• Korean journal of health promotion
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• 제19권2호
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• pp.91-95
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• 2019

연구배경: 비만과 폐 기능의 저하는 만성 질환 이환율과 사망률 증가와 관련 있는 것으로 알려져 있다. 하지만 국내에서 체중이나 체질량지수(BMI)의 변화가 폐 기능에 미치는 영향에 대한 연구는 없어 본 연구는 건강증진센터에서 연속적인 검진을 받은 한국인 수검자를 대상으로 체중이나 BMI 변화가 폐 기능 검사(PFT)의 인자들에 미치는 영향에 대해 알아보고자 한다. 방법: 2015년과 2017년에 일개 건강증진센터에서 건강검진을 연속적으로 받은 사람 중 신체계측과 PFT를 모두 시행한 5,032명을 대상으로 체중과 BMI의 변화와 PFT와 연관성을 상관분석 및 t-검정을 통하여 분석하였다. 결과: 체중과 BMI 변화에 따른 PFT 인자들과의 관련성에 있어서 남성에서는 유의미한 차이를 확인할 수 없었고 다만 체중이 증가한 그룹에서 FEV₁이 체중이 감소한 그룹에 비해 더 낮은 것으로 확인되었다. 여성에서는 체중과 BMI가 증가한 그룹에서 FEV₁/FVC와 FEF_25-75%가 체중이 감소한 그룹에 비해 더 낮았고, 체중과 BMI 변화에 따른 PFT 인자들과의 관련성에서 FEV₁/FVC와 FEF_25-75%가 음의 상관관계를 보여 비만도의 증가에 따라 FEV₁/FVC와 FEF_25-75%가 낮아지는 것과 관련이 있을 수 있음을 확인하였다. 결론: 본 연구에서는 비만도의 변화에 따라 PFT의 인자들의 변화가 있을 수 있음을 확인하였고 비만의 적절한 관리가 폐 기능에도 긍정적인 영향을 미칠 수 있을 가능성을 확인한 것에 의의가 있다. 향후 대규모 다기관 연구를 통해 지속적인 비만의 관리가 폐 기능 및 폐질환에 미치는 영향에 대한 연구가 필요할 것으로 생각된다.

• 한국기계기술학회지
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• 제13권4호
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• pp.131-136
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• 2011

In commercial vehicle, sub-frame which equipped in main frame supporting dump deck and oil tanker. This is the main structure for all equipment which including joint function. Sub-frame is made by welding process, this susceptible to deform and crack by its longitudinal size. Also various kind of sub-frame make it difficult to standardization in manufacturing process and exclusive jig is not adapted yet. Frame size is over 6~8m and weight is more than 300kg this make re-work more difficult. If manufacturing company made precise sub-frame, this is not only convenient for customers but also save the company money by reducing the working time. In this study manufacture the sub-frame be suitable for its main function and develop exclusive welding jig for obtain checking fixture function as well.

• Korean Journal of Mathematics
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• 제30권4호
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• pp.593-601
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• 2022

Let C(Q) denote Yeh-Wiener space, the space of all real-valued continuous functions x(s, t) on Q ≡ [0, S] × [0, T] with x(s, 0) = x(0, t) = 0 for every (s, t) ∈ Q. For each partition τ = τ_m,n = {(s_i, t_j)|i = 1, . . . , m, j = 1, . . . , n} of Q with 0 = s₀ < s₁ < . . . < s_m = S and 0 = t₀ < t₁ < . . . < t_n = T, define a random vector X_τ : C(Q) → ℝ^mn by X_τ (x) = (x(s₁, t₁), . . . , x(s_m, t_n)). In this paper we study the conditional integral transform and the conditional convolution product for a class of cylinder type functionals defined on K(Q) with a given conditioning function X_τ above, where K(Q)is the space of all complex valued continuous functions of two variables on Q which satify x(s, 0) = x(0, t) = 0 for every (s, t) ∈ Q. In particular we derive a useful equation which allows to calculate the conditional integral transform of the conditional convolution product without ever actually calculating convolution product or conditional convolution product.

