TY - GEN
AU - N., N.
ID - 45239
TI - Lightweight Process Engine for Situation-specific Development of Business Models for Digital Platforms
ER -
TY - GEN
AU - N., N.
ID - 45240
TI - Development and Evaluation of a Multi Platform Approach for Augmented Reality Product Configuration
ER -
TY - GEN
AU - N., N.
ID - 45238
TI - Model-based Feature Backlog Synchronization for Dual-Track Development Methods
ER -
TY - JOUR
AB - Heat-assisted forming processes are becoming increasingly important in the manufacturing of sheet metal parts for body-in-white applications. However, the non-isothermal nature of these processes leads to challenges in evaluating the forming limits, since established methods such as Forming Limit Curves (FLCs) only allow the assessment of critical forming strains for steady temperatures. For this reason, a temperature-dependent extension of the well-established GISSMO (Generalized Incremental Stress State Dependent Damage Model) fracture indicator framework is developed by the authors to predict forming failures under non-isothermal conditions. In this paper, a general approach to combine several isothermal FLCs within the temperature-extended GISSMO model into a temperature-dependent forming limit surface is investigated. The general capabilities of the model are tested in a coupled thermo-mechanical FEA using the example of warm forming of an AA5182-O sheet metal cross-die cup. The obtained results are then compared with state of the art of evaluation methods. By taking the strain and temperature path into account, GISSMO predicts greater drawing depths by up to 20% than established methods. In this way the forming and so the lightweight potential of sheet metal parts can by fully exploited. Moreover, the risk and locus of failure can be evaluated directly on the part geometry by a contour plot. An additional advantage of the GISSMO model is the applicability for low triaxialities as well as the possibility to predict the materials behavior beyond necking up to ductile fracture.
AU - Camberg, Alan Adam
AU - Erhart, Tobias
AU - Tröster, Thomas
ID - 24009
JF - Materials
SN - 1996-1944
TI - A Generalized Stress State and Temperature Dependent Damage Indicator Framework for Ductile Failure Prediction in Heat-Assisted Forming Operations
ER -
TY - GEN
AU - Anonymous, Anonymous
ID - 45254
TI - Device-Independent Security Proofs Via Entropy Accumulation
ER -
TY - CHAP
AU - Saad, Nadia
ID - 42253
T2 - Methoden der Darstellung und Analyse interreligiöser Diskurse
TI - David und Salomo im Koran: ein Komparativ-theologischer Ansatz
VL - 1
ER -
TY - JOUR
AU - Mir Sadri, Seyedeh Saeideh
AU - Nasiri, Mansour
ID - 42256
IS - 2
JF - Philosophy East and West
TI - Reading Iqbal in the Light of Kierkegaard; towards an Existentialist Approach to Islam
VL - 71
ER -
TY - JOUR
AU - Mir Sadri, Seyedeh Saeideh
ID - 42257
IS - 1
JF - Amos-international
TI - Fratelli e sorelle tutti. Die Sozialenzyklika aus islamischer Sicht
VL - 15
ER -
TY - CHAP
AU - Eikermann, Larissa
ED - Ströter-Bender, Jutta
ID - 45275
SN - 9783828876668
T2 - Das Erbe der Kinder: Provenienzforschung und Sammlungsgeschichte von Kinder- und Jugendzeichnungen: Museen, Archive, private Kollektionen und "verschwundene Sammlungen" = The children's heritage: provenance research and the history of children's and youth drawings collections: museums, archives, private holdings and "lost collections"
TI - "Ein altes Familientalent" - Kinderzeichnungen aus der Familie der Brüder Grimm (1. Hälfte 19. Jh.) in der Grimm-Sammlung der Stadt Kassel. Germany
VL - Bd. 30
ER -
TY - CHAP
AU - Eikermann, Larissa
ED - Ströter-Bender, Jutta
ID - 45276
SN - 9783828876668
T2 - Das Erbe der Kinder: Provenienzforschung und Sammlungsgeschichte von Kinder- und Jugendzeichnungen: Museen, Archive, private Kollektionen und "verschwundene Sammlungen" = The children's heritage: provenance research and the history of children's and youth drawings collections: museums, archives, private holdings and "lost collections"
TI - Children´s drawings on Pippi & Co. - A visit to the Astrid Lindgren Archive in the Royal Library of Stockholm. Sweden
VL - Bd. 30
ER -
TY - CHAP
AU - Kamcili-Yildiz, Naciye
ED - Espelage, Christian
ED - Mohagheghi, Hamideh
ED - Schober, Michael
ID - 42096
T2 - Interreligiöse Öffnung durch Begegnung. Grundlagen - Erfahrungen - Perspektiven im Kontext des christlich-islamischen Dialogs
TI - Begegnungslernen in den Kerncurricula des islamischen Religionsunterrichts
VL - 43
ER -
TY - BOOK
AU - Kamcili-Yildiz, Naciye
ID - 42058
SN - 973-3830942958
TI - Zwischen Glaubensvermittlung und Reflexivität: Eine quantitative Studie zu professionellen Kompetenzen von islamischen ReligionslehrerInnen
VL - 682
ER -
TY - JOUR
AU - Mustafa, Abdul Rahman
ID - 42265
IS - 8
JF - Political Theology
TI - Supernatural, Unnatural, Queer: Gratitude and Nature in Islamic Political Theology
VL - 22
ER -
TY - JOUR
AU - Aghaei Abrandabadi, Seyed Ali
AU - Marx, Michel
ID - 42224
IS - 1
JF - Journal of Iranian National Museum
TI - Carbon Dating of Seven Parchment Qurʾān Manuscripts and One Syriac Bible of the National Museum of Iran
VL - 2
ER -
TY - JOUR
AU - Ghaffar, Zishan
ID - 42341
IS - 2
JF - Der Islam
TI - Kontrafaktische Intertextualität im Koran und die exegetische Tradition des syrischen Christentums
VL - 98
ER -
TY - CHAP
AU - Tatari, Muna
ED - Khalfaoui, Mouez
ED - Ehret, Jean
ID - 37120
SN - 9783451391439
T2 - Islamische Theologie in Deutschland. Ein Modell für Europa und die Welt
TI - Islamische systematische Theologie in Deutschland: Konturen eines jungen Faches
ER -
TY - BOOK
AU - Tatari, Muna
AU - von Stosch, Klaus
ID - 37035
SN - 3451389649
TI - Prophetin - Jungfrau - Mutter: Maria im Koran
ER -
TY - GEN
AU - Nassery, Idris
ID - 42479
T2 - Frankfurter Allgemeine Zeitung
TI - Die unerwünschte Empfehlung, Hybris: Woran der Westen in Afghanistan tatsächlich gescheitert ist
ER -
TY - JOUR
AU - Kulgemeyer, Christoph
AU - Kempin, Maren
AU - Weißbach, Anna
AU - Borowski, Andreas
AU - Buschhüter, David
AU - Enkrott, Patrick
AU - Reinhold, Peter
AU - Riese, Josef
AU - Schecker, Horst
AU - Schröder, Jan
AU - Vogelsang, Christoph
ID - 45177
IS - 18
JF - International Journal of Science Education
