• Resources Recycling
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• v.32 no.1
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• pp.42-49
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• 2023

The glass ceramic secondary resource containing Li-Al-Si is used in inductor, fireproof glass, and transparent cookware and accounts for 14% of the total consumption of Li, which is the second most widely used after Li-ion batteries. Therefore, new Li resources should be explored when the demand for Li is exploding, and extensive research on Li recovery is needed. Herein, we recovered Li from fireproof Li-Al-Si glass ceramic, which is a new secondary resource containing Li. The fireproof glass among all Li-Al-Si glass ceramics was used as raw material that contained 1.5% Li, 9.4% Al, and 28.9% Si. The process for recovering Li from the fireproof glass was divided into two parts: (1) calcium salt roasting and (2) water leaching. In calcium salt roasting, a sample of fireproof glass was crushed and ground below 325 mesh. The leaching efficiency was compared based on the presence or absence of heat treatment of the fireproof glass. Moreover, the leaching rates based on the input ratios of calcium salt, Li-Al-Si glass, and ceramics and the leaching process based on calcium salt roasting temperatures were compared. In water leaching, the leaching and recovery rates of Li based on different temperatures, times, solid-liquid ratios, and number of continuous leaching stages were compared. The results revealed that fireproof glass ceramics containing Li-Al-Si should be heat treated to change phase to beta-type spodumene. CaCO₃ salt should be added at a ratio of 6:1 with glass ceramics containing Li-Al-Si, and then leached 4 times or more to achieve a recovery efficiency of Li over 98% from a solution containing 200 mg/L of Li.

• Journal of The Korean Association For Science Education
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• v.43 no.3
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• pp.265-276
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• 2023

The purpose of this study was to develop a plan to ensure that students lacking basic science skills acquire the minimum needed science learning ability while completing the common curriculum. We surveyed 27 elementary and secondary science teachers with experience in research and teaching related to basic skills support to investigate their perceptions of the criteria for minimum achievement standards using Consensual Qualitative Research (CQR) and Analytic Hierarchy Process (AHP). The results indicated that the science teachers tended to describe low achievers as lacking science learning competency, accumulating a science learning deficit, and lacking prerequisite knowledge. However, there were some differences in the characteristics that the elementary and secondary teachers paid attention to in students with insufficient science and basic academic skills. Specifically, the secondary teachers demonstrated greater sensitivity towards low learning motivation and difficulties in using scientific symbols, whereas the elementary teachers were more sensitive towards students' attitudes towards science or lack of experience. Furthermore, it has been observed that the prioritization of items, categorized by school level, differs in terms of setting minimum achievement standards to ensure basic skill support. This implies the need to develop minimum achievement standards considering various variables based on the school level. As there are diverse opinions among science teachers, depending on their expertise, regarding the factors to be considered when developing these standards to guarantee science and basic skill support. Based on the findings of the study, policy support is required to enhance teachers' professionalism in developing students' basic skills while considering the individual context and diversity of low achievers. Additionally, it is crucial to establish a shared vision for students lacking basic skills to reduce the gap between national policy and the practices of science teachers in ensuring support for basic skills.

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.315-325
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• 2023

The purpose of this study was to predict abdominal obesity with 3-Dimensional computed tomography (3D CT) measurements of kidneys by analyzing the correlation between kidney sizes and abdominal obesity level. The subjects were 178 healthy adults without underlying diseases who had a comprehensive health examination at the Health Medical Center of Jesus Hospital in Jeonju. Abdominal obesity was measured by CT cross-sectional image at the level of the umbilicus and divided into visceral fat area, subcutaneous fat area, visceral fat/total fat ratio. The average comparison of kidney sizes classified according to abdominal obesity were performed through one-way analysis of variance (ANOVA) and Scheffe test. Pearson correlation analysis was performed to correlate all measurement values. The results of kidney size ANOVA analysis according to abdominal obesity were as follows. The means of kidney measurements according to visceral fat classification were significantly different in all kidney measurements (p<0.05). And in case of subcutaneous fat classification, the means of kidney measurements by 3D CT of the severe obesity group were significantly different in the right kidney width (p<0.05). In case of visceral fat area/total fat area ratio, the means of kidney measurements by 3D CT of the severe obesity group were significantly different in both kidneys width (p<0.05). Pearson correlation between kidneys measurements and CT abdominal obesity showed that visceral fat area had the highest correlation with the left kidney width measured by 3D CT (r=0.467) and subcutaneous fat area had correlation with the right kidney width measured by 3D CT (r=0.249). The visceral fat area/total fat area ratio had correlation with the left kidney width measured by 3D CT (r=0.291).

