• Progress in Superconductivity and Cryogenics
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• v.25 no.2
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• pp.10-13
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• 2023

High-T_C superconductivity (HTSC) has been the central issue in the field of condensed matter physics for decades. An essential part of the research on superconductivity is finding new exotic superconductors. It was recently suggested that Ir-substituted La_0.7Sr_0.3MnO₃ (LSMIO) is a new high-T_C superconductor. However, systematic studies to experimentally verify the superconductivity have not been done. Here, we report the growth processes of LSMIO thin films and their electrical transport properties. We observed a clear negative correlation between the intensity of the laser utilized for film deposition and the Curie temperature of the deposited film. We attributed this effect to the suppression of Sr concentration in the LSMIO films as the laser intensity increased. However, our LSMIO films show conventional ferromagnetism instead of HTSC. To realize the HTSC in LSMIO systems, further exploration of diverse compositions of LSMIO compounds is essential.

• Journal of Practical Engineering Education
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• v.15 no.3
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• pp.605-614
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• 2023

In In the era of digital transition, AI-based personalized services are emerging in the field of education. This research aims to examine the development strategies for implementing AI-based learning services in school. Focusing on AI-based math learning service "Math Cell" developed by i-Scream Edu, this study surveyed the functional requirements from the perspective of an educator. The results were analyzed for importance and suitability using IPA, and expert opinions were surveyed to explore specific development directions for the service. Consequently, importance in all areas such as diagnosis, learning, evaluation, and management averaged 4.82 and performance averaged 4.56, showing excellent results in most questions, and in particular, importance was higher than performance. Among certain detailed functions, concept learning, customized task presentation, evaluation result analysis function, dashboard-related functions, and learning materials in the dashboard were not intuitive for students to understand and had to be supplemented. This study provides meaningful insights by summarizing expert opinions on AI-based personalized mathematics learning services, thereby contributing to the exploration of the development strategies for "Math Cell".

• Journal of the Microelectronics and Packaging Society
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• v.30 no.3
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• pp.20-34
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• 2023

Single or multi-layered two-dimensional (2D) materials, with thicknesses in the order of a few nanometers, have garnered substantial attention across diverse research domains owing to their distinct properties, including electrical conductivity, flexibility, and optical transparency. These materials are frequently subjected to repetitive mechanical actions in applications like electronic skin (E-Skin) and smart textiles. Moreover, they are often exposed to external factors like temperature, humidity, and pressure, which can lead to a deterioration in component durability and lifespan. Consequently, significant research efforts are directed towards developing self-healing properties in these components. Notably, recent investigations have revealed promising outcomes in the field of self-healing composite materials, with Ti₃Ci₂Ti_x MXene being a prominent component among the myriad of available 2D materials. In this paper, we aim to introduce various synthesis methods and characteristics of Ti₃Ci₂Ti_x MXene, followed by an exploration of self-healing application technologies based on Ti₃Ci₂Ti_x MXene.

• Journal of the Korean Society of Radiology
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• v.17 no.6
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• pp.977-983
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• 2023

Due to the development of the domestic economy and science, the people's standard of living has increased. Accordingly, we want to improve the quality of life. In other words, we guarantee human rights and pursue dignity and value as human beings. Therefore, the medical field extends human life and helps maintain a healthy life. The social medicine that protects human rights is forensic medicine. Forensic medicine identifies deaths and analyzes the cause using forensic radiology images. Forensic radiology is the acquisition and provision of medical images by the radiographer. Therefore, the radiographer must have expertise by completing forensic science-related courses. Recently, medical and nursing schools have opened and operated various subjects such as forensic medicine and forensic nursing. However, the Department of Radiology science is the only school that offers courses related to forensic science. For the future development and exploration of the radiographer and department of radiology science, forensic education should be considered. For this purpose, we investigated the necessity and demand for forensic education in the department of radiology science undergraduate and graduate schools. The department of radiology science students' awareness of forensic science was found to be 2.977 points, but the need for forensic science education for the radiographer was high at 3.759 points. In addition, current students' demand for forensic science courses was high at 84.1%, with the majority responding that it was necessary to open and operate the course. This study was able to determine the demand for forensic science-related subjects among the department of radiology science undergraduate and graduate students, and there is a need to explore diversity and expertise in education. We hope that it will be used as basic data for the development of forensic medicine and radiology science.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.599-609
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• 2023

