• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.167-172
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• 2024

In major wars of the 21st century, drones are expanding beyond surveillance and reconnaissance to include land and air as well as sea and underwater for purposes such as precision strikes, suicide attacks, and cognitive warfare. These drones will perform multi-domain operations, and to this end, they will continue to develop by improving the level of autonomy and strengthening scalability based on the High-Low Mix concept. Recently, drones have been used as a major means in major wars around the world, and there seems to be a good chance that they will evolve into game changers in the future. North Korea has also been making significant efforts to operate reconnaissance and attack drones for a long time. North Korea has recently continued to engage in provocations using drones, and its capabilities are gradually becoming more sophisticated. In addition, with the recent emergence of new strategic Drones, wartime and peacetime threats such as North Korea's use of these to secure surveillance, reconnaissance and early warning capabilities against South Korea and new types of provocations are expected to be strengthened. Through this study, we hope to provide implications by analyzing the capabilities of North Korea's strategic Drones, predicting their operation patterns, and conducting active follow-up research on the establishment of a comprehensive strategy, such as our military's drone deployment and counter-drone system solutions.

• The Journal of the Convergence on Culture Technology
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• v.10 no.2
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• pp.323-331
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• 2024

The concept of 'Han' is a psychological characteristic formed by Koreans through long-lasting national hardships. It has deeply influenced every Korean as a form of collective unconscious and has merged with various forms of art over time. Director Bong Joon-ho's works, rich in social consciousness, symbolically visualize sensitive issues like social class, presenting harsh satire on class oppression. His movies continuously emphasize human desires, the homogeneity of good and evil, insurmountable class barriers, and moral decay caused by desires. They produce a wealth of symbols filled with layers and power dynamics. Bong Joon-ho dramatically portrays and directs various forms of symbols. The metaphorical symbols in his movies provide a unique research value for delving into the deeper meanings of the films.This study examines the theme of 'class Han' in six of Bong Joon-ho's films, exploring the 'Han culture' of Korea. It applies semiotic concepts by categorizing into character and non-character symbols for an in-depth analysis of the films. The representative works from the late 1990s to the late 2010s articulate the class layers of the 'visible' and the 'invisible' through a blend of realism and surrealism. The study analyzes Bong Joon-ho's films in the sequence of 'satire-exposure-hope', examining the culturally critical nature of 'Han culture' on class and its psychological and cultural impact on the general public.

• The Journal of the Acoustical Society of Korea
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• v.43 no.1
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• pp.1-8
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• 2024

For measuring the performance of passive sonars, we usually consider the maximum Detection Range (DR) under the environment and system parameters in operation. In shallow water, where sound waves inevitably interacts with sea surface or bottom, detection generally maintains up to the maximum range. In deep water, however, sound waves may not interact with sea surface or/and bottom, and thus there may exist shadow zones where sound waves can hardly reach. In this situation, DR alone may not completely define the performance of each sonar. For complete description of sonar performance, we employ the concept 'Robustness Of Detection (ROD)'. In the coastal region of the East Sea, the spatial variations of water masses have close relations with DR and ROD, where the two parameters show reverse spatial variations in general. The spatial and temporal analysis of the temperature by employing the Empirical Orthogonal Function (EOF) shows that the 1-st mode represents typical pattern of seasonal variation and the 2-nd mode represents strength variations of mixed layers and currents. The two modes are estimated to explain about 92 % of the variations. Assuming two types of targets located at the depths of 5 m (shallow) and 100 m (deep), the passive sonar performance (DR) gives high negative correlations (about -0.9) with the first two modes. Most of temporal variations of temperature occur from the surface up to 200 m in the water column so that when we assume a target at 100 m, we can expect detection performance of little seasonal variations with passive sonars below 100 m.

