• Title, Summary, Keyword: Bow-tie

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Bow-tie Mode Lasing in a Grooved Rectangular Semiconductor Microcavity

  • Moon, Hee-Jong;Hyun, Kyung-Sook
    • Journal of the Optical Society of Korea
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    • v.16 no.2
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    • pp.162-165
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    • 2012
  • Bow-tie modes were proposed in a grooved rectangular resonator and their lasing characteristics were investigated in semiconductor microcavities. The observed spacing between two adjacent lasing peaks from the grooved cavity was reduced compared to that of 4-bounce whispering gallery modes (WGMs) from the same-sized simple rectangular cavity due to increased round-trip path length of the bow-tie modes. The lasing spectra of bow-tie modes obtained from two adjacent corners showed highly correlated patterns while those of 4-bounce WGMs did not.

A Design of Enhanced Bandwidth Bow-tie Slot Antenna with Tapered Feeder Line (대역폭 개선을 위한 Taper 형태의 급전선로를 갖는 Bow-tie 슬롯 안테나의 설계)

  • 황석진;윤현보
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • pp.127-131
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    • 2001
  • 본 논문에서는 공진 주파수가 2 GHz 이며 크기가 작고, 광대역 특성을 갖는 Taper 형태의 급전선로를 갖는 마이크로스트립 Bow-tie 슬롯 안테나를 제안하였다. 이 구조에서는 대역폭을 향상시키기 위하여 마이크로스트립 슬롯 안테나 방사 슬롯을 변형된 bow-tie 모양으로 설계하여 기존의 Bow-tie 슬롯 안테나와 다른 구조를 제안하였고 Electromagnetic coupling를 좋게 하기 위하여 급전선로에 Taper를 첨가하여 급전기와 안테나의 정합을 이루어 광대역 특성을 갖도록 하였다.

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A Study on Risk Analysis of Manufacturing Process Using the Bow-Tie Method (Bow-Tie기법을 이용한 제조공정의 위험성평가 연구)

  • Tae, Chan Ho;Lee, Heon Seok;Byun, Chul Hyun;Yang, Jae Mo;Park, Chulhwan;Ko, Jae Wook
    • Journal of the Korean Institute of Gas
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    • v.17 no.3
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    • pp.33-38
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    • 2013
  • The chemical industries have used large amounts of chemicals. If an accident occurs, it caused physical and human damage. We intended to investigate risk assessment for the prevention of accidents. The risk assessment by HAZOP technique has been applide to major chemical industries, and that result has been utilized efficiently. In this study, we analyzed Bow-Tie and HAZOP technique, and risk assesment was performed by Bow-Tie on toxic material process. As a result, the risk that can not be found in the risk assessment of the other is derived, and improvements of 14 to remove the dangers derived. Bow-Tie risk assessment is suitable to derive the applicability of risk factors in the field and to establish the improvement measures.

Efficiency Analysis of Storage Tank Prevention Measures by Bow-Tie (Bow-Tie 분석을 통한 저장탱크 방지대책 효율성 분석)

  • Lee, Hyun-Jin;Jung, Soomin;Kang, Seok-Min;Chae, Seungbeen;Kang, Seung-Gyun;Ko, Jae Wook
    • Journal of the Korean Institute of Gas
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    • v.24 no.4
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    • pp.73-83
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    • 2020
  • The problem addressed in this study is that the reduction in process accidents is less than the reduction in industrial safety, and the losses from major accidents in the oil and gas processing industry have not decreased over the years. In particular, current risk approaches in storage tanks place more emphasis on improving the safety of the design than maintaining safe operation. The Bow-Tie method can be used properly to improve process safety. The Bow-Tie method can assess compliance by focusing on operational aspects, clearly highlighting all important safety barriers, and analyzing barrier effectiveness.

Effect of electrolyte on Bow-tie Water tree (Electrolyte 가 Bow-tie 형 수트리에 미치는 영향)

  • Kang, T.O.;Yang, W.Y.;Kim, K.S.;Chun, C.O.
    • Proceedings of the KIEE Conference
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    • pp.1550-1552
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    • 1994
  • In order to investigate the effect of electrolyte solutions on the activities of bow-tie water trees in XLPE insulated power cable, we have tried to observe the characteristics on water treeing ( bow-tie type ) using several electrolyte solutions such as $CH_3COOH$, $MgCl_2$,HCl and NaCl solution and tap water. Bow-tie tree density in $CH_3COOH$ and $MgCl_2$ solution was higher than in any other solution, and the growth of tree was stimulated in NaCl and $CH_3COOH$ solution, and diffusion of bow-tie trees into insulation in $MgCl_2$, HCl and NaCl solutions was faster than in $CH_3COOH$ solution and water. Also, although the increase of applied voltage caused bow-tie tree density to be high, it didn't affect the growth of tree maximum length noticeably.

