• 보존과학연구
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• s.32
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• pp.5-24
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• 2011

Neunghwaji(Embossed patterned paper) is a unique paper used for a traditional book cover in Korea. The research was carried out to investigate Neunghwaji's features. Physical property was studied through a test of tensile strength and folding endurance. Also, comparative analysis of virus resistance and waterproof ability was undertaken on Neunghwaji. 1. Folding endurance test showed that strength of non-embossed CB and HB decreased during deteriorating duration. Embossed CN and HN showed the strength increasing at early stage and decreasing from the 27th day of the deteriorating duration. Tensile strength was decreasing in both cases as deterioration progressed. 2. Growth of Arthrinium sp. fungus on embossed paper was 10% less than plain paper while Cladosporium sp. showed 20~30% less growth. Amur cork dyeing(H) showed 10~30% lower fungi growth than Gardenia seed dyeing(C). The result indicated that embossed paper has better virus resistance than Hanji, and Amur cork dyeing has better virus resistance than Gardenia seed dyeing. 3. Average contact angle of CN, CB, HN, and HB was $85{\sim}92^{\circ}$ and NON-N and NON-B was $59{\sim}63^{\circ}$. In detail, CN's contact angle was $1{\sim}7^{\circ}$ higher than CB's; HN was $1{\sim}6^{\circ}$ higher than HB. Therefore, it was found that embossed paper has higher contact angle than Hanji thus the former has better waterproof ability. The research suggested production technique of Neunghwaji and studied its features related to the technique. Neunghwaji was confirmed to have superior quality to Hanji though further study regarding above test result is needed to complement the research.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.3 no.2 s.5
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• pp.1-8
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• 2004

Characteristics of digital broadcasting are multi-channel, high-definition and multi-function. especially, multi-function is enable us to do a variety of services except for an image and a voice. This paper, therefore, is analyzed propagation environment in Busan into ETRI model application about 지상파 DMB service. It takes to be simulated in Busan area around the mountains area and high building. So it measures the electric field strength in standards. Distribution pattern are similar with mutually in the 이론 and real measurement. Even areas are almost the same, but urban areas and mountains are different with mutually. Therefore, we conclude that ETRI propagation model and theoretical modeling in a free space in Busan area is not suitable.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.26 no.11
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• pp.951-959
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• 2015

Ground radiation antenna in mobile devices is becoming an issue for satisfying both miniaturization and high performance. Ground radiation antenna controls the characteristic mode of the ground plane and couples this mode with the ground radiation antenna, thereby having good radiation performance. In this paper, the characteristic mode theory and applications of ground radiation antenna will be introduced. The operating mechanism of single band, wideband and dual-band ground radiation antennas are studied.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.213-213
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• 2004

최근 작업장에서 용접을 위해 로봇을 도입하는 사례가 많다. 단순한 장소뿐만 아니라 선체 블록 내와 같은 제약된 장소에서도 로봇을 많이 사용한다. 그렇기 때문에 로봇의 다양화와 고기능화가 더욱더 요구되고 있다. 로봇의 용접을 위한 위빙 궤적은 용접 품질과 생산성에 큰 영향을 주기 때문에 중요하다. 그러나 로봇을 도입하여 열악한 작업 환경에서 유연한 동작을 적용하기에는 말은 시행착오와 비용이 소요된다. 그래서 용접 로봇의 도입 이전 단계에서 위빙 궤적이 작업 환경에 맞게 로봇에 적용되는지 확인하는 것이 필요하다.(중략)

• Proceedings of the Korean Information Science Society Conference
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• 2004.04a
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• pp.463-465
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• 2004

베디드 시스템의 발전으로 인하여 고성능화, 소형화, 편의성 등이 강조되어 지는 시점에서 의료장비 또한 임베디드 시스템 기술 도입이 빠르게 진행되어 지고 있다. 본 논문에서는 초음파 영상진단 단말기 (Magic-Probe)를 구현하기 위해 SA-1100 마이크로 프로세스 레퍼런스 보드에 리눅스 커널을 포팅하고 포팅된 플랫폼을 기반으로 초음파 영상진단을 처리하기 위한 응용프로그램의 설계 및 구현에 관하여 논하도록 하겠다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.1
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• pp.43-49
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• 2015

