• 대한수학회지
• /
• 제28권1호
• /
• pp.79-86
• /
• 1991

• 대한수학회논문집
• /
• 제37권4호
• /
• pp.1131-1146
• /
• 2022

In this paper we present another characterization of the norming set of T ∈ 𝓛(²𝒍²_∞) in terms of Norm(T) ∩ Ω whose proofs are more systematic than those of Kim [6], where Ω = {((1, 1), (1, 1)), ((1, 1), (1, -1)), ((1, -1), (1, 1)), ((1, -1), (1, -1))}.

• 충청수학회지
• /
• 제34권4호
• /
• pp.369-378
• /
• 2021

In this paper, we give an upper bound for the fundamental tone of stable constant mean curvature hypersurfaces in hyperbolic space. Let M be an n-dimensional complete non-compact constant mean curvature hypersurface with finite L²-norm of the traceless second fundamental form. If M is weakly stable, then λ₁(M) is bounded above by n² + O(n^2+s) for arbitrary s > 0.

• 충청수학회지
• /
• 제4권1호
• /
• pp.61-69
• /
• 1991

By $C^{(1)}$[0, 1] we denote the Banach algebra of complex valued continuously differentiable functions on [0, 1] with norm given by $${\parallel}f{\parallel}=\sup_{x{\in}[0,1]}({\mid}f(x){\mid}+{\mid}f^{\prime}(x){\mid})\text{ for }f{\in}C^{(1)}$$. By A we denote the sub algebra of $C^{(1)}$ defined by $$A=\{f{\in}C^{(1)}:f(0)=f(1)\text{ and }f^{\prime}(0)=f^{\prime}(1)\}$$. By an isometry of A we mean a norm-preserving linear map of A onto itself. The purpose of this article is to describe the isometries of A. More precisely, we show tht any isometry of A is induced by a point map of the interval [0, 1] onto itself.

• Nuclear Engineering and Technology
• /
• 제54권6호
• /
• pp.2230-2243
• /
• 2022

The tin tailing processing industry in Malaysia has operated with minimal regard and awareness for material management and working environment safety, impacting the environment and workers in aspects of radiation and heavy metal exposure. RIA was conducted where environmental samples were analyzed, revealing concentrations of ²²⁶Ra, ²³²Th and ⁴⁰K between the range of 0.1-10.0, 0.0-25.7, and 0.1-5.8 Bq/g respectively, resulting in the AED exceeding UNCEAR recommended value and regulation limit enforced by AELB (1 mSv/y). Ra_eq calculated indicates that samples collected pose a significant threat to human health from gamma-ray exposure. Assessment of heavy metal content via pollution indices of soil and sediment showed significant contamination and enrichment from processing activities conducted. As and Fe were two of the highest metals exposed both via soil ingestion with an average of 4.6 × 10^-3 mg/kg-day and 1.4 × 10^-4 mg/kg-day, and dermal contact with an average of 5.6 × 10^-4 mg/kg-day and 6.0 × 10^-4. mg/kg-day respectively. Exposure via accidental ingestion of soil and sediment could potentially cause adverse non-carcinogenic and carcinogenic health effect towards workers in the industry. Correlation analysis indicates the presence of a relationship between the concentration of NORM and trace elements.

• Nonlinear Functional Analysis and Applications
• /
• 제26권2호
• /
• pp.331-345
• /
• 2021

