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Suche nach „[2017]“ hat 227 Publikationen gefunden
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    DigitalF: Angewandte Wirtschaftswissenschaften

    Zeitschriftenartikel

    Christian Mandl, S. Minner

    Von Predictive zu Prescriptive Analytics. Big Data in der Rohstoffbeschaffung

    Beschaffung aktuell, no. 4

    2017

    DigitalF: Angewandte Wirtschaftswissenschaften

    Buch (Monographie)

    Christian Mandl, S. Minner

    When Do Commodity Spot Price Regimes Matter for Inventory Managers?

    2017

    Abstract anzeigen

    An increasing number of firms buy commodities at spot markets characterized by price volatility. Due to different market regimes (e.g., bull and bear), spot price dynamics are non-stationary and only partially observable; neither the underlying stochastic price process, nor its parameters are known with certainty. To capture uncertainty in both price and price model, we exploit recent spot price observations to dynamically update (learning) probabilistic price regime information in the context of inventory control under stochastic demand and purchase price. By means of Bayesian dynamic programming, we prove that, if prices evolve according to doubly embedded stochastic processes described by hidden Markov regime switching (MRS) models, price(s)- and regime-belief-dependent (prior respectively posterior) base-stock policies, rather than price-dependent policies, are optimal. We distinguish between independent and Markovian price processes and demonstrate the difference concerning optimal base-stock functions and monotonicity properties. We numerically establish that ignoring regime shifts leads to suboptimal inventory decisions and we quantify the operational value of spot price models. We find that Bayesian regime belief updates (learning) can yield significant cost savings that are particularly high when demand volatility and inventory holding cost are low and regime persistence is high. However, in empirical environments, stochastic price models induce misleading speculation resulting in misspeculative inventory. Based on real spot market data, we show that price forecast accuracy and operational performance are not perfectly correlated and that it can be advantageous for inventory managers to ignore sophisticated price forecasting and instead follow a naïve strategy.

    DigitalF: Europan Campus Rottal-Inn

    Zeitschriftenartikel

    R. Brandenberg, Matthias Huber, M. Silbernagl

    The summed start-up costs in a unit commitment problem

    EURO Journal on Computational Optimization, vol. 5, no. 1-2, pp. 203-238

    2017

    DOI: 10.1007/s13675-016-0062-2

    Abstract anzeigen

    We consider the sum of the incurred start-up costs of a single unit in a Unit Commitment problem. Our major result is a correspondence between the facets of its epigraph and some binary trees for concave start-up cost functions CU, which is bijective if CU is strictly concave. We derive an exponential H-representation of this epigraph, and provide an exact linear separation algorithm. These results significantly reduce the integrality gap of the Mixed Integer formulation of a Unit Commitment Problem compared to current literature.

    DigitalF: Angewandte Informatik

    Zeitschriftenartikel

    Patrick Glauner, J. Meira, P. Valtchev, R. State, F. Bettinger

    The Challenge of Non-Technical Loss Detection Using Artificial Intelligence: A Survey

    International Journal of Computational Intelligence Systems, vol. 10, no. 1, pp. 760-775

    2017

    DOI: 10.2991/ijcis.2017.10.1.51

    Abstract anzeigen

    Detection of non-technical losses (NTL) which include electricity theft, faulty meters or billing errors has attracted increasing attention from researchers in electrical engineering and computer science. NTLs cause significant harm to the economy, as in some countries they may range up to 40% of the total electricity distributed. The predominant research direction is employing artificial intelligence to predict whether a customer causes NTL. This paper first provides an overview of how NTLs are defined and their impact on economies, which include loss of revenue and profit of electricity providers and decrease of the stability and reliability of electrical power grids. It then surveys the state-of-the-art research efforts in a up-to-date and comprehensive review of algorithms, features and data sets used. It finally identifies the key scientific and engineering challenges in NTL detection and suggests how they could be addressed in the future.

    NachhaltigS: TC Hutthurm

    Zeitschriftenartikel

    Sebastian Kölbl, J. Leßlhumer, A. Haider, O. Brüggemann, W. Buchberger

    Oxidationsinduktionszeit - dass passende Qualitätskriterium für WPC-Terrassendielen?

