• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.396-398
• /
• 2005

IEC 60287-3-2 standards suggests the selection method of economic conductor size for power cables. This method deals solely with the economic choice of conductor size based on joule losses. This paper introduces the method and example study which is proposed by IEC standards.

• Journal of Korean Society of Environmental Engineers
• /
• v.38 no.4
• /
• pp.169-176
• /
• 2016

This research explored the feasibility of preparing and utilizing preformed polymeric solution of Fe(III) as coagulants for water treatment. The differentiation and quantification of hydrolytic Fe(III) species in coagulant was done by utilizing spectrophotometric method based on the interaction of Fe(III) with Ferron as a complexing agent. The properties of the synthesized polymeric iron chloride (PICl) showed that the quantity of polymeric Fe(III) produced at r = 1.5 was 20% of the total iron in solution, as showing maximum contents. Coagulation experiments were conducted under the condition of various coagulant doses and pH for each coagulant prepared. From the comparison of the characterization of coagulation for $FeCl_3$ (r = 0.0) and PICl (r = 0.5, 1.0, 1.5) coagulants, PICl (r = 0.5, 1.0, 1.5) coagulants was found to be more effective than other coagulant for the removal of organic matters. The experimental results for the coagulation tests at various pH ranges showed that the PICl was least affected by the coagulation pH and PICl was very effective for the removal of turbidity and organic materials over wide pH range (pH 4-9) tested.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.197-200
• /
• 2001

In this letter, we report on the investigation of Ni/Si/Ni Ohmic contacts to n-type 4H-SiC. Ohmic contacts have been formed by a vacuum annealing and $N_2$ gas ambient annealing method at $950^{\circ}C$ for 10 min. The specific contact resistivity ( $\rho_{c}$ ), sheet resistance($R_s$), contact resistance($R_c$), transfer length($L_T$) were calculated from resistance($R_T$) versus contact spacing(d) measurements obtained from 10 TLM(transmission line method) structures. The resulting average values of vacuum annealing sample were $\rho_{c}=3.8{\times}10^{-5}\Omega cm^{3}$, $R_{c}=4.9{\Omega}$, $R_{T}=9.8{\Omega}$ and $L_{T}=15.5{\mu}m$, resulting average values of another sample were $\rho_{c}=2.29{\times}10^{-4}\Omega cm^{3}$, $R_{c}=12.9{\Omega}$ and $R_{T}=25.8{\Omega}$. The physical properties of contacts were examined using X-Ray Diffraction and Auger analysis, there was a uniform intermixing of the Si and Ni, migration of Ni into the SiC.

• Proceedings of the KIEE Conference
• /
• summer
• /
• pp.135-137
• /
• 2004

This paper describes new land use estimation method for long term load forecast using $R\startree$ algorithm. Where $R\startree$ algorithms is a proposed method for efficient spatial search. An estimation result showed that execute time of the proposed method is prior to execute time of conventional method.

• Journal of Information Technology Applications and Management
• /
• v.12 no.1
• /
• pp.231-239
• /
• 2005

This paper describes a new algorithm for pixel-based skin color detection to differentiate human form in color images by the ratio of R to H. In order to detect skin color efficiently, we examine the distribution of the R, G and B color elements combining to constitute the skin color in various color images. It shows that R is located in a narrower area than G and B on the RGB color space. And skin color is more related to R than G and B. Meanwhile, when the color image is transformed to the HSI color space, the S is variously changed in accordance with skin colors. The I is changed in accordance with the quantity and angle of light. But the H is less influenced by other conditions except for color. On the basis of the aforementioned study, we propose that the threshold for skin color detection is decided by the ratio of R to H. The proposed method narrows down the range of threshold, detects more skin color and reduces mis-detection of skin color in comparison to detection by R or H. In experimentation. it shows that the proposed algorithm overcomes changes of brightness and color to detect skin color in color images.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.150.3-151
• /
• 2003

To analyze the genome of Cucumber mosaic virus(CMV) in pepper, we developed a new extraction method for double-stranded RNA(dsRNA). To isolate the dsRNA, 0.1g of pepper leaves homogenized with 1ml of 5${\times}$EXB extraction buffer[0.5M glycin, 0.5M NaCl, 5mM EDTA(pH9.0/NaOH), 10％ Sodium N-lauryl salcosinate(NLS), 10％ Sodium dodecylsulfate(SDS)] and purified with the 1/4 volume of phenol： chloroform： isoamylalcohol(25：24：1). dsRNAs from the aqueous phase was precipitated with isopropanol. This procedure was able to detect a minimal amount of dsRNA from CMV infected plant tissue and to distinguish different CMV satellite RNAs by polyacrylamide gel electrophoresis(PAGE). Moreover, this method can be applied CMV infected in pepper or Rice dwarf virus (RDV) infected rice.

• Journal of the Korean Society of Safety
• /
• v.12 no.3
• /
• pp.45-51
• /
• 1997

To evaluate the elastic-plastic fracture toughness by this modified offset method, the origin of J-R curve is set with drawing the blunting line on the maximum point of the negative crack growth and R curve is modified by adding the blunting factor of the experimented point on the R curve. The elastic-plastic fracture toughness $J_{IC]$ of A5083-H112 material by the modified offset method we 44kN/m on the smooth CT specimens.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.4
• /
• pp.395-400
• /
• 2001

The effects of ortho- (R = H and CH3) and Y-substituents (Y = OCH3, CH3H and CN), which are directly attached to the carbonyl carbon, on the protonation equilibria of the para-X-substituted benzoyl derivatives, 4-X -2, 6-di-R-C6H2-C(=O)-Y, are investigated theoretically using the B3LYP method with 6-31+G* basis set. Structurally, both of the (B) and (BH+ ) forms in the species with R = H are nearly coplanar regardless of the Y-substituents implying that the steric repulsion between Y-substituent and R = H is relatively small. In the species with R = CH3 , the tortional angle (Θ) between the carbonyl moiety and aryl ring varies from zero to near right angle depending on the degree of steric repulsion between Y and R = CH3 and the resonance demand. However the reaction energies, ΔG°, for the protonation processes are more favorable for R = CH3 than for R = H due to stronger electron donating effect of R = CH3 , although the species with R = CH3 are unfavorable sterically. On the other hand, the Hammett type plots are progressively better correlated with б+ than with б values on going from Y = OCH3 to Y = CN for both species with R = H and CH3 indicating that the degree of resonance delocalization between carbonyl moiety and X-substituent is increased for a more electron accepting Y-substituent. Nevertheless the effects of R = CH3 on the magnitude of Hammett type reaction constants ( б or б+ ) are not much different from those of R = H.

• Proceedings of the KIEE Conference
• /
• 2004.07c
• /
• pp.1835-1837
• /
• 2004

The UHF electromagnetic waves excited by PD pulses propagate along the GIS busbar not only TEM mode, but also TE and TM mode. Generally the waves detected by the UHF sensors are those of high order modes and such waves can only propagate the higher than cut-off frequency. In this paper, computed cut-off frequency of 362[kV] GIS by each modes and simulated electromagnetic field of each propagation modes by FEM(Finite Element Method) program. Frequency band of each TEmn/TMmn modes were determinated by simulation results and were discussed optimal position of UHF sensor from this results.

• Proceedings of the KIEE Conference
• /
• 2005.07a
• /
• pp.402-404
• /
• 2005

This paper represents the amapcity calculation method of power cables installed in a concrete construction above a bridge which is exposed to solar radiation.