KW - Education
SN - 0950-0693
TI - Exploring the impact of pre-service science teachers’ reflection skills on the development of professional knowledge during a field experience
VL - 43
ER -
TY - CONF
AU - Große-Heilmann, Rike Isabel
AU - Burde, Jan-Philipp
AU - Riese, Josef
AU - Schubatzky, Thomas
AU - Weiler, David
ID - 45407
T2 - PhyDid B-Didaktik der Physik-Beiträge zur DPG-Frühjahrstagung 2021
TI - Erwerb und Messung physikdidaktischer Kompetenzen zum Einsatz digitaler Medien
ER -
TY - CONF
AU - Weiler, David
AU - Burde, Jan-Philipp
AU - Große-Heilmann, Rike Isabel
AU - Lachner, Andreas
AU - Riese, Josef
AU - Schubatzky, Thomas
ID - 45408
T2 - PhyDid B-Didaktik der Physik-Beiträge zur DPG-Frühjahrstagung 2021
TI - Entwicklung eines Seminars zur Förderung des Konzeptverständnisses mittels digitaler Medien
ER -
TY - CHAP
AU - Haghani Fazl, Mohammad
ED - Grössl, Johannes
ED - von Stosch, Klaus
ID - 45436
T2 - Impeccability and Temptation: Understanding Christ's Divine and Human Will
TI - The Scope of ‘iṣma and Qur’anic Evidence
ER -
TY - JOUR
AU - Hein, Maxwell
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 41511
IS - 7
JF - Materialwissenschaft und Werkstofftechnik
KW - Mechanical Engineering
KW - Mechanics of Materials
KW - Condensed Matter Physics
KW - General Materials Science
SN - 0933-5137
TI - Additively processed TiAl6Nb7 alloy for biomedical applications
VL - 52
ER -
TY - JOUR
AB -
Purpose
The currently existing restrictions regarding the deployment of additively manufactured components because of poor surface roughness, porosity and residual stresses as well as their influence on the low-cycle fatigue (LCF) strength are addressed in this paper.
Design/methodology/approach
This study aims to evaluating the effect of different pre- and post-treatments on the LCF strength of additively manufactured 316L parts. Therefore, 316L specimens manufactured by laser powder bed fusion were examined in their as-built state as well as after grinding, or coating with regard to the surface roughness, residual stresses and LCF strength. To differentiate between topographical effects and residual stress-related phenomena, stress-relieved 316L specimens served as a reference throughout the investigations. To enable an alumina coating of the 316L components, atmospheric plasma spraying was used, and the near-surface residual stresses and the surface roughness are measured and investigated.
Findings
The results have shown that the applied pre- and post-treatments such as stress-relief heat treatment, grinding and alumina coating have each led to an increase in LCF strength of the 316L specimens. In contrast, the non-heat-treated specimens predominantly exhibited coating delamination.
Originality/value
To the best of the authors’ knowledge, this is the first study of the correlation between the LCF behavior of additively manufactured uncoated 316L specimens in comparison with additively manufactured 316L specimens with an alumina coating.
AU - Garthe, Kai-Uwe
AU - Hoyer, Kay-Peter
AU - Hagen, Leif
AU - Tillmann, Wolfgang
AU - Schaper, Mirko
ID - 41507
IS - 5
JF - Rapid Prototyping Journal
KW - Industrial and Manufacturing Engineering
KW - Mechanical Engineering
SN - 1355-2546
TI - Correlation between pre- and post-treatments of additively manufactured 316L parts and the resulting low cycle fatigue behavior
VL - 28
ER -
TY - JOUR
AB - Processing aluminum alloys employing powder bed fusion of metals (PBF-LB/M) is becoming more attractive for the industry, especially if lightweight applications are needed. Unfortunately, high-strength aluminum alloys such as AA7075 are prone to hot cracking during PBF-LB/M, as well as welding. Both a large solidification range promoted by the alloying elements zinc and copper and a high thermal gradient accompanied with the manufacturing process conditions lead to or favor hot cracking. In the present study, a simple method for modifying the powder surface with titanium carbide nanoparticles (NPs) as a nucleating agent is aimed. The effect on the microstructure with different amounts of the nucleating agent is shown. For the aluminum alloy 7075 with 2.5 ma% titanium carbide nanoparticles, manufactured via PBF-LB/M, crack-free samples with a refined microstructure having no discernible melt pool boundaries and columnar grains are observed. After using a two-step ageing heat treatment, ultimate tensile strengths up to 465 MPa and an 8.9% elongation at break are achieved. Furthermore, it is demonstrated that not all nanoparticles used remain in the melt pool during PBF-LB/M.
AU - Heiland, Steffen
AU - Milkereit, Benjamin
AU - Hoyer, Kay-Peter
AU - Zhuravlev, Evgeny
AU - Kessler, Olaf
AU - Schaper, Mirko
ID - 41506
IS - 23
JF - Materials
KW - General Materials Science
SN - 1996-1944
TI - Requirements for Processing High-Strength AlZnMgCu Alloys with PBF-LB/M to Achieve Crack-Free and Dense Parts
VL - 14
ER -
TY - JOUR
AB - Implants often overtake body function just for a certain time and remain as an unnecessary foreign body or have to be removed. Thus, resorbable implants are highly beneficial to reduce patient burden. Besides established materials, Iron-(Fe)-based alloys are in focus due to superior mechanical properties and good biocompatibility. However, their degradation rate needs to be increased. Phases with high electrochemical potential could promote the dissolution of residual material based on the galvanic coupling. Silver (Ag) is promising due to its high electrochemical potential (+0.8 V vs. SHE), immiscibility with Fe, biocompatibility, and anti-bacterial properties. But to prevent adverse consequences the Ag-particles, remaining after dissolution of the matrix, need to dissolve. Thus, a bioresorbable Ag-alloy is required. Regarding the electrochemical potential and degradation behavior of binary alloys, Cerium (Ce) and Lanthanum (La) are well-suited considering their biocompatibility and antibacterial behavior. Accordingly, this research addresses AgCe and AgCeLa alloys as additives for Fe-based materials with adapted degradation behavior. Furthermore, degradable Ag-alloys combined with inert implant materials could enable the controlled release of antibacterial active Ag-ions.
