• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.8
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• pp.1085-1091
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• 2014

A model based SOC estimation scheme using parameter identification is described and applied to a Lithium-ion battery module that can be installed in electric vehicles. Simulation studies are performed to verify the effect of sensor faults on the SOC estimation results for terminal voltage sensor and load current sensor. The sensor faults should be detected and isolated as soon as possible because the SOC estimation error due to any sensor fault seriously affects the overall performance of the BMS. A new fault detection and isolation(FDI) scheme by which the fault of terminal voltage sensor and load current sensor can be detected and isolated is proposed to improve the reliability of the BMS. The proposed FDI scheme utilizes the parameter estimation of an input-output model and two fuzzy predictors for residual generation; one for terminal voltage and the other for load current. Recently developed dual polarization(DP) model is taken to develope and evaluate the performance of the proposed FDI scheme. Simulation results show the practical feasibility of the proposed FDI scheme.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.5
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• pp.7-12
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• 2010

The bandwidth of a Jerusalem AMC was investigated based on the equivalent circuit model. Using the circuit model and the derivative of the admittance(Y'), the relation between the bandwidth and various circuit parameters was analyzed. It was shown that the substrate thickness and permeability enhance the bandwidth whereas the loadings on FSS grid degrade the bandwidth. Among the two loadings, the capacitive loading had better bandwidth characteristics than the inductive loading. AMC with single polarization was suggested to relax the bandwidth degradation by the inductive loading.

• Journal of the Optical Society of Korea
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• v.13 no.1
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• pp.15-21
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• 2009

High-order harmonic generation from a solid surface affected by the contrast of a laser pulse was studied using an oscillating mirror model. High-order harmonics generated from solid surfaces have unusual properties such as spectral redshift, and an intensity difference between even- and odd-order harmonics which is not reported for high-order harmonics generated by a gas medium. We confirmed that high-order harmonics from solid surfaces have selectivity of polarization as well as cut-off extension and the enhancement of conversion efficiency proportional to laser intensity. And the principle of operation and the characteristics of a plasma mirror system developed for achieving high contrast laser pulses to pursue the experimental realization of high-harmonic generation from solid surfaces are reported. Energy fluence on the plasma mirrors is tunable between $10\;J/cm^2$ and $1000\;J/cm^2$ and around 1000 shots are available before the plasma mirrors require replacement.

• Proceedings of the Membrane Society of Korea Conference
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• 2004.05a
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• pp.19-24
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• 2004

ED method is employed to effectively remove the organic acid salts in actual PDO fermentation broth. The lower electrical potential is selected to avoid the serious membrane fouling so as to ensure a stable and durative desalination process. Under the selected operation conditions, about 90% of organic acids salts are removed from PDO fermentation broth successfully by ED process. To reduce the loss of PDO product due to the diffusion, the operation time should be considered carefully. And based on mass balance equation and irreversible thermodynamics approach, a mathematical model is developed to describe the desalination process of an aqueous solution containing neutral solute by ED method. While the influence of concentration polarization is reflected by decreasing the conductivity of membrane, the model is verified well to describe the ED processes under varied operation conditions. Through the model, ED process of actual PDO fermentation broth is simulated to get a suitable scope of initial concentration in concentrated compartment.

• Archives of Pharmacal Research
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• v.15 no.2
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• pp.152-161
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• 1992

Selective quenching of 1, 6-diphenyl-1, 3, 5-hexatriene (DPH) by trinitrophenyl groups was utilized to examine the transbilayer fluidity asymmetry of model membranes of phospholipids (SPMVPL) extracted from synaptosomal plasma membrane vesicles (SPMV). The polarization (P), anisotropy (r), limiting anisotropy $(r_\infty$), and order parameter (S) of DPH in the inner monolayer were 0.019, 0.014, 0.018, and 0.047, respectively, greater than calculated for the outer monolayer of SPMVPL. Selective quenching of DPH by trinitrophenyl groups was also utilized to examine the effects of n-alkanols on the individual monolayer structure of SPMVPL. n-Alkanols fluidized the hydrocarbon region of bulk SPMVPL and the potencies of n-alkanols up to 1-nonanon increased with carbon chain length. It appears that the potencies in bilayer fluidization increase by 1 order of magnitude as the carbon chain length increases by two carbon atoms. The cut-off phenomenon was reached at 1-decanol, where further increase in hydrocarbon length resulted in a decrease in pharmacological activity. The n-alkanols had greater fluidizing effects on the outer monolayer as compared to the inner monolayer of SPMVPL, even though these selective effects tended to become weaker as the carbon chain length increased. Thus, it has been proven that n-alkanols exhibit selective rather than nonselective fludizing effects within transbilayer domains of SPMVPL.

