• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.11
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• pp.1194-1200
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• 2009

An internal antenna which has 1 cc volume was implemented on the FPCB(Flexible Printed Circuit Board) for the mobile phone. We increased antenna gain and efficiency by the applying of current direction concept on the antenna pattern for this small antenna. Short antenna length for the GSM band was compensated by the spiral inductor on the FPCB. For broadening bandwidth on GSM band, it's applied 2 spiral inductors. A conductor pattern for the DCS band was positioned perpendicular with the FPCB. Antenna was implemented on FPCB that is dielectric constant 4.4 and thickness 0.05 mm, and FPCB was attached on a carrier dimensioned $L{\times}W{\times}H=30{\times}7{\times}5\;mm$. Measurements showed that max. VSWR 2:1, efficiency 42.49~60.95 % and 47.95~73.21 %, average gain -3.72~-2.15 dBi and -3.19~-1.35 dBi on the GSM and DCS band, respectively. These results are good performances among the small antenna. And the radiation patterns are omnidirectional on the H-plane to both band.

• Journal of Broadcast Engineering
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• v.24 no.2
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• pp.299-305
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• 2019

In ISO MPEG, MPEG-H has been standardized to smoothly deliver huge volume of ultra-high resolution videos over heterogeneous network environments for the consumers. In the MPEG-H standard, MMT(MPEG Media Transport) protocol is the next generation MPEG media transport technology to provide hybrid media delivery over heterogeneous environments. It is important to sustain accurate media synchronization to provide ultra-high resolution video services over heterogeneous network environments. In this paper, we propose and verify an in-band media synchronization scheme to circumvent the problem of additional session setup and excessive traffic problems of the conventional out-of-band media synchronization supported by the MMT technology.

• Korean Journal of Food Science and Technology
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• v.25 no.1
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• pp.39-45
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• 1993

The effects of enzymatic modification with pepsin and actinidin was studied on molecular weight distributions and functional properties of hydrolysates from soy protein isolate (SPI) differing in degree of hydrolysis. The hydrolyzed SPI by pepsin showed 41.5% degree of hydrolysis after 5 min, and maximum hydrolysis was obtained after 2 hours. Actinidin hydrolyzed SPI 26.71% degree after 1 hour. On SDS-PAGE, native SPI showed 9 distinguishable bands on SDS-PAGE gel. Pepsin treated SPI showed one broad band in the lower part of gel. This band was shifted further to the bottom of the gel and became faint as hydrolysis time increased. While actinidin treated SPI showed different SDS-PAGE pattern from pepsin. However PAGE patterns were similar with pepsin and actinidin treated groups. With pepsin treatment, solubility of SPI distinctively increased around isoelectric point(pI). Emulsifying activity (EA) and emulsifying stability (ES) showed marked increase over pH range of $3.0{\sim}8.0$. 5 min modified group had most excellent foam expansion (FE). Foam stability (FS) was increased as pepsin treatment time increased at pI. With actinidin treatment, solubility was increased. 60 min modified SPI had the most effective EA at pH 4.5. However ES was not effected by actinidin treatment. 5 min modified group was most effect in FE. FS was higher at alkaline pH.

• Carbon letters
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• v.6 no.2
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• pp.96-100
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• 2005

Taguchi methodology has been applied to get an idea about the parameters related to the chemical vapour deposition technique, which influences the formation of semiconducting carbon thin film of a desired band gap. L9 orthogonal array was used for this purpose. The analysis based on Taguchi methodology suggests that amongst the parameters selected, the temperature of pyrolysis significantly controls the magnitude of band gap (46%). Sintering time has a small influence (30%) on the band gap formation and other factors have almost no influence on the band gap formation. Moreover this analysis suggests that lower temperature of pyrolysis (${\leq}$ $750^{\circ}C$) and lower time of sintering (${\leq}$ 1 h) should be preferred to get carbon thin film with the desired band gap of 1.2eV.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.18 no.6
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• pp.233-240
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• 2019

In this paper, due to the development of 5G communication technology, an antenna capable of covering both LTE and 5G bands is currently needed. In addition, we designed and manufactured a single feed antenna for the integrated public network (LTE) and 5G frequency dual band cover to satisfy the frequency bandwidth of more than 10% in each band. The antenna designed by adopting the dipole of the basic dipole antenna in a planar structure is a form in which the radiating element is vertically extended at all of the 700 MHz antennas and folded into a 'ㄷ' shape. In addition, the radiating element of the 700MHz band serves as a reflector of the 3.5GHz band radiating element. As a result, the 700 MHz band -10 dB bandwidth 104 MHz(14.8%) and 3.5 GHz band -10 dB bandwidth 660 MHz(18.8%) were obtained and the radiation pattern characteristic resulted in gains of 8.46 dBi, beam width E-plane 55°, H-plane 81° and 3.5 GHz bands 6.14 dBi, beamwidth E-plane 79°, H-Plane 49°.

