• Title/Summary/Keyword: Variance Gamma

검색결과 89건 처리시간 0.021초

ICF 모델에 근거한 노인의 삶의 질 예측 모형 (Prediction Model of Quality of Life in Elderly Based on ICF Model)

  • 소희영;김현리;주경옥
    • 대한간호학회지
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    • 제41권4호
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    • pp.481-490
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    • 2011
  • Purpose: The purpose of this study was to identify from the International Classification of Functioning model, factors influencing quality of life in elderly persons and to describe the concrete pathway of influence and the power of each variable. Methods: The sample included 334 elders who lived in 5 districts of D Metropolitan City. A structured questionnaire was used and the collected data were analyzed for fitness, using the AMOS 18.0 program. Results: This model was concise and extensive in predicting the quality of life of elders. The research verified the factors influencing quality of life for elders as direct factors such as activity of daily living (ADL) (${\beta}$=.13, t=2.47), leisure activity (${\beta}$=.55, t=5.04), social disengagement (${\beta}$=-.25, t=-2.25), and depression (${\beta}$=-.62, t=-10.86). Indirect factors including economic status (${\gamma}$=.17, p=.009), type of residence (${\gamma}$=.19, p=.004), ADL (${\gamma}$=.12, p=.027) were important factors in predicting quality of life for elders. These variables explained 75.6% of variance in the prediction model. Conclusion: The findings indicate a need for the nursing scientific community to develop intervention programs considering these variables to improve the quality of life for elders.

EM기반의 감마 CT 영상복원을 위한 가중치 함수 비교분석 (Comparative Analysis of the Weight Functions for the Reconstruction of a Gamma-ray CT based on the EM Technique)

  • 이나영;정성희;김종범;김진섭;김재호
    • 비파괴검사학회지
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    • 제27권5호
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    • pp.449-458
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    • 2007
  • 본 논문에서는 감마선을 이용하여 석유화학 공정설비 내부의 단면영상을 복원하였다. 감마 CT 영상 복원을 위해 $5\;mm{\phi}$ 감마선을 팬텀에 조사하여 NaI(T1) 섬광검출기로 스캔하였으며 반복적인 영상복원 방법인 EM 기법으로 가중치 함수를 비교하였다. 감마 CT 영상이 정확히 복원되었는지 확인하기위하여 3가지 가중치 함수에 대해 히스토그램의 명암값 분포를 비교하였다. 실험 결과를 통해 빔 면적에 의한 가중치 함수로 복원할 경우, 원 영상에 가장 가깝게 복원되는 것을 확인하였다.

Shielding design and analyses of the cold neutron guide hall for the KIPT neutron source facility

  • Zhong, Zhaopeng;Gohar, Yousry
    • Nuclear Engineering and Technology
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    • 제50권6호
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    • pp.989-995
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    • 2018
  • Argonne National Laboratory of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have cooperated on the development, design, and construction of a neutron source facility. The facility was constructed at Kharkov, Ukraine, and its commissioning process is underway. The facility will be used for researches, producing medical isotopes, and training young nuclear specialists. The neutron source facility is designed with a provision to include a cryogenically cooled moderator system-a cold neutron source (CNS). This CNS provides low-energy neutrons, which will be used in the scattering experiment and material structures analysis. Cold neutron guides, coated with reflective material for the low-energy neutrons, will be used to transport the cold neutrons to the experimental site. The cold neutron guides would keep the cold neutrons within certain energy and angular space concentrated inside, while most of the gamma rays and high-energy neutrons are not affected by the cold neutron guides. For the KIPT design, the cold neutron guides need to extend several meters outside the main shield of the facility, and curved guides will also be used to remove the gamma and high-energy neutron. The neutron guides should be installed inside a shield structure to ensure an acceptable biological dose in the facility hall. Heavy concrete is the selected shielding material because of its acceptable performance and cost. Shield design analysis was carried out for the CNS guide hall. MCNPX was used as the major computation tool for the design analysis, with neutron and gamma dose calculated separately. Weight windows variance reduction technique was also used in the shield design. The goal of the shield design is to keep the total radiation dose below the $5.0{\mu}Sv/hr$ guideline outside the shield boundary. After a series of iterative MCNPX calculations, the shield configuration and parameters of CNS guide hall were determined and presented in this article.

Gamma-Aminobutyric Acid Production from a Novel Enterococcus avium JS-N6B4 Strain Isolated from Edible Insects

  • Jo, Min-Ho;Hong, Seong-Jin;Lee, Ha-Nul;Ju, Jung-Hyun;Park, Bo-Ram;Lee, Jun-ho;Kim, Sun-Am;Eun, Jong-Bang;Wee, Young-Jung;Kim, Young-Min
    • Journal of Microbiology and Biotechnology
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    • 제29권6호
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    • pp.933-943
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    • 2019
  • Gamma-aminobutyric acid (GABA)-producing strains were isolated from four edible insects and subjected to 16S rRNA sequence analysis. Among the four GABA-producing bacteria, Enterococcus avium JS-N6B4 exhibited the highest GABA-production, while cultivation temperature, initial pH, aerobic condition, and mono-sodium glutamate (MSG) feeding were found to be the key factors affecting GABA production rate. The culture condition was optimized in terms of glucose, yeast extract, and MSG concentrations using response surface methodology (RSM). GABA production up to 16.64 g/l was obtained under the conditions of 7 g/l glucose, 45 g/l yeast extract, and 62 g/l MSG through the optimization of medium composition by RSM. Experimental GABA production was 13.68 g/l, which was close to the predicted value (16.64 g/l) calculated from the analysis of variance, and 2.79-fold higher than the production achieved with basic medium. Therefore, GABA-producing strains may help improve the GABA production in edible insects, and provide a new approach to the use of edible insects as effective food biomaterials.

