TY - JOUR
AU - Fuchs, Christian
ID - 38147
IS - 7-8
JF - Critical Sociology
TI - Cornel West and Marxist Humanism
VL - 47
ER -
TY - BOOK
ED - Fuchs, Christian
ED - Unterberger, Klaus
ID - 38133
TI - The Public Service Media and Public Service Internet Manifesto
ER -
TY - CHAP
AU - Alessandro, D'Arma
AU - Fuchs, Christian
AU - Horowitz, Minna
AU - Unterberger, Klaus
ED - Fuchs, Christian
ED - Unterberger, Klaus
ID - 38152
T2 - The Public Service Media and Public Service Internet Manifesto
TI - The Future of Public Service Media and the Internet
ER -
TY - CHAP
AU - Fuchs, Christian
AU - Unterberger, Klaus
ED - Fuchs, Christian
ED - Unterberger, Klaus
ID - 38154
T2 - The Public Service Media and Public Service Internet Manifesto
TI - Introduction
ER -
TY - JOUR
AU - Fuchs, Christian
ID - 38148
IS - 1
JF - Westminster Papers in Communication and Culture
TI - The Digital Commons and the Digital Public Sphere: How to Advance Digital Democracy Today
VL - 16
ER -
TY - JOUR
AU - Fuchs, Christian
ID - 38157
IS - 1
JF - tripleC: Communication, Capitalism & Critique
TI - How Did Donald Trump Incite a Coup Attempt?
VL - 19
ER -
TY - JOUR
AU - Fuchs, Christian
ID - 38149
IS - 4
JF - Journal of Media Ethics
TI - Foundations of Communication/Media/Digital (In)Justice
VL - 36
ER -
TY - GEN
AU - Fuchs, Christian
ID - 38156
T2 - The Conversation
TI - Channel 4: Rather Than Privatising Public Service Media We Should Be Expanding It Online
ER -
TY - JOUR
AU - Fuchs, Christian
ID - 42483
IS - 2
JF - tripleC: Communication, Capitalism & Critique
TI - Preface: Manfred Knoche’s Critique of the Political Economy of the Media and Communication [Preface to the article “Media Concentration” by Manfred Knoche]
VL - 19
ER -
TY - JOUR
AB - Lithium niobate (LiNbO3), a material frequently used in optical applications, hosts different kinds of polarons that significantly affect many of its physical properties. In this study, a variety of electron polarons, namely free, bound, and bipolarons, are analyzed using first-principles calculations. We perform a full structural optimization based on density-functional theory for selected intrinsic defects with special attention to the role of symmetry-breaking distortions that lower the total energy. The cations hosting the various polarons relax to a different degree, with a larger relaxation corresponding to a larger gap between the defect level and the conduction-band edge. The projected density of states reveals that the polaron states are formerly empty Nb 4d states lowered into the band gap. Optical absorption spectra are derived within the independent-particle approximation, corrected by the GW approximation that yields a wider band gap and by including excitonic effects within the Bethe-Salpeter equation. Comparing the calculated spectra with the density of states, we find that the defect peak observed in the optical absorption stems from transitions between the defect level and a continuum of empty Nb 4d states. Signatures of polarons are further analyzed in the reflectivity and other experimentally measurable optical coefficients.
AU - Schmidt, Falko
AU - Kozub, Agnieszka L.
AU - Gerstmann, Uwe
AU - Schmidt, Wolf Gero
AU - Schindlmayr, Arno
ID - 21946
JF - Crystals
TI - Electron polarons in lithium niobate: Charge localization, lattice deformation, and optical response
VL - 11
ER -
TY - JOUR
AB - Tailor-made ordered mesoporous materials bear great potential in numerous fields of application where large interfaces are required. However, the inherent surfacechemical properties of conventional materials, such as silica, carbon or organosilica, poses some limitations with respect to their application. Surface manipulation by functionalization with chemically more reactive groups is one way to improve materials for their desired purpose. Another approach is the design of high surface-area composite materials. The surface manipulation, either by functionalization or by introducing guest species, can be performed selectively. This means that when several distinct, i.e. , hierarchical, types of surfaces or pore systems exist in a material, each of them may be chosen for manipulation. Several strategies can be identified to achieve this goal. Molecules or molecule assemblies can be utilized to temporarily protect pores or surfaces (soft protection), while manipulation occurs at the accessible sites. This approach is a recurring motive in this review and can also be applied to rigid template matrices (hard protection). Furthermore, the size of functionalization agents (size protection) and their reactivity/diffusion (kinetic protection) into the pores can also be utilized to achieve selectivity. In addition, challenges in the synthesis and characterization of selectively manipulated ordered mesoporous materials are discussed.
