• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.1
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• pp.468-476
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• 2021

This study examined the effects of a hydrothermal pretreatment (HP) on the nutritional values and in vitro fermentation characteristics of tall fescue and corn silage. This study was conducted through a factorial design of 2 (control or HP) × 2 (hay; tall fescue or silage; corn). For the HP, forage was placed into a glass bottle with 20% w/v of water, and the glass bottle was sealed and heated to reach a temperature of 121℃ (0.12 MPa). The solid residue and liquid were collected and oven-dried at 65℃ for three days. The dried materials were tested for in vitro fermentation at 39℃ for 24 and 48 h. The content of ADF increased significantly regardless of the forage type. After in vitro incubation for 24 h, the total VFA content was significantly lower after HP, regardless of the forage type (p ≤ 0.05), and the propionate concentration was increased in corn silage with HP (p ≤ 0.05). After 48 hours of in vitro incubation, the propionate content increased significantly (p ≤ 0.03) in corn silage with HP (p ≤ 0.05), but the butyrate content decreased significantly (p ≤ 0.05). There was no change in the in vitro dry matter and neutral detergent fiber digestibility by HP regardless of the forage type. Therefore, the use of hydrothermally pretreated corn silage could be advantageous for the supply of energy for ruminants.

• Journal of Nutrition and Health
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• v.54 no.1
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• pp.39-53
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• 2021

Purpose: This study examined the dietary behavior, health status and nutrient intake by considering the level of household income of elderly people using data obtained from the Korea National Health and Nutrition Survey (KNHANES VII) 2018. Methods: The study subjects were 1,355 elderly people over 65 years old (558 men, 797 women). Based on their household income, participants were classified into three groups: low-income, middle-income, and high-income. The variables consisted of general characteristics, dietary behavior, health status, health related behavior, and dietary intakes. Dietary data were estimated by the 24-hour dietary recall. Results: In men, the low-income group encompassed older, less educated, less employed, and living with family of first generation. However, in women, there were no differences in employment by the level of income, and women living alone had lower income than subjects living with family. Elderly men in the high-income group had a significantly higher level of nutrient intake (energy, protein, fat, phosphorous, riboflavin, niacin and vitamin C). Men in the low-income group consumed a significantly lower intake of fruits, seaweeds and eggs, including total food. Women in the low-income group had significantly less intake of protein, fat, calcium, phosphorous, iron, vitamin A, riboflavin, and niacin whereas women in the high-income group had significantly higher intake of sugar & sweet, eggs, and beverages, including total food. Conclusion: These results suggest that the level of household income is an important factor that influences food and nutrient intake in the Korean elderly. The socioeconomic status needs to be considered differently among elderly men and women when implementing food assistant programs and designing nutrition education programs.

• Journal of Nutrition and Health
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• v.54 no.1
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• pp.10-22
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• 2021

Purpose: Key Foods refers to foods that have a high contribution in the nutrient intake of individuals, and exert important effects on their health. This study was undertaken to identify Korean Key Foods, using data from the 7th Korea National Health and Nutrition Examination Survey (KNHNES). Methods: The data source for the extraction of Key Foods was the 24-hour dietary survey data obtained from the 7th KNHNES (2016-2018), and 21,271 subjects were evaluated. A total of 17 nutrients were selected as the key nutrients for identifying the Key Foods, including energy, carbohydrates, protein, lipid, dietary fiber, calcium, phosphorus, iron, sodium, potassium, vitamin A, thiamin, riboflavin, niacin, vitamin C, cholesterol, and sugars. The nutrient consumption approach was applied to generate a list of potential Key Foods. Foods included in 85% of the cumulative intake contribution from one or more key nutrients, were subsequently selected as Key Foods. Results: Of the 1,728 foods consumed by survey respondents, we extracted 728 Key Foods. These Key Foods explained 94% key nutrient intakes of the subjects. Based on the contribution rate to key nutrient intake, the top 10 Key Foods identified were multigrain rice (5.32%), plain white rice (4.23%), milk (3.3%), cabbage kimchi (2.82%), grilled pork belly (1.56%), apples (1.52%), fried eggs (1.49%), cereal (1.36%), instant coffee mix (1.21%), and sweet potatoes (1.12%). These 10 foods accounted for 23.93% total key nutrient intake of the survey respondents. Conclusion: Seven hundred and twenty-eight foods were extracted and identified as the 2020 Korean Key Foods. These Key Foods can be considered the priority foods to be analyzed for establishing a national nutrient database.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.194-203
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• 2022

