• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 학회창립 10주년 기념 1999년도 가을 학술발표회 논문집
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• pp.285-288
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• 1999

Creep is a major parameter to represent long-term behavior of concrete structures concerning serviceability and durability. The effect of creep is recently taking account into crack resistance analysis of early-age concrete concerning durability evaluation. Since existing creep prediction models were proposed to predict creep for hardened concrete, most of them cannot consider effectively the information on microstructure formation and hydration developed in the early-age concrete. In this study, creep tests for early-age concrete made of the type I cement and the type V cement are carried out respectively and creep prediction models are evaluated for the prediction of creep behavior in early-age concrete. A creep prediction model is modified for the prediction of creep in early-age concrete and also verified by comparing prediction results with results of creep tests on early-age concrete.

• International Journal of Reliability and Applications
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• 제12권2호
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• pp.131-143
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• 2011

In most of literatures of age replacement policy, the authors consider the case that a new item starts operating at time zero and is to be replaced by new one at time T. It is, however, often to purchase used items because of the limited budget. In this paper, we consider age replacement policy of a used item whose age is $t_0$. The mathematical formulas of the expected cost rate per unit time are derived for both infinite-horizon case and finite-horizon case. For each case, we show that the optimal replacement age exists and is finite and investigate the effect of the age of the used item.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계학술발표회 논문집(I)
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• pp.458-461
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• 2006

Early age cracking of concrete is a widespread and complicated problem, and diverse applications in practical engineering have focused on this issue. Since massive concrete base slab composes the infrastructure of other concrete structures such as pier, concrete dam, and high rise buildings, early age cracking of that is considered as a crucial problem. In this study, finite element analysis (FEA) implemented with the age-dependent microplane model was performed. For a massive concrete base slab, cracking initiation and propagation, and deformation variation were investigated with concrete age. In massive concrete slab, autogenous shrinkage increases the risk of early age cracking and it reduces reinforcement effect on control of early age cracking. Gradual crack occurrence is experienced from exterior surface towards interior of the slab in case of combined hydration heat and autogenous shrinkage. FEA implemented with enhanced microplane model successfully simulates the typical cracking patterns due to edge restraint in concrete base slab.

• Journal of Korean Neurosurgical Society
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• 제51권1호
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• pp.24-30
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• 2012

Objective : This study was conducted to assess the clinical significance of traumatic brain stem injury (TBSI) reflected on Glasgow Coma Score (GCS) and Glasgow Outcome Score (GOS) by various clinical variables. Methods : A total of 136 TBSI patients were selected out of 2695 head-injured patients. All initial computerized tomography and/or magnetic resonance imaging studies were retrospectively analyzed according to demographic- and injury variables which result in GCS and GOS. Results : In univariate analysis, mode of injury showed a significant effect on combined injury (p<0.001), as were the cases with skull fracture on radiologic finding (p<0.000). The GCS showed a various correlation with radiologic finding (p<0.000), mode of injury (p<0.002), but less favorably with impact site (p<0.052), age (p<0.054) and skull fracture (p<0.057), in order of statistical significances. However, only GOS showed a definite correlation to radiologic finding (p<0.000). In multivariate analysis, the individual variables to enhance an unfavorable effect on GCS were radiologic finding [odds ratio (OR) 7.327, 95% confidence interval (CI)], mode of injury (OR; 4.499, 95% CI) and age (OR; 3.141, 95% CI). Those which influence an unfavorable effect on GOS were radiologic finding (OR; 25.420, 95% CI) and age (OR; 2.674, 95% CI). Conclusion : In evaluation of TBSI on outcome, the variables such as radiological finding, mode of injury, and age were revealed as three important ones to have an unfavorable effect on early stage outcome expressed as GCS. However, mode of injury was shown not to have an unfavorable effect on late stage outcome as GOS. Among all unfavorable variables, radiological finding was confirmed as the only powerful prognostic variable both on GCS and GOS.

• 대한가정학회지
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• 제43권12호
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• pp.153-163
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• 2005

The purposes of this study were to investigate the differences of appearance behavior and ego integrity of elderly women according to demographic variables, and health, and to examine how the ego integrity of elderly women was influenced by appearance behavior, health, and demographic variables. The subjects were 117 elderly women(aged 60 to 70) in Jinju, Korea who were interviewed face-to face with a survey questionnaire. The results of the study were as follows. There were significant differences in appearance adornment and ego integrity (wise living and attitude toward life) according to age. After controlling for age, there were significant differences in appearance interest, makeup, and ego integrity according to education. There was a significant difference in ego integrity (attitude toward life) according to the presence of a spouse or mate. There were significant differences in appearance interest, makeup, and ego integrity according to health. Health and education had a significant effect on satisfaction with the present living. Health, age(-), and appearance behavior had a significant effect on wise living. Health, age(-), and education had a significant effect on attitude toward life. Education and health had a significant effect on appearance behavior. The present findings indicate that health state and appearance behavior, such as appearance interest and makeup, had a significant effect on the ego integrity of elderly women. On the whole, the ego integrity of elderly women was positively correlated with the level of health state, education, and appearance behavior.

