• 한국섬유공학회:학술대회논문집
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• 한국섬유공학회 2003년도 The Korea-Japan Joint Symposium
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• pp.5-6
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• 2003

Kinetic study on the colloidal crystallization of single component and mixture of different sizes or densities of spheres was made in the exhaustively deionized suspensions and in microgravity, and compared with the results in normal gravity. Colloidal crystallization rates were retarded in microgravity for single component of spheres, whereas rates of alloy crystallization were enhanced substantially in microgravity. The rotational diffusion coefficients of colloids and the formation reaction rates of colloidal silica spheres were also studied in microgravity.

• International Journal of Reliability and Applications
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• 제10권2호
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• pp.81-88
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• 2009

A non-parametric procedure is presented for testing exponentially against used better than aged in convex ordering class (UBAC) of life distributions based on u-test. Convergence of the proposed statistic to the normal distribution is proved. Selected critical values are tabulated for sample sizes 5(5)40. The Pitman asymptotic relative efficiency of my proposed test to tests of other classes is studied. An example of 40 patients suffering from blood cancer disease demonstrates practical application of the proposed test.

• Communications for Statistical Applications and Methods
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• 제9권1호
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• pp.261-270
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• 2002

In this paper, we demonstrate the more accurate confidence intervals for median survival time under the simple proportional hazard model of Koziol and Green (1976) via the Edgeworth expansion for the distribution of the studentized ACL estimator derived in Jeong (2000). The numerical results show that the intervals, so-called test-based and reflect intervals (Slud et al., 1984), outperform normal approximating method in the small sample sizes and/or heavy censoring.

• Journal of Magnetics
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• 제16권4호
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• pp.368-373
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• 2011

Particle size distributions in 10 nm magnetite ferrofluids are analyzed based on both dc and ac magnetic measurements. Modified log-normal distributions are used for fitting the experimental results, which allows for a proper account of the narrow distributions. The calculated average particle sizes are in good agreement with the TEM results. However the ac method gives a much narrower distribution width than that of the dc magnetization curve fit. The proposed measurements combined with the analysis methods are useful for the characterization of ferrofluids being considered for biomedical applications.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.358-365
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• 1996

Lightweight foamed concrete is a concrete which is lighter than normal concrete by mixing prefoamed foam in cement slurry. The objective of this study are to develop prefoamed optimal lightweight foamed concrete using polymer foam agent and to obtain its mechanical characteristics experimentally. This paper presents extensive test data on young's modulus, poisson's ratio, stress-strain curve, the characteristics of strength of the foamed concrete and also presents the mechanical characteristics of the foamed concrete according to foam sizes.

• 대한방사선기술학회지:방사선기술과학
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• 제30권4호
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• pp.407-417
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• 2007

과거로부터 사회 경제학적인 문제로 주목을 받고 있는 요통은 노화와 유의한 관계가 있음이 보고되고 있으며, 이러한 노화에 의해 추간판의 여러 형태 조직학적 변화도 이미 여러 연구를 통해 보고되었으나 노화에 따른 추간판의 크기 변화에 대한 연구와 이러한 추간판의 변화가 요통과 관련이 있는지에 대한 연구는 거의 이루어지고 있지 않고 있는 실정이다. 이에 본 연구는 노화에 의한 추간판 변인의 변화를 알아보고, 이런 요인들이 정상 피검자와 요통 환자 사이에 차이가 있는지를 MRI 실계측에 의해 알아보고자 수행하였다. 본 연구는 근골격계 질환이 없는 20대$\sim$60대의 정상 성인 50명과 $20{\sim}60$대 요통 환자 50명을 대상으로 L4-5, L5-S1 추간판의 가로 직경, 세로 직경 그리고 면적을 MRI 영상을 통해 실계측하여 노화에 따른 변화와 정상 피검자와 요통 환자 사이의 차이를 비교하는 방식으로 진행하였다. 본 연구 결과 L4-5와 L5-S1 추간판의 가로 및 세로 직경, 면적은 노화에 의해 의미 있는 증가 경향을 보였으며 정상 피검자에 비해 요통 환자의 추간판 변인들이 큰 것을 확인하였다. 따라서 추간판의 크기 변화는 노화에 의한 자발적인 변화이며, 요통 환자의 추간판 변인 증가를 요통 진단에 참조할 수 있는 자료로 사용할 수 있을 것으로 사료되나, 차후 광범위한 피검자를 대상으로 하는 보다 폭넓고 다각적인 연구가 필요한 것으로 사료된다.

