• Convergence Security Journal
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• v.19 no.3
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• pp.13-19
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• 2019

MANET has many security vulnerabilities because it consists of only mobile nodes using wireless. In particular, it is a very important factor determining network performance that excludes the participation of malicious nodes through accurate reliability measurements and authentication of nodes participating in the network. In this paper, we proposed a technique applied with blockchain technology in order to prevent forgery of authentication information for nodes participating in the network. And, an area-based hierarchical structure was applied to increase the efficiency of authentication for nodes and apply the optimal technique of block generation and exchange protocol. In addition, four data payloads were added to the block header in order to add authentication information for nodes in block. To improve the reliability by applying the blockchain technique to the hop-by-hop data transfer method between mobile nodes, blockchain exchange protocol through transaction creation, block packaging and verification processes were implemented. We performed the comparative experiment with the existing methods to evaluate the performance of the proposed method and confirmed the excellent performance by the experiment results.

• Korean Institute of Interior Design Journal
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• v.18 no.6
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• pp.115-123
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• 2009

The change of digital technology caused not only the whole human life but also the change of a thinking form and an expression method of human beings. Also, the interactive communication structure became to form in space structure, and space users also get changed to an active system. The interaction between a human being and space, which uses digital media as a medium, makes a human being experience sensitivity through a cognitive process of a human being. The present research aimed to find out characteristics and expression of emotional space applied with digital technology based on the relationship between media space and cognitive functioning and to realize new emotional space. The research method was to define on digital media and experience by cognition of a human being through a literature research and a precedent research and to consider on approach to emotional space through experience of a cognition process like this. Based on the theory like this, the present research progressed by focusing on dramatized characteristics of experience in the digital media space and emotional space expression by induced characteristics. Through the analysis like this, the space applied with digital media could appear as a field of communication that can experience by forming mutual relation through perception of a human being. Additionally, the space induces active participation of a human being through various productions of media and responds to movement, and thus, this suggested infinite possibility as emotional space that can try new experience by stimulating a sense as effect of a cognitive process of a human being.

• Informatization Policy
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• v.24 no.3
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• pp.42-66
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• 2017

This study investigated the ecological change of public software industry, comparing the pre and post structure of industry network based on the application of the regulation restricting large company participation in public software market. For this purpose, we used big data of the software market from Korea Public Procurement Service and used the SNA(Social Network Analysis) methodology which is being actively used in the area of social science recently. Finally, we highlighted the contribution of open public data. By analyzing order and contract data of the public software industry for 3 years - from 2013 to 2015 - we found out two main things. First, we observed that Power Law distribution had been going on in the public software industry, regardless of the external impact of regulation. Second, despite the existence of such Power Law distribution, we also observed the ecological change of industry structure from year to year. We presented the implication of such findings and discussed the advantage of open public data as the original motivator of this study.

• Journal of the Korea Convergence Society
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• v.10 no.4
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• pp.175-182
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• 2019

The purpose of this study is to test whether credit rating agencies highly evaluate the credit ratings of corporate bonds based upon management participation and ownership share by family governance in ownership structure forms. The samples of this study for empirical analysis were 1,449 non-financial companies listed on Korean Exchange from 2011 to 2016, over whose firm/year data this study conducted regression analysis. The results of empirical analysis in this study are as follows. First, family businesses had positive effects on the evaluation of corporate credit ratings. Second, if the ownership share of family businesses was higher, corporate credit ratings were higher. This result means that high ownership share in family businesses has very positive effects on the credit ratings of related businesses. It is meaningful that this study tested the effect that family businesses can alleviate agency problems and reduce information asymmetry. Furthermore, it is also academically meaningful that this study can contribute to future studies on the role of ownership structure.

• International Journal of Computer Science & Network Security
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• v.22 no.8
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• pp.7-14
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• 2022

This study aimed to test the factor structure of the measure of student participation in distance education. The study population consisted of all teachers in public education and faculty members in higher education in the Kingdom of Saudi Arabia by applying it to a sample of bachelor's and graduate students at the college of Education at umm al-Qura University. The (ESE) was applied to a random sample representing the study population consisting of (216) respondents. The results of the study showed that the scale consists of three main factors, with showed a high degree of construct validity through fit indices of the confirmatory factor analysis. The results have shown a gradual consistency of the measure's invariance that reaches the high level of the Measurement Invariance across the gender and study groups variables.

