• 제목/요약/키워드: Characteristic radiation

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A Study on the Characteristic of the $^6Li$ Neutron Spectrometer ($^6Li$ 중성자분광계 특성 연구)

  • Choe, Seong-Ho;Kang, Sam-Woo;Lee, Kwang-Pill;Lee, Kyung-Ju;Hwang, Sun-Tae
    • Analytical Science and Technology
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    • v.5 no.1
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    • pp.57-61
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    • 1992
  • For the neutron spectrum measurement, $^6Li$ neutron spectrometer system is installed. The characteristic of the $^6Li$ detector are investigated using a $^{137}Cs$ and $^{207}Bi$ point source, and the neutron capture peaks and the pulse height spectrum using an $^{214}Am-Be$ neutron source are measured. Furthermore, the pulse height spectrum for the irradiation time variation from the (214)^Am-Be neutron source, and for the distance variation between detector and source, and the threshold variation of discriminator are measured.

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A study on the Radiation Properties of Far-infrared and PTC Effect in the $BaTiO_3$ system by $MnO_2$ Amounts of Additives ($MnO_2$ 첨가량에 따른 $BaTiO_3$계의 PTC효과와 원적외선 방사특성에 관한 연구)

  • Song, Min-Joon;Park, Choon-Bae;Kang, Dou-Youl
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1993.05a
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    • pp.3-5
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    • 1993
  • It is very important that a spectrum of reflectance is in accord wi th a spectrum of absorbance for a effective heating. Therefore. the objective of this study was to achieve a technical composite for material plan which PTC thermistor increase a radiation property of far-infrared and keep a characteristic of R-T The Ceramic speciman studies had the composition $BaTiO_3$ with additive of 1.67 $Al_2O_3$, 3.75 $SiO_2$, 1.25 $TiO_2$, 0.15 $Sb_2O_3$ and 0.00-0.182 $MnO_2$. $MnO_2$ amounts of additives was both increase on the anomalous resistivity-temperature characteristics and high efficiency on the radiation properties bodies of far-infrared. This result shows that specimens produced high emissivity(average 0.8) of far-infrared at 4.5-15$[{\mu}m]$ by measuring a characteristic of IR and R-T.

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An Ultra Wideband Printed Monopole Antenna Using Modified Ground Plane (변형된 접지면을 이용한 초광대역 프린티드 모노폴 안테나)

  • Kim Myoung-Bum;Jung Jong-Ho;Park Ikmo
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.16 no.3 s.94
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    • pp.260-269
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    • 2005
  • In this paper, we propose a microstrip line fed printed monopole antenna which has an ultra-wideband characteristic. Proposed antenna can improve the bandwidth characteristic with the taper structure formed by modified ground plane and radiating element. Measured impedance bandwidth ratio of the antenna is more than 30:1; from the lower frequency of 0.89 GHz to the upper frequency of more than 30 GHz for VSRW$\leq$2. The antenna has conical radiation pattern that has low radiation gain to $\theta$=0$^{\circ}$ direction and higher radiation gains as $\theta$ increases.

Modeling of Combustion in Co-Generation / Industrial Boiler Furnace (열병합/산업용 보일러 화로에서의 연소 해석)

  • Kim, Byoung-Yun;Park, Pu-Min;Lee, Kyoung-Mo
    • Proceedings of the KSME Conference
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    • 2001.11b
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    • pp.842-846
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    • 2001
  • Our company produces boilers for industrial usages or power plants. The aim of this study is to investigate the flame structure, heat transfer to evaporator tube wall and NOx emission in the furnaces. Also we are to derive correct FEGT(Furnace Exit Gas Temperature) characteristic curve. When we design furnace and superheater, economizer etc. FEGT characteristic curve is very important factor for optimum design. We calculated turbulent reacting flow, heat transfer and NOx emission in furnace by using numerical modeling with the help of commercial code. Three dimensional steady state calculation is done. k-e turbulence model and equilibrium chemistry combustion model with $\beta-probability$ density function is used. To calculate radiation heat transfer discrete ordinates model is used. And we measured FEGT at several operating plants. Measurement is done by R-type thermocouple. Radiation shield is attached to the thermocouple to prevent radiation effect. Measured and calculated results show good agreement. And we could understand the flame structure and NOx formation positions in each furnaces.

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A Study on Monopole Antenna Radiation Pattern inside Vehicle (차량 내부에서의 모노폴 안테나 방사패턴 연구)

  • Lee, Tae-Hak;Pyo, Seong-Min;Park, Sang-Myeong;Kim, Young-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.11
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    • pp.4537-4542
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    • 2010
  • In this paper, the antenna radiation pattern inside the vehicle is presented for observing the change occurring in non-anechoic environment using monopole antenna. The environment for radio communication can be affected by antenna characteristic variation inside the small space existing multi reflection waves. To perform simulation and measurement about antenna radiation pattern, the radio frequency bands for GPS and Wibro services expected to use inside the vehicle is selected. The simulation is based on the ray-tracing method and the radiation pattern is measured inside the vehicle and in free space using monopole antenna having those frequency bands. In accordance with the measurement and simulation results, when two antennas are put inside the vehicle, the omni-directional characteristic of the antenna is maintained but the received power is increased than free space case and the difference between the each case of measurements is increased as the operating frequency is increased.

