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861.
在二进提升方案相关理论的基础上,结合双正交性、消失矩性和对称性条件,提出一种构造提升双正交小波的新方法.此方法从二进小波出发,考虑小波所具有的特性,通过选取适当的提升参数,具体构造了具有紧支撑、对称性、高阶消失矩和速降性的提升双正交小波. 相似文献
862.
863.
诺基亚在互联网时代日渐没落,并最终走向衰亡。本文先从诺基亚近五年手机市场份额下降、品牌关注度降低、大量裁员和被微软收购这四个方面叙述诺基亚衰落的具体表现,继而分析诺基亚衰落的主要原因,最后阐述诺基亚的衰落给我国电子企业带来的启示。经过深入思考,一个企业要想在激烈的市场竞争中立于不败之地,就必须充分利用现有资源、不断创新、准确定位、提高顾客满意度。 相似文献
864.
电力企业进行良好的营销业务扩展既是其降低运营经济成本、经营压力和营销风险的重要举措,也是适应当今经济发展新形势和电力行业激烈竞争的有效手段。本文结合目前电力企业营销中存在的问题,从三个方面来具体探讨了新形势下电力企业营销业务扩展的要点,希望对电力企业的营销工作有所启示。 相似文献
865.
本文结合CFD与FEM方法,对国际热核聚变实验堆(ITER)的双冷锂铅(DCLL)包层进行了"磁-热-流-固"多物理耦合场的三维数值模拟.基于电势方法,采用PISO算法和相容守恒格式求解了包含Lorentz力的不可压Navier-Stokes方程。应用有限元方法分析了DCLL包层关键部件流道插件(FCI)在热场和磁场耦合作用下的热应力.利用多物理场的顺序耦合算法获得了在强磁场作用下,包层内金属流体的压力、速度和温度分布,研究了各种厚度和导电率的FCI对于包层内MHD效应和传热性能的影响。 相似文献
866.
Spectrum analysis of natural gamma ray spectral logging (SGR) data is a critical part of surface information processing systems. Due to the low resolution, which is an inherent weakness of SGR, and the low signal-to-noise ratio problem of logging measurements, SGR is usually treated with a low confidence level. The Direct Demodulation (DD) method is an advanced technique to solve modulation equations interactively under physical constraints. It has higher sensitivity and spatial resolution than the traditional methods and can effectively suppress the logging noise. Based on standard count rate spectral data obtained from the China Offshore Oil Logging Company SGR Calibration Facility, this paper presents the application of the DD method to gamma-ray logging. The results are compared with four traditional algorithmic methods, showing that the DD method is a credible choice, with higher sensitivity and higher spatial resolution in gamma-ray log interpretation. The Point-Spread-Function of the Shengli Oil Logging Company's natural gamma ray spectroscopy instrument is obtained for the first time. The quantities of various radionuclides in their calibration pits are also obtained. The DD method was applied successfully to gamma-ray logging, offering a new option for SGR logging algorithm selection. 相似文献
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869.
The cluster synchronization problem of complex dynamical networks with each node being a Lurie system with exter- nal disturbances and time-varying delay is investigated in this paper. Some criteria for cluster synchronization with desired H∞ performance are presented by using a local linear control scheme. Firstly, sufficient conditions are established to realize cluster synchronization of the Lurie dynamical networks without time delay. Then, the notion of the cluster synchronized region is introduced, and some conditions guaranteeing the cluster synchronized region and unbounded cluster synchro- nized region are derived. Furthermore, the cluster synchronization and cluster synchronized region in the Lurie dynamical networks with time-varying delay are considered. Numerical examples are finally provided to verify and illustrate the theoretical results. 相似文献
870.
Spectrum analysis of natural gamma ray spectral logging (SGR) data is a critical part of surface informa- tion processing systems. Due to the low resolution, which is an inherent weakness of SGR, and the low signal-to-noise ratio problem of logging measurements, SGR is usually treated with a low confidence level. The Direct Demodulation (DD) method is an advanced technique to solve modulation equations interactively under physical constraints. It has higher sensitivity and spatial resolution than the traditional methods and can effectively suppress the logging noise. Based on standard count rate spectral data obtained from the China Offshore Oil Logging Company SGR Calibration Facility, this paper presents the application of the DD method to gamma-ray logging. The results are compared with four traditional algorithmic methods, showing that the DD method is a credible choice, with higher sensitivity and higher spatial resolution in gamma-ray log interpretation. The Point-Spread-Function of the Shengli Oil Logging Company's natural gamma ray spectroscopy instrument is obtained for the first time. The quantities of various radionuclides in their calibration pits are also obtained. The DD method was applied successfully to gamma-ray logging, offering a new option for SGR logging algorithm selection. 相似文献