• 제목/요약/키워드: Z-M school

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ON THE EXISTENCE OF SOLUTIONS OF FERMAT-TYPE DIFFERENTIAL-DIFFERENCE EQUATIONS

  • Chen, Jun-Fan;Lin, Shu-Qing
    • 대한수학회보
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    • 제58권4호
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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)fm(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 = er(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.

REDUCING SUBSPACES OF A CLASS OF MULTIPLICATION OPERATORS

  • Liu, Bin;Shi, Yanyue
    • 대한수학회보
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    • 제54권4호
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    • pp.1443-1455
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    • 2017
  • Let $M_{z^N}(N{\in}{\mathbb{Z}}^d_+)$ be a bounded multiplication operator on a class of Hilbert spaces with orthogonal basis $\{z^n:n{\in}{\mathbb{Z}}^d_+\}$. In this paper, we prove that each reducing subspace of $M_{z^N}$ is the direct sum of some minimal reducing subspaces. For the case that d = 2, we find all the minimal reducing subspaces of $M_{z^N}$ ($N=(N_1,N_2)$, $N_1{\neq}N_2$) on weighted Bergman space $A^2_{\alpha}({\mathbb{B}}_2)$(${\alpha}$ > -1) and Hardy space $H^2({\mathbb{B}}_2)$, and characterize the structure of ${\mathcal{V}}^{\ast}(z^N)$, the commutant algebra of the von Neumann algebra generated by $M_{z^N}$.

EXISTENCE OF TRANSCENDENTAL MEROMORPHIC SOLUTIONS ON SOME TYPES OF NONLINEAR DIFFERENTIAL EQUATIONS

  • Hu, Peichu;Liu, Manli
    • 대한수학회보
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    • 제57권4호
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    • pp.991-1002
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    • 2020
  • We show that when n > m, the following delay differential equation fn(z)f'(z) + p(z)(f(z + c) - f(z))m = r(z)eq(z) of rational coefficients p, r doesn't admit any transcendental entire solutions f(z) of finite order. Furthermore, we study the conditions of α1, α2 that ensure existence of transcendental meromorphic solutions of the equation fn(z) + fn-2(z)f'(z) + Pd(z, f) = p1(z)eα1(z) + p2(z)eα2(z). These results have improved some known theorems obtained most recently by other authors.

FRACTIONAL INTEGRATION AND DIFFERENTIATION OF THE (p, q)-EXTENDED MODIFIED BESSEL FUNCTION OF THE SECOND KIND AND INTEGRAL TRANSFORMS

  • Purnima Chopra;Mamta Gupta;Kanak Modi
    • 대한수학회논문집
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    • 제38권3호
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    • pp.755-772
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    • 2023
  • Our aim is to establish certain image formulas of the (p, q)-extended modified Bessel function of the second kind Mν,p,q(z) by employing the Marichev-Saigo-Maeda fractional calculus (integral and differential) operators including their composition formulas and using certain integral transforms involving (p, q)-extended modified Bessel function of the second kind Mν,p,q(z). Corresponding assertions for the Saigo's, Riemann-Liouville (R-L) and Erdélyi-Kober (E-K) fractional integral and differential operators are deduced. All the results are represented in terms of the Hadamard product of the (p, q)-extended modified Bessel function of the second kind Mν,p,q(z) and Fox-Wright function rΨs(z).

A CLASS OF MULTIVALENT FUNCTIONS WITH NEGATIVE COEFFICIENTS DEFINED BY CONVOLUTION

  • Ali Rosihan M.;Khan M. Hussain;Ravichandran V.;Subramanian K.G.
    • 대한수학회보
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    • 제43권1호
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    • pp.179-188
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    • 2006
  • For a given p-valent analytic function g with positive coefficients in the open unit disk $\Delta$, we study a class of functions $f(z) = z^p - \sum\limits{_{n=m}}{^\infty} a_nz^n(a_n{\geq}0)$ satisfying $$\frac 1 {p}{\Re}\;(\frac {z(f*g)'(z)} {(f*g)(z)})\;>\;\alpha\;(0{\leq}\;\alpha\;<\;1;z{\in}{\Delta})$$ Coefficient inequalities, distortion and covering theorems, as well as closure theorems are determined. The results obtained extend several known results as special cases.

REDUCING SUBSPACES FOR TOEPLITZ OPERATORS ON THE POLYDISK

  • Shi, Yanyue;Lu, Yufeng
    • 대한수학회보
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    • 제50권2호
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    • pp.687-696
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    • 2013
  • In this note, we completely characterize the reducing subspaces of $T_{{z^N_1}{z^M_2}}$ on $A^2_{\alpha}(D^2)$ where ${\alpha}$ > -1 and N, M are positive integers with $N{\neq}M$, and show that the minimal reducing subspaces of $T_{{z^N_1}{z^M_2}}$ on the unweighted Bergman space and on the weighted Bergman space are different.

