삼차동맥존속증을 동반한 정중엽 다리뇌경색

하윤석,김명국,유봉구 고신대학교 의과대학 2010 고신대학교 의과대학 학술지 Vol.25 No.2

Persistent trigeminal artery (PTA) is the most frequently observed fetal anastomosis between the carotid and vertebrobasilar circulations. PTA is usually associated with hypoplasia or aplasia of the vertebrobasilar artery. A 56-year-old woman presented with right hemiparesis and dysarthria. Brain MRI showed acute infarction in the right paramedian pons. CT angiogram revealed right persistent trigeminal artery and hypoplasia of the proximal basilar artery

건강질단 질병 유소견자들의 순천향구미병원 외래이용에 영향을 미치는 요인

김진석,우극현,함정오,유재영,최태성,하봉구,윤성용 순천향의학연구소 2002 Journal of Soonchunhyang Medical Science Vol.8 No.1

Background ; The purpose of routine health screening of employee is not only to detect worker's disease at early stage but also to provide early appropriate health service. But, majority of patients who diagnosed by routine health screening haven't underwent health service utilization. Soonchunhyang Kumi Hospital had been provide total occupational health service in kumi industrial estate including health screening, worker interview at workplace by occupational nurses and doctors. Object ; We want to know how much proportion of patient who are diagnosed by routine health screening had visited Soonchunhyang Kumi hospital out-patient clinic and factors influencing such health care service utilization. Method ; Initial study subject were 189 workers who had proved to have hypertension, diabetes mellitus, hyperlipidemia in routine health screening which performed during year of 2000. Among those, 160 workers who had finished questionnaire were selected for final study subject. We investigate whether they had visited health services or not, if they had, what kind of health care facility they visited, and other factors which influencing their health service utilization. Result ; Among 160 workers, 59(36.9%) had visited Soonchunhyang Kumi hospital, 47(29.4%) had visited other health care facility, and 54(33.8%) had not went to any health care facility. Factors which influencing Soonchunhyang Kumi hospital utilization is sex, job, staff's support to hospital visit during worktime, history of medical consultation about health screening result.

Blind Post-Processing for Ringing and Mosquito Artifact Reduction in Coded Videos

Seok Bong Yoo,Kyuha Choi,Jong Beom Ra IEEE 2014 IEEE Transactions on Circuits and Systems for Vide Vol.24 No.5

<P>Block-based video-coding standards produce unwanted spatial and temporal artifacts in reconstructed videos. Among them, ringing and mosquito artifacts arise due to the quantization of high-frequency discrete cosine transform coefficients. Most of the existing artifact-reduction algorithms assume that coding information such as a standard quantization table and the corresponding quantization parameter for each block are available. In many multimedia applications, however, external video inputs are usually supplied without coding information. To effectively reduce the ringing and mosquito artifacts in a decoded input video sequence, it is necessary to control the filter strength block by block. In this paper, we present a blind block-based method to estimate the quantization amount and propose a novel post-processing algorithm based on the visibility of artifacts in terms of the human visual system using the estimated quantization amount. Experimental results demonstrate that the proposed algorithm better alleviates ringing and mosquito artifacts in various coded videos compared with the existing algorithms.</P>

Efficient Texture Creation Based on Random Patches in Database and Guided Filter

YOO, Seok Bong,HAN, Mikyong 'Institute of Electronics, Information and Communi 2018 IEICE transactions on information and systems Vol.101e.d No.11

Temporal matching prior network for vehicle license plate detection and recognition in videos

Yoo, Seok Bong,Han, Mikyong Electronics and Telecommunications Research Instit 2020 ETRI Journal Vol.42 No.3

In real-world intelligent transportation systems, accuracy in vehicle license plate detection and recognition is considered quite critical. Many algorithms have been proposed for still images, but their accuracy on actual videos is not satisfactory. This stems from several problematic conditions in videos, such as vehicle motion blur, variety in viewpoints, outliers, and the lack of publicly available video datasets. In this study, we focus on these challenges and propose a license plate detection and recognition scheme for videos based on a temporal matching prior network. Specifically, to improve the robustness of detection and recognition accuracy in the presence of motion blur and outliers, forward and bidirectional matching priors between consecutive frames are properly combined with layer structures specifically designed for plate detection. We also built our own video dataset for the deep training of the proposed network. During network training, we perform data augmentation based on image rotation to increase robustness regarding the various viewpoints in videos.