• Membrane Journal
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• v.6 no.4
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• pp.203-212
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• 1996

The operating parameters influencing on limiting flux was investigated in the ultrafiltration of PVA, and a new model, which is based on the Amiar model using the concept of heat transfer coefficient, was devised to overcome the limitation of gel-layer model. Using polysulfone plate-unit membrane (MWCO=20,000) and hollow-fiber membrane (MWCO= 30,000), ultrafiltration characteristics of PVA was examined with the variation of operating parameters such as cross flow velocity, transmembrane pressure, temperature, and PVA concentration. According to experimental results, the ultrafiltration of PVA through polysulfone membrane is mainly controlled by well-known phenomena of concentration polarization caused by gel-layer formation. On the contrary, in hollow fiber membrane was observed upward limiting flux which can not be explained by gel-layer model. New model was applied to predict the upward limiting flux behavior with partial satisfaction. The application of new model including viscosity correction factor, however, revealed that PVA ultrafiltration is closely related to the viscosity of permeating fluid.

• Journal of Korean Academy of Nursing Administration
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• v.19 no.5
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• pp.565-577
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• 2013

Purpose: This study was done to propose an improvement in the Nursing Fee Differentiation Policy to alleviate polarization of nursing staffing level among hospitals and to rectify the confusion of legally mandated standards between the Korean Medical Law and National Health Insurance Act. Methods: The policy regulation was reconstructed related to nurse staffing standards and nurse-to-patients ratios. Data on nurse staffing grades were obtained from database of the Health Insurance Review & Assessment Service (HIRA) for the third quarter of 2010 for 44 tertiary hospitals, 274 general hospitals, and 1,262 hospitals. A break-even analysis was used to estimate financial burden of the revised policy improvement proposal. An industrial engineering method was used to calculate Nurse-to-Patients ratios per shift. Results: Twelve tertiary hospitals were downgraded. 74 general hospitals and 102 hospitals were upgraded after application of the regulation. Finances for total hospitalization expenditures changed from -3.55% to +3.14%. Conclusion: The results indicate that the proposed policy would decrease polarization between tertiary hospitals and small hospitals, and would not put a major strain on the finances of the Korean National Health Insurance. Therefore, it is suggested that government stake-holders and many interest groups consider this policy proposal and build a consensus.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.568-574
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• 2020

Gas diffusion layer (GDL) is one of the main components of PEMFC as a pathway of reactants from a flow field to an electrode, water transport in reverse direction, heat management and structural support of MEA. In this study, the effect of GDL on fuel cell performance was investigated for commercial products such as 39BC and JNT30-A3. Polarization curve measurements were performed at different flow rates and relative humidity conditions using 25 ㎠ unit cell. The parameters on operating conditions were calculated using an empirical equation. The electrical resistance increased as the GDL PTFE content increased. The crack of microporous layer had influence on the concentration loss as water pathway. In addition, the ohmic resistance increased as the relative humidity decreased, but decreased as the current density increased due to water formation. Curve fitting analysis using the empirical equation model was applied to identify the tendency of performance parameters on operating conditions for the gas diffusion layer.

• Korean Journal of Materials Research
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• v.11 no.3
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• pp.207-214
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• 2001

Silica glass is a core material for optical fiber in optical telecommunications, but its centrosymmetry eliminates the second order nonlinearity. But it is experimentally well known that the space charge polarization induces the Second Harmonic Generation (SHG) when a strong DC voltage is applied to silica glass for a long period of time with metal blocking electrodes. In this report, the results of a theoretical calculation of the nonlinear optical property caused by the space charge polarization, and a model of a numerical analysis to predict the small chance in nonlinear optical property as functions of time and space are provided. Assuming that amorphous silica is a solid state electrolyte and sodium ion is the only mobile charge carrier, 'Finite Difference Method' was employed for modeling of numerical analysis. The distributions of the concentration of sodium ion and electric field as functions of a normalized length of the specimen and a normalized applied voltage were simulated.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.10 no.7
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• pp.998-1009
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• 1999

In this paper, a microstrip aperture-patch antenna and a microstrip ring antenna, which have single microstrip line feeding systems for the circular polarization, are designed, and experimental results are presented at X-band. The microstrip aperture-patch antenna is characterized by its wide operating frequency range, and the microstrip ring antenna is suitable for a basic radiator in the large array antenna due to its small size. Several design parameters for these antennas are considered and analyzed to improve antenna characteristics such as VSWR bandwidth and axial ratio. Initially, the sizes of the aperture and ring radiator are determined on a basis of the cavity model, then shapes of the patch within the aperture and the inner stub of the ring are optimized using Ensemble software. Measurement results show that the aperture-patch antenna has 25% of VSWR bandwidth and 1.2dB of axial ratio at the boresight, and the ring antenna has 6.7% of VSWR bandwidth and 1.6dB of axial ratio at the boresight.