• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2013년도 추계학술대회
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• pp.973-974
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• 2013

이 논문에서는 OFDMA PON에서의 일반적인 동적 캐리어 및 동적대역할당 방법의 특성을 분석한다. 또한 이러한 방법들을 하드웨어로 구현할 때의 문제점을 분석한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2001년도 ICCAS
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• pp.23.5-23
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• 2001

This paper is concerned with the vehicle platooning in the AHS (Automated Highway Systems). For this, a relative navigation system is developed for the vehicles operating as a platoon. The relative navigation system is based on two sensors including GPS and MMWR (Millimeter-Wave Radar) and the federated Kalman Iter processing measurements of them. The architecture of this system requires GPS measurements of a preceding vehicle via communication link. Even if GPS measurements are available, they contain errors which are unacceptably high in vehicle platooning. Therefore, GPS carrier phase is considered. Integer ambiguities of GPS carrier phase measurements are determined by using MMWR ...

• 적정기술학회지
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• 제7권1호
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• pp.26-32
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• 2021

콜드체인의 마지막 단계인 백신전달 과정에서 대부분 얼음을 넣은 단열컨테이너로 온도를 조절하며, 백신의 온도 조절이 적절하지 않아 낭비되는 백신의 양이 상당하다. 예방접종을 관리하고 운영하는데 온도 데이터가 중요하며, 본 연구에서는 실시간 백신전달 모니터링 시스템을 개발하였다. 휴대용 백신 냉장고의 온도, 위치 및 전력 소비 데이터를 수집하기 위해 문자(Short Message Service) 통신 방법을 사용하였고, 한국과 탄자니아(아루샤 및 킬리만자로 지역)에서 시스템을 테스트하였다. 개발된 백신 냉장고는 문자통신을 통해 데이터 손실없이 실시간으로 백신상태를 모니터링을 할 수 있었다. 백신의 상태 및 데이터는 클라우드 서버를 통해 웹 기반 유저 인터페이스에서 확인할 수 있었다.

• 한국기계가공학회지
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• 제14권1호
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• pp.92-97
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• 2015

The design of the glass-carrier was studied using simulations of the temperature distribution of an ITO deposition inline-sputter process. The temperature distribution was simulated in Heating Chamber 7, and in the ITO Deposition Chambers 8 and 9. The temperature distribution of the glass sheets was low in both the lower and upper lines. Moreover, it was observed that the temperature in Chamber 8 significantly affected the temperature in Chamber 9, and that the latter was hotter. The rear of the chambers were subjected to more heating than the fronts, so the temperature range at the back was wider. Redesigning the shape of the carrier made it possible to load more glass sheets on the glass carrier, and to make deposits on the ITO glass at higher temperature, over a wider area.

• Tribology and Lubricants
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• 제28권5호
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• pp.240-245
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• 2012

In this study, we developed a new carrier finger to prevent scratches in a sheet metal forming line. The developed carrier finger was designed to have a streamlined shape with a larger radius of curvature at the edges, as well as a smaller contact area. To evaluate the scratch alleviation effect, a sliding contact analysis and scratch test using the pin on a plate wear tester were conducted for both the old and new carrier fingers. The results show that, for both transverse and longitudinal movements of the strip, the newly designed carrier finger reduces both the friction and scratch depth by its streamlined shape, which decreases the pressure spike at the edge.

• Journal of Positioning, Navigation, and Timing
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• 제1권1호
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• pp.7-14
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• 2012

Due to inaccurate safe navigation estimates, maritime accidents have been occurring consistently. In order to solve this, the precise positioning technology using carrier phase information is used, but due to high buildings near inland waterways or inclination, satellite signals might become weak or blocked for some time. Under this weak signal environment for some time, the GPS raw measurements become less accurate so that it is difficult to search and maintain the integer ambiguity of carrier phase. In this paper, a method to generate code and carrier phase measurements under this environment and maintain resilient navigation is proposed. In the weak signal environment, the position of the receiver is estimated using an inertial sensor, and with this information, the distance between the satellite and the receiver is calculated to generate code measurements using IGS product and model. And, the carrier phase measurements are generated based on the statistics for generating fractional phase. In order to verify the performance of the proposed method, the proposed method was compared for a fixed blocked time. It was confirmed that in case of a weak or blocked satellite signals for 1 to 5 minutes, the proposed method showed more improved results than the inertial navigation only, maintaining stable positioning accuracy within 1 m.

