• 제목/요약/키워드: university mathematics

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수학 창의성 평가에서 독창성의 점수화 방법 (A Scoring System for the Originality in Evaluation of Mathematical Creativity)

  • 이강섭
    • 한국수학교육학회지시리즈A:수학교육
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    • 제49권1호
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    • pp.111-118
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    • 2010
  • This paper attempts to establish a scoring system for the originality in evaluation of mathematical creativity. The scoring system is composed of three categories; fluency, flexibility and originality. In this paper, we proposed an evaluation method for originality as following based on relative frequency and standard normal distribution. (1) Fluency: It is judged on the basis of the number of correct answers a student made. If several correct answers are given for a single category, then its maximum score is set to 5 points. (2) Flexibility: We examined how many categories the students' responses can be classified into. If at most 15 answers are allowed for each question, the maximum score of flexibility is 15 points. (3) Originality: Originality score is given if a student made some original response that other students did not show. That is, it reflects relative rarity. The originality is measured according to the following steps: Step 1: Analyze the frequency of how many students made an answer to the response type categorized at low level, and calculate the relative frequency p of each category. Step 2: Find the originality point os for each response, that is, os = max{0,z} where z satisfies P(Z > z) = p with standard normal distributed random variable Z. For example, - p is greater than 0.5: 0 point - p is 0.1587: 1 point - p is 0.0228: 2 points - p is 0.0013: 3 points Step 3: Assign the one's originality score to the sum of originality point for each response. Remark. There is no upper limit of originality score.

한국의 여성교육과 정책의 흐름 : 수학, 과학, 직업선택을 중심으로 (Trends in Education and Polices for Women in Korea: Focusing on Mathematics, Science, and Career Choice)

  • 박경빈;문정화;하종덕
    • 영재교육연구
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    • 제16권2호
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    • pp.193-214
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    • 2006
  • 본 연구는 한국 여성들의 교육과 정책 변화의 흐름을 알아보는 것이다. 먼저 여성 교육에 대한 편견이 깊이 뿌리박혀 있는 한국에서의 여성 교육의 역사적 배경을 살펴보았다. PISA와 TIMSS와 같은 학업성취도 국제 비교 연구와, 국가수준 학업성취도 연구를 통해 특별히 과학과 수학에서 남녀 학생의 성취 수준의 차이를 알아보았다. 여학생들이 일반적인 학업성취에서는 남학생보다 우수하거나 같았고, 국제평가에서는 읽기 소양에서는 남학생보다 높은 성취를 보였으나, 수학과 과학에서는 남학생보다 훨씬 낮은 수준이었다. 남여 학생 간의 성취도의 차이는 OECD 회원국 중에서 가장 컸다. 또한 교육 제도와 학업과 직업적 성취를 중심으로 현대사회에서 여성의 위치가 어떻게 변하고 있는지를 조사했다. 더불어 여성 전문가 양성을 지원하는 다양한 계획과 정책에 대해서도 소개했다. 끝으로, 남학생과 여학생의 학업성취 격차에 대한 원인들을 살펴보았고, 수학과 과학의 남녀 학생의 차이를 줄이기 위한 몇 가지 제안을 했다.

DIRECT PRODUCTED W*-PROBABILITY SPACES AND CORRESPONDING AMALGAMATED FREE STOCHASTIC INTEGRATION

  • Cho, Il-Woo
    • 대한수학회보
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    • 제44권1호
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    • pp.131-150
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    • 2007
  • In this paper, we will define direct producted $W^*-porobability$ spaces over their diagonal subalgebras and observe the amalgamated free-ness on them. Also, we will consider the amalgamated free stochastic calculus on such free probabilistic structure. Let ($A_{j},\;{\varphi}_{j}$) be a tracial $W^*-porobability$ spaces, for j = 1,..., N. Then we can define the corresponding direct producted $W^*-porobability$ space (A, E) over its N-th diagonal subalgebra $D_{N}\;{\equiv}\;\mathbb{C}^{{\bigoplus}N}$, where $A={\bigoplus}^{N}_{j=1}\;A_{j}\;and\;E={\bigoplus}^{N}_{j=1}\;{\varphi}_{j}$. In Chapter 1, we show that $D_{N}-valued$ cumulants are direct sum of scalar-valued cumulants. This says that, roughly speaking, the $D_{N}-freeness$ is characterized by the direct sum of scalar-valued freeness. As application, the $D_{N}-semicircularityrity$ and the $D_{N}-valued$ infinitely divisibility are characterized by the direct sum of semicircularity and the direct sum of infinitely divisibility, respectively. In Chapter 2, we will define the $D_{N}-valued$ stochastic integral of $D_{N}-valued$ simple adapted biprocesses with respect to a fixed $D_{N}-valued$ infinitely divisible element which is a $D_{N}-free$ stochastic process. We can see that the free stochastic Ito's formula is naturally extended to the $D_{N}-valued$ case.

