• Title/Summary/Keyword: Alphabetic Optimality

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Animated Quantile Plots for Evaluating Response Surface Designs (반응표면실험계획을 평가하기 위한 동적분위수그림)

  • Jang, Dae-Heung
    • The Korean Journal of Applied Statistics
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    • v.23 no.2
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    • pp.285-293
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    • 2010
  • The traditional methods for evaluating response surface designs are alphabetic optimality criteria. These single-number criteria such as D-, A-, G- and V-optimality do not completely reflect the prediction variance characteristics of the design in question. Alternatives to single-numbers summaries include graphical displays of the prediction variance across the design regions. We can suggest the animated quantile plots as the animation of the quantile plots and use these animated quantile plots for comparing and evaluating response surface designs.

Multi-Optimal Designs for Second-Order Response Surface Models

  • Park, You-Jin
    • Communications for Statistical Applications and Methods
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    • v.16 no.1
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    • pp.195-208
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    • 2009
  • A conventional single design optimality criterion has been used to select an efficient experimental design. But, since an experimental design is constructed with respect to an optimality criterion pre specified by investigators, an experimental design obtained from one optimality criterion which is superior to other designs may perform poorly when the design is evaluated by another optimality criterion. In other words, none of these is entirely satisfactory and even there is no guarantee that a design which is constructed from using a certain design optimality criterion is also optimal to the other design optimality criteria. Thus, it is necessary to develop certain special types of experimental designs that satisfy multiple design optimality criteria simultaneously because these multi-optimal designs (MODs) reflect the needs of the experimenters more adequately. In this article, we present a heuristic approach to construct second-order response surface designs which are more flexible and potentially very useful than the designs generated from a single design optimality criterion in many real experimental situations when several competing design optimality criteria are of interest. In this paper, over cuboidal design region for $3\;{\leq}\;k\;{\leq}\;5$ variables, we construct multi-optimal designs (MODs) that might moderately satisfy two famous alphabetic design optimality criteria, G- and IV-optimality criteria using a GA which considers a certain amount of randomness. The minimum, average and maximum scaled prediction variances for the generated response surface designs are provided. Based on the average and maximum scaled prediction variances for k = 3, 4 and 5 design variables, the MODs from a genetic algorithm (GA) have better statistical property than does the theoretically optimal designs and the MODs are more flexible and useful than single-criterion optimal designs.

A graphical method for evaluating the effect of design augmentation, missing observation, and outlier in mixture experiments (혼합물 실험계획에서 실험점의 확장, 결측치, 이상치의 영향을 평가할 수 있는 그래픽 방법)

  • Jang, Dae-Heung;Park, Sang-Hyun
    • Journal of Korean Society for Quality Management
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    • v.24 no.4
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    • pp.156-167
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    • 1996
  • D-optimality is used often in design augmentation of mixture experiments. Although such alphabetic criteria provide a valuable foundation for generating designs, they often fail to convey the true nature of the design's support of the fitted model in terms of prediction variance over a region of interest. Thus, a graphical method is proposed to evaluate augmented designs in mixture experiments. This method can be used to evaluate the effect of missing observation and outlier in mixture experiments.

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Animated Quantile Plots for Evaluating Response Surface Designs (반응표면실험계획을 평가하기 위한 동적분위수그림)

  • Jang, Dae-Heung
    • Proceedings of the Korean Society for Quality Management Conference
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    • 2010.04a
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    • pp.115-120
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    • 2010
  • 반응표면실험계획들을 평가하기 위한 방법으로서 전형적인 방법이 알파벳최적화이다. 그러나 이러한 알파벳최적화(D-, A-, G-, V-최적화 등)는 하나의 수치이므로 그 유용성에도 불구하고 반응표면실험 계획들이 갖는 추정반응값분산의 분포에 대한 정보에 한계를 갖는다. 이를 극복하고자 하는 대안으로서 그래픽 방법들이 있는데 우리는 그 중에 분위수그림을 애니메이션화한 동적분위수그림을 제안할 수 있고 이 동적분위수그림을 이용하여 반응표면실험계획들이 갖는 추정반응값분산의 분포를 서로 비교, 평가 할 수 있다.

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