• The Korean Journal of Ceramics
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• v.6 no.2
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• pp.124-128
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• 2000

Electrical properties of $ZrO_2-TiO_2Yb_2O_3$mixed conductor (Ti-YbSZ) were investigated. This mixed conductor can be applied as a membrane for gas separation at high temperatures. The total conductivity decreased with increasing the $TiO_2$concentration. At high temperatures, the rate of the conductivity degradation became smaller than that at low temperatures. From the oxygen partial pressure dependence of the total conductivity of Ti-YbSZ, the electronic conductivity increased with increasing $TiO_2$concentration at low oxygen partial pressures and at high temperatures. Both 15 and 20 mol% $TiO_2$doped YbSZ showed high oxygen permeability. Mixed conductors, which has high $TiO_2$concentration in YbSZ, are promising materials for using as a membrane for gas separation at high temperatures.

• MALSORI
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• no.52
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• pp.133-144
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• 2004

The quality of narrowband speech can be enhanced by the bandwidth extension technology. This paper proposes a mixed excitation and an energy compensation method based on Gaussian Mixture Model (GMM). First, we employ the mixed excitation model having both periodic and aperiodic characteristics in frequency domain. We use a filter bank to extract the periodicity features from the filtered signals and model them based on GMM to estimate the mixed excitation. Second, we separate the acoustic space into the voiced and unvoiced parts of speech to compensate for the energy difference between narrowband speech and reconstructed highband, or lowband speech, more accurately. Objective and subjective evaluations show that the quality of wideband speech reconstructed by the proposed method is superior to that by the conventional bandwidth extension method.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.2
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• pp.187-193
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• 2012

Nash Equilibrium (NE) is as useful tool for investigating a participant's strategic generation quantity in a competitive electricity market. Cournot model may give a mixed strategy NE instead of a pure strategy when transmission constraints are considered. A mixed strategy is difficult to compute, complicated to understand conceptually, and hard to implement in an electricity market practically. This paper presents that a mixed strategy does not appear in Stackelberg leader-follower model even under a transmission congestion. A solution method is proposed for the leader-follower model under a nondifferentiable space of a strategy variable. Based on the pure strategy NE with a transmission line congested, the merit of leader-follower model is shown from a social welfare point of view.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.262-264
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• 2005

We propose a filter design method to suppress the effect of gyroscope mixed random errors at INS system level. It is based on the result that mixed random errors can be represented by a single equivalent ARMA model. At first step, the time difference of equivalent ARMA process is performed, which consider the characteristic of indirect feedback Kalman filter used in INS filter. Next, a state space conversion of time differenced ARMA model is achieved. If the order of AR is greater than that of MA, the controllable or observable canonical form is used. Otherwise, we introduce the state equation of which the state variable is composed of the ARMA model output and several step ahead predicts of that. At final step, a complete form state equation is presented. The simulation results shows that the proposed method gives less transient error and better convergence compared to the conventional filter which assume the mixed random errors as white noise.

• Journal of The Korean Digital Architecture Interior Association
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• v.11 no.1
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• pp.23-31
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• 2011

In order to cope with the demands of the rapidly changing society, advanced countries enrolled in OECD have been establishing corresponding directions as integrating their fields in economy, society, and education as one system. To be a part of the international changes, Korea has presented "Mixed-Use of schools and community facilities." "Mixed-Use of schools and community facilities" enables schools to expand necessary facilities, which were not secured due to insufficient budget, through community funding. Communities could not secure enough convenient facilities because they did not have enough sites for the facilities; however, school sites have made the communities possible to have facilities. As a result, the demand for "Mixed-Use of schools and community facilities" has increased. Therefore, this study redefines the concept of the Mixed-Use of School Facilities in the perspective of the main users, researches the current state of the Mixed-Use of School Facilities through case studies in Korea, and intends to research preferences of the synthesis through surveys. In addition, the study proposes the proper size and the standard of the facilities that are possible to synthesize them with schools. In the future, in running this Mixed-Use of School Facilities business, the data from this study can be utilized.

