@inproceedings{BaumannSaboo, author = {Baumann, Timo and Saboo, Ashutosh}, title = {Evaluating Heuristics for Audio-Visual Translation}, series = {Proceedings of the Conference of Computational Humanities Research, (CHR2021): November 17-19, 2021, Amsterdam, The Netherlands}, booktitle = {Proceedings of the Conference of Computational Humanities Research, (CHR2021): November 17-19, 2021, Amsterdam, The Netherlands}, editor = {Ehrmann, Maud}, publisher = {CEUR Workshops}, address = {Amsterdam, the Netherlands}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:18-228-7-2592}, pages = {171 -- 180}, abstract = {Dubbing, i.e., the lip-synchronous translation and revoicing of audio-visual media into a target language from a different source language, is essential for the full-fledged reception of foreign audio-visual media, be it movies, instructional videos or short social media clips. In this paper, we objectify influences on the 'dubbability' of translations, i.e., how well a translation would be synchronously revoiceable to the lips on screen. We explore the value of traditional heuristics used in evaluating the qualitative aspects, in particular matching bilabial consonants and the jaw opening while producing vowels, and control for quantity, i.e., that translations are similar to the source in length. We perform an ablation study using an adversarial neural classifier which is trained to differentiate "true" dubbing translations from machine translations. While we are able to confirm the value of matching lip closure in dubbing, we find that the opening angle of the jaw as determined by the realized vowel may be less relevant than frequently considered in audio-visual translation.}, language = {en} } @article{WeissGarloff, author = {Weiss, Matthias and Garloff, Alfred}, title = {Skill-biased technological change and endogenous benefits: The dynamics of unemployment and wage inequality}, series = {Applied Economics}, volume = {43}, journal = {Applied Economics}, number = {7}, publisher = {Taylor \& Francis}, issn = {1466-4283}, doi = {10.1080/00036840802599933}, url = {http://nbn-resolving.de/urn:nbn:de:0168-ssoar-242195}, pages = {811 -- 821}, abstract = {In this paper, we study the effect of skill-biased technological change on unemployment and wage inequality in the presence of a link between social benefits and average income. In this case, an increase in the productivity of skilled workers and hence their wage leads to an increase in average income and hence in benefits. The increased fallback income, in turn, makes unskilled workers ask for higher wages. As higher wages are not justified by respective productivity increases, unemployment rises. More generally, we show that skill-biased technological change leads to increasing unemployment of the unskilled and to a moderately increasing wage inequality when benefits are endogenous. The model provides a theoretical explanation for diverging dynamics in wage inequality and unemployment under different social benefits regimes: Analyzing the social legislation in 14 countries, we find that benefits are linked to the evolution of average income in Continental Europe but not in the U.S. and the UK. Given this institutional difference, our model predicts that skill-biased technological change leads to rising unemployment in Continental Europe and rising wage inequality in the U.S. and the UK....}, language = {en} } @inproceedings{Baumann, author = {Baumann, Timo}, title = {Coordinating Speech Delivery to Gesture Progress for Deictic Expressions with Incremental Speech Synthesis}, series = {Proceedings of the Timing in Human-Robot Interaction Workshop held in conjunction with the 9th ACM/IEEE International Conference on Human-Robot Interaction (HRI 2014), Bielefeld, 3. March 2014}, booktitle = {Proceedings of the Timing in Human-Robot Interaction Workshop held in conjunction with the 9th ACM/IEEE International Conference on Human-Robot Interaction (HRI 2014), Bielefeld, 3. March 2014}, url = {http://nbn-resolving.de/urn:nbn:de:gbv:18-228-7-1991}, abstract = {This paper presents ongoing work in incremental speech synthesis that enables a system to adapt speech delivery to unforeseen changes in the timing of motor events (e. g. a robot actuator working faster or slower than anticipated) in order to improve the coordination of speech and gestures for deictic expressions.}, subject = {Sprachverarbeitung}, language = {en} } @misc{Baumann, author = {Baumann, Timo}, title = {Ubiquity of Computing and SLIVAR}, series = {Spoken Language Interaction with Virtual Agents and Robots (SLIVAR): Towards Effective and Ethical Interaction}, volume = {10}, journal = {Spoken Language Interaction with Virtual Agents and Robots (SLIVAR): Towards Effective and Ethical Interaction}, editor = {Devillers, Laurence and Kawahara, Tatsuya and Moore, Roger K. and Scheutz, Matthias}, publisher = {Schloss Dagstuhl - Leibniz-Zentrum f{\"u}r Informatik}, address = {Dagstuhl, Germany}, doi = {10.4230/DagRep.10.1.1}, url = {http://nbn-resolving.de/urn:nbn:de:0030-drops-124009}, pages = {16}, language = {en} } @misc{MeyerSickendiekHusseinBaumann, author = {Meyer-Sickendiek, Burkhard