• 제목/요약/키워드: Dipoles

검색결과 156건 처리시간 0.03초

An Advanced Correlation Algorithm between GTEM and OATS for Radiated Emission Tests

  • Lee, Ae-Kyoung
    • ETRI Journal
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    • 제17권3호
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    • pp.45-63
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    • 1995
  • This paper proposes an algorithm to improve the correlation between giga-hertz transverse electromagnetic (GTEM) cell and open area test site (OATS). It is based on the dipole modeling process of an unknown source object in a GTEM cell and on the evaluation of the approximate far field equations correlated with measured GTEM powers at output port of the GTEM cell. In this algorithm, the relative phase differences between dipole moments play an important part in modeling the test object as a set of dipoles and offer stable calculation of emission values. The radiated emission test using this algorithm requires fifteen orientations of equipment under test, but the increased orientations as compared with the previous method have little effect on the time needed for testing. Radiation from a notebook computer has been tested for statistical analysis of the correlation between GTEM data and OATS data. The emission test results of the notebook computer show that the mean, the standard deviation, and the correlation coefficient are -0.62, 1.99, and +0.85, respectively. These figures indicate that this algorithm provides improved accuracy in the measurement of electromagnetic emissions over the previous method.

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전자결합 다이폴을 이용한 편파공용 안테나 소자의 설계 (Design for Dual Polarization Antenna Element using Electromagnetic-Coupled Dipole)

  • 민경식;서성기;전종성;박세현;김동철;임학규
    • 한국정보통신학회:학술대회논문집
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    • 한국해양정보통신학회 2000년도 춘계종합학술대회
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    • pp.128-131
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    • 2000
  • This paper describes design for dual-linear polarization antenna using EMC(electromagnetic-coupled) dipole. EMC dipole has a simple element structure and it is fed by microstrip line. Vortical and horizontal polarization are determined by structure of dipole fed by microstrip line. FDTD Method is used for an analysis of antenna element. Length, width, height and offset of dipole are designed for 1-element antenna. Resonant length of diploe differs from the calculated value by a formula because of coupling effect of dipole and feed line. Radiation Power is controlled by the offset of dipole. In prectical fabrication of antenna array, a constant height of dipoles is required. Therefore, the teflon plate with height of 0.8 mm is considered in antenna element design for the vertical polarization.

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근거리 전송에 적합한 가이딩 코일의 파라미터 (Parameters of a guiding coil for wireless power transfer)

  • 우대웅;김재희;이동현;박경호;박위상
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2008년도 하계종합학술대회
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    • pp.345-346
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    • 2008
  • We analyzed the structural parameters of a guiding coil and a feeding loop for wireless power transfer in mid-range. The length, diameter, and number of turns of the guiding coil are the major factors to determine the resonant frequency. The separation distance between the coil and the loop also affects the power transfer ratio. This scheme has a greater transmission efficiency than using dipoles.

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Scattering from a Periodic Array of Duble-Dipole Elements over a Grounded Dielectric Slab

  • Ko, Jin-Whan
    • ETRI Journal
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    • 제20권1호
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    • pp.46-54
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    • 1998
  • An analysis method of electromagnetic scattering from periodic patch array of double-dipole elements on a grounded dielectric substrate in case of oblique incident and arbitrary polarization is considered. The basis functions are chosen to be entire consinusoidal functions are chosen to be entire consinusoidal functions covering the rectangular shaped domain in which the original dipoles are inscribed, unlike the conventional method in which basis functions are defined only for the conducting element region. To confirm the validity of the proposed analysis method, we calculate the normalized scattered power for two propagating modes and compare the results with those obtained by the previous numerical method for the double dipole elements of rectangular type and parallelogram type which have the property of frequency scanned reflection and polarizer. Good correspondence has been observed between them. Some numerical results such as variation of power and axial ratio of first-order diffracted wave by a periodic array of double-dipole elements are compared with previous results.

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THE BOUNDARIES OF DIPOLE GRAPHS AND THE COMPLETE BIPARTITE GRAPHS K2,n

  • Kim, Dongseok
    • 호남수학학술지
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    • 제36권2호
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    • pp.399-415
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    • 2014
  • We study the Seifert surfaces of a link by relating the embeddings of graphs with induced graphs. As applications, we prove that every link L is the boundary of an oriented surface which is obtained from a graph embedding of a complete bipartite graph $K_{2,n}$, where all voltage assignments on the edges of $K_{2,n}$ are 0. We also provide an algorithm to construct such a graph diagram of a given link and demonstrate the algorithm by dealing with the links $4^2_1$ and $5_2$.

