• 공업화학
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• 제10권2호
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• pp.299-303
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• 1999

경제적, 환경적인 이유로 신문용지를 생산하는데 신문고지가 상당량 재이용되고 있다. 본 연구에서는 국내 외 신문고지의 열화기간에 따른 제반 성질의 변화를 조사하기 위하여 시도하였다. 시료의 백색도, 수율 및 펄프 강도를 고려하면 열화기간이 증가할수록 탈묵성이 호주산 신문고지에서 가장 우수하고, 국내 신문원지를 사용한 신문고지와 일본 신문고지는 비슷하며, 카나다산 신문원지를 사용한 신문고지에서 가장 낮았다. 국내 신문원지를 사용한 신문고지의 경우, 열화기간 90일까지는 약 83%의 수율과 백색도 50% 이상을 나타내지만 그 이후에는 급격히 감소하였다. 또한 국내 신문용지의 경우 수입된 신문용지보다 섬유의 길이는 짧지만 제반 강도적성질은 높았다. 국내 신문용지와 수입 신문용지는 전반적으로 열화기간에 따라 인장강도와 파열강도는 증가하다가 감소하였으며, 인열강도는 점차 증가하였다.

• 한국콘텐츠학회논문지
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• 제15권9호
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• pp.210-222
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• 2015

본 연구의 목적은 노인의 노화불안이 성공적 노화에 미치는 영향에서 사회적 지지의 매개효과를 검증하는 것이다. 연구결과, 첫째, 노인의 노화불안이 증가할수록 성공적 노화는 감소되는 것으로 나타났다. 둘째, 노인의 노화불안과 사회적 지지 관계에서 노화불안이 증가할수록 사회적 지지는 감소되는 것으로 나타났다. 셋째, 사회적 지지와 성공적 노화 관계에서 사회적 지지의 증가는 성공적 노화를 증가시키는 것으로 나타났다. 넷째, 노인의 노화불안과 성공적 노화의 관계에서 사회적 지지의 부분매개효과를 확인하였다. 이에 본 연구는 고령화 사회에서 노인의 노화불안 감소와 성공적 노화를 위한 방안과 후속연구를 위한 제언을 하였다.

• 한국운동역학회지
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• 제15권3호
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• pp.51-59
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• 2005

To examine the influence of aging on the mechanism of muscle fatigue, we compared the magnitude of central and peripheral fatigue in young and old women before, during and after a sustained submaximaI isometric contraction of elbow flexor muscles. Twelve women (6 young. $20.7{\pm}1.2$ years and 6 old, $68.8{\pm}29$ years) performed a contraction at 20% of maximal voluntary contraction (MVC) torque with their non-dominant arm. The old women were weaker than the young women, however their endurance time for the 20% contraction was longer compared with the young women ($1822{\pm}444$ vs. $1061{\pm}678$ sec, P <. 05). Both groups had a similar reduction in voluntary activation ratio (VA) during and after the fatiguing contraction. However, the old women showed much greater variability in VA before and after the contraction ($91.61{\pm}4.54%$ and $76.70{\pm}19.55\;%$ range of $79{\sim}99$ to $87{\sim}99%$ respectively) compared with the young women ($95.71{\pm}1.86\;%$ and $83.46{\pm}7.57\;%$ range of $39{\sim}75$ to $69{\sim}90%$, respectively). Furthermore, the EMG activity of the elbow flexor muscles and triceps brachii was greater for the old women compared with the young women throughout the fatiguing contraction, indicating different activation strategies with age. Indices of peripheral fatigue including twitch properties, showed that fatigue within the muscle was more rapid for the young women compared with the old women. These results suggest that although old women are weaker than young women, they have greater endurance due to mechanisms within muscle. Furthermore, old women showed great variability in their ability to optimally activate all muscle fiber compared with young women for an isometric contraction.

• 한국컴퓨터정보학회논문지
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• 제20권7호
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• pp.115-120
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• 2015

The old people's feelings, emotions, and self-evaluative judgements fluctuate overtime. The purpose of this paper is to proof relations among well-being factors in social activity. Major results of this paper was as follows. First, the social activity participated elderly had higher health status, self-esteem, mental-health, and successful aging than the non-participated elderly. Second, self-esteem and mental health were exposed as important variable for all of the two groups to improve the successful aging. Thus, self-esteem and mental health can become significant indicator of self-empowering and psychological resilience. Third, the strongest total causal effect of successful aging was health status in social activity participated elderly, while self-esteem was the greatest total causal effect of it in the non-participated elderly. Health status had higher indirect effect of successful aging than direct effect of it in both of them.

