• Journal of the Korean Chemical Society
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• v.56 no.5
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• pp.548-555
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• 2012

Ultrasonic velocity and density measurements have been undertaken for a number of binary liquid mixtures involving different commercial solvent extractants, LIX reagents. The binary mixtures under investigation have been classified under two categories such as polar-polar, and polar-non-polar types. Different theories and relations such as Schaaff's Collision Factor Theory (CFT), Nomoto's relation (NOM), and Van Dael & Vangeel ideal mixing relation (IMR) have been used to evaluate the velocity theoretically for all these binary systems. The relative merits of afore-mentioned theories and relations compared to experimental values of velocity have been discussed in terms of percentage variations. However, the CFT and Nomoto's relation show better agreement with the experimental findings than the ideal mixing relation for all the systems under investigation.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.5 no.1
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• pp.35-43
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• 1993

A numerical model for the solidification of binary mixture is proposed. Numerical model, which employs enthalpy method, is modified from Continuum model, that is, improved relation is proposed for the Enthalpy - Temperature - Concentration - Liquid Mass Fraction. One dimensional example was selected to verify the proposed model. The results show that the new relation can be applied successfully to the solidification or melting of binary mixture.

• Journal of the Korean Institute of Intelligent Systems
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• v.19 no.4
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• pp.592-594
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• 2009

In this paper we consider voting analysis in the political science in connection with $B_n$(or $M_n${0, 1}), the semigroup of the binary relations on X with n elements. We also consider it in connection with $M_n$(F) (or $B_n$(F)), the semigroup of all fuzzy binary relations on X. Also we establish a possibility theorem and an impossibility theorem in voting analysis based on preferences in $B_n$ and $M_n$(F).

• Korean Chemical Engineering Research
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• v.55 no.5
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• pp.668-678
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• 2017

Intermolecular interactions were studied for binary mixtures of 2-propanol + cyclohexane, n-hexane, benzene, toluene, o-, m- and p-xylenes by measuring ultrasonic speeds (u) over the entire range of composition at 298.15 K and 308.15 K. From these results the deviation in ultrasonic speed was calculated. These results were fitted to the Redlich-Kister equation to derive the binary coefficients along with standard deviations between the experimental and calculated data. Acoustic parameters such as excess isentropic compressibility ($K_s^E$), intermolecular free length ($L_f$) and available volume ($V_a$) were also derived from ultrasonic speed data and Jacobson's free length theory. The ultrasonic speed data were correlated by Nomoto's relation, Van Dael's mixing relation, impedance dependence relation, and Schaaff's collision factor theory. Van Dael's relation gives the best prediction of u in the binary mixtures containing aliphatic hydrocarbons. The ultrasonic speed data and isentropic compressibility were further analyzed in terms of Jacobson's free length theory.

• Journal of Surface Science and Engineering
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• v.47 no.1
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• pp.48-52
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• 2014

Electric conductivities of $LaCl_3$-KCl binary melts have been measured by the Kohlausch bridge method over the range from their liquidus temperatures to about 1280 K. The electric conductivity increased with the content of KCl for all over the composition range of binary melts. The composition dependence of the electric conductivity and molar conductivity for the binary melt showed a non-linear relation from the additivity line, and the deviation showed a maximum value at about 60 mol.% KCl. The deviation implies the existence of complex ion of $LaCl^{4-}$ in the melt. Activation energy for electric conductivity of the binary melts decreased monotonously with increasing content of KCl.

• Journal of Surface Science and Engineering
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• v.39 no.6
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• pp.282-287
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• 2006

Viscosities of $LaCl_3-NaCl$ binary melts were measured by the capillary method over the range of their liquidus temperatures to about 1200K. The cell constant were determined by using pure water. The results obtained are summerized as follows: Viscosities were decreased with the content of NaCl for all over the composition range of binary melts. Composition - viscosity relation for the binary melts show a non-linear from the additivity line and the deviations shows a maximum at about 60 mol% NaCl. This suggests the existence of the complex ion of $LaCl_4^-$ in the melt. Activation energy for viscous flow of the binary melts decrease monotonously with the increasing content of NaCl.

