Modified rate distortion optimization using inter-block dependence for H.264/AVC intra coding

Jongmin You,Changryoul Choi,Jechang Jeong IEEE 2008 IEEE TRANSACTIONS ON CONSUMER ELECTRONICS - Vol.54 No.3

<P>H.264/AVC allows several prediction schemes including variable modes for intra and inter predictions. To take full advantage of all allowed modes, H.264 employs rate distortion optimization (RDO) as its mode decision method. However, RDO incorporated into the H.264 encoder assumes block independence because calculating rate distortion (RD) cost for all possible mode sets requires a huge number of computations. In contrast to this assumption, coding efficiency of intra prediction in the H.264 encoder is affected by reference pixels in neighboring blocks. Thus, RDO in the H.264 encoder has potential to improve coding performance by considering the accuracy of intra prediction for the next blocks during the mode decision process of the current block. In this paper, we propose new criteria for I4 times 4 mode decision and by using this criteria, the proposed method considers more mode sets to improve RD performance compared to the original RDO. Although the proposed method requires more computations compared to the original RDO, experimental results indicate that the proposed method noticeably improves coding efficiency compared to the original RDO.</P>

SKIP 모드 왜곡의 구분을 통한 H.264/AVC 부호화 P 슬라이스에서의 고속 모드 결정 방법

유종민(Jongmin You),정제창(Jechang Jeong) 한국방송·미디어공학회 2009 방송공학회논문지 Vol.14 No.1

Omission of chemotherapy for hormone receptor-positive and human epidermal growth factor receptor 2-negative breast cancer: patterns of treatment and outcomes from the Korean Breast Cancer Society Registry

Jongmin Sim*,Hannah Lois Kangleon-Tan*,Ji Young You,Eun-Shin Lee,Haemin Lee,Sun Moon Yang,Min-Ki Seong,Eun Hwa Park,Seok Jin Nam,박민호,Seokwon Lee,Woo-Chan Park,Rogelio G. Kangleon Jr,Crisostomo B. Dy,S 대한외과학회 2022 Annals of Surgical Treatment and Research(ASRT) Vol.103 No.6

Purpose: Although adjuvant chemotherapy (CTx) is still recommended for high-risk patients with hormone receptorpositive and human epidermal receptor (HER)-2-negative breast cancer, recent studies found that selected patients with low disease burden may be spared from CTx and receive hormonal treatment (HT) alone. This study aims to evaluate the trends of treatment (CTx + HT vs. HT alone) in Korea and to assess the impact on overall survival (OS) according to treatment pattern. Methods: The Korean Breast Cancer Society Registry was queried (2000 to 2018) for women with pT1-2N0-1 hormone receptor-positive and HER2-negative disease who underwent surgery and adjuvant systemic treatment (CTx and HT). Clinicopathologic factors, change in pattern of treatment over time, and OS for each treatment option were analyzed. Results: A total of 40,938 women were included in the study; 20,880 (51.0%) received CTx + HT, while 20,058 (49.0%) received HT only. In recent years, there has been a steady increase in the use of HT alone, from 21.0% (2000) to 64.6% (2018). In Cox regression analysis, age, type of breast and axillary operations, T and N stages, body mass index, histologic grade, and presence of lymphovascular invasion were prognostic indicators for OS. There was no significant difference between CTx + HT and HT alone in terms of OS (P = 0.126). Conclusion: Over the years, there has been a shift from CTx + HT to HT alone without a significant difference in OS. Therefore, HT alone could be a safe treatment option in selected patients, even those with T2N1 disease.

Assessing Accuracy of Wrist-Worn Wearable Devices in Measurement of Paroxysmal Supraventricular Tachycardia Heart Rate

Jongmin Hwang,Jun Kim,Kee-Joon Choi,Min Soo Cho,남기병,You-Ho Kim 대한심장학회 2019 Korean Circulation Journal Vol.49 No.5

Background and Objectives: Wrist-worn wearable devices provide heart rate (HR) monitoring function via photoplethysmography technology. Recently, these devices have been used by patients to measure the HR when palpitation occurs, but few validation studies of these instruments have been conducted. We assessed the accuracy of these devices for measuring a HR. Methods: This study enrolled 51 consecutive patients with a history of paroxysmal supraventricular tachyarrhythmia (SVT) or paroxysmal palpitations who were scheduled to undergo an electrophysiological study (EPS). Three devices were assessed: Apple Watch Series 2 (Apple), Samsung Galaxy Gear S3 (Galaxy), and Fitbit Charge 2 (Fitbit). Patients were randomly assigned to wear 2 different devices. The HR at baseline and induced SVT were measured during the EPS. After successful ablation of SVT, HR measurements was also done during atrial and ventricular pacing study. Results: The mean patient age was 44.4±16.6 years and 27 patients were male (53%). The accuracy (within ±5 beats per minute [bpm] of an electrocardiogram [ECG] measurement) of the baseline HR measurements was 100%, 100%, and 94%, for Apple, Galaxy, and Fitbit, respectively. The HR during induced SVT ranged from 108 bpm to 228 bpm and the accuracy (within ±10 bpm of an ECG) was 100%, 90%, and 87% for the Apple, Galaxy, and Fitbit, respectively. During pacing study, accuracy of these devices was also acceptable but tended to decrease as the HR increased, and showed differences between the devices. Conclusions: Wrist-worn wearable devices accurately measure baseline and induced SVT HR.