Cultivation of tomatoes in Korea grown in soil covers 89% of the total area for tomato cultivation. Tomatoes grown in soil often encounter various environment stresses including not only salt stress and soil-borne diseases but also cold stress in the winter season. This study was conducted to comparatively analyze the performance of rootstocks with cold stress by measuring the growth, yield, and photosynthetic efficiency in tomatoes grown in soil. The rootstocks were used 'Powerguard', 'IT173773', and '20LM' for the domestic rootstock cultivars and 'B-blocking' for a control cultivar. The tomato cultivar 'Red250' was used as the scion and the non-grafted tomatoes. Stem diameter, flowering position, leaf length, and leaf width were investigated for the growth parameters. The stem diameter of the non-grafted tomatoes decreased by 15% compared to the grafted tomatoes at 80 days after transplanting when exposed to low temperatures of 9-14℃ for 14 days. The leaf length and width of the non-grafted tomatoes were the lowest with 42.4 cm and 41.8 cm at 80 days after transplanting. The total yield per plant was the highest in tomato plants grafted on 'Powerguard' with 1,615 g and lowest in non-grafted tomatoes with 1,299 g. As the result of measuring the chlorophyll fluorescence parameters, PI_ABS and DI₀/RC, which mean the performance index and dissipated energy flux, 'Powerguard' was the highest with 3.73 in PI_ABS and the lowest with 0.34 in DI₀/RC, whereas non-grafted tomatoes was the lowest with 2.62 in PI_ABS and the highest with 0.41 in DI₀/RC at 80 days after transplanting. The stem diameter has positive correlation with PI_ABS, while it has negative correlation with DI₀/RC. The results indicate that can be analyzed by chlorophyll fluorescence parameters can be used for analyzing the differences in the growth of tomato plants grafted on different rootstocks when exposed to cold stress.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.1
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• pp.42-56
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• 2005

Hyperlipidemia is one of the risk factors for coronary artery disease. Despite of epidemiological evidence that tea consumption is associated with the reduced risk of coronary heart disease, experimental studies designed to show that drinking tea affects blood lipid concentration or oxidative stress have been unsuccessful. The purpose of this study was to investigate whether functional tea (three servings/day) supplement with medical nutrition therapy (MNT) lead to a beneficial outcomes in mildly hyperlipidemic adults. From February to October, 2003, the 43 hyperlipidemic (23 men, 20 women) subjects (total cholesterol$\geq$200 mg/dL or triglyceride$\geq$150 mg/dL) admitted to K Medical Center were studied. Subjects were randomly divided into 3 groups; placebo tea (PT), half dose of functional tea (HFT), full dose of functional tea (FFT). During 12 weeks of study period, the subjects were given placebo or functional tea daily with MNT. Anthropometric measurements, blood chemical analysis including lipid levels, total superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) levels, and dietary assessment were carried out at the beginning and end of experiment. The effects of functional tea were compared with the placebo in randomized clinical trial study. The placebo was prepared to match with the functional tea in color and taste. After the 12 weeks of MNT, the subjects had regular and balanced meal pattern. Consumption of foods high in cholesterol and saturated fat, salty foods, fried foods, and instant foods decreased significantly in all three groups (p<0.05). Intake of energy and cholesterol also decreased (p<0.05). Drinking three servings per day (390 mL/day) of functional tea significantly reduced the levels of blood triglyceride (HFT, 42.5%; FFT, 29.4%), total cholesterol (HFT, 8.5%; FFT, 13.7%), and atherogenic index (HFT, 14.6%; FFT, 21.7%). Whereas no changes were found in the LDL-, HDL-cholesterollevels, and LDL/HDL ratio. Plasma homocysteine (Hcy) concentration decreased significantly (p<0.05) in functional tea groups (HFT, 14.9%; FFT, 14.1%). SOD increased significantly (p<0.05) in HFT (8.3%). GSH-Px increased significantly (p<0.05) in FFT (12.8%). In conclusion, the MNT improved the dietary habits, in addition, functional tea supplement decreased blood lipid levels and Hcy, and increased SOD and GSH-Px levels. These results indicate that functional tea consumption may decrease the risk of cardiovascular disease via improving blood lipid levels and antioxidant status.

