• Korean Journal of Environment and Ecology
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• v.15 no.4
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• pp.394-400
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• 2002

A mixed forest community of broad-leaved trees in Guryongsan area was studied to determine the adequate number of plots of tree and shrub strata for investigating forest community structure. Fifteen 10m$\times$10m plots were set up in the tree stratum and fifteen 5m$\times$5m plots were set up in the shrub stratum. Species-area curves and performance curves were made from vegetation analysis of the plots. In tree stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the same percentage in number of species was five. In tree stratum, minimum number of plots where a given percentage increase in nuts her of plots produced less than the half of the percentage increase in number of species was ten. In tree stratum, minimum number of plots where the dominant species was distinguished from the subdominant species was four In tree stratum. minimum number of plots where the subdominant species were distinguished from each other was eight. In tree stratum, the difference of species diversity(H') between seven or more plots and total fifteen plots was less than 0.05 Similarity index was more than 80% between aye or more plots and total fifteen plots, and more than 90% between nine or more plots and total fifteen plots. In shrub stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the same percentage in number of species was five . In shrub stratum, the minimum number of plots where a given percentage increase in number of plots produced less than the half of the percentage increase in number of species was twelve. In shrub stratum. minimum number of plots where the dominant species was distinguished from the subdominant species was four. In shrub stratum, the minimum number of plots where the subdominant species were distinguished from each other was thirteen. In shrub stratum, the difference of species diversity(H') between six or more plots and total fifteen plots was less than 0.05. Similarity index was more than 80% between five or more plots and total fifteen plots, and more than 90% between nine or more plots and total fifteen plots. It may be given as a conclusion that adequate number of 10m$\times$10m plots for the tree stratnm was about 5 in general acse and 10 in case of requiring more accuracy, and that the adequate number of 5m$\times$5m plots for ahrub stratum was about 5 in general case and 13 in case of requiring more accuracy.

• Communications for Statistical Applications and Methods
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• v.21 no.1
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• pp.105-114
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• 2014

In this paper we suggest an efficient method to estimate the distribution function using the Bezier curve, and compare it with existing methods by simulation studies. In addition, we suggest a robust version of cross-validation criterion to estimate the number of Bezier points, and showed that the proposed method is better than the existing methods based on simulation studies.

• Communications of the Korean Mathematical Society
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• v.10 no.2
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• pp.483-490
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• 1995

A parametric cubic spline interpolating at fixed number of nodes is constructed by formulating a parametric cubic $g^2$ B-splines $S_3(t)$ with not equally spaced parametric knots. Since the fact that each component is in $C^2$ class is not enough to provide the geometric smoothness of parametric curves, the existence of $S_3(t)$ oriented toward the modified second-order geometric continuity is focalized in our work.

• Bulletin of the Korean Mathematical Society
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• v.48 no.1
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• pp.105-114
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• 2011

In this paper, we classify (C, $\cal{L}$) such that a smooth curve C of genus g has a nonspecial very ample line bundle $\cal{L}$ of deg $\cal{L}$ = 2g-2-a failing to be normally generated, in terms of the number a.

• Journal of Integrative Natural Science
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• v.7 no.1
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• pp.67-73
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• 2014

We consider the mean value function for NHPP software reliability model and time series regression model in software failure data. We estimate parameters for the proposed models from two data sets. The values of SSE and MSE is presented from two data sets. We compare the predicted number of faults with the actual two data sets using the mean value function and regression curve.

