• The Mathematical Education
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• v.63 no.3
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• pp.393-409
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• 2024

The number line model, which intuitively marks numerical magnitudes in space, is widely utilized to help in understanding the magnitudes that fractions and decimals represent. The study analyzed 6^th graders' understanding of fractions and decimals, their problem solving strategies, and whether individual differences in the flexibility of various strategy uses are associated with the accuracy of numerical representation, calculation fluency, and overall mathematical achievement. As a result of the study, students showed relatively lower accuracy in representing fractions and decimals on a number line compared to natural numbers, especially for fractions with odd denominators compared to even denominators, and for two-digit decimals compared to three-digit decimals. Regarding strategy use, students primarily used benchmark, segmentation, and approximation strategies for fractions, and benchmark, rounding, and transformation strategies for decimals sequentially. Lastly, as students used various representation strategies for fractions, their accuracy in representing fractions and their overall mathematical achievement scores showed significantly better outcomes. Taken together, we suggest the need for careful instruction on different interpretations of fractions, the place value of decimals, and the meaning of zero in decimal places. Moreover, we discuss instructional methods that integrate the number line model and its diverse representation strategies to enhance students' understanding of fractions and decimals.

• Journal of the Korean Society of Earth Science Education
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• v.17 no.2
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• pp.168-180
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• 2024

In this study, we developed a STEAM program based on digital astronomical and space resources and applied it to 167 randomly selected elementary school students to examine the effectiveness of the STEAM program in enhancing creative problem solving skills. The results of this study are as follows: first, the statistical analysis of pre-test and post-test scores for creative problem-solving skills related to the STEAM program showed significant results (p<.05). This suggests that the STEAM program contributed to improving creative problem-solving skills through the procedural process involved in generating ideas and convergent thinking during the digital problem-solving. Second, the paired sample t-test based on the pre-test and post-test of the STEAM attitude test also showed significant results (p<.05). Analyzing digital materials and presenting pixel art projects positively influenced STEAM attitudes in terms of interest, communication, and usefulness. This underscores the need for developing integrative education programs utilizing advanced technologies in the future. Third, in the class satisfaction test conducted after the application of the STEAM program, the satisfaction factor scored an average of 3.55, interest scored 3.35, and overall class difficulty scored 3.46. The main difference from traditional classes was the focus on 'acquisition of future career information.' However, given the slight decrease in interest during the digital transformation and interpretation process, it is recommended that future classes allocate sufficient time for experiential activities. To generalize the developed program, future studies should consider various school levels, implementation periods, and difficulty levels.

• Studies on Life and Culture
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• v.52
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• pp.225-248
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• 2019

This study examines the variables affecting the cyberbullying of adolescents. The purpose of this study is to analyze the difference of variables that personal, domestic environmental, school environment, digital media factors, and more specifically, gender differences. In order to achieve the purpose of the study, we used 811 online survey data of youths with smart phones nationwide. The results of technical statistics, T-test, correlation analysis and multiple regression analysis can be summarized as follows. First, the descriptive statistics showed that male cyberbullying scores were higher than female students, and t-test results were statistically significant. Second, multiple regression analysis including gender variables showed that male cyberbullying was higher than female students. Finally, multiple regression analysis of male and female students showed that the variables affecting the cyberbullying of boys and girls were somewhat different. The common causative variables were 'parental stress', 'peer attachment', and 'game addiction'. The direction was statistically significant (+) direction. The causes of 'depression', 'aggression', and 'SNS addiction' were different among males and females were 'academic stresses', suggesting that there are differences in cyberbullying factors according to gender.

• Journal of the Korean Geotechnical Society
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• v.40 no.5
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• pp.113-129
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• 2024

This study reclassifies the risk levels of cut-slopes and addresses the limitations inherent in existing evaluation methods using road slope maintenance data. Conventional risk assessment predominantly relies on subjective expert judgment, resulting in issues of consistency and reliability. To mitigate these limitations, this study applies dimensionality reduction techniques, specifically Principal Component Analysis (PCA) and Linear Discriminant Analysis (LDA), followed by K-means clustering, to classify new risk levels. The clustering results using PCA demonstrated more distinct cluster separation compared to LDA, and also showed superior performance in terms of the silhouette coefficient and other clustering metrics. This suggests that the existing risk level labels may not adequately capture the underlying data structure. Furthermore, the inconsistency observed between LDA-based clustering results and current risk labels indicates potential reliability issues in the present labeling approach. To resolve this, new risk levels were assigned using PCA and K-means clustering, with cluster risk levels evaluated based on risk scores. A quantitative analysis of key risk factors was also conducted to establish criteria for risk classification and assess the impact of each variable on the different risk levels. This study proposes a data-driven, objective, and quantitative approach to risk level evaluation, aiming to improve the efficiency and reliability of road slope management.

