• 한국의류학회지
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• 제38권6호
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• pp.887-895
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• 2014

The study provides baseline data on developing ready-to-wear clothes for adult females in their twenties who have finished shaping their bodies and have realized an ideal shape. We analyzed the data from females aged from 20 to 29 in "The $5^{th}$ Size Korea Survey" and "The $6^{th}$ Size Korea Survey", and sorted body shapes into several types according to drop values before analyzing and comparing the characteristics among groups. We also referred to the change by year in the size of upper inner wear. To classify body shapes, three drop values were assigned for bust girth - waist girth, hip girth - waist girth, hip girth - bust girth; through cluster analysis all data were classified into three body types. Type 1 is more like normal body shapes with small drop values at the bust girth - waist girth and well-build lower body. Type 2 is X-shaped body shaped like a fiddle with big drop values at all parts. Type 3 is Y-shaped body with a big drop value at the bust girth - waist girth and well-build upper body. Type 2, X-shaped body, has the majority of distribution in every year, which proved to be the most idealistic body shape. There was a change in the brassiere cup size. Korean ladies in their twenties have larger breasts. The body shapes of Korean females in their twenties are increasingly like those of westerners. Bust girth is a very critical element to set measurements and design patterns for upper wear; consequently, a change in the size of breasts should be considered.

• 공업화학
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• 제16권1호
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• pp.34-38
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• 2005

직경이 0.102 m이고 높이가 2.5 m인 유동층 액-액 추출기에서 액적의 크기와 분포 그리고 상승속도의 특성에 대하여 연구하였다. 분산상(0~0.04 m/s)과 연속상(0.02~0.14 m/s)의 유속변화, 그리고 유동고체 입자의 크기변화(1.0, 2.1, 3.1, 6.0 nm)에 따른 액적의 특성을 검토하였다. 액적의 흐름 거동은 추출기 내부에서 액적의 흐름 거동은 분산상과 연속상의 증가와 액적의 크기에 따라 상당히 영향을 받았다. 액적의 크기는 분산상의 속도가 증가함에 따라 증가하였지만, 유동입자의 크기가 증가함에 따라 따라서는 감소하는 경향을 나타내었다. 그러나 연속상의 유속이 증가함에 따른 액적의 크기는 국부적인 최대값을 나타낸 후 감소하는 경향을 나타내었다. 액적의 크기와 상승속도는 실험변수들과 잘 상관됨을 알 수 있었다.

• 유기물자원화
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• 제23권4호
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• pp.52-62
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• 2015

본 연구에서는 퇴비화공정에서 첨가재로 주로 사용되는 톱밥을 대상으로 톱밥 내 공기투과성 변화에 영향을 미치고 있는 요인별 특성과 총차감압력에 미치는 기여도를 평가하였다. 공기투과성 변화에의 영향요소로서 층류속도(v), 난류속도($v^2$), 수분함량(MC*v), 공기공극률(AFP*v), 입자크기(SIZE*v)를 선정하여 차감압력 산정을 위한 회귀식을 제시하였다. 차감압력에의 증가요인은 층류속도(v)와 입자크기(SIZE*v)이며, 감소요인은 난류속도($v^2$), 수분함량(MC*v), 공기공극률(AFP*v)이다. 공기유입속도를 높이면 총차감압력이 지속적으로 증가하였으며, 이러한 총차감압력 변화에 영향을 크게 미치는 증가요인은 입자크기(SIZE*v)이며, 감소요인은 공기공극률(AFP*v)이다. 또한 총차감압력에의 증가기여도는 낮은 유속에서는 층류속도(v)가 높은 유속에서는 입자크기(SIZE*v)의 기여도가 높았으며, 감소기여도는 공기공극률(AFP*v)이 가장 높았다. 반면에 수분함량 변화에 따른 총차감압력 변화는 그리 크지 않았다. 따라서 총차감압력은 증가요인보다는 감소요인인 공기공극률(AFP*v)과 수분함량(MC*v)에 의하여 영향을 받고 있음을 알 수 있다. 본 연구결과로서, 효율적 퇴비화공정을 위하여는 적정 수분함량 유지와 함께 공기공극률이 높은 첨가재를 선정하여 공기투과성을 향상시키는 방법이 적절할 것이다.