AU - Tiemann, Michael
AU - Weinberger, Christian
ID - 25893
JF - Advanced Materials Interfaces
SN - 2196-7350
TI - Selective Modification of Hierarchical Pores and Surfaces in Nanoporous Materials
ER -
TY - JOUR
AU - Fuchs, Christian
ID - 41431
IS - 1
JF - tripleC: Communication, Capitalism & Critique
TI - Engels@200: Friedrich Engels in the Age of Digital Capitalism
VL - 19
ER -
TY - JOUR
AU - Möhring, Julia
AU - Krumhöfner, Anika
AU - Gräfin von Plettenberg, Elisabeth Gudila Sophia Ida Maria
ID - 43016
JF - -
TI - Bewegungsförderung in Ganztagsschulen
ER -
TY - GEN
AU - Leineweber, Jonas
ID - 33210
TI - Veranstaltungsbericht: Immaterielles Kulturerbe in Nordrhein-Westfalen – Steigerlied und Trinkhallenkultur im Ruhrgebiet erhalten Auszeichnung anlässlich der Neuaufnahmen in das nordrhein-westfälische Landesinventar
ER -
TY - GEN
AU - Leineweber, Jonas
ID - 33209
TI - Tagungsbericht: Immaterielles Kulturerbe und regionale Identität. Gesellschaftliche Repräsentation und Partizipation im Schützenwesen
ER -
TY - JOUR
AB - We perform a theoretical analysis of the structural and electronic properties of sodium potassium niobate K1-xNaxNbO3 in the orthorhombic room-temperature phase, based on density-functional theory in combination with the supercell approach. Our results for x=0 and x=0.5 are in very good agreement with experimental measurements and establish that the lattice parameters decrease linearly with increasing Na contents, disproving earlier theoretical studies based on the virtual-crystal approximation that claimed a highly nonlinear behavior with a significant structural distortion and volume reduction in K0.5Na0.5NbO3 compared to both end members of the solid solution. Furthermore, we find that the electronic band gap varies very little between x=0 and x=0.5, reflecting the small changes in the lattice parameters.
AU - Bidaraguppe Ramesh, Nithin
AU - Schmidt, Falko
AU - Schindlmayr, Arno
ID - 22960
IS - 8
JF - The European Physical Journal B
SN - 1434-6028
TI - Lattice parameters and electronic band gap of orthorhombic potassium sodium niobate K0.5Na0.5NbO3 from density-functional theory
VL - 94
ER -
TY - JOUR
AU - Friedrich, Christoph
AU - Blügel, Stefan
AU - Schindlmayr, Arno
ID - 22761
IS - 3
JF - Physical Review B
SN - 2469-9950
TI - Erratum: Efficient implementation of the GW approximation within the all-electron FLAPW method [Phys. Rev. B 81, 125102 (2010)]
VL - 104
ER -
TY - JOUR
AB - Employing the ultrafast control of electronic states of a semiconductor quantum dot in a cavity, we introduce an approach to achieve on-demand emission of single photons with almost perfect indistinguishability and photon pairs with near ideal entanglement. Our scheme is based on optical excitation off resonant to a cavity mode followed by ultrafast control of the electronic states using the time-dependent quantum-confined Stark effect, which then allows for cavity-resonant emission. Our theoretical analysis considers cavity-loss mechanisms, the Stark effect, and phonon-induced dephasing, allowing realistic predictions for finite temperatures.
AU - Bauch, David
AU - Heinze, Dirk Florian
AU - Förstner, Jens
AU - Jöns, Klaus
AU - Schumacher, Stefan
ID - 23816
JF - Physical Review B
KW - tet_topic_qd
SN - 2469-9950
TI - Ultrafast electric control of cavity mediated single-photon and photon-pair generation with semiconductor quantum dots
VL - 104
ER -
TY - JOUR
AB - Density-functional theory within a Berry-phase formulation of the dynamical polarization is used to determine the second-order susceptibility χ(2) of lithium niobate (LiNbO3). Defect trapped polarons and bipolarons are found to strongly enhance the nonlinear susceptibility of the material, in particular if localized at NbV–VLi defect pairs. This is essentially a consequence of the polaronic excitation resulting in relaxation-induced gap states. The occupation of these levels leads to strongly enhanced χ(2) coefficients and allows for the spatial and transient modification of the second-harmonic generation of macroscopic samples.
AU - Kozub, Agnieszka L.
