• Proceedings of the Korean Nuclear Society Conference
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• 2004.10a
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• pp.669-670
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• 2004

• Proceedings of the Korean Vacuum Society Conference
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• 2006.02a
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• pp.241-241
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• 2006

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.625-628
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• 2015

POLARBEAR is a ground-based experiment located in the Atacama desert of northern Chile. The experiment is designed to measure the Cosmic Microwave Background B-mode polarization at several arcminute resolution. The CMB B-mode polarization on degree angular scales is a unique signature of primordial gravitational waves from cosmic inflation and B-mode signal on sub-degree scales is induced by the gravitational lensing from large-scale structure. Science observations began in early 2012 with an array of 1.274 polarization sensitive antenna-couple Transition Edge Sensor (TES) bolometers at 150 GHz. We published the first CMB-only measurement of the B-mode polarization on sub-degree scales induced by gravitational lensing in December 2013 followed by the first measurement of the B-mode power spectrum on those scales in March 2014. In this proceedings, we review the physics of CMB B-modes and then describe the Polarbear experiment, observations, and recent results.

• Journal of the Korean Vacuum Society
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• v.15 no.4
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• pp.331-337
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• 2006

Cavity-type beam position monitors were developed in collaboration with KEK to use for the future accelerators such as international linear collider (ILC) or x-ray free electron laser (XFEL) in PAL. BPM components such as BPM cavity, beam tubes, waveguides and feedthroughs were assembled by brazing at the same time to reduce mechanical errors during the fabrication. There are four screwed pins around outer rim of the cavity for the tuning of cavity frequency and x-y isolation. The resonance frequency of BPM is 6.422 GHz, the inner diameter of cavity is 53.822 mm, and the range of mechanical adjusting is $+ / - 250{\mu}m$. The x-y isolation was measured better than -40 dB after tuned. Test results of signal forms, x-y isolations, sensitivities are satisfied within requirements for the KEK ATF2 beam line.

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.159.1-159.1
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• 2007

• Korean journal of communication and information
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• v.61
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• pp.98-117
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• 2013

In 2009, Korea Communications Commission(KCC) added a new clause which regulates the protection of the media diversity to the Broadcasting Act. Specifically, the provision, Article 35-4, contains the creation of the Media Diversity Committee which is responsible for (1) the measure of TV audience share by media company; and (2) the development of summing up index of the different media influence by the end of 2012. Although the Korean version of diversity index as German KEK was made after a careful consideration based on the necessity to devise a criterion to determine the appropriate level of ownership regulation for the media companies, several issues including the measurement method have been raising the consistent controversy among experts. This study focuses on the evaluation of the media diversity policy by indicating the problems of the devised index and showing the concrete issues of the contention. As the result of the policy delphi-analysis targeted 10 media experts, this study suggest that the Article 35-4 of Broadcasting Act needs to be amend into the realistic and rational directions in well with the tenets of the law.

• Progress in Superconductivity
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• v.14 no.2
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• pp.99-101
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• 2012

Fluorescent yield X-ray absorption fine structure (XAFS) spectroscopy is useful for analyzing local structure of specific elements in matrices. We developed an XAFS apparatus with a 100-pixel superconducting tunnel junction (STJ) detector array with a high sensitivity and a high resolution for light-element dopants in wide-gap semiconductors. An STJ detector has a pixel size of $100{\mu}m$ square, and an asymmetric layer structure of Nb(300 nm)-Al(70 nm)/AlOx/Al(70 nm)-Nb(50 nm). The 100-pixel STJ array has an effective area of $1mm^2$. The XAFS apparatus with the STJ array detector was installed in BL-11A of High Energy Accelerator Research Organization, Photon Factory (KEK PF). Fluorescent X-ray spectrum for boron nitride showed that the average energy resolution of the 100-pixels is 12 eV in full width half maximum for the N-K line, and The C-K and N-K lines are separated without peak tail overlap. We analyzed the N dopant atoms implanted into 4H-SiC substrates at a dose of 300 ppm in a 200 nm-thick surface layer. From a comparison between measured X-ray Absorption Near Edge Structure (XANES) spectra and ab initio FEFF calculations, it has been revealed that the N atoms substitute for the C site of the SiC lattice.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.11 no.7
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• pp.1332-1340
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• 2007

This paper describes an efficient hardware design of key wrap/unwrap algorithm for security layer of WiBro system. The key wrap/unwrap core (WB_KeyWuW) is based on AES (Advanced Encryption Standard) algorithm, and performs encryption/decryption of 128bit TEK (Traffic Encryption Key) with 128bit KEK (Key Encryption Key). In order to achieve m area-efficient implementation, two design techniques are considered; First, round transformation block within AES core is designed using a shared structure for encryption/decryption. Secondly, SubByte/InvSubByte blocks that require the largest hardware in AES core are implemented by using field transformation technique. As a result, the gate count of the WB_KeyWuW core is reduced by about 25% compared with conventional LUT (Lookup Table)-based design. The WB_KeyWuW con designed in Verilog-HDL has about 14,300 gates, and the estimated throughput is about $16{\sim}22-Mbps$ at 100-MHz@3.3V, thus the designed core can be used as an IP for the hardware design of WiBro security system.

• Proceedings of the Korea Association of Crystal Growth Conference
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• 1997.06a
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• pp.131-134
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• 1997

Scintillation crystals for industrial field are used in fundamental physics i.e. nuclear and high energy physics experiments besides the medical imaging, process control and gauging, container inspection, mineral process etc. For the reason of limited marketability, there are not so many studies with emphasis paced on the crystal growth. The scintillation crystal is an important theme in the studies in the fundamental physics and researchers for crystal growth are expected participate it. The present work is partly supported by a Grant-in-Aid from the Japanese Ministry of Education, Science and Culture.

• Journal of Plant Biotechnology
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• v.8 no.1
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• pp.9-14
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• 2006

As an alternative method to produce low cost reagents for immunodiagnosis and protect the plants from viral disease, a gene encoding a single chain variable fragment(scFv) recombinant antibody targeted to the coat protein of cucumber mosaic virus (CMV) was expressed in Nacotiana tabacum. The source of the scFv recombinant antibody gene was from spleen tissue of an immunized mouse. The gene was initially cloned into the pCANTAB5E phagemid and expressed in E. coli. In the following study, the antibody gene was subcloned into the plant expression vector, pCAMBIA-1301 and introduced into tobacco leaf tissue via Agrobacterium tumefacients mediated transformation. After transformation, 56 out of 58 plants were shown to carry the desired anti-CMV scFv gene by PCR analysis. Overall, only 12.5% of the 56 putative transgenic plants were found to express the antibody to a detectable level.