共查询到20条相似文献,搜索用时 750 毫秒
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单形体几何学方法是混合像元分解中一类重要的方法,这类方法均需要一个较强的前提假设,即每一端元在图像中均至少存在一个纯像元.当此前提不满足时,该类方法的精度会大受影响.本文提出一种新的基于非负矩阵因式分解(NMF)算法的混合像元分解方法,以解决上述问题.加入适当的约束条件,可用于多通道混合像元分解问题.模拟数据实验与实际数据实验结果表明,该方法在端元光谱特性提取和丰度解混两方面的精度均优于单形体几何学方法. 相似文献
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点钞机中夹版人民币的检测 总被引:1,自引:0,他引:1
本文提出了夹版纸币的位置检测方法。在点钞机中使用一对光电位置传感器和一对光电计数传感器,来检测一叠同版100圆面额人民币中夹入的其它币种中夹入的其它币种。经实测精度可达每100张100圆(同版)中夹入2张其它币种点100次,漏检不超过1次。 相似文献
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An approximate evaluation is proposed for the individual mean waiting time, and loss probability for mixed delay and loss (nondelay) systems with renewal and Poisson inputs handled by servers with exponential service time. The approximation is based on the GI approximation previously proposed by H. Akimaru, et al. (1983, 1985), in which the mixed input process is regarded as renewal. The systems with mixed delay renewal and nondelay Poisson inputs, and ones with mixed nondelay renewal and delay Poisson inputs are analyzed. Approximate formulas for the mean waiting time and loss probability for the respective inputs are presented in simple closed form, and comparisons to simulations show good accuracy. The formulas are expected to be useful for analysis and optimum design of the mixed delay and loss systems 相似文献
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本文应用网络图论提出了圈-离集混合基矩阵的概念、混合基中基尔霍夫定律的矩阵表示和一般线性网络的混合基方程,进而建立了一般线性网络的圈电流-离集电压混合分析法。这个方法把文献[4]关于无源和无互感网络的混合分析法推广到包括有源和有互感网络在内的一般的线性时不变集总参数网络的情况。 相似文献
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LIU LI LIANG Xi-xia BAO Jin 《光电子快报》2007,3(6):466-469
The surface exciton-polaritons in ternary mixed crystals are investigated. The numerical calculations for several III-V and II-VI compound systems are performed and the polariton frequencies as functions of the wave-vector and the compositions for ternary mixed crystals AlxGa1-xAs, CdxZn1-xSe and AlxGa1-xN as examples are given and discussed. The results show that the dependence of the energies of surface polaritons on the composition of ternary mixed crystals are slightly nonlinear different from the bulk modes. 相似文献
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Krishnamurthy R.K. Carley L.R. 《Very Large Scale Integration (VLSI) Systems, IEEE Transactions on》1997,5(4):388-400
This paper describes and explores the design space of a mixed voltage swing methodology for lowering the energy per switching operation of digital circuits in standard submicron complementary metal-oxide-semiconductor (CMOS) fabrication processes. Employing mixed voltage swings expands the degrees of freedom available in the power-delay optimization space of static CMOS circuits. In order to study this design space and evaluate the power-delay tradeoffs, analytical polynomial formulations for power and delay of mixed swing circuits are derived and HSPICE simulation results are presented to demonstrate their accuracy. Efficient voltage scaling and transistor sizing techniques based on our analytical formulations are proposed for optimizing energy/operation subject to target delay constraints; up to 2.2× improvement in energy/operation is demonstrated for an ISCAS'85 benchmark circuit using these techniques. Experimental results from HSPICE simulations and measurements from an And-Or-Invert (AO1222) test chip fabricated in the Hewlett-Packard 0.5 μm process are presented to demonstrate up to 2,92× energy/operation savings for optimized mixed swing circuits compared to static CMOS 相似文献
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调幅信号的参数循环累量估计 总被引:2,自引:1,他引:1
本文利用循环累量讨论讽调幅混合相位信号的参数估计方法。首先给出了调幅信号的基于任意阶循环累量的参数方程。对于调幅混合相位AR,MA和ARMA模型,提出了相应的参数估计方法。模拟实验表明了本文方法的有效性。 相似文献
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The least squares (LS), total least squares (TLS), and mixed LS-TLS approaches are compared as to their properties and performance on several classical filtering problems. Mixed LS-TLS is introduced as a QR-decomposition-based algorithm for unbiased, equation error adaptive infinite impulse response (IIR) filtering. The algorithm is based on casting adaptive IIR filtering into a mixed LS-TLS framework. This formulation is shown to be equivalent to the minimization of the mean-square equation error subject to a unit norm constraint on the denominator parameter vector. An efficient implementation of the mixed LS-TLS solution is achieved through the use of back substitution and inverse iteration. Unbiasedness of the system parameter estimates is established for the mixed LS-TLS solution in the case of uncorrelated output noise, and the algorithm is shown to converge to this solution. LS, TLS, and mixed LS-TLS performance is then compared for the problems of echo cancellation, noise reduction, and frequency equalization. 相似文献
