• Title/Summary/Keyword: 안정기 핀

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Development of a Energy-saving LED module Using K-band Microwave Motion Detecting Sensor (K대역 마이크로파 움직임 감지 센서를 이용한 에너지 절감형 LED 모듈 개발)

  • Kim, Howoon;Woo, Dong Sik
    • Journal of IKEEE
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    • v.24 no.2
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    • pp.446-452
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    • 2020
  • In this paper, we propose a energy-saving LED module using K-band microwave motion detecting sensor. To oscillate K-band microwave signal, An oscillator using a hairpin-type microstrip resonator was designed to increase stability and make fabrication easier. To radiate the microwave signal, a two-channel(TX/RX) patch antenna arrays was developed. Wilkinson power divider and ring hybrid mixer were developed and applied to obtain Doppler shift from the received signal. Shield cans were installed to protect the stability of the signals and unwanted external noise. The proposed motion detection sensor was mounted on a demonstration LED module and the energy saving performance through pre-test was verified.

Mechanical Properties of Epoxy Paint using Oxidized Graphene Nanoplatelet as a Reinforcement (산화 그래핀 나노플레이트릿을 강화제로 사용한 에폭시 도료의 역학적 특성)

  • Seo, Won-Woo;Kim, Gyu-Yong;Yoon, Min-Ho;Lee, Bo-Kyeong;Nam, Jeong-Soo
    • Journal of the Korea Institute of Building Construction
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    • v.17 no.5
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    • pp.465-471
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    • 2017
  • In this study, oxidized graphene nanoplatelet(GO) was prepared by oxidizing graphene nanoplatelet(GNP) with nitric acid in order to solve the problem of dispersion of GNP, one of nano materials. The surface chemical composition of the prepared GO was analyzed by fourier transform infrared spectroscopy(FT-IR) before incorporation into the epoxy paint, and the dispersibility in the solvent was confirmed. Meanwhile, GNP/Epoxy and GO/Epoxy paint were prepared by mixing GNP, GO with 0.1, 0.3, 0.5 and 1.0wt.% in epoxy paint and the mechanical properties were evaluated. As a result, GNP/Epoxy and GO/Epoxy paints showed better mechanical properties than Neat Epoxy which did not incorporate GNP, GO. Especially, when 0.3wt.% of GO was incorporated into epoxy resin, it showed higher tensile strength than Neat Epoxy. It was confirmed that acid treatment of GNP was effective in improving the mechanical properties of epoxy paint.

A Study on the Data Transmission Characteristics of Low-Voltage CMOS using FPGA (FPGA를 이용한 저전압 CMOS에서의 데이터 전달특성 연구(반도체 및 통신소자))

  • 김석환;정학기;허창우
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.407-410
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    • 2003
  • 현재 통신시스템에서 많이 사용되고 있는 Xilinx FPGA를 이용하여, 여러 가지 로직을 구현하고 데이터 전달특성을 분석하기 위하여 신호의 노이즈와 데이터 손실을 방지하기 위하여 10층의 PCB(Printed Circuit Board)를 만들었다. FPGA에 클럭과 64bit의 데이터를 동기 시켜 전송선로의 길이의 변화와 입력된 클럭의 주파수 변화에 따른 최대 안정된 데이터 전달속도와 전송선로의 길이를 알아보았다. 제작된 PCB보드에서 FPGA의 출력 핀에서 출력포트 사이의 전송선로 길이는 13cm이며 확장된 테스트용 전송선로 보드의 길이는 30cm, 60cm, 120cm이다. 그러므로 전송선로의 길이를 13cm, 43cm, 73cm, 133cm간격으로 측정하였으며, 데이터 전송특성에 대한 클럭 주파수는 10MHz, 50MHz, 100MHz, 125MHz, 150MHz로 나누어 측정하였다. 데이터 전달 특성에서 125Mbps까지는 불가능 하지만 전송선로의 길이가 30cm일 경우 최대 100Mbps까지 안정하게 데이터를 전달할 수 있었다.

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Perfluorosulfonic Acid Composite Membranes Containing Antioxidant Grafted Graphene Oxide for Polymer Electrolyte Membrane Fuel Cell Applications (산화방지 작용기를 함유한 산화 그래핀이 도입된 과불소화계 복합 막의 고분자 전해질 막 연료전지로의 응용)

  • Inhyeok Hwang;Kihyun Kim
    • Membrane Journal
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    • v.33 no.6
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    • pp.416-426
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    • 2023
  • In this study, hindered amine-grafted graphene oxide (HA-GO) with antioxidant properties was prepared and incorporated into Nafion-based composite membranes as an effective filler material for polymer electrolyte membrane fuel cell applications. HA-GO was synthesized via a ring-opening reaction between amine groups in 4-amino-2, 2, 6, 6-tetramethyl piperidine and epoxy groups on the surface of GO. Nafion-based composite membranes containing different weight contents of HA-GO were fabricated to compare the polymer electrolyte membrane properties with those of the pure Nafion membrane. The composite membranes with HA-GO were found to have better mechanical properties, chemical stability, and proton conductivity than the pure Nafion membrane. In particular, the conductivity retention behavior confirmed by the decrease in proton conductivity after Fenton's test of the composite membranes was better than that of the pure Nafion membrane due to the incorporation of HA-GO with effective antioxidant properties.

