• Journal of the Institute of Electronics Engineers of Korea SP
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• v.45 no.1
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• pp.55-63
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• 2008

Ridge orientations of fingerprint image are crucial informations in many parts of fingerprint recognition such as enhancement, matching and classification. Therefore it is essential to extract the ridge orientations of image accurately because it directly affects the performance of the system. The two main properties of ridge orientation are 1) global characteristic(gradual change in whole part of fingerprint) and 2) local characteristic(abrupt change around core and delta points). When we only consider the local characteristic, estimated ridge orientations are well around singular points but not robust to noise. When the global characteristic is only considered, to estimate ridge orientation is robust to noise but cannot represent the orientation around singular points. In this paper, we propose a novel method for estimating ridge orientation which represents local characteristic specifically as well as be robust to noise. We reduce the noise caused by scar using iterative outlier rejection. We apply adaptive measurement resolution in each fingerprint area to estimate the ridge orientation around singular points accurately. We evaluate the performance of proposed method using synthetic fingerprint and FVC 2002 DB. We compare the accuracy of ridge orientation. The performance of fingerprint authentication system is evaluated using FVC 2002 DB.

• Journal of Ginseng Research
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• v.41 no.3
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• pp.284-289
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• 2017

Background: Compound FK506 is an immunosuppressant agent that is frequently used to prevent rejection of solid organs upon transplant. However, nephrotoxicity due to apoptosis and inflammatory response mediated by FK506 limit its usefulness. In this study, the protective effect of Korean Red Ginseng (KRG) against FK506-induced damage in LLC-PK1 pig kidney epithelial cells was investigated. Methods: LLC-PK1 cells were exposed to FK506 with KRG and cell viability was measured. Western blotting and RT-PCR analyses evaluated protein expression of MAPKs, caspase-3, and KIM-1. TLR-4 gene expression was assessed. Caspase-3 activities were also determined. The number of apoptotic cells was measured using an image-based cytometric assay. Results: The reduction in LLC-PK1 cell viability by $60{\mu}M$ FK506 was recovered by KRG cotreatment in a dose-dependent manner. The phosphorylation of p38, p44/42 MAPKs (ERK), KIM-1, cleaved caspase-3, and TLR-4 mRNA expression was increased markedly in LLC-PK1 cells treated with $60{\mu}M$ FK506. However, with the exception of p-ERK, elevated levels of p-p38, KIM-1, cleaved caspase-3, and TLR-4 mRNA expression were significantly decreased after cotreatment with KRG. Activity level of caspase-3 was also attenuated by KRG cotreatment. Moreover, image-based cytometric assay showed that apoptotic cell death was increased by $60{\mu}M$ FK506 treatment, whereas it was decreased after cotreatment with KRG. Conclusion: Taken together, these results suggest that the molecular mechanism of KRG in the FK506-induced nephrotoxicity may lead to the development of an adjuvant for the inhibition of adverse effect FK506 in the kidney.

• The Korean Journal of Nuclear Medicine
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• v.39 no.3
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• pp.163-173
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• 2005

Purpose: Abutted scatter energy windows used for a triple energy window (TEW) method may provide wrong estimation of scatter. This study is to propose an extended TEW (ETEW) method, which doesn't require abutted scatter energy windows and overcomes the shortcomings of TEW method. Materials & Methods: The ETEW is a modification of the TEW which corrects for scatter by using abutted scatter rejection windows, which can overestimate or underestimate scatter. The ETEW is compared to the TEW using Monte Carlo simulated data for point sources as well as hot and cold spheres in a cylindrical water phantom. Various main energy window widths (10 %, 15 % and 20 %) were simulated. Both TEW and ETEW improved image contrast, % recovery coefficients and normalized standard deviation. Results: Both of TEW and ETEW improved image contrast and % recovery coefficients. Estimated scatter components by the TEW were not proportional to the true scatter components over the main energy windows when ones of 10 %, 15 %, and 20 % were simulated. The ETEW linearly estimated scatter components over the width of the main energy windows. Conclusion: We extended the TEW method into the method which could linearly estimate scatter components over the main energy windows.

