• Progress in Medical Physics
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• v.25 no.4
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• pp.205-209
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• 2014

Medical polymers require sterilization and must be able to maintain material properties for a specified shelf life. Sterilization can be achieved by using gamma or e-beam exposure. In this study, accelerated aging tests of poly(ether-block-amide) (PEBA) copolymer samples is presented. PEBA copolymer samples with different polyether content that result in Shore hardness of 35D to 72D, were sterilized using e-beam radiation followed by accelerated aging at $55^{\circ}C$. E-beam sterilization effect on molecular weight and mechanical property has performed and analyzed. The average molecular weight significantly reduced as a result of ageing. The enlarged proportion of low molecular weight chains in the aged samples is consistent with the generation of degradation products produced by oxidative chain scission. Also E-beam materials have shown decreased tensile strength and elongation. Overall, this study demonstrated that the medical grade PEBA was significantly affected by radiation exposure over aging time, particularly at high irradiation doses. For medical use in case of radiation sterilization required, it is recommended to avoid Pebax material. If Pebax material must be in use for medical device, recommend to use alternate sterilization method such as Ethylene Oxide sterilization.

• Journal of The Korean Society of Grassland and Forage Science
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• v.4 no.2
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• pp.89-97
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• 1983

This experiment was carried out in order to study the effect of seasonal changes and location differences on the productivity of the native reed (Phragmites Communis Trinius). The samples of reed were taken at about 30-days interval from May to October, 1982, on the open field of the reclaimed land, the river bank and the tideland in Chonnam area, and measured the yield, the feed compositions and in vitro dry-matter digestibility(IVD). The results are summarized as follow: 1. Plant height was rapidly heightened in May and June, and the number of leaves rapidly increased from May to August. However, dry matter yield increased until September and gradually decreased thereafter. 2. In general, the content of crude protein and the in vitro dry matter digestibility decreased with ageing, and the content of fiber increased. 3. Considerable difference by location in the chemical composition including $SiO_2$, Ca and P was observed. 4. There was a significant negative correlation (p<0.05) between the content of crude protein and that of crude fiber. There was a significant positive correlation(p<0.05) between the in vitro dry-matter digestibility(IVD) by two-stage method and the content of crude protein, and also was a significant negative correlation(p<0.05) between the content of fiber and that of crude protein.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.371-381
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• 2019

This study explored how retirement satisfaction or dissatisfaction influences on retirees' life satisfaction, comparing to workers and the gender differences were examined. The study sample was 2,609 persons (1,886 workers, 723 retirees) aged 45 or older who participated in the 1-2 waves of the Korean Longitudinal Study of Ageing (KLoSA), and the retirees were classified into continuously dissatisfied retirees and satisfied retirees during wave 1 and 2. Using SPSS 21.0, the multiple regression models were examined, and in order to clarify the gender difference, the multi-group analysis and the wald-test were conducted to test the difference of the regression coefficients according to gender using Mplus 7.3. According to the results, the life satisfaction of dissatisfied retirees was lower than that of the employed, but when satisfied with retirement, the life satisfaction was higher than that of the employed. In addition, the dissatisfied retirees in both gender were less satisfied with life than the employed, and this effect was greater in female group. However, the life satisfaction of female satisfied with retirement was higher than that of the employed, whereas the evidence of the male influence was not found to be significant. Based on the results of this study, discussion about heterogeneity of retirees and gender differences in life span were presented.

• Phonetics and Speech Sciences
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• v.14 no.1
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• pp.37-47
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• 2022

The purpose of the this study is to observe the effects of healthy adults' age on temporal features of speech and identify which could differentiate older and young adults. We examined speech rates(i.e., overall speaking rate, articulation rate), occurrence of pause, and duration of pause per utterance by utilizing the National Institute of Korean Language's open corpus. We selected a total of 30 healthy adults (10 young, 10 middle-aged, and 10 older adults) in this study. There were significant differences among the groups in the overall speaking rate, articulation rate, total occurrence of pause, the occurrence of pause between syntactic words, total duration of pause, and duration of pause between syntactic words. The older and middle-aged adults showed slower speech rates and longer and more frequent pause than young adults. But there were no significant differences among the three groups in terms of pause within syntactic word. The overall speaking rate significantly differentiated older adults from young adults. These findings suggested that the effect of speakers' age was reflected in gradual changes in the temporal features of their speech.

