• Composites Research
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• v.31 no.4
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• pp.122-127
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• 2018

Sandwich composites of carbon fiber reinforced plastic(CFRP) and polymer foam will be used to automobile and aerospace industry according to increasing importance of light weight. In this study, mechanical and heat resistance properties of sandwich composites were compared with type of polymer foam (polyethylene terephthalate(PET), polyvinylchloride(PVC), epoxy and polyurethane). All types of polymer foams were degraded to 30, 60, 120, 180 minutes in $180^{\circ}C$. After heat degradation, the polymer foams were observed using optical microscope and compressive test was performed using universal testing machine(UTM). Epoxy foam had the highest compressive property to 2.6 MPa and after thermal degradation, the mechanical property and structure of foam were less changed than others. Epoxy foam had better mechanical properties than other polymer foams under high temperature. Because the epoxy foam was post cured under high temperature. As the results, Epoxy foam was optimal materials to apply to structures that thermal energy was loaded constantly.

• Korean Journal of Adult Nursing
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• v.13 no.1
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• pp.108-122
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• 2001

The cause of essential hypertension is yet unknown, but in general is caused by interaction of hereditary factors, diet, obesity, lack of exercise and stress. The aging process influences various physiological mechanism related to regulation of blood pressure. So elderly hypertensives have a tendancy to consider the disease as a result of the physiological aging process. This attitude causes many complications, worsening of the disease and even early death because of inappropriate care. In order to improve self-management of elderly hypertensives in this study the researcher examined the effect of blood pressure regulation by an education program that improves self-care behavior, through increasing self-efficacy. The education program consisted of group education on hypertension and self-care strategies, and encouraging and reinforcing self-efficacy resources such as verbal persuation, performance accomplishment and vicarious experiences. A quasi-experimental pre-and post-test design was used. Thirty-two elderly hypertensives participated in the study. Eighteen in the education group and fourteen in the control group. The education program consisted of eight sessions twice a week for four weeks. There was no intervention for the control group. Data were analysed using SPSS for Windows(Version 8.0). The results were as follows. 1. There was a significant decrease in systolic and diastolic blood pressure between the experimental group and control group over three different times, and interaction by groups and over time. 2. There was no significant difference in the level of self-care behavior between the experimental group and control group over three different times, and interaction by groups and over time. 3. There was significant difference in selfefficacy of experimental and control group, depending on the measuring period, but there was no difference between these groups on interaction by groups and over time. 4. There was positive correlation between self efficacy and self care behavior depending on the measuring period. There was negative correlation between diastolic blood pressure and self-care behavior on the posttest of the program, and between systolic blood pressure and self-care behavior on the follow-up test of the program. Findings indicate that this study will contribute to develop nursing strategies for the regulation of blood pressure for the elderly, which is easy for the elderly to learn as a nonpharmacologic approach.

• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.4
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• pp.313-319
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• 2015

This study relates to an investigation into semi-dry manufacturing process of BP sludge based on non-heating production method. In this study, we conducted a research into reduction of water content ratio which arose from mixture of BP by-products of high water content ratio(50% or higher) with industrial by-products to use such BP by-products as construction materials in large quantity. We measured the reduction rate of water content ratio at the feeding ratio of water content reduction agent(1:0.5) in BP by-products. The results showed that water content ratio was the lowest with 18.5% in the mixture of PA+CFA(1:0.5). Moreover, water content ratio ranged between approximately 9.2% and 11.4% at the age of 1 day to 2 days at the aging temperature of $20-30^{\circ}C$, suggesting that the water content ratio was in the range within 10% which was a level suitable for use as construction material in this study. Meanwhile, we compared and evaluated the physical properties of non-heated BP by-products based on post-aging pulverization method. The results showed that there was no significant difference, depending on pulverization method. When production efficiency and economic feasibility were taken into consideration, it was found desirable to use fine particle pulverizer or pin mill enabling continuous production.

