• Title/Summary/Keyword: slits

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A Study on Design and Microwave Characteristics of a RF/IR Multispectral Absorber (전자파/적외선 다중파장 흡수체의 설계와 초고주파 특성에 관한 연구)

  • Minah Yoon;Suwan Jeon;Youngeun Ra;Yerin Jo;Wonwoo Choi;Yukyoung Lee;Kwangseop Kim;Jonghak Lee;Kichul Kim;Taein Choi;Hakjoo Lee
    • Journal of the Korea Institute of Military Science and Technology
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    • v.27 no.3
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    • pp.311-318
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    • 2024
  • In this paper, a design for a radio frequency(RF) and infrared(IR) absorber with metasurfaces is discussed in microwave frequency bands. The RF absorber includes double layers of metasurfaces to operate in S- and X-bands. Effects of sheet resistance of the metasurfaces and thicknesses of dielectric supporting layers on reflection responses are investigated. An IR stealth layer incorporates an array of conductive grids with slits to reflect IR signals but to transmit RF signals and visible rays. Periodicity of the grids and slits is studied for transmission responses in the X-band and a surface area ratio. Reflection responses of the RF/IR multispectral absorber are found to be lower than -10 dB and -16 dB in the S- and X-bands, respectively, from full-wave simulation. Finally, the RF/IR multispectral absorber is fabricated and its reflection responses are measured to verify designed performance.

A study on the Turfan's costume in the period of Uighur (위구르(회골, Uighur)기의 투르판(토노번,Trufan) 복식연구)

  • 김소현
    • Journal of the Korean Society of Clothing and Textiles
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    • v.23 no.6
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    • pp.829-840
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    • 1999
  • Ordinarily hair styles and headclothes show the racial characteristics. Uighur's men had let their long hair hang down their back in many queues, According to the order of estates men wore double high coronets hthree-pointed coronets from the headdress. Married women wore the felt headdress. The type of men's clothes were long caftans which had a round collar slits on the both sides and tight sleeves. They tied Chan Die belts and wore long boots. Women wore long tunics with everted collar which was decorated. Later the type of women's dress was changed into the long caftan. Late period of Turfan Uighur Mongol style had appeared.

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A study on analysis of particle swarm optimization algorithm for the optimum design of rectenna for wireless power transmission (무선전력전송용 렉테나 최적 설계를 위한 PSO 알고리즘 분석 연구)

  • Kim, Koon-Tae;Nam, Yeong-Bin;Oh, Seung-Hun;Lee, Jung-Hyeok;Kang, Seong-In;Kim, Hyeong-Seok
    • Journal of The Institute of Information and Telecommunication Facilities Engineering
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    • v.11 no.2
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    • pp.34-38
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    • 2012
  • In this paper, the particle swarm optimization (PSO) algorithm is adopted to design a modified ring-slot type patch rectenna with a resonance frequency of 2.45GHz. In order to accomplish minimization of dimensions and circular polarization (CP) and harmonic suppression, axial direction slits and side-cuts are added to the patch of the ring. The PSO manipulated this kind of multi-dimensional problem very well, and as a result, the designed rectenna shows a desirable performance of return loss of 21.36dB and axial ratio of 2.92dB at the frequency of 2.45GHz with compact sizing.

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Development of Real-time Control System for White bBamline and Microprobe Beamline (백색광 및 X선 미세탐침 빔라인용 실시간 제어시스템 개발)

  • 윤종철;이진원;고인수
    • 제어로봇시스템학회:학술대회논문집
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    • 1997.10a
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    • pp.748-751
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    • 1997
  • The White Beamline of the Pohang Accelerator Laboratory(PAL) consists of main and second slits, a microprobe system, two ion chambers, a video-microscope, and a Si(Li) detector. These machine components must be controlled remotely through computer system to make user experiments precise and speedy. A real-time computer control system was developed to control and monitor these machine components. A VNIEbus computer with OS-9 real-time operating system was used for low-level data acquisition and control. VME I/O modules were used for step motor control and scaler control. The software has modular structure for maximum performance and easy maintenance. We developed database, I/O driver, and control software. We used PC/Window95 for data logging and operator interface. Visual C++ was used graphical user interface programming. RS232C was used for communication between VME and PC.

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Improvement of Shielding for Electromagnetic Compatibility

  • Chien, Tang Tan;Tu, Bui Thi Minh;Do, Tran Nguyen
    • IEIE Transactions on Smart Processing and Computing
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    • v.5 no.1
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    • pp.63-69
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    • 2016
  • This paper presents methods to improve the effectiveness of electromagnetic shielding. The slit appears in an enclosure's surface to ventilate. Slits may also appear due to power supply lines or to serve as a communication link between electronic circuits inside and outside the box. We simulated electromagnetic radiation in different conditions in order to propose a method to improve the effectiveness of electromagnetic shielding to ensure electromagnetic compatibility using CST software (Computer Simulation Technology).

