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Kim Jiwoong,Lee Sun Jung,Ko Bonggyun,Lee Myungeun,Lee Young-Shin,Lee Ki Hong 대한의학회 2024 Journal of Korean medical science Vol.39 No.5
Background: The acquisition of single-lead electrocardiogram (ECG) from mobile devices offers a more practical approach to arrhythmia detection. Using artificial intelligence for atrial fibrillation (AF) identification enhances screening efficiency. However, the potential of singlelead ECG for AF identification during normal sinus rhythm (NSR) remains under-explored. This study introduces a method to identify AF using single-lead mobile ECG during NSR. Methods: We employed three deep learning models: recurrent neural network (RNN), long short-term memory (LSTM), and residual neural networks (ResNet50). From a dataset comprising 13,509 ECGs from 6,719 patients, 10,287 NSR ECGs from 5,170 patients were selected. Single-lead mobile ECGs underwent noise filtering and segmentation into 10-second intervals. A random under-sampling was applied to reduce bias from data imbalance. The final analysis involved 31,767 ECG segments, including 15,157 labeled as masked AF and 16,610 as Healthy. Results: ResNet50 outperformed the other models, achieving a recall of 79.3%, precision of 65.8%, F1-score of 71.9%, accuracy of 70.5%, and an area under the receiver operating characteristic curve (AUC) of 0.79 in identifying AF from NSR ECGs. Comparative performance scores for RNN and LSTM were 0.75 and 0.74, respectively. In an external validation set, ResNet50 attained an F1-score of 64.1%, recall of 68.9%, precision of 60.0%, accuracy of 63.4%, and AUC of 0.68. Conclusion: The deep learning model using single-lead mobile ECG during NSR effectively identified AF at risk in future. However, further research is needed to enhance the performance of deep learning models for clinical application.
황사(미세먼지)가 시설재배에 미치는 영향과 피해 경감 기술
이재한 ( Jae Han Lee ),국준국 ( Joon Kook Kwon ),이중섭 ( Jung Sup Lee ),방지웅 ( Jiwoong Bang ),김진현 ( Jin Hyun Kim ),이동수 ( Dong Soo Lee ),김혜민 ( Hye Min Kim ),홍은미 ( Eun Mi Hong ),이승재 ( Seung Jae Lee ) 한국환경농학회 2019 한국환경농학회 학술대회집 Vol.2019 No.-
우리나라로 날아오는 황사의 근원지는 중국, 고비사막으로 알려져 있으며, 주로 3월∼5월까지 심하게 발생되고 있다. 이러한 지리적 여건외에도 산업화, 석탄·석유 등 화석연료를 연소할 때, 공장 자동차 등의 배출가스에서 발생하는 공해물질이 공기와 반응하여 농작물 재배시설의 외부 피복재에 부착되어 일조량을 감소시켜 많은 문제를 야기시키고 있다. 먼지는 입자의 크기에 따라서 TSP, PM으로 구분하고 있다. 지금까지 농업 분야에서는 대부분 황사, 분진 등에 관해서는 연구를 수행한바 있으나, 미세먼지에 관한 연구는 거의 없는 실정이다. 최근에는 미세먼지는 연중 발생빈도가 높게 증가하고 있어 농업의 문제를 넘어서 사회문제로 확산되고 있다. 2000년 12월에서 2010년 3월 일조량은 지난 30년 평균보다 20% 이상 감소하였으며, 이는 농산물의 생산량 감소로 이어져 가격이 폭등하는 등 많은 문제점을 야기한 바 있다. 따라서 본 연구에서는 미세먼지 및 황사 등에 의한 시설재배 작물의 생육저하, 수량감소 수준과 저일조피해를 경감하기 위한 세척기술, 보광기술 등에 대하여 연구를 소개하고자 한다. The source of the yellow dust(micro dust) which is flying to korea is known as the Gobi desert in China, and it is mainly occurring from March to May. Pollutants from the exhaust gases when burning fossil fuels such as coal and oil, factory and automobiles reacts with air and they attached to the outer covering material of the crop cultivation facility to reduce the amount of sunshine. The dust is classified into TSP and PM depending on the particle size. So far, the researches about yellow dust have been carried out in the field of agriculture, but there are few studies on micro dust. In recent years, the occurrence frequency of micro dust increases year by year, so it is spreading beyond agriculture and social problems. From December 2000 to March 2010, the amount of sunshine has decreased by more than 20% from the average of last 30 years and this has caused many problems such as a decrease in production of agricultural products and an increase in prices. Therefore, in this study, we will introduce the cleaning technology of outer covering materials and supplemental lighting technology to prevent the decrease of yield and growth of plant by micro dust.