• The Korean Journal of Ecology
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• 제14권3호
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• pp.327-343
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• 1991

Clonal growth and rhizome architecture of calmagrostis epigeios, were studied in a 15-year old coastal reclamed land. As c. epigeios patch grew from center to margin radially over time, concentric annuli were added. the radial increases of the mature patch were 80~130cm/yr. the patch ages of c. epigeios estimated by relationships between the diameter and is radial increament, were 1~6year old. There were the marked variations of density, phytomass, shoot height and inflorecence frequency with increasing age of rhizome system within the patch. the maximum performance occurred at 2-year-old concentric annuli of the patch. The growth phasic continuum with aging was divided into 5 grwth phases ; pioneer, building, matyre, senile and degenerate. The rhizome aging had a more significant effect on the inflorescence frequency than on the other attributes. new rhizomes tended to diverge from the direction of the parent ramet by sympodial growth. in a 1-year-old patch, average length of rhizome segment was 7cm, average number of internode was 6, and the tillering frequency was 27%. The tillering in the early stage resultd in the increase of shoot density and the producation of multibranching rhizome. as the result of that, circular patchwas formed in a year. The branching structure based on such facts was represented graphically in branching degree of 60 and 100. therefore, c. epigeios with clonal growth may establish and grow vigorously earlier than other glycophytes in high salt conditions such as the coastal reclaimed land.

• 한국축산식품학회지
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• 제39권1호
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• pp.54-64
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• 2019

Wet and dry aging methods were applied to improve the quality of three different beef cuts (butt, rump, and sirloin) from Hanwoo cows (quality grade 2, approximately 50-mon-old). After 28 d of wet aging (vacuum packaged; temperature, $2{\pm}1^{\circ}C$) and dry aging (air velocity, 2-7 m/s; temperature, $1{\pm}1^{\circ}C$; humidity, $85{\pm}10%$), proximate composition, cooking loss, water holding capacity, shear force, color, nucleotides content, and sensory properties were compared with a non-aged control (2 d postmortem). Both wet and dry aging significantly increased the water holding capacity of the butt cuts. Dry aging in all beef cuts induced lower cooking loss than that in wet-aged cuts. Shear force of all beef cuts was decreased after both wet and dry aging and CIE $L^*$, $a^*$, and $b^*$ color values in butt and sirloin cuts were higher in both wet and dry aging (p<0.05) groups than those in the non-aged control. Regardless of the aging method used, inosine-5'-monophosphate content among beef cuts was the same. The sensory panel scored significantly higher values in tenderness, flavor, and overall acceptability for dry-aged beef regardless of the beef cuts tested compared to non- and wet-aged cuts. In addition, dry-aged beef resulted in similar overall acceptability among the different beef cuts, whereas that in wet-aged meat was significantly different by different beef cuts. In conclusion, both wet and dry aging improved the quality of different beef cuts; however, dry aging was more suitable for improving the quality of less preferred beef cuts.

• 대한통합의학회지
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• 제10권3호
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• pp.199-208
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• 2022

Purpose : The study aimed to examine gender-differences in muscle tone, elasticity, and stiffness of the erector spinae in young and old subjects. This study also aimed to assess the effect of aging on muscle tone, elasticity, and stiffness of the erector spinae in men and women, and compare the trend of the aging effect between the two gender groups. Methods : With the muscle in the relaxed state and subjects in the prone position, a myotonometer was used to quantify muscle tone, elasticity, and stiffness, of the erector spinae in 102 participants[46 males (29 young subjects, aged 22.48±2.23 years and 17 old subjects, aged 76.35±3.71 years), 56 females (40 young subjects, aged 20.38±1.43 years and 16 old subjects, aged 74.56±5.40 years)]. Results : The tone and stiffness of the erector spinae muscles were greater in men than in women for both age groups (p<.001-.01), while elasticity did not show a significant difference between men and women. For the direction of change, both male and female groups showed significantly increased tone and stiffness, and decreased elasticity with increasing age (p<.001). For age-related changes, a different tendency was observed between men and women. Men showed a greater increase in tone than women with aging. in contrast, both men and women exhibited a similar decrease or increase in elasticity and stiffness. Conclusion : Gender-differences in the erector spinae in terms of muscle tone and stiffness were observed. Regardless of the age, men had higher muscle tone and stiffness than women, but not elasticity. The erector spinae muscles showed age-related changes in all aspects of muscle tone, elasticity, and stiffness, in both men and women. Notably, men presented greater variation than women in the amount of increase of muscle tone with aging. These findings have implications for musculoskeletal therapeutic approaches, and gender-customized tuning may be indicated for designing exercise interventions to prevent and manage gender-sensitive muscular injuries or diseases and frailty.

