Robust asymptotic stability for BAM neural networks with time-varying delays via LMI approach

Several novel stability conditions for BAM neural networks with time-varying delays are studied.Based on Lyapunov-Krasovskii functional combined with linear matrix inequality approach,the delay-dependent linear matrix inequality（LMI） conditions are established to guarantee robust asymptotic stability for given delayed BAM neural networks.These criteria can be easily verified by utilizing the recently developed algorithms for solving LMIs.A numerical example is provided to demonstrate the effectiveness and less conservatism of the main results.     

GLOBAL DYNAMICS OF DELAYED BIDIRECTIONAL ASSOCIATIVE MEMORY （BAM） NEURAL NETWORKS

IntroductionConsiderthebidirectionalassociativememory (BAM )neuralnetworkswithconstanttransmissiondelaysdescribedbyasystemofdelaydifferentialequationsoftheform[1,2 ]:dxi(t)dt =-aixi(t) nj=1bijfj(yj(t-σij) ) Ii,　　i=1 ,2 ,… ,m ,dyj(t)dt =-cjyj(t) mi=1djigi(xi(t-τji) ) Jj,　　j=1 ,2 ,… ,n ,fort >0 .Thesystem ( 1 )consistsoftwosetsofneurons (orunits)arrangedontwolayers,namely ,I_layerandJ_layer.Inthesystem ( 1 ) ,xi( ·)andyj( ·)denotemembranepotentialoftheithneuronsfromtheI_laye…     

S-分布时滞随机BAM神经网络的指数同步

通过构造Lyapunov泛函,利用Ito公式以及随机分析的方法研究一类BAM神经网络的指数同步问题,给出了指数同步的新判据,举例说明了结果的实用性,推广了相关文献的结果。     

具有时滞的双向联想记忆神经网络的鲁棒稳定性

应用线性矩阵不等式技术研究了时滞双向联想记忆神经网络的平衡点稳定性问题.针对存在参数不确定的时滞双向联想记忆神经网络,根据Lyapunov稳定理论,通过构造适当的Lyapunov-Krasovskii泛函,给出了保证双向联想记忆神经网络平衡点全局鲁棒稳定的两个新判据.所得到的结果能够表示成线性矩阵不等式形式,具有易于验证和独立于时变时滞幅值大小等特点.对于慢时变时滞的情况,当时滞幅值较大时,所得结果具有较小的保守性.通过一个仿真例子表明了所得结果的有效性.     

Ba/Mg 比值对(BaxMg)2/(x+1)Al10O17∶Eu2+晶体结构和发光特性的影响

采用溶液燃烧法在600℃成功合成了(BaxMg)2/(x 1)Al10O17∶Eu2 (0.6≤x≤1.2)蓝色荧光粉,着重研究了基质阳离子Ba/Mg比值的变化对其晶体结构及发光特性的影响。结果表明,合成的产物为纯相,且随Ba/Mg比值的增加,样品的晶格参量逐渐增加;当Ba/Mg比增加时,发射光谱的强度明显增强,至Ba/Mg为0.9时达到最大值,然后随Ba/Mg比继续增大,发射光谱的强度反而下降;Ba/Mg比值减少,导致基质的晶场增强和电子云膨胀效应的发生,致使Eu2 发射主峰向长波方向移动。Eu2 的掺杂浓度对样品的发光性能有显著的影响,随Eu2 浓度增大,发光中心增多,Eu2 离子间相互作用增强,能量传递加快,发光强度逐渐增大,并达到一个最大值。此后,随Eu2 的浓度进一步增加,Eu2 之间的能量传递速率将超过发射速率,呈现浓度猝灭特性。     

BaMgAl10O17:Eu2+的MgF2表面包覆

采用溶胶-凝胶法对蓝色荧光粉BaMgAl10O17:Eu2 (BAM)进行表面包膜处理,获得了表面均匀包覆MgF2膜层的BAM荧光粉.并用SEM、XRD和IR手段对其表面形貌、晶格结构性能进行了表征;用EDS对BAM粉体的表面元素进行了定性分析;用荧光光谱测试对荧光粉的发光性能进行了研究.结果表明,在BAM粉体表面均匀包覆MgF2层后,BAM的晶格结构,发光性能没有改变,初始亮度较未包覆的荧光粉有所降低,经过相同条件的热处理后,包覆MgF2荧光粉的亮度热衰减程度明显低于未包覆的荧光粉,且色坐标偏移现象不明显.     

时滞离散时间双向联想记忆模型的研究

提出一类时滞离散时间双向联想记忆神经网络模型,研究了平衡点的全局吸引性,并且以具体仿真算例给出了利用平衡点的全局吸引性建立这类双向记忆神经网络的方法.     

Global attracting sets for neutral-type BAM neural networks with time-varying and infinite distributed delays

In this paper, the asymptotic property of a class of neutral-type BAM neural networks with time-varying and infinite distributed delays is discussed. By developing a new integral inequality and applying the properties of nonnegative matrix, some sufficient conditions for the Lagrange stability and the existence of the global attracting set of the considering model are obtained. Meanwhile, the estimation of the global attractive set is also given out. The results derived here generalize and improve the earlier publications. Finally, two numerical examples are given and analyzed to demonstrate our results.     

具连续分布时滞与非线性脉冲BAM神经网络的全局指数稳定性

研究了具有连续分布时滞与非线性脉冲影响的BAM型神经网络的全局指数稳定性问题.利用M-矩阵以及谱理论等工具得到了系统存在惟一全局指数稳定的平衡点的充分条件.并给出一个例子说明结论的有效性.