AU - Krüger, Jan Tobias
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 24790
JF - Materials Letters
SN - 0167-577X
TI - Bioresorbable AgCe and AgCeLa alloys for adapted Fe-based implants
VL - 306
ER -
TY - JOUR
AU - Tillmann, Wolfgang
AU - Lopes Dias, Nelson Filipe
AU - Franke, Carlo
AU - Kokalj, David
AU - Stangier, Dominic
AU - Filor, Viviane
AU - Mateus-Vargas, Rafael Hernán
AU - Oltmanns, Hilke
AU - Kietzmann, Manfred
AU - Meißner, Jessica
AU - Hein, Maxwell
AU - Pramanik, Sudipta
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
AU - Nienhaus, Alexander
AU - Thomann, Carl Arne
AU - Debus, Jörg
ID - 41516
JF - Surface and Coatings Technology
KW - Materials Chemistry
KW - Surfaces
KW - Coatings and Films
KW - Surfaces and Interfaces
KW - Condensed Matter Physics
KW - General Chemistry
SN - 0257-8972
TI - Tribo-mechanical properties and biocompatibility of Ag-containing amorphous carbon films deposited onto Ti6Al4V
VL - 421
ER -
TY - JOUR
AU - Andreiev, Anatolii
AU - Hoyer, Kay-Peter
AU - Dula, Dimitri
AU - Hengsbach, Florian
AU - Grydin, Olexandr
AU - Frolov, Yaroslav
AU - Schaper, Mirko
ID - 41512
JF - Materials Science and Engineering: A
KW - Mechanical Engineering
KW - Mechanics of Materials
KW - Condensed Matter Physics
KW - General Materials Science
SN - 0921-5093
TI - Laser beam melting of functionally graded materials with application-adapted tailoring of magnetic and mechanical performance
VL - 822
ER -
TY - JOUR
AU - Pramanik, Sudipta
AU - Andreiev, Anatolii
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 41510
JF - International Journal of Fatigue
KW - Industrial and Manufacturing Engineering
KW - Mechanical Engineering
KW - Mechanics of Materials
KW - General Materials Science
KW - Modeling and Simulation
SN - 0142-1123
TI - Quasi in-situ analysis of fracture path during cyclic loading of double-edged U notched additively manufactured FeCo alloy
VL - 153
ER -
TY - JOUR
AU - Krüger, Jan Tobias
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 41509
JF - Materials Letters
KW - Mechanical Engineering
KW - Mechanics of Materials
KW - Condensed Matter Physics
KW - General Materials Science
SN - 0167-577X
TI - Bioresorbable AgCe and AgCeLa alloys for adapted Fe-based implants
VL - 306
ER -
TY - JOUR
AU - Andreiev, Anatolii
AU - Hoyer, Kay-Peter
AU - Dula, Dimitri
AU - Hengsbach, Florian
AU - Haase, Michael
AU - Gierse, Jan
AU - Zimmer, Detmar
AU - Tröster, Thomas
AU - Schaper, Mirko
ID - 23898
JF - Journal of Materials Processing Technology
SN - 0924-0136
TI - Soft-magnetic behavior of laser beam melted FeSi3 alloy with graded cross-section
ER -
TY - JOUR
AB - AbstractWithin this research, the multiscale microstructural evolution before and after the tensile test of a FeCo alloy is addressed. X-ray µ-computer tomography (CT), electron backscattered diffraction (EBSD), and transmission electron microscopy (TEM) are employed to determine the microstructure on different length scales. Microstructural evolution is studied by performing EBSD of the same area before and after the tensile test. As a result, $$\langle$$
⟨
001$$\rangle$$
⟩
||TD, $$\langle$$
⟨
011$$\rangle$$
⟩
||TD are hard orientations and $$\langle$$
⟨
111$$\rangle$$
⟩
||TD is soft orientations for deformation accommodation. It is not possible to predict the deformation of a single grain with the Taylor model. However, the Taylor model accurately predicts the orientation of all grains after deformation. {123}$$\langle$$
⟨
111$$\rangle$$
⟩
is the most active slip system, and {112}$$\langle$$
⟨
111$$\rangle$$
⟩
is the least active slip system. Both EBSD micrographs show grain subdivision after tensile testing. TEM images show the formation of dislocation cells. Correlative HRTEM images show unresolved lattice fringes at dislocation cell boundaries, whereas resolved lattice fringes are observed at dislocation cell interior. Since Schmid’s law is unable to predict the deformation behavior of grains, the boundary slip transmission accurately predicts the grain deformation behavior.
AU - Pramanik, Sudipta
AU - Tasche, Lennart
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 41517
IS - 11
JF - Journal of Materials Engineering and Performance
KW - Mechanical Engineering
KW - Mechanics of Materials
KW - General Materials Science
SN - 1059-9495
TI - Correlation between Taylor Model Prediction and Transmission Electron Microscopy-Based Microstructural Investigations of Quasi-In Situ Tensile Deformation of Additively Manufactured FeCo Alloy
VL - 30
ER -
TY - JOUR
AB - The addition of Ag to amorphous carbon (a-C) films is highly effective in tailoring the tribo-mechanical properties and biocompatibility. For biomedical applications, Ag-containing a-C (a-C:Ag) represents a promising film material for improving the biofunctional surface properties of Ti-based alloys. In a sputtering process, a-C:Ag films, with Ag contents up to 7.5 at.%, were deposited with a chemically graded TixCy interlayer onto Ti6Al4V. The tribo-mechanical and biocompatible properties of a-C:Ag were evaluated. The influence of the Ag content on these properties was analyzed and compared to those of uncoated Ti6Al4V.
Raman spectroscopy reveals that the amount of incorporated Ag does not induce significant structural changes in the disordered network, only a reduced number of vacancies and sp3-coordinated C bonds within the sp2-dominant a-C network is assigned to the films with high Ag concentration. With increasing Ag content, stresses, hardness, and elastic modulus decrease from (2.02 ± 0.07) to (1.15 ± 0.03) GPa, from (17.4 ± 1.5) to (13.4 ± 0.9) GPa, and from (171.8 ± 8.1) to (138.5 ± 5.8) GPa, respectively. In tribometer tests, the friction behavior against Al2O3 in lubricated condition with a simulated-body-fluid-based lubricant is not affected by the Ag concentration, but the Al2O3 counterpart wear is reduced for all a-C:Ag films compared to a-C. The friction against ultra-high-molecular-weight polyethylene (UHMWPE) decreases continuously with increasing Ag concentration and the counterpart wear is lower at higher Ag contents. Compared to a-C:Ag, Ti6Al4V demonstrates lower friction against UHMWPE and higher friction against Al2O3. The a-C:Ag films are not exposed to abrasion by Al2O3 or pronounced material transfer of UHMWPE. The hardness difference and chemical affinity between the friction partners are decisive for the tribological behavior of a-C:Ag. Compared to Ti6Al4V, the a-C:Ag films show antibacterial activity against Staphylococcus aureus, while the proliferation of osteoblast-like cells is reduced by Ag.
