• Journal of the Ergonomics Society of Korea
• /
• v.29 no.4
• /
• pp.575-584
• /
• 2010

The aim of study is to suggest the design procedure of automobile headlamp by considering driver's experience in regard of the visibility and glare during nighttime driving. The characteristics of driver were investigated in terms of the drivers' cognitive ability and reaction time, headlamp specification and visibility, light source and glare. And, the degree of visual discomfort was categorized and recognized as a tool to represent the subjective user experience. The UX point of view was stated when the existing results were seemingly lacking of it. The visual comfort and safety of elderly drivers were also discussed by reviewing the studies of ageing regarding the visibility and driving responses. Finally, this study suggested how to reduce the negative effect of nighttime driving due to the height of headlamp, angle of lighting, color spectrum, discomfort glare, source of light by using the UX perspective and methodology.

• Journal of Family Resource Management and Policy Review
• /
• v.15 no.1
• /
• 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.

• Advances in materials Research
• /
• v.4 no.1
• /
• pp.1-12
• /
• 2015

Low carbon steel of composition 0.05C - 0.18 Mn - 0.012 Si is intercritically annealed at temperatures $750^{\circ}C$, $775^{\circ}C$ and $800^{\circ}C$. The equilibrated alloys of different amounts of austenite with varying carbon contents are quenched in iced water. The same alloys are subcritically annealed at $675^{\circ}C$ and $700^{\circ}C$ for varying periods of times; the subcritically annealed alloy samples are quenched in iced water. Optical, scanning electron and transmission electron microscopy are carried out for all the samples. The dislocation structure, its distribution and density present in the above prepared duplex ferrite martensite steels are studied. The martensites are found to be highly dislocated due to lattice invariant deformation. At the same time ferrite adjoining the martensite areas also exhibits quite a high dislocation density. The high dislocation density is favorable for strain ageing and hence bakes hardenability. EDS analyses were carried out for both martensite and ferrite phases; it is found that the degree of supersaturation in ferrite together with carbon content in martensite varies with the process parameters. The microhardness test results show that the hardness values of different phases differ appreciably with process parameters. The microstructures and the corresponding microanalyses reveal that differently processed steels contain phases of varying compositions and different distribution.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
• /
• v.32 no.6
• /
• pp.490-495
• /
• 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.

• The Journal of the Convergence on Culture Technology
• /
• v.8 no.5
• /
• pp.207-218
• /
• 2022

This study, to confirm the mediating effect of knee pain on cognitive functions and depression in older adults, and as an interdisciplinary research between the physical and psychological mechanisms, confirmed the identifying group differences by gender, age, and educational attainment of older adults, and aimed to research the improvement of cognitive functions, which is a main factor of dementia's risk prediction. The analysis data was from the 8th Korean Longitudinal Study of Ageing (KLoSA) in 2020, and the research model was verified using Process macro and model #4. The main analysis results are as follows. First, depression partially mediation effect of knee pain on cognitive functions. Second, the mediation effect of depression by gender was significant, but the direct effect in the male older adults group was twice that in the female older adults; the indirect effect did not vary significantly based on gender. Third, the mediating effect of depression by age was relatively greater in the old-old aged group than in the young-old aged one. Fourth, as for the mediating effect of depression according to the classification of educational attainment, the mediating effect was not significant in the group with a college degree or higher education but was significant in the remaining three sub-groups. Based on the results, this study makes implications for the need for active intervention strategies to improve cognitive functions, focusing on group differences by gender, age, and educational attainment in the management of knee pain and depression.

• Advances in Traditional Medicine
• /
• v.10 no.4
• /
• pp.239-253
• /
• 2010

Coenzyme $Q_{10}$ ($CoQ_{10}$, or ubiquinone) is an electron carrier of the mitochondrial respiratory chain (electron transport chain) with antioxidant properties. In view of the involvement of $CoQ_{10}$ in oxidative phosphorylation and cellular antioxidant protection a deficiency in this quinone would be expected to contribute to disease pathophysiology by causing a failure in energy metabolism and antioxidant status. Indeed, a deficit in $CoQ_{10}$ status has been determined in a number of neuromuscular and neurodegenerative disorders. Primary disorders of $CoQ_{10}$ biosynthesis are potentially treatable conditions and therefore a high degree of clinical awareness about this condition is essential. A secondary loss of $CoQ_{10}$ status following HMG-CoA reductase inhibitor (statins) treatment has been implicated in the pathophysiology of the myotoxicity associated with this pharmacotherapy. $CoQ_{10}$ and its analogue, idebenone, have been widely used in the treatment of neurodegenerative and neuromuscular disorders. These compounds could potentially play a role in the treatment of mitochondrial disorders, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, Friedreich's ataxia, and other conditions which have been linked to mitochondrial dysfunction. This article reviews the physiological roles of $CoQ_{10}$, as well as the rationale and the role in clinical practice of $CoQ_{10}$ supplementation in different neurological diseases, from primary $CoQ_{10}$ deficiency to neurodegenerative disorders. These will help in future for treatment of patients suffering from neurodegenerative disease.

