A primer on noise-induced transitions in applied dynamical systems

Noise plays a fundamental role in a wide variety of physical and biological dynamical systems. It can arise from an external forcing or due to random dynamics internal to the system. It is well established that even weak noise can result in large behavioral changes such as transitions between or escapes from quasi-stable states. These transitions can correspond to critical events such as failures or extinctions that make them essential phenomena to understand and quantify, despite the fact that their occurrence is rare. This article will provide an overview of the theory underlying the dynamics of rare events for stochastic models along with some example applications

Uneven geographies of organizational practice: explaining the cross-national transfer and adoption of ISO 9000

There is growing recognition that organizational innovations can have a major influence on the geography of economic activity. Yet, very little is known about the mechanisms and geographic preconditions underlying their diffusion, particularly at the global level. In this paper we seek to fill this gap using the example of ISO 9000, the internationally- recognized set of standards for quality management. We develop a series of hypotheses about the conditions under which organizations are most likely to adopt ISO 9000. These hypotheses are then tested using panel data for 130 countries over the period 1995-2001. Our findings support the idea that transnational network ties linking countries to the wider global community influence adoption decisions. Thus, exports to the EU and Japan, local involvement of transnational corporations (TNCs), colonial ties to Europe and the availability of telecommunications, all emerge as statistically significant determinants of ISO 9000 counts. Our results also underscore the importance of national environmental conditions. Low regulatory burden, a high share of manufacturing activity, high rates of secondary school enrolment and low levels of productivity are positively associated with a high number of certificates. We conclude that globalization has increased the mobility of organizational innovations across national borders. Yet, country- level variations in (a) transnational network linkages and (b) environmental conditions influencing the receptiveness of organizations to new economic practices, suggest that spatial unevenness is an inevitable feature of organizational diffusion at the global level.ISO 9000, standards, cross-national diffusion, globalization, institutionalism

Do membership benefits buy regulatory compliance?: an empirical analysis of EU directives 1978-1999.

Underlying several theories of European integration is the idea that countries' willingness to sign up to supranational rules is dependent on the expectation and/or realization of various benefits. In this paper, we explore whether such benefits also affect member states' implementation of these rules. Using econometric techniques, we estimate the influence of several measures of membership benefits on the annual number of legal infringements received by 15 member states over the period from 1978 to 1999. Our results provide qualified support for the idea that benefits positively influence compliance. We find that greater intra-EU trade dependence and voting power in European institutions relative to population size are negatively associated with legal infringements. Yet, contrary to a priori expectations, net fiscal transfers are positively correlated with infringements.

Implementing multilateral environmental agreements: an analysis of EU directives.

While a number of different theoretical models have been advanced to explain why states implement—or, indeed, do not implement—multilateral environmental agreements (MEAs), very little empirical work has been undertaken to validate their predictions. With a view to narrowing this gap, the present article adopts a large-N, econometric approach to test the explanatory power of four distinct models of compliance—domestic adjustment, reputational, constructivist and managerial—in the context of European Union (EU) environmental policy. Using data on the number of ofıcial infringements received by 15 member states for non-implementation of environmental directives over the period 1979–2000, we ınd that all four models make a statistically signiıcant contribution to explaining spatio-temporal differences in legal implementation. Thus, our results suggest that the implementation of MEAs is shaped by a combination of rational calculations of domestic compliance costs and reputational damage, domestically institutionalized normative obligations, and legal and political constraints. We conclude by suggesting a greater need for multi-causal theoretical models of supranational legal compliance.

Mixed-Criticality Scheduling with I/O

This paper addresses the problem of scheduling tasks with different criticality levels in the presence of I/O requests. In mixed-criticality scheduling, higher criticality tasks are given precedence over those of lower criticality when it is impossible to guarantee the schedulability of all tasks. While mixed-criticality scheduling has gained attention in recent years, most approaches typically assume a periodic task model. This assumption does not always hold in practice, especially for real-time and embedded systems that perform I/O. For example, many tasks block on I/O requests until devices signal their completion via interrupts; both the arrival of interrupts and the waking of blocked tasks can be aperiodic. In our prior work, we developed a scheduling technique in the Quest real-time operating system, which integrates the time-budgeted management of I/O operations with Sporadic Server scheduling of tasks. This paper extends our previous scheduling approach with support for mixed-criticality tasks and I/O requests on the same processing core. Results show the effective schedulability of different task sets in the presence of I/O requests is superior in our approach compared to traditional methods that manage I/O using techniques such as Sporadic Servers.Comment: Second version has replaced simulation experiments with real machine experiments, third version fixed minor error in Equation 5 (missing a plus sign

Heavy-Quark Hybrid Mass Splittings: Hyperfine and "Ultrafine"

It is argued that the heavy-quark limit of QCD requires a certain combination of hyperfine mass splittings in heavy-quark hybrid-meson multiplets to be unusually small. This observation will assist in the exploration of the heavy-quark hybrid spectrum at facilities such as PANDA. Alternatively, a large measured value for this mass splitting indicates that at least one member of the multiplet must contain significant light-quark degrees of freedom.Comment: Version to appear in Few-Body Systems. Substantial modifications from previous version, including extensive additional references and an expanded discussion of relevant operators. 7 page

Predictable migration and communication in the Quest-V multikernal

Quest-V is a system we have been developing from the ground up, with objectives focusing on safety, predictability and efficiency. It is designed to work on emerging multicore processors with hardware virtualization support. Quest-V is implemented as a ``distributed system on a chip'' and comprises multiple sandbox kernels. Sandbox kernels are isolated from one another in separate regions of physical memory, having access to a subset of processing cores and I/O devices. This partitioning prevents system failures in one sandbox affecting the operation of other sandboxes. Shared memory channels managed by system monitors enable inter-sandbox communication. The distributed nature of Quest-V means each sandbox has a separate physical clock, with all event timings being managed by per-core local timers. Each sandbox is responsible for its own scheduling and I/O management, without requiring intervention of a hypervisor. In this paper, we formulate bounds on inter-sandbox communication in the absence of a global scheduler or global system clock. We also describe how address space migration between sandboxes can be guaranteed without violating service constraints. Experimental results on a working system show the conditions under which Quest-V performs real-time communication and migration.National Science Foundation (1117025