• Title/Summary/Keyword: Radiation electric field

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A Study on a Planar Folded RFID Reader Antenna by Minimizing Hand Effects For UHF Band Application (Hand effect를 최소화한 평판 격자형 UHF대역 RFID 리더 안테나에 관한 연구)

  • Park, Joung-Geun;Lee, Jong-Chul
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.11 no.4
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    • pp.80-85
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    • 2012
  • In this paper, a new planar folded UHF band RFID reader antenna is suggested. For the antenna suggested in this paper, 4 PIFA (Planar Inverted F Antenna) micro-strip structures are adopted. The size is $50mm{\times}50mm{\times}6.2mm$. The gain of the antenna is 1.1 dBi, the VSWR is 1.2:1, and the efficiency is 63.3 %. The radiation pattern is designed as upper direction. Identification distance for the RFID tags is improved by minimizing hand effects with properly integrating 4 PIFAs.

Dipole Antennas and Radiation Patterns in the Three-Dimensional GPR Modeling (쌍극자 안테나를 고려한 3차원 지표레이다 탐사 모델링과 방사 패턴에 대한 고찰)

  • Choi Yun-Gyoung;Seo1 Soon-Jee;Suh Jung-Hee
    • Geophysics and Geophysical Exploration
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    • v.4 no.2
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    • pp.45-54
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    • 2001
  • A three-dimensional finite difference time-domain modeling algorithm based on staggered grid and considering transmitting and receiving antennas has been developed to simulate Ground Penetrating Radar (GPR) survey. This algorithm adopted the subcellular method to simulate the dipole antennas being used in GPR system and added resistors to reduce ringing caused by the reflections at the ends of an antenna. Comparison of the output voltages in the presence of the resistors for half-space said that the ringing and the amplitude of output voltage decreased as the number of resistors increased, and the antenna was designed based upon this result. Radiation patterns were derived to understand the distribution of electric field energy in the planes including or normal to the antenna. The electric field energy concentrated on vertical direction in the plane including antenna more than in normal plane.

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A Study on the Public Evacuation Time Estimates for Radiological Emergency Plan and Preparedness of Wolsong Nuclear Power Plant Site (방사선 비상계획을 위한 월성원전 주변 주민 소개시간 예측 연구)

  • Lee, Gab-Bock;Bang, Sun-Young;Chung, Yang-Geun
    • Journal of Radiation Protection and Research
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    • v.32 no.2
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    • pp.79-88
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    • 2007
  • When an accident occurs at nuclear power plant and radionuclide material is released to the area around the plant, public evacuation is considered as a measure to protect the safety of the residents nearby. This study draws factors required to estimate evacuation time and make estimation of the time to evacuate all residents from the EPZ of Wolsong site in consideration of traffic condition in the neighborhood and on the basis of field data around the site for each factor. The traffic capacity and the traffic volume by season were investigated for the traffic analysis and simulation within EPZ of Wolsong site. As a result, the background traffic volume by season were established. To estimate TGT(Trip Generation Time), the questionnaire surveys were carried out for resident and transient. The TSIS code was applied to traffic analysis in the events of daytime/night and normal/adverse weather under normal day/summer peak traffic condition. The results showed that the evacuation time required for total vehicles to move out from EPZ took generally from 118 to 150 minutes. The evacuation time took longer maximum 17 minutes at night than daytime during summer peak traffic.

Supplementary Blue and Red Radiation at Sunrise and Sunset Influences Growth of Ageratum, African Marigold, and Salvia Plants

  • Heo, Jeong-Wook;Lee, Yong-Beom;Bang, Hea-Son;Hong, Seung-Gil;Kang, Kee-Kyung
    • Korean Journal of Environmental Agriculture
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    • v.30 no.4
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    • pp.382-389
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    • 2011
  • BACKGROUND: Light-emitting diodes (LEDs) with lower electric cost and the specific wavelength have been considering as a novel light source for plant production in greenhouse conditions as well as in a closed culture system. Supplementary lighting for day-length extension was considered as light intensity, light quality, and/or photoperiod control on plant growth and development. Effects of supplementary blue or red LED radiation with lower light intensity on growth of Ageratum (Ageratum houstonianum Mill., cv. Blue Field), African marigold (Tagetes erecta L., cv. Orange Boy), and Salvia (Salvia splendens F. Sello ex Ruem & Schult., cv. Red Vista) were discussed during sunrise and sunset twilight in the experiment. METHODS AND RESULTS: Supplementary lighting by blue and red LEDs for 30 (Treatment B30; R30) or 60 (Treatment B60; R60) min. per day were established in greenhouse conditions. Photosynthetic photon flux for supplementary radiation was kept at $15{\mu}mol\;m^{-2}\;s^{-1}$ on the culture bed. Natural condition without supplementary light was considered as a control. The highest shoot and root dry weights were shown in African marigold exposed by red light for 60 min. per day. Supplementary blue and red lighting regardless of the radiation time significantly stimulated development of lateral branches in African marigold. Stem growth in Ageratum and Salvia seedlings was significantly promoted by red radiation as well as natural light. CONCLUSIONS: Extending of the radiation time at sunrise and sunset twilight using LEDs stimulated reproductive growth of flowering plant species. Different characteristics on growth under supplementary blue or red lighting conditions were also observed in the seedlings during supplementary radiation.

