An effective step-down algorithm for the construction and the identification of nonisomorphic orthogonal arrays

In this paper we present an effective algorithm for the construction and the identification of two-level nonisomorphic orthogonal arrays. Using this algorithm, we identify and list a full catalogue of nonisomorphic orthogonal arrays with parameters OA(24,7,2,t), OA(28,6,2,t) and OA(32,6,2,t), t ≥ 2. Some statistical properties of these designs are also considered.     

18-run nonisomorphic three level orthogonal arrays

In this paper we construct all possible orthogonal arrays OA(18,q, 3,2) with 18 runs and 3 ≤ q ≤ 7 columns and present those that are nonisomorphic. A discussion on the novelty and the superiority of many of the designs found in terms of isomorphism and generalized minimum aberration has been made.      

Truthful germs are contagious: A local-to-global characterization of truthfulness

We study the question of which social choice functions from an abstract type space to a set of outcomes are truthful, i.e., implementable by truthful mechanisms, when utilities are quasi-linear. For convex domains, our main theorem characterizes truthful social choice functions as those satisfying two properties: local weak monotonicity and vortex-freeness. The first of these constrains the function values at any two sufficiently proximal points, while the second asserts that its line integrals around sufficiently small triangular loops must vanish.The characterization implies a local-to-global principle that allows one to deduce truthfulness of a function from its behavior on arbitrarily small neighborhoods of each point. Other consequences include a simple alternate derivation of the Saks–Yu Theorem that weak monotonicity characterizes truthfulness of functions having a convex domain and finite range, and a sufficient condition for constructing truthful functions by “stitching together” truthful subfunctions on different subsets of the domain.     

$$\mathcal{D}$$-optimal Minimum Support Mixture Designs in Blocks

An easy method to construct efficient blocked mixture experiments in the presence of fixed and/or random blocks is presented. The method can be used when qualitative variables are involved in a mixture experiment as well. The resulting designs are -optimal in the class of minimum support designs. It is illustrated that the minimum support designs are more efficient than orthogonally blocked mixture experiments presented in the literature and only slightly less efficient than -optimal designs.     

应用正交设计筛选小叶章诱导培养基的配方

以小叶章的茎段作外植体,采用正交设计法,考察6-BA、TDZ、NAA三种激素对小叶章初代培养产生的影响,确定适宜的激素种类及水平,优化筛选出适宜小叶章的诱导培养基.研究表明,激素6-BA是茎段诱导的关键因素;适宜小叶章初代培养的培养基配方为:1/2MS+6-BA0.5 mg·L~(-1)+TDZ0.1mg·L~(-1)+NAA0.1 mg·L~(-1)。     

Lagrange插值多项式平均算子的逼近

本文引入以第二类 Chebyshev 多项式 U_n(x)的零点为基点的 Lagrange 插值多项式平均算子 F_n(f,x),研究用 F_n(f,x)逼近连续函数 f(x)的阶。     

Mean squared error of the empirical best linear unbiased predictor in an orthogonal finite discrete spectrum linear regression model

The mean squared error (MSE) of the empirical best linear unbiased predictor in an orthogonal finite discrete spectrum linear regression model is derived and a comparison with the MSE of the best linear unbiased predictor in this model is made. It is shown that under weak conditions these two mean square errors are asymptotically the same.     

用正交试验法优选刀具切削角度

本文结合实例阐述了用正交试验法优造刀具切削角度的步骤和具体方法。     

山楂内消分散片中药材提取工艺研究

目的：优选山楂内消分散片中药材的最佳提取工艺。方法以正交试验法为核心,结合提取液中熊果酸的总含量以及总固体得率对优选山楂内消分散片中药材的提取工艺进行评判。结果较为理想的药材提取工艺：加水9倍,并先后2次提取,1 h/次。结论优选山楂内消分散片中药材的提取工艺各活性部位具有较高提取率,且利于操作,方便生产。     

循环前缀在OFDM系统中的应用

本文详细论述了OFDM系统中循环前缀在削弱符号间干扰（ISI）、载波间干扰（ICI）以及在实现时频同步中的应用。在OFDM符号间插入循环前缀，可以减小ISI和ICI，并为实时时频偏移估计提供足够信息，使得系统同步结构简单且工作高效。