• Child Health Nursing Research
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• v.4 no.1
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• pp.60-75
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• 1998

The parents have much expectation upon the pregnancy and child birth, and in most cases, they expect the healthy parturient child. However, we can be placed on the high-risk conditions which have the physical, social and immature infant, due to the unexpected results, among the new-born. Accordingly, these high-risk newborn and premature infants will be mostly in NICU, which the concentrated medical treatment can be given, upon their conditions. After their birth and during these periods, they will be divided from the parents, and the nurse will accomplish the bringing-up activities which they can take care of the infant, expected by the parents after their birth. The hospitalization of high-risk newborn including these premature infants is the shocking experience to the parents of family, and thus they can feel the fear and uneasiness, and these reactions of parents are troubled in the behavior at the usual days, and cause the disorder and spiritless status, and these results break the supporting ability of parents, and cause the obstruction. Also, the unavoidable division between the parents and the children as like hospitalization of children can make the parents to feel the alienation emotionally, and this causes the results which the pride on the bringing-up ability of baby gets to be lost. These problems can cause the difficulties on the bonding or the parenting in the further days, and can be related to the neglect and abuse of children. Also, it is gradually increased to study and report which the emotional division by the physical division between the mother and the baby obstructs the normal affection course between the parent and the infant. The stress caused by the birth and the hospitalization of high-risk newborn, as like this, is important in the points which it can uncertainly affect the potential energy for the relationship of parent-child who are finally healthy. Accordingly, the significance and purpose of this study are to understand the contents and degree of stress which the parents of high-risk newborn including the immature child can be experienced from the hospitalization of ICU for their new borns, and thus to offer the basic program to the nursing intervention program for these. The subject of this study is the mother of newborn in NICU of 10 General Hospitals located at the 3one of Pusan, Korea from September 1997 to October 1997, and thus makes the subject of 95 person of parents who agreed to take part in the study and it is descriptive study related to the stress of mother having the newborn in NICU. The method is based on the preceding study related to the stress of mother having the experience of child hospitalization and chronic disease child, and then acquires the advice of specialists group as like 5 nursing professors, and then is amended and supplemented. Total number of questions is 43 items and consists of 5 factors as like medical treatment &nursing procedures, disease status & prognosis, role of parents, communication & inter-personal relationships, hospital environment, and is 5 point Likert Scale. The reliability of this study method is very highly shown to be Cronbach α=0.95. The collected data is analysed as Average, Frequency, Standard Deviation, T-test, ANOVA, Pearson Correlation Coefficient, Duncan multifulrange test by use of SPSS /PC (V7.5). The results of this study is summarized as under. 1. Every characteristics of subject is which the party of mother is 28.70age(±7.48) in the average ages, 51% in the high-school graduate, 38.5% in the christianity, total monthly income is 212.55 thousand won(±1.971), 74.5% in the housewife, 72.9% in the parents and children together living and the number of children to be 1.48person(± 0.6) in average, the recognition on the prognosis of baby is 74.0% in 'Don't know', the relationship with the husband after the hospitalization of babyis 37.3% in 'More Intimate', the relationship with the family of husband to be 48% in 'No-change', and the degree which is consulted with the husband about the baby is 55% in 'very frequently' and the visiting number per week is 4.59(±1.63) in average and the accompanying person in the time of visiting is which the number of husband is 56.3% and thus is the highest. The characteristics of baby is which the age is 21.88days(±16.47) after the birth in average, the sex to be 50 person in the female 52.1% and the order of birth to be 54.2% in the first chid, and the weight in the birth to be 2770gm(±610) and the height in the birth to be 46.26cm(±7.62) in aver age. The medical diagnosis is 37.5% in the premature infant, the career of hospitalization is 96.9% in 'None', and the operation plan is 90.6% in 'None' and the execution of operation is 88% in 'None' and the nursing of incubator is 55.2% in 'Yes', and the method of feeding is 50.5% in 'Oral' and the contents of feeding is 46.9% in the 'Milk'. 2. The total stress degree of subject is almost highly shown to be as 3.36(±0.86). If it is compared upon each cause, 'stress on disease status & prognosis' is highest 3.79(±1.28), and it is in the order of 'stress on medical treatment & nursing procedures' 3.70(±0.93), 'stress on hospital environment' 3.14(±0.86), 'stress on role of parents' 3.18(±0.92) and 'stress on communication & inter personal relationship' 2.62(± 0.77) 3. As the results of checking the notworthiness of stress degree upon each variable of subject, the variable showing the noted difference was the birth weight(γ=-0.16, P=0.04), birth height(γ=-0.23, P=0.03), nursing in the incubator(F=8.93, P=0.04), feed method(F=2.94, P=0.04). That is to say, it is shown which the smaller the birth weight is, the higher the stress degree of mother is noteworthily. Also, the smaller the birth height baby is, the higher the stress of mother is. In the incubator, it os shown which the mother whose baby is nursing in the incubator is higher in the stress degree than other mothers. Upon the feeding method of baby, that is to say, TPNis the highest, and it is shown in the order of NPO, Tube feeding, and P.O. feeding. When we review the above-mentioned results, as the status is serious, it is thought which we include the supporting nursing for coping with the stress of parents in the setting-up od nursing plan for the baby in the NICU.