Let p(z)be a polynomial of degree n. Then Bernstein's inequality [12,18] is $${\max\limits_{{\mid}z{\mid}=1}}\;{\mid}p^{\prime}(z){\mid}\;{\leq}\;n\;{\max_{{\mid}z{\mid}=1}{\mid}(z){\mid}}$$. For q > 0, we denote $${\parallel}p{\parallel}_q=\{{\frac{1}{2{\pi}}}{\normalsize\displaystyle\smashmargin{2}{\int\nolimits_{0}}^{2{\pi}}}\;{\mid}p(e^{i{\theta}}){\mid}^qd{\theta}\}^{\frac{1}{q}}$$, and a well-known fact from analysis [17] gives $${{\lim_{q{\rightarrow}{{\infty}}}}\{{\frac{1}{2{\pi}}}{\normalsize\displaystyle\smashmargin{2}{\int\nolimits_{0}}^{2{\pi}}}\;{\mid}p(e^{i{\theta}}){\mid}^qd{\theta}\}^{\frac{1}{q}}={\max\limits_{{\mid}z{\mid}=1}}\;{\mid}p(z){\mid}$$. Above Bernstein's inequality was extended by Zygmund [19] into L^q norm by proving ║p'║_q ≤ n║p║_q, q ≥ 1. Let p(z) = a₀ + ∑ⁿ_𝜈=𝜇 a_𝜈z^𝜈, 1 ≤ 𝜇 ≤ n, be a polynomial of degree n having no zero in |z| < k, k ≥ 1. Then for 0 < r ≤ R ≤ k, Aziz and Zargar [4] proved $${\max\limits_{{\mid}z{\mid}=R}}\;{\mid}p^{\prime}(z){\mid}\;{\leq}\;{\frac{nR^{{\mu}-1}(R^{\mu}+k^{\mu})^{{\frac{n}{\mu}}-1}}{(r^{\mu}+k^{\mu})^{\frac{n}{\mu}}}\;{\max\limits_{{\mid}z{\mid}=r}}\;{\mid}p(z){\mid}}$$. In this paper, we obtain the L^q version of the above inequality for q > 0. Further, we extend a result of Aziz and Shah [3] into L^q analogue for q > 0. Our results not only extend some known polynomial inequalities, but also reduce to some interesting results as particular cases.

• Kyungpook Mathematical Journal
• /
• 제60권3호
• /
• pp.485-505
• /
• 2020

We present a complete description of all the extreme points of the unit ball of 𝓛_s(²𝑙³_∞) which leads to a complete formula for ║f║ for every f ∈ 𝓛_s(²𝑙³_∞)^∗. We also show that $extB_{{\mathcal{L}}_s(^2l^3_{\infty})}{\subset}extB_{{\mathcal{L}}_s(^2l^n_{\infty})}$ for every n ≥ 4. Using the formula for ║f║ for every f ∈ 𝓛_s(²𝑙³_∞)^∗, we show that every extreme point of the unit ball of 𝓛_s(²𝑙³_∞) is exposed. We also characterize all the smooth points of the unit ball of 𝓛_s(²𝑙³_∞).

• 대한간호학회지
• /
• 제53권2호
• /
• pp.222-235
• /
• 2023

Purpose: The aim of this study was to identify the factors explaining protective behaviors against radiation exposure in perioperative nurses based on the theory of planned behavior. Methods: This was a cross-sectional study. A total of 229 perioperative nurses participated between October 3 and October 20, 2021. Data were analyzed using SPSS/WIN 23.0 and AMOS 23.0 software. The three exogenous variables (attitude toward radiation protective behaviors, subjective norm, and perceived behavioral control) and two endogenous variables (radiation protective intention and radiation protective behaviors) were surveyed. Results: The hypothetical model fit the data (χ²/df = 1.18, SRMR = .02, TLI = .98, CFI = .99, RMSEA = .03). Radiation protective intention (β = .24, p = .001) and attitude toward radiation protective behaviors (β = .32, p = .002) had direct effects on radiation protective behaviors. Subjective norm (β = .43, p = .002) and perceived behavior control (β = .24, p = .003) had direct effects on radiation protective intention, which explained 38.0% of the variance. Subjective norm (β = .10, p = .001) and perceived behavior control (β = .06, p = .002) had indirect effects via radiation protective intention on radiation protective behaviors. Attitude toward radiation protective behaviors, subjective norm, and perceived behavioral control were the significant factors explaining 49.0% of the variance in radiation protective behaviors. Conclusion: This study shows that the theory of planned behavior can be used to effectively predict radiation protective behaviors in perioperative nurses. Radiation safety guidelines or education programs to enhance perioperative nurses' protective behaviors should focus on radiation protective intention, attitude toward radiation protective behaviors, subjective norm, and perceived behavioral control.

• 대한수학회논문집
• /
• 제21권4호
• /
• pp.719-727
• /
• 2006

In this paper, we study the boundedness and the com-pactness of weighted composition operator between $H^{\infty}$ and Bergman type space on the unit ball of $\mathbb{C}^n$. Also, the norm of corresponding weighted composition operator is computed.

• East Asian mathematical journal
• /
• 제35권3호
• /
• pp.297-303
• /
• 2019

In this paper, the author introduces the class $L^p$-BV of functions which are of bounded variation in the sense of $L^p$-norm and investigates the degree of convergence for Fourier series of functions belonging to this class.