    holztechnologie, vol. 58, no. 2, pp. 38-45

    2017

    Abstract anzeigen

    Over the last years the popularity and approval of wood-polymer composites (WPC) are growing. Particularly in the field of terrace deckings the produced amounts have increased considerably. Outdoor applications lead to the questions of durability of these bio-composites. Therefore, in this work the determination of the oxidation induction time (OIT) as a possible quality criterion for WPC was evaluated. For this purpose, WPC-profiles were produced via direct-extrusion, with different amounts of additives. The produced profiles were treated by artificial weathering and examined continuously. In the course of the work, numerous influencing factors on the measurement were revealed and it was shown that an initial high OIT-value is no warranty for a long-lasting product. Parallelly conducted high-performance liquid chromatography (HPLC) measurements revealed what kind of additive has the biggest influence on the oxidation induction time and to what extent the amount of additives in the bio-composite is decreased by artificial weathering. In den letzten Jahren erfreut sich der Werkstoff WPC zunehmender Beliebtheit und Akzeptanz. Vor allem im Bereich der Terrassendielen (sogenannte "Deckings") sind die produzierten Mengen deutlich angestiegen. Die Anwendung im Außenbereich wirft aber auch die Frage der Dauerhaftigkeit dieser Bio-Composite auf. In der vorliegenden Arbeit wurde daher die Bestimmung der Oxidationsinduktionszeit als ein mögliches Qualitätskriterium für WPC unter die Lupe genommen. Dazu wurden WPC-Profile ohne und mit Additiven mittels Direktextrusion hergestellt, künstlich bewittert und fortlaufend untersucht. Dabei wurden zahlreiche Einflussfaktoren auf die OIT-Messung aufgezeigt sowie dargestellt, dass ein anfänglich hoher OIT-Wert keine Garantie für ein langlebiges Produkt ist. Durch HPLC-Messungen wurde des Weiteren nachgewiesen, welche Additive großen Einfluss auf die Oxidationsinduktionszeit haben und in welchem Maße diese durch UV-Bestrahlung und Beregnung abgebaut werden. Schlüsselwörter: Dauerhaftigkeit, Antioxidationsmittel, UV-Stabilisierung, Oxidationsinduktionszeit, Hochleistungsflüssigchromatographie

    NachhaltigS: TC Teisnach Sensorik

    Patent

    Günther Ruhl, K. Pruegl

    Method for processing a carrier

    2017

    GesundF: Europan Campus Rottal-Inn

    Zeitschriftenartikel

    I. Meyhöfer, M. Steffens, E. Faiola, Anna-Maria Kasparbauer, V. Kumari, U. Ettinger

    Combining two model systems of psychosis: The effects of schizotypy and sleep deprivation on oculomotor control and psychotomimetic states

    Psychophysiology, vol. 54, no. 11, pp. 1755-1769

    2017

    DOI: 10.1111/psyp.12917

    Abstract anzeigen

    Model systems of psychosis, such as schizotypy or sleep deprivation, are valuable in informing our understanding of the etiology of the disorder and aiding the development of new treatments. Schizophrenia patients, high schizotypes, and sleep‐deprived subjects are known to share deficits in oculomotor biomarkers. Here, we aimed to further validate the schizotypy and sleep deprivation models and investigated, for the first time, their interactive effects on smooth pursuit eye movements (SPEM), prosaccades, antisaccades, predictive saccades, and measures of psychotomimetic states, anxiety, depression, and stress. To do so, n  = 19 controls and n  = 17 high positive schizotypes were examined after both a normal sleep night and 24 h of sleep deprivation. Schizotypes displayed higher SPEM global position error, catch‐up saccade amplitude, and increased psychotomimetic states. Sleep deprivation impaired SPEM, prosaccade, antisaccade, and predictive saccade performance and increased levels of psychotomimetic experiences. Additionally, sleep deprivation reduced SPEM gain in schizotypes but not controls. We conclude that oculomotor impairments are observed in relation to schizotypy and following sleep deprivation, supporting their utility as biomarkers in model systems of psychosis. The combination of these models with oculomotor biomarkers may be particularly fruitful in assisting the development of new antipsychotic or pro‐cognitive drugs.

