• Title/Summary/Keyword: 최윤식

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A Video Streaming Adaptive Packet Pre-marker in DiffServ Networks (DiffServ 네트워크에서 비디오 스트리밍을 위한 적응적 트래픽 마커 알고리듬 연구)

  • Jung, Young-H.;Kang, Young-Wook;Choe, Yoon-Sik
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.12B
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    • pp.735-742
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    • 2007
  • We propose an effective packet marking algorithm for video streaming in DiffServ network. Because legacy packet markers such as srTCM(single rate three color marker) cannot distinguish the importance of packet, these markers can cause quality degradation of streaming during the network congestion period. Recently proposed TMS (Two Marker System) [4] shows effectiveness in such scenario that video streaming service is struggling with other types of service traffic. However, if many video streaming services co-exist in DiffServ network and result in competition among themselves, then both legacy packet markers and even TMS cannot prevent drastic streaming quality degradation. To cope with this, we suggest A-TCPM (Adaptive time sliding window Three Color Marker) algorithm. In this algorithm, an A-TCPM module decides the color of a racket based upon the probability which is lead by current channel status and frame importance ratio. Simulation results show that proposed A-TCPM algorithm can enhance streaming service quality especially when overbooked video streaming sessions struggle with themselves.

A study on MPEG-7 descriptor combining method using borda count method (Borda count 방법을 이용한 다중 MPEG-7 서술자 조합에 관한 연구)

  • Eom, Min-Young;Choe, Yoon-Sik
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.43 no.1 s.307
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    • pp.39-44
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    • 2006
  • In this paper, search result list synthesis method is proposed using borda count method for still image retrieval based on MPEG-7 descriptors. MPEG-7 standardizes descriptors that extract feature information from media data. In many cases, using a single descriptor lacks of correctness, it is suggested to use multiple descriptors to enhance retrieval efficiency. In this paper, retrieval efficiency enhancement is achieved by combining multiple search results which are from each descriptor. In combining search result, newly calculated borda count method is proposed. Comparing current frequency compensated calculation, rank considered frequency compensation is used to score animage in database. This combining method is considered in Content based image retrieval system with relevance feedback algorithm which uses high level information from system user. In each relevance iteration step, adoptive borda count method is used to calculate score of images.

A preliminary study on women's anginal pain induced by exercise stress test (운동부하검사로 유발된 여성의 협심통증에 대한 예비연구)

  • Choe, Myoung-Ae;An, Kyung-Ae;Choo, Ji-Na;Choi, Yoon-Sik
    • Journal of Korean Biological Nursing Science
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    • v.4 no.2
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    • pp.5-18
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    • 2002
  • Purpose: Women have been often underdiagnosed and undertreated when they have as high mortality as men of ischemic heart disease, such as angina. One of the reasons of women's under treatment is associated with either vague, non-traditional symptoms or longer delay in seeking professional help when they experience ischemic heart disease. This study was conducted to investigate the characteristics of women's anginal pain induced by the treadmill test and to explore the potential relationship(s) between anginal pain and other psycho-physiologic factors. Methods: Of 22 female patients referred to treadmill test, 7 with positive finding participated in this study. Anginal pain in the past was analyzed by Rose questionnaire, whereas anginal pain induced by the treadmill test was identified by McGill pain scale, visual analogue scale and present pain index. Results: Women expressed more heaviness than sharp pain, and complained splitting more often than subjects in previous study that included both men and women. Pain intensity by VAS $3.64{\pm}3.94$, Pain rating index was $5.14{\pm}7.29$, present pain index was $1.57{\pm}1.81$, duration of pain was $5.14{\pm}4.8$ min. Exercise intensity was $6.0{\pm}4.63$ METs, exercise duration was $364.29{\pm}141.39$ sec, ST change was -2.0mm and rate of perceived exertion was $16.29{\pm}2.06$. The relationships between pain intensity and pain duration, ST segment changes were significant. Correlation among pain measures was significant. Conclusion: Generalization of these pilot findings may be inappropriate, and therefore, further larger study is needed.

