http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
APWM Resonant Converter with SST for EMI Filter Size Reduction
Hwa-Pyeong Park,Sangyeong Jeong,Mina Kim,Jingook Kim,Jee-Hoon Jung 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5
A spread spectrum technique has been introduced to alleviate electromagnetic interference problem in switch mode power converters. In the previous works, the SST has been employed to low power and small size power converters, such as buck, boost, and flyback topologies, because those converters have insensitive voltage gains according to switching frequency variations. However, the resonant converters are hard to apply the spread spectrum technique, because the resonant converter has a sensitive input-output voltage gain according to the variation of switching frequency. In this paper, a half-bridge resonant converter using the asymmetric pulse width modulation and the spread spectrum technique is developed for 100 W offline power supply applications. The design methodology of its resonant tank is designed to obtain tight output voltage regulation performance. The input EMI filter is analyzed to reduce the filter size with and without the spread spectrum technique. The output voltage regulation performance and the filter size reduction are experimentally verified using a 100 W prototype converter.
Kim Pyeong Hwa,Yoon Hee Mang,Kim Jeong Rye,Hwang Jae-Yeon,Choi Jin-Ho,Hwang Jisun,Lee Jaewon,Sung Jinkyeong,Jung Kyu-Hwan,Bae Byeonguk,Jung Ah Young,Cho Young Ah,Shim Woo Hyun,Bak Boram,Lee Jin Seong 대한영상의학회 2023 Korean Journal of Radiology Vol.24 No.11
Objective: To develop a deep-learning-based bone age prediction model optimized for Korean children and adolescents and evaluate its feasibility by comparing it with a Greulich-Pyle-based deep-learning model. Materials and Methods: A convolutional neural network was trained to predict age according to the bone development shown on a hand radiograph (bone age) using 21036 hand radiographs of Korean children and adolescents without known bone development-affecting diseases/conditions obtained between 1998 and 2019 (median age [interquartile range {IQR}], 9 [7–12] years; male:female, 11794:9242) and their chronological ages as labels (Korean model). We constructed 2 separate external datasets consisting of Korean children and adolescents with healthy bone development (Institution 1: n = 343; median age [IQR], 10 [4–15] years; male: female, 183:160; Institution 2: n = 321; median age [IQR], 9 [5–14] years; male: female, 164:157) to test the model performance. The mean absolute error (MAE), root mean square error (RMSE), and proportions of bone age predictions within 6, 12, 18, and 24 months of the reference age (chronological age) were compared between the Korean model and a commercial model (VUNO Med-BoneAge version 1.1; VUNO) trained with Greulich-Pyle-based age as the label (GP-based model). Results: Compared with the GP-based model, the Korean model showed a lower RMSE (11.2 vs. 13.8 months; P = 0.004) and MAE (8.2 vs. 10.5 months; P = 0.002), a higher proportion of bone age predictions within 18 months of chronological age (88.3% vs. 82.2%; P = 0.031) for Institution 1, and a lower MAE (9.5 vs. 11.0 months; P = 0.022) and higher proportion of bone age predictions within 6 months (44.5% vs. 36.4%; P = 0.044) for Institution 2. Conclusion: The Korean model trained using the chronological ages of Korean children and adolescents without known bone development-affecting diseases/conditions as labels performed better in bone age assessment than the GP-based model in the Korean pediatric population. Further validation is required to confirm its accuracy.
Rim, Hwa Pyeong,Min, Kyung Hyun,Lee, Hong Jae,Jeong, Seo Young,Lee, Sang Cheon WILEY‐VCH Verlag 2011 Angewandte Chemie Vol.123 No.38
<P><B>Die Hüllen fallen gelassen</B>: Ein pH‐responsives, mesoporöses Siliciumoxid‐Nanopartikel mit einer Hülle aus porenblockierendem Calciumphosphat (CaP) wurde durch enzymvermittelte Oberflächenmineralisation unter milden Bedingungen hergestellt. Wird das Partikel zellulären lysosomalen pH‐Werten ausgesetzt, löst sich der CaP‐Porenblocker auf, und ein in den Poren eingelagerter Antitumorwirkstoff kann freigesetzt werden (siehe Bild; HAp=Hydroxyapatit).</P>
Neuroimaging Findings in Patients with COVID-19: A Systematic Review and Meta-Analysis
Kim Pyeong Hwa,Kim Minjae,Suh Chong Hyun,Chung Sae Rom,Park Ji Eun,Kim Soo Chin,Choi Young Jun,Lee Jeong Hyun,Kim Ho Sung,Baek Jung Hwan,Choi Choong Gon,Kim Sang Joon 대한영상의학회 2021 Korean Journal of Radiology Vol.22 No.11
Objective: Central nervous system involvement in coronavirus disease 2019 (COVID-19) has been increasingly reported. We performed a systematic review and meta-analysis to evaluate the incidence of radiologically demonstrated neurologic complications and detailed neuroimaging findings associated with COVID-19. Materials and Methods: A systematic literature search of MEDLINE/PubMed and EMBASE databases was performed up to September 17, 2020, and studies evaluating neuroimaging findings of COVID-19 using brain CT or MRI were included. Several cohort-based outcomes, including the proportion of patients with abnormal neuroimaging findings related to COVID-19 were evaluated. The proportion of patients showing specific neuroimaging findings was also assessed. Subgroup analyses were also conducted focusing on critically ill COVID-19 patients and results from studies that used MRI as the only imaging modality. Results: A total of 1394 COVID-19 patients who underwent neuroimaging from 17 studies were included; among them, 3.4% of the patients demonstrated COVID-19-related neuroimaging findings. Olfactory bulb abnormalities were the most commonly observed (23.1%). The predominant cerebral neuroimaging finding was white matter abnormality (17.6%), followed by acute/subacute ischemic infarction (16.0%), and encephalopathy (13.0%). Significantly more critically ill patients had COVID-19-related neuroimaging findings than other patients (9.1% vs. 1.6%; p = 0.029). The type of imaging modality used did not significantly affect the proportion of COVID-19-related neuroimaging findings. Conclusion: Abnormal neuroimaging findings were occasionally observed in COVID-19 patients. Olfactory bulb abnormalities were the most commonly observed finding. Critically ill patients showed abnormal neuroimaging findings more frequently than the other patient groups. White matter abnormalities, ischemic infarctions, and encephalopathies were the common cerebral neuroimaging findings.