• 한국정밀공학회지
• /
• 제18권4호
• /
• pp.151-159
• /
• 2001

As huge energy transfer systems like a nuclear power plant, steam power plant and petrochemical plant are operated for a long time, mechanical properties are changed by degradation. The life time of the systems can be affected by the mechanical properties. BI(Ball Indentation) test has a potential to replace conventional fracture tests like a uniaxial tensile test, fracture toughness test, hardness test and so on. In this paper, we would like to present the ageing evaluation technique by the BI method. The four classes of the thermally aged 1Cr-!mo-0.25V specimens were prepared using an artificially accelerated aging method. Tensile tests, fracture toughness tests, hardness tests and BI tests were performed. The results of the BI tests were in good agreement with fracture characteristics by a standard fracture test method within 5%. The IDE(Indentation Deformation Energy) of a BI technique as a new parameter for evaluating a degradation was suggested and the new IDE parameter clearly depicts the degradation degree.

• 한국실내디자인학회논문집
• /
• 제19권5호
• /
• pp.122-129
• /
• 2010

The basic premise of this study was that the elderly family would be one user type to live in apartment houses. This means that apartment houses should be designed by considering the elderly family as well as general young families. The purpose of this study was to carry out POE of apartment houses by the elderly resident and to suggest the design direction of apartment houses from the elderly's point of view. The subject was 150 elderly residents who lived in apartment houses in Jangyu new urban area, Kyungnam. The individual interview was done for this POE by six interviewers. They asked about how degree they were satisfied with 30 design elements of apartment houses. Those consisted of 8 elements related to outdoor environments, 16 ones to indoor environments, and 6 design evaluative elements for the elderly housing. The conclusions were as followings; 1) In general, the elderly subject was very satisfied with their apartment design. However, more considerations of the design evaluative elements for the elderly were needed in order to be apartment houses for the old generation. 2) Natural facilities such as small parks and walks, and local amenities should be arranged systematically to be used easily by the old residents. 3) The design solutions for reducing noise should be added. 4) The same quality of housing environment should be provided in all sizes of housing units.

• 한국멀티미디어학회논문지
• /
• 제23권1호
• /
• pp.15-23
• /
• 2020

Recently, the increase in the elderly population due to an aging society has led to a relative increase in senile diseases such as vascular dementia or Alzheimer's disease, and the social burden for rehabilitation has increased. In addition, studies have been conducted for the risk assessment and prevention of musculoskeletal disorders. The purpose of this study is to suggest a system that can be used to help with dementia prevention training by tracking the movement of motion and virtual reality contents for the risk factors of musculoskeletal disorders of the elderly. We propose a training method for preventing dementia through musculoskeletal motion analysis algorithm and virtual reality content. Through motion recognition algorithm based on motion region design, we will track and analyze the moving radius of the target joint. The purpose of this study is to calculate and evaluate scores based on the time to accomplish the goals on virtual reality contents for the prevention of musculoskeletal disorders and the support of dementia prevention training, and the degree of difficulty, and to analyze the correlation between the results of performing K-MMSE and VR contents.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2010년도 춘계 학술논문 발표대회 1부
• /
• pp.77-81
• /
• 2010

This study deals with the analysis of color-difference and physical property of anti-corrosion coatings using at inside of concrete tank for drinking water. Because anti-corrosion coatings are effected by chemical attack, color and physical property are changed. So in this study when epoxy resin coatings of 3 types were received chemical attack by Cl- and NaOH, we present the co-relationship between color-difference and bond strength. For this study, we used the colorimetry, which can measure the degree of color difference on surface of materials. As the results, in case of Cl-, color change is appeared, bond strength also is decreased. From this experiment, we could know that color change due to chemical aging has the deep relationship with physical performance(bond strength) materials. further researches are needed.

• 가족자원경영과 정책
• /
• 제15권2호
• /
• pp.85-101
• /
• 2011

The purpose of this study is to ascertain the actual conditions of volunteering activities in respect to age-integrated leisure. This study is based on the 2010 Korea Leisure Life Survey. The participants in this study were 3015 people who reside in Korean cities, except for Jeju-do. Questionnaires from the 2010 Korea Leisure Life Survey were used for the final analysis. Data were analyzed through a descriptive analysis, Chi-Square test and ANOVA by SPSS WIN 17.0. The findings indicated that 18% of the participants participated in volunteer activities as leisure in the last one year. The major findings were as follows. First, demographic characteristics such as age, academic career, income, and marital status had a positive correlation with the degree of volunteer participation. Second, there were differences in duration and field of activities according to age. Third, though most of the non-volunteer reasons were 'lack of resources', there were different reasons based on age. In detail, the reason for 10-50 year-olds (economically active population) was 'lack of time', but the more than 60 year-olds was 'health concern'. Consequently, this access to the life cycle study shows the need to improve life satisfaction.

