• Journal of the Korean Society of Earth Science Education
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• v.15 no.3
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• pp.354-372
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• 2022

The purpose of this study is to explore the philosophical position of various scientific theories based on the scientific worldviews for science education. In addition, it aims to expand science education, which has usually dealt with epistemology and methodology, to ontology, that is, to the problem of metaphysics. It can be said that there exists a physical realism, traditionally defined as a strong determinism of the metaphysical belief. That is fixed and unchanging objective scientific knowledge independent of our minds, which was established by Newton, Einstein and Schridinger. What can be seen in the natural laws of dynamics can be called 'mathematicization'. Einstein also shook the traditional views to some extent through the theory of relativity, but his theory was still close to traditional thinking. On the contrary, to escape from this rigid determinism, we need anthropomorphic concepts such as 'possibility' and 'chance'. It is a characteristic of the modern scientific worldviews that leads the change of scientific theory from a classically strong deterministic thought to a weak deterministic accidental accident, probability theory, and a naturalistic point of view. This can be said to correspond to Darwin's theory of evolution and quantum mechanics. We can have three types of epistemological worlds that justify this ontological worldviews. These are rationalism, empiricism and naturalism. In many cases, science education does not tell us what kind of metaphysical beliefs the scientific theories we deal with in the field of education are based on. Also, science education focuses only on the understanding of scientific knowledge. However, it can be said that true knowledge can bring understanding only when it is connected to the knowledge of learned knowledge and the learner's own metaphysical belief in the world. Therefore, in the future, science education needs to connect various scientific theories based on scientific worldviews and philosophical position and present them to students.

• Korean Journal of Psychosomatic Medicine
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• v.30 no.2
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• pp.73-79
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• 2022

Objectives : Suicide is a global social problem. Social burden caused by suicide is gradually increasing. Various efforts have been made to prevent suicide. Lifestyle changes to western style, especially diet changes, have increased the risk for suicide. Therefore, in this study, we discussed diet as an adjuvant treatment for suicide. Methods : In this review, we summarized the biochemical mechanism of suicide, and diet as a risk factor for suicide and diet as a protective factor through a web search. Results : In this study, biochemical mechanisms for suicide were reviewed and diet as a risk factor and diet as a protective factor for suicide were investigated. It was confirmed that neurotoxic effects such as oxidative stress and inflammation in the neural system could increase the risk of suicide. Based on results of previous studies on the relationship between suicide and diet, it was found that heavy use of alcohol, coffee, carbonated soft drink, and fast food were risk factors for suicide. Protective factors for suicide included antioxidants such as vitamin C, carotene, and anti-inflammatory agents such as omega-3 fatty acids found in seafood in large amounts. Conclusions : The only treatment for suicide is prevention. In this context, effectiveness, accessibility, and safety are important for preventing for suicide. Antioxidants and anti-inflammatory agents that are relatively safe and readily available to the public could be effective adjuvant treatments to decrease the risk of suicide. In addition, it is necessary to educate the public on reducing diets that could increase the risk of suicide

• Land and Housing Review
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• v.14 no.1
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• pp.47-66
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• 2023

This study reviews prior studies on the residential environment characteristics, residential satisfaction, residential ownership consciousness and housing movement of MZ generation and analyze the structural equation models using the 2020 Korea Housing Survey data. Using 14 residential characteristics based on three classifications, we explore the effects on residential satisfaction, residential ownership consciousness, and housing movement. The empirical results are summarized as follows. First, based on factor analysis with Varimax of principal component analysis, parking facility items were excluded from the analysis by hindering validity, and as a result, KMO was 0.925 and Bartlett's test result showed a significant probability of less than 0.01. This indicates that the factor analysis model was suitable. Second, the results of the structural equation analysis for the MZ generation show that the surrounding environment, which is a potential variable of the residential environment characteristics, was statistically significant, but the accessibility and convenience were not statistically significant. Third, we find that the higher the satisfaction with the accessibility of commercial facilities, the more significant the sense of housing ownership appears. This suggests that the younger generation such as the MZ generation has a stronger desire for consumption. Fourth, the overall housing satisfaction of the MZ generation was significant for housing movement, but not for housing ownership. Compared to the industrialized generation, the baby boom generation, and the X generation, MZ generation shows distinct factors for housing satisfaction, housing ownership, and housing movement. Therefore, the residential environment characteristics of the residential survey should be improved and supplemented following the trend of the times. In addition, the government and local governments should prioritize actively participating in the housing market that suits the environment and characteristics of the target generation. Finally, our study provides implications regarding the need for housing-related research on how differ in special temporal situations such as COVID-19 in the future.

