• Journal of Korean Elementary Science Education
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• v.43 no.2
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• pp.219-232
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• 2024

This study aims to determine the perspectives of pre-service elementary school teachers on the science curriculum in the fourth industrial revolution era. In this study, 128 pre-service elementary school teachers were asked to express their perspectives on the Saber-toothed Tiger Curriculum through photovoice activities. The resulting images were classified into three types: conservative, progressive, and radical perspectives. The number of both conservative and progressive perspectives was similar and high, whereas the number of radical perspectives was l ow. Those who had conservative perspectives on the Saber-toothed Tiger curriculum regarded "Inquiry" as the basis of the science curriculum, which should be maintained regardless of the time period and environment. Similarly, older teachers believed that this curriculum was based on eternal truth, which should be protected. Those who showed progressive perspectives on the Saber-toothed Tiger curriculum regarded a progressive person as someone succeeding to the blood of "New fist," and they showed positive attitudes toward AI-based education such as coding and meta-verse, regarding these practices as part of the teaching and learning method that could replace the existing inquiry-based education. Those who showed radical perspectives on the Saber-toothed Tiger Curriculum assumed critical attitudes toward the rapidly changing political circumstances of science education and criticized conflicts between different social classes formed through progressive curriculum. Based on these results, this study found that pre-service elementary school teachers needed to consider the science curriculum from several different perspectives rather than just one.

• Journal of The Korean Association For Science Education
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• v.44 no.2
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• pp.141-153
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• 2024

The 2022 revised science curriculum aims to develop the ability to solve scientific problems arising in daily life and society based on convergent thinking stimulated through participation in research activities using artificial intelligence (AI). Therefore, we developed a science-AI convergence education program that combines the science curriculum with artificial intelligence and employed it in convergence classes for high school students. The aim of the science-AI convergence class was for students to qualitatively understand the movement of a damped pendulum and build an AI model to predict the position of the pendulum using the block coding platform KNIME. Individual in-depth interviews were conducted to understand and interpret the learners' experiences. Based on Giorgi's phenomenological research methodology, we described the learners' learning processes and changes, challenges and limitations of the class. The students collected data and built the AI model. They expected to be able to predict the surrounding phenomena based on their experimental results and perceived the convergence class positively. On the other hand, they still perceived an with the unfamiliarity of platform, difficulty in understanding the principle of AI, and limitations of the teaching method that they had to follow, as well as limitations of the course content. Based on this, we discussed the strengths and limitations of the science-AI convergence class and made suggestions for science-AI convergence education. This study is expected to provide implications for developing science-AI convergence curricula and implementing them in the field.

• Journal of Korean Neurosurgical Society
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• v.67 no.3
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• pp.354-363
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• 2024

Objective : This study aims to determine the optimal dose of recombinant-human bone morphogenic protein-2 (rhBMP-2) for successful bone fusion in minimally invasive lateral lumbar interbody fusion (MIS LLIF). Previous studies show that rhBMP is an effective alternative to autologous iliac crest bone graft, but the optimal dose remains uncertain. The study analyzes the fusion rates associated with different rhBMP doses to provide a recommendation for the optimal dose in MIS LLIF. Methods : Ninety-three patients underwent MIS LLIF using demineralized bone matrix (DBM) or a mixture of rhBMP-2 and DBM as fusion material. The group was divided into the following three groups according to the rhBMP-2 usage : group A, only DBM was used (n=27); group B, 1 mg of rhBMP-2 per 5 mL of DBM paste (n=41); and group C, 2 mg of rhBMP-2 per 5 mL of DBM paste (n=25). Demographic data, clinical outcomes, postoperative complication and fusion were assessed. Results : At 12 months post-surgery, the overall fusion rate was 92.3% according to Bridwell fusion grading system. Groups B and C, who received rhBMP-2, had significantly higher fusion rates than group A, who received only DBM. However, there was no significant increase in fusion rate when the rhBMP-2 dosage was increased from group B to group C. The groups B and C showed significant improvement in back pain and Oswestry disability index compared to the group A. The incidence of screw loosening was decreased in groups B and C, but there was no significant difference in the occurrence of other complications. Conclusion : Usage of rhBMP-2 in LLIF surgery leads to early and increased final fusion rates, which can result in faster pain relief and return to daily activities for patients. The benefits of using rhBMP-2 were not significantly different between the groups that received 1 mg/5 mL and 2 mg/5 mL of rhBMP-2. Therefore, it is recommended to use 1 mg of rhBMP-2 with 5 mL of DBM, taking both economic and clinical aspects into consideration.

