• Journal of the Korean Society for Marine Environment & Energy
• /
• v.15 no.2
• /
• pp.156-162
• /
• 2012

Outlier detection and treatment process is highly required as the first step for the statistical analysis of the monitoring data having many outliers frequently occurred in the coastal environmental monitoring projects. In this study, the outlier detection method using the approximate and detail (or residual) components of the (raw) data is suggested. The approximate and detail components of the data can be separated by the diverse filtering and smoothing methods. The decomposition of the data is carried out by the harmonic analysis and local regression curve, respectively. Then, the Grubbs' test and modified z-score method widely used to detect outliers in the data are applied to the detail components of the water temperature data. The new data set is reconstructed after removed the outliers detected by these methods. It can be shown that the suggested process is successfully applied to the outlier detection of the coastal water temperature monitoring data provided by the Real-time Information System for Aquaculture Environment, National Fisheries Research and Development Institute (NFRDI).

• Proceedings of the Korea Water Resources Association Conference
• /
• 2016.05a
• /
• pp.309-314
• /
• 2016

본 연구에서는 확률강우량 산정을 위한 빈도해석 시 보다 타당하고, 신뢰도 높은 강우자료를 선정하여 수공구조물 설계 및 재난방재계획에 합리적인 기준을 제시하고자 이상치 적용에 따른 확률강우량을 산정 비교하였다. 이상치검정의 비교를 위하여 Grubbs and Beck 방법과 미국 수자원평의회 방법을 적용하였으며, 적용결과에 따라 강우자료를 조정하여 확률강우량을 산정 비교하여 타당성을 검토하였다. 본 연구의 수행으로 이상치검정에 따라 강우자료 년수에 변화가 있었으며, 기존의 방법과 확률강우량을 비교하였을 때, 증감이 나타났다.

• Journal of the Korea Concrete Institute
• /
• v.27 no.6
• /
• pp.695-703
• /
• 2015

Acceptance criteria for chemical admixtures of cement concrete were investigated in domestic and international specifications. The reliability was verified for solid content test method of chemical admixture examined statistical analysis by round robin test. The applicability of FT-IR spectroscopy for qualitative measurement of multi-compound chemical admixtures verified. From solid content experimental results, outlier analysed using Cochran, Grubbs and Dickson's Q test. Repeatability and reproducibility standard deviation for solid content results showed 0.25 and 0.098% respectively according to KS A ISO 5725-2 procedure, it can be confirmed reliability of test methods. FT-IR spectrum of liquefied or oven-dried chemical admixtures condition showed big differences. It is needed that the FT-IR analysis is performed on dry material. However there's no difference with the applicability of FT-IR spectroscopy for multi-compound chemical admixtures. So the utility of method analysis could not identify.

• Journal of the Korean Society for Precision Engineering
• /
• v.27 no.4
• /
• pp.40-45
• /
• 2010

Evaluation of uncertainty is an ongoing process that can consume time and resources. It can also require the service of someone who is familiar with data analysis techniques. Therefore, it is important for laboratory personnel who are approaching uncertainty analysis for the first time to be aware of the resources required. International inclination of measurement filed to guarantee the traceability and confidence of measurement results discards the error concept and instead analyzes the measurement uncertainty. In this paper, we analyzed the elements of measurement uncertainty on surface roughness test which are the important things in mechanical parts test. Repeat the test by 3 men, the measurement uncertainty could be calculated.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2004.04a
• /
• pp.266-269
• /
• 2004

In this study, bond strengths for the self-healing agents were evaluated through the modified lap shear test in order to suggest the optimal healing conditions for the repair of polymeric composites. The healing agents of DCPD, ENB, and their mixtures were activated with Grubbs' catalysts. According to the results, the mixture of DCPD and ENB gave better opportunity than DCPD only due to the rapid acivation with catalyst in view of the economic and practical use.

