• Journal of Korean Clinical Health Science
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• v.2 no.4
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• pp.239-246
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• 2014

Purpose. to describe the prevalence of refractive error according to aging in young children in South Korea. Methods : From July 2013 to June 2014, five hundred subjects( 250 male subjects, 250 female subjects; aged between 7 and 12 years) were performed in refraction test using the Auto-Refraction. Myopia, hyperopia, astigmatism, and anisometropia were defined as spherical equivalent(SE)${\leq}-0.50$ diopters, SE ${\geq}+2.00$ D, cylinder error ${\geq}0.75$ D and SE difference${\geq}1.00$ D between binocular eyes, respectively. Results. The refractive error by spherical equivalent among all subjects was myopia 80.41%, astigmatism 44.89%, emmetropia 18.27%, anisometropia 16.92%, and hyperopia 1.32%. The prevalence of myopia increased with age. but hyperopia was decrease. Myopia and astigmatism were much more common in male than females although the difference was not statically significant. Emmetropia and hyperopia were much more common in female than males although the difference was not statically significant. The prevalence of spherical equivalent was much common from -1.00 diopter to 0.99 diopter. On the other hand, the prevalence of myopia was much more than hyperopia. There was a statistical significance between 9 year and 10 year of female in the spherical equivalent power(p>0.05). In all another group of age, there was not a statistical significance as aging in spherical equivalent power(p>0.5). However, there was a statistical significance between male and female as age in the spherical equivalent power(P>0.01). Conclusions: Myopia was the most common refractive error in Korea young children, while hyperopia was decreased after 7 years. There was a statistical significance as age between male and female at spherical equivalent power(P> 0.01). these results suggested that the analysis of the refractive error as age at young children can give the useful diagnosis data for the correction of visual function.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.148-151
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• 2005

This paper is concerned with the thermo-mechanical behavior and temperature dependent strain rate sensitivity of steel sheet for an auto-body. In order to Identify the temperature dependent strain rate sensitivity of SPRC35R and SPRC45E, uniaxial tension tests are performed with the variation of the strain rates from 0.001/sec to 200/sec, and the variation of environmental temperatures from $-40^{\circ}C\;to\;200^{\circ}C$. The thermo-mechanical response at the quasi-static state is obtained with the static tensile test and at the intermediate strain rate is from the high speed tensile test. The experimental results show that the strain rate sensitivity increases at low temperature and it decreases at high temperature. It means that as the strain rate getting increasing, the variation of flow stress is more sensitive on the temperature. The results also indicates that the material properties of SPRC35R is more depend on the changes of strain rates and temperature than those of SPRC45E.

• Transactions of Materials Processing
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• v.15 no.2 s.83
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• pp.132-137
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• 2006

This paper is concerned with the thermo-mechanical behavior including temperature dependent strain-rate sensitivity of steel sheet for an auto-body. In order to identify the temperature dependent strain-rate sensitivity of SPRC35R and SPRC45E, uniaxial tension tests are performed with the variation of the strain-rates from 0.001 /sec to 200 /sec at environmental temperatures varied from $-40^{\circ}C\;to\;200^{\circ}C$. The thermo-mechanical response at the quasi-static state is obtained with the static tensile test and at the intermediate strain-rate is from the high speed tensile test. Experimental results show that the strain-rate sensitivity increases at low temperature. It represents that as the strain-rate increases, the variation of flow stress becomes sensitive on the temperature. The results indicate that the flow stress of SPRC35R is more dependent on the changes of strain-rate and temperature than those of SPRC45E.

• Journal of Auto-vehicle Safety Association
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• v.13 no.3
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• pp.102-110
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• 2021

As an alternative to solving safety, environments, and aging problems, ADS (Automated driving system) in the global automotive market is actively being developed as a new growth industry. In time for the appearance of ADS, relevant regulations and assessment programs must also be developed. For example, safety standards for the Level 3 automated driving system were promulgated in December 2019 by the Ministry of Land, Infrastructure and Transport of Korean government. However, assessment programs such as KNCAP for autonomous functions of ADS have not yet been introduced in Korea as well as globally. The autonomous driving functions of ADS at Level 3 or higher must be capable to recognize, judge and respond to objects and events in a wide variety of complex situations. In this paper, we examined and studied the complex situations, considerations and assessment items that ADS must respond to in the interest of safety for passengers, pedestrians and other road users. We hope this paper will be helpful to develop an execution program in the future.

• International Journal of Safety
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• v.11 no.1
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• pp.11-14
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• 2012

Hazard of Biodiesel (BDF) was studied. Biodiesel is a name for a variety of ester-based fuel made from vegetable oils. Recently importance of biodiesel is increasing, and its fires were sometimes reported. Therefore we studied on hazard of biodiesel comparing (petroleum) diesel oil and vegetable oil, raw materials of biodiesel. We found that biodiesel is auto-oxidized easily and ignites, and its flash point decreases when even small amount of methanol exists. And there are various raw materials to manufacture biodiesel, so we studied the difference of these materials, and their aging on safety.

