• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.1-10
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• 2021

The interest in underwater acoustic sensor networks (UWASNs), along with the rapid development of underwater industries, has increased. To operate UWASNs efficiently, it is important to adopt well-designed medium access control (MAC) protocols that prevent collisions and allow the sharing of resources between nodes efficiently. On the other hand, underwater channels suffer from a narrow bandwidth, long propagation delay, and low data rate, so existing terrestrial node pairing schemes for non orthogonal multiple access (NOMA) cannot be applied directly to underwater environments. Therefore, a multi-dimensional node pairing scheme is proposed to consider the unique underwater channel in UWASNs. Conventional NOMA schemes have considered the channel quality only in node pairing. Unlike previous schemes, the proposed scheme considers the channel gain and many other features, such as node fairness, traffic load, and the age of data packets to find the best node-pair. In addition, the sender employs a list of candidates for node-pairs rather than path loss to reduce the computational complexity. The simulation results showed that the proposed scheme outperforms the conventional scheme by considering the fairness factor with 23.8% increases in throughput, 28% decreases in latency, and 5.7% improvements in fairness at best.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.6
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• pp.147-154
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• 2021

Recently, it has been observed that as the level of Science and Technology in Korea is improving, the demand for technology transfer from overseas buyers is also increasing. A technical value is an important factor for the technology transfer process and the valuation of technology should be performed reasonably. Specifically, a non-economical value has to be examined thoroughly when conducting the valuation for a technology that depends on public values. Since public technology has public benefit as its purpose when compared to technology from the private sector, its discount rate should be appropriately assessed and reflected in its valuation process. In this context, this study presents the methodology of valuation of public technology particularly relating to the transfer of technology from the national defense industries. To be specific, both an application method of the discount rate according to the characteristics and the purpose of the target technology and a qualitative and quantitative evaluation method to reflect the public values are presented. The proposed method for the valuation of defense technology could be used practically both in strengthening bargaining capability based on the reasonably derived technical values for transfer of national defense technology abroad and in the compilation of budgets for technology development in the future.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.2
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• pp.102-116
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• 2021

For the safe operation of autonomous vehicles, the representative technology of the 4^th industrial revolution era, a combination of various technologies such as sensor technology, software technology and car technology is required. An autonomous vehicle is a vehicle that recognizes current location and situation by using the various sensors, and makes its own decisions without depending on the driver. Perfect recognition technology is required for fully autonomous driving. Since the precise road maps provide various road information including lanes, stop lines, traffic lights and crosswalks, it is possible to minimize the cognitive errors that occur in autonomous vehicles by using the precise road maps with location information of the road facilities. In this study, the definition, necessity and technical trends of the precise road map have been analyzed, and the HD(High Definition) map prototype based on the web GIS has been built in the autonomous driving-specialized areas of Daegu Metropolitan City(Suseong Medical District, about 24km), the Happy City of Sejong Special Self-Governing City(about 33km), and the FMTC(Future Mobility Technical Center) PG(Proving Ground) of Seoul National University Siheung Campus using the MMS(Mobile Mapping System) surveying results given by the National Geographic Information Institute. In future research, the built-in precise road map service will be installed in the autonomous vehicles and control systems to verify the real-time locations and its location correction algorithm.

• Journal of The Korean Association of Information Education
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• v.25 no.3
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• pp.557-569
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• 2021

In preparation for the future society, the educational curriculum is changing according to the trend of the times, and with the advent of the era of the 4th Industrial Revolution, the purpose of the new 2015 revised curriculum was suggested to foster the convergence creativity of students. The purpose of software education is to promote creativity and further develop problem-solving skills in connection with real life. In addition, flow in learning leads to outstanding educational achievement. However, in elementary school computer education, there is still a lack of development of a convergence class model for students to easily immerse themselves and promote creative problem-solving skills. Therefore, in this study, we designed convergence computer education using Novel Engineering, which is a convergence class model suitable for these educational conditions and applied it to classes. Further, to measure the effect on the improvement of learning flow and creative problem-solving ability. the Novel Engineering-based computer class was applied to the experimental group for 6th graders, and the general computer class was applied to the control group. As a result of the pre-post test between groups, it was found that computer classes using Novel Engineering had a positive effect on learning flow and creative problem-solving ability.

• Journal of the Korean GEO-environmental Society
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• v.12 no.7
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• pp.67-76
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• 2011

In this present study, to evaluate a behavior characteristics of the sea dyke coastal covering stone by sea waves. sea waves act on coastal structures as an impact load. During impact loading, erosion and bluff slumping occur in the coastal structures. Also, the covering stone are worn down by wave impact. The sea dyke has been used near coastal region for protection of infra-structure since 1970s in Korea. The sea dyke consist of dredged sand and covering stone mainly. The damage type of covering stone has been reported since 1970s. However, the interaction of impact load by sea wave with the covering stone has not been investigated yet properly. Mainly damage type of covering stone is an abrasion. But the study of covering stone abrasion is not sufficient. Hence, In this study, it was analyzed the interaction of impact load by sea wave and the covering stone during sea wave action on coastal structures. In order to analyze the behavior characteristics of coastal covering stone considering the magnitude and period of impact loading and to evaluate the displacement increment of covering stone during impact load, numerical analysis was carried out considering impact loading by sea wave.