• Journal of Surface Science and Engineering
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• v.37 no.5
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• pp.301-306
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• 2004

Electric Conductivities of $LaCl_3$-LiCl binary melts have been measured by the Kohlausch bridge method over the range of their liquidus temperatures to about 1200 K. The electric conductivity increases with the content of LiCl for all over the composition range of binary melts. Composition dependence of the electric conductivity and molar conductivity for the binary melt shows a non-linear relation from the additivity line, and the deviations displays a maximum value at about 60 mol % LiCl. This suggest the existence of the complex ion of$ LaCl_{4}^{-}$ in the melt. Activation energy for electric conductivity of the binary melts decrease monotonously with increasing content of LiCl.l.

• Journal of Surface Science and Engineering
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• v.46 no.2
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• pp.87-92
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• 2013

Viscosities of $LaCl_3$-CsCl binary melts were measured by the capillary method over the range of their liquidus temperatures to about 1200 K. The cell constant were determined by using pure water. The results obtained are summerized as follows: Viscosities of melted $LaCl_3$ were decreased with the content of CsCl for all over the composition range of binary melts. Composition versus viscosity relation for the binary melt showed a non-linear relationship from the additivity line and the deviations showed a maximum value at about 60 mol% CsCl. This suggest the existence of the complex ion of $LaCl_4{^-}$ in the melt. Activation energy for the viscous flow of the binary melts decreased monotonously with the increasing content of CsCl after a few increasement till 40 mol% CsCl. All of these results were the resemble with the viscosities of $LaCl_3$-NaCl binary melts.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.20 no.4
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• pp.1437-1448
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• 1996

This paper presents a simplified model for approximate analysis of the solute redistribution in coarsening dendrite arms during solidification of binary metal alloys. By introducing a quadratic concentration profile with a time-dependent coefficient, the integral equation for diffusion in the solid phase is reduced to a simple differential relation between the coefficient and the solid-liquid interface position. The solid fraction corresponding to the system temperature is readily determined from the relation, phase equilibrium and the overall solute balance in which the liquid phase is assumed to be completely mixed. In order to validate the developed model, calculations are performed for the directional solidification of Al-4.9 mass Cu alloy. The predicted eutectic fractions for a wide range of the cooling rate reasonably agree with data from the well-known experiment as well as sophisticated numerical analyses. Also, the results for the back diffusion limits are consistent with available references. Additional calculations show that the characteristic parameters such as the coarsening, density variation and nonlinarity in the phase diagram significantly affect the microsegregation. Owing to the simplicity, efficiency and compatibility, the present model may be suitable for the micro-macroscopic solidification model as a microscopic component.

• Annual Conference of KIPS
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• 2006.05a
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• pp.81-84
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• 2006

유비쿼터스 컴퓨팅 환경으로 발전하면서 문자열 위주의 획일적 형태에서 음성, 이미지 등 다양한 형태의 데이터들을 처리하게 되었으며, 또한 빠르고 정확하게 처리되기를 요구하고 있다. 현재 데이터 처리 중심부에 있는 Database는 대부분이 Relation DB 위주로 되어 있어 Datafile 에 데이터를 저장하고 있어 대용량의 이미지 데이터 처리에 적합하지가 않다. 본 논문에서는 이러한 단점을 보강하기 위해 Relation DB 하에서 대용량의 이미지 데이터 처리를 가능하게 하는 기법을 제시한다. 이렇게 함으로써 이미지 데이터를 Upload, Download 시 따른 응답 속도를 보장 할 수 있도록 LRU 알고리즘 기반으로 제안을 하였다. 본 논문에서 제안된 기법은 시뮬레이션을 통해 (1)기존 RDB(Relational Database)의 BLOB(Binary Large Object)필드를 이용한 이미지 데이터 처리 방식, (2)별도의 저장 공간에 이미지 데이터를 입/출하는 방식, (3)별도의 저장 공간에 이미지 데이터를 입/출력할 때 LRU(least Recently Used)알고리즘을 이용하는 방식에 대하여 성능 평가를 하였다. 그 결과 (3)별도의 저장 공간에 LRU(least Recently Used)알고리즘을 이용하여 입/출력하는 방식이 (1)기존의 RDB(Relational Database)형태에 BLOB(binary large object)필드를 이용한 것 보다 성능이 높음을 확인하였다.