Current Issue : October - December Volume : 2014 Issue Number : 4 Articles : 6 Articles
This paper aims to enlarge the family of one-class classification-based control charts, referred to as OC-charts, and extend their\napplications. We propose a new OC-chart using the ????-means data description (KMDD) algorithm, referred to as KM-chart.The\nproposed KM-chart gives the minimum closed spherical boundary around the in-control process data. It measures the distance\nbetween the center of KMDD-based sphere and the new incoming sample to be monitored. Any sample having a distance greater\nthan the radius ofKMDD-based sphere is considered as an out-of-control sample. Phase I and II analysis of KM-chart was evaluated\nthrough a real industrial application. In a comparative study based on the average run length (ARL) criterion, KM-chart was\ncompared with the kernel-distance based control chart, referred to as K-chart, and the ????-nearest neighbor data description-based\ncontrol chart, referred to as KNN-chart. Results revealed that, in terms of ARL, KM-chart performed better than KNN-chart in\ndetecting small shifts in mean vector. Furthermore, the paper provides theMATLAB code for KM-chart, developed by the authors....
We propose an automatic selection of the bandwidth of the recursive kernel estimators of a probability density function defined by\nthe stochastic approximation algorithmintroduced byMokkadem et al. (2009a).We showed that, using the selected bandwidth and\nthe stepsizewhich minimize the MISE (mean integrated squared error) of the class of the recursive estimators defined inMokkadem\net al. (2009a), the recursive estimator will be better than the nonrecursive one for small sample setting in terms of estimation error\nand computational costs.We corroborated these theoretical results through simulation study....
For a T-variate density function, the present paper defines the point-symmetry, quasi-point-symmetry of order k (< T), and the\nmarginal point-symmetry of order k and gives the theorem that the density function is T-variate point-symmetric if and only if it\nis quasi-point-symmetric and marginal point-symmetric of order k.The theorem is illustrated for the multivariate normal density\nfunction....
In this paper, we study the estimators of the population total in adaptive cluster sampling by using the information of the auxiliary\nvariable.The numerical examples showed that the ratio estimator in adaptive cluster sampling without replacement of networks is\nmore efficient than the ratio estimators in adaptive cluster sampling without replacement of units....
This paper reports the development of an approach to integrate the appropriate modeling techniques for estimating the effect of\nproject quality management (PQM) on construction performance. This modeling approach features a causal structure that depicts\nthe interaction among the PQM factors affecting quality performance in a given construction operation. In addition, it makes use\nof fuzzy sets and fuzzy logic in order to incorporate the subjectivity and uncertainty implicit in the performance assessment of these\nPQM factors to discrete-event simulation models. The outcome is a simulation approach that allows experimenting with different\nperformance levels of the PQM practices implemented in a construction project and obtaining the corresponding productivity\nestimates of the construction operations. These estimates are intended to facilitate the decisionmaking regarding the improvement\nof a PQM system implemented in a construction project. A case study is used to demonstrate the usefulness of the proposed\nsimulation approach for evaluating diverse performance improvement alternatives for a PQM system....
We consider the distribution of the sum of Bernoulli mixtures under a general dependence structure. The level of dependence is\nmeasured in terms of a limiting conditional correlation between two of the Bernoulli random variables. The conditioning event\nis that the mixing random variable is larger than a threshold and the limit is with respect to the threshold tending to one. The\nlarge-sample distribution of the empirical frequency and its use in approximating the risk measures, value at risk and conditional\ntail expectation, are presented for a new class of models which we call double mixtures. Several illustrative examples with a Beta\nmixing distribution, are given. As well, some data from the area of credit risk are fit with the models, and comparisons are made\nbetween the new models and also the classical Beta-binomial model....
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