Extended SBM 공정을 이용하여 단일 실리콘 기판상에 제작된 새로운 z 축 가속도계 (A Novel z-axis Accelerometer Fabricated on a Single Silicon Substrate Using the Extended SBM Process)

  • 고형호;김종팔;박상준;곽동훈;송태용;조동일;허건수;박장현
    • 센서학회지
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    • 제13권2호
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    • pp.101-109
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    • 2004
  • This paper presents a novel z-axis accelerometer with perfectly aligned vertical combs fabricated using the extended sacrificial bulk micromachining (extended SBM) process. The z-axis accelerometer is fabricated using only one (111) SOI wafer and two photo masks without wafer bonding or CMP processes as used by other research efforts that involve vertical combs. In our process, there is no misalignment in lateral gap between the upper and lower comb electrodes, because all critical dimensions including lateral gaps are defined using only one mask. The fabricated accelerometer has the structure thickness of $30{\mu}m$, the vertical offset of $12{\mu}m$, and lateral gap between electrodes of $4{\mu}m$. Torsional springs and asymmetric proof mass produce a vertical displacement when an external z-axis acceleration is applied, and capacitance change due to the vertical displacement of the comb is detected by charge-to-voltage converter. The signal-to-noise ratio of the modulated and demodulated output signal is 80 dB and 76.5 dB, respectively. The noise equivalent input acceleration resolution of the modulated and demodulated output signal is calculated to be $500{\mu}g$ and $748{\mu}g$. The scale factor and linearity of the accelerometer are measured to be 1.1 mV/g and 1.18% FSO, respectively.

GOLDIE EXTENDING PROPERTY ON THE CLASS OF z-CLOSED SUBMODULES

  • Tercan, Adnan;Yasar, Ramazan;Yucel, Canan Celep
    • 대한수학회보
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    • 제59권2호
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    • pp.453-468
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    • 2022
  • In this article, we define a module M to be Gz-extending if and only if for each z-closed submodule X of M there exists a direct summand D of M such that X ∩ D is essential in both X and D. We investigate structural properties of Gz-extending modules and locate the implications between the other extending properties. We deal with decomposition theory as well as ring and module extensions for Gz-extending modules. We obtain that if a ring is right Gz-extending, then so is its essential overring. Also it is shown that the Gz-extending property is inherited by its rational hull. Furthermore it is provided some applications including matrix rings over a right Gz-extending ring.

Changes of the growth plate in children: 3-dimensional magnetic resonance imaging analysis

  • Yun, Hyung Ho;Kim, Hyun-Jung;Jeong, Min-Sun;Choi, Yun-Sun;Seo, Ji-Young
    • Clinical and Experimental Pediatrics
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    • 제61권7호
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    • pp.226-230
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    • 2018
  • Purpose: This pilot study assessed changes in the growth plate and growth rates in children during a 6-month period. Methods: The study included 31 healthy children (17 boys, 14 girls) under evaluation for growth retardation. Height, weight, bone age, insulin like growth factor-1 (IGF-1), and insulin like growth factor binding protein 3 (IGF-BP3) were measured at baseline and after 6 months. In addition, the diameter, thickness, and volume of the femoral and tibial growth plates were measured using magnetic resonance imaging. Results: The mean bone age in boys and girls was 11.7 and 10.7 years, respectively. In boys, height (z score) (-0.2 vs. 0.0), weight (z score) (0.8 vs. 1.1), body mass index (BMI) (z score) (1.27 vs. 1.5), IGF-1 (ng/mL) (343.6 vs. 501.8), and IGF-BP3 (ng/mL) (5,088.5 vs. 5,620.0) were significantly higher after 6 months. In girls, height (z score) (-1.0 vs. -0.7), weight (z score) (-0.5 vs. 0.1), BMI (z score) (-0.02 vs. 0.3), IGF-1 (ng/mL) (329.3 vs. 524.6), and IGF-BP3 (ng/mL) (4,644.4 vs. 5,593.6) were also significantly higher after 6 months. In both sexes, the mean diameter and volume of the femoral and tibial growth plates were significantly increased 6 months later. Conclusion: No significant correlation was found between changes in the growth plate and clinical parameters in children with growth retardation in this study, other than correlations of change in femoral diameter with weight and BMI. A larger, long-term study is needed to precisely evaluate the correlation between change in the growth plate and growth.