• Proceedings of the IEEK Conference
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• 1999.06a
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• pp.825-828
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• 1999

A Viterbi Decoder for IMT2000 Mobile Station based on cdma200 is implemented in this paper. There are fundamental traffic channel, supplemental traffic channel for user data transmission and dedicated control channel for signal transmission in cdma2000. This decoder can decode these channels simultaneously, and support l/2, l/3, 1/4 code rate decoding. In case of fundamental channel decoding, it needs about 1100 logic cells and 30000 bit memory block.

• IEIE Transactions on Smart Processing and Computing
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• v.3 no.5
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• pp.251-258
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• 2014

This paper proposes an efficient token flow design methodology for a decoder in the MPEG Reconfigurable Media Coding (RMC) framework. The MPEG RMC framework facilitates a decoder to be configured with a set of modules called functional units (FUs) that are connected by tokens. Such a modular design philosophy of the MPEG RMC framework enables the reusability and reconfigurability of FUs. One drawback of the MPEG RMC framework is that the decoder performance can be affected by increasing the token transmissions between FUs. The proposed method improves the design of the FU network in the RMC framework toward real-time decoder implementation. In the proposed method, the merging of FU, the separation of token flow, and the merging of token transactions are applied to minimize the token traffic between FUs. The experimental results of the MPEG-4 SP decoder show that the proposed method reduces the total decoding time by up to 77 percent compared to the design of the RMC simulation model.

• Journal of the Institute of Electronics Engineers of Korea CI
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• v.44 no.3
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• pp.108-123
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• 2007

As H.264/AVC standard has proven to be a key technology of multimedia application, many researches to improve H.264/AVC standard are actively conducted. Those researches are conducted in various ways such as algorithm analysis and improvement or structure enhancement for reducing bottlenecks of performance. Even though targets and directions of those studies are not the same, performance of H.264/AVC standard is commonly analyzed in the early phase. In analysis phase, potential problems with H.264/AVC standard are identified and the most critical problem which has serious effects on performance is determined. Therefore, analysis phase is one of the important steps to decide overall directions and targets of the research. This research proposes a mathematical model which can be used in the early performance analysis phase to estimate performance in conducting research of improving the performance of H.264/AVC Baseline Profile decoder. The proposed model is designed by considering many variables of H.264/AVC decoder operation so that it is easy to predict its performance according to changes in each element.

• Proceedings of the IEEK Conference
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• 1998.06a
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• pp.713-716
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• 1998

We propose the dejittering method against the jitter originated from the cell losses in ATM network when CBR traffic is transfereed on AAL5. Cell numbering algong with maintaining a timer at receier side introduces 0.669 times peak-to-peak PDV of the AAL5 PDU to that in ITU-T AAL5 standard, and the AAL5 user-HDTV decoder-receives the same or more error-free transport packets in the proposed algorithm than those in the ITU-T AAL5 standard for the same network simulation environment.

• Proceedings of the IEEK Conference
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• 2003.11a
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• pp.241-244
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• 2003

Nowadays image processing is very useful for some field of traffic applications. The one reason is we can construct the system in a low price, the other is the improvement of hardware processing power, it can be more fast to processing the data. In this study, I propose the traffic monitoring system that implement on the embedded system environment. The whole system consists of two main part, one is host controller board, the other is image processing board. The part of host controller board take charge of control the total system, interface of external environment. and OSD(On screen display). The part of image processing board takes charge of image input and output using video encoder and decoder, image classification and memory control of using FPGA, control of mouse signal. And finally, fer stable operation of host controller board, uC/OS-II operating system is ported on the board.

