• Advances in pediatric surgery
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• v.13 no.1
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• pp.1-12
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• 2007

Biliary atresia (BA) is the result of fibrosing destructive inflammatory process affecting intrahepatic and extrahepatic bile ducts, which lead to cirrhosis and portal hypertension. Kasai portoenterostomy has been the standard operative procedure in biliary atresia. Recently, there has been remarkable increase in the survival rate in cases of BA. However, long-term survivors are not clearly evaluated in Korea. To define long-term prognosis factors of patients who underwent surgery for BA, a retrospective study was undertaken of 10 (37 %) patients surviving more than 10 years among 27 patients who underwent one of Kasai procedures between 1981 and 1995. Hepatomegaly was present in 4 and splenomegaly in 7 patients. Serum bilirubin was normalized at 1 year after operation. Aspartate aminotransferase (AST, GOT), Alanine aminotransferase(ALT, GPT) were normalized at 12 years and alkaline phosphatase(ALP) was normalized at 13.5 years. Cholangitis developed mainly within 5 years after operation so close follow up is needed. Life long follow-up is needed because of progressive deterioration of liver function even after 10 years.

• Proceedings of the Korean Statistical Society Conference
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• 2005.05a
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• pp.277-283
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• 2005

In general, stock prices do not follow normal distributions and mean trend indexes, volatility indexes, and volume indicators relating to these non-normal stock price are widely used as buy-sell strategies. These general buy-sell strategies are rather intuitive than statistical reasoning. The non-normality problem can be solved by normalizing process and statistical buy-sell strategy can be obtained by using mean trend and volatility indexes together with normalized stock prices. In this paper, buy-sell strategy based on mean trend and volatility index with normalized stock prices are proposed and applied to KOSPI200 data to see the feasibility of the proposed buy-sell strategy.

• Proceedings of the KIPE Conference
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• 2001.07a
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• pp.348-351
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• 2001

In this paper, voltage-fed high frequency resonant inverter of instantaneous current phaser control method used to DC voltage source separated is proposed. In the output control method, a novel circuit type of phase shift driving signal method with CVCF illustrated, also the operation principle of the proposed circuit is described in detail and its characteristics are presented as to normalized parameters. According to the each mode, in order to the circuit analysis and characteristic evaluation of the state equation are derives and present used to normalized parameter. In the future, this proposed inverter show that it can be practically used as power source system for the lighting equipment of discharge lamp, DC-DC converter etc.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.216-220
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• 2000

AC Superconducting Generators (ACSG) are featured by 3D magnetic flux distribution, which decreases in the direction of axis. For this reason, when ACSG is optimal designed, 3D magnetic field analysis is required. This paper proposes 2D Finite Element Analysis (FEA) results normalized by 3D FEA according to the position of armature coil and the ratio of field coil width to axial length in order to reduce the analysis time. By using the proposed data, the reasonable 3D FEA results of ACSG can be only predicted by 2D FEA results. The validity of the 3D FEA results is verified by comparison with the experimental results of 30kVA superconducting synchronous generator.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1165-1167
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• 2000

This paper describes a current fed high frequency resonant inverter used as the power supply for sealing-wax. The proposed inverter can reduce switching losses, noise and voltage stress at turn-on and turn-off. The analysis of proposed circuit uses normalized parameter and characteristic estimation which is needed in each step before design is generally described according to normalized frequency ($\mu$), coefficient of coupling($\kappa$) and all parameters. The theoretical analysis is proved through experiment and this circuit shows that it can be used practically as the power supply system for sealing wax and DC-DC converter.

• Proceedings of the IEEK Conference
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• 2001.06e
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• pp.77-80
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• 2001

In this paper, we devised volume pulse detection system which can quantitatively represent a artery elasticity for oriental clinic. Volume pulse wave detecter system consist of transducer which has IRLED-photodiode detecter, temperature sensor and filter and preprocessing circuits, data conversion and serial communication parts, and computer system. The high-pass filter are detect volume pulse wave and lowpass filter detect tissue thickness. The detected volume pulse wave are normalized by tissue thickness value with a division process. As the result of experiment, we can detect normalized volume pulse wave with effectively.

• Proceedings of the IEEK Conference
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• 2003.07a
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• pp.190-193
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• 2003

The DOA(Direction Of Arrival) estimation to select a best beam for receiving a particular signal in switched beam antenna systems, and to shape the optimal beam in adaptive array antenna systems, is typically performed under the assumption that the target user motion is almost negligible. In this paper, we model the user as the time-varying source and adopt the LPA(Local Polynomial Approximation) tracking algorithm, proposed by Katkovnik, to solve the time-varying DOA estimation problem. Then, we compare the power spectrum functions between the LPA beamformer and the conventional beamformer, also, the normalized SNRs of each beamformer. The results show that the LPA beamformer is robuster than the conventional beamformer in tine-varying environments. In addition, in case of the conventional beamformer, more array elements give rise to more degradation in the aspect of SNR.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.121-124
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• 2000

The time dependence of irreversible magnetization of grain aligned infinite layer superconductor Sr$_{0.9}$La$_{0.1}$CuO$_2$ was measured in temperature range of 2 K < T < 30 K for H= 0.5 T, 1.0 T and 1.5 T parallel to c-axis. From this, we calculated normalized flux creep rate S(T) ${\equiv}$ dlnM/dlnt and found that the temperature independent region in S(T) is significantly wide in comparision with other cuprate superconductors. Using the method of Maley et al., we also deduce the current density dependence of pinning potential and glassy exponent ${\mu}$.

• 한국초전도학회:학술대회논문집
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• v.10
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• pp.103-106
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• 2000

We have studied the magnetic properties in Bi$_2$Sr$_2$CaCu$_2$O$_8$ single crystal with columnar defects using micro Hall-probe array. We found that fold profiles inside sample were similar to the Bean's critical state model from the magnetic hysteresis measurement. In the magnetic relaxation measurement, the normalized relaxation rates were maximum near the center and decreased toward the edge of the sample expect zero gauss. The relaxation rates as a function of the temperature were maximum near the 40K and rapidly decreased both sides of the peak.

• The Journal of Engineering Geology
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• v.31 no.3
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• pp.395-432
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• 2021

Groundwater recharge rates vary widely by location and with time. They are difficult to measure directly and are thus often estimated using simulations. This study employed frequency and regression analysis and a classification and regression tree (CART) algorithm in a machine learning method to estimate groundwater recharge. CART algorithms are considered for the distribution of precipitation by subbasin (PCP), geomorphological data, indices of the relationship between vegetation and landuse, and soil type. The considered geomorphological data were digital elevaion model (DEM), surface slope (SLOP), surface aspect (ASPT), and indices were the perpendicular vegetation index (PVI), normalized difference vegetation index (NDVI), normalized difference tillage index (NDTI), normalized difference residue index (NDRI). The spatio-temperal distribution of groundwater recharge in the SWAT-MOD-FLOW program, was classified as group 4, run in R, sampled for random and a model trained its groundwater recharge was predicted by CART condidering modified PVI, NDVI, NDTI, NDRI, PCP, and geomorphological data. To assess inter-rater reliability for group 4 groundwater recharge, the Kappa coefficient and overall accuracy and confusion matrix using K-fold cross-validation were calculated. The model obtained a Kappa coefficient of 0.3-0.6 and an overall accuracy of 0.5-0.7, indicating that the proposed model for estimating groundwater recharge with respect to soil type and vegetation cover is quite reliable.