• 국제초고층학회논문집
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• 제3권1호
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• pp.1-8
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• 2014

When seismic isolation system is applied to high aspect-ratio (height/wide-ratio) steel structures, there are several problems to be taken into consideration. One is lifting up tensile force on the isolation bearing by overturning moment caused by earthquake. Another is securing building stiffness to produce seismic isolation effects. Under these conditions, this paper reports the structural design of high-rise research building in the campus of Tokyo Institute of Technology. With the stepping-up system for the corner bearings, the narrow sides of single span framework are designed to concentrate the dead load as counter-weight for the tensile reaction under earthquake. Also we adopted concrete in-filled steel column and Mega-Bracing system covering four layers on north & south framework to secure the horizontal stiffness of the building.

• 한국공간구조학회논문집
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• 제19권3호
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• pp.33-40
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• 2019

A seismic isolation system is one of the most effective control devices used for mitigating the structural responses due to earthquake loads. This system is generally used as a type of base isolation system for low- and mid-rise building structures. If the base isolation technique is applied to high-rise buildings, a lot of problems may be induced such as the movement of isolation bearings during severe wind loads, the stability problem of bearings under large compression forces. Therefore, a mid-story isolation system was proposed for seismic protection of high-rise buildings. Residence-commerce complex buildings in Korea have vertical irregularity because shear wall type and frame type structures are vertically connected. This problem can be also solved by the mid-story isolation system. An effective analytical method using super elements and substructures was proposed in this study. This method was used to investigate control performance of mid-story isolation system for residence-commerce complex buildings subjected to seismic loads. Based on numerical analyses, it was shown that the mid-story isolation system can effectively reduce seismic responses of residence-commerce complex tall buildings.

• 가정과삶의질연구
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• 제26권5호
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• pp.91-107
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• 2008

This study investigated the isolation hypothesis and the buffer hypothesis of Demand-Control-Support model in relation to activity satisfaction and psychological well-being. The subjects were 300 elderly women participating in productive activity for example paid work, voluntary activity, and grancdhildren care. This research tested four hypotheses concerning the DCS model. Is there support for the isolation hypothesis, such that the lowest level of activity satisfaction is experienced by the elderly women working in an isolation situation(high demand-low control-low support)? Is there support for the isolation hypothesis, such that the lowest level of psychological well-being is experienced by the elderly women working in an isolation situation(high demand-low control-low support)? Is there support for the buffer hypothesis, i. e. interaction between demand, control, and support, indicating a buffering effect of support on the negative impact of high strain on activity satisfaction? Is there support for the buffer hypothesis, i. e. interaction between demand, control, and support, indicating a buffering effect of support on the negative impact of high strain on psychological well-being? Major results of this study were as follows. and were supported. Activity satisfaction and psychological well-being of the elderly women in isolation situation was the lowest among the sample. was supported that family support level buffered the negative impact of high strain on activity satisfaction. But was not supported. Only main effect of demand level was showed on psychological well-being.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2005년도 추계종합학술대회
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• pp.921-924
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• 2005

We report low conversion loss and high LO to RF isolation 94 GHz MMIC resistive mixers based on 0.1 ${\mu}m$ InGaAs/InAlAs/GaAs metamorphic HEMT technology. The fabricated resistive mixers applied a one-stage amplifier on RF port of the mixer. By using the one-stage amplifier, we obtained the decrement of conversion loss and the increment of LO to RF isolation. So, we can obtain higher performances than conventional resistive mixers. The modified mixer shows excellent conversion loss of 6.7 dB at a LO power of 10 dBm. We also observed an extremely high isolation characteristic from the MMICs exhibiting the LO-RF isolation of 21 ${\pm}$ 0.5dB in a frequency range of 93.7${\sim}$ 94.3 GHz. The low conversion loss and high LO-RF isolation characteristics of the MMIC modified resistive mixers are mainly attributed to the performance of the MHEMTs exhibiting a maximum transconductance of 654 mS/mm, a current gain cut-off frequency of 173 GHz and a maximum oscillation frequency of 271 GHz.

• IEIE Transactions on Smart Processing and Computing
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• 제5권3호
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• pp.164-168
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• 2016

A low insertion-loss, high-isolation switch based on single pole double throw (SPDT) for a 2.4GHz Bluetooth low-energy transceiver is presented in this paper. In order to increase isolation, the body floating technique is implemented. Based on characteristics whereby the ratio of the sizes of the shunt and the series transistors significantly affect the performance of the switches, the device sizes are optimized. A simple matching network is also designed to enhance the insertion loss. Thus, the SPDT switch has high isolation and low insertion loss without increasing the complexity of the circuit. The proposed SPDT is designed and simulated in a complementary metal-oxide semiconductor 65nm process. The switch has a $530{\mu}m{\times}270{\mu}m$ area and achieves 0.9dB, 1.78dB insertion loss and 40dB, 41dB isolation of transmission, reception modes, respectively.

