University of Passau

About: University of Passau is a education organization based out in Passau, Bayern, Germany. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 1543 authors who have published 4763 publications receiving 93338 citations.

The METAFrame'95 Environment

Abstract: 1 The MetaFrameEnvironment MetaFrame is a meta-level framework designed to ooer a sophisticated support for the systematic and structured computer aided generation of application-speciic complex objects from collections of reusable components. Figure 1 shows its overall organization. Special care has been taken in the design of an adequate, almost natural-language speciication language, of a user-friendly graphical interface , of a hypertext based navigation tool, and a of semi-automatic synthesis process and repository management. This application-independent core is complemented by application-speciic libraries of components, which constitute the objects of the synthesis. The principle of separating the component implementation from its description is systematically enforced: for each application we have a distinct Meta-Data repository containing a logic view of the components. The tools themselves and their documentation are available in a diierent repository. This organization ooers a maximum of exibility since the synthesis core is independent of the direct physical availability of the tools (except for the execution, which is a diierent matter). MetaFrame constitutes a sophisticated programming environment for large to huge grain programs whose implementation is supported by the automatic, library-based synthesis of linear compositions of modules. More complex control structures glueing the linear portions together must be programmed by hand. Still, being able to synthesize linear program fragments drastically improves over other methods where only single components can be retrieved from the underlying repository. This is already true in cases where one is only interested in the functionality of single components, because our synthesis algorithm will automatically determine the required interfacing modules. Thus MetaFrame supports the rapid and reliable realization of eecient application speciic complex systems without sophisticated user interaction, making it an ideal means for a systematic investigation and construction of adequate implementations in a problem speciic scenario. The MetaFrame approach abstracts from implementational details by allowing designers a high-level-development of the tools. Speciications express constraints in a temporal logic that uniformly and elegantly captures an abstract view of the repository. Implementations are in a high-level language tailored to express the combination of reusable analysis, veriication and transformation components stored in the repository, which are considered as atomic on this level.

“Why Would I Read a Mobile Review?” Device Compatibility Perceptions and Effects on Perceived Helpfulness

Abstract: The proliferation of mobile devices means that mobile-generated customer reviews are on the rise, though research into their peculiarities and appraisals is rare. With field data and a scenario experiment, the current research demonstrates how recipients perceive mobile-generated customer reviews fundamentally differently from nonmobile-generated reviews. First, behavioral field data provide evidence that consumers discount the helpfulness of mobile reviews due to their text-specific content and style particularities. Second, the scenario experiment shows that identifying a review as written on a mobile device lowers recipients’ perceptions of its value, but only if they use a nonmobile device to read the review. Recipients rely on device information as a source cue to assess compatibility. If they perceive themselves as compatible with the device, recipients perceive the review as more helpful because they attribute the review's content to the quality of the reviewed object; if they regard it as incompatible, recipients assume the review reflects the personal dispositions of the reviewer and discount its helpfulness. Managers of online opinion platforms thus must acknowledge the peculiarities of mobile-generated reviews and the impact of tagging content as mobile or not.

JSON Sensor Signatures (JSS): End-to-End Integrity Protection from Constrained Device to IoT Application

Abstract: Integrity of sensor readings or actuator commands is of paramount importance for a secure operation in the Internet-of-Things (IoT). Data from sensors might be stored, forwarded and processed by many different intermediate systems. In this paper we apply digital signatures to achieve end-to-end message level integrity for data in JSON. JSON has become very popular to represent data in the upper layers of the IoT domain. By signing JSON on the constrained device we extend the end-to-end integrity protection starting from the constrained device to any entity in the IoT data-processing chain. Just the JSON message's contents including the enveloped signature and the data must be preserved. We reached our design goal to keep the original data accessible by legacy parsers. Hence, signing does not break parsing. We implemented an elliptic curve based signature algorithm on a class 1 (following RFC 7228) constrained device (Zolertia Z1: 16-bit, MSP 430). Furthermore, we describe the challenges of end-to-end integrity when crossing from IoT to the Web and applications.

Structured Specifications: Syntax, Semantics and Proof Calculus

Abstract: In this paper, a small but expressive language is presented that allows to write algebraic specifications in a structured and modular way. Proof rules are developed for each construct of the language; in particular, proof systems are given for flat specifications, for structured specifications and the verification of implementations. The language consists of four constructs: one for constructing a flat specification (from a signature and a set of axioms) and three operators for exporting a subsignature, for renaming and for combining specifications.