• Journal of the Korean Society of Radiology
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• v.17 no.3
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• pp.297-303
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• 2023

Pediatric Computed Tomography (CT) examinations can often result in exam failures or the need for frequent retests due to the difficulty of cooperation from young patients. Deep Learning Image Reconstruction (DLIR) methods offer the potential to obtain diagnostically valuable images while reducing the retest rate in CT examinations of pediatric patients with high radiation sensitivity. In this study, we investigated the possibility of applying DLIR to reduce artifacts caused by respiration or motion and obtain clinically useful images in pediatric chest CT examinations. Retrospective analysis was conducted on chest CT examination data of 43 children under the age of 7 from P Hospital in Gyeongsangnam-do. The images reconstructed using Filtered Back Projection (FBP), Adaptive Statistical Iterative Reconstruction (ASIR-50), and the deep learning algorithm TrueFidelity-Middle (TF-M) were compared. Regions of interest (ROI) were drawn on the right ascending aorta (AA) and back muscle (BM) in contrast-enhanced chest images, and noise (standard deviation, SD) was measured using Hounsfield units (HU) in each image. Statistical analysis was performed using SPSS (ver. 22.0), analyzing the mean values of the three measurements with one-way analysis of variance (ANOVA). The results showed that the SD values for AA were FBP=25.65±3.75, ASIR-50=19.08±3.93, and TF-M=17.05±4.45 (F=66.72, p=0.00), while the SD values for BM were FBP=26.64±3.81, ASIR-50=19.19±3.37, and TF-M=19.87±4.25 (F=49.54, p=0.00). Post-hoc tests revealed significant differences among the three groups. DLIR using TF-M demonstrated significantly lower noise values compared to conventional reconstruction methods. Therefore, the application of the deep learning algorithm TrueFidelity-Middle (TF-M) is expected to be clinically valuable in pediatric chest CT examinations by reducing the degradation of image quality caused by respiration or motion.

• Journal of agricultural medicine and community health
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• v.48 no.2
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• pp.103-117
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• 2023

Objectives: This study aims to reveal the relationship between social relations and physical activity in the young-old and old-old elderly. Methods: Data from 2020 National survey of Older Koreans were used, and a total of 10,097 subjects over the age of 65 were included in analysis. The dependent variable was physical activity, and the independent variables were social relations barrier and motivational factors. x²-test and binary logistic regression were performed for data analysis. Results: The physical activity rate in the elderly were 40.8% in the young-old and 29.2% in the old-old. The socio-demographic characteristics affecting physical activity were the young-old elderly were sex, residential area, employment status and household income, and the old-old elderly were sex, age, residential area, education level and household income. The social relations barrier factors affecting physical activity were the young-old elderly were number of close friends, family care, exercise information search and video viewing, and the old-old elderly were household type, number of close friends, participation in exercise education, exercise information search and video viewing. The social relations motivational factors affecting physical activity were the young-old elderly were call with children/relative/friend, participation in sports activity, access time from home to parks, and the old-old elderly were call with children/relative/friend, participation in sports activity, satisfaction with green spaces. Conclusions: It was found that social relations barrier and motivational factors of the elderly are important factors to consider when developing physical activity promotion strategy, and there are also difference between the age of the elderly.

