• Explosives and Blasting
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• v.40 no.3
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• pp.44-53
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• 2022

This study evaluates the applicability of the TNT Equivalency Method, Multi-Energy Method, and Baker-Strehlow-Tang (BST) Method, which are blast prediction models used to determine the overpressure of blast wave generated from vapor cloud explosion. It is assumed that the propane leaked from a propane storage container with a capacity of 2000 kg installed in an area where studio houses and shopping centers are concentrated causes a vapor cloud explosion. The equivalent mass of TNT calculated by applying the TNT Equivalency Method is found to be 4061 kg. Change of overpressure with the distance obtained by the TNT Equivalency Method, Multi-Energy Method, and BST Method is rapid and the magnitude of overpressure obtained by the TNT Equivalency Method and BST method is generally similar within 100 m from explosion center. As a result of comparing the overpressure observed in the actual vapor cloud explosion case with the overpressure obtained by applying the TNT Equivalent Method, Multi-Energy Method, and BST Method, the BST Method is found to be the best fit. As a result of comparing the overpressure with the distance obtained by each explosion prediction model with the damage criteria for structure, it is estimated that the structure located within 90 m from explosion center would suffer a damage more than partial destruction, and glass panes of the structure separated by 600 m would be fractured.

• Journal of Environmental Health Sciences
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• v.48 no.4
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• pp.236-243
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• 2022

Background: In the case of multiple exposures to different types of heavy metals, such as the conditions faced by residents living near a smelter, it would be preferable to group hazardous substances with similar characteristics rather than individually related substances and evaluate the effects of each group on the human body. Objectives: The purpose of this study is to evaluate the utility of factor analysis in the assessment of health effects caused by exposure to two or more hazardous substances with similar characteristics, such as in the case of residents living near a smelter. Methods: Heavy metal concentration data for 572 people living in the vicinity of the Janghang smelter area were grouped based on several subfactors according to their characteristics using factor analysis. Using these factor scores as an independent variable, multiple regression analysis was performed on health effect markers. Results: Through factor analysis, three subfactors were extracted. Factor 1 contained copper and zinc in serum and revealed a common characteristic of the enzyme co-factor in the human body. Factor 2 involved urinary cadmium and arsenic, which are harmful metals related to kidney damage. Factor 3 encompassed blood mercury and lead, which are classified as related to cardiovascular disease. As a result of multiple linear regression analysis, it was found that using the factor index derived through factor analysis as an independent variable is more advantageous in assessing the relevance to health effects than when analyzing the two heavy metals by including them in a single regression model. Conclusions: The results of this study suggest that regression analysis linked with factor analysis is a good alternative in that it can simultaneously identify the effects of heavy metals with similar properties while overcoming multicollinearity that may occur in environmental epidemiologic studies on exposure to various types of heavy metals.

• Journal of Animal Science and Technology
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• v.64 no.3
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• pp.539-563
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• 2022

Nine pig farms were evaluated for the welfare quality in Korea using animal- and environment-based parameters (particularly air quality parameters) during the winter of 2013. The Welfare Quality^® (WQ^®) protocol consists of 12 criteria within four principles. The WQ^® protocol classifies farms into four categories ranging from 'excellent' to 'not classified'. Each of these criteria has specific measures for calculating scores. Calculations for the welfare scores were conducted online using the calculation model in the WQ^® protocol. Environment-based parameters like microclimate (i.e., temperature, relative humidity, air speed, and particulate matter), bacteria (total airborne bacteria, airborne total coliform, and airborne total Escherichia coli), concentration of gases (carbon dioxide, ammonia, and hydrogen sulfide) were measured to investigate the relationship between animal- and environment-based parameters. Correlations between the results of animal- and environment-based parameters were estimated using spearman correlation coefficient. The overall assessments found that five out of nine farms were 'acceptable', and four farms were 'enhanced'; no farm was 'not classified'. The average score for the four principles across the nine farms, in decreasing order, were 'good feeding' (63.13 points) > 'good housing' (59.26 points) > 'good health' (33.47 points) > 'appropriate behaviors' (25.48 points). In the result of the environment aspect, the relative humidity of farms 2 (93.4%), 3 (100%), and 9 (98%) was much higher than the recommended maximum relative humidity of 80%, and four out of the nine farms had ammonia concentrations greater than 40 ppm. Ammonia had negative correlations with 'positive social behaviors' and positive emotional states: content, enjoying, sociable, playful, lively, happy and it had positive correlations with negative emotional states: aimless, distressed. The concentration of carbon dioxide had negative correlations with positive emotional states; calm, sociable, playful, happy and it had a positive correlation with negative emotional state; aimless. Our results indicate that the control of the environment for growing pigs can help improve their welfare, particularly via good air quality (carbon dioxide, ammonia, hydrogen sulfide).

