• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.1
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• pp.1-9
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• 2014

In this paper, a reconfigurable polarization patch antenna that uses a Y-shaped feed is proposed. The proposed antenna consists of a square patch, a Y-shaped feeding structure, a PIN diode, and a bias circuit for diode operation. The structural symmetry/asymmetry of the feeding structure is determined by the on/off operation of the PIN diode that inserted into the side of one of the lines of the Y-shaped feeding structure. For the proposed reconfigurable antenna, the two microstrip lines of the feeding structure have the same length when the PIN diode operates in the on state, and the antenna exhibits linear polarization(LP). On the other hand, when the PIN diode operates in the off state, the length of one side line of the feeding structure is relatively shorter than that of the other line. Therefore, the antenna exhibits circular polarization(CP). From the measurement results, it is found that the proposed antenna exhibits good impedance matching and axial ratio. In addition, polarization switching can be easily achieved in the same operating band.

• Composites Research
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• v.26 no.2
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• pp.123-128
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• 2013

The PVDF (polyvinylidene fluoride) fibers were prepared using the wet spinning processing. To improve ${\beta}$-phase crystalline which closely related piezoelectric property PVDF wet spun fibers conducted post treatment. Post treatment is consisted of heat stretching and annealing process. The heat stretching and annealing conditions were controlled by changing temperature between glass transition temperature and melting temperature. From these experimental data, the resulting crystal structure of the ${\beta}$-phase crystalline was confirmed by FT-IR and XRD experiments. From these analysis results, optimum stretching and annealing conditions of the wet spun PVDF fibers were founded to increase high ${\beta}$-phase crystalline. Furthermore results showed that thermal processing had a direct effect on modifying the crystalline microstructure and also confirmed that heat stretching and annealing could increase the degree of crystallinity and ${\beta}$-phase crystalline. Finally, piezoelectric constant ($d_{11}$) of the post heat treated PVDF fibers reinforced composite were measured to investigate the feasibility for the sensing materials.

• KIPE Magazine
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• v.13 no.1
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• pp.20-25
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• 2008

• Journal of the Korean Society of Costume
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• v.18
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• pp.145-153
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• 1992

• 한국사회복지학회:학술대회논문집
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• 1996.04a
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• pp.117-131
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• 1996

• Cement Symposium
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• no.21
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• pp.116-125
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• 1993

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.4
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• pp.941-950
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• 2018

The form of information security organization of a financial company has various organizational forms in accordance with the responsibilities and roles of the Chief Information Officer (CIO), the Chief Information Security Officer (CISO) and the Chief Privacy Officer (CPO). However, it is necessary to examine whether these various types of information protection organizations are the optimal organizational forms. In this study, six types of information security organizations among the various types of information security organizations in terms of CISO, CIO, and CPO relationship were selected as candidates. This paper aims to study and elucidate the optimal organizational form of information security for financial companies.

• Journal of the Korean Geotechnical Society
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• v.15 no.6
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• pp.219-238
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• 1999

In the present study, laboratory tests including the seepage-induced consolidation test, suction test, and desiccation shrinkage test are performed to investigate characteristics of the desiccation shrinkage in reclaimed hydraulic fills. Soil samples for laboratory tests are obtained from three sites (districts of Haenam, Kogeum and Koheung in Chunnam area). Desiccation shrinkage settlement caused by three dimensional volume change is numerically evaluated using finite difference technique based on the governing equation proposed by Abu-Hejleh & Znidarcic. Also characteristics of the desiccation shrinkage analyzed from the test results are used as input data for numerical evaluations. Further predicted total settlements including the self-weight consolidation settlement are compared with values measured at the site of Haenam district. Finally, effects of parameters related to the desiccation shrinkage on settlements are examined.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.22 no.12
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• pp.176-182
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• 2008

It is the paper that this study develops the small plate-type ozonizer(PTO) for improvements of indoor air and water, and investigated the characteristics. Electric discharge area of ozonizer of each form is same to 60[$cm^2$] and discharge power is the maximum 30[W]. Ozonizer of various forms was devised according to size, numbers and arrangement. The main study object is discharge power-ozone concentration characteristics, discharge power-ozone yield characteristics, amount of gas flow-ozone concentration characteristics and amount of gas flow-ozone yield characteristics. PTOL-P appeared so as to be most excellent, and ozone generation characteristics were able to get the similar results at three kinds of remaining ozonizer ($PTO_{P-P}$, $PTO_{C-P}$, $PTO_{T-P}$).

• The Journal of the Acoustical Society of Korea
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• v.20 no.8
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• pp.24-30
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• 2001

This article is concerned with automatic segmentation for Korean speech signals. All kinds of transition cases of phonetic units are classified into 3 types and different strategies for each type are applied. The type 1 is the discrimination of silence, voiced-speech and unvoiced-speech. The histogram analysis of each indicators which consists of wavelet coefficients and SVF (Spectral Variation Function) in wavelet coefficients are used for type 1 segmentation. The type 2 is the discrimination of adjacent vowels. The vowel transition cases can be characterized by spectrogram. Given phonetic transcription and transition pattern spectrogram, the speech signal, having consecutive vowels, are automatically segmented by the template matching. The type 3 is the discrimination of vowel and voiced-consonants. The smoothed short-time RMS energy of Wavelet low pass component and SVF in cepstral coefficients are adopted for type 3 segmentation. The experiment is performed for 342 words utterance set. The speech data are gathered from 6 speakers. The result shows the validity of the method.