• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
• /
• v.15 no.4
• /
• pp.356-361
• /
• 1986

An optimum design condition for a basic refrigeration cycle is defined as the condition which minimizes the total cost of heat exchanges (condenser and evaporator) and compressor for the refrigeration effect. Thermodynamic properties of ammonia (R717) are approximated by rational functions in order to obtain the optimum condition for a basic refrigeration cycle. Optimum condition depends on the heat capacity rates (mass flow rate times specific heat) of cooling water and brine used in condenser and evaporator. The difference between the cooling water temperature and condensation temperature at the optimum condition increases as the heat capacity rates and the coat of heat exchangers relative to the cost of compressor increase. Numerical examples of optimum conditions are obtained when the condensation temperature is $30^{\circ}C$ and the evaporator temperature is $-10^{\circ}C$.

• Applied Microscopy
• /
• v.39 no.1
• /
• pp.73-77
• /
• 2009

Contaminative artifacts such as carbonaceous materials on carbon-coated microgrids are unavoidable, which is induced by electron beam exposure inside electron microscopes. This phenomenon raise a source to produce confusing information to the samples investigated by analytical TEM, which should be alleviated as much as possible. As experimental precautions for reducing this unwanted effect, the use of $LN_2$ cooled anti-contaminator and pre-illumination of electron beam at low magnification can be helpful. Nevertheless, we should be cautious to set an illumination condition for microanalysis because the contaminative effect is dependent with the types of irradiation situations, which is well known to be a decisive factor for causing the carbonaceous artifacts. Accordingly, it is necessary that optimal illumination to minimize the contaminative effect should be selected for improving the accuracy of microanalysis. In this paper, we introduce the practical method to determine the optimal illumination condition by evaluating the contaminative effect as a function of instrumental spot size, which is directly linked with electron current density.

• Journal of applied mathematics & informatics
• /
• v.26 no.1_2
• /
• pp.395-400
• /
• 2008

Although the properties of flatness and condition (E) for Sacts over a monoid S are incomparable, Liu([10]) showed that necessary and sufficient condition for a monoid S over which all left S-acts that satisfy condition (E) are flat is the regularity of S. But the problem of describing a monoid over which all cyclic flat left S-acts satisfy condition (E) is still open. Thus the purpose of this paper is to characterize monoids over which all cyclic flat right S-acts satisfy condition (E).

• Preventive Nutrition and Food Science
• /
• v.7 no.1
• /
• pp.52-56
• /
• 2002

This study was conducted to evaluate the possibility of gamma radiation for reducing egg allergies through the observation of conformational and allergenic changes of egg ovomucoid (OM) in basic pH conditions. An OM solution of 2.0 mg/mL was individually prepared with different pH conditions, pH 7.0, 9.0 or 10.0, and was irradiated with the absorbed dose of 10 kGy. Irradiated OM solutions were tested by Ci-ELISA formatted with egg-hypersensitive patients'IgE. Binding abilities of IgE to OM in irradiated solution decreased with the increase of pH. Turbidity of the solution highly increased by irradiation and the increase of pH. A yellowish color was observed in the irradiated OM solution of basic condition. Coagulation of OM by irradiation decreased with the increase of pH, when observed by SDS-PAGE.

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2006.05a
• /
• pp.419-420
• /
• 2006

• Proceedings of the Korean Society of Potoscience Conference
• /
• 2005.06a
• /
• pp.113-113
• /
• 2005

• Journal of the Optical Society of Korea
• /
• v.9 no.2
• /
• pp.39-44
• /
• 2005

Unlike for the bound states, several different boundary conditions are used for the continuum states above the barrier in semiconductor quantum wells. We employed three boundary conditions, infinite potential barrier boundary condition, periodic boundary condition and scattering boundary condition, and calculated the local number of states, wavefunctions and optical matrix elements for the symmetric and asymmetric quantum wells. We discussed how these quantities are related in the three boundary conditions. We argue that the scattering boundary condition has several advantages over the other two cases. These results would be useful in understanding quantum well lasers and detectors involving continuum states.

• Proceedings of the KSR Conference
• /
• 2000.05a
• /
• pp.589-597
• /
• 2000

This paper deals with the basic design of the traction motor(TM) by performing the train performance simulation(TPS). The TPS, considering min condition, provides some important information about selecting the latins of TM such as current, power and frequency, etc. Especially, calculating the current flowing into the TM by the TPS in the situation of normal condition and M-car cut out respectively, we can inspect whether the TM endures thermally under the contingency or not. This paper reviews the tractive effort of the train to meet the demands of consumer and then designs the TM electrically. finally, performing the TPS under emergency condition, it checks the thermal capacity of the TM to insure the justice of the TM under construction.

• Nonlinear Functional Analysis and Applications
• /
• v.28 no.2
• /
• pp.337-363
• /
• 2023

In this paper, we propose a new subgradient extragradient algorithm for finding a solution of monotone bilevel equilibrium problem in reflexive Banach spaces. The strong convergence of the algorithm is established under monotone assumptions of the cost bifunctions with Bregman Lipschitz-type continuous condition. Finally, a numerical experiments is reported to illustrate the efficiency of the proposed algorithm.

• Korean Journal of Mathematics
• /
• v.6 no.1
• /
• pp.17-26
• /
• 1998

In this paper, we briefly study the condition number of stiffness matrix with $h$-version and analyze it with $p$-version of the finite element method.