• The Pure and Applied Mathematics
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• v.25 no.2
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• pp.161-170
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• 2018

In this paper, we introduce and solve the following additive (${\rho}_1,{\rho}_2$)-functional inequality (0.1) $${\parallel}f(x+y+z)-f(x)-f(y)-f(z){\parallel}{\leq}{\parallel}{\rho}_1(f(x+z)-f(x)-f(z)){\parallel}+{\parallel}{\rho}_2(f(y+z)-f(y)-f(z)){\parallel}$$, where ${\rho}_1$ and ${\rho}_2$ are fixed nonzero complex numbers with ${\mid}{\rho}_1{\mid}+{\mid}{\rho}_2{\mid}$ < 2. Using the fixed point method and the direct method, we prove the Hyers-Ulam stability of the additive (${\rho}_1,{\rho}_2$)-functional inequality (0.1) in complex Banach spaces.

• Journal for History of Mathematics
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• v.30 no.3
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• pp.185-199
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• 2017

In tropical geometry, the sum of two numbers is defined as the minimum, and the multiplication as the sum. As a way to build tropical plane curves, we could use Newton polygons or amoebas. We study one method to convert the representation of an algebraic variety from an image of a rational map to the zero set of some multivariate polynomials. Mikhalkin proved that complex curves can be replaced by tropical curves, and induced a combination formula which counts the number of tropical curves in complex projective plane. In this paper, we present close examinations of this particular combination formula.

• Kyungpook Mathematical Journal
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• v.56 no.3
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• pp.819-829
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• 2016

In this paper, we study the order of growth of solutions to the non-homogeneous linear differential equation $$f^{(k)}+A_{k-1}e^{az}f^{(k-1)}+{\cdots}+A_1e^{az}f^{\prime}+A_0e^{az}f=F_1e^{az}+F_2e^{bz}$$, where $A_j(z)$ (${\not\equiv}0$) ($j=0,1,{\cdots},k-1$), $F_j(z)$ (${\not\equiv}0$) (j = 1, 2) are entire functions and a, b are complex numbers such that $ab(a-b){\neq}0$.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.1
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• pp.184-192
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• 1994

The parameters such as Richardson numbers or stability parameters are widely used to account for the extra straining effects due to three-dimensionality, curvature, rotation, swirl and others arising in paractical complex flows. Existing expressions for the extra strain in turbulence models such as $k-{\epsilon}$ models, however, do not satisfy the tensor invariant condition representing the coordinate indifference. In the present paper, considering the characteristics of both the mean strain rate and the mean vorticity, a new parameter to deal with the extra straining effects is proposed. The new parameter has a simple form and satisfies the tensor invariant condition. A semi-quantitative analysis between the present and previous parameters for several typical complex flows suggests that the newly proposed parameter is more general and adequate in representing the extra straining effects than the previous ad-hoc parameters.

• Structural Engineering and Mechanics
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• v.55 no.4
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• pp.885-900
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• 2015

This paper introduces Romberg-Richardson's method as one of the numerical integration tools for computation of stress intensity factor in a pre-cracked specimen subjected to a complex stress field across the crack faces. Also, the computation of stress intensity factor for various stress fields using existing three methods: average stress over interval method, piecewise linear stress method, piecewise quadratic method are modified by using Richardson extrapolation method. The direct integration method is used as reference for constant and linear stress distribution across the crack faces while Gauss-Chebyshev method is used as reference for nonlinear distribution of stress across the crack faces in order to obtain the stress intensity factor. It is found that modified methods (average stress over intervals-Richardson method, piecewise linear stress-Richardson method, piecewise quadratic-Richardson method) yield more accurate results after a few numbers of iterations than those obtained using these methods in their original form. Romberg-Richardson's method is proven to be more efficient and accurate than Gauss-Chebyshev method for complex stress field.

• The Pure and Applied Mathematics
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• v.24 no.1
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• pp.21-31
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• 2017

In this paper, we introduce and solve the following additive (${\rho}_1$, ${\rho}_2$)-functional inequality $${\Large{\parallel}}2f(\frac{x+y}{2})-f(x)-f(y){\Large{\parallel}}{\leq}{\parallel}{\rho}_1(f(x+y)+f(x-y)-2f(x)){\parallel}+{\parallel}{\rho}_2(f(x+y)-f(x)-f(y)){\parallel}$$ where ${\rho}_1$ and ${\rho}_2$ are fixed nonzero complex numbers with $\sqrt{2}{\mid}{\rho}_1{\mid}+{\mid}{\rho}_2{\mid}<1$. Using the fixed point method and the direct method, we prove the Hyers-Ulam stability of the additive (${\rho}_1$, ${\rho}_2$)-functional inequality (1) in complex Banach spaces.