• Journal of the Korean housing association
• /
• v.20 no.5
• /
• pp.113-122
• /
• 2009

The purpose of this study is to offer and analysis the stage of elderly in order to improve the quality of living environment of elderly in Korea. Taking into account the retirement age in Korea, those households with people over 60 years old were chosen for the investigation. For the study methods, an examination of documents centering on previous related studies and the analysis of references from the National Statistical Office, from which a general social situation can be clearly obtained, are used. The results are as follows; From viewpoint of the stage of elderly, Parents and children of families mostly live together stage 1 and 2, mostly live separately at stage 3, the rate of living together increases stage 4 and 5. In over stage 4, there are some cases in which the Korean tradition of three generations living under one roof appears as well. The residing period at one place becomes longer as people grow older, which shows clearly the characteristic of 'ageing in place', therefore in order to continue to provide housing support to the elderly, the characteristics of each elderly stage will have to be considered. In the life of the elderly, more and more hobby groups and meetings among the older population have been created, which means that elderly centered social activities will become more various, and facilities and community activated methods will have to be provided accordingly. Elderly people become less adaptable in new housing environments as they get older, therefore the housing has to accommodate their capability to adapt and the degree of aging. The stage of elderly can be used as a basic reference for a more effective solution when planning elderly housing in the future.

• Carbon letters
• /
• v.8 no.4
• /
• pp.280-284
• /
• 2007

Samples of active carbon of $1150\;m^2/g$ surface area were impregnated with ammoniacal salts of copper, chromium and silver, with and without triethylenediamine. The samples of impregnated carbon were aged at $50^{\circ}C$, with and without 90% RH (relative humidity), for a little more than one year and chemically evaluated periodically. Initially copper (II) and chromium (VI) reduced very fast in the samples in humid atmosphere to the extent of 30% and 60% respectively in four months. These values were found to be unaffected by the presence of triethylenediamine (TEDA) indicating that the chemical did not retard the reduction process of chromium (VI) and copper (II). However, in the absence of humidity the reduction of the impregnants was significantly less (10-12%, w/w) in four months. It was quite evident; therefore, that the moisture was mainly responsible for the reduction of chromium (VI) and copper (II) species in impregnated carbons. The prolonged ageing of the samples with and without triethylenediamme after four months with and without humid atmosphere showed that the extent of reduction of chromium (VI) was very low, i.e. 5-10% and of copper (II) was 2-25%. Silver is not reduced due to carbon, as it remained unchanged in concentration on storage. The impregnated carbon samples (100 g) without triethylenediamine, which were aged at room temperature for 5 years in absence of humidity and unaged when evaluated against cyanogen chloride (CNCl) at a concentration of 4 mg/L and airflow rate of 30 lpm showed a high degree of protection (80- 110 minutes).

• Steel and Composite Structures
• /
• v.34 no.1
• /
• pp.91-105
• /
• 2020

Steel-concrete composite beam with profiled steel sheet has gained its popularity in the last two decades. Due to the ageing of these structures, retrofitting in terms of flexural strength is necessary to ensure that the aged structures can carry the increased traffic load throughout their design life. The steel ribs, which presented in the profiled steel deck, limit the use of shear connectors. This leads to a poor degree of composite action between the concrete slab and steel beam compared to the solid slab situation. As a result, the shear connectors that connects the slab and beam will be subjected to higher shear stress which may also require strengthening to increase the load carrying capacity of an existing composite structure. While most of the available studies focus on the strengthening of longitudinal shear and flexural strength separately, the present work investigates the effect of both flexural and longitudinal shear strengthening of steel-concrete composite beam with composite slab in terms of failure modes, ultimate load carrying capacity, ductility, end-slip, strain profile and interface differential strain. The flexural strengthening was conducted using carbon fibre reinforced polymer (CFRP) or steel plate on the soffit of the steel I-beam, while longitudinal shear capacity was enhanced using post-installed high strength bolts. Moreover, a combination of both the longitudinal shear and flexural strengthening techniques was also implemented (hybrid strengthening). It is concluded that hybrid strengthening improved the ultimate load carrying capacity and reduce slip and interface differential strain that lead to improved composite action. However, hybrid strengthening resulted in brittle failure mode that decreased ductility of the beam.

• Journal of Information Technology Services
• /
• v.21 no.1
• /
• pp.163-179
• /
• 2022

Two dominant phenomena in modern world; population ageing and digitalization, have led public sector organizations to heavily rely on B2C(Business-to-Consumer) mobile applications. Yet, fatal concerns and complaints have often been raised by the mobile application users, notably from social welfare sector. With the continual expansion of digital landscape as well as the growth of life expectancy, usage of mobile applications has become prevalent across the stakeholders involved in social welfare sector. 'Smart Long-Term Care (SLTC)', inter alia, is a primary example of such mobile applications, designed to support Long-Term Residential Care (LTRC) service. The main goal of SLTC is to serve more convenient and practical LTRC service for both caregivers and care receivers. To examine user satisfaction of SLTC mobile application, this study investigates existing challenges and means to improve user satisfaction. Hence, we conducted this study using two methods: in-depth interview and topic modeling. Interestingly, two research outcomes commonly indicated that 5 factors (stability, accessibility, usefulness, responsiveness, and ease of use) were found significant in affecting user satisfaction of SLTC. Our findings suggest that the aforementioned factors can be seen as potential causes of the genuinely low user satisfaction. Eventually, this work will be a stepping-stone to elevate the overall quality level of LTRC service along with the user satisfaction degree of SLTC mobile application.