• Title/Summary/Keyword: Radiatin

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Characteristics mode analysis for the finite slotted parallel-plate waveguide as a leaky wave antenna structure (유전체로 채워진 유한한 슬롯을 가지는 평행평판 도파관 누설파 안테나 구조에 대한 특성 모드 해석)

  • 윤이호;조영기
    • Journal of the Korean Institute of Telematics and Electronics D
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    • v.34D no.10
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    • pp.32-38
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    • 1997
  • A characteristic mode analysis of parallel-plate waveguide with finite number of slot as a leaky wav eantenna structure is considered for calculating the characteristics currents, the characteristic patterns, radiatin patterns, and the complex propagation constants. For the cases of 1, 11 and 29 slots, numericl resutls for the equivalent magnetic currents, the radiatin patterns, and thecomplex propagation constants are computed and compared with those obtained by use of the conventional method of moments. Good correspondence between them is observed.

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Trial Design of a Very Large Floating Airport (General Arrangement and Decision of Depth) (초대형 부유식 해상공항의 시설계 (일반배치와 깊이 결정))

  • 신현경;임춘규;정재희
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.10a
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    • pp.45-49
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    • 2001
  • The length and the breadth or a very large floating airport are determined by airplane types and airport facilities. However, the depth affect not only the structural strength but also the functional requirement such as a possibility of taking off and landing. The optimization problem for determining the depth is to select a design so that the cost is minimized. In this paper, a general arrangement and a method to decide the depth are proposed. Strength, functional requirement, and possibility of occurrence of deck wetness and slamming are considered in order to determine the depth of structure. Hydrodynamic forces of the diffraction and radiatin problems are predicted by applying the source-dipole distribution method, and the structural responses are obtained by the finite element method.

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Combustion Characteristics and Soot Formation in a Jet Diffusion Flame (제트 확산화염의 연소특성과 매연생성에 관한 연구)

  • 이교우;백승욱
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.10
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    • pp.2712-2723
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    • 1994
  • Numerical simulation of an axisymmetric ethylene-air jet diffusion flame has been carried out in order to investigate flame dynamics and soot formation. The model solves the time-dependent Navier-Stokes equations and includes models for soot formation, chemical reaction, molecular diffusion, thermal conduction, and radiation. Numerically FCT(Flux Corrected Transport) and DOM(Discrete Ordinate Method) methos are used for convection and radiation trasport respectively. Simulation was conducted for a 5 cm/sec fuel jet flowing into a coflowing air stream. The maximum flame temperature was found to be approximately 2100 K, and was located at an axial position of approximately 5 cm from the base of the flame. The maximum soot volume fraction was about $7{\times}10^{-7}$, and was located within the high temperature region where the fuel mole fraction ranges from 0.01 to 0.1. The buoyancy-driven low-frequency(12~13 Hz) structures convected along the outer region of the flame were captured. In case without radiation trasport, the maximum temperature was higher by 150 K than in case with radiation. Also the maximum soot volume fraction reached about $8{\times}10^{-6}$. As the the hydrocarbon fuel forms many soot particles, the radiation transport becomes to play a more important role.

The analysis of radiatin field accuracy in uterine cervical cancer patients using verification films. (조사야 확인용 film을 이용한 자궁 경부암 환자의 조사야 정확성 연구)

  • Jung Hee-Young;Kweon Young-Ho;Jeong Deok-Yang;Whang Woong-Ku;Kim You-Hyun
    • The Journal of Korean Society for Radiation Therapy
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    • v.7 no.1
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    • pp.133-145
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    • 1995
  • 1. Purpose : 30 patients with uterine cervical cancer who had been treated at Department of radiation Oncology of Korea university Hospital from June, 1, 1994. to December. 31, 1994. were analyzed to the radiation field accuracy using verification films. 2. Methods and Materials : 30 patients were divided by 6 groups, 5 patients respectively : Group (1) : Standard physique, supine not-fixed Group (2) : Standard physique, supine fixed Group (3) : Obesity physique, supine, not-fixed Group (4) : Obesity physique, supine, not-fixed Group (5) : Obesity physique, prone, not-fixed Group (6) : Obesity physique, prone, fixed All groups were taken verification fimls during the whole treatment period, and it compared with simulation films and portal fimls, 3. Results : This results suggest that all patients should be immovilized and especially obesity physique patients should be treated by prone position in order to reduce radiation field discrepancy. In addition, this results should help to prescribe appropriate safty margins for patients simulation.

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The Outcome of Glioblastoma Patients Treated with Surgery and Radiation Therapy (두개 내 다형성아교모세포종 환자의 방사선치료 결과)

  • Nam Hee Rim;Lim Do Hoon;Ahn Yong Chan;Lee Jung I1;Nam Do-Hyun;Kim Jong Hyun;Hong Seung-Chyul;Lee Jeong Eun;Kang Min Kyu;Park Young Je;Kim Kyung Ju;Park Won;Huh Seung Jae
    • Radiation Oncology Journal
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    • v.22 no.2
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    • pp.91-97
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    • 2004
  • Propose: To Analyze the survival outcomes and prognostic factors In glioblastoma patients treated with surgery and radiation therapy. Materials and Methods : One hundred twenty glloblastoma patients treated with postoperative radiation therapy from 1994 to 2003 at Samsung Medical Center were retrospectively reviewed. Surgical extents were gross total resection in 22 patients (18$\%$), subtotal resection in 69 (58$\%$), and biopsy only in 29 (24$\%$). The median radiation dose was 50 Gy, ranging from 45 Gy to 72 Gy The median follow-up period was 12 months ranging from 2 to 52 months. Results The overall 1- and 2-year survival rates were 52$\%$ and 14$\%$, respectively, and the median survival duration was 13 months. Favorable prognostic factors by Uunivarlate analyses of prognostic factors on 1-year survival rate were revealed that age under 50 (p<0.01), ECOG performance status 0 or 1 (p=0.03), single lesion (p=0.02), and gross total resection (p=0.04), were the favorable prognostic (actors. and by Mmultlvarlate analyses were revealed that female (p<0.01), age under 50 (p<0.01), ECOG performance status 0 or 1 (p=0.05) and gross total resection (p=0.05) were the favorable prognostic factors. Conclusions : The results of our study were comparable with those previously reported. To Improve treatment outcome, various modifications, Including radiation dose escalation through newer radiation therapy techniques and use of effective chemotherapy regimen, should be further Investigated. Investigated. Also Furthermore, the application of Individualized treatment strategy based on 4he patient's prognostic factors might be needed.