• 제목/요약/키워드: escape probability

검색결과 38건 처리시간 0.025초

A Parametric Study on Secondary Electron Emission from MgO

  • Yoon, Sang-Hoon;Kim, Yong-Seog
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.953-956
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    • 2008
  • Using the theoretical model of Auger electron emission, effects of MgO properties which include band gap energy, escape probability, gas ion, and doping elements on the yield of secondary electron emission were examined. The results indicated that the band gap of MgO must be decreased and escape probability must be enhanced in order to increase the yield of secondary electrons from Xe ions and that may proved to be a critical for achieving high luminance efficacy in ac-PDPs.

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FORMATION OF LINE PROFILE: SEI METHOD

  • CHOE SEUNG-URN;KANG MIN-YOUNG;KIM KYUNG-MEE
    • 천문학회지
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    • 제29권2호
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    • pp.93-105
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    • 1996
  • We have solved the radiative transfer problem using a Sobolev approximation with an escape probability method in case of the supersonic expansion of a stellar envelope to an ambient medium. The radiation from the expanding envelope turns out to produce a P-Cygni type profile. In order to investigate the morphology of the theoretical P-Cygni type profile, we have treated $V_\infty,\;V_{sto},\;\beta$ (parameters for the velocity field), it and E(parameter for collisional effect) as model parameters. We have investigated that the velocity field and the mass loss rate affect the shapes of the P-Cygni type profiles most effectively. The secondarily important factors are $V_\infty,\;V_{sto}$. The collisional effect tends to make the total flux increased but not so much in magnitude. We have infered some physical parameters of 68 Cyg, HD24912, and $\xi$ persei such as $V_\infty,\;M$ from the model calculation, which shows a good agreenment with the observational results.

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Investigation of the Sensitivity Depletion Laws for Rhodium Self-Powered Neutrorn Detectors (SPNDs)

  • Kim, Gil-Gon;Cho, Nam-Zin
    • Nuclear Engineering and Technology
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    • 제33권2호
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    • pp.121-131
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    • 2001
  • An investigation of the sensitivity depletion laws for rhodium SPNDs was performed to reduce the uncertainty of the sensitivity depletion laws used in Combustion Engineering (CE) reactors and to develop calculational tools that provide the sensitivity depletion laws to interpret the signal of the newly designed rhodium SPND into the local neutron flux. The calculational tools developed in this work are computer programs for a time-dependent neutron flux distribution in the rhodium emitter during depletion and for a time-dependent beta escape probability that a beta particle generated in the emitter escapes into the collector. These programs provide the sensitivity depletion laws and show the reduction of the uncertainty by about 1 % compared to that of the method employed by CE in interpreting the signal into the local neutron flux. A reduction in the uncertainty by 1 % in interpreting the signal into the local neutron flux reduces the uncertainty tv about 1 % in interpreting the signal into the local power and lengthens the lifetime of the rhodium SPND by about 10% or more.

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FORMATION OF LINE PROFILES BY THE WINDS OF EARLY TYPE STARS

  • KANG IVIIN-YOUNG;KIM KYUNG-MEE;CHOE SEUNG-URN
    • 천문학회지
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    • 제29권spc1호
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    • pp.263-264
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    • 1996
  • We have solved the radiative transfer problem using a Sobolev approximation with an escape probability method in case of the supersonic expansion of a stellar envelope to an ambient medium. The radiation from the expanding envelope turns out to produce a P-Cygni type profile. In order to investigate the morphology of the theoretical P-Cygni type profile, we have treated $V{\infty},\;V_{sto},\;{\beta}$ (parameter for the velocity field), M and $\epsilon$ (parameter for collisional effect) as model parametrs. We have found that the velocity field and the mass loss rate affect the shapes of the P-Cygni type profiles most effectively. The secondarily important factors are $V{\infty},\;V_{sto}$. The collisional effect tends to make the total flux increase but not so .much in magnitude. We have infered some physical parameters of 68 Cyg, HD24912, and $\xi$ persei such as V$\infty$, M from the model calculation, which shows a good agreement with the observational results.

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희소 신호의 복원을 위한 확률적 배제 기반의 직교 정합 추구 알고리듬 (Probabilistic Exclusion Based Orthogonal Matching Pursuit Algorithm for Sparse Signal Reconstruction)

  • 김시현
    • 전기전자학회논문지
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    • 제17권3호
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    • pp.339-345
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    • 2013
  • 본 논문에서는 희소한 신호의 압축센싱를 위해 확률적 배제에 기반한 직교정합추구 (PEOMP) 신호 복원 알고리듬을 제안하였다. CoSaMP, gOMP, BAOMP 등의 알고리듬들은 매 반복 단계에서 새로운 atom들을 support set에 추가할 뿐만 아니라 부적절하다고 판단되어지는 atom들은 삭제하기 때문에 우수한 신호 복원 성능을 보인다. 그러나 반복 과정 중에 support set의 구성이 국소 최저점에서 벗어나지 못하여 신호 복원에 실패하는 경우가 발생하는 단점을 가지고 있다. 제안된 알고리듬은 매 반복 단계에서 확률적으로 임의의 atom을 배제하여 support set이 국소 최저점에 빠져 있는 경우 그곳에서 탈출하는데 도움을 준다. 모의실험을 통해 PEOMP가 기존의 OMP 기반의 알고리듬들과 $l_1$ 최적화 방법보다 신호 복원 능력 관점에서 우수한 성능을 보임을 확인하였다.

