• Title/Summary/Keyword: Endurance Life

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A study on field Application of Ultrathin Pavement (초박층 포장의 현장적용 성능평가 연구)

  • Kim, Kwang-Tae;Kim, Wan-Sang;Lee, Suck-Hong;Kim, Nak-Seok
    • 한국방재학회:학술대회논문집
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    • 2007.02a
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    • pp.349-352
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    • 2007
  • Asphalt overlay resurfacing techniques have been widely utilized in maintaining asphalt concrete in Korea, causing severe traffic congestions while being in construction and difference in level due to the repeated overlay. Besides on these technical difficulties, there have been financial disadvantages associated with technique, mainly because overlay method has been executed for pavements with intact foundations, which is contrary to the norm. This study is aiming to increase the expected life length of the asphalt pavement up to the endurance period, to raise the efficiency of the pavement by maximizing the social benefit and to enhance public character of the street through combining ceramics with epoxy resins, which has advantages in compatibility with the existing pavement materials, durability to abrasion and endurance. It has been expected that the adoption of new method and pavement materials to the actual work sites will develop the performance of the pavements, and to lengthen the durability of the existing materials. The other advantages of the 'thin surfacing' method could be the improved adhesiveness, waterproof, corrosion-proof and bending strength.

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Effects of relative humidity on the physical properties of PVA impregnated paper (상대습도의 변화가 PVA 함침처리지의 물성에 미치는 영향)

  • Kim, Tae-Young;Joung, Yang-Jin;Kim, Du-Ki;Heo, Yong-Dae;Sung, Yong-Joo
    • Journal of Korea Technical Association of The Pulp and Paper Industry
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    • v.42 no.3
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    • pp.37-42
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    • 2010
  • The properties of paper are very susceptible to moisture content originated from relative humidity. This propensity of PVA impregnated paper was investigated in this study. Especially the hardening effect of borax treatment after PVA impregnation on the response of paper sample to the relative humidity was evaluated. When the moisture content was increased with the relative humidity, tensile stretch and tear resistance were increased while tensile strength and stiffness were decreased. A great increase in folding endurance of PVA impregnated paper sample was found at the higher relative humidity. The borax treatment could reduce the response of PVA impregated paper to the relative humidity.

Synthesis of WS$_2$ Solid Lubricant and Its Application to the Ball Bearing (WS$_2$ 고체윤활제의 합성 및 구름베어링 적용)

  • 신동우;윤대현;최인혁;김경도
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1998.04a
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    • pp.173-179
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    • 1998
  • The processing conditions for the synthesis of platelet WS$_2$ lubricant powder through the solid-gas reaction were optimized. The tungsten and sulfur powders were sealed in a vacuum of 10$^{-6}$ torr, prior to heat-treating at 850$\circ$C for 8 days. The react~on product showed the well-developed platelet WS$_2$ powder with an average size of 3.8 $\mu$m. The synthesized WS$_2$ powder was coated on the commercial deep grooved ball bearing (No. 6203) to examine the effects of WS$_2$ coating layer on the noise and endurance of the ball bearing. The level of noise obtained from WS$_2$ coated-ball bearing was higher (56 dB) than the value occurred in the case of greece (37 dB). The life-time of the ball-bearing assembled after coating WS$_2$ powder increased 50 times compared to the non-coated bali-bearing.

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Analysis of Photovoltaic module's Phenomena of aging with Acceleration Test (외부환경적 가속시혐에 의한 PV모듈의 열화성능 분석)

  • Kang, Gi-Hwan;Kim, Kyung-Soo;Park, Chi-Hong;Yu, Gwon-Jong;Ahn, Hyung-Gun;Han, Deuk-Young
    • Proceedings of the KIEE Conference
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    • 2006.07b
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    • pp.1151-1152
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    • 2006
  • In this paper, we examined 10 domestic samples of three different model using thermal, humidity freeze, thermal-endurance and damp heat test under IEC61215 photovoltaic module environmental endurance test condition. Three was almost no changes on power generation. Insulation resistance capacity was much higher than judgement standard but, showed unstable results depending on environmental test items. On external appearance test, there were two models which showed bubble, humidity penetration, seal melted frame phenomenon. From this results, the degree of aging under the external environment is a main cause that shortens photovoltaic module life time. So it is considered that the efforts for finding optimum condition of manufacturing process should be needed.

