• Journal of electromagnetic engineering and science
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• 제2권2호
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• pp.87-92
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• 2002

A short-ended electromagnetically coupled coaxial dipole array antenna is investigated theoretically. The antenna has an advantage of structural simplicity. The integral equations are derived for the proposed structure by use of the Fourier transform and mode expansion, and the simultaneous linear equations are obtained. The slot electric field and strip current are obtained by solving the simultaneous linear equations. The effects of slot and strip numbers on the radiation efficiency, beamwidth and directivity gain of the antenna are presented.

• Journal of electromagnetic engineering and science
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• 제18권1호
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• pp.46-51
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• 2018

In this paper, a planar printed hybrid short/open-ended slot antenna with capacitive coupling feed strips is proposed for hepta-band mobile applications. The proposed antenna is comprised of a slotted ground plane on the top plane and two capacitive coupling feed strips with a chip inductor on the bottom plane. At the low frequency band, the short-ended long slot fed by strip 1 generates its half-wavelength resonance mode, whereas the T-shaped open ended slot fed by strip 2 generates its quarter-wavelength resonance mode for the high frequency band. The antenna provides a wide bandwidth covering GSM850/GSM900/DCS/PCS/UMTS/LTE2300/LTE2500 operation bands. Moreover, the antenna occupies a small volume of $15mm{\times}50mm{\times}1mm$. The operating principle of the proposed antenna and the simulation/measurement results are presented and discussed.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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• pp.399-403
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• 2000

A new type of collinear antenna called short-ended coaxial slot-coupled strip array antenna is investigated theoretically. The antenna has an advantage of structural simplicity. The integral equations are derived for the proposed structure by use of the Fourier transform and mode expansion, and the simultaneous linear equations are obtained. The slot electric field and strip current are then obtained by solving the simultaneous linear equation. The effects of slot and strip number on the radiation efficienty, beamwidth and directivity gain are also presented.

• Progress in Superconductivity
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• 제10권2호
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• pp.116-122
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• 2009

We introduce a measurement method that enables to measure the penetration depth($\lambda$) of superconductor films by using a short-ended parallel plate sapphire resonator. Variations in the $\lambda$ of $MgB_2$ films could be measured down to the lowest temperature using a sapphire resonator with a $YBa_2Cu_3O_{7-x}$ film at the bottom. A model equation of $\lambda=\lambda_0[1-(T/T_c)^{\tau}]^{-1/2}$ for $MgB_2$ films appeared to describe the observed variations of the resonant frequency of the sapphire resonator with temperature, with $\lambda_0,\;\tau$, and $T_C$ used as the fitting parameters.

• 한국전자파학회:학술대회논문집
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• 한국전자파학회 2000년도 종합학술발표회 논문집 Vol.10 No.1
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• pp.238-242
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• 2000

In this paper, the method for dielectric constant and less tangent measurements of microwave substrates using a microstrip line is presented. The two samples of an open-ended line and a short-ended tine are made and complex propagation constant is evaluated from the one-port scattering parameter measurements. This method has been automated fully using a personal computer and a vector network analyzer.

• 한국초전도학회:학술대회논문집
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• 한국초전도학회 2009년도 Korea Superconductivity Society Meeting 2009
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• pp.69-69
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• 2009

• 한국지반공학회논문집
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• 제15권2호
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• pp.165-180
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• 1999

