Felix Wortmann

Felix Wortmann

Title

Prof. Dr.

Last Name

Wortmann

First name

Felix

Email

felix.wortmann@unisg.ch

Phone

+41 71 224 7325

Homepage

http://www.item.unisg.ch

Now showing 1 - 10 of 32

Blockchain for the IoT: Privacy-Preserving Protection of Sensor Data

(Assoc. of Information Systems, )
Chanson, Mathieu
;
Bogner, Andreas
;
Bilgeri, Dominik
;
Fleisch, Elgar
;
Wortmann, Felix

A constantly growing pool of smart, connected Internet of Things (IoT) devices poses completely new challenges for business regarding security and privacy. In fact, the widespread adoption of smart products might depend on the ability of organizations to offer systems that ensure adequate sensor data integrity while guaranteeing sufficient user privacy. In light of these challenges, previous research indicates that blockchain technology may be a promising means to mitigate issues of data security arising in the IoT. Building upon the existing body of knowledge, we propose a design theory, including requirements, design principles, and features, for a blockchain-based sensor data protection system (SDPS) that leverages data certification. We then design and develop an instantiation of an SDPS (CertifiCar) in three iterative cycles that prevents the fraudulent manipulation of car mileage data. Furthermore, we provide an ex-post evaluation of our design theory considering CertifiCar and two additional use cases in the realm of pharmaceutical supply chains and energy microgrids. The evaluation results suggest that the proposed design ensures the tamper-resistant gathering, processing, and exchange of IoT sensor data in a privacy-preserving, scalable, and efficient manner.

Type: journal article

Journal: Journal of the Association for Information Systems

Volume: Vol. 20, Issue 9

Issue: Article 10

DOI: 10.17705/1jais.00567

URI: https://www.alexandria.unisg.ch/handle/20.500.14171/116717

Scopus© Citations 91
Machine learning for non-invasive sensing of hypoglycaemia while driving in people with diabetes

(Wiley Online Library, 2023-02-15)
Lehmann, Vera
;
Zueger, Thomas
;
Maritsch, Martin
;
Kraus, Mathias
;
Albrecht, Caroline
;
Bérubé, Caterina
;
Feuerriegel, Stefan
;
Wortmann, Felix
;
Kowatsch, Tobias
;
Styger, Naïma
;
Lagger, Sophie
;
Laimer, Markus
;
Fleisch, Elgar
;
Stettler, Christoph

Type: journal article

Journal: Diabetes, Obesity and Metabolism

Volume: 26

DOI: https://doi.org/10.1111/dom.15021

URI: https://www.alexandria.unisg.ch/handle/20.500.14171/107754
A Scalable Risk-Scoring System Based on Consumer-Grade Wearables for Inpatients With COVID-19: Statistical Analysis and Model Development

(JMIR, 2022-05-25)
Föll, Simon
;
Lison, Adrian
;
Maritsch, Martin
;
Klingberg, Karsten
;
Lehmann, Vera
;
Züger, Thomas
;
Srivastava, David
;
Jegerlehner, Sabrina
;
Feuerriegel, Stefan
;
Fleisch, Elgar
;
Exadaktylos, Aristomenis
;
Wortmann, Felix

Type: journal article

Volume: 6

Issue: 6

DOI: https://doi.org/10.2196/35717

URI: https://www.alexandria.unisg.ch/handle/20.500.14171/108692
A KPI Set for Steering the IoT Business in Product Companies

( 2022-02-17)
Lamprecht, Claudio
;
Gebauer, Heiko
;
Fleisch, Elgar
;
Wortmann, Felix

Type: journal article

Journal: Research Technology Management

Volume: 65

Issue: 2

URL: https://doi.org/10.1080/08956308.2022.2015951

DOI: 10.1080/08956308.2022.2015951

URI: https://www.alexandria.unisg.ch/handle/20.500.14171/108995

Scopus© Citations 3
Towards Non-intrusive Camera-Based Heart Rate Variability Estimation in the Car Under Naturalistic Condition

(IEEE, 2022-07-15)
Liu, Shu
;
Koch, Kevin
;
Zhou, Zimu
;
Maritsch, Martin
;
He, Xiaoxi
;
Fleisch, Elgar
;
Wortmann, Felix

Type: journal article

Journal: IEEE Internet of Things Journal

Volume: 09

Issue: 14

DOI: 10.1109/JIOT.2021.3131742

URI: https://www.alexandria.unisg.ch/handle/20.500.14171/108487

Scopus© Citations 5
Bidding on a peer-to-peer energy market - an expoloratory field study

