• Proceedings of the Korea Information Processing Society Conference
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• 2012.04a
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• pp.1033-1034
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• 2012

본 논문은 제한된 대역폭의 효율적인 활용을 위한 가변 전송률 코덱을 목표로 제안된 서포트벡터머신 기반의 음성/음악 분류기의 실용도를 높이기 위한 기법을 제안한다. 서포트벡터머신 기반의 음성/음악 분류기는 높은 분류능력을 가지고 있지만 많은 계산량을 요구하기 때문에 실시간으로 사용하기에는 부적합한 면이 있다. 따라서 계층적 분류를 통해 서포트벡터머신 기반의 음성/음악 분류기의 실용성을 향상시키는 기법을 제안한다.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.12
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• pp.2343-2352
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• 2015

In this paper, we propose novel motion field estimation method using U-disparity map and forward-backward error removal in vehicles environment. Generally, in an image obtained from a camera attached in a vehicle, a motion vector occurs according to the movement of the vehicle. but this motion vector is less accurate by effect of surrounding environment. In particular, it is difficult to extract an accurate motion vector because of adjacent pixels which are similar each other on the road surface. Therefore, proposed method removes road surface by using U-disparity map and performs optical flow about remaining portion. forward-backward error removal method is used to improve the accuracy of the motion vector. Finally, we predict motion of the vehicle by applying RANSAC(RANdom SAmple Consensus) from acquired motion vector and then generate motion field. Through experimental results, we show that the proposed algorithm performs better than old schemes.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2007.02a
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• pp.13-17
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• 2007

스케일러블 비디오 코딩(SVC, Scalable Video Coding)은 MPEG(Moving Picture Expert Group)과 VCEG (Video Coding Expert Group)의 JVT(Joint VIdeo Team)에 의해 현재 표준화 되고 있는 새로운 압축 표준 기술이며 시간, 공간 및 화질의 스케일러빌리티를 지원하기 위해 계층 구조를 가지고 있다. 공간적 스케일러빌리티를 위해 기본 계층으로부터 텍스처, 움직임 그리고 잔차신호 정보를 예측하여 사용한다. 그러나 고효율의 압축효과를 얻기 위해 기존의 방식에서는 기본계층에서 얻은 세가지 정보이외에 현재 향상 계층에서 자체적으로 얻은 부호화 정보를 비교하여 최소의 RD(Rate Distortion) 비용을 가지는 정보를 이용하여 부호화 하도록 되어 있다. 하지만 이러한 방식은 향상 계층에서 인터 모드 결정 시 $16\times16,\;16\times8,\;8\times16,\;8\times8,\;4\times4,\;4\times8,\;4\times4$ 블록 모드에 대한 움직임 벡터 예측 및 보상 과정을 거쳐야 하기 때문에 향상 계층에서의 부호화 복잡도는 기본 계층에 비해 상당히 증가하게 된다. 본 논문에서는 기본계층에서 예측한 움직임 벡터 정보를 이용하여 항상 계층에서 모드 결정을 고속화하는 방법에 대해 소개한다. 제안된 방법은 기본 계층에서 예측한 블록모드 중에서 큰 블록인 $16\times16$ 블록에서 움직임 벡터가 (0, 0) 일 경우에 대하여 향상 계층에서는 $16\times16$매크로 블록에 대해서만 움직임 예측 및 보상을 수행함으로써 향상 계층에서 움직임 모드 결정을 조기에 완료하게 된다. 이것은 하위 공간 계층에서 예측한 움직임 벡터 정보가 아주 작을 때는 큰 블록 크기로 모드로 결정되는 일반적인 원리를 이용한 것이고 이 제안 방법을 이용하였을 경우 향상계층에의 모드 결정과정을 고속화함으로써 전체 스케일러빌 비디오 부호하기의 연산량 및 복잡도를 최대 70%까지 감소 시켰다. 그러나 연산량 감소에 따른 비트율의 증가와 화질 열화는 각각 최대 1.32%와 최대 0.11dB로 무시할 수 있을 정도로 작음을 확인 하였다.

• The Journal of the Korea Contents Association
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• v.7 no.2
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• pp.1-10
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• 2007

In this paper, we propose a face recognition system using AAM and Gabor feature vectors. EBGM, which is prominent among face recognition algorithms employing Gabor feature vectors, requires localization of facial feature points where Gabor feature vectors are extracted. However, localization of facial feature points employed in EBGM is based on Gator jet similarity and is sensitive to initial points. Wrong localization of facial feature points affects face recognition rate. AAM is known to be successfully applied to localization of facial feature points. In this paper, we propose a facial feature point localization method which first roughly estimate facial feature points using AAM and refine facial feature points using Gabor jet similarity-based localization method with initial points set by the facial feature points estimated from AAM, and propose a face recognition system based on the proposed localization method. It is verified through experiments that the proposed face recognition system using the combined localization performs better than the conventional face recognition system using the Gabor similarity-based localization only like EBGM.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.40 no.4
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• pp.275-285
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• 2003

The now video coding standard H.264 employs variable block size motion compensation, multiple references, and quarter-pel motion vector accuracy. These techniques are key features to accomplish higher coding gain, however, at the same time main factors that increase overall computational complexity. Therefore, in order to apply H.264 to many applications, key techniques are requested to improve their speed. For this reason, we propose a fast motion estimation which is suited for variable block size motion communication. In addition, we propose a fast mode decision method to choose the best mode at early stage. Experimental results show the reduction of the number of SAT SATD calculations by a factor of 4.5 and 2.6 times respectively, when we compare the proposed fast motion estimation and the conventional MVFAS $T^{［8-10］}$. Besides, the number of RDcost computations is reduced by about 45%. Therefore, the proposed methods reduces significantly its computational complexity without noticeable coding loss.