• Korean Journal of Culture and Social Issue
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• v.29 no.3
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• pp.321-340
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• 2023

This study was conducted to understand the emotional and situational context where non-suicidal self-injury occurs in everyday life. Sixty adults(age 19-35) completed daily surveys assessing positive and negative emotions, stressful events, self-injury thoughts, and behaviors for two weeks. Using a total of 663 collected entries, we analyzed specific personal emotions and stressful events related to non-suicidal self-injurious thoughts and behaviors. As a result, high negative emotions, low positive emotions, and total stress event scores were significantly related to self-injury thoughts and behaviors. In the model in which both emotion and stress were inserted as predictors, the low level of positive emotion showed a significant related to non-suicidal self-injurious behavior. These results suggest that negative emotion management and overall positive emotion reinforcement are important in emotion regulation intervention for non-suicidal self-injurious patients. The meaning of this study is that it searched for risk factors of non-suicidal injury in everyday life using a short-term longitudinal method.

• Journal of Korean Elementary Science Education
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• v.42 no.3
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• pp.434-454
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• 2023

This study explored the composition and attributes of modeling instructions and factors of teacher competence in elementary science classes. The study also examined educational research papers regarding modeling instruction cases in elementary schools and elementary teachers' perceptions of modeling instructions using qualitative meta-analysis, which can integrate findings from qualitative research. This investigation led to creating a small group to compose modeling instructions. Furthermore, the modeling approach was demonstrated to go through the process of generating, evaluating, and modifying the model. The attributes of modeling instructions can be divided into factors that affect modeling instructions and competence factors necessary for students participating in modeling instructions. The factors affecting modeling instructions included "small group interactions" and "time limitation in classes." The competence factors necessary for students participating in modeling instructions included "scientific knowledge," "meta-modeling knowledge," and the "ability to control emotions." The teacher competence factors in modeling instructions regarding knowledge, function, and attitude were explored. The teacher competence factors in elementary modeling instructions included "meta-modeling knowledge," "knowledge of modeling assessment," "emotional support for students," and the "awareness of modeling value." Accordingly, this study offered some recommendations for effective modeling instructions.

• Nutrition Research and Practice
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• v.17 no.2
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• pp.241-256
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• 2023

BACKGROUND/OBJECTIVES: Diabetes-specific oral nutritional supplements (ONS) have anti-hyperglycemic effects, while D-allulose exerts anti-diabetic and anti-obesity effects. In this study, we investigated the efficacy and safety of diabetes-specific ONS, including allulose, on glycemic and weight changes in overweight or obese patients with type 2 diabetes mellitus (T2DM). SUBJECTS/METHODS: A single-arm, historical-control pilot clinical trial was conducted on 26 overweight or obese patients with T2DM (age range: 30-70 yrs). The participants were administered 2 packs of diabetes-specific ONS, including allulose (200 kcal/200 mL), every morning for 8 weeks. The glycemic profiles, obesity-related parameters, and lipid profiles were assessed to evaluate the efficacy of ONS. RESULTS: After 8 weeks, fasting blood glucose (FBG) level significantly decreased from 139.00 ± 29.66 mg/dL to 126.08 ± 32.00 mg/dL (P = 0.007) and glycosylated hemoglobin (HbA1c) improved (7.23 ± 0.82% vs. 7.03 ± 0.69%, P = 0.041). Moreover, the fasting insulin (δ: -1.81 ± 3.61 μU/mL, P = 0.017) and homeostasis model assessment for insulin resistance (HOMA-IR) (δ: -0.87 ± 1.57, P = 0.009) levels decreased at 8 weeks, and body weight significantly decreased from 67.20 ± 8.29 kg to 66.43 ± 8.12 kg (P = 0.008). Body mass index (BMI) also decreased in accordance with this (from 25.59 ± 1.82 kg/m² to 25.30 ± 1.86 kg/m², P = 0.009), as did waist circumference (δ: -1.31 ± 2.04 cm, P = 0.003). CONCLUSIONS: The consumption of diabetes-specific ONS with allulose in overweight or obese patients with T2DM improved glycemic profiles, such as FBG, HbA1c, and HOMA-IR, and reduced body weight and BMI.

• Nutrition Research and Practice
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• v.17 no.2
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• pp.228-240
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• 2023

