• Title/Summary/Keyword: mixed-effects.

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The Frictional Modes of Piston Rings for an SI Engine (SI 엔진 피스톤-링의 마찰모드)

  • 조성우;최상민;배충식
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.5
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    • pp.114-120
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    • 2000
  • Friction forces of piston rings for a typical SI engine were independently measured while excluding the effects of cylinder pressure, oil starvation and piston secondary motion using a floating liner system. Friction patterns, represented by the measured friction forces, were classified into five frictional modes with regard to the combination of predominant lubrication regimes(boundary, mixed and hydrodynamic lubrication) and stroke regions(mid-stroke and dead centers). The modes were identified on the Stribeck diagram of the dimensionless bearing parameter and friction coefficients which were evaluated at the mid-stroke and at the dead centers. And the frictional modes were estimated to the full operation range. The compression rings behave in the mode where hydrodynamic lubrication is dominant at the mid-stroke and mixed lubrication is dominant at the dead centers under steady operating conditions. However, the oil control ring behave in the mode where mixed lubrication is dominant throughout the entire stroke.

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Analysis of Mixed Convection Heat Transfer in Arbitrarily Shaped Flat Tubes (임의형상을 갖는 납작관에서의 혼합대류 열전달 해석)

  • 박희용;박경우;이상철
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.13 no.5
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    • pp.398-410
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    • 2001
  • The flow and heat transfer characteristics for three-dimensional mixed convection flows in a radiator flat tube with U--shaped grooves are analyzed numerically. The flow and temperature fields are calculated by using the modified SIMPLE algorithm for irregular geometry. One tube specification among the various flat tube exchangers is recommended by considering the heat transfer and pressure drop. The effects of variation of coolant flow conditions and external air conditions on the flow and the thermal characteristics for the selected tube are investigated. the results show that inlet velocity of coolant flow is the very important factor in heat transfer and pressure drop, and top side is better position than the others as fin cleave to tube.

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Effects of Mixed Abrasive Slurry(MAS) on Metal CMP Characteristics (MAS (Mixed Abrasive Slurry)가 Metal CMP에 미치는 영향)

  • Lee, Young-Kyun;Park, Sung-Woo;Lee, Woo-Sun;Seo, Yong-Jin
    • Proceedings of the KIEE Conference
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    • 2006.10a
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    • pp.81-82
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    • 2006
  • Chemical mechanical polishing (CMP) technology has been widely used for global planarization of multi-level interconnection for ULSI applications. However, the cost of ownership and cost of consumables are relatively high because of expensive slurry. In this paper, so as to investigate the influence of mixed abrasive slurry (MAS), such as $ZrO_2$, $CeO_2$, and $MnO_2$ for Ti-CMP application.

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A Note on Performance of Conditional Akaike Information Criteria in Linear Mixed Models

  • Lee, Yonghee
    • Communications for Statistical Applications and Methods
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    • v.22 no.5
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    • pp.507-518
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    • 2015
  • It is not easy to select a linear mixed model since the main interest for model building could be different and the number of parameters in the model could not be clearly defined. In this paper, performance of conditional Akaike Information Criteria and its bias-corrected version are compared with marginal Bayesian and Akaike Information Criteria through a simulation study. The results from the simulation study indicate that bias-corrected conditional Akaike Information Criteria shows promising performance when candidate models exclude large models containing the true model, but bias-corrected one prefers over-parametrized models more intensively when a set of candidate models increases. Marginal Bayesian and Akaike Information Criteria also have some difficulty to select the true model when the design for random effects is nested.