and Hussein, Hussein and Baumann, Timo}, title = {From Fluency To Disfluency: Ranking Prosodic Features Of Poetry By Using Neural Networks}, series = {Proceedings of the International Conference on Digital Humanities (DH 2019), Utrecht, the Netherlands 9-12 July, 2019}, journal = {Proceedings of the International Conference on Digital Humanities (DH 2019), Utrecht, the Netherlands 9-12 July, 2019}, doi = {10.34894/EGZNMI}, language = {en} } @article{StichelLaumerLinnenweberetal., author = {Stichel, Thomas and Laumer, Tobias and Linnenweber, Tim and Amend, Philipp and Roth, Stephan}, title = {Mass Flow Characterization of Selective Deposition of Polymer Powders with Vibrating Nozzles for Laser Beam Melting of Multi-material Components}, series = {Physics Procedia}, volume = {83}, journal = {Physics Procedia}, publisher = {Elsevier}, address = {Amsterdam [u.a.]}, issn = {1875-3892}, doi = {10.1016/j.phpro.2016.08.099}, pages = {947 -- 953}, abstract = {The generation of multi-material components by laser beam melting (LBM) is a challenge which requires the invention of new coating devices for preparation of arbitrary powder patterns. One solution is the usage of vibration-controlled nozzles for selective deposition of polymer powders. Powder flow can be initiated by vibration enabling a start-stop function without using any mechanical shutter. In this report, the delivery of polymer powder by vibrating nozzles is investigated with respect to their application in LBM machines. Therefore, a steel nozzle attached to a piezo actor and a weighing cell is used in order to measure the stability and time-dependence of the powder mass flow upon vibration excitation with the usage of different kind of powder formulations. The results show that precompression of the powder inside the nozzle by vibration excitation is essential to realize a reliable start-stop function with reproducible discharge cyles and to prevent a initial flush of powder flow. Moreover, the use of different powder materials showed that mass flow is even possible with powders which are not optimized regarding flowability, but is readily enhanced with a factor of 2 to 3 by admixing Aerosil® fumed silica.}, language = {en} } @article{StichelLaumerBaumuelleretal., author = {Stichel, Thomas and Laumer, Tobias and Baum{\"u}ller, Tobias and Amend, Philipp and Roth, Stephan}, title = {Powder Layer Preparation Using Vibration-controlled Capillary Steel Nozzles for Additive Manufacturing}, series = {Physics Procedia}, volume = {56}, journal = {Physics Procedia}, publisher = {Elsevier}, issn = {1875-3892}, doi = {10.1016/j.phpro.2014.08.158}, pages = {157 -- 166}, abstract = {In this report, the dry delivery of polyamide 12 powders by vibrating capillary steel nozzles is investigated and discussed regarding its potential for powder layer preparation in Laser Beam Melting. Therefore, a setup including a steel nozzle assembled on a piezoelectric actuator is presented, which enables the precise control over very small powder quantities by vibration excitation. An analysis reveals that the mass flow through the nozzle can be adjusted by the vibration modes in a certain range depending on the nozzle's specifications, whereas the vibration modes themselves show a complicated behaviour. Using a positioning system in combination with the vibrating nozzle, single-layer patterns consisting of polyamide 12 are produced and characterized regarding surface homogeneity and selectivity using a laser stripe sensor.}, language = {en} } @article{StichelGeisslerJanderetal., author = {Stichel, Thomas and Geißler, Bastian and Jander, Julius and Laumer, Tobias and Frick, Thomas and Roth, Stephan}, title = {Electrophotographic multi-material powder deposition for additive manufacturing}, series = {Journal of Laser Applications}, volume = {30}, journal = {Journal of Laser Applications}, number = {3}, publisher = {AIP Publishing}, doi = {10.2351/1.5040619}, abstract = {In this paper, the use of electrophotographic polymer powder transfer for the preparation of multi-material layers is discussed with respect to the application in powder bed-based additive manufacturing technologies as selective laser sintering (SLS). Therefore, the challenges of this task are considered verifying the critical process steps in order to develop a concept for an electrophotograhic laser sintering machine. On that basis, an experimental setup with a two-chamber design is realized which enables the investigation of the electrophotographic powder transfer at typical process conditions of SLS. Using this setup, transfer tests of polypropylene powder patterns were performed and qualitatively analyzed by photographic imaging. The results confirm the high potential of the application of electrophotography for multi-material powder deposition and show how a residual electrophotographic powder deposition can be achieved in general, which is independent from the already produced part height, in order to build up three-dimensional multi-material components.