• Proceedings of the IEEK Conference
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• summer
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• pp.147-151
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• 2004

QoS is a subject of high interest for successful deployment of various services in a home gateway and the gateway is possible to support QoS by installing existing queuing disciplines, which control the outgoing traffic to guarantee only QoS of the traffic. But m the home gateway it is also important to guarantee QoS of the incoming traffic. This paper proposes an adaptive control of the traffic to guarantee QoS of incoming traffic into the home gateway. In the proposed method, the upper limit of the available bandwidth of sending rate varies with receiving rate. And the proposed method makes the gap between the allocated rate and the actual service rate of the traffic narrow. Some experiments on a test bed show that the proposed method is valid.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.42 no.9 s.339
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• pp.11-18
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• 2005

In ad hoc networks, many applications use the broadcast service that is elementary operation to support various important functions such as route discovery procedure. This paper presents several adaptive probabilistic broadcast schemes base on local information to alleviate the broadcast storm problem for wireless ad hoc network. Our schemes dynamically determine the rebroadcast probability at each node based on the neighbor information within two-hop span. Simulation results are presented, which show our schemes have a better performance over the deterministic flooding approach.

• 한국HCI학회:학술대회논문집
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• 2007.02c
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• pp.158-163
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• 2007

본 논문의 목적은 PC 용으로 구축되어 있는 웹 컨텐츠를 PDA나 휴대폰과 같은 다양한 멀티플랫폼 단말기에도 제공할 수 있도록 하는 것이다. 기존의 대부분 방식은 모든 단말기에 서비스 할 수 없으므로 단말기용으로 모바일 컨텐츠를 미리 생성해 놓고 그 제한된 단말기에만 서비스하였다. 이때 가장 큰 문제점은 하나의 PC 웹 컨텐츠를 이용하여 다양한 하드웨어 특성을 가지는 모바일 단말기 마다 재생 가능한 모바일 컨텐츠를 모두 생성하는 것이다. 본 논문에서는 MPEG-21 멀티미디어 프레임워크를 이용하여 유선 웹 컨텐츠를 다양한 멀티 플랫폼 단말기에 실시간으로 맞추어 서비스하는 시스템을 제안한다. 제안한 시스템은 다양한 단말기별로 모바일 컨텐츠를 생성하는 것이 아니라 모바일 컨텐츠의 구성 및 표현방법을 MEPG-21 의 DIDL 을 이용하여 중간언어로써 기술한다. 그리고 멀티미디어 데이터 부분(Resource)만 Off-line으로 미리 변환한다. 이동단말기 접속 시 멀티미디어 서술(Description)부분을 실시간으로 변환하고 그 단말기가 사용 가능한 변환된 리소스를 통하여 단말기에 적합한 모바일 컨텐츠를 실시간으로 생성하여 서비스한다. 본 논문은 추가적으로 모바일 웹 서비스를 제공하는 과정에서 발생할 수 있는 응답시간 지연 현상을 최소화 하기 위하여 선 서비스 후 변환 방법을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.3B
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• pp.175-182
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• 2006

In this paper, we propose a Localized Adaptive QoS Routing Scheme using POMDP and Exploration Bonus Techniques. Also, this paper shows that CEA technique using expectation values can be simply POMDP problem, because performing dynamic programming to solve a POMDP is highly computationally expensive. And we use Exploration Bonus to search detour path better than current path. For this, we proposed the algorithm(SEMA) to search multiple path. Expecially, we evaluate performances of service success rate and average hop count with $\phi$ and k performance parameters, which is defined as exploration count and intervals. As result, we knew that the larger $\phi$, the better detour path search. And increasing n increased the amount of exploration.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7A
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• pp.629-634
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• 2002

The next generation of wireless communication system is expected to provide users with wireless multimedia services such as high speed internet access and wireless mobile computing. Depending on the Quality of Service(QoS) requirements and different applications per user, many wireless communication systems have been proposed. The simple decoding algorithm of space-time block coding is based on the assumption of flat fading channel, where no intersymbol interference exists. In this paper, we propose to combine space-time transmit diversity with adaptive equalizer. The proposed system effectively eliminates interference caused by multipath environment. Simulation results show that the proposed system provides improved bit error rate performance.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.15 no.5
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• pp.1141-1146
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• 2011

In this paper, an adaptive RFID tag antenna in 900MHz for using in inadequate electromagnetic environment is designed and implemented. The dimension of the proposed passive tag is $102mm{\times}102mm{\times}9mm$, the operating frequency band is 908~914MHz and the detection range is 5.1m. This paper describes the development of the thermal, water and impact resisting tag. The implemented tag can be used for the inadequate environment such as in-built tag on the ground for the car management service.

