• Proceedings of the Korea Concrete Institute Conference
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• 1999.04a
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• pp.123-128
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• 1999

Recently, as a performance based design concept is introduced, assurance of expected performances on serviceability and safety in the whole span of life is exactly requested. So, quantitative assessments about durability related properties of concrete in early-age long term are come to necessary, Especially in early age, deterioration which affects long-term durability performance can be occurred by hydration heat and shrinkage, so development of reasonable hydration heat model which can simulate early age behavior is necessary. The micor-pore structure formation property also affects shrinkage behavior in early age and carbonations and chloride ion penetration characteristic in long term, So, for the quantitative assessment on durability performance of concrete, modelings of early age concrete based on hydration process and micor-pore structure formation characteristics are important. In this paper, a micromechanics based hydration heat evolution model is adopted and a quantitative model which can simulate micro-pore structure development is also verified with experimental results. The models can be used effectively to simulate the early-age behavior of concrete composed of different mix proportions.

• International Journal of Concrete Structures and Materials
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• v.2 no.1
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• pp.9-14
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• 2008

The cracking problem in concrete is widespread and complex. This paper reviews the problem and focuses on those parts of the problem that are more readily solved. Polymer fibers are shown to have promise in several important areas of the cracking problem. To investigate one of these areas of the cracking problem more completely, an experimental research program focusing on the early-age properties of fibers was carried out. This study researched the properties of four polymer fibers; two of the fibers were macrofibers, and two were microfibers. Each fiber was tested at several dosage rates to identify optimum dosage levels. Early-age shrinkage, long-term shrinkage, compressive strength, and tensile strength were investigated. Long-term shrinkage and strength impacts from the polymer fibers were minimal; however, the polymer fibers were shown to have a great impact on early-age shrinkage and a moderate impact on early-age strength.

• Journal of Society of Preventive Korean Medicine
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• v.22 no.2
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• pp.41-53
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• 2018

Objectives : It was to classify and its affecting factors to the patients of Korean medicine hospital with short term and long term hospitalization. Methods : I focused on long-term hospitalized patients. I was conducted on 344 hospitalized patients among the original data of usage and consumption of Korean medical report in 2014. Among those patients, I have classified them into long term inpatients(131 patients) and short term inpatients(213 patients) based on 16 days of hospitalization. Also multiple regression analysis was conducted to investigate the characteristics of the hospitalization, treatment satisfaction and dissatisfaction, the characteristics of long term hospitalization according to the sociodemographic of the subjects, the top 21 diseases and the distribution of human bodies, side effects and kinds of Korean medicine. Results : There was a statistically significant difference between the short term and long term hospitalized patients due to age, occupation, marital status, all 21 diseases and institutional fees, experience of Korean medical treatment due to traffic accidents. There was no significant difference in gender, education level, residence, income level, type of medical insurance, whether private insurance, type of medical treatment for Korean medicine, medical expenses for car accidents, reason for dissatisfaction with treatment. The number of long term patients at Korean medicine hospitals increased by a statistically significant by age in model 1 where confounding factors were differently controlled. In model 2, the number of long term patients at Korean medicine hospitals increased by a statistically significant by age, among those who earned 5,000,000 Korean won or more, and among those with nerve diseases. The number of long term patients at Korean medicine hospitals decreased by a statistically significant amount among the unemployed and others in model 2. In model 3, the number of long term patients at Korean medicine hospitals increased by a statistically significant by age, among those who earned 5,000,000 Korean won or more, and among those with nerve diseases, while the number decreased by a statistically significant amount among the married. Conclusions : These results suggest that the factors affecting the short term and long term hospitalization of patients with Korean medicine hospital are different from each other. Especially it was significant by age, over 5,000,000won Income per month, nerve disease, but decrease significant married.