Design of TE10 to TEM mode convertor for W-band radial power combiner (W밴드 radial 전력 결합기용 TE10-TEM 모드 변환기 설계)

  • Young-Gon Kim;Myung-Hun Yong;Han-Chun Ryu;Se-Hoon Kwon;Seon-Keol Woo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.23 no.6
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    • pp.41-46
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    • 2023
  • Design of W-band TE10 to TEM mode converter for radial power combiner is proposed in this paper. The proposed structure is used with generally available pin to realize TEM mode and is designed to convert TE10 to TEM mode gradually using 2-step impedance transformer and back short. The pin of proposed mode converter is well bonded to the housing so that environment conditions such as vibration or shock are not affected. The proposed mode converter, in a back-to-back configuration, has less than 1.55 dB insertion loss and more than 10 dB return loss from 92.5 GHz to 97.7 GHz. Proposed converter is expected compact radar and various applications requiring for high power and stable environment conditions.

Observation of the Preionization effect and Operational Characteristics of a Nitrogen Laser by a Pulse type high Voltage Power Supply (펄스형 고전압 전원에 의한 선전리 현상의 관측과 질소레이저의 동작 특성)

  • Lee, Bong-Yeon
    • Korean Journal of Optics and Photonics
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    • v.17 no.1
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    • pp.60-67
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    • 2006
  • We constructed a TEA $N_2$ laser which consists of spark gap, pulse type high voltage power supply, Blumlein transmission line circuit, laser tube with Ernst electrode. We observed the self-preionization with an optical fiber in the spark gap and laser tube. The higher voltage power supplied to the Blumlein transmission line circuit, the better preionization was. An U-type transformer yielded better stability and output power than an I-type transformer. The discharge time after triggering a spark gap for the U-type transformer was also short. We obtained the stability of $2.7\%$ and output power of $36{\mu}J$ when the optimum conditions of the laser operation were spark gap distance of 6.0 mm, electrode distance in laser tube of 5.0 mm, $N_2$ gas flow rate in spark gap of 1500 cc/min, $N_2$ gas flow rate in laser tube of 4 ${\iota}$/min, output window reflectivity of $40\%$ and repetition rate of 10 Hz.

Modeling and Simulation of a Ship with Anti-Rolling Devices in Waves (자세제어장비를 장착한 선박의 파랑중 운동 모델링 및 시뮬레이션)

  • 윤현규;이경중;이창민
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.285-290
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    • 2004
  • Wave exciting force and moment generate the motions of a ship in waves. Since ship motion exerts the negative influences on a crew's operability, the safety of cargos, passenger's comfort, etc, the anti-rolling devices may be required to reduce such motion. In this paper, the dynamics of the anti-rolling devices such as passive and active moving weight stabilizer and anti-rolling tank, and fin stabilizer are mathematically modeled. While the effect of the motion of the anti-rolling device on a ship was taken into consideration in roll mode only in the past, the 6 DOF coupled equations of motion between a ship and the anti-rolling devices are constituted. Finally the motion of a ship with anti-rolling devices in waves is simulated through the developed simulation program.

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Study on Prediction and Control of Wind-Induced Heel Motion of Cruise Ship (바람 하중에 의한 크루즈선의 횡경사 예측 및 제어에 관한 연구)

  • Kim, Jae-Han;Kim, Yonghwan;Kim, Yong-Soo
    • Journal of the Society of Naval Architects of Korea
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    • v.50 no.4
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    • pp.206-216
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    • 2013
  • The present study considers the prediction of wind-induced heel of cruise ship and its stabilization. Wind load in ocean exerts on the surface of superstructure of cruise ship, which causes the heel moment on the ship. The calculation of wind load starts from choosing wind speed profile, so that the logarithmic wind profile model is applied in this study. Heel moment by wind load is calculated by adopting approximate formulation and applied to the ship motion analysis in time domain. Motion stabilizers, such as stabilizing fin and U-tube tank, are considered to reduce the heel effect as well as excessive roll motion. From this study, it is expected that the present method can be applied to the prediction and stabilization of the heel motion of cruise ships.

Analysis of Flow Characteristic and Optimum Design for Subminiature Pressure Reducer Under High Pressure (고압 적용용 초소형 감압기 설계를 위한 유동 해석 및 최적 설계)

  • Lee, WonJun;Baek, JongTae;Yun, Rin
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.41 no.8
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    • pp.497-503
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    • 2017
  • A theoretical study on oxygen flow is fundamental to comprehend the practical production of an oxygen respirator and its stability. In this study, an orifice-type pressure-reducing component was designed for the newly developed oxygen respirator, using the commercial CFD tool, COMSOL Multiphysics, which increases its operational time compared to the existing component. The orifice was optimized by changing the length by 3, 6, and 9 mm within the entire computational domain of the oxygen respirator. Based on an oxygen flow rate of 0.028 kg/s, the oxygen respirator equipped with the newly developed orifice satisfied the flow rate within 33% for a respirator inlet pressure of 300 bar, and within 32.7% for 50, 75, and 100 bar. In terms of component manufacturing, the orifice length was selected as 3 mm, which removes additional changes to the existing component.

Design of W-band 12-way radial power combiner (W-밴드 12-way radial 전력 결합기 설계)

  • Young-Gon Kim;Hyo-Chul Kim;Heung-Rae Cho;Han-Chun Ryu;Se-Hoon Kwon;Seon-Keol Woo
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.24 no.3
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    • pp.21-26
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    • 2024
  • Design and fabrication method of W-band 12-way radial power combiner is proposed in this paper. The proposed structure is used with TE10 to TEM mode converter, which is realized using 2-step impedance transformer. The pin structure for mode converter is well bonded to the housing so that environment conditions such as vibration or shock are not affected. Proposed W-band power combiner has less than 0.7 dB insertion loss and more than 13 dB return loss from 88 GHz to 98 GHz. The measured output isolations between each other are greater than 7.5 dB from 82 to 100 GHz and phase differences are less than 10 degree from 88 to 96 GHz. Proposed power combiner is expected compact radar and various applications requiring for high power and stable environment conditions.