• Journal of the Korean Statistical Society
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• v.18 no.2
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• pp.118-124
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• 1989

In the one-way random effect model, we often estimate the variance components by the ANOVA method and then estimate the population mean. Whe there are only two distint group sizes, the conventional mean estimator is represented as a weighted average of two normal means with weights being the function of variance component estimators. In this paper, we will study a method which can compute the exact variance of the mean estimator when we set the negative variance component estimate to zero.

• Journal of KSNVE
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• v.3 no.1
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• pp.77-82
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• 1993

In general, the dynamic analysis with FEM(Finite Element Method) of large structures requires large computer memory space and long computational time. For the purpose of economical dynamic analysis of large structures, most of engineers want to use an efficient solution algorithm. This paper reports the modified CMS(Component Mode Synthesis) method which uses more efficient algorithm than the classical CMS method. In this paper, it is shown that Ritz vector sets can play the role of normal mode vector sets of substurctures in the CMS algorithm. The modified CMS method has good convergence performance compared with that of the classical CMS method.

• Structural Engineering and Mechanics
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• v.23 no.6
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• pp.615-634
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• 2006

Seismic response of the liquid storage tanks isolated by the elastomeric bearings and sliding systems is investigated under near-fault earthquake motions. The fault normal and parallel components of near-fault motion are applied in two horizontal directions of the tank. The continuous liquid mass of the tank is modeled as lumped masses known as sloshing mass, impulsive mass and rigid mass. The corresponding stiffness associated with these lumped masses has been worked out depending upon the properties of the tank wall and liquid mass. It is observed that the resultant response of the isolated tank is mainly governed by fault normal component with minor contribution from the fault parallel component. Further, a parametric study is also carried out to study the effects of important system parameters on the effectiveness of seismic isolation for liquid storage tanks. The various important parameters considered are: aspect ratio of tank, the period of isolation and the damping of isolation bearings. There exists an optimum value of isolation damping for which the base shear in the tank attains the minimum value under near-fault motion. The increase of damping beyond the optimum value will reduce the bearing and sloshing displacements but increases the base shear. A comparative performance of five isolation systems for liquid storage tanks is also studied under normal component of near-fault motion and found that the EDF type isolation system may be a better choice for design of isolated tank in near-fault locations. Finally, it is also observed that the satisfactory response can be obtained by analysing the base-isolated tanks under simple cycloidal pulse instead of complete acceleration history.

• Journal of the Korean Institute of Gas
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• v.23 no.4
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• pp.19-27
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• 2019

The consumption of liquefied natural gas (LNG) has increased annually due to the strengthening of international environmental regulations. In order to produce stable and efficient LNG, it is essential to divide the global (overall) operating condition and construct a quick and accurate monitoring system for each operation condition. In this study, multi-mode monitoring system is proposed to the LNG plant fractionation process. First, global normal operation data is divided to local (subdivide) normal operation data using global principal component analysis (PCA) and k-means clustering method. And then, the data to be analyzed were matched with the local normal mode. Finally, it is determined the state of process abnormality through the local PCA. The proposed method is applied to 45 fault case and it proved to be more than 5~10% efficient compared to the global PCA and univariate monitoring.

• Proceedings of the KOSOMBE Conference
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• v.1997 no.11
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• pp.451-454
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• 1997

It has been reported that sudden cardiac death and ventricular tachycardia occur after treatment of tetralogy of fallot(TOF). It is regarded that ventricular arrythmia is the main source or the sudden cardiac death, but it is not verified. It is likely that TOF has effect on the heart rate variability because of the ventricular arrythmia. We study how complex and periodic heart rate dynamics change in the normal children (n=13) and TOF children (n=13) throughout 24 hours. We recorded 24-hour holter ECG, and segmented each ECG data into 1 hour length. We analyze each HR time series, and quantify the overall complexity of each HR time series by its correlation dimension. We also calculate the power spectrum of HR, and obtain low-frequency component (0.03-0.15Hz) and high-frequency component (0.15-0.4Hz). We compare the results between normal and TOF groups throughout 24 hours. TOF group have lower correlation dimension ($4.055{\pm}0.4134$ vs. $4.9310{\pm}0.2054$, p<0.05) than the normal group, even though there are no significant differences in the low($0.9864{\pm}0.5598$ vs. $1.5560{\pm}0.8325$, p<0.05) and high($1.1168{\pm}0.1.1448$ vs. $0.9271{\pm}0.6528$, p<0.05) frequency components. It can be concluded that HR time series of TOF group are more regular than that of normal group, and that correlation dimension reveals a nonlinear characteristics of HR time series which is not determined in the frequency domain.

