• Journal of Dental Rehabilitation and Applied Science
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• v.37 no.4
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• pp.217-224
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• 2021

Purpose: The purpose of this study was to evaluate the porosity of resin modified glass ionomer (RMGI) by different mixing methods. Materials and Methods: Five specimens were prepared for each groups according to capsules and mixing methods. Two RMGI capsule and two mixing machines were used for this study. One resin-modified glass ionomer cement is Fuji II LC (F2LC) and the other is Photac Fil Quick Aplicap (PFQ). For Mixing of RMGI capsule, Rotomix using rotating motion and CM-II using shaking motion were used. After measuring height, radius and mass of specimens, Density was calculated. And porosity was measured using micro-computed tomography (micro-CT). All data were statistically analyzed using T-test, two-way ANOVA to compare between groups at 95% significance level to evaluate the affect of capsule and mixing method on the porosity. Results: The porosity was observed in all specimens generally. And there is significant differece between porosities according to RMGI capsule and Mixing method. The porosity of PFQ was lower than that of F2LC and the porosity of Rotomix was lower than that of CM-II. Conclusion: There was a difference of porosity according to kind of capsules and mixing methods. When using same capsule, less porosity was observed on PFQ than F2LC. When using same mixing mehod, less porosity was observed on Rotomix than CM-II. Using mixing machine of same coporation as that of RMGI capsule did not lead to lower porosity. Therefore, Selecting optimal mixing machine is important.

• Journal of the Daesoon Academy of Sciences
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• v.35
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• pp.331-358
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• 2020

This paper is a study of Kim Si-seup's maniacal tendency. The properties of mania can be divided into two categories. One is mental mania wherein the mind has fallen into madness, and the other is morphological mania wherein madness is revealed in real world actions. This thesis analyzes two aspects of the madness of Kim Si-seup, who showed madness in the morphological dimension as well as madness of the mind in the Joseon Dynasty. One notion that is analyzed is 'Longing to never return', and the other is 'To live in obscurity, yet practice wonders.' Kim Si-seup was a promising talent when he was young and was a so-called "infant prodigy." However, when 'Saejo' took the throne of 'Danjong,' he left the house on the road to 'burn all the books' and became a monk as a way of disappearing from the world. Thereafter, Kim Si-seup gave up on the test to become a bureaucrat and lived in hiding while doing strange things while he falsely pretended to be "crazy." He never felt regret hearing others describe him as a strange person. He lived a life of not returning to the mundane world for a long time as he traveled through famous mountains and streams. Also, he pursued a life in 'the world outside the world' without any greed. Sometimes he expresses his own free spirit and madness through poetry with 'what he talks about' and 'wonderful words.' This life was far from a form of neutralization aesthetics achieved by pursuing a 'gentle and magnanimous' life as claimed by Confucian scholars. Kim Si-seup, sometimes referred to as 'a maniac with mental clarity,' directed his efforts at 'false maniacal behavior,' 'weird behavior,' 'life pursuing the world outside the world,' and 'life of breaking off one's relationship with the world.' This maniac-like life of Kim Si-seup was not crazy but conveyed a deep desire to criticize the absurd reality of Joseon society at the time. Regarding Kim Si-seup, Li Hwang criticizes him for wishing 'to live in obscurity yet practice wonders.' Unlike Li Hwang, Yi Yi, who wrote The Records of Kim Si-seup when commissioned to do so by Sun Jo, positively evaluated Kim Si-seup as "a Confucian who followed Buddhism." Although the contents of these evaluations of Kim Si-seup were different, both agreed that Kim Si-seup was a maniacally-oriented individual. Kim Si-seup, who was mentally maniacal and morphological maniacal, represents a unique case in the study history of the Joseon Dynasty, wherein the 'the doctrines of Zhu Zi' exerted great influence.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.4
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• pp.41-54
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• 2021

