• Journal of Korean Society for Quality Management
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• v.25 no.2
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• pp.47-59
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• 1997

In this paper we develop computational algorithms to calculate M-estimators of regression parameters from right-censored data that are naturally collected in quality control. In the case of M-estimators, a new statistical method is also introduced to incorporate concomitant scale estimation in the presence of right censoring on the observed responses. Furthermore, we illustrate this by simulations.

• Korean Journal of Agricultural and Forest Meteorology
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• v.9 no.4
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• pp.260-267
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• 2007

This research note introduces the procedure of the quality control and quality assurance applied to the eddy covariance data collected at the two KoFlux sites (i.e., Gwangneung forest and Haenam farmland). The quality control was conducted through several steps based on micrometeorological theories and statistical tests. The data quality was determined at each step of the quality control procedure and was denoted by five different quality flags. The programs, which were used to perform the quality control, and the quality assessed data are available at KoFlux website (http://www.koflux.org/).

• Journal of Korean Academy of Fundamentals of Nursing
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• v.25 no.3
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• pp.197-209
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• 2018

Purpose: To examine the effects of auricular acupressure on symptoms of patients with allergic rhinitis and their quality of life. Methods: A quasi experimental was used with a nonequivalent control group pretest-posttest method involving 56 adult outpatients who were seen in the Allergy & Asthma clinic at a tertiary referral hospital in Seoul, Korea. The experimental group (n=28) received 2 weeks of auricular acupressure to the Shenmen, wind stream, endocrine, adrenal, and lung acupuncture points; no acupressure was provided to the control group (n=28). Outcome measures included Total Nasal Symptom Score used to assess nasal symptoms, and the Rhinoconjunctivitis Quality of Life Questionnaire to assess the quality of life. Repeated measure ANOVA and independent t-test were used to calculate statistical significance. Results: The experimental group showed significant improvements in terms of allergic rhinitis symptoms (p<.001) and on the Rhinoconjunctivitis Quality of Life Questionnaire (p<.001) compared to the control group. Conclusion: Finding in this study indicate that auricular acupressure can be used as a nursing intervention to alleviate nasal symptoms and improve rhinoconjuctivitis quality of life in allergic rhinitis patients.

• Journal of Korean Society for Quality Management
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• v.41 no.3
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• pp.457-463
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• 2013

Purpose: For effective quality assurance activities, BOM-based quality assurance method is presented. This study introduces various BOM conversions such as Q-BOM, T-BOM, and S-BOM based on M-BOM structure. Methods: Product quality control via Q-BOM manages inspection/audit information, overall supply-chain of product, part requirements, and inventory status. T-BOM manages part traceability, and S-BOM enables statistical control over key process and parts at various hierarchy levels. Results: Quality plan template was developed based on the study results of BOM system including Q-BOM, T-BOM, and S-BOM. Conclusion: Through BOM(Q-BOM, T-BOM, and S-BOM) study and development of quality plan template, more systematic and comprehensive quality management plan is achieved.

• Proceedings of the Korean Society of Near Infrared Spectroscopy Conference
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• 2001.06a
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• pp.1081-1081
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• 2001

The constant need for quality improvement and production rationalization in the chemical and related industries has led to the increasing replacement of conservative control procedures by more specific and environmentally compatible analytical techniques. In this respect, vibrational spectroscopy has developed over the last yews - in combination with new instrumental accessories and statistical evaluation procedures - to one of the most important analytical tools for industrial chemical quality control and process monitoring in a wide field of applications. In the present communication this potential is demonstrated in order to further support the implementation of mid-infrared (MIR), near-infrared (NIR) and Raman spectroscopy Primarily as industrial on-line tools. To this end the data of selected feasibility studies will be discussed in terms of the individual strengths of the different techniques for the respective application.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.284-289
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• 2009

We determined the influence of Sargassum beds on the water quality in Gamak Bay, Korea. Water temperature and salinity range from 3.3 to $23.4^{\circ}C$ and from 29.6 to 33.7 psu, respectively. Dissolved oxygen was 10.45 mg L-1 in the Sargassum bed and 9.23 mg L-1 in the control. Chlorophyll-a was $3.90{\mu}g\;L^{-1}$ in the Sargassum bed and 2.21${\mu}g \;L^{-1}$ in the control. Chemical oxygen demand were 1.14${\mu}g\;L^{-1}$ in the Sargassum bed and 1.43${\mu}g\;L^{-1}$ in the control. Total nitrogen were 0.038${\mu}g\;L^{-1}$ in the Sargassum bed and 0.067${\mu}g \;L^{-1}$ in the control. Total phosphorus were 0.043${\mu}g \;L^{-1}$ in the Sargassum bed and 0.072${\mu}g \;L^{-1}$ in the control. Multivariate statistical analysis was used to analyze data. Water temperature was highly positively correlated with DO (p<0.01). T-N was highly positively correlated with T-P (p<0.01).

• Communications for Statistical Applications and Methods
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• v.4 no.3
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• pp.715-723
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• 1997

Multivariate control statistics to simultaneously monitor both means and variances for several quality variables under multivariate normal process are proposed. Performances of the proposed multivariate charts are evaluated in terms of average run length(ARL). Multivariate Shewhart chart is also proposed to compare the performances of multivariate exponentially weighted moving average(EWMA) charts. A numerical comparison shows that multivariate EWMA charts are more efficient than multivariate Shewhart chart for small and moderate shifts and multivariate EWMA scheme based on accumulate-combine approach is more efficient than corresponding multivariate EWMA chart based on combine-accumulate approach.

• Proceedings of the Korean Statistical Society Conference
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• 2005.05a
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• pp.191-196
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• 2005

Knowing the time of the process change could lead to quicker identification of the responsible special cause and less process down time, and it could help to reduce the probability of incorrectly identifying the special cause. In this paper, we propose a MLE of the process change point when control charts with the fixed sampling rate (FSR) scheme or the variable sampling rate (VSR) scheme monitor a process to detect changes in the process mean and/or variance of a normal quality variable.

• Journal of Korean Society for Quality Management
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• v.45 no.2
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• pp.209-225
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• 2017

Purpose: Since traditional p chart is unable to deal with the variation of attribute data, this paper proposes a new attribute control chart for nonconforming proportions incorporating overdispersion with a beta-binomial model. Methods: Statistical theories for control chart developed under the beta-binomial model and a new approach using this control chart are presented Results: False alarm probabilities of p chart with the beta-binomial model are evaluated and demerits of p chart under overdispersion are discussed from three examples. Hence a concrete procedure for the proposed control chart is provided and illustrated with examples Conclusion: The proposed chart is more useful than traditional p chart, individual chart to treat observed proportions nonconforming as variable data and Laney p' chart.

• Journal of Korean Society for Quality Management
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• v.32 no.4
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• pp.169-183
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• 2004

The synthetic control chart (SCC) proposed by Wu and Spedding (2000) is to detect shifts in the process mean. The performance was re-evaluated by Davis and Woodall (2002), and the steady-state average run length (ARL) performance was shown to be inferior to cumulative sum (CUSUM) or exponentially weighted moving average (EWMA) chart This paper proposes a simple adaptive scheme to improve the performance of the synthetic control chart. That is, once a non-conforming (NC) sample occurs, we investigate the next L-consecutive samples with larger sample sizes and shorter sampling intervals. We employ a Markov chain model to derive the ARL and the average time to s19na1 (ATS). We also propose a statistical design procedure for determining decision variables. Comprehensive comparative study shows that the proposed control chart is uniformly superior to the original SCC or double sampling (DS) Χ chart and comparable to the EWMA chart in ATS performance.