• 호남수학학술지
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• 제45권3호
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• pp.397-409
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• 2023

Let R be an associative ring with identity and M be a left R-module. In this paper, we define modules that have the property (δ-CE) ((δ-CEE)), these are modules that have a δ-supplement (ample δ-supplements) in every cofinite extension which are generalized version of modules that have the properties (CE) and (CEE) introduced in [6] and so a generalization of Zöschinger's modules with the properties (E) and (EE) given in [23]. We investigate various properties of these modules along with examples. In particular we prove these: (1) a module M has the property (δ-CEE) if and only if every submodule of M has the property (δ-CE); (2) direct summands of a module that has the property (δ-CE) also have the property (δ-CE); (3) each factor module of a module that has the property (δ-CE) also has the property (δ-CE) under a special condition; (4) every module with composition series has the property (δ-CE); (5) over a δ-V -ring a module M has the property (δ-CE) if and only if M is cofinitely injective; (6) a ring R is δ-semiperfect if and only if every left R-module has the property (δ-CE).

• 호남수학학술지
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• 제45권1호
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• pp.146-159
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• 2023

In this paper, we define ⊕_δ-co-coatomically supplemented and co-coatomically δ-semiperfect modules as a strongly notion of ⊕-co-coatomically supplemented and co-coatomically semiperfect modules with the help of Zhou's radical. We say that a module A is ⊕_δ-co-coatomically supplemented if each co-coatomic submodule of A has a δ-supplement in A which is a direct summand of A. And a module A is co-coatomically δ-semiperfect if each coatomic factor module of A has a projective δ-cover. Also we define co-coatomically amply δ-supplemented modules and we examined the basic properties of these modules. Furthermore, we give a ring characterization for our modules. In particular, a ring R is δ-semiperfect if and only if each free R-module is co-coatomically δ-semiperfect.

• 한국치위생학회지
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• 제8권3호
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• pp.13-22
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• 2008

Objectives: The purpose of this study was to identify the correlation between calcium in soft drinks and enamel remineralization. Method: Six soft drinks were used in this study. These were calcium milk, normal milk, calcium yoghurt, normal yoghurt, calcium orange juice, and orange juice. Enamel specimens which 300- 400Vickers Hardness Number (VHN) were selected. These samples were immersed in each soft drink for 12 hours in an in vitro remineralization model. All specimens were processed for SEM image of the enamel surface. Results were analyzed by SPSS 13.0 package program. Results: Calcium milk was the most influential and normal yoghurt was the least to enamel surface. There was not significant difference according to calcium supplement in milk although the difference of enamel hardness was ${\Delta}f13.4$ in calcium milk, and ${\Delta}f4.7$ in normal milk (P>0.05). Other soft drinks showed a little change about calcium but they were insignificant. Demineralization effect was remarkably observed in calcium yoghurt ($-{\Delta}f269.1$) and this effect was confirmed by SEM images. In conclusion, calcium supplemented soft drinks had little influences to hardness of enamel surface.

• Journal of applied mathematics & informatics
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• 제28권5_6호
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• pp.1171-1184
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• 2010

In this paper, by using fixed point theorems in cones, the existence of positive solutions is considered for nonlinear m-point boundary value problem for the following second-order dynamic equations on time scales $({\phi}(u^{\Delta}))^{\nabla}+a(t)f(t,\;u(t))=0$, t $\in$ (0, T), $u(0)=\sum\limits^{m-2}_{i=1}a_iu(\xi_i)$, $\phi(u^{\Delta}(T))=\sum\limits^{m-2}_{i=1}b_i{\phi}(u^{\Delta}(\xi_i))$, where $\phi$ : R $\rightarrow$ R is an increasing homeomorphism and positive homomorphism and ${\phi}(0)=0$. In [27], we obtained the existence results of the above problem for an increasing homeomorphism and positive homomorphism with sign changing nonlinearity. The purpose of this paper is to supplement with a result in the case when the nonlinear term f is nonnegative, and the most point we must point out for readers is that there is only the p-Laplacian case for increasing homeomorphism and positive homomorphism due to the sign restriction. As an application, one example to demonstrate our results are given.