• The KIPS Transactions:PartA
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• v.13A no.3 s.100
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• pp.211-222
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• 2006

The cluster system with shared-nothing storage cannot escape from the problem of skewed request toward specific contents. This paper, therefore, suggests streaming method using MDC (Multiple Description Coding) instead of using single original content; this method is able to cope with skewed request in shared-nothing storage server as well as to continue to provide services in case of the system failure. Also, the system can support adaptive streaming service according to user player type, network status, the load of server, and client.

• Journal of Electrical Engineering and Technology
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• v.9 no.3
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• pp.1060-1071
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• 2014

Signals of the Electroencephalogram (EEG) can reflect the electrical background activity of the brain generated by the cerebral cortex nerve cells. This has been the mostly utilized signal, which helps in effective analysis of brain functions by supervised learning methods. In this paper, an approach for improving the accuracy of EEG signal classification is presented to detect epileptic seizures. Moreover, Independent Component Analysis (ICA) is incorporated as a preprocessing step and Short Time Fourier Transform (STFT) is used for denoising the signal adequately. Feature extraction of EEG signals is accomplished on the basis of three parameters namely, Standard Deviation, Correlation Dimension and Lyapunov Exponents. The Artificial Neural Network (ANN) is trained by incorporating Levenberg-Marquardt(LM) training algorithm into the backpropagation algorithm that results in high classification accuracy. Experimental results reveal that the methodology will improve the clinical service of the EEG recording and also provide better decision making in epileptic seizure detection than the existing techniques. The proposed EEG signal classification using feed forward Backpropagation Neural Network performs better than to the EEG signal classification using Adaptive Neuro Fuzzy Inference System (ANFIS) classifier in terms of accuracy, sensitivity, and specificity.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.411-419
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• 2011

In this paper, we propose an Adaptive Regulating Drop (ARD) marker, as a novel dropping strategy at the ingressive edge router, to improve TCP fairness in assured services (ASs) without a decrease in the link utilization. To drop packets pertinently, the ARD marker adaptively changes a Temporary Permitted Rate (TPR) for aggregate TCP flows. The TPR is set larger than the current input IN packet rate of aggregate TCP flows while inversely proportional to the measured input OUT packet rate. To reduce the excessive use of greedy TCP flows by notifying droppings of their IN packets constantly to them without a decrease in the link utilization, the ARD marker performs random early fair remarking of their excessive IN packets to OUT packets at the aggregate flow level according to the TPR. In addition, an aggregate dropper is combined to drop some excessive IN packets fairly and constantly according to the TPR. Thus, the throughput of a TCP flow no more depends on only the sporadic and unfair OUT packet droppings at the RIO buffer in the core router. Then, the ARD marker regulates the packet transmission rate of each TCP flow to the contract rate by increasing TCP fairness, without a decrease in the link utilization.

• Proceedings of the Korea Information Processing Society Conference
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• 2014.11a
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• pp.203-206
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• 2014

무선 LAN(Wireless Local Area Networks 의 DCF(Distributed Coordination Function) 방식은 랜덤 백 오프 방식으로 매체에 접근하기 때문에 지연이 발생하여 정해진 시간 내에 전송을 보장할 수 없다는 단점이 있다. [1] 이는 곧 실시간 멀티미디어 트래픽(비디오, 음성 등)의 QoS(Quality Of Service)를 보장할 수 없다는 것을 뜻한다. 또한 IEEF 802.11e 표준 [2]에서 제공하는 QoS 를 위한 EDCA(Enhanced Distributed Channel Access)라는 프로토콜은 제시되어있으나 실제로 구현되어있는 디바이스의 부재로 QoS 를 지원하기가 어렵다. 따라서 무선 랜에서 IEEE 802.11e 를 지원하지 않는 망내 디바이스, 즉 큐가 1 개인 STA, 즉 기본적인 802.11 표준 기술인 DCF 를 사용하는 STA 을 위해서 멀티미디어 트래픽의 실시간 전송을 보장하기 위한 기법을 제시한다.