• Journal of applied mathematics & informatics
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• v.24 no.1_2
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• pp.357-366
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• 2007

Let G(V, E) be a simple graph, and let f be an integer function on V with $1{\leq}f(v){\leq}d(v)$ to each vertex $v{\in}V$. An f-edge cover-coloring of a graph G is a coloring of edge set E such that each color appears at each vertex $v{\in}V$ at least f(v) times. The f-edge cover chromatic index of G, denoted by ${\chi}'_{fc}(G)$, is the maximum number of colors such that an f-edge cover-coloring of G exists. Any simple graph G has an f-edge cover chromatic index equal to ${\delta}_f\;or\;{\delta}_f-1,\;where\;{\delta}_f{=}^{min}_{v{\in}V}\{\lfloor\frac{d(v)}{f(v)}\rfloor\}$. Let G be a connected and not complete graph with ${\chi}'_{fc}(G)={\delta}_f-1$, if for each $u,\;v{\in}V\;and\;e=uv{\nin}E$, we have ${\chi}'_{fc}(G+e)>{\chi}'_{fc}(G)$, then G is called an f-edge covered critical graph. In this paper, some properties on f-edge covered critical graph are discussed. It is proved that if G is an f-edge covered critical graph, then for each $u,\;v{\in}V\;and\;e=uv{\nin}E$ there exists $w{\in}\{u,v\}\;with\;d(w)\leq{\delta}_f(f(w)+1)-2$ such that w is adjacent to at least $d(w)-{\delta}_f+1$ vertices which are all ${\delta}_f-vertex$ in G.

• Journal of Korean Society of Forest Science
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• v.99 no.3
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• pp.331-336
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• 2010

This study was carried out to investigate the dose-dependent effect of methyl jasmonate on both the adventitious root growth and the accumulation of various eleutherosides in the bioreactor culture of Eleutherococcus senticosus adventitious roots. The highest biomass production (5.4 g DW/L) was observed in the absence of methyl jasmonate and the root growth was significantly decreased by increasing the methyl jasmonate concentration. However, methyl jasmonate stimulated the production of both eleutheroside B, E and $E_1$. The highest level of eleutheroside B (359.9 ${\mu}g$/g DW) was obtained at 40 ${\mu}M$ of methyl jasmonate, while eleutheroside E and $E_1$ was accumulated at the highest level by the addition of 10 ${\mu}M$ of methyl jasmonate. Total eleutheroside was increased up to 3818.1 ${\mu}g$ per liter when 10 ${\mu}M$ of methyl jasmonate was applied. In addition, when the adventitious roots were cultured with 20 ${\mu}M$ of methyl jasmonate, the highest levels of eleutheroside B, E and $E_1$ were observed at the 12th, 3th and 9th days of culture, respectively.

• Journal of applied mathematics & informatics
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• v.38 no.3_4
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• pp.221-238
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• 2020

Let G = (V (G), E(G)) be a graph and let g : V (G) → S₃ be a function. For each edge xy assign the label r where r is the remainder when o(g(x)) is divided by o(g(y)) or o(g(y)) is divided by o(g(x)) according as o(g(x)) ≥ o(g(y)) or o(g(y)) ≥ o(g(x)). The function g is called a group S₃ cordial remainder labeling of G if |v_g(i)-v_g(j)| ≤ 1 and |e_g(1)-e_g(0)| ≤ 1, where v_g(j) denotes the number of vertices labeled with j and e_g(i) denotes the number of edges labeled with i (i = 0, 1). A graph G which admits a group S₃ cordial remainder labeling is called a group S₃ cordial remainder graph. In this paper, we prove that subdivision of graphs admit a group S₃ cordial remainder labeling.

• Honam Mathematical Journal
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• v.2 no.1
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• pp.37-44
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• 1980

우리는 먼저 Principal G-bundle와 성질을 살피고 representation of G over C를 irreducible CG-space의 direct sum으로 표시하여 Schur's Lemma를 이용하면 E가 임의의 CG-space, ${\sigma}E=Hom_c(E{\sigma},E)$라 할 때 ${\oplus}_{\sigma}(E_{\sigma}{\otimes}{\sigma}E){\rightarrow}E$ 가 G-ismorphism이 됨을 알아본다. 본 논문의 목적은 이러한 결과를 이용하여 K(X)와 $K_G(X)$의 관계를 구명하는데 있다.

