An industrial application of symbolic model checking

Model checking techniques are recognized to provide reliable and copious results. Instead of examining a few cases only – as it is done in testing – model checking includes the whole state space in mathematical proofs of correctness. Yet, this completeness is seen as a drawback as the state explosion problem is hard to handle. In our industrial case study, we apply automated model checking techniques to an innovative elevator system, the TWIN by ThyssenKrupp. By means of abstraction and nondeterminism, we cope with runtime behaviour and achieve to efficiently prove our specification’s validity. The elevator’s safety requirements are exhaustively expressed in temporal logic along with real-world and algorithmic prerequisites, consistency properties, and fairness constraints. Beyond verifying system safety for an actual installation, our case study demonstrates the rewarding applicability of model checking at an industrial scale. CR subject classification  D.2.4; F.3.1; J.7 ; C.3     

Three Decades of Implementation Research in Higher Education: Limitations and Prospects of Theory Development

The article adopts a comparative approach to review three periods of theory development in research into higher education policy implementation. Given the conceptual affinity between Cerych and Sabatier's 1986 seminal study into higher education policy implementation and public policy implementation theory, the field of public policy is chosen for reference and comparison. The article argues, first, that the underlying characteristics of higher education research such as sector‐isolatedness, application drift and sensitivity to political agendas hindered the development of sector‐specific theories of policy implementation. Second, this gap in theory formation started to be narrowed from the late 1990s onwards, due to critical reappraisal of the 1986 study and due to limited utilisation of mid‐range theory concepts conceived within or related to the public policy field. It is through the utilisation of such public policy theory that higher education implementation research may reach a more mature stage.     

Dueling Co-Authors: How Collaborators Create and Sometimes Solve Contributorship Conflicts

Publishing is central to the academic reward system. Contributorship issues loom large in this context. The need for fairness in authorship decisions is upheld in most collaborations, yet some collaborations are plagued by “nightmare” issues ranging from inappropriate authorship credit to author order issues to exploitation of students and postdocs. This present work analyzes the mechanisms that researchers use for addressing problems in research collaboration and authorship. The data are derived from face-to-face, phone or Skype interviews with 60 university researchers. The extent to which author crediting decisions are explicitly or implicitly communicated and communicated in advance versus in the aftermath of the completion of research are central features in conflict resolution. Explicit approaches are associated with fields characterized by large or infrastructure-intensive projects, whereas implicit approaches often represent unspoken discipline-based norms. Efforts to educate students in how to manage authoring decisions tend to use advance methods. Problems stemming from a difficult researcher’s actions cross these categories. Early communication would seem to be useful for issue resolution, but it is not widely used in part because it can lock-in to an author crediting plan too tightly and reduce flexibility as research directions change.     

Project Author: Visionary training with far reaching consequences

In the 1980s a government initiative was made to meet the need for instructional designers for the emerging Technology Based Training needs of industry and commerce. The course achieved its objectives but also sparked the development of current UK e-learning because the course developed people who were skilled at adaptability and flexibility with ever changing technology coupled with a thorough understanding of how people learn, and these were highly motivated to use their skills. The effectiveness of the course can be seen by the number of people from Project Author who are still in the sector and in highly influential positions.     

Exploiting Hierarchy in Text Categorization

With the recent dramatic increase in electronic access to documents, text categorization—the task of assigning topics to a given document—has moved to the center of the information sciences and knowledge management. This article uses the structure that is present in the semantic space of topics in order to improve performance in text categorization: according to their meaning, topics can be grouped together into meta-topics, e.g., gold, silver, and copper are all metals. The proposed architecture matches the hierarchical structure of the topic space, as opposed to a flat model that ignores the structure. It accommodates both single and multiple topic assignments for each document. Its probabilistic interpretation allows its predictions to be combined in a principled way with information from other sources. The first level of the architecture predicts the probabilities of the meta-topic groups. This allows the individual models for each topic on the second level to focus on finer discriminations within the group. Evaluating the performance of a two-level implementation on the Reuters-22173 testbed of newswire articles shows the most significant improvement for rare classes.