• Title/Summary/Keyword: aging variation

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Evaluation of Lighting Environment of Residential Space for Senior People by each Life Behavior with Mock-up Model (실물대 모형을 이용한 고령자 주거공간의 생활행위별 조명환경 평가에 관한 연구)

  • Kim, Byoung Soo;Yim, Oh Yon
    • KIEAE Journal
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    • v.7 no.5
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    • pp.35-40
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    • 2007
  • The purpose of this study is to execute evaluation experiment to know the evaluation property of lighting environment of residential space for senior people, considering visual characteristics along aging, and finally provide basic data for the lighting plan to ensure the visual amenity. Processes of this study are as follows;1) Analyzed the variation property of visual sensibility and visual ability of senior people along aging. 2) Selected 3 types of life behavior(rest, conversation and reading) after checking life behavior in residential space for senior people based on advanced study. 3) Made the Mock-up Model that Dimming is possible, actual furnace to model. 4) Executed sensitivity evaluation experiment about lighting environment. 5) Analyzed evaluation property of lighting environment of residential space for senior people. Results of this study are as follows, 1) With lens-filter, we got comfort and amenity in bulb-color lamp which has similar color temperature with red of lens filter. 2) Lighting environment tests during conversation : With lens filters, they felt comfort on bulb color in case of higher illuminance than 850lux and daylight color in 500lux. 3) Lighting environment tests at reading : With lens filter, bulb color got better score in brightness and appropriateness than daylight color.

Development of ZnO Varistor for Distribution Surge Arrester (18kV, 5kA) (배전급 피뢰기(18kV, 5kA)용 ZnO 바리스터 소자 개발)

  • 박춘현;윤관준;조이곤;정세영;서형권
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.11a
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    • pp.212-216
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    • 2000
  • ZnO varistors for distribution surge arrester (18kV, 5kA) were developed and tested microstructure and electrical characteristics. Microstructure of ZnO varistor was consisted of ZnO grain, spinel phase and Bi-rich phase. Average grain size of ZnO varistor was $\mu\textrm{m}$ Reference voltage and lightning impulse residual voltage of ZnO varistor exhibited a good haracteristics above 5.5kV and below 11.56kV, respectively. Consequently, discharge capacity which is the most important characteristics of ZnO varistor for surge arrester exhibited excellent properties above 70kA at twice high-current impulse test. Moreover, variation rate of reference voltage and lightning impulse residual voltage showed below 5% and 2% after high-current impulse test, respectively. Leakage current and watt loss of ZnO varistor will not increase during accelerated aging test at stress condition, such as 3.213kV/$115^{\circ}C$/1000h.

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Emerging role of Hippo pathway in the regulation of hematopoiesis

  • Inyoung Kim;Taeho Park;Ji-Yoon Noh;Wantae Kim
    • BMB Reports
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    • v.56 no.8
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    • pp.417-425
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    • 2023
  • In various organisms, the Hippo signaling pathway has been identified as a master regulator of organ size determination and tissue homeostasis. The Hippo signaling coordinates embryonic development, tissue regeneration and differentiation, through regulating cell proliferation and survival. The YAP and TAZ (YAP/TAZ) act as core transducers of the Hippo pathway, and they are tightly and exquisitely regulated in response to various intrinsic and extrinsic stimuli. Abnormal regulation or genetic variation of the Hippo pathway causes a wide range of human diseases, including cancer. Recent studies have revealed that Hippo signaling plays a pivotal role in the immune system and cancer immunity. Due to pathophysiological importance, the emerging role of Hippo signaling in blood cell differentiation, known as hematopoiesis, is receiving much attention. A number of elegant studies using a genetically engineered mouse (GEM) model have shed light on the mechanistic and physiological insights into the Hippo pathway in the regulation of hematopoiesis. Here, we briefly review the function of Hippo signaling in the regulation of hematopoiesis and immune cell differentiation.

The Reliability Evaluation about the Triode-Type CNT Emission Source (삼극형 CNT 전자원에 대한 신뢰성 평가)

  • Kang, J.T.;Kim, D.J.;Jeong, J.W.;Kim, D.I.;Kim, J.S.;Lee, H.R.;Song, Y.H.
    • Journal of the Korean Vacuum Society
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    • v.18 no.2
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    • pp.79-84
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    • 2009
  • The electron emission source of triode type has been fabricated using CNT paste. The nano Ag particle and photosensitive polymers were added to the CNT paste. The surface roughness of the CNT emitter was uniform by the back exposure method. The added nano Ag particle improves the adhesion and the electric conductance with small variation in the CNTs and between electrode. After the aging with heat-exhausting, the reliability of the triode CNT electron source was secured in the high voltage and current operation for 12 hours. At this time, the gate leakage current was about 10 % less than.

