• Journal of the Korean Statistical Society
• /
• v.27 no.2
• /
• pp.237-249
• /
• 1998

Process adjustment has been widely used in production processes in order to set the output characteristic as close as to the target. Box and Kramer(1992) developed a feedback adjustment control procedure for process adjustment. We generalize their procedure by using a rational subgrouping of sequential observations. In this paper the feedback control rule of the rational subgrouping is proposed and the overall expected cost is evaluated. Also properties of the proposed control scheme are illustrated and compared to Box and Kramer's in the context of the expected cost.

• The Korean Journal of Elementary Counseling
• /
• v.10 no.2
• /
• pp.151-165
• /
• 2011

This study aims to demonstrate how well SCM analysis, which indicates social cognitive map of categorizing peer subgroups of elementary school students, corresponds with that of teachers. To do this, the subject of this study includes two classes of the 3rd and the 5th grade students in D elementary school in B-gu, Busan city. Over 30 students of each gender in each grade were surveyed with social network questionnaires to collect data. The result of the social network survey was analyzed by SCM 4.0 program to categorize peer subgroups within each class. The categorized peer subgroups were reported to the class teacher. Based on the report, the class teachers observed peer subgroups in classes. After the teachers observed and categorized the students into several peer groups, an analysis was conducted to compare the peer subgrouping by students with that by teachers. The result showed the two were 80% correspondent to each other regardless of gender and grade. If interobserver reliability stays within the range of 80-100%, it is considered reliable. And this leads to the conclusion that peer subgrouping by students' cognition and that by teachers' observation can be regarded quite corresponding. In conclusion, peer subgrouping through SCM is significant when peer subgrouping Korean children, and it appears to be more significant when analyzed considering different variables including gender and grade. Peer subgrouping by girls is shown to be more accurate than that by boys.

• Journal of the Korea Safety Management & Science
• /
• v.12 no.3
• /
• pp.257-262
• /
• 2010

The study investigates the various Acceptance Control Charts (ACCs) based on the factors that include process independence, data weighting scheme, subgrouping, and use of control charts. USL - LSL > $6{\sigma}$ that used in the good condition processes in the ACCs are designed by considering user's perspective, producer's perspective and both perspectives. ACCs developed from the research is efficiently applied by using the simple control limit unified with APL (Acceptable Process Level), RLP (Rejectable Process Level), Type I Error $\alpha$, and Type II Error $\beta$. Sampling interval of subgroup examines i.i.d. (Identically and Independent Distributed) or auto-correlated processes. Three types of weight schemes according to the reliability of data include Shewhart, Moving Average(MA) and Exponentially Weighted Moving Average (EWMA) which are considered when designing ACCs. Two types of control charts by the purpose of improvement are also presented. Overall, $\alpha$, $\beta$ and APL for nonconforming proportion and RPL of claim proportion can be designed by practioners who emphasize productivity and claim defense cost.

• Journal of Korean Neurosurgical Society
• /
• v.61 no.3
• /
• pp.312-318
• /
• 2018

Surgery and radiotherapy are mainstays of treatment for ependymomas (EPNs). Recent molecular subgrouping could be superior to histopathological grading for predicting the prognosis of patients with EPNs. Gross total resection is an effective treatment approach regardless of its locations or pathologic grades. Adjuvant therapeutic strategies could be decided based on molecular subgrouping with risk-stratification. Information of histologic-molecular biology is now providing clues to therapeutic insights.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.32 no.3
• /
• pp.85-92
• /
• 2021

Attention-deficit/hyperactivity disorder (ADHD) leads to functional decline in academic performance, interpersonal relationships, and development in school-aged children. Early diagnosis and appropriate intervention can significantly reduce the functional decline caused by ADHD. Currently, there is no established biological marker for ADHD. Some studies have suggested that various indicators from the quantitative electroencephalogram (QEEG) may be useful biological markers for the diagnosis of ADHD. Until the 2010s, theta/beta ratio (TBR) was a biomarker candidate for ADHD that consistently showed high diagnostic value. However, limitations of TBR have recently been reported. Studies have demonstrated that phase-amplitude coupling, especially theta phase-gamma amplitude coupling, are related to cognitive dysfunction and may assist in the diagnosis of ADHD. As yet, the underlying mechanism is not clearly established, and the clinical efficacy of these biomarkers needs to be proven through well-controlled studies. Based on the heterogeneous characteristics of ADHD, subgrouping through QEEG plays a key role in diagnosis and treatment planning. Sophisticated, well-designed studies and meta-analyses are necessary to confirm these findings.

