k-Step Relative Inductive Generalization

We introduce a new form of SAT-based symbolic model checking. One common idea in SAT-based symbolic model checking is to generate new clauses from states that can lead to property violations. Our previous work suggests applying induction to generalize from such states. While effective on some benchmarks, the main problem with inductive generalization is that not all such states can be inductively generalized at a given time in the analysis, resulting in long searches for generalizable states on some benchmarks. This paper introduces the idea of inductively generalizing states relative to $k$-step over-approximations: a given state is inductively generalized relative to the latest $k$-step over-approximation relative to which the negation of the state is itself inductive. This idea motivates an algorithm that inductively generalizes a given state at the highest level $k$ so far examined, possibly by generating more than one mutually $k$-step relative inductive clause. We present experimental evidence that the algorithm is effective in practice.Comment: 14 page

Development of a novel metastable composite material

The development of a new family of mouldable metastable composite materials has been demonstrated. Their special quality is derived from the ability to maintain the matrix as a supercooled liquid or gel whose solidification can be triggered mechanically, as desired, by a user. This article describes some aspects of the development work. In particular, the following are explained: the choice of matrix material; the use of additives to enhance the properties of the matrix; and the selection of reinforcement fibre. As part of the work, some mechanical testing was performed on several variations of a matrix-fibre pair and, to demonstrate the potential of such materials, some comparisons were made with a possible competitor material, a glass-reinforced urethane. It was shown that the metastable material could be formulated to provide mechanical properties that would make it suitable for applications such as orthopaedic casting, splinting and body armour, and in items of sports equipment, these being areas where its mouldability could be particularly desirable

GlobalFestival: Evaluating Real World Interaction on a Spherical Display

Spherical displays present compelling opportunities for interaction in public spaces. However, there is little research into how touch interaction should control a spherical surface or how these displays are used in real world settings. This paper presents an in the wild deployment of an application for a spherical display called GlobalFestival that utilises two different touch interaction techniques. The first version of the application allows users to spin and tilt content on the display, while the second version only allows spinning the content. During the 4-day deployment, we collected overhead video data and on-display interaction logs. The analysis brings together quantitative and qualitative methods to understand how users approach and move around the display, how on screen interaction compares in the two versions of the application, and how the display supports social interaction given its novel form factor

Specialization and Variety in Repetitive Tasks: Evidence from a Japanese Bank

Sustaining operational productivity in the completion of repetitive tasks is critical to many organizations' success. Yet research points to two different work-design related strategies for accomplishing this goal: specialization to capture the benefits of repetition or variety to keep workers motivated and allow them to learn. In this paper, we investigate how these two strategies may bring different benefits within the same day and across days. Additionally, we examine the impact of these strategies on both worker productivity and workers' likelihood of staying at a firm. For our empirical analyses, we use two and a half years of transaction data from a Japanese bank's home loan application processing line. We find that over the course of a single day, specialization, as compared to variety, is related to improved worker productivity. However, when we examine workers' experience across days we find that variety, or working on different tasks, helps improve worker productivity. We also find that workers with higher variety are more likely to stay at the firm. Our results identify new ways to improve operational performance through the effective allocation of work.Job Design, Learning, Productivity, Specialization, Turnover, Variety, Work Fragmentation

Third-Party Intervention and the Preservation of Bargaining Relationships

This article uses longitudinal contact data to examine if third-party dispute resolution procedures available in Ontario improve the health of bargaining relationships and contribute to their preservation. It performs this in two manners: (1) using survival analysis to see how the mechanisms correlate with the likelihood of relationship dissolution and (2) using dynamic panel models to observe their state dependence. The latter is undertaken to see if third-party intervention pushes the parties to settle subsequent agreements earlier in the process – a finding that would reveal another aspect of relationship preservation if those earlier interventions are shown to correlate with lower likelihoods of dissolution. While the survival analysis does show that the earlier procedures in the dispute resolution process associate with lower likelihoods of dissolution than later ones, the dynamic panel model estimates do not indicate that third-party intervention induces voluntary or even earlier settlements in subsequent rounds of bargaining