• 한국도로학회논문집
• /
• 제18권3호
• /
• pp.1-9
• /
• 2016

PURPOSES : This study aims to show the difference of the binder aging level in the hot-mix asphalt (HMA) mixture after short-term aging (SA) under different aging conditions, such as mixture temperature and duration in hour. METHODS : Three SA times (i.e., 1 h, 2 h, and 4 h) at two temperatures (i.e., $160^{\circ}C$ and $180^{\circ}C$) were used for the normal mixtures prepared using a PG64-22 asphalt. The field long-term aging (LA) was simulated by applying the same LA procedure (65 h at $110^{\circ}C$) to all compacted specimens, prepared at the air void of 7% using each SA-treated mixture, in a convection oven. The binder aging level was measured in terms of large molecular size by gel-permeation chromatography (GPC) from the mixture and the absolute viscosity (AV) from the recovered binder. The aging levels were evaluated using those two properties after SA and LA, and then compared based on the normal SA (NSA) mixture (1 h at $160^{\circ}C$). The service life reduction caused by SA in various conditions was estimated based on the aging level of the field cores from different locations in various service lives. RESULTS : The results of the laboratory evaluation indicated that the binder of the mixture, which was treated at longer SA time and higher temperature, showed a significantly higher aging level than the NSA mixture. The binder aging level from a longer time, such as 2 h and 4 h SA, or at a higher temperature ($180^{\circ}C$), were estimated to be similar to that of the mixtures, which had already been in field service for several years. CONCLUSIONS : The HMA mixture should be produced at a moderate temperature, such as $160^{\circ}C$, and placed within a limited hauling and queuing time to avoid a significant short-term aging of the binder before placement in the field pavement. The SA for a longer time at a higher temperature than the NSA condition was found to be detrimental to the service life of the asphalt pavement.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2005년도 춘계 학술기술논문발표대회 논문집
• /
• pp.9-12
• /
• 2005

This paper investigated the temperature history of mass concrete mock up structure considering different heat generation by varying with mixture proportion. Setting time difference between high early strength mixture (E-P) and retarding mixture (R-F30) was 14.5hours. Incorporation of $30\%$ of fly ash contributed to $10^{\circ}C$ of hydration heat reduction. In generally used C and D combination, bottom concrete shows earlier hydration, while E-J combination showed reverse tendency and thus, this method can reduce the crack occurrence. Therefore, heat generation difference method has beneficial effect on reducing crack induced by hydration heat resulting from heat generation difference between surface and center section.

• 한국고분자학회:학술대회논문집
• /
• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
• /
• pp.375-375
• /
• 2006

The preparation methods are to be used as "melting method" and "absorption method", respectively. The reaction mixture in the reaction container was heating up the reaction mixture to $200^{\circ}C$ for 2 hour. The mixing time of lab scale preparation should be provided quit long, instead of the short working time in a compounder vessel. And The PP-PCM mixture in the reaction container was heating up the mixture around $60-80^{\circ}C$ for 2 hour. A melting method of frozen gel with 50/50 weight ratio of polypropylene-normal octadecane was prepared by adding PP chip and normal octadecane. An absorption method of frozen gel with 70/30 weight ratio of PP 4.8-normal n-octadecane was prepared by adding PP powder and normal octadecnae.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 2010년도 춘계 학술발표회
• /
• pp.489-494
• /
• 2010

A geo-composite soil (GCS) is a stabilized mixture of bottom ash, cement and dredged soil. Various samples with different mass ratios of mixtures were tested under curing time of 7 and 28 days to investigate physical properties and compressive strength. This paper focused on the effect of bottom ash on the strength characteristics of Busan marine dredged soil. Cement has been added as an additive constituent to enhance self-hardening of the blended mixture. The unconfined compressive strength of GCS increases with an increase in curing time due to pozzolanic reaction of the bottom ash. The strength after 28 days of curing is found to be approximately 1.3 to 2.0 times the strength after 7 days of curing, regardless of mixture conditions. The secant modulus of GCS is in the range of 55 to 134 times the unconfined compressive strength. The correlation of unconfined compressive strength with bottom ash content and initial void ratio are suggested.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2002년도 하계종합학술대회 논문집(4)
• /
• pp.195-198
• /
• 2002

We propose an efficient mixture Gaussian synthesis method for decision tree based state tying that produces better context-dependent models in a short period of training time. This method makes it possible to handle mixture Gaussian HMMs in decision tree based state tying algorithm, and provides higher recognition performance compared to the conventional HMM training procedure using decision tree based state tying on single Gaussian GMMs. This method also reduces the steps of HMM training procedure. We applied this method to training of PBS, and we expect to achieve a little point improvement in phoneme accuarcy and reduction in training time.

• 설비공학논문집
• /
• 제5권4호
• /
• pp.249-256
• /
• 1993

Numerical method is applied to predict the time variation behavior of flammable mixture formation in a two dimensional enclosure from the beginning of gas leak. Additionally experimental method is used to consider qualitative aspects. Characteristics of flammable mixture formation such as distribution of flow and fuel mass fraction at various locations in the enclosure are determined for the following parameters: the various locations of leak at the bottom and aspect ratio of the enclosure. In the case of gas leak with small leak velocity from the bottom of enclosure gravitational force affects the formation of flammable mixture. Aspect ratio of the enclosure also affects the formation of flammable mixture. The volume of the region of recirculating flow is dominant factor affecting the formation mixture.

• 한국잠사곤충학회지
• /
• 제41권3호
• /
• pp.222-227
• /
• 1999

The weavability and bleaching of ramie/silk mixture fabrics were examined. When silk fiber was used as warp or weft in the mixture fabrics, the weaving properties became higher than that of ramile fabrics. Especially, the highest weavabiliy of mixture fabrics was obtained when used as warp silk fiber. The whiteness of ramie and tussah fiber treated with hydrogen peroxide, bleaching agent. was increased up to about 80% without significant changes of tenacity and elongation. As the increase of bleaching agent and treatment time, the whiteness of mixture fabrics was increased and the yellowness was decreased. Also, as the whiteness of mixture fabrics increased, the drape stiffness in warp direction was decreased but crease recovery was increased.

• Journal of the Korean Data and Information Science Society
• /
• 제15권3호
• /
• pp.575-584
• /
• 2004

We propose a Bayesian model-based approach using a mixture of Dirichlet processes model with discrete wavelet transform, for curve clustering in the microarray data with time-course gene expressions.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
• /
• pp.487-492
• /
• 1999

The purpose of this study to find the mixture of concrete for Top-Down method. Throughout test of elapsed time change and L-type flow, it was proposed basic performance and level of top-down method concrete. When change as to elapsed time is considered, so series of F10 added 10% S.P satisfied slump and demanded flow (60$\pm$5cm), and L-type slump, L-type flow satisfied liquidity, it can be considered basic mixture of designed actual frame later.

• Journal of the Korean Data and Information Science Society
• /
• 제24권6호
• /
• pp.1477-1488
• /
• 2013

In this study, we analyze the dependence structure of KOSPI and NYSE indices based on a two-step estimation procedure. In the rst step, we adopt ARMA-GARCH models with Gaussian mixture innovations for marginal processes. In the second step, time-varying copula parameters are estimated. By using these, we measure the dependence between the two returns with Kendall's tau and Spearman's rho. The two dependence measures for various copulas are illustrated.