• Journal of Life Science
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• v.14 no.4
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• pp.702-707
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• 2004

In native-polyacrylamide gel electrophoresis of Pangasius polyuranodon, the lactate dehydrogenase (EC 1.1.1.27, LDH) $A_4$, $A_3$B, $A_2$$B_2$,$AB_3$ and $B_4$ isozymes were expressed in various tissues. The LDH $A_4$ and liver-specific $C_4$ isozymes were expressed in the tissues of Hypostomus Plecostomus. The bands of LDH in skeletal muscle, heart and eye tissues were not detected while one band was detected in kidney and liver, and four bands were detected in brain. The detected one band in liver was identified as alcohol dehydrogenase and an anodal band of skeletal muscle was identified as nothing dehydrogenase. The LDH in skeletal muscle, heart and eye might function as pyruvate reductase. The degree of inhibitions of LDH in skeletal muscle and heart of P. polyuranodon by 10 mM pyruvate were measured 57.6% and 73.8%, respectively. However, those of LDH in tissues of H. plecostomus were measured 52.7-61.8% so tissue specificity did not appear. Therefore, H. ple-costomus might be more acclimated to hypoxic environment by anaerobic metabolism of LDH iso-zymes than P. polyuranodon.

• Progress in Superconductivity
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• v.8 no.2
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• pp.132-137
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• 2007

We have studied superconducting parameters of $MgB_2$ single crystals from reversible magnetization measurements with the magnetic field both parallel and perpendicular to the c-axis of the crystals. The temperature dependence of the London penetration depth, ${\lambda}_{ab}{^{-2}}(T)$, obtained from the Hao-Clem analysis on reversible magnetization, shows a clear discrepancy from single-band theories. It is also found that the anisotropies of the London penetration depth, ${\gamma}_{\lambda}$, slowly increases with temperature while the anisotropy of the upper critical field, ${\gamma}_H$, decreases with temperature. These behaviors are in sharp contrast with the behavior of superconductors with a single band. The temperature dependence of ${\lambda}_{ab}{^{-2}}$, and the opposite temperature dependences of ${\gamma}_{\lambda}\;and\;{\gamma}_H$ can be well explained with the theory of the two-band superconductivity.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1468-1469
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• 2007

포항가속기 연구소에서는 RIS 프로젝트 사업과제의 일환인 L-band 산업용 전자빔 가속기의 제작 및 기술개발 연구를 철원의 물리기술연고소 주관으로 수행하고 있다. L-band 산업용 전자빔 가속기는 전자빔에 의한 고분자개질 공정, 농수산물의 멸균 및 의료기기의 멸균 등에 적용이 가능하다. 포항가속기연구소에서는 10 MeV급 산업용 전자빔 조사장치에 적용되는 RF증폭기용 펄스 전원장치인 모듈레이터를 설계, 제작을 하였다. 펄스 전원장치인 이 모듈레이터 시스템은 평균 출력 60 kW, 펄스폭 7 us, 펄스반복율 300 Hz의 L-band 상업용 RF 증폭기 전원장치이며, RF 증폭기로 사용되는 클라이스트론은 Thales 사의 TV2022D를 사용하였다. 본 논문에서는 펄스 전원장치인 모듈레이터의 운전과 인터록을 위한 제어장치의 개발과 제작에 대하여 논하고자 한다.

• Journal of the Korean Institute of Telematics and Electronics A
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• v.31A no.1
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• pp.33-38
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• 1994

In this paper, waveguide banpass filters using H-plane step discontinuities are designed based on the field theory analysis and optimization of the resonator lengths as well as dimensions of discontinuities, instead of the conventional synthesis method based on the equivalent circuit. The waveguide inductive obstacles introduced by H-plane step discontinuities analyzed using mode-matching method and the generalized scattering parameters are derived. Using the derived scattering parameters of the discontinuities as well as those of resonators, waveguide bandpass filters are designed through optimization method, modified Razor search method proposed by J.H.Bandler. Using this design procedures, waveguide bandpass filters are designed and tested at X-band(center frequency 10GHz) as well as Ka-band(center frequency 35GHz).

• Journal of the Korean Institute of Telematics and Electronics A
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• v.29A no.3
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• pp.66-71
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• 1992

We fabricated highly stable a-Si:H solar cell using low band gap intrinsic layer fabricated by RP-CVD. We obtained a-Si:H with optical band gap of less than 1.65 eV with deposition rate of 0.18 $\AA$/sec, and used this material as bottom i-layer of a-Si:H double stacked solar cells. We have succeeded in the fabrication of very stable a-Si:H double stacked solar cell of which the conversion efficiency is about 9% and the degradation is less than 4% after light illumination for 100h under 350mW/cm$^{2}$.