@book{TingsLehnerHossetal.2021,
  author    = {Tings, Franziska and Lehner, Julian and Hoß, Elena and Gotzens, Franziska and Creutz, Marie-Sophie and Christ, Nils},
  title     = {Aachener Online-Schriften Wirtschaft und Recht. Band 02/2021},
  editor    = {Kroll-Ludwigs, Kathrin and Bassen-Metz, Yasmine and Eggert, Mathias and Fritz, Thomas and H{\"o}hne, Tim and Tran, Duc Hung and Vogt, J{\"u}rgen},
  publisher = {FH Aachen / Fachbereich Wirtschaftswissenschaften},
  address   = {Aachen},
  publisher      = {Fachhochschule Aachen},
  pages     = {404 Seiten},
  year      = {2021},
  abstract  = {Inhaltsverzeichnis 1. Die Haftung des GmbH-Gesch{\"a}ftsf{\"u}hrers in der Insolvenz - Grunds{\"a}tze und Modifikationen infolge der Covid-19 Pandemie - Franziska Tings 3-61 2. Disquotale Gewinnaussch{\"u}ttung in der Organschaft - Die Neuregelung des \S 14 Abs. 2 KStG und die Auslegung durch die Finanzverwaltung - Julian Lehner 62-149 3. Auswirkungen des Mauracher Entwurfs auf die Gesellschaft b{\"u}rgerlichen Rechts - Neuerfindung oder bloße Korrektur des Personengesellschaftsrechts? - Elena Hoß 150-209 4. Befristung von Arbeitsverh{\"a}ltnissen - Rechtliche Rahmenbedingungen und arbeitsmarktpolitische Chancen und Risiken - Franziska Gotzens 210-270 5. Die Rolle der psychischen Gesundheit am Arbeitsplatz Entwicklung exemplarischer Handlungsempfehlungen f{\"u}r den ganzheitlichen Umgang mit psychischen Belastungen im Homeoffice - Marie-Sophie Creutz 271-346 6. Tokenisierung von illiquiden Verm{\"o}genswerten - Wie Blockchain die Immobilienwirtschaft ver{\"a}ndern kann - Nils Christ 347-404},
  language  = {de}
}
@book{AbrahamAhmadianBuettgenbachetal.2021,
  author    = {Abraham, Michelle and Ahmadian, Natalia and B{\"u}ttgenbach, Thomas and Keller, Nadja and Paumer, Marc and Plum, Axel},
  title     = {Aachener Online-Schriften Wirtschaft und Recht. Band 1/2021},
  editor    = {Kroll-Ludwigs, Kathrin and Bassen-Metz, Yasmine and Bernecker, Andreas and Eggert, Mathias and Fritz, Thomas and H{\"o}hne, Tim and Tran, Duc Hung and Vogt, J{\"u}rgen},
  publisher = {FH Aachen / Fachbereich Wirtschaftswissenschaften},
  address   = {Aachen},
  publisher      = {Fachhochschule Aachen},
  pages     = {370 Seiten},
  year      = {2021},
  abstract  = {Inhaltsverzeichnis 1. Whistleblowing - Chancen \& Risiken von Hinweisgebersystemen aus Arbeitnehmer- und Arbeitgebersicht - Michelle Abraham 3-70 2. Die Bedeutung und rechtliche Bewertung von Vesting-Klauseln bei der Venture-Capital Finanzierung einer Start-Up GmbH - Natalia Ahmadian 71-137 3. Bewertung der M{\"o}glichkeit zur Einf{\"u}hrung von Tarifvertr{\"a}gen im deutschen Berufsfußball - Thomas B{\"u}ttgenbach 138-190 4. Pflichten und Haftungsrisiken des GmbH-Gesch{\"a}ftsf{\"u}hrers bei Compliance-Verst{\"o}ßen - Naja Keller 191-234 5. Aktienr{\"u}ckk{\"a}ufe auf dem deutschen Markt nach der Finanzkrise 2008/2009 - Marc Paumer 235-287 6. Will Germany reach its 2030 climate goals in the transportation sector? - An investigation focusing on the new German Emission Trading System - Axel Plum 288-369},
  language  = {de}
}
@book{TruempenerPetersHerzeletal.2021,
  author    = {Tr{\"u}mpener, Nora and Peters, Jan and Herzel, Manuel and Vollmann, Alina and Breuer, Gina},
  title     = {Aachener Online-Schriften Wirtschaft und Recht. Band 3/2021},
  editor    = {Kroll-Ludwigs, Kathrin and Bassen-Metz, Yasmine and Eggert, Mathias and Fritz, Thomas and H{\"o}hne, Tim and Tran, Duc Hung and Vogt, J{\"u}rgen},