• Journal of Korea Multimedia Society
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• v.8 no.9
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• pp.1216-1226
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• 2005

In this paper, a preventive transmission rate decision algorithm, called PTRD, is proposed for the transmission of live video over networks with dynamic bandwidth allocation capability. Frame analyzer predicts the bit-rates of future frames before encoding by analyzing the source information such as spatial variances and the degree of scene changes. By using the predicted bit-rates, transmission rate bounds are derived from the constraints of encoder and decoder buffers. To resolve the problem of renegotiation cost increment due to frequent renegotiations, the PTRD algorithm is presented to decide transmission rates considering the elapsed time after the recent renegotiation and the perceived video quality. From the simulation results, compared to the normalized LMS based method, PTRD is shown to achieve high channel utilization with low renegotiation cost and no delay violation.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.7 no.5
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• pp.887-892
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• 2003

In this paper, we propose a simple scaling algorithm for CDMA mobile communications where a voice traffic signals are transmitted by individual one of several data rates at every frames. The traditional method is based on using look-up table called SMT(symbol metric table), but the proposed algorithm is real-time direct scaling method through simple bit manipulations without lookup table. The bit error rate performance is calculated by computer simulation over AWGN and Rayleigh fading channels. From the results, it is shown that the proposed algorithm outperforms the traditional SMT method on Rayleigh channel by 0.3∼0.8dB, while achieving the less H/W complexity.

• International Journal of Internet, Broadcasting and Communication
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• v.16 no.2
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• pp.22-30
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• 2024

Image compression-decompression methods have become increasingly crucial in modern times, facilitating the transfer of high-quality images while minimizing file size and internet traffic. Historically, early image compression relied on rudimentary codecs, aiming to compress and decompress data with minimal loss of image quality. Recently, a novel compression framework leveraging colorization techniques has emerged. These methods, originally developed for infusing grayscale images with color, have found application in image compression, leading to colorization-based coding. Within this framework, the encoder plays a crucial role in automatically extracting representative pixels-referred to as color seeds-and transmitting them to the decoder. The decoder, utilizing colorization methods, reconstructs color information for the remaining pixels based on the transmitted data. In this paper, we propose a novel approach to image compression, wherein we decompose the compression task into grayscale image compression and colorization tasks. Unlike conventional colorization-based coding, our method focuses on the colorization process rather than the extraction of color seeds. Moreover, we employ the Denoising Diffusion Null-Space Model (DDNM) for colorization, ensuring high-quality color restoration and contributing to superior compression rates. Experimental results demonstrate that our method achieves higher-quality decompressed images compared to standard JPEG and JPEG2000 compression schemes, particularly in high compression rate scenarios.

• Journal of the Institute of Electronics Engineers of Korea SC
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• v.41 no.1
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• pp.25-32
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• 2004

Nowadays image processing is very useful for some field of traffic applications. The one reason is we can construct the system in a low price, the other is the improvement of hardware processing power, it can be more fast to processing the data. In traffic field, the development of image using system is interesting issue. Because it has the advantage of price of installation and it does not obstruct traffic during the installation. In this study, 1 propose the traffic monitoring system that implement on the embedded system environment. The whole system consists of two main part, one is host controller board, the other is image processing board. The part of host controller board take charge of control the total system interface of external environment, and OSD(On screen display). The part of image processing board takes charge of image input and output using video encoder and decoder, Image classification and memory control of using FPGA, control of mouse signal. And finally, for stable operation of host controller board, uC/OS-II operating system is ported on the board.

• Journal of the Korean Operations Research and Management Science Society
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• v.24 no.3
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• pp.63-72
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• 1999

Recent studies on the Constant Bit Rate and Variable Bit Rate transmissions have mainly focused on the frame by frame encoder rate control based on the quantization parameter. With the existing approaches it is difficult to guarantee a consistent video quality. Also, the rate control overhead is too high for the real-time video sources. In this paper, a channel rate allocation scheme based on the control period is proposed to transmit a real-time video, in which the control period is defined by a pre-specified number of frames or group of pictures. At each control period, video traffic information is collected to determine the channel rate at the next control period. The channel rate is allocated to satisfy various channel rate constraints such that the buffer occupancy at the decoder is maintained at a target level. If the allocated channel rate approaches the level at which the negotiated traffic descriptions may be violated, the encoder rate is decreased through adjusting quantization parameters in the MPEG encoder. In the experimental results, the video quality and the overflow and underflow probabilities at the buffer are compared at different control periods. Experiments show that the video quality and the utilization of network bandwidth resources can be optimized through the suitable selection of the control period.