TWO DIMENSIONAL ARRAYS FOR ALEXANDER POLYNOMIALS OF TORUS KNOTS

  • Song, Hyun-Jong
    • 대한수학회논문집
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    • 제32권1호
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    • pp.193-200
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    • 2017
  • Given a pair p, q of relative prime positive integers, we have uniquely determined positive integers x, y, u and v such that vx-uy = 1, p = x + y and q = u + v. Using this property, we show that$${\sum\limits_{1{\leq}i{\leq}x,1{\leq}j{\leq}v}}\;{t^{(i-1)q+(j-1)p}\;-\;{\sum\limits_{1{\leq}k{\leq}y,1{\leq}l{\leq}u}}\;t^{1+(k-1)q+(l-1)p}$$ is the Alexander polynomial ${\Delta}_{p,q}(t)$ of a torus knot t(p, q). Hence the number $N_{p,q}$ of non-zero terms of ${\Delta}_{p,q}(t)$ is equal to vx + uy = 2vx - 1. Owing to well known results in knot Floer homology theory, our expanding formula of the Alexander polynomial of a torus knot provides a method of algorithmically determining the total rank of its knot Floer homology or equivalently the complexity of its (1,1)-diagram. In particular we prove (see Corollary 2.8); Let q be a positive integer> 1 and let k be a positive integer. Then we have $$\begin{array}{rccl}(1)&N_{kq}+1,q&=&2k(q-1)+1\\(2)&N_{kq}+q-1,q&=&2(k+1)(q-1)-1\\(3)&N_{kq}+2,q&=&{\frac{1}{2}}k(q^2-1)+q\\(4)&N_{kq}+q-2,q&=&{\frac{1}{2}}(k+1)(q^2-1)-q\end{array}$$ where we further assume q is odd in formula (3) and (4). Consequently we confirm that the complexities of (1,1)-diagrams of torus knots of type t(kq + 2, q) and t(kq + q - 2, q) in [5] agree with $N_{kq+2,q}$ and $N_{kq+q-2,q}$ respectively.

SKEW POLYNOMIAL RINGS OVER σ-QUASI-BAER AND σ-PRINCIPALLY QUASI-BAER RINGS

  • HAN JUNCHEOL
    • 대한수학회지
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    • 제42권1호
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    • pp.53-63
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    • 2005
  • Let R be a ring R and ${\sigma}$ be an endomorphism of R. R is called ${\sigma}$-rigid (resp. reduced) if $a{\sigma}r(a) = 0 (resp{\cdot}a^2 = 0)$ for any $a{\in}R$ implies a = 0. An ideal I of R is called a ${\sigma}$-ideal if ${\sigma}(I){\subseteq}I$. R is called ${\sigma}$-quasi-Baer (resp. right (or left) ${\sigma}$-p.q.-Baer) if the right annihilator of every ${\sigma}$-ideal (resp. right (or left) principal ${\sigma}$-ideal) of R is generated by an idempotent of R. In this paper, a skew polynomial ring A = R[$x;{\sigma}$] of a ring R is investigated as follows: For a ${\sigma}$-rigid ring R, (1) R is ${\sigma}$-quasi-Baer if and only if A is quasi-Baer if and only if A is $\={\sigma}$-quasi-Baer for every extended endomorphism $\={\sigma}$ on A of ${\sigma}$ (2) R is right ${\sigma}$-p.q.-Baer if and only if R is ${\sigma}$-p.q.-Baer if and only if A is right p.q.-Baer if and only if A is p.q.-Baer if and only if A is $\={\sigma}$-p.q.-Baer if and only if A is right $\={\sigma}$-p.q.-Baer for every extended endomorphism $\={\sigma}$ on A of ${\sigma}$.

