Interblock information in multidimensional block designs

In many experimental situations, d-way heterogeneity among experimental units may be controlled through use of multiple blocking criteria. In some cases it is reasonable to regard some or all of the block effects as random. Then the model is mixed and observations within blocks are correlated. Very general estimators of treatment effects and their dispersion matrix with recovery of interblock information are provided. They apply to designs with d > 1 blocking criteria that may be crossed, nested, or a combination thereof. These general results may be specialized to provide analyses of new classes of MBD's or used directly for numerical analyses of designs in the general class, perhaps through use as the basis for very general computer programs. Estimation of variance components is discussed, and an example is provided to illustrate adaptation of the general results.     

双转子系统临界转速的积木式传递矩阵法

本文提出了用于具有任意多盘及柔性(或刚性,或中介)支承的双转子系统临界转速计算的矩阵法。本文提出的“标准积木块”新概念,为编制通用计算机程序提供了理论基础。在这种指导思想下,任何一个真实的转子系统都能看成由不同的“积木块”迭加而成,并且计算时只需对程序作非常小量的修改。余数趋于无穷大时的转速并非是临界转速,它是一种数学现象,应在计算结果中予以剔除.     

On a robustness property of PBIBD

In this paper we study a robustness property of partially balanced incomplete block designs based on association schemes with m classes (PBIBD(m)) against the unavailability of data in the sense that, when any t (a positive integer) observations are unavailable the design remains connected w.r.t. treatment. We characterize the robustness property of PBIBD(m) completely for m=2 and partially for m=3.     

求模糊逻辑函数范式的方块图法

本文提出了模糊逻辑函数的方块图表示及等效变换法则．并利用方块图化简模糊逻辑函数，给出求取析取范式与合取范式的直观方法．     

模块阅读教学法在英语专业阅读教学中的运用

本文从语篇 (text)的主题、背景知识、结构及词汇四个层面阐述如何将模块阅读教学法 (BlockReading&Writing )运用于英语专业阅读课教学的实践。笔者认为这种教学法有利于提高学生的阅读理解能力 ,扩大词汇量 ,从而扩大学生的知识面 ,使学生所学的知识系统化、结构化 ,增强语言的运用能力和跨文化交际能力。     

滚动摩擦机理和滚动摩擦系数

指出古典滚动摩擦定律存在着一定的局限性,对滚动摩擦机理从摩擦学观点进行了探讨,分析了滚动阻力来自微观滑动和弹性滞后.通过一系列金属和非金属材料的摩擦试验,测得滚动摩擦系数值及其变化规律,从而指出了影响滚动摩擦系数的主要因素.最后认为,滚动摩擦系数还须靠实测来确定.     

On the construction of group divisible incomplete block designs

In this paper a method of constructing group-divisible incomplete block designs has been suggested. A series of balanced incomplete block designs has also been obtained.     

Regular group divisible designs and Bhaskar Rao designs with block size three

Some recursive constructions are given for Bhaskar Rao designs. Using examples of these designs found by Shyam J. Singh, Rakesh Vyas and new ones given here we show the necessary conditions λ≡0 (mod 2), λυ(υ?1)≡0 (mod 24) are sufficient for the existence of Bhaskar Rao designs with one association class and block size 3. This result is used with a result of Street and Rodger to obtain regular partially balanced block designs with 2υ treatments, block size 3, λ₁=0, group size 2 and υ groups.     

Distribution-free subset selection for incompletely ranked data

In market research and some other areas, it is common that a sample of n judges (consumers, evaluators, etc.) are asked to independently rank a series of k objects or candidates. It is usually difficult to obtain the judges' full cooperation to completely rank all k objects. A practical way to overcome this difficulty is to give each judge the freedom to choose the number of top candidates he is willing to rank. A frequently encountered question in this type of survey is how to select the best object or candidate from the incompletely ranked data. This paper proposes a subset selection procedure which constructs a random subset of all the k objects involved in the survey such that the best object is included in the subset with a prespecified confidence. It is shown that the proposed subset selection procedure is distribution-free over a very broad class of underlying distributions. An example from a market research study is used to illustrate the proposed procedure.     

A general scheme for sequential treatment allocation vith balancing for prognostic factors in clinical trials

A general family of dynamic treatment allocations is defined, and it is shown that the permuted block procedure (Zelen 1974) and Begg and Iglewicz method (1980) are extreme choices in this family. A compromise method is suggested. The framework of this general family allows the relationships between these methods to be examined. By means of a simulation study these three methods plus the complete randomization method are compared in terms of efficiency and balance. The compromise method is shown to have good overall properties. In addition, an illustrative example is given