• Journal of Microbiology and Biotechnology
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• v.33 no.6
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• pp.707-714
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• 2023

Plant-derived insecticide-neonicotinoid insecticides (NIs) played a crucial role in the development of agriculture and food industry in recent years. Nevertheless, synthesis of these nitrogen-containing heterocyclic compounds with an effective and greener routing remains challenging especially to the notion raise of "green chemistry" and "atom economy". While bio-catalyzed methods mediated by nicotinate dehydrogenase (NDHase) then provide an alternative. The current review mainly focuses on the introduction of sources, components, structure, catalytic mechanism and applications of NDHase. Specifically, NDHase is known as nicotinic acid hydroxylase and the sources principally derived from phylum Proteobacteria. In addition, NDHase requires the participation of the electron respiratory chain system on the cell membrane. And the most important components of the electron respiratory chain are hydrogen carrier, which is mainly composed of iron-sulfur proteins (Fe-S), flavin dehydrogenase (FAD), molybdenum binding protein and cytochromes. Heterologous expression studies were hampered by the plasmid and host with high efficiency and currently only Pseudomonas entomophila L48 as well as Comamonas testosterone was successfully utilized for the expression of NDHase. Furthermore, it is speculated that the conjugate and inductive effects of the substituent group at position 3 of the substrate pyridine ring exerts a critical role in the hydroxylation reactions at position 6 concerning about the substrate molecular recognition mechanism. Finally, applications of NDHase are addressed in terms of pesticide industry and wastewater treatment. On conclusion, this critical review would not only deepen our understanding of the theory about NDHase, but also provides the guideline for future investigation of NDHase.

• Convergence Security Journal
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• v.22 no.1
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• pp.39-54
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• 2022

Recently, the importance of collecting, analyzing, and real-time sharing of various cybersecurity data has emerged in order to effectively respond to intelligent and advanced cyber threats. To cope with this situation, Korea is making efforts to expand its cybersecurity data sharing system, but many private companies are unable to participate in the cybersecurity data sharing system due to a lack of budget and professionals to collect cybersecurity data. In order to solve such problems, this paper analyzes the research and development trends of existing domestic and foreign cyber security data sharing systems, and based on that, propose a cybersecurity data sharing system model with a hierarchical structure that considers the size of the organization and a step-by-step security policy that can be applied to the model. In the case of applying the model proposed in this paper, it is expected that various private companies can expand their participation in cybersecurity data sharing systems and use them to prepare a response system to respond quickly to intelligent security threats.

• Smart Structures and Systems
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• v.33 no.5
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• pp.365-374
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• 2024

This paper adopts a new approach in which nonlinear vibrations can be controlled using fuzzy controllers by optimal grey evolutionary algorithm. If the fuzzy controller cannot stabilize the systems, then the high frequency is injected into the system to assist the controller, and the system is asymptotically stabilized by adjusting the parameters. This paper uses the GM (grey model) and the neural network prediction model. The structure of the neural network is improved from a single factor, and multiple data inputs are extended to various factors and numerous data inputs. The improved model expands the applicable range of uncontrolled elements and improves the accuracy of controlled prediction, using the model that has been trained and stabilized by multiple learning. The simulation results show that the improved gray neural network model has higher prediction accuracy and reliability than the traditional GM model, improving controlled management and pre-control ability. In the combined prediction, the time series parameters and the predicted values obtained from the GM (1,1) (Grey Model of first order and one variable) are simultaneously used as the input terms of the neural network, considering the influence of the non-equal spacing of the data, which makes the results of the combined gray neural network model more rationalized. By adjusting the model structure and system parameters to simulate and analyze the controlled elements, the corresponding risk change trend graphs and prediction numerical calculation results are obtained, which also realize the effective prediction of controlled elements. According to the controlled warning principle and objective, the fuzzy evaluation method establishes the corresponding early warning response method. The goals of this paper are towards access to adequate, safe and affordable housing and basic services, promotion of inclusive and sustainable urbanization and participation, implementation of sustainable and disaster-resilient buildings, sustainable human settlement planning and manage.

• Journal of the Korean Home Economics Association
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• v.44 no.11
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• pp.117-131
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• 2006

The purpose of this study was to verify a Structural Equation Model that constructed the causations among the structural leisure constraints, interpersonal leisure constraints, intrapersonal leisure constraints, leisure motivation, leisure activity participation, leisure satisfaction and the quality of life from the ecological perspective. The respondents were 301 elderly people residing in 4 free institutionalized elderly homes in Seoul. The data were analyzed by confirmatory factor analysis and covariance structure analysis using USREL 8.0 ver. The major results are summarized as follows: 1) Statistically, a goodness of fit is good of structural equation model presented in the study. 2) The structural leisure constraints and the interpersonal leisure constraints are some types of leisure environment of the aged in public homes from the ecological perspective. Such constraints would inevitably lead to a direct effect on individual leisure life and leisure motivation. 3) The important valuable factor which affected the leisure satisfaction and the quality of life in the elderly was the leisure motivation.

• The Journal of the Korea Contents Association
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• v.14 no.4
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• pp.148-159
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• 2014

The purpose of this study was to comparatively analyze local educational autonomy(LEA) between Korea and the U.S. and investigate the new directions that Korea can follow. To do so, a comparative analysis was employed to study the background, development process, principles and structural elements of the respective LEAs. The conclusions drawn from the study were as follows: First, the structure of the Korean LEA should be selected and established. Second, the LEA principles should be discussed again and decided anew to accomplish the goals of the LEA by mobilizing all local potential resources. Third, 'control by people,' one of essential LEA principles, should be expanded to include the participation of the people.