• Journal of the Earthquake Engineering Society of Korea
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• v.11 no.2 s.54
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• pp.11-17
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• 2007

In current seismic design practice, the response modification factor (R-factor) is used as a factor to reduce the elastic base shear demand to the design force level. As is well-known, the R-factor is a committee-consensus factor and, as such, highly qualitative and empirical. The relationship between the R-factor and the connection rotation capacity available in a particular structural system has remained a missing link. In this paper, a rational procedure to evaluate the R-factor is proposed. To this end, the relationship between the available connection rotation capacity and the R-factor is defined and quantified using nonlinear pushover analysis. An RRS steel frame designed according to IBC 2000 was used to illustrate and verify the proposed procedure. Nonlinear time history analysis results indicated that the R-factor definition proposed in this study is generally conservative from design perspective.

• The Journal of the Convergence on Culture Technology
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• v.5 no.2
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• pp.83-91
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• 2019

The purpose of this study was to investigate the relationship among the variables and the influence of premenstrual syndrome and stress response on the learning flow of nursing students. Method : The participants were 162 nursing students in K city, who were surveyed between June 1 and June 10, 2018, using self-report questionnaire. Result: There were positive correlation between premenstrual syndrome of participants and stress response(r=.389, p<.001). There were negative correlation between premenstrual syndrome and learning flow(r=-1.93, p<.014), between stress response and learning flow(r=-.216 p<.001). The variables for learning flow where stress response(${\beta}=-.314$, p<.001) and Psychological change of menstruation(${\beta}=-.358$, p<.001), with a coefficient of determination($R^2$) of 30.3%. The result of this study will be useful in preparing basic date for improvement of the learning flow of the nursing students and it will be necessary to develop educational programs and strategies related with the premenstrual syndrome and stress response disposition.

• Journal of Applied Biological Chemistry
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• v.54 no.1
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• pp.56-62
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• 2011

Molecular docking of polyhydroxy substituted flavone analogues (1-25) as substrate molecules to the active site of tyrosinase (PDB ID: Deoxy-form (2ZMX) & Oxy-form (1WX2)) and Free-Wilson analysis were studied to understand the roles of hydroxyl substituents ($R_1-R_9$) in substrate molecules for the tyrosinase inhibitory activation. It is founded from Free-Wilson analysis that the $R_1$=hydroxyl among $R_1-R_9$ substituents had the strongest influence on the tyrosinase inhibitory activity. H-bonds between the hydroxyl substituents of substrate molecules and amino acid residues in the active site of tyrosinase were contributed to make a stable substrate-receptor complex compound. Particularly, it is proposed from the findings that the noncompetitive inhibitory activation would take place via H-bonding between peroxide oxygen (Per404) atom in the active site of tyrosinase and the hydroxyl substituents in substrate molecule.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.11
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• pp.1935-1944
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• 2000

This research was performed to investigate the effects of the location of recirculation port on the wastewater treatment efficiency of an anaerobic hybrid reactor consisted of a fluidized bed and a packed bed. The recirculation port was located either at the top of the packed bed (Reactor 2) or above the fluidized bed (Reactor 1). Media for the fluidized bed and the packed bed were granular activated carbon and Pall ring-type plastic media. respectively. At organic loading rates(OLR) up to $6.2kg\;COD/m^3-day$. Reactor 2 showed somewhat better performance than Reactor 1 with COD removal efficiencies of 85.0-95.2%. The COD removal efficiencies of the reactors drastically deteriorated at OLRs above $6.2kg\;COD/m^3-day$, and the tendency was more severe for Reactor 1 than for Reactor 2. Eventhough the two reactors showed similar effluent SS concentrations at OLRs below $3.6kg\;COD/m^3-day$, Reactor 2 showed higher effluent SS concentrations than Reactor 1 at OLRs above $5.3kg\;COD/m^3-day$. Reactor 2 was stabler than Reactor 1 with a methane production rate of $5.5kg\;COD/m^3$-day at the OLR of $13.3kg\;COD/m^3-day$. An abrupt increase in effluent volatile acid concentration was observed at the OLR of $6.2kg\;COD/m^3-day$ for Reactor 1 and $7.1kg\;COD/m^3-day$ for Reactor 2. and the increase was greater in Reactor 1. In conclusion. the range of OLR for adequate treatment in the hybrid reactor was determined according to the location of the internal recirculation port. It is more desirable for higher OLRs to locate the recirculation port at the top of the packed bed in order to utilize the whole volume of the reactor.