• 한국식품영양과학회지
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• 제23권1호
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• pp.7-12
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• 1994

철보충이 납종독된 흰쥐의 체내 무기질 함량과 DALAD activity 및 해독에 미치는 영향을 관찰하기 위해, 흰쥐에게 납 2,000ppm을 함유한 식수를 제한없이 주면서, 철분 100ppm, 500ppm을 보충한 식이로 5주동안 사육하여 얻을 결과는 다음과 같다. 체중증가량, 식이섭취량 및 식이효율은 납급여군이 대조군보다 낮게 나타났으며, 철보충납급여군은 납단독급여군보다 높은 것으로 나타났다. 간과 심장의 무게는 차이를 보이지 않았으나, 신장은 납급여군이 대조군보다 증가를 보였다. 비장은 납단독급여군에서만 증가를 보였고, 철보충납급여군에서는 대조군과 차이를 보이지 않았다. 헤마토크릿치는 철보충납급여군에서는 대조군과 차이를 보이지 않았으나, 납단독급여군은 유의적인 감소를 보였다. DALAD activity는 혈액과 간 모두 납급여군에서 대조군보다 유의적인 감소를 보였으나, 납단독급여군보다 철보충납급여군이 높게 나타났고, 철보충수준이 높을수록 높게 나타났다. 혈청과 간의 amino-transferase activity는 철보충납급여군에서는 대조군과 비슷한 경향을 보였으나 납단독급여군에서는 유의적인 증가를 보였다. 혈청 납함량은 납단독급여군과 철보충납급여군 사이에 차이를 보이지 않았으나, 간의 납함량은 철보충납급여군이 납단독급여군보다 높게 나타났다. 혈청 철함량은 납급여군이 대조군보다 감소했으나, 간의 철함량은 납급여군에서 높게 나타났으며, 철보충납급여군이 납단독급여군보다 증가를 보였다. 혈청과 간의 구리함량은 납단독급여군은 대조군과의 차이를 보이지 않았으나, 철보충납급여군은 감소를 보였다.

• 대한수학회지
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• 제52권3호
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• pp.637-647
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• 2015

For generalized continued fraction (GCF) with parameter ${\epsilon}(k)$, we consider the size of the set whose partial quotients increase rapidly, namely the set $$E_{\epsilon}({\alpha}):=\{x{\in}(0,1]:k_{n+1}(x){\geq}k_n(x)^{\alpha}\;for\;all\;n{\geq}1\}$$, where ${\alpha}$ > 1. We in [6] have obtained the Hausdorff dimension of $E_{\epsilon}({\alpha})$ when ${\epsilon}(k)$ is constant or ${\epsilon}(k){\sim}k^{\beta}$ for any ${\beta}{\geq}1$. As its supplement, now we show that: $$dim_H\;E_{\epsilon}({\alpha})=\{\frac{1}{\alpha},\;when\;-k^{\delta}{\leq}{\epsilon}(k){\leq}k\;with\;0{\leq}{\delta}<1;\\\;\frac{1}{{\alpha}+1},\;when\;-k-{\rho}<{\epsilon}(k){\leq}-k\;with\;0<{\rho}<1;\\\;\frac{1}{{\alpha}+2},\;when\;{\epsilon}(k)=-k-1+\frac{1}{k}$$. So the bigger the parameter function ${\epsilon}(k_n)$ is, the larger the size of $E_{\epsilon}({\alpha})$ becomes.

• 한국식품영양과학회지
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• 제33권10호
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• pp.1606-1610
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• 2004

