• Title/Summary/Keyword: Mixed effects model

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Procedure for monitoring special causes and readjustment in ARMA(1,1) noise model (자기회귀이동평균(1,1) 잡음모형에서 이상원인 탐지 및 재수정 절차)

  • Lee, Jae-Heon;Kim, Mi-Jung
    • Journal of the Korean Data and Information Science Society
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    • v.21 no.5
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    • pp.841-852
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    • 2010
  • An integrated process control (IPC) procedure is a scheme which simultaneously applies the engineering control procedure (EPC) and statistical control procedure (SPC) techniques to reduce the variation of a process. In the IPC procedure, the observed deviations are monitored during the process where adjustments are repeatedly done by its controller. Because the effects of the noise, the special cause, and the adjustment are mixed, the use and properties of the SPC procedure for the out-of-control process are complicated. This paper considers efficiency of EWMA charts for detecting special causes in an ARMA(1,1) noise model with a minimum mean squared error adjustment policy. And we propose the readjustment procedure after having a true signal. This procedure can be considered when the elimination of the special cause is not practically possible.

A Study on Numerical Modeling of the Induced Heat to Gaseous Flow inside the Mixing Area of Ammonia SCR System in Diesel Nox After-treatment Devices (디젤 NOx 후처리 장치에 있어서 암모니아 SCR 시스템 혼합영역 내 가스유동의 유입열 수치모델링에 관한 연구)

  • Bae, Myung-Whan;Syaiful, Syaiful
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.11
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    • pp.897-905
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    • 2008
  • Selective catalytic reduction(SCR) is known as one of promising methods for reducing $NO_x$ emissions in diesel exhaust gases. $NO_x$ emissions react with ammonia in the catalyst surface of SCR system at working temperature of catalyst. In this study, to raise the reacting temperature when the exhaust gas temperature is too low, a heater is located at the bottom of SCR reactor. At an ambient temperature, ammonia is radially injected perpendicular to the exhaust gas flow at inlet pipe and uniformly mixed in the mixing area after being impinged against the wall. To predict the turbulent model inside the mixing area of SCR system, the standard ${\kappa}\;-\;{\varepsilon}$ model is applied. This work investigates numerically the effects of induced heat on the gaseous flow. The results show that the Taylor-$G{\ddot{o}}rtler$ type vortex is generated after the gaseous flow impinges the wall in which these vortices influence the temperature distribution. The addition of heat disturbs the flow structure in bottom area and then stretching flow occurs. Vorticity strand is also formed when heat is continuously increased. Constriction process takes place, however, when a further heat input over a critical temperature is increased and finally forms shed vortex which is disconnected from the vorticity strand. The strong vortex restricts the heat transport in the gaseous flow.

Air Jet Effect on Performance Improvement of Non-Contact Type Seals for Oil Mist Lubrication Systems (공기분사가 오일미스트 윤활 시스템용 비접촉 시일의 성능 향상에 미치는 영향)

  • Na, Byeong-Cheol;Jeon, Gyeong-Jin;Han, Dong-Cheol
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.24 no.9 s.180
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    • pp.2159-2166
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    • 2000
  • Recently, high performance machining center requires special type of sealing mechanism that prevent a leakage of oil jet or oil mist lubrication system. Sealing of oil-air mixture plays important r oles to have an enhanced lubrication for performance machining center. Current work emphasizes on investigations of the air jet effect on the protective collar type labyrinth seal. To improve sealing capabilities of conventional labyrinth seals, air jet is injected against the leakage flow. In this study, an adapted model is introduced to improve sealing capability of conventional non-contact type seals. It has a combined geometry of a protective collar type and an air jet type. Both of a numerical analysis by CFD (Computational Fluid Dynamics) and experimental measurements are carried out to verify sealing improvement. The sealing effects of the leakage clearance and the air jet magnitude aic studied in various parameters. Gas or liquid has been used as a working fluid for most of nori-contact types seals including the labyrinth seal. However, it is more reasonable to regard two-phase flows because oil mist or oil jet are used for high performance spindle's lubrication. In this study, working fluid is regarded as two phases that are mixed flow of oil and air phase. Both of turbulence and compressible flow model are also introduced in a CFD analysis to represent an isentropic process. Estimation of non-leaking property is determined by amount of pressure drop in the leakage path. Results of pressure drop in the experiment match reasonably to those of the simulation by introducing a flow coefficient. Effect of the sealing improvement is explained as decreasing of leakage clearance by air jetting. Thus, sealing effect is improved by amount of air jetting even though clearance becomes larger

Association of the Single Nucleotide Polymorphisms in RUNX1, DYRK1A, and KCNJ15 with Blood Related Traits in Pigs