}, language = {en} } @inproceedings{LaumerStichelAmendetal., author = {Laumer, Tobias and Stichel, Thomas and Amend, Philipp and Roth, Stephan and Schmidt, Michael}, title = {Analysis of Temperature Gradients during Simultaneous Laser Beam Melting of Polymers}, series = {Physics Procedia}, volume = {56}, booktitle = {Physics Procedia}, publisher = {Elsevier}, doi = {10.1016/j.phpro.2014.08.159}, pages = {167 -- 175}, abstract = {By simultaneous laser beam melting (SLBM), different polymer powders can be processed to multi-material parts, which offers the potential to enlarge the field of application for conventional LBM. In a SLBM process, a powder bed consisting of different polymers and therefore with different melting and crystallization temperatures is deposited. Besides the use of infrared emitters for preheating the lower melting polymer, a CO2 laser distributes the necessary preheating temperature of the higher melting polymer. In the last step, a thulium fibre laser distributes the energy necessary for melting the two preheated powders simultaneously. In order to analyze the temperature gradients of the process on the powder surface and in deeper layers, a high-resolution thermal imaging system and thermocouples are used.}, language = {en} } @inproceedings{SelgradLierKoeferletal., author = {Selgrad, Kai and Lier, Alexander and K{\"o}ferl, Franz and Stamminger, Marc and Lohmann, Daniel}, title = {Lightweight, Generative Variant Exploration for High-performance Graphics Applications}, series = {GPCE'15 : Proceedings of the 2015 ACM SIGPLAN International Conference on Generative Programming: Concepts and Experiences ; October 26-27, 2015, Pittsburgh, PA, USA}, booktitle = {GPCE'15 : Proceedings of the 2015 ACM SIGPLAN International Conference on Generative Programming: Concepts and Experiences ; October 26-27, 2015, Pittsburgh, PA, USA}, editor = {K{\"a}stner, Christian and Gokhāl{\´e}, Anir{\"u}ddhā}, publisher = {ACM}, address = {New York, USA}, isbn = {978-1-4503-3687-1}, pages = {141 -- 150}, abstract = {Rendering performance is an everlasting goal of computer graphics and significant driver for advances in both, hardware architecture and algorithms. Thereby, it has become possible to apply advanced computer graphics technology even in low-cost embedded appliances, such as car instruments. Yet, to come up with an efficient implementation, developers have to put enormous efforts into hardware/problem-specific tailoring, fine-tuning, and domain exploration, which requires profound expert knowledge. If a good solution has been found, there is a high probability that it does not work as well with other architectures or even the next hardware generation. Generative DSL-based approaches could mitigate these efforts and provide for an efficient exploration of algorithmic variants and hardware-specific tuning ideas. However, in vertically organized industries, such as automotive, suppliers are reluctant to introduce these techniques as they fear loss of control, high introduction costs, and additional constraints imposed by the OEM with respect to software and tool-chain certification. Moreover, suppliers do not want to share their generic solutions with the OEM, but only concrete instances. To this end, we propose a light-weight and incremental approach for meta programming of graphics applications. Our approach relies on an existing formulation of C-like languages that is amenable to meta programming, which we extend to become a lightweight language to combine algorithmic features. Our method provides a concise notation for meta programs and generates easily sharable output in the appropriate C-style target language.}, language = {en} } @inproceedings{LierMartinekStammingeretal., author = {Lier, Alexander and Martinek, Magdalena and Stamminger, Marc and Selgrad, Kai}, title = {A High-Resolution Compression Scheme for Ray Tracing Subdivision Surfaces with Displacement}, series = {Proceedings of the ACM on Computer Graphics and Interactive Techniques}, volume = {1}, booktitle = {Proceedings of the ACM on Computer Graphics and Interactive Techniques}, number = {2}, publisher = {The Association for Computers in Mathematics and Science Teaching}, doi = {10.1145/3233308}, pages = {1 -- 17}, abstract = {Subdivision surfaces, especially with displacement, are one of the key modeling primitives used in high-quality rendering environments, such as, e.g., movie production. While their use easily maps to rasterization-based frameworks, they pose a significant challenge for ray tracing environments. This is due to the fact that incoherent access patterns require storing or caching fully tessellated and displaced meshes for efficient intersection computations. In this paper we use a two-tier hierarchy built on a scene's patches. It relies on compressed and quantized bounding volumes on the second tier to reduce the size of the BVH itself. Based on this acceleration structure, we propose a quantized, compact approximation for leaf nodes while being faithful to the underlying patch-geometry. We build on recent advances and present a system that shows competitive performance regarding run-time speed, which is close to full-resolution pre-tessellation methods as well as to previous compression approaches. Ultimately, we provide strong compression of up to a factor of 5: 1 compared to state-of-the-art methods while maintaining high geometrical fidelity surpassing similarly compact approximations and getting close to uncompressed geometry.