• Journal of KIISE:Computer Systems and Theory
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• v.27 no.12
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• pp.974-980
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• 2000

Luby-Rackoff의 논문 이후로 유사 랜덤 순열 생성기에 관한 많은 연구가 있었다. 하지만 대부분의 연구는 대칭 피스텔 네트웍 구조를 이용한 유사 랜덤 순열 생성기에 관한 것이었다. 이 논문에서는 비대칭 피스텔 네트웍 구조를 사용하는 순열 생성기가 유사 랜덤 순열 생성기가 되기 위한 조건을 분석한다. 비대칭 피스텔 네트웍 순열 생성기의 입출력의 크기가 (k+1)n 비트인 경우 논문의 결과는 다음과 같다. 비대칭 피스텔 네트웍이 입력 크기가 kn 비트이고 출력 크기가 n 비트인 유사 랜덤 함수 생성기를 사용하는 경우, 전체 라운드 수가 k+2 이상이면 유사 랜덤 순열 생성기이다. 비대칭 피스텔 네트웍이 입력 크기가 n 비트이고 출력 크기가 kn 비트인 유사 랜덤 함수 생성기를 사용하는 경우, 전체 라운드 수가 k+2 이상이면 유사 랜덤 순열 생성기이다.

• Communications of Mathematical Education
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• v.12
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• pp.265-280
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• 2001

고등학교 수학 I 의 확률 및 통계영역의 교육내용을 정리한 후, 고등학생들에게 확률 및 통계영역에 관한 흥미를 돋구기 위하여 2002년 월드컵을 소재로 한 문제들을 활용하여 비주얼 베이직으로 프로그램한 ‘확률상자’ 라는 확률모형을 개발하였다. 확률상자에는 확률의 역사, 경우의 수, 순열, 같은 것이 있는 순열, 원순열, 조합, 이항계수, 통계적 확률, 조건부 확률, 배반사건 등 모두 10가지 모듈을 포함한다. 확률상자의 초기화면에서 메뉴를 선택하면 선택된 내용에 관한 간단한 정의와 함께 문제가 제시되어 정답을 적도록 하였고, 오답일 때는 힌트를 누르면 정답을 이해할 수 있도록 풀이과정을 제시하였다. 특히, 메뉴가운데서 경우의 수, 순열, 같은 것이 있는 순열, 원순열, 조합, 통계적 확률의 경우에는 풀이과정 중에 애니메이션 또는 시뮬레이션이 실행되도록 하여 이해를 돕도록 하였다.

• Journal for History of Mathematics
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• v.32 no.2
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• pp.61-77
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• 2019

The study was conducted based on the 'method of mathematical exploration through history'. In recent school education, 'Probability and Statistics' education has been emphasized, and as a result, the study has conducted a study on permutations. Permutation is used in a variety of fields, and in this study, we looked at the Derangement. The results of this study are as follows. First, analysis was made at current school mathematics level and academic mathematics level for Derangement. Second, the historical development process of derangement was examined. Third, based on this, the research direction of this study was decided to be 'Derangement number's triangle(Rencontres number's triangle)', and the inquiry for education expansion was carried out. Fourth, we have presented data on concrete educational expansion by discovering various mathematical facts of the Derangement number's triangle. We hope that the results of this study will provide meaningful implications for the application of mathematics and the presentation of new inquiry directions.

• The Korean Journal of Applied Statistics
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• v.27 no.1
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• pp.1-11
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• 2014

The Weighted Logrank test and its special case, Logrank test are widely used to compare survival distributions; however, these methods are inappropriate when the sample size is small or censoring distributions are not equal since they use test statistics from approximate distributions. A permutation test can be an alternative for small sample cases; however, this should be used only when censoring distributions are equal. To handle cases with small sample size and unequal censoring distributions, the permutation-imputation method was developed to compare two survival distributions. In this paper, approximate method, permutation method and permutation-imputation method were compared using a Logrank test and Prentice-Wilcoxon test for three or more survival distributions comparison.

• School Mathematics
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• v.7 no.2
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• pp.123-137
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• 2005

Elementary combinatorial problem may be classified into three different combinatorial models(selection, distribution, partition). The main goal of this research is to determine the effect of type of combinatorial operation and implicit combinatorial model on problem difficulty. We also classified errors in the understanding combinatorial problem into error of order, repetition, permutation with repetition, confusing the type of object and cell, partition. The analysis of variance of answers from 339 students showed the influence of the implicit combinatorial model and types of combinatorial operations. As a result of clinical interviews, we particularly noticed that some students were not able to transfer the definition of combinatorial operation when changing the problem to a different combinatorial model. Moreover, we have analysed textbooks, and we have found that the exercises in these textbooks don't have various types of problems. Therefore when organizing the teaching , it is necessary to pose various types of problems and to emphasize the transition of combinatorial problem into the different models.