In the seismic retrofitting of harbor breakwaters in Korea, the recovery rate is often uncertain due to site conditions and site conditions, and problems continue to arise. Therefore, in this study, we analyzed the recovery rate and compressive strength of the improved material through drilling survey by grouting confirmation method after applying low-fluidity mortar injection method, and furthermore, we checked the elastic modulus by downhole test and tomography to confirm the reinforcement effect of soft ground after ground improvement. The experimental results showed that the average shear wave velocity of the ground increased from 229 m/s to 288 m/s in BH-1 and BH-3 boreholes to a depth of 28.0 m, and the average shear wave velocity of the ground to a depth of 30.0 m tended to increase from 224 m/s to 282 m/s in the downhole test. This is believed to be a result of the increased stiffness of the ground after reinforcement. The results of the tomographic survey showed that the Vs of the soft ground of the sample at Site 1 increased from 113 m/s to 214 m/s, and the Vs of the sample at Site 2 increased from 120 m/s to 224 m/s. This shows that the stiffness of the ground after seismic reinforcement is reinforced with hard soil, as the Vs value satisfies 180 m/s to 360 m/s in the classification of rock quality according to shear wave velocity.

• Journal of The Korean Astronomical Society
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• v.56 no.2
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• pp.263-275
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• 2023

The Sun-Earth Lagrange point L4 is considered as one of the unique places where the solar activity and heliospheric environment can be observed in a continuous and comprehensive manner. The L4 mission affords a clear and wide-angle view of the Sun-Earth line for the study of the Sun-Earth and Sun-Moon connections from he perspective of remote-sensing observations. In-situ measurements of the solar radiation, solar wind, and heliospheric magnetic field are critical components necessary for monitoring and forecasting the radiation environment as it relates to the issue of safe human exploration of the Moon and Mars. A dust detector on the ram side of the spacecraft allows for an unprecedented detection of local dust and its interactions with the heliosphere. The purpose of the present paper is to emphasize the importance of L4 observations as well as to outline a strategy for the planned L4 mission with remote and in-situ payloads onboard a Korean spacecraft. It is expected that the Korean L4 mission can significantly contribute to improving the space weather forecasting capability by enhancing the understanding of heliosphere through comprehensive and coordinated observations of the heliosphere at multi-points with other existing or planned L1 and L5 missions.

• Journal of the Korean Geotechnical Society
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• v.39 no.12
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• pp.75-91
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• 2023

In this study, we explore the use of ground penetrating radar (GPR) for the nondestructive survey of subsurface conduits, focusing on the challenges posed by multichannel environments. A key concern is the shadow regions created by conduits, which significantly impact survey results. The shadow regions, which are influenced by conduit position and diameter, hinder signal propagation, thereby making detection within these regions challenging. Using finite-difference time-domain numerical analysis, we examined the characteristics of conduit signals, which typically manifest in hyperbolic patterns. Particularly, we investigated three conduit arrangements: horizontal, vertical, and diagonal. Automatic gain control was applied to amplify the signals, enabling the analysis of variations in shadow regions and signal characteristics for each arrangement. In the horizontal arrangement, the proximity of the two conduits resulted in the emergence of a new hyperbolic pattern between the existing conduits. In the vertical arrangement, the lower conduit could be detected using hyperbolic signals on either side, but the detection was challenging when the upper conduit diameter exceeded that of the lower conduit. In the diagonal arrangement, signal characteristics varied based on the position of shadow regions relative to the detection range of the equipment. Asymmetrical signal patterns were observed when the shadow regions fell within the detection range, whereas the signals of the two conduits were minimally impacted when the shadow regions were outside the detection range. This study provides vital insights into accurately detecting and characterizing subsurface multichannel conduits using GPR-a significant contribution to the field of subsurface exploration and management.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.17 no.6
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• pp.71-88
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• 2022

The purpose of this study is to develop the competencies to help micro entrepreneurs who have experienced failure to successfully re-challenge. To this end, relevant literature published from 1977 to 2022 was analyzed, behavioral event interviews (BEI) were conducted with 7 successful micro entrepreneurs, and focus group interviews (FGI) were conducted three times by inviting competency development and HRD experts. Based on these research activities, the draft about competencies for micro entrepreneurs who had have failure was derived. And then inviting 12 experts in related field for Delphi Analysis, the final competency model that helps micro entrepreneurs successfully recover were developed as follows : Competency Groups(small business owners, recovery from failure), 8 detailed competencies(seize business opportunities, business planning, business differentiation, operation management, market exploration, research and development of products and services, positive self-regulation, overcoming and coping with failure experiences), 22 competency factors, and 72 behavioral indicators. This study has an academic significance in that it developed the competencies required for micro entrepreneurs recovering from failure. In addition, the results of this study can be used to develop a competency-based education program for micro entrepreneurs and to select suitable candidates for support programs.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.33 no.1
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• pp.1-11
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• 2015

