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1.
一种正交多项多混沌全局建模方法   总被引:1,自引:1,他引:0  
本文研究了一种正交多项式混沌全局建模方法,所用正交多项多集以吸引子不变测度为核。通过对Henon映射数据和电离层参数实则数据的分析,表明在待建模系统不很复杂时(其内在机理可用较低阶多项式表达),这种全局建模方法能得到系统动力学特性,在低噪声情况下模型还能充分精确地重构系统方程式。在噪声较大或系统内在机理很复杂的建 模结果仍可用于一步预测,且具有较好效果。  相似文献   

2.
Zernike多项式拟合是一种在光学领域中广泛应用的分析技术.由于现代光学工程中采集数据的离散性和非圆孔径系统的大量使用,Zernike多项式拟合不能完全满足分析需要.提出了一种基于Zernike多项式的非圆孔径离散采样点的正交多项式.通过矩阵的QR分解方法得到在离散采样点上的正交多项式基底.分别使用Zernike多项式和正交多项式对150 mm90 mm的矩形光栅反射波前进行拟合,结果表明两种方法残差波前的PV和RMS值分别相差0.013波长和小于0.001波长.对比不同项数拟合的正交多项式和Zernike多项式系数表明,正交多项式系数之间彼此独立,并由正交多项式系数计算得到了对应的Seidel像差.正交多项式各项系数可以逐项求解,该方法可以显著提高求解速度.  相似文献   

3.
王伟  曹民  朱娟娟  王戈  李龙 《通信技术》2014,(1):111-114
传统多项式常用在功率放大器模型和预失真器模型的设计里。然而,随着多项式阶数逐次增加时,传统多项式模型表现出数据的不稳定性。详细介绍了一种用于功率放大器以及预失真器模型的正交多项式。从理论上讲,传统多项式与正交多项式模型是等效的,但实践表明,在有限精度范围内,这两种方法对数据进行了不同的处理。MATLAB仿真结果表明,正交多项式可以减轻数值不稳定的问题,建立高精度的功率放大器和预失真器模型,进而改善系统的线性化指标。  相似文献   

4.
关永  沈孝本  赵冬生  张聪霞   《电子器件》2007,30(1):318-320,325
为了解决现有教具智能化程度低、系统尺寸庞大等问题,研究一种基于知识发现的智能教具系统,并探讨能够在小型嵌入式系统条件下实现知识发现的方法.为突破传统的数据拟合技术,提出采用正交多项式方法,为避免在盲目搜索时,出现组合爆炸,采用了人工智能启发式搜索函数,以减少搜索次数,提高知识发现的自动化程度.  相似文献   

5.
针对非线性静态输出反馈H_∞控制设计过程复杂、难以得到全局最优解等问题,提出了一种新的控制器设计方法。采用平方和(SOS)方法分析多项式非线性系统H_∞性能;以系统L_2性能指标为目标函数,用遗传算法优化控制参数。仿真结果表明,该方法设计的控制器实现了多项式非线性系统L_2性能指标最优。  相似文献   

6.
在广义频分复用(Generalized Frequency Division Multiplexing, GFDM)系统中,为了应对复杂的信道带来的符号间干扰,基于信道的稀疏特性,使用广义记忆多项式(Generalized Memory Polynomial, GMP)模型对均衡器输入信号进行非线性建模,进而提出了一种基于压缩感知追踪算法和分组数据模式的低计算量分组稀疏均衡方案。该方案中,为了适应复杂变化的信道,均衡过程中采用了分组数据模式,此外,利用分块矩阵求逆的原理,摒弃了复杂的矩阵求逆运算,在每步的循环中使用矩阵乘法进行迭代计算的方式对正交匹配追踪(Orthogonal Matching Pursuit, OMP)算法及双正交匹配追踪(Double OMP,DOMP)算法进行了改进。仿真结果表明,此分组数据模式有效地改善了均衡效果,同时提出的改进算法在保证误符号率性能的前提下明显地降低了计算量,提升了运算速度。  相似文献   

7.
针对复杂非线性系统,提出了一种完全基于输入输出数据的一体化多模型建模与预测控制设计方法.首先,利用模糊空间划分对输入数据进行在线聚类;然后,采用最小二乘法在每一个聚类点处建立一个局部模型,并将模糊空间划分与多模型建模相结合,利用即时输入输出数据对局部模型的数量以及每一个局部模型的参数进行在线更新,从而实现对复杂非线性系统的在线建模;最后,在此基础上进行预测控制器的设计,将系统建模与控制器的设计包含在一个控制系统设计框架以内,对模型不确定性具有更好的鲁棒性.仿真实验的结果表明了该方法的有效性.  相似文献   

8.
研究用于产生多维类正交伪随机矩阵的生成多项式,这既可以由同组的多项式按照顺序的方式组合而成,也可以由不同阶的多项式按照任意的顺序组合而成,同时还可以由多项式的逆组合而成。由不同方法组合而成的生成多项式,经过群变换和数值转换之后得到的多维类正交伪随机矩阵也不同。所以,生成多项式组合方法的多样化,也使其对应产生的多维类正交伪随机矩阵更为丰富,从而得到更多的能应用于码分多址(Code division multiple access,CDMA)等通信系统中的类正交序列。  相似文献   

9.
本文介绍一种利用离散正交多项式进行物体表面局部曲面拟合以检测物体的特征的方法.该方法的拟合涵数力双变量二阶多项式,用该方法对深度图进行特征检测,可避免直接对深度图数据进行数值差分,减少噪声对特征的影响.  相似文献   

10.
用方形区域内的标准正交多项式重构波前   总被引:5,自引:1,他引:4  
提供了一种方形区域上归一化Zernike正交基的生成方法。它采用线性无关组Gram-Schimdt正交组构造方法,根据线性代数内积、欧氏空间及其正交性和范数的相关概念,对标准Zernike多项式进行正交处理,得到了一组新的正交多项式Z-square多项式。采用该正交基实现了方形区域内波前模式的拟合,它不仅可由Z-square模式的集合直接对波前进行表示,而且也可以通过线性反变换,将Z-square多项式表示成标准的Zernike模式的线性组合,使被分解的波前模式与像差之间有明确的对应关系。实验表明,它不仅可以对透镜设计中的波前像差函数进行有效的拟合,而且也能对Hartmann-Shack波前传感器测试得到的实际相位数据进行拟合。  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.  相似文献   

13.
The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.  相似文献   

14.
The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.  相似文献   

15.
Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.  相似文献   

16.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

17.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

18.
A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.  相似文献   

19.
A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.  相似文献   

20.
Call for Papers     
正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks  相似文献   

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