이상자료가 연안 환경자료의 통계 척도에 미치는 영향 SCOPUS KCI

Title
이상자료가 연안 환경자료의 통계 척도에 미치는 영향
Alternative Title
Impact of outliers on the statistical measures of the environmental monitoring data in busan coastal sea
Author(s)
Cho, H.-Y.; Lee, K.-S.; Ahn, S.-M.
KIOST Author(s)
Cho, Hong Yeon(조홍연)
Publication Year
2016
Abstract
The statistical measures of the coastal environmental data are used in a variety of statistical inferences, hypothesis tests, and data-driven modeling. If the measures are biased, then the statistical estimations and models may also be biased and this potential for bias is great when data contain some outliers defined as extraordinary large or small data values. This study aims to suggest more robust statistical measures as alternatives to more commonly used measures and to assess the performance these robust measures through a quantitative evaluation of more typical measures, such as in terms of locations, spreads, and shapes, with regard to environmental monitoring data in the Busan coastal sea. The detection of outliers within the data was carried out on the basis of Rosner’s test. About 5-10% of the nutrient data were found to contain outliers based on Rosner’s test. After removal (zero-weighting) of the outliers in the data sets, the relative change ratios of the mean and standard deviation between before and after outlier-removal conditions revealed the figures 13 and 33%, respectively. The variation magnitudes of skewness and kurtosis are 1.36 and 8.11 in a decreasing trend, respectively. On the other hand, the change ratios for more robust measures regarding the mean and standard deviation are 3.7-10.5%, and the variation magnitudes of robust skewness and kurtosis are about only 2-4% of the magnitude of the non-robust measures. The robust measures can be regarded as outlier-resistant statistical measures based on the relatively small changes in the scenarios before and after outlier removal conditions. © 2016, Korea Ocean Research and Development Institute. All rights reserved.
ISSN
1598-141X
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/38896
DOI
10.4217/OPR.2016.38.2.149
Bibliographic Citation
Ocean and Polar Research, v.38, no.2, pp.149 - 159, 2016
Publisher
Korea Ocean Research and Development Institute
Keywords
Busan coastal sea; Outlier; Robust measures; Rosner’s test; Statistical measures
Type
Article
Language
Korean
Document Type
Article
Publisher
Korea Ocean Research and Development Institute
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