• Communications for Statistical Applications and Methods
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• v.15 no.6
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• pp.969-976
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• 2008

Mixed linear models have been widely used in various correlated data including multivariate survival data. In this paper we extend hierarchical-likelihood(h-likelihood) approach for mixed linear models with right censored data to that for left censored data. We also allow a general random-effect structure and propose the estimation procedure. The proposed method is illustrated using a numerical data set and is also compared with marginal likelihood method.

• The Korean Journal of Applied Statistics
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• v.25 no.3
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• pp.457-464
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• 2012

Small area estimation is a statistical inference method to overcome the large variance due to the small sample size allocated in a small area. Recently some nonparametric estimators have been applied to small area estimation. In this study, we suggest a nonparametric mixed effect small area estimator using kernel smoothing and compare the small area estimators using labor statistics.

• Journal of Korean Society for Atmospheric Environment
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• v.7 no.1
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• pp.41-47
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• 1991

Air pollution potentials of the 7 cities in the central part of Korea were obtained with the mean wind speed within the mixed layer and the mixed layer height calculated by the Jump Model. Seasonal variation of the afternoon mixed layer height in Seoul area shows that low in winter and high in summer. Annual mean of the morning air pollution potential was lowest in Incheon and highest in Wonju. On the other hand annual mean of the afternoon air pollution potential was lowest in Incheon and highest in Chuncheon. Relatively low air pollution potential in Incheon can be explained as high mixed layer height and the effect of sea breeze.

• Communications for Statistical Applications and Methods
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• v.7 no.3
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• pp.677-686
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• 2000

Outliers may occur with respect to any of the random components in mixed linear models. We develop a use of simple, inexpensive updating formulas to consider the effect of case-deletion for mixed linear models. The method described here requires inversions of an n x n matrix, where n is the number of nonempty cells. A numerical example illustrates the use of computational formulas.

• Journal of the Korean Data and Information Science Society
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• v.15 no.2
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• pp.379-386
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• 2004

This paper deals with a mixed logit model for vaccination data. The effect of a newly developed vaccine for a certain chicken disease can be evaluated by a noninfection rate after injecting chicken with the disease vaccine. But there are a lot of factors that might affect the noninfecton rate. Some of these are fixed and others are random. Random factors are sometimes coming from the sampling scheme for choosing experimental units. This paper suggests a mixed model when some fixed factors need to have different experimental sizes by an experimental design and illustrates how to estimate parameters in a suggested model.

• Geomechanics and Engineering
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• v.33 no.5
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• pp.439-451
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• 2023

The construction of shield tunnelling in urban sites is facing serious risks from complex and changeable underground conditions. Construction problems in the sand-clay mixed ground have been more reported in recent decades for its poor control of soil loss in tunnel face, ground settlement and supporting pressure. Since the limitations of observation methods, the conventional physical modelling experiments normally simplify the tunnelling to a plane strain situation whose results are not reliable in mixed ground cases which exhibit more complicated responses. We propose a new method for the study of the mixed ground tunnel through which mixed lays are simulated with transparent soil surrogates exhibiting different mechanical properties. An experimental framework for the transparent soil modelling of the mixed ground tunnel was established incorporated with the self-developed digital image correlation system (PhotoInfor). To understand better the response of face stability, ground deformation, settlement and supporting phenomenon to tunnelling excavation in the sand-clay mixed ground, a series of case studies were carried out comparing the results from cases subjected to different buried depths and mixed phenomenon. The results indicate that the deformation mode, settlement and supporting phenomenon vary with the mixed phenomenon and buried depth. Moreover, a stratigraphic effect exists that the ground movement around mixed face reveals a notable difference.

• Archives of design research
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• v.21
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• pp.207-217
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• 1997

Mixed Use Area (Multifaceted Integration) is getting increasingly demanded since it has several merits such as preventing CBD from being emptied during night time, making daily life comfortable and utilizing the land more efficiently. However, the characteristic of Mixed Use Area -as advantages of it-, which is that it combines residence, retail, office, cultural, entertainment facilities altogether could be regarded as a weakness when it is viewed from each functions' original purposes such as residential and retail areas'. Accordingly, it is needed to do basic research and develop design guidelines of the Mixed Use Area to prepare its another take-off. The purpose of this research is to study theoretical background of Mixed Use Area's birth, understand its status quo by examining examples overseas and presented possible standardized ways of developing it.

• The Korean Journal of Food And Nutrition
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• v.9 no.3
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• pp.331-335
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• 1996

In this study, the attempts were made to Investigate the effect of squalene (200 ppm) on the autooxidation of soybean oil The effect of mixed tocopherols (200 ppm) was also studied In the same way and the results of the study were compared with those of squalene. A put of a commercial soybean oil was stored at 45.0$\pm$0.5t for their autooxidation. The extent of the autooxidation was estimated from the changes of the peroxide value and % conjugated dienoic acid content of the ell substrates The results of the autooxidation, squalene In the soybean oil substrate showed antioxidant activity but the activity was weaker than that of mixed-tocopherols nth the same concentration. The induction periods of the control and substrates with the same concentration. The Induction periods of the control and substrates with squalene and mixed-tocopherols were 448.5 504.9 and 668.9 hours, respectively. Time required to Tech a POV of 30meq/kg oil.

• Journal of Korean Society for Atmospheric Environment
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• v.12 no.3
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• pp.231-241
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• 1996

The effect of radiation and buoyancy on the thermophoresis phenomenon owing to the presence of highly absorbing, emitting particles (such as soot or pulverized coal) suspended in a two phase flow system was investigated numerically for a turbulent mixed convection flow. The analysis of conservation equations for a gas-particle flow system was performed on the basis of a two-fluid model from a continuum Eulerian viewpoint. The modified van Driest and Cebeci mixing length turbulence model was adopted in the anaylsis of turbulent flow. In addition, the P-1 approximation was used to evaluate the radiation heat transfer. As expected from the particle concentration and drift velocity distribution, the cumulative collection efficiency E (x) becomes larger when the buoyancy effect increases (i.e. higher Grashof number), while smaller as the radiation effect increases (i.e. higher optical thickness).

• Journal of Haehwa Medicine
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• v.9 no.1
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• pp.135-142
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• 2000

For the evaluation of protective effect on hepatic damage by Korean red ginseng mixed formula, we used GR(Korean red ginseng), GRF-A(Korean red ginseng-mixed formula) as a materials. The study was performed on protective effect against hepatic damage induced by $CCl_4$. In vitro assay with 1.1 mM galactosamine, protection(%) was 44%(GR), 58%(GRF-A) at 50ug/ml, while maxium protection(%) was 5%(GR) and 24% (GRF-A) against acute hepatotoxicity by $CCl_4$. GRF-A significantly protected ethanol induced-liver damage by lowering ALT and ALP and fatty degenertion in liver tissue.