• Title, Summary, Keyword: 삽입손실

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Optimal Muffler Design Considering the Insertion Loss Calculated Outside the Duct (덕트 밖에서 계산된 삽입 손실을 고려한 머플러 최적 설계)

  • Lee, Jong Kyeom;Oh, Kee Seung;Lee, Jin Woo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.40 no.5
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    • pp.497-503
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    • 2016
  • In this study, we formulate an acoustical topology optimization problem to optimally design a partition layout inside the expansion chamber of a muffler. The lower-limit insertion loss value at a target frequency is constrained, and the partition volume is selected as an object function. In this study, we calculate the insertion loss outside the duct, while to determine the noise-attenuation performance, we use the insertion loss value calculated inside the duct or transmission loss value obtained in a previous study. We employ the finite-element model for acoustical analysis, and we determine the transmission of an incident acoustic wave through each finite element using the functions of design variables that change continuously between "0" and "1." The rigid body elements, which totally reflect incident waves, build up partitions. Finally, we compare optimal topologies that depend on the target frequency and the allowed lower-limit value of insertion loss.

Design of the L-band Rotary Joint in Ring Contact Type to Improve Signal Insertion Loss (삽입손실 개선을 위한 링 접촉식 구조의 L대역 로터리조인트 설계)

  • Na, Jae-Hyun;Roh, Don-Suk;Kim, Dong-Gil
    • The Journal of the Korea institute of electronic communication sciences
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    • v.14 no.1
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    • pp.41-48
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    • 2019
  • This paper deals with the design of the L-band rotary joint, which is a core part of the tracking radar system. The rotary joint is a part that is mounted on the rotating parts of the tracking system antenna, which smoothly transmits RF signals with minimizing signal insertion loss. To improve the insertion loss of rotary joint, 1) dielectric materials, 2) design of distribution ring and 3)dielectric shape are studied. The performance of proposed rotary joint is compared with the conventional product. The prototype rotary joint showed a max insertion loss of 0.68dB, that is improved about 46% compare with conventional product which insertion loss was 1.26dB.

Insertion Loss by Noise Barrier on the Discontinuous Ground (불연속 지면위의 방음벽에 의한 삽입손실에 관한 연구)

  • Kim, Ye-Hyun;Kim, Dong-Ill;Jang, Ho-Kyeong
    • The Journal of the Acoustical Society of Korea
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    • v.14 no.3
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    • pp.114-121
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    • 1995
  • Outdoor experimental study is presented the insertion loss caused by barrier considering discontinuous ground condition. Measurements ware made in 1/3 octave band over the frequency range 315 Hz~3150 Hz with the various geometry of the source, receiver and barriers. The frequency range of the interference pattern depends on the phase difference between path from the edge of barrier to receiver, and hence on the acoustical properties of the ground on the receiver side of the barrier. The insertion loss by barrier, in addition to diffraction, is shown to be dependent on the ground characteristic.

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Reflection-Type 5-bit Digital Phase Shifter with Constant Insertion Loss (균일 삽입 손실 특성을 갖는 반사형의 5-비트 디지털 위상 변위기)

  • 고경석;최익권
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.13 no.6
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    • pp.582-589
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    • 2002
  • This paper presents 12.2 GHz ~ 12.7 GHz frequency band reflection type 5-bit digital phase shifter with constant insertion loss property that was fabricated with relatively low cost's InGaAs HEMT for amplifier. The unavoidable large insertion loss difference between on and off states of HEMT, when it is designed by conventional design theory based on ideal switching device, is removed by transforming the HEMT impedances at on and off states to other proper values connecting a certain length transmission line to HEMT and then applying the conventional design theory. The fabricated 5-bit digital phase shifter shows very good insertion loss properties of less than 1.5 dB insertion loss difference and -4.5 dB ~ -6 dB insertion loss in 35 phase steps at 12.2 GHz ~ 12.7 GHz. These results verify the design method presented in this paper, which is useful to design phase shifter of constant insertion loss with non-ideal switching device.

Characteristics of Insertion Loss of Transmission Line with Equal Line Length Due to a Rectangular Aperture Size in a Backplane (백플레인 개구의 크기 변화에 따른 대칭 전송선로의 삽입 손실)

  • Jung, Sung-Woo;Cho, Jun-Ho;Kim, Ki-Chai
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.12
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    • pp.2518-2524
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    • 2009
  • This paper presents the backplane effects due to a rectangular aperture size for two-wire transmission line with equal line length crossing the changeable rectangular aperture in an infinite ground backplane. It is used to determine the characteristics of the backplane insertion loss of the transmission line from the load section in accordance with the backplane aperture size. The results show that the insertion gain and insertion loss are obtained for the specific frequency range when the transmission line is closed to the backplane aperture size. The insertion loss is decreased that the aperture horizontal length and vertical length is more than a=50 mm and b=20 mm. The measurements of insertion loss are performed to verify the theoretical analysis.