BACKGROUND/OBJECTIVES: Cocoa consumption is associated with health benefits due to its high content of polyphenols. However, the effects of short-term cocoa consumption remain unclear. We aimed to determine the effects generated by cocoa consumption (for 7 days) in young adults in normoweight and class II obesity. SUBJECTS/METHODS: Before-and-after study was carried out in normoweight (NW) (n = 15) and class II obesity (CIIO) (n = 15) young adults. The NW and CIIO participants consumed 25 and 39 g of cocoa, respectively, per day for 7 days. The effect of cocoa consumption was evaluated on the lipid profile, insulin resistance (IR), and inflammation. Oxidative damage was also examined by assessing the biomarkers of oxidative damage in plasma. In addition, recombinant human insulin was incubated with blood obtained from the participants, and the molecular damage to the hormone was analyzed. RESULTS: Cocoa consumption resulted in decreased low-density lipoprotein-cholesterol in both groups (P = 0.04), while the total cholesterol, high-density lipoprotein cholesterol, and triglycerides were maintained at the recommended levels. Initially, IR was detected in the CIIO group (homeostasis model assessment [HOMA] = 4.78 ± 0.4), which is associated with molecular damage to insulin. Interestingly, intervention with cocoa resulted in improved IR (HOMA = 3.14 ± 0.31) (P = 0.0018) as well as molecular damage to insulin. Finally, cocoa consumption significant decreased the arginase activity (P = 0.0249) in the CIIO group; this is a critical enzymatic activity in the inflammatory process associated with obesity. CONCLUSIONS: The short-term consumption of cocoa improves the lipid profile, exerts anti-inflammatory effects, and protects against oxidative damage. Results of this study indicate that cocoa consumption can potentially improve IR and restore a healthy redox status.

• Journal of the Korean Applied Science and Technology
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• v.40 no.2
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• pp.233-243
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• 2023

The purpose of this study is to analyze the relationship between self-determination motivation of high school students on exercise satisfaction and exercise continuation intention. To this end, as of March 2022, an online questionnaire was distributed to 440 male students attending high schools in Seoul and Gyeonggi Province, and they were asked to fill out the questionnaire through self-assessment. 346 copies were selected as a valid sample, excluding 94 copies of insincere responses such as responses of the same pattern and incomplete responses. For data processing, frequency analysis, confirmatory factor analysis, and correlation analysis were conducted using SPSS 24.0 and IBM AMOS 18.0 statistical programs, and the following results were derived through structural equation model analysis to identify the structural relationship between factors. First, among self-determination motivation factors, competence and relatedness had a positive (+) effect on exercise satisfaction, but autonomy had a negative (-) effect on exercise satisfaction. Second, there was no relationship between self-determination motivation and exercise continuation intention in high school students. Third, it was found that the relationship between exercise satisfaction and exercise continuation intention had a positive (+) effect.

• Nuclear Engineering and Technology
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• v.55 no.4
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• pp.1460-1467
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• 2023

A robust approach was conducted to determining the absolute oral bioavailable (f_ab) fractions of ²³⁸U and ²³²Th in rats exposed to contaminated soil along with their hematotoxicity and nephrotoxicity. The soil sample is the International Atomic Energy Agency-312 (IAEA-312) certified reference material, whereas blood, bones, and kidneys of in vivo female Sprague-Dawley (SD) rats estimate ²³⁸U- and ²³²Th-f_ab fractions post-exposure. We predict the bioavailable concentration (C_ab) and f_ab values of ²³⁸U and ²³²Th after acute soil ingestion. The blood ²³⁸U (0.750%) and ²³²Th (0.028%) reach their maximum f_ab values after 48 h. The ²³⁸U (f_ab: 0.169-0.652%) accumulates mostly in the kidney, whereas the ²³²Th (f_ab: 0.004-0.021%) accumulates primarily in the bone. Additionally, ²³⁸U is more bioavailable than ²³²Th. Post 48 h acute ingestion demonstrates noticeable histopathological and hematological alterations, implying that intake of ²³⁸U in co-contaminated soil can lead to erythrocytes and proximal tubules damage, whereas, ²³²Th intake can harm erythrocytes. Our study provides new directions for future research into the health implications of acute oral exposures to ²³⁸U and ²³²Th in co-contaminated soils. The findings offer significant insight into the utilization of in vivo SD rat testing to estimate ²³⁸U and ²³²Th bioavailability and toxicity in exposure assessment.

• Journal of the Korean Society for information Management
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• v.40 no.2
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• pp.211-241
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• 2023

With rapidly changing technological implementation of operating systems of businesses, the Ministry of foreign affairs (MOFA) of the Republic of Korea (ROK) has been undergoing digital transformation to its overall operations with the intent to innovate information and knowledge management (IKM) strategies since the mid-2000s. However, assessment as to the effectiveness of implemented IKM has been inadequately analyzed. This study aims to assess the concepts and limitations of the MOFA's current IKM strategies and the methods it employs to deliver its IKM framework, in light of strengthening the organizational ambidexterity and absorptive capacity, and also fostering organizational innovation through a qualitative study that involves interviews and analysis of reports from MOFA. The MOFA's IKM possesses dynamic capabilities to adapt to changing digital technologies. However, the institution's IKM is constrained by limitations associated with the utilization of the IKM system such as a structure that handles confidential documents and a lack of a collaborative system for IKM, and external limitations such as changes in the domestic political situation governing MOFA's priorities and the hierarchy of government organizations. Consequently, developing the organizational ambidexterity and absorptive capacity was not possible. To develop an IKM framework for organizational innovation, the MOFA must devise a way to minimize the impact of external changes by overcoming internal limitations. To that end, a detailed study on the development of a practically usable IKM system should include establishing a dialogue between job groups and enhancing employee competency in preparation for a changing environment.