• Korean Journal of Food Science and Technology
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• v.39 no.4
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• pp.432-437
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• 2007

In this study, we examined the conditions for an auto-aging system placed within a kimchi refrigerator for optimal fermentation, and to prolong the storage time of kimchi. Various characteristics of kimchi fermented at different temperatures ($5-23^{\circ}C$) were compared. We observed that the higher the fermentation temperature, the less desirable the overall acceptability of the product. To establish the time point in which to convert the fermentation mode to the storage mode, kimchi was stored at $-1^{\circ}C$ for 1 week once it reached the designated acidity (0.4, 0.6, and 0.8%). The results indicated that the lower the kimchi acidity, the higher the sensory score. The storage temperature of $-1^{\circ}C$ was not low enough to retard microorganism growth completely; however, the kimchi stored at $-2{\pm}0.5^{\circ}C$ became frozen. Accordingly, $15^{\circ}C$ and $-2{\pm}0.5^{\circ}C$ are suggested as the fermentation and storage temperatures for the kimchi refrigerator, respectively. A kimchi acidity of 0.4% can be used as an index for the time point to convert fermentation to storage. Subsequently, the time required for the fermentation course can be calculated based on this.

• Korean Journal of Food Science and Technology
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• v.40 no.6
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• pp.661-668
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• 2008

This study was investigated to determine the conditions for an auto-aging system placed within a kimchi refrigerator for optimal fermentation, as well as the optimal conditions for the prolongation of dongchimi storage time. Various fermentation characteristics of dongchimi stored at different temperatures ($5-23^{\circ}C$) were compared. The pH and acidity of dongchimi associated with the highest levels of overall acceptability were $3.9{\pm}0.1$ and $0.25{\pm}0.05%$, respectively. In order to establish the time point for the conversion of fermentation to storage, dongchimi was fermented at $10^{\circ}C$ or $15^{\circ}C$ until the acidity reached the designated points (0.1, 0.2, and 0.3%), and was then stored at $-1^{\circ}C$ for 1 week. According to the sensory evaluation, the dongchimi acidity of 0.2% fermented at $10^{\circ}C$ evidenced the highest levels of overall acceptability after 1 week of storage among the samples. In conclusion, we suggest conditions of $10^{\circ}C$ and $-2.5{\pm}0.5^{\circ}C$ for the fermentation and storage temperature, respectively, and a dongchimi acidity of 0.2% as an index for the time point for the conversion of fermentation to storage in the kimchi refrigerator.

• The Korean Journal of Applied Statistics
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• v.29 no.5
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• pp.987-998
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• 2016

Auto insurance is an insurance product that requires the proper application of pricing techniques due to intense market competition and the rate regulations of financial authorities. Especially, population change according to aging and rating faction segmentation mainly affect the pricing process. This study suggests a pricing optimization methodology through the proper estimation of age factors. To properly estimate the future distribution of age factor, age change, renewal and conversion of customers are considered as main effects for the optimization of estimation and application. The properness and effectiveness for the suggested method will be proved by a comparison of results applied (one for current distribution and the other for future distribution) at the off-balance process. This study suggests an appropriate risk estimation methodology based on optimization that uses the proper estimation of future distribution to protect from the over or under estimation of risk.

• Journal of Physiology & Pathology in Korean Medicine
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• v.30 no.5
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• pp.338-346
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• 2016

Signal transducer and activator of transcription 3 (STAT3) is associated with various human diseases, such as cancer, auto-immune disease, and intestinal inflammation. The limited and inadequate effect of standard approaches for treating inflammatory bowel disease (IBD) has prompted to develop alternative anti-colitis agents through inhibition of STAT3. Here, we show that gallic acid (GA), a 3,4,5-trihydroxybenzoic acid, markedly reduced phosphorylation of STAT3. Among the derivatives of benzoic acids, GA showed significant inhibition on STAT3 phosphorylation. In addition, GA ameliorated the dextran sodium sulfate (DSS)-induced acute colitis as determined by the measurement of symptomatic and histological indices. The suppression of DSS-induced acute colitis by GA treatment may be related to the regulation of cytokines and growth factors. Furthermore, GA inhibited phosphorylation of STAT3 in the colon tissue of DSS-treated mice. These findings may be useful in comprehending the molecular action of GA on STAT3 phosphorylation and provide novel insights into the potential application of GA in the treatment of STAT3-related inflammatory disease, such as IBD.

• Journal of The Korean Society of Integrative Medicine
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• v.6 no.4
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• pp.149-169
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• 2018

Purpose : This study was to develop a strategy for modeling future workforce projections to serve as a basis for analyzing annual supply of and demand for physical therapists across the South Korea into 2030. Methods : In-and-out movement model was used to project the supply of physical therapists. The demand was projected according to the demand-based method which consists of four-stages such as estimation of the utilization rate of the base year, forecasting of health care utilization of the target years, forecasting of the requirements of clinical physical therapists and non-clinical physical therapists based on the projected physical therapists. Results : Based on the current productivity standards, there will be oversupply of 39,007 to 40,875 physical therapists under the demand scenario of average rate in 2030, undersupply of 44,663 to 49,885 under the demand scenario of logistic model, oversupply of 16,378 to 19,100 under the demand scenario of logarithm, and oversupply of 18,185 to 20,839 under the demand scenario of auto-regressive moving average (ARIMA) model in 2030. Conclusion : The result of this projection suggests that the direction and degree of supply of and demand for physical therapists varied depending on physical therapists productivity and utilization growth scenarios. However, the need for introduction of a professional physical therapist system and the need to provide long-term care rehabilitation services are actively being discussed in entering the aging society. If community rehabilitation programs for rehabilitation of disabled people and the elderly are activated, the demand of physical therapists will increase, especially for elderly people. Therefore, healthcare policy should focus on establishing rehabilitation service infrastructure suitable for an aging society, providing high-quality physical therapy services, and effective utilization of physical therapists.