• Journal of the Korean Ceramic Society
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• v.27 no.8
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• pp.1027-1033
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• 1990

In order to identify the origin of phase coexistence at morphotropic tetragonal and rhombohedral boundary in PZT ceramics, the effect of chemical inhomogeneity on phase coexistence region was investigated. Two kinds of PZT ceramics with different chemical homogeneity were prepared by conventional solid state reaction and co-precipitation method. There was coexistence of tetragonal and rhombohedral phase over a wide composition range in PZT ceramics calcined by solid state reaction, and there was also phase coexistence of which region was reduced considerably in sintered samples. And phase coexistence region was not observed in co-precipitated PZT ceramics(within 1 mole%). Therefore compositional fluctuation is considered to be major origin of the phase coexistence at morphotropic phae boundary in PZT ceramics.

• Korean Journal of Mathematics
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• v.12 no.1
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• pp.77-90
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• 2004

The purpose of this paper is to give a sufficient condition for the existence, nonexistence and uniqueness of coexistence of positive solutions to a rather general type of elliptic competition system of the Dirichlet problem on the bounded domain ${\Omega}$ in $R^n$. The techniques used in this paper are upper-lower solutions, maximum principles and spectrum estimates. The arguments also rely on some detailed properties for the solution of logistic equations. This result yields an algebraically computable criterion for the positive coexistence of competing species of animals in many biological models.

• Journal of Contemporary Eastern Asia
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• v.19 no.2
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• pp.20-39
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• 2020

In order to overturn the exclusion of Korean schools from the newly implemented free tuition program (2010) as part of sanctions against North Korea, members of Korean schools and Japanese supporters have focused on "students' innocence" and "multicultural coexistence" as viable frameworks to explain why the students are sympathetic and legitimate subjects who deserve equal rights. Examining different political strategies employed by the Korean schools and their supporters through ethnography and media analysis, the article pays close attention to how they claim their eligibility for these rights while they negotiate state surveillance and intervention in the process. I argue that in their efforts to gain recognition as deserving and sympathetic subjects, Korean schools are trapped in what political theorist Patchen Markell calls a "permanent temptation" in pursuing "recognition." Anti-North Korea sentiments in Japan have made the desire for good recognition even more urgent among Korean school community members. The paper will demonstrate that the search for recognition unwittingly reinforces and perpetuates existing relations of subordination and state dominance over their education as it has forced the Korean schools to accept various "conditions" that would radically alter the core principle, mission, and pedagogy of Korean school education that is rooted in decolonizing theory and praxis. This paper will shed lights on dilemma of multicultural coexistence the Korean minority population faces in Japan today.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• v.24 no.4
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• pp.351-362
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• 2020

Adaptive behaviors are one of ubiquitous features in evolutionary dynamics of populations, and certain adaptive behaviors can be witnessed by individuals' movements which are generally affected by local environments. In this paper, by revisiting the previous work, we investigate the sensitivity of species coexistence in the system of cyclic competition where species movement can be affected by local environments. By measuring the extinction probability through Monte-Carlo simulations, we find the relativistic effect of weights of local fitness and exchange rate for adaptive movement on species biodiversity which promotes species coexistence as the relativistic effect is intensified. In addition, by means of basins of initial conditions, we also found that adaptive movement can also affect species biodiversity with respect to the choice of initial conditions. The strong adaptive movement can eventually lead the coexistence as a globally stable state in the spatially extended system regardless of mobility.

• Progress in Superconductivity
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• v.11 no.2
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• pp.135-140
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• 2010

We propose a variational wave function for the ground state of the magnetic heavy fermion (HF) systems, in which both the Kondo and the RKKY interactions are variationally incorporated and the local f-orbital state exists as a linear combination of a full local moment state and a fully compensated state (mixed wave state). We describe the mechanism for the mixed wave ground state based on the large-N treatment of the Kondo lattice Hamiltonian added with RKKY interaction. With the mixed wave ground state we can explain several puzzling experiments in magnetic HF compounds such as a small value of local moment, coexistence of the antiferromagnetic (AFM) and the paramagnetic (PM) phases, local quantum criticality, etc.

