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2. Decreased but diverse activity of cortical and thalamic neurons in consciousness-impairing rodent absence seizures

Author

McCafferty, Cian, Gruenbaum, Benjamin F., Tung, Renee, Li, Jing-Jing, Zheng, Xinyuan, Salvino, Peter, Vincent, Peter, Kratochvil, Zachary, Ryu, Jun Hwan, Khalaf, Aya, Swift, Kohl, Akbari, Rashid, Islam, Wasif, Antwi, Prince, Johnson, Emily A., Vitkovskiy, Petr, Sampognaro, James, Freedman, Isaac G., Kundishora, Adam, Depaulis, Antoine, David, François, Crunelli, Vincenzo, Sanganahalli, Basavaraju G., Herman, Peter, Hyder, Fahmeed, and Blumenfeld, Hal

Published
2023
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15. Human visual consciousness involves large scale cortical and subcortical networks independent of task report and eye movement activity

Author

Kronemer, Sharif I., Aksen, Mark, Ding, Julia Z., Ryu, Jun Hwan, Xin, Qilong, Ding, Zhaoxiong, Prince, Jacob S., Kwon, Hunki, Khalaf, Aya, Forman, Sarit, Jin, David S., Wang, Kevin, Chen, Kaylie, Hu, Claire, Agarwal, Akshar, Saberski, Erik, Wafa, Syed Mohammad Adil, Morgan, Owen P., Wu, Jia, Christison-Lagay, Kate L., Hasulak, Nicholas, Morrell, Martha, Urban, Alexandra, Todd Constable, R., Pitts, Michael, Mark Richardson, R., Crowley, Michael J., and Blumenfeld, Hal

Published
2022
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29. Mitigating Defect States of All‐Inorganic CsPbI2Br Perovskite via Multifunctional 2‐Amino‐5‐Nitrothiazole Additive for an Efficient Air‐Processed Outdoor/Indoor Photovoltaics.

Author

Bahadur, Jitendra, Cho, SungWon, Pandey, Padmini, Yoon, Saemon, Lee, Dong‐Gun, Ryu, Jun, Song, Jun Tae, Lim, Jongchul, and Kang, Dong‐Won

Subjects
PHOTOVOLTAIC power generation, ION recombination, PEROVSKITE, CRYSTAL growth, SOLAR cells, LIGHT emitting diodes, ADDITIVES
Abstract

All‐inorganic CsPbI2Br mixed halide perovskites show promise as wide‐bandgap photoabsorbers in photovoltaics. However, the rapid crystal growth observed in solution‐processed CsPbI2Br often leads to morphologies plagued by pinholes and defects, which limit device performance. This study introduces 2‐Amino‐5‐nitrothiazole (ANT), an innovative precursor additive, to enhance film quality. ANT's selective interactions with the perovskite precursor moderate the crystal growth, resulting in a dense, flawless CsPbI2Br film characterized by superior crystallinity and coverage. Furthermore, the NH2 group in ANT coordinates with Pb octahedra, effectively mitigating charge defects through NHI/Br bonds. Simultaneously, SCN sites interact with uncoordinated Pb2+ ions, reducing defect states and nonradiative recombination. This innovation achieves an impressive device efficiency of 17.13% with a fill factor (FF) of 83.41%, surpassing the control's efficiency of 15.21% (FF of 80.45%). Notably, the champion device maintains an efficiency of 29.47% under indoor light‐emitting diode lighting at 1000 lux. Additionally, the optimized perovskite solar cell demonstrates remarkable stability, retaining ≈90% of its efficiency for over 720 h at 85 °C in air, even without encapsulation. [ABSTRACT FROM AUTHOR]

Published
2024
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44. A machine‐learning approach for predicting impaired consciousness in absence epilepsy

Author

Springer, Max, Khalaf, Aya, Vincent, Peter, Ryu, Jun Hwan, Abukhadra, Yasmina, Beniczky, Sandor, Glauser, Tracy, Krestel, Heinz, and Blumenfeld, Hal

Subjects
Machine Learning, Consciousness, Epilepsy, Absence, Seizures, General Neuroscience, Humans, Electroencephalography, Neurology (clinical)
Abstract

