• 한국건설관리학회논문집
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• 제13권2호
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• pp.110-119
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• 2012

초고층 건축물의 수요가 늘어나면서 수직 양중 계획과 장비에 대한 중요성이 증대되고 있으며, 경제적이고 효율적인 리프트 사용을 위하여 무인 리프트의 사용 비중이 늘어나고 있다. 하지만 리프트의 정지위치 에러가 발생하거나 누적되는 경우 작업 효율성이 떨어지고, 문제 해결을 위해 리프트 업체가 리프트를 재 세팅 하는 동안 리프트 사용이 불가하게 되어 공사 진행에 장애가 된다. 본 연구에서는 리프트 정지위치 에러에 의한 시간 및 비용 손실을 방지하기 위해 리프트 정지위치 감지장치를 개발하였다. 실험을 통해, 정지위치 에러 발생 시 이를 보정하는 기능을 검증하였고, 정확도도 약 9.75mm 증가하는 것을 확인하였다.

• International Journal of Contents
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• 제11권3호
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• pp.34-38
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• 2015

A band stop filter is proposed with cascading unit cells that are based on a dual composite right/left-handed (D-CRLH) conductorbacked coplanar waveguide. The parameters of the unit cell have been analyzed to confirm the behavior of each component for the equivalent circuit of the cell. We simulated the dispersion characteristics and energy distribution and have determined that the unit cell has a D-CRLH property. The band stop filter was implemented by symmetrically cascading two of the proposed unit cells. The experimental results for the band stop filter revealed a band rejection performance of 32 dB and a return loss of 0.35 dB in the stopband frequency range from 869MHz to 954MHz. Finally, we show that there is a good agreement in the experimental results and those obtained through the simulations.

• 한국에너지공학회:학술대회논문집
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• 한국에너지공학회 2000년도 추계 학술발표회 논문집
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• pp.127-137
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• 2000

Accelerator Driven System (ADS) named HYPER(Hybrid Power Extraction Reactor) is being developed for the transmutation of nuclear waste in Korea Atomic Energy Research Institute(KAERI). The concept of the HYPER is using 1GeV proton to drive a subcritical core. HYPER system is believed to have much more stable dynamics than the critical system in terms of neutronics. However, the HYPER system is supposed to have some drawbacks for the cooling system accidents. Loss of Flow(LOF) and Loss of Heat Sink (LOHS) cause a strong damage. As results, those accidents would stop the power production in the critical system. On the other hand, the negative reactivity feedback could not stop the HYPER system because the HYPER is driven by an accelerator rather than reactivity.(omitted)

• 한국전기전자재료학회논문지
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• 제25권4호
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• pp.253-260
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• 2012

IGBT (insulated gate bipolar transistor) have received wide attention because of their high current conduction and good switching characteristics. To reduce the power loss of IGBT, the on state voltage drop should be lowered and the switching time should be shorted. However, there is Trade-off between the breakdown voltage and the on state voltage drop. To achieving good electrical characteristics, field stop IGBT (FS IGBT) is proposed. In this paper, 1,200 V planar gate non punch-through IGBT (planar gate NPT IGBT), planar gate FS IGBT and trench gate FS IGBT is designed and optimized. The simulation results are compared with each three structures. In results, we optain optimal design parameters and confirm excellence of trench gate FS IGBT. Experimental result by using medici, shows 40% improvement of on state voltage drop.

• 한국인터넷방송통신학회논문지
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• 제14권1호
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• pp.7-13
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• 2014

본 논문에서는 위성통신 시스템에 사용 가능한 새로운 구조의 도파관 저역통과 여파기를 제안하였다. 제안된 저역통과 여파기는 고차모드의 간섭이 없는 광대역 특성과 저지대역에서의 충분한 감쇠 그리고 도파관의 소형화와 경량화를 위하여 evanescent-mode 리지 구조를 사용하여 설계 하였고, 도파관 내에 리지를 둘러싸는 직사각형 링을 삽입하여 반사손실과 격리도를 향상시켰다. 또한 매칭을 위해 여파기의 입출력 포트 단은 임피던스 스텝 구조를 사용하여 설계하였다. 제작된 저역통과 여파기는 통과 대역 주파수인 7.25 ~ 8.4 GHz에서 반사손실이 19.5 dB이상, 삽입손실은 1.41 dB이하로 측정 되었으며 억제 대역 주파수인 12.25 ~ 14.5 GHz에서의 격리도는 67.2 dB이상을 만족하였다.

