• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.16 no.6
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• pp.241-248
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• 2021

Firms have many ways to expand their businesses including M&A. Big companies in online and offline businesses show different ways of expansion with different objectives to expand their digital businesses quickly. Expansions for technical reasons are to acquire technologies they do not have while those for business reasons are M&A for offline companies to have competence in markets by acquiring online companies. Other ways of expansions include spin-off and group participation after investments for startups. Various ways of expansions are chosen because they are optimal choices depending on situations the companies face, and they have different strengths and weaknesses. To analyze the strengths and weaknesses of those options for expansion at this stage would be academically valuable, and also practically meaningful in terms of providing insights for companies' decision making in choosing opitions for expansions. M&A of online companies to make multi-channels by offline companies have risks of failing to internalize online companies and have enough synergy effects. Also, spin-off is a relatively less risky way of expansion while the speed of expansion is slower than establishing external startups with some shares of equity and making them as affiliated companies. External startups are good for speed of expansion while there are risks of legal regulations and negative awareness by the public.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.333-346
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• 2022

This study proposes a strategy to attract visitors by analyzing the justification for hosting the 2027 Summer World University Games in Chungcheong, Korea, as well as by assessing the internal and external factors to promote regional development. Using Environmental Analysis as the diagnostic approach, we focus on strength/opportunity (SO), strength/threat (ST), weakness/opportunity (WO), and weakness/threat (WT) analyses. SO analysis show that a matching strategy of mid- to long-term cooperation among the four cities and provinces in Chungcheong and development of local sports by promoting its linkages to science, and industry offer best strategic use-value. ST analysis shows that optimal infrastructure development and establishment of competition management strategies in preparation for non-face-to-face engagement make balanced regional development possible. WO analysis shows the need for rearrangement and renovation of outdated sports facilities, development of programs linked to convergence sports tourism products, efficient and strategic attraction activities, and promoting sustainable development of bed town cities. WT analysis suggests that the imbalance in regional development due to expansion of sports facilities, insufficient cultural contents in tourism, and tourism demand fluctuation are potential problems. Follow-up studies can focus on deeper analysis of the possibility and attractiveness of hosting the Summer World University Games in Chungcheong, Korea using qualitative methods such as focus group interviews and in-depth interviews with stakeholders and local residents.

• Journal of Industrial Convergence
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• v.20 no.11
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• pp.135-140
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• 2022

A study to estimate the appropriate size for the quota of civil servants during the period of change of government is required. Therefore, in this study, we would like to introduce a study that uses DEA to estimate the appropriate size of public officials. The department of a public institution is DMU, and the number of employees in each department is applied as an input variable, and the number of electronic approval production documents and the number of electronic approval expenditures are applied as output variables. MaxDEA 8 was used as an analysis program for this purpose. As a result of the analysis, when the efficiency level was 1.00 (100%), 3 out of 14 departments showed the optimal level by satisfying the efficiency, and 10 of the remaining departments scored 0.50 (50%) with a score of 0.50 (50%), confirmed to be relatively inefficient. In other words, it was confirmed that most departments had inefficient surplus staff. As an additional analysis, we calculated the number of possible staff reductions using the efficiency level. Using this, it is expected that the field of manpower reduction can be discovered in advance through an analysis of manpower efficiency by department, and based on this, it can be used to relocate manpower by department according to future response strategies.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.36 no.5
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• pp.454-462
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• 2023

Flash lamp annealing (FLA) of metal nanoparticle (NP) ink has provided powerful strategies to fabricate high-performance electrodes on a flexible substrate because of its rapid processing capability (in milliseconds), low-temperature process, and compatibility with to roll-to-roll process. However, metal NPs [e.g., gold (Au), silver (Ag), copper (Cu), etc.] have limitations such as difficulty in synthesizing fine metal NPs (diameter less than 10 nm), high price, and degradation during ink storage and FLA processing. In this regard, organometallic ink has been proposed as a material that can replace metal NPs due to their low-cost (usually 1/100 times cheaper than metal nano inks), low-temperature processability, and high material stability. Despite these advantages, the fabrication of flexible electrodes through FLA treatment of organometallic compounds has not been extensively researched. In this paper, we experimentally guide how to determine the optimal conditions for forming electrodes on flexible substrates by considering material parameters, and flashlight processing parameters (energy density, pulse duration, etc) to minimize the difficulties that may arise during the FLA of organometallic ink.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.6A
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• pp.965-976
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• 2006

