• Journal of the Korean Chemical Society
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• v.68 no.5
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• pp.259-273
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• 2024

This study aimed to investigate changes in metamodeling recognition among chemistry teachers through a teacher educational program related to redox models and water electrolysis experiments. To this end, a science model education program was developed for 9 chemistry teachers and conducted over 10 lessons for a total of 40 hours. In addition, a pre- and post-survey was administered to determine teachers' metamodeling recognition in non-contextual and contextual situations. As a result of the study, through the science model education program, teachers showed educational effects in both non-contextual and contextual situations. In the case of non-contextual situations, the stages of scientific metamodeling knowledge development of chemistry teachers came out differently depending on the type of question. For example, the nature or purpose of the model, the modeling process, or the evaluation and improvement of the model improved from low to high, but there was no significant change because the perception of model change and diversity was already high in advance. In the case of contextual situations, the stage of scientific metamodeling knowledge development improved from objectivity to subjectivity in both the redox model theory class and the water electrolysis model experiment class. Therefore, through the 5E circular learning model-based education program, chemistry teachers' perception of metamodeling was clearly improved. However, the modeling activities of teachers in the water electrolysis model experiment class were different from the change in metamodeling perception. The types that teachers selected as additional experiments for modeling were analyzed in two ways. The first type is when they are interested in finding an ideal condition in which the ratio of hydrogen and oxygen gas is close to 2:1 through additional experiments. The second type is when additional experiments are designed with interest in why the experimental results are coming out like that. It was analyzed that the second type was the experiment necessary for modeling. In addition, modeling activities were analyzed into two types. The first was a type in which water molecules were directly decomposed in two electrodes to generate hydrogen and oxygen gas. This type was the case of regression to the textbook model regardless of the experimental results, and 6 chemistry teachers out of 8 were analyzed as this type. The second type was the type in which water reacted at the (+) electrode to generate other substances, and hydrogen ions reacted at the (-) electrode to generate hydrogen gas. Teachers who performed these modeling activities corresponded to the second type in additional experiments, and 2 chemistry teachers out of 8 corresponded to this. Therefore, it is necessary to provide an experience of activities corresponding to the second type of experiment and modeling through an educational program that provides an experience of directly modeling through experiments in order to develop modeling capabilities, unlike the development of metamodeling knowledge.

• Journal of the Korean Society of Radiology
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• v.18 no.4
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• pp.327-334
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• 2024

The purpose of this study is to develop a customized foot disease analysis and management system for diabetic patients to prevent foot ulcers in diabetic foot disease patients. This system utilizes image analysis technology to measure not only foot pressure, but also ankle deformation, body balance, and foot wounds. Through various data, it is possible to accurately analyze the state of foot deformation, and based on this, the exact state of deformation of the foot of a patient with diabetic foot disease was identified and a customized insole was produced. This study was conducted to examine the satisfaction level of using an application that checks the status of diabetic foot disease wounds and to identify the degenerative status of diabetic foot disease patients and foot disease patients by wearing customized insoles and to survey the satisfaction of wearing insoles. As a result of the study, the knee angle measured for plantar pressure was -0.8 ± 1.3 degrees and ranged from a minimum of -2.4 degrees to a maximum of 1.1 degrees, and there was no significant difference in valgus knee between both lower extremities (p = 0.534). There was a significant difference in tibial angle between both lower extremities (p < 0.001). Ankle angle on the left side was 2.6 ± 2.0 degrees, ranging from a minimum of 0 degrees to a maximum of 6.3 degrees, and on the right, it was 4.5 ± 2.1 degrees, with a distribution of minimum 1.5 degrees to a maximum of 9.1 degrees. There was a significant difference in ankle angle between both lower extremities (p = 0.011). They responded that they felt an average of 4.3 points of satisfaction with the plantar pressure measurement application. Respondents responded that they felt an average of 3.9 points of satisfaction with the use of customized insoles.

