• Journal of the Korean Institute of Landscape Architecture
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• v.47 no.3
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• pp.12-21
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• 2019

In order to investigate the effect of various pavement materials (artificial grass, natural grass, and clay sand) on the human thermal environment, the microclimate data in early autumn (air temperature, humidity, wind speed, and shortwave and longwave radiation) were measured and compared on each surface. The mean air temperature, humidity and wind speed of the pavement materials did not differ significantly and showed the greatest difference in the mean radiant temperature. Natural grass, which has the highest albedo, has the highest amount of shortwave radiation. The artificial turf had the highest surface temperature and the highest amount of longwave radiation. In the human thermal environment index PET, artificial grass > clay sand > natural grass. Natural grass had a maximum 2/3 level lower and a mean 1/2 level lower in PET as compared to artificial grass. The clay sand pavement had a maximum 2/3 level lower and a mean 1/3 level lower than the artificial grass. Natural grass had a maximum 1/3 level lower than the clay sand pavement. Their UTCIs showed smaller differences than the PETs. Therefore, it is necessary to carefully choose materials from the planning stage when designing outdoor spaces, including playgrounds.

• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.199-205
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• 2020

As many government policies have been announced today regarding real estate, especially housing, interest in prices in the housing market has increased significantly. In this study, I would like to present the direction of government policies by analyzing the relationship among income instability, the psychological condition of real estate price changes and willingness to adjust real estate holding ratio. First, major variables were extracted through the prior study review, and using a survey, data were collected and path analysis was conducted. According to the analysis, the current income instability had a negative impact on the psychological condition of real estate price changes, and a positive influence on the willingness to adjust real estate holding ratio, but the psychological condition of real estate price changes did not have a statistically significant impact on the willingness to adjust real estate holding ratio. Thus, the difference analysis was conducted between groups by dividing the ages and the number of dependents respectively. According to the analysis, the impact of income instability and psychological condition of real estate price changes on willingness to adjust real estate holding ratio differed between groups divided by ages and number of dependents. The results of this analysis will help the government to establish real estate policies and help each household to use the analysis as basic data when they make a decision about real estate. On the other hand, this study has limitations that have only been conducted cross-sectional analysis and analyzing time series changes and differences in perception between regions are going to be conducted in a future study.

• Journal of Dairy Science and Biotechnology
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• v.40 no.2
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• pp.57-65
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• 2022

This study was conducted to evaluate the potential use of milk mineral (MM) as the calcium source for the production of calcium-fortified yogurt. MM was composed of 83% minerals, 7.5% lactose, 3.3% protein, and < 1% fat. Calcium (Ca) content in MM was about 46%; calcium: phosphorous ratio was 1.28:1. The aqueous solubility of Ca increased with the decrease in pH; the solubility at pH 4 and 5 was 98% and 53%, respectively. Ca-fortified yogurt with up to 200 mg Ca/100 mL did not show significant differences in acid production and number of viable cells; however, the viscosity increased significantly (p<0.05) with the increase in Ca levels. Microstructure analysis of Ca-fortified yogurt using confocal scanning laser microscopy indicated that the protein network became denser with increasing fortification with MM. There was no significant difference in the sensory quality between the control and Ca-fortified yogurts. Therefore, MM could be used for the production of Ca-fortified yoghurt without compromising the quality characteristics of yogurt.

• Korean Journal of Radiology
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• v.23 no.4
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• pp.446-454
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• 2022

Objective: To evaluate whether hyperoxia-induced ΔR₁ (hyperO₂ΔR₁) can accurately identify histological infarction in an acute cerebral stroke model. Materials and Methods: In 18 rats, MRI parameters, including hyperO₂ΔR₁, apparent diffusion coefficient (ADC), cerebral blood flow and volume, and ¹⁸F-fluorodeoxyglucose uptake on PET were measured 2.5, 4.5, and 6.5 hours after a 60-minutes occlusion of the right middle cerebral artery. Histological examination of the brain was performed immediately following the imaging studies. MRI and PET images were co-registered with digitized histological images. The ipsilateral hemisphere was divided into histological infarct (histological cell death), non-infarct ischemic (no cell death but ADC decrease), and nonischemic (no cell death or ADC decrease) areas for comparisons of imaging parameters. The levels of hyperO₂ΔR₁ and ADC were measured voxel-wise from the infarct core to the non-ischemic region. The correlation between areas of hyperO₂ΔR₁-derived infarction and histological cell death was evaluated. Results: HyperO₂ΔR₁ increased only in the infarct area (p ≤ 0.046) compared to the other areas. ADC decreased stepwise from non-ischemic to infarct areas (p = 0.002 at all time points). The other parameters did not show consistent differences among the three areas across the three time points. HyperO₂ΔR₁ sharply declined from the core to the border of the infarct areas, whereas there was no change within the non-infarct areas. A hyperO₂ΔR₁ value of 0.04 s^-1 was considered the criterion to identify histological infarction. ADC increased gradually from the infarct core to the periphery, without a pronounced difference at the border between the infarct and non-infarct areas. Areas of hyperO₂ΔR₁ higher than 0.04 s^-1 on MRI were strongly positively correlated with histological cell death (r = 0.862; p < 0.001). Conclusion: HyperO₂ΔR₁ may be used as an accurate and early (2.5 hours after onset) indicator of histological infarction in acute stroke.

