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151.
Analysis of variance (ANOVA) is an important method in exploratory and confirmatory data analysis. The simplest type of ANOVA is one-way ANOVA for comparison among means of several populations. In this article, we extend one-way ANOVA to a case where observed data are fuzzy observations rather than real numbers. Two real-data examples are given to show the performance of this method. 相似文献
152.
In this paper, we propose a method for estimating a signal-to-noise ratio (SNR) in order to improve the performance of a dual-microphone speech enhancement algorithm. The proposed method is able to reliably estimate both a priori and a posteriori SNRs by exploring a direction-of-arrival (DOA)-based local SNR that is defined by using spatial cues obtained from dual-microphone signals. The estimated a priori and a posteriori SNRs are then incorporated into a Wiener filter. Consequently, it is shown from an objective perceptual evaluation of speech quality (PESQ) comparison and a subjective listening test that a speech enhancement algorithm employing the proposed SNR estimate outperforms those using conventional single- or dual-microphone speech enhancement algorithms such as the Wiener filter, beamformer, or phase error-based filter under different noise conditions ranging from 0 to 20 dB. 相似文献
153.
Nien Fan Zhang Adam L. Pintar 《Quality and Reliability Engineering International》2015,31(8):1383-1396
Processes that arise naturally, for example, from manufacturing or the environment, often exhibit complicated autocorrelation structures. When monitoring such a process for changes in variance, accounting for that structure is critical. While charts for monitoring the variance of processes of independent observations and some specific autocorrelated processes have been proposed in the past, the chart presented in this article can handle a general stationary process. The performance of the proposed chart was examined through simulations for the first‐order autoregressive and first‐order autoregressive‐moving average processes and demonstrated with examples. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
154.
Visualization Approaches for Evaluating Ridge Regression Estimators in Mixture and Mixture‐Process Experiments 下载免费PDF全文
Dae‐Heung Jang Christine M. Anderson‐Cook 《Quality and Reliability Engineering International》2015,31(8):1483-1494
When the component proportions in mixture experiments are restricted by lower and upper bounds, the input space of a designed experiment space can become an irregular region that can induce multicollinearity problems when estimating the component proportion parameters. Thus, ridge regression provides a beneficial means of stabilizing the coefficient estimates in the fitted model. Previous research has focused on using prediction variance as a metric for determining an appropriate value of the ridge constant, k. We use visualization techniques to illustrate and evaluate ridge regression estimators and the robustness of estimation with respect to the variance and the bias. The addition of bias allows better balancing between the stability of the estimators and minimally changing the estimates. We illustrate the graphical methods with mixture and mixture‐process examples from the literature. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
155.
文章引用“产业结构演变城市化响应系数”,并将之细化为第二产业结构响应系数和第三产业结构响应系数,运用泰尔指数方法,考察了安徽省78个县(市)产业结构演变响应系数、第二产业响应系数和第三产业响应系数空间差异,并将安徽省划分为皖北、皖中和皖南3大区域,分析区域之间差异和区域内部差异对安徽省总体差异的贡献。结果表明安徽省产业结构演变城市化响应系数较小且变化不明显,第二产业响应系数较呈现减小趋势,第三产业响应系数呈现增大趋势;3大区域中,皖南的差异较大,皖中次之,皖北差异较小。 相似文献
156.
157.
公租房是我国当代社会发展阶段的必然产物.文章依托南京市公租房“民心公寓”实地调研成果,介绍了公租房相关概念及南京市公租房建设概况,并以公租房空间可变性的视角切入,从非承重结构可变性、家具模块化、整体卫生间装配式生产等三个方面探讨公租房设计的应对策略,期望达到在保证公租房使用方便舒适的同时提高空间利用效益的目的. 相似文献
158.
虚拟权平差的方差估计 总被引:1,自引:0,他引:1
本文基于虚拟权平差函数模型,首先推导了单位权方差σ_0~2的边缘极大似然估计(?)_0~(n~2),证明了(?)_0~(n~2)是σ_0~(n~2)的无偏、有效估计量,然后构造了σ_0~2的另一无偏估计(?)_0~2,通过平差实例验证了(?)_0~2的基本有效性. 相似文献
159.
Hasan Kouchakzadeh Seyed Abbas Shojaosadati Fazel Shokri 《Chemical Engineering Research and Design》2014
Herein, the poorly water-soluble drug, Tamoxifen (Tmx), was loaded in the amphipathic matrix of human serum albumin (HSA) nanoparticles by a modified desolvation method. In order to enhance the drug loading (DL) and drug entrapment efficiency (DEE) (<2% and 10%, respectively), ultrasonication of Tmx-HSA mixture was performed prior to desolvation process. Tmx loading and entrapment efficiency were optimized by employment of the response surface methodology (RSM)-central composite design (CCD) of experiments. Under the optimum conditions of 1.59 mg Tmx/ml concentration, 7.76 pH and 5 h incubation of HSA-Tmx, the DL of 6.7% and DEE of 74% are achievable. Particles with the average size of 195 nm, zeta potential of −21 mV and polydispersity index of 0.09 were produced under these conditions. A more sustained Tmx release behavior was observed from polyethylene glycol (PEG) conjugated nanoparticles in comparison to the non-PEGylated ones. The short-term stability investigation showed no alteration in physicochemical properties of nanoparticles at 4 and 37 °C, but small increase in nanoparticles size was observed after three months of storage at room temperature. This is the first report for efficient production of a Tmx delivery system based on HSA nanoparticles. 相似文献
160.
为解决较多图像匹配算法主要通过测量关键点之间的距离来实现特征匹配,忽略了图像的结构信息,使其存在较多的误匹配的问题,本文设计了方差约束耦合几何不变特性的图像匹配算法。借助于Forstner算子计算像素点的兴趣值,以检测图像的特征;计算图像的梯度信息,获取图像的方向值,并切割图像特征的圆形邻域,从而获取扇形子域;以图像的方向值为基础,通过计算扇形子域中的灰度不变矩,输出对应的特征向量;引入区域方差函数,获取图像的结构信息,将其加入至图像特征的匹配过程,以约束欧式距离的测量结果,实现图像特征匹配;最后利用匹配点间的几何不变特性,对匹配特征去伪求真,优化匹配结果。测试数据表明:相对于已有的匹配技术,在对无变换图像、缩放图像以及旋转图像匹配时,所提算法拥有更高的匹配准确度,分别达到了96.56%、95.38%和93.52%。 相似文献