• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 추계학술대회논문집 I
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• pp.349-353
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• 2001

An air foil bearing is developed for the high speed generator. The bearing is type of multi-leaf and is stable on 60,000RPM. The vibration level is 12um(p-p) and the highest temperature level is below 100$^{\circ}C$. The dynamic parameter of air foil bearing is acquired by experimental method using exciter. The air foil bearing is also good condition at test of real generator and load condition. The condition of foil is very good after 3,000cycle start-stop test. Therefore the air foil bearing is ideal for high speed, light weight and modem turbo-machinery.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 2008년도 추계종합학술대회 B
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• pp.836-841
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• 2008

21세기를 들어서면서 본격적으로 차세대 IT패러다임으로 등장한 유비쿼터스(Ubiquitous) 분야는 정보기술의 패러다임이 PC와 인터넷 중심에서 유비쿼터스로 이동하면서 미래 유비쿼터스 시장을 선점하기 위한 세계 주요국가와 IT기업들이 치열한 전쟁터로 인식되고 있다. 본 연구에서는 유비쿼터스 디바이스에 관련된 국내외 기술 및 연구동향을 알아보고, 유비 쿼터스 사회의 진화에 따른 미래효과와 그에 따른 연구방향 등을 살펴보도록 한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 춘계학술대회논문집
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• pp.227-233
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• 2002

For the purpose of high outlet pressure, compactness and low vibration and noise, modem reciprocating air compressors are tend to have a multi-stage W-type or V-type cylinder arrangement. An effective counter weight calculation method is presented for reducing the inertia forces of the compressor. This calculation method is using the complex representation and verified its validity. A design program for the counter weight of W-type or V-type air compressor was presented to the manufacturer, A designed counter weight was attached to the W-type or V-type air compressor. Vibration test results gave us improved performance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 D
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• pp.2543-2545
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• 2002

There are many applicable services such as remote metering, load control, distribution line automation, Pole transformer Monitoring having their own networks in the electric power company. The application of the optical network technology as the back-born network to the Automation Systems in KEPCO is potentially beneficial in reliability, speed, and expandability. The 1-core and 2-core optical modems were developed and used by the Distribution Automation System. But, They had some disadvantages and advantages. So, We designed the new optical modems applied each advantages. This paper presents some of design efforts and test results for the multi-channel optical modem at KRPRI.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1455-1458
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• 2002

In this paper, we propose a modified CP-AFC(Cross-Product Automatic Frequency Control) algorithm to enhance coherent signal detection for WCDMA reverse link receiver. We introduce a moving average filter at the FDD(Frequency Difference Detector) input to increase the number of cross-products, since pilot symbol in WCDMA is not transmitted continuously. We also add normalization algorithm to overcome the conventional CP-FDD's sensitivity to the variance of input signal amplitude and to increase the linear range of S- curve. For rapid frequency acquisition and tracking, we adopt a multi-stage tracking mode. We applied the proposed algorithm in the implementation of WCDMA base station modem successfully.

• 한국군사과학기술학회지
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• 제13권3호
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• pp.388-396
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• 2010

Generally, flight information is transmitted by voice signal over legacy UHF radio in ground to air communication system. In this paper, we have implemented the transceiver of TDL(tactical data link) which transmits tactical information, such as flight information, using digital signal. For transmitting digital information over radio path, we have designed data modem that is processing CPFSK modulation, and TDMA(Time Division Multiple Access) network for Synchronization among multi user(platform). By simulating aeronautical propagation modeling with the environment of Korea terrain, it is predicted the maximum performance of communication range of the transceiver. As result of the transceiver's aviational boarding test, it is proved that the transceiver of TDL over legacy UHF radio transmits and receives the tactical information in TDMA network within communication range of 160km.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2002년도 춘계학술발표논문집 (하)
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• pp.1239-1242
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• 2002

In this paper, the implementation of MAI(multiple access interference)-cancelled SSMA(spread spectrum multiple access) system using orthogonal carriers was presented. Employing the pseudo periodic spreading codes and orthogonal carriers frequency offset, proposed system have the features no MAI during a certain local time-duration. Spreading signals designed by pseudo periodic method and repetition, have zero correlation duration(ZCD) by orthogonal frequency shift method. The SSMA modem has been designed and implemented using surface-acoustic-wave(SAW) device as the matched filter of receiver. The effects of frequency offset on stability have been evaluated using computer simulation.