• East Asian mathematical journal
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• v.4
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• pp.157-173
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• 1988

• Textile Coloration and Finishing
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• v.29 no.4
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• pp.268-275
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• 2017

As the substitute of synthetic coloring materials for hair dyeing, we selected some natural ones of three primary colors such as sappan wood, logwood(red), gardenia blue(blue) and amur cork tree(yellow). Mixed colorants and metallic mordanting technique were used to widen the color space of dyed samples. In view of similarity in morphological and chemical structure, wool was adopted as the reference material for human hair to evaluate the color properties of hair dyeing. The color properties of the dyed samples were evaluated by using CIE $L^*a^*b^*$ and Munsell color systems. The addition of an alum or ferrous mordants was effective to expand the color space of hair and to increase the colorfastness to washing and light more than the rating of 1. Displaying the dyed samples by using Munsell color system, better linearity of hue values between the dyed samples of wool and human hair was shown when alum mordant was used.

• Proceedings of the Korean Institute of Interior Design Conference
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• 2005.10a
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• pp.143-146
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• 2005

Human activity pattern has been changed as the contemporary urban society changes. Diverse activities repeat regular patterns as time passes. Diagram is a simple drawing which aims to organize and unify various information. The elements of the social behaviour could be spatialized by means of diagram applications. By using diagrams, architects understand contemporary urban society and form new space conditions. Time-based activity patterns consists of activity pattern in a restricted space and in urban structure for space use. Activity patterns for different time zones are explained by two types of diagrams, space occupation and flexibility of space, By the characteristic of space system structred by these diagrams, activities and programs are rearranged and variety of space is allowed through flexibility. Also, programs are mixed to apply to simultaneous occurrence of ever-changing human activities.

• Tunnel and Underground Space
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• v.31 no.6
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• pp.549-560
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• 2021

Forces exerted on a shield TBM (tunnel boring machine) such as cutter head torque, thrust force, chamber pressure, and upward force are key factors determining TBM performance. However, the forces acting on the TBM when tunnelling the mixed ground have different tendencies compared to that of the uniform ground, which could impair TBM performance. In this study, the effect of mixed ground tunnelling was numerically investigated with torque, thrust force, chamber pressure, and upward force. A coupled discrete element method (DEM) and finite difference method (FDM) model for TBM driving model was used. This numerical study simulates TBM tunnelling in mixed ground composed of upper weathered granite soil and lower weathered rock. The effect on the force acting on the TBM according to the location and slope of the boundary of the mixed ground was numerically examined.

• Ocean Science Journal
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• v.42 no.4
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• pp.241-246
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• 2007

Northern Arabian Sea (NAS) between $17^{\circ}N-20.5^{\circ}N$ and $59^{\circ}E-69^{\circ}E$ was observed by using Argo float daily data fur about 9 months, from April 2002 through December 2002. Results showed that during April - May mixed layer shoaled due to light winds, clear sky and intense solar insolation. Sea surface temperature (SST) rose by $2.3^{\circ}C$ and ocean gained an average of 99.8 $Wm^{-2}$. Mixed layer reached maximum depth of about 71 m during June - September owing to strong winds and cloudy skies. Ocean gained abnormally low $\sim18Wm^{-2}$ and SST dropped by $3.4^{\circ}C$. During the inter monsoon period, October, mixed layer shoaled and maintained a depth of 20 to 30 m. November - December was accompanied by moderate winds, dropping of SST by $1.5^{\circ}C$ and ocean lost an average of 52.5 $Wm^{-2}$. Mixed layer deepened gradually reaching a maximum of 62 m in December. Analysis of surface fluxes and winds suggested that winds and fluxes are the dominating factors causing deepening of mixed layer during summer and winter monsoon periods respectively. Relatively big]h correlation between MLD, net heat flux and wind speed revealed that short term variability of MLD coincided well with short term variability of surface forcing.