• Computers and Concrete
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• v.33 no.2
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• pp.175-193
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• 2024

Researchers have embarked on an active investigation into the feasibility of adopting alternative materials as a solution to the mounting environmental and economic challenges associated with traditional concrete-based construction materials, such as reinforced concrete. The examination of concrete's mechanical properties using laboratory methods is a complex, time-consuming, and costly endeavor. Consequently, the need for models that can overcome these drawbacks is urgent. Fortunately, the ever-increasing availability of data has paved the way for the utilization of machine learning methods, which can provide powerful, efficient, and cost-effective models. This study aims to explore the potential of twelve machine learning algorithms in predicting the tensile strength of geopolymer concrete (GPC) under various curing conditions. To fulfill this objective, 221 datasets, comprising tensile strength test results of GPC with diverse mix ratios and curing conditions, were employed. Additionally, a number of unseen datasets were used to assess the overall performance of the machine learning models. Through a comprehensive analysis of statistical indices and a comparison of the models' behavior with laboratory tests, it was determined that nearly all the models exhibited satisfactory potential in estimating the tensile strength of GPC. Nevertheless, the artificial neural networks and support vector regression models demonstrated the highest robustness. Both the laboratory tests and machine learning outcomes revealed that GPC composed of 30% fly ash and 70% ground granulated blast slag, mixed with 14 mol of NaOH, and cured in an oven at 300°F for 28 days exhibited superior tensile strength.

• The Korean Journal of Applied Statistics
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• v.37 no.2
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• pp.255-263
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• 2024

GDP represents the total market value of goods and services produced by all economic entities, including households, businesses, and governments in a country, during a specific time period. It is a representative economic indicator that helps identify the size of a country's economy and influences government policies, so various studies are being conducted on it. This paper presents a GDP growth rate forecasting model based on a dynamic factor model using key macroeconomic indicators of G20 countries. The extracted factors are combined with various regression analysis methodologies to compare results. Additionally, traditional time series forecasting methods such as the ARIMA model and forecasting using common components are also evaluated. Considering the significant volatility of indicators following the COVID-19 pandemic, the forecast period is divided into pre-COVID and post-COVID periods. The findings reveal that the dynamic factor model, incorporating ridge regression and lasso regression, demonstrates the best performance both before and after COVID.

• Journal of the Korean Geotechnical Society
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• v.40 no.2
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• pp.65-79
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• 2024

This study employs traditional statistical auto-regressive integrated moving average (ARIMA) and deep learning-based long short-term memory (LSTM) models to predict the deformation of earth retaining walls using inclinometer data from excavation sites. It compares the predictive capabilities of both models. The ARIMA model excels in analyzing linear patterns as time progresses, while the LSTM model is adept at handling complex nonlinear patterns and long-term dependencies in the data. This research includes preprocessing of inclinometer measurement data, performance evaluation across various data lengths and input conditions, and demonstrates that the LSTM model provides statistically significant improvements in prediction accuracy over the ARIMA model. The findings suggest that LSTM models can effectively assess the stability of retaining walls at excavation sites. Additionally, this study is expected to contribute to the development of safety monitoring systems at excavation sites and the advancement of time series prediction models.

• The Korean Journal of Applied Statistics
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• v.37 no.1
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• pp.103-118
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• 2024

The horseshoe prior is notably one of the most popular priors in sparse regression models, where only a small fraction of coefficients are nonzero. The parameter space of the horseshoe prior is much smaller than that of the spike and slab prior, so it enables us to efficiently explore the parameter space even in high-dimensions. However, on the other hand, the horseshoe prior has a high computational cost for each iteration in the Gibbs sampler. To overcome this issue, various MCMC algorithms for the horseshoe prior have been proposed to reduce the computational burden. Especially, Johndrow et al. (2020) recently proposes an approximate algorithm that can significantly improve the mixing and speed of the MCMC algorithm. In this paper, we compare (1) the traditional MCMC algorithm, (2) the approximate MCMC algorithm proposed by Johndrow et al. (2020) and (3) its variant in terms of computing times, estimation and variable selection performance. For the variable selection, we adopt the sequential clustering-based method suggested by Li and Pati (2017). Practical performances of the MCMC methods are demonstrated via numerical studies.