A Consideration on the Characteristics of Electron Beam Dose Distributions for Clinical Applications (임상적용을 위한 전자선의 선량분포 특성에 대한 고찰)

  • Cha, Dong-Soo
    • Korean Journal of Digital Imaging in Medicine
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    • v.12 no.1
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    • pp.65-69
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    • 2010
  • High energy electron beams were to concentrically dose inside a tumor and more energy is a shape decreased of dose. Therefore, it is useful to radiation therapy of a tumor. Also high energy electron beams ionized into collision with a atom in structure material of tissue and it has big changes to dose distribution by multiple scattering. The study had to establish characteristic of electron beams from interaction of electron beams and materials. Experiment method was to measure dependence of electron beam central axis for depth dose curve, field flatness and symmetry and field size dependence. The results were able to evaluate data for a datum pint of electron beam. Also radiotherapy has to be considered for not only energy pencil of lines but characteristic, electron guide and isodose curves distribution.

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Design and Fabrication of Direct Conversion RF Module using Even Harmonic Mixer for 2-4GHz ISM band (Even Harmonic Mixer를 이용한 2.4GHz ISM band용 Direct Conversion방식의 RF Module 설계 및 제작)

  • 이주갑;윤영섭;최현철
    • Proceedings of the Korea Electromagnetic Engineering Society Conference
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    • 2001.11a
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    • pp.222-226
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    • 2001
  • In this paper, 2.4GHz RF Module using Even Harmonic Mixer(EHM) was designed and fabricated for Direct conversion(DC) system. By minimizing performance degradation of DC system with DC offset and LO radiation, the capability of minimization and one chip solution in wireless system was proposed. The designed EHM using anti-parallel diode pair represented 9dB conversion loss and about -60dBm 2LO leakage radiation in RF port, and output reflection and reverse transmission characteristic of low noise amplifier was improved. So superior DC offset suppression characteristic is expected. RF Module which consists of EHM, LNA, RF amplifier, Frequency synthesizer and Duplexer was designed and fabricated.

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Trapezoidal Monopole Microstrip Antenna for UWB (UWB용 사다리꼴 모노폴 마이크로스트립 안테나)

  • Joo, Chang-Bok
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.46 no.2
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    • pp.134-140
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    • 2009
  • In this paper, we discussed the trapezoidal antenna model in the microstrip structure for UWB communications in the frequency band of $3.1{\times}10.6GHz$. Through the computer simulations for the difference size of trapezoidal monopole microstrip antenna model, the good impedance matching characteristic of return loss less than -10dB(VSWR<2) in all the band of UWB showed. The optimized antenna of this paper also showed the quasi-isotropic radiation characteristics in the horizontal plane and linear phase characteristic of nondispersive property.

Characteristic Plain Radiographic and Intravenous Urographic Findings of Bladder Calculi Formed over a Hair Nidus: A Case Report

  • Hak Jong Lee;Seung Hyup Kim
    • Korean Journal of Radiology
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    • v.2 no.1
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    • pp.61-62
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    • 2001
  • We present the characteristic plain radiographic and intravenous urographic (IVU) findings of calculus formed over a hair. A 66-year-old man who had been quadriplegic for 40 years because of vertebral injury was admitted for further evaluation of frequent urinary tract infection. Plain radiography showed a linear, serpiginous calcification in the lower abdomen, and IVU revealed a round filling defect with linear radiopacity in the bladder, suggesting calculus. The gross appearance of the stone after extraction demonstrated that calcification had formed over a hair.

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System Development for Road Noise Prediction of Automobile Tire (자동차 타이어 도로소음 예측 시스템 개발)

  • 김병삼
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.7 no.2
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    • pp.81-90
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    • 1998
  • Noise produced by surface transportation vehicles affects our daily lives, penetrating wherver man lives or works. In this paper, a theoretical model has been studied to describe the sound radiation by the surface vibration of in-service tires and studied about an experiment on sound radiation characteristic due to tire vibration. When a tire is analyzed, it has been modeled as a curved beams with distributed sprongs and dash-pots which represent the radial, tangential stiffnes and damping of tire, respectively. The experimental investigation for the sound radiation of a radial tire has been made. Based on the sound intensity and STSF(Spatial Transformation of Sound Field) techniques. the sound pressure and the sound radiation are measured. The comparison of numerically analyzed results with experimental results was made seperately for the tire in rotation. As a result of this study, a program for the prediction of the tire vibration sound radiation was intended to by developed which enables a designer of a tire to foresee the influence of the various design factors on the tire vibration sound radiation.

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