• The Journal of the Korea Contents Association
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• v.19 no.10
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• pp.560-567
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• 2019

South Korea, which has entered an aged society, is about to enter a super-aged society in 2025. With the increase of an aging population, traffic accidents by aged drivers have been settled as a social problem. Now, when Korea is facing a super-aged society to come, a study was conducted to prevent traffic accidents that occur while the elderly people are driving through a disaster prevention design. For theoretical research, this study examined the concept and necessity of disaster prevention design, the present condition of an aged society, aged drivers' physical and cognitive characteristics, and the policies related to the forms of traffic lights the elderly people see. In addition, to propose the design, this study investigated and analyzed the traffic safety forms and colors of the International Standards Organization and proposed the first and second forms of the design of traffic lights for the gradual improvement of the traffic lights based on that. The first improved design form is a plan for displaying a triangle, an arrow with a large area, and a quadrangle in the lens of the head of the existing traffic lights, and the second improved design form is a plan for introducing a new traffic light head and forming the traffic light with a bigger triangle, an arrow with a large area and a quadrangular lens. Since it has a visually clearer form than the present traffic lights, it is expected that aged drivers who have physical and cognitive characteristics due to aging can secure better visibility and conspicuity and that they can make better reflex responses than they can now, also in the change of driving environment (rain and heavy snowstorm, etc.). In addition, it is expected that this study would be a preceding study to prepare standard guidelines on traffic safety signs other than traffic lights to be prepared for the super-aged society.

• Journal of the Daesoon Academy of Sciences
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• v.40
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• pp.115-153
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• 2022

Korea has rapidly become an aging society, and this phenomenon is found not only in common population but also in many religious circles. In this context, interest in the welfare of retired clergy members is increasing, and some religious organizations are trying to devise and perform rules and/or policies that ensure a secure post-retirement life for their clergy. However, the welfare benefits differ from one religion to another according to the characteristics of the given religion's organizational structure. For instance, denominations with a centralized hierarchy such as Catholicism or Won Buddhism implement a relatively stable welfare system for their elderly clergy members whereas autonomous denominations like many Buddhist or Christian orders are often found to have somewhat insecure welfare systems. Clergy welfare in Daesoon Jinrihoe, one of the representative new religions in Korea, is emerging as an important issue as Daesoon Jinrihoe is also affected by the problems of Korea's aging society. However, since the order has a mixed system of a centralized hierarchy and autonomous local branches, the welfare for their elderly clergy lacks clear lines of accountability. Consequently, there have been talks to devise a proper welfare system; however, these talks have come to a standstill. In this regard, this study aims to look into and analyze how various structures and welfare systems within Korean religious organizations impact elderly clergy. Lastly, this research will provide suggestions on practical alternatives for Daesoon Jinrihoe which could resolve the problems within their welfare system that negatively impact elderly clergy members at present.

• The Journal of Advanced Prosthodontics
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• v.13 no.3
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• pp.160-171
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• 2021

