선형 모델 기반 매크로블록 레이어 비트율 제어 기법

서동완,최윤식,Seo Dong-Wan,Choe Yoonsik 대한전자공학회 2005 電子工學會論文誌-SP (Signal processing) Vol.42 No.6

In this paper, we propose the bit-rate control algorithm for the block based image compression like H.263, H.263+ or MPEG-4. The proposed algorithm is designed to identify the quantization parameter set through the Lagrangian optimization technique based on the well-known linear source model. We set the Lagrangian cost function with the rates and distortion calculated from the linear source model. We calculate the quantization parameter set using the Vitervi algorithm to solve the Lagrangian optimization problem considering the Dquant method of H.263 and MPEG-4. The proposed algorithm improves the video quality by up to 1.5 dB compared with the TMN8 scheme, and is more effective in the video sources with dynamic activities than the consistent quality approaches. 본 논문에서는 H.263, H.263+, MPEG-4와 같은 블록 기반 비디오 압축을 위한 비트-율 제어 기법을 제안한다. 제안 알고리즘은 선형 모델에 기반한 라그랑지안 최적화 기법을 통해서 매크로블록 당 할당되는 양자화 파라미터의 조합을 산출한다. 제안 알고리즘에 사용하는 라그랑지안 비용함수는 선형 모델에 의해서 산출되는 비트-율과 왜곡을 통해 구한다. H.263과 MPEG-4의 양자화 파라미터를 부호화하는 Dquant 방법에 맞도록 하기 위해 Dquant 방법을 고려하면서 동시에 라그랑지안 최적화 기법에 의한 해를 구하는 비터비 알고리즘에 의해 양자화 파라미터 조합을 구한다. 제안 알고리즘은 모델 기반 비트-율 제어 기법 중 하나인 TMN8 기법에 비해 1.5 dB 정도의 비디오 화질 개선 효과를 가지며, 선형 모델 기반 비트-율 제어 기법인 일정화질 접근 방법에 비해 화질은 거의 동일하게 유지하면서 비트-율의 변동폭이 줄어드는 효과가 있다.

Equal Bit Rate Control for Low Bit-rate Coder based on Frame Statistics

서동완,최윤식,Seo Dong-Wan,Choe Yoon-Sik The Korea Institute of Convergence Signal Processi 2005 융합신호처리학회 논문지 (JISPS) Vol.6 No.4

본 논문은 프레임간의 특성 변화를 이용한 균등 비트 할당 기법을 제안한다. 모델 기반 비트율 조정 알고리즘에 대한 기존의 연구는 양자화 파라미터와 비트율 및 왜곡 모델간의 관계를 찾는 것에 초점을 맞추어 진행해 왔다. 본 논문에서는 비트율-왜곡 모델을 새로이 설정하는 것 대신에 모델 기반 접근 알고리즘 내에서 프레임 특성 변화에 따라 모델 파라미터를 조절하여 모델 기반의 비트율 조정 알고리즘의 성능을 향상시킨다. 모델 기반 접근의 성능은 비트율-왜곡 모델 자체의 정확성과 프레임 간의 비트율-왜곡 특성 차이를 보상하는 모델 파라미터의 정확한 설정이 알고리즘의 성능을 좌우한다. 제안 알고리즘은 프레임의 특성 변화를 모델 파라미터에 의해 파악하고 모델 파라미터를 현재 프레임에 맞도록 조정한다. 제안 알고리즘은 MPEG-4 비디오 부호를 이용하여 설계하고, 성능은 모델 기반 접근의 대표적인 방법인 TMN8과 비교하여 0.6dB 정도의 성능 향상을 나타낸다. This paper presents an equal bit rate control algorithm utilizing the statistical change between the previous frame and the current frame. The previous studies on the model-based rate control have focused on the models of bit rate and distortion in types of coders, in terms of the quantization parameter. The proposed algorithm improves the typical model-based rate control by updating a model parameter instead of modeling a better model of the rate and distortion. The proposed algorithm updates this model parameter by recognizing the change in statistics between the previous frame and the current frame. We implement the proposed algorithm in MPEG-4 coders and verify its performance while comparing it to the TMN8's approach (up to 0.6dB of improvement).

