• Title/Summary/Keyword: $D_{32}$

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Design of V-Band Waveguide Slot Sub-Array Antenna for Wireless Communication Back-haul (무선통신 백-홀용 V-밴드 도파관 슬롯 서브-배열 안테나의 설계)

  • Noh, Kwang-Hyun;Kang, Young-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.7
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    • pp.334-341
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    • 2016
  • In this paper, the study of a waveguide aperture-coupled feed-structured antenna has been conducted for the purpose of applying it to a wireless back-haul system sufficient for high-capacity gigabits-per-second data rates. For this study, a $32{\times}32$ waveguide slot sub-array antenna with a corporate-feed structure was designed and produced. Also, this antenna is used at 57 GHz to 66 GHz in the V-band. The construction of the antenna is a laminated form with radiating parts (outer groove and slot, cavity), a coupled aperture, and feeds in each. The antenna was designed with HFSS, which is based on 3D-FEM, produced with aluminum processed by a precision-controlled milling machine, and assembled after a silver-plating process. The measurement result from analysis of the characteristics of the antenna shows that return loss is less than -12 dB, VSWR < 2.0, and a wide bandwidth ranges up to 16%. An overall first side lobe level is less than -12.3 dB, and a 3 dB beam width is narrow at about $1.85^{\circ}$. Also, antenna gain is 38.5 dBi, offering high efficiency exceeding 90%.

Demulsification of Oil-Water Emulsions Using Different Microwave Irradiation Mode (마이크로파 조사 방식에 의한 Oil-Water 에멀젼 분리)

  • Hong, Joo-Hee;Kim, Byoung-Sik;Kim, Dok-Chan
    • Applied Chemistry for Engineering
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    • v.16 no.5
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    • pp.653-659
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    • 2005
  • When emulsion is irradiated by a microwave, the energy absorbed by the emulsion is proportional to irradiation time. In case of a long exposure, the temperature of emulsion rises, its viscosity decrease, and subsequently increase the rate of demulsification. In this work, in order to improve demulsification rate, the studies on demusification and the Sauter mean diameter ($D_{32}$) for each microwaved emulsion with different irradiation mode(continuous, pulsative, and periodical irradiation) have been carried out. When the 30% W/O emulsion (sample #1) was irradiated for 600 sec and settled for 24 h, oil recovery rates from continuous, pulsative, and periodical microwave irradiation were 60.0%, 62.3%, and 96.2%, and the amounts of separated water were 26.5%, 35.0%, and 93.9%, respectively. Also, the Sauter mean diameters ($D_{32}$) were $47.183{\mu}m$, $111.547{\mu}m$, and $220.476{\mu}m$, respectively.

Performance Analysis and Evaluation of Hybrid Compensation Algorithm for Localization (하이브리드형 위치인식 보정 알고리즘 성능 분석 및 평가)

  • Kwon, Seong-Ki;Lee, Dong-Myung
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.6
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    • pp.2263-2268
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    • 2010
  • In this paper, the hybrid compensation algorithm($A_{HB}$) for localization using the Compensation Algorithm distance($CA_d$) and the Algorithm of Equivalent Distance Rate(AEDR) in SDS-TWR(Symmetric Double-Sided Two-Way Ranging) is suggested and the performance of the proposed algorithm is analyzed by practical experimentations. From experimentations, it is confirmed that the errors are reduced in 28 coordinates of total 32 coordinates in the experimental region and the errors are reduced about above 70% in the assigned 3 type error level ranges by $A_{HB}$. Also, it is analyzed that the average localization error is reduced from 2.67m to 1.19m as 55.4% in total 32 coordinates by $A_{HB}$ and the error compensation capability of $A_{HB}$ is very excellent as above 90%. From above results, we have seen that the error reduction ratio and error compensation capability of $A_{HB}$ is more excellent than each $CA_d$ or AEDR.