• Applied Chemistry for Engineering
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• v.8 no.3
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• pp.347-356
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• 1997

Solution copolymerization of Styrene(St) and n-Butylmethacrylate(BMA) was carried out with Benzoylperoxide (BPO) as an initiator in toluene at $80^{\circ}C$ in a continuous stirred tank reactor. Reaction volume and residence time were 0.6 liters, 3 hours respectively. The monomer reactivity ratios, $r_1$(St) and $r_2$(BMA) were determined by both the Kelen-Tlidos method and the Fineman-Ross method ; $r_1$=0.75(0.67), $r_2$=0.61(0.56). The cross-termination factor, $\phi$ factor of the copolymer over the entire St compositions ranged from 0.44 to 0.78. The $\phi$ factors of St-BMA copolymer increased with increasing St compositions. Our present system showed that the continuous copolymerization of St with BMA followed second-order kinetic behavior. The simulated conversions and copolymerization rates were compared with the experimental results. The average time to reach dynamic steady-state was three times and half of the residence time.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.752-755
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• 2008

Mesoporous SBA-15 silica-supported TsCHDA and TsDPEN ligands have been prepared by reaction of SBA-15 silica with (1R,2R)-N-(trimethoxysilylpropyl-N-sulfonyl)-1,2-cyclohaxanediamine or (1R,2R)-N-(trimethoxysilylpropyl-N-sulfonyl)-1,2-diphenylethylenediamine-1,2-diphenylethylenediamine, respectively. The Ru complexes exhibited excellent catalytic activity and satisfactory enantioselectivity in the asymmetric hydrogen transfer of ketones under microwave conditions. The heterogeneous Ru catalyst was reusable as well as air-stable to allow easy use. Microwave-assisted efficient procedure has been developed for asymmetric hydrogen transfer.

• Korean Journal of Cognitive Science
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• v.5 no.2
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• pp.25-45
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• 1994

The presnt study investigated the effect of stimulus-response compatibility (S-R compatibility) on Hangul transcription typing. In this experiment, two condition were manipulated, the first was a low S-R compatibility condition in which consonants were typed with left hand and vowels with right hand; the second was a high S-R compatibility condition in which hands for consonants and vowels were reversed. Subjects were requested to type the letter presented on the screen as accurately and immediately as possible. It was found that the compatibility interacted with the vowel shape. That is, in the high S-R compatibility condition, the response time was shorter when letters of vertically- shaped vowel were typed than when those of horizontally-shaped vowel were typed. In the low S-R compatibility codition, however, the response time was shorter for letters of horizontally-shaped vowel than for those of vertically-shaped vowel.

• Applied Chemistry for Engineering
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• v.10 no.6
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• pp.863-870
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• 1999

The catalytic performance of Co-Mn-Br system was performed in the 2,6-dimethylnaphthalene(DMN) oxidation at relatively mild reaction conditions such as $160^{\circ}C$ and $6kg/cm^2$. Experiments were conducted using a $2{\ell}$ batch reactor with varying the concentrations of catalysts. The reaction route of DMN oxidation was considered by measuring the concentration of intermediate species. As the intermediate species, 2-formyl-6-naphthoic acid, 2-methyl-6-naphthoic acid and 2-hydroxymethyl-6-methylnaphthalene are found. It was found that the yield of 2,6-naphthalene dicarboxylic acid(NDA) is largely dependent on the Co and Br concentrations. In addition, it was observed that color-b was closely related with Mn concentration in this experimental range. The burning loss of solvent could be reduced by controlling the concentration of Mn and Br. Addition of small amount of Ce and Cu compounds led to increase the NDA yields and decrease the burning amount of solvent.

• Journal of the Korean Institute of Gas
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• v.2 no.3
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• pp.60-69
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• 1998

Methane, the major constituent of natural gas, had been converted to higher hydrocarbons by microwave and radio-frequency plasma in vacuum condition. Methane had been activated to plasma by suppling high energy then converted to ethane, ethylene, acetylene. The direct conversion process of methane had produced few by-products and demanded low-energy. The plasma sources were microwave and radio-frequency. Two types of reactor had been used to activate methane. One is common single tubular-type reactor and the other is series coil-type reactor which used for the first time in this study. To produce more C2 products, methane had been converted by a plasma and catalyst. The results of this study could be used to study mechanism of plasma reaction of methane, design the plant-scale reactor.

• Korean Journal of Food Science and Technology
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• v.46 no.3
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• pp.315-322
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• 2014

Immobilized lipases were prepared by physical adsorption using lipase AK, AY, AH, PS and R on Amberlite$^{(R)}$XAD$^{(R)}$7 HP resin. With the immobilized lipases (10%), structured lipid was synthesized by enzymatic interesterification of canola oil, palmitic ethyl ester, and stearic ethyl ester in order to study the reaction characteristics. Among the lipase, the highest protein content was obtained from lipase AH (11.41%) before immobilization, while the highest levels of bound protein was observed from immobilized lipase AK (63.91%). Immobilized lipase AK had the highest interesterification activity (38.3% of total saturated fatty acid). Lipase AK was also used for a continuous reaction in which the slow flow of reactant resulted in increased reaction rate. Reusability of immobilized AK, AH and PS increased at the second reaction (120-196.5%). However, the activity of immobilized AK, which had the highest bound protein content (63.91%) decreased after the third reaction, while the activity of immobilized AH and PS was maintained until the sixth reaction.