ON THE RATES OF THE ALMOST SURE CONVERGENCE FOR SELF-NORMALIZED LAW OF THE ITERATED LOGARITHM

  • Pang, Tian-Xiao
    • 대한수학회보
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    • 제48권6호
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    • pp.1137-1146
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    • 2011
  • Let {$X_i$, $i{\geq}1$} be a sequence of i.i.d. nondegenerate random variables which is in the domain of attraction of the normal law with mean zero and possibly infinite variance. Denote $S_n={\sum}_{i=1}^n\;X_i$, $M_n=max_{1{\leq}i{\leq}n}\;{\mid}S_i{\mid}$ and $V_n^2={\sum}_{i=1}^n\;X_i^2$. Then for d > -1, we showed that under some regularity conditions, $$\lim_{{\varepsilon}{\searrow}0}{\varepsilon}^2^{d+1}\sum_{n=1}^{\infty}\frac{(loglogn)^d}{nlogn}I\{M_n/V_n{\geq}\sqrt{2loglogn}({\varepsilon}+{\alpha}_n)\}=\frac{2}{\sqrt{\pi}(1+d)}{\Gamma}(d+3/2)\sum_{k=0}^{\infty}\frac{(-1)^k}{(2k+1)^{2d+2}}\;a.s.$$ holds in this paper, where If g denotes the indicator function.

전력 공급신뢰도 평가를 위한 교육용 소프트웨어 개발 (A Development of Educational Software for Power System Reliability Assessment)

  • 김광원
    • 조명전기설비학회논문지
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    • 제29권7호
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    • pp.71-79
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    • 2015
  • This paper is on the development of computer software which can be utilized as a power system analysis tool for reliability assessment education. The input data of the developed software are so simple that even a non-expert easily understand how to use it. The software provides not only reliability indices but also their distributions, moreover, it provides the factors those effect the indices, which made the software even more useful for educational purpose. The developed software utilized Monte-carlo simulation based on the state duration sampling, therefore it can manage various probability distributions such as exponential, Weibull, gamma and lognormal distribution. Within the software, the parameters of the distribution can be decided automatically from its mean and variance, that is another advantage as an educational software.

Average performance of risk-sensitive controlled orbiting satellite and three-degree-of-freedom structure

  • Won, Chang-Hee
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1995년도 Proceedings of the Korea Automation Control Conference, 10th (KACC); Seoul, Korea; 23-25 Oct. 1995
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    • pp.444-447
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    • 1995
  • The satellite in a circular orbit about a planet with disturbances and a three-degree-of-freedom (3DOF) structure under seismic excitations are modeled by the linear stochastic differential equations. Then the risk-sensitive optimal control method is applied to those equations. The mean and the variance of the cost function varies with respect to the risk-sensitivity parameter, .gamma.$_{RS}$ . For a particular risk-sensitivity parameter value, risk-sensitive control reduces to LQG control. Furthermore, the derivation of the mean square value of the state and control action are given for a finite-horizon full-state-feedback risk-sensitive control system. The risk-sensitive controller outperforms a classical LQG controller in the mean square sense of the state and the control action.

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On the Dependence Structure of Concornitants of Order Statistics

  • Song-Ho Kim;Tae-Sung Kim
    • Journal of the Korean Statistical Society
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    • 제25권2호
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    • pp.255-263
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    • 1996
  • Let $(X_{1j}, X_{2j}, … , X_{nj}, Y_j/)$j = 1, 2, … , n, be a sample of size n on an (m + l)-dimensional vector $(X_1, X_2, … , X_m, Y)$, m .geq. 1. If $Y_{(r)}$ denote the rth order statistic from Y, then the $X_{[r:n]}$ paired with $Y_(r)$ is termed the concomitant vector of the order statistics. The general distributions of concomitant of order statistics will be found. The mean, variance and covariance of$X_{[r:n]}$ Will be studied. Then we will apply the results to the multivariate normal variate case.e.

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최적 한켈 놈 근사화 문제의 통합형 해 (A unified solution to optimal Hankel-Norm approximation problem)

  • 윤상순;권오규
    • 제어로봇시스템학회논문지
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    • 제4권2호
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    • pp.170-177
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    • 1998
  • In this paper, a unified solution of Hankel norm approximation problem is proposed by $\delta$-operator. To derive the main result, all-pass property is derived from the inner and co-inner property in the $\delta$-domain. The solution of all-pass becomes an optimal Hankel norm approximation problem in .delta.-domain through LLFT(Low Linear Fractional Transformation) inserting feedback term $\phi(\gamma)$, which is a free design parameter, to hold the error bound desired against the variance between the original model and the solution of Hankel norm approximation problem. The proposed solution does not only cover continuous and discrete ones depending on sampling interval but also plays a key role in robust control and model reduction problem. The verification of the proposed solution is exemplified via simulation for the zero-order Hankel norm approximation problem and the model reduction problem applied to a 16th order MIMO system.

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Sensory Difference Testing: The Problem of Overdispersion and the Use of Beta Binomial Statistical Analysis

  • Lee, Hye-Seong;O'Mahony, Michael
    • Food Science and Biotechnology
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    • 제15권4호
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    • pp.494-498
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    • 2006
  • An increase in variance (overdispersion) can occur when a binomial statistical analysis is applied to sensory difference test data in which replicate sensory evaluations (tastings) and multiple evaluators (judges) are combined to increase the sample size. Such a practice can cause extensive Type I errors, leading to serious misinterpretations of the data, especially when traditional simple binomial analysis is applied. Alternatively, the use of beta binomial analysis will circumvent the problem of overdispersion. This brief review discusses the uses and computation methodology of beta binomial analysis and in practice evidence for the occurrence of overdispersion.