• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.291-294
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• 2017

최근 국내에서 신 변종 공격이 대량으로 발생함에 따라, 한정적인 보안전문 인력과 기존의 장비로 분석 및 대응하는데 어려움이 있다. 본 논문에서는, 대량으로 발생하는 침해사고에 대해 분석 우선순위를 확인하고자, 침해사고에 활용된 침해지표들의 위협을 분석하고 이를 정량적인 값인 침해지표 위협수준(TL_IoC, Threat Level of IoC)로 도출하는 방안을 제안한다. 이를 통해, 침해지표의 위협수준을 직관적으로 확인함으로써 침해사고의 대응수준을 신속하게 판단하고, 위협수준이 높은 침해사고에 대해 능동적으로 빠르게 분석함으로써 대량의 침해사고를 효율적으로 대응할 수 있다.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.52 no.1
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• pp.42-47
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• 2016

This study was conducted to investigate visual threshold of nigro (Cichlasoma nigrofasciatum) on white LED light. The visual threshold was obtained by analyzing electrocardiogram (ECG) of the nigro. 5 individuals (body weight: 15.62~45.49 g; TL: 8.9~12.4 cm) were trained for lights by an electric stimulus. And then the heart rate (beats/10s) before and after switching on the light were compared. Light intensity range was from 0.00 to 226.4 lux. Average heart rate was 10.36 beats/10s in the normal condition. When the fish perceived the light, the heart rate was decreased. Visual threshold of the fish was 2.59 lux.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.45 no.5
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• pp.507-512
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• 2012

One leptocephalus (TL 59.9 mm) from the family Ophichthidae collected from Jeju Island, Korea, was identified using morphological and molecular methods. Our ophichthid leptocephalus was identified as belonging to the genus Muraenichthys based on morphological characters: 157 myomeres; the origin of the dorsal fin located a little in front of the anus; a distinct melanophore present on the opercle; and six gut swellings present. An analysis of 886 base pairs of the 12S rRNA mtDNA sequences showed that our leptocephalus must be Muraenichthys gymnopterus, because its sequences were concordant with those of an adult M. gymnopterus (d=0.001) and next to those of Muraenichthys sp. leptocephalus (d=0.034). Here, we are the first to describe the morphological characteristics of the M. gymnopterus leptocephalus.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.4
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• pp.171-178
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• 1996

DCB(pure mode I) and CLS(mixed mode) tests were performed to investigate the effect of fracture mode on the interlaminar fracture of composite laminate. Mode I critical strain energy release rate was found to be $133J/m^2$ from the DCB test and total strain energy release rate decreased from $1, 270J/m^2$ as thickness ratio(tl/t) varied from 0.333 to 0.667 from the crease from the CLS test. Crack length had no effect on the total strain energy release rate and load was almost constant during the crack growth of the specimen which had the specific thickness ratio. Crack initiated when the stress of the strap ply reached constant stress $42kgf/mm^2$ which was found to be independent of the thickness ratio.

• Proceedings of the Korea Institutes of Information Security and Cryptology Conference
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• 2003.12a
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• pp.160-165
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• 2003

최근 들어 무선 랜에 대한 사람들의 인식이 높아지고, KT의 NESPOT과 같은 공중망 사업자들에 의한 핫스팟 서비스가 제공되면서 무선 랜의 수요 또한 급증하고 있다. 무선 랜의 사용자가 증가하면서 무선 랜 보안의 중요성 역시 증가하고 있으며, 실제로 무선 랜에서의 안전한 네트워킹을 위하여 여러 단체들이 다양한 방향에서 연구를 진행 중에 있다. 그 한 예가 802.1X인데, 이것은 인증 서버를 따로 두어 AP를 통해 네트워크에 접속하려는 사용자들을 인증하여 주는 것이다. 이 논문에서는 802.1X 인증 방법 중 X.509 기반의 인증서를 사용하여 서버와 클라이언트간의 상호 인증을 가능하게 하여 주는 EAP-TLS 환경을 분석하고, LINUX 환경에서 공개 소스로 구축하여, 실제로 무선 랜을 사용하는 환경에 적용하는 과정을 기술한다.

