• 한국수학교육학회지시리즈A:수학교육
• /
• 제43권4호
• /
• pp.405-417
• /
• 2004

This study is on the use of mathematics program for School Mathematics Education. According to the ‘technology principle’ by NCTM and teaching-learning methods by the 7th curriculum, we developed mathematics learning activities with mathematics program. This activity is to construct designs with graphs by using mathematics program(GrafEq.). In this study, we practiced these learning activities with pre-service mathematics teachers. The mathematics educational effects of these learning activities in this study are analyzed as follows; active & spontaneous search for mathematical knowledge, the experience of problem solving, affirmative view-point of mathematics, understanding of practical use of mathematics, acquisition an interest & motivation of learning mathematics etc. When students learn graphs of function, the concept of inequality in secondary school mathematics class., mathematics teachers can make a good use of constructing designs by mathematics program(GrafEq.). This will help to practice of teaching-learning methods by the 7th curriculum.

• Journal of applied mathematics & informatics
• /
• 제19권1_2호
• /
• pp.105-125
• /
• 2005

Motivated by the field experimental designs in agriculture, the theory of block designs has been applied to several areas such as statistics, combinatorics, communication networks, distributed systems, cryptography, etc. An explicit formula and its fast computational algorithm for a class of symmetric balanced incomplete block designs are presented. Based on the formula and the careful investigation of the modulus multiplication table, the algorithm is developed. The computational costs of the algorithm is superior to those of the conventional ones.

• Journal of the Korean Statistical Society
• /
• 제15권2호
• /
• pp.127-130
• /
• 1986

Constantine(1981) extended the results of Takeuchi(1961) by adding some new blocks to certain known E-optimal block design. But they are confined to equal blocksize designs. In this paper we agin generalize them to different blocksize case. By augmenting some known E-optimal block designs having blocks of equalsize with blocks of different sizes, additional E-optimal block designs are obtained.

• 대한수학회논문집
• /
• 제20권1호
• /
• pp.15-21
• /
• 2005

Null designs on the poset of dual polar spaces are considered. A poset of dual polar spaces is the set of isotropic subspaces of a finite vector space equipped with a nondegenerate bilinear form, ordered by inclusion. We show that the minimum number of isotropic subspaces to construct a nonzero null t-design is ${\prod}^{t}_{i=0}(1+q^{i})$ for the types $B_N,\;D_N$, whereas for the case of type $C_N$, more isotropic subspaces are needed.

• Journal of the Korean Statistical Society
• /
• 제35권2호
• /
• pp.201-212
• /
• 2006

The technique of foldover is usually used by experimenters to de-alias the effects that are interesting in follow-up experiment. Employing a $2^{k-p}$ design with resolution III or higher, Li and Lin (2003) developed an algorithm and used computer programs to search its corresponding optimal foldover design for selected 16-run and 32-run experiments. Based on the minimum aberration criterion, the strong combined-optimal design, defined by Li and Lin, is the better choice of the initial design. In this article, we apply the technique of blocking to find the strong combined-optimal designs. Furthermore, we will tabulate all 16-run and 32-run strong combined-optimal designs and their corresponding core foldover plans for practical use. Some new designs that have not appeared in the other literature but constructed by the technique of blocking are also proposed in this article.

• Journal of the Korean Statistical Society
• /
• 제34권2호
• /
• pp.141-151
• /
• 2005

Under the assumption that the three-level factors are quantitative, the linear effects are taken more attention than the quadratic effects of the interaction terms. Webb (1971) presented some small incomplete factorial designs that are mixed two- and three-level designs with 20 or fewer runs. The designs provided the estimating linear-by-linear components of interactions between the three-level factors; moreover, they could also offer estimation of interactions that interest the experiments. Webb used ad hoc methods to find these plans; hence, there was still no unified structure to those experiments. In this paper, we develop the methods to construct the $2^{n}3^3$ and $2^{1}3^3$ designs. The designs constructed by these methods not only supply orthogonal estimates of all the main effects but also permit estimation of all the two-factor interactions not involving the quadratic effects. Furthermore, the designs we find are nearly orthogonal.

• 대한수학교육학회지:학교수학
• /
• 제7권4호
• /
• pp.337-352
• /
• 2005

본 연구에서는 학교수학수업에의 공학적 도구 활용을 논의의 주제로 설정하고 예비수학교사교육에서 사례연구를 실시하였다. 예비관찰을 통해 사례로 선정된 사범대학 재학생들을 대상으로 수학교육프로그램을 활용하여 7${\~}$9단계 수학 학습에 적용할 수 있는 교수-학습 자료를 개발하는 수업활동을 시행하였다. NCTM과 제7차 교육과정의 교수-학습방법 제안을 배경으로 하여 본 연구에서는 공학적 도구를 활용하여 수학학습의 효과를 높일 수 있다는 명제를 개념적 틀로 설정하였다. 그리고 이를 연구의 방향과 자료분석의 토대로 삼았다. 연구과정에서 수집된 관찰자료, 면담자료, 문서자료 등을 토대로 연구의 초기에 설정된 세 가지 연구문제에 대한 결과를 분석하였다. 아울러 학교현장의 수학수업에 활용할 수 있는 공학적 도구 활용교수${\cdot}$학습 보조자료를(단계별 수학디자인 산출물) 개발하여 제시하였다.

• Communications for Statistical Applications and Methods
• /
• 제14권3호
• /
• pp.483-495
• /
• 2007

In a general fractional factorial design, the n-levels of a factor are coded by the $n^{th}$ roots of the unity. Pistone and Rogantin (2007) gave a full generalization to mixed-level designs of the theory of the polynomial indicator function using this device. This article discusses the optimal blocking scheme for nonregular designs. According to hierarchical principle, the minimum aberration (MA) has been used as an important criterion for selecting blocked regular fractional factorial designs. MA criterion is mainly based on the defining contrast groups, which only exist for regular designs but not for nonregular designs. Recently, Cheng et al. (2004) adapted the generalized (G)-MA criterion discussed by Tang and Deng (1999) in studying $2^p$ optimal blocking scheme for nonregular factorial designs. The approach is based on the method of replacement by assigning $2^p$ blocks the distinct level combinations in the column with different blocks. However, when blocking level is not a power of two, we have no clue yet in any sense. As an example, suppose we experiment during 3 days for 12-run Plackett-Burman design. How can we arrange the 12-runs into the three blocks? To solve the problem, we apply G-MA criterion to nonregular mixed-level blocked scheme via the mixed-level indicator function and give an answer for the question.

• Journal of applied mathematics & informatics
• /
• 제26권3_4호
• /
• pp.563-572
• /
• 2008

In this paper, we discuss about a generalization of the Key Distribution Pattern which was proposed by C. Mitchell and F. Piper[6]. It is allowing secure communication between every n-pair of users($n\leq2$) in a large network for reducing storage requirements. We further suggest a generalization of K. Quinn's bounds in [9] for the number of subkeys in such general Key Distribution Patterns.

• Journal of the Korean Data and Information Science Society
• /
• 제14권3호
• /
• pp.707-714
• /
• 2003

Because of complex aliasing, nonregular designs have traditionally been used for screening only main effects. However, complex aliasing actually may allow some interactions entertained and estimated without making additional runs. According to hierarchical principle, the minimum aberration has been used as an important criterion for selecting regular fractional factorial designs. The criterion is not applicable to nonregular designs. In this paper, we give a criterion for choosing fractional factorial designs based on the fan theory. The criterion is focused on the partial ordering given by set inclusion on estimable sets which is called leaves.