• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.383-394
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• 2023

In Korea, the U.S. Tier-4 Final emission standards have been applied to agricultural machinery since 2015. This study was conducted to analyze the emission characteristics of agricultural tractors during plow tillage operations using PEMS (portable emissions measurement systems). The tractor working speed was set as M2 (5.95 km/h) and M3 (7.60 km/h), which was the most used gear stage during plow tillage operation. An engine idling test was conducted before the plow tillage operation was conducted because the level of emissions differed depending on the temperature of the engine (cold and hot states). The estimated level of emissions for the regular area (660 m²), which was the typical area of cultivation, was based on an implement width of 2.15 m and distance from the work area of 2.2 m. As a result, average emission of CO (carbon monoxide), THC (total hydrocarbons), NOx (nitric oxides), and PM (particulate matter) were approximately 6.17×10-2, 3.36×10^-4, 2.01×10^-4, and 6.85×10^-6 g/s, respectively. Based on the regular area, the total emission of CO, THC, NOx, and PM was 2.62, 3.76×10^-2, 1.63, and 2.59×10^-4 g, respectively. The results of total emission during plow tillage were compared to Tier 4 emission regulation limits. Tier 4 emission regulation limits means maximum value of the emission per consumption power (g/kWh), calculated as ratio of the emission and consumption power. Therefore, the total emission was converted to the emission per power using the rated power of the tractor. The emission per power was found to be satisfied below Tier 4 emission regulation limits for each emission gas. It is necessary to measure data by applying various test modes in the future and utilize them to calculate emission because the emission depends on various variables such as measurement environment and test mode.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.967-971
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• 2023

Recently, a variety of AI-based platform services are available, and one of them is ChatGPT that processes a large quantity of data in the natural language and generates an answer after self-learning. ChatGPT can perform various tasks including software programming in the IT sector. Particularly, it may help generate a simple program and correct errors using C Language, which is a major programming language. Accordingly, it is expected that ChatGPT is capable of effectively using Verilog HDL, which is a hardware language created in C Language. Verilog HDL synthesis, however, is to generate imperative sentences in a logical circuit form and thus it needs to be verified whether the products are executed properly. In this paper, we aim to select small-scale logical circuits for ease of experimentation and to verify the results of circuits generated by ChatGPT and human-designed circuits. As to experimental environments, Xilinx ISE 14.7 was used for module modeling, and the xc3s1000 FPGA chip was used for module embodiment. Comparative analysis was performed on the use area and processing time of FPGA to compare the performance of ChatGPT products and Verilog HDL products.

• Communications of Mathematical Education
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• v.37 no.3
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• pp.349-368
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• 2023

The revised 2022 educational curriculum highlighted the significance of mathematical literacy as a foundational competency that can be cultivated through the learning of various subjects, along with language proficiency and digital literacy. However, due to the lack of a precise definition for mathematical literacy, there exists a challenge in systematically implementing it across all subjects in the educational curriculum. The aim of this study is to clarify the definition of mathematical literacy in the curriculum through a literature review and to analyze the application patterns of mathematical literacy in other subjects so that mathematical literacy can be systematically applied as a basic literacy in Korea's curriculum. To achieve this, the study first clarifies and categorizes the meaning of mathematical literacy through a comparative analysis of terms such as numeracy and mathematical competence via a literature review. Subsequently, the study compares the categories of mathematical literacy identified in both domestic and international educational curricula and analyzes the application of mathematical literacy in the education curriculum of New South Wales (NSW), Australia, where mathematical literacy is reflected in the achievement standards across various subjects. It is expected that understanding each property by subdividing the meaning of mathematical literacy and examining the application modality to the curriculum will help construct a curriculum that reflects mathematical literacy in subjects other than mathematics.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.6
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• pp.392-399
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• 2023

This paper proposes a deep learning model to determine the region and depth of cabbage cores for robotic automation of the cabbage core removal process during the kimchi manufacturing process. In addition, rather than predicting the depth of the measured cabbage, a model was presented that simultaneously detects and classifies the area by converting it into a discrete class. For deep learning model learning and verification, RGB images of the harvested cabbage 522 were obtained. The core region and depth labeling and data augmentation techniques from the acquired images was processed. MAP, IoU, acuity, sensitivity, specificity, and F1-score were selected to evaluate the performance of the proposed YOLO-v4 deep learning model-based cabbage core area detection and classification model. As a result, the mAP and IoU values were 0.97 and 0.91, respectively, and the acuity and F1-score values were 96.2% and 95.5% for depth classification, respectively. Through the results of this study, it was confirmed that the depth information of cabbage can be classified, and that it can be used in the development of a robot-automation system for the cabbage core removal process in the future.