  publisher = {FH Aachen / Fachbereich Wirtschaftswissenschaften},
  address   = {Aachen},
  publisher      = {Fachhochschule Aachen},
  pages     = {304 Seiten},
  year      = {2021},
  abstract  = {Inhaltsverzeichnis 1. Die ordentliche K{\"u}ndigung chronisch Kranker im Anwendungsbereich des KSchG - Nora Tr{\"u}mpener 3-56 2. Die Legitimationswirkung der Gesellschafterliste - Erfolg trotz Grenzen? - Jan Peters 57-112 3. Marktmanipulation - Arten, Abgrenzung und gesetzliche Handhabe - Manuel Herzel 113-170 4. Die Zul{\"a}ssigkeit der Verdachtsk{\"u}ndigung im Arbeitsverh{\"a}ltnis - Alina Vollmann 171-248 5. Praxisorientierter Arbeitgeberleitfaden zur rechtssicheren Einf{\"u}hrung von Homeoffice im Arbeitsverh{\"a}ltnis - Gina Breuer 249-304},
  language  = {de}
}
@masterthesis{Niedermeier2021,
  type      = {Bachelor Thesis},
  author    = {Niedermeier, Jacqueline},
  title     = {Aachener Tierpark Euregiozoo: Corporate Design f{\"u}r eine Institution mit Bildungsauftrag},
  publisher = {FH Aachen},
  address   = {Aachen},
  school      = {Fachhochschule Aachen},
  pages     = {107 Seiten},
  year      = {2021},
  abstract  = {Der Aachener Tierpark Euregiozoo l{\"a}sst die Aspekte "Bildung" und "Forschung" mit "Erholung" und "Erhaltung" an einem Ort miteinander verschmelzen. Auf einer Fl{\"a}che von rund 8,9 ha beherbergt der Zoo etwa 1.000 Tiere aus 200 verschiedenen Arten und Rassen in großz{\"u}gigen und nat{\"u}rlich gestalteten Gehegen. Das neue Designkonzept soll den Bildungsaspekt in den Vordergrund r{\"u}cken und modernisieren. Der Einsatz verschiedenster Medien soll die breite Zielgruppe von Jung bis Alt ansprechen und das Interesse nach neuem Wissen anregen. Das neue Leitsystem sorgt nicht nur f{\"u}r Orientierung im Park, es erm{\"o}glicht auch interaktive und individuelle F{\"u}hrungen durch den Zoo. Kombiniert mit einem Wissensquiz und zahlreichen spannenden Fakten {\"u}ber die Tierwelt des Parks wird der Zoobesuch zu einem ganz besonderen Erlebnis.},
  language  = {de}
}
@inproceedings{UlmerBraunChengetal.2021,
  author    = {Ulmer, Jessica and Braun, Sebastian and Cheng, Chi-Tsun and Dowey, Steve and Wollert, J{\"o}rg},
  title     = {Adapting augmented reality systems to the users' needs using gamification and error solving methods},
  series = {Procedia CIRP - 54th CIRP CMS 2021 - Towards Digitalized Manufacturing 4.0},
  volume    = {104},
  booktitle = {Procedia CIRP - 54th CIRP CMS 2021 - Towards Digitalized Manufacturing 4.0},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {2212-8271},
  doi       = {10.1016/j.procir.2021.11.024},
  pages     = {140 -- 145},
  year      = {2021},
  abstract  = {Animations of virtual items in AR support systems are typically predefined and lack interactions with dynamic physical environments. AR applications rarely consider users' preferences and do not provide customized spontaneous support under unknown situations. This research focuses on developing adaptive, error-tolerant AR systems based on directed acyclic graphs and error resolving strategies. Using this approach, users will have more freedom of choice during AR supported work, which leads to more efficient workflows. Error correction methods based on CAD models and predefined process data create individual support possibilities. The framework is implemented in the Industry 4.0 model factory at FH Aachen.},
  language  = {en}
}
@inproceedings{UlmerBraunWollert2021,
  author    = {Ulmer, Jessica and Braun, Sebastian and Wollert, J{\"o}rg},
