• KSCE Journal of Civil and Environmental Engineering Research
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• v.44 no.1
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• pp.63-73
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• 2024

Autonomous vehicles at Levels 3 to 5, currently under global research and development, seek to replace the driver's perception, judgment, and control processes with various sensors integrated into the vehicle. This integration enables artificial intelligence to autonomously perform the majority of driving tasks. However, autonomous vehicles currently obtain temporary driving permits, allowing them to operate on roads if they meet minimum criteria for autonomous judgment abilities set by individual countries. When autonomous vehicles become more widespread in the future, it is anticipated that buyers may not have high confidence in the ability of these vehicles to avoid hazardous situations due to the limitations of temporary driving permits. In this study, we propose a method for grading the judgment abilities of autonomous vehicles based on a driving simulator experiment comparing and evaluating drivers' abilities to avoid hazardous situations. The goal is to derive evaluation criteria that allow for grading based on specific scenarios and to propose a framework for grading autonomous vehicles. Thirty adults (25 males and 5 females) participated in the driving simulator experiment. The analysis of the experimental results involved K-means cluster analysis and independent sample t-tests, confirming the possibility of classifying the judgment abilities of autonomous vehicles and the statistical significance of such classifications. Enhancing confidence in the risk-avoidance capabilities of autonomous vehicles in future hazardous situations could be a significant contribution of this research.

• Journal of Chest Surgery
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• v.37 no.6
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• pp.504-510
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• 2004

Background: Vasodilatory shock after cardiac surgery may result from the vasopressin deficiency following cardio-pulmonary bypass and sepsis, which did not respond to usual intravenous inotropes. In contrast to the adult patients, the effectiveness of vasopressin for vasodilatory shock in children has not been known well and so we reviewed our experience of vasopressin therapy in the small babies with a cardiac disease. Material and Method: Between February and August 2003, intravenous vasopressin was administrated in 6 patients for vasodilatory shock despite being supported on intravenous inotropes after cardiac surgery. Median age at operation was 25 days old (ranges; 2∼41 days) and median body weight was 2,870 grams (ranges; 900∼3,530 grams). Preoperative diag-noses were complete transposition of the great arteries in 2 patients, hypoplastic left heart syndrome in 1, Fallot type double-outlet right ventricle in 1, aortic coarctation with severe atrioventricular valve regurgitation in 1, and total anomalous pulmonary venous return in 1. Total repair and palliative repair were undertaken in each 3 patient. Result: Most patients showed vasodilatory shock not responding to the inotropes and required the vasopressin therapy within 24 hours after cardiac surgery and its readministration for septic shock. The dosing range for vasopressin was 0.0002∼0.008 unit/kg/minute with a median total time of its administration of 59 hours (ranges; 26∼140 hours). Systolic blood pressure before, 1 hour, and 6 hours after its administration were 42.7$\pm$7.4 mmHg, 53.7$\pm$11.4 mmHg, and 56.3$\pm$13.4 mmHg, respectively, which shows a significant increase in systolic blood pressure (systolic pressure 1hour and 6 hours after the administration compared to before the administration; p=0.042 in all). Inotropic indexes before, 6 hour, and 12 hours after its administration were 32.3$\pm$7.2, 21.0$\pm$8.4, and 21.2$\pm$8.9, respectively, which reveals a significant decrease in inotropic index (inotropic indexes 6 hour and 12 hours after the administration compared to before the administration; p=0.027 in all). Significant metabolic acidosis and decreased urine output related to systemic hypoperfusion were not found after vasopressin admin- istration. Conclusion: In young children suffering from vasodilatory shock not responding to common inotropes despite normal ventricular contractility, intravenous vasopressin reveals to be an effective vasoconstrictor to increase systolic blood pressure and to mitigate the complications related to higher doses of inotropes.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.168-178
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• 2023

