• Communications of the Korean Mathematical Society
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• v.14 no.1
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• pp.75-80
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• 1999

First, we shall improve the superstability result of the exponential equation f(x+y)=f(x) f(y) which was obtained in [4]. Furthermore, the superstability problems of the functional equation f(x\ulcorner+…+x\ulcorner)=f(x\ulcorner)…f(x\ulcorner) shall be investigated in the special settings (2) and (9).

• Journal of the Chungcheong Mathematical Society
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• v.22 no.4
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• pp.757-770
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• 2009

In this paper, we prove the generalized Hyers-Ulam stability of the following additive-quadratic-cubic-quartic functional equation (0.1) f(x + 2y) + f(x - 2y) = 4f(x + y) + 4f(x - y) - 6f(x) + f(2y) + f(-2y) - 4f(y) - 4f(-y) in Banach spaces.

• Honam Mathematical Journal
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• v.29 no.2
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• pp.193-204
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• 2007

In this paper, we investigate some results concerning the stability of the following quadratic type functional equation: f(x + y) + f(x - y) + f(y + z) + f(y - z) + f(z + x) + f(z - x) = 4f(x) + 4f(y) + 4f(z).

• Communications of the Korean Mathematical Society
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• v.19 no.3
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• pp.477-493
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• 2004

In this paper we prove the solution and stability of the quadratic type functional equations with two variables $4f(\frac{x-2y}{2}) + f(x) + 2f(y)= 8f(\frac{x-y}{2})+ f(2y)$ and f(x-2y)+f(x)+sf(y)-2f(x-y)+f(2y).

• Journal of the Chungcheong Mathematical Society
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• v.33 no.1
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• pp.77-87
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• 2020

In this paper, we investigate the stability of a functional equation f(x + 3y) - 5f(x + 2y) + 10f(x + y) - 8f(x) + 5f(x - y) - f(x - 2y) - 2f(-x) - f(2x) + f(-2x) = 0 by using the fixed point theory in the sense of L. Cǎdariu and V. Radu.

• MALSORI
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• no.61
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• pp.15-29
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• 2007

The present study investigates acoustic cues of russian soft plosive consonants. In previous studies, russian soft consonants are distinguished from hard consonants by F1, F2 of following vowels. The result showed: (1) that F0 of soft plosive consonants in following vowels were lower than those of hard plosive consonants; (2) and that VOT of soft plosive consonants were longer than those of hard plosive consonants. Hence, the present that, in addition to F1, F2, VOT and F0 are detected as acoustic cues that differentiate soft plosive consonants from hard plosive consonant in Russian.

• Bulletin of the Korean Mathematical Society
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• v.53 no.2
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• pp.365-371
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• 2016

Let f be a transcendental meromorphic function in the complex plane $\mathbb{C}$, and a be a nonzero constant. We give a quantitative estimate of the characteristic function T(r, f) in terms of $N(r,1/(f^2(f^{\prime})^n-a))$, which states as following inequality, for positive integers $n{\geq}2$, $$T(r,f){\leq}\(3+{\frac{6}{n-1}}\)N\(r,{\frac{1}{af^2(f^{\prime})^n-1}}\)+S(r,f)$$.

• Bulletin of the Korean Mathematical Society
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• v.60 no.1
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• pp.75-81
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• 2023

If a multiplicative function f is commutable with a quadratic form x² + xy + y², i.e., f(x² + xy + y²) = f(x)² + f(x) f(y) + f(y)², then f is the identity function. In other hand, if f is commutable with a quadratic form x² - xy + y², then f is one of three kinds of functions: the identity function, the constant function, and an indicator function for ℕ ＼ pℕ with a prime p.

• The Journal of Korean Medicine
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• v.16 no.1 s.29
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• pp.209-226
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• 1995

In order to investigate the protective effects of Jiyusaenggan-Tang by F-I(Jiyusaenggan-Tang aspirated by distilled water), F-II(Non-polysaccharides in Jiyusaenggan-Tang) and F-III(Polysaccharides in Jiyusaenggan-Tang), experimental studies were performed in mice with liver injury induced by $CCI_4$, and d-galactosamine. The results were summarized as follows : 1. The increases of the serum GOT activities in mice induced by $CCI_4$ were inhibited significantly by the administration of highly concentrated FIII. The increases of the serum GPT, LDH, and ALP activities in mice induced by $CCI_4$ were inhibited significantly by the administration of highly concentrated FI and FIII. 2. The increases of the serum total-cholesterol and triglyceride activities in mice induced by $CCI_4$ were inhibited significantly by the administration of highly concentrated FI, FII and FIII. 3. On liver injury induced by the $CCI_4$, the activities of GOT, GPT, ALP, LDH were inhibited by highly concentrated FIII, F-I, F-II, and F-I, F-II, F-III on total cholesterol level and F-III, F-I, F-II on triglyceride level in order of their efficacies. And F-III is considered to be the most effective component. 4. The increases of the serum GOT, GPT activities in mice induced by d-galactosamine were inhibited significantly by the administration of FI and FIII. The increases of the serum LDH, ALP activities in mice induced by d-galactosamine were inhibited significantly by the administration of FI and FIII. 5. The increases of the serum Total-cholesterol, Triglyceride activities in mice induced by d-galactosamine were inhibited significantly by the administration of FI, FII and FIII. 6. The increases of the serum GOT, GPT activities in mice induced by d-galactosamine were inhibited significantly in F-III administrated group and then F-I in order of efficacies. FII does not showed significant effect, on inhibiting the activities of serum GOT and GPT levels. The activity of ALP was inhibited by F-III, F-I, F-II, LDH by F-III, F-I in order of efficacies, and F-II did not showed significant effect on LDH activity. The triglyceride level was decreased significantly by F-III, F-II, F-I and the total cholesterol level by F-II, F-I, F-III in order of their efficacies. Judging from the above results, it is considered that Jiyusaenggan-Tang has protective effect against liver injury, and that Polysaccharides in Jiyusaenggan-Tang is more effective.

• Korean journal of food and cookery science
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• v.19 no.5
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• pp.609-615
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• 2003

In the Kimchi manufacturing industry, the process of brining baechu produces a vast amount of high salinity waste water. To study if this brine can be recycled, the quality characteristics of Kimchi salted by waste brine(F), which was used five times successively, was compared with those salted using water after recycling filtration through sand (F1) and activated carbon (F2) columns. No significant difference in the salinity and soluble solid contents, during fermentation at 10 was observed among the samples, but the salinity and soluble solid contents of the F-sample were slightly higher than in the control. The F1 and control Kimchi showed similar pHs and titratable acidities, while the F-Kimchi had a lower pH and a higher acidity during fermentation. The numbers of total viable cells were highest in the F, and lowest in the F2-Kimchi, while the counts of lactic acid bacteria were lowest in the F-Kimchi. The sensory tests for appearance, odor, taste and overall acceptance showed that the F-Kimchi was the least desirable, the F2-Kimchi had lower sour odor and taste, and a higher toughness, than the others. The F1- and control Kimchi had similar sensory grades for appearance, odor, and tastes, and there were no significant difference in the overall acceptance, showing the possibility of recycling wastewaters as brine for the production of baechu Kimchi.