• 한국수학교육학회지시리즈A:수학교육
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• 제57권3호
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• pp.215-229
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• 2018

Despite the importance of learning to do mathematical proofs, researchers have reported that not only secondary school students but also undergraduate students have difficulties in learning proofs. In this study, we introduced a new toll for learning proofs and explored the reliability and the validity of peer assessment on proofs. In the course of a university in Seoul, students were given weekly proof assignments prior to class. After solving the proofs, each student had to assess other students' proofs. The inter-rater reliabilities of weekly peer assessment was higher than .9 over 90 percent of the observed cases. To examine the validity of peer assessment, we check whether students' assessments were similar to expert assessment. Analysis showed that the equivalence has been quite high throughout the semester and the validity was low in the middle of the semester but rose by the end of the semester. Based on these results, we believe instructors can consider the application of peer assessment on proving tasks as a tool to help students learn.

• 한국과학교육학회지
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• 제22권5호
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• pp.957-969
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• 2002

Theoretical benefits and research findings on the use of Microcomputer-based Laboratory (MBL) are considered for using MBL in a way that will be of benefit to students and teachers, and discussed as a whole for further synthesis, including the formulation of a research agenda for future consensus-based action. Based on the findings obtained from a comprehensive review of the literature, using a systematic approach, the uses of MBL were compared and contrasted for advancing understanding of the teaching and learning processes in science and mathematics. A number of benefits were proposed by MBL developers but not investigated by educational researchers. A few research studies considered the following practical aspects raised by classroom science teachers: technical problems of MBL equipment; inaccuracy or incompleteness of presentation; efficient ways for handling class time with MBL instruction; and development of MBL curriculum materials for their own instruction. This lack of research related to the use of MBL in science classrooms resulted in educational research that was neither respected nor utilized by science teachers. Setting a research agenda based on the theoretical benefits and research findings is necessary for the effective use of MBL in science classrooms can help to maximize the prospects for successful school improvement projects while minimizing the innovation-related frustrations of individuals.

• 한국수학교육학회지시리즈A:수학교육
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• 제55권1호
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• pp.41-71
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• 2016

The purpose of this study is to investigate elementary students' communication in process of applying mathematical modeling. For this study, 22 fifth graders in an elementary school were observed by applying mathematical modeling process (presentation of problem ${\rightarrow}$ model inducement activity ${\rightarrow}$ model exploration activity ${\rightarrow}$ model application activity). And the level of their communication with their activity sheets and outputs, observation records and interviews were also analyzed. Additionally, by analyzing the activity cases of and , this study researched that what is a positive influence on students' communication skills. Whereas showed significant advance in the level of communication, who communicated actively on speaking area but not on every areas showed insensible changes. To improve communication abilities, cognitive tension and debate situation are needed. This means, mathematical education should continuously provide students with mathematical communication learning, and a class which contains mathematical communication experiences (such as mathematical modeling) will be needed.

• International Journal of Control, Automation, and Systems
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• 제4권5호
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• pp.637-644
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• 2006

Biomedical image is often complex. An applied image analysis system should deal with the images which are of quite low quality and are challenging to segment. This paper presents a framework for color cell image segmentation by learning and classification online. It is a robust two-stage scheme using kernel method and watershed transform. In first stage, a two-class SVM is employed to discriminate the pixels of object from background; where the SVM is trained on the data which has been analyzed using the mean shift procedure. A real-time training strategy is also developed for SVM. In second stage, as the post-processing, local watershed transform is used to separate clustering cells. Comparison with the SSF (Scale space filter) and classical watershed-based algorithm (those are often employed for cell image segmentation) is given. Experimental results demonstrate that the new method is more accurate and robust than compared methods.

• 한국전자통신학회논문지
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• 제13권4호
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• pp.737-744
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• 2018

RSA 암호계는 가장 널리 쓰이는 공개키 암호계로서, 암호화뿐만 아니라 전자서명이 가능한 최초의 알고리즘으로 알려져 있다. RSA 암호계의 안정성은 큰 수를 소인수 분해하는 것이 어렵다는 것에 기반을 두고 있다. 이러한 이유로 큰 정수의 소인수분해 방법에 많은 연구가 진행되고 있으나, 지금까지 알려진 연구 결과는 모두 실험적이거나 확률적이다. 본 논문에서는, 복소 이차체의 order의 류 반군의 구조와 비 가역 이데알의 성질을 이용하여 인수분해를 하지 않으면서 큰 정수의 소인수를 구하는 알고리즘을 구성한 다음, RSA 암호계에 대한 결정적 공격법을 제안하기로 한다.

• 대한수학회논문집
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• 제16권4호
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• pp.679-690
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• 2001

Doubly stochastic matrices are n$\times$n nonnegative ma-trices whose row and column sums are all 1. Convex polytope $\Omega$$_{n}$ of doubly stochastic matrices and more generally (R,S), so called transportation polytopes, are important since they form the domains for the transportation problems. A theorem by Birkhoff classifies the extremal matrices of , $\Omega$$_{n}$ and extremal matrices of transporta-tion polytopes (R,S) were all classified combinatorially. In this article, we consider signed version of $\Omega$$_{n}$ and (R.S), obtain signed Birkhoff theorem; we define a new class of convex polytopes (R,S), calculate their dimensions, and classify their extremal matrices, Moreover, we suggest an algorithm to express a matrix in (R,S) as a convex combination of txtremal matrices. We also give an example that a polytope of signed matrices is used as a domain for a decision problem. In this context of finite reflection(Coxeter) group theory, our generalization may also be considered as a generalization from type $A_{*}$ n/ to type B$_{n}$ D$_{n}$. n/.

