• Title/Summary/Keyword: 혼합 효과

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Predicting soft tissue artefact with linear mixed models (선형혼합모형을 이용한 피부움직임 오차의 예측)

  • Kim, Jinuk
    • The Korean Journal of Applied Statistics
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    • v.31 no.3
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    • pp.353-366
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    • 2018
  • This study uses mixed-effects models to predict thigh soft tissue artefact (STA), relative movement of soft tissue such as skin to femur occurring during hip joint motions. The random effects in the model were defined as STA and the fixed effects in the model were considered as skeletal motion. Five male subjects without musculoskeletal disease were selected to perform various hip joint rotational motions. Linear mixed-effects models were applied to markers' position vectors acquired from non-invasive method, photogrammetry. Predicted random effects showed similar patterns of STA among subjects. Large magnitudes of STA appeared on the points near the hip joint regardless of sides; however, small values appeared on the distal anterior.

Utillization of Mineral Admixtures for the Reduction of Slump Loss in Fresh Concrete (굳지 않은 콘크리트의 슬럼프손실 저감을 위한 혼화재의 활용)

  • 문한영;문대중
    • Magazine of the Korea Concrete Institute
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    • v.10 no.2
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    • pp.155-165
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    • 1998
  • 굳지 않은 콘크리트의 슬럼프손실을 저감시키기 위한 목적으로 고로슬래그 미분말 및 플라이애쉬의 혼합비율과 혼화제의 첨가방법을 변화시킨 콘크리트의 믹싱후 경과시간에 따른 슬럼프 변화에 대하여 고찰하였다. 연구결과 보통포틀랜드시멘트에 고로슬래그 비분말 또는 플라이애쉬를 혼합한 콘크리트가 혼화재를 혼합하지 않은 콘크리트보다 슬럼프손실을 줄일 수 있었으며, 고로슬래그 미분말과 플라이애쉬를 각각 50 및 5%를 혼합한 3성분계 콘크리트의 경우 슬럼프손실을 저감시키는데 유효하였다. 또한 혼화제의 일부를 15분후 분할하여 후첨가하는 혼합방법이 굳지않은 콘크리트의 슬럼프손실을 저감시키는데 가장 큰 효과가 있다. 한편 혼화재를 혼합한 3성분계 보통강도용 및 고강도용 콘크리트의 재령 28일까지의 압축강도는 혼화재를 혼합하지 않은 콘크리트보다 작았으나 재령 91일 압축강도는 31% 및 15%정도 크게 증가하였다.

봉다발을 지나는 저 Prandtl 수 유체 유동에서의 난류 혼합율 예측

  • Kim, Sin;Cho, Kyung-Ho;Lee, Yun-Jun
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05a
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    • pp.520-525
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    • 1998
  • 난류혼합율에 대한 예측은 원자로의 노심 열수력 설계에 있어 매우 중요한 일이다. 봉다발 구조에서 난류혼합의 주요 원인으로 지목되고 있는 유동액동(flow pulsation) 현상에 대한 척도평가(scale analysis)틀 통해 봉다발 유동장을 흐르는 저 Prandtl 수 유채에 대판 난류혼합율 평가식을 유도하였다. 난류혼합에 기여하는 인자가 분자운동, 등방성 난류운동(유동맥동 효과률 배제한 난류운동), 그리고 유동맥동의 세 부분으로 구성되어 있다고 가정하고, 각각에 대한 길이 및 속도척도를 평가하여 난류혼합율을 유도하였다. 평가식에는 P/D, Re수 P${\gamma}$ 수 등의 인자가 고려되어 있어 다양한 기하학적, 수력학적 조건과 유체의 물리적 특성이 반영되어 있다. 유도원 난류혼합율 평가식을 실험 상관식과 비교하였으며, 비교 결과 만족스러운 것으로 나타났다.

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Extended Unmixing-Mixing Scheme for Prediction of 3D Behavior of Porous Composites (다공성 복합재료의 삼차원 거동 예측을 위한 분리-혼합 기법의 확장)

  • Choi, Hoi Kil;Shin, Eui Sup
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.41 no.2
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    • pp.91-97
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    • 2013
  • Pyrolysis and surface recession of charring composites are progressed primarily in the thickness direction. The unmixing-mixing scheme is applied to describe the in-plane and through-thickness behaviors of porous composites. The extended unmixing-mixing equations are based on transverse isotropy of unidirectionally fiber-reinforced composites. The strain components of gas pressure in pores, thermal expansion, and chemical shrinkage are included in the constitutive model. By analyzing micromechanical representative volume elements of porous composites, the validity of the derived equations are examined.

The Mixing of Forced Plume In the Coastal Waters (연안해역 중력 분류의 혼합 과정)

  • Jang, Seon-Deok;Seo, Jeong-Mun;Lee, Jong-Seop
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.26 no.1
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    • pp.26-33
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    • 1990
  • The behavior and mixing process of the forced plume are studied in the hydraulic laboratory. The dilution rate of discharged waste water from the port in various hydraulic condition was analized. The effect of densimetric Froude number and the discharge type on the dilution rate are discussed: In the vertical discharge, the forced plume of small densimetric Froude number mixes more actively than that of the large one. In the horizontal discharge, forced plume of large densimetric Froude number dilutes more rapidly than that of the small one. The mixing takes place more vigorously in the horizontal discharge than in the vertical one. The multi-port diffuser is more effective for the waste water discharge system than the single port diffuser in the tidal swinging coastal sea.