모형 압력 토조에 개단, 폐단, 관내토 그라우팅, 그리고 선단 하부지반 그라우팅 말뚝들을 설치하여 수행된 재하실험을 통해 그 지지력을 비교하였고, 유사화된(Simulated) 해진시 말뚝의 설치깊이를 변화시켜 선단 하부지반 그라우팅 말뚝의 안정성을 검토하였다. 또한, 재하실험과 해진 실험은 2개와 4개로 된 군말뚝에 대해서도 수행되었다. 관내토 선단부만 그라우팅한 말뚝의 지지력은 선단 지반 교란으로 인한 선단지지력 감소로 개단말뚝에 비해 극한지지력이 약 11.2~30.8%정도 작았다. 관내토 선단 하부지반 그라우팅한 말뚝의 지지력은 개단말뚝의 지지력보다 약 23.8~33.9%정도 증가하였으며, 이는 폐단말뚝의 지지력과 비슷하였다. 선단 하부지반 그라우팅된 군말뚝은 개단 군말뚝에 비해 증가하였는데, 2개의 군말뚝의 경우에는 14.6~31.8%만큼 지지력이 증가하였으며, 4개의 군말뚝의 경우는 15.3~22.4%만큼 증가하였다. 심해에서 발생된 해진시 관내토 선단 하부지반 그라우팅된 개단말뚝의 안정성은 말뚝의 설치 형태와 말뚝의 지중관입 길이에 따라 달라졌다. 외말뚝의 경우에는 지중 관입 깊이가 20m보다 깊어지면 안정한 상태를 유지할 수 있었으나, 12m보다 짧은 말뚝은 파괴될 수 있었고, 12m보다 긴 말뚝의 경우에는 가동(Mobility) 상태를 유지할 수 있었다. 군말뚝의 경우에는 지중 관입깊이가 7m이상이면 지지력의 일부만 감소하여 약간 변위하는 "Mobility" 상태를 유지할 수 있었다.유지할 수 있었다.

• ETRI Journal
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• 제31권3호
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• pp.254-262
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• 2009

This paper presents a novel simple filter design method based on a parallel short-ended coupled-line structure with capacitive loading for size reduction and ultra-broad rejection of spurious passbands. In addition, the introduction of a cross-coupling capacitor into the miniaturized coupled-line can create a transmission zero at the second harmonic frequency for better frequency selectivity and attenuation level. The aperture compensation technique is also applied to achieve a strong coupling in the coupled-line section. The influence of using the connecting transmission line to cascade two identical one-stage filters is studied for the first time. Specifically, such a two-stage bandpass filter operating at 2.3 GHz with a fractional bandwidth of 10% was designed and realized with low-temperature co-fired ceramic technology for application in base stations that need high power handling capability. It achieved attenuation in excess of -40 dB up to $4f_0$ and low insertion loss of -1.2 dB with the size of 10 mm ${\times}$ 7 mm ${\times}$ 2.2 mm. The measured and simulated results showed good agreement.

• 융합신호처리학회논문지
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• 제5권4호
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• pp.317-324
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• 2004

전자기 결합된 동축 다이폴 안테나를 이론적으로 해석하였다. 방사도파관 모드와 퓨리어 변환을 이용하여 적분 방정식을 유도하였다. 적분 방정식에 포함된 적분들을 빠르게 계산하기 위하여 실수축을 따른 적분을 브랜치 컷 (branch cut)을 따른 적분 경로로 변환하여 계산하였다. 방사 특성에 미치는 슬롯과 다이폴 그리고 단락면의 길이 그리고 유전체 코팅의 영향을 조사하였다. 방시특성 또한 연구하였다. 제안된 방법의 타당성을 증명하기 위하여 기존에 발표된 방법으로 계산한 안테나의 방향성 이득과 비교하였고 또한 전력 보존 법칙을 만족시키는지를 확인하였다. 본 논문에서 제시한 방법으로 계산된 결과를 전자파 상용 시뮬레이터의 결과와 비교하여 잘 일치함을 확인하였다.

• 아동학회지
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• 제21권1호
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• pp.163-178
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• 2000

Institutions included in this study of emergency short term shelters for children in crisis included 2 public counseling centers providing short term protection services for children and 12 emergency shelters for runaway children located in a metropolitan city in Korea. The institutions were examined with respect to their establishment, management, and programs. The researcher visited and interviewed workers employed in the institutions. In additions, 12 children who had been cared for emergency shelters were surveyed with open-ended questions. The data consisted of information on founders, locations, purpose, current management, personnel, length of care, and number and grouping of children. Programs and daily schedules were also examined. Effective models of emergency short term shelters were discussed on the basis of the collected data.