• Convergence Security Journal
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• v.24 no.1
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• pp.51-57
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• 2024

Although industrial control systems (ICSs) recently keep evolving with the introduction of Industrial IoT converging information technology (IT) and operational technology (OT), it also leads to a variety of threats and vulnerabilities, which was not experienced in the past ICS with no connection to the external network. Since various control command messages are sent to field devices of the ICS for the purpose of monitoring and controlling the operational processes, it is required to guarantee the message integrity as well as control center authentication. In case of the conventional message integrity codes and signature schemes based on symmetric keys and public keys, respectively, they are not suitable considering the asymmetry between the control center and field devices. Especially, compromised node attacks can be mounted against the symmetric-key-based schemes. In this paper, we propose message authentication scheme based on double hash chains constructed from cryptographic hash function without introducing other primitives, and then propose extension scheme using Merkle tree for multiple uses of the double hash chains. It is shown that the proposed scheme is much more efficient in computational complexity than other conventional schemes.

• Information Systems Review
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• v.25 no.1
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• pp.189-212
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• 2023

This study uses various methods, including media analysis, expert interviews, and large-scale surveys, to derive notable digital business trends in 2023. Most trend studies have yet to deal with digital business trends in Korea. They also often have limitations in the objectivity of the results using unclear methods. On the other hand, this study emphasizes the validity of the results by collecting opinions from Korean digital business experts in various fields. First, Korean IT news articles were collected and analyzed through topic modeling analysis. Then, based on the results, interviews were conducted with 13 academic and industrial experts to derive 16 IT business trend candidates. Then, a survey was conducted on 210 experts to finalize the list of Korean IT business trends. Finally, to compare overseas and domestic views, we conducted an additional survey using the items developed by the Society for Information Management, SIM. This study is meaningful in that it drew prospects for digital business trends in consideration of the domestic business environment by scientifically converging various opinions of Korean digital business leaders. Our study contributes to developing strategies for IT technology and IT service business markets.

• Information Systems Review
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• v.21 no.2
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• pp.1-27
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• 2019

It is possible to provide Smart Tourism Service through the development of information technology. It is necessary for the tourism industry to understand and utilize Big Data that has tourists' consumption patterns and service usage patterns in order to continuously create a new business model by converging with other industries. This study suggests to activate Jeju Smart Tourism by analyzing Big Data based on credit card usage records and location of tourists in Jeju. The results of the study show that First, the percentage of Chinese tourists visiting Jeju has decreased because of the effect of THAAD. Second, Consumption pattern of Chinese tourists is mostly occurring in the northern areas where airports and duty-free shops are located, while one in other regions is very low. The regional economy of Jeju City and Seogwipo City shows a overall stagnation, without changes in policy, existing consumption trends and growth rates will continue in line with regional characteristics. Third, we need a policy that young people flow into by building Jeju Multi-complex Mall where they can eat, drink, and go shopping at once because the number of young tourists and the price they spend are increasing. Furthermore, it is necessary to provide services for life-support related to weather, shopping, traffic, and facilities etc. through analyzing Wi-Fi usage location. Based on the results, we suggests the marketing strategies and public policies for understanding Jeju tourists' patterns and stimulating Jeju tourism industry.

• Journal of Korean Medical classics
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• v.37 no.3
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• pp.83-106
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• 2024