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采用近红外透射法建立了一种灵芝孢子油识别方法。分别在灵芝孢子油中掺入葵花油、薏仁油、花生油、玉米油和食用调和油。这些掺杂油品的体积百分比范围为0-100%。采用近红外透射法进行测定。选择最佳的光谱波段,然后用偏最小二乘fPartialLeastSquares,PLS)法分别建立了定量分析模型。对于不同比例的掺杂油料,预测相对误差范围在-0.357-0.435之间。研究结果表明,基于化学计量学和近红外光谱技术的分析手段可以作为一种简便、快捷、准确、廉价的方法应用于油类品种识别和掺杂量检测中。 相似文献
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一种基于GA的混合属性特征大数据集聚类算法 总被引:2,自引:0,他引:2
在数据挖掘中,经常会遇到和分析大量具有数值和类属特征的数据。然而,现有的大多数算法只能单独处理数值特征数据或类属特征数据,而不能分析具有混合属性的数据。为此,该文提出了一种基于GA的模糊聚类新算法,通过改进聚类目标函数将数值特征与类属特征相结合,从而实现具有混合属性特征数据的聚类分析;通过引入GA算法能够快速得到全局最优解,而且不依赖于原型初始化。实验结果表明,基于GA的新聚类算法对于处理具有混合特征的大数据集聚类问题是相当有效的。 相似文献
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Jianfeng Yan Guisheng Zou Aiping Wu Jialie Ren Anming Hu Y. Norman Zhou 《Journal of Electronic Materials》2012,41(7):1886-1892
A simple method has been proposed to prepare polymer-protected Cu-Ag mixed nanoparticles (NPs), which are suitable for use as low-temperature bonding materials. The polymer coated on the Cu-Ag mixed NPs can protect them from oxidation effectively when heated in air at temperature lower than 280°C. The low-temperature bonding process utilizing Cu-Ag mixed NPs as the bonding material is investigated. The bonding experiments show that robust joints are formed using Cu-Ag mixed NPs at 160°C in air. The shear test shows that addition of copper to silver is helpful for improving joint strength. This novel sintering-bonding technology using Cu-Ag mixed NPs as an interconnection material has potential for application in the electronics packaging industry. 相似文献
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Under the circumstance that white Gaussian noise and random erasures exist all at once,the stability condition for LDPC codes over mixed channel was proposed.And it was proved that a good degree sequence of LDPC codes was not optimized over mixed channel.It can also be proved by simulation.The random particle swarm optimization (RPSO) and simulated annealing (SA) algorithm were combined to find some capacity-approaching degree sequences over mixed channel with different erasure probabilities.The threshold of signal-to-noise ratio improves 1.615 9 dB than that of the classical degree sequences calculated by Gaussian approximation over mixed channel.These degree sequences are optimal for optical recording and frequency-hopping communication with narrow-band interference. 相似文献
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针对含有混合噪声的声呐图像,提出了中值滤波与形态学滤波的组合算法,并对常用的图像滤波算法以及算法组合进行了定量分析比较,仿真结果表明,中值滤波和形态学滤波的组合算法对于声呐图像中混合噪声的滤除是较为理想的. 相似文献
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Achilleas Savva Rawad Hallani Camila Cendra Jokubas Surgailis Tania C. Hidalgo Shofarul Wustoni Rajendar Sheelamanthula Xingxing Chen Mindaugas Kirkus Alexander Giovannitti Alberto Salleo Iain McCulloch Sahika Inal 《Advanced functional materials》2020,30(11)
Conjugated polymers that support mixed (electronic and ionic) conduction are in demand for applications spanning from bioelectronics to energy harvesting and storage. To design polymer mixed conductors for high‐performance electrochemical devices, relationships between the chemical structure, charge transport, and morphology must be established. A polymer series bearing the same p‐type conjugated backbone with increasing percentage of hydrophilic, ethylene glycol side chains is synthesized, and their performance in aqueous electrolyte gated organic electrochemical transistors (OECTs) is studied. By using device physics principles and electrochemical analyses, a direct relationship is found between the OECT performance and the balanced mixed conduction. While hydrophilic side chains are required to facilitate ion transport—thus enabling OECT operation—swelling of the polymer is not de facto beneficial for balancing mixed conduction. It is shown that heterogeneous water uptake disrupts the electronic conductivity of the film, leading to OECTs with lower transconductance and slower response times. The combination of in situ electrochemical and structural techniques shown here contributes to the establishment of the structure–property relations necessary to improve the performance of polymer mixed conductors and subsequently of OECTs. 相似文献