• 제목/요약/키워드: design wave

검색결과 3,251건 처리시간 0.028초

광대역특성을 가지는 전파흡수체의 설계에 관한 연구 (A Study of Electromagnetic Wave Absorber with Broad-Band Frequency Characteristics.)

  • 이창우;김동일;전상엽;박지용;정세모
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 1994년도 추계학술발표회
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    • pp.59-68
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    • 1994
  • A wide band design method of an double layerred electromagnetic wave absorber sintered ferrite which has a flat and an anti-grid shape layers is proposed and discussed. The wide band electomagnetic wave absorber can be designed by the equivalent material constants method for the each layer, As a result the wide band ferrite electonmagnetic wave absorber with the band width of 30MHz to 3670, 3680 or 3690MHz were designed under the tolerance limits of -20dB reflectivity.

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Standing Wave Pressure Acting on the Mixed Type Breakwater

  • Oh, Young-Min;Lee, Kil-Seong;Chun, In-Sik
    • 한국해안해양공학회:학술대회논문집
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    • 한국해안해양공학회 1995년도 정기학술강연회 발표논문 초록집
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    • pp.120-121
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    • 1995
  • In the design of mixed type breakwater, the most important factor to be considered is the wave pressure. In particular, the standing wave pressure has a significant effect on the vertical wall breakwater or mixed type breakwater. Many wave pressure formulas were developed and the Goda's formula[1] was very frequently used among them by the coastal engineers due to its simplicity and accuracy. (omitted)

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항만공진주기와 선박동요량을 고려한 항만가동율 산정 (Evaluation of Effective Working Days in a Harbor Considering Harbor Resonance and Moored Ship Motion)

  • 곽문수;문용호
    • 한국해안·해양공학회논문집
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    • 제27권1호
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    • pp.14-24
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    • 2015
  • 본 연구는 선박의 크기, 계류조건, 파랑의 주기, 파향 등에 의한 계류선박의 동요량을 해석하고 선박의 하역한계파고 산정 및 항만가동율을 평가하는 방법을 제시한 것이다. 본 방법은 포항신항 제8부두의 파랑관측자료를 이용하여 타당성을 검증하였다. 하역중단 시 파랑관측 자료는 파고 0.10~0.75 m, 주기 7~13 s 이었으며, 이때 계류된 선박은 800~35,000톤 이었다. 그리고 본 방법으로부터 산정된 제 8부두의 하역한계파고는 선박 5,000, 10,000, 30,000톤에 대하여 파고 0.19~0.50 m, 주기 8~12 s로 산정되었다. 본 방법의 결과는 연구대상 선박의 크기가 현지 선박의 크기와 정확히 일치하지는 않아서 파고는 관측치와 다소 차이를 보이지만 주기변화에 따라 하역한계파고를 잘 재현하고 있음을 알 수 있었다. 그리고 파향이 75도 인 경우의 본 방법에 의한 하역한계파고는 현행 항만설계 기준에 제시된 한계파고 보다 장단주기 파를 고려하면 16~62% 감소하였고, 단주기 파랑만 고려하면 0~46%감소하였다. 특히 현행 항만설계기준의 하역한계하고는 10,000톤 이하의 선박에 대해서는 과대 평가되었음을 확인할 수 있었다. 한편, 선박의 동요량을 고려하여 산정된 포항신항 제 8부두의 가동율은 설계기준 파고에 의한 가동율 에 비하여 6.5% 감소하였다.

9.45GHz용 전파흡수체의 설계 방법 (Design Method for the Electromagnetic Wave Absorber at 9.45 GHz)

  • 김왕섭;김경용
    • 한국전자파학회지:전자파기술
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    • 제4권2호
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    • pp.11-16
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    • 1993
  • A design method for the electromagnetic wave absorber with the attenuation over 20 dB at a frequency was formulated. In addition to the matching boundary which is determined by the theoretical equation, several limiting conditions due to the fabrication process were examined. Based on the study on the effects of the variance of the thickness and permittivity on the electromagnetic wave absorbing characteristics, a mean to exclude such effects was also included in the proposed design method. The ranges of variables were limited as the frequency of 9.45 GHz and .epsilon.' = 5 ~ 30, when the effect of .epsilon. " was not considered.

