混合水平因子超饱和设计的构造方法

混合水平因子设计在工业试验和其他科学试验中得到了非常广泛的应用,但混合水平因子超饱和设计还是一个新的研究课题。本文给出了这类设计的优良性准则,同时通过的Wang and Wu(1991）给出的构造算法进行修正,给出了这类设计的构造方法,并且利用所给方法对某些适中的试验次数,得到了相应的混合水平因子超饱和设计表。     

用填充方法构造最优超饱和设计

超饱和设计是一种试验次数不足以同时估计其设计矩阵的列所代表的主效应的因子设计, 在这样的设计中因子各水平等重复出现且没有全混杂的因子. 这种设计因其在因子筛选试验中的优势而得到了越来越多的关注. 而填充设计是组合设计理论中一类重要的研究对象. 本文建立起了这两种不同设计之间的紧密联系. 提出了比较超饱和设计的几个准则, 讨论了它们的性质及与现有准则的关系, 给出了构造最优超饱和设计的一种组合方法, 即填充方法, 研究了所构造设计的性质并与现有的其他设计做了比较, 结果表明所构造的方法和新构造的设计具有优良的性质.     

多水平超饱和设计的一类构造方法

过去超饱和设计的研究集中在2水平设计的范围内,Lu and Sun(2000)首次讨论了高于2水平因子的超饱和设计问题,该文提出了用E（d^2)作为构造超饱和设计的准则,并给出了E（d^2)最优的一些设计,本文讨论了以给定的Max(d^2)为前提构造超饱和设计的方法,并给出了一些三水平和四水平的超饱和设计。     

超饱和设计在参数设计中的应用

虽然田口先生提出的综合噪声因子法比内外表的直积法，能减少许多试验次数，但这种方法存在着明显的不足．另外当外表中的噪声因子个数过多时，利用均匀设计进行外表设计或内表设计也会使试验次数增大．鉴于此，本文提出利用超饱和设计作为外表以减少试验次数，并对两个可计算性项目进行了数据分析．     

最优试验次序的几类构造方法

许多领域都离不开试验,例如在新产品的研发以及测试中都需要进行精心设计的科学试验.当在试验中因子的水平改变非常困难时,如何合理安排试验次序是一个非常重要的问题.本文研究了具有最小和最大水平变化次数的试验次序的一些基本理论,并针对完全因析设计、非正规部分因析设计和均匀设计等设计讨论了最优试验次序构造方法.作为实际中广泛应用的一些设计,利用本文的结果给出了其具有最小和最大水平变化次数的试验次序及相应的水平变化次数.     

超饱和试验设计中的参数估计问题

超饱和试验设计是一种因子个数大于试验次数的试验设计；它是工业统计中的一个新的研究课题，在工业质量控制中有重要的应用。在超饱和设计中，因子效应参数的无偏估计一般不存在，一个因子效应的估计会受到其它因子效应的影响，这种影响是设计本身带来的，称之为交互影响。本文讨论两种参数估计：最小方差可比估计与最小交互影响可比估计。模拟计算的结果显示，在正确地搜寻活动因子的能力方面，最小交互影响可比估计在与实际情况相接近的模拟条件下强于最小方差可比估计。     

一种构造多水平超饱和设计的新方法

超饱和设计在搜索试验中有重要应用.自上世纪九十年代迄今, 超饱和设计的研究取得了丰硕成果,研究的设计从二水平发展到多水平, 进而到混合水平;构造方法从巧妙的构思到利用组合理论进行系统构造,进而到各种算法的开发; 对于超饱和设计的评优准则也有更深入的认识.本文介绍一种构造多水平超饱和设计的新方法. 这种方法简单易行,很容易构造出具有优良性质的多水平超饱和设计, 有很强的实用性.     

一种构造E（s^2）最优超饱和设计的方法

本文中我们基于Ｅ（ｓ＾２）最优超饱和设计和区组设计对等关系。利用构造区组设计的方法之一,－－循环设计法,通过最小化ｆｒｍａｘ的进一步区分,对试验次数≤２４的情形,构造了相应的一系列超饱和设计,同时与现有的一些结果作了比较,验证了我们构造的设计和优良性。     

一种构造E(s~2)最优超饱和设计的方法

本文中我们基于E(s2)最优超饱和设计和区组设计之间存在的对等关系,利用构造区组设计的方法之一－循环设计法,通过最小化ｆｒｍａｘ的进一步区分,对试验次数２４的情形,构造了相应的一系列超饱和设计．同时与现有的一些结果作了比较,验证了我们构造的设计的优良性。     

一类新的１６次试验的超饱和设计

该文利用Ｈａｌｌ（１９６１）提出的１６阶的Ｈａｄａｍａｒｄ阵之一构造了一类新的１６次试验的二水平因子超饱和设计，讨论了这类新的设计的统计性质并与其他已有类似设计作了比较，同时指出了该类新设计的适用范围．     

Geometric isomorphism check for symmetric factorial designs

Two designs are geometrically isomorphic if one design can be obtained from the other by reordering the runs, relabeling the factors and/or reversing the level order of one or more factors. In this paper, some new necessary and sufficient conditions for identifying geometric isomorphism of symmetric designs with prime levels are provided. A new algorithm for checking geometric isomorphism is proposed and a searching result for geometrically non-isomorphic 3-level orthogonal arrays of 18 runs is presented.     

