• The Journal of the Korea institute of electronic communication sciences
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• v.5 no.1
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• pp.10-16
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• 2010

90/150 CA is a CA completely specified by using rule 90 and rule 150. Since 90/150 CA whose minimal and characteristic polynomials are identical has outstanding randomness, this CA is more attractive than LFSR. Sarkar proposed a scheme based on the 90 uniform CA and the 150 uniform CA. That scheme provided authentication by digital signature and other basic security requirements like confidentiality. In this paper we analyze 90 or 150 uniform CA and give a synthesis method of 2n-cell uniform CA and (2n+1)-cell uniform CA using a special n-cell 90/150 CA. And we propose an effective method of computation of characteristic polynomial corresponding to uniform CA.

• The Journal of the Korea institute of electronic communication sciences
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• v.13 no.3
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• pp.593-600
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• 2018

Cellular automata (CA) have been applied to effective cryptographic system design. CA is superior in randomness to LFSR due to the fact that its state is updated simultaneously by local interaction. To apply these CAs to the cryptosystem, a study has been performed how to synthesize CA corresponding to given polynomials. In this paper, we analyze the recurrence relations of the characteristic polynomial of the 90 UCA and the characteristic polynomial of the 90/150 CA whose transition rule is <$00{\cdots}001$>. And we synthesize the 90/150 CA corresponding to the trinomials $x^{2^n}+x+1(n{\geq}2)$ satisfying f(x)=f(x+1) using the 90 UCA transition rule blocks and the special transition rule block. We also analyze the properties of the irreducible factors of trinomials $x^{2^n}+x+1$ and propose a 90/150 CA synthesis algorithm corresponding to $x^{2^n}+x^{2^m}+1(n{\geq}2,n-m{\geq}2)$.

• Korean Journal of Hydrosciences
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• v.6
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• pp.51-66
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• 1995

Various Eulerian-Lagerangian numerical models for the one-dimensional longtudinal dispersion equation are studied comparatively. In the models studied, the transport equation is decoupled into two component parts by the operator-splitting approach ; one part governing advection and the other dispersion. The advection equation has been solved using the method of characteristics following flud particles along the characteristic line and the result are interpolated onto an Eulerian grid on which the dispersion equation is solved by Crank-Nicholson type finite difference method. In solving the advection equation, various interpolation schemes are tested. Among those, Hermite interpo;ation po;ynomials are superor to Lagrange interpolation polynomials in reducing both dissipation and dispersion errors.

• ETRI Journal
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• v.35 no.5
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• pp.880-888
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• 2013

The preexisting pairings ate, $ate_i$, R-ate, and optimal-ate use q-expansion, where q is the size of the defining field for the elliptic curves. Elliptic curves with small embedding degrees only allow a few of these pairings. In such cases, efficiently computable endomorphisms can be used, as in [11] and [12]. They used the endomorphisms that have characteristic polynomials with very small coefficients, which led to some restrictions in finding various pairing-friendly curves. To construct more pairing-friendly curves, we consider ${\mu}$-expansion using the Gallant-Lambert-Vanstone (GLV) decomposition method, where ${\mu}$ is an arbitrary integer. We illustrate some pairing-friendly curves that provide more efficient pairing from the ${\mu}$-expansion than from the ate pairing. The proposed method can achieve timing results at least 20% faster than the ate pairing.

• Journal of the Society of Naval Architects of Korea
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• v.42 no.4 s.142
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• pp.396-401
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• 2005

In this study, the assumed mode method using characteristic polynomials of Timoshenko beam is applied to the free vibration analysis for the stiffened plate of ship tank side in contact with water. The hydro-elastic effect of the fluid-structure interaction is considered by fluid velocity potential, derived from boundary conditions for fluid and structure, and utilized in the calculation of added mass matrix using assumed modes. To verify the validity and effectiveness of the presented method, free vibration analysis for the stiffened plates in contact with finite and infinite fluids have been carried out and its results were compared with those obtained by a general purpose FEA software.

