• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2002년도 ITC-CSCC -3
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• pp.1944-1947
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• 2002

The importance of security in WLAN(Wireless LAN) service is very critical, so IEEE organization has made the IEEE 802.1x standard. The IEEE 802.1x standard uses the EAP as authentication protocol which requires AAA(Authentication, authorization, and Accounting) server for authentication & accounting. for the reliable and scalable AAA service, the Diameter protocol has more advanced characteristics than existing radius protocol. So the Diameter protocol can be used for WLAN service provider who has large scale WLAN system and a large number of subscriber. This paper proposes the design of Diameter AAA server for the authentication and accounting of WLAN system which is adopting IEEE 802.1x standard.

• 정보처리학회논문지D
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• 제11D권5호
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• pp.1073-1086
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• 2004

최근 전 세계적으로 IT 분야의 새로운 키워드로 부각되고 있는 것 중에 하나가 바로 무선 인터넷이다. 무선 인터넷이란 무선단말기를 사용하여 무선 환경에서 인터넷에 접속하여 데이터 통신이나 인터넷 서비스를 제공받을 수 있는 아키텍처와 기술 및 서비스를 말한다. 이러한 무선인터넷 기술은 기존의 유선 인터넷 기술과 더불어 정보의 활용 범위를 확장시키고 있다. 그러나 무선 인터넷 기술을 효과적으로 사용하기 위해서는 컨텐츠의 질적, 양적 공급이 확대되어야 한다. 이를 위해서는 기존의 유선환경에서 서비스되던 양질의 컨텐츠를 재사용하는 방안이 효과 적일 수 있다. 이에 본 논문에서는 무선 컨텐츠의 새로운 구축의 개념에서 벗어나 컨텐츠 자동 재작성 기술을 바탕으로 부분조합방식의 컨텐츠 생성기법을 설계 구현하고자 한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제6권9호
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• pp.2118-2135
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• 2012

With the rapid development of heterogeneous emerging wireless technologies and numerous types of mobile devices, the need to support robust mobile video streaming based on the seamless handover in Future Internet is growing. To support the seamless handover, several IP-based mobility management protocols such as Mobile IPv6 (MIPv6), fast handover for the MIPv6 (FMIPv6), Hierarchical MIPv6 (HMIPv6) and Proxy Mobile IPv6 (PMIPv6) were developed. However, MIPv6 depreciates the Quality-of-Service (QoS) and FMIPv6 is not robust for the video services in heterogeneous emerging wireless networks when the Mobile Node (MN) may move to another visited network in contrast with its anticipation. In Future Internet, the possibility of mobile video service failure is more increased because mobile users consisting of multiple wireless network interfaces (WNICs) can frequently change the access networks according to their mobility in heterogeneous wireless access networks such as 3Generation (3G), Wireless Fidelity (Wi-Fi), Worldwide Interoperability for Microwave Access (WiMax) and Bluetooth co-existed. And in this environment, seamless mobility is coupled according to user preferences, enabling mobile users to be "Always Best Connected" (ABC) so that Quality of Experience is optimised and maintained. Even though HMIPv6 and PMIPv6 are proposed for the location management, handover latency enhancement, they still have limit of local mobility region. In this paper, we propose a robust mobile video streaming in Heterogeneous Emerging Wireless Systems. In the proposed scheme, the MN selects the best-according to an appropriate metric-wireless technology for a robust video streaming service among all wireless technologies by reducing the handover latency and initiation time when handover may fail. Through performance evaluation, we show that our scheme provides more robust mechanism than other schemes.

• 산업기술연구
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• 제27권A호
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• pp.131-139
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• 2007

The recent advance in wireless network technologies has enabled the streaming media service on the mobile devices such as PDAs and cellular phones. Since the wireless network has low bandwidth channels and mobile devices are actually composed of limited hardware specifications, the transcoding technology is needed to adapt streaming media to given mobile devices. Futhermore owing to the diversity of bandwidth in the wireless network by reason of mobile users' movements and environments, it is difficult to provide stable QoS. In this paper, the autonomic multimedia transcoding system is proposed in order for users to provide network adaptive QoS. Our proposed system is based on the estimation of available bandwidth in wireless network for seamless multimedia streaming service. The proposed system is designed and implemented for various mobile clients. In experiments, we evaluate its seamless multimedia streaming and the adaptation transcoding bit rate according to the changes of bandwidth in wireless network.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 신호처리소사이어티 추계학술대회 논문집
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• pp.287-290
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• 2003

In recent years, one of the main trends of GIS is to construct and provide realistic and human-perceptible information of spatial object using video data. The rapid progress of wireless mobile technology makes the multimedia source using video data possible on mobile environment. Instead of traditional map-based service, video-based location services, that provide video data as location context, would be of interest in connection with various mobile applications requiring location service, such as telematics, LBS, etc. In this paper, we present the location service system using geo-referenced video on wireless mobile environment.