• Journal of Korea Port Economic Association
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• v.40 no.2
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• pp.21-38
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• 2024

The current situation of ports and related industries is transitioning from quantitative growth in increased cargo volume and expansion of port facilities to qualitative growth in the role of ports through the creation of high value-added. Ports are now recognized as playing an important role in economic growth and development by generating high value-added, not just by increasing the amount of cargo and expanding port facilities. This study evaluated the importance of factors affecting the improvement of the Busan Port's marine equipment industry by using the Analytic Hierarchy Process(AHP) to derive the priority of improvement measures by factor and evaluate the importance of factors affecting the marine equipment industry. The factors that should be considered when selecting improvement measures for the marine equipment industry were selected as four factors: strengthening price competitiveness, increasing government and local government interest, strengthening promotion, and establishing a global network. The main sub-factors were composed of eight detailed evaluation factors by selecting two factors for each layer. The analysis was designed by dividing the factor hierarchy for selecting improvement measures for the marine equipment industry into three levels and creating survey questions for pairwise comparison. The priority of the analysis results using AHP showed that the factor with the highest priority was strengthening price competitiveness, followed by increasing government and local government interest, establishing a global network, and strengthening promotion. According to the analysis results for the second-level sub-factors, among the factors for strengthening price competitiveness, low distribution costs and storage costs were considered most important, followed by avoiding excessive competition among marine equipment companies. Among the factors for increasing government and local government interest, improving customs procedures and tariff refund procedures were considered most important, followed by strengthening incentives from the government and Busan City. Among the factors for establishing a global network, promoting large-scale marine equipment companies was considered most important, followed by actively participating in international marine equipment-related associations. Among the factors for strengthening promotion, active use of the Internet was considered most important, followed by holding domestic and international exhibitions. Based on this study, we hope to help activate Busan Port's market by enhancing its competitiveness through revitalizing its marine equipment industry, generating water traffic, and creating new value-added.

• Journal of Life Science
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• v.34 no.8
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• pp.567-575
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• 2024

New breeding techniques (NBT) recognize specific DNA sequences and remove, modify, or insert DNA at a desired location, and can be used to treat genetic diseases in humans or to improve the traits of livestock or crops. In this study, we conducted a comparative analysis of various agricultural traits and assessed the safety of gene transferability in third-generation genome-editing rice (OsCKq1-G₃) with T and G nucleotide insertions developed using the CRISPR/Cas9 SDN-1 method, in comparison to its parental line (Oryza sativa L., cv Ilmi). The analyzed traits included heading date, culm length, panicle length, tiller number, yield, germination rate, viviparous germination rate, shattering, after wintering seed viability, the presence of toxins and allergens. The target trait, heading date, exhibited a high significant difference of approximately 5 days. Culm length, panicle length, tiller number, yield showed no significant differences compared to the parental line. No T-DNA bands indicating gene transfer were detected. In the third generation of genome-edited rice, the T-DNA was confirmed to be eliminated as successive generations advanced through self-pollination. Through the analysis of germination rate, viviparous germination rate, shattering, and after wintering viability, we confirmed that the genome-editing rice has no potential for weediness. The ORF and amino acid sequences of the genome-editing rice did not reveal any toxins and allergens. The results of this study can be utilized as important data for the environmental risk assessment of genome-editing rice.

• Korean Journal of Ichthyology
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• v.36 no.3
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• pp.240-252
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• 2024

The distribution status of the nature monument species, Hemibarbus mylodon, was investigated from 2021 to 2024 in Geumgang River and Mujunamdae Stream (a tributary of the Geumgang River). In 2021 to 2023, five individuals from Gemgang River upstream were collected by Geumsan-gun, Chungchangnam-do. In 2021 to 2024, 1,592 induviduals juvenile from seven sites were collected by surveying 15 sites from Mujunamdae Stream. The main habitat of juvenile was about 0.3~1.5 meters water deep, 0.14~0.16 meters per second in the middle-upper stream of rock and sand bottom with slow rapids and pools. The age groups for H. mylodon estimated by the frequency distribution of total length in after spawning season (May) to October indicated the 10~65 mm is 0-year old, 75~90 mm is 1-year old group. In addition, over the 120 mm group is 2-years old, the 190~250 mm is more than 3-years old group. In 2024, we identified 35 spawning place from six sites were sites were collected by surveying 15 sites. Spawning place at the river bottom were top of the rapids, 30~60 cm (mean 48.2 cm) water deep, and the place was covered with stone and gravel, water velocity was 0.13~0.34 (mean 0.25 m/sec) meter per second. The spawning place size of the gravel piles was as follows: length 35~48 cm (mean 40.7 cm), width 25~37 cm (mean 34.5), and height 5~12 cm (mean 8.6 cm). Thus, H. mylodon reintroduced to Mujunamdae Stream has successfully settled down and increase in abundance within the natural habitat.