• The Korean Journal of Applied Statistics
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• v.31 no.2
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• pp.241-251
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• 2018

The analysis of gene sets in microarray has advantages in interpreting biological functions and increasing statistical powers. Many statistical methods have been proposed for detecting significant gene sets that show relations between genes and phenotypes, but there is no consensus about which is the best to perform gene sets analysis and permutation based tests are considered as standard tools. When many gene sets are tested simultaneously, a large number of random permutations are needed for multiple testing with a high computational cost. In this paper, several parametric approximations are considered as alternatives of the permutation distribution and the moment based gene set test has shown the best performance for providing p-values of the permutation test closely and quickly on a general framework.

• Proceedings of the Korea Information Processing Society Conference
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• 2004.05a
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• pp.409-412
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• 2004

Plot Units는 이야기를 형성하는 줄거리 또는 줄거리에 나오는 여러 사건을 하나로 구성하여 표현하는 단위이다. 한편, 개연규칙은 문장간 구성성분들의 개연적인 결속성을 나타낸다. 이러한 결속은 개연사슬로 나타낼 수 있다. 개연사슬은 개념을 연결하는 어휘들과 그 연결을 설명하는 관계들의 목록이다. 이중에서 기능관계순열로는 해당 개연규칙을 보다 개념적으로 설명할 수 있다. 본 논문에서는 이러한 기능관계순열을 분석하고 Plot Units과 비교해 보았다. 실험을 통하여 주어진 기능관계순열이 Plot Units의 어떤 유형에 해당하는지 알 수 있었다.

• Journal of KIISE:Information Networking
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• v.27 no.1
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• pp.12-21
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• 2000

Arrangement graph has desirable properties for design requirements of a multihop lightwave network, such as node and edge symmetry, low diameter, simple routing, etc. In this paper, arrangement lightwave network based on arrangement graph model is proposed as new logical topology of multihop lightwave network. In the proposed scheme, multistar and grouping of network are used for improving reusability of wavelength and scalability. Also, this paper shows that the proposed scheme is an alternative logical topology for application requiring more nodes with limited wavelengths by evaluating performance with related works.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.240-243
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• 2011

웹 문서를 비롯한 여러 가지 문서의 양이 급증함에 따라, 문서로부터 주요정보를 얻거나 자동으로 요약하는 연구들이 진행되어왔다. 특히, 문서를 요약하는 연구들은 문서에 존재하는 문장을 추출하는 방법과 요약문을 새롭게 생성하는 방법, 이렇게 크게 두 가지 방법으로 진행되었다. 이 연구에서는, 잠재 토픽 모델을 통하여 얻어낸 각 문장의 토픽 순열을 이용하여 문서를 대표하는 문장, 즉 요약문으로서 적합한 문장들을 추출하는 새로운 기법을 소개한다. 특히, 잠재 토픽 모델이 일반적으로 가지고 있는 속성인 토픽 순열의 교환성(exchangeability)을 배제하고 토픽의 순열을 이용하여 요약문을 추출해내므로 이 기법을 통하여 문서 혹은 문장의 구조를 반영한 요약문을 만들 수 있다.

• The Korean Journal of Applied Statistics
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• v.34 no.6
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• pp.863-874
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• 2021

In this paper, we propose a post-selection inference procedure for the fused lasso signal approximator (FLSA). The FLSA finds underlying sparse piecewise constant mean structure by applying total variation (TV) semi-norm as a penalty term. However, it is widely known that this convex relaxation can cause asymptotic inconsistency in change points detection. As a result, there can remain false change points even though we try to find the best subset of change points via a tuning procedure. To remove these false change points, we propose a post-selection inference for the FLSA. The proposed procedure applies a permutation test based on CUSUM statistic. Our post-selection inference procedure is an extension of the permutation test of Antoch and Hušková (2001) which deals with single change point problems, to multiple change points detection problems in combination with the FLSA. Numerical study results show that the proposed procedure is better than naïve z-tests and tests based on the limiting distribution of CUSUM statistics.