Post-Processing for Blocking Artifact Reduction Based on Inter-Block Correlation

Seok Bong Yoo,Kyuha Choi,Jong Beom Ra IEEE 2014 IEEE transactions on multimedia Vol.16 No.6

<P>Block-based coding introduces an undesirable discontinuity between neighboring blocks in reconstructed images. This image degradation, referred to as blocking artifacts, arises mainly due to the loss of inter-block correlation in the quantization process of discrete cosine transform coefficients. In many multimedia broadcasting applications, such as a television, decoded video sequences suffer from blocking artifacts. In this paper, we present a novel post-processing algorithm based on increment of inter-block correlation aimed at reducing blocking artifacts. We first smooth the three lowest frequency discrete cosine transform (DCT) coefficients between neighboring blocks, in order to reduce blocking artifacts in the flat region, which are most sensitive to the human visual system. We then group each edge block and its matched blocks together and apply group-based filtering to increase the correlation between grouped blocks. This suppresses blocking artifacts in the edge region while preserving details. In addition, the algorithm is extended to reduce flickering artifacts as well as blocking artifacts in video sequences. Experimental results show that the proposed method successfully alleviates blocking artifacts in both images and videos coded with low bit-rates.</P>

패치 데이터베이스 기반 고효율 텍스쳐 세밀감 향상 기법

유석봉(Seok Bong Yoo),이훈기(Hoon-Ki Lee),한미경(Mikyong Han) 대한전자공학회 2018 대한전자공학회 학술대회 Vol.2018 No.6

스크린도어의 장애물 검지를 위한 Area센서와 다중공간분할 3D센서의 검지율 비교 분석

유봉석(Bong Seok Yoo),이현수(Hyun Su Lee),진주현(Ju Hyun Jin),김종식(Jong Sik Kim) 한국전자통신학회 2016 한국전자통신학회 논문지 Vol.11 No.6

승강장에는 승객의 안전사고를 방지하기 위하여 스크린도어를 설치하고 있으며 스크린도어에는 장애물 검지를 위해 Area센서를 설치하고 있다. 그러나 먼지, 햇빛, 눈, 벌레 등으로 인한 스크린도어의 빈번한 동작오류가 원활한 열차운행을 방해하고 있어 장애물 감지 센서의 동작오류 감소와 장애물 검지 기능을 고도화하기 위한 대체 검지기의 연구가 필요하다. 본 논문에서는 대구 문양역에 시범운영 중인 로프타입 상하개폐식 스크린도어에 Area센서와 장애물검지 다중공간분할 검지알고리즘을 적용한 3D센서를 설치하여 검지 데이터를 수집하고 CCTV를 이용한 영상데이터 판독결과를 비교하였다. 3D 센서의 장애물 검지율은 약 86.91%로 Area센서의 약 78.88% 대비 장애물 검지율이 6.87∼9.79%가 더 높아 설치비용의 절감과 검지성능을 개선한 3D 센서의 적용 가능성을 확인 할 수 있었다. A subway platform is equipped with screen doors in oder to avoid accidents of passengers, where Area sensors are installed for detecting obstacles in the screen doors. However, there exist frequent operating errors in screen doors due to dusts, sunlight, snow, and bugs. It is required to develope a detection device which reduces errors and elaborates detection function. In this paper, we compared the detection rates of the Area sensor the 3D sensor using CCTV-based image data with installing sensors at the screen door in Munyang station Daegu, where 3D sensor is applied with the space division multiple detection algorithms. It is measured that the detection rate of 3D sensor and Area sensor is approximately 89.61% and 78.88%, respectively. The results confirmed that 3D senor has higher detection rate compared with Area sensor with the rate of 6.87~9.79%, and 3D sensor has benefit in the aspect of installation fee.