• 대한수학회논문집
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• 제37권2호
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• pp.455-472
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• 2022

For j = 0, 1, 2,…, k - 1; k ≥ 2; and - 1 ≤ B < A ≤ 1, we have introduced the functions classes denoted by ST_[j,k](A, B) and K_[j,k](A, B), respectively, called the generalized (j, k)-symmetric starlike and convex functions. We first proved the sharp bounds on |f(z)| and |f'(z)|. Various radii related problems, such as radius of (j, k)-symmetric starlikeness, convexity, strongly starlikeness and parabolic starlikeness are determined. The quantity |a²₃ - a₅|, which provide the initial bound on Zalcman functional is obtained for the functions in the family ST_[j,k]. Furthermore, the sharp pre-Schwarzian norm is also established for the case when f is a member of K_[j,k](α) for all 0 ≤ α < 1.

• Korean Journal of Mathematics
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• 제31권2호
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• pp.229-242
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• 2023

In this paper, we investigate the [p, q] - φ order and [p, q] - φ type of f₁ + f₁, ${\frac{f_1}{f_2}}$ and f₁ f₁, where f₁ and f₁ are analytic or meromorphic functions with the same [p, q]-φ order and different [p, q]-φ type in the unit disc. Also, we study the [p, q]-φ order and [p, q]-φ type of different f and its derivative. At the end, we investigate the relationship between two different [p, q] - φ convergence exponents of f. We extend some earlier precedent well known results.

• Journal of applied mathematics & informatics
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• 제38권3_4호
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• pp.221-238
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• 2020

Let G = (V (G), E(G)) be a graph and let g : V (G) → S₃ be a function. For each edge xy assign the label r where r is the remainder when o(g(x)) is divided by o(g(y)) or o(g(y)) is divided by o(g(x)) according as o(g(x)) ≥ o(g(y)) or o(g(y)) ≥ o(g(x)). The function g is called a group S₃ cordial remainder labeling of G if |v_g(i)-v_g(j)| ≤ 1 and |e_g(1)-e_g(0)| ≤ 1, where v_g(j) denotes the number of vertices labeled with j and e_g(i) denotes the number of edges labeled with i (i = 0, 1). A graph G which admits a group S₃ cordial remainder labeling is called a group S₃ cordial remainder graph. In this paper, we prove that subdivision of graphs admit a group S₃ cordial remainder labeling.

• 대한수학회논문집
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• 제38권2호
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• pp.461-468
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• 2023

This paper attempts to investigate a new subfamily 𝓢𝓣_𝜗,𝜎 (𝛼, 𝛽, 𝛾, 𝜇) of spirallike functions endowed with Mittag-Leffler and Wright functions. The paper further investigates sharp coefficient bounds for functions that belong to this class.

• 대한수학회논문집
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• 제35권1호
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• pp.201-215
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• 2020

In this paper, a boundary version of Carathéodory's inequality on the right half plane for p-valent is investigated. Let Z(s) = 1+c_p (s - 1)^p +c_p+1 (s - 1)^p+1 +⋯ be an analytic function in the right half plane with ℜZ(s) ≤ A (A > 1) for ℜs ≥ 0. We derive inequalities for the modulus of Z(s) function, |Z'(0)|, by assuming the Z(s) function is also analytic at the boundary point s = 0 on the imaginary axis and finally, the sharpness of these inequalities is proved.

• 대한수학회보
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• 제46권4호
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• pp.673-689
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• 2009

We analyze $MAP_1,\;MAP_2$/G/1 finite queues with service scheduling function dependent upon queue lengths. The customers are classified into two types. The arrivals of customers are assumed to be the Markovian Arrival Processes (MAPs). The service order of customers in each buffer is determined by a service scheduling function dependent upon queue lengths. Methods of embedded Markov chain and supplementary variable give us information for queue length of two buffers. Finally, the performance measures such as loss probability and mean waiting time are derived. Some numerical examples also are given with applications in telecommunication networks.

• Kyungpook Mathematical Journal
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• 제60권3호
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• pp.507-518
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• 2020

We consider a boundary version of the Schwarz Lemma on a certain class of functions which is denoted by 𝒩. For the function f(z) = z + a₂z² + a₃z³ + … which is defined in the unit disc D such that the function f(z) belongs to the class 𝒩, we estimate from below the modulus of the angular derivative of the function ${\frac{f{^{\prime}^{\prime}}(z)}{f(z)}}$ at the boundary point c with f'(c) = 0. The sharpness of these inequalities is also proved.