• Tuberculosis and Respiratory Diseases
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• v.84 no.3
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• pp.188-199
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• 2021

Background: Chronic obstructive pulmonary disease (COPD) is a common chronic respiratory disease with increased prevalence in the elderly. Telomeres are repetitive DNA sequences found at the end of the chromosome, which progressively shorten as cells divide. Telomere length is known to be a molecular marker of aging. This study aimed to assess the relationship between telomere length and the risk of COPD, lung function, respiratory symptoms, and emphysema index in Chronic Obstructive Pulmonary Disease in Dusty Areas (CODA) cohort. Methods: We extracted DNA from the peripheral blood samples of 446 participants, including 285 COPD patients and 161 control participants. We measured absolute telomere length using quantitative real-time polymerase chain reaction. All participants underwent spirometry and quantitative computed tomography scan. Questionnaires assessing respiratory symptoms and the COPD Assessment Test was filled by all the participants. Results: The mean age of participants at the baseline visit was 72.5±7.1 years. Males accounted for 72% (321 participants) of the all participants. The mean telomere length was lower in the COPD group compared to the non-COPD group (COPD, 16.81±13.90 kb; non-COPD, 21.97±14.43 kb). In COPD patients, 112 (75.7%) were distributed as tertile 1 (shortest), 91 (61.1%) as tertile 2 and 82 (55%) as tertile 3 (longest). We did not find significant associations between telomere length and lung function, exacerbation, airway wall thickness, and emphysema index after adjusting for sex, age, and smoking status. Conclusion: In this study, the relationship between various COPD phenotypes and telomere length was analyzed, but no significant statistical associations were shown.

• Nutrition Research and Practice
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• v.16 no.3
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• pp.405-417
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• 2022

BACKGROUND/OBJECTIVES: This study examined the changes in food behaviors of dietary fatty acids over 2007-2018 among Korean adults. SUBJECTS/METHODS: This study used data from the 4th (2007-2009), 5th (2010-2012), 6th (2013-2015), and 7th (2016-2018) Korea National Health and Nutrition Examination Surveys. A total of 46,307 adults aged 19-64 yrs were selected and dietary data were obtained from a single 24-h recall. In the 4th and 7th data, the major food sources for each fatty acid based on the contributing percentage of the food item were compared. The consumption trends in the major food sources were presented as grams per day over 2007-2018 and compared across the survey periods using the multiple regression model. RESULTS: From 2007 to 2018, for total fat, saturated fatty acid (SFA), and monounsaturated fatty acid, the contribution of animal food sources, including beef, chicken, and eggs increased but plant food sources (e.g., tofu, soybean, and plant oil) decreased. As polyunsaturated fatty acid sources, mayonnaise, eggs, and bread showed higher contributions, whereas soybean and tofu showed lower contributions in the 7th data compared to the 4th data. For n-3 fatty acids, the contribution of fish decreased between the 4th and 7th data. Over 12 yrs, the significant increases in the absolute amount of consumption from animal sources were observed. In contrast, decreases in the consumption from plant sources and fish were seen across the survey periods. CONCLUSIONS: In Korean adults, increases in the intake of dietary fatty acids along with changes in the food behaviors during 2007-2018 have evoked great concern for SFA intake, which is a cardiovascular disease risk factor. Healthy food sources of dietary fatty acids should be emphasized in this population.

• Journal of Information Technology Services
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• v.21 no.3
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• pp.63-72
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• 2022

The extinction crisis of local cities, caused by a population density increase phenomenon in capital regions, directly causes the increase of vacant houses in local cities. According to population and housing census, Gunsan-si has continuously shown increasing trend of vacant houses during 2015 to 2019. In particular, since Gunsan-si is the city which suffers from doughnut effect and industrial decline, problems regrading to vacant house seems to exacerbate. This study aims to provide a foundation of a system which can predict and deal with the building that has high risk of becoming vacant house through implementing a data driven vacant house prediction machine learning model. Methodologically, this study analyzes three types of machine learning model by differing the data components. First model is trained based on building register, individual declared land value, house price and socioeconomic data and second model is trained with the same data as first model but with additional POI(Point of Interest) data. Finally, third model is trained with same data as the second model but with excluding water usage and electricity usage data. As a result, second model shows the best performance based on F1-score. Random Forest, Gradient Boosting Machine, XGBoost and LightGBM which are tree ensemble series, show the best performance as a whole. Additionally, the complexity of the model can be reduced through eliminating independent variables that have correlation coefficient between the variables and vacant house status lower than the 0.1 based on absolute value. Finally, this study suggests XGBoost and LightGBM based machine learning model, which can handle missing values, as final vacant house prediction model.

