• The Korean Journal of Ecology
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• v.16 no.1
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• pp.115-131
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• 1993

Six nutrient cycles involving terrestrial plants are identified and characterized. Plants affect biotic and abiotic cycles through their effects on soil properties. They determine their internal nutritional status and nutrient concentrations in their environment via internal and external cycles. Contributions of organic matter to mycorrhizal, trophic, and detrital mediated external cycles and alterations of nutrient concentrations by plants can promote positive feedbacks leading to increased availability and retention of soil nutrients in open systems. Recognizing alternative cycles through plants leads to a definition of nutrient use efficiency for ecosystems: the ratio of system production to nutrient content of organic matter. A simple graph model to predict changes of nutrient use efficiency during primary succession is then presented.

• Journal of Physiology & Pathology in Korean Medicine
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• v.24 no.5
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• pp.779-783
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• 2010

Formation of nutrient qi is one of the most important functions in the human body. In medical classic such as "Hwangdineijing", it is described through several chapters. However, it is just focused on the first formation of the nutrient qi from water and food by digestion. I will mention how to get nutrient qi in human body and how to circulate and act in physiological phenomena through "Hwangdineijing". Human body should get nutrient qi from essense not only from water and food. Human body, because it is a live, must have had a nutrient material before he or she gets water and food by formation of nutrient qi. So he or she can have physiological functions.

• The Korean Journal of Ecology
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• v.26 no.6
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• pp.335-340
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• 2003

Patterns of mass loss and nutrient release from decomposing oak (Quercus mongolica) and mixed litters (Q. mongolica, Betula schmidtii, Acer pseudo-sieboldianum, Kalopanx pictus and Tilia amurensis) in a natural hardwood forest in Gyebangsan (Mt.) were examined using litterbags placed on the forest floor for 869 days. Mass loss rates from decomposing litter were consistently higher in mixed litter (59%) than in oak litter types (52%) during the study period. Nutrient concentrations such as nitrogen (N), phosphorus (P), potassium (K), and magnesium (Mg) from decomposing litter were also higher in mixed litter than in oak litter types. Nutrient concentrations (N, P, Ca, and Mg) increased compared with initial concentration of litter, while K concentrations dropped rapidly at the first 5 months and then stabilized. The results suggest that mas loss and nutrient release obtained from decomposing litter of single species in mixed hardwood forest ecosystem should be applied with caution because of the potential differences of mass loss and nutrient release between single litter and mixed litter types.

• Journal of the Korean Dietetic Association
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• v.5 no.1
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• pp.100-115
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• 1999

With the growing number of nutrient calculation software packages on the market, there are need to compare each programs. Since each program use different nutrient databases, the result of calculation may be different in value. In this study, we use three(A, B, C) most popular program package to compare the result of nutrient calculation. For the analysis, 24hour recall data from 97 preschool children, 66 university students and 95 aged persons were used. For the calculation if subjects gave the complete recipe, recipes from the subjects were used. Otherwise, recipe from the program database were used. Common 15 nutrients of which all program can give results, are analyzed and compared for mean nutrient intake and nutrient intake for food groups. Ten nutrients among 15 nutrients which have RDA were analyzed for % of RDA and the distribution of RDA. Mean nutrient intake of Fe, vitamin A, Na were statistically different among results of the calculation using three programs(p<0.001). The distribution of Fe, vitamin A and vitamin $B_2$, niacin were statistically different among three results of the calculation using three program(p<0.001, p<0.05). Nutrient intakes of food groups were statistically different in cereal and products, bean and products, vegetables, fruits, fishes and shellfishes, milk and products, beverages, and seasonings(p<0.0001). It is hard to say that the difference among three program are coming from the difference from nutrient database or recipe database in this study. With these result, we conclude that it is necessary to evaluate nutrient database and recipe database as the foremost consideration in selecting nutrient calculation software. Those differences should be considered when interpreting results, comparing results with other studies, and when developing treatment plans in the clinical settings.

• Journal of Nutrition and Health
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• v.33 no.8
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• pp.882-889
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• 2000

This study was conducted to examine contribution of specific foods to absolute intake and between-person variation in nutrients consumed by 2037 adults living in Korean rural area using one day 24-hour recall method. To measure contribution of food to absolute nutrient intake, all foods consumed were ranked by percentages calculated as the sum of the nutrient intake contributed by a given food divided by the total nutrient intake from al categories. To assess between-person variability in nutrient intake, stepwise multiple regression analysis was used with total nutrient intake from al foods as the dependent variable and the nutrient amount from each of all foods as independent variables. The kind and the number of foods necessary to account for the variation in nutrient intake among persons varied significantly depending on the nutrient. The nutrients contributing more than 80% of total intake with a few number of food items were ${\beta}$-carotene(ll), vitamin C(15) and vitamin A(16). Foods sometimes overlooked as important sources were found in some instances to be quantitatively important to population intake. Even though rice and Korean cabbage kimchi do not contain much nutrients in quantity, they made a major contribution to most nutrient intake of subjects because of large serving size and high frequency of intake. The food items and contributing order for between person variance was different from those of absolute intake. A large fraction of the variability of nutrient intake in this population was explained by a small number of foods. Fewer foods were required to explain a given proportion of the between-person variance in intake than to account for the same proportion of the popylation\`s total intake. These data may be useful in the development of dietary assessment instrument and in nutrition education. (Korean J Nutrition 33(8) : 882-889, 2000)