Objectives : This paper aims to examine the meaning of Shengmaisan in relation to original qi based on the discussion of Zhangyuansu, Lidongyuan and other doctors. Methods : Discussion of Shengmaisan made by Zhang, Li and others were examined. Afterwards, the medicinal properties of renshen, maimendong, and wuweizi as written in the Bencaogangmu, Donguibogam, Benjingshuzheng and texts of Zhang and Li were studied in relation to original qi. Related concepts such as '肺中伏火'·'補肺中元氣不足'·'補天眞元氣'·'夏食寒' were analyzed as well. Results & Conclusions : 1. Various pathology related to deficiency in original qi could act as internal pathogen for Shengmaisan application with which external factors such as summerheat and dampness heat meet results in most damage in the Lung metal. Therefore the upper body Lung is emphasized as pathogen. 2. The pathology of Shengmaisan application is depletion of humor, which should be refined, due to summer or dampness heat in a state of original qi deficiency which damages the Lungs, disabling its function of managing clear and pure qi. 3. The disease pattern for Shengmaisan in relation to original qi, according to other doctors, includes symptoms related to the Lungs such as dryness in the mouth due to excessive perspiration, blankness, loss of consciousness, shortness of breath, coughing, fast breathing, along with general bodily symptoms such as heavy sensation of the body, lethargy, difficulty walking, limping. These general bodily symptoms are due to either qi deficiency of the Lung, or humor deficiency due to failure of qi convergence in the lower body, or symptoms caused by Jing deficiency in severe cases. Symptoms related to problems in the lower body could manifest as dysfunction in urination and defecation, weakness in the limbs caused by original qi deficiency. 4. The Lungs circulate the clear and pure qi, converging qi and creating humor to assist the Triple Burner's Qi-Humor metabolism, enabling smooth communication of original qi throughout the body. With the original qi well tonified, the shen mechanism which is rooted in original qi allows for autonomous and consistent qi circulation within the body. Therefore, both Zhang and Li emphasized the importance of original qi. The property of Shengmaisan is explained as 'supplement qi/create liquid, convergence of yin/stop perspiration'. Zhang and Li explained its property as managing the circulation of original qi, to tonify Lungs' original qi and origin of water-humor.

• Information Systems Review
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• v.15 no.3
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• pp.1-37
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• 2013

This study is conducted to explore the possibility of service convergence to promote mobile learning. This study has attempted to identify how mobile learning service is provided, which services among them are considered most popular, and which services are highly demanded by users. This study has also investigated the potential opportunities for service convergence of mobile service and e-learning. This research is then extended to examine the possibility of active convergence of common services in mobile services and e-learning. Important variables have been identified from related web pages of portal sites using social network analysis (SNA) and association rules. Due to the differences in number and type of variables on different web pages, SNA was used to deal with the difficulties of identifying the degree of complex connection. Association analysis has been used to identify association rules among variables. The study has revealed that most frequent services among common services of mobile services and e-learning were Games and SNS followed by Payment, Advertising, Mail, Event, Animation, Cloud, e-Book, Augmented Reality and Jobs. This study has also found that Search, News, GPS in mobile services were turned out to be very highly demanded while Simulation, Culture, Public Education were highly demanded in e-learning. In addition, It has been found that variables involving with high service convergence based on common variables of mobile and e-learning services were Games and SNS, Games and Sports, SNS and Advertising, Games and Event, SNS and e-Book, Games and Community in mobile services while Games, Animation, Counseling, e-Book, being preceding services Simulation, Speaking, Public Education, Attendance Management were turned out be highly convergent in e-learning services. Finally, this study has attempted to predict possibility of active service convergence focusing on Games, SNS, e-Book which were highly demanded common services in mobile and e-learning services. It is expected that this study can be used to suggest a strategic direction to promote mobile learning by converging mobile services and e-learning.

• Journal of Nutrition and Health
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• v.51 no.4
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• pp.275-286
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• 2018

Purpose: Our previous study demonstrated that persimmon (Diospyros kaki Thumb.) at different stages of ripening provided different protective effects against high-fat/cholesterol diet (HFD)-induced dyslipidemia in rats. In this study, we compared the metabolites profile and gene expressions related to triglyceride (TG)/cholesterol metabolism in vitro and in vivo after treating with persimmon water extracts (PWE) or tannin-enriched persimmon concentrate (TEP). Methods: Primary and secondary metabolites in test materials were determined by GC-TOF/MS, UHPLC-LTQ-ESI-IT-MS/MS, and UPLC-Q-TOF-MS. The expression of genes related to TG and cholesterol metabolism were determined by RT-PCR both in HepG2 cells stimulated by oleic acid/palmitic acid and in liver tissues obtained from Wistar rats fed with HFD and PWE at 0, 150, 300, and 600 mg/d (experiment I) or TEP at 0, 7, 14, and 28 mg/d (experiment II) by oral gavage for 9 weeks. Results: PLS-DA analysis and heatmap analysis demonstrated significantly differential profiling of metabolites of PWE and TEP according to processing of persimmon powder. In vitro, TEP showed similar hypolipidemic effects as PWE, but significantly enhanced hypocholesterolemic effects compared to PWE in sterol regulatory element-binding protein 2 (SREBP2), HMG-CoA reductase (HMGCR), proprotein convertase subtilisin/kexin type 9 (PCSK9), cholesterol $7{\alpha}-hydroxylase$ (CYP7A1), and low density lipoprotein receptor (LDLR) gene expression. Consistently, TEP and PWE showed similar hypolipidemic capacity in vivo, but significantly enhanced hypocholesterolemic capacity in terms of SREBP2, HMGCR, and bile salt export pump (BSEP) gene expression. Conclusion: These results suggest that column extraction after hot water extraction may be a good strategy to enhance tannins and long-chain fatty acid amides, which might cause stimulation of hypocholesterolemic actions through downregulation of cholesterol biosynthesis gene expression and upregulation of LDL receptor gene expression.

