• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.11a
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• pp.165-172
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• 2009

Integrated management model (SNMP/SMI) for lubiquitous egacy remote communication network or service make possible combination of various architecture. However, legacy management system cannot be applied some problems such as inefficient, complexly, implement and large network by reason of integration of voice and data, wired and wireless, and service area between service provider. For improve this, supplied JMX(Java Management eXtensions) on network management technology from SUN. JMX is integrated architecture for existing network management and monitoring. In this paper, we design and implement for integrated network management through multi-protocol agent using JMX.

• International journal of advanced smart convergence
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• v.1 no.1
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• pp.27-33
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• 2012

In this paper, we analyze and simulate performance of space time block coded (STBC) binary pulse amplitude modulation-direct sequence (BPAM-DS) ultra-wideband (UWB) systems with double binary turbo code in indoor environments for various ubiquitous healthcare (u-healthcare) applications. Indoor wireless channel is modeled as a modified Saleh and Valenzuela (SV) model proposed as a UWB indoor channel model by the IEEE 802.15.SG3a in July 2003. In the STBC encoding process, an Alamouti algorithm for real-valued signals is employed because UWB signals have the type of real signal constellation. It is assumed that the transmitter has knowledge about channel state information. From simulation results, it is shown that the STBC scheme does not have an influence on improving bit error probability performance of the BPAM-DS UWB systems. It is also confirmed that the results of this paper can be applicable for u-healthcare applications.

• Proceedings of the Korean Information Science Society Conference
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• 2005.11b
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• pp.7-9
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• 2005

본 논문에서는 모바일 무선 네트워크 상에서 효율적으로 XML문서를 방송하기 위한 기법을 제안한다. 이를 위해 XML 문서의 구조정보를 무선 방송 데이터의 색인으로 활용하여 XML문서를 스트링으로 재구성한다. 방송되는 XML스트링의 색인은 XML 경로 요약을 이용하여 축약된 형태로 표현하며, 구조 정보를 XML스트림의 색인으로 사용하기 위해 XML문서는 구조정보와 컨텐츠 정보로 분리한다. 축약된 색인을 이용하여 각 클라이언트는 방송되는 XML 스트림에 대하여 지역적으로 질의를 수행함으로써 전체 XML문서 중 자신이 원하는 정보만을 수신한다. 성능평가를 통해 제안하는 기법이 접근 시간 및 튜닝시간에서 많은 이득을 볼 수 있음을 보인다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.6
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• pp.1041-1046
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• 2004

Orthogonal frequency division multiplexing(OFDM) is becoming the chosen modulation technique for wire and wireless communications with fast data rate because of good spectral efficiency and sufficient robustness of fading channel. Digital Video Broadcating is using OFDM to modulate. But Digital Video Broadcating has performance degradation in moving reception according to DOA(Direction of Arrival). The purpose of this paper is to improve reception performance using array antenna in environment with doppler effect.

• 한국정보통신설비학회:학술대회논문집
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• 2005.08a
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• pp.290-296
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• 2005

In this paper, we describe ubiquitous environments and the trend of convergence that is an evolution path of current telecommunication, and show the concept of broadband convergence network, service feature and evolution path. In order to converge wire and wireless communication, telecommunication and broadcasting, voice and data efficiently, broadband convergence network divides a network into service layer, control layer, transport layer, ubiquitous access and terminal layer. Broadband convergence network will be a network that can provide and control broadband multimedia services with QoS and securityof different and customized level. Then we depict characteristics and types of broadband multimedia service, and describe the characteristic of broadband convergence network. Finally, we show ubiquitous network based on the broadband convergence network to provide ubiquitous service which is a future telecommunication service. We also describe requirements of ubiquitous network such as an intelligent and context based platform, convergence terminals, ubiquitous computing devices, etc., and give various emerging technologies and those applications.

