• Journal of Chest Surgery
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• 제20권4호
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• pp.655-658
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• 1987

Aortic annulus size was measured by two-dimensional echocardiography [2DE] in 29 patients undergoing aortic valve replacement or double valve replacement in order to predict prosthetic aortic valve size. Fifteen patients had aortic stenoinsufficiency, eleven had aortic insufficiency, and three had aortic stenosis. 2DE measurements of aortic annulus diameter, as determined from the parasternal long-axis view, demonstrated a high correlation with actual prosthetic valve size implanted at surgery [r=0.85, p<0.05]. 2DE exactly predicted actual prosthetic valve size in 8 of 29 patients [27.6%], was within 1mm of prosthetic valve size in 11 of 29 patients [37.9%], was within 2mm of prosthetic valve size in 8 of 29 patients, and was within 3mm of prosthetic valve size in 2 patients.

• 조명전기설비학회논문지
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• 제26권8호
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• pp.27-34
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• 2012

This paper proposes variable incremental conductance(IC) algorithm for maximum power point tracking(MPPT) control of photovoltaic. The conventional perturbation & observation(PO) and IC MPPT control algorithm generally uses fixed step size. A small step size reduces a tracking error in the steady state but slows a tracking speed in the transient state. Also, a large step size is fast a tracking speed but increases a tracking error. Therefore, this paper proposes variable IC MPPT algorithm that adjust automatically step size according to operating conditions. To improve a tracking speed and accuracy, when operating point is far from the maximum power point(MPP), the step size uses maximum value and when a operating point is near from the MPP, the step size uses variable step size that adjust according to slope of P-V curve. The validity of MPPT algorithm proposed in this paper prove through compare with conventional PO and IC MPPT algorithm.

• 한국생활과학회지
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• 제9권2호
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• pp.205-213
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• 2000

The purpose of this study was to study the degree of consciousness and satisfaction of body cathexis of high school girls' lower bodyshape. The subjects in this study were 296 high school girls. The results were as follows : 1. The degree of satisfactions of girth items in lower part of the body were influenced by real body size than ideal body size. But the degree of satisfaction of weight was influenced by ideal body size and height was influenced by real size body. 2. The high school girls thought ideal body shape was tall in height, long in leg, slim in girth and light in weight. Therefore, they wanted to have slimmer, longer, and lighter body size than real body size. 3. The high school girls were more satisfied with lean body type than with standard body type or with obesity body type. Therefore they wanted to be lean body type.

• Computers and Concrete
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• 제9권1호
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• pp.1-19
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• 2012

The size-effect study of various fracture parameters obtained from two parameter fracture model, effective crack model, double-K fracture model and double-G fracture model is presented in the paper. Fictitious crack model (FCM) for three-point bend test geometry for cracked concrete beam of laboratory size range 100-400 mm is developed and the different fracture parameters from size effect model, effective crack model, double-K fracture model and double-G fracture model are evaluated using the input data obtained from FCM. In addition, the fracture parameters of two parameter fracture model are obtained using the mathematical coefficients available in literature. From the study it is concluded that the fracture parameters obtained from various nonlinear fracture models including the double-K and double-G fracture models are influenced by the specimen size. These fracture parameters maintain some definite interrelationship depending upon the specimen size and relative size of initial notch length.

• 조명전기설비학회논문지
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• 제27권11호
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• pp.20-26
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• 2013

This paper proposes the maximum power point tracking(MPPT) control of photovoltaic system using fuzzy based variable step size perturbation & observation(FVSS-PO) method. Conventional PO and incremental conductance(IC)MPPT control algorithm generally uses fixed step size. A small fixed step size will cause the tracking speed to decrease and tracking accuracy of the MPP will decrease due to large fixed step size. Therefore, the fixed step size can't be satisfying both the tracking speed and the tracking accuracy. This paper proposes FVSS-PO MPPT algorithm that adjusts automatically step size of PO by fuzzy control according to operating conditions. The validity of MPPT algorithm proposed in this paper prove through compare with conventional PO MPPT algorithm.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.116-117
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• 2006