• Journal of Intelligence and Information Systems
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• v.26 no.1
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• pp.135-149
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• 2020

Artificial intelligences are changing world. Financial market is also not an exception. Robo-Advisor is actively being developed, making up the weakness of traditional asset allocation methods and replacing the parts that are difficult for the traditional methods. It makes automated investment decisions with artificial intelligence algorithms and is used with various asset allocation models such as mean-variance model, Black-Litterman model and risk parity model. Risk parity model is a typical risk-based asset allocation model which is focused on the volatility of assets. It avoids investment risk structurally. So it has stability in the management of large size fund and it has been widely used in financial field. XGBoost model is a parallel tree-boosting method. It is an optimized gradient boosting model designed to be highly efficient and flexible. It not only makes billions of examples in limited memory environments but is also very fast to learn compared to traditional boosting methods. It is frequently used in various fields of data analysis and has a lot of advantages. So in this study, we propose a new asset allocation model that combines risk parity model and XGBoost machine learning model. This model uses XGBoost to predict the risk of assets and applies the predictive risk to the process of covariance estimation. There are estimated errors between the estimation period and the actual investment period because the optimized asset allocation model estimates the proportion of investments based on historical data. these estimated errors adversely affect the optimized portfolio performance. This study aims to improve the stability and portfolio performance of the model by predicting the volatility of the next investment period and reducing estimated errors of optimized asset allocation model. As a result, it narrows the gap between theory and practice and proposes a more advanced asset allocation model. In this study, we used the Korean stock market price data for a total of 17 years from 2003 to 2019 for the empirical test of the suggested model. The data sets are specifically composed of energy, finance, IT, industrial, material, telecommunication, utility, consumer, health care and staple sectors. We accumulated the value of prediction using moving-window method by 1,000 in-sample and 20 out-of-sample, so we produced a total of 154 rebalancing back-testing results. We analyzed portfolio performance in terms of cumulative rate of return and got a lot of sample data because of long period results. Comparing with traditional risk parity model, this experiment recorded improvements in both cumulative yield and reduction of estimated errors. The total cumulative return is 45.748%, about 5% higher than that of risk parity model and also the estimated errors are reduced in 9 out of 10 industry sectors. The reduction of estimated errors increases stability of the model and makes it easy to apply in practical investment. The results of the experiment showed improvement of portfolio performance by reducing the estimated errors of the optimized asset allocation model. Many financial models and asset allocation models are limited in practical investment because of the most fundamental question of whether the past characteristics of assets will continue into the future in the changing financial market. However, this study not only takes advantage of traditional asset allocation models, but also supplements the limitations of traditional methods and increases stability by predicting the risks of assets with the latest algorithm. There are various studies on parametric estimation methods to reduce the estimated errors in the portfolio optimization. We also suggested a new method to reduce estimated errors in optimized asset allocation model using machine learning. So this study is meaningful in that it proposes an advanced artificial intelligence asset allocation model for the fast-developing financial markets.

