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1.
毕楷明 《价值工程》2014,(25):238-240
本文讨论在碎纸机以不同方式破碎纸片的情况下建立碎纸片的拼接复原模型,以解决碎片数量巨大时人工拼接的难题,本文建立了三个具有针对性的模型。模型一:方差分析法下的碎纸片拼接模型。在以纵切方式破碎纸片的情况下,提取碎纸片左右边缘的灰度列向量,利用碎纸片边缘处为单边同宽空白区域的特殊性对碎纸片进行定位,再利用方差分析法和欧式距离解决了纵切碎纸片的拼接复原问题。模型二:文字行间距一致性的碎纸片拼接模型。以纵横方式破碎纸片,利用同行文字行间距一致性的主要特性可解决横向碎纸片的拼接复原问题,简化了模型,将离散的像素灰度矩阵平均化处理,进而利用欧氏距离对碎纸片进行匹配,得到了碎纸片复原后的完整图片。模型三:二值化Otsu算法的碎纸片拼接复原模型。本文从双面纵横破碎纸片的问题出发,建立了纸片二值化Otsu法拼接模型,先对碎纸片分组预处理,为将复杂模型简单化,再利用全局阈值方法中典型的Otsu法求取碎纸片的最佳阈值,以该阈值对碎纸片中所含灰度值信息进行划分实现二值化处理,将边缘区域明显化,利用统计学方法求取拼接后的纸片间成功匹配的像素点占纸片边缘的概率,最终双面纵横破碎纸片的拼接复原问题得以解决。  相似文献   

2.
    
In multivariate analysis, the measure of variance accounted for plays a central role. In this paper, we show that an alternative approach, distance-based multivariate analysis, also yields solutions that can be summarized by a ratio of variances. For classical multivariate analysis, this ratio is equal to the variance accounted for (VAF) and in distance-based multivariate analysis it equals distance accounted for (DAF). We show that DAF in distance-based multivariate analysis can always be made higher than VAF in classical multivariate analysis. This property is illustrated for principal components analysis, multiple correspondence analysis, multiple regression, and analysis of variance.  相似文献   

3.
The optimal number of levels is studied for the one-way random model with normally distributed effects. The optimum criteria used are based on the variances of the traditional analysis of variance estimators of the variance components. Exact solutions are compared to earlier results based on lower bounds of the sampling variances. Comparisons are also made to the large-sample variances of the estimates based on restricted maximum likelihood. Received February 2002  相似文献   

4.
Abstract. We consider methods for the analysis of successive measurements, with emphasis on practical usefulness. It is described how the methods can be applied by using common techniques like regression analysis and analysis of variance.  相似文献   

5.
Summary For an inclusion probability proportional to size (IPPS) sampling scheme recently proposed by Saxena, Singh and Srivastava (1986), it is shown that under certain simple verifiable conditions (1) the Horvitz-Thompson (1952) estimator based on it has a smaller variance than the variance of the Hansen-Hurwitz (1943) estimator based on probability proportional to size (PPS) sampling with replacement (WR) both involving the same size-measures and the expected sample size in the former being equal to the number of draws in the latter and (2) the Yates-Grundy (1953) estimator for the variance of the Horvitz-Thompson estimator based on this IPPS scheme is uniformly non-negative.  相似文献   

6.
On the base of budget or plan information, comparing with actual results, making variance analysis, finding real reasons behind variance, this is important way of control and also important function of budget. However, without consideration of changes of environment, there are some limitations for static variance analysis with benchmark of plan data. Adjusting for benchmark according to actual condition, then doing variance analysis, these will improve utilization of variance analysis. Adjusted benchmark is often known as authorized cost/profit. For different understanding for authority concept, with RCA's (the abbreviation for Resource Consumption Accounting) view and numerical examples, this paper brings out the concept of consumption rate variance to promoting deeper understanding and analyzing reasons behind variance.  相似文献   

7.
The beta–binomial distribution is reported in literature as a useful generalization of the binomial in case of heterogeneous binomial sampling. An extra model parameter is introduced to accommodate for extra–binomial variation. Some additions to results already available will be given by presenting approximate F–tests for factorial designs, where the response variable is of 0–1 type and sampling is heterogeneous binomial. These tests can be used when sample sizes are large and equal and some degrees of freedom are left from replicates or negligible interactions to estimate the extra model parameter.  相似文献   

8.
The analysis of unbalanced linear models with variance components   总被引:2,自引:0,他引:2  
Statistical inference for fixed effects, random effects and components of variance in an unbalanced linear model with variance components will be discussed. Variance components will be estimated by Restricted Maximum Likelihood. Iterative procedures for computing the estimates, such as Fisher scoring and the EM-algorithm, are described.  相似文献   

9.
李丹青 《价值工程》2014,(31):140-142
基于对武汉市新生代农民工的抽样调查结果,运用单因素分析方法,研究了收入对新生代农民工幸福感的影响。发现绝对收入对新生代农民工的幸福感有着显著影响,并没有出现"收入-幸福悖论";而且相对收入越高,大体上看幸福感也越强。在实证研究结果的基础上,从收入角度出发,提出了提高新生代农民工幸福感水平的政策建议。  相似文献   