(INFORMS, 2022-09-09)
Wörner, Anselma Meret
;
Tiefenbeck, Verena
;
Wortmann, Felix
;
Meeuw, Arne
;
Ableitner, Liliane
;
Fleisch, Elgar
;
Azevedo, Inês

Type: journal article

Journal: Information Systems Research

Volume: 33/3

DOI: 10.1287/isre.2021.1098

URI: https://www.alexandria.unisg.ch/handle/20.500.14171/108317

Scopus© Citations 6
FLIRT: A Feature Generation Toolkit for Wearable Data

( 2021-11-11)
Föll, Simon
;
Maritsch, Martin
;
Spinola, Federica
;
Mishra, Varun
;
Barata, Filipe
;
Kowatsch, Tobias
;
Fleisch, Elgar
;
Wortmann, Felix

Background and Objective: Researchers use wearable sensing data and machine learning (ML) models to predict various health and behavioral outcomes. However, sensor data from commercial wearables are prone to noise, missing, or artifacts. Even with the recent interest in deploying commercial wearables for long-term studies, there does not exist a standardized way to process the raw sensor data and researchers often use highly specific functions to preprocess, clean, normalize, and compute features. This leads to a lack of uniformity and reproducibility across different studies, making it difficult to compare results. To overcome these issues, we present FLIRT: A Feature Generation Toolkit for Wearable Data; it is an open-source Python package that focuses on processing physiological data specifically from commercial wearables with all its challenges from data cleaning to feature extraction. Methods: FLIRT leverages a variety of state-of-the-art algorithms (e.g., particle filters, ML-based artifact detection) to ensure a robust preprocessing of physiological data from wearables. In a subsequent step, FLIRT utilizes a sliding-window approach and calculates a feature vector of more than 100 dimensions – a basis for a wide variety of ML algorithms. Results: We evaluated FLIRT on the publicly available WESAD dataset, which focuses on stress detection with an Empatica E4 wearable. Preprocessing the data with FLIRT ensures that unintended noise and artifacts are appropriately filtered. In the classification task, FLIRT outperforms the preprocessing baseline of the original WESAD paper. Conclusion: FLIRT provides functionalities beyond existing packages that can address unmet needs in physiological data processing and feature generation: (a) integrated handling of common wearable file formats (e.g., Empatica E4 archives), (b) robust preprocessing, and (c) standardized feature generation that ensures reproducibility of results. Nevertheless, while FLIRT comes with a default configuration to accommodate most situations, it offers a highly configurable interface for all of its implemented algorithms to account for specific needs.

Type: journal article

Journal: Computer Methods and Programs in Biomedicine

Volume: 212

Issue: November

URL: https://doi.org/10.1016/j.cmpb.2021.106461

DOI: 10.1016/j.cmpb.2021.106461

URI: https://www.alexandria.unisg.ch/handle/20.500.14171/109734

Scopus© Citations 15
When Do Drivers Interact with In-Vehicle Well-being Interventions? An Exploratory Analysis of a Longitudinal Study on Public Roads

(Association for Computing Machinery, 2021)
Koch, Kevin
;
Mishra, Varun
;
Liu, Shu
;
Berger, Thomas
;
Fleisch, Elgar
;
Kotz, David
;
Wortmann, Felix

Type: journal article

Journal: Proc. ACM Interact. Mob. Wearable Ubiquitous Technol.

Volume: 5

Issue: 1

URL: https://doi.org/10.1145/3448116

URI: https://www.alexandria.unisg.ch/handle/20.500.14171/111117
Growth paths for overcoming the digitalization paradox

(Elsevier, 2020-02-13)
Gebauer, Heiko
;
Fleisch, Elgar
;
Lamprecht, Claudio
;
Wortmann, Felix

Type: journal article

Journal: Business Horizons

DOI: https://doi.org/10.1016/j.bushor.2020.01.005

URI: https://www.alexandria.unisg.ch/handle/20.500.14171/112410
Implementing a blockchain-based local energy market: Insights on communication and scalability.

(Elsevier, 2020-07-01)
Meeuw, Arne
;
Schopfer, Sandro
;
Woerner, Anselma
;
Ableitner, Liliane
;
Tiefenbeck, Verena
;
Fleisch, Elgar
;
Wortmann, Felix

Type: journal article

Journal: Computer Comunications

Volume: Volume 160

URL: https://doi.org/10.1016/j.comcom.2020.04.038

URI: https://www.alexandria.unisg.ch/handle/20.500.14171/111985

Felix Wortmann

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