• Journal of Korean Tunnelling and Underground Space Association
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• v.23 no.5
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• pp.339-357
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• 2021

As the construction of trans infrastructure using the underground tunnel have been rapidly increased, various nearby excavation of existed underground facility including subway structure has been occurred in urban tunnelling. The concern and worry relating to the safety and stability of the existed facility by nearby excavation is becoming the key issues in urban tunnelling. In this study, it was conducted for existed the subway station structure at Seoul subway line which was closely located in the new Dongbuk urban metro railway to determine the behavior characteristics of station structure according to adjacent tunnel construction. Also, it was reviewed the evaluation of the safety zone and excavation method for subway structure. And after a review of damage evaluation, track irregularities and structural calculation by using a numerical analysis, stability of the subway structure according to nearby tunnel excavation was evaluated to be secured. This study is expected to be applied as useful reference in advance if you need to review the effects of existed structure according to nearby construction in complex urban tunnelling.

• Membrane Journal
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• v.30 no.6
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• pp.395-408
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• 2020

Polymer electrolyte membrane fuel cells (PEMFCs) have gained much attention as eco-friendly energy conversion devices without emission of environmental pollutant. Polymer electrolyte membrane (PEM) that can transfer proton from anode to cathode and also prevent fuel cross-over has been regarded as a key component of PEMFCs. Although perfluorinated polymer membranes such as Nafion® were already commercialized in PEMFCs, their high cost and toxic byproduct generated by degradation have still limited the wide spread of PEMFCs. To overcome these issues, development of hydrocarbon based PEMs have been studied. Incorporation of cross-linked structure into the hydrocarbon based PEM system has been reported to fabricate the PEMs showing both high proton conductivity and outstanding physicochemical stability. This study focused on the various cross-linking strategies to the preparation of cross-linked PEMs based on hydrocarbon polymers with ion conducting groups for application in PEMFCs.

• Applied Chemistry for Engineering
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• v.22 no.5
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• pp.551-554
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• 2011

One of the key issues in the research of organic field-effect transistors (OFETs) is the low-voltage operation. To address this issue, we synthesized poly(styrene-r-benzocyclobutene-r-methyl methacrylate) (P(S-r-BCB-r-MMA)) as a thermally cross-linkable gate dielectrics. The P(S-r-BCB-r-MMA) showed high quality dielectric properties due to the negligible volume change during the cross-linking. The pentacene FETs based on the 34 nm-thick P(S-r-BCB-r-MMA) gate dielectrics operate below 5 V. The P(S-r-BCB-r-MMA) gate dielectrics yielded high device performance, i.e. a field-effect mobility of $0.25cm^2/Vs$, a threshold voltage of -2 V, an sub-threshold slope of 400 mV/decade, and an on/off current ratio of ${\sim}10^5$. The thermally cross-linkable P(S-r-BCB-r-MMA) will provide an attractive candidate for solution-processable gate dielectrics for low-voltage OFETs.

• The Journal of Korean Philosophical History
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• no.30
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• pp.259-282
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• 2010

Ethical value of Confucianism seeks to realize the ideal of life to the reality, through ethical life. It is discussed based on myself, which is the main ethical agent, in relationship with the others. These traditional values include universality in the homogeneous aspect such as humanism that has been commonly sought by the human race, or awe toward the absolute one. 'Pursuit of universality in the Korean context' ultimately seeks 'Korean ethics', that prevailed in Korea, based on the Korean traditional culture. Therefore, we should comprehensively understand this universality and diversity, so called 'us'. Through the understanding, we should play an active role of culture creators as noble persons that realize fraternity, along with respect to each culture. Studies on traditional ethics will not only be an important opportunity to look at the history and current status of ethics, but also it will be a cornerstone to understand the Korean mind-set based on the Korean culture. Recently, establishing Korean identity and recovery of ethics damaged due to anomie of value are key social issues. Studies on traditional value are not separated from this issue. If our adolescents are able to correctly understand the traditional ethics and pursue a life recreating it, they will be able to enjoy healthier life, contributing to a healthier society.

• The Journal of Korean Philosophical History
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• no.31
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• pp.113-141
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• 2011

Everyone knows the importance of environmental education, which is essentially required especially today. In particular, the education could influence greatly students who have to get in their class and they might build their own thought on the basic concept regarding environment and ecosystem through their elementary school period. But the current elementary education has not the independent subject of 'environment' but only refers to other courses some dealing with it, leading to the highly possible failure of achieving comprehensive and concrete approaches toward environmental education. In that sense, it will be meaningful that based on existing academic discussions and approaches about various environmental issues facing our society, we seek desirable directions for environmental education at primary school for sustainable development that is needed in this era and its possible applications. The concept of sustainable development that puts an importance on the harmony between the development of environment and its preservation should be rather the one which helps to satisfy desires of the future and now generation together and also emphasizes that environmental protection should be primarily considered even in the situation in which economic development could be seen necessary. Therefore, the key to environmental education for sustainable development lies in building the attitude respecting 'life and nature' and such value will be accomplished through education.