• Convergence Security Journal
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• v.23 no.4
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• pp.141-151
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• 2023

Since the end of the Cold War in the 1990s, European countries have cut defense costs and reduced armaments as an era of peace without large-scale wars continues, and as a result, the West's defense industry base has gradually weakened. On the other hand, South Korea, the world's only divided country, was able to achieve high growth in the defense industry as a result of continuous arms strengthening in the face of North Korea's nuclear and missile threats. With the rapid increase in demand for conventional weapons systems and changes in the structure of the global defense market due to the Russia-Ukraine war, Korea's weapons system drew great attention as a large-scale defense export contract with Poland was signed in 2022. In 2023, K-Defense ranked ninth in the world's arms exports and aims to become the world's fourth-largest defense exporter by 2027. Therefore, this study analyzed the case of Korea-Poland defense exports to derive problems, and presented development strategies related to export revitalization of K-Defense, a national strategic industry. In order for the defense industry to become Korea's next growth engine, it is necessary to establish a defense organization, prepare government-level measures to protect defense industry technology, and expand military and security cooperation with allies linked to defense exports.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.36 no.2
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• pp.37-49
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• 2024

To date, numerous empirical formulas have been proposed through hydraulic model experiments to predict the wave breaker index, including wave height and depth of wave breaking, due to the inherent complexity of generation mechanisms. Unfortunately, research on the characteristics of wave breaking and the prediction of the wave breaker index for gravel beaches has been limited. This study aims to forecast the wave breaker index for gravel beaches using representative linear-based machine learning techniques known for their high predictive performance in regression or classification problems across various research fields. Initially, the applicability of existing empirical formulas for wave breaker indices to gravel seabeds was assessed. Various linear-based machine learning algorithms were then employed to build prediction models, aiming to overcome the limitations of existing empirical formulas in predicting wave breaker indices for gravel seabeds. Among the developed machine learning models, a new calculation formula for easily computable wave breaker indices based on the model was proposed, demonstrating high predictive performance for wave height and depth of wave breaking on gravel beaches. The study validated the predictive capabilities of the proposed wave breaker indices through hydraulic model experiments and compared them with existing empirical formulas. Despite its simplicity as a polynomial, the newly proposed empirical formula for wave breaking indices in this study exhibited exceptional predictive performance for gravel beaches.

• Journal of Environmental Health Sciences
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• v.50 no.2
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• pp.83-92
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• 2024

Background: In this study, we investigate the rapid increase in environmental odors and notable rise in civil complaints near Dorim Stream in the Gwanak-gu area of Seoul. Objectives: This study aims to identify the causal compounds responsible for environmental odors in the Dorim Stream and investigate the structural characteristics of the stream that influence odor generation. Methods: The research methodology involved setting up 41 sampling points, selecting panels for direct sensory evaluation to assess odor intensity, measuring dissolved oxygen and hydrogen sulfide concentrations, and using all-in-one low-temperature desorption gas chromatography (ATD-GC) and thermal desorption-gas chromatography-mass spectrometry (TD-GC/MS) analysis to identify odor-causing compounds. Results: The evaluation of Dorim Stream revealed that in areas with complete meandering, there were lower dissolved oxygen levels (4.5±2.67 mg/L) and higher odor intensity (4.0±0.92), while in partially meandering sections, higher dissolved oxygen levels (7.8±1.15 mg/L) and lower odor intensity (2.8±1.06) were observed. Hydrogen sulfide levels measured with sensors increased with higher temperatures, especially in the afternoon hours (12:00~14:00). Acetaldehyde was the dominant odor compound detected in both the Bonglim Bridge (0.4 ppm) area and Guro Bridge area (0.867 ppm), with concentrations more than twice as high near Guro Bridge. Odor-causing compounds identified by TD-GC/MS indicated a pungent, sulfurous odor in the Guro Bridge area and a musty odor in the Bonglim Bridge area. Conclusions: This study categorizes and analyzes the sources of odor in Dorim Stream in Seoul based on meandering patterns and the distribution of sewage facilities, highlighting the potential odor issues associated with combined sewage systems and sewer junctions and suggesting policy improvements.