• Journal of Broadcast Engineering
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• v.14 no.1
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• pp.59-69
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• 2009

A bi-directional symmetric prediction technique has been developed to improve coding efficiency of B-slice and to reduce the computational complexity required to estimate two motion vectors. On the contrary to the conventional bi-directional mode which encodes both forward and backward motion vectors, it only encodes a single forward motion vector, and the missing backward motion vector is derived in a symmetric way from the forward motion vector using temporal distance between forward/backward reference frames to and from the current B picture. Since the backward motion vector is derived from the forward motion vector, it can halve the computational complexity for motion estimation, and also reduces motion vector data to encode. This technique always derives the backward motion vector from the forward motion vector, however, there are cases when the forward motion vector is better to be derived from the backward motion vector especially in scene changes. In this paper, we generalize the idea of the symmetric coding with forward motion vector coding, and propose a new symmetric coding with backward motion vector coding and adaptive selection between the conventional symmetric mode and the proposed symmetric mode based on rate-distortion optimization.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.46 no.5
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• pp.135-142
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• 2009

Since hold-type display systems have been developed, frame-rate up conversion (FRUC) is an essential technique to improve the temporal resolution in the display. FRUC improves the temporal resolution by interpolating one or multiple intermediate frames between two adjacent frames. In this paper, a new frame-rate up-conversion algorithm based on bilateral motion refinement with rotation is proposed. First, we perform bi-directional motion estimation between adjacent two frames to obtain a motion vector for each block. Then, we apply a modified median filtering to motion vectors for outlier-rejection and motion field smoothing. The filtered motion vectors are updated by the bilateral motion refinement with rotation. After the refined motion vector is obtained, the intermediate frame is generated by applying the overlapped block motion compensation (OBMC). Experimental results show that the proposed algorithm provides a better performance than the previous methods subjectively and objectively.

• The Journal of the Acoustical Society of Korea
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• v.30 no.3
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• pp.136-141
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• 2011

In this paper, a method for measuring rhythmic similarity between two sound signals for auditory memory game is proposed. The proposed method analyzes energy fluctuation, the temporal duration of energy peak, the timbre of two signals, and detects beat positions for each signal. Then, it determines the rhythm vector after compensating a difference in tempo and the number of beats between two signals. Finally, a method for rhythmic similarity measurement is defined as a function of the dissimilarity between two rhythm vectors and a difference in the number of beats. The rhythmic similarity measured by the proposed method and that by the subjective listening test are compared, and the correlation of 0.86 between two results is achieved.

• Journal of the Institute of Electronics Engineers of Korea SP
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• v.44 no.6
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• pp.100-110
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• 2007

When compressed video data is transmitted over error-prone network such as wireless channel, data is likely to be lost, so the quality of reconstructed picture is severely decreased. It is specially so in case that important information such as motion vector or macroblock mode is lost. H.264/AVC standard includes DP as error resilient technique for protecting important information from error in which data is labeled according to its relative importance. But DP technique requires a network that supports different reliabilities of transmitted data. In general, the benefits of UEP is sought by sending multiple times of same packets corresponding to important information. In this paper, we propose MDC technique based on data partitioning technique. The proposed method encodes motion vector of H.264/AVC standard into multiple parts using MDC and transmits each part as independent packet. Even if partial packet is lost, the proposed scheme can decode the compressed bitstream by using estimated motion vector with partial packets correctly transmitted, so that achieving improved performance of error concealment with minimal effect of channel error. Also in decoding process, the proposed multiple description matching increases the accuracy of estimated lost motion vector and quality of reconstructed video.

• Korean Journal of Microbiology
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• v.51 no.4
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• pp.319-328
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• 2015

The $sdu1^+$ gene encodes Sdu1, a PPPDE superfamily member of deubiquitinating enzymes (DUBs) in Schizosaccharomyces pombe. Sdu1 was previously shown to contain an actual ubiquitin C-terminal hydrolase (UCH) activity using the recombinant plasmid pYSTP which harbors the $sdu1^+$ gene. This work was designed to assess a thermotolerant role of Sdu1 against high incubation temperatures. In the temperature-shift experiments, the S. pombe cells harboring pYSTP grew much better after the shifts to $37^{\circ}C$ and $42^{\circ}C$, when compared with the vector control cells. After being shifted to $37^{\circ}C$ and $42^{\circ}C$ for 6 h, the S. pombe cells harboring pYSTP contained lower reactive oxygen species (ROS) levels, compared with the vector control cells. The nitric oxide (NO) levels of the S. pombe cells harboring pYSTP were slightly lower than those of the vector control cells in the absence or presence of the temperature shifting. The total glutathione (GSH) levels of the S. pombe cells harboring pYSTP were significantly higher than those of the vector control cells. Total superoxide dismutase (SOD) and GSH peroxidase activities were also higher in the S. pombe cells harboring pYSTP after the temperature shifts than in the vector control cells. In brief, the S. pombe Sdu1 plays a thermotolerant role against high incubation temperature through the down-regulation of ROS and NO and the up-regulation of total GSH content, total SOD and GSH peroxidase activities.