• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.1
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• pp.39-51
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• 2016

In accordance to rapid aging of population, the accidents of elderly pedestrian and pedestrian safety are becoming very important issues. In terms of smartphone technologies, older people are increasingly looking for useful and friendly ICT services that which can add a value on their silver life. This paper introduced a new IT-based service for elderly walking assist using a smart-phone accompanied by a wearable watch. We describe the functional requirements and a systems architecture model with an interface between a smart-phone and wearable watch. Moreover, this study attempted to verify what services are needed and to estimate elderly pedestrians' WTP (willingness to pay) for IT-based walking assistance device. A total of 189 elderly pedestrians were randomly surveyed through face-to-face interviews. The questionnaire consisted of 3 categories: (1) questions pertaining to socio-economic status, (2) 12 questions regarding walking attitudes, and (3) a question to measure WTP. With this gathered data, factor analysis and path model estimating were conducted. The results identified the elderly user requirements and the use-value of new innovative products for IT-based walking assistance services by two groups(latent elderly and elderly). The modeling result shows that elderly's service preference would increase the possibilities for the commercialization of IT-based walking device with improving their walking safety.

• Journal of the Korea Concrete Institute
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• v.19 no.6
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• pp.693-700
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• 2007

The maturity method is used to estimate the effects of time and temperature on the strength development of concrete. The purpose of this paper is to show how variable curing temperatures affect strength development for both normal and high-strength concrete using the maturity concept. The experimental results for normal-strength concrete show clearly the cross-over effect of strength development as the time of the peak temperature varied. However, this cross-over effect does not exist after the actual ages are converted to the temperature dependent equivalent age. In other words, the existing maturity method does not include the effect of varying the time to peak temperatures but instead includes the effect of the magnitude of peak temperatures. For high-strength concrete, the results were inconclusive. This fact for normal-strength concrete coincides with the ASTM stated limitation that the existing maturity method doesn't take into account the effect of early age temperature on long-term ultimate strength. The results of this 3-year study are used as a basis for an improved concrete maturity function.

• Restorative Dentistry and Endodontics
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• v.27 no.6
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• pp.569-576
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• 2002

This study was peformed to evaluate the interfacial shear bond strength of base (direct and indirect) and repair composites with aging and surface treatment methods. Direct composite resin specimens ($Charisma^{\circledR}$, Heraeus Kulzer, Germany) were aged for 5 min, 1 hour, 24 hours, and 1 week in $37^{\circ}C$ distilled water before surface treatment, and then divided into five groups Group 1, grinding; Group 2, grinding and application of bonding agent, Group 3, grinding, etching with 37% phosphoric acid for 30sec, and application of bonding agent, Group 4, grinding, etching with 37% phosphoric acid for 30sec, silane treatment, and application of bonding agent ; Group 5, grinding, etching with 4% hydrofluoric acid for 30sec. silane treatment, and application of bonding agent. Indirect composite resin specimens ($Artglass^{\circledR}$, Heraeus Kulzer, Germany) were aged for 1 week in $37^{\circ}C$ distilled water and divided into seven groups Group 1 - Group 5, equal to Charisma specimens; Group 6, grinding, etching with 37% phosphoric acid for 60sec, silane treatment, and application of bonding agent; Group7, grinding, etching with 4% hydrofluoric acid for 60 sec, silane treatment, and application of bond-ing agent. The repair material($Charisma^{\circledR}$) was then added on the center of the surface (5 mm in diameter. 5 mm in height). The shear bond strength was tested and the data was analyzed using one-way ANOVA and the Student- Newman-Keuls test. The following conclusions were drawn. 1 The shear bond strength of $Charisma^{\circledR}$ specimens aged for 1 hour was significantly higher in Group 2 and Group 5 than in Group 1 (p<0.05), and that of $Charisma^{\circledR}$ specimens aged for 1 week was signifi-cantly higher in Group 3 and Group 5 than in Group 1 (p<0.05). No significant difference was found in the bond strength of specimens aged for 5 min and 24 hours. 2. In Group 2 of the $Charisma^{\circledR}$ specimens, there was significant difference between the bond strength of 24 hours and that of 1 week (p<0.05). 3. In Group 4 of the $Charisma^{\circledR}$ specimens, the shear bond strength of specimens aged for 24 hours was significantly higher than the others(p<0.05) 4. There was no significant difference between the shear bond strength of the $Artglass^{\circledR}$ specimens, 5. Most of the $Charisma^{\circledR}$ specimens showed cohesive fractures. Artglass^{\circledR}$ specimens that were etched with acid (phosphoric or hydrofluoric) for 30 sec showed more cohesive fractures.