Instrumental Measurements of Hand Attributes on Microfiber Polyester/Cotton Blend Fabric Finished with Silicone Mixed Fluorochemical

  • Ahn, Young-Moo
    • Journal of Fashion Business
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    • v.10 no.6
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    • pp.16-27
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    • 2006
  • The purpose of this study was to examine the effects of chemical finishes on performance characteristics of microfiber blend fabrics. A 60% polyester microfiber /40% cotton blend woven fabric was finished by ten chemicals: three silicone softeners, one fluorochemical, and their mixtures. Performance characteristics examined were fabric hand attributes. Fabric hand was evaluated by instrumental measures using Kawabata KES-F system instruments. Silicone-only finishes did not change the bending properties significantly from those of the control fabric. The fluorochemical-only finish made the fabric stiffer and crisper. When the two chemicals were mixed they tended to offset this adversary effect. Most of the chemical finishes made the surface finer and smoother. Fluorochemical-only finish improved fabric strength. Likewise, dimethylpolysiloxane silicone improved fabric strength. Amino-functional hydrophilic and diamino-functional silicone softeners, on the other hand, reduced fabric strength. However, when mixed with the fluorochemical, the adversary effect was diminished.

Effects of mixed contents of carbon nanoreinforcements on the impact resistance of epoxy-based nanocomposites

  • Ayatollahi, M.R.;Naeemi, A.R.;Alishahi, E.
    • Structural Engineering and Mechanics
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    • v.56 no.2
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    • pp.157-167
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    • 2015
  • The impact behavior of epoxy-based nanocomposites reinforced with carbon nano tube (CNT), carbon nano fiber (CNF) and mixed contents of these nanoparticles was investigated using Izod impact test. The results showed that while the impact strength of nanocomposites containing 1 wt% of CNT and 1 wt% of CNF increased 19% and 13% respectively, addition of mixed contents of these nanofillers (0.5-0.5 wt%) demonstrated higher improvement (21%) in the impact resistance. The trend of the results is explained on the basis of different fracture mechanisms of nanocomposites. Furthermore, the fracture surface of specimens and the dispersion state of nanoenhancers have been studied using scanning electron microscopy (SEM) photographs.

Research On The Relevance Between Mixed-use Complex and User Behaviour Based On Three-dimensional Spatial Analysis

  • Zhendong Wang;Yihan Pan;Yi Lu;Xihui Zhou
    • International Journal of High-Rise Buildings
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    • v.12 no.1
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    • pp.83-91
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    • 2023
  • Under the dual pressure of population growth and land shortage, threedimensional development is the inevitable choice for cities in China. In such a scenario, a mixed-use complex has considerable potential in its realization and research. Based on space syntax and the three-dimensional visibility graph analysis, this paper describes the spatial and functional layout of the Shanghai Super Brand Mall and studies the relationship between spatial visibility and user behaviour through linear regression analysis and correlation analysis. This paper studies three different types of user behaviour, namely, path selection, staying selection, and store selection, and finds that spatial visibility and accessibility have different effects on user behaviour depending on the type and purpose of the activity. This paper reveals the influence of spatial and functional layout on user behaviour and puts forward the corresponding design strategy under the three-dimensional environment.

Effects of cellulose nanocrystals and graphene oxide on hydration heat of cement paste (셀룰로오스 나노크리스탈과 산화그래핀이 시멘트 페이스트의 수화열에 미치는 영향)

  • Lee, Yun-Kyung;Kim, Ji-Hyun;Chung, Chul-Woo
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2023.11a
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    • pp.189-190
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    • 2023
  • In this study, the compressive strength and hydration heat of cement paste mixed with cellulose nanocrystal(CNC) and graphene oxide (GO) were evaluated. The difference was compared by mixing 0.1 vol.% ~0.4 vol.% of CNC and 0.05 wt.% ~ 0.1 wt.% of GO in a cement paste with a water cement ratio of 0.3. As a result, it was confirmed that the compressive strength increased as CNC and GO were mixed respectively, and then the compressive strength decreased when the appropriate mixing rate was exceeded. In the hydration heat measurement, there was no significant difference when only CNC was mixed, but it was confirmed that the hydration heat decreased as the amount of CNC mixing increased when used in combination with GO.

