• 제목/요약/키워드: Sample Size

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A Sampling Design of the Korean Anthropometric Survey

  • Park, Jinwoo;Kim, JinHo;Hwang, Inkeuk
    • Communications for Statistical Applications and Methods
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    • 제10권3호
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    • pp.707-718
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    • 2003
  • The Korean Anthropometric Survey (Size Korea) is a sample survey which estimates on percentiles of several dimensional measurements of the human body and its component parts. The purpose of this study is to design a sample, which is designed on the base of 1997 survey database. Two different methods are considered to get the sample size for estimating the 5th and 95th percentile of body dimensions of Korean age range 0-80 years.

Optimal Sequential Tests which minimize the Average Sample Size

  • Kim, Sung Lai
    • 충청수학회지
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    • 제3권1호
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    • pp.97-101
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    • 1990
  • For testing a hypothesis $H:{\theta}={\theta}_1$, vs $A:{\theta}={\theta}_2$ (${\theta}_1$ < ${\theta}_2$, we obtain a truncated sequential bayes procedure which minimizes the average sample size between ${\theta}_1$ and ${\theta}_2$.

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국소 최적성과 순차 기준을 바탕으로 한 검파 기법: 2. 성능 분석 (Detection Schemes Based on Local Optimality and Sequential Criterion: 2. Performance Analysis)

  • 최상원;강현구;이주미;박소령;김선용;송익호
    • 한국통신학회논문지
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    • 제30권10C호
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    • pp.1027-1035
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    • 2005
  • 이 논문에서는, 약한 신호를 검파하는 데에 알맞도록 1부에서 얻은 순차 검파 방식의 성능을 고정 표본 검파방식, 순차 확률비 검파 방식, 끝을 자른 순차 확률비 검파 방식의 성능과 견주어 본다. 제안한 순차 검파 방식은 순차 확률비 검파 방식과 견주어 볼 때, 얼개가 같거나 덜 복잡하고 신호를 더 빠르게 검파할 때가 많다. 아울러, 제안한 순차 검파 방식은 고정 표본 검파 방식과 끝을 자른 순차 확률비 검파 방식과 견주어 얼개가 덜 복잡하거나 같고 필요한 관측수가 늘 적다.

고차원 자료의 재현성과 표본 수 (Reproducibility and Sample Size in High-Dimensional Data)

  • 서원석;최지아;정형철;조형준
    • 응용통계연구
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    • 제23권6호
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    • pp.1067-1080
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    • 2010
  • 임상시험을 위한 표본 수 산정방법에 대해 지금까지 많은 방법이 개발되었고 현재 국내외 임상시험 기관에서 이 방법들을 토대로 표본 수를 산정하고 있다. 하지만 마이크로어레이칩 을 이용한 실험에 필요한 표본 수 산정에 대한 연구는 아직 미비하여 제대로 이용되지 않고 있다. 본 연구의 목적은 마이크로어레이 실험에 필요한 표본 수를 산정하는 데 있어 실제 마이크로어레이 자료의 재현성에 대한 정보를 이용하여 그 지침을 제공하는데 있다. 재현성 비교에서는 5가지 검정방법 즉, Fold change, Two-sample t-test, Wilcoxon rank-sum test, SAM, LPE 방법 별로 재현성을 측정하였다. 발현 값의 표준화 방법에 있어서는 MAS5, RMA 두 가지로 세분화 하였으며 반복수에 따라 상위 20개 또는 100개 유전자에 대한 일치성도 측정하였다. 또한, 표본수를 산정하는데 있어 기존에 제시한 방법에 현실적인 정보를 이용하여 좀 더 세분화하여 실험에 필요한 표본수를 산정해 보았다.

쌀가루 입자크기와 녹차첨가량을 달리한 녹차다식 개발과 품질특성연구 (Quality Characteristics and of Green Tea Dasik Processing with Varied Levels of Rice Grain Particle Size and Green Tea Powder)

  • 김혜영
    • 한국식생활문화학회지
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    • 제22권5호
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    • pp.609-614
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    • 2007
  • Quality characteristics of dasik were studied with varied the levels of rice grain particle size and green tea powder and compared them with commercially sold dasik. Among the samples with the same number of grinding times, the sample groups with the higher amount of green tea showed significantly the less mosture content(p<0.05). Hardness was higher in the samples containing higher amount of green tea among the ones with the same grain size (p<0.05). The M13G0.5 was evaluated to have the highest savory aroma with significance (p<0.05), and C1 to have the highest sweetness by sensory analysis. The developed dasik samples with lower rice grain particle size had significantly lower adhesiveness, chewiness, gumminess, and cohesiveness compared to those of commercial sample groups. In sensory tests, the compared groups showed significantly the higher savory aroma and flavor and very lower hardness when compared to those of commercial sample groups. With the results above, dasik with with varied the levels of rice grain particle size and green tea powder were developed with improved qualities compared to those of commercially sold dasik.