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High Performance Lossless Data Embedding Using a Moving Window (움직이는 창을 이용한 고성능 무손실 데이터 삽입 방법)

  • Kang, Ji-Hong;Jin, Honglin;Choe, Yoon-Sik
    • Journal of Broadcast Engineering
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    • v.16 no.5
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    • pp.801-810
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    • 2011
  • This paper proposes a new lossless data embedding algorithm on spatial domain of digital images. A single key parameter is required to embed and extract data in the algorithm instead of embedding any additional information such as the location map. A $3{\times}3$ window slides over the cover image by one pixel unit, and one bit can be embedded at each position of the window. So, the ideal embedding capacity equals to the number of pixels in an image. For further increase of embedding capacity, new weight parameters for the estimation of embedding target pixels have been used. As a result, significant increase in embedding capacity and better quality of the message-embedded image in high capacity embedding have been achieved. This algorithm is verified with simulations.

Video De-noising Using Adaptive Temporal and Spatial Filter Based on Mean Square Error Estimation (MSE 추정에 기반한 적응적인 시간적 공간적 비디오 디노이징 필터)

  • Jin, Changshou;Kim, Jongho;Choe, Yoonsik
    • Journal of Broadcast Engineering
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    • v.17 no.6
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    • pp.1048-1060
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    • 2012
  • In this paper, an adaptive temporal and spatial filter (ATSF) based on mean square error (MSE) estimation is proposed. ATSF is a block based de-noising algorithm. Each noisy block is selectively filtered by a temporal filter or a spatial filter. Multi-hypothesis motion compensated filter (MHMCF) and bilateral filter are chosen as the temporal filter and the spatial filter, respectively. Although there is no original video, we mathematically derivate a formular to estimate the real MSE between a block de-noised by MHMCF and its original block and a linear model is proposed to estimate the real MSE between a block de-noised by bilateral filter and its original block. Finally, each noisy block is processed by the filter with a smaller estimated MSE. Simulation results show that our proposed algorithm achieves substantial improvements in terms of both visual quality and PSNR as compared with the conventional de-noising algorithms.

An Adaptive Filtering Method for Enhancement of Inter-color Plane Estimation in HEVC RExt RGB Images (HEVC RExt RGB 영상의 색평면 간 예측 향상을 위한 적응적 필터링 기법)

  • Choi, Jangwon;Choe, Yoonsik
    • Journal of Broadcast Engineering
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    • v.18 no.4
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    • pp.647-650
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    • 2013
  • HEVC RExt(High Efficiency Video Coding Range Extension) set a goal to support RGB/YUV 4:2:2 4:4:4 color sampling and over 10 bit-depth images. Unlike the previous 4:2:0 color sampling images, RGB images have the high correlation in inter-color planes. Using this characteristic, some methods which are contributed in JCT-VC standardization meetings estimate the pixel values of inter-color plane. But when we use the estimation of inter-color plane in RGB images, high frequency components of RGB images are caused to reduce the coding efficiency because they usually have the low inter-color plane correlation. Therefore, in this paper, we propose an adaptive low pass filtering method in the inter-color plane estimation. Using this method, we can improve the estimation efficiency of inter-color plane in RGB images. The experimental results with HEVC RExt RGB test sequences show that the proposed method has 0.6% BD(Bjontegaard Distortion)-rate gain and some increased complexity compared to the previous inter-color plane estimation method.

