• Title/Summary/Keyword: permutation

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LOCAL PERMUTATION POLYNOMIALS OVER FINITE FIELDS

  • Lee, Jung-Bok;Ko, Hyoung-June
    • Communications of the Korean Mathematical Society
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    • v.9 no.3
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    • pp.539-545
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    • 1994
  • Let $q = p^r$, where p is a prime. A polynomial $f(x) \in GF(q)[x]$ is called a permutation polynomial (PP) over GF(q) if the numbers f(a) where $a \in GF(Q)$ are a permutation of the a's. In other words, the equation f(x) = a has a unique solution in GF(q) for each $a \in GF(q)$. More generally, $f(x_1, \cdots, x_n)$ is a PP in n variables if $f(x_1,\cdots,x_n) = \alpha$ has exactly $q^{n-1}$ solutions in $GF(q)^n$ for each $\alpha \in GF(q)$. Mullen ([3], [4], [5]) has studied the concepts of local permutation polynomials (LPP's) over finite fields. A polynomial $f(x_i, x_2, \cdots, x_n) \in GF(q)[x_i, \codts,x_n]$ is called a LPP if for each i = 1,\cdots, n, f(a_i,\cdots,x_n]$ is a PP in $x_i$ for all $a_j \in GF(q), j \neq 1$.Mullen ([3],[4]) found a set of necessary and three variables over GF(q) in order that f be a LPP. As examples, there are 12 LPP's over GF(3) in two indeterminates ; $f(x_1, x_2) = a_{10}x_1 + a_{10}x_2 + a_{00}$ where $a_{10} = 1$ or 2, $a_{01} = 1$ or x, $a_{00} = 0,1$, or 2. There are 24 LPP's over GF(3) of three indeterminates ; $F(x_1, x_2, x_3) = ax_1 + bx_2 +cx_3 +d$ where a,b and c = 1 or 2, d = 0,1, or 2.

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Methods of generating Hopping Patterns Based on Permutation Frequency Hopping SSMA System (치환방법을 이용한 주파수 도약 확산 시스템의 주파수 도약 패턴 발생 방법)

  • Choon Sik YIM;Ryuji KOHNO;Hideki IMAI
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.16 no.12
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    • pp.1357-1365
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    • 1991
  • This paper proposes the generation of several classes of frequency hopping patterns. which are derived by permutation, for an asynchronous frequency hopping spread spectrum multiple accecss system (FH/SSMA). The first class of hopping patterns is obtained by using a Latin square. The second class of hopping patterns is derived by generalizing the first class which is designed by using a permutation technique. The third class of hopping patterns is designed by using a rotational base of elements. We evaluate the hit property of the proposed classes of hopping patterns when these patterns are nutually shifted in an FH/SSMA system. Compared to the Reed Slolmon sequences generated by the conventional method, the sequence obtained by the permutation technique can reduce the number of hits among hopping frequencies in asynchronous time/frequency shift.

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Testing the Equality of Two Linear Regression Models : Comparison between Chow Test and a Permutation Test

  • Um, Yonghwan
    • Journal of the Korea Society of Computer and Information
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    • v.26 no.8
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    • pp.157-164
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    • 2021
  • Regression analysis is a well-known statistical technique useful to explain the relationship between response variable and predictor variables. In particular, Researchers are interested in comparing the regression coefficients(intercepts and slopes) of the models in two independent populations. The Chow test, proposed by Gregory Chow, is one of the most commonly used methods for comparing regression models and for testing the presence of a structural break in linear models. In this study, we propose the use of permutation method and compare it with Chow test analysis for testing the equality of two independent linear regression models. Then simulation study is conducted to examine the powers of permutation test and Chow test.

Outlier Impact on the Power of Significance Test for Cronbach Alpha Reliability Coefficient

  • Yonghwan Um
    • Journal of the Korea Society of Computer and Information
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    • v.28 no.5
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    • pp.179-187
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    • 2023
  • In this paper, we studied the impact of outliers on the power of the significance tests for Cronbach alpha reliability coefficient. Four variables were varied: sample size, the number of items, the number of outliers and population Cronbach Alpha levels. We simulated data using multivariate normal distribution and used outliers sampled from uniform distribution. To test the significance of Cronbach Alpha Reliability, parametric approach(F statistic) and permutation method were used. Consequently, we observed that the powers of permutation test are equal to or greater than those of F test under all conditions, and also both F test and permutation test lose the power as the number of outliers increases, and that these effects of outliers on the power are enhanced for increasing population alpha levels.

