• 제목/요약/키워드: Sample Size

검색결과 3,903건 처리시간 0.028초

독립인 두 모집단 설계에서의 표본수 비교 (Sample size comparison for two independent populations)

  • 고해원;김동재
    • Journal of the Korean Data and Information Science Society
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    • 제21권6호
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    • pp.1243-1251
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    • 2010
  • 임상시험을 시행하는 경우 위약을 신약과 비교하는 경우가 대다수이다. 기존에 독립인 두 모 집단의 표본수를 계산하는 방법으로 모수적 방법에서는 t검정을 이용하였고, 비모수적 방법에서는 Wilcoxon 순위합검정 (Wilcoxon, 1945)을 이용하였다. 본 논문에서는 Orban과 Wolfe (1982)가 제안한 선형위치통계량의 검정법과, Kim (1994)이 선형위치통계량에 기초하여 계산한 검정력의 결과를 이용하여 표본수 구하는 방법을 제안한다. 또한 앞서 제안한 방법의 표본수를 기존의 Wilcoxon 순위합검정을 이용하여 Wang 등 (2003)이 제안한 공식을 이용한 표본수, 그리고 모수적 방법을 이용한 t검정의 표본수와 비교하였다.

유도무기 시험평가 방법과 신뢰성 성장을 고려한 시험 수량 산출 (Calculation of Sample Size for Guided Missile Considering Test Method and Reliability Growth)

  • 이연호;김재황;이계신;이종신;이명진;김두현
    • 한국군사과학기술학회지
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    • 제20권6호
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    • pp.844-852
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    • 2017
  • Since guided weapon is high-cost and one-shot device which is non-reusable, it requires a lot of resources to prove required accuracy as a part of reliability demonstration. Once a test for proving accuracy rate of guided missile fails, it causes an additional cost and delay of schedule. This study introduces an equation for proper sample size and plan for guided-missile accuracy rate test in order to minimize the risk of test failure. Proper sample size for the test is derived by considering the reliability growth. Furthermore, each task for accuracy rate test is defined according to the development step. Therefore, this study can contribute to reduce sample size for accuracy rate test in order to meet the reliability requirement and assure transparency in the test process.

구간 교통량의 표준오차를 이용한 최적 O/D 표본수 산출 (Optimal O/D Sample Size Computation using link Volume Estimates)

  • 윤성순;김원규
    • 대한교통학회지
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    • 제12권1호
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    • pp.75-84
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    • 1994
  • In this paper we address the issue of how an optimal sample size computation relates the level of precision required for travel demand estimations and transportation planning. We approach the problem by 1) deriving a theoretical solution, 2) developing a computational procedure (algorithm) to implement the theoretical solution, and 3) demonstrating a practical application. Ultimately, we construct a formal scheme of optimal sample size computation for use in travel data collection processe.

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파괴시험 계수형 샘플링검사 경제적 시료 크기 결정에 관한 연구 (A Study on the Determination of the Economic Sample Size of the Attribute Acceptance Sampling Plans for Destructive Testing)

  • 김병재
    • 산업경영시스템학회지
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    • 제4권5호
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    • pp.11-14
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    • 1981
  • This study intends to decide the economic sample size based on the cost of sampling Inspection for destructive testing. The marginal percent defective is used as the lot tolerance percent defective (LTPD), and the Newton's iterative method is adopted to calculate the optimum sample size(n), given by the consumer's risk($\beta$ - risk) and the acceptance number(c).

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NEW SELECTION APPROACH FOR RESOLUTION AND BASIS FUNCTIONS IN WAVELET REGRESSION

  • Park, Chun Gun
    • Korean Journal of Mathematics
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    • 제22권2호
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    • pp.289-305
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    • 2014
  • In this paper we propose a new approach to the variable selection problem for a primary resolution and wavelet basis functions in wavelet regression. Most wavelet shrinkage methods focus on thresholding the wavelet coefficients, given a primary resolution which is usually determined by the sample size. However, both a primary resolution and the basis functions are affected by the shape of an unknown function rather than the sample size. Unlike existing methods, our method does not depend on the sample size and also takes into account the shape of the unknown function.

ASYMPTOTIC DEPENDENCE BETWEEN RANDOM CENTRAL QUASI-RANGES AND RANDOM EMPIRICAL QUANTILES

  • Nigm, E.M.
    • Journal of applied mathematics & informatics
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    • 제16권1_2호
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    • pp.289-302
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    • 2004
  • The asymptotic dependence between the central quasi-ranges and empirical quantiles was studied. The asymptotic dependence are obtained when the sample size is a positive integer valued random variable (r. v.). The dependence conditions and limit forms are obtained under generl conditions such as : the interrelation of the basic variables (the original random sample) and the random sample size is not restricted. In additition the normalizing constants do not depend on the random size.

Estimating the Population Size from a Truncated Sample

  • Yeo, Sung-Chil
    • Journal of the Korean Statistical Society
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    • 제29권2호
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    • pp.169-185
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    • 2000
  • Given a random sample of size N (unknown) with density f(x│$\theta$), suppose that only n observations which lie outside a region r are recorded. On the basis of n observation, the Bayes estimators of $\theta$ and N are considered and their asymptotic expansions are developed to find the third order asymptotic properties with those of the maximum likelihood estimators and the Bayes modal estimators. The asymptotic m.s.e.'s of these estimators are expressed. An example is given to illustrate the results obtained.

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Sample Size and Power Estimation in Case-Control Genetic Association Studies

  • Ahn Chul
    • Genomics & Informatics
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    • 제4권2호
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    • pp.51-56
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    • 2006
  • In planning a genetic association study, it is necessary to determine the number of samples to be collected for the study in order to achieve sufficient power to detect the hypothesized effect. The case-control design is increasingly used for genetic association studies due to the simplicity of its design. We review the methods for the sample size and power calculations in case-control genetic association studies between a marker locus and a disease phenotype.

2단계 추출을 이용한 표본크기 결정에 대한 평가 (Assessment for Sample Size Determination using Two-Stage Sampling Scheme)

  • 최경호
    • 응용통계연구
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    • 제11권2호
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    • pp.403-413
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    • 1998
  • 표본크기 결정 문제는 추정의 정밀도 및 조사비용에 영향을 주는 중요한 사안이다. 정규 모집단의 모평균 추정시 필요한 표본크기는 일반적으로 2단계 추출을 이용한 결정방법들에 의하여 이루어지는데, 이들에 대한 평가를 통하여 올바른 표본크기 결정을 행할 수 있는 토대를 마련하였다

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베이지안 기법을 적용한 일회성 장비의 경제적 시험 수량 연구 (A Study of Economical Sample Size for Reliability Test of One-Shot Device with Bayesian Techniques)

  • 이연호;이계신;이학재;김상문;문기성
    • 한국신뢰성학회지:신뢰성응용연구
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    • 제14권3호
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    • pp.162-168
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    • 2014
  • This paper discusses the application of Bayesian techniques with test data on similar products for performing the Economical Reliability Test of new one-shot device. Using the test data on similar products, reliability test required lower sample size currently being spent in order to demonstrate a target reliability with a specified confidence level. Furthermore, lower sample size reduces cost, time and various resources on reliability test. In this paper, we use similarity as calculating weight of similar products and analyze similarity between new and similar product for comparison of the essential function.