동영상 트랜스코더를 위한 적응적 인트라 매크로블록 업데이트에 대한 연구

서동완,최윤식,Seo Dong-Wan,Choe Yoon-Sik 한국융합신호처리학회 2006 융합신호처리학회 논문지 (JISPS) Vol.7 No.1

일반적으로 동영상 트랜스코딩 기술에서는 시스템의 복잡도를 줄이기 위해, 입력 비트열로부터 매크로블록 종류와 움직임 벡터, DCT 계수 등의 중간 데이터를 추출하여 사용한다. 본 논문에서는 프레임 내에서 매크로블록의 중요도를 이용한 새로운 인트라 매크로블록 업데이트 방법을 제안한다. 매크로블록의 중요도는 입력 비트열을 복호화하는 과정에서 얻어지는 움직임벡터에 의해 계산한다. 참조 프레임 내의 매크로블록의 참조율은 현재 복호화하는 프레임의 움직임 벡터에 의해서 계산이 가능하며, 참조율이 놀은 매크로블록은 다음 프레임과 그 이후 프레임에 영향력이 놀다 제안한 기법을 통해, 전송 오류에 대해 강인하고 더 우수한 화질을 나타내는 동영상 비트열을 얻을 수 있다. To reduce the complexity of video transcoder, transcoding techniques generally use intermediate data such as macroblock types, motion vectors, DCT coefficients, which are extracted from incoming video bitstream. In this Paper, we Propose a new adaptive INTRA update scheme utilizing the importance of each macroblock in a given frame. The importance measure is calculated from the motion vectors which are extracted from the decoding procedure of a incomming video data.'rho ratio of the macroblock to be referred by the next frame is calculated by the motion vectors of the next frame and the macroblocks to be refered higher ratio has more effect on the next frame and the followed frames. The proposed scheme can obtain transcoded bitstreams which has better image quality and more improved resilience against transmission errors.

담즙내 Oxysterol에 의한 담낭 상피세포의 Apoptosis와 그 기전에 관한 연구

서동완 ( Seo Dong Wan ),이성구 ( Lee Seong Gu ),김명환 ( Kim Myeong Hwan ),( Geoffrey Haigh ),( Sum P. Lee ) 대한소화기학회 2003 대한소화기학회 추계학술대회 Vol.2003 No.-

<목적> 담낭은 담즙을 저장하고 농축하는 기능이 있어서 담낭 상피세포는 고농도의 콜레스테롤에 노출되어 있다. 한편 콜레스테롤의 산화물인 oxysterol은 혈액과 여러 장기에서 검출되고 있으며 담즙과 담석내에서도 oxysterol의 일종인 cholest-4-en-3-one, cholesta-4,6-dien-3-one 그리고 cholesta-3,5-dien-7-one 등이 존재한다고 보고된 바 있다. 그러나 이러한 oxysterol들이 담도내에서 어떤 역

DCT 히스토그램 기반 비트 왜곡 추정에 의한 H.264 비트 율 제어

서동완(Seo Dong Wan),정진우(Jeong Jin Woo),최윤식(Choe Yoon Sik) 한국통신학회 2006 한국통신학회 학술대회논문집 Vol.2006 No.7

결핵성 및 암성 흉수의 감별진단에서 흉수내 SC5b - 9 농도 측정의 진단적 의의

서동완(Dong Wan Seo),곽승민(Seung Min Kwak),김우성(Woo Sung Kim),김동순(Dong Soon Kim),서을주(Eul Ju Seo),민원기(Won Ki Min),김원동(Won Dong Kim),고윤석(Youn Suk Koh) 대한내과학회 1994 대한내과학회지 Vol.47 No.6