}, language = {en} } @article{Richter, author = {Richter, Stefanie}, title = {Integrated Care for People with Dementia}, series = {Geriatrics}, volume = {2}, journal = {Geriatrics}, number = {1}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/geriatrics2010001}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-22091}, pages = {1 -- 13}, abstract = {This article presents results of the social-scientific evaluation of an established care model for people with dementia developed by the professionals as a result of acute problems in care in north-east Germany. In addition to the central elements of the model, the conditions of intersectoral and interprofessional cooperation as well as the qualification profile requirements of the professional groups involved are presented in detail. The results can give suggestions for the organization of integrated care for people with dementia in other countries. Further, the author would hereby like to highlight the gain from the scientific examination of solutions to problems in the field.}, subject = {Demenz}, language = {en} } @article{ThiemePfingstenSchilleretal., author = {Thieme, H. and Pfingsten, Andrea and Schiller, S. and Spitzer, L. and Borgetto, Bernhard}, title = {Pr{\"a}diktoren der Teilnahme an Gespr{\"a}chskreisen und Funktionstraining von Patienten mit rheumatischen Erkrankungen.}, series = {Aktuelle Rheumatologie}, volume = {38}, journal = {Aktuelle Rheumatologie}, number = {6}, edition = {eFirst 18.9.2013}, publisher = {Thieme}, doi = {10.1055/s-0033-1353179}, pages = {375 -- 379}, language = {de} } @article{PfingstenSchillerTrickesetal., author = {Pfingsten, Andrea and Schiller, S. and Trickes, Claudia and Spitzer, Lena and Thieme, H. and Borgetto, Bernhard}, title = {Wirkungen von Gespr{\"a}chskreisen und Funktionstraining bei Patienten mit rheumatischen Erkrankungen}, series = {Aktuelle Rheumatologie}, volume = {38}, journal = {Aktuelle Rheumatologie}, number = {6}, publisher = {Thieme}, doi = {10.1055/s-0033-1357176}, pages = {380 -- 384}, abstract = {Hintergrund: Die ad{\"a}quate Versorgung von Personen, die von rheumatischen Erkrankungen betroffen sind, stellt eine Herausforderung dar, die ohne aktive Mitarbeit der Betroffenen und Selbsthilfe (SH) nicht bew{\"a}ltigt werden kann. In Anbetracht knapper {\"o}ffentlicher Ressourcen steht auch die mit staatlichen Mitteln unterst{\"u}tzte SH zunehmend in der Verantwortung, die Wirkung ihrer Angebote nachzuweisen. Patienten/Material und Methode: In einer beobachtenden prospektiven Studie wurden zu 4 Zeitpunkten im Abstand von 6 Monaten Frageb{\"o}gen an von rheumatischen Erkrankungen Betroffene verschickt. Diese wurden in verschiedenen Einrichtungen der gesundheitlichen Versorgung sowie in der Rheuma-Liga Baden-W{\"u}rttemberg rekrutiert. Erhoben wurden gesundheits- und personenbezogenen Faktoren, Versorgungsinformationen und ab der zweiten Welle der Gesundheitszustand sowie die Inanspruchnahme von SH-Angeboten. Es wurden u. a. durch Quer- sowie L{\"a}ngsschnittanalysen Nutzungsverhalten und Wirkung von Funktionstraining und Gespr{\"a}chskreisen bei von Fibromyalgie (FM) und Rheumatoider Arthritis (RA) betroffenen Erwachsenen analysiert. Ergebnisse: SH-Nutzer waren in ihrer Funk­tionskapazit{\"a}t st{\"a}rker eingeschr{\"a}nkt als Nicht-Nutzer. Dieser Unterschied ging prim{\"a}r auf Studienteilnehmer mit RA zur{\"u}ck. SH-Nutzer wurden mit Ausnahme der geringeren Behandlung von FM-Patienten durch einen Schmerztherapeuten leitliniengerechter {\"a}rztlich betreut und behandelt. SH-Angebote wurden von Patienten mit FM h{\"a}ufiger genutzt als von Personen mit RA. Es bestand ein Zusammenhang zwischen ­der Prozessqualit{\"a}t des Funktionstrainings (bes. Warmwassergymnastik) und der Funktionskapazit{\"a}t der Betroffenen. Die Ergebnisse hinsichtlich der Lebensqualit{\"a}t waren im Zeitverlauf widerspr{\"u}chlich und nicht interpretierbar. Die Funktionskapazit{\"a}t der Befragten nahm erwartungsgem{\"a}ß ab. Den deutlichsten R{\"u}ckgang zeigten SH-Nutzer mit RA, was nicht auf das Nutzungsverhalten zur{\"u}ckgef{\"u}hrt werden konnte. SH-Nutzer mit FM zeigten im Gegensatz zu Nicht-Nutzern nahezu keinen R{\"u}ckgang der Funktionskapazit{\"a}t. Dieser Unterschied konnte auf die Inanspruchnahme von SH-Angeboten zur{\"u}ckgef{\"u}hrt werden. Schlussfolgerung: Die Wirkung von SH-Angeboten konnte best{\"a}tigt werden, fiel aber in großen Teilen gering und bei Patienten mit RA hinsichtlich Funktionskapazit{\"a}t anscheinend negativ aus. Weitere Analysen der vorliegenden Daten sollten genutzt werden, um Maßnahmen zur Wirkungssteigerung zu entwickeln. Die Ergebnisse legen nahe, dass eine Steigerung der Prozessqualit{\"a}t der Angebote einen ersten Ansatz bietet.