In recent years, the amount of heat generated inside of the computer has more increased because of high performance, multi-function, miniaturization and light weight. It is necessary to control the effective heat generation to improve performance and life extension of the computer. In this study, thermoelectric cooling system was manufactured using thermoelectric module and was attached to computer in order to control the heat generated inside computer. And the temperature distributions inside computer were experimentally measured and compared with and without thermoelectric cooling system to investigate the effect of cooling system. Also, to estimate the new cooling system which can substitute for the existing computer cooling system, temperature distributions inside computer were calculated by numerical analysis when there was no cooling system and was applied only cooling system to computer.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.9
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• pp.5467-5473
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• 2014

This study examined the numerical analysis results with respect to the thermal behavior of a natural convection cooled pin-fin heat sink. The heat sink consisted of pin fins integrated with plate fins. The heat sinks were designed with two different types to fit the limited internal space. The two types of heat sinks designed were analyzed using the ANSYS software package, and the numerical analysis results were compared with the cooling performance of the two types of heat sinks. The results of the simulation were analyzed according to the temperature distribution and air flow characteristics, heat flux etc. This study examined the correlation of the cooling performance with the heat sink internal structure and fin shape. FEM (Finite Element Method) confirmed the cooling performance of heat sink type A under natural convection conditions as the best results. The results of the numerical simulation showed that the heat sink type A shape showed an approximately 70 percent better heat transfer rate with natural convection than that of type B.

• Journal of IKEEE
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• v.15 no.4
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• pp.324-329
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• 2011

In recent years, the performance and functions of portable devices has increased. so it requires more power efficiency and energy density while using the battery for a long time. therefore Battery pack which are made up from several battery cells in series in order to achieve higher operating voltage is being used. when using a Li-ion battery, we need a protection circuit to protect from overcharge, over discharge, high temperature and over current. Also, when using battery pack, we need to Cell voltage balancing circuit that each cell in tune with the balancing. In this paper, the proposed IC is applicable by mobile devices as well as E-bike, hybrid vehicles, electric vehicles, and is expected to contribute to the development of domestic PMIC.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.12 no.1
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• pp.17-24
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• 2008

This paper deals with a millimeter wave source which is utilizing sub-harmonic injection-synchronization technique. A 8.7GHz oscillator with MES-FET is fabricated, and is driven as a harmonic output oscillator at 17.4GHz by means of sub-harmonic injection-synchronization. The oscillator operates as a multiplier as well as oscillator in this system. Adopting this technique, we can obtain a high stable, high frequency millimeter wave source even though self-oscillating frequency of an oscillator is relatively low. In the experiments, the range of injection-synchronization is about 26MHz and is proportional to the input sub-harmonic power. From the spectrum analysis of the 2nd harmonic output. we blow that the phase noise of the harmonic oscillator is remarkably decreased.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.110-117
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• 2018

Recently, as weapon systems have become more complex and multi-functional, the difficulty of the operation and maintenance of weapon systems in the military have become increasingly difficult. On the other hand, the service period of operations and maintenance workers who perform operations and maintenance has been shortened, and the skill of system operation and maintenance has been lowered. This complexity and multi-functionality of equipment cause malfunctions and errors of users and maintenance personnel, and degradation of the reliability affects availability and combat readiness. In addition, life cycle costs have been gradually increasing. Therefore, I would like to suggest an improvement plan of the design of weapon systems and ILS (Integrated Logistics Support) in order to examine the implications of failure in the military. The weapon system is operated in the ROK Navy. Data from 730 cases of failure of weapon systems was collected, and analyzed. The results of the analysis are classified into failures that can be prevented in advance and failures that cannot be prevented. This shows the portion of preventable failures in weapon systems and proposes measures to minimize failures.