Lee, Sangwon,Choi, Yong,Jung, Jin Ho,Jung, Jiwoong,Kim, Kyu Bom,Choe, Hyeok-jun,Leem, Hyun Tae,Lee, Hwunjae,Huh, Yong-Min Institute of Physics in association with the Ameri 2019 Physics in medicine & biology Vol.64 No.4
<P>Small animal positron emission tomography (PET) is a noninvasive imaging modality that enables <I>in vivo</I> imaging and quantification of the biological processes of small experimental animals. We have developed a small animal PET that utilizes a high-resolution multiplexed readout and charge signal transmission (CST) method. The small animal PET was composed of six detector blocks consisting of SiPMs and LYSO arrays. Six detector blocks were mounted on a PET gantry having an inner diameter of 76 mm, outer diameter of 112 mm, and axial length of 40.8 mm. The charge signals of SiPM output were transmitted to the input of multiplexed readout using 4 m flexible flat cables. The multiplexed readout was composed of six main boards, each of which included 36 detector boards, to reduce the number of readout channels by a factor of 36, with a multiplexing ratio of 144:4. The performance of the small animal PET was evaluated using NEMA NU 4-2008 standards, and its imaging capability was demonstrated by <I>in vivo</I> mouse imaging studies. The average energy and time resolutions were 13.2% ± 0.3% and 3.8 ns, respectively. The spatial resolution at the center of the transaxial FOV was 1.1 mm, and the peak sensitivity at the center of the axial FOV was 1.5%. The peak noise equivalent count (NEC) rate and scatter fraction were 21.1 kcps at 18.2 MBq and 21%, respectively. The acquired images demonstrated high quality tracer uptake patterns of small experimental animals. The results of performance evaluation and animal imaging indicate that the small animal PET developed in this study can provide high-quality small animal imaging with cost-effectiveness and compactness.</P>
Design and Analysis of a Cooperative Multichannel MAC Protocol for Heterogeneous Networks
Jiwoong Lee,Jeonghoon Mo,Tran Minh Trung,Walrand, Jean,So, Hoi-Sheung Wilson IEEE 2010 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY Vol.59 No.7
<P>Many incompatible wireless protocols proliferate in unlicensed bands, creating complex coexistence and connectivity problems. If the trend continues, such problems will continue to exist in future unlicensed bands. We take a different approach to spectrum sharing. Instead of proposing a distinct medium-access control (MAC) protocol for each type of application, we propose a family of parameterized MAC protocols called WiFlex, which can be tailored to different application needs, ranging from wireless sensors to media centers. However, these protocols allow communication and spectrum-sharing coordination among different types of devices. We envision this family to be based on a multichannel physical layer. The contributions of this paper include a novel asynchronous split phase (ASP) protocol with dynamic priority support, even in multiple-collision-domain environments. When links are bidirectional, WiFlex resolves the multichannel hidden-node problem, achieving collision-free data exchange in a multihop environment. ASP provides a mechanism for prioritization and fairness. The performance of the protocol is evaluated through analysis and simulation. The coexistence of heterogeneous devices and the support for different applications with high performance are demonstrated.</P>