A realistic lifetime seismic-reliability based approach is unavoidable to perform Life-Cycle Cost (LCC)-effective optimum design, maintenance, and retrofitting of structures against seismic risk. So far, though a number of researchers have proposed the LCC-based seismic design and retrofitting methodologies, most researchers have only focused on the methodological point. Accordingly, in most works, they have not been quantitatively considered critical factors such as the effects of seismic retrofit, maintenance, and environmental stressors on lifetime seismic reliability assessment of deteriorating structures. Thus, in this study, a systemic lifetime seismic reliability analysis methodology is proposed and a program HPYER-DRAIN2DX-DS is developed to perform the desired lifetime seismic reliability analysis. To demonstrate the applicability of the program, it is applied to an example bridge with or without seismic retrofit and maintenance strategies. From the numerical investigation, it may be positively stated that HYPER-DRAIN2DX-DS can be utilized as a useful numerical tool for LCC-effective optimum seismic design, maintenance, and retrofitting of bridges.

• Journal of Internet Computing and Services
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• v.24 no.6
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• pp.137-144
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• 2023

Cyberattack technology is evolving to an unpredictable degree, and it is a situation that can happen 'at any time' rather than 'someday'. Infrastructure that is becoming hyper-connected and global due to cloud computing and the Internet of Things is an environment where cyberattacks can be more damaging than ever, and cyberattacks are still ongoing. Even if damage occurs due to external influences such as cyberattacks or natural disasters, intelligent self-recovery must evolve from a cyber resilience perspective to minimize downtime of cyber assets (OS, WEB, WAS, DB). In this paper, we propose an intelligent self-recovery technology to ensure sustainable cyber resilience when cyber assets fail to function properly due to a cyberattack. The original and updated history of cyber assets is managed in real-time using timeslot design and snapshot backup technology. It is necessary to secure technology that can automatically detect damage situations in conjunction with a commercialized file integrity monitoring program and minimize downtime of cyber assets by analyzing the correlation of backup data to damaged files on an intelligent basis to self-recover to an optimal state. In the future, we plan to research a pilot system that applies the unique functions of self-recovery technology and an operating model that can learn and analyze self-recovery strategies appropriate for cyber assets in damaged states.

• Journal of Korea Water Resources Association
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• v.56 no.11
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• pp.705-720
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• 2023

In South Korea, ongoing incidents related to drinking water quality have eroded consumer trust. Specifically, beyond quality incidents, there have been complaints about taste, odor, and other issues stemming from the presence of chlorine. To address this, water service operators are employing various management strategies from both temporal (scheduling) and spatial (rechlorination) perspectives to ensure uniform and safe distribution of chlorine residuals. In this study, we focus on the optimal monthly management of chlorine residuals, based on water distribution network analysis. Water quality reaction coefficients, including bulk fluid and wall reaction coefficients, were estimated through lab-scale tests and EPANET water quality simulations, respectively, accounting for temperature variations in a large-scale water distribution network. Utilizing these estimated coefficients, we examined the monthly variations in chlorine residual distribution under different chlorine injection conditions. The results indicate that the efficient concentration for chlorine injection, which satisfies the residual chlorine limit range, varies with temperature changes. Consequently, it is imperative to establish a specific and quantitative chlorine injection plan that considers the accurate spatial distribution of monthly chlorine residuals.

• Journal of Korean Society of Rural Planning
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• v.30 no.1
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• pp.57-66
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• 2024