Information Hiding Application Method Using Steganography (스테가노그라피를 활용한 정보은닉 응용기법 연구)

  • Lee, Cheol;Kim, Yong-Man;Yoo, Seung-Jae
    • Convergence Security Journal
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    • v.10 no.2
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    • pp.19-26
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    • 2010
  • In this study, we try to make up for the vulnerability in steganography that it is easily revealed the hidden logo image in cover image by bit-plane extraction. For this, we apply some methods, the permutation which shift the scattered pieces of logo image to one side, bit-plane dispersion insertion method and pack-type compressor.

Nonparametric test on dimensionality of explantory variables (설명변수 차원 축소에 관한 비모수적 검정)

  • 서한손
    • The Korean Journal of Applied Statistics
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    • v.8 no.2
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    • pp.65-75
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    • 1995
  • For the determination of dimension of e.d.r. space, both of Sliced Inverse Regression (SIR) and Principal Hessian Directions (PHD) proposed asymptotic test. But the asymptotic test requires the normality and large samples of explanatory variables. Cook and Weisberg(1991) suggested permutation tests instead. In this study permutation tests are actually made, and the power of them is compared with asymptotic test in the case of SIR and PHD.

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Permutation Predictor Tests in Linear Regression

  • Ryu, Hye Min;Woo, Min Ah;Lee, Kyungjin;Yoo, Jae Keun
    • Communications for Statistical Applications and Methods
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    • v.20 no.2
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    • pp.147-155
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    • 2013
  • To determine whether each coefficient is equal to zero or not, usual $t$-tests are a popular choice (among others) in linear regression to practitioners because all statistical packages provide the statistics and their corresponding $p$-values. Under smaller samples (especially with non-normal errors) the tests often fail to correctly detect statistical significance. We propose a permutation approach by adopting a sufficient dimension reduction methodology to overcome this deficit. Numerical studies confirm that the proposed method has potential advantages over the t-tests. In addition, data analysis is also presented.

Quasi-Cyclic Low-Density Parity-Check Codes with Large Girth Based on Euclidean Geometries (유클리드 기하학 기반의 넓은 둘레를 가지는 준순환 저밀도 패리티검사 코드)

  • Lee, Mi-Sung;Jiang, Xueqin;Lee, Moon-Ho
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.47 no.11
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    • pp.36-42
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    • 2010
  • This paper presents a hybrid approach to the construction of quasi-cyclic (QC) low-density parity-check (LDPC) codes based on parallel bundles in Euclidean geometries and circulant permutation matrices. Codes constructed by this method are shown to be regular with large girth and low density. Simulation results show that these codes perform very well with iterative decoding and achieve reasonably large coding gains over uncoded system.

COLORED PERMUTATIONS WITH NO MONOCHROMATIC CYCLES

  • Kim, Dongsu;Kim, Jang Soo;Seo, Seunghyun
    • Journal of the Korean Mathematical Society
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    • v.54 no.4
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    • pp.1149-1161
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    • 2017
  • An ($n_1,\;n_2,\;{\ldots},\;n_k$)-colored permutation is a permutation of $n_1+n_2+{\cdots}+n_k$ in which $1,\;2,\;{\ldots},\;n_1$ have color 1, and $n_1+1,\;n_1+2,\;{\ldots},\;n_1+n_2$ have color 2, and so on. We give a bijective proof of Steinhardt's result: the number of colored permutations with no monochromatic cycles is equal to the number of permutations with no fixed points after reordering the first $n_1$ elements, the next $n_2$ element, and so on, in ascending order. We then find the generating function for colored permutations with no monochromatic cycles. As an application we give a new proof of the well known generating function for colored permutations with no fixed colors, also known as multi-derangements.

Comparison of Some Nonparametric Statistical Inference for Logit Model (로짓모형의 비모수적 추론의 비교)

  • 정형철;김대학
    • The Korean Journal of Applied Statistics
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    • v.15 no.2
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    • pp.355-366
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    • 2002
  • Nonparametric statistical inference for the parameter of logit model were examined. Usually nonparametric approach is milder than parametric approach based on normal theory assumption. We compared the two nonparametric methods for legit model, the bootstrap and random permutation in the sense of coverage probability. Monte Carlo simulation is conducted for small sample cases. Empirical power of hypothesis test and coverage probability for confidence interval estimation were presented for simple and multiple legit model respectively. An example were also introduced.