Study On Irradiation Effect By Co$^{60}$To The Condensers Which Are Used In Electronic Circuit (O.F paper condenser를 비롯한 전자회로용 condenser들에 대한 Co$^{60}$의 조사효과에 관한 연구)

  • 지철근;조성욱
    • 전기의세계
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    • v.23 no.3
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    • pp.67-69
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    • 1974
  • The electric characteristics of all the instruments and materials used in atomic field is changed due to radiation damages by the effects of radio activities. In this study, when the condenser is radiated by Gamma-ray, variations in its electric properties have been investigated. The following results are obtained. (1) The capacitance in O.F paper condenser is exponentially increased as the quantity of irradiation by Gamma-ray is increased, but polyethylene, ceramic, chemical, neostyrene, mylar condenser are decreased. and in case of more than 10$^{7}$ of irradiation it has saturated state, (2) The breakdown voltage and the .delta. in condensers except the O.F paper condenser are exponentially increased as the quantity of irradiation by Gamma-ray is increased but in case of more than 10$^{7}$ .gamma. of irradiation it has decreased.

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A Study on the Directivity of Portable Telephone Antenna (휴대 전화용 안테나의 지향성에 관한 연구)

  • 선승호;박수봉;김재이;고영혁
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.5 no.6
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    • pp.1151-1156
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    • 2001
  • In this paper, the electric field distribution and directivity on human head caused by portable phone is analyzed. An analysis model is composed of a human head model and the antenna mounted on the same ground plane as portable telephone size. The QMSA to load a capacitor without limitation of the electric force is used In the computational model to apply to the antenna mounted on portable phone. This antenna is designed to operate in the near of frequency 2.0㎓, is observed the radiation characteristics of the antenna and their variations as a function of distance from the human head.

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Prediction of Performance considering Ablated PTFE in High Voltage Self-blast Circuit Breaker (PTFE 용삭을 고려한 초고압 복합소호 차단기의 성능 예측)

  • Kim, Jin-Bum;Kweon, Ki-Yeoung;Lee, Hahk-Sung
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.695-698
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    • 2008
  • Self-blast circuit breakers utilize the energy dissipated by the arc itself to create the required conditions for arc quenching during the current zero. During the arcing period, high pressure, temperature and radiation of the arc could burn in pure SF6 gas and PTFE nozzle. Ablated nozzle shape and $SF_6$-PTFE mixture vapor affect the performance of an self-blast circuit breaker. After a number of tests, nozzle in circuit breaker is disassembled, a section of ablated nozzle is investigated precisely. Using computational fluid dynamics, the conservation equation for the gas and temperature, velocity and electric fields within breaker is solved. Before applying a section model, developed program is verified with experimental data. Performance of ablated nozzle shape is compared with original model through analysis program.

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Optimization Analysis for Homogeneous Field Structure of GTEM-CELL (GTEM-CELL의 균일한 필드구조를 갖기위한 최적화 분석)

  • Kim, Jong-Seong;Seo, Kang;Jeong, Seong-IL;Lee, Han-Young;Lee, Jong-Arc
    • Journal of IKEEE
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    • v.7 no.2 s.13
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    • pp.218-222
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    • 2003
  • Even if using the standard field test which radiation of electric wave and measurement test equipment there are difficult thing that building test equipment. so, we can use the substitution test field. In this paper, for optimization analysis for homogeneous field structure of GTEM-CELL (Giga hertz Transverse Electro Magnetic Cell) that calculate electromagnetic field characteristic for variable of each structure and characteristic impedance inner conductor.

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Analysis of the Transversely fed EMC Microstrip Dipole Array Antenna (급전선과 직교된 전자기결합 마이크로스트립 다이폴 배열안테나의 해석)

  • 손영수;윤현보
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.7 no.2
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    • pp.105-116
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    • 1996
  • The design and analysis of the transversely fed EMC(electromagnetically coupled) microstrip dipole have been accomplished by using the integral equation and MOM(method of moment)in frequency domain in order to find the current distribution of the dipole. In this study, we proposed the possibilities for design and analysis of EMC micro-strip dipole array antenna by means of calculating the current distribution of each dipole directly using the FDTD(finite difference time domain) method. In this case, we applied the formulation which is the finite difference expression of the Maxwell's integral equation. From the current distribution of each dipole, we calculated the far field electric component and showed that the calculation process and running time was reduced with respect to the method which calculates the radiation field with surface electric and magnetic current density.

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A Study on the Antenna for Mobile Communication (이동체 통신용 안테나에 관한 연구)

  • 고영혁;김재민;이종악
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.7 no.2
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    • pp.139-146
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    • 1996
  • In this paper, the total electric field antenna in the small loop and aperture plane structure to load a capacitance on transformed QMSA(Quarter-wavelength Microstrip Antenna) from MSA(Microstrip Antenna) is proposed, and the total electric field is shown that the calculated value is agreed resonably with experimental value. Itis a smalled antenna of the radiation element and ground plane with equal width. The designed and manufactured antenna can receive borth vertically and horizontally polarised waves to operating frequency of 1.5GHz; therefore this is available as a smalled antenna for wireless telephones and will be quit useful for indoor communication. Also, antenna's equivalent circuit with transmission line model is designed to find more accurate resonant frequency and is calculated return loss value. The calculated value is agreed resonably with experimental value.

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