• Journal of Ginseng Research
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• v.32 no.1
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• pp.39-47
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• 2008

UV irradiation causes skin-aging involving coarse wrinkles, thickening, dyspigmentation, and rough skin surface. These phenomena in complex skin tissue is controlled with receptor of cell surface growth factor and cytokine receptors. The activation of receptors induces multiple downstream signaling pathways including expression of MMPs (matrix metalloproteinases). This study was aimed to elucidate the mechanism for anti-wrinkle activity of Korean red ginseng, Torilis fructus and Corni fructus mixture (KTNG0345). In this animal study, we have investigated decreasing effects of Korean red ginseng mixture on MMP-3 synthesis through diminishing $TNF-{\alpha}$ signaling that express MMP-1, -3, and -9. c-Jun and c-fos as a component of transcription factor AP-1 (activator protein-1) were analyzed the expression level using real time PCR and western blotting. c-Jun was decreased dose dependent manner both gene and protein level where as cfos was not changed. In upstream, JNK and PAK was not changed, but p38 was decreased in down stream. MMP-3, final product in this pathway was significantly decreased in dose dependent manner. These results suggest that Korean red ginseng mixture have a anti-wrinkle activity through $TNF-{\alpha}$ mediated MMPs expression pathway.

• Journal of the Korean housing association
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• v.21 no.2
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• pp.123-132
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• 2010

The housing market requires customized housing to be supplied according to the various characteristics of households. Multinominal Logistic Regression was used to analyze the effects of variables of household characteristics according to the number of family members on the choice of housing size in the scope of the whole country's housing market. Analysis showed that the number of family members has its own characteristics. When a household has a smaller number of family members, there are more variables affecting choice of housing size. Living and housing expenses variables served as significant variables that affect all household types. Results showed that households with more living and housing expenses are more likely to choose a large sized house and where households have a greater number of family members, there is more influence on that choice. The age of the householder was only found to be a meaningful variable in 1-2 person households and 3-4 person households, particularly in the choice of a small or large sized house. This shows that the age of the householder does not play an important role in choosing medium sized houses for households of under 4 people, but affects the choice of small and large sized houses. The academic ability of household members also served as a significant variable. While 1-2 person households with high academic ability tend to select a large sized house, 3-4 person households with high academic ability tend to select a small sized house. It is observed that members of both 1-2 person households and 3-4 person households tend to select their house between a large sized house and a small sized house in order to own their own houses. The result of this research suggests that there are various and detailed variables on the choice of housing size. Especially, a notable result is that household characteristics more significantly affect the housing size choice of 1-2 person households, while the trend of an aging society will more significantly affect a 3-4 person households' choice of a large sized house. Therefore, a study on the choice of housing size according to characteristics of elderly households and 1-2 person households should be continually analyzed.

• Journal of Nutrition and Health
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• v.35 no.2
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• pp.183-191
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• 2002

The purpose of this study was to investigate the effect of dietary mushroom powder on blood glucose levels, seam lipid levels, glucose 6-phosphtase (G6Pase), thiobarbituric arid reactive substance (TBARS) and glutathione enzymes in diabetic rats treated with streptozotocin (STZ). Four groups of rats (Sprague-Dawley male rats, 180-200 g) were fed as follows: normal rats were fed a control diet (C), diabetic rats were file a control diet (CD), normal fats were fed a mushroom powder diet (M), and diabetic rals were find mushroom powder diet (MD). Diabetes was induced by single injection of streptozotocin (60 mg/kg B.W.). The animals were fed ad libium each of the experimental diets for five weeks. Food and water intake was determined every day. Blood glucose and serum total cholesterol levels were determined every week. After five weeks, the rats were sacrificed and blood glucose, serum total cholesterol, triglyceride levels and glutathione enzymes were measured. HDL-cholesterol levels were analyzed and LDL-cholesterol concentrations were calculated by equation. There was body weight loss in the diabetic rats, but the MD group showed less body weight loss than the CD group. Blood glucose and serum total cholesterol level of the MD group were lower than those of the CD group (p < 0.05). Also, serum total cholesterol of the M group was lower than that of the C group (p < 0.05). But the serum triglyceride level of the diabetic rats (CD and MD) was higher than that of the normal rats (C and M). However, there was no significant difference between the control diet group and the mushroom diet group. Serum HDL-cholesterol levels of the C group and CD group were higher than that of the M group (p < 0.05), and the MD group was not significantly different. But the serum LDL-cholesterol levels of the M group were lower than those of the C group (p < 0.05). Activity of hepatic microsomal G6Pase significantly increased in the CD and MD, reaching levels higher than those of the C and M groups. Hepateic gutathione S-transferase (GST, glutathione reductase (GR) and glutathione peroxidase (GPX) activity was not significant. But renal GST, GR and GPX activity in the MD group was lower than that of the CD group (p < 0.05). These results suggest that dietary mushroom reduces renal disorders such as oxidation and aging of tissue. In conclusion, dietary mushroom groups reduced blood glucose and cholesterol levels in STZ-induced diabetic rats and renal glutathione enzymes activity was averted in diabetic rats.

