• Asian Journal of Atmospheric Environment
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• v.9 no.1
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• pp.91-99
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• 2015

The Multi-wavelength Raman LIDAR (MRL) system was developed to enable a better understanding of the complex properties of aerosols in the atmosphere. In this study, the microphysical, optical, and radiative properties of mixed aerosols were retrieved using the discrete aerosol observation products from the MRL. The dust mixing ratio, which is the proportion of dust particles to the total mixed, was derived using the particle depolarization ratio. It was employed in the retrieval of backscattering and extinction coefficient profiles for dust and non-dust particles. The vertical profiles of aerosol optical properties were then used as input parameters in the inversion algorithm for the retrieval of microphysical parameters including the effective radius, refractive index, and the single scattering albedo (SSA). Those products were successfully applied to an analysis of radiative flux using a radiative transfer model. The relationship between the MRL derived extinction and aerosol radiative forcing (ARF) in short-wavelength was assessed over Gwangju, Korea. The results clearly demonstrate that the MRL-derived extinction profiles are a good surrogate for use in the estimation of optical, microphysical, and radiative properties of aerosols. It is considered that the analytical results shown in this study can be used to provide a better understanding of air quality and the variation of local radiative effects due to aerosols.

• Composites Research
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• v.20 no.6
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• pp.15-20
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• 2007

In this work, the structural response of thin-walled, composite beams with built-in twist angles is analyzed using a mixed beam approach. The analytical model includes the effects of elastic couplings, shell wall thickness, and torsion warping. Reissner's semi-complimentary energy functional is used to describe the beam theory and also to deal with the mixed-nature in the beam kinematics. The bending and torsion related warpings introduced by the non-zero pretwist angles are derived in closed-form through the proposed beam formulation. The theory is validated with available literature and detailed finite element analysis results for rectangular solid section beams with elastic couplings. Very good correlation has been obtained for the cases considered.

• Journal of the Korea Society of Computer and Information
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• v.27 no.3
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• pp.13-23
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• 2022

In this study we leveraged a probing method to evaluate how a pre-trained L2 LSTM language model represents sentences with relative and coordinate clauses. The probing experiment employed adapted models based on the pre-trained L2 language models to trace the syntactic properties of sentence embedding vector representations. The dataset for probing was automatically generated using several templates related to different sentence structures. To classify the syntactic properties of sentences for each probing task, we measured the adaptation effects of the language models using syntactic priming. We performed linear mixed-effects model analyses to analyze the relation between adaptation effects in a complex statistical manner and reveal how the L2 language models represent syntactic features for English sentences. When the L2 language models were compared with the baseline L1 Gulordava language models, the analogous results were found for each probing task. In addition, it was confirmed that the L2 language models contain syntactic features of relative and coordinate clauses hierarchically in the sentence embedding representations.

• Applied Chemistry for Engineering
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• v.9 no.7
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• pp.968-973
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• 1998

The critical micelle concentrations($CMC^*$) of the mixed surfactant systems of cationic surfactant cetylpyridinium chloride(CPC) and nonionic surfactant Triton X-100(TX-100) in aqueous solutions of salts(KCl and $Na_2CO_3$) and isomeric butanols(tert-butanol, iso-butanol and n-butanol) were determined by UV spectroscopy method. The various thermodynamic values in aqueous solutions of salts and isomeric butanols were compared with the values in pure water, calculated by means of the equation derived from the pseudo-phase separation model. Thermodynamic parameters($X_1$, $\beta$, ${\gamma}i$, $ai^M$, $C_i$ and ${\Delta}H_{mix}$) were found to have great effects of salts and isomeric butanols on the mixed micellization of CPC/TX-100 mixtures, and also in good agreements with the nonideal mixed micelle model. They showed all negative deviations from the ideal mixed micellar behavior.

• Clean Technology
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• v.20 no.3
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• pp.314-320
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• 2014

The purpose of this work is to optimize composition of mixture refrigerants used in the C3MR (Propane & Mixed Refrigerants) process by a statistical optimization technique. C3MR studied in this work is one of widely used commercial natural gas liquefaction processes with high efficiency. Process simulation was performed in a commercial process simulator and methane ($C_1$), ethane ($C_2$), propane ($C_3$), and nitrogen ($N_2$) were selected as mixed refrigerants. Using the process model, optimum composition of refrigerants mixture was determined via mixture design and central composite design to produce minimum energy consumption. As a result, it was confirmed that energy consumption is reduced down to 11.3% comparing to existing design. It was also compared with heat effectiveness through temperature profile of MCHE (main cryogenic heat exchanger).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.23 no.8
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• pp.987-996
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• 1999

An algorithm for modeling the filling of metal into a mold and solidification has been developed. This algorithm uses the implicit VOF method for a filling and a general implicit source-based method for solidification. The model for simultaneous filling and solidification is applied to the two-dimensional filling and solidification of a square cavity. The effects of the wall temperature and gate position on the solidification are examined. The mixed natural convection flow and residual flow resulting from the completion of a filling are included in this study to investigate the coupled effects of the filling and natural convection on solidification. Two different filling configurations (assisting flow and opposite flow due to the gate position) are analysed to study the effects of residual flow on solidification. The results clearly show the necessity to carry out a coupled filling and solidification analysis including the effect of natural convection.

