• Title/Summary/Keyword: sample number

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

  • 김병재
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.4 no.5
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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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ALMOST SURE LIMITS OF SAMPLE ALIGNMENTS IN PROPORTIONAL HAZARDS MODELS

  • Lim Jo-Han;Kim Seung-Jean
    • Journal of the Korean Statistical Society
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    • v.35 no.3
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    • pp.251-260
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    • 2006
  • The proportional hazards model (PHM) can be associated with a non- homogeneous Markov chain (NHMC) in the sense that sample alignments in the PHM correspond to trajectories of the NHMC. As a result the partial likelihood widely used for the PHM is a probabilistic function of the trajectories of the NHMC. In this paper, we show that, as the total number of subjects involved increases, the trajectories of the NHMC, i.e. sample alignments in the PHM, converges to the solution of an ordinary differential equation which, subsequently, characterizes the almost sure limit of the partial likelihood.

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

  • Ahn Chul
    • Genomics & Informatics
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    • v.4 no.2
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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.

A Procedure for Indentifying Outliers in Multivariate Data (다변량 자료에서 다수 이상치 인식의 절차)

  • Yum, Joon-Keun;Park, Jong-Goo;Kim, Jong-Woo
    • Journal of Korean Society for Quality Management
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    • v.23 no.4
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    • pp.28-41
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    • 1995
  • We consider the problem of identifying multiple outliers in linear model. The available regression diagnostic methods often do not succeed in detecting multiple outliers because of the masking and swamping effect. Recently, among the various robust estimator of reducing the effect of outliers, LMS(Least Meadian Square) estimator has been to be a suitable method proposed to expose outliers and leverage points. However, as you know it, the data analysis method with LMS estimator is to be taken the median of the squared residuals in the sample which is extracted the sample space. Then this model causes the trouble, for the number of the chosen sample is nCp, i.e. as the size of sample space n is increasing, the number is increasing fastly. And the covariance matrix may be the singular matrix, so that matrix is approching collinearity. Thus we propose a procedure ELMS for the resampling in LMS method and study the size of the effective elementary set in this algorithm.

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A Study on Small-Sample Inspection Plan for New Product Quality Evaluation of Finite Population (유한모집단의 신제품 품질평가를 위한 소표본 샘플링검사 방법에 대한 소고)

  • Byun, Jai-Hyun;Shin, Byung-Cheol;Lee, Chang-Woo
    • Journal of Korean Institute of Industrial Engineers
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    • v.41 no.1
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    • pp.115-120
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    • 2015
  • Evaluating product quality level is necessary before the manufactured items are delivered to the customer. When the amount of the items to be manufactured is limited and the product is of high price and should be evaluated by destructive testing, the number of samples to be tested should be as small as possible. This paper presents a small-sample inspection method using hyper-geometric distribution and Bayesian approach for finite small-sized population. A method of determining the minimum sample size is presented for given population size, allowable number of defectives, warranteed defective level, and confidence level which is the degree of confidence on the product quality level recognized by both the producer and the customer.

How Should We Randomly Sample Marine Fish Landed at Korea Ports to Represent a Length Frequency Distribution of Those Fish? (한국 연근해 어업에서 수집되는 어류 개체군 체장자료의 표집(sampling) 방법 제안)

  • Park, Min Gyou;Hyun, Saang-Yoon
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.54 no.1
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    • pp.80-89
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    • 2021
  • In Korea, marine fish landed at ports are randomly sampled on a periodic basis (e.g., daily or weekly), and body sizes (e.g., lengths and weights) of those sampled fish are measured. The motivation for our study is whether or not such measurements reflect the size distribution, especially the length distribution of fish landed (= a population), because such length measurements are key data for a length-based assessment model. The current sampling method is to sample fish landed at ports by body size group (e.g., very small, small, medium, large, very large), using the sampling weights as the number of boxes by body size group. In this study, we showed that length composition data about fish sampled by the current method did not represent the length frequency distribution of the fish landed, and suggested that an alternative sampling method should be applied of using the sampling weights as the number of fish landed by body size group. We also introduced a method for determining an appropriate sample size.