• 대한인간공학회지
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• 제28권2호
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• pp.27-34
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• 2009

The purpose of this study was to evaluate aging (young and old), gender (male and female), and handle shape effects on grip force, finger force, and subjective comfort. Four handle shapes of A, D, I, and V were implemented by a multi-finger force measurement (MFFM) system which was developed to measure every finger force with different grip spans. Forty young (20 males and 20 females) and forty old (20 males and 20 females) subjects participated in twelve gripping tasks and rated their comfort for all handles using a 5-point scale. Grip forces were calculating by summation of all four forces of the index, middle, ring and little fingers. Results showed that young males (283.2N) had larger gripping force than old males (235.6N), while young females (151.4N) had lower force than old females (153.6N). Young subjects exerted the largest gripping force with D-shape due to large contribution of the index and middle fingers and the smallest with A-shape; however, old subjects exerted the largest with I-shape and the smallest with V-shape due to small contribution of the ring and little fingers. As expected, the middle finger had the largest finger force and the little finger had the smallest. The fraction of contribution of index and ring fingers to grip force differed among age groups. Interestingly, young subjects provided larger index finger force than ring finger force, whereas old subjects showed that larger ring finger forces than index finger force in the griping tasks. In the relationship between performance and subjective comfort, I-shape exerting the largest grip force had less comfort than D-shape producing the second largest grip force. The findings of this study can provide guidelines on designing hand tool handle to obtain better performance as well as users' comfort.

• 한국실내디자인학회:학술대회논문집
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• 한국실내디자인학회 2006년도 춘계학술발표대회 논문집
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• pp.173-178
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• 2006

An increase in the proportion of Korean population in older age is much faster than the rest of the world. Along with rise of nuclear family due to rapid industrialization, informatization and materialization, ageing, on current situation in Korea that a reality of being diminished consciousness involving the sense of filial piety, and of respect or honor for the elders, does mean that such topics in ageing have become sociocultural issues that a nation should get more deeply involved in caring later life of the elderly population in an official and obligatory manner. Under this circumstance, an exhibition space in the hall intended for experiencing the later life of the elderly will surely play the role of locomotive in the respect of education to understand aging adults, and to promote development of health and welfare industry, especially for older population, also in creating and developing a positive and desirable culture and environment. To implement design project concerned with the space for the elderly population in a more careful and effective manner, the features of the Old Age Experience Hall that will satisfy the requirements thereof and the space compositions as well as characteristics of three exhibition halls having already been operated were analyzed examining closely the current facing issues in this aging society and also investigating the aging process related to physical functions of older adults. Based on those analyses, this study was aimed to prepare an efficient and systematic theoretical foundation for planning space composition of the Old Age Experience Hall further having extracted basic directions for design from, which should be meticulously considered and reflected so as to make the Old Age Experience Hall function properly.

• 한국안전학회지
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• 제26권3호
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• pp.91-97
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• 2011

The weight of elderly people in Korea has been increasing. Statistics show that the percentage of the elderly people in Korea was 3.1% in 1970; 3.8% in 1980; 5.1% in 1990, and 7.2% in 2000. Based on this trend, thus, the number of elderly people could be estimated to be 14% of the whole Korean population in 2018. This reveals that Korea is entering a super-aging society with remarkable fast pace. In such a change, the statistics related to elderly people driving license and the occurrence of traffic accidents are showing a noticeable numerical value. The number of traffic accident fatality in Korea ranks the highest value in OECD Countries. However, the research on old drivers in the nation is going on partially centering on system improvement and management scheme. Thus, first of all, researches about the linkage & characteristics between the driving behavior of old drivers and traffic accident should be implemented, in order properly to draw system improvement and management scheme for the old drivers. Therefore, the focus of this study is the influence model for discerning the severity of the age-old-caused traffic accidents by inquiring into the relation between the Driving Aptitude Test items that make it possible to measure their behavioral characteristics and influential factors by age group on the basis of the data on traffic accidents. The analysis results can be used as basic data for suggesting the behavioral research and countermeasure for traffic safety and its management for old driver in preparation for the aging society.