Purpose. This in-vitro study evaluated and compared the color stability of 3D-printed and conventional heat-polymerized acrylic resins following aging, mechanical brushing, and immersion in staining medium. Materials and methods. Forty disc-shaped specimens (10 mm in diameter and 3 mm thick) were prepared from two 3D-printed [DentaBASE (DB) and Denture 3D+ (D3D)] and one conventional polymethylmethacrylate (PMMA) denture materials. The specimens were thermo-cycled, subjected to mechanical brushing, and were immersed in either coffee, lemon juice, coke, or artificial saliva (AS) to simulate one and two years of oral use. Color measurements of the specimens were recorded by a spectrophotometer at baseline (T0), and after one (T1) and two years (T2) of simulation. The color changes (ΔE) were determined and also quantified according to the National Bureau of Standards (NBS) units. Descriptive statistics, followed by factorial ANOVA and Bonferroni post-hoc test (α=.05), were applied for data analysis. Results. The independent factors, namely material, staining medium, and immersion time, and interaction among these factors significantly influenced ΔE (P<.009). Irrespective of the materials, treatments, and time, the highest and the lowest mean ΔEs were observed for PMMA in lemon juice (4.58 ± 1.30) and DB in AS (0.41 ± 0.18), respectively. Regarding the material type, PMMA demonstrated the highest mean ΔE (2.31 ± 1.37), followed by D3D (1.67 ± 0.66), and DB (0.85 ± 0.52), and the difference in ΔE between the materials were statistically significant (P<.001). All the specimens demonstrated a decreased color changes at T2 compared to T1, and this difference in mean ΔE was statistically significant (P<.001). Conclusion. The color changes of 3D-printed denture resins were low compared to conventional heat polymerized PMMA. All the tested materials, irrespective of the staining medium used, demonstrated a significant decrease in ΔE values over time.

• The Journal of Korean Obstetrics and Gynecology
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• v.22 no.1
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• pp.1-14
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• 2009

Purpose: Oxidative stress was thought to play a critical role in neurodegenerative disease. Many in vivo and in vitro reports explained the possible pathway of human aging. But in therapeutic aspects, there was no clear answers to prevent aging associated with neural diseases. In this study, we investigated the antioxidant and neuroprotective effects of the Insamyangyung-tang (IYT). Methods: To estimate the antioxidant effects, we carried out 1.1-diphenyl-2-picrylhydrazyl (DPPH) free radical scavenging assay, 2,2'-azinobis-(3- ethylbenzothiazoline-6- sulfonic acid (ABTS) radical cation decolorization assay, and measurement of total polyphenolic content. To evaluate neuroprotective effect of IYT in vitro. We performed thiazolyl blue tetrazolium bromide (MTT) assay, reactive oxygen species (ROS) creation in SH-SY5Y. Tyrosine hydroxylase (TH) immunocytochemistry, nitric oxide (NO) assay, and TNF-${\alpha}$ assay in primary rat mesencephalic dopaminergic neurons. Results: The $IC_{50}$ values were $571.6{\mu}g/m{\ell}$ and $202.3{\mu}g/m{\ell}$ in DPPH and ABTS assay respectively. Total polyphenolic content was 1.05%. In SH-SY5Y culture, IYT significantly increased the decreased cell viability by 6-OHDA at the concentrations of $10{\mu}g/m{\ell}$ in pre-treatment group, $10-100{\mu}g/m{\ell}$ in post-treatment group, and $100{\mu}g/m{\ell}$ in co-treatment group. The production of ROS induced by 6-OHDA was significantly inhibited in IYT treated group. In mesencephalic dopaminergic cell culture, the IYT group reduced the dopaminergic cell loss against 6-OHDA toxicity and the production of No and TNF-${\alpha}$ at the concentration of $0.2{\mu}g/m{\ell}$. Conclusion: These results showed that IYT has antioxidant and neuroprotectctive effects in the dopaminergic cells through decreasing the production of ROS, NO and TNF-${\alpha}$ which can cause many neurodegenerative changes in brain cell.

• Journal of Digital Convergence
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• v.21 no.3
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• pp.49-62
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• 2023

Due to social and cultural changes and the growth of aging people living as a single because of aging, lonely deaths are steadily increasing, and each local government has begun to define them as a social problem. The legal basis began to be established. In order to explore policy measures to prevent lonely deaths, this study examined cases of lonely death prevention policies using smart digital information technology (AI, IOT), which is being promoted by Daegu Metropolitan City to promote non-face-to-face policies to prevent lonely deaths. Policies related to lonely deaths are divided into two axes: lonely death prevention projects and post-excavation support projects. In order to operate these businesses efficiently, the provision of non-face-to-face services through artificial intelligence and the Internet of Things is recognized as a new service delivery system, so the importance and necessity of non-face-to-face services is increasing. It is time that multifaceted changes and preparations are needed, such as establishing a system to expand the non-face-to-face industry at the national level. In order to respond to another national disaster situation in the future, the non-face-to-face smart care system is being expanded in various welfare policies such as preventing lonely deaths. It will have to be activated.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.126-135
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• 2007