  • Lee, Jae-Bong;Yoo, Chae-Kyoung;Park, Hee-Bok;Cho, In-Cheol;Lim, Hyun-Tae
    • Asian-Australasian Journal of Animal Sciences
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    • v.29 no.12
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    • pp.1675-1681
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    • 2016
  • The aim of this study was to detect positional candidate genes located within the support interval (SI) regions based on the results of red blood cell, mean corpuscular volume (MCV), and mean corpuscular hemoglobin quantitative trait locus (QTL) in Sus scrofa chromosome 13, and to verify the correlation between specific single-nucleotide polymorphisms (SNPs) located in the exonic region of the positional candidate gene and the three genetic traits. The flanking markers of the three QTL SI regions are SW38 and S0215. Within the QTL SI regions, 44 genes were located, and runt-related transcription factor 1, dual-specificity tyrosine-(Y)-phosphorylation regulated kinase 1A (DYRK1A), and potassium inwardly-rectifying channel, subfamily J, member 15 KCNJ15-which are reported to be related to the hematological traits and clinical features of Down syndrome-were selected as positional candidate genes. The ten SNPs located in the exonic region of the three genes were detected by next generation sequencing. A total of 1,232 pigs of an $F_2$ resource population between Landrace and Korean native pigs were genotyped. To investigate the effects of the three genes on each genotype, a mixed-effect model which is the considering family structure model was used to evaluate the associations between the SNPs and three genetic traits in the $F_2$ intercross population. Among them, the MCV level was highly significant (nominal $p=9.8{\times}10^{-9}$) in association with the DYRK1A-SNP1 (c.2989 G$F_2$ intercross, our approach has limited power to distinguish one particular positional candidate gene from a QTL region.

Effects of Hair Tonic and Food including Korean Medicinal Herbs on Hair Growth in an Alopecia Model of C57BL/6 Mice (한약재 함유 헤어토닉 및 식품이 C57BL/6 마우스의 탈모 모델에서 모발성장에 미치는 영향)

  • Choi, Hye-Min;Hwang, Su-Jung;Lee, Jin-Sang;Do, Eun-Ju;Kim, Mu-Young;Kim, Mi-Ryeo
    • The Korea Journal of Herbology
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    • v.26 no.1
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    • pp.119-124
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    • 2011
  • Objective : This study was carried out to investigate effect of korean medicinal herbs-included hair tonic (MHT) and food (MF) on hair growth in an alopecia model of C57BL/6 mice. Methods : Six-weeks old mice were given laboratory rodent chow diet for 1 week. Then, we used a depilatory for hair removal on mice. The next day, mice were randomized and separated in 3 groups of 6 mice; normal group (N, vehicle epidermal application+normal diet-treated group), positive control group (C, 3% minoxidil sulfate epidermal application+normal diet-treated group), and the treatment group (T, HT epidermal application+ MF diet-treated group). The hair regrowth was determined by photograph, which was taken at 7, 14 and 21 days. And scoring indices, hair density and hair thickness, were evaluated by Folliscope at same day. In addition, the hair regrowth was analyzed insulin-like growth factor (IGF-1) in the dorsal skin of mice. Results : As a result, not only external appearance but also hair density and hair thickness on dorsal skin were increased more in C, T groups than in N group at 21 days with mixed treatment. Therefore, distinct regrowth pattern is appeared by treatment of herbal tonic and natural food for 21 days. Also, the expressions of IGF-1 on dorsal skin were higher in C, T groups than in N group. Conclusion : These results suggested that this herbal hair tonic and natural food has hair growth promoting activities and may be useful for treatment of bald or alopecia.

Generalized Linear Mixed Model for Multivariate Multilevel Binomial Data (다변량 다수준 이항자료에 대한 일반화선형혼합모형)

  • Lim, Hwa-Kyung;Song, Seuck-Heun;Song, Ju-Won;Cheon, Soo-Young
    • The Korean Journal of Applied Statistics
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    • v.21 no.6
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    • pp.923-932
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    • 2008
  • We are likely to face complex multivariate data which can be characterized by having a non-trivial correlation structure. For instance, omitted covariates may simultaneously affect more than one count in clustered data; hence, the modeling of the correlation structure is important for the efficiency of the estimator and the computation of correct standard errors, i.e., valid inference. A standard way to insert dependence among counts is to assume that they share some common unobservable variables. For this assumption, we fitted correlated random effect models considering multilevel model. Estimation was carried out by adopting the semiparametric approach through a finite mixture EM algorithm without parametric assumptions upon the random coefficients distribution.