• Journal of the Korean Statistical Society
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• v.23 no.2
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• pp.325-340
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• 1994

Effects of temporal aggregation on estimation for ARMA models are studied by investigating the Hannan & Rissanen (1982)'s procedure. The temporal aggregation of autoregressive process has a representation of an autoregressive moving average. The characteristic polynomials associated with autoregressive part and moving average part tend to have roots close to zero or almost identical. This caused a numerical problem in the Hannan & Rissanen procedure for identifying and estimating the temporally aggregated autoregressive model. A Monte-Carlo simulation is conducted to show the effects of temporal aggregation in predicting one period ahead realization.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.14 no.11
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• pp.2507-2513
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• 2010

In this paper, we show that the shrinking generator with two LFSR whose characteristic polynomials are primitive is an interleaving generator and analyze phase shifts in shrunken sequence. Also for a given intercepted sequence of shrunken sequence, we propose. the method of reconstructing some deterministic bits of the shrunken sequence using phase shifts.

• Korean Journal of Geomatics
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• v.3 no.1
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• pp.53-57
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• 2003

As the Korea Multi-Purpose Satellite-I (KOMPSAT-1) satellite can roll tilt up to $\pm$45$^{\circ}$, we have analyzed some KOMPSAT-1 EOC images taken at different tilt angles for this study. The required ground coordinates for bundle adjustment and geometric accuracy are obtained from the digital map produced by the National Geography Institution, at a scale of 1:5,000. Followings are the steps taken for the tilting angle of KOMPSAT-1 to be present in the evaluation of geometric accuracy of each different stereo image data: Firstly, as the tilting angle is different in each image, the characteristic of satellite dynamic must be determined by the sensor modeling. Then the best sensor modeling equation should be determined. The result of this research, the difference between the RMSE values of individual stereo images is mainly due to quality of image and ground coordinates instead of tilt angle. The bundle adjustment using three KOMPSAT-1 stereo pairs, first degree of polynomials for modeling the satellite position, were sufficient.

• Bulletin of the Korean Mathematical Society
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• v.42 no.4
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• pp.679-690
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• 2005

Let K be a commutative ring with unity, R a prime K-algebra of characteristic different from 2, d a non-zero derivation of R, I a non-zero right ideal of R, f($x_1,{\cdots},\;x_n$) a multilinear polynomial in n non-commuting variables over K, a $\in$ R. Supppose that, for any $x_1,{\cdots},\;x_n\;\in\;I,\;a[d(f(x_1,{\cdots},\;x_n)),\;f(x_1,{\cdots},\;x_n)]$ = 0. If $[f(x_1,{\cdots},\;x_n),\;x_{n+1}]x_{n+2}$ is not an identity for I and $$S_4(I,\;I,\;I,\;I)\;I\;\neq\;0$$, then aI = ad(I) = 0.

• Journal of the Korean Mathematical Society
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• v.52 no.1
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• pp.191-207
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• 2015

Let $\mathcal{R}$ be a prime ring of characteristic different from 2, $\mathcal{Q}_r$ be its right Martindale quotient ring and $\mathcal{C}$ be its extended centroid. Suppose that $\mathcal{G}$ is a nonzero generalized skew derivation of $\mathcal{R}$, ${\alpha}$ is the associated automorphism of $\mathcal{G}$, f($x_1$, ${\cdots}$, $x_n$) is a non-central multilinear polynomial over $\mathcal{C}$ with n non-commuting variables and $$\mathcal{S}=\{f(r_1,{\cdots},r_n)\left|r_1,{\cdots},r_n{\in}\mathcal{R}\}$$. If $\mathcal{G}$ acts as a Jordan homomorphism on $\mathcal{S}$, then either $\mathcal{G}(x)=x$ for all $x{\in}\mathcal{R}$, or $\mathcal{G}={\alpha}$.