• Proceedings of the KSPS conference
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• 2005.11a
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• pp.67-70
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• 2005

Voice conversion (VC) is a technique for modifying the speech signal of a source speaker so that it sounds as if it is spoken by a target speaker. Most previous VC approaches used a linear transformation function based on GMM to convert the source spectral envelope to the target spectral envelope. In this paper, we propose several nonlinear GMM-based transformation functions in an attempt to deal with the over-smoothing effect of linear transformation. In order to obtain high-quality modifications of speech signals our VC system is implemented using the Harmonic plus Noise Model (HNM)analysis/synthesis framework. Experimental results are reported on the English corpus, MOCHA-TlMlT.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.890-891
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• 2013

인터넷이 발달함에 따라 사용자들은 웹에서 여러 가지 일의 처리가 가능하게 되었다. 최근에는 휴대폰의 성능과 기능이 발달하고 스마트폰의 보급이 급속히 확산되면서 스마트폰을 사용하여 많은 양의 데이터들의 전달이 이루어지고 있다. 이러한 처리 과정에서 개인 및 기업정보들이 유출될 수 있는 위험이 증가하고, 스마트폰과 클라이언트 사이에서의 개인, 기밀 정보가 SSL (Secure Sockets Layer) 또는 TLS (Transport Layer Security)프로토콜을 통해 암호화 되어 전송 되어도 프록시 서버에서 인증서 변조를 통하여 유출될 가능성이 점점 높아지고 있다. 본 논문에서는 스마트폰 상의 안전한 통신을 위해 많이 이용되는 SSL/TLS의 전송구간에 대한 취약점 분석 등 보안 이슈와 연구 방향에 대해 논의한다.

• Korean Journal of Ecology and Environment
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• v.57 no.1
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• pp.39-50
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• 2024

In ecosystems within limited resources, interspecific competition is inevitable, often leading to the competitive exclusion of inferior species. This study aims to provide foundational information for the conservation and restoration management of Microphysogobio rapidus by evaluating species' ecological response to biological factors within its habitat. To understand this relationship, we collected food web organisms from site where M. rapidus coexist with Microphysogobio yaluensis, a specie ecologically similar to M. rapidus, and evaluated the trophic levels (TL), isotopic niche space (INS), and the overlap of INS among fishes within the habitat using stable isotope analysis. Our analysis revealed that the M. rapidus exhibited a higher TL than M. yaluensis, with TL of 2.6 and 2.4, respectively. M. yaluensis exhibited a broad INS, significantly influencing the feeding characteristics of most fish. Conversely, M. rapidus showed a narrow INS and asymmetric feeding relationships with other species, in habitats with high competition levels. This feeding characteristics of M. rapidus indicate that the increase in competitors sharing the similar resources lead to a decrease in available resources and, consequently, is expected to result in a decrease in their density.

• Korean Journal of Environmental Biology
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• v.37 no.2
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• pp.217-227
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• 2019

The purpose of this study was to investigate the initial growth, burrowing depth, and relative growth of mud shrimps (Upogebia major and Austinogebia wuhsienweni), living in damaged high density tidal flat shellfish farms form 2008 in the Western coast of Korea. By August, young mud shrimps (Upogebia major), which had settled down on the tidal flats in early May, grew to more than 10 mm in carapace length (CL). At the end of the first year, their CL and total length (TL) increased to 14.21 mm and 42.28 mm, respectively. The inhabiting depth of the young mud shrimps (Upogebia major) increased rapidly up to about 6 months after stocking (5 cm in July, 12.5 cm in September, and 28 cm in November, respectively). The inhabiting depth of adult mud shrimps in their burrows was about 10-93 cm during the year. As results, the analysis of the relative growth between the carapace length (CL) - the total length (TL) and the CL - total wet weight (TWW), the total wet weight of mud shrimps at Boryeong Saho (inner part of the Cheonsu-bay) was estimated to be 1.2-4 g heavier than those of Boryeong Jugyo (Outer part of the Cheonsu-bay) tidal flat. The young mud shrimps primarily grew from April to October. It is therefore crucial to observe whether the settlement of young mud shrimps on tidal shellfish farms from May to June to minimize the damage of shellfish farms by newly stocked young mud shrimps. In addition, it is recommended that young mud shrimps grown in fisheries be harvested before they dig deep into the sediment until early December.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.14 no.4
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• pp.331-341
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• 2016

To evaluate the physicochemical and radiological properties of raw materials and by-products in domestic distribution, about 220 samples with 16 species were prepared. We measured the energy spectrum and the chemical content, such as U, Th, and K, using a $LaBr_3$ scintillation detector and ED-XRF. In addition, HPGe detector was used to analyze the radioac-tivity of $^{234}Th$, $^{234}mPa$, and $^{214}Bi$ in uranium decay series and $^{228}Ac$, $^{212}Pb$, and $^{208}Tl$ in thorium decay series, and $^{40}K$. The correlation between characteristic variables, such as the count rate in several ROIs, chemical content, and radioactivity, was assessed to infer the radioactivity of natural radionuclides through a rapid screening method. Based on the results, a characteristic database for raw material and by-product in domestic distribution was established and it will provide useful information in the analysis procedure and improve the accuracy and reproducibility in the analysis of natural radionuclides.