DC Accelerated Aging Characteristics of $Pr_6O_{11}$ ZnO Varistors ($Pr_6O_{11}$계 ZnO 바리스터의 DC 가속열화특성)

  • 남춘우;류정선;김향숙;정영철
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.14 no.10
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    • pp.808-814
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    • 2001
  • The electrical properties and stabiltiy of Pr$_{6}$O$_{11}$ -based ZnO varistors, which are composed of ZnO-Pr$_{6}$O$_{11}$-Cr$_{2}$O$_{3}$-Er$_{2}$O$_{3}$ based ceramics, were investigated in the Er$_{2}$O$_{3}$ content range of 0.5 to 2.0 mol%. As Er$_{2}$O$_{3}$content is increased up to approximaterly 1.0mol%, the nonlinearity was decreased. Increasing Er$_{2}$O$_{3}$ content further caused the nonlinearity to increase. The varistors with 2.0 mol% Er$_{2}$O$_{3}$ exhibited a high nonlinearity, in which the nonlinear exponent is 47.41 and the leakage current is 1.82 $\mu$A. Furthermore, they showed a very excellent stability, in which the variation rates of the varistor voltage, the nonlinear exponent, and leakage current are -0.52%, -4.09%, and 152.75%, respectively, under DC accelerated aging stress, such as (0.80 V$_{1mA}$9$0^{\circ}C$/12h)+(0.85 V$_{1mA}$115$^{\circ}C$/12h)+(0.90 V$_{1mA}$12$0^{\circ}C$/12h)+(0.95 V$_{1mA}$1$25^{\circ}C$/12h)+(0.95 V$_{1mA}$1$25^{\circ}C$/12h).2h).TEX>/12h).2h).

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Factors Influencing Successful Aging in Elders (노인의 성공적 노화와 영향요인)

  • Han, Su-Jeong;Han, Jin-Sook;Moon, Young-Sook
    • Korean Journal of Adult Nursing
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    • v.21 no.4
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    • pp.423-434
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    • 2009
  • Purpose: This study was conducted to evaluate successful aging (SA) in elderly individuals and to determine the factors that influence SA. Methods: The subjects included 207 elderly individuals from D city, Korea. The data were obtained between July 1 and August 30, 2008. The participants were assured of anonymity and confidentiality. For the evaluation, Kim & Shin's SA scale, Lawton's instrumental activities of daily living (IADL) scale, Jon's self-esteem scale, Kee's geriatric depression scale short form-Korean (GDSSF-K), and Hong's productive activities scale were used. The data were analyzed using descriptive statistics, the t-test, analysis of variance (ANOVA), and Pearson correlation coefficients; multiple regression analysis was performed using the SPSS/WIN 10.0 program. Results: The maximum score for SA was 34, and the mean score was 22.62. It was found that SA was significantly correlated to IADL, self-esteem, depression, and productive activity. Depression was the most powerful predictor of SA and it accounted for 40.6% of the total variance in SA. Self-esteem, productive activity, living situation, economic status, and age together accounted for 62.1% of the total variation in SA. Conclusion: Depression, self-esteem, and productive activity were identified as variables that influence SA. On the basis of these results, we conclude that nurses should assist elderly individuals in order to facilitate SA. Moreover, individualized nursing management strategies must be developed in order to facilitate SA.

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Prediction of Compressive Strength of Fly Ash Concrete by a New Apparent Activation Energy Function (새로운 겉보기 활성에너지 함수에 의한 플라이애시 콘크리트의 압축강도 예측)

  • 한상훈;김진근;박연동
    • Journal of the Korea Concrete Institute
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    • v.13 no.3
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    • pp.237-243
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    • 2001
  • The prediction model is proposed to estimate the variation of compressive strength of fly ash concrete with aging. After analyzing the experimental result with the model, the regression results are presented according to fly ash replacement content and water-cement ratio. Based on the regression results, the influence of fly ash replacement content and water-cement ratio on apparent activation energy was investigated. According to the analysis, the model provides a good estimate of compressive strength development of fly ash concrete with aging. As the fly ash replacement content increases, the limiting relative compressive strength and initial apparent activation energy become greater. The concrete with water-cement ratio smaller than 0.40 shows that the limiting relative compressive strength and apparent activation energy are nearly constant according to water-cement ratio. But, the concrete with water-cement ratio greater than 0.40 has the increasing limiting relative compressive strength and apparent activation energy with increasing water-cement ratio.