  title     = {Adaptive VR-Produktionsumgebungen f{\"u}r Evaluations- und Schulungst{\"a}tigkeiten},
  series = {Automation 2021: Navigating towards resilient Production},
  booktitle = {Automation 2021: Navigating towards resilient Production},
  publisher = {VDI},
  address   = {D{\"u}sseldorf},
  isbn      = {978-3-18-092392-5},
  issn      = {0083-5560},
  doi       = {10.51202/9783181023921-55},
  pages     = {55 -- 64},
  year      = {2021},
  abstract  = {Industrie 4.0 stellt viele Herausforderungen an produzierende Unternehmen und ihre Besch{\"a}f-tigten. Innovative und effektive Trainingsstrategien sind erforderlich, um mit den sich schnell ver{\"a}ndernden Produktionsumgebungen und neuen Fertigungstechnologien Schritt halten zu k{\"o}nnen. Virtual Reality (VR) bietet neue M{\"o}glichkeiten f{\"u}r On-the-Job, On-Demand- und Off-Premise-Schulungen. Diese Arbeit stellt ein neues VR Schulungssystem vor, welches sich flexible an unterschiedliche Trainingsobjekte auf Grundlage von Rezepten und CAD Modellen anpassen l{\"a}sst. Das Konzept basiert auf gerichteten azyklischen Graphen und einem Level-system. Es erm{\"o}glicht eine benutzerindividuelle Lerngeschwindigkeit mittels visueller Ele-mente. Das Konzept wurde f{\"u}r einen mechanischen Anwendungsfall mit Industriekomponen-ten implementiert und in der Industrie 4.0-Modellfabrik der FH Aachen umgesetzt.},
  language  = {de}
}
@misc{MayntzKeimerTegtmeyeretal.2021,
  author    = {Mayntz, Joscha and Keimer, Jona and Tegtmeyer, Philipp and Dahmann, Peter and Hille, Sebastian and Stumpf, Eike and Fisher, Alex and Dorrington, Graham},
  title     = {Aerodynamic Investigation on Efficient Inflight Transition of a Propeller from Propulsion to Regeneration Mode},
  series = {AIAA SCITECH 2022 Forum},
  journal   = {AIAA SCITECH 2022 Forum},
  publisher = {AIAA},
  address   = {Reston, Va.},
  doi       = {10.2514/6.2022-0546},
  year      = {2021},
  abstract  = {This paper discusses a new way of inflight power regeneration for electric or hybrid-electric driven general aviation aircraft with one powertrain for both configurations. Three different approaches for the shift from propulsion to regeneration mode are analyzed. Numerical cal-culation and wind tunnel results are compared and show the highest regeneration potential for the "Windmill" approach, where the propeller blades are flipped, and rotation is reversed. A combination of all regeneration approaches for a realistic flight mission is discussed.},
  language  = {en}
}
@article{GoettenHavermannBraunetal.2021,
  author    = {G{\"o}tten, Falk and Havermann, Marc and Braun, Carsten and Marino, Matthew and Bil, Cees},
  title     = {Aerodynamic Investigations of UAV Sensor Turrets - A Combined Wind-tunnel and CFD Approach},
  series = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021},
  journal   = {SciTech 2021, AIAA SciTech Forum, online, WW, Jan 11-15, 2021},
  publisher = {AIAA},
  address   = {Reston, Va.},
  doi       = {10.2514/6.2021-1535},
  pages     = {1 -- 12},
  year      = {2021},
  language  = {en}
}
@article{Maurischat2021,
  author    = {Maurischat, Andreas},
  title     = {Algebraic independence of the Carlitz period and its hyperderivatives},
  pages     = {1 -- 12},
  year      = {2021},
  language  = {en}
}
@masterthesis{Anders2021,
  type      = {Bachelor Thesis},
  author    = {Anders, Milena},
  title     = {Alternative Landwirtschaft - Wo kommt unser Essen her?},
  publisher = {FH Aachen},
  address   = {Aachen},