Increasing the solvent molecular size leads to shrinkage of the polymer chains and increase of the critical overlap concentrations. In addition, the dependency of $R_{g}$ on polymer concentration under normal solvent conditions and solvent molecular size is in good agreement with scaling laws. When the solvent molecular size approaches the ideal end-to-end distance of the polymer chain, an extra aggregation of polymer chains occurs, and the solvent becomes the so-called medium-sized solvent. When the size of solvent molecules is smaller than the medium size, the polymer chains are swollen or partially swollen. However, when the size of solvent molecules is larger than the medium size, the polymer coils shrink and segregate, enwrapped by the large solvent molecules.

• 대한인간공학회지
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• 제15권2호
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• pp.1-13
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• 1996

The purpose of this study is to suggest a brassiere sizing chart for elderly women. 2 control dimensions(under bust girth and cup size) were chosen as 2 axes of brassiere size chart. A loss function was used to determined intervals of under bust girth and cup size of size chart, because the loss function introduces the concept of frequency to size chart for better customer's satisfaction. From the dual distribution table whose intervals had been determined by a loss function. The 15 sizs, which had more than 2% of appearance were suggested for brassiere size chart. The suggested brassiere sizes covered 87.6% of all subjects. Considering that KS brassiere size chart consisting of 32 sizes covers 88.5%, the suggested brassiere size chart would be considered quite feasible. Also it is suggested supply reference measurement chart relevant to brassiere manufacturing for 10 most frequent sizes.

• 한국전자통신학회논문지
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• 제7권3호
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• pp.573-578
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• 2012

광통신네트워크를 효율적으로 연결 시키기 위해 단순화 된 Spot-Size Converter 구조를 제안하였다. Spot-Size Converter를 설계하기 위해 수치해석으로 모드필드를 확인하고, 빔 전송법을 통해 최적화 설계를 도출하였다. 최적화 된 구조는 직선도파로와 Taper된 도파로를 조합하여 설계하였으며, 이를 시뮬레이션 한 결과 효율이 약 99%이상이 됨을 확인하였다.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.135-140
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• 1999

The size effect of axial compressive strength of concrete in notched specimens was experimentally investigated. Based on the concept of the fracture mechanics and size effect law, theoretical studies for axial compressive failure of concrete were reviewed, and two failure modes of concrete specimen under compression were discussed. In this study, experiment of axial compressive failure, which is one of the two failure modes, was carried out by using double cantilever fracture specimens. By varying the slenderness of cantilevers and the eccentricity of applied loads with respect to the axis of each cantilever, the size effect of axial compressive strength of concrete was investigated, and predicted by Bazant's size effect law. The test results show that size effect appears conspicuously for all series of specimens. For the eccentricity of loads, the influence of tensile and compressive stress at the notch tip are significant and so that the size effect is varied. In other words, if the influence of tensile stress at the notch tip grows up, the size effect of concrete increases. And the fact that the fracture process zone must be sufficiently secured for more accurate experiment was affirmed.

• 한국세라믹학회지
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• 제29권9호
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• pp.711-718
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• 1992

Pb(Fe1/2Nb1/2)O3 was prepared by the molten salt synthesis method using an equimolar mixture of NaCl-KCl. Initial particle size could be controlled by varying the weight ratio of the NaCl-KCl to raw materials from 0.1 to 1.0, and the initial particle size effects on the sintering and dielectric properties of Pb(Fe1/2Nb1/2)O3 were investigated at the sintering temperature range from 90$0^{\circ}C$ to 105$0^{\circ}C$. As the weight ratio of salt increased, the average particle size decreased and the particle size distributions tended to narrow. As the initial particle size decreased, the linear shrinkage and density increased due to the promotion of densification. Dielectric constant increased with decreasing the initial particle size resulting from the increase of density and grain size.