• Proceedings of the IEEK Conference
• /
• 2000.06c
• /
• pp.141-144
• /
• 2000

Current Internet and Intranet developments are focusing on network multimedia services involving the transport of real-time multimedia streams. In this paper, we present a real-time MPEG2 Encoding/Decoding systems and a MPEG2 stream player running on client systems based on real-time transport protocol(RTP). The MPEG2 player has been implemented by using JMF and java applet. We have tested our prototype systems with one of possible multimedia sources, camcoder, to verify its functional correctness and measure its performance.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2001.06a
• /
• pp.12-15
• /
• 2001

본 논문에서는 고효율 멀티미디어 프로세서 아키텍쳐에 대해 논의하였다. 제안한 멀티미디어 프로세서 아케텍쳐는 제안한 방법은 기존의 멀티미디어 프로세서의 단점들인 각종 텍스트, 사운드, 비디오 등의 미디어 들을 1개의 칩 속에서 처리할 수 있도록 하였으며, 또한 멀티미디어의 특성인 상호대화식 처리도 가능하게 하였다. 특히, 완전한 그래프에 기반을 둔 네트워크를 지향하므로 소프트웨어 없이 메모리 맵의 노드어드레싱을 가능하게 하였으며, 데이터 형태에 의존하는 완전한 재구성이 가능하며 동기/비동기를 갖는 시간 공유와 공간 공유 처리가 가능하다. 또한, 연속적임과 동적인 매체 데이터의 버스 충돌을 방지할 수 있으며 지역적임과 전반적인 공유 메모리 구조로부터의 버스 충돌도 방지할 수 있으며, 또한 가상현실과 흔합현실에도 적용할 수 있으리라 사료된다.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.829-832
• /
• 1999

KORTASAT-III is planning to provide Ka-band broadband communication service, including eastsouth Asia area. In this paper, we calculate the link budget for Ka-band KOREASAT-III multimedia service and describe the performance of multimedia services according to link design parameters. There are Trunk service, Television receive only service, Two-way point-to-multipoint service, Tele-education service in the service scenario.

• Proceedings of the IEEK Conference
• /
• 1999.11a
• /
• pp.931-934
• /
• 1999

For applications in multimedia to which genuine RISC microprocessors are not suitably applicable, a new generation of fast and flexible microprocessors is required. In this paper, as a technique of integrating DSP functionality in a general RISC processor, a RISC that can execute DSP extension instructions is developed to improve the performance of multimedia application execution. This processor can execute DSP instructions in parallel with the execution of ALU instructions for efficient and fast execution. In addition, the execution ability of integer instructions is improved by enhancing the RISC core itself.

• Journal of the Korea Society for Simulation
• /
• v.9 no.3
• /
• pp.65-75
• /
• 2000

In recent years, significant advances in computers and communication technologies have made multimedia services feasible. As a result, various queuing models and cost models on architecture and data placement for multimedia server have been proposed. However, these analytical techniques use only probabilistic models to represent the behavior of a system, and then they have several limitations like accuracy. Simulation is a viable alternative to analytical model. It avoids many of the limitations associated with analytical techniques, allowing for more precise representation of system attributes like workload in program code. In this paper, we propose a simulation test bed that can evaluate performance of real-time multimedia server by using simulation model.

• Proceedings of the Korea Multimedia Society Conference
• /
• 2004.05a
• /
• pp.302-305
• /
• 2004

최근 들어 개발 및 보급이 확산되고 있는 포터블 임베디드 시스템에서는 전력이 중요한 성능 지표로 작용한다. 특히 메모리 시스템의 전력 소모량은 전체 전력 중 매우 큰 비중을 차지하므로, 정확한 전력 분석에 기초하여 전력 소모를 줄일 수 있는 구조에 관한 연구가 수행되고 있다. 본 논문에서는 포터블 임베디드 시스템의 주요 처리 대상인 멀티미디어 응용 프로그램의 낮은 데이터 재사용성을 극복하기 위하여 참조 예측기를 포함하는 메모리 시스템의 전력 분석 모델을 제안한다.

• Journal of Korea Multimedia Society
• /
• v.17 no.9
• /
• pp.1084-1091
• /
• 2014

When demand for transmitting multimedia data increases, network congestion is more likely to occur and users will suffer high loss rate as well as high delay. In order to enhance quality-of-service (QoS) of video multicasting, we need to raise transmission reliability and reduce end-to-end delay. This paper proposes a routing mechanism for a OpenFlow-based small-scale network in order to multicast video reliably with low delay. In our method, multipath routing will be applied to Multiple Description (MD) Coded video to exploit its multi-description property. Through performance evaluation, our method shows improvement on loss rate, delay and video distortion.

• Proceedings of the IEEK Conference
• /
• 2002.07b
• /
• pp.868-871
• /
• 2002

Nowadays, zerotrees based digital watermarking techniques are considered to be an efficient watermarking technique used for multimedia data in a compressed form. This paper presents a technique for watermarking an image, by employing zerotrees derived from the wavelet packet coefficients of the transformed image to carry the watermark signal. By setting a proper threshold in zerotrees determining process, the watermark signal can be recovered without the need of original image. With our proposed technique, more amount of watermark signal can be embedded within the image, compared to ordinary wavelet transform based techniques. The experimental results show the improved performance in both qualities of the resultant watermarked image and robustness of the embedded watermark signal against common signal processing such as brightness/contrast enhancement, high-pass filtering, Gaussian noise adding and JPEG compression scheme

• ETRI Journal
• /
• v.34 no.4
• /
• pp.492-502
• /
• 2012

We consider an overlaid broadcast service, where a spread spectrum (SS)-based broadcast signal is overlaid onto the existing terrestrial Digital Multimedia Broadcasting (T-DMB) band. The system is similar to the augmented data transmission in the ATSC DTV, for which it was investigated mostly in terms of link level performance, such as bit error rate. Our focus in this paper is on the system-level performances. More specifically, utilizing both a large scale path loss and a small scale fading channel model, the primary objective is to explore the tradeoff between the coverage and the achievable rate of the overlaid service and, finally, to determine the achievable rate in the overlaid service for marginal coverage reduction in the existing broadcast service. The analytical and simulation results show that an SS-based add-on service of 10 kbps to 20 kbps can co-exist with the T-DMB service while resulting in only a marginal degradation in T-DMB coverage (for example, less than one percent reduction).

• KSII Transactions on Internet and Information Systems (TIIS)
• /
• v.4 no.6
• /
• pp.1327-1342
• /
• 2010

With the wide deployment of biometric authentication systems, several issues pertaining security and privacy of the biometric template have gained great attention from the research community. To resolve these issues, a number of biometric template protection methods have been proposed. However, the design of a template protection method to satisfy four criteria, namely diversity, revocability and non-invertibility is still a challenging task, especially performance degradation when template protection method is employed. In this paper, we propose a novel method to generate a revocable minutiae-based fingerprint template. The proposed method consists of feature extraction from fingerprint minutiae pairs, quantization, histogram binning, binarization and eventually binary bit-string generation. The contributions of our method are two fold: alignment-free and good performance. Various experiments on FVC2004 DB1 demonstrated the effectiveness of the proposed methods.