• Restorative Dentistry and Endodontics
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• v.32 no.3
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• pp.248-259
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• 2007

The aim of this research was to study the effect of intermittent polymerization on marginal adaptation by comparing the marginal adaptation of intermittently polymerized composite to that of continuously polymerized composite. The materials used for this study were Pyramid (Bisco Inc., Schaumburg, U.S.A.) and Heliomolar (Ivoclar Vivadent, Liechtenstein) . The experiment was carried out in class II MOD cavities prepared in 48 extracted human maxillary premolars. The samples were divided into 4 groups by light curing method: group 1- continuous curing (60s light on with no light off), group 2-intermittent curing (cycles of 3s with 2s light on & 1s light off for 90s); group 3- intermittent curing (cycles of 2s with 1s light on & 1s light off for 120s); group 4- intermittent curing (cycles of 3s with 1s light on & 2s light off for 180s). Consequently the total amount of light energy radiated was same in all the groups. Each specimen went through thermo-mechanical loading (TML) which consisted of mechanical loading (720,000 cycles, 5.0 kg) with a speed of 120 rpm for 100hours and thermocycling (6000 thermocycles of alternating water of $50^{\circ}C$ and $55^{\circ}C$). The continuous margin (CM) (%) of the total margin and regional margins, occlusal enamel (OE), vertical enamel (VE), and cervical enamel (CE) was measured before and after TML under a $\times200$ digital light microscope. Three-way ANOVA and Duncan's Multiple Range Test was performed at 95% level of confidence to test the effect of 3 variables on CM (%) of the total margin: light curing conditions, composite materials and effect of TML. In each group, One-way ANOVA and Duncan's Multiple Range Test was additionally performed to compare CM (%) of regions (OE, VE CE). The results indicated that all the three variables were statistically significant (p < 0.05). Before TML, in groups using Pyramid, groups 3 and 4 showed higher CM (%) than groups 1 and 2, and in groups using Heliomolar. groups 3 and 4 showed higher CM (%) than group 1 (p < 0.05). After TML, in both Pyramid and Heliomo)ar groups, group 3 showed higher CM (%) than group 1 (p < 0.05) CM (%) of the regions are significantly different in each group (p < 0.05). Before TML, no statistical difference was found between groups within the VE and CE region. In the OE region, group 4 of Pyramid showed higher CM (%) than group 2, and groups 2 and 4 of Heliomolar showed higher CM (%) than group 1 (p < 0.05). After TML, no statistical difference was found among groups within the VE and CE region. In the OE region, group 3 of Pyramid showed higher CM (%) than groups 1 and 2, and groups 2,3 and 4 of Heliomolar showed higher CM (%) than group 1 (p < 0.05). It was concluded that intermittent polymerization may be effective in reducing marginal gap formation.

• Journal of Nutrition and Health
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• v.49 no.5
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• pp.347-357
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• 2016