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Effects of the Feeding Mixed with Various Levels of n-3 and n-6 Polyunsaturated Fatty Acid on the Lipid Components and Fatty Acid Metabolism of Serum Lipoprotein in Hyperlipidemic Rats (n-3 및 n-6계 다불포화 지방산의 함유비율이 다른 유지가 고지혈증 흰쥐의 혈청 지단백 지질성분 및 지방산 대사에 미치는 영향)

  • 김한수;김성희;정효숙;강정옥;정승용
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.22 no.5
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    • pp.543-551
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    • 1993
  • This study was designed to observe the effects of the feeding mixed with the sardine oil containing n-3 EPA, DHA and the safflower oil in which rich n-6 linoleic acid on the improvement of the lipids and on the fatty acid matabolism of serum lipoprotein in the dietary hyperlipidemic rats. Experimental oils mixed with 16% butter(control group) and 8% butter+8% olive oil, 8% butter and various level of sardine and safflower oils were administered to the male rats of the Sprague Dawley for 4 weeks. Concentrations of total cholesterol in serum lipoproteins were highest in the LDL, followed by VLDL, HDL and chylomicron components. in the triglyceride concentrations, chylomicron were highest, and much VLDL, LDL, HDL components. There were highest in the HDL, followed by LDL, VLDL and chylomicron in phospholipid concentrations of serum lipoproteins. Concentrations of total cholesterol, triglyceride and phospholipid in serum lipoprotein were lower in the other groups than in the control groups, and particularly, lowest in the group 5(4% sardine oil+4% safflower oil). From this results, the feeding equal quantity mixed oil with n-3 PUFA rich sardine oil and n-6 PUFA rich safflower oil were effective on the improvement of the lipid composition in the serum lipoprotein. It might be due to the effects of appropriate rations of P/S, 0.85 and n-6/n-3P, 2.85 in the test lipids. In the fatty acid composition of serum lipoprotein, ratio of P/S and n-3/n-6P were influenced from the fatty acid compositions of the mixed test lipids. And EPA contents were higher in the chylomicron components.

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Effects of dietary supplementation with a combination of plant oils on performance, meat quality and fatty acid deposition of broilers

  • Long, Shenfei;Xu, Yetong;Wang, Chunlin;Li, Changlian;Liu, Dewen;Piao, Xiangshu
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.11
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    • pp.1773-1780
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    • 2018
  • Objective: This study was to evaluate effects of mixed plant oils (identified as mixed oil 1 [MO1] and mixed oil 2 [MO2]) on performance, serum composition, viscera percentages, meat quality, and fatty acid deposition of broilers. Methods: A total of 126 one-day-old Arbor Acres male broiler chicks (weighing $44.91{\pm}0.92g$) were randomly allocated to 1 of 3 treatments with 7 replicate pens per treatment (6 broilers per pen). Dietary treatments included a corn-soybean basal diet supplemented with 3% soybean oil (CTR), basal diet with 3% MO1 (a mixture of 15% corn oil, 10% coconut oil, 15% linseed oil, 20% palm oil, 15% peanut oil and 25% soybean oil; MO1), or basal diet with 3% MO2 (a combination of 50% MO1 and 50% extruded corn; MO2). The trial consisted of phase 1 (d 1 to 21) and phase 2 (d 22 to 42). Results: Compared to CTR, broilers fed MO (MO1 or MO2) had greater (p<0.05) average daily gain in phase 1, 2, and overall (d 1 to 42), redness in thigh muscle, concentrations of serum glucose, serum albumin, saturated fatty acids (SFA) and n-6/n-3 polyunsaturated fatty acids (PUFA) ratio in breast muscle, while these broilers also showed lower ($p{\leq}0.05$) drip loss and concentrations of C18:3n-3 and PUFA/SFA ratio in breast muscle. Broilers fed MO2 had higher (p<0.05) liver percentage, while broilers fed MO1 had lower ($p{\leq}0.05$) feed conversion ratio in phase 1 and increased (p<0.05) contents of C18:2n-6, C20:5n-3, C22:6n-3, and n-3 PUFA in breast muscle compared to CTR. Conclusion: Mixed plant oils had positive effects on performance, serum parameters, meat quality, liver percentage and fatty acid deposition in broilers, which indicates they can be used as better dietary energy feedstocks than soybean oil alone.