• Communications of the Korean Mathematical Society
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• v.18 no.4
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• pp.603-613
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• 2003

When X is a threefold of general type, it is well known h/sup 0/(X, O/sub X/(nK/sub X/)) ≥ 1 for a sufficiently large n. When X(O/sub X/) 〉 0, it is not easy to obtain such an integer n. A. R. Fletcher showed that h/sup 0/(X, O/sub X/(nK/sub X/)) ≥ 1 for n = 12 when X(O/sub X/)=1. We introduce a technique different from A. R. Fletcher's. Using this technique, we also prove the same result as he showed and have a new result.

• Journal of applied mathematics & informatics
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• v.19 no.1_2
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• pp.371-384
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• 2005

Usual symmetric duality results are proved for Wolfe and Mond-Weir type nondifferentiable nonlinear symmetric dual programs under F-convexity F-concavity and F-pseudoconvexity F-pseudoconcavity assumptions. These duality results are then used to formulate Wolfe and Mond-Weir type nondifferentiable minimax mixed integer dual programs and symmetric duality theorems are established. Moreover, nondifferentiable fractional symmetric dual programs are studied by using the above programs.

• JSTS:Journal of Semiconductor Technology and Science
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• v.9 no.3
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• pp.153-159
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• 2009

A CMOS frequency synthesizer for $5{\sim}6$ GHz UNII-band sub-harmonic direct-conversion receiver has been developed. For quadrature down-conversion with sub-harmonic mixing, octa-phase local oscillator (LO) signals are generated by an integer-N type phase-locked loop (PLL) frequency synthesizer. The complex timing issue of feedback divider of the PLL with large division ratio is solved by using multimodulus prescaler. Phase noise of the local oscillator signal is improved by employing the ring-type LC-tank oscillator and switching its tail current source. Implemented in a $0.18{\mu}m$ CMOS technology, the phase noise of the LO signal is lower than -80 dBc/Hz and -113 dBc/Hz at 100 kHz and 1MHz offset, respect-tively. The measured reference spur is lower than -70 dBc and the power consumption is 40 m W from a 1.8 V supply voltage.

• Journal of the Korean Mathematical Society
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• v.59 no.5
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• pp.945-962
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• 2022

For a positive integer ℓ, $\bar{A}_{\ell}(n)$ denotes the number of over-partitions of n into parts not divisible by ℓ. In this article, we find certain Ramanujan-type congruences for $\bar{A}_{r{\ell}}(n)$, when r ∈ {8, 9} and we deduce infinite families of congruences for them. Furthermore, we also obtain Ramanujan-type congruences for $\bar{A}_{13}(n)$ by using an algorithm developed by Radu and Sellers [15].

• The Journal of Korean Institute of Communications and Information Sciences
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• v.15 no.2
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• pp.166-175
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• 1990

The conventional FIR filters can be very expensive to implement due to the complexity of multibit multipliers. This paper presents an new type of multiplierless structure which is particularly suited to the hardware implementation of small, low cost, low power, high speed digital filters. The filter structures consisting of a transversal filter with tap coefficiented to the combination of two elements of the set {0, $\pm$$2^n$;n = integer} and cascaded with a integrator are proposed. Performance has been tested via simulation on a digital computer, and the results show that the response characteristics of presented filters are as equally good as those of conventional finitewordlength filters.

• Honam Mathematical Journal
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• v.41 no.2
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• pp.421-433
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• 2019

Let n denote an integer greater than 2 and let c denote a nonzero complex number. In this paper, we introduce a family of elements of the rational Cherednik algebra $H^{sl_n}(c)$ of type $sl_n$, which are analogous to the Dunkl-Cherednik elements of the rational Cherednik algebra $H^{gl_n}(c)$ of type $gl_n$. We also introduce the raising and lowering element of $H^{sl_n}(c)$ which are useful in the representation theory of the algebra $H^{sl_n}(c)$, and provide simple results related to these elements.

• Kyungpook Mathematical Journal
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• v.54 no.3
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• pp.401-411
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• 2014

In this paper, we prove the generalized Hyers-Ulam stability of the following Jensen type functional equation $$f(\frac{x-y}{n}+z)+f(\frac{y-z}{n}+x)+f(\frac{z-x}{n}+y)=f(x)+f(y)+f(z)$$ in p-Banach spaces for any fixed nonzero integer n.

• Journal of the Korean Mathematical Society
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• v.45 no.5
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• pp.1483-1503
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• 2008

Let f : M ${\rightarrow}$ M be a self-map on the Klein bottle M. We compute the Lefschetz number and the Nielsen number of f by using the infra-nilmanifold structure of the Klein bottle and the averaging formulas for the Lefschetz numbers and the Nielsen numbers of maps on infra-nilmanifolds. For each positive integer n, we provide an explicit algorithm for a complete computation of the Nielsen type numbers $NP_n(f)$ and $N{\Phi}_{n}(f)\;of\;f^{n}$.

• Bulletin of the Korean Mathematical Society
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• v.45 no.3
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• pp.509-522
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• 2008

The main aim of this paper is to present some results related to asymptotic behavior of distribution functions of random variables of chi-square type $X^2_N={\Sigma}^N_{i=1}\;X^2_i$ with degrees of freedom N, where N is a positive integer-valued random variable independent on all standard normally distributed random variables $X_i$. Two ways for computing the distribution functions of chi-square type random variables with random degrees of freedom are considered. Moreover, some tables concerning considered distribution functions are demonstrated in Appendix.

• Bulletin of the Korean Mathematical Society
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• v.58 no.4
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• pp.983-1002
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• 2021

We investigate the non-existence of finite order transcendental entire solutions of Fermat-type differential-difference equations [f(z)f'(z)]ⁿ + P²(z)f^m(z + 𝜂) = Q(z) and [f(z)f'(z)]ⁿ + P(z)[∆_𝜂f(z)]^m = Q(z), where P(z) and Q(z) are non-zero polynomials, m and n are positive integers, and 𝜂 ∈ ℂ \ {0}. In addition, we discuss transcendental entire solutions of finite order of the following Fermat-type differential-difference equation P²(z) [f^(k)(z)]² + [αf(z + 𝜂) - 𝛽f(z)]² = e^r(z), where $P(z){\not\equiv}0$ is a polynomial, r(z) is a non-constant polynomial, α ≠ 0 and 𝛽 are constants, k is a positive integer, and 𝜂 ∈ ℂ \ {0}. Our results generalize some previous results.