• Title/Summary/Keyword: Small Field

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Small Nuclear Units and Distributed Resource Prospects(1) (Small Nuclear Units에 의한 분산전원으로서의 전망(1))

  • Lee, Sang-Seung
    • Proceedings of the KIEE Conference
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    • 2005.07a
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    • pp.223-225
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    • 2005
  • This paper will be introduce a new paradigm and prospects for energy supply system in near future which produces electric and district heat cogeneration with dispersed power grid with small nuclear power units. Recently, in nuclear field, a lot of effort has been done in nuclear major countries to develop small and medium reactor for enhancement of nuclear peaceful use as like in district heating, electric power generation, seawater desalination or hydrogen generation. This paper presents a new way and prospects for power source in distribution system by using the distributed & remote cogeneration system using small reactor.

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Development of Mach Small-scaled Composite Blade for Helicopter Articulated Rotor System (헬리콥터 관절형 로터 시스템용 마하 축소 복합재료 블레이드 개발)

  • Kim, Deog-Kwan;Song, Keun-Woong;Kim, Joune-Ho;Joo, Gene
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.04a
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    • pp.57-60
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    • 2003
  • This Paper contains the development procedure of Mach small-scaled composite rotor blade for helicopter articulated rotor system. This mach small-scaled composite blade design is conducted by using CORDAS program developed by KARI. The Dynamic analysis for an articulated rotor system with this blade is conducted by using FLIGHTLAB which is commercial software for helicopter analysis. Also the optimizing procedure of iterative design was described. The designed composite blades were manufactured after establishing the effective curing method. For small-scaled rotor test, strain gauges were embedded in composite blade spar to obtain bending & torsion strain value. To verify sectional properties of a blade, the bench test is accomplished. After comparing a designed data and tested data, Dynamic Calculation was repeated using tested data. Through this research, experiences of mach small-scaled composite blade development were accumulated and will be applied to the related research field.

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Overview of Reliability Rank Measures for Small Sample (소표본인 경우 신뢰성 순위 척도의 고찰)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.9 no.2
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    • pp.161-169
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    • 2007
  • This paper presents three methods for expression of reliability measures for large and small data. First method is to express parametric estimation of cardinal reliability measure data for large sample, which requires numerous sample. Second is to obtain nonparametric distribution classification of ordinal reliability measure data for small sample. However it is difficult for field user to understand this method. Last method is to acquire parametric estimation of ordinal reliability measure data for small data. Because this method requires small sample and is comprehensive, we recommend this one among the proposed methods. Various reliability rank measures are presented.

Dosimetric Characteristics of Edge $Detector^{TM}$ in Small Beam Dosimetry (소조사면 선량 계측을 위한 엣지검출기의 특성 분석)

  • Chang, Kyung-Hwan;Lee, Bo-Ram;Kim, You-Hyun;Choi, Kyoung-Sik;Lee, Jung-Seok;Park, Byung-Moon;Bae, Yong-Ki;Hong, Se-Mie;Lee, Jeong-Woo
    • Progress in Medical Physics
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    • v.20 no.4
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    • pp.191-198
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    • 2009
  • In this study, we evaluated an edge detector for small-beam dosimetry. We measured the dose linearity, dose rate dependence, output factor, beam profiles, and percentage depth dose using an edge detector (Model 1118 Edge) for 6-MV photon beams at different field sizes and depths. The obtained values were compared with those obtained using a standard volume ionization chamber (CC13) and photon diode detector (PFD). The dose linearity results for the three detectors showed good agreement within 1%. The edge detector had the best linearity of ${\pm}0.08%$. The edge detector and PFD showed little dose rate dependency throughout the range of 100~600 MU/min, while CC13 showed a significant discrepancy of approximately -5% at 100 MU/min. The output factors of the three detectors showed good agreement within 1% for the tested field sizes. However, the output factor of CC13 compared to the other two detectors had a maximum difference of 21% for small field sizes (${\sim}4{\times}4\;cm^2$). When analyzing the 20~80% penumbra, the penumbra measured using CC13 was approximately two times wider than that using the edge detector for all field sizes. The width measured using PFD was approximately 30% wider for all field sizes. Compared to the edge detector, the 10~90% penumbras measured using the CC13 and PFD were approximately 55% and 19% wider, respectively. The full width at half maximum (FWHM) of the edge detector was close to the real field size, while the other two detectors measured values that were 8~10% greater for all field sizes. Percentage depth doses measured by the three detectors corresponded to each other for small beams. Based on the results, we consider the edge detector as an appropriate small-beam detector, while CC13 and PFD can lead to some errors when used for small beam fields under $4{\times}4\;cm^2$.

