• Coupled systems mechanics
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• v.7 no.1
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• pp.27-42
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• 2018

Behavior of soil is usually described with continuum type of failure models such as Mohr-Coulomb or Drucker-Prager model. The main advantage of these models is in a relatively simple and efficient way of predicting the main tendencies and overall behavior of soil in failure analysis of interest for engineering practice. However, the main shortcoming of these models is that they are not able to capture post-peak behavior of soil nor the corresponding failure modes under extreme loading. In this paper we will significantly improve on this state-of-the-art. In particular, we propose the use of a discrete beam lattice model to provide a sharp prediction of inelastic response and failure mechanisms in coupled soil-foundation systems. In the discrete beam lattice model used in this paper, soil is meshed with one-dimensional Timoshenko beam finite elements with embedded strong discontinuities in axial and transverse direction capable of representing crack propagation in mode I and mode II. Mode I relates to crack opening, and mode II relates to crack sliding. To take into account material heterogeneities, we determine fracture limits for each Timoshenko beam with Gaussian random distribution. We compare the results obtained using the discrete beam lattice model against those obtained using the modified three-surface elasto-plastic cap model.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.1
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• pp.23-33
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• 2020

With growing expectations for economic cooperation between the two Koreas, there is much interest in participating in the construction of infrastructure in North Korea. In particular, water and sewage infrastructure is the four major social infrastructures in addition to housing, transportation, electricity and telecommunications. North Korea is known to have severe water pollution and ecosystem destruction in major rivers, water pollution and soil pollution in mining areas are serious, and water and sewage infrastructures in cities other than Pyongyang are known to be weak. Preemptive investment in water supply and drainage in North Korea is the foundation for securing the quality of life of the North Korean and is the foundation of public health and industry. It is a leading investment to reduce the cost of unification and is a new growth engine for the water reloded industry. In this study, we proposed a plan to exchange and cooperate in water environment for building water infrastructure of North Korea by examining the data related to water quality, water resources, water disaster, related legal system and human resources exchange situations in North Korea.

• Journal of Engineering Education Research
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• v.21 no.2
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• pp.51-59
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• 2018

The author investigated the momentum of the maker movement and its educational implications with the following four research questions: 1. What is the maker movement? 2. What is the nature of our societal interest in the maker movement? 3. Which learning theories are associated with the maker movement? 4. What are the educational implications of the maker movement? The author reviewed the history of education in terms of the maker movement and concluded that Papert's learning-by-making approach provided a theoretical foundation of the maker movement. The maker movement aims to engage participants in Do-It-Yourself(DIY) activities, the spirit of tinkering, and a hands-on approach. Also, the maker movement meets the educational demands of fostering students' 21st-century abilities and technological literacy. Lastly, the author anticipated the issues that may arise following the introduction of the maker movement in K-12 schools. In conclusion, the author discussed the challenges of the school maker education movement and suggested the bottom-up approach to utilize the school resources of technology and engineering education.

• Journal of Environmental Health Sciences
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• v.47 no.1
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• pp.55-63
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• 2021

Objectives: Cefotaxime is an antibiotic used to treat several bacterial infections. Specifically, it is used to treat pelvic inflammatory disease, meningitis, pneumonia, urinary tract infections, and sepsis. It is given by injection into either a vein or muscle. Antibacterial polymers prepared by chemical bonding and simple blending of antibacterials into polymers has attracted much interest because of their long-lasting antibacterial activity. This study attempted to review the possibility of hydrogel films as functional antibacterial materials by antimicrobial activity. Methods: In this study, CTX-PAA was synthesized by the chemical reaction of polyacrylic acid with cefotaxime by N,N'-Dicyclohexylcarbodiimide (DCC) method. Synthetic antibacterial hydrogel films were then prepared with PVA and CTX-PAA for functional application. Results: The increase in the cefotaxime content of the hydrogel films showed a similar decrease in tensile strength and elongation. The values of films impregnated with chemically bonded cefotaxime showed no significant difference. Antibacterial susceptibility was determined against Streptococcus pneumoniae and Escherichia coli using a standardized disc test. Conclusion: The synthetic antibacterial hydrogel films exhibited broad susceptibility against Streptococcus pneumoniae and Escherichia coli. Notably, the antibacterial effect of antibacterial hydrogel films against Grampositive (Streptococcus pneumoniae) was superior to that against Gram-negative (Escherichia coli).

• Journal of the Korean Geotechnical Society
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• v.23 no.5
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• pp.63-75
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• 2007

Piled raft is known to be an unfavorable foundation type in soft clay because foundation is associated with both excessive settlement and bearing capacity failure problems. Despite these reasons, in recent decades, an increasing number of structures have been constructed over soft clay area, piled raft concepts arouse interest as the foundation of structures on soft clay area becomes popular. This study described 3 dimensional behavior of piled raft on soft clay based on a numerical study using 3D finite element method. A series of numerical analyses were performed for a various pile lengths and the pile configurations on the raft were subjected to vertical uniform or point loading. Based on the results of the parametric study, comparisons were made among the effect of loading type, various pile length and configurations, and the load-settlement behavior and load sharing characteristics of piled raft were also evaluated. From the results, the characteristic of piled raft on soft clay was examined.