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A Study of Related Factors in the Bone Mineral Density of the Institutionalized Elderly (시설노인의 골다공증 관련요인 연구)

  • Kim, Hee-Ja
    • Research in Community and Public Health Nursing
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    • v.8 no.1
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    • pp.31-44
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    • 1997
  • The purpose of this study was to measure and determine the relationship of femoral neck and lumbar bone mineral density with their and related factors. It were measured and determined the relationships among bone mineral density, bone mineral content in the lumbar and femoral neck, muscle strength (arm, back, leg), muscle endurance, instrumental activity of daily living (IADL), quality of life, cognitive perceptual variables(self efficacy, perceived health status), age, age at menopausal period. The twenty five subjects participating in this study consisted of twelve males and thirteen females at a C-institution in Chung Buk province. The mean age of subjects was 73.64 years. The data was collected from August, 1993 to September, 1993. The data was analyzed with $x^2-test$, t-test, Correlation, multiple regression using a SPSS pc+ program. 1. The mean femoral neck bone mineral density was $0.636g/cm^2$, 66.7% of young bone mineral density, the mean lumbar($L_2-L_4$) bone mineral density was $0.807g/cm^2$, 79.86% of young bone mineral density. The mean fermoral neck bone mineral content was 2.906g and the mean lumbar bone mineral content was 36.898g. 2. The mean muscle strength was 17.14kg(grip strength), 32.05kg(back lift strength), 17.14kg (leg lift strength) and the mean muscle endurance was 9.92times. 3. Men showed a significantly higher score (p<0.01) in muscle strength and muscle endurance than women, as well as a significantly higher score on self efficacy and perceived health status(p<0.05). 4. The femur neck bone mineral density had a significant correlation(p<0.0l) with leg lift strength, back lift strength, and their was a significant correlations (p<0.05) with arm strength and muscle endurance. Lumbar ($L_2-L_2$) bone mineral density had a significant correlation(p<0.05) with muscle endurance, grip strength and IADL. 5. With the multiple regression analysis the most significant predictor for lumbar bone mineral density were IADL, the most significant predictor for femoral neck bone mineral density was leg strength. This study concluded: As the mean bone mineral density and bone mineral content were low, the aged showed osteopenia. Bone mineral density, muscle strength and IADL were correlated. The aged could pro mote muscle strength, bone mineral density and IADL through Leg Press exercise which was safe and efficient for the aged. This Leg Press exercise contributed to prevention of osteoporosis and promoted the health of the aged.

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FATIGUE LIFE PREDICTION OF RUBBER MATERIALS USING TEARING ENERGY

  • Kim, H.;Kim, H.Y.
    • International Journal of Automotive Technology
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    • v.7 no.6
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    • pp.741-747
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    • 2006
  • It has been almost impossible to predict the fatigue life in the field of rubber materials by numerical methods. One of the reasons is that there are no obvious fracture criteria and excessively various ways of mixing processes. Tearing energy is considered as a fracture criterion which can be applied to rubber compounds regardless of different types of fillers, relative to other fracture factors. Fatigue life of rubber materials can be approximately predicted based on the assumption that the latent defect caused by contaminants or voids in the matrix, imperfectly dispersed compounding ingredients, mold lubricants and surface flaws always exists. Numerical expression for the prediction of fatigue life was derived from the rate of rough cut growth region and the formulated tearing energy equation. Endurance test data for dumbbell specimens were compared with the predicted fatigue life for verification. Also, fatigue life of industrial rubber components was predicted.