• 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 Food Hygiene and Safety
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• v.37 no.6
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• pp.418-428
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• 2022

The purpose of this study was to obtain the codex classification information on the primary food commodity (fresh state) of processed foods of plant origin that are included in the Codex Classification of Foods and Animal Feeds. Furthermore, whether or not the primary food commodity is included in the primary food classification from the Food Code of Korea was investigated. The results are summarized as follows: First, the Codex Classification information (number of classification codes/number of the primary food commodity group that fresh commodities of processed foods are classified/number of primary food commodity that is not included in the Codex Classification) by a processed food group appeared to be 46/8/0 for dried fruits, 76/11/1 for dried vegetables, 54/4/12 for dried herbs, 36/1/0 for cereal grain milling fractions, 17/4/3 for oils and fats (crude), 34/8/9 for oils and fats (refined), 20/8/0 for fruit juices, 3/2/0 for vegetable juices, and 19 codes for teas (in the Codex Classification, the primary food commodity group for tea does not exist). Second, the number of the primary food commodities not included in the Food Code of Korea was 9 for dried fruits, 14 for dried vegetables, 35 for dried herbs, 0 for cereal grain milling fractions, 6 for teas, 3 for oils and fats (crude), 9 for oils and fats (refined), 2 for fruit juices, and 0 for vegetable juices. Third, it was demonstrated that caution should be exercised when using Codex Classification due to differences in food classification between Codex and Korea, such as coconut (Codex, as tree nut as well as assorted tropical and sub-tropical fruit) and olive (Codex, as assorted tropical and sub-tropical fruit as well as olives for oil production), as well as special cases in the Codex Classification, such as dried chili pepper (Codex, as spice), tomato juice (Codex, as vegetable for primary food commodity and as fruit juice for juice) and ginger (Codex, as spice for rhizome and not including as primary commodity for leaves).

• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.447-455
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• 2022

Fully dehydrated Tl₁₂-LTA (|Tl₁₂|[Si₁₂Al₁₂O₄₈]-LTA,Tl₁₂-A) was treated with 6.0×10³ Pa of ZrI₄ (g) at 623 K for 72 hr under anhydrous conditions. The crystal structure of product, |Zr_0.25I_1.5Tl₁₂|[Si₁₂Al₁₂O₄₈]-LTA, was determined by single-crystal crystallography using synchrotron X-radiation in the cubic space group Pm3m (a = 12.337(2) Å). It was refined using all data to the final error index (for the 712 unique reflections for which F_o> 4σ(F_o) R₁/wR₂= 0.055/0.189. In this structure, octahedral ZrI₆^2- ions center about 25% of the large cavities (Zr-I = 2.91(4) Å). Each coordinates to eight Tl⁺ ions and they are further bridged by Tl⁺ ions in the planes of 8-rings to form a cubic three-dimensional ZrI₆Tl₁₁⁹⁺ cationic cluster. About 1.5 Tl⁺ ions per unit cell moved to deeper side of sodalite cavity after reaction with ZrI₄(g). The remaining Tl⁺ ions occupy well-established cation positions near 6- and 8-rings.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.4
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• pp.414-427
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• 2022

This study aims to analyze the color distribution of maxillary permanent incisors in Korean pediatric patients and determine the effects of age and root developmental stage on tooth color. The L^*a^*b^* values of 404 sound and fully erupted maxillary incisors without dental caries, restorations, trauma history or discoloration from 101 Korean patients between ages 7 and 15, with a mean age 10.0 ± 1.5, were analyzed with a spectrophotometer. CIE L^*a^*b^* values were 84.01, 0.17, and 24.07 in maxillary central incisors, and 82.33, 0.31, and 25.99 in maxillary lateral incisors. L^* values of maxillary central incisors were higher, and b^* values of maxillary central incisors were lower than those of maxillary lateral incisors (p < 0.001). The color differences among the subregions exceeded the clinical perceptibility threshold in both of the maxillary central and lateral incisors. L^* value for children at age 10 and younger was 84.13 in maxillary central incisors and 84.04 in maxillary lateral incisors, and those of older patients were 80.62 and 80.56, respectively. L^* value of maxillary incisors of children at age 10 and younger was significantly higher than that of older patients. The root developmental stage did not affect tooth color. This study suggests that the color differences between maxillary central and lateral incisors and among the subregions of a tooth and the effects of age should be considered for aesthetic restorations of permanent incisors in pediatric patients.

