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1.
时滞细胞神经网络的全局渐近稳定性和指数稳定性   总被引:4,自引:0,他引:4  
利用Brouwer不动点定理,证明了具有变时滞的细胞神经网络模型平衡点的存在性;利用Barbarlet引理、Dini导数与导数之间的关系,构造了一个特殊的Lyapunov函数,表明具有变时滞的细胞神经网络模型存在惟一全局指数平衡点并且全局渐近稳定;在此基础上,通过构造一个新的M-矩阵,利用Halanay时滞微分不等式和M-矩阵的特性,得出:细胞神经网络模型在一定的条件下,在平衡点处,全局指数稳定且与时滞无关.  相似文献   

2.
讨论了具有一般输出函数的时滞细胞神经网络模型的全局指数稳定性,给出了一个使模型具有惟一的全局指数稳定的平衡点的充分条件,这一结果包含已有文献中的许多结果作为特例.  相似文献   

3.
讨论一类具有时滞和变时滞的细胞神经网络的指数稳定性问题,利用Lyapunov泛函的方法,给出了判定此类时滞细胞神经网络平衡点全局指数稳定性的几个充分条件,推广了一些文献的结果,使此类模型的应用更加广泛.  相似文献   

4.
时滞神经网络的指数稳定性分析   总被引:1,自引:0,他引:1  
研究了一类时滞细胞神经网络的指数稳定性问题,利用Razumikhin定理和线性不等式技术得到新的全局指数稳定性准则.与其他方法不同之处在于,对神经网络模型的“线性化”,将神经网络模型变成一个线性时变的系统.所获的条件具有较少的保守性.最后用1个数值例子说明文中所得的结果是有效的.  相似文献   

5.
具有变时滞的细胞神经网络的全局指数稳定性   总被引:6,自引:3,他引:3  
研究具有可变时滞的细胞神经网络的全局指数稳定性问题,得出了可变时滞的细胞神经网络全局指数稳定性的几个充分条件.在实际应用中,设计验证满足这些条件很方便,甚至无须知道时滞的具体形式.因而具有重要的理论意义和应用价值.    相似文献   

6.
吴亮  尹景本  王军涛 《河南科学》2009,27(12):1493-1496
利用Lyapunov—Krasovskii稳定性理论和线性矩阵不等式(LMI)处理方法,研究了一类具有混合时变时滞的中立型细胞神经网络的全局指数稳定性问题,获得了该模型平衡点全局指数稳定的一个新的充分条件.改进和推广了已有文献的结果,降低了系统的保守性.所得结论对更好的模拟细胞神经网络的行为具有重要的指导意义.  相似文献   

7.
具有脉冲和时滞的细胞神经网络的全局指数稳定性   总被引:1,自引:1,他引:0  
讨论了一类具有时滞的脉冲细胞神经网络的全局指数稳定性.利用Lyapunov函数和不等式技巧得到了该系统全局指数稳定的一个新的充分条件,该结果具有更好的适用性.  相似文献   

8.
研究了一类变时滞细胞神经网络平衡点的全局指数稳定性问题.在不要求激励函数全局Lipschitz条件下,利用Lyapunov函数方法和M-矩阵的特性,结合Young不等式和Halanay时滞微分不等式,得到了细胞神经网络模型在一定条件下全局指数稳定的一些充分条件.数值例子说明了本文结果的有效性.  相似文献   

9.
讨论了一类具有可变时延的细胞神经网络的平衡点的存在性及全局指数稳定性,利用Brouwer不动点定理和推广的Halanaly时延微分不等式,构造合适的Lyapunov函数,获得了该神经网络全局指数稳定的简单实用的判别条件.一个例子说明了它的应用.  相似文献   

10.
研究了一类变时滞的Hopfield型神经网络的全局指数稳定性,在对网络系统施加两个不同的非线性神经元激励函数的条件下,利用M-矩阵的特性,得到了细胞神经网络模型在一定的条件下全局指数稳定的易于判定的充分条件,数值例子说明了本文结果的有效性.  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.  相似文献   

13.
王慧 《科技信息》2008,(10):240-240
Wuthering Heights, Emily Bronte's only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.  相似文献   

14.
The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3~4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰~ -7.8‰, PDB) and matrix dolomites (-6.6‰~ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084~0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078~0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.  相似文献   

15.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

16.
Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.  相似文献   

17.
以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.  相似文献   

18.
AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…  相似文献   

19.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

20.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

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