• 제목/요약/키워드: quantum interference

검색결과 151건 처리시간 0.031초

Relay Selection Scheme Based on Quantum Differential Evolution Algorithm in Relay Networks

  • Gao, Hongyuan;Zhang, Shibo;Du, Yanan;Wang, Yu;Diao, Ming
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제11권7호
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    • pp.3501-3523
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    • 2017
  • It is a classical integer optimization difficulty to design an optimal selection scheme in cooperative relay networks considering co-channel interference (CCI). In this paper, we solve single-objective and multi-objective relay selection problem. For the single-objective relay selection problem, in order to attain optimal system performance of cooperative relay network, a novel quantum differential evolutionary algorithm (QDEA) is proposed to resolve the optimization difficulty of optimal relay selection, and the proposed optimal relay selection scheme is called as optimal relay selection based on quantum differential evolutionary algorithm (QDEA). The proposed QDEA combines the advantages of quantum computing theory and differential evolutionary algorithm (DEA) to improve exploring and exploiting potency of DEA. So QDEA has the capability to find the optimal relay selection scheme in cooperative relay networks. For the multi-objective relay selection problem, we propose a novel non-dominated sorting quantum differential evolutionary algorithm (NSQDEA) to solve the relay selection problem which considers two objectives. Simulation results indicate that the proposed relay selection scheme based on QDEA is superior to other intelligent relay selection schemes based on differential evolutionary algorithm, artificial bee colony optimization and quantum bee colony optimization in terms of convergence speed and accuracy for the single-objective relay selection problem. Meanwhile, the simulation results also show that the proposed relay selection scheme based on NSQDEA has a good performance on multi-objective relay selection.

Numerical study of topological SQUIDs

  • Soohong, Choi;Yeongmin, Jang;Sara, Arif;Yong-Joo, Doh
    • 한국초전도ㆍ저온공학회논문지
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    • 제24권4호
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    • pp.11-15
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    • 2022
  • We conducted numerical calculations to obtain the critical current as a function of the magnetic flux through the topologically trivial and non-trivial superconducting quantum interference devices (SQUIDs), with varying the capacitive and inductive couplings of Josephson junctions (JJs). Our calculation results indicate that a nontrivial SQUID is almost indistinguishable from trivial SQUID, considering the effective capacitance coupling. When the SQUID contains 2π- and 4π-periodic supercurrents, the periodicity of the current-flux relation can be distinguished from the purely trivial or nontrivial SQUID cases, and its difference is sensitive to the relative ratio between the topologically trivial and nontrivial supercurrents. We believe that our calculation results would provide a practical guide to quantitatively measure the portion of the topologically nontrivial supercurrents in experiments.

Liquid Crystal Alignment on the Multiple Photo-treated Layers by the Interfered Laser Light

  • Lee, Eun-Kyu;Kim, Jong-Hyun
    • Journal of Information Display
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    • 제8권1호
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    • pp.6-9
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    • 2007
  • Orientational alignment patterns have been proven to be that they are very useful for realizing diverse properties of liquid crystals. Here we produced the patterns combining interfered laser beams. A photo-isomerizable polymer including azo unit, which induces nematic liquid crystal alignment to the polarized laser light, was used as the alignment to layer. Double irradiations into two orthogonal directions brought the orientation patterns similar to the checkerboard. It indicates the possibility of bistability on those patterns.

Detection of the mechanical resonance of a micromechanical cantilever using dynamic flexural measurement technique and its mass sensing application

  • 김학성;윤호열;정운석;유나리;박정호;이상욱
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2011년도 제40회 동계학술대회 초록집
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    • pp.447-447
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    • 2011
  • We studied to detect the mass variation using micro mechanical resonator. For measuring the resonance frequency of the micro mechanical system, optical method using laser interference is selected. A simple resonator is prepared by attaching an AFM cantilever on the piezo stack. The piezo stack makes a the cantilever vibrated with its resonance frequency. To change the mass of the resonator, gold was evaporated on the cantilever. We measured how much resonance frequency was changed according to the amount of gold attached on cantilever. This resonator is able to perform the role of a mass sensor and has a resolution of the order of micrograms. The fabrication of the resonator and measurement setup for detecting the mechanical resonance will be introduced in this presentation.

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진동수가 서로 다른 얽힘상태 광자쌍의 4차 간섭 (The fourth-order interference between entangled state photon pairs with different frequencies)

  • 김헌오;고정훈;김태수
    • 한국광학회지
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    • 제13권4호
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    • pp.308-313
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    • 2002
  • 매개하향변환과정에서 동시에 발생한 서로 다른 진동수의 광자쌍을 이용한 4차 간섭실험에서 비고전적인 맥놀이 효과를 측정하였다. 각진동수가 각각 $\omega1$$\omega2$인 광자쌍을 빔분할기에서 중첩시키고, 빔분할기의 두 출구에 놓인 두 검출기로 동시계수 할 때, 두 광자가 빔분할기에 도달하는 시간 간격에 따라 cos($\omega1$-$\omega2$)의 함수로 동시계수의 변화를 나타내었다. 두 광자의 파장 차이가 41㎚일 때 측정된 맥놀이 진동수 ($\omega1$-$\omega2$)/2$\pi$는 0.29${\times}10^{14}$㎐이었고, 진동수 차이에 해당하는 두 광자의 시간간격은 34.82fs로 측정되었다.