• Title/Summary/Keyword: sample median

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Median Ranked Ordering-Set Sample Test for Ordered Alternatives

  • Kim, Dong-Hee;Ock, Bong-Seak
    • Communications for Statistical Applications and Methods
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    • v.15 no.6
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    • pp.947-957
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    • 2008
  • In this paper, we consider the c-sample location problem for ordered alternatives using median ranked ordering-set samples(MROSS). We propose the test statistic using the median of samples that have the same ranked order in each cycle of ranted ordering-set sample(ROSS). We obtain the asymptotic property of the proposed test statistic and Pitman efficiency with respect to other test statistic. In simulation study, our proposed test statistic has good powers for some underlying distributions we consider.

Outlier Tests in Sample Surveys

  • Namkyung, Pyong;Lee, Joon Suk
    • Communications for Statistical Applications and Methods
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    • v.7 no.2
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    • pp.447-456
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    • 2000
  • In this paper, we considered three methods for outlier identification sample surveys. First, we studied method of handling and adjusting outliers in normal population. Second, we studied existing methods using mean, maximum and minimum and proposed a test using of median which well reflects characteristic of data regardless of sampling distribution. Finally, we showed our test using median works better than Dixon and mean test through simulation.

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An Improved Method for Constructing Confidence Interval of Median : Small Sample Case

  • Park, Sang-Gue;Choi, Ji-Yun
    • Journal of the Korean Data and Information Science Society
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    • v.15 no.4
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    • pp.973-980
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    • 2004
  • Phase I clinical trials are often pharmacologically oriented and usually attempt to find the best dose of drug to employ. However, other purposes like determination of sizes and types of side effects and toxicity and organ system involved are equally important. Estimation of treatment effects or side effects is usually ignored since it is usually based on too small sample, even though Phase II clinical trials would be designed based on the Phase I studies. Statistical methods for constructing the approximate confidence interval for population median in case of small sample are considered and an improved method is proposed. The proposed estimator is compared with current methods through simulation studies.

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New Definition of the Fibrogram and Its Application to Cotton Blending

  • Jeon, Boong-Soo
    • Fibers and Polymers
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    • v.6 no.4
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    • pp.332-335
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    • 2005
  • The fibrogram theory is newly derived from the superposition principle of the conventional staple diagram, in which the left-hand ends of the fibers have to share a common starting point in order for the fiber length distribution to be measured, and the right-hand ends of the fibers form points. It is shown that the fibrogram is the staple diagram of the fiber sample having different random starting points, as well as the double cumulative distribution function of the frequency length function in the length biased sample. Also, the various means, viz. the numerical mean length, numerical mean length in median, length biased mean length, and length biased mean length in median, and the various upper half means, viz. the numerical upper half mean length, numerical upper half mean length in median, length biased upper half mean length, and length biased upper half mean length in median, are discussed in relation to the cotton blending process.

Design of Median Control Chart for Unsymmetrical Weibull Distribution (비대칭(非對稱)와이블분포공정(分布工程)에서 메디안특수관리도(特殊管理圖)의 설계(設計))

  • Sin, Yong-Baek;Hwang, Ui-Mi
    • Journal of Korean Society for Quality Management
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    • v.14 no.2
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    • pp.2-8
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    • 1986
  • This thesis is concerned with the design of control chart based on the sample median which is easy to use in practical situations and to analyze the properties for non-normally distributed Weibull process. In this cases are use to the quality characteristics of the process are not normally distributed but skewed due to the intermitted production, small lot size and sample size is small one n=3 or n=5, etc. And when it relates unsymmetrically distributed process, model designed median control chart is more effective than Shewhart $\bar{x}$-chart which assumed on normal distribution, when we exactly should be known Weibull distribution or estimated. The median control chart in this thesis is more robustness compared with other conventionally developed control chart.

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Two-sample Linear Rank Tests for Efficient Edge Detection in Noisy Images (잡음영상에서 효과적인 에지검출을 위한 이표본 선형 순위 검정법)

  • Lim Dong-Hoon
    • Journal of the Korea Society of Computer and Information
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    • v.11 no.4 s.42
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    • pp.9-15
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    • 2006
  • In this paper we propose Wilcoxon test, Median test and Van der Waerden test such as linear rank tests in two-sample location problem for detecting edges effectively in noisy images. These methods are based on detecting image intensity changes between two pixel neighborhoods using an edge-height model to perform effectively on noisy images. The neighborhood size used here is small and its shape is varied adaptively according to edge orientations. We compare and analysis the performance of these statistical edge detectors on both natural images and synthetic images with and without noise.

