• Journal of Electrical Engineering and Technology
• /
• v.10 no.3
• /
• pp.990-1001
• /
• 2015

This paper presents analysis of Switched Reluctance Machine (SRM) using Geometry Based Analytical Model (GBAM), Finite Element Analysis (FEA) and Fourier Series Model (FSM) with curve fitting technique. Further a Transient Analysis (TA) technique is proposed to corroborate the analysis. The main aim of this paper is to give in depth procedure in developing a Geometry Based Analytical Model of Switched Reluctance Machine which is very accurate and simple. The GBAM is developed for the specifications obtained from the manufacturer and magnetizing characteristic of the material used for the construction. Precise values of the parameters like Magneto Motive Force (MMF), flux linkage, inductance and torque are obtained for various rotor positions taking into account the Fringing Effect (FE). The FEA model is developed using MagNet7.1.1 for the same machine geometry used in GBAM and the results are compared with GBAM. Further another analytical model called Fourier Series Model is developed to justify the accuracy of the results obtained by the methods GBAM and FEA model. A prototype of microcontroller based SRM drive system is constructed for validating the analysis and the results are reported.

• Tunnel and Underground Space
• /
• v.18 no.1
• /
• pp.44-57
• /
• 2008

In this study, a 2D finite-element analysis, using the SEEP/W program, was carried out to estimate the amount of groundwater flawing into a tunnel, as well as the groundwater tables around wetland areas during and after a tunnel excavation through rock mass. Four sites along the Wonhyo-tunnel in Cheonseong Mountain (Gyeongnam, Korea) were analysed, where the model damain of the tunnel included both wetland and fault zone. The anisotropy of the hydraulic conductivities of the rock mass was calculated using the DFN model, and then used as an input parameter for the cantinuum model. Parametric study on the influencing factors was perofrmed to minimize uncertainties in the hydraulic properties. Moreover, the volumetric water content and hydraulic conductivity functions were applied ta the model to reflect the ability of a medium ta store and transport water under both saturated and unsaturated conditions. The conductivity of fault zone was assumed ta be $10^{-5}m/sec\;or\;10^{-6}m/sec$ and the conductivity of grouting zone was assumed as 1/10, 1/50 or 1/100 of the conductivity of rock mass. Totally $6{\sim}8$ cases of transient flow simulation were peformed at each site. The hydraulic conductivities of fault zone showed a significant influence on groundwater inflow when the fault zone crossed the tunnel. Also, groundwater table around wetland maintained in case that the hydraulic conductivity of grouting zone was reduced ta be less than 1/50 of the hydraulic conductivity of rock mass.

• Proceedings of the Korean Society of Embryo Transfer Conference
• /
• 2002.11a
• /
• pp.97-97
• /
• 2002

Human eryhropoietin (EPO) is acidic glycoprotein hormone that plays key role in hematopoiesis by facilitating differentiation of erythrocyte and formation of hemoglobin (Hb) and is used for the treatment of anemia. Human EPO is consist of 166 amino acids which is modified by three N-glycosylations (24, 38, 83) and single O-glycosylation (126). N-glycosylation is reported to be related to the cellular secretion and activity of EPO. In this study, we examined effects of mutagenesis in glycosylation site of recombinat hEPO for the cellular secretion during production from cultured CHO cell. We produced rhEpo which was cloned by PCR from human liver cDNA (TaKaRa) in cultured CHO cell. Using supernatant of the culture, ELISA assay and western analysis were performed. To estimate biological activity, 20IU of rhuEpo was subcutaneously injected into four ICR mice. After 8 days, HCT level was increased average 13 per cent, RBC was increased ca. 2${\times}$10$\^$6//${\mu}\ell$. In disease model Rat (anemia c-kit, WSRC-WS/WS), HCT was increased ca. 12%, RBC was increased ca. 1.6${\times}$10$\^$6//${\mu}\ell$. These results suggests that rhEpo we produced has biological activity. To remove glycosylation site by substituting 24, 38, 83, and 126th asparagine (or serine) with glutamic acid, overlapping -extension site-directed mutagenesis was performed. To add novel glycosylation sites, 69, 105th leucine was mutated to asparagine. Mutant EPO construct was transfected into CHO cell. Supernatant of the cell culture was analyzed using ELISA assay with monoclonal anti-EPO antibody (Medac, Germany). Since, several reports for mutagenesis of glycosylation sites showed case-by-case results, we examined both transient expression and stable expression. Addition of novel glycosylation sites resulted no secretion while deletion mutants had little effect except some double deletion mutants (24/83 and 38/83) and triple mutant. We suggest that not single but combination of glycosyl group affect secretion of EPO.