• Progress in Medical Physics
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• v.20 no.2
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• pp.72-79
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• 2009

Scatter correction for I-131 plays a very important role to improve image quality and quantitation. I-131 has multiple and higher energy gamma-ray emissions. Image quality and quantitative accuracy in I-131 imaging are degraded by object scatter as well as scatter and septal penetration in the collimator. The purpose of this study was to estimate scatter and septal penetration and investigate two scatter correction methods using Monte Carlo simulation. The gamma camera system simulated in this study was a FORTE system (Phillips, Nederland) with high energy, general-purpose, parallel hole collimator. We simulated for two types of high energy collimators. One is composed of lead, and the other is composed of artificially high Z number and high density. We simulated energy spectrum using a point source in air. We estimated both full width at half maximum (FWHM) and full width at tenth maximum (FWTM) using line spread function (LSF) in cylindrical water phantom. We applied two scatter correction methods, triple energy window scatter correction (TEW) and extended triple energy window scatter correction (ETEW). The TEW method is a pixel-by pixel based correction which is easy to implement clinically. The ETEW is a modification of the TEW which corrects for scatter by using abutted scatter rejection window, which can overestimate or the underestimate scatter. The both FWHM and FWTM were estimated as 41.2 mm and 206.5 mm for lead collimator, respectively. The FWHM and FWTM were estimated as 27.3 mm and 45.6 mm for artificially high Z and high density collimator, respectively. ETEW showed that the estimation of scatter components was close to the true scatter components. In conclusion, correction for septal penetration and scatter is important to improve image quality and quantitative accuracy in I-131 imaging. The ETEW method in scatter correction appeared to be useful in I-131 imaging.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.17 no.10 s.113
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• pp.967-975
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• 2006

In this paper, design and implementation of a very compact and cost effective front-end module are presented for IEEE 802.16 FWA(fixed Wireless Access) in the 40 GHz band. A multi-layer LTCC(Low Temperature Co-fred Ceramic) technology with cavity process to achieve excellent electrical performances is used to fabricate the front-end module. The wirebond matching circuit design of switch input/output port and waveguide transition to connect antenna are optimally designed to keep transmission loss low. To reduce the size of the front-end module, the dielectric waveguide filter is developed instead of the metal waveguide filter. The LTCC is composed of 6 layers(with the thickness of a layer of 100 um) having a relative dielectric constant of 7.1. The front-end module is implemented in a volume of $30{\times}7{\times}0.8mm^3$ and shows an overall insertion loss < 5.3 dB, and image rejection value > 49 dB.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.6
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• pp.175-181
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• 2019

For the purpose of Application to the small radar sensor, the MMIC Chip, which is the core component of the W-band, was designed in Korea according to the characteristics of the transceiver and manufactured by 0.1㎛ GaAs pHEMT process, and compared with the MMIC chip purchased overseas. The noise figure of low noise amplifier, insertion loss of the switch and image rejection performance of the down-converted mixer MMIC chip showed better characteristics than those of commercial chips. The MMIC chip developed in domestic was applied to the transmitter and receiver through W-band waveguide low loss transition structure design and impedance matching to verify the performance after the fabrication is 9.17 dB, which is close to the analysis result. As a result, it is judged that the transceiver can be applied to the small radar sensor better than the MMIC chip purchased overseas.

• The Journal of Engineering Geology
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• v.22 no.4
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• pp.459-466
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• 2012

A difficulty encountered in engineering seismic mapping is that reflection events from shallow discontinuities are commonly overlapped with coherent noise such as air wave, direct waves, head waves, and high-amplitude surface waves. Here, the radial trace transform, a simple geometric re-mapping of a trace gather (x-t domain) to another trace gather (v-t domain), is applied to investigate the rejection effect of coherent linear noises. Two different types of data sets were selected as a representative database: good-quality data for intermediate sounding (hundreds of meters) in a sedimentary basin and very noisy data for shallow (${\leq}50m$) mapping of the weathered zone and bedrock surface. Results obtained with cascaded application of the radial transform and low-cut filtering proved to be as good as, or better than, those produced using f-k filtering, and were especially effective for air wave and direct wave. This simple transform enables better understanding of the characteristics of various types of noise in the RT domain, and can be generally applied to overcoming diffractions and back-scatterings caused by joints, fractures, and faults commonly that are encountered in geotechnical problems.

