• Journal of the Korean Statistical Society
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• v.22 no.1
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• pp.71-81
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• 1993

Among k independent normal populations with unknown means and a common unknown variance, the problem of detecting the population with the largest absolute value of mean is considered. This problem is formulated in a manner close to the framework of testing hypotheses, and the maximum error probability and the minimum power are considered. The power charts necessary to determine the sample size are provided. The problem of detecting the population with the smallest absolute value of mean is also considered.

• Journal of Korean Society for Quality Management
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• v.25 no.3
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• pp.74-85
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• 1997

In this paper we calculate the subgroup size necessary for detecting the change of percent defective with several detection probabilities for orginal population fraction nonconforming p, changed population fraction nonconforming $p^*$, and the ratio k=$p^*$/p in the usage of p control charts. From our calculation we can know the error level of normal a, pp.oximation in detection probability calculation and recommend the subgroup size with lower error levels of normal a, pp.oximation, and then we show the reasonable subgroup size necessary for p, $p^*$, k, and the detection probability of the change of fraction nonconforming in a process. The information that we here show in tables will be useful when p control chart users decide the subgroup size in the p control chart users decide the subgroup size in the p control chart.

• Journal of Bone Metabolism
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• v.25 no.4
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• pp.235-241
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• 2018

Background: Procollagen type I N-terminal propeptide (PINP) is one of the most clinically useful bone formation biomarkers. Therefore, the purpose of this study was to independently evaluate the performance of automated total PINP assay and established age- and gender- specific reference intervals for PINP in healthy Korean population. Methods: The imprecision, linearity, and detection capability of Elecsys total PINP assay was determined and reference interval was established using 599 serums from Korean population with normal bone mineral densities based on bone densitometry. Age groups were divided into 20s, 30s, 40s, 50s, 60s and over. Results: Elecsys total PINP had excellent performance in imprecision, linearity, and detection capability. When partitioning age groups in Korean male and female populations, there was significant difference in total PINP between different age groups. In male populations, PINP level was decreased with increasing age, then it remained steady after middle-age. In female populations, there was a decreasing tendency similar to that in the male population with a sharp increase in the 50 to 59 age group. Conclusions: Elecsys total PINP assay showed precise and reliable performance in our study. We established age-related PINP reference intervals for Korean male and female population with normal bone mineral densities.

• Journal of Environmental Impact Assessment
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• v.4 no.2
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• pp.93-103
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• 1995

This study was carried out to suggest the best statistical test to analyze the trend in monthly water quality data. Traditional parametric tests such as t-test and regression analysis are based on the assumption that the underlying population has a normal distribution and regression analysis additionally assumes that residual errors are independent. Analyzing 9-years monthly COD data collected at Paldang in Han River, the underlying population was found to be neither normal nor independent. Therefore parametric tests are invalid for trend detection. Four Kinds of nonparametric statistical tests, such as Run Test, Daniel test, Mann-Kendall test, and Time Series Residual Analysis were applied to analyze the trend in the COD data, Daniel test and Mann-Kendall test indicated upward trend in COD data. The best nonparametric test was suggested to be Daniel test, which is simple in computation and easy to understand the intuitive meaning.

• The Bulletin of The Korean Astronomical Society
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• v.40 no.1
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• pp.72.1-72.1
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• 2015

We investigate black hole (BH) activities of 16 red active galactic nuclei (AGNs). The 16 red AGNs selected by red colors in optical through near-infrared (NIR) and radio detection. In order to derive BH activities of the red AGNs, we use $P{\beta}$ line with NIR spectra obtained by the SpeX on the IRTF. The $P{\beta}$ line suffers from dust extinction less than UV/optical BH mass estimators. We compared Eddington ratios of the red AGNs and "normal" AGNs, and the Eddington ratios of red AGNs are significantly higher than those of "normal" AGNs. The result is consistent with a scenario that red AGNs are the intermediate population between star forming galaxies and "normal" AGNs, and BHs of red AGNs are very active and grow rapidly in such a stage.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.4
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• pp.339-344
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• 2000

Objective: To evaluate silane-coated silica particles (Sil-select) as an alternative to polyvinylpyrrolidone-coated particles (Percoll) for gradient separation of spermatozoa, for use in assisted reproduction. Methods: 20 normal semen based on WHO criteria were included in this study. Recovery of motile and morphologically normal spermatozoa after using two-layer Percoll and Sil-select gradient respectively was recorded. Motility, HOST (hypoosmotic swelling test) and the detection of malondialdehyde for LPO (lipid peroxidation) after 24 h of incubation at $37^{\circ}C$ in a 5% $CO_2$ incubator were compared. Results: Percoll (78.5%) and Sil-select (79.1%) showed a significant increase in the motility compared to ejaculate (60.9%) but no difference between Percoll and Sil-select. Normal sperm morphology significantly increased after Percoll (57.6%) and Sil-select (53.7%) compared to ejaculate (35.8%) but no difference between Percoll and Sil-select. No differences in the recovery of motile spermatozoa and motility, HOST and the production of malondialdehyde after 24 h incubation were found when comparing the use of Percoll and Sil-select. Conclusion: Sil-select seems to be an attractive alternative to Percoll for sperm separation in assisted reproduction.