• 패션비즈니스
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• 제12권4호
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• pp.88-98
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• 2008

In order to improve the problems with obese women's ready-to-wear by age range, this study surveyed the actual clothing purchase and wearing of women in their 20s and 30s with normal and obese body types, and compared and analyzed their satisfaction with ready-to-wear by age and body type. First, for normal body types, both women in their 20s and 30s use department stores the most. Meanwhile, obese women in their 20s make most of their purchases at internet shopping malls, while those in their 30s mostly go to department stores. For criteria for purchasing clothing, normal women both in their 20s and 30s value design most whereas, obese women put size and fit before design regardless of their age. Normal women in their 20s and 30s both were most unsatisfied with standardized design because they could not find designs they wanted. Obese women in their 20s and 30s also showed disapproval of unvaried sizes, indicating a distinct difference in body types and age. As well, the study found that both normal and obese women wear casual style the most, followed by semi-formal style. Also, regarding the images they were seeking when wearing clothing, the normal women wanted to look fashionable, while obese women wanted to look slim, regardless of age. Both body-type groups generally like preferred semi loose-fits the most, followed by tight-fit. They however, dislike relaxed loose-fitting.

• 대한영양사협회학술지
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• 제17권4호
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• pp.378-386
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• 2011

To examine the effect of obesity on volume perception according to size and color of rice bowl, we divided female college students into a normal weight group (<30% fat mass, n=100) and obese group (${\geq}30%$ fat mass, n=83) and then measured perceived volume of rice bowls of various sizes (general size; 350 ml vs. small size; 188 ml) and color (yellow, white, blue, and black) containing the same amount of cooked white rice (210 g). Normal weight group perceived that the general rice bowl contained significantly more cooked white rice compared to the small rice bowl. In contrast, the obese group perceived that the general rice bowl contained significantly less cooked white rice than the small rice bowl. The estimated variance in perceived volume of both bowls was significantly bigger in the obese group compared to the normal group. There were no differences in perceived volume among any of the subjects (both normal and obese groups) according to rice bowl color. However, the estimated variance in perceived volume in the obese group was significantly larger than that in the normal group for all of the rice bowls. In conclusion, rice bowl size and color might affect volume perception, and volume perception in obese people may be different from that of normal weight people.

• Clinical and Experimental Reproductive Medicine
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• 제13권1호
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• pp.67-75
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• 1986

Follicle monitoring in the normal and clomiphene·stimulated cycles were analyzed in the Seoul IVF and ET (In vitro fertilization and embryo transfer) program. Ovarian follicular diameters were measured by the real·time sector scanner and plasma estradiol levels were assayed by radioimmunoassay methods during periovulatory period. The maximum follicular sizes of the clomiphene-stimulated and normal cycles were 21.1+-3.4mm and 19.2+-0.8mm, respectively. The peak levels of plasma estradiol in the clomiphene-stimulated and normal cycles were 10538+-553.6ng/ml and 298.3+-39.6pg/ml, respectively. Daily growth rate of the follicular diameters of the clomiphene-stimulated and normal cycles were 2.1mm and 1.9mm, respectively. Mean follicular number of the clomiphene-simulated and normal cycles were 2.28+-1.12 and 1.12+-0.21, respectively. There was a good statistical correlation between the mean follicular diameters and the plasma estradiol levels in the normal ovulatory and c1omiphene-stimulated ovulatory menstrual cycles (p<0.05). Our data revealad that the mean follicular diameter and the plasma estradiol level prior to HCG administration in IVF and program should reach at the level of 17.8+-3.0mm and 949.4+-487.1 pg/ml, respectively.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2002년도 제18회 학술발표대회 논문초록집
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• pp.64-64
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• 2002

Two dimensional velocity distributions outside a Mach 2.0 supersonic nozzle have been investigated using digital particle image velocimetry (PIV). Mean velocities, turbulence intensities, vorticity field and volume dilatation field are obtained from 300 instantaneous PIV images using 0.33 $\mu\textrm{m}$ $TiO_2$ particle. The seeding particle of larger size, 1.4 $\mu\textrm{m}$ $TiO_2$, is also used for the experimental measurements of velocity lag downstream of shock waves according to particle sizes. The results have been compared and analyzed with schlieren photographs and computational fluid dynamics (CFD) results for the velocity distribution, the locations of shock waves and over-expanded shock structure. It was shown that the locations of normal shock and shock waves can be resolved by the axial or radial velocities, and the velocity lag is more significantly increased due to particle inertia as a particle size increases. And it was also found that over-expanded shock structures call be predicted by volume dilatation fields, and streamwise turbulence intensities are influenced significantly by normal shock waves.