• The Pure and Applied Mathematics
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• v.22 no.1
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• pp.91-99
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• 2015

A normal surface is determined by how the surface under consideration meets each tetrahedron in a given triangulation. We call such a nice embedded disk, which is a component of the intersection of the surface with a tetrahedron, an elementary disk. We classify all elementary disk types in a truncated ideal triangulation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.9
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• pp.4342-4348
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• 2013

The present study was intended to reveal the relationships between serum lipid levels and various factors of obesity and blood pressure. The study subjects were 1,838 adult women measured at a mass health screening during the period from January through December, 2011. TC, TG, HDL-C, LDL-C, SBP, DBP, degree of obesity, body fat rate were measured and the relation between these obesity and blood pressure measurements to serum lipid levels were studied. As a results, TC, TG, LDL-C, body fat rate and degree of obesity increased linearly with advancing age. TC, TG and LDL-C increased linearly with increasing blood pressure, and these values were higher in hypertension group than that of normal group. TC, TG and SBP increased linearly with increasing degree of obesity, and these values were higher in obesity group than that of normal group. HDL-C decreased linearly with increasing degree of obesity, and these values were lower in obesity group than that of normal group. TC, TG, HDL-C, degree of obesity, body fat rate was positive correlation with each others, but these values negatively correlated to HDL-C. Principal component analysis, showed that subjects could be divided into the group having the hypertensive group(1st principal component), the obesity group(2nd principal component), the hyperlipidemia group(3rd principal component), and HDL-C(4th principal component). In multiple regression analysis, age, TC, TG and body fat rate were affected to HDL-C. Above results suggest that higher the degree of obesity and blood pressure, the higher the serum lipid levels.

• Transactions on Electrical and Electronic Materials
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• v.10 no.5
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• pp.156-160
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• 2009

In an ultrasonic motor, a piezoelectric ceramic material forms the active element which vibrates the stator, thus initiating the rotational motion. In the operation of ultrasonic motors, many factors exist that can affect the resonance characteristics of the piezoelectric ceramic component. For examples, these factors are the bonding conditions with the piezoelectric element, the magnitude of the input voltage, the normal force in the frictional drive and the emission of heat due to vibration and friction etc. Therefore, it is important to research properly the inclination for variation of piezoelectric ceramics in the circumstance where complex elements are involved. In this paper, we focus on the analysis of the resonance characteristics of an ultrasonic motor as a function of the magnitude of the input voltage and the normal force.

• Journal of the Korean Statistical Society
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• v.20 no.1
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• pp.67-76
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• 1991

The empirical Bayes version involves ″independent″ repetitions(a sequence) of the component decision problem. With the varying sample size possible, these are not identical components. However, we impose the usual assumption that the parameters sequence $\theta$=($\theta$$_1$, $\theta$$_2$, …) consists of independent G-distributed parameters where G is unknown. We assume that G $\in$ g, a known family of distributions. The sample size $N_i$ and the decisin rule $d_i$ for component i of the sequence are determined in an evolutionary way. The sample size $N_1$ and the decision rule $d_1$$\in$ $D_{N1}$ used in the first component are fixed and chosen in advance. The sample size $N_2$and the decision rule $d_2$ are functions of *see full text($\underline{X}^1$equation omitted), the observations in the first component. In general, $N_i$ is an integer-valued function of *see full text(equation omitted) and, given $N_i$, $d_i$ is a $D_{Ni}$/-valued function of *see full text(equation omitted). The action chosen in the i-th component is *(equation omitted) which hides the display of dependence on *(equation omitted). We construct an empirical Bayes decision rule for estimating normal mean and show that it is asymptotically optimal.

• Herbal Formula Science
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• v.9 no.1
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• pp.215-230
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• 2001

The purpose of this study was to investigate the effect of Bojungikgitang(補中益氣湯), Soeumin bojungikgitang(少陰人 補中益氣湯) and its component groups on diabetes in alloxan induced diabetic rats. Sprague-Dawley male rats weighing $200{\pm}10\;gm$ were randomly assigned to one normal, one control and five experimental groups. The experimental groups was classified into to Bojungikgitang(B1 group), Soeumin bojungikgitang(B2 group), Bogihyulyak(B0 group), Siho-sengma(B1+ group) and Gwakhyang- soyeup(B2+ group). Diabetes was experimentally induced by abdomenal injection of 100 mg/kg of body weight of alloxan. Animals were sacrificed at the 6th day and 11th day of diabetic states. The results were obtained as follows: In carbohydrate metabolism, the level of glucose in control group was three-fold higher after alloxan injection than that of normal group. In B1, B2 groups the level of glucose was decreased by 39% and 43% compared with that of control group, and in component groups it was decreased by 73%, 81%, and 80% respectively. In fat metabolism, the level of triglyceride and total cholesterol in serum were lower in B1 and B2 groups with high significant difference and had similar tendency in components groups compared with that of control group. The level of HDL cholesterol on serum were increased in B1 and B2 group with significant difference. And in component group it had similar tendency compared with that of control group. In protein metabolism, the level of total protein and albumin were higher in B1 and B2 group with significant difference, and in component group also increased but with no significancy compared with control group. In kidney function, the level of creatinine group with significant difference, and other compared with control group. In liver function, the level of GOT, GPT, ${\gamma}$-GTP. ALP and bilirubin were lower in B1 and B2 group with significant difference, and in component had similar tendency compared with control group. But in the level of LDH, it was decreased with no significancy. These results indicate that Bojungikgitang(補中益氣湯), Soeumin bojungikgitang(少陰人 補中益氣湯) has strong effect on diabetes and it is useful to prevent diabetes, and in component groups the difference between B1+ and B2+ group was not significant.