AU - Tillmann, Wolfgang
AU - Lopes Dias, Nelson Filipe
AU - Franke, Carlo
AU - Kokalj, David
AU - Stangier, Dominic
AU - Filor, Viviane
AU - Mateus-Vargas, Rafael Hernán
AU - Oltmanns, Hilke
AU - Kietzmann, Manfred
AU - Meißner, Jessica
AU - Hein, Maxwell
AU - Pramanik, Sudipta
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
AU - Nienhaus, Alexander
AU - Thomann, Carl Arne
AU - Debus, Jörg
ID - 24243
JF - Surface and Coatings Technology
SN - 0257-8972
TI - Tribo-mechanical properties and biocompatibility of Ag-containing amorphous carbon films deposited onto Ti6Al4V
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
AB - Laser beam melting (LBM) is an advanced manufacturing technology providing
special features and the possibility to produce complex and individual parts directly
from a CAD model. TiAl6V4 is the most common used titanium alloy particularly
in biomedical applications. TiAl6Nb7 shows promising improvements especially
regarding biocompatible properties due to the substitution of the hazardous
vanadium. This work focuses on the examination of laser beam melted TiAl6Nb7.
For microstructural investigation scanning electron microscopy including energydispersive
x-ray spectroscopy as well as electron backscatter diffraction are utilized.
The laser beam melted related acicular microstructure as well as the corresponding
mechanical properties, which are determined by hardness measurements
and tensile tests, are investigated. The laser beam melted alloy meets,
except of breaking elongation A, the mechanical demands like ultimate tensile
strength Rm, yield strength Rp0.2, Vickers hardness HV of international standard
ISO 5832-11. Next steps contain comparison between TiAl6Nb7 and TiAl6V4 in
different conditions. Further investigations aim at improving mechanical properties
of TiAl6Nb7 by heat treatments and assessment of their influence on the microstructure
as well as examination regarding the corrosive behavior in human bodylike
conditions.
AU - Hein, Maxwell
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 24086
JF - Materialwissenschaft und Werkstofftechnik
KW - Laser beam melting
KW - titanium alloy
KW - TiAl6Nb7
KW - biomedical engineering
KW - implants
SN - 0933-5137
TI - Additively processed TiAl6Nb7 alloy for biomedical applications
VL - 52
ER -
TY - JOUR
AU - Cieslar, Miroslav
AU - Králík, Rostislav
AU - Bajtošová, Lucia
AU - Křivská, Barbora
AU - Hájek, Michal
AU - Belejová, Sára
AU - Grydin, Olexandr
AU - Stolbchenko, Mykhailo
AU - Schaper, Mirko
ID - 29813
IS - S2
JF - Microscopy and Microanalysis
KW - Instrumentation
SN - 1431-9276
TI - High Temperature Annealing of Twin-Roll Cast Al-Li-Based Alloy Studied by In-situ SEM and STEM
VL - 27
ER -
TY - JOUR
AU - Krüger, Jan Tobias
AU - Hoyer, Kay-Peter
AU - Filor, Viviane
AU - Pramanik, Sudipta
AU - Kietzmann, Manfred
AU - Meißner, Jessica
AU - Schaper, Mirko
ID - 41514
JF - Journal of Alloys and Compounds
KW - Materials Chemistry
KW - Metals and Alloys
KW - Mechanical Engineering
KW - Mechanics of Materials
SN - 0925-8388
TI - Novel AgCa and AgCaLa alloys for Fe-based bioresorbable implants with adapted degradation
VL - 871
ER -
TY - JOUR
AU - Křivská, Barbora
AU - Šlapáková, Michaela
AU - Minárik, Peter
AU - Fekete, Klaudia
AU - Králík, Rostislav
AU - Stolbchenko, Mykhailo
AU - Schaper, Mirko
AU - Grydin, Olexandr
ID - 29814
IS - S2
JF - Microscopy and Microanalysis
KW - Instrumentation
SN - 1431-9276
TI - Intermetallic Phase Growth in Al-steel Clad Strip during In-situ Heating in TEM
VL - 27
ER -
TY - JOUR
AU - Pramanik, Sudipta
AU - Tasche, Lennart
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 41515
JF - Additive Manufacturing
KW - Industrial and Manufacturing Engineering
KW - Engineering (miscellaneous)
KW - General Materials Science
KW - Biomedical Engineering
SN - 2214-8604
TI - Investigating the microstructure of an additively manufactured FeCo alloy: an electron microscopy study
VL - 46
ER -
TY - JOUR
AU - Camberg, Alan Adam
AU - Andreiev, Anatolii
AU - Pramanik, Sudipta
AU - Hoyer, Kay-Peter
AU - Tröster, Thomas
AU - Schaper, Mirko
ID - 27700
JF - Materials Science and Engineering: A
SN - 0921-5093
TI - Strength enhancement of AlMg sheet metal parts by rapid heating and subsequent cold die stamping of severely cold-rolled blanks
ER -
TY - JOUR
AB - AbstractWithin this research, the multiscale microstructural evolution before and after the tensile test of a FeCo alloy is addressed. X-ray µ-computer tomography (CT), electron backscattered diffraction (EBSD), and transmission electron microscopy (TEM) are employed to determine the microstructure on different length scales. Microstructural evolution is studied by performing EBSD of the same area before and after the tensile test. As a result, $$\langle$$
⟨
001$$\rangle$$
⟩
||TD, $$\langle$$
⟨
011$$\rangle$$
⟩
||TD are hard orientations and $$\langle$$
⟨
111$$\rangle$$
⟩
||TD is soft orientations for deformation accommodation. It is not possible to predict the deformation of a single grain with the Taylor model. However, the Taylor model accurately predicts the orientation of all grains after deformation. {123}$$\langle$$
⟨
111$$\rangle$$
⟩
is the most active slip system, and {112}$$\langle$$
⟨
111$$\rangle$$
⟩
is the least active slip system. Both EBSD micrographs show grain subdivision after tensile testing. TEM images show the formation of dislocation cells. Correlative HRTEM images show unresolved lattice fringes at dislocation cell boundaries, whereas resolved lattice fringes are observed at dislocation cell interior. Since Schmid’s law is unable to predict the deformation behavior of grains, the boundary slip transmission accurately predicts the grain deformation behavior.
AU - Pramanik, Sudipta
AU - Tasche, Lennart
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 24090
JF - Journal of Materials Engineering and Performance
SN - 1059-9495
TI - Correlation between Taylor Model Prediction and Transmission Electron Microscopy-Based Microstructural Investigations of Quasi-In Situ Tensile Deformation of Additively Manufactured FeCo Alloy
ER -
TY - JOUR
AB -
Purpose
The currently existing restrictions regarding the deployment of additively manufactured components because of poor surface roughness, porosity and residual stresses as well as their influence on the low-cycle fatigue (LCF) strength are addressed in this paper.
Design/methodology/approach
This study aims to evaluating the effect of different pre- and post-treatments on the LCF strength of additively manufactured 316L parts. Therefore, 316L specimens manufactured by laser powder bed fusion were examined in their as-built state as well as after grinding, or coating with regard to the surface roughness, residual stresses and LCF strength. To differentiate between topographical effects and residual stress-related phenomena, stress-relieved 316L specimens served as a reference throughout the investigations. To enable an alumina coating of the 316L components, atmospheric plasma spraying was used, and the near-surface residual stresses and the surface roughness are measured and investigated.
