• 제목/요약/키워드: RMC

검색결과 90건 처리시간 0.028초

RMC를 이용한 미지 선원의 방향, 거리 예측 (Estimating the Direction and Distance of an Unknown Radiation Source Using RMC)

  • 신영준;김기현;이계민
    • 전자공학회논문지
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    • 제53권9호
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    • pp.118-125
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    • 2016
  • 방사능 누출 사고 시 대응이나 핵안보 검증을 위한 핵물질 탐지에 있어서, 방사선을 방출하는 미지의 선원에 대한 위치 정보를 파악하는 것은 중요하다. 그러한 기구 중 하나인 회전 변조 시준기는 미지 선원을 원격 감지하기 위한 장비로서 영상화를 통해 선원의 위치 탐지가 가능하다. 본 논문에서는 Kowash의 연구를 기초로 회전 변조 시준기의 시스템 모델과 그를 영상화하는 알고리즘을 소개한다. 하지만 결과 영상화 이미지는 선원의 방향은 보여줄 수 있으나 선원의 거리를 찾지 못하는 문제점이 있다. 또한 선원의 실제 방향뿐 아니라 $180^{\circ}$ 대칭방향에서도 선원을 추정하는 모호성 문제를 안고 있다. 본 논문에서 우리는 영상화 결과의 방향 대칭적 모호성을 해결하고, 두 대의 RMC를 이용해 거리를 추정하는 방법을 제안한다. 그리고 이를 RMC 시뮬레이션 데이터를 이용하여 성능을 검증한다.

Design and Fabrication of CLYC-Based Rotational Modulation Collimator (RMC) System for Gamma-Ray/Neutron Dual-Particle Imager

  • Kim, Hyun Suk;Lee, Jooyub;Choi, Sanghun;Bang, Young-bong;Ye, Sung-Joon;Kim, Geehyun
    • Journal of Radiation Protection and Research
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    • 제46권3호
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    • pp.112-119
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    • 2021
  • Background: This work aims to develop a new imaging system based on a pulse shape discrimination-capable Cs2LiYCl6:Ce (CLYC) scintillation detector combined with the rotational modulation collimator (RMC) technique for dual-particle imaging. Materials and Methods: In this study, a CLYC-based RMC system was designed based on Monte Carlo simulations, and a prototype was fabricated. Therein, a rotation control system was developed to rotate the RMC unit precisely, and a graphical user interface-based software was also developed to operate the data acquisition with RMC rotation. The RMC system was developed to allow combining various types of collimator masks and detectors interchangeably, making the imaging system more versatile for various applications and conditions. Results and Discussion: Operational performance of the fabricated system was studied by checking the accuracy and precision of the collimator rotation and obtaining modulation patterns from a gamma-ray source repeatedly. Conclusion: The prototype RMC system showed reliability in its mechanical properties and reproducibility in the acquisition of modulation patterns, and it will be further investigated for its dual-particle imaging capability with various complex radioactive source conditions.

Secondary Neurulation Defects-1 : Retained Medullary Cord

  • Kim, Kyung Hyun;Lee, Ji Yeoun;Wang, Kyu-Chang
    • Journal of Korean Neurosurgical Society
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    • 제63권3호
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    • pp.314-320
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    • 2020
  • Retained medullary cord (RMC) is a relatively recent term. Pang et al. newly defined the RMC as a late arrest of secondary neurulation leaving a non-functional vestigial portion at the tip of the conus medullaris. RMC, which belongs to the category of closed spinal dysraphism, is a cord-like structure that is elongated from the conus toward the cul-de-sac. Because intraoperative electrophysiological confirmation of a non-functional conus is essential for the diagnosis of RMC, only a tentative or an assumptive diagnosis is possible before surgery or in cases of limited surgical exposure. We suggest the term 'possible RMC' for these cases. An RMC may cause tethered cord syndrome and thus requires surgery. This article reviews the literature to elucidate the pathoembryogenesis, clinical significance and treatment of RMCs.