• Steel and Composite Structures
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• v.28 no.1
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• pp.39-49
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• 2018

The concrete bridge decks are usually precast and in-situ assembled with steel girders with post-pouring joint in the construction practice of super-wide steel-concrete composite beam. But the difference of concrete age between the precast slabs and the post-pouring joint has been not yet considered for the long-term performance analysis of this kind composite beam. A simply supported precast-assembled T-shaped beam was taken as an example to analyze the long-term performance of steel-concrete composite beam with post-pouring joint. Based on the deformation coordination conditions of the old-new concrete deck and steel girder, a theoretical model for the long-term behavior of precast-assembled composite beam is proposed in this paper according to age-adjusted effective modulus method. Then, the feasibility of the proposed model is verified by the available test data from the Gilbert's composite beams. Parametric studies were preformed to evaluate the influences of the cross-sectional area ratio of the post-pouring joint to the whole bridge deck, as well as the difference of concrete age between the precast slabs and the post-pouring joint, on the long-term performance of the composite beam. The results indicate that the traditional method without considering the age difference would seriously underestimate the effect of creep and shrinkage of concrete bridge decks. The concrete age difference between the precast slabs and the post-pouring joint should be demonstrated for the life cycle design and long-term performance analysis of precast-assembled steel-concrete composite beams.

• 한국사회정책
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• v.25 no.1
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• pp.125-159
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• 2018

The purpose of this study is to analyze the factors affecting service use intention of long-term care among the disabled. This study conducts a longitudinal study using the modified Andersen model by the disabled age groups of the 50-64 group and the 65 over group. This study examined random effects panel logit analysis for the 50-64 group and the 65 over group by age variations. The results have shown that there are different factors Influencing factors for each specific age group of the disabled(50-64, 65 over). The results were as follows: there are differences of factors between the 50-64 group and the 65 over group. This study found that predisposing factors of the service use intention of long-term care were significantly related to age, residential area, education status, existence of spouses. Enabling factors of the service use intention of long-term care were significantly related to long-term care service recognition, saving, personal salary income level, housing status. Need factors of the service use intention of long-term care were significantly related to chronic diseases, psychological health, IADL. So, there are a need for a policy considerations such as service for the mid-old age disabled by age groups. Finally, implications and future research directions were discussed based on the finding of the study.

• Structural Engineering and Mechanics
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• v.66 no.2
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• pp.263-271
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• 2018

Compressive strength and elastic modulus of concrete are constantly changing with age. In order to determine long-term development of compressive strength and elastic modulus of concrete, an investigation of C30 concrete cured in air conditions was carried out. Changes of compressive strength and elastic modulus up to 975 days were given. The results indicated that compressive strength and elastic modulus of concrete rapidly increased with age during the initial 150 days and then increased slowly. The gain in elastic modulus was slower than that of compressive strength. Then relationships of time-compressive strength, time-elastic modulus and compressive strength-elastic modulus were proposed by regression analysis and compared with other investigations. The trends of time-compressive strength and time-elastic modulus with age agreed best with ACI 209R-92. Finally, factors contributed to long-term development of compressive strength and elastic modulus of concrete were proposed and briefly analyzed.

• Food Science of Animal Resources
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• v.32 no.4
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• pp.414-427
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• 2012

Carcass characteristics and meat quality traits as a function of endpoint months of slaughter age (26 vs 32 mon) and chiller ageing (1 vs 10 d) were evaluated for m. longissmus of 26 Hanwoo steers fed with commercial diets including whole crop barley silage. Totally twenty six Hanwoo steers for 6 mon of age that were fed until 26 mon of age constituted the short term-fed group and fed until 32 mon of age constituted long-term fed group. Carcasses were chilled for 24 h and were graded. Strip loin samples were divided into two age groups (1 d and 10 d). Long-term feeding increased carcass weight, rib-eye area, yield grade, marbling score, firmness and quality grade of the meat. The feeding for 32 mon produced tender, juicy meat (p<0.01) with lower cooking loss and higher rating score (p<0.05) than short term feeding, while other quality traits were not influenced by the length of feeding. Intramuscular fat content and oxidative stability (TBARS value) were significantly (p<0.05) higher in beef from long-term feeding however the length of feeding did not alter the fatty acid composition. Chiller aging reduced instrumental tenderness (WBSF value), improved color, sensory tenderness, acceptability and rating of beef. The results of the present study mirrors that Hanwoo steers until 32 mon of age overall improved carcass traits and palatability compared to that for 26 mon. However, from the viewpoints of economical and environmental aspects, cost of the additional feeding for 6 mon for value-adding of eating quality was relatively high and the effects in turn were limited.