Monte Carlo 방법을 이용한 바나듐 자발 중성자계측기 초기 민감도 계산 (Calculation of Initial Sensitivity for Vanadium Self-Powered Neutron Detector (SPND) using Monte Carlo Method)

  • 차균호;박영우
    • 센서학회지
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    • 제25권3호
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    • pp.229-234
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    • 2016
  • Self-powered neutron detector (SPND) is being widely used to monitor the reactor core of the nuclear power plants. The SPND contains a neutron-sensitive metallic emitter surrounded by a ceramic insulator. Currently, the vanadium (V) SPND has been being developed to be used in OPR1000 nuclear power plants. Some Monte Carlo simulations were accomplished to calculate the initial sensitivity of vanadium emitter material and alumina insulator with a cylindrical geometry. An MCNP code was used to simulate some factors (neutron self-shielding factor and beta escape probability from the emitter) and space charge effect of an insulator necessary to calculate the sensitivity of vanadium detector. The simulation results were compared with some theoretical and experimental values. The method presented here can be used to analyze the optimum design of the vanadium SPND and contribute to the development of TMI (Top-mount In-core Instrumentation) which might be used in the SMART and SMR.

The $Schl\ddot{o}gl$ Model with the Second Order Transition Under the Influence of a Singular Multiplicative Random Force

  • Kyoung-Ran Kim;Dong J. Lee;Cheol-Ju Kim;Kook Joe Shin
    • Bulletin of the Korean Chemical Society
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    • 제15권8호
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    • pp.631-636
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    • 1994
  • For the Schlogl model with the second order transition under the influence of the multiplicative noise singular at the unstable steady state, the detailed discussions are presented for various kinds of stochastic phenomena, suchas the effects of parameters on stationary probability distribution, noise-induced phase transitions and escape rate.

농촌관광객의 지출비용 영향요인 분석 (An Analysis of Factors Affecting Rural Tourists' Expenditure)

  • 김경희;황대용;이혜영
    • 농촌지도와개발
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    • 제27권3호
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    • pp.135-144
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    • 2020
  • The aim of this study is to analyze the factors affecting rural tourists' expenditure. This study used the data from the fact-finding survey on rural tourism, and analyzed 4,223 cases who had experienced rural tourism for one year in 2018. The linear multiple regression analysis were used to identify factors affecting rural tourists' expenditure. The result indicate that the factors influencing the rural tourists' total expenditure were age, monthly income, number of accompany, length of stay, accommodation type(pension), accommodation type(friend's house/relatives'house), accommodation type(camping), distance to the destination, accompany(family/relatives), accompany(solo traveler), occupation(white color), motivation(daily escape and rest), motivation(new experience). The result indicate that the higher the age, the higher the average monthly income of the household, the fewer companions, the longer the length of stay higher the expenditure. As for the accommodation, the pension, motel/inn, hotel/condominium, and recreational forest higher probability of expenditure, while, friend/relative's house or camping higher the probability of less expenditure. The longer the distance to the destination, the solo traveler higher the probability of expenditure in rural tourism.

디지털 방송용 한글 허프만 부호 설계 및 PSIP 구조 (Huffman Code Design and PSIP Structure of Hangul Data for Digital Broadcasting)

  • 황재정;진경식;한학수;최준영;이진환
    • 방송공학회논문지
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    • 제6권1호
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    • pp.98-107
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    • 2001
  • 본 논문은 한글 텍스트 데이터에 대한 부호화 효율을 극대화시키는 관점에서 예외 부호화를 통해 최적의 허프만 부호를 얻는 다. 한글 코드는 표준 완성형과 유니 코드를 대상으로 하였으며 같은 허프만 부호를 부여하였다. 현재 우리나라의 디지털 TV는 한글 문자를 압축하지 않고 전송하는 형태이며. 본격적인 데이터 방송이 시작되면 한글 데이터가 차지하는 전송량으로 인한 심자 한 문제가 야기된다. 본 논문에서는 데이터 방송에서 문제가 되는 전송량을 줄이기 위해 한글 진용 퇴적의 허프만 부호를 생성한 다. 미국의 ATSC 표준을 바탕으로 한 디지털 TV 국내 표준에 적용하기 위해 프로그램 및 시스템 프로토콜(PSIP) 구조를 제안한 다. 결과로서. 발생확률 0.0043 이하의 확률을 갖는 문자를 예외 부호화하여 최대 47%의 압축율을 얻는 기법을 제안하였다.

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Improvement of dynamic encoding algorithm for searches (DEAS) using hopping unidirectional search (HUDS)

  • Choi, Seong-Chul;Kim, Nam-Gun;Kim, Jong-Wook;Kim, Sang-Woo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2005년도 ICCAS
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    • pp.324-329
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    • 2005
  • Dynamic Encoding Algorithm for Searches (DEAS) which is known as a fast and reliable non-gradient optimization method, was proposed [1]. DEAS reaches local or global optimum with binary strings (or binary matrices for multi-dimensional problem) by iterating the two operations; bisectional search (BSS) and unidirectional search (UDS). BSS increases binary strings by one digit (i.e., 0 or 1), while UDS performs increment or decrement of binary strings in the BSS' result direction with no change of string length. Because the interval of UDS exponentially decreases with increment of bit string length (BSL), DEAS is difficult to escape from local optimum when DEAS falls into local optimum. Therefore, this paper proposes hopping UDS (HUDS) which performs UDS by hopping as many as BSL in the final point of UDS process. HUDS helps to escape from local optimum and enhances a probability searching global optimization. The excellent performance of HUDS will be validated through the well-known benchmark functions.

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