• The Journal of Engineering Geology
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• v.33 no.4
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• pp.737-753
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• 2023

Abandoned mines represent unused space resulting from resource use and changes in industrial environments. Efforts are underway to repurpose such underground spaces, leveraging their unique attributes of temperature stability, shading, and security. This study aimed to assess the feasibility of operating high-demand data centers and public sports facilities as potential recycling options for abandoned mine spaces. The status of data centers located in abandoned mines abroad was examined, including their operational technology capitalizing on the advantages of underground spaces. Considering the varying sizes of underground spaces in different types of abandoned mine in South Korea, the suitability of installing facilities for 12 different sports was evaluated for potential contributions to the health and welfare of local residents. The utilization of abandoned mine spaces as data centers and public sports facilities is expected to not only recycle industrial heritage but also to allow new development opportunities for local communities.

• Korean Journal of Remote Sensing
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• v.39 no.5_2
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• pp.755-770
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• 2023

Due to recent severe climate change, abnormal weather phenomena, and other factors, the frequency and magnitude of natural disasters are increasing. The need for disaster management using artificial satellites is growing, especially during large-scale disasters due to time and economic constraints. In this study, we have summarized the current status of next-generation medium-sized satellites and microsatellites in operation and under development, as well as trends in satellite imagery analysis techniques using a large volume of satellite imagery driven by the advancement of the space industry. Furthermore, by utilizing satellite imagery, particularly focusing on recent major disasters such as floods, landslides, droughts, and wildfires, we have confirmed how satellite imagery can be employed for damage analysis, thereby establishing its potential for disaster management. Through this study, we have presented satellite development and operational statuses, recent trends in satellite imagery analysis technology, and proposed disaster response strategies that utilize various types of satellite imagery. It was observed that during the stages of disaster progression, the utilization of satellite imagery is more prominent in the response and recovery stages than in the prevention and preparedness stages. In the future, with the availability of diverse imagery, we plan to research the fusion of cutting-edge technologies like artificial intelligence and deep learning, and their applicability for effective disaster management.

• Knowledge Management Research
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• v.24 no.4
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• pp.219-235
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• 2023

The advancement of digital technology and the impact of COVID-19 have brought about changes in corporate innovation and organizational culture, thereby highlighting the significance of Smart Learning in the field of HRD (Human Resource Development). This trend has led to an increased interest in personalized Smart Learning among employees due to the growth of hybrid work and the widespread adoption of smart work practices. This study aimed to illuminate the relative importance of the factors that constitute Smart Learning from the perspective of HRD practitioners. Through a review of prior literature, Smart Learning hierarchy and factors most fitting to the current context were identified, and their relative importance was determined using the AHP method. Consequently, in the first-tier factors, importance was confirmed in the order of 'Learning Activities', 'Teaching Activities', 'Learning Content', 'Assessment and Evaluations', and 'Learning Time and Space'. At the second-tier encompassing all factors, 'Pedagogical Strategy', 'Learning Results', 'Learning Tasks', 'Learning Goal', and 'Learning Support' emerged within the top five factors. These findings are significant in that they redefine the concept of smart learning and propose an academic framework for future research. Additionally, from a practical perspective, it is anticipated that this study will contribute valuable insights for HRD practitioners, aiding them in focusing on which factors to prioritize for enhancing and advancing Smart Learning initiatives.

• Journal of the Korea Institute of Construction Safety
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• v.6 no.1
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• pp.12-18
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• 2024

High-rise, large-scale, and diversification of buildings are possible, and the reduction of concrete cross-sections reduces the weight of the structure, thereby increasing or decreasing the height of the floor, securing a large number of floors at the same height, securing a large effective space, and reducing the amount of materials, rebar, and concrete used for designating the foundation floor. In terms of site construction and quality, a low water binder ratio can reduce the occurrence of dry shrinkage and minimize bleeding on the concrete surface. It has the advantage of securing self-fulfilling properties by improving fluidity by using high-performance sensitizers, making it easier to construct the site, and shortening the mold removal period by expressing early strength of concrete. In particular, with the rapid development of concrete-related construction technology in recent years, the application of ultra-high-strength concrete with a design standard strength of 100 MPa or higher is expanding in high-rise buildings. However, although high-rise buildings with more than 120 stories have recently been ordered or scheduled in Korea, the research results of developing ultra-high-strength concrete with more than 130 MPa class considering field applicability and testing and evaluating the actual applicability in the field are insufficient. In this study, in order to confirm the applicability of ultra-high-strength concrete in the field, a preliminary experiment for the member of a reduced simulation was conducted to find the optimal mixing ratio studied through various indoor basic experiments. After that, 130 MPa-class ultra-high-strength concrete was produced in a ready-mixed concrete factory in a mock member similar to the life size, and the flow characteristics, strength characteristics, and hydration heat of concrete were experimentally studied through on-site pump pressing.

