• KSCE Journal of Civil and Environmental Engineering Research
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• v.29 no.5C
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• pp.207-215
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• 2009

Cemented soils or concrete are usually cured under moisture conditions and their strength increases with curing time. An insufficient supply of water to cemented soils can contribute to hydration process during curing, which results in the variation of bonding strength of cemented soils. In this study, by the consideration of in situ water supply conditions, cemented sand with cement ratio less than 20% is prepared by air dry, wrapped, moisture, and underwater conditions. A series of unconfined compression tests are carried out to evaluate the effect of curing conditions on the strength of cemented soils. The strength of air dry curing specimen is higher than those of moisture and wrapped cured specimens when cement ratio is less than 10%, whereas it is lower when cement ratio is greater than 10%. Regardless of cement ratio, air dry cured specimens are stronger than underwater cured specimens. A strength increase ratio with cement ratio is calculated based on the strength of 4% cemented specimen. The strength increase ratio of air dry cured specimen is lowest and that of wrapped, moisture, and underwater cured ones increased by square. Strength of air dry cured specimen drops to maximum 30% after wetting when cement ratio is low. However, regardless of cement ratio, strength of moisture and wrapped specimens drops to an average 10% after wetting. The results of this study can predict the strength variation of cemented sand depending on water supply conditions and wetting in the field, which can guarantee the safety of geotechnical structures such as dam.

• Progress in Superconductivity and Cryogenics
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• v.25 no.2
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• pp.10-13
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• 2023

High-T_C superconductivity (HTSC) has been the central issue in the field of condensed matter physics for decades. An essential part of the research on superconductivity is finding new exotic superconductors. It was recently suggested that Ir-substituted La_0.7Sr_0.3MnO₃ (LSMIO) is a new high-T_C superconductor. However, systematic studies to experimentally verify the superconductivity have not been done. Here, we report the growth processes of LSMIO thin films and their electrical transport properties. We observed a clear negative correlation between the intensity of the laser utilized for film deposition and the Curie temperature of the deposited film. We attributed this effect to the suppression of Sr concentration in the LSMIO films as the laser intensity increased. However, our LSMIO films show conventional ferromagnetism instead of HTSC. To realize the HTSC in LSMIO systems, further exploration of diverse compositions of LSMIO compounds is essential.

• The Korean Journal of Zoology
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• v.23 no.3
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• pp.125-136
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• 1980

The purpose of the present study is to investigate the electrophoretic patterns of ADH isozymes and activity at various developmental stages of Oregon-R and Kwangju strains of D. melanogaster. The ADH isozymes were seperated by agarose gel plate eletrophoresis and they were stained for ADH activity study. The optical density was measured by using densitometer and the total activity was determined by measuring the enzyme solution's absorbance of 340 nm by spectrophotometer. The results are as follows: 1. At egg stages of Oregon-R and Kwangju strains ADH 2, ADH 3, ADH 4 were observed in te zymograms, but all of ADH 1, ADH 2, ADH 3, ADH 4 and ADH 5 were detected in larval, pupal and imaginal stages. 2. The amount of ADH 1+ADH 2 (anion) was 20-40% and that of ADH 3+ADH 4+ADH 5 (cation) was 60-805. In the developmental stages other, than egg stages, ADH 3 of both strains showed the largest amount among all ADH isozymes, and especially ADH 4 of Kwangju strain showed less amount than that of Oregon-R strain. 3. The total activity of the ADH at the egg stage was found to be the lowest, at larval stage became to be higher and to be lower at pupal stage and then became to be the highest at the imaginal stage. It is noticeable that the activity of the ADH in Kwangju strain was higher than that in Oregon-R strain.

• 한국노년학
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• v.25 no.2
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• pp.143-154
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• 2005

This study was conducted to examine the environmental status, FIM(Function Independence Measure), Illness intrusiveness of home stayed stroke patients. Data were collected on 145 patients living in K city and the neighborhood located in southern part of Korea. The data were analyzed by means of SPSS program. Results : In assessment of environmental safety, 46.2%(67) felt unsafe around their residential area. The most dangerous facilities in their residence was stairs(58.2%), gas/electric facilities(14.9%). For sanitary problems, 28.2%(41) felt they have problems at their home. The most important problems were outdoor polluted toilet(22.0%) and scattered and dirty residential circumstances(22.0%). The average FIM score was 74.52(4.14) of total score 126(7). In motor area FIM was lowest at stair walking(3.01) and bathing(3.16). In cognitive area FIM was lowest at social activities(3.36). The mean score of Illness intrusiveness was 58.86(4.52) of total score 91(7). The major area largely impacted by stroke were health(5.61), working(5.68), active leisure activities(5.56). There was significant reverse correlation between FIM and illness intrusiveness(r=-0.66, p=0.00). Conclusion : It was needed environmental improvement and rehabilitation program for stroke patients, and repeated follow up study.

• 한국노년학
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• v.30 no.4
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• pp.1281-1292
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• 2010

This study was performed to identify older adults' self-reported difficulties in understanding and utilizing health information and their relationships with health status and to investigate the differences between age groups and among education levels. Data were collected from July 1 to August 31 in 2007 from older adults in senior centers located in Daegu, Kyungpook, and Busan area. A total of 103 subjects participated in the study. The level of understanding health information in older adults was 50 on average (possible score 15-75). The most difficult items to understand were patient educational materials, written information provided by health care providers, and medical forms. The lower level of difficulty in utilizing health information was associated with better physical and mental health status. There were differences in their self-reported difficulties between the young-old and the old-old as well as among different education levels. Health care providers may need to tailor educational materials and medical forms to the cognitive ability of older adults under the consideration of their age and education levels.