Behavior during 3-4 Hz spike-wave discharges (SWDs) in absence epilepsy can vary from obvious behavioral arrest to no detectible deficits. Knowing if behavior is impaired is crucial for clinical care but may be difficult to determine without specialized behavioral testing, often inaccessible in practice. We aimed to develop a pure electroencephalography (EEG)-based machine-learning method to predict SWD-related behavioral impairment. Our classification goals were 100% predictive value, with no behaviorally impaired SWDs misclassified as spared; and maximal sensitivity. First, using labeled data with known behavior (130 SWDs in 34 patients), we extracted EEG time, frequency domain, and common spatial pattern features and applied support vector machines and linear discriminant analysis to classify SWDs as spared or impaired. We evaluated 32 classification models, optimized with 10-fold cross-validation. We then generalized these models to unlabeled data (220 SWDs in 41 patients), where behavior during individual SWDs was not known, but observers reported the presence of clinical seizures. For labeled data, the best classifier achieved 100% spared predictive value and 93% sensitivity. The best classifier on the unlabeled data achieved 100% spared predictive value, but with a lower sensitivity of 35%, corresponding to a conservative classification of 8 patients out of 23 as free of clinical seizures. Our findings demonstrate the feasibility of machine learning to predict impaired behavior during SWDs based on EEG features. With additional validation and optimization in a larger data sample, applications may include EEG-based prediction of driving safety, treatment adjustment, and insight into mechanisms of impaired consciousness in absence seizures.

Published
2022

47. Optimum Design Process of Coaxial Magnetic Gear Using 3D Performance Prediction Method Considering Axial Flux Leakage

Author

Lee, Seung-Hun, Im, So-Yeon, Ryu, Jun-Yeol, and Lim, Myung-Seop

Abstract

This article proposes a rapid and optimum design method that considers axial flux leakage for a coaxial magnetic gear (CMG). Conventional CMG optimum design methods perform two-dimensional (2D) finite element analysis (FEA) to evade the long computational time of three-dimensional (3D) FEA. However, conventional design methods do not consider axial flux leakage and are therefore less accurate than computationally exhaustive optimum design through 3D FEA. Therefore, as an alternative to reduce computational time, this article proposes a method that considers axial flux leakage for predicting the CMG performance combining correlation coefficients and 2D FEA instead of 3D FEA. The correlation coefficient is determined as the ratio of the square of the radial direction air gap flux in the equivalent magnetic circuit (EMC) that considers axial flux leakage to the square of the radial direction air gap flux in the EMC that does not consider axial flux leakage. The electromagnetic performance of the CMG predicted by the proposed method is used to develop a surrogate model for reducing computational time during the optimum design process. Based on the surrogate model, the optimum CMG design is analyzed to fabricate a prototype, and the proposed design process is validated through experiments.

Published
2024
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48. Investigation on Radial Vibration of FSCW PMSM According to Pole/Slot Combination Considering Phase of Radial, Tangential Force and Moment

Author

Kim, Jae-Hyun, Ryu, Jun-Yeol, Park, Soo-Hwan, Cha, Kyoung-Soo, Won, Yun-Jae, Park, Chi-Sung, and Lim, Myung-Seop

Abstract

In this study, the radial vibration of fractional-slot concentrated winding (FSCW) permanent magnet synchronous motor (PMSM) was analyzed according to pole/slot combination considering phase relationship of modulated radial, tangential forces, and moment. First, to calculate the modulated forces and moment according to pole/slot combination, the amplitude and phase of modulated radial, tangential force and moment converted by radial air-gap electromagnetic force density (AEFD) are analytically derived. Since the lever arm effect by tangential force varies according to the tooth length, tangential force was translated on the yoke and an equivalent modulated moment was derived. Subsequently, to analyze the radial vibration caused by modulated forces and moment, the radial displacement response owing to a unit radial AEFD is calculated using 3D structural finite element analysis by applying unit modulated forces and moment. It was found out that the tooth modulation effect hardly varied with pole/slot combination and shape of the PMSM such as tooth length. Rather, it was confirmed that the tooth modulation effect was significantly influenced by the slot opening width. Especially, it was analyzed that the radial vibration of PMSM is not simply reduced by optimizing the slot opening width with reduced modulated radial force, but the amplitude and phase of the modulated tangential force and moment should also be considered. Finally, four prototypes of the PMSM with different slot opening widths of two 12-slot 10-pole and two 12-slot 14-pole are fabricated, and the test and simulation results are compared and verified.

Published
2024
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