Felix Njap
Former Research Associate
Publications
2022
Marco
Maaß,
Christine
Droigk,
Mathias
Eulers, and
Alfred
Mertins,
An analytical equilibrium solution to the Néel relaxation Fokker-Planck equation, International Journal on Magnetic Particle Imaging , vol. 8, no. 1, pp. 1--4, 2022. Infinite Science Publishing.
An analytical equilibrium solution to the Néel relaxation Fokker-Planck equation, International Journal on Magnetic Particle Imaging , vol. 8, no. 1, pp. 1--4, 2022. Infinite Science Publishing.
Huy
Phan,
Alfred
Mertins, and
Mathias
Baumert,
Pediatric Automatic Sleep Staging: A comparative study of state-of-the-art deep learning methods, IEEE Transactions on Biomedical Engineering , pp. 1-1, 2022.
Pediatric Automatic Sleep Staging: A comparative study of state-of-the-art deep learning methods, IEEE Transactions on Biomedical Engineering , pp. 1-1, 2022.
DOI: | 10.1109/TBME.2022.3174680 |
Bibtex: | ![]() @Article{Phan2022a, author = {Phan, Huy and Mertins, Alfred and Baumert, Mathias}, journal = {IEEE Transactions on Biomedical Engineering}, title = {Pediatric Automatic Sleep Staging: A comparative study of state-of-the-art deep learning methods}, year = {2022}, pages = {1-1}, abstract = {Despite the tremendous progress recently made towards automatic sleep staging in adults, it is currently unknown if the most advanced algorithms generalize to the pediatric population, which displays distinctive characteristics in overnight polysomnography (PSG). To answer the question, in this work, we conduct a large-scale comparative study on the state-of-the-art deep learning methods for pediatric automatic sleep staging. Six different deep neural networks with diverging features are adopted to evaluate a sample of more than 1,200 children across a wide spectrum of obstructive sleep apnea (OSA) severity. Our experimental results show that the individual performance of automated pediatric sleep stagers when evaluated on new subjects is equivalent to the expert-level one reported on adults. Combining the six stagers into ensemble models further boosts the staging accuracy, reaching an overall accuracy of 88.8%, a Cohens kappa of 0.852, and a macro F1-score of 85.8%. At the same time, the ensemble models lead to reduced predictive uncertainty. The results also show that the studied algorithms and their ensembles are robust to concept drift when the training and test data were recorded seven months apart and after clinical intervention. However, we show that the improvements in the staging performance are not necessarily clinically significant although the ensemble models lead to more favorable clinical measures than the six standalone models. Detailed analyses further demonstrate "almost perfect" agreement between the automatic stagers to one another and their similar patterns on the staging errors, suggesting little room for improvement.}, doi = {10.1109/TBME.2022.3174680}, } |
Fabrice
Katzberg, and
Alfred
Mertins,
Sparse Recovery of Sound Fields Using Measurements from Moving Microphones, in Compressed Sensing in Information Processing , Gitta Kutyniok, Holger Rauhut and Robert J. Kunsch, Eds. Springer International Publishing, 2022, pp. 471-505.
Sparse Recovery of Sound Fields Using Measurements from Moving Microphones, in Compressed Sensing in Information Processing , Gitta Kutyniok, Holger Rauhut and Robert J. Kunsch, Eds. Springer International Publishing, 2022, pp. 471-505.
Huy
Phan,
Kaare
Mikkelsen,
Oliver Y.
Chén,
Philipp
Koch,
Alfred
Mertins, and
Maarten
De Vos,
SleepTransformer: Automatic Sleep Staging With Interpretability and Uncertainty Quantification, IEEE Transactions on Biomedical Engineering , vol. 69, no. 8, pp. 2456-2467, 2022.
SleepTransformer: Automatic Sleep Staging With Interpretability and Uncertainty Quantification, IEEE Transactions on Biomedical Engineering , vol. 69, no. 8, pp. 2456-2467, 2022.