• Journal of Korea Water Resources Association
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• v.55 no.12
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• pp.1041-1052
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• 2022

This study is to estimate the optimal ecological flow and analysis the spatial distribution of fish habitat for Andong dam downstream reach (4,565.7 km²) using PHABSIM (Physical Habiat Simulation System) and River2D. To establish habitat models, the cross-section informations and hydraulic input data were collected uisng the Nakdong river basic plan report. The establishment range of PHABSIM was set up about 410.0 m from Gudam streamflow gauging station (GD) and about 6.0 km including GD for River2D. To select representative fish species and construct HSI (Habitat Suitability Index), the fish survey was performed at Pungji bridge where showed well the physical characteristics of target stream located downstream of GD. As a result of the fish survey, Zacco platypus was showed highly relative abundance resulting in selecting as the representative fish species, and HSI was constructed using physical habitat characteristics of the Zacco platypus. The optimal range of HSI was 0.3~0.5 m/s at the velocity suitability index, 0.4~0.6 m at the depth suitability index, and the substrate was sand to fine gravel. As a result of estimating the optimal ecological flow by applying HSI to PHABSIM, the optimal ecological flow for target stream was 20.0 m³/sec. As a result of analysis two-dimensional spatial analysis of fish habitat using River2D, WUA (Weighted Usable Area) was estimated 107,392.0 m²/1000 m under the ecological flow condition and it showed the fish habitat was secured throughout the target stream compared with Q₃₅₅ condition.

• Journal of Food Hygiene and Safety
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• v.37 no.3
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• pp.166-172
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• 2022

This study evaluated the migrant and residue tests of lead (Pb), cadmium (Cd), nickel (Ni), arsenic (As), and antimony (Sb) in 70 tumbler samples. The migration levels of hazardous metals in all the samples were within the migration limits outlined in the Korean standards and specifications for utensils, containers, and packages. Moreover, in all the tumbler samples, only Ni was detected in 0.5% citric acid solution of a food stimulant. The maximum level of Ni 0.0144 mg/L was 14.4% of the migrant specification (not more than 0.1 mg/L), which was relatively safe. The 0.5% citric acid solution was eluted at 4℃, 70℃, and 100℃ for 30 min, and only Ni was detected while testing for migration levels according to the temperature variations; all temperature conditions conformed to the standards. The level of Ni migration increased significantly with increasing migration temperature. Regarding the residue level outside the paint-coated tumbler samples, the Pb level was found to range from N.D. to 20638.1323 mg/kg. The risk of Ni was further estimated to be at a safe level of 0.00 to 0.01% compared to the %TDI as a result.

• Journal of the Korean Geotechnical Society
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• v.38 no.7
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• pp.49-62
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• 2022

The hollow modular concrete block reinforced foundation method is one of the ground reinforcement foundation methods that uses hexagonal honeycomb-shaped concrete blocks with mixed crushed rock to reinforce soft grounds. It then forms an artificial layered ground that increases bearing capacity and reduces settlement. The hollow modular honeycomb-shaped concrete block is a geometrically economical, stable structure that distributes forces in a balanced way. However, the behavioral characteristics of hollow modular concrete block reinforced foundations are not yet fully understood. In this study, a bearing capacity test is performed to analyze the reinforcement effectiveness of the hollow modular concrete block through the laboratory model tests. From the load-settlement curve, punching shear failure occurs under the unfilled sand condition (A-1-N). However, the filled sand condition (A-1-F) shows a linear curve without yielding, confirming the reinforcement effect is three times higher than that of unreinforced ground. The bearing capacity equation is proposed for the parts that have contact pressure under concrete, vertical stress of hollow blocks, and the inner skin friction force from horizontal stress by confining effect based on the schematic diagram of confining effect inside a hollow modular concrete block. As a result of calculating the bearing capacity, the percentage of load distribution for contact force on the area of concrete is about 65%, vertical force on the area of hollow is 16.5% and inner skin friction force of area of the inner wall is about 18.5%. When the surcharge load is applied to the concrete part, the vertical stress occurs on the area of the hollow part by confining effect first. Then, in the filled sand in the hollow where the horizontal direction is constrained, the inner skin friction force occurs by the horizontal stress on the inner wall of the hollow modular concrete block. The inner skin friction force suppresses the punching of the concrete part and reduces contact pressure.