• 호남수학학술지
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• 제40권4호
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• pp.809-816
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• 2018

The aim of this research paper is to evaluate fifty double integrals invoving generalized hypergeometric function (25 each) in the form of $${{\int}^1_0}{{\int}^1_0}\;x^{{\gamma}-1}y^{{\gamma}+c-1}(1-x)^{c-1}(1-y)^{c+{\ell}}(1-xy)^{{\delta}-2c-{\ell}-1}{\times}_3F_2\[{^{a,\;b,\;2c+{\ell}+1}_{\frac{1}{2}(a+b+i+1),\;2c+j}}\;;{\frac{(1-x)y}{1-xy}}\]dxdy$$ and $${{\int}^1_0}{{\int}^1_0}\;x^{{\gamma}-1}y^{{\gamma}+c+{\ell}}(1-x)^{c+{\ell}}(1-y)^{c-1}(1-xy)^{{\delta}-2c-{\ell}-1}{\times}_3F_2\[{^{a,\;b,\;2c+{\ell}+1}_{\frac{1}{2}(a+b+i+1),\;2c+j}}\;;{\frac{1-y}{1-xy}}\]dxdy$$ in the most general form for any ${\ell}{\in}{\mathbb{Z}}$ and i, j = 0, ${\pm}1$, ${\pm}2$. The results are derived with the help of generalization of Edwards's well known double integral due to Kim, et al. and generalized classical Watson's summation theorem obtained earlier by Lavoie, et al. More than one hundred ineteresting special cases have also been obtained.

• Journal of Audiology & Otology
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• 제24권2호
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• pp.61-70
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• 2020

Background and Objectives: To assess the academic performance, communication skills, and psychosocial development of prelingual deaf children with cochlear implants (CIs) attending mainstream schools, and to evaluate the impact of auditory speech perception on their classroom performance. Subjects and Methods: As participant, 67 children with CI attending mainstream schools were included. A survey was conducted using a structured questionnaire on academic performance in the native language, second language, mathematics, social studies, science, art, communication skills, self-esteem, and social relations. Additionally, auditory and speech performances on the last follow-up were reviewed retrospectively. Results: Most implanted children attending mainstream school appeared to have positive self-esteem and confidence, and had little difficulty in conversing in a quiet classroom. Also, half of the implanted children (38/67) scored above average in general academic achievement. However, academic achievement in the second language (English), social studies, and science were usually poorer than general academic achievement. Furthermore, half of the implanted children had difficulty in understanding the class content (30/67) or conversing with peers in a noisy classroom (32/67). These difficulties were significantly associated with poor speech perception. Conclusions: Improving the listening environment for implanted children attending mainstream schools is necessary.

• 대한청각학회지
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• 제24권2호
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• pp.61-70
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• 2020

Background and Objectives: To assess the academic performance, communication skills, and psychosocial development of prelingual deaf children with cochlear implants (CIs) attending mainstream schools, and to evaluate the impact of auditory speech perception on their classroom performance. Subjects and Methods: As participant, 67 children with CI attending mainstream schools were included. A survey was conducted using a structured questionnaire on academic performance in the native language, second language, mathematics, social studies, science, art, communication skills, self-esteem, and social relations. Additionally, auditory and speech performances on the last follow-up were reviewed retrospectively. Results: Most implanted children attending mainstream school appeared to have positive self-esteem and confidence, and had little difficulty in conversing in a quiet classroom. Also, half of the implanted children (38/67) scored above average in general academic achievement. However, academic achievement in the second language (English), social studies, and science were usually poorer than general academic achievement. Furthermore, half of the implanted children had difficulty in understanding the class content (30/67) or conversing with peers in a noisy classroom (32/67). These difficulties were significantly associated with poor speech perception. Conclusions: Improving the listening environment for implanted children attending mainstream schools is necessary.

• Korean Journal of Mathematics
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• 제30권4호
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• pp.593-601
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• 2022

Let C(Q) denote Yeh-Wiener space, the space of all real-valued continuous functions x(s, t) on Q ≡ [0, S] × [0, T] with x(s, 0) = x(0, t) = 0 for every (s, t) ∈ Q. For each partition τ = τ_m,n = {(s_i, t_j)|i = 1, . . . , m, j = 1, . . . , n} of Q with 0 = s₀ < s₁ < . . . < s_m = S and 0 = t₀ < t₁ < . . . < t_n = T, define a random vector X_τ : C(Q) → ℝ^mn by X_τ (x) = (x(s₁, t₁), . . . , x(s_m, t_n)). In this paper we study the conditional integral transform and the conditional convolution product for a class of cylinder type functionals defined on K(Q) with a given conditioning function X_τ above, where K(Q)is the space of all complex valued continuous functions of two variables on Q which satify x(s, 0) = x(0, t) = 0 for every (s, t) ∈ Q. In particular we derive a useful equation which allows to calculate the conditional integral transform of the conditional convolution product without ever actually calculating convolution product or conditional convolution product.