Efficient Token Flow Design for the MPEG RMC Framework

  • Cui, Li;Kim, Sowon;Kim, Hyungyu;Jang, Euee S.
    • IEIE Transactions on Smart Processing and Computing
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    • 제3권5호
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    • pp.251-258
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    • 2014
  • This paper proposes an efficient token flow design methodology for a decoder in the MPEG Reconfigurable Media Coding (RMC) framework. The MPEG RMC framework facilitates a decoder to be configured with a set of modules called functional units (FUs) that are connected by tokens. Such a modular design philosophy of the MPEG RMC framework enables the reusability and reconfigurability of FUs. One drawback of the MPEG RMC framework is that the decoder performance can be affected by increasing the token transmissions between FUs. The proposed method improves the design of the FU network in the RMC framework toward real-time decoder implementation. In the proposed method, the merging of FU, the separation of token flow, and the merging of token transactions are applied to minimize the token traffic between FUs. The experimental results of the MPEG-4 SP decoder show that the proposed method reduces the total decoding time by up to 77 percent compared to the design of the RMC simulation model.

유성기어 소음을 고려한 pRMC 프로그램 개발 및 적용에 관한 연구 (Research for the Development of a pRMC Program for the Planetary Gear Noise)

  • 이현구;김무석;서현승;김진호;칼만아멧;하리안또자니;권현식
    • 한국소음진동공학회논문집
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    • 제23권7호
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    • pp.669-674
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    • 2013
  • To design the optimized low noise planetary gear sets, a program called pRMC(planetary run many cases) is developed. The pRMC is especially using a combination analysis method for all gear specifications and also able to analyze any type of planetary gear sets. The pRMC is composed of the 5 sections those are generate, setting, evaluate, combine and analysis. After calculating all candidate gear sets, the pRMC could show many results that represent the character of each gear set including the transmission error which is the main gear noise factor, the contact ratios, the bending stress and so on. By comparing the results objectively, user could predict and select the optimized gear set which has quiet noise level and desired durability. The planetary gear designed by pRMC could have reduced noise and vibration level from 5 to 10 dB than previous-designed one.

폴리프로필렌 섬유를 혼입한 레미콘의 강도 및 비파괴 시험 (Strength and Non-fracture Test of Ready Mixed Concrete Using Polypropylene Fiber)

  • 남기성;윤동채;윤여훈;성찬용
    • 한국농공학회:학술대회논문집
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    • 한국농공학회 2003년도 학술발표논문집
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    • pp.403-406
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    • 2003
  • This study is performed to evaluate the strength and nan-fracture test of the ready mixed concrete(RMC) using polypropylene. The slump is reached in $8{\pm}2cm$ of each RMC using polypropylene or without polypropylene, air content is reached in $4.5{\pm}1.5%$, the chloride content is below $0.3kg/m^3$. The compressive strength of RMC not using polypropylene is appeared over $210kgf/cm^2$ at the curing age 7 days and $239kgf/cm^2$ at the curing age 28 days. The compressive strength of RMC using polypropylene is appeared over $188kgf/cm^2$ at the curing age 7 days and $238kgf/cm^2$ at the curing age 28 days. The dynamic modulus of elasticity of RMC not using polypropylene is appeared over $298{\times}10^3kgf/cm^2$ at the curing age 7 days and $342{\times}10^3kgf/cm^2$ at the curing age 28 days. The RMC using polypropylene is appeared over $284{\times}10^3kgf/cm^2$ at the curing age 7 days and $238{\times}10^3kgf/cm^2$ at the curing age 28 days. The pulse velocity of RMC not using polypropylene is appeared over 4,198m/s at the curing age 7 days and 4,382m/s at the curing age 28 days. The RMC using polypropylene is appeared over 4,182m/s at the curing age 7 days and 4,342m/s at the curing age 28 days.