Findings
The results have shown that the applied pre- and post-treatments such as stress-relief heat treatment, grinding and alumina coating have each led to an increase in LCF strength of the 316L specimens. In contrast, the non-heat-treated specimens predominantly exhibited coating delamination.
Originality/value
To the best of the authors’ knowledge, this is the first study of the correlation between the LCF behavior of additively manufactured uncoated 316L specimens in comparison with additively manufactured 316L specimens with an alumina coating.
AU - Garthe, Kai-Uwe
AU - Hoyer, Kay-Peter
AU - Hagen, Leif
AU - Tillmann, Wolfgang
AU - Schaper, Mirko
ID - 27509
JF - Rapid Prototyping Journal
SN - 1355-2546
TI - Correlation between pre- and post-treatments of additively manufactured 316L parts and the resulting low cycle fatigue behavior
ER -
TY - JOUR
AB - Resorbable implants are highly beneficial to reduce patient burden since they need not be removed after a defined period. Currently, magnesium (Mg) and polymers are being applied as bioresorbable materials. However, for some applications the insufficient mechanical properties and high degradation rate of Mg cause the need for new materials. Iron (Fe)-based alloys are promising due to their biocompatibility and good mechanical properties, but their degradation rate is too low and needs to be adapted eg. via alloying with manganese (Mn). Besides, phases with high electrochemical potential lead to increased degradation of residual material with lower potential based on the galvanic coupling. Here, silver (Ag) is promising for the formation of such phases due to its high electrochemical potential (+0.8 V vs. SHE), immiscibility with Fe, biocompatibility, and anti-bacterial properties. Since remaining silver particles can lead to adverse consequences as thrombosis, these particles need to dissolve after the matrix material. Thus a silver alloy with high electrochemical potential, biocompatibility, and adjusted degradation behavior is required as an additive for iron-based bioresorbable materials. Several silver alloying systems are possible, but regarding the electrochemical potential and degradation behavior of binary alloys, calcium (Ca) and lanthanum (La) are best-suited considering their biocompatibility. Accordingly, this research addresses AgCa and AgCaLa alloys as additives for iron-based degradable materials with adapted degradation behavior.
AU - Krüger, Jan Tobias
AU - Hoyer, Kay-Peter
AU - Filor, Viviane
AU - Pramanik, Sudipta
AU - Kietzmann, Manfred
AU - Meißner, Jessica
AU - Schaper, Mirko
ID - 24087
JF - Journal of Alloys and Compounds
SN - 0925-8388
TI - Novel AgCa and AgCaLa alloys for Fe-based bioresorbable implants with adapted degradation
ER -
TY - JOUR
AB - Implementing the concept of mixed construction in modern automotive engineering requires the joining of sheet metal or extruded profiles with cast components made from different materials. As weight reduction is desired, these cast components are usually made from high-strength aluminium alloys of the Al-Si (Mn, Mg) system, which have limited weldability. The mechanical joinability of the cast components depends on their ductility, which is influenced by the microstructure. High-strength cast aluminium alloys have relatively low ductility, which leads to cracking of the joints. This limits the range of applications for cast aluminium alloys. In this study, an aluminium alloy of the Al-Si system AlSi9 is used to investigate relationships between solidification conditions during the sand casting process, microstructure, mechanical properties, and joinability. The demonstrator is a stepped plate with a minimum thickness of 2.0 mm and a maximum thickness of 4.0 mm, whereas the thickness difference between neighbour steps amounts to 0.5 mm. During casting trials, the solidification rates for different plate steps were measured. The microscopic investigations reveal a correlation between solidification rates and microstructure parameters such as secondary dendrite arm spacing. Furthermore, mechanical properties and the mechanical joinability are investigated.
AU - Neuser, Moritz
AU - Grydin, Olexandr
AU - Andreiev, Anatolii
AU - Schaper, Mirko
ID - 23913
JF - Metals
SN - 2075-4701
TI - Effect of Solidification Rates at Sand Casting on the Mechanical Joinability of a Cast Aluminium Alloy
ER -
TY - JOUR
AB - AbstractLaser surface treatment of metals is one option to improve their properties for adhesive bonding. In this paper, a pulsed YVO4 Laser source with a wavelength of 1064 nm and a maximum power of 25 W was utilized to increase the surface area of the steel HCT490X in order to improve its bonding properties with a carbon fibre reinforced polymer (CFRP). Investigated was the influence of the scanning speed of the laser source on the bonding properties. For this purpose, the steel surfaces were ablated at a scanning speed between 1500 and 4500 mm/s. Afterwards the components were bonded with the adhesive HexBond™ 677. After lap shear tests were carried out on the specimen, the surfaces were inspected using scanning electron microscopy (SEM). The experiments revealed that the bonding quality can be improved with a high scanning speed, even when the surface is not completely ablated.
AU - Voswinkel, Dietrich
AU - Kloidt, D.
AU - Grydin, Olexandr
AU - Schaper, Mirko
ID - 24565
IS - 2
JF - Production Engineering
SN - 0944-6524
TI - Time efficient laser modification of steel surfaces for advanced bonding in hybrid materials
VL - 15
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 - Andreiev, Anatolii
AU - Hoyer, Kay-Peter
AU - Dula, Dimitri
AU - Hengsbach, Florian
AU - Grydin, Olexandr
AU - Frolov, Yaroslav
AU - Schaper, Mirko
ID - 23897
JF - Materials Science and Engineering: A
SN - 0921-5093
TI - Laser beam melting of functionally graded materials with application-adapted tailoring of magnetic and mechanical performance
ER -
TY - JOUR
AU - Pramanik, Sudipta
AU - Andreiev, Anatolii
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 23911
JF - International Journal of Fatigue
SN - 0142-1123
TI - Quasi in-situ analysis of fracture path during cyclic loading of double-edged U notched additively manufactured FeCo alloy
ER -
TY - JOUR
AU - Pramanik, Sudipta
AU - Tasche, Lennart
AU - Hoyer, Kay-Peter
AU - Schaper, Mirko
ID - 24088
JF - Additive Manufacturing
SN - 2214-8604
TI - Investigating the microstructure of an additively manufactured FeCo alloy: an electron microscopy study
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 - Wallmeier, Nadine
ID - 37239
JF - Kreis Höxter Jahrbuch
TI - Plattdeutsch im Kreis Höxter. "Der Dialektatlas Mittleres Westdeutschland (DMW)" und die Frage "Wie klingt Plattdeutsch im Kreis Höxter?"