A study on the stabilization characteristics of the diffusion flame formed behind a bluff body (Bluff Body 후류에 형성되는 확산화염의 보염특성에 관한 연구)

  • ;;An, Jin-Geun;Song, Kyu-Keun
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.12
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    • pp.3344-3351
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    • 1995
  • The stability of diffusion flame formed behind a bluff body with fuel injection slits was experimentally investigated in various fuel injection angles, fuel injection ratios, grids and extension ducts. The flame stability limits, temperature distributions and length of recirculation zones, direct photographs of flames were measured in order to discuss the stabilization mechanism of the diffusion flame. The results from this study are as follows. The fuel injection angle is an important factor in determining the flame stability. Stability limits can be improved by variety of the fuel injection ratio. When the grid and extension duct are set, stability characteristics are varied with the blockage ratios, grid intervals, and grid numbers. The recirculation zone not only serves as a steady ignition source of combustion stream but also governs the stabilization mechanism.

Magnetic Shielding Effects of the Electrothermal Shield of a Superconducting Generator with Quick-Response Excitation (속응 여자식 초전도 발전기 열전자 차폐막의 전자 차폐 특성 해석)

  • Lee, H.B.;Bae, D.J.;Kim, S.Wh;Hahn, S.C.;Cha, G.S.;Hahn, S.Y.
    • Proceedings of the KIEE Conference
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    • 1990.11a
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    • pp.49-52
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    • 1990
  • In this paper, we proposed a new electrothermal shield model with slits for the purpose of applying to the Superconducting Generator with Quick-Response Excitation. Via experimental and finite element analysis, we compared the magnetic shielding effects of the proposed electrothermal shield model with the conventional one. It is considered that he proposed models meet the needs for the electrothermal shields of the Superconducting Generator with Quick-Response Excitation.

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Discharge and Ozone Generation Characteristics of a Wire-Plate Discharge System with a Slit Barrier (슬릿 유전체 장벽을 갖는 선대 평판형 방전장치의 방전 및 오존 발생특성)

  • Moon Jae-Duk;Jung Jae-Seung
    • The Transactions of the Korean Institute of Electrical Engineers C
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    • v.54 no.9
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    • pp.421-426
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    • 2005
  • A wire-plate discharge system with a slit barrier has been proposed and investigated experimentally by focusing on the discharges on the slit barrier and ozone generation characteristics. This wire-plate discharge system with a slit barrier can generate an intensive corona discharges, and produce corona discharge twice, once from the corona wire electrode and second time from the surface and the slits of the slit dielectric barrier. As a result this propose wire-plate discharge system with the slit barrier can produce greatly increased ozone than without the slit barrier. This type of wire-plate discharge system with the slit barrier could be used for effective ozone generation as a means with retard to the removal of pollutant gas

A Study on the spiritual Shaman(Gangsin-mu)'s Po -in Seoul-gut Shaman's Costume- (降神巫服의 袍에 관한 연구 - 서울굿 무복을 중심으로 -)

  • Kim, Eun-Jung
    • Journal of the Korean Home Economics Association
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    • v.41 no.9
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    • pp.43-54
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    • 2003
  • The purpose of study is to survey the system of the Korean Gangsin-mu shaman costume and its formative character and to fine out the traditional follow patterns of government officials' attires and Po's meaning of it. The overall shape of variety 'Po's in modern times are similar to the traditional ones, but they differ greatly in size, detail color, and ornamental design. The sleeves have slits in the armholes, which can allow the hands to be drawn out easily. In addition, the knot buttons are used in the modern costumes. They are based on different formation skills from those of the traditional The original color of the shaman's costume is not their taste in color but symbolic, modern costumes color show the shaman's taste in color. This change mean a more accentuated visual effect than incantatory meaning. Another reason for color change is also the costume's material. A kind of constituent element uses synthetic fiber in modern times.

Prediction of the Radiated Emission(RE)s due to the PCB Power-Bus' Resonance Modes and Mitigation of the RE Levels

  • Kahng, Sung-Tek
    • Journal of electromagnetic engineering and science
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    • v.7 no.1
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    • pp.7-11
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    • 2007
  • PCB Power-Bus (comprising power/ground planes) impedance and fields are evaluated by an efficient series expansion method that is suggested in this paper. It is used to investigate the structure's radiated emission(RE) levels and find acceptable ways of loading the power/ground planes such as decoupling capcitor(DeCap)s, balanced feeding and slits, in order to reduce the interferences. Also, the calculations and measurements of a proposed geometry are verified by vector fitting as a analysis model to check the behavior of the slit.