• Bulletin of the Korean Mathematical Society
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• v.43 no.1
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• pp.43-52
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• 2006

We study the genericity of the first weak inverse shadowing property and the second weak inverse shadowing property in the space of homeomorphisms on a compact metric space, and show that every shift homeomorphism does not have the first weak inverse shadowing property but it has the second weak inverse shadowing property.

• Communications of the Korean Mathematical Society
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• v.38 no.1
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• pp.243-256
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• 2023

We deal with a type of inverse pseudo-orbit tracing property with respect to the class of continuous methods, as suggested and studied by Pilyugin [54]. In this paper, we consider a continuous method induced through the diffeomorphism of a compact smooth manifold, and using the concept, we proved the following: (i) If a diffeomorphism f of a compact smooth manifold M has the robustly pointwise inverse pseudoorbit tracing property, f is structurally stable. (ii) For a C1 generic diffeomorphism f of a compact smooth manifold M, if f has the pointwise inverse pseudo-orbit tracing property, f is structurally stable. (iii) If a diffeomorphism f has the robustly pointwise inverse pseudo-orbit tracing property around a transitive set Λ, then Λ is hyperbolic for f. Finally, (iv) for C¹ generically, if a diffeomorphism f has the pointwise inverse pseudo-orbit tracing property around a locally maximal transitive set Λ, then Λ is hyperbolic for f. In addition, we investigate cases of volume preserving diffeomorphisms.

• Journal of the Chungcheong Mathematical Society
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• v.32 no.1
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• pp.157-164
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• 2019

In this article, we study expansiveness of the shift maps on orbital inverse limit spaces which consist of two cross bonding mappings. On orbital inverse limit systems, horizontal directions express inverse limit systems and vertical directions mean orbits based on horizontal axes. We characterize the c-expansiveness of functions on orbital spaces. We also prove that the c-expansiveness of the functions is equivalent to the expansiveness of the shift maps on orbital inverse limit spaces.

• Journal of applied mathematics & informatics
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• v.26 no.3_4
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• pp.541-547
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• 2008

Suppose R is an idempotence-diagonalizable ring. Let n and m be two arbitrary positive integers with $n\;{\geq}\;3$. We denote by $M_n(R)$ the ring of all $n{\times}n$ matrices over R. Let ($J_n(R)$) be the additive subgroup of $M_n(R)$ generated additively by all idempotent matrices. Let ($D=J_n(R)$) or $M_n(R)$. In this paper, by using an additive idem potence-preserving result obtained by Coo (see [4]), I characterize (i) the additive preservers of tripotence from D to $M_m(R)$ when 2 and 3 are units of R; (ii) the additive preservers of inverses (respectively, Drazin inverses, group inverses, {1}-inverses, {2}-inverses, {1, 2}-inverses) from $M_n(R)$ to $M_n(R)$ when 2 and 3 are units of R.

• Journal of applied mathematics & informatics
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• v.19 no.1_2
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• pp.297-310
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• 2005

The concept of the Moore-Penrose inverse in an indefinite inner product space is introduced. Extensions of some of the formulae in the Euclidean space to an indefinite inner product space are studied. In particular range-hermitianness is completely characterized. Equivalence of a weighted generalized inverse and the Moore-Penrose inverse is proved. Finally, methods of computing the Moore-Penrose inverse are presented.

• Journal of applied mathematics & informatics
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• v.18 no.1_2
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• pp.45-57
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• 2005

An efficient algorithm for finding the inverse and the group inverse of the FLS $\gamma-circulant$ matrix is presented by Euclidean algorithm. Extension is made to compute the inverse of the FLS $\gamma-retrocirculant$ matrix by using the relationship between an FLS $\gamma-circulant$ matrix and an FLS $\gamma-retrocirculant$ matrix. Finally, some examples are given.

• Journal of applied mathematics & informatics
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• v.25 no.1_2
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• pp.513-518
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• 2007

There is a one to one correspondence between Artinian algebras $k[x_1,...,x_n]/Ann(M)$ and finitely generated $k[x_1,...,x_n]-submodules$ M of $k[y_1,...,y_n]$ by Inverse System. In particular, any Artinian level algebra $k[x_1,...,x_n]/Ann(M)$ can be obtained when M is finitely generated by only maximal degree generators. We prove that H = (1, 4, 8, 13,..., 27, 8, 2) is not a level Artinian O-sequence using this inverse system.

• The Journal of Korea Robotics Society
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• v.1 no.1
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• pp.73-80
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• 2006

Bicycle is one of convenient transportation system. In this paper, we derive a more precise kinematics of bicycle system compared with other ones which were suggested by other researchers. In the derivation of kinematics we adopted a physical concept called virtual wheel. We also propose an algorithm for deriving inverse kinematics of a bicycle system. In this paper, the meaning of inverse kinematics is to find the time functions of steering angle and driving wheel speed for a given desired path trajectory. From the computer simulation, we show the validity of our proposed algorithm for inverse kinematics of bicycle system.

• Journal of the Chungcheong Mathematical Society
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• v.35 no.1
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• pp.69-76
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• 2022

In this article, we investigate minimality, transitivity and mixing property for a shift map on the orbital inverse limit systems.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.12 no.2
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• pp.83-91
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• 1987

In this paper, the extended inverse Chebyshev function have been derived from Chebyshev function. We presented normalized biquads coefficients of n=5, 6 for passband attenuation Ap(dB)=0.1, 0.2, 0.5, 1.0, 2.0, 3.0 and stopband frequency Ws(rad/s)=1.2, 1.3, 1.4, 1.5, 1.6. A designed low-pass filter from extended inverse Chebyshev transfer function produces the magnitude haracteristic which is maximally flat in the passband and equalripple in the stopband as shown in fig. 3(c), (d). Finally, it showed the magnitude and loss characteristics through realistic circuit simulation, and presented element values.