• Title/Summary/Keyword: permutation method

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Post-Processing of IVA-Based 2-Channel Blind Source Separation for Solving the Frequency Bin Permutation Problem (IVA 기반의 2채널 암묵적신호분리에서 주파수빈 뒤섞임 문제 해결을 위한 후처리 과정)

  • Chu, Zhihao;Bae, Keunsung
    • Phonetics and Speech Sciences
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    • v.5 no.4
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    • pp.211-216
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    • 2013
  • The IVA(Independent Vector Analysis) is a well-known FD-ICA method used to solve the frequency permutation problem. It generally works quite well for blind source separation problems, but still needs some improvements in the frequency bin permutation problem. This paper proposes a post-processing method which can improve the source separation performance with the IVA by fixing the remaining frequency permutation problem. The proposed method makes use of the correlation coefficient of power ratio between frequency bins for separated signals with the IVA-based 2-channel source separation. Experimental results verified that the proposed method could fix the remaining frequency permutation problem in the IVA and improve the speech quality of the separated signals.

Combining Independent Permutation p Values Associated with Mann-Whitney Test Data

  • Um, Yonghwan
    • Journal of the Korea Society of Computer and Information
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    • v.23 no.7
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    • pp.99-104
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    • 2018
  • In this paper, we compare Fisher's continuous method with an exact discrete analog of Fisher's continuous method from permutation tests for combining p values. The discrete analog of Fisher's continuous method is known to be adequate for combining independent p values from discrete probability distributions. Also permutation tests are widely used as alternatives to conventional parametric tests since these tests are distribution-free, and yield discrete probability distributions and exact p values. In this paper, we obtain permutation p values from discrete probability distributions using Mann-Whitney test data sets (real data and hypothetical data) and combine p values by the exact discrete analog of Fisher's continuous method.

A Comparison of Survival Distributions with Unequal Censoring Distributions (이질적인 중도절단분포 하에서 생존분포의 동일성 검정법 비교연구)

  • Song, Sujeong;Lee, Jae Won
    • 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.

A high reliable optical image encryption system which combined discrete chaos function with permutation algorithm (이산 카오스 함수와 Permutation Algorithm을 결합한 고신뢰도 광영상 암호시스템)

  • 박종호
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.9 no.4
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    • pp.37-48
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    • 1999
  • Current encryption methods have been applied to secure communication using discrete chaotic system whose output is a noise-like signal which differs from the conventional encryption methods that employ algebra and number theory[1-2] We propose an optical encryption method that transforms the primary pattern into the image pattern of discrete chaotic function first a primary pattern is encoded using permutation algorithm, In the proposed system we suggest the permutation algorithm using the output of key steam generator and its security level is analyzed. In this paper we worked out problem of the application about few discrete chaos function through a permutation algorithm and enhanced the security level. Experimental results with image signal demonstrate the proper of the implemented optical encryption system.

Permutation P-values for Inter-rater Agreement Measures

  • Um, Yonghwan
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.12
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    • pp.169-174
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    • 2015
  • Permutation p-values are provided for the agreement measures for multivariate interval data among many raters. Three agreement measures, Berry and Mielke's measure, Janson and Olsson's measure, and Um's measure are described and compared. Exact and resampling permutation methods are utilized to compute p-values and empirical quantile limits for three measures. Comparisons of p-values demonstrate that resampling permutation methods provide close approximations to exact p-values, and Berry and Mielke's measure and Um's measure show similar performance in terms of measuring agreement.

수세기를 통한 순열과 조합의 이해

  • Jung, In-Chul
    • East Asian mathematical journal
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    • v.25 no.3
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    • pp.247-262
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    • 2009
  • Permutation and combination are the part of mathematics which can be introduced the pliability and diversity of thought. In prior studies of permutation and combination, there treated difficulties of learning, strategy of problem solving, and errors that students might come up with. This paper provides the method so that meaningful teaching and learning might occur through the systematic approach of permutation and combination. But there were little prior studies treated counting numbers that basic of mathematics' action. Therefore this paper tries to help the understanding of permutation and combination with the process of changing from informal knowledge to formal knowledge.

Permutation Test for the Equality of Several Independent Cronbach's Alpha Coefficients

  • Um, Yonghwan
    • Journal of the Korea Society of Computer and Information
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    • v.24 no.6
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    • pp.159-164
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    • 2019
  • The statistical inference of Cronbach's alpha measure of internal reliability is known to be inaccurate when sample size is small and the assumption of normality is violated. In this paper, we describe the permutation method in which we compute resampling p-values for testing the difference between two or more independent Cronbach's alpha coefficients. When the over-all permutation test is significant, we also make pairwise post-hoc comparisons using permutaion method. The permutation tests for the equality of two independent Cronbach's alpha coefficients and three independent Cronbach's alpha coefficients are illustrated with an example analysis of survey data.

Testing the Equality of Several Correlation Coefficients by Permutation Method

  • Um, Yonghwan
    • Journal of the Korea Society of Computer and Information
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    • v.27 no.6
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    • pp.167-174
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    • 2022
  • In this paper we investigate the permutation test for the equality of correlation coefficients in several independent populations. Permutation test is a non-parametric testing methodology based upon the exchangeability of observations. Exchangeability is a generalization of the concept of independent, identically distributed random variables. Using permutation method, we may construct asymptotically exact test. This method is asymptotically as powerful as standard parametric tests and is a valuable tool when the sample sizes are small and normality assumption cannot be met. We first review existing parametric approaches to test the equality of correlation coefficients and compare them with the permutation test. At the end, all the approaches are illustrated using Iris data example.

Pavement Maintenance System Through using the Permutation Algorithm (순열알고리즘을 이용한 도로포장의 유지보수)

  • Jang-Rak, Kim;Sang-Yum, Lee;Sungho, Mun
    • International Journal of Highway Engineering
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    • v.16 no.5
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    • pp.67-72
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    • 2014
  • PURPOSES : This study focuses on conducting pavement rehabilitation for more deteriorated roads given a limited government budget. METHODS : Therefore, we apply a optimization programming model of the permutation algorithm used for rehabilitating more deteriorated pavement areas, which is subjected to the limited budget. RESULTS : The permutation algorithm was evaluated in terms of determining the maximized rehabilitation of deteriorated pavement areas, using the newly developed performance models such as fatigue cracking, rutting, international roughness index(IRI) through the surveying data from 2006 to 2012. When compared with a traditional model of the so-called worst-first sequence(WFS) method, the permutation algorithm worked better than the WFS method, resulting in covering more deteriorated pavement areas given the limited government budget. CONCLUSIONS : Through a case study, it could be concluded that the permutation algorithm provides more reliable results in terms of rehabilitating more deteriorated pavement areas given the limited budget.

Method-Free Permutation Predictor Hypothesis Tests in Sufficient Dimension Reduction

  • Lee, Kyungjin;Oh, Suji;Yoo, Jae Keun
    • Communications for Statistical Applications and Methods
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    • v.20 no.4
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    • pp.291-300
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    • 2013
  • In this paper, we propose method-free permutation predictor hypothesis tests in the context of sufficient dimension reduction. Different from an existing method-free bootstrap approach, predictor hypotheses are evaluated based on p-values; therefore, usual statistical practitioners should have a potential preference. Numerical studies validate the developed theories, and real data application is provided.