BubbleDoc: 클라우드 환경에서의 agent-free 파일시스템 분석을 통한 문서 위/변조 탐지 (BubbleDoc: Document Forgery and Tamper Detection through the Agent-Free File System-Awareness in Cloud Environment)

  • 전우진;홍도원;박기웅
    • 정보보호학회논문지
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    • 제28권2호
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    • pp.429-436
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    • 2018
  • 전자문서는 생성 및 관리가 효율적이나 유통 및 전달 과정에서 사본이 생성되기 때문에 원본성을 상실하기 쉽다. 이러한 이유로 전자문서에 대한 다양한 보안 기술이 적용되었으나, 현재 사용되고 있는 보안 기술은 대부분 파일 접근 권한 제어, 파일 버전 및 이력 관리 등과 같은 문서 관리에 대한 것이므로 기밀문서와 같이 원본성 확보가 절대적으로 요구되어지는 환경에서는 사용이 불가능하다. 따라서 본 논문에서는 클라우드 컴퓨팅 환경에서 인스턴스 운영체제 내부에 별도의 에이전트 설치 없이 파일시스템 분석을 통하여 문서 위/변조를 탐지하는 기법을 제안한다. BubbleDoc은 인스턴스의 가상 볼륨 스토리지의 최소 영역을 모니터링하기 때문에 문서에 대한 위/변조를 효율적으로 탐지할 수 있다. 실험 결과에 따르면 본 논문에서 제안한 기술은 문서 위/변조 탐지를 위한 모니터링 수행에 있어서 1,000ms 주기로 설정하였을 때 0.16%의 디스크 읽기 연산 오버헤드를 보였다.

측정 영역의 문제해결 과정에서 나타나는 초등학교 6학년 학생의 오류 분석 (Error Analysis of 6th Grade Elementary Students in Problem Solving in the Measurement Domain)

  • 김성경
    • 과학교육연구지
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    • 제41권3호
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    • pp.480-498
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    • 2017
  • 본 연구는 측정 영역의 문제해결 과정에서 나타나는 초등학교 6학년 학생의 오류를 분석하였다. 초등 5~6학년군의 내용에서 학생들이 어려워하는 부분에 대한 오류를 분석함으로써 학생들의 성취기준 도달을 도울 수 있는 교수 학습에서의 시사점을 도출하고자 하였다. 첫째, 문제를 해결할 수 있는 충분한 시간을 학생들에게 제공했음에도 불구하고 풀이과정을 바르게 쓰지 못한 학생이 문항에 따라 약 30~60%에 이르렀다는 점은 학생들이 측정 영역의 일부에서 어려움을 겪고 있음을 시사한다. 둘째, 단위 사이의 관계에 대한 불충분한 이해 등 측정 단위에 대한 학생들의 이해가 낮은 것을 확인하였다. 셋째, 학생들은 삼각형에서 밑변이 정해지면 그에 따라 높이가 결정되고 이로부터 삼각형의 넓이를 구하는 여러 개의 식을 도출할 수 있다는 것에 대한 이해가 낮은 것으로 나타났다.