It is very essential to estimate the water body area using remote exploration for water resource management, analysis and prediction of water disaster damage. Hydrophysical detection using satellites has been mainly performed on large satellites equipped with optical and SAR sensors. However, due to the long repeat cycle, there is a limitation that timely utilization is impossible in the event of a disaster/disaster. With the recent active development of Micro satellites, it has served as an opportunity to overcome the limitations of time resolution centered on existing large satellites. The Micro satellites currently in active operation are ICEYE in Finland and Capella satellites in the United States, and are operated in the form of clusters for earth observation purposes. Due to clustering operation, it has a short revisit cycle and high resolution and has the advantage of being able to observe regardless of weather or day and night with the SAR sensor mounted. In this study, the operation status and characteristics of micro satellites were described, and the water area estimation technology optimized for micro SAR satellite images was applied to the Daecheong Dam basin on the Korean Peninsula. In addition, accuracy verification was performed based on the reference value of the water generated from the optical satellite Sentinel-2 satellite as a reference. In the case of the Capella satellite, the smallest difference in area was shown, and it was confirmed that all three images showed high correlation. Through the results of this study, it was confirmed that despite the low NESZ of Micro satellites, it is possible to estimate the water area, and it is believed that the limitations of water resource/water disaster monitoring using existing large SAR satellites can be overcome.

• Journal of Korea Entertainment Industry Association
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• v.14 no.3
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• pp.201-210
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• 2020

The aim of this thesis is to investigate exhibition spaces which are being expanded and transformed concurrently with social phenomena that are also the result of rapid changes, all of which are reflective of a modern society in transition. Such investigation would also include an analysis of changes in the viewing public and artworks themselves, and also an assessment of the public nature of art and its effective aspects. Expansion of exhibition spaces and the increasing connection between art and the public have very important ramifications, in many respects. They present opportunities for the viewing public to immerse themselves in artistic spaces, with some reaching further into other activities - activities that they often share with other individuals. This also leads them to expand their range of activities, turning them into more mobile, proactive audiences. In connection, many corporations have turned their attention to this public aspect of art, which has resulted in a display of art in different types of spaces. The government also began to adopt 'public art' as a matter of policy, using it as a medium of communication between the state and its populace. The public aspect of art, being highlighted as a result of expansion and diversification of exhibition spaces, will have a significant impact not only on the viewing public, but also on the art market. This represents a momentous change for creators of art, which naturally warrants close scrutiny and research.

• Korean Journal of Remote Sensing
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• v.38 no.6_1
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• pp.1423-1444
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• 2022

In this study, the sensitivity of the mid-infrared radiance to atmospheric and surface factors was analyzed using the radiative transfer model, MODerate resolution atmospheric TRANsmission (MODTRAN6)'s simulation data. The possibility of retrieving the land surface temperature (LST) using only the mid-infrared bands at night was evaluated. Based on the sensitivity results, the LST retrieval algorithm that reflects various factors for night was developed, and the level of the LST retrieval algorithm was evaluated using reference LST and observed LST. Sensitivity experiments were conducted on the atmospheric profiles, carbon dioxide, ozone, diurnal variation of LST, land surface emissivity (LSE), and satellite viewing zenith angle (VZA), which mainly affect satellite remote sensing. To evaluate the possibility of using split-window method, the mid-infrared wavelength was divided into two bands based on the transmissivity. Regardless of the band, the top of atmosphere (TOA) temperature is most affected by atmospheric profile, and is affected in order of LSE, diurnal variation of LST, and satellite VZA. In all experiments, band 1, which corresponds to the atmospheric window, has lower sensitivity, whereas band 2, which includes ozone and water vapor absorption, has higher sensitivity. The evaluation results for the LST retrieval algorithm using prescribed LST showed that the correlation coefficient (CC), the bias and the root mean squared error (RMSE) is 0.999, 0.023K and 0.437K, respectively. Also, the validation with 26 in-situ observation data in 2021 showed that the CC, bias and RMSE is 0.993, 1.875K and 2.079K, respectively. The results of this study suggest that the LST can be retrieved using different characteristics of the two bands of mid-infrared to the atmospheric and surface conditions at night. Therefore, it is necessary to retrieve the LST using satellite data equipped with sensors in the mid-infrared bands.