• Membrane Journal
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• v.12 no.2
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• pp.75-89
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• 2002

The effect of addition of inorganic salts in polyethersulfone (PES) polymer solution on the membrane formation and ultrafiltartion performance was studied through the thermodynamic and kinetic properties of casting solution. To control the thermodynamic and kinetic properties of casting solution, various inorganic salts $[CaC1_2, LiCl, LiClO_4, ZnC1_2 $and Mg(ClO_4)_2]$ were added in the PES/NMP solution. Variation of membrane morphology and performance of the resulting membranes with change of the salt type and content added in tasting solution were discussed using viscosity, coagulation value, light transmittance measurement, overall membrane porosity, ultrafiltration experiment and cross-sectional SEM image. For all kind of inorganic salts, according as increase of the salt content in casting solution, viscosity is increased, coagulation value becomes lower, top layer thickness below the skin surface is increased, bovine serum albumin(BSA) rejection decreased and pure water flux is increased except $CaC1_2$ and LiCl. In case of $CaC1_2$ and LiCl, it is found that when the salt content is increased, the formation of macrovoids is suppressed and the precipitation rate becomes slow while instantaneous demixing of precipitation type is maintained. However, in case of $LiClO_4$ and $Mg(ClO_4)_2,$ it is found that precipitation rate becomes faster.

• 한국보건간호학회:학술대회논문집
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• 2002.10a
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• pp.224-227
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• 2002

Alcoholism affects not only the individuals who depend on it, but also their families. Children who have an alcohol dependent parent have various problems and need help, but little attention has been given to them. Many references report only negative characteristics of these children. In order to help the children of alcohol dependent parents, health professionals need more information. A wholistic understanding and analysis of these children is needed as a basis for the development of suitable programs of help them. A phenomenological methodology was used to identify the experience of children whose fathers were addicted to alcohol. The findings portray the essence of the lived experience of children of alcohol dependent fathers. Nine adolescents participated in in-depth inverviews and observation with the researcher, done between October and December 2001. The data were recorded on audio tape and transcribed. Sampling was continued until the data were theorectically saturated. The Colaizzi's method was used for data analysis. The results of this study are as follows. Three themes and twenty six meanings were identified. The first theme is Living Alone: living abusively as partner to an alcohol dependent father, living dangerously like an explosive fury, living as an object that ha no self, living with rejection of fatherly being, living with felt responsibility but having no power to help mother who suffers patiently with pain and abuse, living along with no shoulder to lean on, and living with the prejudice of sex discrimination. The second theme is Paradoxical Coping in Life. The meanings are obsessive behavior as a way to control father's behavior, always on the defensive due to anxiety and tension, being afraid of life alone due to paranoid thoughts, contradictory expectation about father's drinking behavior due to life with chronic tension, stress becoming familiar and life being boring and tendious without stimulation, life that is fake and filled with misinterpretations about reality, affection sought from others due to loneliness, compensatory life within peer group, negative expectation about the future due to negative experiences, controling others to protect ego, denial of real emotion to protect self from hurt, life of regretting self, and strong need for approval from others. The third theme is sustaining life. The meanings are ambivalence between revenge on father and pity, struggle for desirable self against fear of gather-like image, understanding father through self reflection, hope to find fatherly being through father's recovery, being able to stand through emotional control and cognitive restructuring, nurturing the seed of hope for the future while in a situation of desperation. The contribution of this study is to give a wholistic understanding of the empirical reality of children of alcohol dependent parents and to develop substantive theory in nursing knowledge. In nursing practice, the results of this study can provide a foundation for the development of programs for children of alcohol dependent parents.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.1 s.116
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• pp.37-43
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• 2007

In this.paper, we introduce design and implementation results of the single balanced diode mixer for European point-to-point microwave radio in order to improve flatness performance. When a resonator such as RF filter is integrated with a mixer, impedance characteristic of 50 ohm is maintained only in RF band, not in LO band resulting deterioration of flatness performance because of LO power variation on the diode. In the paper, we suggest a design method of mixer integrated with image rejection filter and LO harmonic filter to have a better performance of flatness using embedding electrical length between filter and mixer's port. Frequency specification of fabricated mixer is $21.2{\sim}22.6\;GHz$ for RF, $19.32{\sim}20.72\;GHz$ for LO and 1.88 GHz+/-50 MHz for IF, respectively. Measured results show conversion loss of 8.5 dB, flatness of 2 dB, input PldB of 8 dBm, IIP3 of 15 dBm under LO power level of 10 dBm. Return losses of RF, LO and IF port are under -12 dB, -10 dB and -5 dB, respectively. Isolations of LO/RF and LO/IF are 20 dB and 50 dB, respectively.