Online product reviews, originally intended to reduce consumers’ pre-purchase search and evaluation costs, have become so numerous that they are now themselves a source for information overload. To help consumers find high-quality reviews faster, review rankings based on consumers’ evaluations of their helpfulness were introduced. But many reviews are never evaluated and never ranked. Moreover, current helpfulness-based systems provide little or no advice to reviewers on how to write more helpful reviews. Average review quality and consumer search costs could be much improved if these issues were solved. This requires identifying the determinants of review helpfulness, which we carry out based on an adaption of Wang and Strong’s well-known data quality framework. Our empirical analysis shows that review helpfulness is influenced not only by single-review features but also by contextual factors expressing review value relative to all available reviews. Reviews for experiential goods differ systematically from reviews for utilitarian goods. Our findings, based on 27,104 reviews from Amazon.com across six product categories, form the basis for estimating preliminary helpfulness scores for unrated reviews and for developing interactive, personalized review writing support tools. 相似文献
In the paper, an integrated approach for the modeling and enforcement of delegation policies in process-aware information systems is presented. In particular, a delegation extension for process-related role-based access control (RBAC) models is specified. The extension is generic in the sense that it can be used to extend process-aware information systems or process modeling languages with support for process-related RBAC delegation models. Moreover, the detection of delegation-related conflicts is discussed and a set of pre-defined resolution strategies for each potential conflict is provided. Thereby, the design-time and runtime consistency of corresponding RBAC delegation models can be ensured. Based on a formal metamodel, UML2 modeling support for the delegation of roles, tasks, and duties is provided. A corresponding case study evaluates the practical applicability of the approach with real-world business processes. Moreover, the approach is implemented as an extension to the BusinessActivity library and runtime engine. 相似文献
In general, research in business and information systems engineering (BISE) focuses on the design of business information systems. So far, the prevailing design-oriented research has taken a technique-oriented perspective, which focuses on the creation and application of innovative techniques such as methods, models, software prototypes, and similar artifacts for system design. In this paper we argue that design knowledge is of considerable importance for system design. Relevant design knowledge includes, for example, knowledge about design objectives, design techniques, and effects resulting from the use of techniques. This design knowledge can be produced, evaluated, and used in a scientific way. In this paper we present necessary basics for conceptualizing design knowledge. We illustrate the applicability of the conceptual foundations and the relevance of design knowledge using the example of “event-driven process chains (EPC)”. A discussion of implications of the presented results and future challenges for design-oriented BISE concludes the contribution. 相似文献
Zusammenfassung Drei Einschließungskreise werden definiert für Mengen, die bei Addition, Subtraktion, Multiplikation und Division komplexer Kreise entstehen. Die algebraische Struktur der dadurch erzeugten Arithmetiken und die Radien der Einschließungskreise werden verglichen. Neben zwei von N. Krier [5] dargestellten Arithmetiken sind die kleinsten Einschließungskreise angegeben, durch die die algebraische Struktur vonP() voll erhalten bleibt (optimale Kreisarithmetik). Bei der Berechnung einer inversen Matrix mit Arithmetiken für komplexe Kreise und achsenparallele Rechtecke werden Fehlerschranken und Rechenzeiten angegeben.
Arithmetic procedures for complex circles
Three enclosing circles are defined for sets that are obtained by addition, subtraction, multiplication and division of complex circles. The algebraic structures resulting from these arithmetic procedures and the radii of the enclosing circles are compared. In addition to the two arithmetic procedures described by N. Krier [5], the smallest enclosing circles are defined which preserve the algebraic structure ofP() (optimal circular arithmetic). Calculations of an inverse matrix are made by arithmetic procedures for complex circles and axially-parallel rectangles, and the error bounds and computation times are compared.
The cloud computing market divides into public (commercial) and private (self-provisioned) clouds. The concept of cloud bursting combines public and private clouds: The private cloud (internal resources) provides the computational capacity, but a part of the demand is offloaded onto public clouds. This article proposes an easy-to-apply economic decision support model for determining on the one hand the optimal size of the internal capacity for cloud bursting technology, and on the other hand the cost savings. The model uses an expected value approach that considers stochastic workload and is flexible with respect to the distribution choice. Two empirical examples demonstrate the applicability of the model. 相似文献
Consultative Assistance Systems (CASS) enhance today’s transaction-oriented applications by case-driven, rule-based and interactive components geared towards individual needs of the end-user.