• 대한기계학회논문집A
• /
• 제24권12호
• /
• pp.2995-3002
• /
• 2000

The remaining life estimation for the aged components in power plants as well as chemical plants are very important beacuse mechanical properties of the components are degraded with time of service exposure in high temperature. Since it is difficult to take specimens from the operating components to evaluate mechanical properties of components nondestructive techniques are needed to estimate the degradation. In this study, test materials with 4 different degradation levels were prepared by isothermal aging heat treatment at 630$\^{C}$. And the DC potential drop method and destructive methods such as tensile, K(sub)IC and hardness tests were used in order to evaluate the degradation of 1-Cr-1Mo-0.25V steels. The objective of this study is to investigate the possibility of the application of DCPD method to estimated the material degradation, and to analyse the relationship between the electrical relationship between the electrical resistivity and the degree material degradation.

• Journal of Welding and Joining
• /
• 제22권2호
• /
• pp.59-68
• /
• 2004

Plasma transferred arc welding (PTAW) has been taken into consideration for repairing Ni-based superalloy components used gas turbine blades. Various cracks has been generally reported to be found in the base metal heat affected zone(HAZ) along grain boundary. Thus, hot cracking susceptibility of Ni-based superalloys was evaluated according to heat treatments. Hot ductility test was conducted on specimens with solution treated at 112$0^{\circ}C$ for 2 hours and aging treated at 845$^{\circ}C$ for 24hours after solution treatment. The results of the hot ductility test appeared that solution treated specimens were the highest ductility recovery rate among three conditions. The loss of ductility at high temperature in Ni-based superalloy was mainly controlled by the degree of pain boundary wetting due to constitutional liquation of MC carbide precipitates. Meanwhile, the highest ductility recovery rate in solution-treated alloys seems to be lack of M23C6, which can be dissolved during heating and then result in the local enrichment of Cr in the vicinity of the grain boundary.

• 가족자원경영과 정책
• /
• 제15권1호
• /
• pp.29-49
• /
• 2011

Social capital theory provides a robust framework for analyzing economic well being. The purpose of this study was to investigate the effects of social capital on the economic satisfaction of retirees in Korea. The data from the first wave of KLoSA(Korean Longitudinal Study of Aging) were used(n=1,628). SPSS 12.0 was used for descriptive statistics and multiple regression analysis. The major findings were as follows: First, after controlling for gender, age, region, housing tenure, and personal income, the social capital of the retirees, including cognitive social capital(trust and reciprocity) and structural social capital(emotional and economic familial support, and a well-developed social network), contributes to increases in their economic well-being. Second, the degree of effect social capital has on well-being varied by gender and age; the effect was also different according to gender, regardless of the person's age. These empirical results provide a basis for the institution of policies that help bolster economic wellbeing for retirees by creating conditions that increase social capital in this group.

• 성인간호학회지
• /
• 제26권2호
• /
• pp.159-170
• /
• 2014

Purpose: This research investigated the degree and predictors of hot flashes and hypogonadism symptoms in patients with prostate cancer receiving hormone replacement therapy. Methods: The subjects were 111 patients with prostate cancer receiving hormone replacement therapy in two university hospitals located in D city. The measurement tools included Hot Flash Diary and AMS (Aging Male's Symptoms rating scales). The data were analyzed using t-test, ANOVA, and binary logistic regression analysis. Results: The percentage of patients who experienced hot flashes among the participants was 14.4%. The predictors for hot flashes were eating irregularly, having coffee frequently and the types of hormone. The average score of hypogonadism symptom was 2.16 out of five-point scale and the highest score of hypogonadism symptom was the sexual symptoms (2.77 out of five-point scale). The predictors for hypogonadism symptom were eating habits and years of having the illness. Conclusion: These findings provide the information that irregularly eating habit was an important factor in hot flashes and hypogonadism symptoms of the participants. Therefore the development of a nutritional education encouraging regular meals is necessary for the given population.

• 한국분말재료학회지
• /
• 제1권1호
• /
• pp.42-51
• /
• 1994

6061Al-SiCP metal matrix composite materials(MMCs) were fabricated by injecting SiCP particles directly into the atomized spray. The main attraction of this technique is the rapid fabrication of semi-finished, composite products in a combined atomization, particulate injection(10 $\mu\textrm{m}$, 40 $\mu\textrm{m}$, SiCP) and deposition operation. Conclusions obtained are as follows; The microstructure of the unreinforced spray formed 6061Al alloy consisted of relatively fine(50 $\mu\textrm{m}$) equiaxed grains. By comparision, the microstructure of the I/M materials was segregated and consisted of relatively coarse(150 $\mu\textrm{m}$) grains. The probability of clustering of SiCP particles in co-sprayed metal matrix composites increased it ceramic particle size(SiCP) was reduced and the volume fraction was held constant. Analysis of overspray powders collected from the spray atomization and deposition experiments indicated that morphology of powders were nearly spherical and degree of powders sphercity was deviated due to composite with SiCp particles. Interfacial bonding between matrix and ceramics was improved by heat treatment and addition of alloying elements(Mg). Maximum hardness values [Hv: 165 kg/mm2 for Al-10 $\mu\textrm{m}$ SiCp Hv--159 kg/mm2 for Al-40 $\mu\textrm{m}$SiCp] were obtained through the solution heat treatment at $530^{\circ}C$ for 2 hrs and aging at $178^{\circ}C$, and there by the resistance were improved.