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The Design of Calculable Standard Dipole Antennas in the Frequency Range of 1~3 GHz

  • Kim, Ki-Chai;Kim, Sang-Myeong;Kwon, Jae-Yong;Kang, Tae-Weon;Kim, Jeong-Hwan
    • Journal of electromagnetic engineering and science
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    • 제12권1호
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    • pp.63-69
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    • 2012
  • This paper presents the design of a calculable standard dipole antenna with a hybrid balun in the frequency range of 1 GHz to 3 GHz. A new formula of the antenna factor for a dipole antenna with a hybrid balun is derived using the power mismatch-loss concept. The antenna factors derived in this paper are in good agreement with the results calculated from S-parameters. The design results show that the calculable dipole antenna with a hybrid balun can be characterized by power mismatch-loss component factors.

중적외선 영상 잡음 감소를 위한 SW 필터의 설계 및 구현 (Design and Software Implementation of Noise Reduction Filter for Mid-wave Infrared Images)

  • 박현성;김정호;이성호
    • 한국군사과학기술학회지
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    • 제19권4호
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    • pp.500-507
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    • 2016
  • In order to increase the survivability of combatant ship, measuring and analyzing the infrared radiation is important. Consequently, providing analysis report is also important for the progress of the new combatant ship design. This paper proposes a design and software implementation of filtering for the noise reduction of mid-wave IR camera image. We reduced the total test cost by using the suggested software filtering technique instead of hardware replacement or re-calibration. In addition, we enhanced the accuracy of analysis results by adjusting the parameters of software filtering according to the results of filtered image.

피에조 잉크젯의 셀프 센싱 검출 및 응용 (Self-sensing measurement of piezo inkjet and its Applications)

  • 권계시;김우식;김상일;신승주;김성진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2007년도 춘계학술대회논문집
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    • pp.366-372
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    • 2007
  • Self-sensing measurement of piezo inkjet and its application are discussed. The pressure wave inside the inkjet dispenser was measured by current measurement due to self-sensing capability of PZT. The pressure wave measured from current was verified by commercially available laser vibrometer. Here, two applications using self-sensing signal were discussed: waveform design for high speed jetting and condition monitoring. For waveform design, two pulse waveform was designed based on self-sensing signal such that the pressure wave after droplet formation can be minimized. For condition monitoring, self-sensing signal was shown to be effective in detecting air bubble trapped in inkjet printhead.

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진행파를 이용한 쌍방향 초음파 리니어 모터 설계 및 제작 (Design and Fabrication of Traveling Wave Type Bi-directional Ultrasonic Linear Motors)

  • 한우석;김연보;노용래
    • 한국음향학회지
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    • 제18권8호
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    • pp.25-31
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    • 1999
  • 본 논문에서는 진행파를 이용하여 쌍방향으로 움직일 수 있는 새로운 구조의 초음파 리니어 모터를 개발하고, 그 시제품을 제작하였다. 설계과정에서는 유한요소해석법을 이용해 모터구조의 타당성을 검증하였고, 진행파가 왜곡되지 않는 최적구조, 재질, 크기, 경계조건을 결정하였다. 설계 결과에 따라 리니어 모터를 실제로 제작하고, 특성을 평가함으로써 개발된 새로운 구조의 이용 가능성을 확인하였다.

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X-대역 진행파 슬롯 배열 안테나 설계 (Design of An X-Band Traveling-Wave Slot Array)

  • 유상길;이석곤;최재현;안병철
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2002년도 하계종합학술대회 논문집(1)
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    • pp.455-458
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    • 2002
  • Design methods are presented for an X-band traveling-wave slot array realized on a rectangular waveguide. An array of 21 longitudinal slots is realized on the broad wall of a rectangular waveguide. The squint of the antenna main beam is adjusted using the element spacing and the waveguide broad wall dimension. The excitation of the array is controlled by the slot offset from the waveguide center line Multiple I-plane steps are placed around last slot elements so that the second-order beam due to tile reflected wave Is minimized A waveguide-to-coaxial adapter Is designed for feeding the array antenna from a coaxial system. Results of the design show an outstanding performance of the antenna 17.1 dB gain. 36"beam 1111, and -21 dB maximum sidelobe level.evel.

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