• Title/Summary/Keyword: double array

Search Result 177, Processing Time 0.026 seconds

Design of micro lens array (Micro lens array 설계)

  • 홍경희
    • Korean Journal of Optics and Photonics
    • /
    • v.5 no.2
    • /
    • pp.204-211
    • /
    • 1994
  • Micro array lens systems are designed for a faximile or copy machine. The array type is hexagonal. Diameter of a lens is 0.16 mm and the distance of the center of the nearest neighbor is 0.192 mm. The magnitude of the lens system is 1:1. Working distane is 10.55 mm and the spot size is less than 0.04 mm radius on axis and 0.20 mm off-axis in case of single layer system. Working distance is 7.90 mm and the spot size is less than 0.07 mm radius on axis and 0.09 mm radius off axis in case of double layer system. Performance of single layer micro array lens system and double layer micro array lens system are compared with the characteristics of the ray fans.y fans.

  • PDF

Performance Analysis of Double Circular Array Antenna (이중 원형 배열 안테나의 성능 분석)

  • 이봉수;송우영
    • Journal of the Korea Society of Computer and Information
    • /
    • v.6 no.1
    • /
    • pp.51-59
    • /
    • 2001
  • In this paper, performance of the double circular array antenna was analyzed, which has sharp directivity with specific direction and is compatible to shape pencil beam. The character of each array geometry which N numbers of isotropic point source is arranged in planar with type of a square, circular and double circular was compared and analyzed. As a result, we fined that double circular geometry was good performance rather than square and circular array geometry in the point of directivity. SLL and HPBW.

  • PDF

CONVERGENCE OF DOUBLE SERIES OF RANDOM ELEMENTS IN BANACH SPACES

  • Tien, Nguyen Duy;Dung, Le Van
    • Journal of the Korean Mathematical Society
    • /
    • v.49 no.5
    • /
    • pp.1053-1064
    • /
    • 2012
  • For a double array of random elements $\{X_{mn};m{\geq}1,n{\geq}1\}$ in a $p$-uniformly smooth Banach space, $\{b_{mn};m{\geq}1,n{\geq}1\}$ is an array of positive numbers, convergence of double random series ${\sum}^{\infty}_{m=1}{\sum}^{\infty}_{n=1}X_{mn}$, ${\sum}^{\infty}_{m=1}{\sum}^{\infty}_{n=1}b^{-1}_{mn}X_{mn}$ and strong law of large numbers $$b^{-1}_{mn}\sum^m_{i=1}\sum^n_{j=1}X_{ij}{\rightarrow}0$$ as $$m{\wedge}n{\rightarrow}{\infty}$$ are established.

Analysis of Computational Complexity for Cascade AOA Estimation Algorithm Based on Single and Double Rim Array Antennas (단일 및 이중 림 어레이 안테나 기반 캐스케이드 AOA 추정 알고리즘의 계산복잡도 분석)

  • Tae-Yun, Kim;Suk-Seung, Hwang
    • The Journal of the Korea institute of electronic communication sciences
    • /
    • v.17 no.6
    • /
    • pp.1055-1062
    • /
    • 2022
  • In order to use the Massive MIMO (Multi Input Multi Output) technology using the massive array antenna, it is essential to know the angle of arrival (AOA) of the signal. When using a massive array antenna, the existing AOA estimation algorithm has excellent estimation performance, but also has a disadvantage in that computational complexity increases in proportion to the number of antenna elements. To solve this problem, a cascade AOA estimation algorithm has been proposed and the performance of a single-shaped (non)massive array antenna has been proven through a number of papers. However, the computational complexity of the cascade AOA estimation algorithm to which single and double rim array antennas are applied has not been compared. In this paper, we compare and analyze the computational complexity for AOA estimation when single and double rim array antennas are applied to the cascade AOA estimation algorithm.

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

  • Ko, Jin-Whan
    • ETRI Journal
    • /
    • v.20 no.1
    • /
    • pp.46-54
    • /
    • 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.

  • PDF

Characteristic comparison of double-side PMSM/G according to magnetization pattern for flywheel energy storage system (플라이휠 에너지 저장 시스템용 양측식 영구자석 동기 전동/발전기의 착자 형태에 따른 특성 비교)

  • Jang, Seok-Myeong;Choi, Ji-Hwan;You, Dae-Joon;Seong, So-Yeong;Han, Sang-Chul;Lee, Jeong-Phil
    • Proceedings of the KIEE Conference
    • /
    • 2011.07a
    • /
    • pp.1021-1022
    • /
    • 2011
  • This paper presents the double side PM synchronous motor/generator for core loss reduction in flywheel energy storage system. The use of double PM rotor causes the elimination of core loss in no-load state of machine. Because flywheel rotational speed is reduced by core loss, double PM rotor is very effective in flywheel system. This paper suggests two types of double side PM rotor, Halbach magnetized array and parallel magnetized array. And characteristic comparison according to thickness of rotor back core is performed.

  • PDF

Effects on the Escapement of Juvenile Bastard Halibut Paralichthys olivaceus of Actively Stimulating Devices Inside a Model Cod End

  • Kim, Yong-Hae
    • Fisheries and Aquatic Sciences
    • /
    • v.14 no.1
    • /
    • pp.62-69
    • /
    • 2011
  • The effects of actively stimulating devices (ASD) on juvenile flatfish escape were studied to increase escape rates from the cod end by encouraging fish to approach the net wall. Two kinds of ASD were designed: a fluttering net panel, i.e., a free-end flag-like net panel, and a double conical rope array. Escape responses of juvenile bastard halibut were observed in a circulating water channel using two model cod ends, one made with diamond-shaped 43-mm-mesh-size polyethylene (PE) as a high-contrast cod end and the other with polyamid (PA) mono-ply as a low-contrast cod end. Retention rate was significantly lower with the double conical rope-array ASD in the PE cod end than with conventional PE cod ends only or the fluttering net-panel ASD inside the PE cod end. Mean retention rate with the low-contrast PA cod end was also significantly lower than that with the high-contrast PE conventional cod end. Therefore, active fluttering devices using a double conical rope array together with less visible low-contrast netting in the cod end could help to reduce the bycatch of juvenile flatfish by weakening their optomotor response and actively driving fish to the side net panel.

Broadband 8 dBi Double Dipole Quasi-Yagi Antenna Using 4×2 Meanderline Array Structure (4×2 미앤더라인 배열 구조를 이용한 광대역 8 dBi 이중 다이폴 준-야기 안테나)

  • Junho Yeo;Jong-Ig Lee
    • Journal of Advanced Navigation Technology
    • /
    • v.28 no.2
    • /
    • pp.232-237
    • /
    • 2024
  • In this paper, a broadband double dipole quasi-Yagi antenna using a 4×2 meander line array structure for maintaining 8 dBi gain was studied. The 4×2 meanderline array structure consists of a unit cell in the shape of a meanderline conductor, and it was placed above the second dipole antenna of the double dipole quasi-Yagi antenna. A double dipole quasi-Yagi antenna with generally used multiple strip directors was designed on an FR4 substrate with the same size, and the input reflection coefficient and gain characteristics were compared. Comparison results showed that the impedance frequency bandwidth increased by 6.3% compared to when using the multiple strip directors, the frequency bandwidth with a gain of 8 dBi or more increased by 10.1%, and average gain also slightly increased. The frequency band of the fabricated antenna for a voltage standing wave ratio less than 2 was 1.548-2.846 GHz(59.1%), and gain was measured to be more than 8 dBi in the 1.6-2.8 GHz band.