• 한국정보전자통신기술학회논문지
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• 제11권1호
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• pp.89-94
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• 2018

본 논문에서는 IoT (Internet of Things) 서비스 구현을 위한 스마트센서의 설계 방안을 연구하였다. 지속적인 데이터 수집을 위한 센서의 전원 공급부는 에너지 하베스팅 (Energy Harvesting) 기술을 적용하였으며, 주변 환경으로부터 영향을 줄일 수 있는 압전소자 (piezoelectric transducer)를 선택하여 전원 공급부를 설계하였다. 데이터 전송을 위한 무선통신 인터페이스는 BLE (Bluetooth Low Energy) 기술을 적용하여 설계하였다. BLE는 저전력 단거리 무선 통신에 적합하며, 주요 응용분야인 BLE 비콘 (beacon)은 O2O (Online to Offline) 서비스, 실내 측위 기반의 내비게이터, 도난/미아 방지 서비스에서 모바일 게임 등으로 활용 범위가 확대되고 있다. BLE 무선통신의 짧은 전송 거리를 보완하기 위해 무선 커버리지를 확대할 수 있는 방안을 연구하였으며, 네트워크 구축이 용이하고 무선 커버리지 확대할 수 있는 CATV 망을 활용한 BLE 센서 네트워크 구축 방안을 제안하였다.

• 정보화연구
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• 제10권1호
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• pp.63-70
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• 2013

본 연구는 특허 선행기술 조사분석 및 서비스 전략에 대한 것으로, 주로 무선 충전기술 분야의 동향과 선행 특허를 조사하고 해당 기술을 스마트폰 및 비스마트폰, 기술 및 디자인 및 UX/UI, 각 무선 충전기술 등과 연계하여 사용하기 적합한 서비스 및 전략을 제시하는 것이다. 무선충전시장의 시장 전망은 꾸준히 상승하고 있으며, 최근의 경우 2010년 1억 2,390만 달러 수준에서 2011년 8억 8,580만 달러로 약 6배정도 성장하였으며, 2014년에는 180억 달러 규모에 이를 것으로 예상되고 있다. 이 기술분야에 대한 관심은 꾸준히 증가하고 있는 추세이며 관련 상품도 지속적으로 등장하고 있다. 따라서 전 세계적으로 무선 충전 기술을 활용할 수 있는 기틀이 마련되고 있으며, 이 기술을 응용한 서비스나 제품에 대한 개발 및 연구가 후속되려면 다양한 관심과 노력이 수반되어야 한다. 본 연구의 결과로는 무선 충전 기술관련 특허전략 및 특정 제품관련 특허 무효화 전략이나 라이센싱 혹은 권리화 전략이 가능하고, 또한 새로운 디자인 및 배터리 공유와 내구성 강화 등을 가능케 하는 신규 특허전략이 도출되었다.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.608-611
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• 2005

The existing wired emergency call such as 119, 112 have its own location information to serving immediate rescue service. For the case of wireless emergency call by mobile phone, the location information should be provided by wireless network. This paper describes the network architecture and protocol for mobile emergency service referring TIAlEWJ-SID-036-A with reviews about technical issues, legacy factors and related researches. The mobile emergency service is divided into mobile emergency rescue service and mobile emergency alert service. The network reference model for mobile emergency rescue service is released in KOREA. In this paper, the interfaces between elements of the network reference model, and service scenarios, message flows are defined. Supplement to mobile emergency rescue service, the network reference model, interfaces and message flows for mobile emergency alert service are developed. The protocol is described by DID, and the proposed works are on processing for domestic standard of TTA.

• Journal of Communications and Networks
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• 제15권1호
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• pp.61-70
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• 2013

The increasing number of mobile users and the popularity of real-time applications make wired-wireless integrated network extremely attractive. In this case, quality of service (QoS) adaptability is particularly important since some important features of the integrated network call for QoS adaptability, such as mobility, bursty applications and so on. Traditional QoS schemes include integrated service (IntServ) and differentiated service (DiffSev) as well as their variants. However, they are not able to balance well between scalability and QoS granularity. For example, IntServ faces the scalability problem, while DiffServ can only provide coarse granular QoS. In addition, they are also unable to efficiently support QoS adaptability. Therefore, a per-packet differentiated queueing service (DQS) was proposed. DQS was originally proposed to balance between scalability and QoS granularity in wired networks and then extended to wireless networks. This paper mainly discusses how to use DQS to support QoS adaptability in wired-wireless integrated networks. To this end, we propose a scheme to determine dynamic delay bounds, which is the key step to implement DQS to support QoS adaptability. Simulation studies along with some discussions are further conducted to investigate the QoS adaptability of the proposed scheme, especially in terms of its support of QoS adaptability to mobility and to bursty real-time applications.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 하계종합학술대회 논문집(3)
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• pp.229-232
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• 2001

Wireless Internet based in WAP(Wireless Application Protocol) has been a very useful and attractive means picking up information through service irrelavant to time and space. And more the request of user has been diverse. In this paper, we implemented a Diet Menu System using expert knowledge-based rules on the WAP environment. This enables the moving man interested in diet to get information through wireless mobil hand phone. There are only connection-oriented system for this type of service till now. This paper has designed basic expert knowledge rules for result display, verified and implemented for WAP environment.