• KSII Transactions on Internet and Information Systems (TIIS)
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• v.8 no.3
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• pp.945-964
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• 2014

In this paper, we investigate the performance of Signal to Leakage and Noise Radio (SLNR) based user scheduling in uplink of multi-cell with large-scale antenna system. Large antenna array is desired to improve the performance in future system by providing better beamforming capability. However, some studies have found that the signal channel is 'hardened' (becomes invariant) when the antenna number goes extremely large, which implies that the signal channel aware user scheduling may have no gain at all. With the mathematic tool of order statistics, we analyzed the signal and interference terms of SLNR in a homogeneous multicell network. The derived distribution function of signal and interference shows that the leakage channel's variance is much more influential than the signal channel's variance in large-scale antenna regime. So even though the signal channel is hardened, the SLNR-based scheduling can achieve remarkable multiuser diversity (MUD) gain due to the fluctuation of the uplink leakage channel. By providing the final SINR distribution, we verify that the SLNR-based scheduling can leverage MUD in a better way than the signal channel based scheduling. The Monte Carlo simulations show that the throughput gain of SLNR-based scheduling over signal channel based scheduling is significant.

• Journal of The Korean Association of Information Education
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• v.16 no.4
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• pp.483-488
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• 2012

As propagation of mobile smart devices is widespread, it is an observable trend that the cases of utilizing them are increasing in the school programs, and it is also anticipated that they will be very important part of the educational equipment in near future. For this reason the department of education and science technology has announced a medium and long term project on the education with smart device, which is undergoing the preparation stage, and the various academic and industrial institutes have actively produced the related research results and the application prototypes. In this paper we propose a framework on design and implementation of a visual context recognition system for educational purpose usable in the school program by utilizing a module for recognition of the texts embedded in the image captured by video camera from mobile smart device. The system proposed in this paper is consisted of the four modules, such as, image acquisition, image processing, information extraction, and knowledge representation, which are explained in details with the practical examples.

• Advances in nano research
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• v.8 no.1
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• pp.83-94
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• 2020

An analytical formulation and solution process for the buckling analysis of porous magneto-electro-elastic functionally graded (MEE-FG) beam via different thermal loadings and various boundary conditions is suggested in this paper. Magneto electro mechanical coupling properties of FGM beam are taken to vary via the thickness direction of beam. The rule of power-law is changed to consider inclusion of porosity according to even and uneven distribution. Pores possibly occur inside FGMs due the result of technical problems that lead to creation of micro-voids in these materials. Change in pores along the thickness direction stimulates the mechanical and physical properties. Four-variable tangential-exponential refined theory is employed to derive the governing equations and boundary conditions of porous FGM beam under magneto-electrical field via Hamilton's principle. An analytical model procedure is adopted to achieve the non-dimensional buckling load of porous FG beam exposed to magneto-electrical field with various boundary conditions. In order to evaluate the influence of thermal loadings, material graduation exponent, coefficient of porosity, porosity distribution, magnetic potential, electric voltage and boundary conditions on the critical buckling temperature of the beam made of magneto electro elastic FG materials with porosities a parametric study is presented. It is concluded that these parameters play remarkable roles on the buckling behavior of porous MEE-FG beam. The results for simpler states are proved for exactness with known data in the literature. The proposed numerical results can serve as benchmarks for future analyses of MEE-FG beam with porosity phases.

• The Journal of Korean Association of Computer Education
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• v.6 no.3
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• pp.173-183
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• 2003

E-learning education methodology using the web has been as much activated with the introduction of the internet to our society. As for the web-based education, there is no exception in case of mathematics. However, when it comes to representing math equations by using HTML image tags, a type of web marked-up language, it can be hard to represent math equations that have structural features, and to do the search, resulting in the difficulty in reusing math related applications. Therefore, based on MathML and using ActiveX control technology, a math equation generating website was designed and implemented in this study. Since this system employed ActiveX control technology, it is possible to generate math equations without the limit of time and place on the web, and to manage the program with the most up-to-dale version. And in this system, it is also possible to save the math equations generated in this system to be referred to for their reuse in the future.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.4
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• pp.309-315
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• 2018

Currently, the commercialization of the $5^{th}$ Generation (5G) service is becoming more prevalent in domestic communication network technology. This has reduced communication delay time and enabled large-capacity data transmission and video streaming services in real-time. In order to keep pace with these developments, K-water has introduced a smart process control system in water purification plants to monitor the status of the water purification process. However, since wireless networks are based on the public Long Term Evolution (LTE) network, communication delay time remains high, and high-resolution video services are limited. This is because communication networks still have a closed structure due to expense and security issues. Therefore, with 5G in its current form, it is very difficult to accommodate future services without improving the infrastructure of its communication networks. In recognition of these problems, this study implemented the authentication and management function of wireless networks on a wired network management system in the K-water Bansong water purification plant. The results confirmed that wired Local Area Network (LAN) services give a higher security performance than an expensive commercial wireless LAN system. This was achieved by using an Internet Protocol (IP) address management system of wired networks and the packet filtering function of the Layer2 (L2) switch. This study also confirmed that it is possible to create a wireless LAN service that is 3.7 times faster than the existing LTE communication network.