}, language = {de} } @article{PfingstenBorgetto, author = {Pfingsten, Andrea and Borgetto, Bernhard}, title = {Physiotherapie in der Rheumatologie. Versorgungsbedarf aus Sicht von Patienten}, series = {Aktuelle Rheumatologie}, volume = {38}, journal = {Aktuelle Rheumatologie}, number = {1}, publisher = {Georg Thieme Verlag}, doi = {10.1055/s-0032-1311574}, pages = {50 -- 54}, abstract = {Hintergrund: Die Effektivit{\"a}t von Physiotherapie bei rheumatischen Erkrankungen, die aus experimentellen Studien zu erwarten ist, kann unter Alltagsbedingungen nicht erreicht werden. Ziel der hier vorgestellten Studie ist es, durch Erhebung des Versorgungsbedarfs aus Sicht der Patienten dazu beizutragen, die Diskrepanz zu verringern. Patienten/Material und Methode: 5 Patienten mit rheumatischen Erkrankungen wurden in qualitativen Interviews hinsichtlich der Versorgung mit Physiotherapie befragt. Ergebnisse: Die Befragten bewerten Physiotherapie als wichtigen Bestandteil der Versorgung. Sie halten die derzeitige Versorgung f{\"u}r nicht ausreichend und wenig auf symptomatische und andere Parameter abgestimmt. Pers{\"o}nliches Engagement und der verordnende Arzt werden als Haupteinflussfaktoren auf die Versorgung mit Therapie empfunden. Von Therapeuten erwarten sie eine Spezialisierung auf rheumatische Erkrankungen und besonderes Einf{\"u}hlungsverm{\"o}gen. Schlussfolgerung: Eine st{\"a}rkere Abstimmung der Verordnungen und Interventionen auf die Bed{\"u}rfnisse der Betroffenen und eine Steigerung der Therapiequalit{\"a}t durch Spezialisierung k{\"o}nnte helfen, die potenziellen Effekte in der Routineversorgung zu erzielen.}, language = {de} } @article{BorgettoTomlinTrickesetal., author = {Borgetto, Bernhard and Tomlin, George S. and Trickes, Claudia and Max, Susanne and Pfingsten, Andrea}, title = {Die Forschungspyramide - Evidenz f{\"u}r die ergotherapeutische Praxis. Ein Update}, series = {Ergoscience}, volume = {10}, journal = {Ergoscience}, number = {1}, doi = {10.2443/skv-s-2015-54020150104}, pages = {30 -- 34}, abstract = {F{\"u}r die Aufbereitung und Systematisierung wissenschaftlicher Forschungsergebnisse und die Beantwortung klinischer Fragestellungen im Hinblick auf Entscheidungen in der allt{\"a}glichen Versorgungspraxis bietet die Forschungspyramide ein Modell zur Bewertung und Integration externer Evidenz aus unterschiedlichen Forschungsans{\"a}tzen. Dieser Beitrag bietet ein Update zu den neueren Entwicklungen und dem aktuellen Stand des Modells sowie den Grundlagen eines Pyramidenreviews.}, language = {de} } @article{Pfingsten, author = {Pfingsten, Andrea}, title = {Die Forschungspyramide: wirklichkeitsnahe Evidenz f{\"u}r die Praxis. Integration der Ergebnisse unterschiedlicher Forschungsans{\"a}tze f{\"u}r die Physiotherapie}, series = {pt - Zeitschrift f{\"u}r Physiotherapeuten}, volume = {65}, journal = {pt - Zeitschrift f{\"u}r Physiotherapeuten}, number = {12}, publisher = {Pflaum}, address = {M{\"u}nchen}, issn = {1614-0397}, pages = {76 -- 78}, language = {de} } @article{DendorferMaierTayloretal., author = {Dendorfer, Sebastian and Maier, Hans J{\"u}rgen and Taylor, David and Hammer, Joachim}, title = {Anisotropy of the fatigue behaviour of cancellous bone}, series = {Journal of Biomechanics}, volume = {41}, journal = {Journal of Biomechanics}, number = {3}, doi = {10.1016/j.jbiomech.2007.09.037}, pages = {636 -- 641}, abstract = {The fatigue behaviour of materials is of particular interest for the failure prediction of materials and structures exposed to cyclic loading. For trabecular bone structures only a few sets of lifetime data have been reported in the literature and structural measures are commonly not considered. The influence of load contributions which are not aligned with the main physiological axis remains unclear. Furthermore site and species dependent relationships are not well described. In this study five different groups of trabecular bone, defined in terms of orientation, species and site were exposed to cyclic compression. In total, 108 fatigue tests were analysed. The lifetimes were found to decrease drastically when off-axis loads were applied. Additionally, species and site strongly affect fatigue lifetimes. Strains at failure were also found to be a function of orientation.}, subject = {Erm{\"u}dung}, language = {en} } @article{KellnerUtz, author = {Kellner, Florian and Utz, Sebastian}, title = {Sustainability in supplier selection and order allocation: Combining integer variables with Markowitz portfolio theory}, series = {Journal of Cleaner Production}, volume = {214}, journal = {Journal of Cleaner Production}, publisher = {Springer Nature}, doi = {10.1016/j.jclepro.2018.12.315}, pages = {462 -- 474}, abstract = {This research presents a decision support methodology for the multi-criteria supplier selection and order allocation problem. The proposed approach supports purchasing managers in assembling mid-term supplier portfolios while making them aware of the trade-offs between the supplier sustainability, the purchasing costs, and the overall supply risk. First, we propose a multi-objective optimization model with three objectives: to maximize the supplier sustainability, to select the supplier portfolio with the lowest purchasing costs, and to minimize the supply risk. Our model extends existing mathematical approaches that follow the portfolio theory fathered by H. Markowitz by integrating the