Algebraic Accuracy Verification for Division-by-Convergence based 24-bit Floating-point Divider Complying with OpenGL (Division-by-Convergence 방식을 사용하는 24-비트 부동소수점 제산기에 대한 OpenGL 정확도의 대수적 검증)

  • Yoo, Sehoon;Lee, Jungwoo;Kim, Kichul
    • Journal of IKEEE
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    • v.17 no.3
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    • pp.346-351
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    • 2013
  • Low-cost and low-power are important requirements in mobile systems. Thus, when a floating-point arithmetic unit is needed, 24-bit floating-point format can be more useful than 32-bit floating-point format. However, a 24-bit floating-point arithmetic unit can be risky because it usually has lower accuracy than a 32-bit floating-point arithmetic unit. Consecutive floating-point operations are performed in 3D graphic processors. In this case, the verification of the floating-point operation accuracy is important. Among 3D graphic arithmetic operations, the floating-point division is one of the most difficult operations to satisfy the accuracy of $10^{-5}$ which is the required accuracy in OpenGL ES 3.0. No 24-bit floating-point divider, whose accuracy is algebraically verified, has been reported. In this paper, a 24-bit floating-point divider is analyzed and it is algebraically verified that its accuracy satisfies the OpenGL requirement.

Effect of Water Management after Fertilizer Application on Fate and Efficiency of Applied Nitrogen (시식 후 물관리 방법이 실소의 동태 및 이용효율에 미치는 영향)

  • 이변우;명을재;최관호
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.40 no.2
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    • pp.157-166
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    • 1995
  • The fate and use efficiency of applied nitrogen were evaluated in a pot experiment with different fertilizers and water management practices during 30days after fertilizer application. N-P-K compound fertilizers, 13-10-1l(F-l) for upland Crop use and 15-10-10(F-3) for rice Crop use, and mixed fertilizer, 21-17-17(F-2) for basal dressing in rice were used. Fertilizers corresponding to 1.8g N were mixed thoroughly with the whole volume of sandy loam soil in a pot. The pots were flooded upto 3cm above soil surface for O(0dF), 10(10dF), 20(20dF), and 30(30dF) days after fertilizer application and all the treatments were flooded continuously from 30 days after fertilizer application. During the flooding period water percolation rate was adjusted to 2.5mm/day. Rice seedlings were transplanted 40 days after fertilizer application. The pH of infiltrated water increased with increasing duration of flooding. The pH of F-2 was higher than those of F-1 and F-3 between which there were no differences. The applied nitrogen remained 23% in F-1, 29% in F-2, and 29.1 % in F-3, and 45.0% in 0dF, 26.6% in 10dF, 24.8% in 20dF, and 20.3% in 30dF as inorganic nitrogen at 63 days after fertilizer application. Nitrogen losses by leaching amounted to 51.3%, 32.1% and 48.1% of applied nitrogen in F-1, F-2 and F-3, respectively. Nitrogen leaching losses increased with increasing duration of flood- ing, amounting to 25.7%, 29.8%, 32.7%, and 35.8% in 0dF, 10dF, 20dF and 30dF, respectively. Gaseous loss of applied nitrogen was greatest in F-2, followed by F-1 and F-3. Total loss of nitrogen due to gaseous volatilization and leaching was greatest in F -1, followed by F -2 and F-3, and were greater in the treatments with longer flooding after fertilizer application. Nitrogen recovery by rice shoot until 72 days after transplanting were 23.2%, 24.7% and 27.4% of applied nitrogen in F-1, F-2 and F-3, respectively and 34.1%, 25.5%, 21.1%, and 21.2% in 0dF, 10dF, 20dF and 30dF, respectively.

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32'-diagonal Gated CNT Cathode

  • Lee, Chun-Gyoo;Lee, Sang-Jo;Lee, Sang-Jin;Chi, Eung-Joon;Lee, Jin-Seok;Yun, Tae-Il;Lee, Byung-Gon;Han, Ho-Su;Ahn, Sang-Hyuck;Jung, Kyu-Won;Kim, Hun-Yeong;Yun, Bok-Chun;Park, Sung-Man;Choi, Jong-Sik;Oh, Tae-Sik;Kang, Sung-Kee;Kim, Jong-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.303-304
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    • 2002
  • 32"-diagonal gated carbon nanotube(CNT) cathodes named under-gate cathodes for large-size display applications have been fabricated and characterized. The emission uniformity looks fine, even without the resistive layer. The emission performance has been improved by scaling down the cathode electrode dimension.

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