Purpose: This study investigated bone mineral density and nutritional state according to consumption of milk in Korean postmenopausal women who drink coffee. Methods: Using the 2008~2009 Korean National Health & Nutrition Examination Survey data, a total of 1,373 postmenopausal females aged 50 yrs and over were analyzed after excluding those with diseases related to bone health. According to coffee and/or milk consumption, subjects were divided into four groups: coffee only, both coffee & milk, milk only, and none of the above. All data were processed after application of weighted values and adjustment of age, body mass index, physical activity, drinking, and smoking using a general linear model. For analysis of nutrient intake and bone density, data were additionally adjusted by total energy and calcium intake. Results: The coffee & milk group had more subjects younger than 65 yrs and higher education, urban residents, and higher income than any other group. The coffee only group showed somewhat similar characteristics as the none of the above group, which showed the highest percentage of subjects older than 65 and in a lower education and socio-economic state. Body weight, height, body mass index, and lean mass were the highest in coffee & milk group and lowest in the none of the above group. On the other hand, the milk only group showed the lowest values for body mass index and waist circumference, whereas percent body fat did not show any difference among the groups. The coffee and milk group showed the highest bone mineral density in the total femur and lumbar spine as well as the highest nutritional state and most food group intakes, followed by the milk only group, coffee only group, and none of the above group. In the assessment of osteoporosis based on T-score of bone mineral density, although not significant, the coffee and milk group and milk only group, which showed a better nutritional state, included more subjects with a normal bone density, whereas the none of the above group included more subjects with osteoporosis than any other group. Conclusion: Bone mineral density in postmenopausal women might not be affected by coffee drinking if their diets are accompanied by balanced food and nutrient intake including milk.

• Journal of Nutrition and Health
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• v.48 no.6
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• pp.476-487
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• 2015

Purpose: This study was conducted to examine the concentration of nutrients in transitional breast milk from Korean lactating mothers and to evaluate daily intakes of their infants based on the Dietary Reference Intakes for Koreans 2010 (KDRIs 2010). Methods: Breast milk samples were collected at 5~15 days postpartum from 100 healthy lactating Korean mothers. Macro- and micro-nutrients, and immunoglobulin (Igs) concentrations in breast milk were analyzed. Results: The mean energy, protein, fat, and carbohydrate concentrations in breast milk were $59.99{\pm}8.01kcal/dL$, $1.47{\pm}0.27g/dL$, $2.88{\pm}0.89g/dL$, and $6.72{\pm}0.22g/dL$. The mean linoleic acid (LA), a-linolenic acid (ALA), arachidonic acid (AA), and docosahexaenoic acid (DHA) concentrations were $181.44{\pm}96.41mg/dL$, $28.15{\pm}8.89mg/dL$, $5.67{\pm}1.86mg/dL$, and $5.74{\pm}2.57mg/dL$. The mean vitamin A, vitamin D, vitamin E, vitamin $B_1$, vitamin $B_2$, vitamin $B_{12}$, and folate concentrations were $2.75{\pm}1.75{\mu}g/dL$, $2.31{\pm}1.12ng/dL$, $0.74{\pm}1.54mg/dL$, $3.02{\pm}1.84mg/dL$, $7.51{\pm}20.96{\mu}g/dL$, $61.78{\pm}26.78{\mu}g/dL$, $63.71{\pm}27.19ng/dL$, and $0.52{\pm}0.26{\mu}g/dL$. The mean concentrations of calcium, iron, potassium, sodium, zinc, and copper were $20.71{\pm}3.34mg/dL$, $0.59{\pm}0.86mg/dL$, $66.71{\pm}10.35mg/dL$, $27.72{\pm}10.16mg/dL$, $0.44{\pm}0.41mg/dL$, and $70.48{\pm}30.41{\mu}g/dL$. The mean IgA and total IgE concentrations were $61.85{\pm}31.97mg/dL$ and $235.00{\pm}93.00IU/dL$. The estimated daily intakes of infants for protein, vitamin D, vitamin E, vitamin $B_2$, vitamin $B_{12}$, iron, potassium, sodium, zinc, and copper were sufficient compared to KDRIs 2010 adjusted by transitory milk intakes. The estimated infants' intakes of energy, fat, carbohydrate, vitamin A, vitamin C, vitamin $B_1$, folate, and calcium did not meet KDRIs 2010 adjusted by transitory milk intakes. Conclusion: In general most estimated nutrient intakes of Korean breast-fed infants in transitory breast milk were sufficient, however some nutrient intakes were not sufficient based on KDRIs 2010. These results warrant conduct of future studies for investigation of important dietary factors associated with nutrients in breast milk to improve the quality of breast milk, which may contribute to understanding nutrition in early life and promoting growth and development of breast-fed infants.