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941.
942.
嵌入式脉象采集仪电路设计 总被引:1,自引:1,他引:0
该脉象采集仪采用IP核技术、SoPC技术,将脉象采集的大部分功能都集成在一片FPGA内部,并自主进行了脉象采集控制的FPGA设计。该设计采用在SoPC系统外做控制电路部分,三路脉搏信号共用一个ADC,只需要很少的外部器件就能实现。与早期采用工控机、PC机,或者现在多采用的ARM设计方法相比,该脉象采集仪具有成本低,功耗低,体积小,便于扩展,稳定性高和系统维护方便等优点。 相似文献
943.
A branching particle system with changes of size is considered as a model for transport of particulate matter in air. This type of model is motivated by problems arising in the context of air pollution. High-density fluctuation limits for the process recording the positions and sizes of the particles through time are presented. These results allow to compute approximate probabilities for the temporal and spatial concentrations of particles of given sizes (in particular the small-sized pollutant particles which pose a health hazard). 相似文献
944.
Shigeto Nishimura 《Discrete Applied Mathematics》2008,156(12):2352-2358
In this contribution the Riemann hypothesis analogue presented by Iwan Duursma is considered. Whether the analogue for a given selfdual code holds depends on its Hamming weight enumerator. A necessary and sufficient condition is provided in the case of genus less than 3 for the homogeneous polynomials in two variables invariant under the MacWilliams transform. Also the case of half integral genus is studied and similar results are obtained. 相似文献
945.
We consider a new class of estimators for volatility functionals in the setting of frequently observed Itō diffusions which are disturbed by i.i.d. noise. These statistics extend the approach of pre-averaging as a general method for the estimation of the integrated volatility in the presence of microstructure noise and are closely related to the original concept of bipower variation in the no-noise case. We show that this approach provides efficient estimators for a large class of integrated powers of volatility and prove the associated (stable) central limit theorems. In a more general Itō semimartingale framework this method can be used to define both estimators for the entire quadratic variation of the underlying process and jump-robust estimators which are consistent for various functionals of volatility. As a by-product we obtain a simple test for the presence of jumps in the underlying semimartingale. 相似文献
946.
947.
Several choices of scaling are investigated for a coupled system of parabolic partial differential equations in a two‐phase medium at the microscopic scale. This system may be regarded as modelling a reaction–diffusion problem, the Stokes problem of single‐phase flow of a slightly compressible fluid or as a heat conduction problem (with or without interfacial resistance), for example. It is shown that, starting with the same problem on the microscopic scale, different choices of scaling of the diffusion coefficients (resp. permeability or conductivity) and the interfacial‐exchange coefficient lead to different types of macroscopic systems of equations. The characterization of the limit problems in terms of the scaling parameters constitutes a modelling tool because it allows to determine the right type of limit problem. New macroscopic models, not previously dealt with, arise and, for some scalings, classical macroscopic models are recovered. Using the method of two‐scale convergence, a unified approach yielding rigorous proofs is given covering a very broad class of different scalings. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
948.
He Shuyuan 《中国科学A辑(英文版)》1999,42(3):238-245
Two-dimensional hidden periodic model is an important model in random fields. The model is used in the field of two-dimensional
signal processing, prediction and spectral analysis. A method of estimating the parameters for the model is designed. The
strong consistency of the estimators is proved.
Project supported by the National Natural Science Foundation of China (Grant No. 19571002). 相似文献
949.
Chen Hua Wu Shaohua 《偏微分方程(英文版)》2008,21(1):45-58
We prove the local existence and uniqueness of week solution of the hyperbolic-parabolic Chemotaxis system with some nonlinear product terms. For one dimensional case, we prove also the global existence and uniqueness of the solution for the problem. 相似文献
950.
张怀钦 《核聚变与等离子体物理》1989,9(3):168-171
本文介绍一个用来测量中子辐照锂化合物产生的氚氢(HT)和氚水(HTO)系统。包括工作原理、操作步骤及初步实验结果。 相似文献