• Journal of Microbiology and Biotechnology
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• v.11 no.2
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• pp.211-216
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• 2001

The growth of Selenastrum capricornutum in culture was investigated as a function of ionic copper concentrations to verify the toxicity and physiological variation. In a $Cu^{++}$ excess culture (E: $Cu^{++}$ of $130{\mu}g/l$), the growth rate (K)(0.32) was lower than that of the control culture (C: $Cu^{++}$ of $0.065{\mu}g/l$) (0.61) after 8 days and the exponential growth rate ($R_E$) was also found to be lower in culture E (1.1) than culture C (2.9). On the contrary, the K of S. capricornutum in trace $Cu^{++}$ culture ($T_1$ and $T_2$, 0.72) after 6 days tended to be more increased than culture C (0.68). From 8 to 14 days of culture, the amounts of chlorophyllls a and b were increased in culture C (chlorophyll a, $106->126{\mu}g/g$ dry wt; chlorophyll b, $158->208{\mu}g/g$ dry wt; chlorophyll b were decreased in culture E (chlorophyll a, $309->235{\mu}g/g$ dry wt; chlorophyll b, $405->352{\mu}g/g$ dry wt). The amounts of chlorophylls in ionic copper trace culture ($T_1$ and $T_2$) [(chl a/b) of $T_1$: $384/620\;{\mu}g/g$ dry wt; (chl a/b) of $T^2$:$320/467{\mu}g/g$ dry wt] were increased more than the culture C($260/387{\mu}g/g$ dry wt). Howeveer, when photosynthetic rates were normalized to the dry weight of algae, the control culture continued to showed higher values than the treated culture ($T_1$). An appropriate amount of ionic copper ($T_1:\;26\;{\mu}g/l$) stimulated the grwoth of S. capricornutum than the ionic copper content of $13\;{\mu}g/l$ ($T_2$), while the excess amount of ionic copper ($130\;{\mu}g/l$) resulted in the highest toxicity to the growth of S. capricornutum.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.296.1-296.1
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• 2002

Bisphenol A(BPA). a monomer used in the manufacturing epoxy resins and polycarbonates. has been reported to induce estrogenic activity, it has been considered as an environmental endocrine disruptor. But the immunomodulatory effects of BPA exposure have not been systemically evaluated. We investigated whether BPA effects on the ability of immunoglobulin(lg) production of mice. To initiate investigation of BPA-induced alterations of the immune system. BPA at dose of 100. 500,1000 mg/kg b.w./day with or without OVA-antigen for 30 days were orally administered to female ICR mice. Mice were sacrificed and serum was colleted on day 2 following administration of BPA for 30days. Total lgG1. total lgG2a. total lgE. OVA-specific lgG1. OVA-specific lgG2a. and OVA-specific lgE in serum were detetmined and compared with those of non-treated mice. In the groups of BPA with OVA antigen, total 1gG1, total lgG2a, total lgE. OVA-specific lgG1 and OVA-specific lgG2a were significantly decreased at dose of 500mg/kg/day. However, in mice treated with BPA alone, total lgG1, and lgG2 were not much altered and total lgE was significantly increased at dose of 1000mg/kg/day. These results demonstrated the BPA modulates the production of immunoglobulin.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.19-28
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• 2021

Vitamin E and K are essential micronutrients required by our body in small amounts for proper metabolic functions; however, the content of vitamin E and K commonly consumed in foods has not been comprehensively defined. In this study, the contents of vitamins E and K in sea algae and vegetables were analyzed and the analytical methods were validated. The α-tocopherol equivalent (α-TE) and vitamin K1 content in sea algae ranged from 0.15 to 1.14 mg/100 g and from 11.91 to 1,629.5 ㎍/100 g, respectively. In addition, α-TE and vitamin K1 of vegetables were detected in the range of 0.02-2.48 mg/100 g and 16.15-979.60 ㎍/100 g, respectively. In particular, β- and γ-tocopherol and α- and β-tocotrienol were detected in several vegetables. The analytical methods were accurate and reproducible. These results provide reliable data on the vitamin E and K contents of foods consumed in Korea for the development of National Standard Food Composition Database.