DOI: | 10.1109/TBME.2022.3147187 |
Bibtex: | ![]() @Article{Phan2022, author = {Phan, Huy and Mikkelsen, Kaare and Chén, Oliver Y. and Koch, Philipp and Mertins, Alfred and De Vos, Maarten}, journal = {IEEE Transactions on Biomedical Engineering}, title = {SleepTransformer: Automatic Sleep Staging With Interpretability and Uncertainty Quantification}, year = {2022}, number = {8}, pages = {2456-2467}, volume = {69}, abstract = {Background: Black-box skepticism is one of the main hindrances impeding deep-learning-based automatic sleep scoring from being used in clinical environments. Methods: Towards interpretability, this work proposes a sequence-to-sequence sleep-staging model, namely SleepTransformer. It is based on the transformer backbone and offers interpretability of the model's decisions at both the epoch and sequence level. We further propose a simple yet efficient method to quantify uncertainty in the model's decisions. The method, which is based on entropy, can serve as a metric for deferring low-confidence epochs to a human expert for further inspection. Results: Making sense of the transformer's self-attention scores for interpretability, at the epoch level, the attention scores are encoded as a heat map to highlight sleep-relevant features captured from the input EEG signal. At the sequence level, the attention scores are visualized as the influence of different neighboring epochs in an input sequence (i.e. the context) to recognition of a target epoch, mimicking the way manual scoring is done by human experts. Conclusion: Additionally, we demonstrate that SleepTransformer performs on par with existing methods on two databases of different sizes. Significance: Equipped with interpretability and the ability of uncertainty quantification, SleepTransformer holds promise for being integrated into clinical settings.}, doi = {10.1109/TBME.2022.3147187}, } |
Fabrice
Katzberg,
Marco
Maaß,
René
Pallenberg, and
Alfred
Mertins,
Positional Tracking of a Moving Microphone in Reverberant Scenes by Applying Perfect Sequences to Distributed Loudspeakers, in Proc. International Workshop on Acoustic Signal Enhancement (IWAENC) , Bamberg, Germany , 2022.
Positional Tracking of a Moving Microphone in Reverberant Scenes by Applying Perfect Sequences to Distributed Loudspeakers, in Proc. International Workshop on Acoustic Signal Enhancement (IWAENC) , Bamberg, Germany , 2022.
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Bibtex: | ![]() @InProceedings{katzberg2022, Title = {Positional Tracking of a Moving Microphone in Reverberant Scenes by Applying Perfect Sequences to Distributed Loudspeakers}, Author = {Katzberg, Fabrice and Maass, Marco and Pallenberg, René} and Mertins, Alfred}, Booktitle = {Proc. International Workshop on Acoustic Signal Enhancement (IWAENC)}, Year = {2022}, Address = {Bamberg, Germany}, Month = {September}, } |
Tim J.
Parbs,
Philipp
Koch, and
Alfred
Mertins,
Convolutive Attention for Image Registration, in Proc. European Signal Processing Conference , Belgrade, Serbia: IEEE, 2022. pp. 1348--1352.
Convolutive Attention for Image Registration, in Proc. European Signal Processing Conference , Belgrade, Serbia: IEEE, 2022. pp. 1348--1352.
Paul
Wimmer,
Jens
Mehnert, and
Alexandru Paul
Condurache,
Interspace Pruning: Using Adaptive Filter Representations to Improve Training of Sparse {CNN}s, in Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, {CVPR} 2022, New Orleans, LA, USA, June 19-24, 2022 , 2022.
Interspace Pruning: Using Adaptive Filter Representations to Improve Training of Sparse {CNN}s, in Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, {CVPR} 2022, New Orleans, LA, USA, June 19-24, 2022 , 2022.
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Bibtex: | ![]() @InProceedings{wimmer_interspace_cvpr_2022, author={Wimmer, Paul and Mehnert, Jens and Condurache, Alexandru Paul}, booktitle = {Proceedings of the IEEE/CVF Conference on Computer Vision and Pattern Recognition, {CVPR} 2022, New Orleans, LA, USA, June 19-24, 2022}, title = {Interspace Pruning: Using Adaptive Filter Representations to Improve Training of Sparse {CNN}s}, year = {2022}, } |
Julia
Lust, and
Alexandru P.
Condurache,
Efficient detection of adversarial, out-of-distribution and other misclassified samples, Neurocomputing , vol. 470, pp. 335-343, 2022.
Efficient detection of adversarial, out-of-distribution and other misclassified samples, Neurocomputing , vol. 470, pp. 335-343, 2022.