aspect 'risk' into the supplier selection problem. Secondly, since we allow for integer variables in our model—in contrast to the classical Markowitz portfolio theory—we use the ε-constraint method to visualize the efficient surface. The possibility of considering the non-dominated set of supplier portfolios is advantageous for purchasing managers as they gain a picture of the different optimal supplier portfolios and are able to analyze the trade-offs between the different purchasing goals before making a decision. Finally, we illustrate the applicability of the proposed methodology in a real-world supplier selection and order allocation case from the automotive industry. In the example case, we identify 1754 optimal supplier portfolios that may be assembled based on the eight available suppliers. Our analyses show that each optimal portfolio consists of two suppliers, with one specific supplier being included in each portfolio. Furthermore, four suppliers are not part of any optimal solution.}, language = {en} } @article{KellnerLienlandUtz, author = {Kellner, Florian and Lienland, Bernhard and Utz, Sebastian}, title = {A multi-criteria decision-making approach for assembling optimal powertrain technology portfolios in low GHG emission environments}, series = {Journal of Industrial Ecology}, volume = {25}, journal = {Journal of Industrial Ecology}, number = {6}, publisher = {Wiley}, doi = {10.1111/jiec.13148}, pages = {1412 -- 1429}, abstract = {Environmental regulations force car manufacturers to renew the powertrain technology portfolio offered to the customer to comply with greenhouse gas (GHG) emission targets. In turn, automotive companies face the task of identifying the "right" powertrain technology portfolio consisting of, for example, internal combustion engines and electric vehicles, because the selection of a particular powertrain technology portfolio affects different company targets simultaneously. What makes this decision even more challenging is that future market shares of the different technologies are uncertain. Our research presents a new decision-support approach for assembling optimal powertrain technology portfolios while making decision-makers aware of the trade-offs between the achievable profit, the achievable market share, the market share risk, and the GHG emissions generated by the selected vehicle fleet. The proposed approach combines "a posteriori" decision-making with multi-objective optimization. In an application case, we feed the outlooks of selected market studies into the proposed decision-support system. The result is a visualization and analysis of the current real-world decision-making problem faced by many automotive companies. Our findings indicate that for the proposed GHG restriction at work in 2030 in the European Union, no optimal powertrain technology portfolio with less than 35\% of vehicles equipped with an electric motor exists.}, language = {en} } @article{NeumuellerLaschKellner, author = {Neum{\"u}ller, Claudia and Lasch, Rainer and Kellner, Florian}, title = {Integrating sustainability into strategic supplier portfolio selection}, series = {Management decision}, volume = {54}, journal = {Management decision}, number = {1}, publisher = {Emerald}, doi = {10.1108/MD-05-2015-0191}, pages = {194 -- 221}, abstract = {Purpose - The purpose of this paper is to propose a comprehensive methodology and a problem-specific model for the configuration of the optimal strategic supplier portfolio in terms of traditional, performance-related objectives and sustainability targets. Design/methodology/approach - To bridge the research gap, i.e., to align strategic supplier portfolio selection with corporate sustainability targets, a hybrid model of the analytic network process (ANP) and goal programming (GP) is developed. To validate the model, a case example is presented and managerial feedback is collected. Findings - By enabling the integration of sustainability targets into strategic supplier portfolio configuration, the hybrid ANP-GP model contributes to research in the area of sustainable supply chain management. Results indicate that simplifying the model by omitting one or more details may lead to unfortunate actions. Research limitations/implications - The model has been applied using a case example in the automotive industry. To strengthen the findings, it should be examined under other terms as well. Practical implications - Integrating economic, environmental, and social targets into strategic supplier portfolio configuration reduces supply risks and promotes the achievement of the sustainability goals of the purchasing company. Social implications - Strategic supplier selection counts among the decisions that have an impact on the environment and society for several years. Configuring economically rational, environmentally friendly, and socially responsible supplier bases supports worldwide efforts towards sustainable development. Originality/value - Although sustainable supplier selection has gained importance in recent years, this is the first time that a comprehensive model for the determination of the optimal strategic supplier portfolio in terms of performance-related objectives and sustainability targets has been proposed.