• Journal of the Korean earth science society
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• v.35 no.5
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• pp.375-384
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• 2014

The number of students choosing science, technology, engineering, and mathematics (STEM) related careers are declining. Thus it became a worldwide challenge in the $21^{st}$ century. As public images of the engineers are unfavorable and inaccurate, misconceptions and stereotypes about engineers are prevailing. The purpose of this study was to investigate elementary school students' perceived mental and pictorial images of engineers and the nature of engineering work. This study involved 512 fifth and sixth grade students (Boys: 287 and Girls: 225) from four elementary schools at one of metropolitans in South Korea. The Draw An Engineer-Korean version (DAE-K) was developed based on Draw an Engineer (DAE) and Draw a Scientist (DAS), and Song and Kim (1999)'s instruments. A pilot-tested was conducted with 33 elementary students prior to the main study. The students were asked to answer how they think the engineers would be, to draw an engineer at work, and to write the engineer's personal information and the job description. Engineers were perceived as a person fixing, building, manufacturing, working outdoors in labors' clothes such as a robe. Engineers were shown with building tools, robots, airplanes, machines, conveyor belt, etc. Moreover, compared to the scientists, engineers were perceived as less intelligent, less imaginative, and less accurate. The results of this study revealed that elementary school students had a lack of accurate images of engineers. Students' current perceived images of engineers could help educators find the baselines for the future engineering education in elementary schools. In addition, the findings of this study could also contribute to the development of engineering education in terms of gender issues, STEM career choice, and even cultural diversity.

• Journal of Digital Convergence
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• v.19 no.6
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• pp.29-38
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• 2021

The social studies, mathematics, and science textbooks of the elementary curriculum will begin to be authorized from 2022. This study explores the effect of textbooks based on a gamification motivation strategy on learner interest. For this purpose, this study analyzes whether the systematic application of the gamification motivation strategy to elementary studies textbooks, which will be authorized from 2022, can develop this textbook into a "learner-centered curriculum book that induces interest." More specifically, this study applied Kumsung Publishing's experimental social studies textbooks in class and conducted a questionnaire among 121 third graders to verify the effectiveness of the textbooks. The results show that studies textbooks based on a gamification motivation strategy greatly influence increased learner interest in the classroom. The textbooks also represent a positive influence in learner understanding, interest, and curiosity regarding the class content and assistance. Demonstrating that gamification motivation strategy is worthwhile to actively apply in future textbook development for the enhancement of learners' interests, this study is significant in that it has presented a meaningful textbook development model.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.367-370
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• 2012

Background: Breast cancer is the most commonly diagnosed cancer in women worldwide In Iran, it ranks first among cancers diagnosed in women and is the fifth most common cause of death. The aim of this study was to present the mortality trends from breast cancer for Iranian women during a period of almost a decade, in order to provide update information regarding the likely future. Methods: We analyzed National death Statistic reported by the Iranian Ministry of Health and Medical Education from 1995 to 2004 to generate annual mortality rates/100,000, overall, by age group (<15, 15-49 and ${\geq}50$ years of age) and age standardized rate (ASR). Results: The age standardized mortality rate of breast cancer increased dramatically during these years from 1.40 to 3.52 per 100,000 and its mortality was increasing 151.4% for Iranian women, although it seemed that the rate leveled off from 2002 to 2004. Moreover the increasing rate was higher for those aged between 15-49 compared to age >50 years old. Conclusion: There is an increasing trend for breast cancer mortality in Iran. Thus, health education programs to rectify the lack of women awareness about breast cancer signs and effective screening are urgently needed.

• Journal of the Korea Convergence Society
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• v.10 no.2
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• pp.75-81
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• 2019

The purpose of this study was to perform a convergence study for the investigation of the trend of research topics related to thyroid cancer in Korea. We collected related research papers from DBpia and employed LDA-based topic model. In result, we identified four research topics, each of which concerns "Surgery", "Disease aggressiveness", "Survival analysis", and "Well-being of patients". With multinomial logistic regression, we found significant time trend, where "Surgery"-related topic was popular before 2000, topics regarding "Disease aggressiveness" and "Survival analysis" were frequently addressed in the 2000s, and "Survival analysis" and especially "Well-being of patients" have been pursued since 2010. The findings would serve as a reference guide for research directions. Future work may examine whether the recent change in research topics is observed in other diseases.

• YAKHAK HOEJI
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• v.51 no.1
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• pp.13-34
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• 2007

Traditional Medicine (TM) is called as philosophical medicine in Korea. An unified theory named as Sihnsang-hanron (SSHR) was hypothesized through studies of scientific analyses on various theories of TM. SSHR has extracted seven concepts which are six common ones from the great three books (三大原典) and the Logic of Laotzu & Chuangtzu (老莊思想). Six common concepts are the affecting by cold (傷寒), qi (氣), cold or heat (寒熱), exterior & interior of body (表裏), deficiency or excessiveness (虛實), and yin & yang (陰陽). We have tried to apply these seven concepts to Physics and Life Science. The affecting by cold means anti-sunlight and the origin of all diseases. The difference between TM and modern medical science would be in diagnostic methods as well as their theoretical analyses for various diseases. The modern science follows Haeckel's positive dialectics applied by the biological monism, and oriental one(SSHR) does Yin-Yang monism from the studies of Logic of Laotzu (老子) & Chuangtzu (莊子). SSHR would make the theory of exterior & interior of body (表裏論) and six channels (六經) develope scientifically as a diagnostic technique of disease. This theory is an excellent one that can't be found out in modern medical science, and so it should be developed as a scientific theory by using modern mechanic instrument. Chuangtzu asserted that ai was the basic substance of the universe. It is hypothesized that qi (氣) is like small particles -higgs, with dynamic power in modern Physics. We consider cautiously qi could be calculated by mathematics through higgs' bosons in near future.