• Journal of Medicine and Life Science
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• 제20권1호
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• pp.21-31
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• 2023

We aimed (a) to investigate the associations between age, body mass index (BMI), and breast size with mammographic density based on the breast imaging reporting and data system (BI-RADS) and volumetric breast density measurement (VBDM) with Volpara, (b) to evaluate the associations of age, BMI, and breast size with fibroglandular tissue volume (FGV), and (c) to demonstrate the association of mammographic density grade with FGV. From April 2012 to May 2012, 1,203 women consecutively underwent mammography, and their breast density was calculated using the density grade and volume determined by Volpara. In total, 427 women were included in this study. The BMI and breast size of the 427 women were determined. The associations between mammographic density and age, BMI, and bra cup size were assessed. In addition, the associations between FGV and age, BMI, bra cup size, and mammographic density were assessed. The mean age of the women was 51 years (range, 27-83). Age was associated with mammographic density based on BI-RADS (P<0.0001), and both age and BMI were associated with mammographic density based on Volpara (P<0.0001). The mean FGV significantly decreased as age increased (P<0.0001) and increased as BMI and bra cup size increased (P<0.0001 and P=0.0007, respectively). Age was associated with mammographic density, according to both the BI-RADS and VBDM; however, BMI was only associated with mammographic density based on the VBDM. Larger FGV was associated with younger age, higher BMI, larger bra cup size, and higher mammographic density

• Composites Research
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• 제31권5호
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• pp.251-259
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• 2018

본 논문에서는 섬유강화복합재의 멀티스케일 해석을 위해 필요한 대규모/소규모 통계적 체적요소 모델을 개발하였다. 미시영역모델의 크기효과를 최소화하기 위해서 섬유를 최대한 포함한 거대모델을 구성하였다. 이를 위해 국부 영역의 요소 절단법을 이용하여 전체 유한요소 크기에 상관없이 신속한 격자 섬유/기지의 모델링이 가능한 요소생성기를 구성하였다. 이를 통해 대규모 통계 체적 모델을 도출하여 체적모델의 크기에 따른 국부하중 공유의 차이를 고찰하고, 섬유방향의 연속체손상역학모델을 BSVEs 모델 해석으로부터 도출 하였다. BSVEs 모델을 보편적인 RVE모델과 비교 검증하였다.

• 한국의류산업학회지
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• 제15권2호
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• pp.240-246
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• 2013

Data from 540 subjects (included in the obesity group whose BMI was over 25) was selected from 2,445 subjects in the $6^{th}$ Korean Body Size Survey. A total of 25 direct measurements were selected for the relevant literature lower body size measurement analysis, that included 9 components related to BMI, height and circumferences, 3 components related to width and thickness, 5 components related to length, 3 components related to height, and 2 other components. Descriptive statistics, factor analysis, cluster analysis and variance analysis were executed using PASW 18.0 to analyze the data. In accordance with the factor analysis results to classify the lower body shape of overweight women in their 20s to 60s whose BMI was over 25, 4 factors were identified (lower body volume, leg volume, lower body length and leg length). A total of 4 lower body shapes of overweight women were found through cluster analysis using 4 factor scores from the factor analysis. Body Shape 1 had the largest lower body and leg volume. It was the heaviest group. Leg length was at a normal level. Body Shape 1 was 22.2% (122 subjects). Body Shape 2 had the longest legs and the smallest body shape; however, Body Shape 2 was the leg obesity group with the largest leg volume. It was 39.8% (215 subjects). Body Shape 3 had a smaller leg volume in proportion to the lower body thickness and a long lower body length. It comprised 27.8% (150 subjects). Body Shape 4 comprised 9.8% (53 subjects) with the shortest leg. Its lower body obesity was at a normal level.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표논문집(II)
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• pp.258-261
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• 1998

Aggregate is cheaper than cement and confers considerable technical advantages on concrete, which has a higher volume stability and better durability than hydrated cement paste alone. and coarse aggregate is the largest particle size out of concrete and is much affect on the fruidity, compaction and non-segregation ability of high flowing concrete. As the compaction, fillingability and shrinkage of high flowing concrete, the volume ratio of coarse aggregate is prescribed by Japanese Architectural Standard Specificateon (JASS 5) : from 0.500 to 0.500㎥/㎥. It is the aim of this study to compare and analysis the fruidity, fillingability and non-segregation of high flosing concrete according to the volume ratio of coarse aggregate of concrete(G/Glim).