• 한국노년학
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• v.40 no.4
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• pp.707-727
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• 2020

This study aims to empirically analyze the role that perception of the probability of lonely death among the elderly people living alone plays in the relationship between perceived social support and preference for institutional care based on Andersen's expanded Behavioral Model (2002). The subjects (n=676) of this study were the elderly people living alone, extracted from the "2018 Seoul Aging Survey." With "perceived social support" as an independent variable, "preference for institutional care" as a dependent variable, and "perception of the probability of lonely death" as a mediator variable, we conducted a Binary Logistic Regression to follow the three steps of analyzing mediation effect, as suggested by Baron and Kenny (1986). The results showed that perceived social support has a negative effect on the preference for institutional care and perception of the probability of lonely death among the elderly people living alone; at the same time, perception of the probability of lonely death was found to have a positive effect on their preference for institutional care. Lastly, perception of the probability of lonely death was found to partially mediate the effect of perceived social support among the elderly people living alone in terms of their preference for institutional care. Based on these findings, the practical implications of this study can be summarized as follows. First, various programs and support should be provided to the elderly people living alone in order to enhance the level of perceived social support, a factor that has been confirmed to increase preference for institutional care among the elderly people living alone. Second, as the perception of the probability of lonely death was confirmed to be a psychosocial factor of the preference for institutional care, we need to promote education and support for older people living alone to prepare them for lonely death. These efforts are expected to form a foundations for implementing a community-based integrated care system, "Aging in Place," which is the policy direction required for older people care.

• 한국노년학
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• v.40 no.4
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• pp.801-821
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• 2020

There are a number of prior studies on the poverty experience of Korean women, but little is known about the poverty experience of Korean elderly women in the U.S. The purpose of this study is to examine the poverty experiences of Korean elderly women who immigrated to the U. S. Qualitative case study methods were used to achieve these research objectives. Three Korean elderly women living in Oakland of California who received Supplemental Security Income (SSI) from the U.S. federal government were included in the study. The data were collected by conducting a total of six meetings per participant, and the researcher read the consent form directly to the participants and obtained a hand-written signature. The analysis and interpretation began by repeating the interview transcript several times, and the repeated keywords were to be understood in the context, focusing on time, space, and relationships with other people. The contextual understanding of Korean elderly women's experiences in poverty was interpreted in three dimensions: extending poverty in their mother country, double torture as female immigrants, and limiting labor due to aging and diseases. Before moving to the U.S., they had a difficult livelihood by farming and one of them had to live in poverty due to the bereavement to her husband. But even after moving to the U.S., they have continued to live in poverty. As female immigrants with low education and no special skills, they were incorporated into the periphery of the labor market in the industrialized U.S. and were forced to make a living with low wages. Korean elderly women were unable to return to the labor market in the surrounding areas due to aging and diseases, and were continuing their impoverished lives relying on SSI. From the findings, we discussed the role of the Korean immigrants community as a way to improve the quality of life for Korean elderly women in the U.S.

• The Journal of Engineering Geology
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• v.31 no.4
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• pp.647-658
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• 2021