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색차 데이터 축소 기법을 사용한 BTC (Block Truncation Coding) 컬러 이미지 압축 (Block Truncation Coding using Reduction Method of Chrominance Data for Color Image Compression)

  • 조문기;윤영섭
    • 대한전자공학회논문지SD
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    • 제49권3호
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    • pp.30-36
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    • 2012
  • BTC 압축은 간단하고 효율적인 압축 알고리즘으로 알려져 있다. 본 논문에서는, 컬러 이미지 압축을 위한 RMC-BTC 알고리즘(RMC : reduction method chrominace data)을 제안한다. RMC-BTC coding은 chrominace data를 축소시키기 위해서, 각 BTC 블록에서, chrominace data를 평균으로 표현하는 방법과, luminance 데이터 의 bit-map을 chrominace 데이터의 bit-map으로 활용하여 chrominace 데이터를 표현하는 방법을 사용하였다. 시뮬레에션 결과는 기존의 BTC 알고리즘의 PSNR과 압축비율의 비교를 통해서, 제안한 알고리즘의 효율성을 확인하였다.

Criticality benchmarking of ENDF/B-VIII.0 and JEFF-3.3 neutron data libraries with RMC code

  • Zheng, Lei;Huang, Shanfang;Wang, Kan
    • Nuclear Engineering and Technology
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    • 제52권9호
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    • pp.1917-1925
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    • 2020
  • New versions of ENDF/B and JEFF data libraries have been released during the past two years with significant updates in the neutron reaction sublibrary and the thermal neutron scattering sublibrary. In order to get a more comprehensive impression of the criticality quality of these two latest neutron data libraries, and to provide reference for the selection of the evaluated nuclear data libraries for the science and engineering applications of the Reactor Monte Carlo code RMC, the criticality benchmarking of the two latest neutron data libraries has been performed. RMC was employed as the computational tools, whose processing capability for the continuous representation ENDF/B-VIII.0 thermal neutron scattering laws was developed. The RMC criticality validation suite consisting of 116 benchmarks was established for the benchmarking work. The latest ACE format data libraries of the neutron reaction and the thermal neutron scattering laws for ENDF/B-VIII.0, ENDF/B-VII.1, and JEFF-3.3 were downloaded from the corresponding official sites. The ENDF/B-VII.0 data library was also employed to provide code-to-code validation for RMC. All the calculations for the four different data libraries were performed by using a parallel version of RMC, and all the calculated standard deviations are lower than 30pcm. Comprehensive analyses including the C/E values with uncertainties, the δk/σ values, and the metrics of χ2 and < |Δ| >, were conducted and presented. The calculated keff eigenvalues based on the four data libraries generally agree well with the benchmark evaluations for most cases. Among the 116 criticality benchmarks, the numbers of the calculated keff eigenvalues which agree with the benchmark evaluations within 3σ interval (with a confidence level of 99.6%) are 107, 109, 112, and 113 for ENDF/B-VII.0, ENDF/B-VII.1, ENDF/B-VIII.0 and JEFF-3.3, respectively. The present results indicate that the ENDF/B-VIII.0 neutron data library has a better performance on average.

변동하중을 받는 강구조부재의 피로거동 해석 (The Fatigue Evaluation of Structural Steel Members under Variable-Amplitude Loading)

  • 장동일;곽종현;박용걸
    • 대한토목학회논문집
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    • 제8권2호
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    • pp.167-175
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    • 1988
  • 본 연구의 목적은 변동하중을 받는 구조부재의 피로거동을 해석하는 것이다. 이 연구의 해석과정은 다음과 같다. (1) 도로교의 실동응력파측정 및 통계적해석 (2) 등가의 일정진폭하중과, 통계적해석에 의해 모형화된 변동하중하(下)의 피로시험 (3) 등가응력개념의 RMC 모델에 의한 변동하중하(下)의 피로해석 등가응력개념에 의한 변동하중하(下)의 피로해석은 대부분의 구조용강재의 균열성장속도회귀지수가 $m{\fallingdotseq}3$이므로 이론적으로 RMC 모델이 합당하다. 변동하중하(下)의 피로시험해석결과 RMC 모델이 기존의 RMC 모델보다 변동하중에 의한 피로거동치(da/dN-${\Delta}K$, $N_f$)에 더 가까웠다. 또 변동하중하(下)에서 응력범위의 변화로 인한 interaction효과나 응력범위적용순서(sequence)효과 등은 피로수명에 거의 영향을 미치지 않으며, 응력범위변화속도가 클수록 피로균열성장속도가 빨라짐을 알 수 있었다.

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