Objectives: This study aimed to compare the physical properties and antibacterial effectiveness of iodoform based root filling pastes, Vitapex^® and Metapex^®, with sodium iodide root filling paste (NaI paste) for primary teeth. Materials and Methods: The physical properties (flowability, film thickness, radiopacity) of the pastes were evaluated according to ISO 6876:2012. The antibacterial activity against Enterococcus faecalis strain (ATCC 6538) was evaluated using a direct contact test. Results: There was no significant statistical difference (p > 0.05) observed in the flow and film thickness of NaI paste when compared to the currently available root canal filling materials. The average flow capacities for Vitapex^®, Metapex^®, and NaI paste were 15.40 mm, 21.25 mm, and 20.01 mm, respectively. The average film thickness for Vitapex^®, Metapex^®, and NaI paste were 33.3 ㎕, 22.6 ㎕, and 25.0 ㎕, respectively. However, NaI paste showed lower radiopacity than the existing materials, and this difference was statistically significant (p < 0.05) NaI paste demonstrated higher antimicrobial activity than the available materials, and this difference was also statistically significant (p < 0.05). Conclusion: Compared to the existing commercialized root canal filling materials, NaI paste exhibited similar performance in terms of flow and film thickness, and superior antimicrobial activity against E. faecalis. Hence, NaI paste could be a promising root filling material for primary teeth and may be a potential alternative to existing materials.

• Journal of agricultural medicine and community health
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• v.43 no.1
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• pp.18-30
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• 2018

Objectives: This study was conducted to examine the association of serum Vitamin D with insulin resistance and ${\beta}-cell$ function in Korean health checkup examinees. Methods: This study subjects were 374 healthy adults (199 males, 175 females) over the age of 20, who visited a general hospital medical center located in Haenam-gun, Jeollanam-do. To find the association of Vitamin D with HOMA-IR and $HOMA-{\beta}$, the used statistical analysis were ANOVA and ANCOVA. Results: Of the study subjects, the level of serum Vitamin D defined by deficient group, insufficient group and sufficient group was 38.5%, 48.1% and 13.4%, respectively. According to the level of serum Vitamin D, the mean values of HOMA-IR were $1.92{\pm}1.08$ in sufficient group, $1.99{\pm}1.04$ in the insufficient group and $2.91{\pm}1.05$ in deficient group and there were statistically significant different(p<0.001). The mean values of $HOMA-{\beta}$ were $84.69{\pm}1.07$ in sufficient group, $78.41{\pm}1.04$ in the insufficient group and $80.48{\pm}1.04$ in deficient group, and there were not significant. As a result of ANCOVA, adjusted mean of HOMA-IR were statistically significant different (p<0.001), but those of $HOMA-{\beta}$ were not statistically significant according to the level of serum Vitamin D. Conclusion: The insufficient level of serum Vitamin D was relatively high in healthy adults who live in rural area, and it was found that HOMA-IR significantly increased when Vitamin D was deficient. To prevent insulin resistance or diabetes, it is necessary to provide sufficient information related to sufficient production of Vitamin D such as Vitamin D supplement, sun exposure, food intake and etc.

• Journal of The Korean Association For Science Education
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• v.34 no.5
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• pp.421-436
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• 2014

The purposes of this study were to develop the customized instructional programs by the causes of science underachievement and to identify the effectiveness of these programs. For these, we analyzed the characteristics of underachievers and causes of science underachievement and classified 22 7th grade science underachievers into three different types such as lack of science process skill, lack of science learning motivation, and lack of science learning strategy. They then were divided into the experimental and comparative groups. Instructional programs treated for both groups covered the same topics and were conducted once a week for 60 minutes each time for 15 weeks. Eleven students in the comparative group were treated with an activity-centered science program that dealt with basic science concepts. Unlike science underachievers in the comparative group, those in the experimental group were given customized instructional program. After the treatment, students were administered several tests including a test on awareness of the program, science process skill test, science learning motivation and strategy test, and academic science achievement test. In addition to the results of those tests, worksheets, daily activity reports, and interviews were used to evaluate a customized instructional program that was applied to the experimental group. Results of the study showed that these programs relieved science underachievers from the cause of poor achievement and accordingly help them achieve better performance in academics. In addition, both lack of learning motivation and lack of learning strategy types tended to relieve the other causes of science underachievement. Also, the experimental group showed a high level of satisfaction with the customized instructional programs.

