• Journal of Korea Multimedia Society
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• v.24 no.6
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• pp.768-788
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• 2021

The reversible data hiding technique safely transmits secret data to the recipient from malicious attacks by third parties. In addition, this technique can completely restore the image used as a transmission medium for secret data. The reversible data hiding schemes have been proposed in various forms, and recently, the reversible data hiding schemes based on interpolation are actively researching. The reversible data hiding scheme based on the interpolation method expands the original image into the cover image and embed secret data. However, the existing interpolation-based reversible data hiding schemes did not embed secret data during the interpolation process. To improve this problem, this paper proposes embedding the first secret data during the image interpolation process and embedding the second secret data into the interpolated cover image. In the embedding process, the original image is divided into blocks without duplicates, and the maximum and minimum values are determined within each block. Three way searching based on the maximum value and two way searching based on the minimum value are performed. And, image interpolation is performed while embedding the first secret data using the PVD scheme. A stego image is created by embedding the second secret data using the maximum difference value and log function in the interpolated cover image. As a result, the proposed scheme embeds secret data twice. In particular, it is possible to embed secret data even during the interpolation process of an image that did not previously embed secret data. Experimental results show that the proposed scheme can transmit more secret data to the receiver while maintaining the image quality similar to other interpolation-based reversible data hiding schemes.

• Composites Research
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• v.34 no.3
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• pp.148-154
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• 2021

Carbon/epoxy composite bipolar plate (BP) is a BP that is likely to replace existing graphite bipolar plate of vanadium redox flow cell (VRFB) due to its high mechanical properties and productivity. Multi-functional carbon/epoxy composite BP requires graphite coating or additional surface treatment to reduce interfacial contact resistance (ICR). However, the expanded graphite coating has the disadvantage of having low durability under VRFB operating conditions, and the surface treatments incur additional costs. In this work, an excessive resin absorption method is developed, which uniformly removes the resin rich area on the surface of the BP to expose carbon fibers by applying polyester fabric. This method not only reduces ICR by exposing carbon fibers to BP surfaces, but also forms a unique ditch pattern that can effectively hold carbon felt electrodes in place. The acidic environmental durability, mechanical properties, and gas permeability of the developed carbon/epoxy composite BP are experimentally verified.

• The Journal of the Korea Contents Association
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• v.22 no.10
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• pp.103-113
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• 2022

As globalization progresses and localization takes place, interest in local culture is increasing. In line with this trend, the Cultural Heritage Administration has been promoting the Cultural Heritage Night Tour Project as a night-type cultural property tourism content since 2016. Cultural property nightlife, part of the regional regeneration project, creates new added value by converging and combining various historical and cultural-related contents centered on local cultural heritage. Although the "cultural nightlife" has been greatly activated, it is judged that changes are needed to continue. This is because fixed nightlife programs are positive in terms of establishing a nationwide network, but there is a limitation in that they cannot be standardized and expanded to various forms. Therefore, in this study, the meaning and limitations of nightlife programs were identified, and cognitive theory applicable to nightlife programs was considered. Through this process, it was confirmed that cognitive poetry's 'circular for dynamic semantic composition', 'surreal foreground', and 'adventures in time and space' can be applied to nightlife programs. As a result of combining cognitive poetry with nightlife programs, it was possible to present a strategy for implementing nightlife programs differentiated from existing nightlife programs.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.891-897
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• 2022

In big data analysis, raw text data mostly exists in various unstructured data forms, so it becomes a structured data form that can be analyzed only after undergoing heuristic pre-processing and computer post-processing cleansing. Therefore, in this study, unnecessary elements are purified through pre-processing of the collected raw data in order to apply the wordcloud of R program, which is one of the text data analysis techniques, and stopwords are removed in the post-processing process. Then, a case study of wordcloud analysis was conducted, which calculates the frequency of occurrence of words and expresses words with high frequency as key issues. In this study, to improve the problems of the "nested stopword source code" method, which is the existing stopword processing method, using the word cloud technique of R, we propose the use of "general stopword corpus" and "user-defined stopword corpus" and conduct case analysis. The advantages and disadvantages of the proposed "unstructured data cleansing process model" are comparatively verified and presented, and the practical application of word cloud visualization analysis using the "proposed external corpus cleansing technique" is presented.

• Journal of Practical Engineering Education
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• v.14 no.1
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• pp.11-18
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• 2022

As the need for software development manpower increases, various educational programs appear and the popularity of bootcamp style education program for software development increases. However, despite the operations and forms of bootcamp education programs are completely different from the existing software development education programs, there is a lack of research in understanding bootcamp as a software education program. Therefore, this study tried to derive the core elements of the education program through a case study on bootcamp software developer education program. After conducting interviews of 7 members who have completed a series of bootcamp software developer education program X, seven characteristics of bootcamp-type software development education program were derived: intensive theory education, sense of growth and achievement, team project-based learning, community characteristics, peer pressure, stress and fatigue due to short-term learning, and contact-free specialty. Based on the derived characteristics, the advantages and improvements of bootcamp-type education were described, and the direction of the bootcamp-type education program for software developer was discussed.