• Research in Community and Public Health Nursing
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• v.27 no.4
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• pp.309-318
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• 2016

Purpose: This study investigated the correlation between person-centered care (PCC) and nursing service quality of nurses in long-term care hospitals. Methods: The subjects were 114 nurses working in 8 long-term care hospitals. Instruments for evaluating PCC and nursing service quality were used. The data were analyzed by descriptive statistics, two samples-test, one-way ANOVA, Pearson's correlation and Multiple regression. Results: The mean of PCC was $3.25{\pm}0.45$ out of 5 and the nursing service quality was $3.87{\pm}0.40$. There were significant differences in PCC in terms of age and income satisfaction, the application of their opinions, the satisfaction of hospital managers, administrators and nurse managers. There were significant differences in nursing service quality according to age, position, the satisfaction of hospital managers, administrators and nurse managers. Nurses' PCC showed a significant positive correlation with nursing service quality. Factors influencing nursing service quality included PCC, their position and age and the most influencing one was PCC. Conclusion: This study suggests that the PCC is the strongest affecting element to the quality of nursing service in long-term care hospitals. Therefore, the strategies to improve the practice of person-centered care should be carried out to enhance the quality of nursing service.

• Journal of the Korean Home Economics Association
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• v.38 no.1
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• pp.59-73
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• 2000

The purposes of this study were to determine the factors that influence consumer concerns for safety to cow's milk produced using food-related biotechnology and to find the similarity and difference among concern factors relating short-term and long-term risk perception. Telephone interviews were conducted and the data were collected from households(n=1,466) nationwide in the U.S. And the data were analyzed by probit model and LIMDEP softare package. The data demonstrated that consumers were concerned about food safety from consuming milk produced using food-related biotechnology. The concerns were found to be influenced by demographic factors(gender in short-term, gender and age in long-term) as well as psychological aspect such as outrage(heard about bGH, milk belief about naturalness, expected benefit in short-term, heard about bGH, expected benefit in long-term) and attitudinal factors(animal rights group, locus of control in short-term, animal rights group, cancer history, locus of control in long-term). The results suggest that consumers have concerns for safety to cow's milk produced by biotechnology and the most factors influencing consumer concerns were similar between short-term and long-term period, though a few factors such as cancer history, milk belief about naturalness and age were different.

• Food Science and Biotechnology
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• v.18 no.1
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• pp.234-238
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• 2009

Effects of ginseng on in vivo antioxidant capacities with age were studied in rats. All rats were reared in the conventional system. Ginseng-treated rats were supplied with ginseng water extracts (25 mg/kg/day) continuously from 6 weeks of age to spontaneous death. None of the rats showed any discernible adverse effects of treatment with ginseng-containing water. There was no significant difference in body weight (BW) gains with age between treated and control groups. However, ginseng extracts did cause a decrease in the level of serum low density lipoprotein (LDL)-cholesterol, glucose, and thiobarbituric acid reactive substances (TBARS) in the treated rats. The activities of superoxide dismutase (SOD), catalase, and glutathione peroxidase in liver cytosol decreased with age in the control group. However, these enzyme activities were well maintained in the ginseng-treated rats and, especially, catalase and glutathione peroxidase activities were consistently higher than in control rats. The levels of total sulfhydryl group (T-SH) and glutathione reductase (GR) were unchanged, and glutathione-s-transferase (GST) activity gradually decreased with age in both groups. There were no differences in T-SH, GR, or GST between the control and treatment groups. These results indicate that long-term administration of ginseng retards age-related deterioration in some biochemical parameters such as cholesterol, glucose, and lactate dehydrogenase in serum and it has an enhancing effect on antioxidant capacity in the liver.