  school      = {Fachhochschule Aachen},
  pages     = {79 Seiten},
  year      = {2021},
  abstract  = {In den letzten 1.5 Jahren haben wir sehr deutlich gemerkt, dass es den Klimawandel wirklich gibt - ein Virus, welches unsere gesamte Welt auf links dreht, {\"U}berschwemmungskatastrophen, extreme Temperaturschwankungen, etc. Es ist also Zeit etwas zu ver{\"a}ndern, es ist Zeit aktiv hinzusehen und zu handeln - bewusst zu leben, bewusst zu konsumieren. Das Thema Ern{\"a}hrung wird zwar immer wichtiger f{\"u}r einige von uns, jedoch reicht mir die Aufmerksamkeit bisher nicht. Es sind nicht nur Lebensmittel, welche nach dem Aufenthalt im Supermarkt in unserem K{\"u}hlschrank und anschließend in unserem Bauch landen. Mit diesen Lebensmitteln gehen außerdem folgende Aspekte einher: der Klimawandel, unsere Gesundheit, die Ausbeutung von Tieren, Menschen und Natur. Also wie sieht eigentlich der Enstehungsprozess hinter all diesen (meist) verpackten Lebensmitteln aus? Einen Teil dieser Prozesse habe ich mir im Rahmen meiner Bachelorarbeit angeschaut. Ich habe ausschließlich Bio-H{\"o}fe besucht, um mir ein eigenes Bild von "alternativer Landwirtschaft" zu machen. Die Arbeit erm{\"o}glicht Interessierten einen neutralen Einblick hinter die Kulisse unserer Lebensmittel und schafft eine Anregung f{\"u}r einen bewussteren Konsum.},
  language  = {de}
}
@article{PoghossianWeldenBuniatyanetal.2021,
  author    = {Poghossian, Arshak and Welden, Rene and Buniatyan, Vahe V. and Sch{\"o}ning, Michael Josef},
  title     = {An Array of On-Chip Integrated, Individually Addressable Capacitive Field-Effect Sensors with Control Gate: Design and Modelling},
  series = {Sensors},
  volume    = {21},
  journal   = {Sensors},
  number    = {18},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {1424-8220},
  doi       = {10.3390/s21186161},
  pages     = {17},
  year      = {2021},
  abstract  = {The on-chip integration of multiple biochemical sensors based on field-effect electrolyte-insulator-semiconductor capacitors (EISCAP) is challenging due to technological difficulties in realization of electrically isolated EISCAPs on the same Si chip. In this work, we present a new simple design for an array of on-chip integrated, individually electrically addressable EISCAPs with an additional control gate (CG-EISCAP). The existence of the CG enables an addressable activation or deactivation of on-chip integrated individual CG-EISCAPs by simple electrical switching the CG of each sensor in various setups, and makes the new design capable for multianalyte detection without cross-talk effects between the sensors in the array. The new designed CG-EISCAP chip was modelled in so-called floating/short-circuited and floating/capacitively-coupled setups, and the corresponding electrical equivalent circuits were developed. In addition, the capacitance-voltage curves of the CG-EISCAP chip in different setups were simulated and compared with that of a single EISCAP sensor. Moreover, the sensitivity of the CG-EISCAP chip to surface potential changes induced by biochemical reactions was simulated and an impact of different parameters, such as gate voltage, insulator thickness and doping concentration in Si, on the sensitivity has been discussed.},
  language  = {en}
}
@article{Staat2021,
  author    = {Staat, Manfred},
  title     = {An extension strain type Mohr-Coulomb criterion},
  series = {Rock mechanics and rock engineering},
  volume    = {54},
  journal   = {Rock mechanics and rock engineering},
