Interface Roughening, Grain Growth, and Sintering

윤덕용 한국분말야금학회 2004 한국분말야금학회 학술대회논문집 Vol.2004 No.1

Preparing for a New World: Making Friends with Digital Health

윤덕용 연세대학교의과대학 2022 Yonsei medical journal Vol.63 No.-

While digital health solutions have shown good outcomes in numerous studies, the adoption of digital health solutions in clinical practice faces numerous challenges. To prepare for widespread adoption of digital health, stakeholders in digital health will need to establish an objective evaluation process, consider uncertainty through critical evaluation, be aware of inequity, and consider patient engagement. By “making friends” with digital health, health care can be improved for patients.

탄소비율에 따른 Diamond-like Carbon Film의 광학적 및 기계적 특성

윤덕용,박용섭,최원석,홍병유,Yun, Deok-Yong,Park, Yong-Seob,Choi, Won-Seok,Hong, Byung-You 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.9

Optical and mechanical properties of diamond-like carbon (DLC) films synthesized by RF plasma enhanced chemical vapor deposition were investigated as a function the C/H ratio in gas mixture. The C/H ratio was varied from 6 to 10 %, adjusting the amount of $CH_4$ and $H_2$ as the source gas. The optical and mechanical properties of DLC films were characterized by UV spectrometer, Ellipsometer and Nano-indenter. The change of the C/H ratio during synthesis of DLC films had many effects on the growth rate, transmittance, refractive index and hardness. The growth rate of the films increased exponentially with the increase in C/H ratio. The hardness of the films showed the tendency to improve with increasing C/H ratio, whereas the transmittance decreased. The refractive index was varied from 2.03 to 2.17, and these refractive indexes close to 2.0 indicates that it can be applied to Si-based solar cell.

운이 좋아야

윤덕용 한국공학교육학회 1995 Ingenium(人材니움) Vol.2 No.3

벡터제어 유도전동기의 최대효율 운전

윤덕용,최규하,홍순찬,백수현,이은웅,Yoon, Duck-Yong,Choe, Gyu-Ha,Hong, Soon-Chan,Baek, Soo-Hyun,Lee, Eun-Woong 전력전자학회 1996 전력전자학회지 Vol.1 No.1

This paper proposes the control algorithm for maximum efficiency drive of PWM inverter - induction motor system with high dynamic performance. If the induction motor is driven under light load with rated magnetizing current, the Iron loss is excessively large compared with the codder loss which results in doer motor efficiency. Maximum efficiency drive of an induction motor can be achieved by controlling the magnetizing current to satisfy the optimal ratio that leads the total motor loss to be a minimum value at a given speed. The proposed control algorithm essentially uses vector control technique and adopts voltage decoupling control strategy to prevent the degradation of dynamic performance due to reduced magnetizing current. To verify the proposed method, digital simulations and experiments are carried out for a squirrel-cage induction motor with the rating of 2.2[kW].

계면구조가 소결과 입자성장에 미치는 영향

윤덕용 한국분말야금학회 1998 한국분말야금학회 학술대회논문집 Vol.1998 No.1

Deep Learning-Based Electrocardiogram Signal Noise Detection and Screening Model

윤덕용,임홍석,정경원,김태영,이석훈 대한의료정보학회 2019 Healthcare Informatics Research Vol.25 No.3

Objectives: Biosignal data captured by patient monitoring systems could provide key evidence for detecting or predicting critical clinical events; however, noise in these data hinders their use. Because deep learning algorithms can extract features without human annotation, this study hypothesized that they could be used to screen unacceptable electrocardiograms (ECGs) that include noise. To test that, a deep learning-based model for unacceptable ECG screening was developed, and its screening results were compared with the interpretations of a medical expert. Methods: To develop and apply the screening model, we used a biosignal database comprising 165,142,920 ECG II (10-second lead II electrocardiogram) data gathered between August 31, 2016 and September 30, 2018 from a trauma intensive-care unit. Then, 2,700 and 300 ECGs (ratio of 9:1) were reviewed by a medical expert and used for 9-fold cross-validation (training and validation) and test datasets. A convolutional neural network-based model for unacceptable ECG screening was developed based on the training and validation datasets. The model exhibiting the lowest cross-validation loss was subsequently selected as the final model. Its performance was evaluated through comparison with a test dataset. Results: When the screening results of the proposed model were compared to the test dataset, the area under the receiver operating characteristic curve and the F1-score of the model were 0.93 and 0.80 (sensitivity = 0.88, specificity = 0.89, positive predictive value = 0.74, and negative predictive value = 0.96). Conclusions: The deep learning-based model developed in this study is capable of detecting and screening unacceptable ECGs efficiently.