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Nonparametric Estimators of Ratio of Scale Parameters Based on Rank-Like Tests

  • Song, Moon-Sup;Chung, Han-Young
    • Journal of the Korean Statistical Society
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    • v.9 no.2
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    • pp.181-193
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    • 1980
  • A class of nonparametric estimators of the ratio of scale parameters is proposed. The estimators are based on the distribution-free rank-like test suggested by Fligner and Killeen (1976). An explicit form of the estimator is the median of the ratios of absolute deviations from the combined sample median. A small-sample Monte Carlo study shows that the proposed estimator is more efficient than the Bhattacharyya (1977) estimator. The proposed estimator is is reasonably insensitive to small failures in the assumption of equal medians. A modified estimator is also considered when the meidans are unequal.

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The anatomical variations of median nerve in Shiraz, Iran

  • Zia Moasses;Arefeh Aryan;Ashraf Hassanpour-Dehnavi;Mohammad Zarenezhad;Alireza Dorodchi
    • Anatomy and Cell Biology
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    • v.57 no.1
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    • pp.18-24
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    • 2024
  • The origin and distribution of median nerve varies among the different individuals. The median nerve variations in axillary region were reported by many authors previously. Understanding of these variations is especially necessary for clinicians to prevent iatrogenic nerve damage. The current work aimed to evaluate the possible anatomical variations of median nerve in the axillary region in a sample of the Iranian cadavers (Shiraz, Fars). We dissected 26 upper limbs from 13 male cadavers to investigate the different variations of median and musculocutaneous nerves according to Venieratos and Anagnostopoulou classification. In 23.07% of specimens (n=6), the medial root united with 2 lateral roots and formed the median nerve proximal to the coracobrachialis muscle. In one case, a communicating branch separated from the musculocutaneous nerve distal to the coracobrachialis and connected to the median nerve in upper arm. Our results suggest that there are anatomical variations of the median nerve in terms of its origin and its communication with the musculocutaneous nerve in the population of southern Iran. The anatomical knowledge of the median nerve variations is important for clinicians to improve patient health outcome. Theses variations of the median nerve should be considered during surgical procedures of the axillary region and nerve block of the infra clavicular part of the brachial plexus.

A Nonparametric Detector Based on Median-Shift Sign: Asymptotic and Finite Sample-Size Performance (중앙값을 움직인 부호를 바탕으로 한 비모수 검파기: 점근 성능과 유한 표본 성능)

  • 김홍길;박소령;윤석호;이주식;송익호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.23 no.6
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    • pp.1454-1460
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    • 1998
  • In this ppaer, we propose a new detector based on the median-shift sign, and then investigate its asymptotic and finite sample-size performance. We call it the median-shift sign (MSS) detector, which is an extension of the classical sign detector. First, we consider the asymptotic opti$$\mu$ median shift values and their characteristics. Next, we consider the asymptotic relative efficiency of the MSS detectors. we then consider the problem of detecting known signals in noise of known probability density function, and the problem of detecting known signals when only partial information is available on the noise.

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Multivariate analysis of longitudinal surveys for population median

  • Priyanka, Kumari;Mittal, Richa
    • Communications for Statistical Applications and Methods
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    • v.24 no.3
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    • pp.255-269
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    • 2017
  • This article explores the analysis of longitudinal surveys in which same units are investigated on several occasions. Multivariate exponential ratio type estimator has been proposed for the estimation of the finite population median at the current occasion in two occasion longitudinal surveys. Information on several additional auxiliary variables, which are stable over time and readily available on both the occasions, has been utilized. Properties of the proposed multivariate estimator, including the optimum replacement strategy, are presented. The proposed multivariate estimator is compared with the sample median estimator when there is no matching from a previous occasion and with the exponential ratio type estimator in successive sampling when information is available on only one additional auxiliary variable. The merits of the proposed estimator are justified by empirical interpretations and validated by a simulation study with the help of some natural populations.