포털 뉴스와 인터넷신문 편집자의 전문가 역할 인식과 게이트키핑 차이 분석

유봉석(Yoo, Bong-Seok),정일권(Jeong, Ir-Kwon) 사이버커뮤니케이션학회 2012 사이버 커뮤니케이션 학보 Vol.29 No.4

본 연구는 온라인 공간에서 뉴스 유통의 가장 큰 축을 담당하는 포털 뉴스 편집자와 인터넷신문 편집자 간 게이트키핑 차이를 비교·분석했다. 두 편집자 그룹을 대상으로 개인, 관행 관련 게이트키핑 차원과 언론인 의식조사 때 사용하는 전문가 역할개념에 대해 설문 조사를 실시했다. 비록 응답자 수는(n=74) 많지 않으나 전체 포털 뉴스 편집자의 70%가 응답했다는 점에서 의미있는 수라고 할 수 있다. 분석결과 첫째, 포털 뉴스편집자의 전문가 역할개념은 상당히 높은 수준이며 주요 역할인지에서 인터넷신문 편집자보다 높았다. 둘째, 두 그룹 모두 편집업무 수행 때 오프라인 매체 영향을 가장 많이 받는 것으로 분석됐다. 또 개인보다는 관행 관련 게이트키핑 차원이 게이트키핑 행위에 더 많은 영향을 준다는 선행연구의 결과를 지지했다. 셋째, 편집 품질에 대한 상호 인식과 관련해 포털 뉴스가 인터넷신문보다 품질이 높다고 보는 경향이 발견되었다. 인터넷신문 편집자는 타사 인터넷신문보다 포털 뉴스의 편집품질을 높게 인식했다. 이상의 결과를 종합하면 포털 뉴스편집자의 전문성이나 포털 뉴스의 편집품질이 인터넷신문 편집자에 비해 떨어지지 않았다고 할 수 있다. This thesis overviews and analyzes the difference between portal news editors and internet media news editors who consist of mainstays of online news service. A survey of both editor groups is conducted on individual gatekeeping forces, journalistic routines and professional role conceptions. Although the number of respondents (n=74) is not large, it is meaningful in that 70% of portal news editors in Korea answered. The results reveal: First, the professional role conceptions of portal news editors is considerably high compared with internet media editors. In most of specific dimensions of professional role conceptions, the scores of portal news editors are higher than those of internet media editors. Second, both groups are most significantly influenced by off-line media when they are editing news. Also, they are affected by routine level forces rather than by individual level forces. It supports what Shoemaker and Reese noted in 1996. Third, regarding the mutual perception between two editor groups, the quality of portal news-editing is recognized better than that of internet media news-editing. The salient finding of this thesis is that professionalism of portal news editors and quality of portal news service are not inferior to those of internet media.

이동통신 기지국 기반 도시철도 지하 역사 및 구간 위치 측위 기술 연구

유봉석(Bong Seok Yoo),김규호(Gyu Ho Kim),진주현(Ju Hyun Jin),장기백(Ki Baek Jang) 한국전자통신학회 2016 한국전자통신학회 논문지 Vol.11 No.5

Urban railway can be divided into ground and underground sections. In particular, the center of the metropolitan has been built mostly underground stations and tunnels. Underground section is difficult to measure the position because GPS signal is unavailable, so it is necessary to apply the indoor positioning technology. For this purpose, we analyzed the positioning technologies which are based on Wi-Fi and mobile base stations. The positing technology for smart phone which uses mobile base station’ information is developed in the underground area of urban railway where the core technique is to implement base station ID into the positing technology by considering hand-off point. 도시철도는 지상과 지하 구간으로 분류할 수 있으며, 특히 수도권 중심부는 대부분이 지하 역사 및 터널로 구축되어 있다. 지하 구간은 지상과 달리 GPS 수신이 불가능하여 위치 측정이 힘들기 때문에 실내 측위 기술적용이 필요하다. 이를 위하여 본 연구에서는 Wi-Fi 기반과 이동통신 기지국 기반의 측위 기술에 대하여 분석하였다. 특히 도시철도 지하구간에는 핸드폰 통신을 위한 이동통신 기지국 정보를 활용한 기술을 연구하였으며, 핵심적인 기술로 터널 구간에서의 Hand-off 지점 간 변화되는 기지국 ID정보를 측위 기술에 적용하는 방안을 연구하였다.