This study was conducted to identify the effects of the oriental medicine Qigong Exercise on the brain power, HRV, pulsation, live blood condition among young boys and girls. The study was performed with two group(control group and experimental group) in a pre-test/post-test design. The subjects were 44 young boys and girls selected by a some middle school in Busan. The oriental medicine Qigong Exercise program consists of 80-minute sessions three times a week over 5 months. All of the subjects were examined on the congnition assessment tool, stress assessment tool, oriental medicine pulsation 3-D MAC, live blood condition analyzer Prior and post surveys were measured before and after the experiment. In the cognition assessment, the amplitude of ERS were increased afer Qigong Exercise. The Success and the Concentration were significantly increased afer Qigong Exercise, the Error was significantly decreased afer Qigong Exercise. The Cognition strength was significantly increased, but the Reponse time was not significantly decreased afer Qigong Exercise. And the Workload was not significantly decreased, the Total Score was not significantly increased afer Qigong Exercise. Among the stress assessment, RRV tachogram's ‘mean RR’ was significantly increased, ‘mean HRV’ was significantly decreased afer Qigong Exercise. SDNN was not significantly increased, Complexity was not significantly increased afer Qigong Exercise. And TP(RRV power's total power) was not significantly increased, VLF and HF was significantly increased, and LF was significantly decreased afer Qigong Exercise. ANS's norm LF was not significantly decreased, but norm HF was significantly increased afer Qigong Exercise. In the RRV's Phase Plot, RMSSD and SDSD were not significantly increased, pnn50 was not significantly decreased afer Qigong Exercise. On the whole, Parasympathetic Activity and Stress Endurance were significantly increased, but Cardiac Activity and Physical Arousal were not significantly increased afer Qigong Exercise. Cardiac Aging was not significantly decreased afer Qigong Exercise. Sympathetic Activity, Autonomic Nervous System Balance and Heart-load were not significantly decreased afer Qigong Exercise. In the pulsation, press power was increased(15%), and w/t(pressurization time / pulsation time) was decreased(20%) afer Oigong Exercise. And the live blood condition was not changed afer Qigong Exercise. As mentioned above; the oriental medicine Qigong Exercise program was identified the effects of the inspiration of the brain power, heart rate and anti-stress.

• Korean Journal of Animal Reproduction
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• v.20 no.4
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• pp.467-472
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• 1997

This study was conducted to determine the optimal DC voltage for NT of in vivo donor embryo nuclei and investigate the effect of donor embryo guality on fusion and in vitro development of NT embryos . Recpient oocytes were enucleated 25~27h after IVM and further cuitured for 18~20h prior to fusion for oocyte aging. Donor embryos of molura stage were recovered from superovulated heifers and classified l into good and low quality group. Their nuclei were transferred in to the emucleated oocytes 42~44h post-IVM and fused 43-45h post-IVM with a single 0.75kV /cm or 1.0kV /cm DC voltage for 70${\mu}\textrm{A}$sec. The fusion rate of oocytes was not different between two DC voltages. However, the cleavage and M + B developmnent was more high at 1.0kV /cm DC voltage and the proportion of M+B was 19.0% at 0.75kV /cm DC and 29.4% at 1.0kV /cm DC voltage. Donor embryo qualtiy did not greatly affect the fusion and cleavage of NT oocytes, but none of NT embryos derived from low embryo quatity reached the morula stage. The results indicate that the most suitable DC v voltage for electrofusion of in vivo donor muclei was a single 1.0kV /cm DC voltage and donor embryo quality was an important factor affecting the development in vitro of NT embryos.