• Science of Emotion and Sensibility
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• v.27 no.3
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• pp.37-50
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• 2024

Many people are interested in vegetarianism for health and animal welfare reasons, but putting it into practice is difficult. This study aims to examine how an individual's thoughts on the mind-body connection influence their choice of vegetarian products. In Study 1, the impact of two types of thoughts on health behaviors and the selection of vegetarian products was compared: dualism and physicalism. The mind and body are separated in dualism, whereas the mind and body are connected in physicalism. Study 2 tested whether thoughts about the mind-body connection activate the social values that an individual aspires. Study 3 used priming with healthy and unhealthy food images to examine whether the mind-body dualism connection was bidirectional. Study 1 shows a lower intention for health-related behaviors under dualism conditions, compared to physicalism conditions, where the mind and body are connected. In Study 2, the intention to engage in health-related behaviors and the preference for self-transcendence values were lower than in the physicalism condition. Study 3 shows that participants primed with unhealthy images had higher dualistic scores than those primed with healthy plant-based images. These results suggest that an individual's thoughts about the mind-body connection may affect health behaviors and social value activation differently.

• The Korean journal of internal medicine
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• v.39 no.3
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• pp.439-447
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• 2024

Background: Helicobacter pylori infection, prevalent in more than half of the global population, is associated with various gastrointestinal diseases, including peptic ulcers and gastric cancer. The effectiveness of early diagnosis and treatment in preventing gastric cancer highlights the need for improved diagnostic methods. This study aimed to develop a simple scoring system based on endoscopic findings to predict H. pylori infection. Methods: A retrospective analysis was conducted on 1,007 patients who underwent upper gastrointestinal endoscopy at Asan Medical Center from January 2019 to December 2021. Exclusion criteria included prior H. pylori treatment, gastric surgery, or gastric malignancies. Diagnostic techniques included rapid urease and ¹³C-urea breath tests, H. pylori culture, and assessment of endoscopic features following the Kyoto gastritis classification. A new scoring system based on endoscopic findings including regular arrangement of collecting venules (RAC), nodularity, and diffuse or spotty redness was developed for predicting H. pylori infection, utilizing logistic regression analysis in the development set. Results: The scoring system demonstrated high predictive accuracy for H. pylori infection in the validation set. Scores of 2 and 3 were associated with 96% and 99% infection risk, respectively. Additionally, there was a higher prevalence of diffuse redness and sticky mucus in cases where the initial H. pylori eradication treatment failed. Conclusions: Our scoring system showed potential for improving diagnostic accuracy in H. pylori infection. H. pylori testing should be considered upon spotty redness, diffuse redness, nodularity, and RAC absence on endoscopic findings as determined by the predictive scoring system.

• Korean Journal of Radiology
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• v.25 no.7
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• pp.673-683
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• 2024

Objective: To evaluate the role of visual and quantitative chest CT parameters in assessing treatment response in patients with severe asthma. Materials and Methods: Korean participants enrolled in a prospective multicenter study, named the Precision Medicine Intervention in Severe Asthma study, from May 2020 to August 2021, underwent baseline and follow-up chest CT scans (inspiration/expiration) 10-12 months apart, before and after biologic treatment. Two radiologists scored bronchiectasis severity and mucus plugging extent. Quantitative parameters were obtained from each CT scan as follows: normal lung area (normal), air trapping without emphysema (AT without emph), air trapping with emphysema (AT with emph), and airway (total branch count, Pi10). Clinical parameters, including pulmonary function tests (forced expiratory volume in 1 s [FEV1] and FEV1/forced vital capacity [FVC]), sputum and blood eosinophil count, were assessed at initial and follow-up stages. Changes in CT parameters were correlated with changes in clinical parameters using Pearson or Spearman correlation. Results: Thirty-four participants (female:male, 20:14; median age, 50.5 years) diagnosed with severe asthma from three centers were included. Changes in the bronchiectasis and mucus plugging extent scores were negatively correlated with changes in FEV1 and FEV1/FVC (ρ = from -0.544 to -0.368, all P < 0.05). Changes in quantitative CT parameters were correlated with changes in FEV1 (normal, r = 0.373 [P = 0.030], AT without emph, r = -0.351 [P = 0.042]), FEV1/FVC (normal, r = 0.390 [P = 0.022], AT without emph, r = -0.370 [P = 0.031]). Changes in total branch count were positively correlated with changes in FEV1 (r = 0.349 [P = 0.043]). There was no correlation between changes in Pi10 and the clinical parameters (P > 0.05). Conclusion: Visual and quantitative CT parameters of normal, AT without emph, and total branch count may be effective for evaluating treatment response in patients with severe asthma.