New key parameter deriving method for lossless data embedding algorithm (무손실 데이터 삽입 알고리즘을 위한 새로운 키 파라미터 유도 방법)

  • Kang, Ji-Hong;Jin, Hong-Lin;Choe, Yoon-Sik
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.291-293
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    • 2010
  • 이 논문은 공간 영역에서 하나의 키 파라미터로 영상에 데이터를 삽입하고 추출해 내는 무손실 데이터 삽입 알고리즘에 기반하여, 키 파라미터의 유도 및 데이터 삽입 방법을 개선한 알고리즘을 제안한다. 제안한 알고리즘은 기존의 방법에 비해 삽입 가능한 데이터 용량의 효율이 크게 증가하였다.

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A micromachined 2$\times$2 optical switch aligned with beveled fibers for low return loss (경사 단면의 광섬유를 이용한 낮은 반사 손실의 멤스형 2$\times$2 광 스위치)

  • 권호남;심유석;박종삼;이종현
    • Proceedings of the Optical Society of Korea Conference
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    • pp.260-261
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    • 2002
  • 파장 다중화(WDM) 방식의 광통신시스템에서 그림 1(a),(b)에 나타낸 바와 같이 한 쌍의 입출력 포트의 신호 방향을 바꾸는 광 가감기(Optical Add Drop Multiplexer)용의 2$\times$2 광 스위치가 사용된다 특히 멤스형 광 스위치는 삽입손실, 누화, 편광 및 파장 의존 손실 등이 낮아 많은 연구가 이루어지고 있다.(1-3) 광 스위치의 삽입손실을 낮추기 위해, 렌즈나 굴절률 맞춤액을 사용하는데, 광섬유를 정렬, 혹은 패키징할 때 렌즈나 맞춤액의 취급이 어렵다는 문제점이 있다. (중략)

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3-Port Circulator for X-Band Radar (X-Band 레이더를 위한 3-포트 서큘레이터)

  • Yoon, Sung-Hyun
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.2
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    • pp.355-362
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    • 2015
  • In this study, we have fabricated 9.385[GHz] circulator that is composed of WR112 waveguide and Ferrite for X-band radar. For designing Ferrite, B/R mode(Below Resonance mode) was used and calculated the condition of 120 degree rotation of the electric field in Ferrite and calculated internal DC magnetic field and external DC magnetic field. Also, dielectric materials of the same shape with Ferrite was filled between two Ferrite for improving the performance of the circulator, including impedance matching, bandwidth, quality factor, insertion loss. To obtain optimum shape of the Ferrite and dielectric material, we used CST MWS. Simulation result of the circulator is that 1.02 : 1 VSWR, -40dB isolation, 0.2dB insertion loss and measurement result is that 1.03 : 1, -38dB, 1.2dB at 9.385[GHz]. We can get good agreement at isolation and VSWR, but insertion loss was 1 dB great than simulation result.

Analysis of the Plane-Concave Fabry-Perot cavity for a tunable filter (파장가변 필터를 위한 Plane-Concave Fabry-Perot 공진기의 해석)

  • Yeh YunHae
    • Korean Journal of Optics and Photonics
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    • v.15 no.6
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    • pp.495-502
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    • 2004
  • We proposed an analysis model for a Fabry-Perot cavity constructed with a plane-mirrored optical fiber and a concave-mirrored one. We presented the analysis results calculated by inserting practical values into the equations derived. The coupling loss of the cavity and the mirror loss are the most important parameters in reducing the insertion loss of the filter. In order to build a filter of finesse 600, FSR 57 nm, and insertion loss < 3 dB, the plane-concave cavity using mirrors of loss < 0.09% should be aligned for the coupling loss to be less than 0.1 %.

Lossless Information Hiding Based on the Histogram of the Difference Image (차분 영상의 히스토그램 특성을 이용한 무손실 정보은닉 알고리즘)

  • Lee Sang-Kwang;Ho Yo-Sung
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • pp.31-34
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    • 2003
  • 본 논문에서는 숨겨진 정보를 검출한 후. 정보가 삽입 된 영상으로부터 왜곡 없이 원본 영상을 복원할 수 있는 무손실 정보은닉(lossless information hiding) 알고리즘을 제안한다. 제안된 알고리즘은 차분 영상(difference image)의 히스토그램 특성을 기반으로 화소 값을 수정하여 데이터를 삽입한다. 이 알고리즘은 기존의 무손실 정보은닉 알고리즘들에 비해 정보 삽입으로 인한 왜곡이 적고. 많은 양의 정보를 삽입할 수 있다 이론적인 증명과 실험 견과를 통해 제안된 알고리즘에 의해 정보가 삽입된 영상의 PSNR(peak singal-to-noise ratio) 값은 대략 51dB 이상의 값을 나타내며. 이 값은 다른 무손식 정보은닉 알고리즘들 보다 훨씬 높다. 또한, 제안된 알고리즘은 여러 형태로 변형되어 다양한 응용에 적절히 적용될 수 있다

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