreover, a new type of equality expression is developed to handle the sector bounds of the nonlinear function, which achieves fewer LMIs in the derived condition, compared with those based on the convex representation. Therefore, the proposed method is less conservative than the existing ones. Simulation examples are given to demonstrate the validity of the approach.
基金Supported by the Major State Basic Research Development Program(973 Program)(2014CB460611)~~
文摘In order to study the stability of desert climate, the instability of climate in Minqin desert in response to global warming during 1961-2013 was analyzed by sliding standard deviation and a linear trend line. The results show that the instabili- ty of average temperature in January and April increased, and the isothermal date in February was 10.36 d earlier from 1961 to 2013. The instability of extreme maxi- mum temperature in December and January improved. The instability of extreme minimum temperature in July instability also increased. The coefficient of variation of extreme minimum temperature in May was up to 287.3%. It is concluded that the instability of desert climate of Minqin County increased with global warming. The stability of climate is more worthy of attention.