• 근관절건강학회지
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• 제5권2호
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• pp.222-237
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• 1998

In an attempt to investigate the effect of long-term aquatic exercise program on lower limbs' muscle strength, knee Joint flexion, pain reduction and weight changes with aquatic exercise program. Forty three women with arthritis were pre and post tested for changes of muscle strength, range of motion, weight and pain. This data was collected from April 1, 1997 to February 24, 1998. The mean age was 52.5. Statistically significant in lower limbs' muscle strength with an aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 12 weeks after experiment. Statistically significant in knee joint flexion with aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 12 weeks after experiment. Statistically significant in pain reduction with aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 12 weeks after experiment. Statistically significant in weight changes with aquatic exercise program by age, BMI, education, rheumatic drug use, illness duration until 6 weeks after experiment. As a conclusion, aquatic exercise programs for the patients with arthritis require at least 12 weeks and a variety of aquatic exercise programs for the effective control should be developed.

• 한국초지조사료학회지
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• 제11권2호
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• pp.97-101
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• 1991

This experiment was carried out to determine the effect of pure mineral nitrogen fertilization on dry matter yield and the amounts of advisable mineral nitrogen on grassland according to its age at the "Federal Institue for Agriculture in the Alps" in Austria. The results obtained were as follows: 1. With only PK-fertilizing average dry matter yields per year were progressively declined during the period of the studies. Compared with the relatively younger grassland(1st-5th year) the DM-yields were decreased by 35% in older grassland (11th-final year). 2. Due to the less reduction of DM-yields by mineral nitrogen application according to the age of grassland. With N-fertilizing the reduction of DM-yields in relatively older grassland was less than that of younger grassland by 11-21%. 3. At 4-and 5-cut systems the nitrogen amounts for the highest marginal yield(the "most efficient" Ndressing rate) per ha and year were distinctly declined in the relatively older grassland. 4. Required efficiencies of mineral nitrogen were not influenced by the age of grassland.he age of grassland.

• The Journal of Korean Physical Therapy
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• 제6권1호
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• pp.75-84
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• 1994

This study was carried out to know correlation between age and balance performance. factors to effect on balance and prepare the basic data in balance performance evaluation clinically. 180 adults without neurosurgical and orthopedic disability from 20 to 79 years of age participated in this study voluntarily. The subjects performed One Legged Stance Test in five conditions 1) eye open 2) eye close 3) eye open & ear close 4) eye & ear close 5) on sponge. The results of this study were as follows : 1. The mean balance performance time by one legged stance test was 25.97 seconds in eye open, 10.45 seconds in eye close, 23.14 seconds in eye open & ear close, 10.18 seconds in eye & ear close and 23.15 seconds in on sponge. 2. The balance performance declined according to age increasing. 3. The visual factor effected on balance performance greatly. 4. The auditory factor effected less than visual factor on balance performance 5. The compliant surface effected on balance performance in over-fifty age group greatly.

• Asian-Australasian Journal of Animal Sciences
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• 제12권3호
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• pp.354-357
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• 1999

Hypothyroidism was induced in three age groups (8 months, 1 year and 2 years) of Black Bengal goats by administering thiourea subcutaneously for 30 days. From fourth day onwards the animals were observed to be in hypothyroid state. For 8 months age group, a control group of similar age was taken. For the 1 year and 2 years age groups there was no control group but the values obtained on the pre-treatment day were considered as control values. For confirming the establishment of hypothyroidism, peripheral plasma triiodothyronine $(T_3)$ and thyroxine $(T_4)$ were estimated in all the animals before and during the treatment period by radioimunoassay. In the thiourea treated 8 months age group the $T_3$ and $T_4$ levels were significantly (p<0.001) lower than those in the control group during the treatment period. In all the thiourea treated groups the $T_3$ and $T_4$ levels observed during the treatment period were significantly (p<0.01) lower than the pre-treatment levels. A nonsignificant loss in the body weight was observed in all the thiourea treated groups whereas there was a significant growth in the control group of animals. The study indicates that hypothyroidism has a negative effect on growth in goats.

• The Korean Journal of Pain
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• 제21권1호
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• pp.51-56
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• 2008

Background: Preoperative dexamethasone improves the surgical outcome after laparoscopic cholecystectomy(LC). The purpose of this study was to determine the effect of preoperative dexamethasone on the postoperativepain according to age and gender in patients who undergo LC.Methods: In this double blind prospective study, 400 patients, males or females :< 45 yr and males or femaless 65 yr (n = 50 in each of eight groups) who undergoing LC were randomized to receive dexamethasone 8mg (5 ml) or saline 5 ml intravenously 100 minutes before their operation, Postoperative pain was assessedon a visual analog scale (VAS) at 1, 6, 12, and 24 hour, and the time to administering the first postoperativeanalgesics was recorded.Results: Dexamethasone was administered without consideration for age and gender, and it reduced thepostoperative pain VAS score at 1, 6, and 12 hours, and the opioid analgesic requirement, but there was nosignificant difference between administering saline or dexamethasone in the same gender and age groups.Females U 45 yr who were administered saline had the most pain sensitivity and males S 65 yr who wereadministered dexamethasone had the least pain sensitivity.Conclusions: Preoperative dexamethasone reduces the pain intensity and opioid consumption, but does notreduce the pain intensity, according to age and gender in the patients undergoing LC. As a result, Preoperativedexamethasone should be considered for routine use for patients who are undergoing laparoscopic cho-lecystectomy. (Korean J Pain 2008; 21: 51 56)