• Journal of Intelligence and Information Systems
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• v.26 no.2
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• pp.105-129
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• 2020

This study uses corporate data from 2012 to 2018 when K-IFRS was applied in earnest to predict default risks. The data used in the analysis totaled 10,545 rows, consisting of 160 columns including 38 in the statement of financial position, 26 in the statement of comprehensive income, 11 in the statement of cash flows, and 76 in the index of financial ratios. Unlike most previous prior studies used the default event as the basis for learning about default risk, this study calculated default risk using the market capitalization and stock price volatility of each company based on the Merton model. Through this, it was able to solve the problem of data imbalance due to the scarcity of default events, which had been pointed out as the limitation of the existing methodology, and the problem of reflecting the difference in default risk that exists within ordinary companies. Because learning was conducted only by using corporate information available to unlisted companies, default risks of unlisted companies without stock price information can be appropriately derived. Through this, it can provide stable default risk assessment services to unlisted companies that are difficult to determine proper default risk with traditional credit rating models such as small and medium-sized companies and startups. Although there has been an active study of predicting corporate default risks using machine learning recently, model bias issues exist because most studies are making predictions based on a single model. Stable and reliable valuation methodology is required for the calculation of default risk, given that the entity's default risk information is very widely utilized in the market and the sensitivity to the difference in default risk is high. Also, Strict standards are also required for methods of calculation. The credit rating method stipulated by the Financial Services Commission in the Financial Investment Regulations calls for the preparation of evaluation methods, including verification of the adequacy of evaluation methods, in consideration of past statistical data and experiences on credit ratings and changes in future market conditions. This study allowed the reduction of individual models' bias by utilizing stacking ensemble techniques that synthesize various machine learning models. This allows us to capture complex nonlinear relationships between default risk and various corporate information and maximize the advantages of machine learning-based default risk prediction models that take less time to calculate. To calculate forecasts by sub model to be used as input data for the Stacking Ensemble model, training data were divided into seven pieces, and sub-models were trained in a divided set to produce forecasts. To compare the predictive power of the Stacking Ensemble model, Random Forest, MLP, and CNN models were trained with full training data, then the predictive power of each model was verified on the test set. The analysis showed that the Stacking Ensemble model exceeded the predictive power of the Random Forest model, which had the best performance on a single model. Next, to check for statistically significant differences between the Stacking Ensemble model and the forecasts for each individual model, the Pair between the Stacking Ensemble model and each individual model was constructed. Because the results of the Shapiro-wilk normality test also showed that all Pair did not follow normality, Using the nonparametric method wilcoxon rank sum test, we checked whether the two model forecasts that make up the Pair showed statistically significant differences. The analysis showed that the forecasts of the Staging Ensemble model showed statistically significant differences from those of the MLP model and CNN model. In addition, this study can provide a methodology that allows existing credit rating agencies to apply machine learning-based bankruptcy risk prediction methodologies, given that traditional credit rating models can also be reflected as sub-models to calculate the final default probability. Also, the Stacking Ensemble techniques proposed in this study can help design to meet the requirements of the Financial Investment Business Regulations through the combination of various sub-models. We hope that this research will be used as a resource to increase practical use by overcoming and improving the limitations of existing machine learning-based models.

• The Journal of Korean Academy of Prosthodontics
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• v.51 no.4
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• pp.284-291
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• 2013

Purpose: This study compared fracture strength and fracture modes between metal wire reinforcement and glass fiber reinforcement in repaired maxillary complete denture. Materials and methods: In this study, fracture was reproduced on center of maxillary complete dentures and the denture was repaired with auto-polymerizing resin. The experimental groups (n = 10) were subjected to the following condition: without reinforcing material (control group), reinforcing with metal wire (W group), reinforcing with glass fiber pre-impregnated with light-curing resin (SES MESH, INNO Dental Co., Yeoncheon, Korea, G group). The fracture strength and fracture modes of a maxillary complete denture were tested using Instron test machine (Instron Co., Canton, MA, USA) at a 5.0 mm/min crosshead speed. The flexure load was applied to center of denture with a 20 mm diameter ball attachment. When fracture occurred, the fracture mode was classified based on fracture lines. The Kruskal-wallis test and the Mann-whitney U test were performed to identify statistical differences at ${\alpha}=.05$. Results: W group showed the highest value of fracture strength, there was no significant difference (P>.05) between control group and G group. Control group and W group showed anteroposterior fracture mainly, group W showed adhesive fracture of denture base and reinforcing material. Conclusion: In limitation of this study, the glass fiber did not improve the fracture strength of repaired maxillary complete denture, and adhesive failure was occurred along the lines of glass fiber.