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Effect of Ceramics on Growth of Rice Seedlings for Machine Transplanting (벼 기계이앙용 상자묘 생육에 미치는 세라믹 분말의 효과)

  • 이철원;한충수;손석용
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.2
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    • pp.141-145
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    • 1997
  • The long wave infrared which is ranged to 4~1, 000 ${\mu}{\textrm}{m}$ is a kind of electromagnetic wave, and the wave is being absorbed by higher plant easily. The absorbed wave in the plant promotes the metabolism of plant cell by way of resonance with the water molecules of plant cell. This experiment was carried out to determine the effect of long wave infrared radiation ceramic on growth of rice seedling, and to make the optimum mixture rate of ceramic powder when ceramics was mixed with bed soil at 4, 8, 12, 16% levels for machine transplanting. The results of this study indicate that the growth of the seedling significantly higher in the treatment sites than that of control sites. However, there was no significant differences in dry matter weight between the treatment and control sites. At the 9.6% mixing ratio, the highest growth of rice seedling was found.

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Estimable functions of mixed models (혼합모형의 추정가능함수)

  • Choi, Jaesung
    • The Korean Journal of Applied Statistics
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    • v.29 no.2
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    • pp.291-299
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    • 2016
  • This paper discusses how to establish estimable functions when there are fixed and random effects in design models. It proves that estimable functions of mixed models are not related to random effects. A fitting constants method is used to obtain sums of squares due to random effects and Hartley's synthesis is used to calculate coefficients of variance components. To test about the fixed effects the degrees of freedom associated with divisor are determined by means of the Satterthwaite approximation.

The Effect of Limestone Powder Admixture Chemical Properties on Workability and Compressive Strength of Composite Cement (석회석 미분말 혼합재의 화학특성이 혼합시멘트 유동성과 강도에 미치는 영향)

  • Suh, Dong Kyun;You, Byeong Know;Choi, Jae Won;Kim, Kyeong Suk;Woo, Ji Wan
    • Cement Symposium
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    • s.49
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    • pp.29-30
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    • 2022
  • Since the climate problem getting severe, carbon neutrality is rising global issue. The limestone powder addition that can substitute clinker in cement is look forward to get positive effect as filler. This study focus on the effect of limestone powder chemical characteristic on mortar workability and compressive strength. Consequently, regardless of type of limestone and subsitution amount, the compressive strength was lower then OPC. But the workability of limestone composite cement showed higher then OPC. Considering latter strength development, using unit water decreasing effect of limestone composite cement is planned further.

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Synergistic Action of Insecticide Mixtures to the Green Peach Aphid(Myzus persicae Sulz.) Resistant to Acephate and Demeton-S-methyl (Acephate, Demeton-S-methyl 저항성계통(抵抗性系統) 복숭아혹진딧물에 대(對)한 살충제간(殺蟲劑間)의 연합독작용(連合毒作用))

  • Choi, S.Y.;Kim, G.H.
    • Korean journal of applied entomology
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    • v.26 no.3 s.72
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    • pp.151-157
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    • 1987
  • The toxicities of binary mixtures of the four insecticides acephate, demeton-S-methyl, cypermethrin and pirimicarb to the two strains of green peach aphid (Myzus persicae Sulz.) resistant to acephate and demeton-S-methyl were investigated and compared to the toxicities of their individual insecticides. The synergistic action of the insecticide mixtures to the insects were greatly varied with the kind of insecticide combinations, their mixture ratios, and the origin of resistance by an insecticide. The maximum synergistic action of acephate for the acephate resistant strain was obtained at 1:1 mixed with demeton-S-methyl. However, there were some antagonistic effects in all acephate mixtures with pirimicarb and cypermethrin. With the strain of demeton-S-methyl resistance, acephate, cypermethrin, and pirimicarb were synergized at the given mixture ratios by demeton-S-methyl. The maximum synergistic effect was observed at 2:3 with acephate, 1:1 with cypermethrin and 3:2 with pirimicarb.

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Xanthan Gum Reduces Aluminum Toxicity in Camelina Roots (잔탄검 혼합에 따른 카멜리나 뿌리의 알루미늄 독성 경감 효과)

  • Shin, Jung-Ho;Kim, Hyun-Sung;Kim, Sehee;Kim, Eunsuk;Jang, Ha-young;Ahn, Sung-Ju
    • Ecology and Resilient Infrastructure
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    • v.8 no.3
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    • pp.135-142
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    • 2021
  • Biopolymers have been known as eco-friendly soil strengthening materials and studied to apply levees. However, the effect of biopolymer on vegetation is not fully understood. In this study, we analyzed the root growth of Camelina sativa L. (Camelina) when the xanthan gum was amended to soil in Aluminum (Al) stress conditions. Amendment of 0.05% xanthan gum increased root growth of Camelina under Al stress conditions. Under the Al stress condition, expression of aluminum activate malate transporter 1 (ALMT1) gene of Camelina root was induced but showed a lower level of expression in xanthan gum amended soil than non-amended soil. Additionally, the binding capacity of xanthan gum with Al ions in the solution was confirmed. Using morin staining and ICP-OES analysis, the Al content of the roots in the xanthan gum soil was lower than in the non-xanthan gum soil. These results suggest that xanthan gum amended soils may reduce the detrimental effects of Al on the roots and positively affect the growth of plants. Therefore, xanthan gum is not only an eco-friendly construction material but also can protect the roots in the disadvantageous environment of the plant.