• East Asian Economic Review
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• v.16 no.3
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• pp.291-314
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• 2012

This paper attempts to investigate to what extent English proficiency can boost international trade in services. To achieve this purpose, this paper estimates the determinants of services trade including language variables with the aggregated and disaggregated data for nine different subsectors of OECD countries. The empirical tests are based on a theory-based gravity model derived from Anderson and von Wincoop. The findings show that English proficiency has a significant influence on services trade, while other languages such as French and German have only weak and mixed effects. In particular, communication, financial, commercial, insurance, and business services are revealed to be the most impacted by the level of English proficiency. The results imply that governments can use their English policies to promote international trade in services.

• Communications for Statistical Applications and Methods
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• v.26 no.5
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• pp.507-517
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• 2019

Statistical matching is a method of combining multiple sources of data that are extracted or surveyed from the same population. It can be used in situation when variables of interest are not jointly observed. It is a low-cost way to expect high-effects in terms of being able to create synthetic data using existing sources. In this paper, we propose the several statistical micro matching methods using a multinomial logistic regression model when all variables of interest are categorical or categorized ones, which is common in sample survey. Under conditional independence assumption (CIA), a mixed statistical matching method, which is useful when auxiliary information is not available, is proposed. We also propose a statistical matching method with auxiliary information that reduces the bias of the conventional matching methods suggested under CIA. Through a simulation study, proposed micro matching methods and conventional ones are compared. Simulation study shows that suggested matching methods outperform the existing ones especially when CIA does not hold.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.6
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• pp.784-788
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• 2008

Studies to detect genes responsible for economic traits in farm animals have been performed using parametric linear models. A non-parametric, model-free approach using the 'expanded multifactor-dimensionality reduction (MDR) method' considering high dimensionalities of interaction effects between multiple single nucleotide polymorphisms (SNPs), was applied to identify interaction effects of SNPs responsible for carcass traits in a Hanwoo beef cattle population. Data were obtained from the Hanwoo Improvement Center, National Agricultural Cooperation Federation, Korea, and comprised 299 steers from 16 paternal half-sib proven sires that were delivered in Namwon or Daegwanryong livestock testing stations between spring of 2002 and fall of 2003. For each steer at approximately 722 days of age, the Longssimus dorsi muscle area (LMA) was measured after slaughter. Three functional SNPs (19_1, 18_4, 28_2) near the microsatellite marker ILSTS035 on BTA6, around which the QTL for meat quality were previously detected, were assessed. Application of the expanded MDR method revealed the best model with an interaction effect between the SNPs 19_1 and 28_2, while only one main effect of SNP19_1 was statistically significant for LMA (p<0.01) under a general linear mixed model. Our results suggest that the expanded MDR method better identifies interaction effects between multiple genes that are related to polygenic traits, and that the method is an alternative to the current model choices to find associations of multiple functional SNPs and/or their interaction effects with economic traits in livestock populations.

• Journal of Mechanical Science and Technology
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• v.16 no.4
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• pp.512-521
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• 2002

The flap-lag-torsion coupled aeroelastic behavior of a hingeless rotor blade with composite flexures in hovering flight has been investigated by using the finite element method. The quasisteady strip theory with dynamic inflow effects is used to obtain the aerodynamic loads acting on the blade. The governing differential equations of motion undergoing moderately large displacements and rotations are derived using the Hamilton's principle. The flexures used in the present model are composed of two composite plates which are rigidly attached together. The lead-lag flexure is located inboard of the flap flexure. A mixed warping model that combines the St. Versant torsion and the Vlasov torsion is developed to describe the twist behavior of the composite flexure. Numerical simulations are carried out to correlate the present results with experimental test data and also to identify the effects of structural couplings of the composite flexures on the aeroelastic stability of the blade. The prediction results agree well with other experimental data. The effects of elastic couplings such as pitch-flap, pitch-lag, and flap-lag couplings on the stability behavior of the composite blades are also investigated.