10.
刘览  孔原 《物流技术》2012,(17):285-288
企业成长能力是物流企业转型升级的重要基石。依据委托代理理论,利用我国物流上市企业2008-2011年数据,实证检验了企业公司治理水平对物流企业成长性的影响。实证研究结果表明,股权集中度与企业成长性成倒U型关系;管理层薪酬水平对物流企业成长有显著的正向影响,无薪酬董事人数则对物流企业成长有显著的负面影响。  相似文献   

11.
This paper presents the results of an experimental determination by Monte Carlo techniques of the power functions of a generalized Friedman's rank test based on "standardized" ranks and a proposed test procedure based on aligned ranks for orthogonal designs. The simulation is carried out for five orthogonal designs and a number of Normal location alternatives and gives some information about the difference in power of the two test procedures for some orthogonal designs.  相似文献   

12.
13.
    
This research derives a numerical taxonomy that classifies manufacturers with similar combinations of supply chain (SC) capabilities into three SC Strategy Groups. This research also explores the relationship between the SC Strategy Groups and contextual factors, competitive priorities and firm performance. There are significant differences among the SC Strategy Groups for the location of the firm, the level of uncertainty, the competitiveness of the market and firm performance. Surprisingly, there is no relationship between the SC Strategy Groups and a firm's competitive priorities, indicating that firms are often not linking their SC strategy to their competitive strategy.  相似文献   

14.
Quality &; Quantity - Cliff (1993) has proposed the use of a measure of effect size alternative to traditionalmean differences: δ {? = Pr(xi1 &;gt; xj2) - Pr(xi1 &;lt; xj2)}which,...  相似文献   

15.
Statistical inference based on the Weibull distribution, a distribution widely used in reliability and survival analysis, is usually difficult as it often involves numerical computation and approximation. However, this distribution can be transformed to near-normality by a simple power transformation. Based on this transformation, a prediction interval (PI) for its median can be easily constructed through an inverse transformation. The procedure for selecting the best power transformation through minimizing Kullback-Leibler information is described. The property of this transformation-based PI is investigated. Simple correction factors are also proposed. It is shown that the transformation-based PI with corrections performs well, irrespective of the sample size and parameter values. Simulation results show that the new PI generally outperforms the existing PI. Numerical examples are given for illustration.  相似文献   

16.
A Caution Regarding Rules of Thumb for Variance Inflation Factors   总被引:22,自引:0,他引:22  
The Variance Inflation Factor (VIF) and tolerance are both widely used measures of the degree of multi-collinearity of the ith independent variable with the other independent variables in a regression model. Unfortunately, several rules of thumb – most commonly the rule of 10 – associated with VIF are regarded by many practitioners as a sign of severe or serious multi-collinearity (this rule appears in both scholarly articles and advanced statistical textbooks). When VIF reaches these threshold values researchers often attempt to reduce the collinearity by eliminating one or more variables from their analysis; using Ridge Regression to analyze their data; or combining two or more independent variables into a single index. These techniques for curing problems associated with multi-collinearity can create problems more serious than those they solve. Because of this, we examine these rules of thumb and find that threshold values of the VIF (and tolerance) need to be evaluated in the context of several other factors that influence the variance of regression coefficients. Values of the VIF of 10, 20, 40, or even higher do not, by themselves, discount the results of regression analyses, call for the elimination of one or more independent variables from the analysis, suggest the use of ridge regression, or require combining of independent variable into a single index.  相似文献   

17.
Abstract  The methodological discussion in D e R oos -S chaafsma (1981) Section 6 is continued by proposing asymptotic methods as a substitute for laborious confidence interval computations.  相似文献   

18.
19.
黄瑞玲 《价值工程》2005,24(2):88-91
结合成本管理的实际情况,利用统计指数分析原理。对传统的成本差异分析内容与方法进行了分析、调整与完善。将变动成本差异与固定制造成本差异分析方法归一,同时将实际开支总额与标准开支总额之间的差额作为总差异.其分支差异有三个差异,即产量差异、用量差异和价格差异。在完善绝对数分析的基础上。补充了相对数分析内容。  相似文献   

20.
  总被引:4,自引:0,他引:4  
Abstract. Pedagogically, literature reviews are instrumental. They summarize the large literature written on a particular topic, give coherence to the complex, often disparate, views expressed about an issue, and serve as a springboard for new ideas. However, literature surveys rarely establish anything approximating unanimous consensus. Ironically, this is just as true for the empirical economic literature. To harmonize this dissonance, we offer a quantitative methodology for reviewing the empirical economic literature. Meta-regression analysis (MRA) is the regression analysis of regression analyses. MRA tends to objectify the review process. It studies the processes that produce empirical economic results as though they were any other social scientific phenomenon. MRA provides a framework for replication and offers a sensitivity analysis for model specification. In this brief essay, we propose a new method of reviewing economic literature, MRA, and discuss its potential.  相似文献   

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