• ETRI Journal
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• v.32 no.2
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• pp.255-264
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• 2010

Interference scenarios and methodologies between a terrestrial mobile service (MS) system and mobile-satellite service (MSS) system in a co-channel environment are established. Taking into account a practical deployment situation for both systems, we perform computational simulation of interference in terms of carrier-to-interference ratio (C/I) and interference-to-noise ratio (I/N) to evaluate the cofrequency interference from an MS system into an MSS system, and from an MSS system into an MS system, respectively. The methodology and results can be used as a guide when planning the deployment of MSS and MS systems with no unacceptable interference impact between them.

• Proceedings of the CALSEC Conference
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• 2001.08a
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• pp.477-482
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• 2001

Under rapidly changing business surrounding, companies need information systems to keep their competitive powers and forecast business surroundings beforehand. In these trends, interests of ASP (Application Service Provider) service is increasing because of the advantage for efficiency to maintain a system and an inexpensive investment to build a system, and this service is rapidly spreading to many parts from simple functions to ERP system. In this research, we argue about these problems and about administrative framework technology for efficient ASP service of ERP system.

• ETRI Journal
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• v.38 no.5
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• pp.858-867
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• 2016

A high dynamic range (HDR) video service is an upcoming issue in the broadcasting industry. For compatibility with legacy devices receiving a non-constant luminance (NCL) signal, new tools supporting an HDR video service are required. The current pre-processing chain of HDR video can produce color noise owing to the chroma component down-sampling process for video encoding. Although a luma adjustment method has been proposed to solve this problem, some disadvantages still remain. In this paper, we present an adaptive color noise reduction method for an NCL signal of an HDR video service. The proposed method adjusts the luma component of an NCL signal adaptively according to the information of the luma component from a constant luminance signal and the level of color saturation. Experiment results show that the color noise problem is resolved by applying our proposed method. In addition, the speed of the pre-processing is increased more than two-fold compared to a previous method.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.14 no.9
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• pp.3907-3923
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• 2020

An enhanced irregular repetition slotted ALOHA (IRSA) protocol is proposed by using polarization characteristic of satellite link and MIMO detection in low earth orbit (LEO) satellite networks, which is dubbed polarized MIMO IRSA (PM-IRSA). In the proposed scheme, one or two packets in one slot can be decoded by employing polarized MIMO detection, and more than two collided packets in multiple slots which can construct the virtual MIMO model can be decoded by the MIMO detection algorithm. The performance of the proposed scheme is analyzed with the density evolution (DE) approach and the degree distribution is optimized to maximize the system throughput by using a differential evolution. Numerical results certify our analysis and show that the normalized throughput of the proposed PM-IRSA can achieve 1.89 bits/symbol.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.2
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• pp.566-578
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• 2018

In this paper, we design a segment training based individual channel estimation (STICE) scheme for the classical two-way relay network (TWRN) with multi-pair sources (MPS) and amplify-and-forward (AF). We adopt the linear minimum mean square error (LMMSE) channel estimator to minimize the mean square error (MSE) without channel estimation error, where the optimal power allocation strategy from the relay for different sources is obtained. Then the MSE gains are given with different source pairs among the proposed power allocation scheme and the existing power allocation schemes. Numerical results show that the proposed method outperforms the existing ones.

• Proceedings of the Korea Information Processing Society Conference
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• 2003.05b
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• pp.1461-1464
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• 2003

웹서비스는 XML, SOAP, WSDL, UDDI 등 기술 표준의 진화를 계기로 기업간의 거래나 인터넷 환경에 있어 가장 핵심이슈로 등장하고 있다. 그러나, 제반 기술 요소와 운영의 특성상 서비스의 품질, 가용성, 성능, 보안등에 대한 보장성 문제가 대두되고 있으며 이로 인해 기업 환경에 적용되어 확산되기까지는 어려움이 많다. 웹 서비스는 Management 영역별로 필요한 핵심요소와 그 기능들의 역할이 웹 서비스 확산 및 운영상의 성공 요인이 될 수 있다. 본 논문에서는 웹서비스 제공자와 사용자간의 중개자 역할을 수행하여 상호간의 신뢰성 있는 서비스 제공의 기반이 되는 Intermediary 영역에 대해 분류 및 기술하고 그 구성요소와 아키텍쳐 모델을 제시한다.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.359-360
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• 2008

As broadband wireless access systems are widely accepted, VoIP service over the wireless network is being requested. Because previous VoIP implementations are designed to provide service over wired network, they does not consider security problem sufficiently that is one of the most vulnerable aspects of wireless communication. Therefore, this paper describes how to implement secure VoIP service over wireless network with minimum overhead.