• ALGAE
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• 제19권2호
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• pp.149-151
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• 2004

Freshwater algae make up a very important portion of the autotrophic component of the aquatic food web. Therefore, the study of freshwater algal structure and biomass is central to aquatic ecosystem studies. Due to variations in cell shape and size for each species (or taxon) and survey site, cell abundance (or cell numbers per chosen volume) often leads to misrepresentation of the true importance of some species because of the great differences in size of various algae. Thus, it is necessary to investigate the freshwater algal species of a site in order to calculate the cell volume. Although direct cell counting, species volume measurement, as well as biomass calculation are time-consuming and requiring specialists in taxonomy.

• Journal of Advanced Marine Engineering and Technology
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• 제33권3호
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• pp.378-386
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• 2009

The effect of fuel mixing on soot structure with methane, ethane, and propane to ethylene-base counterflow diffusion flames has been investigated by measuring the volume fraction, number density, and particle size of soot by adopting the light extinction/scattering techniques. The experimental result showed that the mixing of ethane and propane in ethylene diffusion flame increased soot volume fraction while the mixing of methane decreased. As compare to the ethylene-base flame, the diameters of soot particles for mixture flames are slightly smaller. While the soot number densities for the mixture flames are much higher. Thus, the increase in the soot volume fraction can be attributed to the appreciably increased soot number density by the fuel mixing.

• 소성∙가공
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• 제18권6호
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• pp.482-487
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• 2009

A finite element based microstructural modeling for the size dependent strengthening of particle reinforced aluminum composites is presented. The model accounts explicitly for the enhanced strength in a discretely defined "punched zone" around the particle in an aluminum matrix composite as a result of geometrically necessary dislocations developed through a CTE mismatch. The density of geometrically necessary dislocations is calculated considering volume fraction of the particle. Results show that predicted flow stresses with different particle size are in good agreement with experiments. It is also shown that 0.2% offset yield stresses increases with smaller particles and larger volume fractions and this length-scale effect on the enhanced strength can be observed by explicitly including GND region around the particle. The strengths predicted with the inclusion of volume fraction in the density equation are slightly lower than those without.

• 한국산림과학회지
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• 제96권2호
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• pp.189-196
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• 2007

Allometry, basal area equations, and volume equations were developed with various tree measurement variables for the major species, Quercus mongolica and Quercus variabilis, in Korean natural hardwood forests. For allometry models, the relationships between total height-DBH, crown width-DBH, height to the widest portion of the crown-total height, and height to base of crown-total height were investigated. Multiple regression methods were used to relate annual basal area growth to tree variables of initial size (DBH, total height, crown width) and relative size (relative diameter, relative height) as well as competition measures (competition index, crown class, exposed crown area, percent exposed crown area, live crown ratio). For tree volume equations, the combined-variable and Schumacher models were fitted with DBH, total height and crown width for both species.

• 한국재료학회지
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• 제18권12호
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• pp.683-688
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• 2008

For development of a human body model for electric shock, electroconductive paints with carbon black as a filler material were developed. The characteristics of the volume resistivities of thin films fabricated using the electroconductive paints were investigated as a function of the particle sizes and content of carbon black. With a carbon black particle size over $80\;{\mu}m$, agglomeration of carbon black powders was observed. The volume resistivity of the particles increased as the porosity increased and as the amount of carbon black decreased due to the agglomeration of carbon black powders. With a particle size of $4\;{\mu}m$ and $20\;{\mu}m$, agglomeration of carbon black powders was not observed and their porosities were measured as 0.86% and 1.12% with volume resistivities of $20\;{\Omega}{\cdot}cm$ and $80\;{\Omega}{\cdot}cm$ respectively. A carbon black particle size of less than $20\;{\mu}m$ is considered to be suitable as a type of electric-shock electroconductive paint for a human body model.

• 대한기계학회논문집A
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• 제25권4호
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• pp.564-573
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• 2001

The mechanical properties of short carbon/glass fiber reinforced polypropylene are experimentally measured as functions of fiber content and nozzle diameter. Also, these properties are compared with the survival rate of reinforced fibers and fiber volume fraction using image analysis after pyrolytic decomposition. The survival rate of fiber aspect ratio as well as fiber volume fraction is influenced by injection processing condition, the used materials and mold conditions such as diameter of nozzle, etc. In this study, the survival rate of fiber aspect ratio is investigated by nozzle size variations in injection/mold sides. It is found that the survival rate of glass fiber is higher that the survival rate of glass fiber is higher than that of carbon fiber. Both tensile modulus and strength of short-fiber reinforced polypropylene are improved s the fiber volume fraction and nozzle diameter are increased.