• Journal of Korean Library and Information Science Society
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• v.55 no.1
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• pp.69-97
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• 2024

It is important to plan and operate various training programs at the national level to develop librarians' job performance expertise and future-oriented capabilities. The purpose of this study was to examine the possibility of introducing a librarian learning community as an training program at a professional education and training institution and to suggest an appropriate operation method. To this end, research was conducted using the following contents and methods: 1) theoretical discussion on program operation such as the concept, operation stages, and types of a librarian learning community through a review of related literature; 2) exploring the possibility of operating a librarian learning community through pilot operation and derivation of implications, 3) proposal of a librarian learning community operation model. This study reviewed the librarian learning community operating model through participant observation and participant opinion collection during the pilot operation process to minimize confusion in the early stages of implementation, and also presented an operational roadmap and support system for the successful establishment of the program in the future. There is a need to further develop the librarian learning community operating model presented in this study through implementation and empirical analysis over the next several years. However, the results of this study will also be useful as an initial operating model for a learning community for professional education and training in other fields.

• Education of Primary School Mathematics
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• v.27 no.3
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• pp.227-246
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• 2024

The purposes of this study were to analyze the levels of cognitive demand and questioning types in tasks of 'Data and Chance' presented in elementary mathematics textbooks in Korea, the United States, and Australia. The levels of cognitive demand of textbook tasks were analyzed according to the knowledge and process and thinking types required in the tasks. The tasks were also analyzed for questioning types, answer types, and response types. As a result, in terms of knowledge and process and thinking types in tasks, all three countries had something in common: the percentage of tasks requiring 'representation' and process was the highest, and the percentage of tasks requiring 'basic application of skill/concept' was also the highest. From a thinking types perspective, differences were found between textbook tasks in the three countries in graph and chance learning. The results of analyzing questioning types showed that in all three textbooks, the percentage of observational reasoning questions was highest, followed by the percentage of factual questions. The proportions and characteristics of the constructing questions included in the U.S. and Australian textbooks differed from those in the Korean textbooks. Based on these results, this study presents implications for constructing elementary mathematics textbook tasks in 'Data and Chance.'

• Education of Primary School Mathematics
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• v.27 no.3
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• pp.303-320
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• 2024

This study presents the development and performance evaluation of a custom GPT-based chatbot tailored to provide solutions following Polya's problem-solving stages. A beta version of the chatbot was initially deployed to assess its mathematical capabilities, followed by iterative error identification and correction, leading to the final version. The completed chatbot demonstrated an accuracy rate of approximately 89.0%, correctly solving an average of 57.8 out of 65 image-based problems from a 6th-grade elementary mathematics textbook, reflecting a 4 percentage point improvement over the beta version. For a subset of 50 problems, where images were not critical for problem resolution, the chatbot achieved an accuracy rate of approximately 91.0%, solving an average of 45.5 problems correctly. Predominant errors included problem recognition issues, particularly with complex or poorly recognizable images, along with concept confusion and comprehension errors. The custom chatbot exhibited superior mathematical performance compared to the general-purpose ChatGPT. Additionally, its solution process can be adapted to various grade levels, facilitating personalized student instruction. The ease of chatbot creation and customization underscores its potential for diverse applications in mathematics education, such as individualized teacher support and personalized student guidance.

• The Journal of the Convergence on Culture Technology
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• v.10 no.4
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• pp.681-686
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• 2024

The film crews is a unique organization composed of members with expertise in each field and operated temporarily for a relatively short period of time. This study attempted to infer that the group characteristics and ability of the film crews to draw out the members' capabilities will affect the success or failure of the film, and to investigate their influence relationship. To this end, the research model was designed with diversity, cohesion, and information utilization as independent variables, and the artistry and box office performance of the film as dependent variables. As a result of the analysis, it was found that the diversity of the film crew affects both the artistry and box office performance, and the cohesion only affects the artistry. However, it was found that information utilization had no effect on film performance. It was confirmed that the diversity of the film crews was related to the film performance, and the cohesion had a limited effect. The results of this study provide implications that the design concept of the film crews based on diversity may be more important than process factors such as information utilization.

