In nite wait anomalies associated with a barrier rendezvous model (e.g., Ada) can be divided into two classes: stalls and deadlocks. Although precise static deadlock detection is NP-hard, we present two polynomial time algorithms which operate on a statically derivable program representation, the sync graph, to certify a useful class of programs free of deadlocks. We identify three conditions l...

In most real-time systems, concurrency and access to shared resources are controlled by locking. A serious disadvantage is that locking may give rise to priority inversion, i.e. situations in which a high-priority task has to wait for a low-priority task to release a lock. That is a serious problem, because it can make a task miss its deadline, which, in turn can cause various types of disaster...

BACKGROUND Cataract surgery is the most common operative procedure performed in Canada, and how patients are affected by wait times for this surgery has important clinical, public health and health policy considerations. We conducted a systematic review to understand the relation between wait time for cataract surgery and patient outcomes and the variables that modify this relation. METHODS W...

The aim of this position paper is to promote the use of wait-free implementations for real-time shared objects. Such implementations allow the nonfaulty processes to progress despite the fact the other processes are slow, fast or have crashed. This is a noteworthy property for shared real-time objects. To assess its claim, the paper considers wait-free implementations of three objects: a renami...

How do representations of the future shape behavior? Prior research has shown that people’s willingness to wait for a future reward decreases with increases in time. At the same time, this research has also shown that such effects can depend on the vividness of the future reward, as well as, on individual differences. The present research offers a potential explanation for these additional effe...

The continuing explosive growth of the web has not been matched by an adequate enhancement of the infrastructure on which it depends. Both consumers and producers are often left frustrated at the disappointingly slow speed of service. Yet there has been little systematic attempt to analyse the sources of delay experienced by users. We present a structured timing model which covers the entire pe...

Cardiovascular nuclear medicine uses agents labelled with radioisotopes that can be imaged with cameras (single-photon emission tomography [SPECT] or positron emission tomography [PET]) capable of detecting gamma photons to show physiological parameters such as myocardial perfusion, myocardial viability or ventricular function. There is a growing body of literature providing guidelines for the ...

Extended wait times for elective procedures has been an important issue in the Canadian health care system for many years, and sight restoration was among the five priority clinical areas identified and targeted for wait time reduction by the Canadian first ministers in 2004. The extent to which this initiative has been successful for cataract surgery is unclear. According to a recent report fr...

One of the unusual challenges faced by peer-to-peer algorithms as opposed to classical distributed algorithms is that these have to compute with data non-determinism where there is no guarantee that data from a particular node will be delivered in time or delivered at all. Each distributed component not only has to work in such environment, but also has to decide how long to wait for peers to r...

Items arrive at a processing plant at a Folsson rate X . At time T , all Items are dispatched from the system. An Intermediate dispatch time Is to be chosen to minimize the total wait of all Items. It Is shown that If the dispatch time must be chosen at time 0 then T/2 not only minimizes the expected total wait but it also maximizes the probability that the total wait is less than a for every a...