• Nuclear Engineering and Technology
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• v.53 no.3
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• pp.879-887
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• 2021

The nuclear supply chain attack surface is a large, complex network of interconnected stakeholders and activities. The global economy has widened and deepened the supply chain, resulting in larger numbers of geographically dispersed locations and increased difficulty ensuring the authenticity and security of critical digital assets. Although the nuclear industry has made significant strides in securing facilities from cyber-attacks, the supply chain remains vulnerable. This paper discusses supply chain threats and vulnerabilities that are often overlooked in nuclear cyber supply chain risk analysis. A novel supply chain cyber-attack surface diagram is provided to assist with enumeration of risks and to examine the complex issues surrounding the requirements for securing hardware, firmware, software, and system information throughout the entire supply chain lifecycle. This supply chain cyber-attack surface diagram provides a dashboard that security practitioners and researchers can use to identify gaps in current cyber supply chain practices and develop new risk-informed, cyber supply chain tools and processes.

• Journal of the Korean Institute of Landscape Architecture
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• v.28 no.1
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• pp.109-117
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• 2000

The purpose of this study is to examine the effect factors in suburban rural landscape and significant factors of apartment complex which are effective to the skyline of the sloped mountains. Also it is to propose the basic resources to preserve and improve the suburban rural landscape. The target site is Young-In, which shows the typical of rural development. Sides were take in young-In City along the roads and selected for 20 pieces. This study used questionnaire about the suburban rural landscape surveying of 45 students in Kyunghee Univ.. Also we found 2 dependent variables and 8 independent variables totally. Moreover, we have analyzed the data using descriptive statistics, correlation analysis, and multiple linear regression method between the preference and physical factors, and between the vulnerability and perceptional factors. The results are as follows: 1) With the dependent variable of preference, the areas of "green space" and "agricultural productive lands" were highly influenced in the suburban rural landscape positively, but the areas of "apartment complex" and "other buildings" were negatively effected. 2) With the dependent variable vulnerability, the area "apartment complex" and cutting numbers of the "skyline of mountainous ridge" were proved as significantly positive factors, but the length of the "skyline of mountainous ridge" turned out to be a negative factor. Although this study has the difficulty to be generalized, it can be used for planning and designing of the apartment complex in suburban rural landscapes, and it will provide the basic guideline for preserving and managing of the suburban rural landscapes.uideline for preserving and managing of the suburban rural landscapes.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.484-489
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• 2004

Objective : In order to study the effects of Herba ChelidoniiㆍClematis Florida ThunbㆍChaenomelis Fructus complex herbal acupuncture on anti-inflammation and liver in rats with arthritis induced Freund's complete adjuvant. Method : We performed several experimental items : that is edema value, numbers of WBC. total protein, total bilirrubin, SGOT, SGPT. Result: The change in the right plantar edema shows that Control group was reduced by 0% but, ST group ,Sample A group and Sample B group were reduced by 287.2%, 343.0%, 272.5% respectively. In the WBC count, ST group, Sample A group, Sample B group showed a decrease with statistical significance as compared with control group. In the total protein, Sample B group showed a decrease with statistical significance as compared with control group. In the total bilirrubin, SGOT, SGPT, None showed noxious variation with statistical significance as compared with control group. Conclusion : As a result of this experiment, it is concluded that Herba ChelidoniiㆍClematis Florida ThunbㆍChaenomelis Fructus complex herbal acupuncture showed that therapeutic effect of anti-inflammation in adjuvant arthritis and non-toxic effect of liver.

• Architectural research
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• v.15 no.1
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• pp.9-15
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• 2013

Effects of physical attributes of workstation enclosures on the performance of office workers with different difficult levels of office tasks and moods are presented. Performance scores in complex tasks were expected to increase with greater workstation enclosures while those in simple tasks would be the same. Mood ratings were expected to be higher in lower workstation enclosures. Performance of 102 college students on ambient office sounds (45 dBA) with office tasks were measured for 100 minutes under three different workplace enclosures: (1) four foot partitions on two sides; (2) six foot partitions on three sides; and (3) a fully enclosed workstation with eight foot partitions. The tasks were to memorize a paragraph with 130 words (complex task) and to search phone numbers (simple task). The complex task performance in the fully enclosed workstation was increased compared to that in the workstation with four foot partitions (p < 0.001) and to that in the workstation with six foot partitions (p < 0.05). However, occupants in the fully enclosed workstation with office sounds without speech generally gave higher mood ratings. It indicates that closed individual offices may offer important contributions to collaborative work as well as individual productivity. These findings would help design community revise open plan design to increase collaboration among office workers.