• (The)Study of the Eastern Classic
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• no.34
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• pp.311-338
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• 2009

The moral corruption or the reality of absence of humanity derived from the development of science and society is very serious. Especially the moral education which should provide new breakthroughs facing such issue will be the initial concern in the educational world and the key point that judges our future. This study, as a part of efforts made for such demands of the times, is an attempt to approach the field of the present elementary education specifically by deducing the abundant meaning that the Confucianism's Chungseojidoh(忠恕之道: the principle of "Faithfulness" and "Benevolence") stands for. To build an ethical social community also means to draw voluntary moral practices into this society and this is possible with our (the moral subject) struggling the problems within but not remaining in the limitations of physical norms. Chungseojidoh as universal ethics contains a virtue ethical meaning as Jenlogy, a meaning of identity recognition and self-esteem inspiration, a meaning of social community ethics as ethics of good offices, etc. Such meanings, in particular, can be discussed more profoundly in terms of educational prevention from violence or cliquish issues in school that are largely related to education of humanity if 'applying schemes for elementary education' is seen as the center of the issue. And furthermore, they will be able to open a discussion over problems of the situation which the Korean society is in - especially the insistence, egoism or conflicts between social communities - can be answered in actuality.

• (The)Study of the Eastern Classic
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• no.66
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• pp.163-191
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• 2017

In the Book 1 starting with the narrative, metaphor, prediction, implication and paradox shows the relationship and its significance of Lee Hye-ran and Ho Hong-mae. Especially, these techniques show the key and topic of this work of 'jealousy' and its conflicting 'unjealousy' being materialized and its background are being provided, and they play narrative roles of showing in advance the numerous incidents that occur within the relationship between the main characters. Especially, jealousy and unjealousy are shown through the two main female characters: the unjealousy is connected to with Lee Hye-ran to show the extreme womanhood to lead the narrative. Meanwhile, the jealousy that occurs from the affection and obsession towards one person, it disables Ho Hong-mae from having rational judgment, and maleficence from the jealousy cannot be stopped. Eventually, in the process of finishing the narrative, the jealousy is regarded as the issue of the family, and the cause of the jealousy is emphasized the man not being faithful to the family. Therefore, the solutions to the issues occurred from the jealousy are shown explicitly that it is in the proper management of the family by the man. Therefore, the narrative of is progressed while jealousy and unjealousy conflict, and in the process of repenting the character that shows the perfect womanhood realized in the fiction world and the most radical jealousy through such womanhood, this novel can be regarded as showing the ethical lesson.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.17 no.2
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• pp.125-137
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• 2007

This paper proposes a new scheme to provide the location privacy of sources in Wireless Sensor Networks (WSNs). Because the geographical location of a source sensor reveals contextual information on an 'event' in WSN, anonymizing the source location is an important issue. Despite abundant research efforts, however, about data confidentiality and authentication in WSN, privacy issues have not been researched well so far. Moreover, many schemes providing the anonymity of communication parties in Internet and Ad-hoc networks are not appropriate for WSN environments where sensors are very resource limited and messages are forwarded in a hop-by-hop manner through wireless channel. In this paper, we first categorize the type of eavesdroppers for WSN as Global Eavesdropper and Compromising Eavesdropper. Then we propose a novel scheme which provides the anonymity of a source according to the types of eavesdroppers. Furthermore, we analyze the degree of anonymity of WSN using the entropy-based modeling method. As a result, we show that the proposed scheme improves the degree of anonymity compared to a method without any provision of anonymity and also show that the transmission range plays a key role to hide the location of source sensors.

• Communications of Mathematical Education
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• v.35 no.2
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• pp.137-152
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• 2021

Qualitative research has become a growing area of interest among the Korean educational researchers for the last two decades. As a consequence, the number of studies based on qualitative methods has rapidly increased while the quality of qualitative research has not gained much credit among scholars in Korea. This study explores to current practice of qualitative approaches in mathematics education-related studies. With this in mind, this study also seeks ways to improve the validity and trustworthiness of qualitative approaches, and to present implications for the practical practice of qualitative approaches in mathematics education. To this end, a general trend was investigated by conducting a basic analysis of 13 papers that used qualitative approaches and published in Communications of Mathematical Education from 2019 to 2020. Of the 13 papers. Through the basic analysis, 6 out of 13 papers were selected as the object of qualitative text analysis. The result of this qualitative text analysis discusses issues related to the validity and trustworthiness of qualitative research in a detailed manner. In conclusion, based on the results of this qualitative text analysis, this study suggests several key points to keep in mind when applying qualitative approaches in the field of mathematics education in the future.

• Knowledge Management Research
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• v.22 no.1
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• pp.243-267
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• 2021

Sentiment represents one's own state through the process of change to stimulus, and emotion represents a simple psychological state felt for a certain phenomenon. These two terms tend to be used interchangeably, but their meaning and usage are different. In this study, we try to find out how it affects the helpfulness of reviews by classifying sentiment and emotion through online reviews written by online consumers after purchasing and using various products and services. Recently, online reviews have become a very important factor for businesses and consumers. Helpful reviews play a key role in the decision-making process of potential customers and can be assessed through review helpfulness. The helpfulness of reviews is becoming increasingly important in practice as it is utilized in marketing strategies in business as well as in purchasing decision-making issues of consumers. And academically, the importance of research to find the factors influencing the helpfulness of reviews is growing. In this study, Yelp.com secured reviews on restaurants and conducted a study on how the sentiment and emotion of online reviews affect the helpfulness of reviews. Based on the prior research, a research model including sentiment and emotions for online reviews was built, and text mining analyzes how the sentiment and emotion of online reviews affect the helpfulness of online reviews, and the difference in the effects on emotions It was verified. The results showed that negative sentiment and emotion had a greater effect on review helpfulness, which was consistent with the negative bias theory.