AU - Schindlmayr, Arno
AU - Gerstmann, Uwe
AU - Schmidt, Wolf Gero
ID - 23418
JF - Physical Review B
SN - 2469-9950
TI - Polaronic enhancement of second-harmonic generation in lithium niobate
VL - 104
ER -
TY - JOUR
AU - Martin, Sven
AU - Tröster, Thomas
ID - 24548
JF - ESAFORM 2021
TI - Joint point loadings in car bodies – the influence of manufacturing tolerances and scatter in material properties
ER -
TY - CONF
AB - One of the main objectives of production engineering is to reproducibly manufacture (complex) defect-free parts. To achieve this, it is necessary to employ an appropriate process or tool design. While this will generally prove successful, it cannot, however, offset stochastic defects with local variations in material properties. Closed-loop process control represents a promising approach for a solution in this context. The state of the art involves using this approach to control geometric parameters such as a length. So far, no research or applications have been conducted with closed-loop control for microstructure and product properties. In the project on which this paper is based, the local martensite content of parts is to be adjusted in a highly precise and reproducible manner. The forming process employed is a special, property-controlled flow-forming process. A model-based controller is thus to generate corresponding correction values for the tool-path geometry and tool-path velocity on the basis of online martensite content measurements. For the controller model, it is planned to use a special process or microstructure (correlation) model. The planned paper not only describes the experimental setup but also presents results of initial experimental investigations for subsequent use in the closed-loop control of α’-martensite content during flow-forming.
AU - Arian, Bahman
AU - Homberg, Werner
AU - Riepold, Markus
AU - Trächtler, Ansgar
AU - Rozo Vasquez, Julian
AU - Walther, Frank
ID - 23465
KW - Flow-forming
KW - Spinning
KW - Process Strategy
KW - Martensite Content
KW - Property Control
KW - Micromagnetic Measurement
KW - Metastable Austenitic Stainless Steel
SN - 978-2-87019-302-0
TI - Forming of metastable austenitic stainless steel tubes with axially graded martensite content by flow-forming
ER -
TY - JOUR
AB - Multiprofessionelle Teams sind notwendiger Bestandteil inklusiver Schulen. Die Verteilung von Aufgaben, welche über die Zusammenarbeit von allgemeinen und sonderpädagogischen Lehrkräften im Unterricht hinausgehen, wurde bislang jedoch selten systematisch untersucht. Im Beitrag werden deskriptive Befunde aus dem Projekt BiFoKi (Bielefelder Fortbildungskonzept zur Kooperation in inklusiven Schulen) zu den Zuständigkeiten von allgemeinen (N = 170) und sonderpädagogischen Lehrkräften (N = 24) sowie Schulsozialarbeiterinnen (N = 11) an inklusiven Sekundar- und Gesamtschulen präsentiert. Sie deuten auf eine Persistenz traditioneller Rollenmuster und Aufgabenverteilungen hin. Bei den befragten sonderpädagogischen Lehrkräften können zwei unterschiedliche Rollenmuster herausgearbeitet werden. Die Schulsozialarbeiterinnen weisen ein enges Arbeitsfeld mit einem Fokus auf Eltern-Schule-Kooperation auf.
AU - Neumann, Phillip
AU - Grüter, Sandra
AU - Eckel, Lisa
AU - Lütje-Klose, Birgit
AU - Wild, Elke
AU - Gorges, Julia
ID - 34484
IS - 4
JF - Zeitschrift für Heilpädagogik
KW - Inklusion
KW - Sonderpädagogik
KW - Sekundarstufe
KW - Gesamtschulen
KW - Kooperation
KW - Schulsozialarbeit
KW - BiFoKi
SN - 0513-9066
TI - Aufgaben und Zuständigkeiten von allgemeinen und sonderpädagogischen Lehrkräften sowie Fachkräften der Schulsozialarbeit in inklusiven Schulen der Sekundarstufe I. Erste Ergebnisse aus dem BiFoKi-Projekt
VL - 73
ER -
TY - CONF
AB - Challenges of the development of mechatronic systems and corresponding production systems have increased steadily. Changes are primarily due to increased product complexity and the connection to the internet of things and services, enabling Cyber-Physical Systems (CPS) and Cyber-Physical Production Systems (CPPS). Major innovations of the revised VDI guideline 2206 for developing mechatronic systems are systems thinking as a core element and six checkpoints for structuring deliverables along the V-Model. These checkpoints serve for orientation in result progress and thus enable a structured and complete development process. However, tasks and checkpoints of the new guideline focus on the product development itself without integrating the development of related CPPS, enabling optimization simultaneously to system development. Implications are derived by a three-step analysis. The paper at hand contributes fundamental extensions of the checkpoint questions regarding integrated CPPS development. These questions provide methodical support for system developers of CPPS for CPS by enabling the project manager to check the status, schedule further development steps and evaluate the maturity of the whole, integrated development.