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Accurate FDTD Analysis of Bow-tie Antenna

  • Cho, Young-Il;Park, Dong-Hyuk;Park, Soeng-Ook
    • Journal of electromagnetic engineering and science
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    • v.4 no.1
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    • pp.13-16
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    • 2004
  • In this paper, FDTD analysis of the bow-tie antenna is investigated by incorporating static field solution that is suitable to the bow-tie antenna without increasing computational time. Transforming static feld solution to the rotated grid system, we can obtain the transformed static field solution which is able to represent field behavior near the oblique edge line of the bow-tie antenna. The result shows a good agreement with a MoM analysis and is compared conformal modeling technique and regular FDTD method.

Design Optimization of an Enhanced Stop-band UWB Bow-Tie Antenna

  • Choi, Kyung;Kim, Hyeong-Seok;Hwang, Hee-Yong
    • Journal of IKEEE
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    • v.22 no.3
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    • pp.793-799
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    • 2018
  • An improved design of Ultra Wide Band(UWB) Bow-Tie antenna, which can control an enhanced wide stop-band, is presented. The mutually coupled slot-pair improves and controls the rejection band. The UWB antenna is composed of an electromagnetically coupled Bow-Tie patch and a parasitic ground patch, whose working frequency is extended to full UWB range in this work. By adding slot-pairs on the main patch and optimizing, they can give any requested wide rejection bands and sharp skirt characteristics, as is often required for UWB antennas and multi-band antennas. All the parameters are precisely calculated by an adequate optimization method. The Particle Swarm Optimization(PSO) technique is appropriately adopted. The proposed design and method is proved to give and control the sharp-skirt wide stop-band to UWB Bow-Tie antennas.

5 GHz Bow-tie-shaped Meander Slot Antenna

  • Wi, Sang-Hyuk;Kim, Jung-Min;Yoo, Tae-Hoon;Park, Jae-Yeong;Yook, Jong-Gwan;Park, Han-Kyu
    • Journal of electromagnetic engineering and science
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    • v.2 no.1
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    • pp.50-55
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    • 2002
  • In this paper, Ive propose a bow-tie-shaped meander slot antenna find by a microstrip line to achieve compact size as well as wideband characteristic. While conventional bow-tie slot antennas exhibit wide band characteristic, they have relatively large size. On the other hand, the meander slot antennas are very small, but they reveal quite narrow bandwidth (typically less than 1 %). To realize miniaturized antennas balling large bandwidth, combination of the bow-tie slot and the meander slot geometries is proposed in this paper. Theoretical results show that the proposed antenna with uniform slot width is 65.5 % smaller than that of the conventional bow-tie antenna in size, while the bandwidth is 3 times larger than that of the meander slot antenna. Moreover, the non-uniform slot width antenna shows 60 % smaller in size and about 3.5 times wider in bandwidth than the previous antennas. Measured antenna performance reveals excellent agreement with the predicted values.

Paper-Based Pattern Switchable Antenna Using Inkjet-Printing Technology (잉크젯 프린팅 기술을 이용한 종이 기반의 방사패턴 가변 안테나)

  • Eom, Seung Hyun;Lim, Sungjoon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.26 no.7
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    • pp.613-619
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    • 2015
  • In this paper, we proposed a paper-based pattern-switchable antenna using inkjet-printing technology. The proposed antenna is composed of two bow-tie antennas and a switching network. The bow-tie antennas are inkjet-printed on paper using a low cost home printer. The switching network is built on a printed-circuit-board(PCB) and consists of a single-pole-double-throw(SPDT) switch and balun element. A double-sided parallel-strip line(DSPSL) can convert the unbalanced microstrip mode to the balanced strip mode. Two bow-tie antennas have different radiation patterns because of the different orientation of the reflectors. It is demonstrated from EM simulation and measurement that the radiation patterns of the proposed antenna are successfully switched by the SPDT.

Design and Fabrication of Wideband U-sloted Bow-Tie Microstrip Antenna for 5.25GHz Band Wireless LAN (5.25GHz 대역의 무선 LAN을 위한 광대역 U-슬롯 Bow-Tie 마이크로스트립 안테나 설계 및 제작)

  • 강석엽;이원종;박효달
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.2A
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    • pp.195-201
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    • 2004
  • In this paper, U-Shaped slot Bow-Tie antenna for 5.15㎓∼5.35㎓ is designed, fabricated, and measured. The prototype consist of U-Shaped slot. To obtain suitable bandwidth, the form layer is inserted between ground plane and substrate. Important parameters in the design are U-slot length, width, position, air-gap height, and feed point position. From these parameters optimized, a U-shaped slot Bow-Tie antenna is fabricated and measured. The measured results of the antenna are obtained as follows results. The resonant frequency of the Fabrication U-shaped slot Bow-Tie antenna is 5.28㎓, bandwidth for approximately 7.76%(VSWR<1.2) and the gain is 4∼7dBi. The experimental far-field patterns are stable across the pass band. The 3dB bandwidth in Elevation and Azimuth are 73.63$^{\circ}$and 65.08$^{\circ}$, respectively.