• Journal of Intelligence and Information Systems
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• v.17 no.1
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• pp.127-138
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• 2011

The core service of most research portal sites is providing relevant research papers to various researchers that match their research interests. This kind of service may only be effective and easy to use when a user can provide correct and concrete information about a paper such as the title, authors, and keywords. However, unfortunately, most users of this service are not acquainted with concrete bibliographic information. It implies that most users inevitably experience repeated trial and error attempts of keyword-based search. Especially, retrieving a relevant research paper is more difficult when a user is novice in the research domain and does not know appropriate keywords. In this case, a user should perform iterative searches as follows : i) perform an initial search with an arbitrary keyword, ii) acquire related keywords from the retrieved papers, and iii) perform another search again with the acquired keywords. This usage pattern implies that the level of service quality and user satisfaction of a portal site are strongly affected by the level of keyword management and searching mechanism. To overcome this kind of inefficiency, some leading research portal sites adopt the association rule mining-based keyword recommendation service that is similar to the product recommendation of online shopping malls. However, keyword recommendation only based on association analysis has limitation that it can show only a simple and direct relationship between two keywords. In other words, the association analysis itself is unable to present the complex relationships among many keywords in some adjacent research areas. To overcome this limitation, we propose the hybrid approach for establishing association network among keywords used in research papers. The keyword association network can be established by the following phases : i) a set of keywords specified in a certain paper are regarded as co-purchased items, ii) perform association analysis for the keywords and extract frequent patterns of keywords that satisfy predefined thresholds of confidence, support, and lift, and iii) schematize the frequent keyword patterns as a network to show the core keywords of each research area and connecting keywords among two or more research areas. To estimate the practical application of our approach, we performed a simple experiment with 600 keywords. The keywords are extracted from 131 research papers published in five prominent Korean journals in 2009. In the experiment, we used the SAS Enterprise Miner for association analysis and the R software for social network analysis. As the final outcome, we presented a network diagram and a cluster dendrogram for the keyword association network. We summarized the results in Section 4 of this paper. The main contribution of our proposed approach can be found in the following aspects : i) the keyword network can provide an initial roadmap of a research area to researchers who are novice in the domain, ii) a researcher can grasp the distribution of many keywords neighboring to a certain keyword, and iii) researchers can get some idea for converging different research areas by observing connecting keywords in the keyword association network. Further studies should include the following. First, the current version of our approach does not implement a standard meta-dictionary. For practical use, homonyms, synonyms, and multilingual problems should be resolved with a standard meta-dictionary. Additionally, more clear guidelines for clustering research areas and defining core and connecting keywords should be provided. Finally, intensive experiments not only on Korean research papers but also on international papers should be performed in further studies.

• 대한공업교육학회지
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• v.38 no.1
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• pp.49-67
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• 2013

