Enforcing Termination of Interprocedural Analysis

Interprocedural analysis by means of partial tabulation of summary functions may not terminate when the same procedure is analyzed for infinitely many abstract calling contexts or when the abstract domain has infinite strictly ascending chains. As a remedy, we present a novel local solver for general abstract equation systems, be they monotonic or not, and prove that this solver fails to terminate only when infinitely many variables are encountered. We clarify in which sense the computed results are sound. Moreover, we show that interprocedural analysis performed by this novel local solver, is guaranteed to terminate for all non-recursive programs --- irrespective of whether the complete lattice is infinite or has infinite strictly ascending or descending chains

Correctness Witness Validation by Abstract Interpretation

Witnesses record automated program analysis results and make them exchangeable. To validate correctness witnesses through abstract interpretation, we introduce a novel abstract operation unassume. This operator incorporates witness invariants into the abstract program state. Given suitable invariants, the unassume operation can accelerate fixpoint convergence and yield more precise results. We demonstrate the feasibility of this approach by augmenting an abstract interpreter with unassume operators and evaluating the impact of incorporating witnesses on performance and precision. Using manually crafted witnesses, we can confirm verification results for multi-threaded programs with a reduction in effort ranging from 7% to 47% in CPU time. More intriguingly, we discover that using witnesses from model checkers can guide our analyzer to verify program properties that it could not verify on its own.Comment: 29 pages, 4 figures, 2 tables, extended version of the paper which is to appear at VMCAI 202

Mechanism of the photovoltaic effect in 2-6 compounds Progress report, 1 Oct. 1968 - 31 Mar. 1969

Heat treatment, illumination and darkness effects, and photovoltaic properties of Cu2S-CdS heterojunction

Problem solving and the co-ordination of innovative activities

In the context of increasingly globalized markets, ever more complex supply chains and international manufacturing networks, corporate decision-making processes involve more and more actors, variables and criteria. This is a challenge for corporate head quarters. Many have argued that the role once attributed to the integrated innovative organisation and its R&D laboratories is increasingly associated with the functioning of networks of specialised innovators. The aim of this paper is to argue that the role of large firms may have changed, but it is far from disappeared. It looks at the interplay of increasing knowledge specialisation, the development of products of increasing complexity that perform a widening range of functionalities, and the emergence and diffusion of new design strategies for both products and organisations, namely modularity. The emergence of modularity as a product and organisational design strategy is clearly connected to recent trends in organisational design. Modularity would allow the decoupling of complex artifacts into simpler, self-contained modules. Each module would, at the extreme, become the sole business of a specialised trade. This paper builds upon the idea that there are cognitive limits to this process of modularisation: what kinds of problems firms solve, and how they solve them, set limits to the extent of division of labour among firms. We draw implications of such limits for both management and economic theory.large firms, knowledge specialisation, complex products, modularity,

Gasshūkoku ni okeru hōgakkai to hōjitsumukai [The Worlds of Academics and Legal Practice in the United States]

I prepared this paper for a symposium entitled, Academics and Practitioners in Japan and the United States: Can the Two Worlds Ever Meet? When I saw the symposium title, my first reaction was that it might seem strange to ask whether the worlds of academics and legal practice can ever meet in the United States. After all, to a large degree the history of the law school in the United States has been that of an institution dedicated to the training of legal practitioners; the vast majority of US law professors are members of the bar; and many, if not most, US law professors also practice or serve as legal consultants from time to time. In fact, of any nation in the world, in the US legal education probably has the closest connection to the world of practice. Still, in recent years, a number of observers have claimed that in the US, two worlds that used to meet regularly have begun to drift apart, with law schools becoming so academically and theoretically-oriented that they have started to lose touch with and relevance to legal practice

Mood and Creativity: The Mediating Role of Attention

Within literature there are two opposing views regarding the role of emotions in the creative process. The most commonly held view contends that positive emotions enhance creativity, while negative emotions stifle it; yet, some studies show an opposite trend. To help resolve this conundrum, this research examined the mediating effect of attention on the relationship between mood and creativity. The results showed that positive deactivating and negative activating emotions led to broader attention, while positive activating and negative deactivating emotions caused narrowing of attention. Furthermore, the creative process is not uniform in its requirements of attentional breadth; some creative tasks require broad and others narrow attention for their completion. When differential requirements for global versus local attentional focus at the differing stages of creativity were taken into consideration, the influence of emotions become more straightforward; different attentional breadth requirements corresponded to differential stages of creative performance