• Nutrition Research and Practice
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• v.17 no.5
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• pp.1028-1041
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• 2023

BACKGROUND/OBJECTIVES: This study aimed to analyze the potential of school meals in South Korea as a sustainable tool to reduce carbon emissions by focusing on animal- vs. plant-based protein foods. MATERIALS/METHODS: By using a stratified proportional allocation method, 536 out of the 11,082 schools nationwide were selected including 21 kindergartens, 287 elementary-, 120 middle- and 108 high schools. A total of 2,680 meals served for 5 consecutive days (June 21-25, 2021) were collected. We analyzed the average serving amounts of protein foods (animal- vs. plant-based) per meal and then, calculated the estimated average amounts of carbon emission equivalents per meal by applying the conversion coefficients. The t-test and analysis of variance were used for statistical analyses (α = 0.05). RESULTS: The average serving amount of animal-based protein foods per meal was 12.5 g, which was approximately 3 times higher than that of plant-based ones (3.8 g) (P < 0.001); the Meat-group had the highest average amount of 17.0 g, followed by Egg-group (9.6 g), Fish-group (7.6 g), and Beans-and-Nuts-group (3.8 g) (P < 0.05). Specifically, pork (25.1 g) was ranked first, followed by poultry (19.6 g), processed meat products (18.0 g). The estimated average amount of carbon emission equivalents of animal-based protein foods per meal was 80.1 g CO₂e, which was approximately 31 times higher than that of plant-based ones (2.6 g CO₂e) (P < 0.001); the Meat-group had the highest average amount of 120.3 g CO₂e, followed by Fish-group (44.5 g CO₂e), Egg-group (25.9 g CO₂e), and Beans-and-Nuts-group (2.6 g CO₂e) (P < 0.05). Specifically, processed meat products (270.8 g CO₂e) were ranked first, followed by pork (91.7 g CO₂e), and processed fish products (86.6 g CO₂e). CONCLUSIONS: The results implied that school meals with plant-based alternatives could be a sustainable tool to improve carbon footprint.

• Korean Journal of Plant Resources
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• v.21 no.5
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• pp.408-412
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• 2008

This research was designed to investigate the antioxidant activities and tyrosinase inhibitory effects of guava (Psidium guajava L.) leaf. Total phenol content was obtained from guava leaf extract of 19.0 (g/100g, D.W.). The crude extract exhibited significantly antioxidant activities (IC50value $102.5{\mu}g/ml$, free radical scavenging; $49.4{\mu}g/ml$, SOD like activity). The crude extract of guava leaf was fractionated into four partition layers; hexane (G-H), ethyl acetate (G-E), butanol (G-B) and water (G-W) layer. The extracts of G-E, G-B, G-W showed high radical scavenging activities of over 50% at $100{\mu}g/ml$. SOD like activities of G-E, G-B, G-W were revealed, as 81.8%, 84.7%, 65.3% at $100{\mu}g/ml$, while those of G-H did not showed the effectively. The crude extract of guava leaf showed high tyrosinase inhibitory effect as 60.8% at 1mg/ml, the measurement of G-E, G-B, G-W were 65.2%, 62.8%, 51.6% and that of G-H was not effective. These results indicate that useful bioactive substances exist in the guava leaf extracts, especially G-E, G-B. And the guava leaf has the potential of being developed into health related products.

• Journal of Korean Society of Forest Science
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• v.100 no.2
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• pp.178-183
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• 2011

This study was carried out to investigate the dose-dependent effect of salicylic acid on both the adventitious root growth and the accumulation of various eleutherosides in the bioreactor culture of Eleutherococcus senticosus. The highest biomass production (5.4 g DW/L) was observed in the absence of salicylic acid, while the root growth was significantly decreased by increasing the concentration of salicylic acid. Salicylic acid stimulated the production of both eleutheroside B, E and $E_1$. The highest levels of eleutheroside B ($179.5{\mu}g/g$ DW), E ($1169.9{\mu}g/g$ DW) and $E_1$ ($45.4{\mu}g/g$ DW) were obtained by the addition of $80{\mu}M$ of salicylic acid. The maximum eleutheroside production was $4975.8{\mu}g/L$ when salicylic acid was not added. In addition, when the adventitious roots were cultured in the basal medium supplemented with $80{\mu}M$ of salicylic acid, the highest levels of eleutheroside B was observed at the 9th day, while eleutheroside E and $E_1$ were observed at the 6th day, respectively.