AU - Gräßler, Iris
AU - Wiechel, Dominik
AU - Roesmann, Daniel
AU - Thiele, Henrik
ID - 24080
KW - Cyber-Physical Production System (CPPS)
KW - V-Model
KW - Product System Development
KW - Integrated Development
KW - VDI 2206
SN - 2212-8271
T2 - Procedia CIRP
TI - V-model based development of cyber-physical systems and cyber-physical production systems
ER -
TY - CONF
AB - The battle of developing hardware Trojans and corresponding countermeasures has taken adversaries towards ingenious ways of compromising hardware designs by circumventing even advanced testing and verification methods. Besides conventional methods of inserting Trojans into a design by a malicious entity, the design flow for field-programmable gate arrays (FPGAs) can also be surreptitiously compromised to assist the attacker to perform a successful malfunctioning or information leakage attack. The advanced stealthy malicious look-up-table (LUT) attack activates a Trojan only when generating the FPGA bitstream and can thus not be detected by register transfer and gate level testing and verification. However, also this attack was recently revealed by a bitstream-level proof-carrying hardware (PCH) approach. In this paper, we present a novel attack that leverages malicious routing of the inserted Trojan circuit to acquire a dormant state even in the generated and transmitted bitstream. The Trojan's payload is connected to primary inputs/outputs of the FPGA via a programmable interconnect point (PIP). The Trojan is detached from inputs/outputs during place-and-route and re-connected only when the FPGA is being programmed, thus activating the Trojan circuit without any need for a trigger logic. Since the Trojan is injected in a post-synthesis step and remains unconnected in the bitstream, the presented attack can currently neither be prevented by conventional testing and verification methods nor by recent bitstream-level verification techniques.
AU - Ahmed, Qazi Arbab
AU - Wiersema, Tobias
AU - Platzner, Marco
ID - 20681
T2 - 2021 Design, Automation & Test in Europe Conference & Exhibition (DATE)
TI - Malicious Routing: Circumventing Bitstream-level Verification for FPGAs
ER -
TY - JOUR
AB - Aluminium steel clad materials have high potential for industrial applications. Their mechanical properties are governed by an intermetallic layer, which forms upon heat treatment at the Al-Fe interface. Transmission electron microscopy was employed to identify the phases present at the interface by selective area electron diffraction and energy dispersive spectroscopy. Three phases were identified: orthorhombic Al5Fe2, monoclinic Al13Fe4 and cubic Al19Fe4MnSi2. An effective interdiffusion coefficient dependent on concentration was determined according to the Boltzmann–Matano method. The highest value of the interdiffusion coefficient was reached at the composition of the intermetallic phases. Afterwards, the process of diffusion considering the evaluated interdiffusion coefficient was simulated using the finite element method. Results of the simulations revealed that growth of the intermetallic phases proceeds preferentially in the direction of aluminium.
AU - Křivská, Barbora
AU - Šlapáková, Michaela
AU - Veselý, Jozef
AU - Kihoulou, Martin
AU - Fekete, Klaudia
AU - Minárik, Peter
AU - Králík, Rostislav
AU - Grydin, Olexandr
AU - Stolbchenko, Mykhailo
AU - Schaper, Mirko
ID - 29815
IS - 24
JF - Materials
KW - General Materials Science
SN - 1996-1944
TI - Intermetallic Phases Identification and Diffusion Simulation in Twin-Roll Cast Al-Fe Clad Sheet
VL - 14
ER -
TY - JOUR
AU - Engelkemeier, Katja
AU - Sun, Aijia
AU - Voswinkel, Dietrich
AU - Grydin, Olexandr
AU - Schaper, Mirko
AU - Bremser, Wolfgang
ID - 24566
JF - ChemElectroChem
SN - 2196-0216
TI - Zinc Anodizing: Structural Diversity of Anodic Zinc Oxide Controlled by the Type of Electrolyte
ER -
TY - JOUR
AU - Reitz, Alexander
AU - Grydin, Olexandr
AU - Schaper, Mirko
ID - 23803
JF - Materials Data for Smart Forming Technologies
TI - Characterization of phase transformations during graded thermo- mechanical treatment of steel 22MnB5 by means of optical methods
ER -
TY - JOUR
AU - Masendorf, Lukas
AU - Wächter, Michael
AU - Esderts, Alfons
AU - Otroshi, Mortaza
AU - Meschut, Gerson
ID - 21545
JF - Fatigue & Fracture of Engineering Materials & Structures
SN - 8756-758X
TI - Service life estimation of self‐piercing riveted joints by linear damage accumulation
ER -
TY - CONF
AU - Jensen, Solveig
AU - Gasteiger, Hedwig
