• Title/Summary/Keyword: Mixing processes

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A Note on the Strong Mixing Property for a Random Coefficient Autoregressive Process

  • Lee, Sang-Yeol
    • Journal of the Korean Statistical Society
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    • v.24 no.1
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    • pp.243-248
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    • 1995
  • In this article we show that a class of random coefficient autoregressive processes including the NEAR (New exponential autoregressive) process has the strong mixing property in the sense of Rosenblatt with mixing order decaying to zero. The result can be used to construct model free prediction interval for the future observation in the NEAR processes.

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ON COMPLETE CONVERGENCE OF WEIGHTED SUMS OF ø-MIXING RANDOM VARIABLES WITH APPLICATION TO MOVING AVERAGE PROCESSES

  • Baek, J.I.;Liang, H.Y.;Choi, Y.K.;Chung, H.I.
    • Journal of the Korean Statistical Society
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    • v.33 no.3
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    • pp.271-282
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    • 2004
  • We discuss complete convergence of weighted sums for arrays of ø-mixing random variables. As application, we obtain the complete convergence of moving average processes for ø-mixing random variables. The result of Baum and Katz (1965) as well as the result of Li et al. (1992) on iid case are extended to ø-mixing setting.

Multilayer Coatings on Flexible substrate for Electromagnetic Shielding by Using Dry/Wet Hybrid Processes (건습식 혼합공정을 이용한 유연소재 상 전자파 차폐용 다층막 코팅)

  • Lee, Hoon-Seung;Lee, Myeong-Hoon
    • Journal of the Korean institute of surface engineering
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    • v.50 no.5
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    • pp.373-379
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    • 2017
  • Dry processes like evaporation and sputtering in vacuum chamber are difficult to make a uniform, large area and high quality film on thin PET substrate because of PET degradation and bad adhesion. On the other hand, wet processes like electro or electroless plating have complex processes and require high environmental cost. In this study, we successfully prepared $2{\mu}m$ Zn/Cu/Ni multilayers coated on $12{\mu}m$ polyethylene terephthalate (PET) substrate by using dry-wet mixing processes. Their surface electric resistances were evaluated around $0.2{\Omega}$ by using 4 probe measurements. Furthermore, their corrosion resistance also evaluated by natural potential test and compared with other wet, dry and mixing process samples.

Development of Micro Mixing Device with Using Ultrasonic Wave (초음파를 이용한 마이크로 혼합기 제작)

  • Jeon, Yongho;Choi, Byung-Joo;Kang, Seung-Joon;Kim, Dong-Kwon;Kim, Hyun-Jung;Lee, Moon Gu
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.22 no.3
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    • pp.459-464
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    • 2013
  • The purpose of a micro-mixing device is to enhance the mixing by increasing the diffusion effect between different types of flows. There have been many attempts to actively or passively increase mixing. However, those studies were limited to lab-scale experiments because the production of devices requires a series of processes, time, cost, and the mixing quality itself. For this reason, this study attempted to develop a quick and simple process for micro-mixing device fabrication by using conventional machining and bonding processes and applying ultrasonic waves from the outside of the mixing device. The mixing quality was quantified by using the mixing index, and the results showed that the proposed system increases the mixing from ~33% to ~10% with respect to the flow rates.

Genetic Algorithms for Tire Mixing Process Scheduling (타이어 정련 공정 스케줄링을 위한 유전자 알고리즘)

  • Ahn, Euikoog;Park, Sang Chul
    • Korean Journal of Computational Design and Engineering
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    • v.18 no.2
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    • pp.129-137
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    • 2013
  • This paper proposed the scheduling method for tire mixing processes using the genetic algorithm. The characteristics of tire mixing process have the manufacturing routing, operation machine and operation time by compound types. Therefore, the production scheduling has to consider characteristics of the tire mixing process. For the reflection of the characteristics, we reviewed tire mixing processes. Also, this paper introduces the genetic algorithm using the crossover and elitist preserving selection strategy. Fitness is measured by the makespan. The proposed genetic algorithm has been implemented and tested with two examples. Experimental results showed that the proposed algorithm is superior to conventional heuristic algorithm.

