• International Journal of Computer Science & Network Security
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• v.22 no.3
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• pp.276-284
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• 2022

The research aims to study the dynamics of academic procrastination and its impact on the mental health of students during the transition to distance learning during the COVID-19 pandemic. At the beginning of the COVID-19 pandemic, it was identified a declining tendency of overall rates of academic procrastination and at the same time increase in the number of carriers of mid and high levels of academic procrastination. The decline in the general rates of academic procrastination at the beginning of 2021 testifies to the adaptation processes experienced by students to the conditions of distance learning. It was documented that students' academic procrastination is accompanied by a steady negative emotional tension. During the transition to distance learning, the intensity of students' learning activity has increased, which altogether causes stress as one of the main reasons for the academic procrastination among future psychologists. The study identified a risk of academic procrastination manifestation among students for their mental health, which provides a basis for developing and testing a program to prevent the phenomenon of academic procrastination among degree-seeking students.

• 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.

• Molecules and Cells
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• v.45 no.12
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• pp.923-934
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• 2022

Human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have great potential in applications such as regenerative medicine, cardiac disease modeling, and in vitro drug evaluation. However, hPSC-CMs are immature, which limits their applications. During development, the maturation of CMs is accompanied by a decline in their proliferative capacity. This phenomenon suggests that regulating the cell cycle may facilitate the maturation of hPSC-CMs. Aurora kinases are essential kinases that regulate the cell cycle, the role of which is not well studied in hPSC-CM maturation. Here, we demonstrate that CYC116, an inhibitor of Aurora kinases, significantly promotes the maturation of CMs derived from both human embryonic stem cells (H1 and H9) and iPSCs (induced PSCs) (UC013), resulting in increased expression of genes related to cardiomyocyte function, better organization of the sarcomere, increased sarcomere length, increased number of mitochondria, and enhanced physiological function of the cells. In addition, a number of other Aurora kinase inhibitors have also been found to promote the maturation of hPSC-CMs. Our data suggest that blocking aurora kinase activity and regulating cell cycle progression may promote the maturation of hPSC-CMs.

• International Journal of Internet, Broadcasting and Communication
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• v.15 no.2
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• pp.187-195
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• 2023

Sarcopenia is a phenomenon in which muscle function, including muscle strength, deteriorates as muscle mass decreases in the process of increasing age. The diagnosis of sarcopenia utilizes total muscle mass and limb muscle mass, and limb muscle mass is expressed as height squared, body weight, and BMI. Each divided value is used as an index, mainly less than 7.23 kg/m2 for men and less than 5.67 kg/m2 for women. Grip strength, standing up from a chair, and walking speed were mainly used as physical function factors, and grip strength less than 27 kg for men and less than 16 kg for women were used as indicators. The limb muscle mass showed a decreasing trend after peaking in the mid-20s in men, and maintaining a gradual peak in women from the mid-20s to the mid-40s, showing a more rapid decline in men. The rate of decrease in muscle mass and strength continues to increase after the age of 20, and muscle strength rapidly decreases after the age of 80. In Korean men, total muscle mass and limb muscle mass show a decreasing trend from the mid-30s, and a more markedly rapid decrease from the age of 60. For women, it remains constant from the age of 30 to the age of 50, then gradually decreases after the mid-50s, and shows a rather rapid decrease after the mid-70s, showing a more gradual decrease than that of men. Men show a sharp decrease from the mid-40s when limb muscle mass is divided by height squared, and women show a marked decrease after 70 years old when limb muscle mass is divided by height squared. Exercise for the prevention and treatment of sarcopenia results in an increase in protein assimilation hormone, an increase in antioxidant activity, a decrease in inflammation, an increase in muscle insulin sensitivity, and an increase in protein synthesis. Resistance exercise is basically used, and aerobic exercise and equilibrium A combination of exercises is effective. In addition, for a more efficient effect of sarcopenia through resistance exercise, it is necessary to supplement nutrition including protein.