수산화(水酸化)알미늄. 겔의 Grain Size 와 제산도(制酸度)에 관(關)한 연구(硏究) (Studies on the Grain Size and Acid-consuming Capacity of Aiuminium-Hydroxide Gel)

  • 노태선
    • Journal of Pharmaceutical Investigation
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    • 제2권1호
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    • pp.5-13
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    • 1972
  • There are some repels in which they studied on the change of acid-consuming capacity of aluminium hydroxide resulted from the passing of time. However, the relationship between grain sizes(particle sizes) and the acid-consuming capacity of dried aluminium hydroxide gel was not been studied. And studies on the grain sizes of aluminium hydroxide gel qualified by pharmacopoeia of Korea has not been reported. For the purpose of studying these two problems, the author prepared two-kinds of aluminium hydroxide gel as follows : $Na_2OAl_2O_3+CO_2------{\longrightarrow}Al(OH)_3{\cdots}{\cdots}{\cdots}$sample 1 $Al_2(SO_4)_318H_2O+6NaHCO_3{\longrightarrow}Al(OH)_3{\cdots}{\cdots}{\cdots}$sample 2 Both of sample 1 and 2 are found to be amorphous by X-ray diffraction methods, and their acid-consuming capacities were determined by the method of pharmacopeia of Korea. The grain size was measured by X-ray diffraction method, the particle sizes observed by electron microscopy, and the change of acid-consuming capacity with passing of time was determined by the method of pharmacopoeia of Korea. The results of these studies are summerized as follows: 1. The grain size was linearly enlarged as the time goes by. The aluminium hydroxide gel gradually crystallized in a certain period of time. 2. The acid-consuming capacity was in exponential function, decreased as the grain size of them enlarged. 3. One particle consists of tens of grains.4. Grinding the Sample obtained in any period of testing time in mortar did not change both their grain size and their acid-consuming capacity. 5. The grain size of dried aluminium hydroxide gel ought to be micronized less than $100{\AA}$ for maintaining the ability such as consumes 250m1 of 0. 1N-HC1 solution per Is of $Al(OH)_3$ described in pharmacopoeia of Korea.

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Nonresponse in Repeated Surveys

  • Park, Hyeon-Ah;Na, Seong-Ryong;Jeon, Jong-Woo
    • Communications for Statistical Applications and Methods
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    • 제14권3호
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    • pp.593-600
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    • 2007
  • Under repeated surveys, missing values often appear for various reasons and are replaced by new samples. It is investigated that the existing estimator in repeated survey by Jessen (1942), which has been originally developed for the new samples of fixed size, can be used in such situation where the size of new samples is random. It is shown that the proposed estimator has smaller variance than the sample mean.

Numerical and statistical analysis of permeability of concrete as a random heterogeneous composite

  • Zhou, Chunsheng;Li, Kefei
    • Computers and Concrete
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    • 제7권5호
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    • pp.469-482
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    • 2010
  • This paper investigates the concrete permeability through a numerical and statistical approach. Concrete is considered as a random heterogeneous composite of three phases: aggregates, interfacial transition zones (ITZ) and matrix. The paper begins with some classical bound and estimate theories applied to concrete permeability and the influence of ITZ on these bound and estimate values is discussed. Numerical samples for permeability analysis are established through random aggregate structure (RAS) scheme, each numerical sample containing randomly distributed aggregates coated with ITZ and dispersed in a homogeneous matrix. The volumetric fraction of aggregates is fixed and the size distribution of aggregates observes Fuller's curve. Then finite element method is used to solve the steady permeation problem on 2D numerical samples and the overall permeability is deduced from flux-pressure relation. The impact of ITZ on overall permeability is analyzed in terms of ITZ width and contrast ratio between ITZ and matrix permeabilities. Hereafter, 3680 samples are generated for 23 sample sizes and 4 contrast ratios, and statistical analysis is performed on the permeability dispersion in terms of sample size and ITZ characteristics. By sample theory, the size of representative volume element (RVE) for permeability is then quantified considering sample realization number and expected error. Concluding remarks are provided for the impact of ITZ on concrete permeability and its statistical characteristics.

범주형 자료에서 순서화된 대립가설 검정을 위한 정확검정의 개발 (Developing of Exact Tests for Order-Restrictions in Categorical Data)

  • 남주선;강승호
    • 응용통계연구
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    • 제26권4호
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    • pp.595-610
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    • 2013
  • 범주형 자료에서 순서화된 대립가설을 검정하는 경우는 의학 사회학 경영학 등 다양한 응용분야에서 발생한다. 이러한 검정 방법은 대부분 대표본이론에 근거하여 개발되었다. 하지만 표본크기가 작거나 표본크기가 매우 불균등한 경우 대표본이론에 근거한 검정방법의 제 1종 오류 확률은 목표로 하는 5%와 멀어지는 경우가 많이 발생한다. 본 논문에서는 범주형 자료에서 순서화된 대립가설을 검정하는 경우 표본크기가 작거나 표본크기가 매우 불균등한 경우에 사용될 수 있는 정확검정방법을 소개하고 이에 대한 검정력 및 정확 p-value를 제시할 것이다.

광모듈 솔더 접합부의 시효 특성에 관한 연구 (Aging Characteristics of Solder bump Joint for High Reliability Optical module)

  • 김남규;김경섭;김남훈;장의구
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2003년도 춘계학술대회 논문집 센서 박막재료 반도체 세라믹
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    • pp.204-207
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    • 2003
  • The flip chip bonding utilizing self-aligning characteristic of solder becomes mandatory to meet to tolerances for the optical device. In this paper, a parametric study of aging condition and pad size of sample was conducted. A TiW/Cu UBM structure was adopted and sample was aging treated to analyze the effect of intermetallic compound with time variation. After aging treatment, the tendency to decrease in shear strength was measured and the structure of the fine joint area was observed by using SEM, TEM and EDS. In result, the shear strength was decreased of about 20% in the $100{\mu}m$ sample at $170^{\circ}C$ aging compared with the maximum shear strength of same pad size sample. In the case of the $120^{\circ}C$ aging treatment, 17% of decrease in shear strength was measured at the $100{\mu}m$ pad size sample. Also, intremetallic compound of $Cu_6Sn_5$ and $Cu_3Sn$ were observed through the TEM measurement by using an FIB technique that is very useful to prepare TEM thin foil specimens from the solder joint interface.

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