• The Journal of Korean Medicine
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• v.45 no.1
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• pp.1-16
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• 2024

Introduction: The importance of clinical skills training in traditional Korean medicine education is increasingly emphasized. Since the clinical skills tests are high-stakes tests that determine success in national licensing exams, it is essential to develop reliable multifaceted analysis methods for clinical skills tests in actual education settings. In this study, we applied the multifaceted validity evaluation methods to the evaluation results of the cardiopulmonary resuscitation module to confirm the applicability and effectiveness of the methods. Methods: In this study, we used internal consistency, factor analysis, generalizability theory G-study and D-study, ANOVA, Kendall's tau, descriptive statistics, and other statistical methods to analyze the multidimensional validity of a cardiopulmonary resuscitation test in clinical education settings over the past three years. Results: The factor analysis and internal consistency analysis showed that the evaluation rubric had an unstable structure and low concordance. The G-study showed that the error of the clinical skills assessment was large due to the evaluator and unexpected errors. The D-study showed that the variance error of the evaluator should be significantly reduced to validate the evaluation. The ANOVA and Kendall's tau confirmed that evaluator heterogeneity was a problem. Discussion and Conclusion: Clinical skills tests should be continuously evaluated and managed for validity in two steps of pre-production and actual implementation. This study has presented specific methods for analyzing the validity of clinical skills training and testing in actual education settings. This study would contribute to the foundation for competency-based evidence-based education in practical clinical training.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.37 no.4
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• pp.60-72
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• 2019

The purpose of this study was to identify detailed factors that affect visitor satisfactions of the plants on display, environments of pedestrian road and facility of each theme garden by conducting a survey of visitors to Jade Garden. The 400 data including 100 copies per theme garden were used for statistical analysis. The statistical techniques used in the survey analysis include multi-regression analysis, t-test, and analysis of variance(ANOVA). As a result of the analysis, most of theme gardens tended to have the greatest impact on the satisfaction of the plants on display and the lowest level of facility satisfaction. According to detailed factors analysis of the satisfaction of plants on display satisfaction of plant diversity and the method of plant display were most affected in most of the theme gardens. Among them, promoting the satisfaction of plant diversity is necessary to plant various species, but in case of Ginkgo Maze Garden, a type of tree community as one tree(Ginkgo biloba), the satisfaction of plants diversity did not show a rising-up value. Therefore, it was confirmed that the appropriate degree of plants diversity depends on the theme or environment of the garden. In the case of the pedestrian-road-satisfaction, the width of the pedestrian road was the most affected, It was analyzed that whether the point of intersection can be easily available during peak season has a significant impact on the satisfaction of visitors. In the case of facility satisfaction, it was analyzed that the presence of rest and convenience facilities had the most direct influence on visitors, so the facility diversity had the greatest influence. Therefore, it is necessary to more systematically categorize and consider the influential detailed factors such as plants diversity and methods of plant display, width of pedestrian road and facilities diversity for the management and development of the arboretum.

• Culinary science and hospitality research
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• v.10 no.3
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• pp.135-154
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• 2004

This study surveyed ancestral service preparation and sacrificial consciousness of housewives living in Pusan and Yeosu area. Statistical analysis of chi-square test was carried out by using SAS program. The results are summarized as follows. l. In major general characteristics of subjects, the forties(35.56%), Buddhism (57.79%), high school education(52.54%), a couple with children(63.45%) were the most abundant. 2. The time of sacrificial rites in both areas was usually hold from 23:00 to 01:00 (47.16%). The housewives having a job hold earlier the service than the full-time housewives(p<0.05). 3. The range of ancestor-memorial rites was usually up to 3rd generation(34.47%). The leader of sacrificial ceremony was mainly the eldest grandson by the eldest son (78.28%) in the old subjects and a person of wealth in the young subjects(p<0.05). 4. There were more positive answers for the necessity of a sacrificial ceremony (57.32%). Older than 50 years of subjects thought the sacrificial rites should be held(70.77%), while as the age of subjects was younger, they realized less necessity for that(p<0.05). Sacrificial consciousness was higher in Buddhists than the other religionists(p<0.0001). The sacrificial rites was thought to be needed for their harmonious family(50.43%). Younger subjects thought that it is necessary to succeed that as the tradition, while older housewives thought that it would contribute toward peace in their family(p<0.05). Buddhists and Christians answered that it was good for harmonious family, and Catholics and the others for tradition(p<0.01). Their consideration of sacrificial rites in the future was higher in keeping the traditional practice (37.04%) and Buddhists took higher these consideration(43.17%). Considering the sacrificial consciousness, there were statistical differences among the religionists (p<0.0001). The eldest daughter-in-raw had a different opinion about the following up the method of sacrificial ceremony from second eldest daughter-in-raw and the next one(p<0.05). The housewives in Pusan were showing more the affirmative attitudes to keep the traditional practice than those in Yeosu.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.1
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• pp.126-136
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• 2016