Pharmacogenomic information from CPIC and DPWG guidelines and its application on drug labels

윤덕용,Lee Soyoung,반무성,장인진,이승환 대한임상약리학회 2020 Translational and Clinical Pharmacology Vol.28 No.4

There are several hurdles to overcome before implementing pharmacogenomics (PGx) in precision medicine. One of the hurdles is unawareness of PGx by clinicians due to insufficient pharmacogenomic information on drug labels. Therefore, it might be important to implement PGx that reflects pharmacogenomic information on drug labels, standard of prescription for clinicians. This study aimed to evaluate the level at which PGx was being used in clinical practice by comparing the Clinical Pharmacogenetics Implementation Consortium and Dutch Pharmacogenetics Working Group guidelines and drug labels of the US Food and Drug Administration (FDA) and the Korea Ministry of Food and Drug Safety (MFDS). Two PGx guidelines and drugs labels were scrutinized, and the concordance of the pharmacogenomic information between guidelines and drug labels was confirmed. The concordance of the label between FDA and MFDS was analyzed. In FDA labels, the number of concordant drug with guidelines was 24, while 13 drugs were concordant with MFDS labels. The number of drugs categorized as contraindication, change dose, and biomarker testing required was 7, 12 and 12 for the FDA and 8, 5 and 4 for the MFDS, respectively. The pharmacogenomic information of 9 drugs approved by both FDA and MFDS was identical. In conclusion, pharmacogenomic information on clinical implementation guidelines was limited on both FDA and MFDS labels because of various reasons including the characteristics of the guidelines and the drug labels. Therefore, more effort from pharmaceutical companies, academia and regulatory affairs needs to be made to implement pharmacogenomic information on drug labels.

니켈기 초내열합금에서 γ' - 석출상의 평형모양 및 성장모양

윤덕용,유영수,염승진,최주,M . F . Henry 대한금속재료학회 1993 대한금속재료학회 학술대회 개요집 Vol.1993 No.0

계면의 불규칙 변태가 NbC-30Co-B 합금의 입자성장에 미치는 영향

尹德龍,李宗勳 대한민국 학술원 2008 학술원논문집 : 자연과학편 Vol.47 No.1

NbC-30%Co (무게비) 합금시편을 1450℃에서 소결하여 제조하였다. Co가 많은 액상기지상에 있는 NbC 입자들은 {100} 면으로 형성된 정육면체 모양을 보이며, 비정상으로 자란다. B이 첨가되며, NbC 입자들의 모서리는 둥글게 되어, 4%B에서는 구형이 된다. 이 구형의 입자들은 정상입자성장을 보이며, 입자분포는 시간에 따라 변하지 않는다. 또한 평균 입자크기의 3 제곱 값은 시간에 비례하여 증가한다. B의 양이 3, 2, 1%로 감소함에 따라, 둥근 입자의 모서리 면적이 감소하고, 입자성장은 정상성장에서 벗어나, 비정상 성장에 접근한다. 이 결과들은 B의 양이 늘어남에 따라, NbC 입자 면의 step 자유에너지가 감소하여 4%B에서는 0이 됨을 보여준다. Dislocation이 입자의 {100}면의 성장을 촉진할 것으로 생각된다. NbC-30% Co (by weight) alloy specimens have been made by sintering (heat-treating) powder mixtures at 1450˚C. The NbC grains in the Co-rich liquid matrix have cubic shapes with singular {100}faces and undergo abnormal growth. If B is added to the alloy, the edges (and corners) of the NbC grains become rounded until the grains become spherical with 4% (by weight) B. The spherical grains in the alloy containing 4% B show diffusion controlled normal grain growth with time invariant normalized grain size distributions and the cube of the average grain size increasing linearly with the heat-treatment time. With decreasing B content to 3, 2, and 1 wt%, the areas of the round edges of the grains decrease and the grain growth deviates more from the normal growth, becoming more abnormal. These observations indicate that the step free energy of the cubic NbC grain surfaces decreases with the increasing B content until it vanishes at 4%. It is proposed that dislocations enhance the growth rates of the grains with {100}singular surfaces.