본 실험은 자돈식이내 $\delta$-아미노레불린산의 첨가가 이유자돈의 성장능력 및 혈액성상에 미치는 영향을 조사하기 위하여 실시하였다. 사양시험은 3원 교잡종 자돈 75두(평균체중 7.21$\pm$0.02 kg)를 공시하였다. 시 험 설계는 1) NC(negative control; 무항생제 기초식이), 2) PC(positive control; NC diet+0.1% Apramycin+0.1% Oxytetracycline),3) ALA0.1 (NC diet+0.1% $\delta$-아미노레불린산), 4) ALA0.2(NC diet+0.2% $\delta$-아미노레불린산),5) ALA + AB (PC diet+0.2% $\delta$-아미노레불린산)의 5개 처리를 하였다. 총 사양시험기간동안, 일당증체 량은 ALA+AB 처리구가 NC 처리구와 비교하여 유의적으로 높게 평가되었으나(p<0.05), PC, ALA0.1 그리고 ALA0.2처리구와는 통계적인 차이는 보이지 않았다. 일당식 이섭취량과 식이효율에 있어서는 처리구간의 유의적 차이가 없었다. 시험 개시 후 20일령 에 측정한 영양소 소화율에 있어서는 건물과 질소 소화율에 있어서 ALA+AB처리구가 NC 처리구 및 ALA0.1 처리구와 비교하여 높게 평가되었다(p<0.05). 또한, 혈청내 total protein의 농도에 있어서는 ALA+AB처리구가 NC 처리구 및 PC 처리구와 비교하여 높게 평가되었다(p<0.05). 혈청내 iron의 농도는 $\delta$-아미노레불린산을 첨가한 처리구가 NC 및 PC 처리구에 비하여 유의적으로 높게 평가되었다(p<0.05). 혈청내 TIBC에 있어서는 ALA+AB 처리구가 NC, PC 그리고 ALA0.1 처리구와 비교하여 통계적으로 높게 평가되었다(p<0.05). 혈액내 Hb 및 HCT의 농도는 ALA0.2 처리구와 ALA+AB 처리구가 NC 처리구와 PC 처리구와 비교하여 유의적으로 높게 평가되었다(p<0.05). 혈액내 RBC와 WBC의 농도는 ALA0.2 처리구와 ALA +AB 처리구가 NC 처리구와 비교하여 유의적으로 높게 평가되었다(P<0.05). 혈액내 lymphocyte는 $\delta$-아미노레불린산 처리구가 NC 처리구와 비교하여 유의적으로 증가하였다(p<0,05). 결론적으로, 자돈식 이내 $\delta$-아미노레불린산의 첨가는 자돈의 성장 및 소화율을 향상시키며, 혈액 내 total protein, iron, hemoglobin, lymphocyte의 수준을 증가시켰다. 또한, $\delta$-아미노레불린산과 항생제의 혼합급여는 자돈의 성장 능력에 있어 상승효과를 갖는 것으로 사료된다.

• 대한수의학회지
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• 제24권1호
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• pp.24-30
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• 1984

The protective effects of high levels of dietary iron, copper, zinc or protein on lead toxicity were studied In chicks. Growth retardation, reduction of feed intake, anemia and accumulation of lead in the bone and kidney were observed in chicks fed a diet containing 500mg lead as chloride per kg of feed for 42 days. Early changes due to ingested lead were inhibition of red blood cell ${\delta}$-aminolevulinic acid dehydrase at all doses and no effect of iron, copper, zinc or protein addition were observed. Tibia lead accumulation was reduced in chicks receiving additional dietary iron or zinc compared to the lead only group but increased in chicks given supplementary protein. Decreased body weight gain was overcome by supplementary zinc or protein in chicks fed lead but not by supplementary iron. Overall the results of this study show that lead poisoning can be partly reduced by providing supplementary iron, zinc or protein, but the interaction of these element remained to be elucidated.

• 한국컴퓨터정보학회논문지
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• 제4권4호
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• pp.133-139
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• 1999

본 논문은 현재 사용되고 있는 케이블의 진단을 위해서 열화가중치라는 새로운 접근법을 사용하였다. 케이블은 상시에 높은 온도로 운전된다는 점, 수분이 접촉할 확률이 크다는 점에서 신뢰성 있고 효율적인 열화진단은 필수적이라고 할 수 있다. 종래의 연구는 수트리가 발생되는 절연층을 주 대상으로 삼았으나, 현대에 와서는 절연층뿐만 아니라, 내·외부 반도전층 또한 활발한 연구가 이루어지고 있다. 본 연구에서는 최근에 국내에서 제안된 열화가중치법을 이용하여 케이블의 열화인자가 될 수 있는 부분에 대하여 특성분석을 수행한 다음, 열화가중치를 부여하여 케이블의 최종적인 상태를 파악해 보았다.

• 호남수학학술지
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• 제42권3호
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• pp.511-520
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• 2020

A module M is called cofinitely closed weak δ-supplemented (briefly δ-ccws-module) if for any cofinite closed submodule N of M has a weak δ-supplement in M. In this paper we investigate the basic properties of δ-ccws modules. In the light of this study, we can list the main facts obtained as following: (1) Any cofinite closed direct summand of a δ-ccws module is also a δ-ccws module; (2) Let R be a left δ-V -ring. Then R is a δ-ccws module iff R is a ccws-module iff R is extending; (3) Any nonsingular homomorphic image of a δ-ccws-module is also a δ-ccws-module; (4) We characterize nonsingular δ-V -rings in which all nonsingular modules are δ-ccws.