• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.32-37
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• 2009

Recently, electronic mail(E-mail) is the most popular communication manner in our society. In such conventional environments, spam increasingly congested in Internet. In this paper, Chinese spam could be effectively detected using text and image features. Using text features, keywords and reference templates in Chinese mails are automatically selected using genetic algorithm(GA). In addition, spam containing a promotion image is also filtered out by detecting the text characters in images. Some experimental results are given to show the effectiveness of our proposed method.

• Journal of The Korean Astronomical Society
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• v.37 no.4
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• pp.237-241
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• 2004

We perform numerical experiments on supernova-driven turbulent flows in order to see whether or not supernovae playa major role in driving turbulence in the interstellar medium. In a $(200pc)^3$ computational box, we set up, as initial conditions, uniformly magnetized gas distributions with different pairs of hydrogen number densities and magnetic field strengths, which cover the observed values in the Galactic midplane. We then explode supernovae at randomly chosen positions at a Galactic explosion rate and follow up the evolution of the supernova-driven turbulent flows by integrating numerically the ideal MHD equations with cooling and heating terms. From the numerical experiments we find that the density-weighted velocity dispersions of the flows are in the range of 5-10 km $s^{-l}$, which are consistent with the observed velocity dispersions of cold and warm neutral media. Additionally, we find that strong compressible flows driven by supernova explosions quickly change into solenoidal flows.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.36.1-36.1
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• 2009

We investigate the molecular and atomic gas properties of 20 Virgo cluster spiral galaxies by comparing with optical properties to assess the effect of the Virgo environment on the interstellar media of the Virgo disks. CO maps from FCRAO On-The-Fly (OTF) mapping survey and HI maps from VIVA (VLA Imaging of Virgo spirals in Atomic gas) are shown, and radial properties of molecular and atomic gas are compared. H2 deficiency along with HI is investigated, and gas evolution history of the Virgo cluster spirals is also examined.

• Journal of the Korean Home Economics Association
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• v.46 no.10
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• pp.59-69
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• 2008

The purpose of this study was to analyze the changes and intended meanings of decorations in women pants. Cross correlation was used to analyze 1829 pictures which appeared in national fashion magazines from 1969 to 2005. Three analysis categories were used: 1. type of decoration, 2. style, 3. fabric. The results of this investigation were as follows: (a) the decoration gave salience to the expressive function on the pants by merging different things, (b) the decoration acted on expressive media of new feminine beauty, and (c) the decoration reflected cultural identity through the addition of elements that represents different cultures or subcultures.

• Journal of Korea Game Society
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• v.17 no.4
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• pp.7-16
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• 2017

In this thesis, the objective is to identify and analyze trends in the evolution of virtual reality in the midst of the trend of digital content and the trend of the 4th industrial revolution. The analysis is divided into devices, development, distribution platforms and content fields, which are divided into active, static, and classical content and trend. This thesis is meaningful as a basic material in the planning stage of virtual augmented reality contents.

• Publications of The Korean Astronomical Society
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• v.30 no.2
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• pp.145-148
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• 2015

Young Galactic supernova remnants (SNRs) are where we can observe closely supernova (SN) ejecta and their interaction with the circumstellar/interstellar medium. They also provide an opportunity to explore the explosion and the final stage of the evolution of massive stars. Near-infrared (NIR) emission lines in SNRs mostly originate from shocked dense material. In shocked SN ejecta, forbidden lines from heavy ions are prominent, while in shocked circumstellar/interstellar medium, [Fe II] and $H_2$ lines are prominent. [Fe II] lines are strong in both media, and therefore [Fe II] line images provide a good starting point for the NIR study of SNRs. There are about twenty SNRs detected in [Fe II] lines, some of which have been studied in NIR spectroscopy. We will review the NIR [Fe II] observations of SNRs and introduce our recent NIR spectroscopic study of the young core-collapse SNR Cas A where we detected strong [P II] lines.

• Coupled systems mechanics
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• v.3 no.1
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• pp.73-88
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• 2014

The paper deals with a model founded on the physical processes in concrete subject to high temperatures. The model is developed in the framework of continuum damage mechanics and the theory of porous media and is demonstrated on selected structures. The model comprises balance equations for heat transfer, mass transfer of water and vapour, for linear momentum and for reaction. The balance equations are completed by constitutive equations considering the special behaviour of concrete at high temperatures. Furthermore, the limitation and decline of admissible stresses is achieved by using a composed, temperature depending crack surface with a formulation for the damage evolution. Finally, the complete coupled model is applied to several structures and to different concrete in order to determine their influence on the high-temperature-behaviour.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.06a
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• pp.31-34
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• 2018

최근 유무선 트래픽의 지속적인 증가에 대응하기 위해선 가입자 네트워크의 양적 확충은 물론, 새로운 인터넷 기술을 개발하고 그 구조를 재설계하는 등의 투자가 이루어지고 있다. 특히 차세대 미디어 서비스 등의 인터넷 수요 및 대역폭에 대한 요구가 증가로 인하여 가입자 망 진화의 필요성이 계속해서 이야기되고 있다. 정부에서는 10기가 인터넷 상용화를 목표로 '10기가 인터넷 상용화 촉진 선도 시범 사업'을 추진하고 있으며, KT와 SK브로드밴드 등 주요 통신사에서도 10Gbps 인터넷 상용화를 추진하고 있다. 이에 케이블 사업자도 인터넷 경쟁력 확보를 위해 HFC망 진화 방안에 대한 연구가 필요하다. 우선 상하향 10Gbps 전송이 가능한 DOCSIS 3.1 도입을 위해 망 장비 교체나 업그레이드 없이 주파수 확보가 이루어 져야 하며, 상향 전송 속도 확대를 위해 북미에서 표준화 진행중인 FDX(Full-Duplex) DOCSIS 도입을 위해 망 구조를 개선해야 한다.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2018.11a
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• pp.87-89
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• 2018

We proposed an improved reliable SVD-based watermarking scheme resistant to geometric attacks while having high fidelity with no false-positive problem. Principal components of a watermark image are embedded into singular values of LL, LH, HL, and HH sub-bands of a transformed cover image by RDWT(redundant discrete wavelet transform) with optimal scale factors. Each scale factor is generated by trading-off fidelity and robustness using Differential Evolution (DE) algorithm. Zernike Moment (ZM) is used to estimate the geometric distortion and to correct the watermarked image before extracting watermark. The proposed scheme improves fidelity and robustness of existing reliable SVD based watermarking schemes while resisting to geometric attacks.

• Animal Systematics, Evolution and Diversity
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• v.37 no.1
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• pp.52-63
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• 2021

One of the largest genera of subfamily Banchinae, the genus Glypta has been reported 505 species in the World. In this study, the genus Glypta is reported for the first time from South Korea. Twelve species are recognized, one of which is described as new: Glypta clypeorostrata sp. nov. We diagnose 11 newly recorded species(G. biauriculata, G. breviterebra, G. densepunctata, G. extincta, G. fronticornis, G. incisa, G. media, G. nigrina, G. talitzkii, G. tamanukii, and G. touyaensis) and provide a key along with digital images of 12 South Korean species.