• Journal of the Korea Organic Resources Recycling Association
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• v.17 no.3
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• pp.27-39
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• 2009

The main objective of this study is to investigate the characteristics of combustion by analyzing fuel gases from a combustion equipment with various combustion conditions for refuse-derived fuels (RDFs). CO gas is a parameter for indicating of incomplete combustion during a combustion process. The lowest CO gas was produced when the experiment conditions were m=2 under air-fuel condition and $800^{\circ}C$. $CO_2$ gas is a final product after complete combustions. The highest amount of $CO_2$ gas was produced when the experiment conditions were m=2 under air-fuel condition and $800^{\circ}C$. The highest level of $SO_2$ gas was produced in S.1 sample containing the highest sulfur. The highest level of NOx gas was produced in S.1 sample with the highest nitrogen content and air-fuel condition of m=2 under temperature of $800^{\circ}C$. HCl gas that is generated by reacting with metals catalyst through oxygen catalyst reaction during combustion process is a precursor of dioxin formation. The higher level of HCl gas was produced in the sample with higher chlorine content. The lowest level of HCl gas was produced when the experiment conditions were air-fuel condition of m=2 and $800^{\circ}C$. The lowest level of $NH_3$ gas was generated when the experiment condition was m=2 under air-fuel condition and after 3 minutes. Air-fuel condition is more important to create $NH_3$ gas than operating temperatures. Higher level of $H_2S$ gas was generated in S.1 sample with the higher sulfur content and was created in RDFs that contain higher mixture ratios of sewage sludge and food wastes. A result of combustion, gases and gases levels from the combustion of S.1 and S.2 were very similar to the combustion of a stone coal. As results of this research, when evaluating the feasibility of the RDFs, the RDFs could be used as auxiliary and main fuels.

• Journal of Korea Water Resources Association
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• v.57 no.8
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• pp.509-518
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• 2024

Flash drought is a rapid-onset drought that occurs rapidly over a short period due to abrupt changes in meteorological and environmental factors. In this study, we utilized satellite-based soil moisture product from the Advanced Microwave Scanning Radiometer-2(AMSR2) ascending X-band to calculate the weekly Flash Drought Intensity Index (FDII). We also analyzed the characteristics of flash droughts on the Korean Peninsula over a 10-year period from 2013 to 2022. The analysis of monthly spatial distribution patterns of the irrigation period across the Korean Peninsula revealed significant variations. In North Korea (NK), a substantial increase in the rate of intensification (FD_INT) was observed due to the rapid depletion of soil moisture, whereas South Korea (SK) experienced a significant increase in drought severity (DRO_SEV). Additionally, regional time series analysis revealed that both FD_INT and DRO_SEV were significantly high in the Gangwon province of both NK and SK. The estimation of probability density by region revealed a clear difference in FD_INT between NK and SK, with SK showing a higher probability of severe drought occurrence primarily due to the high values of DRO_SEV. As a result, it is inferred that the occurrence frequency and damage of flash droughts in NK are higher than those in SK, as indicated by the higher density of large FDII values in the NK region. We analyzed the correlation between DRO_SEV and the Evaporative Stress Index (ESI) across the Korean Peninsula and confirmed a positive correlation ranging from 0.4 to 0.6. It is concluded that analyzing overall drought conditions through the average drought severity holds high utility. These findings are expected to contribute to understanding the characteristics of flash droughts on the Korean Peninsula and formulating post-event response plans.