The purpose of this study is to analyze the external systems and the units 'problem solving and invention' of the middle school technology and home economics 1 textbooks of the revised 2011 national curriculum in an effort to provide some information on the content system of invention education in technology class, as invention education was provided as part of a regular subject for the first time. The findings of the study were as follows: First, 'Technology and Inventions' chapter of Technology and Home Economics 1 Textbooks occupied 10-18% share, with the subchapter of 'Problem Solving and Invention' unit taking up 6.7-29% of the textbooks. Second, for most textbooks, 'Technological Problem Solving', 'Idea Generation' 'Multi-dimensional Projection Method', 'Expansive Thought-Processing Methodology', 'Converging Thought Methodology' and 'Invention in Everyday Lives' were included as main contents based on the accomplishment criteria presented in education process interpretation documents. Third, the detailed structures were generally made up as follows: Introduction (Broad Chapter Title, Subchapter Table of Contents, Introduction, Subchapter Title, Study Objectives, Open Thinking); Development (Unit Title, Thinking Ahead, Core Terms, Main Text, Study Helper, Activities, Research Exercises, Supplemental Readings, In-depth Study Topics, Technology in Everyday Lives, Reading Topics, Discussion Topics, and Career Helpers); and Summary (Subchapter Summary, Study Summary, Terms Summary, Writing Follow-up, Self Review, Broad Chapter Evaluation). Fourth, based on the analysis of figures included, photographs had the largest share, followed by figures, tables, and graphs. The photos were used to illustrate various inventions, invention methodologies, and exercise activities, while figures were included to depict the contents included in the main text, and the tables to assist to preparation of process diagrams or materials lists. Fifth, based on the analysis of content weights, greater weights were placed on 'Inventions and Thoughts', and 'Invention Experiment Activities,' while 'Understanding Inventions' and 'Invention and Patents' chapters did not have a lot of texts involved. Sixth, based on the analysis of content presentation methods, most textbooks combined figures, tables, illustrations and texts to discuss the topics. Based on the above study results, we suggest the following: First, a consistent education curriculum should be developed over the topic of invention; and second, more precise and systematic analysis of textbooks would need to be performed.

• Journal of Korean Society of Transportation
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• v.23 no.7 s.85
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• pp.165-179
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• 2005

The object of this study is a development of a stochastic user equilibrium transit assignment algorithm for multiple user classes considering stochastic characteristics and heterogeneous attributes of passengers. The existing transit assignment algorithms have limits to attain realistic results because they assume a characteristic of passengers to be equal. Although one group with transit information and the other group without it have different trip patterns, the past studies could not explain the differences. For overcoming the problems, we use following methods. First, we apply a stochastic transit assignment model to obtain the difference of the perceived travel cost between passengers and apply a multiple user class assignment model to obtain the heterogeneous qualify of groups to get realistic results. Second, we assume that person trips have influence on the travel cost function in the development of model. Third, we use a C-logit model for solving IIA(independence of irrelevant alternatives) problems. According to repetition assigned trips and equivalent path cost have difference by each group and each path. The result comes close to stochastic user equilibrium and converging speed is very fast. The algorithm of this study is expected to make good use of evaluation tools in the transit policies by applying heterogeneous attributes and OD data.

• Journal of Christian Education in Korea
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• v.63
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• pp.221-253
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• 2020

The purpose of this study is to define the key competency as Christian(in another word: Christian key competency) and to interpret the six key competencies of the 2015 revised curriculum in a Christian educational way. Also as an alternative to the key competencies model of the 2015 revised curriculum, this study aims to materialize the formation of a Christian key competencies model based on Christian faith. This study derived 'faith' from the key competencies as Christian throughout preceding research analysis. The 'faith' of the key competencies as Christian means the ability to know oneself, and to know the world and God within the knowledge of the Bible (knowledge of God) in the personal relationship with God, and also it is the ability to think, judge, and act with biblical values, Christian world view, and Christian self-identity. The key competency 'faith' could be the basis (standard) of motivation, attitude and the value of all competencies in cultivation and exercise. The model of Christian key competencies has the structure in which each six key competencies become to be cultivated based on the Christian key competency called "faith." Based on the structure, the six key competencies of the 2015 revised curriculum were interpreted and explained from the perspective of Christian education. In the self-management competency, self-identity can be correctly formed in relations with transcendent God. In aesthetic emotional competency, the empathic understanding of human beings comes from the understanding of the image of God, the supreme beauty, the source of beauty. About the community competency, human community is the source of God who created the universe, human and all of things. It is because a Christian community is a community within the relationship of Trinity God, Nature and others. Therefore regions, countries, and the world become one community. Communication competency first stem from good attitudes toward yourself and others with respectful mind. It comes from an understanding of Christian human beings. Also, there is a need of having a common language for communications. The common language is the Bible that given to us for our communicative companionship. Through the language of the Bible, God made us to know about God, human being and the creative world, and also made us to continue to communicate with God, others and the world. For having the knowledge-information processing competency, a standard of value for the processing and utilization of knowledge and information is required. The standard should be the basis of moral and ethical values for human respect. About creative thinking competency, the source of creativity is God who created the world. Human beings who have the image of God own creative potential. As well as, creativity has different expression forms depending on individual preferences and interests, and different approaches will be made depending on each individual's importance and achievement. Individual creativity can be found through education, and it can be embodied by converging knowledge, skills and experience.