  number    = {12},
  publisher = {Springer Nature},
  address   = {Cham},
  issn      = {1434-453X},
  doi       = {10.1007/s00603-021-02608-7},
  pages     = {6207 -- 6233},
  year      = {2021},
  abstract  = {Extension fractures are typical for the deformation under low or no confining pressure. They can be explained by a phenomenological extension strain failure criterion. In the past, a simple empirical criterion for fracture initiation in brittle rock has been developed. In this article, it is shown that the simple extension strain criterion makes unrealistic strength predictions in biaxial compression and tension. To overcome this major limitation, a new extension strain criterion is proposed by adding a weighted principal shear component to the simple criterion. The shear weight is chosen, such that the enriched extension strain criterion represents the same failure surface as the Mohr-Coulomb (MC) criterion. Thus, the MC criterion has been derived as an extension strain criterion predicting extension failure modes, which are unexpected in the classical understanding of the failure of cohesive-frictional materials. In progressive damage of rock, the most likely fracture direction is orthogonal to the maximum extension strain leading to dilatancy. The enriched extension strain criterion is proposed as a threshold surface for crack initiation CI and crack damage CD and as a failure surface at peak stress CP. Different from compressive loading, tensile loading requires only a limited number of critical cracks to cause failure. Therefore, for tensile stresses, the failure criteria must be modified somehow, possibly by a cut-off corresponding to the CI stress. Examples show that the enriched extension strain criterion predicts much lower volumes of damaged rock mass compared to the simple extension strain criterion.},
  language  = {en}
}
@article{Golland2021,
  author    = {Golland, Alexander},
  title     = {Anforderungen an Transfer Impact Assessments bei Datentransfers in unsichere Drittl{\"a}nder},
  series = {DSB Datenschutz-Berater},
  volume    = {45},
  journal   = {DSB Datenschutz-Berater},
  number    = {7-8},
  publisher = {DFV Mediengruppe},
  address   = {Frankfurt a.M.},
  isbn      = {0170-7256},
  pages     = {229 -- 231},
  year      = {2021},
  language  = {de}
}
@article{HennesLaumann2021,
  author    = {Hennes, Philipp and Laumann, J{\"o}rg},
  title     = {Ansatz der Drehbehinderung aus Koppelpfetten mit d{\"u}nnwandigen kaltgeformten Z-Profilen},
  series = {Stahlbau},
  volume    = {90},
  journal   = {Stahlbau},
  number    = {3},
  publisher = {Ernst \& Sohn},
  address   = {Berlin},
  issn      = {1437-1049},
  doi       = {10.1002/stab.202000104},
  pages     = {158 -- 168},
  year      = {2021},
  language  = {de}
}
@misc{Nahrstedt2021,
  type      = {Master Thesis},
  author    = {Nahrstedt, Sarah},
  title     = {Any Cargo: Das Fahrrad als Hauptverkehrsmittel in der Stadt},
  publisher = {FH Aachen},
  address   = {Aachen},
  pages     = {216 Seiten},
  year      = {2021},
  abstract  = {Durch die Urbanisierung, wird es in St{\"a}dten immer enger und der Verkehr nimmt zu. Das hat hohe Emissionen und Platzmangel zur Folge. In der Masterarbeit wurde die Abh{\"a}ngigkeit zum Auto in der Stadt hinterfragt und ein Konzept erarbeitet, welches die Autonutzung und den Autobesitz abl{\"o}st. Dabei entstand ein neuer Fahrradanh{\"a}nger, der eine multifunktionale Nutzung zul{\"a}sst und einen elektrischen Antrieb besitzt. Dadurch bietet er einen komfortablen Support im Alltag. Zudem wurde ein Gesch{\"a}ftskonzept entwickelt, welches erm{\"o}glicht, den Anh{\"a}nger mit einem digitalen Ausleihsystem unter Nachbarn oder Freunden zu teilen. Ein wichtiges Kriterium f{\"u}r das Produkt und den Service war, dass die Mobilit{\"a}t der Zukunft nicht nur nachhaltig sein soll, sondern auch Laune machen muss.},