• Journal of Information Processing Systems
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• v.7 no.1
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• pp.43-52
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• 2011

Whether it is crosstalk, harmonics, or in-band operation of wireless technologies, interference between a reference system and a host of offenders is virtually unavoidable. In past contributions, a benchmark has been established and considered for coexistence analysis with a number of technologies including FWA, UMTS, and WiMAX. However, the previously presented model does not take into account the mobility factor of the reference node in addition to a number of interdependent requirements regarding the link direction, channel state, data rate and system factors; hence limiting its applicability for the MBWA (IEEE 802.20) standard. Thus, over diverse modes, in this correspondence we analytically derived the greatest aggregate interference level tolerated for high-fidelity transmission tailored specifically for the MBWA standard. Our results, in the form of benchmark indicators, should be of particular interest to peers analyzing and researching RF coexistence scenarios with this new protocol.

• Journal of the Korean Mathematical Society
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• v.39 no.3
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• pp.377-385
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• 2002

In this paper, we concentrate on the uniquencess of the positive solution for the general elliptic system $\Delta$u+u($g_1$(u)-$g_2$(v))=0 $\Delta$u+u($h_1$(u)-$h_2$(v))=0 in$R_{+}$ $\times$ $\Omega$, $u\mid\partial\Omega = u\mid\partial\Omega = 0$. This system is the general model for the steady state of a competitive interacting system. The techniques used in this paper are upper-lower solutions, maximum principles and spectrum estimates. The arguments also rely on some detailed properties for the solution of logistic equations.

• Macromolecular Research
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• v.14 no.2
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• pp.220-229
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• 2006

Several equations of state for hard-sphere chains with various perturbation terms are reviewed. For each model, three characteristic parameters are required to represent phase equilibria of normal fluids and obtained from thermodynamic properties of pure saturated liquids. The models are then compared with computer simulation data to show the effect of attractive contribution forms employed. Calculated values of vapor-liquid equilibria (VLE) of hydrocarbons that can be reproduced for each model are also compared with experimental results. An additional parameter, ${\zeta}_{KB}$, is required to represent the VLE of pure water, which is ascertained to have a strong influence on the theoretical coexistence curve.

• Journal of the Korean Society for Library and Information Science
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• v.29
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• pp.173-204
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• 1995

The purpose of this study is to promote understanding of the book selection theory by researching dialectically of its development process centering on the BSTv(value theory) and BSTd(demand theory). The results of this study are summarized as follows 1. In the period of enlightenment and education, the book selection theory of public libraries was the thesis state of BSTv(d). 2. Antithesis state of BSTv(d), that is, BSTd was raised to real central theory of book selection in the early 20th century. 3. In the 1930-40's, BSTv and BSTd were transformed into balance state or coexistence relations(BSTb $[v(d){\cdot}d(v)$]. 4. After World War II, BSTn(library needs theory) and BSTo(library objective theory) were evoked, and opposed to the existing selection theories. Now, they are developing into BSTbl$[n(d)\cdot\;o(v)\;or\;n(d){\cdot}v(o)]$.

• Korean Journal of Mathematics
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• v.16 no.3
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• pp.259-269
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• 2008

The non-existence and existence of the positive solution for the generalized cooperation biological model for two species of animals $${\Delta}u+u(a-bu+g(v))=0\;in\;{\Omega}\\{\Delta}v+v(d+h(u)-cv)=0\;in\;{\Omega}\\u=v=0\;on\;{\partial}{\Omega}$$ are investigated. The techniques used in this paper are elliptic theory, upper-lower solutions, maximum principles and spectrum estimates. The arguments also rely on some detailed properties for the solution of logistic equations.