Estimating the Size Effect on Relative Species Number in Macrobenthic Community (대형 저서동물 군집의 채집 면적이 상대적 출현 종수에 갖는 효과의 추정)

  • 유재원;김창수;박미라;이형곤;이창근;이재학;홍재상
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.9 no.1
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    • pp.20-29
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    • 2004
  • Macrobenthos species-area relationship was investigated and empirical models were estimated to enable comparisons among species numbers of different sample size. The study aims to choose a way to predict cumulative relative species number (CRSN) in a given sample size Saemangeum, located in the west coast of South Korea, were visited in Apr., May and Aug.,2002 and a total of 261 biological samples from 87 stations were obtained by employing a quantitative sediment sampler, Smith-McIntyre grab and design of 3 replicates at each station. Relative species numbers (%) were baselined at sample size of 1000 $\textrm{cm}^2$ and the patterns of CRSN along the axis of sample size were measured and observed. In correlation analysis performed on a set of abiotic and biotic variables, log-transformed CRSN showed the only significant relationship with log-transformed density. Based on the result, three models, Log CRSN 2000, Log CRSN 3000 and Log CRSN were produced. The former two were devised to predict CRSN at 2000 and 3000 $\textrm{cm}^2$ respectively, and the latter at various sample sizes and samplers (all p-values were <0.001). Database from other studies (intertidal or subtidal macrofaunal samples from Kyonggi Bay and Saemangeum) were used to evaluate validity of the models. Observed CRSN below sample size of 3000 $\textrm{cm}^2$ fell under the range of 95% prediction interval and this was appeared to provide reliability of the models below that sample size.

Effects of Sour Tastes on Blood Components in Anemic mice - Animal Experiment for Nursing Intervention of Female Anemia - (신맛(酸味)이 용혈성 빈혈흰쥐의 혈액성분에 미치는 효과 - 여성빈혈의 간호중재개발을 위한 동물실험 -)

  • 신혜숙;김상우
    • Journal of Korean Academy of Nursing
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    • v.31 no.2
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    • pp.268-278
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    • 2001
  • Many women in the world have suffered from anemia produced by menstruation, pregnancy and delivery. In the theory of oriental medicine, a sour taste is believed to have a tonic effect on the blood. Thus this paper is to investigate the effect of sour tastes on the improvement in anemia-induced female mice, using citric acid and Fructus schizandrae(五味子). The method used in this experiment was the change of RBC, WBC, Hemoglobin, Hematocrit, Fe, and TIBC in the blood of female mice who were fed citric acid and Fructus schizandrae(五味子). The results obtained were as follows ; 1. Compared with the control group (anemia- induced group without treatment), the mean number of RBC in the blood of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae (五味子) 500mg/kg. 2. Compared with the control group (anemia- induced group without treatment), the mean number of WBC in the blood of mice was not significantly larger in both sample groups fed citric acid and Fructus schizandrae(五味子). 3. Compared with the control group (anemia- induced group without treatment), the mean number of Hemoglobin in the blood of mice was significantly larger only in evaluating the change of the sample group fed Fructus schizandrae(五味子). 4. Compared with the control group (anemia- induced group without treatment), the mean percentage of Hematocrit in blood of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg and sample group fed Fructus schizandrae(五味子) 250mg/kg for 3days. 5. Compared with control group (anemia- induced group without treatment), the mean volume of Fe in serum of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg. 6. Compared with control group (anemia- induced group without treatment), the mean TIBC in serum of mice was significantly increased only in evaluating the change of sample group fed Fructus schizandrae(五味子) 500mg/kg and sample group fed Fructus schizandrae(五味子) 250mg/kg for 7days. According to these results, a sour taste is presumed to have a general tonic effect on anemia, but more study must be taken on the effects of citric acid in improving female anemia.

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Study on the Trend of Medical Departments in Hospitals (중소병원의 개설 진료과목의 추세분석)

  • Moon, Kyeong-Jun;Lee, Kwang-Soo
    • The Korean Journal of Health Service Management
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    • v.6 no.3
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    • pp.67-74
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    • 2012
  • This study analyzed the trend of relationship between hospital departments. Hospitals directory issued by Korean Hospital Association in 2009 was used to collect the study sample data. The study sample used 188 hospitals established during the four years from 2005 to 2008, and bed size, establishment year was identified in the directory. Population variable in 2009 was taken from the website of Statistics Korea. SAS 9.2 was used for the statistical analysis. In regression analysis, year of establishment (2008) was statistically significant in explaining the number of hospital departments. Hospitals established in 2008 showed significant positive number of department than other years. Study hospitals showed increasing number of hospital departments during four years. Further study will be needed to analyze the effects of hospital departments on their performances.

Smoothed Local PC0A by BYY data smoothing learning

  • Liu, Zhiyong;Xu, Lei
    • 제어로봇시스템학회:학술대회논문집
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    • 2001.10a
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    • pp.109.3-109
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    • 2001
  • The so-called curse of dimensionality arises when Gaussian mixture is used on high-dimensional small-sample-size data, since the number of free elements that needs to be specied in each covariance matrix of Gaussian mixture increases exponentially with the number of dimension d. In this paper, by constraining the covariance matrix in its decomposed orthonormal form we get a local PCA model so as to reduce the number of free elements needed to be specified. Moreover, to cope with the small sample size problem, we adopt BYY data smoothing learning which is a regularization over maximum likelihood learning obtained from BYY harmony learning to implement this local PCA model.

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