    GesundF: Europan Campus Rottal-Inn

    Zeitschriftenartikel

    U. Ettinger, E. Faiola, Anna-Maria Kasparbauer, N. Petrovsky, Chan, R. C. K., R. Liepelt, V. Kumari

    Effects of nicotine on response inhibition and interference control

    Psychopharmacology, vol. 234, pp. 1093-1111

    2017

    DOI: 10.1007/s00213-017-4542-8

    Abstract anzeigen

    Nicotine is a cholinergic agonist with known pro-cognitive effects in the domains of alerting and orienting attention. However, its effects on attentional top-down functions such as response inhibition and interference control are less well characterised. Here, we investigated the effects of 7 mg transdermal nicotine on performance on a battery of response inhibition and interference control tasks. A sample of N = 44 healthy adult non-smokers performed antisaccade, stop signal, Stroop, go/no-go, flanker, shape matching and Simon tasks, as well as the attentional network test (ANT) and a continuous performance task (CPT). Nicotine was administered in a within-subjects, double-blind, placebo-controlled design, with order of drug administration counterbalanced. Relative to placebo, nicotine led to significantly shorter reaction times on a prosaccade task and on CPT hits but did not significantly improve inhibitory or interference control performance on any task. Instead, nicotine had a negative influence in increasing the interference effect on the Simon task. Nicotine did not alter inter-individual associations between reaction times on congruent trials and error rates on incongruent trials on any task. Finally, there were effects involving order of drug administration, suggesting practice effects but also beneficial nicotine effects when the compound was administered first. Overall, our findings support previous studies showing positive effects of nicotine on basic attentional functions but do not provide direct evidence for an improvement of top-down cognitive control through acute administration of nicotine at this dose in healthy non-smokers.

    DigitalF: Bauingenieurwesen und Umwelttechnik

    Vortrag

    Gerd Maurer

    Fabrik 4.0: Fabrik der Zukunft – Zukunft der Fabrikplanung

    Talk

    2017

    DigitalF: Bauingenieurwesen und Umwelttechnik

    Vortrag

    Gerd Maurer

    Bauindustrie 4.0 – Digitale Transformation

    Talk

    2017

    DigitalF: Bauingenieurwesen und Umwelttechnik

    Vortrag

    Gerd Maurer

    Einsatz von B.I.M. in der Industrieplanung und -realisierung: Praktische Erfahrungen und Ausblick in die Zukunft

    Talk

    Erfahrungsaustausch Industriebau, München

    2017

    DigitalF: Bauingenieurwesen und Umwelttechnik

    Vortrag

    Gerd Maurer

    Einsatz von B.I.M. in der Industrieplanung und -realisierung: Praktische Erfahrungen und Ausblick in die Zukunft

    Talk

    Erfahrungsaustausch Industriebau, Stuttgart

    2017

    DigitalF: Angewandte Informatik

    Zeitschriftenartikel

    Gökçe Aydos, G. Fey

    Empirical results on parity-based soft error detection with software-based retry

    Microprocessors and Microsystems, vol. 48, no. February, pp. 62-68

    2017

    DOI: 10.1016/j.micpro.2016.09.009

    Abstract anzeigen

    Local triple modular redundancy (LTMR) is often the first choice to harden the FFs of a flash-based FPGA application against radiation-induced bitflips in space, but LTMR leads to an area overhead of roughly 300%. To cope with this significant overhead, we propose an error detection based approach. In this work, we compare parity-based error detection with software-based retry, and LTMR on a reference architecture regarding maximum frequency, area overhead and processing time. Our results show that our solution based on parity-based error-detection saves from 29% up to 36% of the area overhead caused by LTMR.

    F: Angewandte Wirtschaftswissenschaften

    Buch (Monographie)

    Wolfgang Nagl, G. Titelbach, K. Valkova

    Digitalisierung der Arbeit: Substituierbarkeit von Berufen im Zuge der Automatisierung durch Industrie 4.0

    Studie im Auftrag des Sozialministeriums

    2017

    F: Angewandte Wirtschaftswissenschaften

    Buch (Monographie)

    S. Loretz, M.-B. Brandl, S. Koch, Wolfgang Nagl, G. Titelbach

    Evaluierung der Mehrwertsteueränderung im Zuge der Steuerreform 2015/16

    Studie im Auftrag des Bundesministeriums für Finanzen (unveröffentlicht)

    2017

    F: Angewandte Wirtschaftswissenschaften

    Buch (Monographie)

    B. Bittschi, B. Brandl, H. Hofer, S. Koch, Wolfgang Nagl, R. Sellner

    Zukunft der Steuern in Österreich - Mittelfristige Projektion der Lohn-, Einkommen-, Körperschaft- und Umsatzsteuer

    Studie im Auftrag des Bundesministeriums für Finanzen (unveröffentlicht)

    2017

    F: Angewandte Wirtschaftswissenschaften

    Zeitschriftenartikel

    S. Müllbacher, Wolfgang Nagl

    Labour supply in Austria: an assessment of recent developments and the effects of a tax reform

    Empirica - Journal of European Economics, vol. 44, no. 3, pp. 465-486

    2017

    DOI: 10.1007/s10663-017-9373-7

    Abstract anzeigen

    We apply a structural discrete choice framework to estimate income-specific own-wage and cross-wage labour supply elasticities in regard to working hours and participation for married and single males and females in Austria. We use data from the Austrian components of the European Statistics of Income and Living Conditions from 2004 to 2012. Own-wage elasticities are very small for males and slightly higher for females. Cross-wage elasticities are practically zero for males and slightly negative for females. Male and female own-wage elasticities decrease with higher incomes. Over time female labour supply elasticities decrease. Furthermore, we assess the labour supply and fiscal effects of the Austrian tax reform of 2016. We find a total increase in working hours by 0.71%. The labour supply effects are stronger on the intensive margin, for females and for low-income earners. On total the tax reform induces a tax relief of 4.7 billion Euros. The positive effects on tax burden and disposable income increase with the individual income.