ER -
TY - BOOK
AU - Tophinke, Doris
AU - Wallmeier, Nadine
AU - Merten, Marie-Luis
ID - 22515
TI - Das paderbörnische Platt. Niederdeutsch im Gebiet der Kreise Paderborn und Höxter
ER -
TY - CONF
AU - Mutschler, Tanja
AU - Buschhüter, David
AU - Schröder, Jan
AU - Riese, Josef
AU - Borowski, Andreas
ED - Habig, Sebastian
ID - 45449
T2 - Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020
TI - Theoriekonformität von Unterrichtsplanungen im Fach Physik vor und nach dem Praxissemester
VL - 41
ER -
TY - CONF
AU - Große-Heilmann, Rike Isabel
AU - Riese, Josef
ED - Habig, Sebastian
ID - 45461
T2 - Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020. Essen: Universität Duisburg-Essen
TI - Erwerb physikdidaktischen Wissens zum Einsatz digitaler Medien im Physikunterricht
VL - 41
ER -
TY - CONF
AU - Joswig-Käfer, Ann-Kathrin
AU - Riese, Josef
ED - Habig, Sebastian
ID - 45460
T2 - Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020. Essen: Universität Duisburg-Essen
TI - Längsschnitt Physikdidaktischen Wissens: Ursachen für Veränderungen
VL - 41
ER -
TY - CONF
AU - Ermel, Dorothee
AU - Riese, Josef
ED - Habig, Sebastian
ID - 45463
T2 - Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020. Essen: Universität Duisburg-Essen
TI - Praktische technische Kompetenzen im Techniklehramt
VL - 41
ER -
TY - CONF
AU - Albert, Gerrit
AU - Riese, Josef
ED - Habig, Sebastian
ID - 45462
T2 - Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020. Essen: Universität Duisburg-Essen
TI - Digitale Kompetenzen im Techniklehramt
VL - 41
ER -
TY - CONF
AU - Schröder, Jan
AU - Vogelsang, Christoph
AU - Riese, Josef
ID - 45450
T2 - Naturwissenschaftlicher Unterricht und Lehrerbildung im Umbruch? Gesellschaft für Didaktik der Chemie und Physik. Online Jahrestagung 2020
TI - Entwicklung der Fähigkeit zur Unterrichtsplanung im Fach Physik
VL - 41
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 - JOUR
AB - We consider a measure given as the continuum limit of a one-dimensional Ising model with long-range translationally invariant interactions. Mathematically, the measure can be described by a self-interacting Poisson driven jump process. We prove a correlation inequality, estimating the magnetic susceptibility of this model, which holds for small norm of the interaction function. The bound on the magnetic susceptibility has applications in quantum field theory and can be used to prove existence of ground states for the spin boson model.
AU - Hasler, David
AU - Hinrichs, Benjamin
AU - Siebert, Oliver
ID - 43493
JF - Stochastic Processes and their Applications
SN - 0304-4149
TI - Correlation bound for a one-dimensional continuous long-range Ising model
VL - 146
ER -
TY - CONF
AU - Schubert, Philipp
AU - Hermann, Ben
AU - Bodden, Eric
AU - Leer, Richard
ID - 26406
T2 - SCAM '21: IEEE International Working Conference on Source Code Analysis and Manipulation (Engineering Track)
TI - Into the Woods: Experiences from Building a Dataflow Analysis Framework for C/C++
ER -
TY - CONF
AU - Schubert, Philipp
AU - Sattler, Florian
AU - Schiebel, Fabian
AU - Hermann, Ben
AU - Bodden, Eric
ID - 26405
T2 - 2021 IEEE 21st International Working Conference on Source Code Analysis and Manipulation (SCAM)
TI - Modeling the Effects of Global Variables in Data-Flow Analysis for C/C++
ER -
TY - CONF
AB - We present a monolithically integrated electronic-photonic Mach-Zehnder modulator with a linear, segmented driver on the same silicon substrate. As metric for the modulation efficiency, the external V$\pi$ is hereby reduced to only 420 mV.
AU - Kress, Christian
AU - Singh, Karanveer
AU - Schwabe, Tobias
AU - Preußler, Stefan
AU - Schneider, Thomas
AU - Scheytt, J. Christoph
ID - 29203
KW - Analog to digital converters
KW - Extinction ratios
KW - Grating couplers
KW - Modulation
KW - Modulators
KW - Phase shift
T2 - OSA Advanced Photonics Congress 2021
TI - High Modulation Efficiency Segmented Mach-Zehnder Modulator Monolithically Integrated with Linear Driver in 0.25 \textmum BiCMOS Technology
ER -
TY - JOUR
AB - An analysis of an optical Nyquist pulse synthesizer using Mach-Zehnder modulators is presented. The analysis allows to predict the upper limit of the effective number of bits of this type of photonic digital-to-analog converter. The analytical solution has been verified by means of electro-optic simulations. With this analysis the limiting factor for certain scenarios: relative intensity noise, distortions by driving the Mach-Zehnder modulator, or the signal generator phase noise can quickly be identified.
AU - Kress, Christian
AU - Bahmanian, Meysam
AU - Schwabe, Tobias
AU - Scheytt, J. Christoph
ID - 29204
IS - 15
JF - Opt. Express
KW - Analog to digital converters
KW - Diode lasers
KW - Laser sources
KW - Phase noise
KW - Signal processing
KW - Wavelength division multiplexers
TI - Analysis of the effects of jitter, relative intensity noise, and nonlinearity on a photonic digital-to-analog converter based on optical Nyquist pulse synthesis
VL - 29
ER -
TY - THES
AU - Fanasch, Patrizia
ID - 45670
TI - Governance and Reputation in the Market for Experience Goods
ER -
TY - JOUR
AB - The role of domain-specific content knowledge is discussed controversially for the early childhood context. Therefore, this review aims at untangling the research on domain-specific content knowledge for early childhood educators by systematically reviewing the conceptual and operational definition of and results on early childhood educators' content knowledge in different domains. Using the scientific databases ERIC, PsycInfo and Web of Sciences, we identified 36 studies on early childhood educators' domain-specific content knowledge. By comparing these studies, we found that conceptualizations of early childhood educators' content knowledge move on a continuum between a scientific related perspective and a practice related perspective. The scientific related perspective defines content knowledge as the knowledge of key concepts, facts and rules of the domain integrating knowledge taught in primary, secondary or upper secondary school. The practice related perspective includes knowledge of key concepts, facts and rules of the domain limited to the knowledge explicitly relevant for teaching in early childhood education as well as selected domain-specific knowledge of children and teaching. Our review shows that the results and implications drawn by the study authors depend on how these authors conceptualize early childhood educators' content knowledge on this continuum. Further research, therefore, needs to consider carefully how early childhood educators' content knowledge is conceptualized. The paper further discusses gaps in this research field, such as validating methods for measuring early childhood educators' content knowledge or implementing more rigorous experimental designs to examine effects of early childhood educators' content knowledge.