• Journal of Ecology and Environment
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• v.47 no.4
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• pp.228-240
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• 2023

Growing complexity in ecosystem structure and functions, under impacts of climate and land-use changes, requires interdisciplinary understandings of processes and the whole-system, and accurate estimates of the changing functions. In the last three decades, observation networks for biodiversity, ecosystems, and ecosystem functions under climate change, have been developed by interested scientists, research institutions and universities. In this paper we will review (1) the development and on-going activities of those observation networks, (2) some outcomes from forest carbon cycle studies at our super-site "Takayama site" in Japan, and (3) a few ideas how we connect in-situ and satellite observations as well as fill observation gaps in the Asia-Oceania region. There have been many intensive research and networking efforts to promote investigations for ecosystem change and functions (e.g., Long-Term Ecological Research Network), measurements of greenhouse gas, heat, and water fluxes (flux network), and biodiversity from genetic to ecosystem level (Biodiversity Observation Network). Combining those in-situ field research data with modeling analysis and satellite remote sensing allows the research communities to up-scale spatially from local to global, and temporally from the past to future. These observation networks oftern use different methodologies and target different scientific disciplines. However growing needs for comprehensive observations to understand the response of biodiversity and ecosystem functions to climate and societal changes at local, national, regional, and global scales are providing opportunities and expectations to network these networks. Among the challenges to produce and share integrated knowledge on climate, ecosystem functions and biodiversity, filling scale-gaps in space and time among the phenomena is crucial. To showcase such efforts, interdisciplinary research at 'Takayama super-site' was reviewed by focusing on studies on forest carbon cycle and phenology. A key approach to respond to multidisciplinary questions is to integrate in-situ field research, ecosystem modeling, and satellite remote sensing by developing cross-scale methodologies at long-term observation field sites called "super-sites". The research approach at 'Takayama site' in Japan showcases this response to the needs of multidisciplinary questions and further development of terrestrial ecosystem research to address environmental change issues from local to national, regional and global scales.

• Tunnel and Underground Space
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• v.34 no.1
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• pp.1-14
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• 2024

An image-reconstruction technology, involving the deployment of an unmanned mobility equipped with high-speed LiDAR (Light Detection And Ranging) has been proposed to reconstruct the shape of abandoned mine. Unmanned mobility operation is remarkably useful in abandoned mines fraught with operational difficulties including, but not limited to, obstacles, sludge, underwater and narrow tunnel with the diameter of 1.5 m or more. For cases of real abandoned mines, quadruped robots, quadcopter drones and underwater drones are respectively deployed on land, air, and water-filled sites. In addition to the advantage of scanning the abandoned mines with 2D solid-state lidar sensors, rotation of radiation at an inclination angle offers an increased efficiency for simultaneous reconstruction of mineshaft shapes and detecting obstacles. Sensor and robot posture were used for computing rotation matrices that helped compute geographical coordinates of the solid-state lidar data. Next, the quadruped robot scanned the actual site to reconstruct tunnel shape. Lastly, the optimal elements necessary to increase utility in actual fields were found and proposed.

• Smart Media Journal
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• v.13 no.4
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• pp.114-123
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• 2024

This paper proposes AR stone tower content, an experiential content based on wearable augmented reality (AR). Although wearable augmented reality is gaining attention, the acceptance of the technology is still focused on specialized applications such as industrial sites. On the other hand, the proposed AR stone tower content is based on the material of 'stone tower' so that general users can relate to it and easily participate in it, and it is organized to utilize space in a moving environment and find and stack stones based on natural hand gestures. The proposed AR stone tower content was implemented in the HoloLens 2 environment and evaluated by general users through a pilot exhibition in a small art museum. The evaluation results showed that the overall satisfaction with the content averaged 3.85, and the content appropriateness for the stone tower material was very high at 4.15. In particular, users were highly satisfied with content comprehension and sound, but somewhat less satisfied with object recognition, body adaptation, and object control. The above user evaluations confirm the resonance and positive response to the material, but also highlight the difficulties of the average user in experiencing and interacting with the wearable AR environment.