• The Journal of Internal Korean Medicine
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• v.44 no.3
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• pp.544-554
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• 2023

Background: Postural hypotension refers to a drop in systolic blood pressure of 20 mmHg or diastolic blood pressure of 10 mmHg or more within three minutes after standing up from lying down. Symptoms of postural hypotension not only include dizziness and blurred vision but also fatigue, cognitive decline, leg weakness, headache, and, in severe cases, fainting. Postural hypotension is a phenomenon that occurs in about 6% of the total population, and in Korea, the number of patients with postural hypotension is continuously increasing. Both pharmacological and non-drug therapies, which are treatment methods for this disease, do not show a satisfactory symptom improvement effect. Case summary: A 65-year-old male patient who visited the hospital complaining of dizziness and paresthesia due to postural hypotension was treated with acupuncture, moxibustion, and herbal medicine. For symptom evaluation, the numeric rating scale (NRS) of each symptom was used, and blood pressure change according to posture was measured. After treatment, the NRSs of dizziness and dysesthesia were decreased, and blood pressure changes according to posture was improved. Conclusion: This case report suggests that Korean medicine treatment, including acupuncture, electro-acupuncture, moxibustion, and herbal medicine, can be an effective treatment for dizziness with postural hypotension.

• The Journal of the Convergence on Culture Technology
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• v.9 no.4
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• pp.51-60
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• 2023

This study is to verify the moderating effect of residential selection on the relationship between marriage and childbirth. According to the analysis results, interactions of first marriage with the financial capacity of local governments for public services, residential stability, the scale of the region, and local economic situation have a moderating effect on childbirth. Interactions of remarriage and marriage with foreigners with the financial capacity of local governments for public services, residential stability, and the scale of the region have a moderating effect on childbirth. These results indicate that when married couples choose to reside in small and medium-sized cities or large cities rather than rural areas, it can more positively affect their intention to have children. While there may be a logical argument against advocating for regional integration based on the moderating effect of residential selection on the relationship between marriage and childbirth, the analysis results of this study and the phenomenon of married couples avoiding rural areas can contribute to raising the need for regional integration.

• Membrane Journal
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• v.33 no.3
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• pp.127-136
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• 2023

In this study, the electrochemical performance of a 5-layer fuel cell stack using silica composite membranes as polymer electrolyte membranes was evaluated. It was observed that the flow rate of the fuel gases plays a crucial role in stack performance, particularly being mainly dependent on the flow rate of hydrogen. Increasing the flow rate of oxygen resulted in negligible changes in performance, whereas an increase in the flow rate of hydrogen demonstrated performance improvements. However, this led to an imbalance in the ratio of hydrogen to oxygen flow rates, causing significant degradation in stack performance and durability. A decline in stack performance was also observed over time due to the degradation of stack components. This phenomenon was consistently observed in individual unit cells. Based on these findings, it was emphasized that, in addition to optimizing the performance of each component during stack operation, it is important to optimize design and operating conditions for uniform flow rate control. Lastly, the developed silica composite membrane was assessed to have sufficient performance for application in actual fuel cell systems, exhibiting a performance of over 25 W based on maximum power.

• (The)Study of the Eastern Classic
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• no.49
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• pp.109-136
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• 2012

