• 대한수학회지
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• 제40권3호
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• pp.341-371
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• 2003

This article discusses in detail how the study of proper holomorphic rational mappings between balls in different dimensions relates to positivity conditions and to isometric imbedding of holomorphic bundles. The first chapter discusses rational proper mappings between balls; the second chapter discusses seven distinct positivity conditions for real-valued polynomials in several complex variables; the third chapter reveals how these issues relate to an isometric imbedding theorem for holomorphic vector bundles proved by the author and Catlin.

• 대한수학회지
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• 제54권6호
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• pp.1817-1828
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• 2017

We give a simple and direct proof of the characterization of positivity preserving semi-flows for ordinary differential systems. The same method provides an abstract result on a class of evolution systems containing reaction-diffusion systems in a bounded domain of ${\mathbb{R}}^n$ with either Neumann or Dirichlet homogeneous boundary conditions. The conditions are exactly the same with or without diffusion. A similar approach gives the optimal result for invariant rectangles in the case of Neumann conditions.

• 한국의류산업학회지
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• 제22권2호
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• pp.170-180
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• 2020

Body positivity has emerged among young social media users with the purpose of enhancing a positive body image. In the social media environment, body positivity is frequently presented in the forms of female models' images and/or words that represent individual attitudes toward the female body. The media effects on female viewers' body image differs based on the viewers' perceptions of their own body size. This experimental study examined how body positivity and types of expression on social media influence women's mood and appearance satisfaction by subjective body size. We randomly assigned to 415 young and middle-aged females to one of six experimental conditions which contained three images and three vignettes, each reflecting non-body positivity, body positivity, and control. We used a 3 (body positivity: non-body positivity vs body positivity vs. control) × 2 (types of body positivity expression on media: images vs vignettes) × 2 (subjective body size: under/normal weight vs overweight/obese) between-subject design. The results of MANCOVA revealed the significant main effects of subjective body size on women's mood and appearance satisfaction. There was a significant interaction effect of body positivity and subjective body size on appearance satisfaction. The stimuli representing body positivity caused positive psychological effects for women who perceive themselves being in the under/normal weight range.

• Journal of applied mathematics & informatics
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• 제23권1_2호
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• pp.243-256
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• 2007

This paper deals with determining the sufficient conditions of minimum for the class of problems in which the necessary conditions of optimum are satisfied in the strengthened form Legendre-Clebsch. To this paper, we shall use the sweep method which analysis the conditions of existence of the conjugated points on the optimal trajectory. The study we have done evaluates the command variation on the neighboring optimal trajectory. The sufficient conditions of minimum are obtained by imposing the positivity of the second variation. The results that this method offers are applied to the problem o the orbital rendez-vous for the linear case of the equations of movement.

• Korean Journal of Mathematics
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• 제16권3호
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• pp.425-437
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• 2008

Let P be a poset and G = G(P) be the incomparability graph of P. Stanley [7] defined the chromatic symmetric function $X_{G(P)}$ which generalizes the chromatic polynomial ${\chi}_G$ of G, and showed all coefficients are nonnegative in the e-expansion of $X_{G(P)}$ for a poset P of rank 1. In this paper, we construct a sign reversing involution on the set of special rim hook P-tableaux with some conditions. It gives a combinatorial proof for (3+1)-free conjecture of a poset P of rank 1.

• Kyungpook Mathematical Journal
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• 제47권1호
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• pp.31-56
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• 2007

In this paper, we consider a delay differential equation model of two competing species with harvesting of the mature and immature members of each species. The time delay in the model represents the time from birth to maturity of that species, which appears in the adults recruitment terms. We study the dynamics of our model analytically and we present results on positivity and boundedness of the solution, conditions for the existence and globally asymptotically stable of equilibria, a threshold of harvesting, and the optimal harvesting of the mature populations of each species.

• 한국산업융합학회 논문집
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• 제5권4호
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• pp.303-307
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• 2002

We consider the problem y"=a(x,y)(y-b), (0$$y(0)=0,\;y^{\prime}(1)=g(y({\xi}),\;y^{\prime}({\xi})),\;{\xi}$$ fixed in (0,1). This is a model of steady-state heat conduction in a rod when the heat flux at the end x=1 is determined by observation of the temperature and heat flux at some interior point ${\xi}$. We establish conditions sufficient for existence, uniqueness, and positivity of solutions.

• 대한한의학원전학회지
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• 제5권
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• pp.200-251
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• 1992