• Journal of the Korea Institute of Building Construction
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• v.24 no.4
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• pp.447-458
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• 2024

This study investigates the effectiveness of Building Information Modeling(BIM) software, specifically SketchUp and Revit, in reducing errors during quantity take-off(QTO) for complex building elements. While 3D modeling offers advantages, existing software may not fully account for manufacturing discrepancies, such as variations in concrete cover thickness and reinforcing bar radius. To address this limitation, this research proposes a BIM-based QTO method for high-insulation wall panels with intricate details. The method utilizes a BIM family library, focusing on key parameters like concrete cover thickness and inner radius of shear reinforcement. A case study compared the cross-sectional details of a wall panel modeled in Revit with the actual manufactured specimen. The analysis revealed a 12% reduction in modeled concrete cover thickness and a 1.27 times larger modeled inner radius of the shear bar compared to the real-world values. The proposed method incorporates these manufacturing variations into the Revit model of the high-insulation wall panel. Software like Navisworks facilitates the identification and correction of any material interferences arising from these adjustments. Furthermore, the method employs a unit wall concept(1m²) to account for the volume of various materials, including insulation and splice sleeves at joints. This allows for the identification of a similar existing family within the BIM library(e.g., "Double RC wall with embedded insulation") that reflects the actual material quantities used in the wall panel. By incorporating these manufacturing-induced variations, the proposed method offers a more accurate QTO process for complex high-insulation wall panels. The "Double RC wall with embedded insulation" family within the Revit program serves as a valuable tool for material quantity estimation in such scenarios.

• Korean Journal of Ecology and Environment
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• v.57 no.3
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• pp.169-188
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• 2024

Recently, Korean government has incorporated the assessment and restoration of river continuity as a key component of its integrated water management policy. While, methodologies for evaluating discontinuities and degradation, as well as the procedures for assessment and restoration, have been developed and proposed, there is a need for further improvement. Therefore, further research is required to establish a conceptual framework for continuity specific to domestic river ecosystems and to formulate appropriate assessment methods and restoration strategies. In this study we conduct a comparative analysis of the concepts, restoration approaches, and comprehensive evaluation methods for river continuity as proposed by Japan, the United States, and the European Union (EU), all of which have long-standing frameworks for river continuity assessment and restoration projects. Each country demonstrates distinct objectives and guidelines: Japan emphasizes habitat continuity within the context of river and watershed continuity, the United States integrates continuity as a tool for watershed management, and the EU prioritizes biodiversity conservation by advocating for the removal of artificial barriers and promoting the restoration of free-flowing rivers (FFR). By investigating these international examples, this study provides insights that can guide the development of long-term strategies and evaluation criteria for securing aquatic ecosystem continuity in Korea.

• The Mathematical Education
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• v.63 no.3
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• pp.451-466
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• 2024

This study investigated elementary preservice teachers' conceptions of a generating line, an ambiguous concept in school mathematics. The preservice teachers' conceptions of a generating line can be classified into four types: (a) only cones have generating lines, (b) only cones and cylinders have generating lines, (c) solids of revolution have generating lines, (d) straight lines on the lateral surface are generating lines. 22.1% of all preservice teachers believed that only cones have generating lines, and most of them followed the definition of a generating line presented in elementary mathematics textbooks. The conception that only cones and cylinders have generating lines was the least investigated. However, since there were instances where generating lines were defined with the use of a director curve, it became important to explore topics more thoroughly, such as generating lines of a truncated cone. 27.9% of all preservice teachers believed that solids of revolution have generating lines. This conception was marked by differing opinions on whether spheres also have generating lines. The conception that straight lines on the lateral surface are generating lines was the most frequently investigated. This conception differs from the traditional view in school mathematics because it suggests using a director curve to define generating lines. Based on these analysis results, the researcher developed specific teaching methods that considered both subject matter knowledge and pedagogical content knowledge for preservice teachers. In addition, the researcher proposed a consensus definition of a generating line in mathematics education.