ÐReal-time systems are being increasingly used in several applications which are time-critical in nature. Fault tolerance is an essential requirement of such systems, due to the catastrophic consequences of not tolerating faults. In this paper, we study a scheme that guarantees the timely recovery from multiple faults within hard real-time constraints in uniprocessor systems. Assuming earliestd...

This paper describes an approach to the analysis of time-critical systems which combines discreteevent simulation and model-checking techniques. The approach rests on Merlin and Farber’s Time Petri Nets (TimePNs) and is supported by a Java toolbox −TPN/DESIGNER− which enables graphical modelling and simulation of modular TimePN models. The toolbox also allows translation of a TimePN model into ...

One aspect often needed when modelling systems of any kind is time-based analysis, especially for real-time or in general time-critical systems. Algebraic place/transition (P/T) nets do not inherently provide a way to model the passing of time or to restrict the firing behaviour with regards to passing time. In this paper, we present an extension of algebraic P/T nets by adding time durations t...

Swendsen–Wang dynamics for the Potts model was proposed in the late 1980’s as an alternative to single-site heat-bath dynamics, in which global updates allow this MCMC sampler to switch between metastable states and ideally mix faster. Gore and Jerrum (1999) found that this dynamics may in fact exhibit slow mixing: they showed that, for the Potts model with q ≥ 3 colors on the complete graph on...

Anytime algorithms offer a tradeoff between solution quality and computation time that has proved useful in solving time-critical problems such as planning and scheduling, belief network evaluation, and information gathering. To exploit this tradeoff, a system must be able to decide when to stop deliberation and act on the currently available solution. This paper analyzes the characteristics of...

Polymorphic inline caches (PICs) provide a new way to reduce the overhead of polymorphic message sends by extending inline caches to include more than one cached lookup result per call site. For a set of typical object-oriented SELF programs, PICs achieve a median speedup of 11%. As an important side effect, PICs collect type information by recording all of the receiver types actually used at a...

This research addresses a problem of how to make effective use of real-time information acquired from multiple sensor and heterogeneous data resources, and reasoning on the gathered information for situation assessment and impact assessment (SA/IA), thus to provide reliable decision support for time-critical operations. A hierarchical collective agents network (HCAN) is presented as a solution ...

Sensor networks that can support time-critical operations pose challenging problems for tracking events of interest. We propose an architecture for a sensor network that autonomously adapts in real-time to data fusion requirements so as not to miss events of interest and provides accurate real-time mobile target tracking. In the proposed architecture, the sensed data is processed in an abstract...

This paper utilizes the Islamic holy month of Ramadan, a period of religious fasting, as a natural experiment to identify the effects of in utero nutrition on the labor market behavior of children in Indonesia when they become adults. Approximately seventy five percent of all pregnancies overlap with Ramadan, suggesting that in 2010 alone, more than 1.2 billion Muslims globally and 155 million ...

Introducing automated formal methods for large industrial real-time systems is an important research challenge. We propose timed process automata (TPA) for modeling and analysis of time-critical systems which can be open, hierarchical, and dynamic. The model offers two essential features for large industrial systems: (i) compositional modeling with reusable designs for different contexts, and (...