• Journal of Nutrition and Health
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• v.35 no.3
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• pp.279-290
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• 2002

This study was performed to assess age-related changes in DNA damage and antioxidative capacity in 4, 8, 12, 16, 20, and 24 months old Sprague-Dawley male rats. The following were measured the degree of oxidative DNA damage as indicated by levels of 8-hydroxy-2'-deoxyguanosine (80HdG) in the kidney ; the peroxidized lipid concentrations in the plasma and the liver, as indicated by the levels of thiobarbituric acid reactive substances (TBARS); and the levels of antioxidant enzyme activities in the erythrocytes and the liver. Both body weight (BW) and epididymal fat pad (EFP) weight per BW increased with age until 16 months, then decreased slightly from 20 to 24 months. However, the weights of the liver, kidney and spleen per BW decreased with age. Concentrations of 8-OHdG in the kidney increased with age, only slightly front 4 to 16 months, and then markedly from 16 to 24 months. TBARS concentrations in the plasma and liver were shown to increase with age, being lowest in the 4 month-old group and highest in the 24 month-old group. Superoxide dismutase (SOD) activity in the erythrocytes increased with age Catalase activity in the erythrocytes increased from 4 to 16 months, then decreased from 20 to 24 months. Glutathione peroxidase (GSH-Px) activity in the erythrocytes showed no age-related change. Liver SOD activity decreased with age, particularly from 16 to 20 months, but catalase and GSH-Px activities in the liver showed no significant changes. These results showed that during the normal aging of SD rats, DNA damage in the kidney and TBARS concentrations in the plasma and liver increased with age, particularly after 16 months, and the imbalance of antioxidative enzyme activities in the erythrocytes accelerated with age.

• Archives of design research
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• v.19 no.1 s.63
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• pp.15-26
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• 2006

As the interest and use of computer have been increased among elderly users according to the entry to the aging society, the issue of universal design for computer usability was brought forward. Especially, it is widely recognized that universal UI(User Interlace) design on MS windows is important. The objective of this study is to conceptualize Universal GUI design on MS windows which can be used more easily and intuitively by novice users such as elderly and housewives. Especially, the solution for Universal GUI design on MS windows was developed by reflecting elderly users' needs because elderly users is the group with more difficulties than other user groups in learning and using MS windows. First, elderly user's needs was collected by participant observation as a teaching assistant in computer dass for elderly people for 4 weeks. Secondly, the experimental test and in-depth interview was implemented to find difficulties factors and needs in addition to participant observation. Based on the findings, the new GUI design solution was suggested. The design solution consists of ideas in several categories such as setting default, simplification of function for easy conceptual model making, customization of function and working environment, and intuitive GUI in interaction process. The new MS windows GUI design can be accessed by novice mode when user login in window XP. This study has the significance in finding elderly users detailed needs through in-depth and long term participant observation. However, the usability of the suggested prototype needs to be verified to various user groups besides elderly users in the future.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.67-74
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• 2009

The strength of concrete is one of the most important parameters in evaluating the properties of concrete. Compressive strength of concrete has been widely used because of its convenience of experiments and generality. Compressive strength of concrete varies according to materials and curing conditions. Even with the same materials, the strength varies according to the curing conditions. Therefore, if we want to know the strength of concrete from the construction field, we have to put it in exactly the same curing condition with the construction field. But it is impossible to make the exactly same curing conditions in the laboratory. Also damages occur in order to measure the strength of concrete, because the core hat to be made into the pavement. To overcome these limits, many studies of nondestructive method have already been researched. It was already proven that shear wave velocity was very closely related to the compressive strength. In this study, three different curing temperatures with the same mixture paste were used, and compressive strength and shear wave velocity, according to the aging were measured. The relationship between these two parameters was examined. As results, curing temperature affected the compressive strength and the shear wave velocity, but did not affect the relation between them.

• International Journal of Highway Engineering
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• v.11 no.2
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• pp.121-132
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• 2009

Thin bonded continuously reinforced concrete overlay(CRCO) was constructed on He existing jointed plain concrete pavement(HCP) surface at Seo-Hae-Ahn express highway in South Korea in order to evaluate its applicability and performance. Two sections of road were considered for this evaluation. In the first section, the concrete overlayer was placed and cut down to the existing layer to form transverse joints while CRCO was constructed on top of the existing layer in the second section. Early strength concrete(Type III) was utilized for both overlay sections. The depth of milling and the thickness of overlaid layer were 5 cm and 10 cm, respectively. Several vibrating wire gauges(VWG) were installed to evaluate the performance of CRCO with respect to curling, delamination, and crack propagation. As a result of the strength test, it was found that strength of the material reaches the design criteria within 1-3 days. Analysis with vibrating wire gauge(VWG) showed CRCO effectively restricts joint movement. High adhesive strength also was observed from the material regardless of length of aging. Meanwhile, transverse cracks were observed on the middle of the section where JPCP overlay was applied whereas arbitrarily cracks in transverse direction were observed on the section where CRCP was applied.