• Nuclear Engineering and Technology
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• 제39권4호
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• pp.249-256
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• 2007

Light water reactors operated under supercritical pressure conditions have been selected as one of the promising future reactor concepts to be studied by the Generation IV International Forum. Whereas the steam cycle of such reactors can be derived from modem fossil fired power plants, the reactor itself, and in particular the reactor core, still need to be developed. Different core design concepts shall be described here to outline the strategy. A first option for near future applications is a pressurized water reactor with $380^{\circ}C$ core exit temperature, having a closed primary loop and achieving 2% pts. higher net efficiency and 24% higher specific turbine power than latest pressurized water reactors. More efficiency and turbine power can be gained from core exit temperatures around $500^{\circ}C$, which require a multi step heat up process in the core with intermediate coolant mixing, achieving up to 44% net efficiency. The paper summarizes different core and assembly design approaches which have been studied recently for such High Performance Light Water Reactors.

• 복식문화연구
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• 제15권5호
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• pp.796-809
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• 2007

The viewpoint of growth pursuit is changed to that of life quality's and happiness' pursuit by modern people. Modern people in digital environment, tired of fast-changing and oppressive daily life, prefer well-being trend providing tranquility and relaxation. Well-being is related to digital, because negative influences of digital lead human-oriented, environment-friendly well-being design. Therefore the purpose of this study is to research and analyze the relation of well-being fashion design and digital environment through case study in contemporary well-being fashion design. The results of this study are as follows: 1. This study shows that the attributes of digital environment make up function-intensive, interactivity, mobility & nomad, human & emotion-oriented and environment-friendly. And this study shows the design characteristics of digital environment consist of function-intensive design by digital convergence, open structure design for interactivity, modular design for mobility & nomad, emotion-oriented & multi-sensory design and environment- friendly design. 2. Function-intensive design in modem well-being fashion composed of vogue of caports style(casual+sports), practical use of multi-functional new-healthy textiles, and popularity of many style's mixture at once. Open structure design consist of wrapover design, use of transparent materials. Modular design are layered styling, practical use of zipper and velcro. Emotion-oriented & multi-sensory design are constitute of fad of wrinkle materials, application of bright & vivid tone, personal color and family look. Environment-friendly design in contemporary well-being fashion are comprised in use of natural color, re-advent of natural floral motif and eco-design.

• Journal of Advanced Marine Engineering and Technology
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• 제35권6호
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• pp.842-848
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• 2011

다중통신을 지원하는 하이브리드 통신 제어보드는 저전력의 8-bit 마이크로콘트롤러인 ATxmega128A1으로 설계하였으며, 마이크로콘트롤러는 다중통신을 위한 모뎀과 GPS 모듈 등을 시리얼 인터페이스 하기 위한 8개의 UART 포트가 갖추어져 있으며, 내부에 2K 바이트의 프로그램 매개변수와 프로그램이 동작하는데 필요한 데이터를 저장할 수 있는 EEPROM과 128K 바이트의 플래시 메모리 및 프로그램이 실행되는 8K 바이트의 SRAM으로 구성되어 있다. 항로표지의 원격 관리를 CDMA, TRS, RF 등 하이브리드 통신을 이용하면 개별 통신 방식별로 음영지역이 존재하는 경우에도, 최적의 통신방식을 선택하여 통신을 수행하게 됨으로써, 통신 음영지역의 해소가 가능하다. 또한 통신장치마다 동일한 데이터 프레임을 사용함으로써 데이터의 호환성을 높였다. 실험은 30일 동안 각 부표에서 매 5분마다 데이터를 취득하였으며, 데이터 수신율은 85 % 이상을 보였다.