This study aimed to develop a precise vegetation cover classification model for small streams using the combination of drone remote sensing and support vector machine (SVM) techniques. The chosen study area was the Idong stream, nestled within Geosan-gun, Chunbuk, South Korea. The initial stage involved image acquisition through a fixed-wing drone named ebee. This drone carried two sensors: the S.O.D.A visible camera for capturing detailed visuals and the Sequoia+ multispectral sensor for gathering rich spectral data. The survey meticulously captured the stream's features on August 18, 2023. Leveraging the multispectral images, a range of vegetation indices were calculated. These included the widely used normalized difference vegetation index (NDVI), the soil-adjusted vegetation index (SAVI) that factors in soil background, and the normalized difference water index (NDWI) for identifying water bodies. The third stage saw the development of an SVM model based on the calculated vegetation indices. The RBF kernel was chosen as the SVM algorithm, and optimal values for the cost (C) and gamma hyperparameters were determined. The results are as follows: (a) High-Resolution Imaging: The drone-based image acquisition delivered results, providing high-resolution images (1 cm/pixel) of the Idong stream. These detailed visuals effectively captured the stream's morphology, including its width, variations in the streambed, and the intricate vegetation cover patterns adorning the stream banks and bed. (b) Vegetation Insights through Indices: The calculated vegetation indices revealed distinct spatial patterns in vegetation cover and moisture content. NDVI emerged as the strongest indicator of vegetation cover, while SAVI and NDWI provided insights into moisture variations. (c) Accurate Classification with SVM: The SVM model, fueled by the combination of NDVI, SAVI, and NDWI, achieved an outstanding accuracy of 0.903, which was calculated based on the confusion matrix. This performance translated to precise classification of vegetation, soil, and water within the stream area. The study's findings demonstrate the effectiveness of drone remote sensing and SVM techniques in developing accurate vegetation cover classification models for small streams. These models hold immense potential for various applications, including stream monitoring, informed management practices, and effective stream restoration efforts. By incorporating images and additional details about the specific drone and sensors technology, we can gain a deeper understanding of small streams and develop effective strategies for stream protection and management.

• Journal of Dental Anesthesia and Pain Medicine
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• v.24 no.3
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• pp.187-193
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• 2024

Background: Patients with autism spectrum disorder (ASD) present challenges in dental treatment cooperation owing to deficits in communication skills and social interaction. Behavioral guidance, sedation, and general anesthesia may be employed to ensure the quality of dental care for individuals with ASD. This study aimed to examine the trends in dental treatment for patients with ASD who visited the Department of Pediatric Dentistry at Dankook University Jukjeon Dental Hospital, an oral health center for the disabled in the Gyeonggi region, over the past 10 years. Methods: This study utilized the order communication system to gather data on sex, age, cooperation level, number of quadrants treated, and administration of sedation or general anesthesia for patients with ASD who visited the Department of Pediatric Dentistry at Dankook University Jukjeon Dental Hospital between January 2013 and December 2022. Results: The total number of patients with ASD increased annually, possibly due to an increase in ASD prevalence and the hospital's designation as a center for disabled oral health. General anesthesia was predominant before 2017, with a shift towards N₂O-O₂ sedation. The most common age group for sedation or general anesthesia was 6-9 years, with a higher prevalence in males than in females. Notably, N₂O-O₂ and midazolam sedation resulted in better cooperation and fewer treated teeth than general anesthesia. Conclusion: This study highlights the evolving trends in dental treatment for individuals with ASD, indicating a shift towards outpatient methods, particularly N₂O-O₂ sedation. The sex distribution aligns with national statistics, emphasizing a higher prevalence of ASD in males than in females. These findings underscore the need for further research to establish evidence-based guidelines for optimal dental care strategies tailored to the unique needs of individuals with ASD.

• The Journal of the Convergence on Culture Technology
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• v.10 no.3
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• pp.299-304
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• 2024

Beyond the first nuclear age, which pitted the United States and the Soviet Union against each other, we are now in the second nuclear age, in which the decision-makers of nuclear weapons are diversified among countries large and small. India and Pakistan, two such countries, are antagonistic toward each other and possess nuclear weapons, but their nuclear posture and nuclear strategies are different. The examples of these two countries can provide clues to the future nuclear posture of North Korea, which faces South Korea. In particular, Pakistan's chosen posture of pre-emptive deterrence is a highly offensive nuclear posture that threatens to use nuclear weapons against an adversary to deter aggression. This is an option that can be accomplished even with a small nuclear arsenal that can be used as a first strike, so it seems to be the optimal posture for a nuclear-powered Pakistan to choose in response to an Indian threat. North Korea, which is outgunned by the United States and South Korea, is likely to continue to threaten to use nuclear weapons preemptively like Pakistan. However, it is expected to be defensive and quite conservative, like India, until it actually uses them to maintain its regime.