• Korean journal of communication and information
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• v.36
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• pp.109-132
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• 2006

It is difficult to found the concept of public interest properly, being ambiguous to distinguish media and service as to the convergence of broadcasting and telecommunications. Accordingly, it is necessary to found the concept of public interest not related to the character of media and service in the age of digital convergence. Therefore this study intended to re-found the concept of public interest, as to industrial changes in the age of convergence of broadcasting and telecommunications. The convergence of broadcasting and telecommunications causes the changes of value chain, which includes contents, platform, network, terminal. It could not help avoiding modifying the industrial structure of broadcasting and telecommunications, because of the changes of value chain. The changes of industrial structure needs the changes of ideology, regulatory policy, regulatory system, and it creates the foundation of new regulatory idea. The purpose of regulatory idea in the age of digital convergence is to practice public interest, and it is an ultimate purpose to increase consumers' welfare. Consequently, for increasing comsumer' welfare, it is necessary to achieve diversity, fairness, objectivity, the preservation of social value in the aspect of contents. Also in the aspect of platform, it is necessary to achieve the protection of privacy, consumer protection, harmful information blocking, and in the aspect of network, it is necessary to achieve the maintenance of secure network, fair competition. Finally, in the aspect of terminal, it is necessary to achieve the maintenance of compatibility, the solution for digital divide. Then regulatory policy of each value chain from a legal and institutional perspective, should be promoted to provide public interest, step by step.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2250-2255
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• 2011

There has been a growing interest toward railroad conjunction with opening of high-speed rail in 2004 and concurrent implementation of nation's green growth policies. Meanwhile, users' expectation on service of public transportation, especially railroad has been growing than since ever due to heightened quality of life, entering aging society, voice of equity for minorities, and greater interest in environments of communities. In order to come up with the expectations, actual improvements for user's convenience/comfort and its assessment strategies in terms of service quality level are necessary. This study defines the index of this aspect of service level as 'Sensitivity Quality'. This is conceived as one of the important factors to define travel cost as do the travel time and fare, but hardly taken into consideration when assessing a transportation system or policy-making for a transportation project. The elements included for the assessment of the sensitivity quality in this study are feeling of a ride, conformability and convenience what users feel and recognize using a train. This paper suggests that establishing sensitivity quality elements would contribute in foundation of assessing service quality and provide improved public transportation services through their scientific and objective development and management.

• Journal of Korea Multimedia Society
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• v.21 no.8
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• pp.876-887
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• 2018

In this paper, we propose an robust CAMShift method to track stage objects with a camera. In order to solve the problem of tracking object misdetection in existing CAMShift technique, MBR region is detected to separate the background and the subject, and the subject size of the region of interest is calculated to solve the problem of erroneously detecting a large region having a similar color distribution ratio. Also, by applying the color corelogram and MB-LBP to the part that can not be solved by the color ratio and the size limitation, accurate texture tracking is enabled by reflecting the texture characteristics. Experimental results show that the proposed method has good tracking performance for objects that do not deviate from the size of the subject set in the area of interest and accurately extracts the texture characteristics of different subjects with similar color distribution ratios.

• Management & Information Systems Review
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• v.25
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• pp.339-370
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• 2008

As the Internet environment develops, Internet has already been being established as important tool of business marketing and branding. In particular, a brand community where customers interact with other customers who have the same interest in brand provides a variety of benefits to customers as well as companies. The brand community makes it possible for company to build, and retain relationships with customers, and capture new market opportunities. Therefore, this study examines the relationship among service quality of brand community, customer value, customer satisfaction, customer trust, and brand community loyalty in online brand communities. The results of empirical analysis can be summarized by the following: First, service quality of brand community had a significant direct effect on customer value. Second, service quality of brand community had a significant direct effect on customer satisfaction. It had also a positive, significant indirect effect on customer satisfaction through customer value and customer trust. Third, service quality of brand community had a significant indirect effect on brand community loyalty through customer satisfaction, customer value, and customer trust. Therefore, These finding will spawn both academic and practitioner interest in brand community and serve as a foundation for further research in this important area.

• Journal of the Korea Furniture Society
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• v.28 no.3
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• pp.185-197
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• 2017

With the advent of industrial society, the phenomenon of nuclear families has brought many changes in the family environment. Of changes, a decrease in the number of new-born babies led to one-child families, which then led to an increase in interest in children. Interest in children gave birth to a consumptive trend called "kids marketing," and phenomena of generous investment and consumption for children appear to continue to the future. In reality, too, the consumer market of children's apparel and learning materials for children has sharply increased over the past few years, and products related to children have become the center of family consumptions. Therefore, at this point when children are the center of consumptive life in the family and the relationship between products and users is becoming an increasingly more important variable, the conductive research focusing on children is necessary. These important factors embraced wide areas of activities in research on children, from children's physical changes, children's preference, such as color and material, to children's consumptive environment, as they can provide a foundation for furniture design suitable for children.