• Communications for Statistical Applications and Methods
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• v.25 no.5
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• pp.545-557
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• 2018

The inclusion of covariates in the model often affects not only the estimates of meaningful variables of interest but also its statistical significance. Such gap between statistical and subject-matter significance is a critical issue in huge sample studies. A popular huge sample study, the sample cohort data from Korean National Health Insurance Service, showed such gap of significance in the inference for the effect of obesity on cause of mortality, requiring careful consideration. In this regard, this paper proposes a sample size calibration method based on a Monte Carlo t (or z)-test approach without Monte Carlo simulation, and also proposes a test procedure for subject-matter significance using this calibration method in order to complement the deflated p-value in the huge sample size. Our calibration method shows no subject-matter significance of the obesity paradox regardless of race, sex, and age groups, unlike traditional statistical suggestions based on p-values.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1109-1114
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• 2008

To investigate the effect of sample size on coefficient of consolidation of non-homogeneous soil, the result of a large size consolidation test using a huge undisturbed sample with $1200mm(D){\times}2000mm(H)$ in dimension is compared with that of oedometer test using undisturbed small sample. In addition, test results are compared with those of same test using remold sample. Experimental results show that, due to the lump of sand/silt was mixed in sample, the coefficient of consolidation of undisturbed samples have a difference for each tests. Whereas, the difference of coefficient of consolidation between remolded large and small samples is not found. Because sample size affects the test results, sample must be carefully selected for non-homogeneous soil.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.419-419
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• 2014

Interdigitated nanogap device (IND) is an attractive tool for biomolecular detection due to its huge on-off signal ratio, great tolerance to the variation in biochemical environment, and relatively simple implementation processes. Here, we report on the IND-based detection of Influneza A virus by sandwich immunoassay. The INEs were fabricated by photo lithography followed by the in-house chemical lithographic technique for the narrowing the initial gap distance. The surface of the silicon oxide between the two gold electrodes was chemically modified to immobilize primary antibodies for the immuno-specific interaction with the influenza A virus antigen. After immersing the functionalized-IND into the sample solution containing the influenza A virus, the device was exposed to the secondary antibody conjugated Au nanoparticles (Au NPs). The INDs showed a huge jump in the electric conductance when the sample solution contained the influenza A virus of the concentration as low as 10 ng/mL. We hope that this IND-based sensing can be applied to the development of simple and reliable diagnostic means of influenza viruses.

• The Korean Journal of Financial Management
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• v.26 no.2
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• pp.181-201
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• 2009

This study is on the forecasting performance analysis of range volatility estimators(Parkinson, Garman and Klass, and Rogers and Satchell) relative to historical one using two-scale realized volatility estimator as a benchmark. American sub-prime mortgage loan shock to Korean stock markets happened in sample period(January 2, 2006~March 10, 2008), so the structural change somewhere within this period can make a huge influence on the results. Therefore sample was divided into two sub-samples by May 30, 2007 according to Zivot and Andrews unit root test results. As expected, the second sub-sample was much more volatile than the first sub-sample. As a result of forecasting performance analysis, Rogers and Satchell volatility estimator showed the best forecasting performance in the full sample and relatively better forecasting performance than other estimators in sub-samples. Range volatility estimators showed better forecasting performance than historical volatility estimator during the period before the outbreak of structural change(the first sub-sample). On the contrary, the forecasting performance of range volatility estimators couldn't beat that of historical volatility estimator during the period after this event(the second sub-sample). The main culprit of this result seems to be the increment of range volatility caused by that of intraday volatility after structural change.

• Bulletin of the Korean Chemical Society
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• v.34 no.6
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• pp.1668-1672
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• 2013

We developed a standoff Raman detection system for explosive molecules (EMs). Our system was composed of reflective telescope with 310 mm diameter lens, 532 nm pulse laser, and Intensified Charge-Coupled Device (ICCD) camera. In order to remove huge background noise coming from ambient light, laser pulses with nanosecond time width were fired to target sample and ICCD was gated to open only during the time when the scattered Raman signal from the sample arrived at ICCD camera. We performed standoff experiments with military EMs by putting the detector at 10, 20 and 30 m away from the source. The standoff results were compared with the confocal Raman results. Based on our standoff experiments, we were able to observe the peaks in the range of 1200 and $1600cm^{-1}$, where vibrational modes of nitro groups were appeared. The wave numbers and shapes of these peaks may serve as good references in detecting and identifying various EMs.

• Journal of Korean Society for Quality Management
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• v.36 no.1
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• pp.7-19
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• 2008

During the past two decades, a huge amount of research on adaptive control charts has been accomplished. Especially, variable sampling interval (VSI), variable sample size (VSS), and variable sample size and sampling interval (VSSI) charts have been focused by many researchers due to their simplicity and efficiency. On the other hand, the difference among notations, assumptions, methodologies may cause confusions in per forming further studies or practical implementations. This research analyses and compares diverse models so as to provide a unified view on statistical and economical characteristics. As a result, we perform comparative study on economical design models of VSI, VSS, and VSSI charts, respectively, We also present practical guidelines to utilize those adaptive control charts.