• 한국공간구조학회논문집
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• 제16권4호
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• pp.59-66
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• 2016

Recently damage of structures and loss of life by terrorism are internationally increasing. Among these terror that have a possibility to can happen in korea and that can caused lot of human life loss is the vehicle terror. To prevent the vehicle terror, the anti-ram barriers are needed. But domestic standard about anti-ram barriers are not clear. So, in this study, we will utilize and analyze the vehicle impact to evaluate the efficiency of the domestic bollard and suggest the installation standard of those. In Korea, granite, elastic, steel and stainless bollard are used. The performance of those bollard is not available. Elastic bollard couldn't stop the vehicle, and the others just could stop the vehicle only at the speed under 10kph. Therefore, set the variable to reinforce, and evaluate the defence efficiency of bollard. As a result, granite and elastic bollard was not suitable for the anti-ram barriers. Performance of steel bollard increased as thickness grew. So steel bollard should must be thicker than 10T. And the concrete compressive strength effected insignificantly on the defence efficiency, so more than 24MPa compressive concrete be used. Performance of stainless bollard increased as thickness grew. So stainless bollard should must be thicker than 13T.

• 마이크로전자및패키징학회지
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• 제15권1호
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• pp.39-44
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• 2008

In this paper, fully embedded 2.4GHz WLAN band pass filter (BPF) was investigated into a multi-layered organic packaging substrate using high Q spiral stacked inductors and high Dk MIM capacitors for low cost RF System on Package (SOP) applications. The proposed 2.4GHz WLAN BPF was designed by modifying chebyshev second order filter circuit topology. It was comprised of two parallel LC resonators for obtaining two transmission zeros. It was designed by using 2D circuit and 3D EM simulators for finding out optimal geometries and verifying their applicability. It exhibited an insertion loss of max -1.7dB and return loss of min -l7dB. The two transmission zeros were observed at 1.85 and 6.7GHz, respectively. In the low frequency band of $1.8GHz{\sim}1.9GHz$, the stop band suppression of min -23dB was achieved. In the high frequency band of $4.1GHz{\sim}5.4GHz$, the stop band suppression of min -l8dB was obtained. It was the first embedded and the smallest one of the filters formed into the organic packaging substrate. It has a size of $2.2{\times}1.8{\times}0.77mm^3$.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2005년도 종합학술발표회 논문집 Vol.15 No.1
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• pp.7-12
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• 2005

A compact microstrip band-selective filter for ultra-wideband (UWB) radio system is proposed. The filter combines the traditional short-circuited stub highpass filter and coupled resonator bandstop filter on both sides of the mitered 50-ohm microstrip line. To realize the pseudo-highpass filtering characteristic over UWB frequency band (3.1 GHz to 10.6 GHz), a distributed highpass filter scheme is adopted. Three coupled resonators are utilized to obtain the band stop function at the desired frequency band. By meandering the coupled resonators, there is 29% reduction in footprint compared to the traditional bandstop filter using L-shaped resonators. The measured results show that the filter has a wide passband of 146.7 % (2.1 GHz to 10.15 GHz) with low insertion loss and the stop band of 7.42 % (5.32 GHz to 5.73 GHz) for 3-dB bandwidth. The measured group delay is less than 0.7 ns within the passband except the rejection band.

• 한국안전학회지
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• 제27권5호
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• pp.16-21
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• 2012

The purpose of this study is to try to find the risk of roller(mixing mill) in working site. In order to achieve the purpose, accident analysis and survey was carried out. This analysis revealed that average of loss days is 334.3 by roller jamming accident and 229.2 by other causes. It means jamming accident entails serious bodily harm. According to our research, we realize that most of rollers have some risk of the jamming accidents. It is simply because the roll gap in the roller is not more than 10cm. It also does not meet minimum distance so as to avoid the risk for jamming accident by KS. Furthermore, 28% of rollers have only one switch and 40% of rollers have two switches operating emergence stop equipment so as to reduce the risk of jamming accidents. Therefore, we presume that it is very difficult to turn on the switch of emergence stop equipment when they confront the accident because most of engineers are working alone.

• 한국산학기술학회논문지
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• 제13권12호
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• pp.6022-6026
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• 2012

본 논문은 마이크로스트립 전송선로에 삽입된 주파수 선택 표면(FSSs)을 사용하여 주기적인 구조를 갖는 대역저지필터(BSF)에 관한 것이다. 제안된 대역저지필터는 변형된 크로스 루프 슬롯 (Cross-loop slot)을 단위 셀로 하여 주기적인 구조로 설계하였으며, 설계된 대역 저지 필터는 등가회로 모델과 분산 도표(dispersion diagram)로 해석하였다. 대역 저지 필터의 중심주파수(fo)는 6.6 GHz이다. 제안된 필터는 단위 셀의 개수가 증가하면 3dB 대역폭은 넓어지고 삽입손실은 줄어드는 특성이 있다. 또한 제안한 대역저지필터는 소형의 평면구조를 가지며, 한 번의 에칭으로 제작이 가능 하여 다양한 분야의 RF 필터로서 사용 가능성이 높다.