• Journal of Korean Society of Water and Wastewater
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• v.37 no.6
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• pp.425-435
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• 2023

Organoleptic parameters such as color, odor, and flavor influence consumer perception of drinking water quality. This study aims to evaluate the taste of the selected bottled and tap water samples using an electronic tongue (E-tongue) instead of a sensory test. Bottled and tap water's mineral components are related to the overall preference for water taste. Contrary to the sensory test, the potentiometric E-tongue method presented in this study distinguishes taste by measuring the mineral components in water, and the data obtained can be statistically analyzed. Eleven bottled water products from various brands and one tap water from I city in Korea were evaluated. The E-tongue data were statistically analyzed using multivariate statistical tools such as hierarchical clustering analysis (HCA), principal component analysis (PCA), and partial least squares discriminant analysis (PLS-DA). The results show that the E-tongue method can clearly distinguish taste discrimination in drinking water differing in water quality based on the ion-related water quality parameters. The water quality parameters that affect taste discrimination were found to be total dissolved solids (TDS), sodium (Na+), calcium (Ca²⁺), magnesium (Mg²⁺), sulfate (SO₄^2-), chloride (Cl^-), potassium (K⁺) and pH. The distance calculation of HCA was used to quantify the differences between 12 different types of drinking water. The proposed E-tongue method is a practical tool to quantitatively evaluate the differences between samples in water quality items related to the ionic components. It can be helpful in quality control of drinking water.

• Journal of Space Technology and Applications
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• v.3 no.4
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• pp.333-341
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• 2023

This study aims to develop technology for testing and verifying the space radiation environment of miniature space components using the facilities of the domestic 100 MeV proton accelerator and the Space Component Test Facility at the Space Testing Center. As advancements in space development progress, high-performance satellites increasingly rely on densely integrated circuits, particularly in core components components like memory. The application of semiconductor components in essential devices such as solar panels, optical sensors, and opto-electronics is also on the rise. To apply these technologies in space, it is imperative to undergo space environment testing, with the most critical aspect being the evaluation and testing of space components in high-energy radiation environments. Therefore, the Space Testing Center at the Korea testing laboratory has developed a radiation testing device for memory components and conducted radiation impact assessment tests using it. The investigation was carried out using 100 MeV protons at a low flux level achievable at the Gyeongju Proton Accelerator. Through these tests, single event upsets observed in memory semiconductor components were confirmed.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.281-287
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• 2024

In general, design education related to transportation has been recognized as a department specialized in transportation design or as an area of detailed transportation majors within industrial design majors. However, as technological, social, and environmental factors change, the concept of mobility and the ecosystem related to the mobility industry are diversifying, and accordingly, the category of mobility-related design is expanding further. Based on this background, this study is not a mobility design major, but it aims to find implications by analyzing the trend and type of topic selection related to the mobility ecosystem among the last five years of graduation design topics conducted in the design engineering major. As a result of the study, of a total of 131 graduation design works conducted over the past five years, about 30 works were highly related to mobility, and their types were very diverse. In conclusion, it was confirmed that the change and expansion of the mobility ecosystem expanding from products to services and systems were also reflected in the selection of graduation works in that various topics approached from user-centered and user experience were proposed and made into works.

• The Journal of the Convergence on Culture Technology
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• v.10 no.1
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• pp.143-152
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• 2024

Due to COVID-19, domestic Duty-free shops have been severely impacted, and with the expansion of the untact market, the proportion of mobile shopping has increased. So far, mobile duty-free shop AR shopping is not active, and related research is scarce. Therefore, we aims to enhance Duty-free Shopping APPs with AR technology by researching the needs of foreign users. First, in the mobile duty-free shop app, the AR shopping interface must be in a prominent position to be open and easy to use. Second, there should be an explanation or help for location and function so that all users can easily recognize the AR shopping interface. Third, when wearing duty-free items in the AR shopping interface or adding them to the storage and shopping cart of interest, the interface must be simple and flexible, making it convenient to use and operate. Fourth, technical improvements must be made to prevent errors. We expect that the research will help develop AR shopping technology and domestic duty-free shop AR shopping technology and revitalize online and offline duty-free shops.