DOI: | https://doi.org/10.1016/j.neucom.2021.05.102 |
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Bibtex: | ![]() @article{LUST2022335, title = {Efficient detection of adversarial, out-of-distribution and other misclassified samples}, journal = {Neurocomputing}, volume = {470}, pages = {335-343}, year = {2022}, issn = {0925-2312}, doi = {https://doi.org/10.1016/j.neucom.2021.05.102}, url = {https://www.sciencedirect.com/science/article/pii/S0925231221010985}, author = {Julia Lust and Alexandru P. Condurache}, keywords = {Deep Neural Networks, Out-of-distribution detection, Adversarial example detection, Uncertainty quantification, Safety}, } |
Christine
Droigk,
Marco
Maaß, and
Alfred
Mertins,
Direct multi-dimensional Chebyshev polynomial based reconstruction for magnetic particle imaging, Physics in Medicine & Biology , vol. 67, no. 4, pp. 045014, 2022.
Direct multi-dimensional Chebyshev polynomial based reconstruction for magnetic particle imaging, Physics in Medicine & Biology , vol. 67, no. 4, pp. 045014, 2022.
DOI: | 10.1088/1361-6560/ac4c2e |
Bibtex: | ![]() @Article{Droigk2022a, author = {Droigk, Christine and Maass, Marco and Alfred Mertins}, journal = {Physics in Medicine & Biology}, title = {Direct multi-dimensional Chebyshev polynomial based reconstruction for magnetic particle imaging}, year = {2022}, doi = {10.1088/1361-6560/ac4c2e}, volume = {67}, number = {4}, pages = {045014}, } |
Matthias
Rath, and
Alexandru Paul
Condurache,
Improving the Sample-complexity of Deep Classification Networks with Invariant Integration, in Proceedings of the 17th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, {VISIGRAPP} 2022, Volume 5: VISAPP, Online Streaming, February 6-8, 2022 , Giovanni Maria Farinella and Petia Radeva and Kadi Bouatouch, Eds. {SCITEPRESS}, 2022. pp. 214--225.
Improving the Sample-complexity of Deep Classification Networks with Invariant Integration, in Proceedings of the 17th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, {VISIGRAPP} 2022, Volume 5: VISAPP, Online Streaming, February 6-8, 2022 , Giovanni Maria Farinella and Petia Radeva and Kadi Bouatouch, Eds. {SCITEPRESS}, 2022. pp. 214--225.
DOI: | 10.5220/0010872000003124 |
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Bibtex: | ![]() @inproceedings{Rath2, author = {Matthias Rath and Alexandru Paul Condurache}, editor = {Giovanni Maria Farinella and Petia Radeva and Kadi Bouatouch}, title = {Improving the Sample-complexity of Deep Classification Networks with Invariant Integration}, booktitle = {Proceedings of the 17th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications, {VISIGRAPP} 2022, Volume 5: VISAPP, Online Streaming, February 6-8, 2022}, pages = {214--225}, publisher = {{SCITEPRESS}}, year = {2022}, url = {https://doi.org/10.5220/0010872000003124}, doi = {10.5220/0010872000003124}, } |
2021
Alexandru P. Condurache,
A Safety View on Generalization for Machine Learning, Oct. 2021. International Conference on Intelligent Computer Communication and Processing (ICCP).
A Safety View on Generalization for Machine Learning, Oct. 2021. International Conference on Intelligent Computer Communication and Processing (ICCP).
File: | Dateilink |
Bibtex: | ![]() @misc{condurache21, author = {Alexandru P. Condurache}, title = {A Safety View on Generalization for Machine Learning}, howpublished = {International Conference on Intelligent Computer Communication and Processing (ICCP)}, year = {2021}, month = {10}, note = {Keynote Lecture}, url = {https://ieeexplore.ieee.org/stamp/stamp.jsp?arnumber=9733460}, } |
Malte
Riedel,
Kawin
Setsompop,
Alfred
Mertins, and
Peter
Börnert,
Segmented simultaneous multi‐slice diffusion‐weighted imaging with navigated {3D} rigid motion correction, Magnetic Resonance in Medicine , vol. 86, no. 3, pp. 1701--1717, 2021.
Segmented simultaneous multi‐slice diffusion‐weighted imaging with navigated {3D} rigid motion correction, Magnetic Resonance in Medicine , vol. 86, no. 3, pp. 1701--1717, 2021.
Huy
Phan,
Oliver Y
Chén,
Minh C
Tran,
Philipp
Koch,
Alfred
Mertins, and
Maarten De
Vos,
XSleepNet: Multi-view sequential model for automatic sleep staging, IEEE Transactions on Pattern Analysis and Machine Intelligence , 2021.
XSleepNet: Multi-view sequential model for automatic sleep staging, IEEE Transactions on Pattern Analysis and Machine Intelligence , 2021.