Biosorption Model and Factors for Removing Lead to Aureobasdium pullulans being Imperfect Fungus (불완전 균류 Aureobasdium pullulans으로 납을 제거하기 위한 인자들과 흡착모델)

  • Suh, Jung-Ho;Suh, Myung-Gyo;Chung, Kyung-Tae;Lee, Yong-Hee
    • Journal of Life Science
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    • v.16 no.6
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    • pp.877-883
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    • 2006
  • An alternative method to remove and recover heavy metals is biosorption based on metal-sequestering properties of natural or biological origin. In this study, the effects of factors such as temperature, pH, initial concentration of lead, and initial amount of biomass on biosorption of lead using Aureobasdium pullulans were investigated. A. pullulans has an excellent selectivity to remove lead than other heavy metals such as cadmium, chromium, nickel in pure and mixed solution. The optimum temperature of biosorption with A. pullulans was $40^{\circ}C$ and the amount of removal increased at high pH. The higher initial lead concentration or the lower cell dry weight, the higher amount of lead was adsorbed. The adsorption isotherm of lead was accorded with Freundlich model. The adsorption capacity and initial adsorption rate of living A. pullulans were about twice higher than that of dead one.

Convergence Study on the Optimization for Suppression of Starch Hydrolysis using Rutin, Quercetin and Dietary Fiber Mixture Design (루틴, 퀘르세틴, 식이섬유 혼합물 설계를 이용한 전분소화 지연 효과의 최적화에 대한 융합 연구)

  • Oh, Imkyung;Bae, In Young
    • Journal of the Korea Convergence Society
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    • v.11 no.5
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    • pp.35-41
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    • 2020
  • This study was conducted to develop the efficient system for starch hydrolysis suppression using rutin, quercetin and dietary fiber through the statistical mixture design. The three components were replaced with wheat flour at the level of 10% and the mixed gel with three components was characterized by in vitro starch digestion. The mixture design was applied by simplex-centroid experimental model. The quadratic model (R2=0.86) was well fitted and the obtained regression equation indicated that the significant positive effects was observed in the quercetin and fiber mixture. Based on the statistical results, the best mixing ratio of quercetin and fiber was 72: 28 that led to the lowest predicted glycemic index (pGI). Their interactions on the pGI of starch digestibility were clearly visualized in the 3D surface plot. These results suggested that the mixture of quercetin and fiber interact strongly with wheat flour, consequently retarding starch hydrolysis by 15%.

Panel data analysis with regression trees (회귀나무 모형을 이용한 패널데이터 분석)

  • Chang, Youngjae
    • Journal of the Korean Data and Information Science Society
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    • v.25 no.6
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    • pp.1253-1262
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    • 2014
  • Regression tree is a tree-structured solution in which a simple regression model is fitted to the data in each node made by recursive partitioning of predictor space. There have been many efforts to apply tree algorithms to various regression problems like logistic regression and quantile regression. Recently, algorithms have been expanded to the panel data analysis such as RE-EM algorithm by Sela and Simonoff (2012), and extension of GUIDE by Loh and Zheng (2013). The algorithms are briefly introduced and prediction accuracy of three methods are compared in this paper. In general, RE-EM shows good prediction accuracy with least MSE's in the simulation study. A RE-EM tree fitted to business survey index (BSI) panel data shows that sales BSI is the main factor which affects business entrepreneurs' economic sentiment. The economic sentiment BSI of non-manufacturing industries is higher than that of manufacturing ones among the relatively high sales group.

Association Analysis of Charcoal Rot Disease Resistance in Soybean

  • Ghorbanipour, Ali;Rabiei, Babak;Rahmanpour, Siamak;Khodaparast, Seyed Akbar
    • The Plant Pathology Journal
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    • v.35 no.3
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    • pp.189-199
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    • 2019
  • In this research, the relationships among the 31 microsatellite markers with charcoal rot disease resistance related indices in 130 different soybean cultivars and lines were evaluated using association analysis based on the general linear model (GLM) and the mixed linear model (MLM) by the Structure and Tassel software. The results of microsatellite markers showed that the genetic structure of the studied population has three subpopulations (K=3) which the results of bar plat also confirmed it. In association analysis based on GLM and MLM models, 31 and 35 loci showed significant relationships with the evaluated traits, respectively, and confirmed considerable variation of the studied traits. The identified markers related to some of the studied traits were the same which can probably be due to pleiotropic effects or tight linkage among the genomic regions controlling these traits. Some of these relationships were including, the relationship between Sat_252 marker with amount of charcoal rot disease, Satt359, Satt190 and Sat_169 markers with number of microsclerota in stem, amount of charcoal rot disease and severity of charcoal rot disease, Sat_416 marker with number of microsclerota in stem and amount of charcoal rot disease and the Satt460 marker with number of microsclerota in stem and severity of charcoal rot disease. The results of this research and the linked microsatellite markers with the charcoal rot disease-related characteristics can be used to identify the suitable parents and to improve the soybean population in future breeding programs.