• Convergence Security Journal
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• v.23 no.4
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• pp.109-119
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• 2023

C4I system is an integrated battlefield information system that automates the five elements of command, control, communications, computers, and information to efficiently manage the battlefield. C4I systems play an important role in collecting and analyzing enemy positions, situations, and operational results to ensure that all services have the same picture in real time and optimize command decisions and mission orders. However, the current C4I has limitations whenever a new weapon system is introduced, as it only provides battlefield visualization in a single area focusing on the battlefield situation for each military service. In a future battlefield that expands not only to land, sea, and air domains but also to cyber and space domains, improved command and control decisions will be possible if organic data from various weapon systems is gathered to quickly visualize the battlefield situation desired by the user. In this study, the visualization technology applicable to the future C4I system is divided into map area, situation map area, and display area. The technological implementation of this future C4I system is based on various data and communication means such as 5G networks, and is expected to enable hyper-connected battlefield visualization that utilizes a variety of high-quality information to enable realistic and efficient battlefield situation awareness.

• Journal of Technologic Dentistry
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• v.17 no.1
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• pp.41-57
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• 1995

This study was conducted to collect and analyze previous information in order to manage efficience, improve experience effect and promote employment rate. The questionnaire interview with 27 chief of dental Laboratory refered clinical experience in technology department about clinical experience in 14 Jumior colleges were also investigated. The results were summarried as follows : The portion of age of 35-39 among chief of dental Laboratory was 40.7% which was the highest, that of male was 96.3%, that of junior college graduate was 97.5%, that of 10years experience was 92.6% and that of ceramic technician was 85.2%, 63.0% dental laboratory for clinical experience was a bore space of 30pyong. Aspect of dental laboratory management, manufacturing all part of prosthetic restoration was 29.6%, othodontic appliance and ceramic restoration was 7.4%, 3.8%, each. The percentage of 40.7 was having connection with 30-3a dental clinics and referring case per day was 10-19 cases(40.7%), manufacturing time of referred prosthetic restoration was 3-4 days(77.8%), places preparing seminar room for education was 29.6%, above a place of 40pyong was 11.1% 30-34 pyong and 35-39 pyong was 7.4% each. During training of 2 years education course student, 18.5% was rack of thorough occupational career. While 44.4% will want the more salary among 3years education course student, 74.1% will expect the more dental techmicians would engaged in their field, 51.9% will hope improve of their theory and practice, 29.6% be expected better skill and 14.8% be expected better theory. Attitude of clinical experience places was distributed by 59.3% of offering only experience chance, 25.9% of wasting time and 29.0% of annoying. The big emphasis of climical experience was thorough occupational career(44.4%). The clinical experience places of our college were selected after direct visiting, so their condition of management was not that bad but most of dental laboratory were poor in management state and working environment. Therefore it is difficult to choose appropriate places and dental Laboratory are also limited manpower and time as suppliers. So that it recommended to induce flexible management of experience period by interval and rotation of experience places among college and to applicate intern-system for employment ant industry-college cooperation aspect.

• Journal of Korea Water Resources Association
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• v.44 no.10
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• pp.797-807
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• 2011

Phenomenon of vegetation recruitment on the sand bar is drastically rising in the streams and rivers in Korea. In the 1960s prior to industrialization and urbanization, most of the streams were consisted of sands and gravels, what we call, 'White River'. Owing to dam construction, stream maintenance, etc. carried out since the '70s, the characteristic of flow duration and sediment transport have been disturbed resulting in the abundance of vegetation in the waterfront, that is, 'Green River' is under progress. This study purposed to identify the correlation among water level, water temperature, rainfall, soil moisture and soil texture out of the factors which give an effect on the vegetation recruitment on the sand bar of unregulated stream. To this purpose, this study selected the downstream of Naeseong Stream, one of sand rivers in Korea, as the river section for test and conducted the monitoring and analysis for 289 days. In addition, this study analyzed the aerial photos taken from 1970 to 2009 in order to identify the aged change in vegetation from the past to the present. The range of the tested river section was 361 m in transverse length and about 2 km in longitudinal length. According to the survey analysis, the tested river section in Naeseong Stream was a gaining river showing the higher underground-water level by 20~30 m compared to Stream water level. The difference in the underground water temperature was less than $5^{\circ}C$ by day and season and the Stream temperature did not fall to $10^{\circ}C$ and less from May when the vegetation germination begins in earnest. The impact factor on soil moisture was the underground water level in the lower layer and the rainfall in the upper layer and it was found that all the upper and lower layer were influenced by soil particle size. The soil from surface to 1 m-underground out of 6 soil moisture-measured points was sand with the $D_{50}$ size of 0.07~1.37 mm and it's assumed that the capillary height possible in the particle size would reach around 14~43 cm. On the other hand, according to the result of space analysis on the tested river section of unregulated stream for 40 years, it was found that the artificial disturbance and drought promoted the vegetation recruitment and the flooding resulted in the frequency extinction of vegetation communities. Even though the small and large scales of recruitment and extinction in vegetation have been repeated since 1970, the present vegetation area increased clearly compared to the past. It's found that the vegetation area is gradually increasing over time.