Adaptive Rate-Distortion Optimized Multiple Loop Filtering Algorithm (적응적 율-왜곡 최적 다중 루프 필터 기법)

  • Hong, Soon-Gi;Choe, Yoon-Sik;Kim, Yong-Goo
    • Journal of Broadcast Engineering
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    • v.15 no.5
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    • pp.617-630
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    • 2010
  • At 37th VCEG meeting in Jan. 2009, Toshiba proposed Quadtree-based Adaptive Loop Filter (QALF). The basic concept of QALF is to apply Wiener filter to decoded image after the conventional deblocking filter and to represent the filter on/off flag data for each basic filtering unit in a more efficient way of quadtree structure. QALF could enhance the compression performance of around more than 9%, but the structure of one filter for a decoded frame leaves room for further improvement in the sense that optimal filter for one region of a frame could quite different from the optimal filter for other parts of a picture. This paper proposes multiple adaptive loop filters for better utilization of local characteristics of decoded frame to optimize the region-based Wiener filters. Additional filters, proposed in this paper, cover separate spatial area of each decoded frame according to the performance of previously designed filter(s) to provide the flexibility of rate-distortion based selection of the number of filters.

Error Resilient Scheme in Video Data Transmission using Information Hiding (정보은닉을 이용한 동영상 데이터의 전송 오류 보정)

  • Bae, Chang-Seok;Choe, Yoon-Sik
    • The KIPS Transactions:PartB
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    • v.10B no.2
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    • pp.189-196
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    • 2003
  • This paper describes an error resilient video data transmission method using information hiding. In order to localize transmission errors in receiver, video encoder embeds one bit for a macro block during encoding process. Embedded information is detected during decoding process in the receiver, and the transmission errors can be localized by comparing the original embedding data. The localized transmission errors can be easily corrected, thus the degradation in a reconstructed image can be alleviated. Futhermore, the embedded information can be applied to protect intellectual property rights of the video data. Experimental results for 3 QCIF sized video sequenced composed of 150 frames respectively show that, while degradation in video streams in which the information is embedded is negligible, especially in a noisy channel, the average PSNR of reconstructed images can be improved about 5 dB by using embedded information. Also, intellectual property rights information can be effectively obtained from reconstructed images.

Splicing Techniques in the PES System Layer for the Editing at a GOP Module of The MPEG-2 based Images (MPEG-2 기반영상 GOP 단위 편집을 위한 PES 시스템 영역에서의 스트림 접함 방법)

  • 김동준;최윤식
    • Journal of Broadcast Engineering
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    • v.7 no.4
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    • pp.355-361
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    • 2002
  • In this paper, several methods which guarantee the seamless editing when the splicing is applied to the MPEG-2 system streams are described. In the MPEG-2 system standard, it is recommended that the splicing technique is applied in the Transport Stream(TS) domain. However, in view of the video editing, the splicing at an arbitrary picture unit can not be guaranteed. The splicing in the PES domain is only considered in this paper because the PES is one of the MPEG-2 system streams and this result could be directly extended to the video splicing techniques in the TS or PS domain. Thus. the problems that might occur when different two PES streams are spliced and its effects to the video quality are compared and analyzed. Based on this analysis. several methods that can resolve these problems directly in the PES domain are proposed. Consequently, the computer simulation demonstrates that the splicing at a GOP modulo is guaranteed to have good video quality even without considering the state of the PES packet only if the PES_packet_length field of the PES packet header is used.

An adaptive frequency-selective weighted prediction of residual signal for efficient RGB video compression coding (능률적 RGB 비디오 압축 부호화를 위한 잔여신호의 적응적 주파수-선택 가중 예측 기법)

  • Jeong, Jin-Woo;Choe, Yoon-Sik;Kim, Yong-Goo
    • Journal of Broadcast Engineering
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    • v.15 no.4
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    • pp.527-539
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    • 2010
  • Most video coding systems use YCbCr color space for their inputs, but RGB space is more preferred in the field of high fidelity video because the compression gain from YCbCr becomes disappeared in the high quality operation region. In order to improve the coding performance of RGB video signal, this paper presents an adaptive frequency-selective weighted prediction algorithm. Based on the sign agreement and the strength of frequency-domain correlation of residual color planes, the proposed scheme adaptively selects the frequency elements as well as the corresponding prediction weights for better utilization of inter-plane correlation of RGB signal. Experimental results showed that the proposed algorithm improves the coding gain of around 13% bitrate reduction, on average, compared to the common mode of 4:4:4 video coding in the state-of-the-art video compression standard, H.264/AVC.