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21.
Phase I is crucial for the success of the overall statistical process control (SPC) and monitoring regime. Shewhart-type charts are recommended in this phase because of their broader shift detection ability. In this paper, a Phase I Shewhart-type X¯ chart is considered for the balanced random effects (also called a variance components) model. The proposed methodology takes proper account of the effects of parameter estimation and uses the false alarm probability (FAP) metric to design the chart. In the sequel, the corrected (adjusted) charting constants are calculated and tabulated. The constant can be found, on demand, from an accompanying R package. Motivations and illustrations with some real data are provided. Performance of the chart is examined in terms of in-control robustness and detection of nonhomogeneity (out-of-control). The proposed chart is shown to be easily adaptable to more general models, with more variance components and nested factors, and can accommodate various estimators of variance. Thus, it enables a broader Phase I process monitoring strategy, under normality, which can be applied within the ANOVA framework applicable for many DOE models. A summary and some recommendations are provided.  相似文献   
22.
论文提出一种结合CANDIDE模型和扩展的Lucas-Kanade算法进行特征跟踪和面部动画参数提取的方法,利用特定人三维扫描数据对动画网格实现特定化,驱动面部动画参数生成动画。实验结果表明面部动画参数提取的准确性和合成动画的真实感是可以接受的。  相似文献   
23.
Control charts play an important role in Phase I studies, which are conducted to establish process control and generate reference data for parameter estimation and calculation of prospective (Phase II) control limits. Researchers have tabulated the necessary charting constants for the normal theory–based Phase I Shewhart X ¯ chart for the process mean to achieve a desired nominal false alarm probability given the number of Phase I subgroups, m, up to 15. However, in practice, when parameters are estimated, the currently recommended number of Phase I subgroups is much larger than covered by their tables. Recognizing the need and taking advantage of some recently available software and computing resources, an extension to these tables is provided for m = 3(1)10 , 15(5)30 , 50(25)300 and n = 3 , 5 , 7 , 10. In addition to the tables, an R program is provided to calculate the charting constant, on demand, for user‐given values of nominal false alarm probability, m, and n. An appendix shows the details of how the program should be used.  相似文献   
24.
文东油田解除近井地带盐堵技术   总被引:2,自引:0,他引:2  
本文评述了近几年在文东油田近开地带解除盐堵的研究、应用成果,主要是化学解堵剂的筛选、评价及包括向地层挤化学药剂解堵、连续接水微渗透淡化解堵、过桥系结合化学药剂冲盐解堵等一套解堵技术。  相似文献   
25.
Protein aggregation into insoluble amyloid fibrils is the hallmark of several neurodegenerative diseases, chief among them Alzheimer’s and Parkinson’s. Although caused by different proteins, these pathologies share some basic molecular mechanisms with familial amyloidotic polyneuropathy (FAP), a rare hereditary neuropathy caused by amyloid formation and deposition by transthyretin (TTR) in the peripheral and autonomic nervous systems. Among the amyloidogenic TTR mutations known, V30M-TTR is the most common in FAP. TTR amyloidogenesis (ATTR) is triggered by tetramer dissociation, followed by partial unfolding and aggregation of the low conformational stability monomers formed. Thus, tetramer dissociation kinetics, monomer conformational stability and competition between refolding and aggregation pathways do play a critical role in ATTR. Here, we propose a new model to analyze the refolding kinetics of WT-TTR and V30M-TTR, showing that at pH and protein concentrations close to physiological, a two-step mechanism with a unimolecular first step followed by a second-order second step adjusts well to the experimental data. Interestingly, although sharing the same kinetic mechanism, V30M-TTR refolds at a much slower rate than WT-TTR, a feature that may favor the formation of transient species leading to kinetic partition into amyloidogenic pathways and, thus, significantly increasing the probability of amyloid formation in vivo.  相似文献   
26.
Drugs targeting type 4 dipeptidyl peptidase (DPP-4) are beneficial for glycemic control, whereas fibroblast activation protein alpha (FAP-α) is a potential target for cancer therapies. Unlike other gliptins, linagliptin displays FAP inhibition. We compared biophysical and structural characteristics of linagliptin binding to DPP-4 and FAP to better understand what differentiates linagliptin from other gliptins. Linagliptin exhibited high binding affinity (KD) and a slow off-rate (koff) when dissociating from DPP-4 (KD 6.6 pM; koff 5.1×10−5 s−1), and weaker inhibitory potency to FAP (KD 301 nM; koff>1 s−1). Co-structures of linagliptin with DPP-4 or FAP were similar except for one second shell amino acid difference: Asp663 (DPP-4) and Ala657 (FAP). pH dependence of enzymatic activities and binding of linagliptin for DPP-4 and FAP are dependent on this single amino acid difference. While linagliptin may not display any anticancer activity at therapeutic doses, our findings may guide future studies for the development of optimized inhibitors.  相似文献   
27.
Control charts are mainly carried out in 2 interconnected phases: Phase I (retrospective phase) and Phase II (monitoring phase). Phase I uses a stable historical sample to establish control limits that will be used later in Phase II. The preciseness of the control limits obtained from Phase I can greatly affect the performance of control charts in Phase II. Monitoring the coefficient of variation (CV) is an effective approach when the process mean or standard deviation is not constant. Until now, little work has been dedicated on investigating the performance of CV control charts in Phase I. Viewed under this perspective, this study investigates the performance of CV control charts in Phase I in terms of probability to signal. A real‐life example is also provided to illustrate the working of CV charts in Phase I.  相似文献   
28.
本文制备了Er3+/Yb3+共掺的透明氟磷酸钙纳米微晶玻璃,并对其近红外发光性质进行了研究。样品经过热处理后,经X射线衍射和透射电镜测试发现:玻璃基质中均匀地析出了20 nm左右的Ca5(PO4)3F晶体,并且稀土离子进入到了析出的纳米晶相中.同热处理之前的样品相比,在808 nm和980 nm激光的激发下,Er3+/Yb3+共掺的微晶玻璃在1.54μm处产生很强的近红外发光,其半高宽高达75 nm.另外,我们对微晶玻璃的近红外发光与Er3+和Yb3+浓度的关系进行了研究.由于其具有高效的近红外发光,表明Er3+/Yb3+共掺的氟磷酸钙纳米微晶玻璃是一种潜在的激光和光放大材料.  相似文献   
29.
王海波  蔡骏  余兆明 《电视技术》2003,(2):10-13,25
MPEG-4通过脸部定义参数FDP和脸部运动参数FAP来对人脸对象进行编码,从而获得码率极低的视频流。本文主要讨论了MPEG-4中人脸对象这类视频码流的结构以及参数编码和解码的过程。  相似文献   
30.
首先阐述了CDMA Femtocell标准的制定历程和发展现状,再从应用和开发的角度出发,对CDMA Femtocell网络架构和关键技术进行深入分析。对3GPP2标准中未明确但十分重要的内容,如汇聚管理、移动性管理等给出具体实现方案,有益于Femtocell产品开发和实现。  相似文献   
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