'Old man' or 'old age' was not the parts of academic discipline in the Joseon era but Yeoheon put it in the philosophical 'problematization' of the learning of the Confucianism. He was argued that the old man or old age is not merely biological decline but it has the goal to achieve. The completion of self is the meaning and end of the life throughout the subjective realization and procedure of attaining the goal step by step. Well-aged old man is affirming the getting old and making the positive changing of old life time in his one sake. This essay is showing the Yeoheon's thought of old aging as the self-realizing well-ageing. Next, it is argued that the predicament of old age or old man is not just social welfare or biological aspects but it is serious philosophical problems. If it was just social or biological aspects then it is just a social phenomenon to approach the view of scientists. However, this is not only life and death and flux of time and relativities but also it is problematizing the self-identification subjectivities. Obviously, it is the significant that the old and or old age is fundamentally philosophical subject rather than social or biological materials. In the third chapter, we are dealing with the views of the life and death of Yeoheon. He was insisted that quite interesting opinion that is the all the lives in the universe include himself is 'a wayfarer'. It looks like a time traveler in the universe; we are just one who stays in a body for awhile. When we follow him, we are living in this universe in a time (disposable) but the same theorem is applying to the whole universe as well myriad creatures. Therefore, man has a job to do as an entity of the universe. Yeoheon was called it is the business as a job and we have to do the Dao till you end. The fourth, Yeoheon was suggested that the old man has his work and business. There are two kind of works for an old man, the former is self control as an old age that is call the old man's job and the latter is staying with the Dao that is called the old man's business. According to Yeoheon, man has charged to realize the law of the universe that means we are the moral entity; therefore we are business to complete ourselves. Old age is decline of physical activities rather than vigorous, therefore, we have to follow our body and self-affirmation of declination is the Dao. The final, Yeoheon was advised that the old man better saved in the current of the Dao, because the physical function is declining but the shining Dao is within the mind in the body. It is motivation of the self-dignity of old man and one who recognizes the work to do even in the old body that he will be the significant among all the society not a lonely old man anymore. Old aging is biological twilight but the considerable real size expertise and self-affirmation is the Dao of old age. We are meditating nowadays in Yeoheon's philosophical context on old man or old aging. By him, the old age is man of dignity as long as he realizes in his Dao through the business and self-affirmation.

• Journal of the Korean Geographical Society
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• v.49 no.5
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• pp.728-746
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• 2014

The purpose of this study is to analyze the influence of the selective migration of young age group and the stage migration which has proceeded through generations, on the transition of fertility and the population growth in the rural and urban in the case of Jeollabuk-do. For this, we use O-D matrix of 20-34 age group, the distribution of that group and women of child bearing age, and vital statistics in 1970-2010. The major findings of this study are as follows. First, the outflows from their birth place are common and dominant features of 20-34 age group in each time. Second, there is the stage migration which preceding generation moved from the rural areas to the cities in Jeollabuk-do and following generation has moved from the cities to Seoul metropolitan area. Third the selective outflow migration of young age group has leaded to reduction of the childbearing population, declining birthrate, aging and natural population decline. Due to the stage migration, these depopulation processes occurred in rural area in the past, and currently it expands to the cities with about 15 years time gap. In fact, there have been the natural population decrease which annual number of deaths exceed that of births from the late 1980s in the most rural areas and in the early 2000s, such a phenomenon has been confirmed also in urban areas. Therefore, this study concludes that the stage migration through generations is one of the crucial factor to the population growth in local cities and also brings out the step-wise population decrease in settlement hierarchies.

• Nutrition Research and Practice
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• v.1 no.2
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• pp.105-112
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• 2007

Ascorbic acid has been reported to extend replicative life span of human embryonic fibroblast (HEF). Since the detailed molecular mechanism of this phenomenon has not been investigated, we attempted to elucidate. Continuous treatment of HEF cells with ascorbic acid at ($200{\mu}M$) from 40 population doubling (PD) increased maximum PD numbers by 18% and lowered $SA-{\beta}-gal$ positive staining, an aging marker, by 2.3 folds, indicating that ascorbic acid extends replicative life span of HEF cells. Ascorbic acid treatment lowered DCFH by about 7 folds and Rho123 by about 70%, suggesting that ascorbic acid dramatically decreased ROS formation. Ascorbic acid also increased aconitase activity, a marker of mitochondrial aging, by 41%, indicating that ascorbic acid treatment restores age-related decline of mitochondrial function. Cell cycle analysis by flow cytometry revealed that ascorbic acid treatment decreased G1 population up to 12%. Further western blot analysis showed that ascorbic acid treatment decreased levels of p53, phospho-p53 at ser 15, and p21, indicating that ascorbic acid relieved senescence-related G1 arrest. Analysis of AP (apurinic/apyrimidinic) sites showed that ascorbic acid treatment decreased AP site formation by 35%. We also tested the effect of hydrogen peroxide treatment, as an additional oxidative stress. Continuous treatment of $20{\mu}M$ of hydrogen peroxide from PD 40 of HEF cells resulted in premature senescence due to increased ROS level, and increased AP sites. Taken together, the results suggest that ascorbic acid extends replicative life span of HEF cells by reducing mitochondrial and DNA damages through lowering cellular ROS.