• Journal of The Institute of Information and Telecommunication Facilities Engineering
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• v.3 no.2
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• pp.81-89
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• 2004

In this paper, we describe ubiquitous environments and the trend of convergence that is an evolution path of. current telecommunication, and show the concept of broadband convergence network, service feature and evolution path. In order to converge wire and wireless communication, telecommunication and broadcasting, voice and data efficiently, broadband convergence network divides a network into service layer, control layer, transport layer, ubiquitous access and terminal layer. Broadband convergence network will be a network that can provide and control broadband multimedia services with QoS and security of different and customized level. Then we depict characteristics and types of broadband multimedia service, and describe the characteristic of broadband convergence network. Finally, we show ubiquitous network based on the broadband convert- gence network to provide ubiquitous service which is a future telecommunication service. We also describe requirements of ubiquitous network such as an intelligent and context based platform, convergence terminals, ubi- quitous computing devices, etc.

• International journal of advanced smart convergence
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• v.10 no.3
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• pp.33-40
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• 2021

Recently, wearable computers equipped with various biosensors such as smart watches, smart bands, and smart patches that support daily health management of users as well as patients have been released. Users of wearable computers such as smart watches face various difficulties in performing biometric information processes such as data sensing, collection, transmission, real-time analysis, and feedback in a weak wireless and mobile biometric information service environment. In particular, the biometric information collection interface is an important basic process that determines the quality and performance of the entire biometric information service. So far, research has focused on sensing hardware and logic. This study intensively considers the interface method for effectively sensing and collecting raw biometric information. In particular, the process of collecting biometric information is designed and analyzed from the perspective of periodicity. Therefore, we propose an efficient and stable periodic collection method.

• Journal of Broadcast Engineering
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• v.21 no.5
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• pp.662-671
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• 2016

In this paper, we propose a wireless video transmission system, providing medium and long communication distance in the 5.8GHz band to decrease the loss of video data. Beamforming with multiple antennas in a radio environment to enable more than 10km communication distance and an image transmission method that combines the retransmission to MCS(modulation and coding scheme) are applied. By applying the proposed method in the indoor environment of 80dB attenuation using the payload size of 1000 bytes, the packet loss rate of at least 0.92% is achieved through the FPING with the time-out of 10ms. The transmission distance of 21.2Km is achieved with the transmission rate of 13Mbps in the outdoor environment.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.38B no.7
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• pp.553-563
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• 2013

When the IEEE 802.11 wireless LAN-based broadcasting services, we use broadcast packets to broadcast multimedia contents to a large number of users using limited wireless resources. However, broadcast transmission is difficult to recover the loss packets compared with unicast transmission. Therefore, analysis of packet loss characteristics is required to perform efficient packet recovery. The packet loss in wireless transmissions is often bursty with high loss data rate. Even if loss patterns have the same average packet loss, they are different in the recovery rate of random loss and burst loss depending on the nature. Therefore, the analysis and research of the nature of the loss are needed to recover loss packets considering bursty characteristics. In this paper, we experimented Wi-Fi broadcast transmission according to transmission rate and analyzed bursty characteristics of loss patterns using 4-state markov model.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.1
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• pp.573-577
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• 2005

Recently there are increasing needs for Internet and various kinds of contents. These traffics for various contents need more amount of data to provide high-quality information and require various QoS depending on the characteristics of contents. However, current Internet service supports BE (Best Effort) service only, therefore IntServ (Integrated Service) scheme and DiffServ (Differentiated Service) scheme are represented to support QoS in IP layer. Moreover, while wireless Internet is getting popular, MAC(Medium Access Control)is also becoming important. This is due to the fact that wireless access, resource allocation and packet scheduling, which are done in another layers before, are performed in MAC layer in many new wireless systems. This paper describes new scheme that provides QoS taking into account the traffic characteristics over Mobile IPv6 network based on IEEE 802.11e EDCF and evaluates the performance through computer simulation.