• 한국지구과학회지
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• 제35권7호
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• pp.518-528
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• 2014

본 연구에서는 대관령 지역에서의 광학우적계(PARSIVEL disdrometer) 강수관측으로부터 산출된 강수율에 따른 강수입자분포 자료를 바탕으로 기존의 강수입자분포 모형을 개선하였다. 선행 연구에서 제안한 다양한 강수입자분포 모형과 측정 자료와의 상관성을 분석한 결과, 대관령 지역에 적용 가능한 원형 모형은 개선된 ${\Gamma}$ 분포 모형임을 확인하였다. 원형 모형을 대관령 지역에 적용할 수 있도록, 민감도 실험을 통해 최적의 매개변수들(${\alpha}$, A, B)을 산정하였으며, 다섯 가지 강수율에 대한 강수입자분포 모형을 제안하였다. 강수율에 따른 강수입자분포 모형의 결과는 관측에서 측정된 값과 높은 상관성($R^2=0.975$)을 보였다. 강수율에 따라 표현되는 강수입자분포 모형을 일반화 형태로 개선하기 위해 강수율과 매개변수의 상관성을 도출하여 일반식을 결정하였다. 일반화된 강수입자분포 모형은 대관령 지역의 강수입자분포 측정 자료와 높은 상관성($R^2=0.953$)을 보였으며, 이는 본 연구에서 제안한 모형이 대관령 지역의 강수입자분포를 모의하는데 효과적임을 의미한다. 그러나 본 연구에서 제안된 강수입자분포 모형은 대관령 지역의 강수입자분포에만 최적화 되었다는 한계성이 있어, 따라서 한반도를 대표하는 모형을 개발하기 위해서는 다른 지역에 대한 광범위한 측정이 필요하다.

• 복식문화연구
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• 제15권1호
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• pp.137-151
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• 2007

This study was performed to narrow down the Sizing System for Female Adult's garments(KS K 0051) following age target and body shapes. The study was based on the sizing system and the anthropometric measurements, called Size-Korea, which were surveyed in the years 2003 and 2004. At first, the subjects of the survey were classified into 4 age groups, $18{\sim}24,\;25{\sim}34,\;35{\sim}49\;and\;50{\sim}59$, based on the most significant differences of body sizes. Secondly, the ranges of four key dimensions - height, bust, waist and hip-of normal sizes were identified through analyzing Rohrer index and percentile. The selected sizes within the ranges were grouped by the drop which was the subtraction of bust girth from hip girth. In conclusion, there was the most frequent drop for each age group; 9cm drop for the $18{\sim}24$ years old group, the 6cm drop for the $25{\sim}34$ years old and $35{\sim}49$ years old and 3cm drop for $50{\sim}59$ years old. The upper body garment sizes of the same drop and target ages could be merged to 10 to 12 sizes, which were remarkably smaller than the Female Adult garment sizing system, and further to 2-5 sizes, considering the percentile importance. However, $50{\sim}59$ years old group needed to be analyzed in different ways, because the number of subjects of normal size in the age decreased rapidly, that the normal sizes for them were very limited. In addition, the reference body sizes of each garment size were apparently different when they were compared to each age groups. These basic data for garment size specification could be usefully adapted for the apparel companies' own sizing system according to their age target and body shapes, to achieve efficient production and better fit.

• 한국자동차공학회논문집
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• 제8권5호
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• pp.28-35
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• 2000

As a second part of the comparison study, microscopic features of an air-assisted fuel injector(AAFI) and a high-pressure swirl injector (HPSI) were characterized. They consist of the internal spray structure in terms of fuel mass and drop diameter, the overall atomization performance with respect to operating parameters and the drop size distribution. Large droplets are concentrated in around the head part of a spray field of the HPSI, while in the case of the AAFI, they were distributed in the tail part. Although the AAFI showed the better atomization performance, the feasible ranges of operating parameters such as injection and ambient pressure were found to be wider in the HPSI. Drop size distribution of the AAFI sprays was more dispersed than that of the HPSI. Drop size distribution of the AAFI sprays was more dispersed than that of the HPSI. However, at the well-atomized condition, it appeared to be very uniform.