• Proceedings of the Korean Society of Agricultural Engineers Conference
• /
• 2005.10a
• /
• pp.284-287
• /
• 2005

The objective of this study is to check into variation trends of design rainfall according to change of the number of years for observed data. To make comparative study of the relation between design rainfall and recorded year, this study was used maximum rainfall for 24-hr consecutive duration at Gangneung, Seoul, Incheon, Chupungnyeong, Pohang, Daegu, Jeonju, Ulsan, Gwangju, Busan, Mokpo and Yeosu rainfall stations. The tests for Independence, Homogeneity and detection of outliers were used Wald-Wolfowitz's test, Mann-Whitney's test and Grubbs and Beck test respectively. To select appopriate distribution, the distribution of genaralized pareto(GPA), generalized extreme value(GEV), generalized logistic(GLO), lognormal and pearson type 3 distribution is judged by L-moment ratio diagram and Kolmogorov-Smirnov (K-S) test. Design rainfall was estimated by at-site frequency analysis using L-moments and Generalized extreme value(GEV) distribution according to change of the number of years for observed data. Through the comparative analysis for design rainfall induced by L-moments and GEV distribution, relationship between design rainfall and recorded year is provided.

• Composites Research
• /
• v.17 no.4
• /
• pp.40-46
• /
• 2004

A single lap shear test was used to investigate the effects of the ratio of a catalyst to a self-healing agent and curing temperature on the bond performance of autonomic polymer composites. DCPD (dicyclopentadiene), ENB (5-ethylidene-2-norbornene), and their mixture were used as self-healing agents and bis(triclohexylphosphine) benzyllidine ruthenium (IV) dichloride Grubbs' catalyst was used as a catalyst. During the experiments, the catalyst ratios of 1.0wt% and 0.5wt% were applied to DCPD, the catalyst ratio of 0.lwt% was applied to ENB, and the catalyst ratio of 0.5wt% was applied to the mixtutes of DPCD and ENB. In addition, the curing temperatures of $25^{\circ}C$, $60{\circ}C$, and $80^{\circ}C$ were considered. According to the results, the higher catalyst ratio and the longer curing time were required to obtain more stabilized bond shear strength of DCPD. ENB with a lower catalyst ratio was cured faster than DCPD. Unlike DCPD, ENB stabilized after a steady fall from its peak as the curing time increased. Moreover, the mixtures of DCPD and ENB revealed similar curing behavior to ENB, but the increase in mixture ratio of ENB to DCPD caused curing process to be faster. Also the increase in curing temperature caused the bond shear strength to be higher and the curing time to be quicker.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.51 no.4
• /
• pp.49-55
• /
• 2009

This paper is to induce design floods through L-moment with 3 and 4 parameter Kappa distributions including test of independence by Wald-Wolfowitz, homogeneity by Mann-Whitney and outlier by Grubbs-Beck on annual maximum flood flows at 9 water level gaging stations in Han, Nakdong and Geum Rivers of South Korea. After analyzing appropriateness of the data of annual maximum flood flows by Kolmogorov-Smirnov test, 3 and 4 Kappa distributions were applied and the appropriateness was judged. The parameters of 3 and 4 Kappa distributions were estimated by L-moment method and the design floods by water level gaging station was calculated. Through the comparative analysis using the relative root mean square errors (RRMSE) and relative absolute errors (RAE) calculated by 3 and 4 parameter Kappa distributions with 4 plotting position formulas, the result showed that the design floods by 4 parameter Kappa distribution with Weibull and Cunnane plotting position formulas are closer to the observed data than those obtained by 3 parameter Kappa distribution with 4 plotting position formulas and 4 parameter Kappa distribution with Hazen and Gringorten plotting position formulas.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 2006.05a
• /
• pp.435-436
• /
• 2006

This study focused on the introduction of the self healing technique for polymeric composites and evaluated the healing efficiency by the use of the interlaminar toughness fracture test. The DCPD (dicyclopentadiene) and ENB (5-ethylidene-2-norbornene) were used for the healing agent and the Grubbs' catalyst was used for the catalyst. According to the results, healing efficiency was found to be 37.9%, 22.3%, 26.3%, 22.8%, 30.8%, 30.8%, 33.0%, 33.4% for mode II fraction of 0%, 20%, 35%, 50%, 65%, 80%, 90%, 100%, respectively.

• Proceedings of the Korean Society For Composite Materials Conference
• /
• 2004.04a
• /
• pp.262-265
• /
• 2004

This study focused on the introduction of the self-healing technique for polymeric composites and evaluated the healing efficiency through the interlainar fracture toughness tests. The DCPD and ENB were used for a healing agent and the Grubbs' catalyst as a catalyst. The healing efficiency was evaluated by the use of mode I and the mode n fracture toughnesses. According to the results, the DCPD-ENB mixture with a suitable ratio revealed better healing efficiency than DCPD only.