COMPLETE CONVERGENCE OF MOVING AVERAGE PROCESSES WITH ${\rho}^*$-MIXING SEQUENCES

  • Han, Kwang-Hee
    • Journal of applied mathematics & informatics
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    • v.27 no.1_2
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    • pp.401-408
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    • 2009
  • Let {$Y_i,-{\infty}<i<{\infty}$} be a doubly infinite sequence of identically distributed and ${\rho}^*$-mixing random variables and {$a_i,-{\infty}<i<{\infty}$} an absolutely summable sequence of real numbers. In this paper, we prove the complete convergence of $\{\sum\limits_{k=1}^n\;\sum\limits_{n=-\infty}^\infty\;a_{i+k}Y_i/n^{1/t};\;n{\geq}1\}$ under suitable conditions.

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ROBUST REGRESSION SMOOTHING FOR DEPENDENT OBSERVATIONS

  • Kim, Tae-Yoon;Song, Gyu-Moon;Kim, Jang-Han
    • Communications of the Korean Mathematical Society
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    • v.19 no.2
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    • pp.345-354
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    • 2004
  • Boente and Fraiman [2] studied robust nonparametric estimators for regression or autoregression problems when the observations exhibit serial dependence. They established strong consistency of two families of M-type robust equivariant estimators for $\phi$-mixing processes. In this paper we extend their results to weaker $\alpha$$alpha$-mixing processes.

A Study on the Reduction of Color in Dye Wastewaters by Physico-chemical Processes (물리, 화학적 처리방법에 의한 염색폐수의 색도제거에 관한 연구)

  • 이준석;김민호;김영규
    • Journal of Environmental Health Sciences
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    • v.19 no.3
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    • pp.29-35
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    • 1993
  • This study was performed to obtain optimal conditions for reduction of color in dye wastewaters using coagulation-sedimentation processes with redox reactions. The reduction of color as well as organic matters variation was observed after coagulation-sedimentation processes using FeSO$_4$ $\cdot$ 7H$_2$O and NaOCl. Coagulation-redox reaction was done with the dose of Coagulant and oxidant at various pH values. Redox reaction was done through jar-mixing and aeration. The results of study were as follows: 1. In the coagulation-sedimentation processes using FeSO$_4$ $\cdot$ 7H$_2$O, color reduction was heigher at pH 3. With variance of dosage of FeSO$_4$ $\cdot$ 7H$_2$O, color reduction was higher at 250 mg/l. When coagulation-sedimentation using FeSO$_4$ $\cdot$ 7H$_2$O 250 mg/l was added at pH 3, the reduction of color, COD$_{Mn}$, and COD$_{Cr}$ showed 47.6%, 21.3% and 22.1%, respectively. 2. When NaOCI was added at level of 100 ppm in raw wastewater at pH 3, the reduction of color, COD$_{Mn}$, and COD$_{Cr}$ showed 30.2%, 5.5% and 6.2%, respectively. 3. After coagulation-sedimentation processes by addition of FeSO$_4$ $\cdot$ 7H$_2$O, when NaOCl was added at level of 250 mg/l in supernant, color reduction was 47.8% in aeration and 37.5% in jar-mixing. 4. Color reduction by aeration was higher than that by jar-mixing.

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Analysis for Scalar Mixing Characteristics using Linear Eddy Model (Linear Eddy Model을 이용한 스칼라의 혼합특성 해석)

  • Kim, Hoo-Joong;Kim, Yong-Mo;Ahn, Kook-Young
    • 한국연소학회:학술대회논문집
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    • 2004.06a
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    • pp.133-137
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    • 2004
  • The present study is focused on the small scale turbulent mixing processes in the scalar field. In order to deal with molecular mixing in turbulent flow, the linear eddy model is addressed. In each realization, the molecular mixing term is implemented deterministically, and turbulent stirring is represented by a sequence of instantaneous, statistically independent rearrangement event called by triplet map. The LEM approach is applied with relatively simple conditions. The characteristics of scalar mixing and PDF profiles are addressed in detail.

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STATIONARY $\beta-MIXING$ FOR SUBDIAGONAL BILINEAR TIME SERIES

  • Lee Oe-Sook
    • Journal of the Korean Statistical Society
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    • v.35 no.1
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    • pp.79-90
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    • 2006
  • We consider the subdiagonal bilinear model and ARMA model with subdiagonal bilinear errors. Sufficient conditions for geometric ergodicity of associated Markov chains are derived by using results on generalized random coefficient autoregressive models and then strict stationarity and ,a-mixing property with exponential decay rates for given processes are obtained.