Gyeongju, Silla capital, hasn't paid much attention to a value of fortress as advanced frame of landscape all the while. All have done until now were maintaining lots of fortress including Gyeongju and setting night landscape lighting for them or building a trail in mountain fortress. Hereupon, this study tried to take a look at historical and scenic value of fortress, landscape frame of Gyeongju-Silla capital, based on Wolseong and Myeonghwalseong and find the way to contribute to it on landscape architectural level. As Wolseong(月城) and Myeonghwalseong(明活城) functioned as royal palace in Silla Dynasty, they need some research and study on fortress inside in detail rather than restoring them by simply maintaining the shapes. While Wolseong has overall excavation investigation going on, Myeonghwalseong representing mountain fortress area is losing its value due to unbefitting management to a title of world heritage. If conducting close research and study on these remains, it seems like it could contribute a lot to landscape architectural research of Silla royal palace through tracks, which will be used as royal palace. Here I suggest research direction on landscape architectural level about fortress remains in Gyeongju area as followings. Firstly, away from all research focusing on fortress shape, consecration way, etc, we need to conduct a research comprisable of inner space of fortress. As Wolseong and Myeonghwalseong functioned as royal palace in Silla Dynasty, it'll be possible to research about ponds, Nu-Jeong(樓亭), drainage facilities, oddly shaped stones, moundings, pavements, circulation systems, planting traces, etc. For this, we need to research and study through comparison with cases of China, Japan and Goguryeo of the same age. Secondly, applying garden archaeological way is possible to translate objectively regarding research of ancient garden with low literature record. But attainable achievement and information will be limited if implementing excavation based on archaeology as excavations so far regarding excavation investigation of Wolseong. The alternative to such problem is participation plan of landscaping field through the foundation of garden archaeology. We might be able to attain many results on landscape architectural level from research, if conducting research and study about Silla capital including Wolseong by applying garden archaeology such as collection of environmental sample and discovery and analysis of remains through aerial photograph, archaeological research, analysis of historical building, surface exploration, excavation technique, analysis of soil and flowerpot, etc. For this, many people majored in landscape architecture need to try and acquire archaeological knowledge. Also, we need to call attention to internal garden archaeology through international academic symposium by inviting global experts in garden archaeology field. I've suggested the study of location of Wolseong and Silla fortress in Gyeongju area, plan research on using and treating trees about the space in and out of fortress and landscape architectural research direction of Wolseong fortress.

• Journal of the Korean Institute of Traditional Landscape Architecture
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• v.36 no.3
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• pp.16-25
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• 2018

Initially from the Taoist scriptures, 'Dongcheon' is a term that can be regarded as a symbolic place in the real world for the enlightened ones who received relief and peace by restoring the human nature taught in the Confucian school. The long for an ideal world apart from the reality embodied as the labeling some places 'Dongcheon,' and the term was used to refer to a scenery where the ideal fairyland is reproduced. Besides, 'Dongcheon' was a term often used by Confucian scholars for various purposes including the attachment to the nearby landscapes, expressing homogeneity and superiority through placeness and the beautification of settlement spaces. This paper is the result of a field study on 'Dongcheon' in the Gyeongsang-Do. The research was conducted from March to August 2018, and we carried out firsthand location surveys on Dongcheons, of which some were lost, others were fairly preserved, and still others could not be located as only their existences were passed down orally. According to the field survey, there were total 111 inscriptions or engravings on the plates in Gyeongsang-Do that include the term 'Dongcheon.' There were 79 'Dongcheon' inscriptions confirmed in the Gyeongsangbuk-Do region: twenty in Yeongju-City, sixteen in Bonghwa-Gun, eleven in Andong-City and seven in Yeongyang-Gun and Ulgin-Gun. Among them, two were in the form of a wooden sign, and six were erected as rock signposts. Fourteen stops reported in the literature were lost or unidentified. Also, among the sixteen signs in Bonghwa-Gun, nine were cursive engravings. Meanwhile, there were 26 Dongcheon inscriptions in the Gyeongsangnam-Do region. Hamyang-Gun and Sancheong-Gun anf Hadong-Gun each housed three inscriptions, and seven places were in the form of rock signposts. 'Hwagaedongcheon' and 'Geumsandongcheon' could not be identified in inscriptions although they appear in Jibong Yuseol and Taengniji with stories of Choi Chiwon. The significance of this study is as a reference for future researches in traditional scenery, epigraphs, or as primary data that helps cultural exploration in the region.