• Proceedings of the Safety Management and Science Conference
• /
• 2010.04a
• /
• pp.259-265
• /
• 2010

The research discusses the implementation of control charts tools of MINITAB which are classified according to the type of data and the existence of subgrouping, weight and multivariate covariance. The paper presents the three integrated models by the use of zone, multivariate $T^2$-GV(Generalized Variance) and ARIMA(Autoregressive Integrated Moving Average).

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.39C no.10
• /
• pp.974-983
• /
• 2014

The commercialization of ITS(Intelligent Transport System) is in sight including V2V(Vehicle-toVehicle) communication and analysis of related electromagnetic circumstances is essential process in relevant legislation. However analysis including numbers of vehicles have electrically large environment which leads to a lack of computational resources. In this letter, we suggest superposition method which require much less computational resources by subgrouping environment and using post-processing of results. Suggested method approximate original result by superpositioning of analysis which include scatterers near source, observation point. This letter also presented guideline of method and example for comparison with full analysis result.

• Korean Journal of Microbiology
• /
• v.38 no.4
• /
• pp.276-280
• /
• 2002

To find the applicability of resemblance of the fatty acid methy1 ester (FAME) profile analysis to the primary examination for the tracing P. aeruginosa contamination in the environment and water plants, we designed this study. Of6l P. aeruginosa isolates including 3 reference strains, 4 fecal or soil isolates and 54 water isolates, the resemblance coefficiencies of the FAMEs were calculated as euclidian distance (ED) and expressed as dendrogram. The 61 strains were clustered as the same group in the ED 8.4, and divided into 4 subgroups in the ED 6.9. The water isolates from Han River were classified into distinctively different subgroups from reference strains. These results provide the possibility of the dendrogram from FAME profile as a useful tools for tracing contamination as well as for identifying the species, especially in case of P. aeruginosa.

• Clinical and Experimental Pediatrics
• /
• v.62 no.2
• /
• pp.55-61
• /
• 2019

Purpose: Myotonic dystrophy, also known as dystrophia myotonica (DM), is an autosomal dominant disorder with 2 genetically distinct forms. DM type 1 (DM1) is the more common form and is caused by abnormal expansion of cytosine/thymine/guanine (CTG) repeats in the DM protein kinase (DMPK ) gene. Our study aimed to determine whether the age of onset is correlated with CTG repeat length in a population of pediatric patients with DM1. Methods: We retrospectively identified 30 pediatric patients with DM1 that underwent DMPK testing, of which the clinical data of 17 was sufficient. The cohort was divided into 2 subgroups based on the clinical phenotype (congenital-onset vs. late-onset) and number of CTG repeats (<1,000 vs. ${\geq}1,000$). Results: We found no significant difference between the age of onset and CTG repeat length in our pediatric patient population. Based on clinical subgrouping, we found that the congenital-onset subgroup was statistically different with respect to several variables, including prematurity, rate of admission to neonatal intensive care unit, need for respiratory support at birth, hypotonia, dysphagia, ventilator dependence, and functional status on last visit, compared to the late-onset subgroup. Based on genetic subgrouping, we found a single variable (poor feeding in neonate) that was significantly different in the large CTG subgroup than that in the small CTG subgroup. Conclusion: Clinical variables exhibiting statistically significant differences between the subgroups should be focused on prognosis and designing tailored management approaches for the patients; our findings will contribute to achieve this important goal for treating patients with DM1.

• Journal of Korean Institute of Industrial Engineers
• /
• v.23 no.4
• /
• pp.635-643
• /
• 1997

The purpose of this paper is to propose an interactive method, using fuzzy Choquet's integral, which is designed to find out the mostly preferred solutions for deterministic MADM problems with many attributes and alternatives. The basic idea of the paper is essentially the same as that of the one we have published before[1]; subgrouping of attributes and eliminating of inefficient solutions. But the difference between these two methods lies in the fact that the present method evaluates and eliminates alternatives using fuzzy Choquet's integral on the basis of decision-maker's judgements about the relative importance of subgroups of attributes, rather than using mathematical programming on the basis of pair-wise comparisons of alternatives. If such information is obtainable from the decision-maker, the method can be proved to be much easier to understand and more efficient to compute.