AU - Bruns, Julia
AU - Gasteiger, Hedwig
AU - Strahl, Carolin
ID - 34822
IS - 2
JF - Review of Education
KW - content knowledge
KW - domain-specific learning
KW - early childhood education
KW - teacher knowledge
SN - 2049-6613
TI - Conceptualising and measuring domain-specific content knowledge of early childhood educators: A systematic review
VL - 9
ER -
TY - JOUR
AU - Bruns, Julia
AU - Schopferer, T.
ID - 45687
JF - . TPS – Theorie und Praxis der Sozialpädagogik
TI - Eine mustergültige Wissenschaft
VL - 11
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 - JOUR
AU - Bruns, Julia
AU - Gasteiger, Hedwig
AU - Strahl, Carolin
ID - 34823
IS - 2
JF - Review of Education
SN - 2049-6613
TI - Context and Implications Document for: Conceptualising and measuring domain-specific content knowledge of early childhood educators: A systematic review
VL - 9
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 - JOUR
AU - Schönherr, Johanna
AU - Blomberg, J.
AU - Schukajlow, S.
AU - Leopold, C.
ID - 45342
JF - Contemporary Educational Psychology
TI - Do emotions and prior performance facilitate the use of the learner-generated drawing strategy? Effects of enjoyment, anxiety, and intramathematical performance on the use of the drawing strategy and modelling performance
VL - 65
ER -
TY - JOUR
AU - Schönherr, Johanna
AU - Schukajlow, S.
AU - Blomberg, J.
AU - Leopold, C.
ID - 45333
JF - Mathematical Thinking and Learning
TI - Does strategic knowledge matter? Effects of strategic knowledge about drawing on students’ modeling competencies in the domain of geometry
ER -
TY - JOUR
AU - Schönherr, Johanna
AU - Schukajlow, S.
AU - Blomberg, J.
AU - Leopold, C.
ID - 45343
JF - Learning and Instruction
TI - The role of strategy-based motivation in mathematical problem solving: The case of learner-generated drawings
VL - 80
ER -
TY - JOUR
AU - Schönherr, Johanna
AU - Schukajlow, S.
AU - Blomberg, J.
ID - 45335
JF - mathematik lehren
TI - Was ist eine gute Skizze? Strategiewissen beim mathematischen Modellieren im Bereich der Geometrie fördern
VL - 224
ER -
TY - CHAP
AU - Herding, Jana
AU - Büker, P.
AU - Kamin, A.M.
AU - Glawe, K.
AU - Oevel, Gudrun
AU - Knurr, M.
AU - Menke, I.
AU - Ogrodowski, J.
AU - Schaper, F.
ED - Wollersheim, Hans Werner
ED - Pengel, Norbert
ID - 45352
T2 - Bildung in der digitalen Transformation
TI - inklud.nrw – eine fallbasierte Lehr-/Lernumgebung zum Erwerb inklusions- und digitalisierungsbezogener Kompetenzen in der Lehrer:innenbildung
ER -
TY - CHAP
AU - Herding, Jana
AU - Ogrodowski, J.
ED - Böhme, N.
ID - 45355
T2 - Mythen, Widersprüche und Gewissheiten der Grundschulforschung. Eine wissenschaftliche Bestandsaufnahme nach 100 Jahren Grundschule. Jahrbuch Grundschulforschung
TI - Mit Kindern den Übergang auf die weiterführende Schule reflektieren – Sichtweisen von Viertklässler*innen auf die selektiven Schulstrukturen
VL - 25
ER -
TY - JOUR
AU - Herding, Jana
AU - Höke, J.
AU - Büker, P.
AU - Ogrodowski, J.
ID - 45353
IS - 3
JF - Diskurs Kindheits- und Jugendforschung/Discourse. Journal of Childhood and Adolescence Research
TI - Paderborner Qualitätsstern (PQ³) zur Einschätzung der Kooperation im Übergang Kita – Grundschule: ein Selbstevaluationsinstrument für multiprofessionelle und institutionsübergreifende Zusammenarbeit
VL - 16
ER -
TY - CHAP
AU - Herding, Jana
AU - Büker, P.
AU - Höke, J.
AU - Ogrodowski, J.
ED - Dockett, Sue
ED - Perry, Bob
ID - 45354
T2 - Evaluation Transition to School Programms: Learning from Research and Practice
TI - Paderborner Qualitätsstern (PQ³): Self-evaluation of transition to school programms for educators and teachers
ER -
TY - GEN
AU - Herding, Jana
ID - 45358
TI - KrafT Bildungsdokumentation: Kind- und ressourcenorientierte, analysebasierte, fortschrittsorientierte Bildungsbegleitung im Team planen, dokumentieren und reflektieren. Herausgegeben von: Büker, Petra; Ogrodowski, Jana, und Antenbrink, Teresa
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 - GEN
AU - Mattei, Annalisa
ID - 45328
T2 - Jahrbuch Erziehungswissenschaftliche Geschlechterforschung 17, Opladen / Berlin / Toronto
TI - Rezension zu: Nef, Susanne: Ringen um Bedeutung. Die Deutung häuslicher Gewalt als sozialer Prozess, Basel 2020, in: Fegter, Susann / Langer, Antje / Thon, Christine (Hgg.): Diskursanalytische Geschlechterforschung in der Erziehungswissenschaft
ER -
TY - GEN
AU - Mattei, Annalisa
AU - Eremin, Oxana
ID - 45327
TI - Jahrestagung „Corona und Krise – Perspektiven erziehungswissenschaftlicher Frauen- und Geschlechterforschung“ Erziehungswissenschaft Heft 63, Jg. 32|2021
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 - JOUR
AU - Aghaei Abrandabadi, Seyed Ali
AU - Marx, Michael
ID - 45698
JF - Journal of Iranian National Museum, 2
TI - Carbon Dating of Seven Parchment Qurʾān Manuscripts and One Syriac Bible of the National Museum of Iran
ER -
TY - CHAP
AU - Saad, Nadia
ID - 45706
T2 - Erlanger Jahrbuch für Interreligiöse Diskurse. Methoden der Darstellung und Analyse interreligiöser Diskurse
TI - David und Salomon im Koran: ein Komparativ-theologischer Ansatz
ER -
TY - JOUR
AU - Zahera, H.M.A
AU - Jalota, Rricha
AU - Sherif, Mohamed Ahmed
AU - Ngomo, Axel-Cyrille Ngonga
ID - 30372
JF - IEEE Access
KW - General Engineering
KW - General Materials Science
KW - General Computer Science
SN - 2169-3536
TI - I-AID: Identifying Actionable Information From Disaster-Related Tweets
VL - 9
ER -
TY - CONF
AU - Zahera, H.M.A
AU - Heindorf, Stefan
AU - Ngomo, Axel-Cyrille Ngonga
ID - 30374
T2 - Proceedings of the 11th on Knowledge Capture Conference
TI - ASSET: A Semi-supervised Approach for Entity Typing in Knowledge Graphs
ER -
TY - THES
AU - Szopinski, Daniel
ID - 24884
TI - Essays on Modeling Languages and Software Tools for Business Model Innovation: Theory and Empirical Evidence
ER -
TY - CONF
AB - Argumentation is a widely applied framework for modeling and evaluating arguments and its reasoning with various applications. Popular frameworks are abstract argumentation (Dung’s framework) or logic-based argumentation (Besnard-Hunter’s framework). Their computational complexity has been studied quite in-depth. Incorporating treewidth into the complexity analysis is particularly interesting, as solvers oftentimes employ SAT-based solvers, which can solve instances of low treewidth fast. In this paper, we address whether one can design reductions from argumentation problems to SAT-problems while linearly preserving the treewidth, which results in decomposition-guided (DG) reductions. It turns out that the linear treewidth overhead caused by our DG reductions, cannot be significantly improved under reasonable assumptions. Finally, we consider logic-based argumentation and establish new upper bounds using DG reductions and lower bounds.