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Feasibility of Shrinking Field Radiation Therapy through 18F-FDG PET/CT after 40 Gy for Stage III Non-Small Cell Lung Cancers

  • Ding, Xiu-Ping;Zhang, Jian;Li, Bao-Sheng;Li, Hong-Sheng;Wang, Zhong-Tang;Yi, Yan;Sun, Hong-Fu;Wang, Dong-Qing
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.1
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    • pp.319-323
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    • 2012
  • Objective: To explore the feasibility of shrinking field technique after 40 Gy radiation through 18F-FDG PET/CT during treatment for patients with stage III non-small cell lung cancer (NSCLC). Methods: In 66 consecutive patients with local-advanced NSCLC, 18F-FDG PET/CT scanning was performed prior to treatment and repeated after 40 Gy. Conventionally fractionated IMRT or CRT plans to a median total dose of 66Gy (range, 60-78Gy) were generated. The target volumes were delineated in composite images of CT and PET. Plan 1 was designed for 40 Gy to the initial planning target volume (PTV) with a subsequent 20-28 Gy-boost to the shrunken PTV. Plan 2 was delivering the same dose to the initial PTV without shrinking field. Accumulated doses of normal tissues were calculated using deformable image registration during the treatment course. Results: The median GTV and PTV reduction were 35% and 30% after 40 Gy treatment. Target volume reduction was correlated with chemotherapy and sex. In plan 2, delivering the same dose to the initial PTV could have only been achieved in 10 (15.2%) patients. Significant differences (p<0.05) were observed regarding doses to the lung, spinal cord, esophagus and heart. Conclusions: Radiotherapy adaptive to tumor shrinkage determined by repeated 18F-FDG PET/CT after 40 Gy during treatment course might be feasible to spare more normal tissues, and has the potential to allow dose escalation and increased local control.

Systematic Studies of Korean Rodents. V. Morphometric and Chromosomal Analyses on Island Populations of Striped Field Mice (Apodemus agrarius coreae) in Southwestern coasts of the Korean Peninsula (한국산 설치류의 계통분류학적 연구 5.한반도 남서해안의 섬들에 살고 있는 등줄쥐들의 형태적 형질 및 염색체의 분석)

  • Koh, Hung Sun
    • Animal Systematics, Evolution and Diversity
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    • v.5 no.1
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    • pp.1-12
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    • 1989
  • Samples of striped field mice, Apodemus agrarius Pallas, from eight localities in s southwestern islands and coasts in Korea were collected and analyzed together with samples from the mainland and Jeju island. In chromosomal analyses no variation was revealed in karyotypes among samples from Korea. In morphometric analyses samples from Wan and Bogil islands formed a large-size g group (A. agrarius chejuensis) with those from Jeju island, whereas samples from Jin and H Hajo islands formed a small-size group (A. agrarius coreae) with those from the mainland including southwestern coasts It is supposed that small-size population of striped field mice in Wan and Bogil islands w were extinct and replaced by large-szie population of striped field mice immigrated from Jeju island by humans.

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Resonant Transmission of a Rectangular Waveguide Probe with H-type Small Aperture (H-형태 소형 개구를 가진 직사각형 도파관 탐침의 공진 투과)

  • Ko, Ji-Hwan;Cho, Young-Ki
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.24 no.12
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    • pp.1198-1204
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    • 2013
  • As a microwave near field probe for near field scanning optical microscope(NSOM) system, H-shaped(ridge type) small aperture is proposed and its performances from the viewpoints of the transmission efficiency(transmission cross section) and spatial confinement(beam spot size) are compared with those of the previous narrow rectangular aperture type. While the transmission efficiencies are comparable to each other for the two structures, the transmitted beam spot size for the proposed H-shaped aperture is much smaller than that for the previous rectangular aperture. This strong point of the H-shaped aperture is expected to significantly improve near-field optical applications such as optical data storage, nanolithography and nanomicroscopy. It is also observed that the transmission efficiency can be improved if the coupling aperture is implemented in the type of the transmission cavity.