}, language = {en} } @article{KellnerIgl, author = {Kellner, Florian and Igl, Johannes}, title = {Greenhouse gas reduction in transport: analyzing the carbon dioxide performance of different freight forwarder networks}, series = {Journal of Cleaner Production}, volume = {99}, journal = {Journal of Cleaner Production}, publisher = {Elsevier}, doi = {10.1016/j.jclepro.2015.03.026}, pages = {177 -- 191}, abstract = {There are growing concerns in the food industry about how supply chains can be managed in a more sustainable way. When distribution activities are outsourced to a logistics service provider (LSP), shippers need to evaluate the LSPs they may (potentially) engage in order to ensure that supply chain sustainability goals are met. In this paper, we present a methodology for LSP evaluation and focus on the ecological dimension of sustainability. We examine how the network carbon footprint of a real-world distribution system is affected by the LSP network that is chosen to forward goods from production facilities to customers. To do this, we analyze the shipment data of an existing Fast Moving Consumer Goods (FMCG) manufacturer. A quantitative distribution network model is set up to study the network carbon footprint of 125 scenarios. Real-world shipments are forwarded via five generic, idealized types of LSP networks. In total, 625 network carbon footprints, specified by three distribution logistics variables and the structure of the LSP network, have been calculated. The results show that LSP structures practicing a geographically decentralized consolidation of shipments are most efficient in reducing of greenhouse gas (GHG) emissions. Furthermore, the effects of changing the manufacturer's and the LSP's strategies for deciding on the tonnage to be forwarded via the LSP network or moved by direct transports are quantified. Finally, we estimate the GHG effect of improving the capacity utilization of the vehicles that move the products.}, language = {en} } @article{Kellner, author = {Kellner, Florian}, title = {Generating greenhouse gas cutting incentives when allocating carbon dioxide emissions to shipments in road freight transportation}, series = {OR Spectrum}, volume = {44}, journal = {OR Spectrum}, number = {3}, publisher = {Springer Nature}, doi = {10.1007/s00291-022-00675-y}, pages = {833 -- 874}, abstract = {Road freight transportation accounts for a great share of the anthropogenic greenhouse gas (GHG) emissions. In order to provide a common methodology for carbon accounting related to transport activities, the European Committee for Standardization has published the European Norm EN-16258. Unfortunately, EN-16258 contains gaps and ambiguities and leaves room for interpretation, which makes the comparison of the environmental performance of different logistics networks still difficult and hinders the identification of best practices. This research contributes to the identification of particularly meaningful principles for the allocation of GHG to shipments in road freight transportation by presenting an analytical framework for studying the performance of the EN-16258 allocation schemes with respect to accuracy, fairness, and the GHG minimizing incentive. In doing so, we continue previous studies that analyzed two important aspects of the EN-16258 allocation rules: accuracy and fairness. This study provides further insights into this allocation problem by investigating the incentive power of the different allocation schemes to opt for the GHG minimal way of running a road freight network. First, we complement the list of transport scenarios introduced in prior studies and present two novel scenarios. Second, we carry out a series of numerical experiments to compare the EN-16258 allocation rules with respect to accuracy, fairness, and the GHG minimizing incentive. We find that the results may differ significantly for the two scenarios, suggesting a case-by-case recommendation. This is particularly interesting because the first scenario confirms the results of the prior studies, while the second scenario rather contradicts them.}, language = {en} } @article{FuchsBeckLienlandetal., author = {Fuchs, Christoph and Beck, Daniel and Lienland, Bernhard and Kellner, Florian}, title = {The role of IT in automotive supplier supply chains}, series = {Journal of Enterprise Information Management}, volume = {31}, journal = {Journal of Enterprise Information Management}, number = {1}, publisher = {emerald insight}, doi = {10.1108/JEIM-03-2017-0038}, pages = {64 -- 88}, abstract = {Purpose The purpose of this paper is to explore the impact of information technology (IT) on supply chain performance in the automotive industry. Prior studies that analyzed the impact of IT on supply chain performance report results representing the situation of the "average industry." This research focuses on the automotive industry because of its major importance in many national economies and due to the fact that automotive supply chains do not represent the supply chain of the average industry. Design/methodology/approach A research