• Journal of Dental Anesthesia and Pain Medicine
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• v.15 no.4
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• pp.207-212
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• 2015

Background: The ideal alternative airway device should be intuitive to use, yielding proficiency after only a few trials. The Clarus Video System (CVS) is a novel optical stylet with a semi-rigid tip; however, the learning curve and associated orodental trauma are poorly understood. Methods: Two novice practitioners with no CVS experience performed 30 intubations each. Each trial was divided into learning (first 10 intubations) and standard phases (remaining 20 intubations). Total time to achieve successful intubation, number of intubation attempts, ease of use, and orodental trauma were recorded. Results: Intubation was successful in all patients. In 51 patients (85%), intubation was accomplished in the first attempt. Nine patients required two or three intubation attempts; six were with the first 10 patients. Learning and standard phases differed significantly in terms of success at first attempt, number of attempts, and intubation time (70% vs. 93%, $1.4 {\pm}0.7$ vs. $1.1{\pm}0.3$, and $71.4{\pm}92.3s$ vs. $24.6{\pm}21.9s$, respectively). The first five patients required longer intubation times than the subsequent five patients ($106.8{\pm}120.3s$ vs. $36.0{\pm}26.8s$); however, the number of attempts was similar. Sequential subgroups of five patients in the standard phase did not differ in the number of attempts or intubation time. Dental trauma, lip laceration, or mucosal bleeding were absent. Conclusions: Ten intubations are sufficient to learn CVS utilization properly without causing any orodental trauma. A relatively small number of experiences are required in the learning curve compared with other devices.

• Journal of Korean Society of Forest Science
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• v.86 no.2
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• pp.158-166
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• 1997

This study presents the method to quantify the stand structure diversity or homogeneity. Gadow's dbh differentiation(Durchmesserdifferenzierung) is introduced which quantifies the horizontal stand structure by the ratio of the dbh between subject tree and neighbour trees. And new stand structure diversity index based on Lorenz curve, which is made by ratio of tree number and basal area or volume by dbh class, is presented. The horizontal stand structure index based on Lorenz curve has a value from 0 to 1 as Gadow's index, and approximates to 1 if the stand structure has high diversity. In the comparative analysis for performance, the new stand structure index based on Lorenz curve is considered to compare with the Gadow's index for describing the stand structure.

• Journal of the Korean Geotechnical Society
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• v.20 no.5
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• pp.27-35
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• 2004

The goal of this study is to investigate the feasibility of the reference state approach in determining the generalized soil-water characteristic curve that is essential fur characterization of unsaturated soil behavior. The soil-water characteristic curves are obtained from a number of specimens of fine-grained residual soils compacted with different void ratios. Based on the experimental test results, the feasibility of using the liquid limit state as the reference state for predicting the soil-water characteristic curve is verified. Finally, through the regression analysis of experimental data using the equation of Fredlund and Xing (1994), a reliable method is proposed to predict the generalized soil-water characteristic curve of fine-grained residual soils using the liquid limit state as the reference state.

• Bulletin of the Korean Mathematical Society
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• v.50 no.1
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• pp.83-96
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• 2013

Let K be a number field and fix a prime number $p$. For any set S of primes of K, we here say that an elliptic curve E over K has S-reduction if E has bad reduction only at the primes of S. There exists the set $B_{K,p}$ of primes of K satisfying that any elliptic curve over K with $B_{K,p}$-reduction has no $p$-torsion points under certain conditions. The first aim of this paper is to construct elliptic curves over K with $B_{K,p}$-reduction and a $p$-torsion point. The action of the absolute Galois group on the $p$-torsion subgroup of E gives its associated Galois representation $\bar{\rho}_{E,p}$ modulo $p$. We also study the irreducibility and surjectivity of $\bar{\rho}_{E,p}$ for semistable elliptic curves with $B_{K,p}$-reduction.

• International Journal of CAD/CAM
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• v.5 no.1
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• pp.11-18
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• 2005

The traditional method of manipulation of knots and degrees gives poor quality of surface, if compatibility of input curves is not good enough. In this work, a new algorithm of multiple refitting of curves has been developed using minimum energy based formulation to get compatible curves for skinning. The present technique first reduces the number of control points and gives smoother surface for given accuracy and the surface obtained is then skinned by compatible curves. This technique is very useful to reduce data size when a large number of data have to be handled. Energy based technique is suitable for approximating the missing data. The volumetric information can also be obtained from the surface data for analysis.