• Journal of Platform Technology
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• v.11 no.5
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• pp.72-83
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• 2023

ChatGPT, commercial launch in late 2022, has shown successful results in various professional exams, including US Bar Exam and the United States Medical Licensing Exam (USMLE), demonstrating its ability to pass qualifying exams in professional domains. However, further experimentation and analysis are required to assess ChatGPT's scholastic capability, such as logical inference and problem-solving skills. This study evaluated ChatGPT's scholastic performance utilizing the Korean College Scholastic Ability Test (KCSAT) subjects, including Korean, English, and Mathematics. The experimental results revealed that ChatGPT achieved a relatively high accuracy rate of 69% in the English exam but relatively lower rates of 34% and 19% in the Korean Language and Mathematics domains, respectively. Through analyzing the results of the Korean language exam, English exams, and TOPIK II, we evaluated ChatGPT's strengths and weaknesses in comprehension and logical inference abilities. Although ChatGPT, as a generative language model, can understand and respond to general Korean, English, and Mathematics problems, it is considered weak in tasks involving higher-level logical inference and complex mathematical problem-solving. This study might provide simple yet accurate and effective evaluation criteria for generative artificial intelligence performance assessment through the analysis of KCSAT scores.

• Korean Journal of Radiology
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• v.25 no.10
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• pp.913-923
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• 2024

Objective: To prospectively compare single-shot (SS) echo-planar imaging (EPI) and field-of-view optimized and constrained undistorted single-shot multiplexed sensitivity-encoding (FOCUS MUSE) for diffusion-weighted imaging (DWI) in evaluating thyroid-associated ophthalmopathy (TAO). Materials and Methods: SS EPI and FOCUS MUSE DWIs were obtained from 39 patients with TAO (18 male; mean ± standard deviation: 48.3 ± 13.3 years) and 26 healthy controls (9 male; mean ± standard deviation: 43.0 ± 18.5 years). Two radiologists scored the visual image quality using a 4-point Likert scale. The image quality score, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and apparent diffusion coefficient (ADC) of extraocular muscles (EOMs) were compared between the two DWIs. Differences in the ADC of EOMs were also evaluated. The performance of discriminating active from inactive TAO was assessed using receiver operating characteristic curves. The correlation between ADC and clinical activity score (CAS) was analyzed using Spearman correlation. Results: Compared with SS EPI DWI, FOCUS MUSE DWI demonstrated significantly higher image quality scores (P < 0.001), a higher SNR and CNR on the lateral rectus muscle (LRM) and medial rectus muscle (MRM) (P < 0.05), and a non-significant difference in the ADC of the LRM and MRM. Active TAO showed higher ADC than inactive TAO and healthy controls with both SS EPI and FOCUS MUSE DWIs (P < 0.001). Inactive TAO and healthy controls did not show a significant ADC difference with both DWIs. Compared with SS EPI DWI, FOCUS MUSE DWI demonstrated better discrimination of active from inactive TAO (AUC: 0.925 vs. 0.779; P = 0.007). The ADC was significantly correlated with CAS in SS EPI DWI (r = 0.391, P < 0.001) and FOCUS MUSE DWI (r = 0.645, P < 0.001). Conclusion: FOCUS MUSE DWI provides better images for evaluating EOMs and better performance in diagnosing active TAO than SS EPI DWI. The application of FOCUS MUSE will facilitate the DWI evaluation of TAO.

• Journal of Dental Anesthesia and Pain Medicine
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• v.24 no.5
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• pp.351-360
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• 2024

Background: This study aimed to evaluate and compare the efficacy of oral premedication with ibuprofen on the anesthetic efficacy of inferior alveolar nerve block (IANB) using 2% lignocaine and 1:100000 epinephrine in tobacco-chewing (TC) and non-tobacco-chewing (NTC) patients with symptomatic irreversible pulpitis (SIP) during nonsurgical endodontic intervention (NEI). Methods: This multicenter, prospective, double-blind, two-arm parallel-group randomized controlled trial involving 160 patients was conducted for a period of 9 months. The patients were classified into the study (TC patients) and control (NTC patients) groups, which were subdivided into two subgroups 1 hour before the procedure based on oral premedication with tab ibuprofen 600 mg. Nicotine dependence was assessed using the Modified Fagerstrom Tolerance Nicotine Scale. Patients were administered an IANB injection of 2% lignocaine containing epinephrine 1:100000 after premedication. Pulpal anesthesia before NEI was confirmed using electric pulp testing and cold spraying. Patients rated their pain on the 10-point visual analog scale (VAS) during NEI thrice at the dentin, pulp, and instrumentation levels. No pain at each level indicated the success of anesthesia. Results: The success and failure rates did not differ between the premedication and non-premedication subgroups in the TC or NTC groups (P > 0.05). However, the success rate was higher in the premedication subgroup of the NTC group (52.5%) than in the TC group (45%). Most patients with premedication experienced failure at the instrumentation level, whereas patients in the non-premedication group experienced pain at the dentin level. Failure rates of IANB did not differ significantly at different levels between the groups (P > 0.05). The mean VAS scores differed significantly at the dentin level in both groups, with lower values in the premedication group (P < 0.05). Conclusions: The efficacy of ibuprofen premedication with IANB during NEI did not differ significantly between the TC and NTC patients with SIP. The effect of premedication was more significant in the NTC group than in the TC group. A causal relationship between nicotine consumption and the success of premedication could not be established, and further studies are required to validate the results of the present study.