• ALGAE
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• v.27 no.4
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• pp.295-301
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• 2012

Carbon concentrating mechanisms play a vital role in photosynthesis in microalgae and cyanobacteria especially in the proper functioning of Rubisco and assimilation of carbon via the Calvin cycle. This study evaluates the role of carbon dioxide on carbon concentrating mechanism (CCM) in a cynaobacteria, Spirulina platensis and a microalga, Chlorella sp. 786. The study organisms were grown in both atmospheric (control sample, 0.035%) and high (exposed sample, 10%) $CO_2$ concentrations. Second dimension (2D) electrophoresis revealed a huge difference in the protein profiles of both organisms suggesting the induction of CCM related proteins in the sample maintained at atmospheric $CO_2$ concentration and the repression of CCM related proteins in the sample maintained at 10% $CO_2$. Liquid chromatography-mass spectroscopy analysis revealed the presence of two important $C_i$ transporter proteins in the control sample of S. platensis, namely ferredoxin-$NADP^+$ reductase and ATP binding cassette (ABC) transport system protein. These proteins were only expressed in the control sample and were downregulated or not expressed at all in the exposed sample. Consequently, this study conclusively proves that CCMs are only inducted at low $CO_2$ concentrations and are not functional at high $CO_2$ concentration.

• Mass Spectrometry Letters
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• v.4 no.2
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• pp.25-29
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• 2013

Proteomics for biomarker validation needs high throughput instrumentation to analyze huge set of clinical samples for quantitative and reproducible analysis at a minimum time without manual experimental errors. Sample preparation, a vital step in proteomics plays a major role in identification and quantification of proteins from biological samples. Tryptic digestion a major check point in sample preparation for mass spectrometry based proteomics needs to be more accurate with rapid processing time. The present study focuses on establishing a high throughput automated online system for proteolytic digestion and desalting of proteins from biological samples quantitatively and qualitatively in a reproducible manner. The present study compares online protein digestion and desalting of BSA with conventional off-line (in-solution) method and validated for real time sample for reproducibility. Proteins were identified using SEQUEST data base search engine and the data were quantified using IDEALQ software. The present study shows that the online system capable of handling high throughput samples in 96 well formats carries out protein digestion and peptide desalting efficiently in a reproducible and quantitative manner. Label free quantification showed clear increase of peptide quantities with increase in concentration with much linearity compared to off line method. Hence we would like to suggest that inclusion of this online system in proteomic pipeline will be effective in quantification of proteins in comparative proteomics were the quantification is really very crucial.

• The Journal of Asian Finance, Economics and Business
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• v.9 no.6
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• pp.151-158
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• 2022

Even after three decades of economic reforms, India's labor market is characterized by stark inter-gender differences in terms of both participation rate and working time. Identification of the causes is necessary to remove the disparity and unequal sharing of economic opportunities to make way for women's empowerment. This research attempts in that direction, examining the prevalence of these inequities in rural areas of North-East Indian states using unit-level data from the 2017-18 Periodic Labour Force Survey (PLFS). The methodology for the estimation here is based on Blinder- Oaxaca decomposition method after correcting for sample bias forwarded by Heckman. The analysis shows that in both labor force participation and the wage gap, the females in the region lag behind their male counterparts by a huge margin. Further, the analysis shows that one of the main factors leading to the difference is the disparities in human capital assets. On top of female educational enrollment being low, there is also a huge lack of higher educational attainment, while males have accomplished much better in both the parameters. Moreover, the presence of social stigma against women working and discrimination put the female labor outcomes in a gloomy state.

• Journal of Sport and Applied Science
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• v.3 no.1
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• pp.27-34
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• 2019

Purpose: Mountain biking as a sport and recreational activity has grown rapidly over the previous two decades. The purpose of this study is to analyze differences of leisure satisfaction by demographic characteristics of mountain bike participants. Research design, data, and methodology: To accomplish the purpose, the study employed purposive sample method among nonprobability sampling and collected data from 300 participants. Of collected data, 288 responses were analyzed excepted for uncompleted responses. To analyze data, study utilized statistical techniques including descriptive statistics, reliability analysis, independent-sample t-test, and one-way ANOVA, and to verify difference between individual groups in relation to significant results, Duncan's multiple range was conducted. Results: Findings indicated no differences of leisure satisfaction by gender. Similarly, education level and occupations have not influence leisure satisfaction. Yet, differences of leisure satisfaction by participation frequencies were observed. Of participation frequencies, participants riding 5 times a week were more satisfied with MTB participation than the other groups participating less 3 times a week. Conclusions: The findings provide a couple of insights in terms of promoting MTB participation. In specific, results indicated that MTB would be attractive sports that is able to appeal huge populations regardless of their education and occupation. Furthermore, consistent participation is judged an effective way to increase psychological, educational, and social satisfaction. In this sense, regional MTB clubs could play a salient role in motivating riders to more participate in MTB. Hence, establishing strategies for encouraging club activities are needed.