• Journal of Korean Academy of Nursing Administration
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• v.14 no.4
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• pp.404-412
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• 2008

Purpose: To analyse hospital nurse staffing level of the general nursing unit, ICU, ER and OR in general hospitals. Method: The study sample was 105 acute general hospitals which had reported the bed size and number of nurses by the nursing units. Number of bed per nurse was analysed by the hospital characteristics and the staffing levels of the doctors and the nursing assistant personnels using t-test or ANOVA and Pearson's correlation. Results: Number of bed per nurse was 3.86 in general nursing units and 0.95 in ICU. Tertiary hospitals employed more nurses in general nursing units and ICU than general hospitals. Hospitals located in Seoul and public hospitals employed more ICU nurses. OR nurse staffing level was higher in academic hospitals. Hospital size was positively correlated with nurse staffing level of the general nursing unit, ICU, ER and OR respectively. Total nurse staffing level of the hospital was positively correlated with doctor and nursing assistant personnels staffing levels. Conclusion : Differentiated nursing fee schedule was needed to implement in ER or OR. Regulation policy should be needed for the hospitals which violated hospital nurse staffing level of the law.

• Nuclear Engineering and Technology
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• v.38 no.4
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• pp.353-358
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• 2006

Alpha track analysis for the determination of the trace amount of alpha emitting nuclides in a very small particle was performed as an efficient and powerful technique during safeguard inspection. Metal particles with well-defined spherical shape, size and isotopic compositions as a reference material were used to correlate the number of tracks or track diameter with an isotopic composition eventually to identify the uranium enrichment in the environmental swipe samples. Slopes in the number of tracks versus the exposure time curve provide a simple insight into the uranium enrichment of an unknown particle. Low enriched uranium metal particles result in slopes still steeper than the depleted or natural uranium metal particles. In addition, a linear relationship between track diameter and particle size Is thought to be a useful first stage analytical tool as an efficient and convenient inspection guide. The significance of the simple linear model was also judged using the usual statistical tests.

• Geomechanics and Engineering
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• v.31 no.5
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• pp.461-476
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• 2022

Research studies on the scale effect on triaxial strength of intact rocks are scarce, being more common those in uniaxial strength. In this paper, the authors present and briefly interpret the peak and residual strength trends on a series of triaxial tests on different size specimens (30 mm to 84 mm diameter) of an intact granitic rock at confinements ranging from 0 to 15 MPa. Peak strength tends to grow from smaller to standard-size samples (54 mm) and then diminishes for larger values at low confinement. However, a slight change in strength is observed at higher confinements. Residual strength is observed to be much less size-dependent. Additionally, this study introduces preliminary modelling approaches of these laboratory observations with the help of three-dimensional particle flow code (PFC3D) simulations based on bonded particle models (BPM). Based on previous studies, two modelling approaches have been followed. In the first one, the maximum and minimum particle diameter (D_max and D_min) are kept constant irrespective of the sample size, whereas in the second one, the resolution (number of particles within the sample or ϕ_v) was kept constant. Neither of these approaches properly represent the observations in actual laboratory tests, even if both of them show some interesting capabilities reported in this document. Eventually, some suggestions are provided to proceed towards improving modelling approaches to represent observed scale effects.

• Journal of Integrative Natural Science
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• v.7 no.3
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• pp.208-213
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• 2014

National-wide and/or large scale sample surveys generally use complex sample design. Traditional Pearson chi-square test is not appropriate for the categorical complex sample data. Rao-Scott suggested an adjustment method for Pearson chi-square test, which uses the average of eigenvalues of design matrix of cell probabilities. This study is to compare the efficiency of Rao-Scott first order adjusted test to Wald test for homogeneity between two populations using 2009 Gyeongnam regional education offices's customer satisfaction survey (2009 GREOCSS) data. The 2009 GREOCSS data were collected based on stratified three-stage cluster sampling with probability proportional to size. The empirical results show that the Rao-Scott adjusted test statistic using only the variances of cell probabilities is very close to the Wald test statistic, which uses the covariance matrix of cell probabilities, under the 2009 GREOCSS data based. However it is necessary to be cautious to use the Rao-Scott first order adjusted test statistic in the place of Wald test because its efficiency is decreasing as the relative variance of eigenvalues of the design matrix of cell probabilities is increasing, specially more when the number of degrees of freedom is small.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.18 no.2
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• pp.124-136
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• 2006

The change pattern of the sediment grain size distribution information (median grain size(D50)) due to some gridding method and sampling density is analyzed with reference to the grid information estimated by the 90 sediment samples which was collected in the coastal water off the Baengnyeongdo Island, in June 2004. The standard deviation of absolute deviation (AD) estimated the selected gridding method shows 8.0 ${\mu}m$ at June, 2004 and 10 ${\mu}m$ November, 2004. The estimated statistical information of absolute deviation in comparison with the grid information of reference and changed sampling density shows that the AD mean error trends increase as the number of samples decrease. The AD mean error is below 10% in the case of the information estimation using 50-sample with reference to the 90-sample information. In this case, the sampling density is suggested as about 9 sediment samples per $km^2$, at coastal zone in Yoggipo port in the condition of the study area is 5.9 $km^2$.

• Journal of Educational Research in Mathematics
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• v.21 no.1
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• pp.17-32
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• 2011

This study investigated pre-service teachers' understanding of statistical sampling. The researchers categorized major topics related to sampling into representativeness of samples, sampling variability, and sampling distribution, and selected concepts connected to each topic. Findings on this study are as follows: Even though most of the pre-service teachers considered the random sampling bringing unbiased outcomes as a proper sampling method, only 64% of them recognized that sample is a quasi-proportional, small-scale version of population; Few pre-service teachers understood that more important is the size of sample, not the portion of sample to population, and half of them appreciated that the number of sampling has a powerful effect on drawing of reliable results than the size of sample; Few pre-service teachers understood that sampling distribute is irrelevant to the shape of population and has a symmetrical bell-shape.

• Journal of Applied Reliability
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• v.5 no.1
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• pp.167-180
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• 2005

Design of a degradation test without replacement is considered based on tightened critical value to reduce the evaluation testing time. The sample size, number of inspections, and the critical values are determined to assure the same probability of acceptance when the testing time is reduced to some degree. Photo-diode balance of an optical pickup is analyzed as a case study.

• Journal of Korean Institute of Industrial Engineers
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• v.23 no.4
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• pp.793-802
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• 1997

A sampling plan is presented for situations where sampling inspection is based on the quality characteristic of interest and items in rejected lots are screened based on a correlated variable. A cost model is constructed which involves the costs of misclassification errors, sampling and screening inspections. A method of finding optimal values of sample size, acceptance number and cutoff value on the correlated variable is presented, and numerical studies are given.

• Journal of the Korean Data and Information Science Society
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• v.18 no.3
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• pp.669-678
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• 2007

An algorithm to detect the number of discontinuity points of the variance function in regression model is proposed. The proposed algorithm is based on the left and right one-sided kernel estimators of the second moment function and test statistics of the existence of a discontinuity point coming from the asymptotic distribution of the estimated jump size. The finite sample performance is illustrated by simulated example.

• Communications for Statistical Applications and Methods
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• v.15 no.3
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• pp.379-386
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• 2008

In this paper, the choice of a primary resolution and wavelet basis functions are introduced under random or irregular design points of which the sample size is free of a power of two. Most wavelet methods have used the number of the points as the primary resolution. However, it turns out that a proper primary resolution is much affected by the shape of an unknown function. The proposed methods are illustrated by some simulations.