This study was performed to investigate menu preferences of adult customers for Korean food made from Korean traditional sauces. A total of 962 valid responses were used for data analysis. Statistical analyses were conducted using the SPSS package program (ver 20.0). The results of this study are summarized as follows: overall preferences were highest for braised spareribs, followed by braised short ribs, grilled beef ribs, and bulgogi. On the other hand, overall preferences were lowest in eggplant namul, followed by squid and radish soup, and grazed lotus roots and burdock. Female's overall preferences were significantly higher than male's for nine menu items, including japchae and seasoned acorn starch curd with vegetables, whereas male's overall preferences were significantly higher than female's for 19 menu items, including grilled deodeok and frozen pollack stew. Moreover, the menu item that was most significantly preferred was soybean sprouts soup in subjects aged under 20 years and Korean meatballs in subjects in their twenties. Subjects in their forties showed significantly higher preferences for 15 menu items, including braised hairtail, grilled deodeok, and seasoned and grilled yellow corvina compared to other age groups. Furthermore, menu preferences of production service workers were significantly higher than other groups for frozen pollack stew, loach stew, grilled dried pollack, steamed dry pollack, dried pollack soup, eggplant namul, and seasoned and grilled yellow corvina, whereas menu preferences of official professional workers and students were significantly higher than those of production service workers for braised short ribs, grilled beef ribs, seasoned and simmered chicken, mixed noodles, Korean meatballs, stir-fried rice pasta with vegetables, spicy soft bean curd stew, japchae, mung bean jelly mixed with vegetables and beef, bibimbap, and stir-fried squid. The results show that menu preferences of adults customers differed depending on gender, age, and occupation. In conclusion, the results of this study should provide foodservice managers with information about menu planning for target customers of commercial or non-commercial foodservice cafeterias and recipe development of low-sodium Korean foods.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.3
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• pp.1-9
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• 2008

Objective : Prolonged use of systemic corticosteroids negatively impacts skin barrier function. Corticosteroids have a major role in the practical management of many diseases, so it is necessary to find the drug or supplement which could keep the skin healthy during the systemic corticosteroids therapy. Seed of Trichossnthcs kiiilowii was commonly used for pulmonary disease in traditional Chinese medicine. Many studies have investigated and found that seed of Trichosanthes kirilowii has anti-bacterial, anti-HIV, anti-tumor and immunoregulatory functions. This study was performed to investigate the effect of seed of Trichosmthes kirilowii on the Skin Barrier Method : Triamcinolone 0.4mg was injected male hairless mice for 5 weeks ( 2 times a week, totally 10 times), Just before the first injection, hairless mice were divided into 3 groups; Control ( normal saline medicated group ), GroupA( seed of Trichosuuhes kirilowii qd/day medicated group ) and GroupB( seed of Trichosuuhes kiiilowii bid/day medicated group ), Body weight of all the groups were checked during the experiment, After $10^{th}$ injection, TEWL (Transeidermal water loss) of 3 groups were artificially increased by 9 times tape stripping and the changes of TEWL were checked at before stripping, right after, 2h, 4h, 6h, 24h, 48 and 72h later after stripping, AST, ALT and CBC were also checked. Indeed, stratum corneum of 3 groups were also examined and compared with that of normal hairless mouse. Results : 1. GroupB showed significantly lower body weight among three groups 2, There was no statistical difference at AST, ALT and CBC among three groups 3. GroupB was showed significantly lower TEWL than TEWL of Control at 48h later. 4 GroupB recovered it's TEWL of before tape stripping at 24h later, GroupA recovered that at 48h and Control recovered that at 72h later at the same condition 5. Stratum corneum of GroupA and GroupB were looked almost normal and healthy. On the contrary, stratum corneum of Control was looked thin and unhealthy. Conclusions : Seed of Ttichossnthes kirilowii has some effects on skin barrier function, especially TEWL of high dose corticosteroids injected hairless mouse and the efficacy seemed to be related with the dosage.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.18-27
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• 2007

${\ll}$Gup Yu Bang${\gg}$ is the first korean book that specialized in pediatrics. It was written by Jo Jeong-jun in 1869 and contains 87 medical records. Medical records is one of the best way to develop one’s abilities of curing a disease without clinical practice and understanding medical condition of the time. These days we are fully aware of the importance of medical records, but there is no sufficient paper or study on medical records. On this study, we investigate 87 medical record of ${\ll}$Gup Yu Bang${\gg}$ by statistical methods. It was analyzed on the base of items such as age, sex, disease, method of medical treatment, treating prescription, modified medicinal substance, progress of disease. ${\ll}$Gup Yu Bang${\gg}$ contain 87 medical records and among of them, 84 records were Jo Jeong-jun own writings of clinical case. Systemic division of disease showed the highest in digestive disease and most frequent case was symptom of vomiting and diarrhea. The distribution of age was showed the highest in the age group under 5 years and the number of male case was more than female case. It showed that he considered observation of the patient's expression in diagnosis methods and have used 87 kinds of treating prescription and the external treatment, acupuncture, moxa. It showed that he quoted a lot of treating prescription from ${\ll}$Dong eui bo gam${\gg}$, ${\ll}$Yi-Hak-Yip-Mun${\gg}$ and ${\ll}$Xiao Er Yao Zheang Zhi Jue${\gg}$. The further study on medical records in traditional medical literatures, would reveal the developmental progress of Korean pediatrics and inform more actual proof on medical condition of the time.