• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.5
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• pp.627-635
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• 2019

A programmable drone is a drone developed not only to experience the basic principles of flight but also to control drones through Arduino-based programming. Due to the nature of the training drones, the main users are students who are inexperienced in controlling the drones, which often cause frequent collisions with external objects, resulting in high damage to the drones' frame. In this study, the structural stability of the drone was evaluated by means of a structural dynamics based collision simulation for educational drone frame. Collision simulations were performed on three cases according to the impact angle of $0^{\circ}$, $+15^{\circ}$ and $-15^{\circ}$, using an analytical model with approximately 240,000 tetrahedron elements. Using ANSYS LS-DYNA, which provides excellent functions for the simulation of the dynamic behavior of three-dimensional structures, the stress distribution and strain generated on the drone upper, the drone lower, and the ring assembly were analyzed when the drones collided against the wall at a rate of 4 m/s. Safety factors resulting from the equivalent stress and the yield strain were calculated in the range of 0.72 to 2.64 and 1.72 to 26.67, respectively. To ensure structural stability for areas where stress exceeds yield strain and ultimate strain according to material properties, the design reinforcement is presented.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.32 no.6
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• pp.553-560
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• 2020

This paper presents an algorithm for identifying and eliminating errors by seagrasses in coastal bathymetry surveying using drone and HD camera. Survey errors due to seagrasses were identified, segmentated and eliminated using a L∗a∗b color space model. Bathymetry survey using a drone and HD camera has many advantages over conventional survey methods such as ship-board acoustic sounder or manual level survey which are time consuming and expensive. However, errors caused by sea bed reflectance due to seagrasses habitat hamper the development of new surveying tool. Seagrasses are the flowering plants which start to grow in November and flourish to maximum density until April in Korea. We developed a new algorithm for identifying seagrasses habitat locations and eliminating errors due to seagrasses to get the accurate depth survey data. We tested our algorithm at Wolpo beach. Bathymetry survey data which were obtained using a drone with HD camera and calibrated to eliminate errors due to seagrasses, were compared with depth survey data obtained using ship-board multi-beam acoustic sounder. The abnormal bathymetry data which are defined as the excess of 1.5 times of a standard deviation of random errors, are composed of 8.6% of the test site of area of 200 m by 300 m. By applying the developed algorithm, 92% of abnnormal bathymetry data were successfully eliminated and 33% of RMS errors were reduced.

• Journal of Cadastre & Land InformatiX
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• v.50 no.2
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• pp.101-115
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• 2020

In this paper, big data analysis method was used to find out global trends in autonomous driving and to derive activate spatial information services. The applied big data was used in conjunction with news articles and patent document in order to analysis trend in news article and patents document data in spatial information. In this paper, big data was created and key words were extracted by using LDA (Latent Dirichlet Allocation) based on the topic model in major news on autonomous driving. In addition, Analysis of spatial information and connectivity, global technology trend analysis, and trend analysis and prediction in the spatial information field were conducted by using WordNet applied based on key words of patent information. This paper was proposed a big data analysis method for predicting a trend and future through the analysis of the connection between the autonomous driving field and spatial information. In future, as a global trend of spatial information in autonomous driving, platform alliances, business partnerships, mergers and acquisitions, joint venture establishment, standardization and technology development were derived through big data analysis.

• International Area Studies Review
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• v.21 no.1
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• pp.163-179
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• 2017

Iran has been focused on FDI by global automobile companies after the economic sanction on Iran was removed except primary sanction. In this paper, some strategies for Korean Automobile Industry to branch out into Iran are suggested. For the purpose, Iran's automobile industry and characteristics are examined. The market situation is analyzed qualitatively and quantitatively. In passenger cars sector, Korean automobile companies would be better to wait and see the development of US-Iran relationships while exporting CKD sets of cars to Iran. It can be a good strategy, however, to put parts companies into Iran first because of Iran Government could be displeasing with exporting CKD only. FDI, licensing, and joint venture are all available for the parts companies. Motor companies can clear the regulation of auto-parts localization proportion by the method. The parts companies will be able to do key roles as supply chains after OEM branch out into Iran. It is also advisable to upgrade outpost in Iran into frontline for exporting cars to MENA area. In such a case it will be a prerequisite to develop a role-division model with facilities in East Europe. It could be called Parts first-then cars strategy. In commercial cars sector, it can be suggested to leverage natural gas as a link to branch out into Iran. Iran government wishes to develop natural gas resources. The strategy can be summarized that automobile companies carry out producing CNG buses in Iran while energy companies are drilling and producing natural gas.