Fatigue Life Analysis and Cooling Conditions Evaluation of a Piston for Large LPLi Bus Engines (LPG 액정분사식 대형 버스용 엔진 피스톤의 피로수명 해석과 냉각조건 평가)

  • 최경호;이부윤
    • Journal of Advanced Marine Engineering and Technology
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    • v.28 no.5
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    • pp.762-772
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    • 2004
  • Fatigue life of a Piston for large liquid Petroleum liquid injection(LPLi) bus engines is analyzed considering effects of cooling condition parameters : temperature of cooling water, and heat transfer coefficients at oil gallery and bottom surface of piston head. Temperature of the piston is analyzed with varying cooling conditions Stresses of the piston from two load cases of pressure loading. and pressure and thermal loading are analyzed Fatigue life under repeated peak pressure and thermal cycle is analyzed by the strain-life theory. For the two load cases, required loading cycles for engine life are defined, and loading cycles to failure and partial damages are calculated. Based on the resulting accumulated fatigue usage factors, endurance of the piston is evaluated and effects of varying cooling condition Parameters are discussed.

A Path Analysis on Factors - Depression, Level of Health status, Physical Function, and Regular Exercise - Influencing Health Related Quality of Life according to sex in Community dwelling Elderly (지역사회 거주 노인의 규칙적 운동, 신체적 기능, 건강수준, 우울이 건강관련 삶의 질에 미치는 영향 : 성별 경로 분석)

  • Park, Jeong-Mo;Kim, Chung-Sook;Kim, MI-Won
    • Journal of Korean Public Health Nursing
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    • v.30 no.2
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    • pp.337-348
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    • 2016
  • Purpose: This study was to examine the factors (depression, level of health status, physical function, depression) influence health related quality of life (EQ5D) in community dwelling elderly according to sex. Methods: A total of 226 elderly subjects over the age of 65 years in community were included. Data were collected by measuring the physical function (muscle endurance, flexibility, balance, and cardiovascular endurance) and by using a questionnaire about EQ5D, depression, health status. Data were analyzed by SPSS 18.0 and AMOS 18.0. Results: The major findings of this study are as follows. Explained variance of EQ5D by regular exercise, physical function, and level of health status was 19% for male elderly subjects and 26.0% for female elderly subjects. The effect was different according to sex. Depression has the effect on EQ5D (${\beta}=-.356$, p<.001) in females, while the level of health status has the effect (${\beta}=.314$, p=.027) in males. Conclusion: The results of this study indicate that the effect of regular exercise, physical function, and level of health status were different on EQ5D according to sex. Thus, different health programs according to sex are necessary to increase the quality of life in elderly individuals.

Mrs. Brown's The Hours: Michael Cunningham's Represented Mrs. Dalloway (브라운부인의 『시간들』: 마이클 커닝햄이 재현한 『댈러웨이 부인』)

  • Kim, Heesun
    • English & American cultural studies
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    • v.13 no.1
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    • pp.29-57
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    • 2013
  • Patricia Waugh once regarded modernism fiction as 'the struggle for personal autonomy' against the opposition existing social institutions and conventions. Michael Cunningham's characterizations of Virginia Woolf and Septimus in The Hours show the two contrasting reactions to individual alienation and mental dissolution in the modern era. As the personifications of endurance and self-destruction against the mechanical power of contemporary world, Woolf and Septimus consist of just the world of diptych where the woman's role is confined to the angel in the house. By creating Mrs. Brown based upon his own alienated mother image, however, Cunningham succeeds in representing the more dramatically vivid world of triptych where woman can have her own room and self-realization despite still facing the dilemma of the traditional family. Accepting Joycean Bloom's optimistic and relaxing way of life in part, Mrs. Brown connects the labyrinths between the author's (and also Richard's) alienation with the theme of celebration of the life. Clarissa in postmodern New York setting is still a concealed and mystified character. Similar to Mrs. Dalloway, on the one hand Clarissa watches other people's tragedy with compassion. Cunningham's Clarissa, on the other hand, is no longer seeking for either winning or defeat in the spectacular world unlike her predecessors. In many resilient attitudes of everyday life Clarissa is closest to Mrs. Brown whom Virginia Woolf originally hopes to describe. Without any fear or rage toward the society Clarissa witnesses and achieves "the humanity, humour, depth" of female values by successfully turning the trivial life into an epic journey.