AU - Bruns, Julia
ED - Inprasitha, Maitree
ED - Changsri, Narumon
ED - Boonsena, Nisakorn
ID - 36527
T2 - Proceedings of the 44th Conference of the International Group for the Psychology of Mathematics Education
TI - Place value and regrouping as seperate constructs of place value understanding
VL - 3
ER -
TY - CONF
AU - Jensen, Solveig
AU - Gasteiger, Hedwig
AU - Bruns, Julia
ID - 36536
T2 - Beiträge zum Mathematikunterricht 2021
TI - Stellenwertverständnis: Verständnis von Stellenwertprinzip und Bündelungsprinzip als separate Konstrukte
ER -
TY - CONF
AU - Mattei, Annalisa
AU - Eremin, Oxana
ID - 45326
T2 - Bericht zur Jahrestagung der Sektion Frauen- und Geschlechterforschung in der Erziehungswissenschaft in der Deutschen Gesellschaft für Erziehungswissenschaft
TI - Corona und Krise. Perspektiven erziehungswissenschaftlicher Frauen- und Geschlechterforschung
ER -
TY - CHAP
AU - Schemmer, Susanne Jutta
AU - Heisler, Dietmar
AU - Rink, Julia
ED - Weyland, Ulrike
ED - Ziegler, Birgit
ED - Driesel-Lange, Katja
ED - Kruse, Annika
ID - 45319
T2 - Entwicklungen und Perspektiven in der Berufsorientierung. Stand und Herausforderungen. Online: (06.12.2021)
TI - Entwicklungschance oder Warteschleife? Berufsorientierung und Berufswahl in der Berufsfachschule
ER -
TY - CONF
AU - Kenter, Tobias
AU - Shambhu, Adesh
AU - Faghih-Naini, Sara
AU - Aizinger, Vadym
ID - 46194
T2 - Proceedings of the Platform for Advanced Scientific Computing Conference
TI - Algorithm-hardware co-design of a discontinuous Galerkin shallow-water model for a dataflow architecture on FPGA
ER -
TY - BOOK
AB - Trotz massiver Förderungen für die Digitalisierung ist die Präsenzlehre noch immer der Standard an deutschen Hochschulen. Aufgrund des Physical Distancing im Zuge der Corona-Pandemie musste sie jedoch kurzfristig fast vollständig digitalisiert werden. Die Beiträge des Bandes bieten einen multiperspektivischen Zugang zu den damit verbundenen Herausforderungen und beleuchten, wie die verschiedenen Akteur*innen die Umstellung auf digitale Lehr- und Lernformate umgesetzt und erlebt haben. Durch die Zusammenführung der verschiedenen Sichtweisen können die Bedarfe und Wünsche der einzelnen Akteursgruppen zusammengebracht und bei der nachhaltigen Weiterentwicklung der Hochschullehre besser berücksichtigt werden.
ED - Neiske, Iris
ED - Osthushenrich, Judith
ED - Schaper, Niclas
ED - Trier, Ulrike
ED - Vöing, Nerea
ID - 46613
SN - 2749-7623
TI - Hochschule auf Abstand
ER -
TY - CONF
AB -
Predictive Maintenance as a desirable maintenance strategy in industrial applications relies on suitable condition monitoring solutions to reduce costs and risks of the monitored technical systems. In general, those solutions utilize model-based or data-driven methods to diagnose the current state or predict future states of monitored technical systems. However, both methods have their advantages and drawbacks. Combining both methods can improve uncertainty consideration and accuracy. Different combination approaches of those hybrid methods exist to exploit synergy effects. The choice of an appropriate approach depends on different requirements and the goal behind the selection of a hybrid approach.
In this work, the hybrid approach for estimating remaining useful lifetime takes potential uncertainties into account. Therefore, a data-driven estimation of new measurements is integrated within a model-based method. To consider uncertainties within the system, a differentiation between different system behavior is realized throughout diverse states of degradation.
The developed hybrid prediction approach bases on a particle filtering method combined with a machine learning method, to estimate the remaining useful lifetime of technical systems. Particle filtering as a Monte Carlo simulation technique is suitable to map and propagate uncertainties. Moreover, it is a state-of-the-art model-based method for predicting remaining useful lifetime of technical systems. To integrate uncertainties a multi-model particle filtering approach is employed. In general, resampling as a part of the particle filtering approach has the potential to lead to an accurate prediction. However, in the case where no future measurements are available, it may increase the uncertainty of the prediction. By estimating new measurements, those uncertainties are reduced within the data-driven part of the approach. Hence, both parts of the hybrid approach strive to account for and reduce uncertainties.
