• Proceedings of the KSME Conference
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• 2001.11b
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• pp.646-651
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• 2001

The present study is an experimental work of the sonic/supersonic air ejector-diffuser system. The pressure-time dependence in the secondary chamber of this ejector system is measured to investigate the steady operation of the ejector system. Six different primary nozzles of two sonic nozzles, two supersonic nozzles, petal nozzle, and lobed nozzle are employed to drive the ejector system at the conditions of different operating pressure ratios. Static pressures on the ejector-diffuser walls are to analyze the complicated flows occurring inside the system. The volume of the secondary chamber is changed to investigate the effect on the steady operation. the results obtained show that the volume of the secondary chamber does not affect the steady operation of the ejector-diffuser system but the time-dependent pressure in the secondary chamber is a strong function of the volume of the secondary chamber.

• Journal of the Korean Society of Propulsion Engineers
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• v.5 no.4
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• pp.50-56
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• 2001

The present study is an experimental work of the soni $c^ersonic air ejector-diffuser system. The pressure-time dependence in the secondary chamber of this ejector system is measured to investigate the steady operation of the ejector system. Six different primary nozzles of two sonic nozzles, two supersonic nozzles, petal nozzle, and lobed nozzle are employed to drive the ejector system at the conditions of different operating pressure ratios. Static pressures on the ejector-diffuser walls are to analyze the complicated flows occurring inside the system. The volume of the secondary chamber is changed to investigate the effect on the steady operation. the results obtained show that the volume of the secondary chamber does not affect the steady operation of the ejector-diffuser system but the time-dependent pressure in the secondary chamber is a strong function of the volume of the secondary chamber.er.

• International Journal of Industrial Entomology and Biomaterials
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• v.25 no.1
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• pp.123-127
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• 2012

An experiment was carried out to boost the production of tasar crops through application of secondary nutrients. Different combinations of secondary nutrients were prepared and its effect was studied on the yield and quality of leaves of tasar food plant Terminalia tomentosa W & A with 2.4 m ${\times}$ 2.4 m spacing and cocoon characters of tasar silkworm Antheraea mylitta Drury reared on them. Among different combinations of secondary nutrients, foliar application of magnesium sulphate (2%, w/v) and basal application of 3 quintal/ha of calcium carbonate (secondary nutrient combination SM5) was found to be the best in crop improvement. It improves the quantity and quality of leaves as well as the commercial characters of cocoons. As a result, silk production improves. Under this combination, leaf yield increased by 26.55% in comparison to control. Average increase in moisture, total mineral, crude protein and total carbohydrate was 3.26%, 20.84%, 15.39% and 17.85% respectively as compared with control. Further, bio assay studies revealed that average larval weight, E.R.R., cocoon weight, shell weight and silk ratio percent increased by 11.25%, 25.71%, 20.05%, 35.14% and 12.17% respectively over control which indicates that secondary nutrient combination $SM_5$ has significant role in improving the production of tasar crops.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2008.11a
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• pp.497-502
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• 2008

In this paper, we studied on an attenuation effect of automobile exhaust noise according to the direction of secondary sound source in duct ANC system. Automobile exhaust noise was recorded at 800rpm. 3500rpm and 5000rpm of a diesel engine. Directions of loudspeaker(second sound source) can be exchanged to $30^{\circ}$, $90^{\circ}$ and $150^{\circ}$ against the primary noise flow by acrylic ducts to be made for experimentation. DSP board with TMS320C6416 chip of Texas Instrument Co used to control adaptive ANC system. This ANC system is based on the single-channel FxLMS algorithm. In experiment result, when the loud speaker direction was $150^{\circ}$, the attenuation effect showed largely. In case of $90^{\circ}$ duct, the noise was a little increased. In case of $30^{\circ}$ duct, the noise was a little increased or decreased according to the frequency range and the sound pressure(dB) of exhaust noise to comply with engine rpm.

• Journal of Korean Society of Water and Wastewater
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• v.30 no.4
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• pp.361-367
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• 2016

Pollutants removal and disinfection effect of secondary effluent from final settling tank of sewage treatment plant of W city were investigated in Loop Reactor using ordinary granular activated carbon(GAC) and GAC coated with silver nanoparticles. The results showed that the removal efficiency of $COD_{Mn}$, T-N and T-P using GAC with silver nanoparticles were higher than using the ordinary GAC. The removal efficiency of T-P using GAC with silver nanoparticles is 45.4% and that of T-P using ordinary GAC is 30.9% in the same case of the input amount of 20 g/L of GAC. The total califorms is reduced according to increasing input amount of GAC with silver nanoparticles and ordinary GAC. The disinfection efficiency of total coliforms in case of GAC with silver nanoparticles is much higher than that in case of ordinary GAC. For all experiments using the silver nanoparticles, the total coliforms is under 26 cfu/mL and this shows very excellent disinfection effect.