• Journal of Gastric Cancer
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• v.23 no.1
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• pp.146-158
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• 2023

Endoscopic resection (ER) is widely performed for early gastric cancer (EGC) with a negligible risk of lymph node metastasis (LNM) in Eastern Asian countries. In particular, endoscopic submucosal dissection (ESD) leads to a high en bloc resection rate, enabling accurate pathological evaluation. As undifferentiated EGC (UD-EGC) is known to result in a higher incidence of LNM and infiltrative growth than differentiated EGC (D-EGC), the indications for ER are limited compared with those for D-EGC. Previously, clinical staging as intramucosal UD-EGC ≤2 cm, without ulceration, was presented as 'weakly recommended' or 'expanded indications' for ER in the guidelines of the United States, Europe, Korea, and Japan. Based on promising long-term outcomes from a prospective multicenter study by the Japan Clinical Oncology Group (JCOG) 1009/1010, the status of this indication has expanded and is now considered 'absolute indications' in the latest Japanese guidelines published in 2021. In this study, which comprised 275 patients with UD-EGC (cT1a, ≤2 cm, without ulceration) treated with ESD, the 5-year overall survival (OS) was 99.3% (95% confidence interval, 97.1%-99.8%), which was higher than the threshold 5-year OS (89.9%). Currently, the levels of evidence grades and recommendations for ER of UD-EGC differ among Japan, Korea, and Western countries. Therefore, a further discussion is warranted to generalize the indications for ER of UD-EGC in countries besides Japan.

• Journal of Yeungnam Medical Science
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• v.40 no.3
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• pp.283-288
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• 2023

Severe chronic neutropenia is classified as severe congenital, cyclic, autoimmune, or idiopathic. However, there is a lot of uncertainty regarding the diagnosis of severe congenital neutropenia (SCN) and chronic idiopathic neutropenia, and this uncertainty affects further evaluations and treatments. A 20-year-old man presented with fever and knee abrasions after a bicycle accident. On admission, his initial absolute neutrophil count (ANC) was 30/µL. He had no medical history of persistent severe neutropenia with periodic oscillation of ANC. Although his fever resolved after appropriate antibiotic therapy, ANC remained at 80/µL. Bone marrow (BM) aspiration and biopsy were performed, and a BM smear showed myeloid maturation arrest. Moreover, genetic mutation test results showed a heterozygous missense variant in exon 4 of the neutrophil elastase ELANE: c597+1G>C (pV190-F199del). The patient was diagnosed with SCN. After discharge, we routinely checked his ANC level and monitored any signs of infection with minimum use of granulocyte colony-stimulating factor (G-CSF), considering its potential risk of leukemic transformation. Considering that SCN can be fatal, timely diagnosis and appropriate management with G-CSF are essential. We report the case of a patient with SCN caused by ELANE mutation who had atypical clinical manifestations. For a more accurate diagnosis and treatment of severe chronic neutropenia, further studies are needed to elucidate the various clinical features of ELANE.

• International Journal of Computer Science & Network Security
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• v.23 no.5
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• pp.148-162
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• 2023

Classification systems can significantly assist the medical sector by allowing for the precise and quick diagnosis of diseases. As a result, both doctors and patients will save time. A possible way for identifying risk variables is to use machine learning algorithms. Non-surgical technologies, such as machine learning, are trustworthy and effective in categorizing healthy and heart-disease patients, and they save time and effort. The goal of this study is to create a medical intelligent decision support system based on machine learning for the diagnosis of heart disease. We have used a mixed feature creation (MFC) technique to generate new features from the UCI Cleveland Cardiology dataset. We select the most suitable features by using Least Absolute Shrinkage and Selection Operator (LASSO), Recursive Feature Elimination with Random Forest feature selection (RFE-RF) and the best features of both LASSO RFE-RF (BLR) techniques. Cross-validated and grid-search methods are used to optimize the parameters of the estimator used in applying these algorithms. and classifier performance assessment metrics including classification accuracy, specificity, sensitivity, precision, and F1-Score, of each classification model, along with execution time and RMSE the results are presented independently for comparison. Our proposed work finds the best potential outcome across all available prediction models and improves the system's performance, allowing physicians to diagnose heart patients more accurately.