Rubber-metal-elements are employed as a use-case to evaluate the developed approach. Rubber-metal-elements, which are used to isolate vibrations in various systems, such as railways, trucks and wind turbines, show various uncertainties in their behavior and their degradation. Those uncertainties are caused by diverse inner and outer factors, such as manufacturing influences and operating conditions. By expert knowledge the influences are described, analyzed and if possible reduced. However, the remaining uncertainties are considered within the hybrid prediction method. Relative temperature is the selected measurand to describe the element’s degradation. In lifetime tests, it is measured as the difference between the element’s temperature and the ambient temperature. Thereby, the influence of the ambient temperature on the element’s temperature is taken into account. Those elements show three typical states of degradation that are identified within the temperature measurements. Depending on the particular state of degradation a new measurement is estimated within the hybrid approach to reduce potential uncertainties.
Finally, the performance of the developed hybrid method is compared to a model-based method for estimating the remaining useful lifetime of the same elements. Suitable performance indices are implemented to underline the differences between the results.
AU - Bender, Amelie
AU - Sextro, Walter
ED - Do, Phuc
ED - King, Steve
ED - Fink, Olga
ID - 22724
IS - 1
KW - Hybrid prediction method
KW - Multi-model particle filtering
KW - Uncertainty quantification
KW - RUL estimation
T2 - Proceedings of the European Conference of the PHM Society 2021
TI - Hybrid Prediction Method for Remaining Useful Lifetime Estimation Considering Uncertainties
VL - 6
ER -
TY - CONF
AB - Several methods, including order analysis, wavelet analysis and empirical mode decomposition have been proposed and successfully employed for the health state estimation of technical systems operating under varying conditions. However, where information such as the speed of rotating machinery, component specifications or other domain-specific information is unavailable, such methods are often infeasible. Thus, this paper investigates the application of classical time-domain features, features from the medical field and novel features from the highly comparative time-series analysis (HCTSA) package, for the health state estimation of rotating machinery operating under varying conditions. Furthermore, several feature selection methods are investigated to identify features as viable health indicators for the diagnostics and prognostics of technical systems. As a case study, the presented methods are evaluated on real-world and experimentally acquired vibration data of bearings operating under varying speed. The results show that the selected features can successfully be employed as health indicators for technical systems operating under varying conditions.
AU - Aimiyekagbon, Osarenren Kennedy
AU - Bender, Amelie
AU - Sextro, Walter
ID - 22507
KW - Wind turbine diagnostics
KW - bearing diagnostics
KW - non-stationary operating conditions
KW - varying operating conditions
KW - feature extraction
KW - feature selection
KW - fault detection
KW - failure detection
T2 - Proceedings of the Seventeenth International Conference on Condition Monitoring and Asset Management (CM 2021)
TI - On the applicability of time series features as health indicators for technical systems operating under varying conditions
ER -
TY - CONF
AB - In the industry 4.0 era, there is a growing need to transform unstructured data acquired by a multitude of sources into information and subsequently into knowledge to improve the quality of manufactured products, to boost production, for predictive maintenance, etc. Data-driven approaches, such as machine learning techniques, are typically employed to model the underlying relationship from data. However, an increase in model accuracy with state-of-the-art methods, such as deep convolutional neural networks, results in less interpretability and transparency. Due to the ease of implementation, interpretation and transparency to both domain experts and non-experts, a rule-based method is proposed in this paper, for prognostics and health management (PHM) and specifically for diagnostics. The proposed method utilizes the most relevant sensor signals acquired via feature extraction and selection techniques and expert knowledge. As a case study, the presented method is evaluated on data from a real-world quality control set-up provided by the European prognostics and health management society (PHME) at the conference’s 2021 data challenge. With the proposed method, our team took the third place, capable of successfully diagnosing different fault modes, irrespective of varying conditions.