• 한국기계가공학회지
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• 제15권4호
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• pp.67-72
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• 2016

Planetary gear sets are widely used in power transmission components, which have high efficiency and good durability. Their most important design parameter is the load-sharing characteristics among several planetary gears. In this study, the load sharing of planetary gears was analyzed according to the carrier pinhole position error of planetary gear sets. The loads acting on planetary gears varied with the pinhole position error of the carrier, and the load sharing of planetary gears improved as the input load increased. In addition, the load of the planetary gear with a carrier pinhole position error was relatively higher than that of other planetary gears without carrier pinhole position errors. This trend appeared more clearly in the non-floating-type carrier than the floating-type carrier.

• 한국지하수토양환경학회지:지하수토양환경
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• 제18권1호
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• pp.46-56
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• 2013

Laboratory scale experiments to remove benzene in solution by using the bio-carrier composed of dead biomass have been performed. The immobilized bio-carrier with dead Bacillus drentensis sp. and polysulfone was manufactured as the biosorbent. Batch sorption experiments were performed with bio-carriers having various quantities of biomass and then, their removal efficiencies and uptake capacities were calculated. From results of batch experiments, 98.0% of the initial benzene (1 mg/L) in 1 liter of solution was removed by using 40 g of immobilized bio-carrier containing 5% biomass within 1 hour and the biosorption reaction reached in equilibrium within 2 hours. Benzene removal efficiency slightly increased (99.0 to $99.4%{\pm}0.05$) as the temperature increased from 15 to $35^{\circ}C$, suggesting that the temperature rarely affects on the removal efficiency of the bio-carrier. The removal efficiency changed under the different initial benzene concentration in solution and benzene removal efficiency of the bio-carrier increased with the increase of the initial benzene concentration (0.001 to 10 mg/L). More than 99.0% of benzene was removed from solution when the initial benzene concentration ranged from 1 to 10 mg/L. From results of fitting process for batch experimental data to Langmuir and Freundlich isotherms, the removal isotherms of benzene were more well fitted to Freundlich model ($r^2$=0.9242) rather than Langmuir model ($r^2$=0.7453). From the column experiment, the benzene removal efficiency maintained over 99.0% until 420 pore volumes of benzene solution (initial benzene concentration: 1 mg/L) were injected in the column packed with bio-carriers, investigating that the immobilized carrier containing Bacillus drentensis sp. and polysulfone is the outstanding biosorbent to remove benzene in solution.

• 한국전자파학회논문지
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• 제19권11호
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• pp.1281-1286
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• 2008

본 논문에서는 6-단자 위상 상관기를 적용한 PSK 반송파 신호 복원 회로를 해석하고 구조를 제안한다. 하나의 전력 분배기와 3개의 hybrid branch line coupler로 구성되는 6-단자 위상 상관기와 변조 신호에 대응하는 반사소자를 갖는 제안된 반송파 신호 복원 회로 구조는 간단하면서 구현이 용이하다. 이 위상편이 방식(BPSK) 신호와 직교 위상편이 방식(QPSK) 신호의 코히어런트 반송파 신호를 복원하며, 기본 구조를 사용하여 고차 모드 PSK 반송파 신호 복원 회로 구조가 가능하다. 모의 실험 결과, 직교 위상편이 방식 신호의 반송파 신호는 일정한 위상값($23.4^{\circ}$)을 갖는 지속파와 반사 소자 스위칭에 의해 발생되는 위상 편차가 ${\pm}0.8^{\circ}$ 이내인 양호한 PSK 반송파 신호 특성을 나타내었다.

• 한국항공운항학회지
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• 제30권3호
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• pp.92-108
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• 2022

This study aims to intensively analyze the effect of ESG activities on the Business performance focused on Korean national flag carrier. The purpose of this study is to provide ESG activities to promote the sustainable development of Korean national flag carriers by verifying the impact of ESG on airline's business performance through mediate variables within the airline industry in consideration of the value and importance of ESG. A survey is conducted with a total of 272 users of Korea's national flag carrier both Korean air and Asiana airline. The collected data is analyzed using a structural equation model. The results show that ESG management has an indirect positive effect on business performance. It is expected that the results of this study may be employed as fundamental data to emphasize the relative importance of an ESG activities, thereby enhancing the Korean national flag carrier's business management and eliciting a positive impact on sustainable growth.