• 한국전자파학회논문지
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• 제16권2호
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• pp.167-173
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• 2005

직렬 PIN 다이오드 스위치의 격리도는 PIN 다이오드의 병렬 커패시턴스에 의해 제한을 받으며, 스위치 구동회로는 PIN 다이오드 스위치의 스위칭 속도를 제한한다. 이런 문제를 극복하기 위해, 병렬 공진 인턱턴스와 TTL 호환의 스위치 구동회로가 적용된 높은 격리도와 고속 스위칭의 PIN 다이오드 스위치를 제안하였다. 3 GHz PIN 다이오드 스위치의 측정 결과, 1 GHz의 주파수 대역폭, 1.5 dB 이내의 삽입 손실, 65 dB의 격리도, 15 dB 이상의 반사 손실 그리고 30 ns 이내의 스위칭 속도를 나타내었다. 특히, 병렬 공진 인덕턴스를 사용한 3 GHz스위치는 15 dB의 격리도 향상을 나타내었다.

• Journal of Power Electronics
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• 제15권6호
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• pp.1468-1479
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• 2015

Renewable energy resources such as wind and photovoltaic power generation systems demand a high step-up DC-DC converters to convert the low voltage to commercial grid voltage. However, the high step-up converter using a transformer has limitations of high voltage stresses of switches and diodes when the transformer winding ratio increases. Accordingly, conventional studies have been applied to series-connect multioutput converters such as forward-flyback and switched-capacitor flyback to reduce the transformer winding ratio. This paper proposes new single-ended converter topologies of an isolation type and a non-isolation type to improve power efficiency, cost-effectiveness, and output ripple. The first proposal is an isolation-type charge-pump switched-capacitor flyback converter that includes an extreme-ratio isolation switched-capacitor cell with a chargepump circuit. It reduces the transformer winding number and the output ripple, and further improves power efficiency without any cost increase. The next proposal is a non-isolation charge-pump switched-capacitor-flyback tapped-inductor boost converter, which adds a charge-pump-connected flyback circuit to the conventional switched-capacitor boost converter to improve the power efficiency and to reduce the efficiency degradation from the input variation. In this paper, the operation principle of the proposed scheme is presented with the experimental results of the 100 W DC-DC converter for verification.

• 전기학회논문지
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• 제60권9호
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• pp.1727-1732
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• 2011

In order to realize a high performance(low loss, high isolation) microwave power divider/combiner, we have designed the power combiner/divider precisely in accordance with the different hight of central part. In the case of the high central part of the hight of $h_r$=10.2, a compensating part of the conical line is inserted in the conical conversion transmission line, and in the case of low central part of the hight of $h_r$=5.0, the conical conversion transmission line is remodeled into the 2-stage bend structure. In both case, the reflection characteristics are improved to 30dB over the operating frequency range of 5GHz bandwidth. A resistance is inserted between the peripheral ports so as to try to improve the isolation characteristics of the device. For the 16-divider/combiner, the isolation characteristics are improved to 10dB over the operating frequency range of 5GHz bandwidth.

• ETRI Journal
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• 제34권1호
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• pp.114-117
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• 2012

A small-sized ($15mm{\times}30mm$) planar monopole MIMO antenna that offers high-isolation performance is presented in this letter. The antenna is miniaturized using inductive coupling within a meander-line radiator and capacitive coupling between a radiator and an isolator. High isolation is achieved by a T-shaped stub attached to the ground plane between two radiators, which also contributes to the small size using a folded structure and the capacitive coupling with radiators. The proposed antenna operates for the WLAN band within 2.4 GHz to 2.483 GHz. The measured isolation (S21) is about -30 dB, and the envelope correlation coefficient is less than 0.1.

• 국제학술발표논문집
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• The 1th International Conference on Construction Engineering and Project Management
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• pp.627-632
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• 2005

The severe acute respiratory syndrome -SARS virus spreaded rapidly in Asia in 2003 caused a lethal and serious epidemic. Establishing special isolation wards of high-level epidemic prevention has becomes one of the most important tasks of epidemic prevention. Taking the biosafety level of US CDC biology laboratory as an example, the laboratory of the highest level, BL4 and that of the second high level, BL3 are only allowed to handle and research this kind of highly dangerous viruses safely, to ensure the safety of researchers and the surrounding environment.This research aims to study the functions and the design requirements of "special isolation wards", which is equivalent to the high-level biotechnology laboratory, and have an integrated discussion about the design and construction techniques of this kind of wards, expecting to provide a reference for constructing special isolation wards and maintaining operation safely in Taiwan.