• Journal of Power System Engineering
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• v.14 no.5
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• pp.10-16
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• 2010

The main object of this study is to investigate the collection characteristics of multi-layer multi-stage porous plate system experimentally. The experiment is carried out to analyze the characteristics of pressure drop and collection efficiency for the present system with the experimental parameters such as inlet velocity, tube diameter, inlet concentration, and stage number, etc. In results, the pressure drop becomes 22 to $115mmH_2O$ with increment of stage number (1 to 5) of porous plate system at tube velocity 15 m/s and tube diameter ${\Phi}8$. In case of fly ash and 5 stage, the collection efficiency becomes 90.5 to 95.7% increasing the tube velocity 12 to 15 m/s at inlet concentration $3g/m^3$ and tube diameter ${\Phi}8$. Additionally, it is estimated that the collection efficiencies of 5 stage are 94.3, 95.6 and 99.1% for fly ash, steel dust and based power, respectively (${\Phi}8$ tube, $V_t$ = 12m/s, inlet concentration $3g/m^3$).

• Journal of the Korean Magnetics Society
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• v.11 no.1
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• pp.38-44
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• 2001

The magnetic field standard below 1 mT with the resolution of 0.26 nT has been established. Earth magnetic field (EMF) is compensated automatically down to 0.1 nT/10 min. by a closed feedback system with Cs optical pumping magnetometer and 3-axis Helmholtz coils in nonmagnetic facilities. A multi-layer precision solenoid with the optimized single-current method generates the uniform magnetic field better than 1.0$\times$10$\^$-7/ within $\pm$ 1 cm region at its center. The coil constant of solenoid determined from Helium optical pumping magnetometer is 1.231 058 9 mT/A, and temperature coefficient is 0.38 nT/$\^{C}$. This standard system is used for calibration of low field magnetometers and testing relates to low field.

• The KIPS Transactions:PartC
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• v.18C no.1
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• pp.1-6
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• 2011

The performance and practicality of cryptosystem for encryption, decryption, and primality test is primarily determined by the implementation efficiency of the modular exponentiation of $a^b$(mod n). To compute $a^b$(mod n), the standard binary squaring still seems to be the best choice. But, the d-ary, (d=2,3,4,5,6) method is more efficient in large b bits. This paper suggests m-numeral system modular exponentiation. This method can be apply to$b{\equiv}0$(mod m), $2{\leq}m{\leq}16$. And, also suggests the another method that is exit the algorithm in the case of the result is 1 or a.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.1
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• pp.142-146
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• 1993

The vibrations of the main spindle of the M/C tools are most important in the consideration of the dymamic performance of the M/C tools. In order to resolve and predict the dynamic behaviour of the main syindle it is necessary to have the mathematical model of the system. The system identification is the procedure to provide us with the mathematical model of the procedure of the system identification of the main spindle of the M/C tools to predict the dynamic behaviour of the machine and further to have the basis for the design of M/C tools.

• Journal of the Korean Ceramic Society
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• v.23 no.5
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• pp.25-34
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• 1986

This study was to refined the crystal structure of solid solution to determine the position and amount of Al in diopside and to relate crystal structure changes and properties of solid solution. Single crystals of the solid solution in the system CaO.MgO.$2 SiO_2-Al_2O_3$ were made from the melt with slow cooling and used to refine the structure. The following were obtained. 1. Tetrahedra rotated around axis parallel to the direction which the angle 03-03-03 became small. 2. Tetrahedron became large and regular. Average T-O bond distance increased 0.53 percent. 3. M1 octahedron became small and average M1-O bond distance decreased 1.1 percent. 4, M2 polyhedron became small and average M2-O bond distance decreased 0.37 percent Polythedron was affected not so much compared with any cation site. 5. Distance between metal ions distances between T and oxygens which were coordinated with M2 and meighboring tetrahedron distances between M2 and oxygens which coordinated with M1 and M2 were not changed almost. 6. $Al^{3+}$ substituted 4Mg^{2+}$ and $Si^{4+}$

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.231-232
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• 2015

R Canis Majoris is a bright, short-period ($1^d$.1359) Algol-type eclipsing binary. For a long time, it was considered to be a low-mass binary star with $M_1=1.1M_{\odot}$ and $M_2=0.17M_{\odot}$ primary and secondary components, respectively (Tomkin, 1985). Glazunova, Yushchenko & Mkrtichian (2009) found new masses for the primary and secondary components of $M_1=1.81M_{\odot}$ and $M_2=0.23M_{\odot}$, respectively and resolved a long-standing problem with the low masses of components for this binary. Budding and Butland (2011) confirmed the results of Glazunova, Yushchenko & Mkrtichian and obtained improved orbits and masses. New spectroscopic observations of R CMa were done during 8 nights on December 2012 with the 2.4-meter telescope of the Thai National Observatory (TNO) and fibre-fed medium resolution echelle spectrograph. We obtained new, accurate orbital radial velocities of the two components of this binary system. Results of these investigations and the new orbital parameters are presented.

