• 대한수학회논문집
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• 제14권1호
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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).

• 충청수학회지
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• 제22권4호
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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.

• 호남수학학술지
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• 제29권2호
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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).

• 대한수학회논문집
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• 제19권3호
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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).

• 충청수학회지
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• 제33권1호
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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.

• 대한음성학회지:말소리
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• 제61호
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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.

• 대한수학회보
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• 제53권2호
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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)$$.

• 대한수학회보
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• 제60권1호
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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.

• 대한한의학회지
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• 제16권1호통권29호
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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.

• 한국식품조리과학회지
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• 제19권5호
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• pp.609-615
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• 2003

배추김치 제조 과정에서 절임염수를 재활용하기위해 5회 반복 사용 폐절임수(F), 5회 사용한 염수를 가는 모래로 처리한 1차 처리수(F1) 및 1차 처리수를 활성탄으로 여과한 2차 처리수(F2)를 절임염수로 김치를 제조하여 김치 숙성 중의 특성을 조사하였다. 염도와 가용성고형물의 김치 숙성 중 변화 양상은 시료사이에 큰 차이는 없었지만 5회 사용염수김치(F)의 염도와 가용성고형물이 다른 시료나 대조군에 비해 약간 높았다. 김치 숙성 동안의 pH와 적정산도는 대조군과 F1김치는 비슷한 pH와 산도 변화를 보였고, F김치는 가장 빠르게 숙성되는 변화를 나타낸 반면 F2는 가장 느린 숙성속도를 나타내었다. 총균수는 F시료가 가장 높았고, F2시료가 가장 낮았으며, 젖산균수는 F시료에서 가장 낮은 수를 나타내었고 대조군과 F1시료는 비슷하였다. 숙성적기의 관능평가 결과 외관, 냄새(신냄새, 부패냄새), 맛(신맛, 전체적 맛)과 질감(질긴정도, 아삭함)에서 F시료에 대하여 가장 바람직하지 않은 점수를 나타내었고, F1과 대조군은 유사한 점수를 받았으며 F2는 가장 신냄새와 신맛이 약하고 질긴정도가 높은 김치로 평가되었다. 김치의 특성과 관능평가 결과 반복 사용한 폐염수는 재사용할 경우 김치 품질이 나빠질 것으로 판단되는 반면 가는 모래나 활성탄으로 여과처리한 후 절임염수로 재활용하는 경우는 대조군 김치와 품질에 유의한 차이가 없는 것으로 나타나 절임염수로서의 재활용 가능성을 보여주었다.