• Journal of Navigation and Port Research
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• v.47 no.6
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• pp.430-436
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• 2023

Study on Changes in Vessel Traffic Services Due to Introduction of Maritime Autonomous Surface ShipsThe development of technologies related to Maritime Autonomous Surface Ships (MASS) has been actively progressing since the mid-2010s, focusing on themes such as collision avoidance, route planning, digital twin, and communication technologies. On the other hand, research on land-based infrastructure connected with MASS, such as logistics systems, port facilities, and vessel traffic services, has relatively received less attention. This study analyzed impact of emergence of MASS on existing vessel traffic service operations and proposed changes in control operations to prepare for its impact. To do this, current vessel traffic service operations were analyzed and elements of MASS technology that could affect vessel traffic control were identified. A survey was conducted among vessel traffic controllers to identify items related to the control of MASS. Results analyzed using the AHP method showed that preparation for emergency response and communication methods with MASS were the most important. Based on this, we were able to derive detailed plans for basic MASS control procedures and emergency response procedures based on data communication within maritime traffic control areas. MASS control procedures proposed in this study are expected to be used as a solution to resolve issues related to traffic safety of MASS in coastal areas.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.24 no.3
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• pp.27-34
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• 2024

The direct and indirect damages caused by fires in underground utility tunnels have a great impact on society as a whole, so efforts are needed to prevent and manage them in advance. To this end, research is ongoing to prevent disasters such as fire flooding by applying digital twin technology to underground utility tunnels. A network is required to transmit the sensed signals from each sensor to the platform. In essence, it is necessary to analyze the application of wireless networks in the underground utility tunnel environments because the tunnel lacks the reception range of external wireless communication systems. Within the underground utility tunnels, electromagnetic interference caused by transmission and distribution cables, and diffuse reflection of signals from internal structures, obstacles, and metallic pipes such as water pipes can cause distortion or size reduction of wireless signals. To ensure real-time connectivity for remote surveillance and monitoring tasks through sensing, it is necessary to measure and analyze the wireless coverage in underground utility tunnels. Therefore, in order to build a wireless network environment in the underground utility tunnels. this study minimized the shaded area and measured the actual cavity environment so that there is no problem in connecting to the wireless environment inside the underground utility tunnels. We analyzed the data transmission rate, signal strength, and signal-to-noise ratio for each section of the terrain of the underground utility tunnels. The obtained results provide an appropriate wireless planning approach for installing wireless networks in underground utility tunnels.

• Korean Journal of Radiology
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• v.25 no.6
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• pp.575-588
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• 2024

Objective: Differentiating intracranial aneurysms from normal variants using CT angiography (CTA) or MR angiography (MRA) poses significant challenges. This study aimed to evaluate the efficacy of proton-density MRA (PD-MRA) compared to high-resolution time-of-flight MRA (HR-MRA) in diagnosing aneurysms among patients with indeterminate findings on conventional CTA or MRA. Materials and Methods: In this retrospective analysis, we included patients who underwent both PD-MRA and HR-MRA from August 2020 to July 2022 to assess lesions deemed indeterminate on prior conventional CTA or MRA examinations. Three experienced neuroradiologists independently reviewed the lesions using HR-MRA and PD-MRA with reconstructed voxel sizes of 0.25³ mm³ or 0.2³ mm³, respectively. A neurointerventionist established the gold standard with digital subtraction angiography. We compared the performance of HR-MRA, PD-MRA (0.25³-mm³ voxel), and PD-MRA (0.2³-mm³ voxel) in diagnosing aneurysms, both per lesion and per patient. The Fleiss kappa statistic was used to calculate inter-reader agreement. Results: The study involved 109 patients (average age 57.4 ± 11.0 years; male:female ratio, 11:98) with 141 indeterminate lesions. Of these, 78 lesions (55.3%) in 69 patients were confirmed as aneurysms by the reference standard. PD-MRA (0.25³-mm³ voxel) exhibited significantly higher per-lesion diagnostic performance compared to HR-MRA across all three readers: sensitivity ranged from 87.2%-91.0% versus 66.7%-70.5%; specificity from 93.7%-96.8% versus 58.7%-68.3%; and accuracy from 90.8%-92.9% versus 63.8%-69.5% (P ≤ 0.003). Furthermore, PD-MRA (0.25³-mm³ voxel) demonstrated significantly superior per-patient specificity and accuracy compared to HR-MRA across all evaluators (P ≤ 0.013). The diagnostic accuracy of PD-MRA (0.2³-mm³ voxel) surpassed that of HR-MRA and was comparable to PD-MRA (0.25³-mm³ voxel). The kappa values for inter-reader agreements were significantly higher in PD-MRA (0.820-0.938) than in HR-MRA (0.447-0.510). Conclusion: PD-MRA outperformed HR-MRA in diagnostic accuracy and demonstrated almost perfect inter-reader consistency in identifying intracranial aneurysms among patients with lesions initially indeterminate on CTA or MRA.