model is proposed to examine the relationships between IT capabilities, supply chain capabilities, and supplier performance. The model divides IT capabilities into functional and data capabilities, and supply chain capabilities into internal process excellence and information sharing. Data have been collected from 343 automotive first-tier suppliers. Structural equation modeling with partial least squares is used to analyze the data. Findings The results suggest that functional capabilities have the greatest impact on internal process excellence, which in turn enhances supplier performance. However, frequent and adequate information sharing also contributes significantly to supplier performance. Data capabilities enable supply chain capabilities through their positive impact on functional capabilities. Practical implications The findings will help managers to understand the effect of IT implementation on company performance and to decide whether to invest in the expansion of IT capacities. Originality/value This research reports the impact of IT on supply chain performance in one of the most important industries in many industrialized countries, and it provides a new perspective on evaluating the contribution of IT on firm performance.}, language = {en} } @article{LienlandBaumgartnerKnubben, author = {Lienland, Bernhard and Baumgartner, Alexander and Knubben, Evelyn}, title = {The undervaluation of corporate reputation as a supplier selection factor}, series = {Journal of Purchasing and Supply Management}, volume = {19}, journal = {Journal of Purchasing and Supply Management}, number = {2}, publisher = {Elsevier}, issn = {1478-4092}, doi = {10.1016/j.pursup.2013.04.001}, pages = {84 -- 97}, abstract = {Prior research studies on supplier selection factors assess vendor reputation as a low ranked criterion. Reputation in these articles, however, only refers to the position in the industry, without considering the role of the final customer. Our results from a survey with 565 individuals suggest that the end user as a stakeholder should be also considered when analyzing a vendor's prestige. We demonstrate that a supplier's standing has negative as well as positive reputational effects on the buyer. Depending on the relevance of the purchased good as well as the reputation of the supplier and the buyer, low/high-ranked ingredients significantly decrease/increase the final customer's perception of the buyer.}, language = {en} } @article{Kellner, author = {Kellner, Florian}, title = {Exploring the impact of urbanization on consumer goods distribution networks}, series = {Journal of Asian Business and Economic Studies}, volume = {28}, journal = {Journal of Asian Business and Economic Studies}, number = {2}, publisher = {Emerald}, doi = {10.1108/JABES-12-2019-0127}, pages = {101 -- 120}, abstract = {Purpose Due to the growing percentage share of urban dwellers, the physical distribution of products faces altering conditions. This research explores the effects that urbanization has on the performance of a fast-moving consumer goods distribution network. A focus is set on changes in distribution cost, the cost-minimal network design, and greenhouse gas emissions. Design/methodology/approach The analyses are based on a quantitative distribution network model of an existing manufacturer of consumer goods. Findings The results indicate that the foreseen population shift will affect the network's economic and environmental performance. Effects are, among others, due to differences in the efficiency of supplying urban and nonurban regions. The combined effects of urbanization and the development of the population size will even more affect the network's performance. Originality/value Research dealing with distribution logistics and urbanization primarily focuses on city logistics. In this paper, the object of analysis is the entire distribution system.}, language = {en} } @article{NeumuellerKellnerGuptaetal., author = {Neum{\"u}ller, Claudia and Kellner, Florian and Gupta, Jatinder N.D. and Lasch, Rainer}, title = {Integrating three-dimensional sustainability in distribution centre selection: the process analysis method-based analytic network process}, series = {International Journal of Production Research}, volume = {53}, journal = {International Journal of Production Research}, number = {2}, publisher = {Taylor \& Francis}, doi = {10.1080/00207543.2014.939241}, pages = {409 -- 434}, abstract = {In this paper, we propose a combined methodology for the selection of distribution centres (DCs) by integrating and balancing economic, environmental and social sustainability aspects. The analytic network process (ANP) permits to systematically evaluate possible DCs on the basis of a situation-specific decision structure. A systematic development of the decision networks, which is one of the core challenges using the ANP, is supported by the process analysis method which we extend for that purpose. The validity and soundness of the proposed framework are demonstrated by means of a case study. The case study results reveal that omitting aspects of sustainability can lead to unfortunate results.}, language = {en} }