• Journal of agricultural medicine and community health
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• v.40 no.1
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• pp.21-31
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• 2015

Objective: This study was to evaluate the health-related quality of life (HRQoL) among patients with diabetes in Korea and to compare them with the HRQoL of individuals without diabetes history. Methods: The study subjects were 17,655 adults aged over 19 who participated in the 5th Korea National Health and Nutrition Examination Survey (2010-2012). The EuroQoL-5Dimension was used to evaluate HRQoL. Chi-square test, t-test, ANOVA and multiple regression analysis were performed to test the difference of HRQoL in diabetic subjects and controls. Results: The mobility dimension was the highest reported problem: 36.4% for diabetic subjects. The proportion of any reported problem was significantly high among diabetic subjects compared with two controls in terms of mobility [reference group: diabetic subjects, chronic controls: adjusted odds ratio (aOR)=0.77, 95% confidence interval (95% CI)=0.66-0.91, healthy controls: aOR=0.61, 95% CI=0.50-0.75], self-care [reference group: diabetic subjects, chronic controls: aOR=0.68, 95% CI=0.55-0.83, healthy controls: OR=0.69, 95% CI=0.51-0.94]. and usual activities [reference group: diabetic subjects, chronic controls: aOR=0.85, 95% CI=0.72-0.99, healthy controls: OR=0.79, 95% CI=0.62-0.98]. Also, EQ-5D index were significantly low in subjects with diabetes compared to two controls. Conclusions: Subjects with diabetes had a significantly lower HRQoL compared with two controls. To improve the quality of life of diabetics, it is necessary to study various variables related to the quality of life, and develop and manage various health programs or welfare policies reflecting socio-demographic characteristics and health related features that affect the quality of life.

• Korean Journal of Environment and Ecology
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• v.28 no.2
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• pp.142-149
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• 2014

This study has compared carbon storages, annual carbon uptakes and annual soil respiration by planting type in Dujeong park, Cheonan city. Four plantations were selected in Dujeong park: Pinus densiflora plantation, Quercus acutissima community, Quercus acutissima-Robinia pseudoacacia plantation, and Robinia pseudoacacia plantation. We investigated each plantations from February 2012 to March 2013. Carbon storage and annual carbon uptake in each plantations were calculated with allometric method (Lee, 2003), and soil respiration was measured by using LI-6400 (LI-COR). Carbon storages in Pinus densiflora plantation, Quercus acutissima community, Quercus acutissima-Robinia pseudoacacia plantation, and Robinia pseudoacacia plantation were $17.36tonCha^{-1}$, $88.63tonCha^{-1}$, $115.38tonCha^{-1}$ and 4$9.88tonCha^{-1}$, and annual carbon uptakes were $1.04tonCha^{-1}yr^{-1}$, $2.12tonCha^{-1}yr^{-1}$, $6.47tonCha^{-1}yr^{-1}$ and $3.67tonCha^{-1}yr^{-1}$, respectively. Average annual carbon uptakes per tree of Pinus densiflora plantation, Quercus acutissima community and Robinia pseudoacacia plantation were $1.81kgC{\cdot}treeyr^{-1}$, $17.86kgC{\cdot}treeyr^{-1}$ and $9.14kgC{\cdot}treeyr^{-1}$ and Quercus acutissima was the greatest. The amounts of carbon released from soil respiration in the same four plantations were $2.20{\mu}molCO_2m^{-2}s^{-1}$, $1.90{\mu}molCO_2m^{-2}s^{-1}$, $2.47{\mu}molCO_2m^{-2}s^{-1}$ and $2.51{\mu}molCO_2m^{-2}s^{-1}$, and annual soil respiration were estimated $6.66tonCha^{-1}yr^{-1}$, $5.33tonCha^{-1}yr^{-1}$, $7.20tonCha^{-1}yr^{-1}$ and $7.25tonCha^{-1}yr^{-1}$, respectively. In this study area, Quercus acutissima-Robinia pseudoacacia plantation has a significant contribution to the role of carbon sink. However, the contribution of Pinus densiflora plantation was evaluated less. The results of this study can be used as the necessary data for tree planting and management in urban park.

• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.4
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• pp.467-475
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• 2021

The purpose of this study was to compare the effect of sodium fluoride(NaF) varnish and potassium iodide(KI) on remineralization efficacy of silver diamine fluoride(SDF) by measuring microhardness and evaluating surface morphology by scanning electron microscope(SEM). Artificial caries lesions were induced on extracted primary molars and vickers microhardness was measured. Specimens were randomly separated into 4 groups for treatment. The specimens in group I were treated with SDF, group II with NaF varnish after SDF, group III with KI after SDF and group IV with distilled water. After 8 days of pH cycling, vickers microhardness was measured and difference before and after treatment was calculated. For SEM, 2 samples were evaluated respectively after enamel polishing, lesion formation and after pH cycling. Group III showed highest increase in microhardness. Group I showed higher increase in microhardness than Group II but without statistical difference. Group IV showed lowest increase in microhardness value among 4 groups. On SEM image, group I, II and III showed smoother and less irregular surface compared to group IV. Amorphous crystal pellicles were observed in group III. In conclusion, SDF, SDF and NaF, SDF and KI groups showed smoother surface and increase in microhardness suggesting the possibility that remineralization effect might take place in oral conditions. In addition, in limited conditions of this study, applying NaF varnish after SDF did not increase the remineralization efficacy of SDF while KI significantly increased the remineralization efficacy of SDF. However, additional study considering various conditions that might affect demineralization and remineralization in clinical situations need to be conducted.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.4
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• pp.379-391
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• 2022

The current study aimed to compare the pH, solubility value, and ion release capability of premixed mineral trioxide aggregates (MTAs) versus conventional pulp capping materials before and after setting. The following materials were used: resin-modified calcium silicate cement (TheraCal LC^®, TLC), resin-modified calcium hydroxide cement (Ultra-Blend^TM plus, UBP), and 2 kinds of premixed MTA (Endocem MTA^® premixed regular [EMPR] and Well-Root^TM PT [WRP]). The specimens of each material were prepared before and after setting and were immersed in distilled water. The materials' pH and solubility value were assessed. Next, three kinds of ion (calcium, sulfide, and strontium) released by pulp capping materials were evaluated via inductively coupled plasma atomic emission spectrometry. In the after-setting group, the pH of TLC and UBP decreased. However, the pH of the premixed MTAs increased with time. TLC released a higher concentration of strontium ion compared with the other materials. Meanwhile, EMPR released a significantly high concentration of sulfide ion (p < 0.05). In the after-setting group, the 2 kinds of premixed MTAs released a significantly higher concentration of calcium ion compared with the other materials (p < 0.05). In the after-setting group, EMPR had a significantly low solubility value (p < 0.05). The Kruskal-Wallis test, followed by the Mann-Whitney U test with Bonferroni correction, was used in statistical analysis. In conclusion, resin-modified calcium silicate cement, modified calcium hydroxide cement, and the 2 kinds of premixed MTAs had an alkaline pH and low solubility value and they released various concentrations of ions after setting.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.2
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• pp.205-216
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• 2023

This study aimed to compare the color stability and surface roughness of three-dimensional (3D) printing resin according to polishing methods. 3D-printed resin specimens were fabricated at TC-80DP (Graphy, Seoul, Korea) with a stereolithography 3D printer, and the specimens were divided into three groups, each of which was not polished, was polished using Enhance^®, and was polished using a Sof-Lex^TM disc. The CIE L^*a^*b^* value and the surface roughness of each group were measured and immersed in artificial saliva and orange juice after 0, 1, 7, 30, and 60 days, and the color difference (ΔE^*) was calculated. As a result of the study, no noticeable color change was observed in artificial saliva, but a noticeable color change was demonstrated in orange juice after 60 days of immersion, and the difference was significant. In the Sof-Lex^TM group, surface roughness according to the solution was found to be significantly higher in the orange juice than that in artificial saliva. No significant difference in color change was found according to the polishing method, but surface roughness was significantly lower in the Sof-Lex^TM group than both that of the unpolished group and that of the Enhance^® group. Nevertheless, all groups exhibited clinically acceptable properties regardless of their higher surface roughness than the threshold for plaque accumulation. Overall, this study recommends utilizing Sof-Lex^TM for polishing 3D printing resin when used in primary anterior tooth coverage.