• 한국노년학
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• v.31 no.3
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• pp.527-538
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• 2011

The purpose of this investigation is to analyze the effect of employment and quality of employment of senior job training. The questionnaire administered to 576 senior job trainees(over 50 years old) and 28 training institute before and after job training to survey job training characteristics, training institute characteristics and trainee characteristics. The results were as follows : First, independence test(X2) revealed that occupational category, period of training, type of institution, training history, location, and trainee's education level had significant difference on employment. Second, The probability of employment was higher in new and well-equipped public institution than private or old public institution. Third, compared with the prior wage, the wage after training decreased. This result suggested that the unemployed senior can hardly be reemployed in prior level job. The result of analysis on the cases of increased wage after training revealed that the trainees who was women, had a little dependent family, a shorter unemployed period, and a higher prior wage showed higher wage than prior wage after training.

• 한국노년학
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• v.29 no.3
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• pp.953-970
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• 2009

The successful aging paradigm suggests that the elderly keep their social ties and actively participate in various activities in later life. Many Korean studies on aging, however, have overlooked the importance of various social activities and relationships beyond kinship. This article aims to investigate the perceived social activities among Korean elders to comprehend the subjectivity of successful aging. 613 respondents, over 50 years old, are selected from a national survey data which was collected by face-to-face interview based on the structured questionnaire. The respondents are classified into pre old (50-64), young old (65-74), old old (over 75). Major findings are as follows. The social activities are grouped into two sub-categories: 'relational activity' and 'productive activity'. The activity types are different by the age cohorts. Various activities are considered in terms of one's needs or motivations, and properly chosen based on the subjective evaluation during life course. Both demographic variables such as sex, area and social context variables such as marital status, living-together show influence on the activity type choices. Plans for later life and work ethics are important as well. Policies regarding social participation emphasizing productivity should positively consider relational motives, as perceived by the Korean elderly.

• 한국노년학
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• v.39 no.1
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• pp.37-60
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• 2019

This study was attempt to derive the aging trajectories of Korean elderly people and identify its characteristics. In particular, this study used the successful aging model of Rowe and Kahn as an analytical framework. Using the Korean Longitudinal Study of Ageing(KLoSA), this study applied group-based multi-trajectory analysis to identify multiple aging trajectories in sample of Korean elder aged 65~74(n=2,682). This study also used several demographic characteristics as baseline predictors to identify the characteristics of each aging trajectory. Five dimensions were analyzed in the multi-trajectory model: chronic disease, physical functional limitation, cognitive functioning, depressive symptom and social engagement. As a result of the analysis, five aging trajectories were identified: successful aging(17.8%), usual aging (33.9%), health declining aging(18.2%), pathological aging(7.9%), and aging with mild cognitive impairment(22.1%). In general, the odds of experiencing successful aging were high in men, low-aged, highly educated, high-income, and spousal elderly. On the other hand, for the elderly, who are under-educated, low-income, and high-aged, there was a high probability of experiencing a relatively difficult aging process. In particular, the odds of experiencing a mild cognitive impairment aging was high in older, lower-income women without a spouse.

• Journal of Korea Entertainment Industry Association
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• v.5 no.1
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• pp.65-72
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• 2011

The major purpose of this study is to investigate the influencing factors toward continuance intention in e-learning services. For this purpose, we introduced Post Acceptance Model(PAM) proposed by Bhattacherjee(2001) as basic analysis framework. Based on the relevant literature reviews, this study posits seven characteristics, that is, contents quality, interactivity, expectation confirmation, perceived ease of use, perceived usefulness, user satisfaction, and continuance intention as key variables to describe the post acceptance behavior in e-learning services. Data have been collected from users who have used e-learning services and the research model and hypotheses were tested through covariance structural model analysis. The results of this study are summarized as follows. First, contents quality, interactivity, and expectation confirmation have positive influence upon perceived usefulness. Second, contents quality, interactivity, expectation confirmation, and perceived ease of use have positive influence upon user satisfaction. Lastly, perceived usefulness have positive effect on the user satisfaction, and perceived usefulness and user satisfaction positively related to continuance intention in e-learning services. The findings have significant implications for e-learning service providers and academic researchers.

• Smart Media Journal
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• v.11 no.9
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• pp.21-29
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• 2022

Ultra Violet(UV) is gradually being replaced with LED instead of general UV lamps. However, the light efficiency of UV LED is still lower than that of the general lamp, and the light efficiency is also low. Due to the current environment and technical problems of UV lamps, the LED replacements are gradually being made. In this study, a new package design and analysis were performed to increase the lifetime and performance of UV LEDs. A new packaging for UV LED were designed and implemented. The new packaging for UV LED was constructed to improve light efficiency. And the electrical and optical characteristics were analyzed respectively. To improve the optical efficiency in UV LED package, the Al has been used based on high reflectivity and applying the optimal lens focusing. Compared to the existing silver Ag, the light efficiency was improved by about 30% or more, and it was confirmed that the light output degradation characteristic was improved by about 10% in the newly applied optical device chip.