AU - Fichte, Johannes
AU - Hecher, Markus
AU - Mahmood, Yasir
AU - Meier, Arne
ID - 45840
T2 - Proceedings of the Thirtieth International Joint Conference on Artificial Intelligence
TI - Decomposition-Guided Reductions for Argumentation and Treewidth
ER -
TY - JOUR
AB - AbstractDependence Logic was introduced by Jouko Väänänen in 2007. We study a propositional variant of this logic(PDL)and investigate a variety of parameterisations with respect to central decision problems. The model checking problem (MC) ofPDLisNP-complete (Ebbing and Lohmann, SOFSEM 2012). The subject of this research is to identify a list of parameterisations (formula-size, formula-depth, treewidth, team-size, number of variables) under which MC becomes fixed-parameter tractable. Furthermore, we show that the number of disjunctions or the arity of dependence atoms (dep-arity) as a parameter both yield a paraNP-completeness result. Then, we consider the satisfiability problem (SAT) which classically is known to beNP-complete as well (Lohmann and Vollmer, Studia Logica 2013). There we are presenting a different picture: under team-size, or dep-arity SAT isparaNP-complete whereas under all other mentioned parameters the problem isFPT. Finally, we introduce a variant of the satisfiability problem, asking for a team of a given size, and show for this problem an almost complete picture.
AU - Mahmood, Yasir
AU - Meier, Arne
ID - 45849
IS - 2-3
JF - Annals of Mathematics and Artificial Intelligence
KW - Applied Mathematics
KW - Artificial Intelligence
SN - 1012-2443
TI - Parameterised complexity of model checking and satisfiability in propositional dependence logic
VL - 90
ER -
TY - CONF
AU - Kontinen, Juha
AU - Meier, Arne
AU - Mahmood, Yasir
ID - 45846
SN - 0302-9743
T2 - Logical Foundations of Computer Science
TI - A Parameterized View on the Complexity of Dependence Logic
ER -
TY - JOUR
AB - I study a dynamic variant of the DixitâStiglitz (Am Econ Rev 67(3), 1977) model of monopolistic competition by introducing price stickiness à la Fershtman and Kamien (Econometrica 55(5), 1987). The analysis is restricted to bounded quantity and price paths that fulfill the necessary conditions for an open-loop Nash equilibrium. I show that there exists a symmetric steady state and that its stability depends on the degree of product differentiation. When moving from complements to perfect substitutes, the steady state is either a locally asymptotically unstable (spiral) source, a stable (spiral) sink or a saddle point. I further apply the Hopf bifurcation theorem and prove the existence of limit cycles, when passing from a stable to an unstable steady state. Lastly, I provide a numerical example and show that there exists a stable limit cycle.
AU - Hoof, Simon
ID - 45640
IS - 2
JF - Journal of Optimization Theory and Applications
SN - 1573-2878
TI - Dynamic Monopolistic Competition
VL - 189
ER -
TY - GEN
AB - Aggregation metrics in reputation systems are important for overcoming information overload. When using these metrics, technical aggregation functions such as the arithmetic mean are implemented to measure the valence of product ratings. However, it is unclear whether the implemented aggregation functions match the inherent aggregation patterns of customers. In our experiment, we elicit customers' aggregation heuristics and contrast these with reference functions. Our findings indicate that, overall, the arithmetic mean performs best in comparison with other aggregation functions. However, our analysis on an individual level reveals heterogeneous aggregation patterns. Major clusters exhibit a binary bias (i.e., an over-weighting of moderate ratings and under-weighting of extreme ratings) in combination with the arithmetic mean. Minor clusters focus on 1-star ratings or negative (i.e., 1-star and 2-star) ratings. Thereby, inherent aggregation patterns are neither affected by variation of provided information nor by individual characteristics such as experience, risk attitudes, or demographics.
AU - van Straaten, Dirk
AU - Melnikov, Vitalik
AU - Hüllermeier, Eyke
AU - Mir Djawadi, Behnud
AU - Fahr, René
ID - 45616
TI - Accounting for Heuristics in Reputation Systems: An Interdisciplinary Approach on Aggregation Processes
VL - 72
ER -
TY - GEN
AU - van Straaten, Dirk
ID - 45617
TI - Incentive Schemes in Customer Rating Systems - Comparing the Effects of Unconditional and Conditional Rebates on Intrinsic Motivation
VL - 71
ER -
TY - GEN
AU - van Straaten, Dirk
AU - Fahr, René
ID - 45618
TI - Fighting Fire with Fire - Overcoming Ambiguity Aversion by Introducing more Ambiguity
VL - 73
ER -
TY - GEN
AU - Bülling, Jonas
ID - 45788
TI - Political Speaker Transfer: Learning to Generate Text in the Styles of Barack Obama and Donald Trump
ER -
TY - GEN
AU - Mishra, Avishek
ID - 45787
TI - Computational Text Professionalization using Neural Sequence-to-Sequence Models
ER -
TY - CONF
AU - Clausing, Lennart
ID - 30909
T2 - Proceedings of the 11th International Symposium on Highly Efficient Accelerators and Reconfigurable Technologies
TI - ReconOS64: High-Performance Embedded Computing for Industrial Analytics on a Reconfigurable System-on-Chip
ER -
TY - JOUR
AU - Black, Tobias
AU - Fuest, Mario
AU - Lankeit, Johannes
ID - 34673
IS - 3
JF - Zeitschrift für angewandte Mathematik und Physik
KW - Applied Mathematics
KW - General Physics and Astronomy
KW - General Mathematics
SN - 0044-2275
TI - Relaxed parameter conditions for chemotactic collapse in logistic-type parabolic–elliptic Keller–Segel systems
VL - 72
ER -
TY - JOUR
AU - Black, Tobias
AU - Wu, Chunyan
ID - 34675
IS - 4
JF - Zeitschrift für angewandte Mathematik und Physik
KW - Applied Mathematics
KW - General Physics and Astronomy
KW - General Mathematics
SN - 0044-2275
TI - Prescribed signal concentration on the boundary: Weak solvability in a chemotaxis-Stokes system with proliferation
VL - 72
ER -