N/A To evaluate the diagnotic value of pleural SCSb-9 in the differential diagnosis of tuberculous and malignant pleural effusion, we measured pleural ADA activity and SCSb-9 concentration in 71 cases of pleural effusions due to tuberculosis (n=35) and malignancy (n=36). And we also measured pleural C4d fragment and Bb fragment concentration to determine by which pathway the complement activation occurs in pleural space. The results were as follows: 1) The median value of pleural SC5b-9 concentration of tuberculous effusion was 6.4 ug/ml (interquartile range 2.6~11.7) and was significantly higher than that of malignant effusion (p<0.005). 2) The median values of pleural C4d fragment concentration were 15.5 mg/ml (9.9~18.9) in tuberculous effusion and 12.8 mg/ml (7.3~19.6) in malignant effusion. There were no significant difference between two groups. The median value of pleural Bb fragment concentration of tuberculous effusion was 7.8 mg/ml (5.5~12.8) and was significantly higher than that of malignant effusion (p<0.01). 3) The SC5b-9 concentration showed no significant correlation with C4d fragment concentration both in tuberculous effusion and malignant effusion. But the SC5b-9 concentration showed significant correlation with Bb fragment concentration both in tuberculous effusion (r=0.48, p<0.005) and malignant effusion (r=0.72, p<0.001). 4) The median value of pleural ADA activity of tuberculous effusion was 64.3 U/L (40.9~103.5) and significantly higher than that of malignant effusion (p<0.001). 5) Pleural ADA activity showed significant correlation with pleural SC5b-9 concentration in tuberculous effusion (r=0.53, p<0.005). 6) According to the receiver-operating characteristic curve analysis, the measurement of pleural ADA activity is superior to that of pleural SC5b-9 concentration in the differential diagnosis of tuberculous and malignant effusion. In conclusion, the measurement of pleural SC5b-9 concentration can be used as an adjunctive test in the differential diagnosis of tuberculous and malignant effusion but pleural ADA activity measurement was superior to pleural SC5b-9 concentration measurement. And pleural SC5b-9 concentration of tuberculous effusion was higher than that of malignant effusion and it seems to be due to the difference in activation of alternative pathway activation of complement in two groups.

진주초전지구 환지방식 도시개발사업의 토지소유자 의식추이 분석을 통한 개선방안 연구

서동완(Seo, Dong-Wan),김영(Kim, Yeong),신재원(Shin, Jae-Won) 한국주거환경학회 2015 주거환경(한국주거환경학회논문집) Vol.13 No.4

When any attempt is made to implement an urban development project based on land reallocation, it is required to get the consent of more than one-half of the total number of people who own the land amounting to more than two-thirds of the lands area in the corresponding urban development project area. It is possible to implement an urban development project based on land reallocation if legal consent requirements are satisfied. However, it is very important to minimize the number of people who disagree with the corresponding project. In this reason, this study analyzed the trends in landowner awareness before and after an urban development project was implemented and presented improvement plans in order to manage an urban development project based on more reasonable land reallocation. This study made tracking interviews with land owners in Chojeon area in Jinju City between January and March in 2013. so, presented three improvement alternatives according to a trend analysis on the landowner awareness in the urban development project based on a land reallocation as follows. The first, plan aims to minimize the number of people who disagree with a development plan on early establishment stage. The second, one intends to minimize the dissatisfaction with the urban development project after it is completed. The last, one intends to activate the promotion in the process of project implementation. As a result, If the number of people who disagree is minimized through an improvement in the implementation method for the urban development project, however, the dissatisfaction with a urban development project based on land reallocation will be minimized.

지방도시 노인주거실태와 노인주택 수요분석

서동완(Seo Dong Wan),김영(Kim Yeong),하창현(Ha Chang Hyoun) 한국주거환경학회 2016 주거환경(한국주거환경학회논문집) Vol.14 No.3

This research aims to prepare policies for elderly housing, based on analysis of current status of elderly housing and demand for elderly housing. As provincial cities lack in terms of understanding elderly residence or housing, the research aims for policies targeting provincial cities, rather than existing policies mainly targeting for sizable cities. The result showed that between elderly and non-elderly age group in provincial cities, elderly age group had inferior living condition, but intention to move into public rental houses or silver towns was higher in non-elderly age group, and in analysis based on household attributes, one-person households had higher demand for elderly housing. The analysis showed interest on elderly housing is higher in non-elderly group, thus the needs for elderly housing should be considered to be more important in the coming years. Providing elderly housing in provincial cities must be focused on ways to provide low-floor housing within the central areas, considering housing types and city spaces, and needs for methods to provide public rental houses or silver towns is being raised. Moreover, ways to increase provision of ultimately lacking elderly welfare houses must be considered as an extremely important issue. Lastly, direct support methods for housing-related cost for the elderly age group were mainly about providing preservation of income and supporting maintenance cost.

순서 맵에 기반한 개선된 주파수 확산 워터마킹

서동완(Dong Wan Seo),최윤식(Yoonsik Choe) 대한전자공학회 2000 대한전자공학회 학술대회 Vol.2000 No.6

췌장의 낭종성 질환 : 내시경초음파의 유용성

서동완 ( Dong Wan Seo ) 대한내과학회 2010 대한내과학회지 Vol.78 No.3

Pancreatic cystic lesions are becoming more and more important because of the advancement of various kinds of imaging modalities. Endoscopic ultrasonography is recognized as an indispensible tool for the differential diagnosis of pancreatic cystic tumors.