• Journal of health informatics and statistics
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• v.43 no.4
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• pp.282-289
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• 2018

Objectives: The purpose of this study was to investigate factors related to nutrients intakes among young children aged 1-5 years and their mothers. Methods: The study subjects were 621 young children and their mothers from the data of 2nd year (2014) and 3rd year (2015) of the 6th National Health and Nutrition Survey. To find a difference of Recommended Nutrient Intake in young children and their mothers, independent t-test, ANOVA, and Duncan test as a post-hoc analysis were used. For the factors influencing young children Recommended Nutrient Intakes, hierarchical multiple regression analysis was used. Results: The mean score of Recommended Nutrient Intakes was $6.92{\pm}2.17$ in young children and $4.74{\pm}2.06$ in mothers. The Recommended Nutrient Intakes of young children was increased according to gender (boy) (p=0.001), increasing young children age ($p{\leq}0.001$), young children breakfast frequency (p<0.001), mothers age (p<0.001), education level (p=0.020) and mothers lunch frequency (p=0.002) and family income (p=0.007). The Recommended Nutrient Intakes of mothers was increased according to their age (p=0.005), family income (p=0.020) and having breakfast (p=0.038). The factor that influenced young children Recommended Nutrient Intakes was their mothers Recommended Nutrient Intakes (${\beta}=0.21$, p<0.001). Conclusions: Given the results, it is necessary to establish a plan or nutrition education for young children's menu differently depending on their age and gender. Since mothers' Recommended Nutrient Intakes influence their young children's Recommended Nutrient Intakes, it is necessary to provide mothers' with nutrition education about the importance of mothers' nutrition management and right nutrient intakes, and to make customized nutrition education guidelines in consideration of mothers' characteristics.

• Journal of Bio-Environment Control
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• v.7 no.2
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• pp.123-129
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• 1998

This experiment was conducted to composition of nutrient solution for tore of endive hydroponics, and was compared the nutrient solution developed in the Seoul City University(SCUE) with the conventional solution of Proefstation voor Tuinbouw ender Glas. Proper compositions of nutrient solution for endive hydroponics were NO$_3$-N 15.0, NH$_4$-N 1.0, PO$_4$-P 3.0. K 10.0, Ca 5.0 and Mg 3.5 me.$\ell$$^{-1}$ , respectively SCUE and PTG standard nutrient solution showed slightly better yields among nutrient solutions. The SCUE nutrient solution and the PTG nutrient solution had no difference on growth and yield of endive Plants.

• The Journal of Natural Sciences
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• v.13 no.1
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• pp.83-96
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• 2003

Effect of Nutrient Concentrations, fertigation frequency, and learching percentage on crop growth and nutrient concentrations in root media were evaluated. The treatment of each irrigation with $50 mg.L^{-1}$ of nitrogen in stage 2 and increase to $80 mg.L^{-1}$ nitrogen in stage 3 had the highest crop growth at 34 days after sowing among treatments tested. Feeding with low nutrient concentrations and elevated frequency decreased crop growth. In treatments of each leaching percentage, feeding with low nutrient concentrations and elevated frequency resulted in increased tissue nutrient contents. The less tissue potassium content and higher calcium and magnesium contents were observed in treatment of 50% leach than those in 0% leach. All treatment tested had soil solution pH higher than 6.8. Electrical conductivity in treatments of 50% leach were lower than those of 0% leach. Feeding with low nutrient concentrations and elevated feeding frequency in each leaching percentage resulted in increased electrical conductivity in soil solution of root media. Trends of medium nutrient concentrations were similar to those of electrical conductivity.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.5
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• pp.1059-1065
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• 2005

In this study, an nutrient solution control system have been designed and implemented, which controls the density of nutrient and the nutrient supply automatically using embedded real time operating system and fuzzy control algorithm. The factors which affect the growth of crop consist of solar radiation, external temperature, and external humidity. Also, nutrient temperature, electric conductivity(ED, and pH are monitored. According to the surveyed results, a fuzzy control algorithm for nutrient control is developed in order to control the density of nutrient and the nutrient supply. The exclusive embedded controller which consists of an embedded real time operating system, a korean LCD, and a graphic is developed for common users.

• ALGAE
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• v.33 no.4
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• pp.329-340
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• 2018

The present study was to determine the effects of salinity on the growth and nutrient bioextraction abilities of Gracilaria and Ulva species, and to determine if these seaweeds can be used for nutrient bioextraction under hypo- and / or hyperosmotic conditions. Two Gracilaria species, G. chorda and G. vermiculophylla, and two Ulva species, U. prolifera and U. compressa, were cultured at various salinity conditions (5, 10, 15, 20, 30, 40, and 50 psu) for 3 weeks. Results showed that the growth rates, nutrient uptake, tissue nutrient contents and nutrient removal were significantly affected by salinity and species. All four species were euryhaline with the highest growth rates at 20 psu. Among the four species, U. prolifera, U. compressa, and G. vermiculophylla showed potential to be used for nutrient bioextraction in estuaries and / or land-based fish farms due to their rapid growth, high nutrient uptake, high tissue carbon and nitrogen accumulation and removal capacities.