As concerned the life and the medical idea of Choo, Tan-Kye(朱丹溪), which it can be summarized as follows by studying. 1. Tan-Kye(丹溪) lived in the end of the won dynasty(元代末期), When the people starved and suffered from a flood-disaster and drought. etc, also the social conditions were in disorder on account of the corrupt ion of politics. And Cheol Kang seong(浙江省), located in the south region of China, has sterile soil and the climate condition humid and heatful. So the south district peoples have very weak constitution. So We can found that his medical idea reflected the phases of the periods and the regional enviornmental situations. 2. For that reason, Tan-Kye(丹溪) rejected the prescription of the "WHa Che Gook Bang(和劑局方)" which was prevalent at that time, in which the the pungent-dried herbs were widly used ; So he persisted in the "Sang Wha Lon(相火論)" and the "Positivity is usually excedeed while the negativity deficient(陽有餘陰不足論)". Then he treated with the drugs to nourish the negativity for the prime object to be applied in the clinic. 3. Tan-Kye(丹溪) refined the follows from the natural law; Heaven is to the positivity(陽) and the Earth is defined the negativity(陰), so the heaven is to the Macro(大) and the earth, micro(小):So the Sun is to the Positivity(陽), the Moon, the Negativity(陰): as to the Sun is always full while the moon always defected too. Therefore the "positivity is always excedeed for that the negativity is deficientalways(陽有餘陰不足)". In Human body, "the negativity energy (陰精) "is hard formed-easily defected(難成易虧)". And the heat(相火) in the body can be moved easily and let the negative energy to leak out. Therefore the more the positivity excedeed, the more the negativity deficient"(陽當有餘陰常不足). 4. He made it expanded the contents of the "Heat(相火)" in the Chapter Woon Chi of the Nae Kyeong(內徑) and discribed, the Life-string of the human body is originated from the movement of the "Heat with unique energy(相火一氣)". And more in human body, it is specifically regulated by the two visceras, Liver and Kidney, and is distributed in the 'Pericardium(心包絡)' 'Tripie Warmer(三焦)' 'Gallbladder(膽)' etc. In the point of his assertion of heat(相火), it is concluded both the physiological and the pathological heat of all. 5. Tan-Kye(丹溪) grew up in the family or the Confucianism. He was instructed the Confucianism(性理學) from Heo-Kyeom(許謙), the fourth diciple of Chu-Ja(朱子), and was received the Yoo Chang Ri(劉 張 李)'s triple doctrine from the La Tae Moo(羅太無), the second disciple of Yoo Wan So(劉完素). So there are much of content of Confucianism(性理學) in his medical thedry, and his theory has succeeded the achievements of the triple study. 6. About the theory of the "positivity is usually excedeed while the negativity deficient"(陽常有餘陰常不足論) of Tan-Kye, it was asserted that the positivity is never sufficient for the vital mainspring, by Chang, Kye-Pin(張介賓) and Lee, Kyoo-Zoon(李奎晙) etc. And for the Heat theory(相火論), eventhough the scholars of postorior generations criicized all of that, there are defect of the content and unification between them. 7. The father of the "Cha Eum Pa(滋陰派), Tan-Kye(丹溪) contributed considerably to the development of the oriental medicine and to the general therapy for the various diseases(一般雜病施治). 8. there are handed down and remained twenty or more of volumes of list of his writings. Among them, except "Kyeok Chi Yeo Ron"(格致餘論), "Kuk Pang Pal Hyeu"(局方發揮), they are reorganized by posteriority. There are Cho, Do-Chin(趙道震). Cho, Ee-Teok(趙以德), Tae, Sa-Gong(戴思恭), Wang Ri(王履) and Yoo, Suk-Yeon(劉淑淵) etc as disciples of his. And Wang Ryoon(王論) and Woo Pak(虞搏) as the admirer of him.

• Journal of applied mathematics & informatics
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• 제38권5_6호
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• pp.375-406
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• 2020

The anti-predator factor due to fear of predator in eco- epidemiological models has a great importance and cannot be evaded. The present paper consists of a modified Lesli-Gower predator-prey model with contagious disease in the predator population only and also consider the fear effect in the prey population. Boundedness and positivity have been studied to ensure the eco-epidemiological model is well-behaved. The existence and stability conditions of all possible equilibria of the model have been studied thoroughly. Considering the fear constant as bifurcating parameter, the conditions for the existence of limit cycle under which the system admits a Hopf bifurcation are investigated. The detailed study for direction of Hopf bifurcation have been derived with the use of both the normal form and the central manifold theory. We observe that the increasing fear constant, not only reduce the prey density, but also stabilize the system from unstable to stable focus by excluding the existence of periodic solutions.

• 한국환경복원기술학회지
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• 제14권5호
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• pp.103-112
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• 2011

Old big tree transcends the simple meaning of trees as they are the natural monuments that embody the people's history and culture of this land. The Cultural Heritage Administration of Korea(CHA) defines and protects old big tree based not only on the size of the tree but also on its definitive cultural and natural factors such as value, implications, and originality. This research aims to identify and analyze the growth conditions, soil conditions and location character of 20 old big tree in Gyeongsangnamdo korea. The research examined the soundness of the arboreal form, the degree of damage on the bark, as well as the quantity of leafs levels to evaluate the overall condition of growth and development. Also, 9 elements such as soil texture, nitrogen and organic matter content, soil pH, phosphoric acid and EC were further analyzed The research analyzed in correlation of Growth condition and soil. Tree health related positivity that total nitrogen and organic matter. The result which analyzes location character, With natural monument old big trees raising a hand the area where is contiguous appeared with the fact that the farming village style where the rice field and the arable land of field etc. This research aimed at generating some foundational reference data for the analysis of the habitation and management conditions of natural monument old big tree within the Gyeongsangnamdo korea.