• The Journal of Korean society of community based occupational therapy
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• v.3 no.2
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• pp.1-12
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• 2013

Objective : The objective of this study is to present basic data to find health care plans for the elderly by comparing time-management ability and ADL and identifying the relationships between groups with subjects of elderly people living alone and living with family in Daejeon Metropolitan City. Method : A total of 80 elders who lived alone or with family that were aged 65 or older were selected with MMSE-K, 40 people were selected as subjects for each group. For time-management ability, a questionnaire was used. ADL were assessed by using FIM. The study period was May to June 2013. Result : Comparison of scores for time-management ability and FIM of the elderly who live alone or living with family did not show any statistically significant difference. In comparison of detailed scores between groups, there were statistically significant differences between the two groups being social interaction, problem solving and memory in social cognition items among detailed items. Conclusion : Through this study, we understood that social cognitive function of the aged living alone who had less opportunity of interaction compared to that of the aged living with family was lowered. Based on this, development and study on various programs should be made with consideration of sociodemographic characteristics of the elderly within community-based occupational therapy in the future.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.4
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• pp.239-244
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• 2015

Each biological tissue has endemic electrical characteristics owing to various differences such as those in cellular arrangement or organization form. The endemic electrical characteristics change when any biological change occurs. This work is a preliminary study surveying the changes in the electrical characteristics of biological tissue caused by radiation exposure. For protection aganinst radiation hazards, therefore the electrical characteristics of living tissue were evaluated after development of the automatic control measurement system using LabVIEW. No alteration of biological tissues was observed before and after measurement of the electrical characteristics, and the biblogical tissues exhibited similar patterns. Through repeated measurements using the impedance/gain-phase analyzer, the coefficient of variation was determined as within 10%. The reproducibility impedance phase difference in electrical characteristics of the biological tissue did not change, and the tissue had resistance. The absolute value of impedance decreased constantly in proportion to the frequency. It has become possible to understand the electrical characteristics of biological tissues through the measurements made possible by the use of the developed. automatic control system.

• The Journal of Korean Medicine
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• v.33 no.3
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• pp.74-81
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• 2012

Objectives: The purpose of this study was to examine whether Sasang medical constitutional distributions of patients with uterine myoma are significantly different from those of healthy women in Korea. Methods: The subjects for this study were 258 patients who were diagnosed with uterine myoma by ultrasonography and classed through a questionnaire for the Sasang Constitution Classification II (QSCC II) among patients who entered Kyunghee Bogung oriental medical clinic from June 7th, 2011 to March 7th, 2012. Results: 1. The average size of myoma of subjects was $5.16{\pm}2.48$ and the average age was $37.1{\pm}7.2$ years old. The average age of menarche was $13.13{\pm}1.44$ years old and average frequency of abortion was $0.65{\pm}1.07$. There were no significant differences by constitution in size of myoma, age, marital status, age of menarche, history of giving birth or history of abortion. 2. The overall average BMI of all subjects in this study was 21.4. By constitution, average BMIs were $24.2{\pm}3.2$, $20.5{\pm}2.0$ and $20.2{\pm}2.2$ for Taeumin, Soyangin and Soeumin, respectively. There was a significant difference by constitution. 3. Sasang medical constitutional distributions of subjects was as follows: Taeumin 28.3% (73 patients), Soyangin 35.7% (92 patients), Soeumin 36.0% (93 patients). When compared with those of healthy Korean adult females who did not have uterine myoma (44.4%, 14.8% and 40.9%, respectively), the proportion of Soyangin was significantly higher. Conclusions: We found that Sasang medical constitutional distribution of subjects differs from those of healthy Korean women without uterine myoma and in particular, among Soyangin is significantly higher.

• Journal of the Korean Home Economics Association
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• v.23 no.3
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• pp.55-61
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• 1985

This study was designed to find out the optimum processing condition and the characteristics of yeots : In this study, Yeoteses were made from glutinous rice, Rice, Millet, Sorghum and Corn by microwave oven. The textural parameters of various Yeotses were determined by sensory evaluation and Rheometermeasurement. RESULTS : 1. The sweetness of all the raw materials before saccharification is 11%. In case of the sweetness of the raw materials after saccharification, Glutinous rice was the highest(28.8%) and Corn was the lowest(17.7%). Also, the sweetness of Glutionous rice Yeots was the highest(86%) and Corn Yeots was the lowest(82.7%).It showed similar tendancy to the sensory evaluation for sweetness. 2. The pH of the raw materials before saccharification was 4.4.The pH of sorgphum after-saccharification was the highest (4.7) and that of Corn was the lowest (4.3). 3. In the sensory evaluation of the various Yeotses, Glutinous rice Yeots showed the best quality and it did not showed any significant difference between glutinous Yeots and Rice Yeots.The overalll quality of Milet, Sorghum and Corn Yeotses were inferior to Glutnous and Rice Yeotses. Textural characteristics by Rheometermeasurement revealed differences among the various Yeotses. Hardness, Cohesiveness, Adhesiveness were the highest in Glutinous rice and Rice Yeotses. Adhesiveness showed similar tendancy to that of the sensory evaluation. 4. However, Becuase glutinous rice is more expensive than rice, it is desirable that we use Rice Yeots.