• Journal of the Korean Statistical Society
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• 제18권2호
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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.

• 소음진동
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• 제3권1호
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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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• 제23권6호
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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.

• 한국가스학회지
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• 제23권4호
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• pp.19-27
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• 2019

세계 환경규제가 강화되면서 액화천연가스의 사용량이 지속해서 증가하고 있다. 안정적이고 효율적인 액화천연가스 생산을 위해서는 운전 조건을 세분화하여 감시하는 시스템 구축이 필수적이다. 본 연구에서는 천연가스 액화플랜트 성분 분리공정을 해석하여 구축한 동적 모델 데이터를 대상으로 다중 모드 감시시스템 개발 방법을 제안하였다. 먼저 전체 정상 데이터를 주성분분석과 k-평균 군집화 방법론을 사용하여 다중 정상 운전 모델로 구분하였다. 그 다음, 새로운 데이터 값을 k-최근접 알고리즘으로 구축된 다중 정상 모드와 매칭하였다. 마지막으로, 다중 모드 주성분분석 감시 기법을 통해 공정 데이터의 이상 여부를 판별하였다. 제시된 방법론은 45가지 이상경우에 적용하였고, 기본 주성분분석 방법론과 단변수 감시 방법론과의 비교를 통해 속도와 정확도 지표에서 평균 약 5~10%이상 우수함을 입증하였다.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 추계학술대회
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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.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제22권1호
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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.

• 한국산학기술학회논문지
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• 제14권9호
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• pp.4342-4348
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• 2013

본 연구는 혈청지질과 비만 및 혈압과의 관련성을 검토하기 위하여 2011년 1월부터 12월까지 1년 동안에 대전광역시의 한 대학병원에서 종합건강검진을 받았던 30세에서 69세의 여성 1,381명을 대상으로 TC, TG, HDL-C, LDL-C, SBP, DBP, 비만도, 체지방률을 측정하여 혈청지질과 비만 및 혈압과의 관련성을 분석하였다. 연구결과, TC, TG, LDL-C, 비만도, 체지방률은 30대에서부터 60대에 걸쳐 단계적으로 상승하는 경향을 보였다. TC, TG 및 LDL-C는 혈압이 높아짐에 따라 상승하였으며, 정상혈압군에 비해 고혈압군에서 유의하게 높은 값을 보였다. TC, TG, SBP 는 비만도가 높아짐에 따라 단계적으로 상승하였고, 정상군에 비해 비만군에서 유의하게 높았으며, HDL-C는 비만도가 높아짐에 따라 감소하는 경향을 보였고, 정상군에 비해 비만군에서 유의하게 낮았다. TC, TG, LDL-C, 체지방률 및 비만도는 상호간에 유의한 정상관을 보인 반면, HDL-C와는 음의 상관을 보였다. 주성분분석 결과 제1주성분은 고혈압 인자, 제2주성분은 비만관련 인자, 제3주성분은 연령과 고지혈증 인자, 제4주성분은 고단백지콜레스테롤 인자가 선정되었다. HDL-C와 관련된 요인을 다중회귀분석을 사용하여 검토한 결과 HDL-C에 영향을 미치는 변수로는 연령, TC, TG 및 체지방률이 선정되었다. 위와 같은 결과는 비만도가 높고 혈압이 높은 군일수록 혈청지질치가 높아짐을 시사하고 있다.

• Transactions on Electrical and Electronic Materials
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• 제10권5호
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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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• 제20권1호
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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.

• 대한한의학방제학회지
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• 제9권1호
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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.