AU - Aimiyekagbon, Osarenren Kennedy
AU - Muth, Lars
AU - Wohlleben, Meike Claudia
AU - Bender, Amelie
AU - Sextro, Walter
ED - Do, Phuc
ED - King, Steve
ED - Fink, Olga
ID - 27111
IS - 1
KW - PHME 2021
KW - Feature Selection Classification
KW - Feature Selection Clustering
KW - Interpretable Model
KW - Transparent Model
KW - Industry 4.0
KW - Real-World Diagnostics
KW - Quality Control
KW - Predictive Maintenance
T2 - Proceedings of the European Conference of the PHM Society 2021
TI - Rule-based Diagnostics of a Production Line
VL - 6
ER -
TY - JOUR
AU - Alhaddad, Samer
AU - Förstner, Jens
AU - Groth, Stefan
AU - Grünewald, Daniel
AU - Grynko, Yevgen
AU - Hannig, Frank
AU - Kenter, Tobias
AU - Pfreundt, Franz‐Josef
AU - Plessl, Christian
AU - Schotte, Merlind
AU - Steinke, Thomas
AU - Teich, Jürgen
AU - Weiser, Martin
AU - Wende, Florian
ID - 24788
JF - Concurrency and Computation: Practice and Experience
KW - tet_topic_hpc
SN - 1532-0626
TI - The HighPerMeshes framework for numerical algorithms on unstructured grids
ER -
TY - GEN
AU - Lammer, Christina
ID - 30961
TI - Andrea Karimé: Sterne im Kopf und ein unglaublicher Plan. Köln: Peter Hammer Verlag 2021
ER -
TY - JOUR
AB - AbstractQuantum well (QW) heterostructures have been extensively used for the realization of a wide range of optical and electronic devices. Exploiting their potential for further improvement and development requires a fundamental understanding of their electronic structure. So far, the most commonly used experimental techniques for this purpose have been all-optical spectroscopy methods that, however, are generally averaging in momentum space. Additional information can be gained by angle-resolved photoelectron spectroscopy (ARPES), which measures the electronic structure with momentum resolution. Here we report on the use of extremely low-energy ARPES (photon energy ~ 7 eV) to increase depth sensitivity and access buried QW states, located at 3 nm and 6 nm below the surface of cubic-GaN/AlN and GaAs/AlGaAs heterostructures, respectively. We find that the QW states in cubic-GaN/AlN can indeed be observed, but not their energy dispersion, because of the high surface roughness. The GaAs/AlGaAs QW states, on the other hand, are buried too deep to be detected by extremely low-energy ARPES. Since the sample surface is much flatter, the ARPES spectra of the GaAs/AlGaAs show distinct features in momentum space, which can be reconducted to the band structure of the topmost surface layer of the QW structure. Our results provide important information about the samples’ properties required to perform extremely low-energy ARPES experiments on electronic states buried in semiconductor heterostructures.
AU - Hajlaoui, Mahdi
AU - Ponzoni, Stefano
AU - Deppe, Michael
AU - Henksmeier, Tobias
AU - As, Donat Josef
AU - Reuter, Dirk
AU - Zentgraf, Thomas
AU - Springholz, Gunther
AU - Schneider, Claus Michael
AU - Cramm, Stefan
AU - Cinchetti, Mirko
ID - 25227
JF - Scientific Reports
SN - 2045-2322
TI - Extremely low-energy ARPES of quantum well states in cubic-GaN/AlN and GaAs/AlGaAs heterostructures
VL - 11
ER -
TY - CONF
AB - Unsupervised blind source separation methods do not require a training phase
and thus cannot suffer from a train-test mismatch, which is a common concern in
neural network based source separation. The unsupervised techniques can be
categorized in two classes, those building upon the sparsity of speech in the
Short-Time Fourier transform domain and those exploiting non-Gaussianity or
non-stationarity of the source signals. In this contribution, spatial mixture
models which fall in the first category and independent vector analysis (IVA)
as a representative of the second category are compared w.r.t. their separation
performance and the performance of a downstream speech recognizer on a
reverberant dataset of reasonable size. Furthermore, we introduce a serial
concatenation of the two, where the result of the mixture model serves as
initialization of IVA, which achieves significantly better WER performance than
each algorithm individually and even approaches the performance of a much more
complex neural network based technique.