• Korean Journal of Heritage: History & Science
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• v.55 no.4
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• pp.72-94
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• 2022

This study is about the architectural changes over time in Dongchun-gotaek, the house of Song Jun-gil, one of the representative figures of the Hoseosarim(湖西士林), also an architectural cultural asset representing Daejeon. Data related to Sangryang(上樑) found in the restoration process of Dongchundang(同春堂) and DongchundangJongtaek(同春堂 宗宅), the state designated heritage application report written by Daejeon Metropolitan City, Deokeun-gaseung(德恩家乘), a book which has been handed down from generation to generation from Dongchundang Munjeonggongpa(同春堂 文正公派) of Eunjin Song's Clan and the results of partial excavation surveys respectively conducted in 2010 and 2020 were used as basic research data, and these data were compared and analyzed to examine the changes of the arrangement of Dongchundang, Jeongchim(正寢), and ancestral shrine buildings. Dongchundang was built by Song Jun-Gil. Rather than a new building, it was a building that was basically relocated to its current area when Cheongjwawa(淸坐窩), which was built by his father, dilapidated, and the timing of its construction can be clarified through Sangryangmun(上樑文). However, in the estimated area of Cheongjwawa, no exact site was found in two surveys of buried cultural heritages. In the case of Jeongchim, it was possible to confirm that it had been relocated two times, and it can be said that the biggest achievement of this study was to confirm that the first relocation was outside the current fence. In addition, one of the building sites which was identified in the excavation survey for confirming the servants' quarters was estimated to be the first construction at the site of Dongchun-gotaek. In the shrine area, there were the first constructed Gamyo(家廟), including Byeolmyo(別廟) dedicated to Bulcheonwi(不遷位), and Jomyo(祧廟) dedicated to Checheon(遞遷), and it can be seen that it was a space where many changes such as new construction, demolition, or mutual exchange of location occurred over time. The present buildings arrangement through these processes was not far from the original plan of Song Joon-gil. Therefore, the name of 'Dongchun-gotaek' is appropriate.

• 한국체육학회지인문사회과학편
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• v.54 no.5
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• pp.867-876
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• 2015

This study was intended to closely examine an effect that the level of physically challenged person's participation in community sports had on positive psychological capital. In order to accomplish the purpose of study, data on 212 physically challenged persons who lived in B city and participated in community sports were analyzed. Korean version of positive psychological capital created by Taehong Lim (2014) through the reconstruction of scales developed by Luthans, Youssef and Avolio(2007) and Sangwan Jeon and Jonghun Yang's (2009) level of participation in community sports was reconstructed through modification·improvement as measurement instrument. An exploratory factor analysis, reliability test, paired difference test, and multiple regression analysis was carried out by using SPSS 18.0 program for data processing. First, It was shown that there was a significant difference in positive psychological capital according to gender, age, and disability grade among physically challenged persons' socio-demographic characteristics. Second, it was shown that, among sub-variables (period, frequency and intensity) of level of physically challenged persons' participation in community sports, the frequency of participation and the intensity of participation had a significant effect on self efficacy. On the other hand, it was shown that the period of participation didn't have a significant effect. Third, it was shown that the frequency of participation had a significant effect on optimism. On the other hand, it was shown that the period of participation and the intensity of participation didn't have a significant effect. Fourth, it was shown that the frequency of participation and the intensity of participation had a significant effect on hope. On the other hand, it was shown that no significant effect was produced on the period of participation. Fifth, it was shown that the frequency of participation had a significant effect on resilience. On the other hand, it was shown that no significant effect was produced on the period of participation and the intensity of participation. Sixth, it was shown that the frequency of participation and the intensity of participation had a significant effect on positive psychological capital. And it was shown that no significant effect was produced on the period of participation.