• Journal of Korean Home Economics Education Association
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• v.36 no.1
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• pp.55-69
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• 2024

This study aims to present a case of implementing educational programs that integrate theory and experience, leading to practical environmental conservation practices within households, and to analyze and evaluate their effectiveness. To achieve these goals, various hands-on environmental education programs related to family life, including carbon-neutral practices, clothing, food, housing, and design, were implemented for early adulthood. Pre- and post-surveys provided by the Korea Environmental Preservation Association were utilized to assess awareness and willingness to engage in environmental conservation among participants, and consultation with an expert was conducted to understand the effectiveness of the educational programs. As a result, the findings confirmed a notable enhancement in participants' environmental consciousness and commitment to action following the program compared to pre-program levels. The results of open-ended questions showed that the content participants wanted to learn and what they actually learned in the classes were similar, validating the effectiveness of the program. The consultation results indicated that presenting various practical methods related to household life would be effective; however, there was a suggestion for the need to consider aspects such as post-practical food management and the unique characteristics of multicultural household members when developing educational programs. This educational initiative holds promise for instigating perceptible shifts in the awareness and proactive engagement of young adults across the spectrum of household dynamics, thereby contributing significantly to the establishment of sustainable living paradigms.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.492-500
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• 2023

The spectrum of this study was research on the closed hydroponic cultivation of netted melons (Cucumis melo L.) using coir substrate, analyzing the impact of this cultivation method on melon yield, fruit quality, and the efficiency of water and nutrient usage. The experimental results showed that the average fruit weight of the melons grown in a closed system was 71.4 g higher than that of the open system, and the fruit width was on average 0.2 cm larger, showing a statistically significant difference. However, there was no difference in the average sugar content of the fruit flesh and height. Although there is no substantial commercial difference, it is conjectured that the change in the macronutrients ratio in the irrigation has played a role in the statistically significant increase in fruit weight, which is attributed to changes in the crops' nutrient uptake concentrations. This necessitates further research for a more comprehensive understanding. In terms of the productivity of irrigation required to produce the fruit, applying the closed system resulted in an increase of 7.6 kg/ton compared to the open system, saving 31.6% of water resources. Additionally, in terms of nutrients, cultivating in a closed system allowed for savings of approximately 59, 25, 55, 83, 76, and 87% of N, P, K, Ca, Mg, and S, respectively, throughout the entire cultivation period. As the drainage was reused, the ratios of NO₃^- and Ca²⁺ increased up to a maximum of 9.6 and 9.1%, respectively, while the ratios of other ions gradually decreased. In summary, these results suggest that closed hydroponic cultivation can effectively optimize the use of water and fertilizer while maintaining excellent fruit quality in melon cultivation.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.366-376
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• 2023

This study was conducted to develop a model for predicting the growth of kimchi cabbage using image data and environmental data. Kimchi cabbages of the 'Cheongmyeong Gaual' variety were planted three times on July 11th, July 19th, and July 27th at a test field located at Pyeongchang-gun, Gangwon-do (37°37' N 128°32' E, 510 elevation), and data on growth, images, and environmental conditions were collected until September 12th. To select key factors for the kimchi cabbage growth prediction model, a correlation analysis was conducted using the collected growth data and meteorological data. The correlation coefficient between fresh weight and growth degree days (GDD) and between fresh weight and integrated solar radiation showed a high correlation coefficient of 0.88. Additionally, fresh weight had significant correlations with height and leaf area of kimchi cabbages, with correlation coefficients of 0.78 and 0.79, respectively. Canopy coverage was selected from the image data and GDD was selected from the environmental data based on references from previous researches. A prediction model for kimchi cabbage of biomass, leaf count, and leaf area was developed by combining GDD, canopy coverage and growth data. Single-factor models, including quadratic, sigmoid, and logistic models, were created and the sigmoid prediction model showed the best explanatory power according to the evaluation results. Developing a multi-factor growth prediction model by combining GDD and canopy coverage resulted in improved determination coefficients of 0.9, 0.95, and 0.89 for biomass, leaf count, and leaf area, respectively, compared to single-factor prediction models. To validate the developed model, validation was conducted and the determination coefficient between measured and predicted fresh weight was 0.91, with an RMSE of 134.2 g, indicating high prediction accuracy. In the past, kimchi cabbage growth prediction was often based on meteorological or image data, which resulted in low predictive accuracy due to the inability to reflect on-site conditions or the heading up of kimchi cabbage. Combining these two prediction methods is expected to enhance the accuracy of crop yield predictions by compensating for the weaknesses of each observation method.