• Proceedings of the Materials Research Society of Korea Conference
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• 1998.11a
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• pp.125-125
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• 1998

No Abstract.see full/text

• Bulletin of the Korean Chemical Society
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• v.15 no.4
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• pp.267-268
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• 1994

• 제어로봇시스템학회:학술대회논문집
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• 1993.10b
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• pp.30-35
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• 1993

Simple recurrence relations for calculating completion times of various storage polices (unlimited, intermediate storages(FIS), finite intermediate storages(FIS), no intermediate storage(NIS), zero wait(ZW) for serial multi-product multi-unit processes are suggested. Not only processing times but also transfer times, set-up (clean-up) times of units and set-up times of storages are considered. Optimal scheduling strategies with zero transfer times and zero set-up times had been developed as a mixed integer linear programniing(MILP) formulation for several intermediate storage policies. In this paper those with non-zero transfer times, non-zero set-up times of units and set-up times of storages are newly proposed as a mixed integer nonlinear programming(MINLP) formulation for various storage polices (UIS, NIS, FIS, and ZW). Several examples are tested to evaluate the robustness of this strategy and reasonable computation times.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.10a
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• pp.58-58
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• 1993

Pervaporation has become important as a method to separate liquid mixtures, sepecially azeotropic and close boiling-point mixtures. Especially, water-alcohol separations have been carried out a lot because of the practical interests in the industries. However, outstanding membranes with high selectivity and high permeability have not been available in common use yet. In order to separate selectively out the water mixed with alcohols with an aim of the purification of the alcohols, a membrane has tO have excellent affinity to water. Among the hydrophilic polymers, polyacrylic acid and poly(vinyl alcohol) are used widely. In recent years, ionomers and polyion complexes, better hydrophitic materials, start to be used. The polyion complex membranes, consisting of polyacrylic acid (PAA) and polycation, showed excellent permeation rates and selectivities. It was known that among the polycations, ioneries, which have quaternary ammonium groups in the backbone chain, were more effective in giving membranes of higher permselectivities. On this base, syntheses and characterizations of the polycations, with different chemical structures from the published ones, for the polyion complex membrane formation were studied in this paper.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.4
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• pp.284-288
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• 2001

Lipid emulsions with saturated triacylglycerols (TAGs) with 4 to 10 carbons in each acyl chain were prepared to study how the oil component alters the stability of the lipid emul-sions when phosphatidylcholines were used as emulsifiers. The average droplet size of the emul-sions became smaller as the chain length of the TAG increased. For a given oil emulsion with smaller droplets was formed with an emulsifier having higher HLB value. The influence of HLB values on the droplet size was biggest for the tributyrin (C4) emulsion. For the tricaprylin(C8) emulsions, droplet size was identical at given emulsifier concentrations regardless of HLB values. The HLB value and the concentration of the emulsifiers also affect the droplet size of the emul-sions. The emulsions with smaller average droplet size were more stable than with bigger size for 20 days. The oil and water (o/w) interfacial tension in inversely proportional to the initial droplet size of the emulsion.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10b
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• pp.106-111
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• 1992

In order to achieve stable and efficient use of energy at iron and steel works, a model for the prediction of supply and demand of electric power system is developed on the basis of the information on operation and particular patterns of electric power consumption. The optimal amount of electric power to be purchased and the optimal fuel allocation for the in-house electric power plants are also obtained by a mixed-integer linear programming(MILP) and a nonlinear programming (NLP) solutions, respectively. The validity and the effectiveness of the proposed model are investigated by several illustrative examples. The simulation results show the satisfactory energy saving by the optimal solution obtained through this research.

• 제어로봇시스템학회:학술대회논문집
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• 1989.10a
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• pp.1035-1040
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• 1989

This paper describes first Boxes algorithm as a good method to generate the pulse patterns for a pulse width modulated inverter which has a good characteristics and simple to excute. Second we present the motor analysis fed by P.W.M. inverter in steady-state operation. In this analysis we improve the MRF ( Multiple Reference Frames ) to can be easy apply to analyse all the induction motor parameters. Finally we presented all the results obtained for a 3-phase induction motor.

• Bulletin of the Korean Mathematical Society
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• v.60 no.5
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• pp.1281-1293
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• 2023

The purpose of this paper is to study the relationship between the structure of a factor ring R/P and the behavior of some derivations of R. More precisely, we establish a connection between the commutativity of R/P and derivations of R satisfying specific identities involving the prime ideal P. Moreover, we provide an example to show that our results cannot be extended to semi-prime ideals.

• Korean Journal of Plant Resources
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• v.12 no.3
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• pp.179-185
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• 1999

The study which was conducted to determine the effects of the polyethylene film on the culture of Pleurotus ostreatus is summarized in the following: 1) The fresh weight of Pleurotus ostreatus cultured by the box culture method mulching with black polyethylene film was 2,237g/box and, 2,028g/box by white polyethylene film mulching, and 1,695g/box at the conventional culture which was by 24.2% and 16.4% higher than that of the conventional culture.2) The fresh weight of P. ostreatus cultured by the shelf culture method mulching with the black polyethylene film was 17.4kg/m$^2$ at the white polyethylene film culture, 14.6kg/m$^2$ at the conventional culture which was by 16.2%, 7.5% higher than that of the conventional culture. 3) The best shape appearance in terms of the diameter in P. ostreatus was 5~30mm and the intervals were 10cm respectively. 4) The black polyethylene film mulching in P. ostreatus observed in good protection against Pseudomonas spp., Trichoderma, or mushroom flies. 5) The black polyethylene film mulching method for the culture of P. ostreatus was much better than that of the shelf-culture, box-culture or the sack culture in terms of total yield and quality. 6) The length of harvesting implement of P. ostreatus was suitable for 45~120cm in order to use on the harvest of the mulching.

• Magazine of the Korea Concrete Institute
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• v.10 no.6
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• pp.61-65
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• 1998