Publications
2021
- TLDKS
Reducing the cost of aggregation in crowdsourcing.
In Transactions on Large-Scale Data and Knowledge-Centered Systems 2021.
Crowdsourcing is a way to solve problems that need human contribution. Crowdsourcing platforms distribute replicated tasks to workers, pay them for their contribution, and aggregate answers to produce a reliable conclusion. A fundamental problem is to infer a correct answer from the set of returned results. Another challenge is to obtain a reliable answer at a reasonable cost: unlimited budget allows hiring experts or large pools of workers for each task but a limited budget forces to use resources at best. Last, crowdsourcing platforms have to detect and ban malevolent users (a.k.a. spammers) to achieve good accuracy of their answers. This paper considers crowdsourcing of simple boolean tasks. We first define a probabilistic inference technique, that considers difficulty of tasks and expertise of workers when aggregating answers. We then propose CrowdInc, a greedy algorithm that reduces the cost needed to reach a consensual answer. CrowdInc distributes resources dynamically to tasks according to their difficulty. The algorithms solves batches of simple tasks in rounds that estimate workers expertize, tasks dificulty, and synthesize a plausible aggregated conclusion and a confidence score using Expectation Maximization. The synthesized values are used to decide whether more workers should be hired to increase confidence in synthesized answers. We show on several benchmarks that CrowdInc achieves good accuracy, reduces costs, and we compare its performance to existing solutions. We then use the estimation of CrowdInc to detect spammers, and study the impact of spammers on costs and accuracy. - PhD Thesis
Data Centric Workflows for Crowdsourcing Application.
2021.
Crowdsourcing uses human intelligence to solve tasks which are still difficult for machines. Tasks at existing crowdsourcing platform are batches of relatively simple microtasks. However, real-world problems are often more difficult than micro-tasks. They require data collection, organization, pre-processing, analysis, and synthesis of results. In this thesis, we study how to specify complex crowdsourcing tasks and realize them with the helpof existing crowdsourcing platforms. The first contribution of this thesis is a complex workflows model that provides high-level constructs to describe a complex task through orchestration of simpler tasks. We provide algorithms to check termination and correctness of a complex workflow for a subset of the language (these questions are undecidable in the general case). A well-known drawback of crowdsourcing is that human answers might be wrong. To leverage this problem, crowdsourcing platforms replicate tasks, and forge a final trusted answer out of the produced results. Replication increases quality of data, but it is costly. The second contribution of this thesis is a set of aggregation techniques where merging of answers is realized using Expectation Maximization, and replication of tasks is performed online after considering the confidence estimated for aggregated data. Experimental results show that these techniques allow to aggregate the returned answers while achieving a good trade-off between cost and data quality, both for the realization of a batches of microtasks, and of complex workflow. - PetriNets
Cost and Quality in Crowdsourcing Workflows.
In International Conference on Applications and Theory of Petri Nets and Concurrency 2021.
2020
- Patent
Cascaded binary classifier for identifying rhythms in a single-lead electrocardiogram (ECG) signal.
2020.
- PetriNets
Data centric workflows for crowdsourcing.
In International Conference on Applications and Theory of Petri Nets and Concurrency 2020.
- Patent
Anomaly detection by self-learning of sensor signals.
2020.
- Patent
Cascaded binary classifier for identifying rhythms in a single-lead electrocardiogram (ECG) signal.
2020.
- ICWS
Reducing the Cost of Aggregation in Crowdsourcing.
In International Conference on Web Services 2020.
- Patent
Anomaly detection by self-learning of sensor signals.
2020.
2019
- Patent
Method and system for physiological parameter derivation from pulsating signals with reduced error.
2019.
- Journal
Detection of atrial fibrillation and other abnormal rhythms from ECG using a multi-layer classifier architecture.
In Physiological measurement 2019.
- HAL
Data Centric Workflows for Crowdsourcing.
In 2019.
- Patent
Synthetic rare class generation by preserving morphological identity.
2019.
- Patent
Generalized one-class support vector machines with jointly optimized hyperparameters thereof.
2019.
- patent
Method and system for physiological parameter derivation from pulsating signals with reduced error.
2019.
- Patent
Method and system for physiological parameter derivation from pulsating signals with reduced error.
2019.
- patent
Systems and methods for detecting anomaly in a cardiovascular signal using hierarchical extremas and repetitions.
2019.
- patent
Method and system for pattern recognition in a signal using morphology aware symbolic representation.
2019.
- Patent
Method and system for joint selection of a feature subset-classifier pair for a classification task.
2019.
2018
- Patent
Noisy signal identification from non-stationary audio signals.
2018.
- IJCNN
AutoModeling: Integrated Approach for Automated Model Generation by Ensemble Selection of Feature Subset and Classifier.
In 2018 International Joint Conference on Neural Networks (IJCNN) 2018.
- EMBC
Pattern Analysis in Physiological Pulsatile Signals: An Aid to Personalized Healthcare.
In 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) 2018.
- Patent
System and method for physiological monitoring.
2018.
- Arxiv
Class Augmented Semi-Supervised Learning for Practical Clinical Analytics on Physiological Signals.
In arXiv preprint arXiv:1812.07498 2018.
- ICASSP
ICASSP 2018.
In 2018.
- ICASSP
Effective Noise Removal and Unified Model of Hybrid Feature Space Optimization for Automated Cardiac Anomaly Detection Using Phonocardiogarm Signals.
In 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) 2018.
2017
- ICASSP
Heartmate: automated integrated anomaly analysis for effective remote cardiac health management.
In 2017 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) 2017.
- EMBC
Analysis of phonocardiogram signals through proactive denoising using novel self-discriminant learner.
In 2017 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) 2017.
- CinC
Identifying normal, AF and other abnormal ECG rhythms using a cascaded binary classifier.
In 2017 Computing in cardiology (cinc) 2017.
- IJCAI
On Solving the Class Imbalance Problem for Clinical Decision Improvement Using Heart Sound Signals.
In Proceedings of the IJCAI 2017 Workshop on Learning in the Presence of Class Imbalance and Concept Drift (LPCICD’17) 2017.
- eHealth
CardioFit: Affordable Cardiac Healthcare Analytics for Clinical Utility Enhancement.
2017.
2016
- ISCC
SensIPro: Smart sensor analytics for Internet of things.
In 2016 IEEE Symposium on Computers and Communication (ISCC) 2016.
- EMBC
An unsupervised learning for robust cardiac feature derivation from PPG signals.
In 2016 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC) 2016.
- SenSys
3S: Sensing Sensor Signal: Demo Abstract.
In Proceedings of the 14th ACM Conference on Embedded Network Sensor Systems CD-ROM 2016.
- ICACCI
Efficient user assignment in crowd sourcing applications.
In 2016 International Conference on Advances in Computing, Communications and Informatics (ICACCI) 2016.
- CinC
Classification of normal and abnormal heart sound recordings through robust feature selection.
In 2016 Computing in Cardiology Conference (CinC) 2016.
- IHWTS
iCarMa: Inexpensive Cardiac Arrhythmia Management–An IoT Healthcare Analytics Solution.
In Proceedings of the First Workshop on IoT-enabled Healthcare and Wellness Technologies and Systems 2016.
2015
- SenSys
IAS: Information analytics for sensors.
In Proceedings of the 13th ACM Conference on Embedded Networked Sensor Systems 2015.