SCALE TRANSFORMATIONS FOR PRESENT POSITION-INDEPENDENT CONDITIONAL EXPECTATIONS

  • Cho, Dong Hyun
    • 대한수학회지
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    • 제53권3호
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    • pp.709-723
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    • 2016
  • Let C[0, t] denote a generalized Wiener space, the space of real-valued continuous functions on the interval [0, t] and define a random vector $Z_n:C[0,t]{\rightarrow}{\mathbb{R}}^n$ by $Zn(x)=(\int_{0}^{t_1}h(s)dx(s),{\cdots},\int_{0}^{t_n}h(s)dx(s))$, where 0 < $t_1$ < ${\cdots}$ < $t_n$ < t is a partition of [0, t] and $h{\in}L_2[0,t]$ with $h{\neq}0$ a.e. In this paper we will introduce a simple formula for a generalized conditional Wiener integral on C[0, t] with the conditioning function $Z_n$ and then evaluate the generalized analytic conditional Wiener and Feynman integrals of the cylinder function $F(x)=f(\int_{0}^{t}e(s)dx(s))$ for $x{\in}C[0,t]$, where $f{\in}L_p(\mathbb{R})(1{\leq}p{\leq}{\infty})$ and e is a unit element in $L_2[0,t]$. Finally we express the generalized analytic conditional Feynman integral of F as two kinds of limits of non-conditional generalized Wiener integrals of polygonal functions and of cylinder functions using a change of scale transformation for which a normal density is the kernel. The choice of a complete orthonormal subset of $L_2[0,t]$ used in the transformation is independent of e and the conditioning function $Z_n$ does not contain the present positions of the generalized Wiener paths.

Pyrophen Produced by Endophytic Fungi Aspergillus sp Isolated from Piper crocatum Ruiz & Pav Exhibits Cytotoxic Activity and Induces S Phase Arrest in T47D Breast Cancer Cells

  • Astuti, Puji;Erden, Willy;Wahyono, Wahyono;Wahyuono, Subagus;Hertiani, Triana
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권2호
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    • pp.615-618
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    • 2016
  • Ethyl acetate extracts obtained from culture of endophytic fungi Aspergillus sp isolated from Piper crocatum Ruiz & Pav, have been shown to possess cytotoxic activity against T47D breast cancer cells. Investigations were here conducted to determine bioactive compounds responsible for the activity. Bioassay guided fractionation was employed to obtain active compounds. Structure elucidation was performed based on analysis of LC-MS, $^1H$-NMR, $^{13}C$-NMR, COSY, DEPT, HMQC, HMBC data. Cytotoxity assays were conducted in 96 well plates against T47D and Vero cell lines. Bioassay guided isolation and chemical investigation led to the isolation of pyrophen, a 4-methoxy-6-(1'-acetamido-2'-phenylethyl)-2H-pyran-2-one. Further analysis of its activity against T47D and Vero cells showed an ability to inhibit the growth of T47D cells with IC50 values of $9.2{\mu}g/mL$ but less cytotoxicity to Vero cells with an $IC_{50}$ of $109{\mu}g/mL$. This compound at a concentration of 400 ng/mL induced S-phase arrest in T47D cells.

RELATING GALOIS POINTS TO WEAK GALOIS WEIERSTRASS POINTS THROUGH DOUBLE COVERINGS OF CURVES

  • Komeda, Jiryo;Takahashi, Takeshi
    • 대한수학회지
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    • 제54권1호
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    • pp.69-86
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    • 2017
  • The point $P{\in}{\mathbb{P}}^2$ is referred to as a Galois point for a nonsingular plane algebraic curve C if the projection ${\pi}_P:C{\rightarrow}{\mathbb{P}}^1$ from P is a Galois covering. In contrast, the point $P^{\prime}{\in}C^{\prime}$ is referred to as a weak Galois Weierstrass point of a nonsingular algebraic curve C' if P' is a Weierstrass point of C' and a total ramification point of some Galois covering $f:C^{\prime}{\rightarrow}{\mathbb{P}}^1$. In this paper, we discuss the following phenomena. For a nonsingular plane curve C with a Galois point P and a double covering ${\varphi}:C{\rightarrow}C^{\prime}$, if there exists a common ramification point of ${\pi}_P$ and ${\varphi}$, then there exists a weak Galois Weierstrass point $P^{\prime}{\in}C^{\prime}$ with its Weierstrass semigroup such that H(P') = or , which is a semigroup generated by two positive integers r and 2r + 1 or 2r - 1, such that P' is a branch point of ${\varphi}$. Conversely, for a weak Galois Weierstrass point $P^{\prime}{\in}C^{\prime}$ with H(P') = or , there exists a nonsingular plane curve C with a Galois point P and a double covering ${\varphi}:C{\rightarrow}C^{\prime}$ such that P' is a branch point of ${\varphi}$.