• Journal of the Korean Society of Radiology
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• v.16 no.4
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• pp.427-434
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• 2022

Atrial fibrillation treatment includes 3D RFCA and Cryo-balloon ablation. Both procedures have in common that they enter after understanding the structure of the heart using angiography equipment. Therefore, there is a disadvantage that the effect of exposure according to the procedure time can be a threat to both the patient and the operator, so this study aims to confirm the relationship between the total ablation time and the effect of radiation exposure. We used follow-up data (retrospective) from 41 patients who underwent coronary angiography and arrhythmia at the same time from March 2019 to July 2022. The range for total ablation time was based on the recorded data from the start to the end of the total ablation. The end point of 3D RFCA was when the ablation was completed for 4 pulmonary veins, and in the case of Cryo-balloon ablation, the data that succeeded in electrical insulation were included. As a result of analyzing the total ablation time, the time taken for Cryo-balloon ablation was 1037.29±103.66 s, which was 2448.61 s faster than 3D RFCA using 3485.9±405.71 s, and was statistically significant. (p<0.05) As a result of analyzing the total fluoroscopy time, the exposure time for 3D RFCA was 2573.75±239.08 s, which was less by 1717.15 s than the exposure time for Cryo-balloon ablation, 4290.9±420.42 s, and was statistically significant. In the case of total area dose product, 3D RFCA was 59.04±13.1 uGy/m², which was lower than Cryo-balloon ablation 980.6±658.07 uGy/m² by 921.56 uGy/m², which was statistically significant. As the insulation time of the Cryo-balloon ablation is shorter than that of the 3D RFCA, the method using the Cryo-balloon ablation is considered to be effective when the patient's condition is not good and a quick procedure is required. However, in patients with permanent Atrial fibrillation, there is a high probability of structural changes in the heart, so it is considered that 3D RFCA is better than Cryo-balloon ablation, which is difficult to manipulate.

• Informatization Policy
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• v.30 no.2
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• pp.22-45
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• 2023

In research on the use of AI-based voice assistant services, problems related to the user's trust and privacy protection arising from the experience of service use are constantly being raised. The purpose of this study was to investigate empirically the effects of individual trust in AI and online privacy concerns on the continued use of AI-based voice assistants, specifically the impact of their interaction. In this study, question items were constructed based on previous studies, with an online survey conducted among 405 respondents. The effect of the user's trust in AI and privacy concerns on the adoption and continuous use intention of AI-based voice assistant services was analyzed using the Heckman selection model. As the main findings of the study, first, AI-based voice assistant service usage behavior was positively influenced by factors that promote technology acceptance, such as perceived usefulness, perceived ease of use, and social influence. Second, trust in AI had no statistically significant effect on AI-based voice assistant service usage behavior but had a positive effect on continuous use intention. Third, the privacy concern level was confirmed to have the effect of suppressing continuous use intention through interaction with trust in AI. These research results suggest the need to strengthen user experience through user opinion collection and action to improve trust in technology and alleviate users' concerns about privacy as governance for realizing digital government. When introducing artificial intelligence-based policy services, it is necessary to disclose transparently the scope of application of artificial intelligence technology through a public deliberation process, and the development of a system that can track and evaluate privacy issues ex-post and an algorithm that considers privacy protection is required.

• Journal of The Korean Association For Science Education
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• v.43 no.3
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• pp.253-263
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• 2023

This study explored the discrepancy between the text of a teacher's guide about straight and reflective light and the content knowledge of pre-service elementary teachers. A total of 455 questions and 543 answers generated by 279 pre-service elementary teachers after reading a 'Shadow and Mirror' unit in the teacher's guide were analyzed. The questions were classified according to the types of concepts and discrepancies, and the answers were analyzed for accuracy. The results of analyzing the concepts of questions revealed that the pre-service elementary teachers were most curious about the shadow in the straight concept, the mirror image in the reflection concept, and the light source in other concepts. The questions with a low correct answer rate due to incorrect- or non-answers, such as those concerning the superposition principle of light by reflection, the principle of experimental tools, and images by lenses, were only partially or not included in the teacher's guide. When the questions were classified according to the type of discrepancy, the frequency of questions due to knowledge deficit was higher than that due to knowledge clash. This demonstrates that the concepts that teachers need to know must be supplemented with the contents of the teacher's guide. Discrepancies due to knowledge clashes are often caused by conflicts between what is experienced in everyday life and what is presented in textbooks. Therefore, it is necessary to reduce the discrepancy between the texts of the teacher's guide and the knowledge of pre-service elementary teachers by including the differences between the actual context of everyday life and the context of the textbook in the teacher's guide.