Three-dimensional clustering of Janus cylinders by convex curvature and hydrophobic interactions

Kim, Jongmin,Oh, Myung Seok,Choi, Chang-Hyung,Kang, Sung-Min,Kwak, Moo Jin,You, Jae Bem,Im, Sung Gap,Lee, Chang-Soo The Royal Society of Chemistry 2015 SOFT MATTER Vol.11 No.24

<P>The three-dimensional (3D) clustering of Janus cylinders is controlled by simply tuning the cylinder geometry and hydrophobic interactions. Janus cylinders were prepared by combining two approaches: micromolding and initiated chemical vapor deposition (iCVD). Hydrophilic cylinders with a flat- or convex-top curvature were prepared by micromolding based on surface tension-induced flow. The iCVD process then provides a hydrophobic domain through the simple and precise deposition of a polymer film on the top surface, forming monodisperse Janus microcylinders. We use these Janus cylinders as building blocks to form 2D or 3D clusters <I>via</I> hydrophobic interactions in methanol. We investigate how cylinder geometry or degree of hydrophobic interaction affects the resulting cluster geometries. The convex-top Janus cylinders lead to 3D clustering through tip-to-tip interactions, and the flat-top Janus cylinders lead to 2D clustering through face-to-face attraction. The number of Janus cylinders in 3D clusters is tuned by controlling the degree of hydrophobic (or hydrophilic) interaction.</P> <P>Graphic Abstract</P><P>The geometry or degree of hydrophobic interaction in Janus microcylinders affects the formation of the assembled structures. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c5sm00734h'> </P>

가로-세로비가 큰 고정익 무인항공기의 자동착륙 프로파일 설계 연구

안종민(Jongmin Ahn),유동일(Dong-il You),이광현(Kwanghyun Lee) 한국항공우주학회 2017 한국항공우주학회 학술발표회 논문집 Vol.2017 No.11

TA-50 공대지 사격 오폭방지 소프트웨어 기능 구현

유은경 ( Eunkyung You ),김종민 ( Jongmin Kim ),오철웅 ( Chulwoong Oh ),진호석 ( Hoseok Jin ),김경중 ( Kyungjung Kim ) 공군사관학교 2016 空士論文集 Vol.67 No.2

최근 이라크에서 폭탄이 비정상 투하되어 민간인 30여명이 사상하는 사고가 발생해 논란이 있었다. 또한 미군이 병원에 폭탄을 잘못 투하해 수십 명이 사망하는 참사를 초래한 바 있다. 국내에서는 이와 같은 인명피해는 없었으나, 훈련 중 폭탄이 비정상 투하되는 사례가 지속적으로 발생하고 있다. 특히, TA-50 항공기는 국산 초음속 전술 훈련기로써, 2012년 6월 공군에 전력화되어, 훈련조종사의 공대공·공대지 사격 등 실전적 전투기술 배양을 위한 훈련을 수행하고 있다. 이는 전투 조종사가 되기 위한 초급 단계의 입문 과정으로써, 이 과정을 수행하는 훈련 조종사의 숙련도 부족으로 인한 의도치 않은 투하 사례가 보고되고 있다. 공대지 정확도 해석 보고서의 투하 에러 요소별 점유율에 따르면 폭탄이 비정상 투하되는 원인중 인적요인에 의한 에러가 34%를 차지하고 있다고 보고되었다. 인적요인에 의한 비정상 투하는 기존의 공대지 시계 무장 투하 모드가 표적의 위치에 관계없이 투하가 가능하기 때문에 발생하는 것으로 분석되었다. 이에 본 논문에서 제시하는 공대지 사격 오폭방지 소프트웨어 기능은 표적 위치를 중심으로 사격 가능범위를 설정하고, 이 범위를 벗어나는 경우 무장 투하 신호를 차단함으로써 오폭 발생 가능성을 감소시키도록 구현한 내용이다. 이를 통해 조종사의 오폭에 대한 부담을 완화시키고 또한 실질적으로 오폭을 방지함으로써 공군의 대내·외적 신뢰도 향상에 기여할 수 있을 것으로 기대된다. Nowadays, criticism upon accidents which were triggered by the negligence of the pilot of fighters are being heated. In Iraq, a fighter which were on its training, dropped a bomb on an are where civilians resided in as a mistake. This caused huge casualties, leading to death or severe injury of more than 30 people. In America, a pilot mistakenly threw a bomb on a hospital, killing many people on site. Even though there has not been human casualties in South Korea, the number of abnormal bomb drops on training is steadily increasing. TA-50 is a supersonic fighter made for training which were introduced in June, 2012. In order to enable trainees to be accustomed to practical techniques for warfare, trainees go through air-to-air and air-to-ground shooting drills with the fighter. Since the trainees are not well versed in controlling fighters, cases of unintentional bombing has been constantly being reported. According to air-to-ground accuracy report, errors on human resource contribute to 34% of all abnormal bombings. Abnormal bombings caused by errors on human resources were viable since existing air-to-ground visual weapon release mode enabled pilots to throw bombs regardless of the target`s position. In order to counter this problem, this treatise will suggest a new software for air-to-ground visual weapon release mode. The software would set a limit of range when it to comes to weapon drop. To be specific, a target will be at the center of the circle-shaped range. If a pilot tries to shoot from the outside of the radius of the range, the weapon release signal would be cut off, leading to lowing the possibility of abnormal dropping. Through this software, Air Force would gain domestic and external trust as the number of abnormal bombing and its possibility would decrease. Moreover, anxiety derives from abnormal bombing that pilots would feel would also be eased, which would be catching two birds with one stone.