• Therapeutic Science for Rehabilitation
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• v.13 no.1
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• pp.75-86
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• 2024

Objective : The purpose of this study was to examine the effects of an occupational therapy program on the school readiness, focusing on adaptation skills and daily life skills, in children with developmental delays. Methods : The study involved a boy with developmental delay, aged 5 years and 8 months. The program was conducted twice a week, with a total of 8 sessions spread over 4 weeks. The Canadian Occupational Performance Measure (COPM) was employed, targeting class preparation and use of the toilet. Pre-post tests and follow-up evaluations were carried out to compare changes. Data analysis involved video recordings of the subject's performance. Results : The COPM results indicated improvements in both the performance and satisfaction levels for class preparation and toilet use. Processing skills showed seven improvements in class preparation and eight improvements in toilet use during post-testing. Activity performance observations further confirmed improvements in both class preparation and toilet use during post-test and follow-up evaluations. Conclusion : Occupational therapy improves school readiness (adaptation skill, daily living activity skill) for children with developmental delays, and has a positive effect on overall school readiness.

• Korean Journal of Culture and Social Issue
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• v.30 no.2
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• pp.121-157
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• 2024

This study explored the essence of psychological burnout experiences due to emotional contagion using a hermeneutic phenomenological approach. In-depth interviews were conducted on 9 participants who work in fields that are subject to emotional contagion. Data analysis was conducted by using van Manen's methodology, insisting that the pure description of an experience can be enriched by adding interpretation. The emotional contagion experiences were identified through this process and the findings were categorized into 3 core themes, 8 essential themes, and 35 subthemes. The first core theme is "emotions in constant exchange". This theme included two essential themes: 'various channels of emotional contagion' and 'subjective states that change depending on the transmitted emotions'. The second core theme, "filtering the experience of emotional contagion" included the essential themes of 'the characteristics susceptible to the emotions of others', 'attitudes of spreading negative emotions' and 'situations that makes one feel overwhelmed by emotions'. The final core theme, "from burnout by emotional contagion to communication" was categorized into the following essential themes: 'burnout-inducing entangled interactions', 'moving toward communication and connection' and 'recovery after psychological burnout'. Finally, the implications and suggestions for future research were discussed by summarizing the core contents of each themes.

• Journal of Korean Library and Information Science Society
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• v.55 no.1
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• pp.193-214
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• 2024

This study aimed to propose a method for collecting and applying media platform based materials at the National Library of Korea. Firstly, we analyzed the current status and limitations of data collection based on domestic media platforms, including the National Library of Korea. Secondly, a literature review method was used to investigate the current status and types of digital content based on media platforms. Thirdly, we identified the types of materials based on media platforms that are not currently included in the National Central Library's online material collection guidelines through the examination of cases from major overseas libraries. Fourthly, after reviewing technical and legal elements such as the definition of collection targets and scope for each new media, and collection methods, we established collection criteria. Fifthly, based on the research results, the policies proposed in this study are as follows: 1) there is a need to establish a clear legal basis for the collection of media platform based materials; 2) the development and presentation of collection guidelines for media platform based materials is necessary; 3) the development of collection tools and infrastructure for media platform based materials is required; 4) for the collection of media platform based materials, it is necessary to obtain permission for collection from targeted social media organizations, and to cooperate in linkage with organizations that produce and service extended reality content; 5) for the service activation of media platform based materials, it is necessary to improve accessibility for the usage activation of these materials, to enhance the content extensibility and ease of use of the e-deposit system including extended reality content, and to advance and construct spaces for reproducing extended reality content.