The 10 most recently published documents
Solving transport network problems can be complicated by non-linear effects. In the particular case of gas transport networks, the most complex non-linear elements are compressors and their drives. They are described by a system of equations, composed of a piecewise linear ‘free’ model for the control logic and a non-linear ‘advanced’ model for calibrated characteristics of the compressor. For all element equations, certain stability criteria must be fulfilled, providing the absence of folds in associated system mapping. In this paper, we consider a transformation (warping) of a system from the space of calibration parameters to the space of transport variables, satisfying these criteria. The algorithm drastically improves stability of the network solver. Numerous tests on realistic networks show that nearly 100% convergence rate of the solver is achieved with this approach.
Since stationary self-checkout is widely introduced and well understood, previous research barely examined newer generations of smartphone-based Scan&Go. Especially from a design perspective, we know little about the factors contributing to the adoption of Scan&Go solutions and how design enables consumers to take full advantage of this development rather than being burdened with using complex and unenjoyable systems. To understand the influencing factors and the design from a consumer perspective, we conducted a mixed-methods study where we triangulated data of an online survey with 103 participants and a qualitative study with 20 participants. Based on the results, our study presents a refined and nuanced understanding of technology as well as infrastructure-related factors that influence adoption. Moreover, we present several implications for designing and implementing of Scan&Go in retail environments.
Due to ongoing digitalization, more and more cloud services are finding their way into companies. In this context, data integration from the various software solutions, which are provided both on-premise (local use or licensing for local use of software) and as a service, is of great importance. In this regard, Integration Platform as a Service (IPaaS) models aim to support companies as well as software providers in the context of data integration by providing connectors to enable data flow between different applications and systems and other integration services. Since previous research has mostly focused on technical or legal aspects of IPaaS, this article focuses on deriving integration practices and design-related barriers and drivers regarding the adoption of IPaaS. Therefore, we conducted 10 interviews with experts from different software as a services vendors. Our results show that the main factors regarding the adoption of IPaaS are the standardization of data models, the usability and variety of connectors provided, and the issues regarding data privacy, security, and transparency.
In the course of growing online retailing, recommendation systems have become established that derive recommendations from customers’ purchase histories. Recommending suitable food products can represent a lucrative added value for food retailers, but at the same time challenges them to make good predictions for repeated food purchases. Repeat purchase recommendations have been little explored in the literature. These predict when a product will be purchased again by a customer. This is especially important for food recommendations, since it is not the frequency of the same item in the shopping basket that is relevant for determining repeat purchase intervals, but rather their difference over time. In this paper, in addition to critically reflecting classical recommendation systems on the underlying repeat purchase context, two models for online product recommendations are derived from the literature, validated and discussed for the food context using real transaction data of a German stationary food retailer.
In diesem Lehrbuch geben die Autoren eine Einführung in die Methoden des traditionellen Projektmanagements in Anlehnung an die deutsche Gesellschaft für Projektmanagement (GPM/IPMA) und das Project Management Institute (PMI). Die typischen Merkmale und Schritte in einem Projekt, wichtige Rollen sowie die hilfreiche Einteilung in Phasen werden aufgezeigt und der Leser lernt, eine realistische Projektplanung aufzustellen und das Projekt zielgerichtet zu steuern. Viele praktische Beispiele sowie eingefügte Video-Sequenzen veranschaulichen das Gelernte. Arbeitsvorlagen sowie Kontrollfragen und Musterlösungen zu jedem Kapitel erleichtern den Einsatz in der Lehre und im Selbststudium. (Verlagsangaben)
Hektor Haarkötter und Filiz Kalmuk, zwei Kommunikationswissenschaftler*innen der Hochschule Bonn-Rhein-Sieg, haben die Medienseiten der überregionalen Printausgaben der SZ, FAZ und taz sowie der Regionalzeitungen WAZ, Tagesspiegel und Kölner Stadt-Anzeiger analysiert. Insgesamt wurden über 2000 Medienartikel untersucht. In Interviews mit verantwortlichen Medienredakteur*innen wichtiger Printorgane wurden Objektivität, Ausgewogenheit und Themenvielfalt der aktuellen Medienberichterstattung diskutiert.
Der Medienjournalismus deutscher Tageszeitungen zeichnet sich durch eine überwiegend sachliche Berichterstattung aus. Festgestellt wurde ein ausgeglichener Mix von ,harten‘ medienpolitischen Themen einerseits und ,weichen‘ Unterhaltungsthemen andererseits. Politische Parteien werden im Medienjournalismus nicht verzerrt dargestellt; über die „Systemkonkurrenz“ der öffentlich-rechtlichen Medien berichten die privatwirtschaftlich organisierten Zeitungen fair und ausgewogen.
Die Studie über „Medienjournalismus in Deutschland“ identifiziert aber auch Schwachstellen. Die dringend gebotene Reflexion über die gesellschaftlichen Folgen der Medienumwälzungen kommt zu kurz. Veränderungen durch die Digitalisierung und die Europäisierung der Medien-Landschaft spielen eine untergeordnete Rolle, für Belange des Hörfunks zeigt er zu wenig Interesse.
This book discusses the development of the Rosenbrock—Wanner methods from the origins of the idea to current research with the stable and efficient numerical solution and differential-algebraic systems of equations, still in focus. The reader gets a comprehensive insight into the classical methods as well as into the development and properties of novel W-methods, two-step and exponential Rosenbrock methods. In addition, descriptive applications from the fields of water and hydrogen network simulation and visual computing are presented. (Verlagsangaben)