• (The)Korea Educational Review
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• v.22 no.3
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• pp.353-383
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• 2016

The purpose of this study is to examine the outcomes and implementation process from various stakeholders' perspectives related to the CAMPUS Asia (Collective Action for Mobility Program of University Student in Asia) pilot project, and thereby provide practical suggestions for it. The pilot projet of the CAMPUS Asia lasted four years from 2012 to 2015. A hybrid approach was used to analyze its implementation process, and diverse sources of data such as documents, surveys, and interviews were employed for analysis. Findings showed the accomplishments of the CAMPUS Asia pilot project for promoting participants' development and building the foundation for international cooperation at the governmental and institutional levels, while various limitations were also identified. In addition, analysis was conducted to identify the contextual factors that influenced the outcomes and limitations of the CAMPUS Asia pilot project at the governmental, institutional, and student levels. Based on these findings, multiple suggestions to maximize the effect of the CAMPUS Asia pilot project were provided, for example, to set up the ultimate goals of the project clearly, for governments to coordinate different academic systems by country and address the issue of credit transfer, to establish the uniqueness of the project, to strengthen the curriculum of each consortium, to co-manage the extra-curricular activities, and to develop the specialized career paths.

• Knowledge Management Research
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• v.23 no.1
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• pp.203-225
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• 2022

Competition in the OTT (Over the Top) service market is getting fiercer since global OTT services enter the domestic market and existing platforms are actively reorganized. As powerful competitors with ultra-luxurious content continue to enter the marke with diversity required by users, various efforts are required for OTT service platforms to prevent subscriber churn in order to generate continuous revenue. Thus, this study tried to examine the effect of OTT service characteristics on continuous use intention through an empirical analysis based on Expectation-Confirmation Model(ECM). A total of 386 responses were collected from individuals who have experience or are currently using OTT service and analyzed using AMOS 24. Results show that content curation, content richness, and audience activity had a significant effect on expectation confirmation. Also, expectation confirmation had a significant effect on perceived usefulness and user satisfaction while perceived usefulness had a significant effect on user satisfaction, significantly influencing continuous intention to use OTT. Finally, price fairness was found to strengthen all proposed relationships. The findings are expected to provide useful information for service and content development for subscriber retention, which has the most direct impact on revenue generation of OTT service providers.

• Journal of Space Technology and Applications
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• v.1 no.2
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• pp.217-240
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• 2021

Upon the human exploration era of the Moon, this paper introduces lunar topography and geologic fundamentals to space scientists. The origin of scientific terminology for the lunar topography was briefly summarized, and the extension of the current Korean terminology is suggested. Specifically, we suggest the most representative lunar topography that are useful to laymen as 1 ocean (Oceanus Procellarum), 10 maria (Mare Imbrium, Mare Serenitatis, Mare Tranuillitatis, Mare Nectaris, Mare Fecundatis, Mare Crisium, Mare Vaporium, Mare Cognitum, Mare Humorum, Mare Nubium), 6 great craters (Tyco, Copernicus, Kepler, Aristachus, Stebinus, Langrenus). We also suggest Korean terms for highland, maria, mountains, crater, rille, rima, graben, dome, lava tube, wrinkle ridge, trench, rupes, and regolith. In addition, we introduce the standard model for the lunar interior and typical rocks. According to the standard model on the basis of historical impact events, the lunar geological eras are classified as Pre-Nectarian, Nectarian, Imbrian, Erathostenesian, and Copernican in chronologic order. Finally, we summarize the latest discovery records on the water on the Moon, and introduce the concept of water extraction from the lunar soil, which is to be developed by the Korea Institute of Geoscience and Mineral Resources (KIGAM).