• Clinical and Experimental Pediatrics
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• v.51 no.9
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• pp.911-921
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• 2008

Learning disabilities (LD) are heterogeneous group of disorders with evidences of genetic or familial trait, intrinsic to the individual and presume to be due to central nervous dysfunction. Learning disabilities and attention deficit hyperactivity disorder (ADHD) are the two of the most common disorders in the population of school-age children. Typically academic achievements in children with learning disabilities are significantly lower than expected by their normal or above normal range of IQ. Although academic and cognitive deficits are hallmarks of children with LD, those children are also at risk for a broad range of behavioral and emotional problems. Almost all cases meet criteria for at least one additional diagnosis such as ADHD, developmental coordination disorder, depression, anxiety, obsessive compulsive disorder, tic disorder, among which ADHD is particularly predominant. Because of the response to the therapeutic intervention program is promising and positive when applied early, it is critical to recognize patients as early as possible. Pediatricians often are the first to hear from parents worried about a childs academic progress. It is not the responsibility of pediatrician to make a diagnosis, referring children for a diagnostic evaluation of LD is a reasonable first step. Pediatricians can make early referral of suspicious children by asking some serial short questions about basic and processing skills. With a basic knowledge about the clinical characteristics, diagnostic and therapeutic procedures of LD, pediatricians also can provide primary counseling and education for parents at their outpatient clinical settings.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.17 no.1
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• pp.13-22
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• 2014

Esophageal pH monitoring is considered the gold standard for the diagnosis of gastroesophageal reflux disease because of the normal ranges across the pediatric age range. However, this method can only detect acid reflux. Multichannel intraluminal impedance-pH (MII-pH) monitoring has recently been used for the detection of bolus reflux in infants and children. This method allows for the detection of liquid, gas or mixed reflux in addition to acid, weakly acidic or weakly alkaline reflux. MII-pH monitoring can record the direction of flow and the height of reflux, which are useful parameters to identify an association between symptoms and reflux. However, the technique is limited by its high cost and the lack of normative data of MII-pH in the pediatric population. Despite certain limitations, MII-pH monitoring will become more common and gradually replace pH monitoring in the future, because pH monitoring is part of MII-pH.

• Genomics & Informatics
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• v.7 no.1
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• pp.32-37
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• 2009

The quality assurance (QA) is of utmost importance in biobanks when archived biomaterials are distributed to biomedical researchers. For sample authentication and cross-contamination detection, the two fundamental elements of QA, STR genotyping is usually utilized. However, the incorporated number of STR markers is highly redundant for biobanking purposes, resulting in time and cost inefficiency. An index to measure the cross-contamination detection capability of an STR marker, the mixture probability (MP), was developed. MP as well as other forensic parameters for STR markers was validated using STR genotyping data on 2328 normal Koreans with the commercial AmpFlSTR kit. For Koreans, 7 STR marker (D2S1338, FGA, D18S51, D8S1179, D13S317, D21S11, vWA) set was sufficient to provide discrimination power of ${\sim}10^{-10}$ and cross-contamination detection probability of ${sim}1$. Interestingly, similar marker sets were obtained from African Americans, Caucasian Americans, and Hispanic Americans under the same level of discrimination power. Only a small subset of commonly used STR markers is sufficient for QA purposes in biobanks. A procedure for selecting optimal STR markers is outlined using STR genotyping results from normal Korean population.

• Journal of Gastric Cancer
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• v.3 no.2
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• pp.97-103
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• 2003

Purpose: This study aims to determine the infection rate of Helicobacter pylori (H. pylori) in gastric cancer patients who received gastrectomies, and to compare the rates of H.pylori infection detected by serological test and that of histopathological test, and to evaluate its clinical meaning. Materials and Methods: Fifty two patients were selected from those who underwent gastrectomies at the Department of Surgery, Samsung Medical Center, from March 1997 to May 1997. The control group consisted of healthy 103 persons visited the center for health promotion in Samsung Medical Center. In both groups, we quantitatively checked serum level of IgG anti H. pylori antibody titer by ELISA using GAP IgG test kit (BioRad, USA) for the serological test, and we microscopically examined the surgical specimen stained by Warthin-Starry silver staining method for the histopathological test. Results: The seropositive rate of H. pylori in the patients' group was $71.2\%$ (37/52), and the control group was $65.0\%$ (67/103). The difference between two groups was statistically significant. However the histopathological study showed that the overall detection rate of H. pylori was $61.5\%$ (32/52) in the patients' group and $61.2\%$ (63/103) in the control group; nd this difference was not statistically significant Conclusion: We could confirm that H.pylori infection rate in the gastric cancer resected patients was statistically higher than in the normal healthy persons even in small population. And the detection method for the H. pylori infection by serological test was presumed to be better than that of histopathological test using surgical specimen. Further study for the larger population by well-organized multicenters will be needed.