( 2 ) using the method of parameter identification in literature [ 117 - 118 ] , selecting gain function : giving the initial value of the parameter observer from the time serial of output variables of the system , the numerical simulation result shows that the parameter observer proposed in this paper can identify the unknown parameters of the system quickly and exactly no matter if the parameters keep invariable or change in some rule , and the identifying speed is faster than the method in [ 117 - 118 ] , when the unknown parameters are being identified , vith parameter compensator , it can synchronizes two hyperchaotic systems completely even if some parameters mismatch ( 2 )采用文獻(xiàn)[ 117 - 118 ]提出的參數(shù)辨識(shí)方法,通過(guò)選取更一般的增益函數(shù): l _ i ( x _ i ) = kx _ ii = 1 , 2 , 3并根據(jù)系統(tǒng)輸出變量的時(shí)間序列給出參數(shù)觀測(cè)器的初始值來(lái)進(jìn)行參數(shù)辨識(shí),數(shù)值模擬結(jié)果表明:采用本文的參數(shù)觀測(cè)器,在系統(tǒng)參數(shù)固定或變化的情況下,都可對(duì)系統(tǒng)未知參數(shù)實(shí)現(xiàn)快速高精度辨識(shí),辨識(shí)的速度快于文獻(xiàn)[ 117 - 118 ]提出的方法;在辨識(shí)參數(shù)的同時(shí),結(jié)合參數(shù)補(bǔ)償器,使兩個(gè)參數(shù)不匹配的超混沌系統(tǒng)同步。
Abstract : in this paper , we study the synchronization approach for hyperchaos system of 4th - order cellular neural network analyze its pefforraance in the presence of parameter mismatch and channel noise , and propose a design method for a spread - spectrum secure communication system based on hyperchaos of cellular neural network 文摘:研究了四階細(xì)胞神經(jīng)網(wǎng)絡(luò)超混沌系統(tǒng)同步方法,分析了系統(tǒng)存在參數(shù)失配和信道噪聲時(shí)的同步性能,提出了一種基于細(xì)胞神經(jīng)網(wǎng)絡(luò)超混沌同步系統(tǒng)的擴(kuò)展頻譜保密通信設(shè)計(jì)方法。
The heteroepitaxial growth of 3c - sic on si substrate not only unfurls the maturity of si process , but also incarnates the excellence of 3c - sic , so that it become for long researchful direction . due to the large lattice parameter mismatch ( ~ 20 % ) and the large thermal expansion coefficient mismatch ( ~ 8 % ) , however , the 3c - sic / si study is very difficult 然而,由于3c - sic與si之間存在較大的晶格失配度(約20 % )和熱膨脹系數(shù)差異(約8 % ) ,因此, 3c - sic / si異質(zhì)外延薄膜的制備非常困難,仍存在許多技術(shù)問(wèn)題需要克服。
High quality epitaxial sto / ybco multilayers can be fabricated due to their similar crystal structure and small lattice parameters mismatch . the filter made from sto / ybco thin films shows high tunable speed , low microwave loss and high power handling capability . so sto / ybco multilayers have attracted much interests for electronically tunable filter in the last decade 因此,利用高質(zhì)量sto / ybco外延薄膜研制的濾波器具有響應(yīng)速度快、微波損耗低、調(diào)諧范圍大、承載功率高等優(yōu)點(diǎn),是一種極具競(jìng)爭(zhēng)力的電調(diào)濾波器技術(shù)方案,也是當(dāng)前的研究熱點(diǎn)和開(kāi)發(fā)重點(diǎn)。