• Journal of Korean Society for Quality Management
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• v.52 no.1
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• pp.43-56
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• 2024

Purpose: The injection molding process, crucial for plastic shaping, encounters difficulties in sustaining product quality when replacing injection machines. Variations in machine types and outputs between different production lines or factories increase the risk of quality deterioration. In response, the study aims to develop a system that optimally adjusts conditions during the replacement of injection machines linked to molds. Methods: Utilizing a dataset of 12 injection process variables and 52 corresponding sensor variables, a predictive model is crafted using Decision Tree, Random Forest, and XGBoost. Model evaluation is conducted using an 80% training data and a 20% test data split. The dependent variable, classified into five characteristics based on temperature and pressure, guides the prediction model. Bayesian optimization, integrated into the selected model, determines optimal values for process variables during the replacement of injection machines. The iterative convergence of sensor prediction values to the optimum range is visually confirmed, aligning them with the target range. Experimental results validate the proposed approach. Results: Post-experiment analysis indicates the superiority of the XGBoost model across all five characteristics, achieving a combined high performance of 0.81 and a Mean Absolute Error (MAE) of 0.77. The study introduces a method for optimizing initial conditions in the injection process during machine replacement, utilizing Bayesian optimization. This streamlined approach reduces both time and costs, thereby enhancing process efficiency. Conclusion: This research contributes practical insights to the optimization literature, offering valuable guidance for industries seeking streamlined and cost-effective methods for machine replacement in injection molding.

• Journal of the Korean Society of Radiology
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• v.83 no.1
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• pp.178-183
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• 2022

Polycythemia vera (PV) is a rare myeloproliferative disease that causes elevated absolute red blood cell (RBC) mass due to uncontrolled RBC production. Moreover, this condition has been associated with a high risk of ischemic stroke and large vessel stenosis or occlusion, with many studies reporting cerebral infarction in PV patients. Despite these findings, there have been no reports on the vessel wall MRI (VW-MRI) findings of the narrowed vessels in PV-associated ischemic stroke patients. To the best of our knowledge, this is the first report in English regarding the carotid VW-MRI findings of a 30-year-old male diagnosed with PV after being hospitalized due to stroke.

• Asia-Pacific Journal of Business
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• v.15 no.2
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• pp.143-157
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• 2024

Purpose - This paper aims to analyze the relationship and correlation between the stock markets of Korea, the US, China, and Japan before and after the outbreak of COVID-19. Design/methodology/approach - This study conducted an empirical analysis using the stock market data from January 2016 to June 2023 for the representative market indices of Korea, the US, China, and Japan. The analysis employed the VAR model, Granger causality test, impulse response function, and variance decomposition. Findings - Analyzing the relationships of these stock markets before and after the outbreak of COVID-19, we obtained the following results. (i) The influence of the U.S. stock market was found to be absolute regardless of the COVID-19 period, and the rise in the U.S. stock market led to rises in other stock markets. (ii) The Chinese stock market had a significant negative impact on the U.S., Korean, and Japanese stock markets before COVID-19, but this influence disappeared after COVID-19. This suggests that the Chinese market exhibited unique characteristics different from the global market after COVID-19. (iii) Analyzing the period excluding the first quarter of 2020, when global stock market volatility was extremely high due to the spread of COVID-19, we found that the results were very similar to the analysis including the first quarter of 2020. Therefore, it is difficult to argue that the increased uncertainty during this period distorted the relationships among the stock markets of these four countries. Research implications or Originality - We anticipate that these findings will offer valuable insights for both individual and institutional investors, aiding them in portfolio diversification and risk mitigation.

• The Journal of Internal Korean Medicine
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• v.30 no.3
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• pp.510-524
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• 2009

Objective : This study was designed to find the correlation between Sasang Constitution and heart rate variability(HRV). Method : There were 665 subjects (280 men and 385 women), between 39 and 72 years old. in a rural community. Sasang Constitution was diagnosed by a Sasang constitutional specialist using PSSC (Phonetic System for Sasang Constitution), face and tongue photo and checkup-list. A structured-questionnaire was used to assess the general characteristics. HRV was recorded using SA-2000 (medi-core). HRV was assessed by time domain and by frequency domain analysis. Metabolic syndrome was defined on the basis of clustering of risk factors, when three or more of the following cardiovascular risk factors were included : blood pressure, fasting blood sugar, triglyceride HDL-cholesterol, and abdominal obesity (waist). Because of the skewness of the data, logarithmic transformation was performed on the absolute units of the spectral components of HRV, and the resulting logarithmic values and normalized units were compared between the groups by a logistic regression. The 95% confidence interval (CI) of the odds ratio was used and calculated from the data laid out for a cross sectional study. Results : 1. Odds ratios of Taeeumin and Soeumin in female adults below 60 years old were significantly lower than that of Soyangin in LF norm and LF/HF ratio. Odds ratios of Taeeumin and Soeumin in female adults below 60 years old were significantly higher than that of Soyangin in HF norm. 2. There was no significant correlation between HRV and Sasang Constitution in female adults from 60 years old and over. 3. There was no significant correlation between HRV and Sasang Constitution in male adults. Conclusion : There is a statistically significant correlation between the HRV and Sasang Constitution. There is a tendency of increase in the sympathetic activity in Soyangin. There is a tendency of decrease in the parasympathetic activity in Taeeumin and Soeumin.