• Solar Energy
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• v.19 no.4
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• pp.63-69
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• 1999

The conventional grid connected PV(Photovoltaic) system has a unstable output pattern due to its dependence on the weather condition, although solar-cell array averagely has a regular output characteristics to have a peak output nearly at noon. Therefore assuming the high density grid connection in the future, this unstable output pattern can be one of the main reasons to generate power disturbance such as voltage variation, frequency variation and harmonic voltage generation in low voltage distribution line. However general grid connected solar-cell system do not have functions to cope with these disturbances. Therefore this study proposed a advanced type grid connected PV system with functions to suppress output power fluctuation due to solar-cell array output variation and showed the levelling effect of fluctuation due to instantaneous array output variation.

• Journal of Ocean Engineering and Technology
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• v.15 no.1
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• pp.45-51
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• 2001

In order to clarify the seasonal variation of the residual current and the material transportation process in Hiroshima Bay, JAPAN, the real-time simulation of residual current and particle tracking by using the Euler-Lagrange model were carried out. The calculated tidal current, water temperature, and salinity showed good agreement with the observed ones. The residual currents showed a southward flow pattern at the upper layer, and a northward flow pattern at the lower layer. The flow structure of the residual current in Hiroshima Bay is an estuarine circulation affected by density flow and wind driven current. The residual current plays an important role of material transportation in the bay.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.12
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• pp.1055-1059
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• 1998

The correlation between the propagation of electrical tree and distributions of partial discharge(PD) pulses accompanying with electrical tree of bush type in low density polyethylene were discussed. We measured the growth of electrical tree by using optical microscope and PD data simultaneously. The PD data detected and analyzed were PD magnitude, repetition rate, average discharge power, average phase angle, and $\psi$-q-n distribution pattern. The average discharge power and repetition rate of PD had good linear relation with area of tree. Repetition rate and peak discharge magnitude and width of discharge phase angle increased with the tree.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.21 no.11
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• pp.995-999
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• 2008

ZnO nanowires with tetrapod shape were formed on the surface of the sample by direct melt oxidation of Al-Zn alloy at $1000^{\circ}C$ in air. X-ray diffraction (XRD) pattern revealed that the ZnO nanowires had wurtzite structure of hexagonal phase. Any other element except Zn and O was not detected in energy dispersive X-ray spectrum. The c- and a-axis lattice constants estimated from the XRD pattern were 0.520 and 0.325 nm, respectively. These are in well accordance with those of bulk ZnO single crystal, indicating high quality crystallinity. The green light emission at a wavelength of 510 nm was observed from the nanowires at room temperature, which was ascribed to high density of oxygen vacancies in nanowires.

• Proceedings of the KIEE Conference
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• 2003.11c
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• pp.898-902
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• 2003

In this paper we proposes a new technique for identification of breast cancer by classification of proteome pattern generated from 2-D polyacrylamide gel electrophoresis (2-D PAGE) and development of cancer diagnosis system : HABIT. Proteome patterns reflect the underlying pathological state of a human organ and it is believed that the anomalies or diseases of human organs are identified by the analysis or classification of the patterns. Proteome patterns consist of quantitative information of the spots such as their size, position, and density in the proteome image produced from 2-D PAGE, for the Image mining of proteome pattern, SVM(support vector machine) and GA(genetic algorithm) are used to generate a decision model for the identification of breast cancer The decision model was then used to classify an independent set of test proteome patterns into the affecter and unaffecter classes. The proposed technique was tested by actual clinical test samples and showed a good performance of a hit ratio of 90%.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.17 no.4
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• pp.342-349
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• 1988

The characteristics of flow pattern transitions in a horizontal cocurrent gas-liquid flow have been investigated by means of a statistical analysis of instantaneous pressure drop curves at an orifice. The dimensionless intensity of pressure drop fluctuation shows a sudden change during the course of flow transitions, indicating that it may be a good measure to identify the flow regime transitions. The probability density function of the curves feature a unique pattern depending upon the flow regimes and the statistical properties of the PDF also have particular ranges for each flow regime. In conclusion, the statistical analysis of instantaneous pressure drops may be a powerful tool for predicting the flow regime transitions.

• Journal of the Korean housing association
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• v.18 no.3
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• pp.31-40
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• 2007

This research starts from the questioning of current housing development situation on hilly sites in Korea. It aims to investigate various design techniques of terraced housing as an alternative housing type on sloped sites. Several generic solutions are proposed, as for site slope and stacking method, combination of dwelling units, access pattern, and sectional variation of unit space. By the comparative analysis of design proposals with the typical two-row vertical-access type, the efficiency of the proposed techniques are verified in terms of development density, provision of community space, habitability of dwelling units.

• Journal of Korean Institute of Industrial Engineers
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• v.38 no.3
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• pp.191-197
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• 2012

One-class classification (OCC) is one of the recent growing areas in data mining and pattern recognition. In the present study we examine a k-nearest neighbors data description (kNNDD) algorithm, one of the OCC algorithms widely used. In particular, we propose to use nonparametric estimation methods to determine the threshold of the kNNDD algorithm. A simulation study has been conducted to explore the characteristics of the proposed approach and compare it with the existing approach that determines the threshold. The results demonstrate the usefulness and flexibility of the proposed approach.

• Journal of Powder Materials
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• v.20 no.2
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• pp.134-137
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• 2013

The quartz glasses were prepared by fumed silica powders sintering method at $1210^{\circ}C$, $1230^{\circ}C$, $1250^{\circ}C$ in air and the effect of sintering temperature on their properties were investigated. The X-ray diffraction pattern, the OH concentration, the light transmittance, the apparent porosity and the density were analyzed. The transparent quartz glass were obtained above $1230^{\circ}C$. The OH-group and macroscopic pores were removed above $1230^{\circ}C$ and highest density and light transmittance were obtained at $1250^{\circ}C$.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.199-204
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• 2002

It has been known that Ganoderma lucidum and Lentinus edodes have anticancer activity and immune enhancing activity. These two mushrooms were grown in liquid culture and harvested. From these mycelia, DNA was isolated and EtBr-CsCl density gradient ultracentrifugation was performed to purify it further. Then mitochondrial DNA was isolated by bisbenzimide-CsCl density ultracentrifugaton. Mitochondrial DNA of Ganoderma lucidum was digested by restriction enzymes, EcoR I, Hind Ⅲ, and Pst I, then electrophoresed. It showed 12, 22, 4 fragments. Mitochondrial DNA of Lentinus edodes was digested by EcoR I. Electric pattern showed 6 fragments. 4 fragments had appeared by Pst 1 digested mitochondrial DNA. Hind ill couldn't digest mitochondrial DNA of Lentinus edodes. Mitochondrial DNA of fusants was isolated to compare to those of parents. The results showed that fusant P₂S₄has new, recombined mitochondrial DNA. But P₂S₄had the same DNA that Ganoderma lucidum had.