• 한국대기환경학회지
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• 제13권3호
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• pp.193-205
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• 1997

Experiments on granular filtration of polydispersed aerosols were conducted to determine the changes in pressure drop necessary to maintain a given gas flow rate as filter becomes clogged with deposited particles. Among the various variables which affect the increase in the pressure drop during the filtration, the most important one was found to be the size of the deposited aerosol particles. It was shown that for a given extent of the total deposition, the extent of increase in pressure drop increases with the decrease of the deposited aerosol size. For the general case where the deposited particles have different sizes, a procedure was proposed for correlating and predicting experimental results on pressure drop. This procedure was found applicable to bidispersed aerosols and polydispersed aerosols.

• Korea-Australia Rheology Journal
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• 제21권4호
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• pp.269-280
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• 2009

The drop formation dynamics of a shear thinning, elastic, yield stress ($\tau_o$) fluid (Carbopol 980 (poly(acrylic acid)) dispersions) in silicone oil has been investigated in a flow-focusing microfluidic channel. The rheological character of each solution investigated varied from Netwonian-like through to highly non-Newtonian and was varied by changing the degree of neutralization along the poly (acrylic acid) backbone. We have observed that the drop size of these non-Newtonian fluids (regardless of the degree of neutralisation) showed bimodal behaviour. At first we observed increases in drop size with increasing viscosity ratio (viscosity ratio=viscosity of dispersed phase (DP)/viscosity of continuous phase (CP)) at low flowrates of the continuous phases, and thereafter, decreasing drop sizes as the flow rate of the CP increases past a critical value. Only at the onset of pinching and during the high extensional deformation during pinch-off of a drop are any differences in the non-Newtonian characteristics of these fluids, that is extents of shear thinning, elasticity and yield stress ($\tau_o$), apparent. Changes in these break-off dynamics resulted in the observed differences in the number and size distribution of secondary drops during pinch-off for both fluid classes, Newtonian-like and non-Newtonian fluids. In the case of the Newtonian-like drops, a secondary drop was generated by the onset of necking and breakup at both ends of the filament, akin to end-pinching behavior. This pinch-off behavior was observed to be unaffected by changes in viscosity ratio, over the range explored. Meanwhile, in the case of the non-Newtonian solutions, discrete differences in behaviour were observed, believed to be attributable to each of the non-Newtonian properties of shear thinning, elasticity and yield stress. The presence of a yield stress ($\tau_o$), when coupled with slow flow rates or low viscosities of the CP, reduced the drop size compared to the Newtonian-like Carbopol dispersions of much lower viscosity. The presence of shear thinning resulted in a rapid necking event post onset, a decrease in primary droplet size and, in some cases, an increase in the rate of drop production. The presence of elasticity during the extensional flow imposed by the necking event allowed for the extended maintenance of the filament, as observed previously for dilute solutions of linear polymers during drop break-up.

• 한국분무공학회지
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• 제4권4호
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• pp.30-37
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• 1999

The breakup characteristics of liquid sheet formed by the liquid rocket injector has a close relation with the combustion efficiency. In this paper, basic characteristics of droplet size and velocity distribution were measured with PDPA for the Like Doublet Impinging Injector. Test variables were the angle of impact, the diameter of orifice and jet velocity. Water was used as test fluid. As a result, for impingement angle less than 90 degree, following correlations were obtained between drop size and design parameters : $D_{32}({\mu}m)=295.0{\times}V^{-0.09}\times(2\theta)^{-0.1}{\times}d^{0.072}$. For impingement angle greater than 100 degree, drop sizes were increased but eventually converged to a certain limiting value.

• 대한기계학회논문집
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• 제13권3호
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• pp.538-546
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• 1989

본 연구에서는 분사액체의 점도가 분무액적의 평균크기뿐만 아니라 표준편차 의 역수적 개념을 가지는 균일도에 주는 영향을 실험을 통하여 살펴보았다.