AU - Boeddeker, Christoph
AU - Rautenberg, Frederik
AU - Haeb-Umbach, Reinhold
ID - 44843
T2 - ITG Conference on Speech Communication
TI - A Comparison and Combination of Unsupervised Blind Source Separation Techniques
ER -
TY - CONF
AU - Boeddeker, Christoph
AU - Zhang, Wangyou
AU - Nakatani, Tomohiro
AU - Kinoshita, Keisuke
AU - Ochiai, Tsubasa
AU - Delcroix, Marc
AU - Kamo, Naoyuki
AU - Qian, Yanmin
AU - Haeb-Umbach, Reinhold
ID - 28259
T2 - ICASSP 2021 - 2021 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
TI - Convolutive Transfer Function Invariant SDR Training Criteria for Multi-Channel Reverberant Speech Separation
ER -
TY - CONF
AU - Schmalenstroeer, Joerg
AU - Heitkaemper, Jens
AU - Ullmann, Joerg
AU - Haeb-Umbach, Reinhold
ID - 23998
T2 - 29th European Signal Processing Conference (EUSIPCO)
TI - Open Range Pitch Tracking for Carrier Frequency Difference Estimation from HF Transmitted Speech
ER -
TY - GEN
AU - Hartung, Olaf
ID - 48787
T2 - H-Soz-Kult
TI - Rezension von: Jörg van Norden, Thomas Must, Lars Deile, Peter Riedel, Susan Krause und Wanda Schürenberg (Hgg.): Geschichtsdidaktische Grundbegriffe. Ein Bilderbuch für Studium, Lehre und Beruf. Hannover 2020
ER -
TY - JOUR
AB - Due to the ad hoc nature of wireless acoustic sensor networks, the position of the sensor nodes is typically unknown. This contribution proposes a technique to estimate the position and orientation of the sensor nodes from the recorded speech signals. The method assumes that a node comprises a microphone array with synchronously sampled microphones rather than a single microphone, but does not require the sampling clocks of the nodes to be synchronized. From the observed audio signals, the distances between the acoustic sources and arrays, as well as the directions of arrival, are estimated. They serve as input to a non-linear least squares problem, from which both the sensor nodes’ positions and orientations, as well as the source positions, are alternatingly estimated in an iterative process. Given one set of unknowns, i.e., either the source positions or the sensor nodes’ geometry, the other set of unknowns can be computed in closed-form. The proposed approach is computationally efficient and the first one, which employs both distance and directional information for geometry calibration in a common cost function. Since both distance and direction of arrival measurements suffer from outliers, e.g., caused by strong reflections of the sound waves on the surfaces of the room, we introduce measures to deemphasize or remove unreliable measurements. Additionally, we discuss modifications of our previously proposed deep neural network-based acoustic distance estimator, to account not only for omnidirectional sources but also for directional sources. Simulation results show good positioning accuracy and compare very favorably with alternative approaches from the literature.
AU - Gburrek, Tobias
AU - Schmalenstroeer, Joerg
AU - Haeb-Umbach, Reinhold
ID - 22528
JF - EURASIP Journal on Audio, Speech, and Music Processing
SN - 1687-4722
TI - Geometry calibration in wireless acoustic sensor networks utilizing DoA and distance information
ER -
TY - CONF
AU - Gburrek, Tobias
AU - Schmalenstroeer, Joerg
AU - Haeb-Umbach, Reinhold
ID - 23994
T2 - ICASSP 2021 - 2021 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
TI - Iterative Geometry Calibration from Distance Estimates for Wireless Acoustic Sensor Networks
ER -
TY - CONF
AU - Gburrek, Tobias
AU - Schmalenstroeer, Joerg
AU - Haeb-Umbach, Reinhold
ID - 23999
T2 - Speech Communication; 14th ITG-Symposium
TI - On Source-Microphone Distance Estimation Using Convolutional Recurrent Neural Networks
ER -
TY - CONF
AU - Chinaev, Aleksej
AU - Enzner, Gerald
AU - Gburrek, Tobias
AU - Schmalenstroeer, Joerg
ID - 23997
T2 - 29th European Signal Processing Conference (EUSIPCO)
TI - Online Estimation of Sampling Rate Offsets in Wireless Acoustic Sensor Networks with Packet Loss
ER -
TY - GEN
AU - Moritz, Tilman
ID - 49017
IS - 10
T2 - sehepunkte
TI - A. Seidler, I. Monok (Hgg.): Reformation und Bücher. Zentren der Ideen – Zentren der Buchproduktion. Wiesbaden 2020
VL - 21
ER -
TY - CONF
AB - In this work we address disentanglement of style and content in speech signals. We propose a fully convolutional variational autoencoder employing two encoders: a content encoder and a style encoder. To foster disentanglement, we propose adversarial contrastive predictive coding. This new disentanglement method does neither need parallel data nor any supervision. We show that the proposed technique is capable of separating speaker and content traits into the two different representations and show competitive speaker-content disentanglement performance compared to other unsupervised approaches. We further demonstrate an increased robustness of the content representation against a train-test mismatch compared to spectral features, when used for phone recognition.
AU - Ebbers, Janek
AU - Kuhlmann, Michael
AU - Cord-Landwehr, Tobias
AU - Haeb-Umbach, Reinhold
ID - 29304
T2 - Proceedings of the IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
TI - Contrastive Predictive Coding Supported Factorized Variational Autoencoder for Unsupervised Learning of Disentangled Speech Representations
ER -