Fabrice
Katzberg,
Marco
Maaß, and
Alfred
Mertins,
Spherical Harmonic Representation for Dynamic Sound-Field Measurements, in Proc. IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) , Toronto, Canada , 2021.
Spherical Harmonic Representation for Dynamic Sound-Field Measurements, in Proc. IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP) , Toronto, Canada , 2021.
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Bibtex: | ![]() @InProceedings{katzberg2021a, Title = {Spherical Harmonic Representation for Dynamic Sound-Field Measurements}, Author = {Katzberg, Fabrice and Maass, Marco and Mertins, Alfred}, Booktitle = {Proc. IEEE International Conference on Acoustics, Speech, and Signal Processing (ICASSP)}, Year = {2021}, Address = {Toronto, Canada}, Month = {June}, } |
Huy
Phan,
Huy Le
Nguyen,
Oliver Y
Chén,
Philipp
Koch,
Ngoc QK
Duong,
Ian
McLoughlin, and
Alfred
Mertins,
Self-attention generative adversarial network for speech enhancement, in Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) , 2021. pp. 7103--7107.
Self-attention generative adversarial network for speech enhancement, in Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) , 2021. pp. 7103--7107.
Philipp
Koch,
Kamran
Mohammad-Zadeh,
Marco
Maaß,
Mark
Dreier,
Ole
Thomsen,
Tim J.
Parbs,
Huy
Phan, and
Alfred
Mertins,
sEMG-Based Hand Movement Regression by Prediction of Joint Angles With Recurrent Neural Networks, in 43nd Annual International Conference of the IEEE Engineering in Medicine \& Biology Society (EMBC) , 2021. pp. 6519--6523.
sEMG-Based Hand Movement Regression by Prediction of Joint Angles With Recurrent Neural Networks, in 43nd Annual International Conference of the IEEE Engineering in Medicine \& Biology Society (EMBC) , 2021. pp. 6519--6523.
DOI: | 10.1109/EMBC46164.2021.9630042 |
Bibtex: | ![]() @InProceedings{Koch2021, author = {Koch, Philipp and Mohammad-Zadeh, Kamran and Maass, Marco and Dreier, Mark and Thomsen, Ole and Parbs, Tim J. and Phan, Huy and Mertins, Alfred}, title = {sEMG-Based Hand Movement Regression by Prediction of Joint Angles With Recurrent Neural Networks}, booktitle = {43nd Annual International Conference of the IEEE Engineering in Medicine \& Biology Society (EMBC)}, year = {2021}, pages = {6519--6523}, doi = {10.1109/EMBC46164.2021.9630042}, } |
L.
Pham,
H.
Phan,
T.
Nguyen,
R.
Palaniappan,
A.
Mertins, and
I.
McLoughlin,
Robust Acoustic Scene Classification using a Multi-Spectrogram Encoder-Decoder Framework, Digital Signal Processing , vol. 110, pp. Article ID 102943, 2021.
Robust Acoustic Scene Classification using a Multi-Spectrogram Encoder-Decoder Framework, Digital Signal Processing , vol. 110, pp. Article ID 102943, 2021.
Lam
Pham,
Huy
Phan,
Alexander
Schindler,
Ross
King,
Alfred
Mertins, and
Ian
McLoughlin,
Inception-Based Network and Multi-Spectrogram Ensemble Applied To Predict Respiratory Anomalies and Lung Diseases, in 2021 43rd Annual International Conference of the IEEE Engineering in Medicine Biology Society (EMBC) , 2021. pp. 253-256.
Inception-Based Network and Multi-Spectrogram Ensemble Applied To Predict Respiratory Anomalies and Lung Diseases, in 2021 43rd Annual International Conference of the IEEE Engineering in Medicine Biology Society (EMBC) , 2021. pp. 253-256.
DOI: | 10.1109/EMBC46164.2021.9629857 |
Bibtex: | ![]() @InProceedings{Pham2021b, author = {Pham, Lam and Phan, Huy and Schindler, Alexander and King, Ross and Mertins, Alfred and McLoughlin, Ian}, booktitle = {2021 43rd Annual International Conference of the IEEE Engineering in Medicine Biology Society (EMBC)}, title = {Inception-Based Network and Multi-Spectrogram Ensemble Applied To Predict Respiratory Anomalies and Lung Diseases}, year = {2021}, pages = {253-256}, doi = {10.1109/EMBC46164.2021.9629857}, } |
Fabrice
Katzberg,
Marco
Maaß, and
Alfred
Mertins,
Coherence Based Trajectory Optimization for Compressive Sensing of Sound Fields, in Proc. 29th European Signal Processing Conference (EUSIPCO) , Dublin, Ireland , 2021.