• Journal of Korean Society of Forest Science
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• v.100 no.4
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• pp.708-714
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• 2011

Wood store carbon that the forest absorbed until burned or decomposed over a long period. Such materials are most used in houses except in paper and pulp, and the use of wood in houses play an important role in reducing green-house gases. Therefore, we estimated the amount of carbon stocks in Korean houses, and analyzed how much contribution such stocks offers to green-house gas reduction. As the result, the carbon stocks amount of the wood products in Korean houses was 28.4 million $tCO_2$, which is 4.6% of the total annual green-house gas emission in Korea (620 million $tCO_2$ e), and 77.4% of forest sinks (LULUCF). Even though few wooden houses which use most wood in housing exist in Korea, the carbon stocks of wood products in houses in 2010 increased to 4.1 times that in 1975 (21.4 million $tCO_2$) because the carbon stocks increased due to apartment construction, which hit its stride from the last 1980's.

• Food Science and Industry
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• v.53 no.1
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• pp.33-42
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• 2020

In accordance with the recent trend of environmentally friendly agricultural policy, product registration of agricultural chitosan among the organic materials has been displayed in various forms such as soil improving agent, crop growth, and pest control. Chitin production industry is expected to bring competitiveness by producing low-quality and low-cost chitin for agriculture, rather than high-quality and high-cost for food, medical products. Since there are various soil microorganisms that can decompose chitin and chitosan in farm soil where crops are produced, it can be applied usefully to agricultural sites suitably for crop growth and pest control using chitin and chitosan as substrates. The purpose of this study is to compare and analyze the registration status of organic materials companies using chitin and chitosan raw materials in the organic materials information system of the NAQS, and to provide an opportunity to further expand the agricultural use of domestic chitin and chitosan.

• The Journal of Korean Philosophical History
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• no.59
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• pp.65-88
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• 2018

Lee Hang Ro's Mind-theory(心說) is an important theory comparable to it of Gi Jeong Jin, Lee Jin Sang and Jeon Woo. In this paper, I examined the influence of the Western-school(西學) in the process of formation of Lee's theory. Since the Western-school had flowed in the beginning of the 17th century, in the 18th century it was subject to Confucian intellectuals along with social stability. However, listed in the 19th century, along with the turmoil of the East Asian international order, the Western-school was also rejected. The Western-school was a tool to analyze the cause of Western invasion(西勢東漸) in him. Lee saw The Western-school from the standpoint of Christianity mainly. Especially Christianity was recognized as a religion that emphasizes God rather than humans. In contrast, Confucianism was understood as a thought system that emphasizes human moral subjectivity rather than God. In this process mind was expanded to the subjectivity of human. However, Lee only emphasized the traditional Confucianism order and ignored the rationality of the Western-school. He could not accommodate western civilization actively and properly respond to the world order in that time. On the other hand, we are now in the era of a new civilization called the Fourth Industrial Revolution. To this the remarks of Lee's Mind-theory will be an important suggestion point for organizing the new civilization actively.

• International Area Studies Review
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• v.21 no.1
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• pp.221-243
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• 2017

In this study, I examine overall conditions and problems of personal asset management processes by the old age people in Korea from the global perspectives. Major recommended policy implications for those are as follows.. First, the IRR (income replacement ratio) of public pensions in Korea is found to rank nearly the lowest among the OECD member countries. The relatively low fund performance compared to that of developed countries as well as this low IRR can be pointed out as major problems of public pension in Korea. It is recommended to reinforce specialty in fund management as a top priority to solve out these problems related with public pensions in Korea. Second, it is needed to set retirement pensions to be mandatory for almost all the firms in Korea to substitute for the above lower IRR of public pensions and to recover from the highest elderly poverty ratio among the OECD countries. Third, it is required to discuss about the expansion of tax refund policy application in the individual pension sector and many financial investment products under the correction of current budget control to motivate voluntary subscription for individual pension planning and to stabilize elderly lives of ordinary people in Korea. Fourth, it is required to induce market mechanism in controling price and longevity risk of reverse mortgages for the long-run sustainability.

• 한국노년학
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• v.32 no.3
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• pp.819-834
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• 2012

The purpose of this study was to examine the degree of successful aging and to investigate influencing factors of it in elderly to types of gender. Subjects were 73 male elderly and 77 female elderly, total 150 elderly living at K city in C province, from May to June, 2012. The data were analyzed using the SPSS Win 18.0 program for $X^2$ test, t-test, Pearson's correlation coefficients and multiple regression analysis. The correlated factors of successful aging among male elders included life satisfaction(r=.525, p<.001), family support(r=.355, p=.004), depression(r=-.555, p<.001) and loneliness(r=-.437, p<.001). Those of successful aging among female elders included life satisfaction(r=.607, p<.001), leisure satisfaction(r=.679, p<.001), family support(r=.784, p<.001), depression(r=-.516, p<.001), loneliness(r=-.644, p<.001) and self-transcendence(r=.576, p<.001). Life satisfaction and depression were statistically significant influencing factors of successful aging in male elders. Especially in the cases of female elders, life satisfaction, depression, family support and self-transcendence affected to successful aging. Life satisfaction, depression, family support, and self-transcendence were explained 52.9% in perception of successful aging among elders. This study suggests that life satisfaction, depression, family support, and self-transcendence will be considered in enhancing the successful aging promoting care and welfare designed for types of gender.