Double Resonance Perfect Absorption in a Dielectric Nanoparticle Array

  • Hong, Seokhyeon;Lee, Young Jin;Moon, Kihwan;Kwon, Soon-Hong
    • Current Optics and Photonics
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    • 제1권3호
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    • pp.228-232
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    • 2017
  • We propose a reflector-type perfect absorber with double absorption lines using electric and magnetic dipoles of Mie resonances in an array of silicon nanospheres on a silver substrate. In the visible range, hundreds of nanometer-sized nanospheres show strong absorption lines up to 99%, which are enhanced by the interference between Mie scattering and reflections from the silver substrate. The air gap distance between the silicon particles and silver substrate controls this interference, and the absorption wavelengths can be controlled by adjusting the diameter of the silicon particles over the entire range of visible wavelengths. Additionally, our structure has a filling factor of 0.322 when the absorbance is nearly 100%.

Regional anomalies of cosmic microwave background power spectrum

  • Ju, Young;Park, Chan-Gyung;Hwang, Jai-Chan
    • 천문학회보
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    • 제43권1호
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    • pp.38.4-39
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    • 2018
  • We analyze the Planck 2015 cosmic microwave background temperature fluctuation data to find any anomaly in the angular power spectra measured for partial regions on the sky. For disks with radius of $20^{\circ}$, $45^{\circ}$ and $90^{\circ}$, which are densely overlapping on the sky, we estimate the power excess and its statistical significance relative to the LambdaCDM expectation for some chosen ranges of angular scales. We also investigate the dipolar asymmetry using the power excess maps obtained for some chosen angular scales, and confirm the previously announced consistent dipole directions. The average dipole amplitude and the inner products of dipoles have been measured from the power excess maps at different angular scales. We conclude that although dipole directions are consistent the measured amplitudes are not statistically significant compared to the LambdaCDM model prediction.

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Solution-processed Organic Trilayer Solar Cells Incorporating Conjugated Polyelectrolytes

  • Cha, Myoung Joo;Walker, Bright;Seo, Jung Hwa
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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    • pp.192.1-192.1
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    • 2014
  • We report solution-processed organic trilayer solar cells consisting of poly (3-hexylthiophene) (P3HT), a conjugated polyelectrolyte (CPE) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), wherein the effect CPE layer thickness on device properties was investigated. The current-voltage characteristics under illumination and dark as well as photoluminescence were characterized using various concentrations (0.02, 0.1, and 0.3wt%) of to deposit the CPE interlayer between the donor and acceptor layers. We also investigated the influence of molecular dipole moments in the trilayer solar cells by external stimuli. These results provide an experimental approach for investigating the influence of interfacial dipoles on solar cell parameters when placed between the donor and acceptor and allow us to obtaining fundamental information about the donor/acceptor interface in organic solar cells.

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심자도 신호를 이용한 전류원 재구성 (Source Current Reconstruction Based on MCG Signal)

  • 권혁찬;이용호;김진목
    • Progress in Superconductivity
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    • 제4권1호
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    • pp.48-52
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    • 2002
  • When applying a SQUID system for diagnosing heart disease, it is informative to obtain the source current distributions from the measured MCG (magnetocardiogram) signals since the bioelectric activity in the heart is generally represented by distributed current sources. In order to estimate the Primary current distribution in a heart, the minimum norm estimate was computed, assuming a source plane below the chest surface. In the simulation, current distributions, which were computed for the test dipoles represented well the essential feature of the test-current configurations. Source current reconstruction was performed for MCG signal of a healthy volunteer, which was recorded using a 40-channel SQUID system in a magnetically shielded room. It was found that the obtained current distribution is consistent with the electrical activity in a heart.

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Rose Bengal 과 Thiourea 의 광촉매 이합체화 반응에 관한 연구 (A Study on the Photocatalytic Dimerization of Rose Bengal and Thiourea)

  • 윤길중
    • 분석과학
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    • 제12권3호
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    • pp.209-217
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    • 1999
  • Rose bengal과 thiourea로 각각 감응 및 초감응된 광전류의 감소 원인을 규명하기 위하여 염료용액을 분광학적인 방법으로 분석하였다. 광조사 전후 감응용액의 흡수 및 형광 스펙트럼을 분석하므로서 RB와 TU사이에 일어나는 광촉매 이합체화 반응 기구를 확인할 수 있었다. 또 두 염료분자가 이루는 쌍극자 모멘트의 기하학적 배열은 사각이었으며, 이들 사이의 각도는 $124^{\circ}$임을 알 수 있었다.

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