  language  = {de}
}
@article{SaretzkiBergmannDahmannetal.2021,
  author    = {Saretzki, Charlotte and Bergmann, Ole and Dahmann, Peter and Janser, Frank and Keimer, Jona and Machado, Patricia and Morrison, Audry and Page, Henry and Pluta, Emil and St{\"u}bing, Felix and K{\"u}pper, Thomas},
  title     = {Are small airplanes safe with regards to COVID-19 transmission?},
  series = {Journal of Travel Medicine},
  volume    = {28},
  journal   = {Journal of Travel Medicine},
  number    = {7},
  publisher = {Oxford University Press},
  address   = {Oxford},
  issn      = {1708-8305},
  doi       = {10.1093/jtm/taab105},
  year      = {2021},
  language  = {en}
}
@article{HunkerGossmannRamanetal.2021,
  author    = {Hunker, Jan L. and Gossmann, Matthias and Raman, Aravind Hariharan and Linder, Peter},
  title     = {Artificial neural networks in cardiac safety assessment: Classification of chemotherapeutic compound effects on hiPSC-derived cardiomyocyte contractility},
  series = {Journal of Pharmacological and Toxicological Methods},
  volume    = {111},
  journal   = {Journal of Pharmacological and Toxicological Methods},
  number    = {Article number 107044},
  publisher = {Elsevier},
  address   = {New York},
  issn      = {1056-8719},
  doi       = {10.1016/j.vascn.2021.107044},
  year      = {2021},
  language  = {en}
}
@masterthesis{Mueller2021,
  type      = {Bachelor Thesis},
  author    = {M{\"u}ller, Elona},
  title     = {Aus den Augen aus dem Sinn?: Ein Bookazine deckt das Problem des Unsichtbaren M{\"u}lls auf},
  publisher = {FH Aachen},
  address   = {Aachen},
  school      = {Fachhochschule Aachen},
  year      = {2021},
  abstract  = {M{\"u}ll ist immer und {\"u}berall vorhanden - auch wenn wir ihn nicht sehen. Gerade unsichtbarer M{\"u}ll birgt f{\"u}r den Menschen und seine Umwelt erhebliche Gefahren, die durch seine Unsichtbarkeit irrelevant erscheinen. Die Publikation mit dem Titel mikromakro deckt durch verschiedene Artikel, Interviews und Texte die Gefahren auf, die durch den unsichtbaren M{\"u}ll entstehen. Ziel war es, eine Bookazine-Reihe zu konzipieren, die in sechs Ausgaben das Thema des unsichtbaren M{\"u}lls beleuchtet. Die erste Ausgabe zum Thema Kunststoff wurde exemplarisch gestaltet. Zus{\"a}tzlich zum redaktionellen Teil untermauern Infografiken die Texte faktisch und Fotoserien emotional. Da unsichtbarer M{\"u}ll auf zwei Ebenen zu finden ist - der Makro- (groß) und Mikroebene (klein) - wurde die Publikation inhaltlich zweigeteilt, sodass sich das Layout und die Fotoserien vom Mikro- und Makroteil unterscheiden. },
  language  = {de}
}
@article{GorzalkaSchmiedtSchorn2021,
  author    = {Gorzalka, Philip and Schmiedt, Jacob Estevam and Schorn, Christian},
  title     = {Automated Generation of an Energy Simulation Model for an Existing Building from UAV Imagery},
  series = {Buildings},
  volume    = {11},
  journal   = {Buildings},
  number    = {9},
  publisher = {MDPI},
  address   = {Basel},
  issn      = {2075-5309},
  doi       = {10.3390/buildings11090380},
  pages     = {15 Seiten},
  year      = {2021},