• Journal of Bio-Environment Control
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• v.16 no.3
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• pp.199-204
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• 2007

This experiment was conducted to investigate the effect of nutrient solution strength on the growth of miniature multiflora P. amabilis and P. Taisuco Red Jewel at two growth stages during four months cultivation in an ebb and flow system. Early stage plants gained the biggest leaf length and width when nutrient solution strength was EC 0.5 or $1.0dS{\cdot}m^{-1}$ in P. amabilis, and EC $1.5dS{\cdot}m^{-1}$ in P. Taisuco Red Jewel. Root length and weight were the greatest when nutrient solution strength was EC $0.5dS{\cdot}m^{-1}$ in both cultivars and this trend was also found in middle stage plants. Fresh and dry weights of leaves increased as nutrient solution strength was elevated and were the greatest when nutrient solution strength was EC $1.5dS{\cdot}m^{-1}$ in P. amabilis. On the contrary elevation of nutrient solution strength decreased fresh weight of roots, being the greatest when nutrient solution strength was EC $0.5dS{\cdot}m^{-1}$. This trend was also found in P. Taisuco Red Jewel and P. amabilis at middle growth stage. The T/R ratio and chlorophyll content increased with nutrient solution strength and were the greatest regardless of cultivar and growth stage when nutrient strength was EC $1.5dS{\cdot}m^{-1}$.

• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.5
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• pp.97-108
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• 1997

Natural wastewater treatment systems using the constructed wetland system were evaluated for the wastewater from the industrial complex in rural areas. For the treatment of wastewater from the industrial complex in rural area, a pilot plant of the constructed wetland system was installed at Baeksuk agri-industrial complex in ChunahnCity, Chunchungnam-Do. The experiment with this pilot plants was performed for 1996 and 1997. Results of the study were summarized as follows. For the BOD and COD, when the pollutant loading of them was about 1 3.8g/$m^2$. day (the concentration was l24.0mg/${\ell}$) arid 24.4g/$m^2$.day(the concentration was 220.Omg/${\ell}$), the removal rate of them was high, 90.2% and 93.4%, respectively. For the SS, the effluent concentration was consistently lower than the water quality standard even though the influent concentration varied significantly, which showed that SS was removed by the system effectively which consist of soil and plants. For the T-N and T-P, when the influent pollutant loading of them were moderately high, 2.8g/$m^2$.day to 7.4g/$m^2$. day(concentration 25.0mg/${\ell}$ to 49.7mg/${\ell}$) for T-N and 1.0g/$m^2$.day to 2.6g /$m^2$.day(concentration 8.6mg/${\ell}$ to 14.7mg/${\ell}$) for T-P, the removal rate of them were 86.5% and 94.0%, respectively. The removal rate by the flow distance increased rapidly in the first 4m from the inlet zone, and gradually there after. The width of system was 2m. Overall, the result showed that constructed wetland system is a feasible alternative for the treatment of wastewater from industrial complex in rural areas. Compared to existing systems, this system is quite competitive because it requires low capital cost, almost no energy and maintenance, and therefore, very cost effective.

• Fisheries and Aquatic Sciences
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• v.13 no.2
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• pp.150-156
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• 2010

The separation performance of a low-pressure hydrocyclone (LPH) was evaluated for suspended-solids removal in a recirculating aquaculture system (RAS). The dimensions of the LPH were 335 mm cylinder diameter, 575 mm cylinder height, 60 mm overflow diameter, 50 mm underflow diameter, and $68^{\circ}$ cone angle. The inflow rate varied (400, 600, 800, and 1,000 mL $s^{-1}$) with 25%, 25%, 20%, and 10% of bypass ($R_f$), respectively. The maximum total separation efficiency (Et) and reduced separation efficiency (E't) for suspended solids from the effluent of the second settlement tank (before biofiltration) were 58.9% and 45.2%, respectively, at an inflow rate of 600 mL $s^{-1}$ and 25% of $R_f$. The maximum Et and E't for suspended solids from the water supply channel (after biofiltration) were 24.4% and 16%, respectively, at an inflow rate of 1,000 mL $s^{-1}$ and 10% of $R_f$. The maximum grade efficiency (Ei) was 51.6% for a 300 ${\mu}m$ particle size at an inflow rate of 600 mL $s^{-1}$ with 23% of $R_f$. The maximum reduced grade efficiency (E'i) was 37.6% for a 300 ${\mu}m$ particle size at an inflow rate of 1,000 mL $s^{-1}$ with 11% of $R_f$. The results indicate that the separation performance of the LPH for suspended solids removal was size selective and that maximum removal occurred at particle sizes ranging from 300 to 500 ${\mu}m$.

• Korean Journal of Materials Research
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• v.5 no.1
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• pp.96-103
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• 1995

This art~cle reports on the formation of T - Gate with O.1$\mu$m foot and 0.4$\mu$m head width at PMMA/P( MMA/MAA) resist structure using a 30KV electron beam lithography system. From the result of Monte Carlo simulation on PMMA/P( MMA/MAA)/GaAs, we obtain the dissipation energy ratio of forwardscattered electron and backscattered electron within 0.1$\mu$m scattering radius is 19.5 : 1 0.1$\mu$m T - gate has been formed with 30KV gaussian electron beam at a 440$\mu C/\textrm{cm}^2$ dosage. The gamma value of PMMA and P(MMA/MAA) at MIBK : IPA=l : 1 developer was 2.3. The overlay accuracy(3$\sigma$) from mix-andmatch of optical stepper and Ekeam lithography system for fabricating HEMT device is accomplished below 0.1$\mu$m.