    DigitalF: Angewandte WirtschaftswissenschaftenS: TC Grafenau

    Zeitschriftenartikel

    Michael Scholz, J. Pfeiffer, F. Rothlauf

    Using PageRank for non-personalized default rankings in dynamic markets

    European Journal of Operational Research, vol. 260, no. 1, pp. 388-401

    2017

    DOI: 10.1016/j.ejor.2016.12.022

    Abstract anzeigen

    Default ranking algorithms are used to generate non-personalized product rankings for standard consumers, for example, on landing pages of online stores. Default rankings are created without any information about the consumers’ preferences. This paper proposes using the product centrality ranking algorithm (PCRA), which solves some problems of existing default ranking algorithms: Existing approaches either have low accuracy, because they rely on only one product attribute, or they are unable to estimate ranks for new or updated products, because they use past consumer behavior, such as previous sales or ratings. The PCRA uses the PageRank centrality of products in a product domination graph to determine their ranks. The product domination graph models products as nodes and the dominance relations between the products’ attribute levels as edges. In a laboratory experiment with three product categories (energy saving lamps, hotel rooms, and washing machines), the PCRA leads to more accurate rankings than existing approaches provide. The PCRA ranks the lamps and washing machines that consumers prefer up to 1.5 positions higher in the default ranking than any of the existing algorithms. Only sorting hotel rooms’ price in ascending order beats the PCRA. Price is by far the most important attribute of hotel rooms for our consumer sample; therefore, a ranking that only considers price can beat a multi-attribute ranking like the PCRA, which assumes equal attribute weights. In summary, the PCRA is especially applicable to products where consumers consider more than one attribute and in markets where the product assortments change constantly.

    DigitalF: Angewandte WirtschaftswissenschaftenS: TC Grafenau

    Zeitschriftenartikel

    Michael Scholz, M. Franz, O. Hinz

    Effects of decision space information on MAUT-based systems that support purchase decision processes

    Decision Support Systems, vol. 97, no. May, pp. 43-57

    2017

    DOI: 10.1016/j.dss.2017.03.004

    Abstract anzeigen

    This paper shows that decision makers often have a misconception of the decision space. The decision space is constituted by the relations among the attributes describing the alternatives available in a decision situation. The paper demonstrates that these misconceptions negatively affect the usage and perceptions of MAUT-based decision support systems. To overcome these negative effects, this paper proposes to use a visualization method based on singular value decomposition to give decision makers insights into the attribute relations. In a laboratory experiment in cooperation with Germany's largest Internet real estate website, this paper moreover evaluates the proposed solution and shows that our solution improves decision makers' usage and perceptions of MAUT-based decision support systems. We further show that information about the decision space ultimately affects variables relevant for the economic success of decision support system providers such as reuse intention and the probability to act as a promoter for the systems.

    DigitalF: Angewandte WirtschaftswissenschaftenS: TC Grafenau

    Zeitschriftenartikel

    Michael Scholz, V. Dorner, G. Schryen, A. Benlian

    A configuration-based recommender system for supporting e-commerce decisions

    European Journal of Operational Research, vol. 259, no. 1, pp. 205-215

    2017

    DOI: 10.1016/j.ejor.2016.09.057

    Abstract anzeigen

    Multi-attribute value theory (MAVT)-based recommender systems have been proposed for dealing with issues of existing recommender systems, such as the cold-start problem and changing preferences. However, as we argue in this paper, existing MAVT-based methods for measuring attribute importance weights do not fit the shopping tasks for which recommender systems are typically used. These methods assume well-trained decision makers who are willing to invest time and cognitive effort, and who are familiar with the attributes describing the available alternatives and the ranges of these attribute levels. Yet, recommender systems are most often used by consumers who are usually not familiar with the available attributes and ranges and who wish to save time and effort. Against this background, we develop a new method, based on a product configuration process, which is tailored to the characteristics of these particular decision makers. We empirically compare our method to SWING, ranking-based conjoint analysis and TRADEOFF in a between-subjects laboratory experiment with 153 participants. Results indicate that our proposed method performs better than TRADEOFF and CONJOINT and at least as well as SWING in terms of recommendation accuracy, better than SWING and TRADEOFF and at least as well as CONJOINT in terms of cognitive load, and that participants were faster with our method than with any other method. We conclude that our method is a promising option to help support consumers’ decision processes in e-commerce shopping tasks.