Weighted Fuzzy Reasoning Scheme for Interlaced to Progressive Conversion

Gwanggil Jeon,Jongmin You,Jechang Jeong IEEE 2009 IEEE transactions on circuits and systems for vide Vol.19 No.6

<P>Video deinterlacing can be realized using time-space interpolation filters. To improve video deinterlacing quality with respect to missing pixels on moving diagonal lines, we developed a fuzzy concept that utilizes deinterlacing methods. The proposed algorithm consists of three parts. The first part is fuzzy rule-assisted edge-preserving-based deinterlacing (FED), which has an edge-preserving unit that utilizes fuzzy theory to find the most accurate edge direction and interpolates the missing pixels. Using the introduced gradients in the interpolation, the vertical resolution in the deinterlaced image is subjectively concealed. The second part is weighted fuzzy-reasoning-assisted deinterlacing (WFD), which works in the spatio-temporal domain. In this part, the computed weights are considered and multiplied by the candidate deinterlaced pixels, which successively build approximations of the deinterlaced sequence. The third part of the proposed algorithm is weighted fuzzy switching filtering, which analyzes the suitability of each method on system performance and uses a switching algorithm between FED and WFD. The outcome of image interpolation can be adjusted continuously by varying the setting of the membership function for fuzzy inference. Compared with conventional image interpolation methods, the algorithm presented in this paper provides improved edge quality in the deinterlaced image without the introduction of evident artifacts.</P>

Complexity control strategy for real-time H.264/AVC encoder

Kim, Wonkyun,You, Jongmin,Jeong, Jechang IEEE 2010 IEEE TRANSACTIONS ON CONSUMER ELECTRONICS - Vol.56 No.2

<P>The H.264/AVC encoder acquires high coding efficiency by using the various coding techniques, but requires very high computational complexity. Therefore, H.264/AVC encoder causes the problem of preserving acceptable video coding performance in the low-power/processor environments, such as wireless mobile. To optimize the ratedistortion (R-D) and complexity, we analyze the encoding structure and establish an analytic model for complexity. From this analysis, we propose a new approach for real-time encoder which maintains both frame rate and video quality. An encoding time control algorithm investigates the results of P16¿16 motion estimation (ME) in the current frame and decides the number of skipped macroblocks (MBs) in order to encode the frame within the allocated target encoding time. A complexity control algorithm manages the coding complexity of each frame by preventing motion estimations for smaller modes. Simulation results show that compared to the existing algorithm, the proposed algorithm can maintain frame rate without significant degradation of visual quality and increase in bit rate.</P>

친환경 페로브스카이트 태양전지 최신 기술 동향

유형렬,최종민,You, Hyung Ryul,Choi, Jongmin 한국전기화학회 2019 한국전기화학회지 Vol.22 No.3

Metal halide perovskite materials are considered as promising semiconducting materials for next-generation solar cells due to their unique electrical and optical properties. Intensive progress in perovskite solar cell yielded a certified power conversion efficiency over 24%. However, most of highly efficient perovskite solar cells required Pb-based perovskite materials, which is a critical obstacle for their commercialization, and development of Pb-free perovskite materials is one of recent urgent issues in this field. In this paper, we will introduce recent research progress on Pb-free perovskite solar cells. 금속 할로겐 페로브스카이트 (perovskite)는 우수한 전기적, 광학적 특성으로 인해 차세대 태양전지의 핵심 소재로 큰 주목을 받고 있다. 페로브스카이트 태양전지는 등장 이후 전례 없는 단기간 효율 향상을 보이며 현재 24% 이상의 인증된 광전 변환 효율을 달성하였지만, 대부분의 고성능 페로브스카이트 태양전지는 유독성 납 (Pb)을 기반으로 한 페로브스카이트를 사용한 것으로, 향후 상용화를 위해서는 납을 쓰지 않는 친환경 페로브스카이트 개발이 필수적이다. 본 글에서는 비납 페로브스카이트 물질 및 연구 동향에 대해서 소개하고자 한다.