• 한국노년학
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• v.31 no.4
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• pp.1135-1153
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• 2011

The study aims to examine the interaction of socio-economic status in education and income in the difference of the level of subjective health, physical health, and mental health of middle-age and the elderly of Korea. While there have been various discussions in precedent study with respect to the serious increase in the number of dependent life alongside with increasing elderly population, research on the health level according to socio-economic status is highly limited, and also how the health level of middle-age and the elderly - whom will arrive at senescence in just a few years - is different. The study aims at analyzing the health level by hierarchy and age based on data targeting the whole nation. As for analysis data, the study utilized 1st Korean Longitudinal Study of Ageing (KLoSA) implemented by Korea Labor Institute, and carried out a path analysis to verify whether income and academic background serve as a parameter to the level of subjective health, physical health, and mental health. As a result, while the subjective health level decreases, the study confirmed an increase in chronic diseases, and extremely low level of mental health when people in middle-age enter the elderly. In addition, the higher the education and income, the more the health levels both on middle-age and the elderly; the result suggests that education background and income have mediated effects in all health level of middle-age and the elderly.

• 한국노년학
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• v.31 no.4
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• pp.1083-1101
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• 2011

The purpose of this study is to describe how the structural and functional features of social network change among widowed middle and older adults and to examine the effect of personal predictors of the social network change. Data was obtained from men and women between 45 to 98 years of age(N=118) who were bereaved by the death of their spouse since the first wave survey and participated in the second wave survey of the Korean Longitudinal Study of Ageing(KLoSA). The main findings are as follows: First, their social network after the bereavement was strengthened centered around children; for example, the number of adult children living in proximity to the parent, frequency of contact with children, and the financial and non-financial support from children generally increased. Second, the social network change pattern was categorized into four types such as "overall increased type," "children-centered increased type," "children/close relationship-centered increased type," and "stagnation type." Finally, the health condition of the widowed middle and older adults was a strong predictor of the social network change.

• Journal of the Institute of Convergence Signal Processing
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• v.24 no.2
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• pp.126-133
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• 2023

In this study, electromyography was obtained in the six muscle areas that move the joints of the two legs, and by analyzing it, an exercise robot system capable of gait rehabilitation was proposed in consideration of the individual's muscle state. Through this, the system was constructed to prevent the effect of exercise from decreasing because the patient's will was not reflected when walking exercise was simply provided automatically. As a result of the evaluation of the developed system, it was confirmed that the pedestrian rehabilitation robot system manufactured through this study had performance suitable for the design requirements, and it was also confirmed that the usability evaluation was comprehensively satisfactory. The results of this study are thought to be of great help to patients who are having difficulty in gait rehabilitation, and are believed to be helpful in the development of electromyography signal-based gait robot systems.

• Journal of Animal Science and Technology
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• v.46 no.3
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• pp.427-436
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• 2004

The current study was conducted to determine the effect of suspension method on satisfaction level of Korean consumers and objective meat quality traits in Hanwoo longissimus dorsi(LD), triceps brachii(TB) and semimembranosus(SM) muscles. Eighteen Hanwoo steers were slaughtered and alternative sides were hung either by pelvic bone(TS) or Achilles tendon(Al). Sensory characteristics, WB-shear force, sarcomere length, water-holding capacity, saroomere length and cooking loss were determined after a 7-d chiller ageing. Higher carcass quality grade received significantly(p < 0.05) greater eating quality for LD, but the grade did not affect eating quality for both TB and SM. TS did not influence objective and subjective meat quality for TB, but that significantly(P < 0.05) improved eating quality for LD and SM. The most noticeable result was that when SM was tenderstretehed, eating quality was equivalent to that of nonna1ly hung LD. In relationship between objective and subjective meat quality assessments, eating qualty for LD had a significant(P < 0.05) relationship with intramuscular fat content, while that for SM was greatly(P < 0.05) related to saroomere length. The current study indicated that pelvic hanging was an effective way to improve eating quality both LD and SM, and carcass quality grades did not greatly reflect eating quality of SM and TB. The data also implied that instnunental measurements poorly estimated the satisfaction level of Korean conswners.

