Combining Expression and Content in Domains for Dialog Managers

We present work in progress on abstracting dialog managers from their domain in order to implement a dialog manager development tool which takes (among other data) a domain description as input and delivers a new dialog manager for the described domain as output. Thereby we will focus on two topics; firstly, the construction of domain descriptions with description logics and secondly, the interpretation of utterances in a given domain.Comment: 5 pages, uses conference.st

Modelling Users, Intentions, and Structure in Spoken Dialog

We outline how utterances in dialogs can be interpreted using a partial first order logic. We exploit the capability of this logic to talk about the truth status of formulae to define a notion of coherence between utterances and explain how this coherence relation can serve for the construction of AND/OR trees that represent the segmentation of the dialog. In a BDI model we formalize basic assumptions about dialog and cooperative behaviour of participants. These assumptions provide a basis for inferring speech acts from coherence relations between utterances and attitudes of dialog participants. Speech acts prove to be useful for determining dialog segments defined on the notion of completing expectations of dialog participants. Finally, we sketch how explicit segmentation signalled by cue phrases and performatives is covered by our dialog model.Comment: 17 page

Overtures to the pulsational instability of ZZ Ceti variables

Results of nonradial, nonadiabatic pulsation calculations on hydrogen-rich white dwarf models are presented. In contrast to earlier attempts, the modeling builds on hydrodynamically simulated convective surface layers supplemented with standard interior models. Based on our stellar models and despite of various simple attempts to couple convection and pulsation we could not reproduce theoretically the presently adopted location of the observed blue edge of the ZZ Ceti variables. When the convective efficiency is high enough we found a sensitive dependence of the stability properties of the g-modes on the pulsational treatment of shear within the convection zone.Comment: 13 pages, postscript figures included in text, uuencoded gzipped ps-file. Submitted for publication in Astron.&Astrophy

E-procurement Structures in Purchasing Consortia: Towards a Conceptual Framework

In the literature there has been little empirical research investigation into purchasing consortium issues focusing on a detailed analysis of information and communication technology (ICT) based procurement strategies. While some anecdotal accounts of such advances in supply chain management can be found, there is a need to relate the term electronic purchasing consortia (EPC) to academic literature, thus empowering clearer theoretical analysis. EPC enable purchasing organisations to varying degrees, to electronically conduct tasks that are necessary for the management of demand aggregation of two or more legal entities, provide efficient ICT-based communication infrastructures and rely more on electronic communication than face-to-face contact. An overall statement was developed for the study of EPC: ‘Effective participation in electronic purchasing consortia can have the potential to enhance competitive advantage. EPC implementation is dependent upon a clear and detailed understanding of the major process enablers and drivers. This understanding requires the development of a taxonomy and a conceptual framework to EPC. One practical use of this taxonomy is the assessment of feasibility in given industry sectors’ This overall statement is assessed by the exploration of academic literature, five multiple case studies and two surveys. 128 purchasing organisations as will as 43 e-Marketplaces/procurement service providers (PSPs) in the automotive and electronics industry sectors participated in the surveys. By adopting methodological pluralism and triangulation techniques, key factors and structures that affect the adoption and diffusion of EPC, based upon the technology-organisation –environment framework, and the performance impact of adoption are investigated. The findings suggest that only 7% of purchasing organisations take advantage of EPC, but 44% of e-Marketplaces /PSPs offer them to date. Organisation size, purchasing maturity and technological competence are strongly associated with adoption of EPC, while the level of industry fragmentation, pressures from the business context, purchasing spend, intensity of multi sourcing strategies and product pooling potential are not. EPC can enhance competitive advantage and have generated on average net reductions in purchasing costs of over 5% and a return on investment of over 70%. However, EPC do not necessarily lead to a higher level of purchasing effectiveness and efficiency, a lower level of maverick purchasing or a reduction in the number of suppliers. More conflict with EPC can arise in the automotive industry due to it OEM concentration, cultural and structural impediments (e.g. overcapacity, vertical integration) and technical factors (e.g. high level of modularised assembly). Sophisticated employment of EPC is still very much at a developmental stage. The empirically derived original model for EPC represents a valuable starting point of EPC research within which to comprehend its current state and the directions for future studies

User Preferences and the Shortest Path

Indoor navigation systems leverage shortest path algorithms to calculate routes. In order to define the "shortest path", a cost function has to be specified based on theories and heuristics in the application domain. For the domain of indoor routing, we survey theories and criteria identified in the literature as essential for human path planning. We drive quantitative definitions and integrate them into a cost function that weights each of the criteria separately. We then apply an exhaustive grid search to find weights that lead to an ideal cost function. "Ideal" here is defined as guiding the algorithm to plan routes that are most similar to those chosen by humans. To explore which criteria should be taken into account in an improved pathfinding algorithm, eleven different factors whose favorable impact on route selection has been established in past research were considered. Each factor was included separately in the Dijkstra algorithm and the similarity of thus calculated routes to the actual routes chosen by students at the University of Regensburg was determined. This allows for a quantitative assessment of the factors' impact and further constitutes a way to directly compare them. A reduction of the number of turns, streets, revolving doors, entryways, elevators as well as the combination of the aforementioned factors was found to have a positive effect and generate paths that were favored over the shortest path. Turns and the combination of criteria turned out to be most impactful

Schematic Maps and Indoor Wayfinding

Schematic maps are often discussed as an adequate alternative of displaying wayfinding information compared to detailed map designs. However, these depictions have not yet been compared and analyzed in-depth. In this paper, we present a user study that evaluates the wayfinding behaviour of participants either using a detailed floor plan or a schematic map that only shows the route to follow and landmarks. The study was conducted in an indoor real-world scenario. The depictions were presented with the help of a mobile navigation system. We analyzed the time it took to understand the wayfinding instruction and the workload of the users. Moreover, we examined how the depictions were visually perceived with a mobile eye tracker. Results show that wayfinders who use the detailed map spend more visual attention on the instructions. Nevertheless, the depiction does not help to solve the task: they also needed more time to orient themselves. Regarding the workload and the wayfinding errors no differences were found