• Honam Mathematical Journal
• /
• v.45 no.3
• /
• pp.397-409
• /
• 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).

• Honam Mathematical Journal
• /
• v.45 no.1
• /
• pp.146-159
• /
• 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.

• Journal of Korean society of Dental Hygiene
• /
• v.8 no.3
• /
• pp.13-22
• /
• 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
• /
• v.28 no.5_6
• /
• pp.1171-1184
• /
• 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.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.23 no.1
• /
• pp.7-12
• /
• 1994

This study was designed to investigate the effects of dietary iron supplementationon ${\delta}-aminolevulinic$ acid dehydratase (DALAD) activity and liver damage of the lead(Pb)-administered rats. The iron (Fe) supplement levels were 100 ppm(Fe100) and 500ppm(Fe500) and the Pb-exposed rats were given 2, 000ppm-Pb in drinking water, while control rats were given neigher iron nor lead. Hematocrit was lower in the Pb, Fe100 -Pb, Fe500-Pb group than in the control, but was not affected by the Pb adminstration when the rats fed the Fe supplementation diet. DALAD activity were reduced by Pb added but, were higher in the Fe500-Pb group than in the Fe100 -Pb group. No significant difference was found in serum Pb content due to Pb administration and Fe supplementation. The liver Pb contentwas higher in the Fe supplementation group than in the Pb-group. Level of serum FE was lower in the Pb added groups than in the control group. Liver Fe contents were increased with Pb administration and higher in the Fe supplement groups than in the Pb-group. Levels of serum and liver copper was decreased with the Fe supplementation. Aminotransferase activity of serum and liver were increased in the Pb group.

• Journal of the Korean Mathematical Society
• /
• v.52 no.3
• /
• pp.637-647
• /
• 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.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.33 no.10
• /
• pp.1606-1610
• /
• 2004

This study was. conducted to investigate the effects of $\delta$-aminolevulinic acid supplementation on growth. performance, nutrient digestibility and hematological changes in weaned pigs. Seventy five Duroc${\times}$Yorkshire${\times}$ Landrace pigs (7.21$\pm$0.02 kg average BW) were used in a 20 d growth assay. Dietary treatments included 1) NC (negative control; basal diet), 2) PC (positive control; NC diet + 0.1% Apramycin + 0.1% Oxytetracycline), 3) ALA0.l (NC diet+0.l% $\delta$-aminolevulinic acid), 4) ALA0.2 (NC diet+0.2% $\delta$-aminolevulinic acid) and 5) ALA + AB (PC diet+0.2% $\delta$-aminolevulinic acid). In entire experimental period, ADG (Average Daily Gain) was greater in pigs fed ALA + AB diet than in pigs fed NC diet (p<0.05). However, there was no significant difference in ADG for pigs fed PC, ALA0.l or ALA0.2 diets. Also, ADFI (Average Daily Feed Intake) and G/F (Gain/Feed) were not affected by treatments. For 20 d, fecal digestibilities of DM (Dry Matter) and N (Nitrogen) were higher (p<0.05) for pigs fed ALA + AB diet than for pigs fed NC and ALA0.l diets. Total protein concentration of serum was increased in ALA + AB treatment compared to NC and PC treatments (p<0.05). In iron concentration of serum, pigs fed $\delta$-aminolevulinic acid supplementation diets were greater than for pigs fed NC and PC diets (p<0.05). TIBC (Total Iron Binding Capacity) concentration of serum was increased in ALA + AB treatment compared to NC, PC and ALA0.l treatments (p<0.05). Pigs fed ALA + AB and ALA0.2 diets were higher hemoglobin (Hb) and hematocrit (HCT) concentration of blood than pigs fed NC and PC diets (p<0.05). RBC and WEC concentrations of blood were significantly higher (p<0.05) for the pigs fed ALA0.2 and ALA + AB diets than for pigs fed NC diet. Lymphocyte concentration of blood was increased in $\delta$-aminolevulinic acid supplementation treatment compared to NC treatment (p<0.05). In conclusion, $\delta$-aminolevulinic acid supplementation for weanling pigs had improved growth performance and nutrient digestibilities and had increased total protein, iron, hemoglobin and lymphocyte concentration of blood. Also, feeding for dietary $\delta$-aminolevulinic acid and antibiotic mixture supplementation may have more higher effective growth performance in weanling pigs.

• Korean Journal of Veterinary Research
• /
• v.24 no.1
• /
• pp.24-30
• /
• 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.

• Journal of the Korea Society of Computer and Information
• /
• v.4 no.4
• /
• pp.133-139
• /
• 1999

Degradation diagnosis of XLPE insulated URD cables was accomplished through out new method, which was to be analyzed by non-electrical experiments and synthesized by degradation points. To supplement this method, It was also carried out using several electrical analyses. Tan$\delta$ had commonly a different tendency by means of temperature and frequency and also appeared higher at the outer part rather than inner part of insulator. PD-q increased generally in proportion to the applied voltage and showed regular patterns in relation to the thickness of insulator Breakdown voltages were measured and breakdown lifetimes were predicted appling for Weibull distribution function.

• Honam Mathematical Journal
• /
• v.42 no.3
• /
• pp.511-520
• /
• 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.