CASS supports in the resolution process with rare cases, which are typically complex in nature.
CASS guides the end-user in finding a solution that covers all legal and economical aspects of each case.
The example described in this article represents a CASS which supports the complex process of public procurement under the tendering by-laws. The application architecture used in this example can be transferred to many eGovernment scenarios.
Zusammenfassung Datenbanksysteme zeichnen sich durch Charakteristika aus, die über den klassischen administrativ-betriebswirtschaftlichen Bereich hinaus zunehmend auch für Ingenieuranwendungen als vorteilhaft erkannt werden. Die Schwierigkeiten für einen sofortigen Einsatz in diesem Sektor liegen darin, daß existierende Systeme hinsichtlich Datenstrukturierung, Konsistenz, Mehrbenutzerbetrieb und Datensicherung keine den neuen Anforderungen entsprechenden Konzepte anbieten. Der Bericht nennt beispielhaft für den Bereich des Entwurfs technischer Objekte die wichtigsten Unterschiede zu traditionellen Anwendungen und stellt Lösungsvorschläge für die genannten Problemkreise vor. 相似文献
Das Semantic Web wird seit dem visionären Artikel von Berners-Lee, Hendler und Lassila [3] allgemein als die nächste Evolutionsstufe des World Wide Web betrachtet.
* Vorschläge an Prof.Dr. Frank Puppe <puppe@informatik.uni-wuerzburg.de> oder Dieter Steinbauer <dieter.steinbauer@schufa.de>Alle Aktuellen Schlagwörter seit 1988 finden Sie unter: www.ai-wuerzburg.de/as 相似文献
The recording industry is currently faced with a remarkable decline in revenues and record sales. Paid music services have failed to deliver on their promise of a full-catalog, easy-to-use shopping experience so far, and file sharing platforms are still widely used for obtaining online music. In this context we conducted an empirical study via the Internet with 2.260 participants. The main results are:
Neither the installation of copy protection measures nor legal actions taken against users of file sharing platforms seem to be appropriate means to increase sales of CDs and online music.
Potential consumers’ willingness to pay is distinctly lower than the prices currently set by the available paid music services.
Our study’s results suggest that a price cut for music downloads would lead to increased sales, thus creating benefits for both suppliers and consumers.
Location Planning for IT Service Vendors On global markets location planning plays an important role in the strategies of IT-service vendors. On the one hand, low wage countries enable new opportunities to offer services at low costs. On the other hand, however, vendors can not neglect the importance of physical closeness to markets and potential customers. In this paper we present a model and prototype to support location planning for IT service vendors. The model is based on the warehouse location problem which is well known from the field of logistics. 相似文献
The German energy market is facing several challenges due to changes in regulation, technical advancements as well as increasing energy costs and climate achievements like CO2 reduction. This results in changing requirements for companies in the energy market and thus business information systems, which support their core tasks and processes. Software product managers in energy and software developing companies in charge of driving the functional development of information systems have to deal with these challenges and need to develop new information systems or enhance existing ones. Conceptual models proved helpful to design and implement information systems within several industries. However, identification and management of models as well as impact analysis of model changes results difficult. This contribution describes methods to construct, use and maintain a domain specific reference model catalog to support requirements analysis for software product manager in the German electricity and gas market. 相似文献
Let G = (V, T, P, S) a c.f. grammar and F(V ? T) the free group generated by V ? T, ((G) = F(V ? T/P is the quotient of F (V ? T) factorized by the relationsystem generated by P. We prove that ((G) only depends on L(G) if G has no superflous variables. This means (fx107-1(G) is an invariant of grammar transformations which preserve the language. Each finitely representable group can be represented by a one sided liner grammar G as ((G).In a straightforward manner one can compute finite basises for the Alexander-ideals of the groups ((G. This ideals are finitely generated in an quotient of a Polynomring by a finitely generated ideal. Therefore this leads to effective computable necessary conditions for the equivalence of c.f. grammars. 相似文献
