• Journal of Nutrition and Health
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• v.30 no.8
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• pp.1018-1024
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• 1997

In order to investigate calcium , phosphorous and magnesium intake of breast-fed infants, consumed volumes of human milk and those mineral contents of the milk were examined at 0.5, 1, 2, 3, 4 and 5 months of lactation. Calcium , phosphorus and magnesium contents of human milk during the first 5 months of lactation averaged 26.0, 13.7 and 3.70mg/100g, respectively. Calcium intake of infants averaged 192.3 and 171.0mg/day which represented 39.7 and 33.5% of the RDA for boys and girls, respectively. Phosphorus intake of infants averaged 100.7 and 85.2mg/day which represented 26.2% and 23.4 % of the RDA for boys and girls respectively. The calcium /phosphorus ratio of human milk averaged 2.00 during lactation. The results of this survey suggest that, the reevaluation of calcium , phosphorus and magnesium intake and recommended dietary allowance of these nutrients during infancy is merited.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.4 no.4
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• pp.42-49
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• 1995

It is not clearly known how defects or inclusions of a low carbon steel affect a fatigue strength. We study this issue using SM15C materials. The investigation is carried out by a quantitative evaluation, and experimental findings are: (1) a fatigue limit of A series smooth specimen is 205MPa, and that of B, C, D series is 245MPa, 304MPa and 245MPa, respectively. (2) the fatigue limit varies with respects to the stress distribution I the vicinity of a defects and crack. (3) the micro hole creates a half-circular shape crack, while the hole depth is not critical to the fatigue strength, (4) considering the fatigue strength, the hole diameter is more significant than the hole depth, and (5) Fatigue limit of artificially defected specimen is lower than that of a flawless one (5-10%), however, there exist allowance size and depth of defect which don't get to influence at fatigue limit.

• Journal of the Korean Society for Precision Engineering
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• v.13 no.1
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• pp.22-28
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• 1996

From the experimental study of Wire-Cut Electric Discharge Machining of STD-11 alloy steel and P-20 tungsten carbide, the characteristics such as hand drum form and discharge gap have been observed and evaluated for various conditions. Hand drum form can be improved when gap have been observed and evaluated for various conditions. Hand drum form can be improved when gap voltage and spark cycle become smaller, thickness become thinner, wire tension become larger and the no of cutting increases. When 60mm thickness tungsten carbide is cut in normal condition, hand drum form becomes larger due to the low conductivity machining allowance become slightly larger when peak discharge current and gap voltage become larger, or wire tension becomes smaller. Under the same condition, machining allowance of tungsten carbide is larger than alloyed steel by 1/100mm.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.11 no.6
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• pp.139-144
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• 2012

In the automobile industry, the various efforts to lower their industrial cost and enhance fuel efficiency have been made through process improvement or weight saving of automobile parts. Gear is one of significant parts of transmission, which is made by cast iron or alloy steel. It is expensive due to complex processing, inferior materials and large machining allowance. In this study, alternative gear cars oil which is based on fluid applications materials is produced by reducing surface induction hardening and carburizing hardened in production. And then, wear characteristic and mechanical properties such as hardness of the sintered alloy which is used as a substitute for small machining allowance is investigated.

• Journal of the Korea Society for Simulation
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• v.12 no.1
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• pp.21-34
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• 2003

This paper deals with a case study of workload analysis of an operator in an automatic line for machining the race of ball bearing. Eleven machines and three hoppers are installed in the line which is operated by an operator. The elements of operation are separated into machine controlled elements, operator controlled elements and machine/operator controlled elements. In order to analyze the system, time and motion studies are used for gathering input data for the simulation model. The first objective of this study is to evaluate whether the workload of operator is reasonable or not. The second objective is to increase throughput by reducing tact time and the last one is to increase frequencies of inspection by reducing interval. Thus we suggest some ideas for improvement, and as a result, the throughput is improved about 9%. In spite of the increasing of throughput, the allowance of operator is also increased about 4%.

• Journal of the Korean Home Economics Association
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• v.39 no.5
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• pp.39-47
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• 2001

The purpose of this study was to investigate two different kinds of t-shirts on thermal responses at air temperature of $23{\pm}2^{\circ}C$, relative humidity of $70{\pm}5%$ and wind velocity not more than 0.5 m/sec. Five healthy men wearing boxy type t-shirts or fitted type t-shirts, participated as the subjects. Rectal temperature, skin temperatures, heart rate, clothing microclimate and subjective sensation were measured every 2 minute during experiment(rest, walking, recovery each 20 min.) and compared between two experimental garments(boxy type and fitted type t-shirts). Rectal temperature was lower in recovery phase at wearing fitted type t-shirts. Chest skin temperature was higher at wearing fitted type t-shirts and thigh and leg skin temperature were higher at wearing boxy type t-shirts.

• Journal of the Korean Home Economics Association
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• v.37 no.5
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• pp.19-30
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• 1999

This study attempts to identify the level of the propensity of college student's conspicuous consumption and clarify the related variables such as socioeconomic variables, consumption-oriented attitude, and influence of reference groupl Data used in this study were collected from 485 college students in seoul. The samples were analyzed by frequency, mean, t-test, ANOVA, Duncan's Multiple Range Test, and regression. The results can be summarized as follows: 1) The average level of the propensity for conspicuous consumption was a little higher than middle point ; 2) the propensity of conspicuous consumption of college students was significantly different according to age, sex, the amount of monthly allowance, and the parents' level of education; 3) the variables with statistically significant effects on college students' conspicuous consumption include the consumption-oriented attitude, the influencing degree of reference group, the amount of monthly allowance, and sex.

• Journal of Nutrition and Health
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• v.1 no.1
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• pp.46-48
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• 1968

• Proceedings of the Korean Fiber Society Conference
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• 1993.06b
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• pp.684-688
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• 1993

• Journal of Families and Better Life
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• v.23 no.2 s.74
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• pp.77-91
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• 2005

The purpose of this study is to investigate general tendencies in credit card use, and determine the causes of the use of cash advance service and deferred payment among college students. Socio-demographic variables(gender, year in college, allowance, family income, parents' education and occupation, having taken a personal financial management course), knowledge and attitudes toward credit card, and financial management practices were incorporated as antecedent variables. Logistic regression analysis and multiple regression analysis were conducted to test the hypotheses. The results were as follows ; First, $32\%$ of the college students with no regular income experienced deferred payment, and $60.4\%$ of them had used a cash advance service. Second, the frequency and amount of cash advance service use were affected by family income, financial practices, and allowance. The financial practice as a parameter was affected by their completion of a personal finance course and their allowance. Third, deferred payment of credit was affected by their knowledge on credit cards and their financial practices. The financial practices as a parameter were affected by the family income and their completion of a personal finance course, and the knowledge on credit cards was affected by gender. Lastly, implications and suggestions for credit card use behavior research and consumer credit education are discussed in this article.