Effect of Korean Traditional Dance Movement Training on Psychophysiological Variables in Korean Elderly Women (율동적 동작(Dance movement) 훈련이 노년기 여성의 생리, 심리적 변수에 미치는 영향)

  • 전미양;최명애
    • Journal of Korean Academy of Nursing
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    • v.26 no.4
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    • pp.833-852
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    • 1996
  • Regular long term dance movement could be one of ways to induce improvement of psychophysiological variables, resulting in improvement of quality of life. However, there have been few studies to evaluate the effect of dance movement training on both physiological and psychological variables in the elderly. This study was focused to determine the effect of Korean traditional dance movement training on psychophysiological variables-body weight, body fat, lean body mass, muscle strength, muscle endurance, flexibility, agility, resting heart rate and blood pressure, depression and life satisfaction-in Korean elderly women. Thirty four subjects, aged between 65 and 75years who have normal cognition, sensory function, cerebellum function, cardiovascular function, participated in this study. Seventeen experimental group subjects were selected from E-elderly university in Kyung Gi province, and Seventeen control group subjects were selected from N-welfare facility in Seoul City. Seventeen experimental group subjects participated for 12weeks dance movement program. Korean traditional dance movement program was developed on the basis of Korean traditional dance and music by the author. The program consisted of approximately 50minutes of dance, 3times a week for 12weeks. During 50minutes workout, there were 15minutes of warm-up dancing, 25minutes of conditioning dance and 10minutes of cool-down dancing. The intensity for the conditioning phase was at between 60% and 65% of age-adjusted maximum heart rates. The body weight, body fat, lean body mass, muscle strength(grip strength, leg strength), muscle endurance, flexibility, agility, resting heart rate and blood pressure, depression and life satis-faction were measured prior to and following the experimental treatment. The participants in dance movement were interviewed focusing on subjective feeling following 12 week's regular dance movement. Data were analyzed with mean, standard deviation, percentage of change, X²-test, t-test, and ANCOVA test using SPSS PC/sup +/ program. Subjective feeling was categorized into cognitopsy-chological and physiological responses. Results were obtained as follows : 1) The body weight (F=15.52, p=.000), body fat (F=18.33, p=.000) and lean body mass (F=7.28, p=.011) of the experimental group were significantly lower than those of the control group following the dance movement training. 2) The leg strength (F=30.96, p=.000), muscle endurance (F=9.06, p=.005), agility(F=44.92, 000), flexibility(F=6.84, p=.014) of the experimental group were significantly higher than those of the control group following the dance movement training. There was no significant difference of grip strength(F=.43, p=.515) between experimental and control groups. 3) The heart rate(F=26.96, p=.000), systolic (F=10.40, p=.000) and diastolic(F=3.99, p=.005) blood pressure at rest of the experimental group were significantly lower than those of the control group following the dance movement training. 4) No significant difference of score of depression (F=3.49, p=.071) was observed between experimental and control groups. 5) Score of life satisfaction of experimental group was remarkably higher than that of control group following 12weeks of dance movement training (p<0.05). 6) Thematic responses about the dance movement following the training were positive. "I feel good" was the most frequent among cognitopsychological responses and "I feel lightness of body" was the most frequent among physiological responses. The results suggest that Korean traditional dance movement training can improve psychophysiological variables of Korean elderly.

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