In this study, the change of temperature, chemical composition, and helium gas of thermal water in Pohang area was observed from January 2018 to June 2019 in order to interpret the relationship with earthquake events. During observation period earthquakes above M 2.0 within 100 km in a radius from a geothermal well occurred 58 including two earthquake events with a magnitude of 3.0~3.9 and two earthquake events with a magnitude of 4.0~4.9. We introduce a q-factor and earthquake effectiveness (ε) to express the influence of each earthquake as magnitude and distance factors. The geothermal well of 715 m deep was developed in the Bulguksa biotite granite, and the water temperature was observed in the variation from 51.8 to 56.3℃ during monitoring period. At M 4.1 and M 4.6 earthquake events, the increase of geothermal water temperature (𝜟T 2.6~4.5℃) was recorded, and slight change in specific ionic components such as SO₄ and Cl, and of chemical types on the Piper diagram were observed. In the ³He/⁴He vs ⁴He/²⁰Ne diagram, the original mixing ratio of helium isotope before and after the magnitude 4.1 earthquake was slightly changed from 83.0% to 83.2% of crust-origin ⁴He, and the from 16.3% to 16.7% of mantle-origin ³He. Hot-cold water mixing ratio before and after earthquakes by using the quartz and chalcedony solubility curves of the silica-enthalpy mixing model was calculated to interpret the temperature change of geothermal water. The model calculation shows the increase of 6.93~7.72% and 1.65~4.94% of hot water ratio at E1 and E2 earthquakes, respectively. Conclusively, the magnitude of earthquake for observable change in the temperature and helium isotope of thermal water is of 4.1 or higher and q-factor value of 30.0 or higher in the study site.

• Journal of Korean Society of Forest Science
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• v.111 no.2
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• pp.201-223
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• 2022

Currently, species extinctions are increasing due to climate change and continued anthropogenic impact. We selected 300 species for conservation with emphasis on plants co-occurring in the Baekdudaegan area, which is a large ecological axis of Korea. We aimed to investigate the vegetation community and environmental characteristics of Zabelia tyaihyonii in the limestone habitat among the target plant species in the Baekdudaegan region to derive effective conservation strategies. In Danyang-gun, Yeongwol-gun, and Jecheon-si, we selected 36 investigation sites where Z. tyaihyonii was present. We investigated the vegetation, flora, soil and physical environment. We also found notable plants such as Thalictrum petaloideum, Sillaphyton podagraria, and Neillia uekii at the investigation sites. We classified forest vegetation community types into 4 vegetation units and 7 species group types. With canonical correspondence analysis (CCA) of the vegetation community and habitat factors, we determined the overall explanatory power to be 75.2%, and we classified the environmental characteristics of the habitat of Z. tyaihyonii into a grouping of three. Among these, we detected a relationship between the environmental factors elevation, slope, organic matter, rock ratio, pH, potassium, and sodium. We identified numerous rare and endemic plants, including Thalictrum petaloideum, in the investigation site, and determined that these groups needed to be preserved at the habitat level. In the classification of the vegetation units analyzed based on the emerging plants and the CCA, we reaffirmed the uniqueness and specificity of the vegetation community in the habitat of Z. tyaihyonii. We anticipate that our results will be used as scientific evidence for the empirical conservation of the native habitats of Z. tyaihyonii.

• Korean Journal of Psychosomatic Medicine
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• v.30 no.2
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• pp.155-164
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• 2022

Objectives : A growing body of evidence links type 2 diabetes (T2D) with a neurodegenerative disease (ND) such as Alzheimer's disease and Parkinson's disease. The purpose of this study is to investigate the relationship between NDs and the development of T2D by comparing the incidence of T2D in a group of various NDs (ND group) and control group. Methods : A population-based 10-year follow-up study was conducted using the Korean National Health Information Database for 2002-2015. We used a retrospective cohort study design to investigate the association of ND with T2D occurrence. The study population included ND (n=8,814) and control (n=37,970) groups, all aged 60 years or over. The Kaplan-Meier method was used to estimate the risk of developing T2D as a function of time. Cox proportional hazards regression models were used to evaluate the relationship between ND and T2D. Results : T2D was developed in a significantly higher percentage of patients in the ND group (53.6%) than in the control group (44.7%). The ND group increased the risk of T2D (HR, 1.43; 95% CI, 1.38-1.47). About one-third of patients in both groups were additionally diagnosed with another ND before the occurrence of T2D during a 10-year follow-up period. When compared to those who did not have another ND during the follow-up period, the incidence of T2D in those who were additionally diagnosed with another ND was higher in both the ND and control groups. Conclusions : The ND group had about 1.4 times higher risk of developing T2D than the control group. Our results showed a positive association between ND and T2D.