Coherence Based Trajectory Optimization for Compressive Sensing of Sound Fields, in Proc. 29th European Signal Processing Conference (EUSIPCO) , Dublin, Ireland , 2021.
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Bibtex: | ![]() @InProceedings{katzberg2021b, Title = {Coherence Based Trajectory Optimization for Compressive Sensing of Sound Fields}, Author = {Katzberg, Fabrice and Maass, Marco and Mertins, Alfred}, Booktitle = {Proc. 29th European Signal Processing Conference (EUSIPCO)}, Year = {2021}, Address = {Dublin, Ireland}, Month = {August}, } |
Lam Dang
Pham,
Huy
Phan,
Ramaswamy
Palaniappan,
Alfred
Mertins, and
Ian
McLoughlin,
C{NN-MoE} based framework for classification of respiratory anomalies and lung disease detection, IEEE Journal of Biomedical and Health Informatics , 2021.
C{NN-MoE} based framework for classification of respiratory anomalies and lung disease detection, IEEE Journal of Biomedical and Health Informatics , 2021.
Paul
Wimmer,
Jens
Mehnert, and
Alexandru Paul
Condurache,
{COPS}: Controlled Pruning Before Training Starts, in 2021 International Joint Conference on Neural Networks (IJCNN), virtual, July 18-22, 2021 , 2021.
{COPS}: Controlled Pruning Before Training Starts, in 2021 International Joint Conference on Neural Networks (IJCNN), virtual, July 18-22, 2021 , 2021.
DOI: | 10.1109/IJCNN52387.2021.9533582 |
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Bibtex: | ![]() @INPROCEEDINGS{wimmer_cops_ijcnn_2021, author={Wimmer, Paul and Mehnert, Jens and Condurache, Alexandru Paul}, booktitle={2021 International Joint Conference on Neural Networks (IJCNN), virtual, July 18-22, 2021}, title={{COPS}: Controlled Pruning Before Training Starts}, year={2021}, doi={10.1109/IJCNN52387.2021.9533582}, url={https://ieeexplore.ieee.org/document/9533582} } |
Huy
Phan,
Huy Le
Nguyen,
Oliver Y
Chén,
Lam
Pham,
Philipp
Koch,
Ian
McLoughlin, and
Alfred
Mertins,
Multi-view Audio and Music Classification, in Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) , 2021. pp. 611--615.
Multi-view Audio and Music Classification, in Proc. IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) , 2021. pp. 611--615.
2020
Yiming
Dong,
Kirsten
Koolstra,
Malte
Steinhoff,
Matthias J. P.
Osch, and
Peter
Börnert,
Regularized joint water/fat separation and B0 map estimation for Echo-Planar Imaging, in ESMRMB 2020 Online, 37th Annual Scientific Meeting , 2020. pp. Presentation no. S02.03, Abstract ID A--1047.
Regularized joint water/fat separation and B0 map estimation for Echo-Planar Imaging, in ESMRMB 2020 Online, 37th Annual Scientific Meeting , 2020. pp. Presentation no. S02.03, Abstract ID A--1047.
Marco
Maaß, and
Alfred
Mertins,
On the Representation of Magnetic Particle Imaging in Fourier Space, International Journal on Magnetic Particle Imaging , vol. 6, no. 1, 2020.
On the Representation of Magnetic Particle Imaging in Fourier Space, International Journal on Magnetic Particle Imaging , vol. 6, no. 1, 2020.
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Bibtex: | ![]() @article{maass2019b, author = {Maass, Marco and Mertins, Alfred }, title = {On the Representation of Magnetic Particle Imaging in Fourier Space}, journal = {International Journal on Magnetic Particle Imaging}, volume = {6}, number = {1}, year = {2020} } |
H.
Phan,
K.
Mikkelsen,
O. Y.
Chen,
P.
Koch,
A.
Mertins,
P.
Kidmose, and
M. De
Vos,
Personalized Automatic Sleep Staging with Single-Night Data: a Pilot Study with KL-Divergence Regularization, Physiological Measurement , vol. 41, pp. Article ID 064004, 2020.
Personalized Automatic Sleep Staging with Single-Night Data: a Pilot Study with KL-Divergence Regularization, Physiological Measurement , vol. 41, pp. Article ID 064004, 2020.