The Behavior Variation of the Ion Viscosity and the Compressive Strength of the Seawater and Freshwater Flooded Chlorosulfonated Polyethylene After Accelerated Thermally Ageing (가속 열화 후 해수 담수 침지된 Chlorosulfonated Polyethylene의 이온 점도와 압축 강도의 특성 변화)

  • Hong, So Young;Kim, Min Ju;Jeong, Eun Mi;Kim, Jin Pyo;Shin, Yong Deok
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.32 no.6
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    • pp.490-495
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    • 2019
  • This study performs the thermal aging of chlorosulfonated polyethylene (CSPE) for 807.36 and 1,614.48 hours at $110^{\circ}C$, which is equivalent to 40 and 80 years of aging at $50^{\circ}C$ in nuclear power plants, respectively. Flat-type CSPEs were soaked in seawater for five days and then dried for five days at room temperature. Furthermore, the soaked CSPEs were cleaned for 5 days with fresh water and dried for 1,100 days at room temperature. Through this process, the log IV of the CSPEs decreases, whereas the dissipation factor of the CSPEs increases as thermally accelerated aged years increase at the measured frequency. Although the phase degree of the response voltage versus excitation voltage of the CSPEs increases, that of the response current versus excitation voltage decreases with the thermally accelerated aging. The thermal conductivity of the CSPEs increases slightly, but the thermal diffusivity does not vary with the thermally accelerated aged year increase. The displacement of the compressive strength of the CSPEs decreases gradually as the thermally accelerated aged years increase.

Effect of Temperature and Aging on the Relationship Between Dynamic and Static Elastic Modulus of Concrete (온도와 재령이 콘크리트의 동탄성계수와 정 탄성계수의 상관관계에 미치는 영향)

  • 한상훈;김진근;박우선;김동현
    • Journal of the Korea Concrete Institute
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    • v.13 no.6
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    • pp.610-618
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    • 2001
  • This paper investigates the relationships between dynamic elastic modulus and static elastic modulus or compressive strength according to curing temperature, aging, and cement type. Based on this investigation, the new model of the relationships we proposed. Impact echo method estimates the resonant frequency of specimens and uniaxial compression test measures the static elastic modulus and compressive strength. Type I and V cement concretes, which have the water-cement ratios of 0.40 and 0.50, are cured under the isothermal curing temperatures of 10, 23, and 50$\^{C}$ Cement type and aging have no large influence on the relationship between dynamic and static elastic modulus, but the ratio of dynamic and static elastic modulus comes close to 1 as temperature increases. Initial chord elastic modulus which is calculated at lower strain level of stress-strain curve, has the similar value to dynamic elastic modulus. The relationship between dynamic elastic modulus and compressive strength has the same tendency as the relationship between dynamic and static elastic modulus according to cement type, temperature and aging. The proposcd relationship equations between dynamic elastic modulus and static elastic modulus or compressive strength properly estimates the variation of relationships according to cement type md temperature.

Changes of Regional Cerebral Glucose Metabolism in Normal Aging Process : A Study With EDG PET (정상적인 노화 과정에서 국소뇌포도당대사의 변화: FDG PET 연구)

  • Yoon, Joon-Kee;Kim, Sang-Eun;Lee, Kyung-Han;Choi, Yong;Choe, Yearn-Seong;Kim, Byung-Tae
    • The Korean Journal of Nuclear Medicine
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    • v.35 no.4
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    • pp.231-240
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    • 2001
  • Purpose: Normal aging results in detectable changes in the brain structure and function. We evaluated the changes of regional cerebral glucose metabolism in the normal aging process with FDG PET. Materials and Methods: Brain PET images were obtained in 44 healthy volunteers (age range 20-69 'y'; M:F = 29:15) who had no history of neuropsychiatric disorders. On 6 representative transaxial images, ROIs were drawn in the cortical and subcortical areas. Regional FDG uptake was normalized using whole brain uptake to adjust for the injection dose and correct for nonspecific declines of glucose metabolism affecting all brain areas equally. Results: In the prefrontal, temporoparietal and primary sensorimotor cortex, the normalized FDG uptake (NFU) reached a peak in subjects in their 30s. The NFU in the prefrontal and primary sensorimotor cortex declined with age after 30s at a rate of 3.15%/decade and 1.93%/decade, respectively. However, the NFU in the temporoparietal cortex did not change significantly with age after 30s. The anterior (prefrontal) posterior (temporoparietal) gradient peaked in subjects in their 30s and declined with age thereafter at a rate of 2.35%/decade. The NFU in the caudate nucleus was decreased with age after 20s at a rate of 2.39%/decade. On the primary visual cortex, putamen, and thalamus, the NFU values did not change significantly throughout the ages covered. These patterns were not significantly different between right and left cerebral hemispheres. Of interest was that the NFU in the left cerebellar cortex was increased with age after 20s at a rate of 2.86%/decade. Conclusion: These data demonstrate regional variation of the age-related changes in the cerebral glucose metabolism, with the most prominent age-related decline of metabolism in the prefrontal cortex. The increase in the cerebellar metabolism with age might reflect a process of neuronal plasticity associated with aging.

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