  abstract  = {An approach to automatically generate a dynamic energy simulation model in Modelica for a single existing building is presented. It aims at collecting data about the status quo in the preparation of energy retrofits with low effort and costs. The proposed method starts from a polygon model of the outer building envelope obtained from photogrammetrically generated point clouds. The open-source tools TEASER and AixLib are used for data enrichment and model generation. A case study was conducted on a single-family house. The resulting model can accurately reproduce the internal air temperatures during synthetical heating up and cooling down. Modelled and measured whole building heat transfer coefficients (HTC) agree within a 12\% range. A sensitivity analysis emphasises the importance of accurate window characterisations and justifies the use of a very simplified interior geometry. Uncertainties arising from the use of archetype U-values are estimated by comparing different typologies, with best- and worst-case estimates showing differences in pre-retrofit heat demand of about ±20\% to the average; however, as the assumptions made are permitted by some national standards, the method is already close to practical applicability and opens up a path to quickly estimate possible financial and energy savings after refurbishment.},
  language  = {en}
}
@article{GriegerSchwabedalWendeletal.2021,
  author    = {Grieger, Niklas and Schwabedal, Justus T. C. and Wendel, Stefanie and Ritze, Yvonne and Bialonski, Stephan},
  title     = {Automated scoring of pre-REM sleep in mice with deep learning},
  series = {Scientific Reports},
  volume    = {11},
  journal   = {Scientific Reports},
  number    = {Art. 12245},
  publisher = {Springer Nature},
  address   = {London},
  issn      = {2045-2322},
  doi       = {10.1038/s41598-021-91286-0},
  year      = {2021},
  abstract  = {Reliable automation of the labor-intensive manual task of scoring animal sleep can facilitate the analysis of long-term sleep studies. In recent years, deep-learning-based systems, which learn optimal features from the data, increased scoring accuracies for the classical sleep stages of Wake, REM, and Non-REM. Meanwhile, it has been recognized that the statistics of transitional stages such as pre-REM, found between Non-REM and REM, may hold additional insight into the physiology of sleep and are now under vivid investigation. We propose a classification system based on a simple neural network architecture that scores the classical stages as well as pre-REM sleep in mice. When restricted to the classical stages, the optimized network showed state-of-the-art classification performance with an out-of-sample F1 score of 0.95 in male C57BL/6J mice. When unrestricted, the network showed lower F1 scores on pre-REM (0.5) compared to the classical stages. The result is comparable to previous attempts to score transitional stages in other species such as transition sleep in rats or N1 sleep in humans. Nevertheless, we observed that the sequence of predictions including pre-REM typically transitioned from Non-REM to REM reflecting sleep dynamics observed by human scorers. Our findings provide further evidence for the difficulty of scoring transitional sleep stages, likely because such stages of sleep are under-represented in typical data sets or show large inter-scorer variability. We further provide our source code and an online platform to run predictions with our trained network.},
  language  = {en}
}