• 한국통신학회:학술대회논문집
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• 한국통신학회 2004년도 하계종합학술발표회논문초록집
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• pp.361-361
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• 2004

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2006년도 하계학술대회
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• pp.43-46
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• 2006

IEEE 802.16 WirelessMAN aiming to broadband wireless access (BWA) is evolving to 4G mobile communication system through the standardization of IEEE 802.16e supporting mobility on existing fixed WirelessMAN system. It is necessary for hand-over to provide seamless data service while MS (Mobile Station) moves to another BS (Base Station). Because the performance of handover affects packet loss or delay of any communications, it must consider low latency handover mechanism in packet based network. In this paper, we describes handover scheme of IEEE 802.16e with the cell edge interference problem and shows the way to solve the problem in frequency reuse one deployment. Our scheme reduces the handover latency and packet loss probability.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.60-60
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• 2000

CAN(Controller Area Network) is a serial communication protocol which specifies very low cost and high performance. It is widely used in rea1-time control applications such as automobiles, aircraft, and automated factories. The main application fields are industrial control systems and embedded network. In this paper, the CAN monitoring system is proposed and implemented. Also its performance is tested in the mobile robot which is integrated by CAN and its performance lot receipt failure rate is evaluated. This can be used to analyze the performance of the network. It can tie also used to manage and monitor the network.

• Journal of information and communication convergence engineering
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• 제5권3호
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• pp.209-214
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• 2007

In this paper, we proposed a new MANET (Mobile Ad hoc Networks) technology of routing protocol. The MANET has a mobility formation of mobile nodes in the wireless networks. Wireless network have two types architecture: the Tree based multicast and shared tree based. The two kind's architecture of general wireless networks have difficult to solve the problems existing in the network, such as connectivity, safety, and reliability. For this purpose, as using that ADDMRP (Ad hoc network Doppler effect-based for Dynamic Multicast Routing Protocol), this study gives the following suggestion for new topology through network durability and Omni-directional information. The proposed architectures have considered the mobility location, mobility time, density, velocity and simultaneous using node by Doppler effects and improved the performance.

• 음성과학
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• 제6권
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• pp.163-179
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• 1999

For the set up, management and repair of a mobile communication system, continuous estimation of speech quality is required. Speech quality measurement can be conducted by listener's judgement in a subjective test such as MOS (Mean Opinion Score) test. However, this method is laborious, expensive and time-consuming, it is advisable to predict subjective speech quality via objective measures. This paper presents a robust objective speech quality measure, PLP-CMS (Perceptual Linear Predictive-Cepstral Mean Subtraction), which can predict subjective speech quality in mobile communication systems. PLP-CMS has a high correlation with subjective quality owing to PLP (Perceptual Linear Predictive) analysis and shows a robust performance not being influenced by PSTN (Public Switched Telephone Network) channel effects due to CMS (Cepstral Mean Subtraction). To prove the performance of our proposed algorithm, we carried out subjective and objective quality estimation on speech samples which are variously distorted in a real mobile communication system. As a result, we demonstrated that PLP-CMS has a higher correlation with subjective quality than PSQM (Perceptual Speech Quality Measure) and PLP-CD (Perceptual Linear Predictive-Cepstral Distance).

• Journal of information and communication convergence engineering
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• 제7권3호
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• pp.330-334
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• 2009

Most security solutions and middleware on home network consider internet users as approaching subject. It is unrealistic where the most subjects are mobile users who want to control home network devices. Therefore minor and fast certification structures are needed to control other devices with mobile device that has lower computing capacity. To solve the above problems, this paper wants to build safe certification frame work for internet and mobile users to control household devices safely. New certification structure is proposed to get out of heavy certification structure like PKI and to minimize encrypting and decrypting operation by compounding session key and public key.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2002년도 춘계학술발표논문집 (하)
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• pp.1289-1292
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• 2002

The number of connected computers in the Internet, which has reached a state in which its address space is becoming insufficient is exponentially increased. Also nowadays modern Laptops and Mobile terminal are being used more and more. As hewn, the number of available IPv4 address is limited and many organizations have limited budget to use the global address. So the way to overcome such problems is using private addresses in their networks. In addition, the use of private address makes the system more secure. Moreover, we have considered about supporting of the scalability of data forwarding processes of nodes in their network especially Mobile IP data communication. Thus, we propose the integration of MPLS and Mobile IP network. Also we propose the security services of a constrained LSP for the MPLS payloads.

• International Journal of Computer Science & Network Security
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• 제21권12spc호
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• pp.565-569
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• 2021

The rapid growth and development of ICT (Information and Communication Technology) and internet services has boosted the adoption of Mobile Government services all around the globe. There is a huge increase in the adoption of government services during COVID-19 pandemic. Existing Mobile Government (MG) solutions are not trustworthy and secure. This paper provides secure and trustworthy solution for mobile government, proposes a centralized smart governance architecture which is based on trust manager. Our proposed work has Wireless Bridge Certifying Authority (WBCA) and Wireless Public Key Infrastructure (WPKI) thereby ensuring security and privacy. Our proposed work ensures trust with WBCA as WBCA acts as a Trust Manager (TM). Proposed protocol has less computational cost and energy cost

• 디지털융복합연구
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• 제10권10호
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• pp.289-294
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• 2012

본 논문에서는 스마트폰의 모바일 특성을 활용하여 시간과 공간의 제약 없이 서비스할 수 있고, 기존의 오프라인에서 이루어지던 다양한 서비스들이 모바일에서도 구현될 수 있는 사례관리 실시간 커뮤니티 시스템을 연구하여 개발하였다. 이를 위하여 일반 PC/노트북이외에 스마트모바일까지 동일한 환경 제공을 위한 HTML5 웹 전환과 동일한 Network 상의, 장치별 브라우저 Size를 고려한 최적의 인터페이스 구성하여 차세대 웹표준 HTML5기반 통합사례관리 웹과 모바일 웹으로 구현하였으며, 다양한 종류의 스마트기기 OS를 지원하는 SenchaTouch Mobile Framework 기반의 Hybrid App 개발하여 서버 간 실시간 동기화 및 메시지 Push Notification 기능 구현을 통하여 관리자와 보호자 간 대상자 실시간 양방향 커뮤니케이션 구현하여 실시간 사례관리 커뮤니티 시스템을 구현하였다.

• 전자공학회논문지CI
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• 제46권5호
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• pp.37-43
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• 2009

광대역 무선 및 이동 통신망에서의 스트리밍 비디오 서비스는 최근 학계와 산업계로부터 많은 주목을 받고 있다. 특히, 모바일 와이맥스 (IEEE 802.16e) 네트워크 환경은 높은 전송율과 유연성있는 서비스 품질을 제공할 수 있기 때문에 이러한 스트리밍 서비스가 특히 매력적이다. 그러나 압축 비디오 시퀀스가 갖는 무선 및 이동망 오류 채널에 대한 민감성을 고려할 경우에, OFDMA 부반송파 물리 채널에서의 오류 발생으로 인해 화면 내의 메크로블록 또는 슬라이스 일부가 손상을 받을 수 있음에 주목할 필요가 있다. 본 논문에서는 교차 계층 설계를 기반으로하여 OFDMA 부반송파 채널 특성에 적응적인 모바일 스트리밍 서버를 소개한다. 이 스트리밍 서버 시스템은 기지국의 기존 스케줄러, 패킷 배열/재조립, 부반송파 할당 전략 등의 변경없이 낮은 신호 세기를 갖는 부반송파에서도 스트리밍 비디오의 품질 악화를 줄이는데 효과적이다.