• Journal of Distribution Research
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• v.15 no.5
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• pp.237-255
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• 2010

The Korean Pharmacist Law has limited the sales of medicine to pharmacies. This has caused difficulty in purchasing medicine late at night or on holidays, which has limited the range of customers' selections and accelerated customers' discomfort, accordingly. Also, the rapid progress of aging has quickly boosted medical expenses for seniors, and has served as a factor that aggravates the budget of national medical insurance. Meanwhile, advanced countries, including the USA and Japan, have allowed the sales of general medicine, of which the safety and efficacy have been tested, in general retail stores such as convenience stores or super markets from the perspective of supporting self-medication. In particular, Japan, which has a strong tendency of pursuing safety in the world, diversified sales channels for general medicine in order to control quickly rising medical expenses. As a result, Japan has achieved the effect of easing various regulations as follows in the economic and social fields. First, the increasing distribution channels of general medicine from pharmacies to general retail stores provoked a potential demand, which also expanded related markets. Second, the competition between sales channels resulted in the reduction of the price of medicine. Third, the growing sales channels of medicine have extended the options of consumers and, subsequently, the convenience in the use of consumers has increased. Fourth, the creation of a competitive environment owing to the diversification of sales channels has accelerated an effort to enhance corporate competitiveness. Fifth, the foundation of enhancing the financial soundness of medical expenses has been prepared through the formation of a self-medication environment. In 2000, the Korean population aged 65 or over exceeded 7%, and it is anticipated to be over 14% by 2018; thus, the increase of national medical expenses will be sped up. As a way of being prepared for the era of aging, we, just as other advanced countries, need to create a self-treatment environment by diversifying the sellers of general medicine, and, thus, reduce spending on personal medical expenses, enhance the financial soundness of national medical insurance, and, further, promote the welfare of consumers.

• 한국노년학
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• v.41 no.4
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• pp.547-566
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• 2021

The purpose of this study is to analyze the effect of social activities on healthy life expectancy (HLE) by gender difference. HLE implies an estimate of how long an individual can expect to live in full health or without disease and/or disability. Morbidity, mortality, and functional health status usually have been known as key variables. Many researchers have tried to investigate factors affecting HLE in countries level by performing comparative analyses. In micro level, there have been some studies about social factors affecting HLE in individual level. However, few studies are found focusing on the relationship between HLE and social activities. This study anlayzes 4,029 over 65 years of age from the first wave (2006) to the seventh wave (2018) of the Korean Longitudinal Study of Ageing (KLoSA), which is a national panel data collected by Korea Employment Information Service. The data has been collected as a part of social and economic policies planning for Korean government. HLE was measured by life period without disease or disability. One of findings is that male older adults (76.9 yrs) show higher HLE in comparing to female group (75.3 yrs). Female group appeared to be more likely to have higher incidence rate and disorders. Another finding indicates that age, number of chronic diseases, and subjective health status affect HLE of both groups. Finally, regarding social activities, religion affiliated activities appear to significantly affect HLE of both groups. In case of male older adults, alumni or hometown gathering also appeared another activities affecting HLE. This study indicates that the effect of social activities types on HLE among older adults appears differently by gender. Further, unlikely of longer life expectancy among female older adults as known, HLE shows a reverse estimate, longer healthy life expectancy among male older adults. This finding may imply that later life of female older adults shows lower quality of life in comparing to that of male group, even if female life expectancy has been higher. This study encourages to develop more social activity programs for older adults in community level. Specifically, more attention is required to planning for programs targeting female older adults.