• The KIPS Transactions:PartA
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• v.13A no.4 s.101
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• pp.295-304
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• 2006

Java has been established as one of the most widely-used languages owing to its support of object-oriented concepts, safety, and flexibility. Garbage collection in the Java virtual machine is a core component that relieves application programmers of difficulties related to memory management. In this paper, we propose a memory manager and a garbage collector that is implemented on a embedded java virtual machine. The memory manager divide a heap into various-sized cells and manages it as blocks of same-sized cells. So it is possible to allocate and free memory fast. We adopted the 3-color based Mark & Sweep garbage collector as our base algorithm and we propose 4-color based Mark & Sweep garbage collector for supporting multi-threaded program. The proposed garbage collector occurs memory fragmentation but we show through a experiment that the fragmentation ratio is almost fixed according as we create objects continuously.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.13 no.1
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• pp.1-7
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• 2020

Directivity control technology of sound system is a key technology for improving sound quality. Providing a line source rather than a point source in an acoustic system can reduce the effects of attenuation interference at long distances, thereby providing high quality sound. In particular, A line-array speaker system can be used to provide coherent, high-quality sound over long distances. However, high frequencies have shorter wavelengths, so the distance between the speakers of a line array system must be shorter, but there are physical limitations. In this paper, we designed a wave guide and installed it in the speaker's compression driver to solve this problem. We measured and tested various acoustic characteristics to verify the performance of the speaker. As a result, when the line array sound system is constructed using the developed speakers, it is possible to provide a line source in all areas including the treble range, thereby achieving the same effect as a single extended source and providing high quality sound up to far distances.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.10 no.6
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• pp.512-521
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• 2017

Telemetry ground station use very high gain directional antenna systems that are sensitive to interference from other RF communication systems, Without appropriate interference protection, these systems could be severely impacted or even rendered useless for mission support. In ECC, we suggested ans interference analysis method between LTE-TDD system and telemetry ground station using 2.3GHz. In this paper, based on the interference analysis scenario considered in Electronic Communication Committee, We have derived mutual coexistence separation distance between telemetry ground station and LTE-TDD system(Base station, User equipment) in Spatial domain.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.05a
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• pp.572-573
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• 2010

This paper performed the basic study for fabricating the low level laser therapy apparatus, and one of the goals of this paper was to make this apparatus used handily. The equipment was fabricated using the 655nm laser diode and microcontroller unit and designed to enable us to control light irradiation time, and reservation.. In case of cell proliferation experiment, each experiment was performed to irradiation group and non-irradiation group for bome marrow cell. MTT assay method was chosen to verify the cell increase of two groups and the effect of irradiation on cell proliferation was examined by measuring.

• The Mathematical Education
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• v.50 no.2
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• pp.247-261
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• 2011

In this study, the researchers developed an inventory which can measure the affective achievement in mathematical learning especially targeted to Korean students. By using EFA and CFA, the six affective factors of mathematical learning such as learning directivity, self control, anxiety, interest, cognizing value and confidence are distinguished. Also, the content validity of this inventory was examined by the experts groups, composed of mathematics education professors, high school mathematics teachers, and measurement experts. The reliability of the instrument was high enough to trust the results. Through a large scaled sampling, the reliability and validity of this inventory were verified. In addition, this inventory was developed not by a partial aspects of a certain theory but based on the recent theories. Due to these reasons, the results of this study can be respected that it plays a leading part in understanding the affective achievement of Korean students.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.11 no.11
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• pp.4515-4521
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• 2010

A Yagi antenna, which is a typical directional antenna, has been designed and fabricated as a surveillance sensor. The proposed Yagi antenna satisfies the requirements as a surveillance sensor; impedance bandwidth of 7.2-8.2GHz, maximum gain of 7dBi, and 3dB beamwidth of $60^{\circ}$ in the azimuthal plane. The proposed Yagi antenna is designed with 3 directors and one driven element on a dielectric substrate. Also, a microstrip-to-CPS balun is designed and applied to the proposed antenna for balanced feeding of the dirven element. The performance of the proposed antenna has been verified by comparing the simulation and measurement results.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.5
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• pp.2870-2881
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• 2014

In this study, I empirically analyzed the factors affecting export performance with domestic ICT companies. I set up 3 variables - companies' factors, marketing factors and factors of export supporting system - as the factors affecting export performance, based on findings of precedent studies; and I set up non-financial performance as a dependent variable. As a result of analysis, I found out that companies' factors(market orientation of CEO, competitiveness in export, experience of export) and marketing factors(diversification of overseas market, barriers to marketing), among the variables affecting export performance, were the variables affecting non-financial performance, set up as the export performance; but the factors of awareness, availability and difficulty, set up as the detail factor among factors of export supporting system, do not affect non-financial performance.

• Journal of Korea Multimedia Society
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• v.16 no.3
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• pp.399-409
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• 2013

The development of IT has led to increase the business's dependence on IT and the interests of enterprises on IT governance. Also, more enterprises have adopted managed services to save operating costs in IT departments and to maximize their business efficiency. However, until recently, there are very few academic as well as practical researches regarding managed services, IT service effectiveness, IT governance and their interrelations. This study analyzes the effects of managed services on IT governance based on the IT-BSC (Balanced Scorecard) model. Using the expert FGI (Focus Group Interview) and survey, the research results present that managed services have the most significant effect on the user-oriented and the operational efficiency in enterprises. Also, managed services through the business process standardization can improve the IT governance more effectively. This study will be a relevant guideline for enterprises that will adopt managed services.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.1
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• pp.7-13
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• 2007

In this paper, we have designed and fabricated a small size wide-band monopole antenna which can integrate the frequency of previous business mobile communication system by adding 4 PCS of post type parasitic element on top-loaded sleeve monopole antenna. We have observed the properties of return loss upon a parameter change of element, and we also examined radiation properties in the band of PCS, W-CDMA, WiBro, W-LAN and S-DMB in order to make sure the suggested antenna's wide-band properties. We have found that the proposed antenna has omni-direction in horizontal plane and figure eight-direction in vertical plane, and we could have good return loss($Return\;loss{\leq}-10\;dB$) and $1.14{\sim}3.66\;dBi$ gain in $1.67{\sim}3.55\;GHz$ of frequency range($B/W{\fallingdotsep}72%$).

• Korean Journal of Comparative Education
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• v.27 no.3
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• pp.1-22
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• 2017

This study aims to examine the continuity of national education between prewar and postwar Japan in the context of nationalism and citizenship education by considering the direction and process of educational reform which has been a turning point in Japanese education policy. It explores the limitations of educational reform at the normative level and institutional and procedural level. Meiji Japan needed to form a united group to support modernization while also cultivating obedient people who supported the emperor, and the modern education system played a major role in achieving this task. After Japan's defeat in World War II, the nation sought to change the framework of authoritarian nationalism inherent in Japanese traditional through educational reforms and achieve the goals of democratization and non-militarization. The postwar educational reform has transformed the educational structure, but democracy and peace orientation have not been rooted internally. Under the backdrop of the Cold War, the education returned to the inverse.