• Korean Journal of Veterinary Service
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• v.41 no.3
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• pp.165-169
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• 2018

This survey is performed for the vector mosquitoes including of Japanese encephalitis, Malaria and West niles virus. Black light traps were installed in 5 sites (Sejong lake, Janggun-myeon, Jeonui-myeon, Yeongi-myeon, Bukang-myeon). Mosquitoes were collected twice every week from five collection sites using a black light trap from May to September. A total of 10 species belonging to 4 genera, 14,234 female mosquitoes were collected and identified as vector mosquitoes. Among ten mosquito species, Culex pipiens complex was the most commonly mosquitoes (6,163 individuals, 43.3%). The greatest number of Culex pipiens pallens was trapped in the first week of July. A total of 115 pools from 14,234 mosquitoes were prepared according to their species, collection date and site. We have screened infection of virus in mosquitoes. All of virus were not detected in mosquitoes. Our findings confirm that population and first appearance time of vectors mosquitoes and virus infection in Sejong city.

• 한국정보통신설비학회:학술대회논문집
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• 2002.08a
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• pp.208-212
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• 2002

통신기술의 발달에 따라 기존의 통신망은 TP 기반의 NGN 구조로 통합이 추진되고 있으며, 서비스 형태도 음성주도형 서비스에서 음성과 데이터가 혼합된 멀티미디어형 서비스로 전환되는 추세이다. 또한 기존 PSTN 서비스를 인터넷기반으로 대체하는 인터넷전화 서비스가 출현하게 되었다. 인터넷전화 서비스는 VoIP 관련 번호 제도가 체계적으로 도입되고 사업자 역무가 구체화될 경우 본격적인 활성화 단계에 진입할 것으로 예상된다. 기업측면에서는 통신 요금을 절감하고 음성과 데이터를 통합하여 사용할 수 있는 사설망 구축을 적극적으로 도입하거나 활용을 검토하고 있는 추세이며 개인 고객들도 향후 IP 기반의 유무선 인터넷전화 서비스를 많이 활용하게 될 것이다. 결국 ITSP와 사설기업망이 많이 생겨나게 되고, 이러한 환경에서는 ITSP(Internet Telephony Service Provider)와 사설 기업망 가입자들은 모든 타사업자 (ITSP, 무선통신사업자. PSTN 사업자, 사설 기업망 등)들간 통신을 위하여 협약을 체결하고, 호 라우팅을 위한 정보를 유지하고 과금 정산 기능을 지원하여야 하는 문제점이 있다. 이를 위한 방안으로서 사업자간 정산 시스템을 중심으로 ITSP와 사설기업망 가입자를 연동하도록 구성할 수 있다. 프로토콜로서는 ETSI 표준 프로토콜 OSP을 사용하도록 한다. 본 고에서는 사업자간 정산 시스템(OSPs : OSP 서버)을 통한 ITSP와 사설 VoIP 망들간의 호 서비스 연동 방안을 제시하였다.

• Korean Journal of Veterinary Service
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• v.24 no.3
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• pp.243-253
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• 2001

Forty-five Salmonella typhimurium isolates were encountered 8 phage types in which DT197 and U302 were the predominant types. The DT104 type which was first found from pig in Korea, and was resistant to chloramphenicol, streptomycin, sulfamethoxazole/trimethoprim, tetracycline, gentamicin and nalidixic acid. Twenty-two S enteritidis isolates were encountered 5 phage types in which PT4 were the representative (predominant). S enteritidis isolates were susceptible to all antimicrobial agents. As a result of PFGE analysis for S typhimurium and S enteritidis, PFGE patterns was better than phage typing in discriminating of strains. PFGE patterns were not in accord with phage type even though some strain had the same phage types.