• KIPS Transactions on Software and Data Engineering
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• v.11 no.11
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• pp.479-488
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• 2022

In recent years, with the rapid development of machine learning technology, research utilizing machine learning has been actively conducted in fields such as cognition, reasoning and judgment, and action among various technologies constituting intelligent systems. In order to utilize this machine learning, it is indispensable to collect data for learning. However, the types of data generated vary according to the environment in which the data is generated, and the types and forms of data required are different depending on the learning model to be used for machine learning. Due to this, there is a problem that the existing data collection method cannot be reused in a new environment, and a specialized data collection module must be developed each time. In this paper, we propose a specification-based methology for data collection in artificial intelligence system to solve the above problems, ensure the reusability of the data collection method according to the data collection environment, and automate the implementation of the data collection function.

• Journal of Creative Information Culture
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• v.5 no.3
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• pp.215-223
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• 2019

The wave of the information age gradually accelerates, and fusion analysis solutions that can utilize these knowledge data according to accumulation of various forms of big data such as large capacity texts, sounds, movies and the like are increasing, Reduction in the cost of storing data accordingly, development of social network service (SNS), etc. resulted in quantitative qualitative expansion of data. Such a situation makes possible utilization of data which was not trying to be existing, and the potential value and influence of the data are increasing. Research is being actively made to present future-oriented education systems by applying these fusion analysis systems to the improvement of the educational system. In this research, we conducted a big data analysis on Twitter, analyzed the natural language of the data and frequency analysis of the word, quantitative measure of how domestic windows education problems and outcomes were done in it as a solution.

• Journal of Soil and Groundwater Environment
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• v.28 no.2
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• pp.12-29
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• 2023

Conceptual site model (CSM) development and enhancement for contaminated sites assists in identifying data gaps during the site investigation process. In this study, CSM was developed and enhanced for a contaminated site in Korea as a case study. Site Y was scrutinized four times previously. The site profiles for each scrutiny were reorganized based on the scrutiny reports, and the relevant data was utilized to develop and enhance CSMs. CSM for the first investigation was developed in various forms including table, flowchart, diagram, and narrative formats. CSM was enhanced in a stepwise manner by incorporating the updated profile information obtained in next investigation to existing CSM. The hypothetical data gap analysis between each investigation step was established to meet the purpose of the follow-up investigation. This case study showed that CSM is a useful tool to identify the history and current status of contaminated sites and thereby help in planning supplementary investigations for better site characterization.

• The Journal of the Korea institute of electronic communication sciences
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• v.18 no.3
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• pp.521-526
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• 2023

Due to the recent pandemic, most educational systems are being conducted through online classes. Unlike face-to-face classes, it is even more difficult for learners to maintain concentration, and evaluating the learners' attitude toward the class is also challenging. In this paper, we proposed a real-time concentration-based review support system for learners in real-time video lectures that can be used in online classes. This system measured the learner's face, pupils, and user activity in real-time using the equipment used in the existing video system, and delivers real-time concentration measurement values to the instructor in various forms. At the same time, if the concentration measurement value falls below a certain level, the system alerted the learner and records the timestamp of the lecture. By using this system, instructors can evaluate the learners' participation in the class in real-time and help to improve their class abilities.

• Journal of the Korean Institute of Rural Architecture
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• v.24 no.4
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• pp.117-124
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• 2022

Recognizing the problem that the definition of the term pan-ock does not appear precisely in the dictionary, the definition of pan-ock was established through analysis by analyzing 183 cases of pan-ock searched in the Korean Classics DB and classifying them into buildings and ships. First of all, the 65 pan-ocks classified as architecture were used in various ways, such as residences, religious facilities, jang-pan-ocks, and prisons, depending on their use. Second, the 90 cases of pan-ock related to ships were the concept of houses that combine work and accommodation on ships. Finally, through military installations, literary expressions, and bureaucrats who have seen trains and wagons, Pan-ock uses boards. It can be used for walls or roofs only, or for both walls and roofs. Therefore, it is necessary to consider the case of the Joseon Dynasty with the definition of Pan-ock in the existing dictionary. In other words, Pan-ock refers to "houses, religious facilities, royal tombs, and prisons, with various uses and forms. In addition, it refers to the joining of only the wall or the roof with planks, or the joining of both the wall and the roof," suggesting a broader interpretation of the category.