• 전기의세계
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• v.23 no.4
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• pp.39-45
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• 1974

In most previous research work, the transverse edge effect has been allowed for only by use of a relativity-increase factor. This paper gives a more exact treatment. A two-dimensional-field analysis is presented for the problem of sheet rotor linear induction motor with finite width the method used takes account of flux leakage in the space between the stator and secondary sheet rotor as well as in the secondary itself. Equations are derived for the flux density distribution in the air gap and for the starting face, in each case as a function of stator current. The cross gap flux density peaks towards athe edge of the stator. This phenomena is known as the transverse edge effect. Measurements of the flux density in the air gap and starting force on a linear induction motor with sheet rotor of different width showed a reasonable agreement,suggest that it would be desirable to take into account also, at least for this motor in which severe redistribution occurs.

• Journal of Advanced Information Technology and Convergence
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• v.9 no.2
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• pp.107-113
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• 2019

In this study, we examined the feasibility of considering the transverse edge effect of flat type linear induction motor as 2D finite element analysis (FEA) by changing the resistivity of secondary conductor. For this purpose, the 3D FEA analysis results were compared with the 2D FEA analysis results with the change of the resistivity of the secondary conductors. As a result, simply changing the resistivity could not accurately account for the transverse edge effect of LIM because of leakage components that could not be considered by 2D FEA.

• Journal of Fisheries and Marine Sciences Education
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• v.26 no.5
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• pp.1026-1036
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• 2014

The purpose of this research is to find the impact of multicultural awareness of pre-service secondary teachers on multicultural efficacy. Specific content of the study for achieving this purpose is as follows: First, the correlation between multicultural awareness of pre-service secondary teachers and multicultural efficacy was analyzed. Second, the effect relation between multicultural awareness of pre-service secondary teachers and multicultural efficacy was examined. As part of quantitative research, the method of study was a survey targeting 234 pre-service Secondary teachers who were sophomores, juniors and seniors at D University, P University and S University located in Busan. The study results earned from this process are as below: First, statistically significantly high positive correlation existed between multicultural awareness of pre-service secondary teachers and multicultural efficacy. The areas of acceptance, openness and respect, which are the sub-scale of multicultural awareness of pre-service secondary teachers, showed high positive correlations with all sub-scale of multicultural efficacy including general efficacy, efficacy in instructional function, efficacy in caring perspectives and efficacy in helping multicultural families. Second, the sub-scale of multicultural awareness that significantly affected general efficacy in the sub-scale of multicultural efficacy of pre-service secondary teachers was acceptance and respect. The sub-scale of multicultural awareness that significantly affected efficacy in instructional function was acceptance. The sub-scale of multicultural awareness that significantly affected efficacy in caring perspectives was acceptance and respect. The sub-scale of multicultural awareness that significantly affected efficacy in helping multicultural families was respect. It showed that openness in the sub-scale of multicultural awareness did not affect multicultural efficacy much.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.130-135
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• 2002

This study investigates the effect of curing method on the bonding strength of aluminum/CFRP composites. The surface of aluminum panel was treated by DC plasma. Lap shear tests and T-peel tests were performed based on the procedure of ASTM 906-94a and ASTMD1876-95, respectively. Test samples were fabricated by using the co-curing method and the secondary curing method. The results showed that the shear strength of test samples made by the co-curing method was 2.5 times greater than that of test samples made by the secondary curing method. The T-peel strength of the co-curing method case was almost 2 times greater than that of the secondary curing method case.

• Journal of information and communication convergence engineering
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• v.9 no.3
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• pp.251-255
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• 2011

In this paper, we investigate an adaptive cognitive radio (CR) scheme where a sensing duration and a detection threshold for spectrum sensing are adaptively determined according to the channel condition in a fading channel. We optimize the sensing duration and detection threshold of a secondary user to maximize the performance of the secondary user guaranteeing a primary user's secure communication. In addition, we analyze the effect of channel fading on the optimization of the sensing duration and detection threshold. Our numerical results show that the performance of the adaptive CR scheme can be drastically improved if a secondary user can take the advantage of channel information between primary and secondary users.