• Korean Journal of Remote Sensing
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• v.38 no.5_2
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• pp.765-779
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• 2022

This study evaluates the accuracy in identifying the burned area in South Korea using multi-temporal data from Sentinel-2 MSI and Landsat 8/9 OLI. Spectral indices such as the Difference Normalized Burn Ratio (dNBR), Relative Difference Normalized Burn Ratio (RdNBR), and Burned Area Index (BAI) were used to identify the burned area in the March 2022 forest fire in Uljin. Based on the results of six indices, the accuracy to detect the burned area was assessed for four satellites using Sentinel-2 and Landsat 8/9, respectively. Sentinel-2 and Landsat 8/9 produce images every 16 and 10 days, respectively, although it is difficult to acquire clear images due to clouds. Furthermore, using images taken before and after a forest fire to examine the burned area results in a rapid shift because vegetation growth in South Korea began in April, making it difficult to detect. Because Sentinel-2 and Landsat 8/9 images from February to May are based on the same date, this study is able to compare the indices with a relatively high detection accuracy and gets over the temporal resolution limitation. The results of this study are expected to be applied in the development of new indices to detect burned areas and indices that are optimized to detect South Korean forest fires.

• Journal of Space Technology and Applications
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• v.1 no.2
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• pp.199-216
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• 2021

In 2020, the solar and space environment division at the Korea Space Science Society surveyed the status of data archives in solar physics, magnetosphere, and ionosphere/upper atmosphere in Korea to promote broader utilization of the data and research collaboration. The survey includes ground- and satellite-based instruments and developing models by research institutes and universities in Korea. Based on the survey results, this study reports the status of the ground-based instruments, data products in the ionosphere and upper atmosphere, and documentation of them. The ground-based instruments operated by the Korea Polar Research Institute and Korea Astronomy and Space Science Institute include ionosonde, Fabry-Perot interferometer in Arctic Dasan stations, Antarctic King Sejong/Jang Bogo stations, and an all-sky camera, VHF radar in Korea. We also provide information on total electron content and scintillation observations derived from the Global Navigation Satellite System (GNSS) station networks in Korea. All data are available via the webpage, FTP, or by request. Information on ionospheric data and models is available at http://ksss.or.kr. We hope that this report will increase data accessibility and encourage the research community to engage in the establishment of a new Space Science Data Ecosystem, which supports archiving, searching, analyzing, and sharing the data with diverse communities, including educators, industries, and the public as wells as the research scientist.

• Journal of Digital Convergence
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• v.20 no.5
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• pp.599-608
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• 2022

There has been criticism that the government-led makerspace did not reflect the actual demand of makers, so there was a limit to performance creation. In this regard, the study aims to diagnose the current status and problems of makerspace and to suggest the implication to respond to policy demand. To this end, we analyzed the current status of makerspace by utilizing the government documents. Then, we conducted a survey of SMEs related to ICT devices that experienced makerspace, and analyzed their opinions on D·N·A technology demand, management difficulties, and governments' support policies. As results, the study proposed several improvement measures to upgrade makerspace as a digital conversion platform as follows. First, due to the nature of the existing industry for introducing D·N·A technology, there is a limit for companies to enter the market on their own, so comprehensive support from the government is needed. Second, it is necessary to establish and expand an empirical test bed for the development of new products and services so that various types of metaverse contents can be discovered and digital transformation convergence models of existing businesses can be derived. Third, by modifying the support method to operate the makerspace as a platform that implements the government-led start-up support policy, boldly transfer what the private sector can do well to the private sector. The participants of Industry·University·Institute Collaboration should freely share ideas and help the common problem be solved. Based on the problems and the findings for improvement, it is expected that the current makerspace would be upgraded to a digital conversion platform suitable for the demand of the field.