一类正交空间填充设计的构造

空间填充设计在计算机试验中应用十分广泛,当拟合回归模型时,正交的空间填充设计保证了因子效应估计的独立性.基于广义正交设计,文章给出了构造二阶正交拉丁超立方体设计和列正交设计的方法,新构造的设计不仅满足任意两列之间相互正交,还能保证每一列与任一列元素平方组成的列以及任两列元素相乘组成的列都正交.当某些正交的空间填充设计不存在时,具有较小相关系数的近似正交设计可作为替代设计使用.设计构造的灵活性为计算机试验在实践中的广泛应用提供了必要的支持.     

Generating and improving orthogonal designs by using mixed integer programming

Analysts faced with conducting experiments involving quantitative factors have a variety of potential designs in their portfolio. However, in many experimental settings involving discrete-valued factors (particularly if the factors do not all have the same number of levels), none of these designs are suitable.In this paper, we present a mixed integer programming (MIP) method that is suitable for constructing orthogonal designs, or improving existing orthogonal arrays, for experiments involving quantitative factors with limited numbers of levels of interest. Our formulation makes use of a novel linearization of the correlation calculation.The orthogonal designs we construct do not satisfy the definition of an orthogonal array, so we do not advocate their use for qualitative factors. However, they do allow analysts to study, without sacrificing balance or orthogonality, a greater number of quantitative factors than it is possible to do with orthogonal arrays which have the same number of runs.     

CONSTRUCTING UNIFORM DESIGNS WITH TWO- OR THREE-LEVEL

When the number of runs is large, to search for uniform designs in the sense of low-discrepancy is an NP hard problem. The number of runs of most of the available uniform designs is small (≤50). In this article, the authors employ a kind of the so-called Hamming distance method to construct uniform designs with two- or three-level such that some resulting uniform designs have a large number of runs. Several infinite classes for the existence of uniform designs with the same Hamming distances between any distinct rows are also obtained simultaneously. Two measures of uniformity, the centered L2-discrepancy (CD, for short) and wrap-around L2-discrepancy (WD, for short), are employed.     

Construction of optimal supersaturated designs by the packing method

A supersaturated design is essentially a factorial design with the equal occurrence of levels property and no fully aliased factors in which the number of main effects is greater than the number of runs. It has received much recent interest because of its potential in factor screening experiments. A packing design is an important object in combinatorial design theory. In this paper, a strong link between the two apparently unrelated kinds of designs is shown. Several criteria for comparing supersaturated designs are proposed, their properties and connections with other existing criteria are discussed. A combinatorial approach, called the packing method, for constructing optimal supersaturated designs is presented, and properties of the resulting designs are also investigated. Comparisons between the new designs and other existing designs are given, which show that our construction method and the newly constructed designs have good properties.     

Uniform supersaturated design and its construction

Supersaturated designs are factorial designs in which the number of main effects is greater than the number of experimental runs. In this paper, a discrete discrepancy is proposed as a measure of uniformity for supersaturated designs, and a lower bound of this discrepancy is obtained as a benchmark of design uniformity. A construction method for uniform supersaturated designs via resolvable balanced incomplete block designs is also presented along with the investigation of properties of the resulting designs. The construction method shows a strong link between these two different kinds of designs     

The choice of screening design

A screening design is an experimental plan used for identifying the expectedly few active factors from potentially many. In this paper, we compare the performances of 3 experimental plans, a Plackett‐Burman design, a minimum run resolution IV design, and a definitive screening design, all with 12 and 13 runs, when they are used for screening and 3 out of 6 factors are active. The functional relationship between the response and the factors was allowed to be of 2 types, a second‐order model and a model with all main effects and interactions included. D‐efficiencies for the designs ability to estimate parameters in such models were computed, but it turned out that these are not very informative for comparing the screening performances of the 2‐level designs to the definitive screening design. The overall screening performance of the 2‐level designs was quite good, but there exist situations where the definitive screening design, allowing both screening and estimation of second‐order models in the same operation, has a reasonable high probability of being successful.     

投影均匀分片拉丁超立方体设计

空间填充设计是有效的计算机试验设计,比如均匀设计、最大最小距离拉丁超立方体设计等.虽然这些设计在整个试验空间中有较好的均匀性,但其低维投影均匀性可能并不理想.对于因子是定量的计算机试验,已有文献构造了诸如最大投影设计、均匀投影设计等相适应的设计;而对于同时含有定性因子和定量因子的计算机试验,尚未有投影均匀设计的相关文献.文章提出了综合投影均匀准则,利用门限接受算法构造了投影均匀的分片拉丁超立方体设计.在新构造设计中,整体设计与每一片设计均具有良好的投影均匀性.模拟结果显示,与随机分片拉丁超立方体设计相比,利用新构造设计进行试验而拟合的高斯过程模型具有更小的均方根预测误差.     

Run orders and quantitative factors in asymmetrical designs

Results on run orders leading to trend-free symmetrical factorial designs are extended to the asymmetrical case, using the character theory of abelian groups. The tools developed apply equally to the construction of designs for quantitative treatment factors with eight or more regularly spaced levels. Abelian group theory can also be used to find minimum-cost run orders for asymmetrical designs, with a cost based on the number of changes of levels between successive runs.