Soft state protocols use periodic refresh messages to keep network state alive while adapting to changing network conditions; this has raised concerns regarding the scalability of protocols that use the soft-state approach. In existing soft state protocols, the values of the timers that control the sending of these messages, and the timers for aging out state, are chosen by matching empirical o...

In large cities, pedestrians account for 40% to 50% of traffic fatalities. Previous studies based on relatively small samples have concluded that Pedestrian Countdown Timers can reduce pedestrian crashes at signalized intersections. The purpose of the present study was to examine the effect of Pedestrian Countdown Timer (PCT) on crashes in a large city with a long baseline and relatively patter...

BACKGROUND AND PURPOSE Physiological effects of therapeutic ultrasound (US) are dependent on the intensity and duration of application. The purpose of this study was to test US machines used in clinical settings for proper calibration of time and power output. METHODS Measurements of power output and timer accuracy were obtained from 83 US units in clinical use. The machines were tested at 4 ...

In this paper we show that every real-time system speciied in a certain subset of Duration Calculus 24] can be decomposed into an untimed system communicating with suitable timers. Both asynchronous and synchronous communication are considered.

Determining the replication factor y settings S aner et al. describe how neighboring DNA regions stochas-tically assemble into replica-tion factories in budding yeast. A replicon is a stretch of DNA duplicated from a single replication origin. In eukaryotes, multiple replicons assemble into sub-nuclear structures called replication factories, where the replicons are duplicated by DNA polymerase...

The problem of determining whether or not the value of an attribute is caused by other observed attributes, or they merely happen to occur together, has been attacked from different angles. In this paper we propose a solution to the problem of distinguishing between causal and acausal temporal rules, and the system that generated the rules. The proposed method, called the Temporal Investigation...

To better support interactive applications, individual network operators are decreasing the timers that affect BGP convergence, leading to greater diversity in the timer settings across the Internet. While decreasing timers is intended to improve routing convergence, we show that, ironically, the resulting timer heterogeneity can make routing convergence substantially worse. We examine the wide...

Precise timing and asynchronous I/O are appealing features for many applications. Unix kernels provide such features on a per-process basis, using signals to communicate asynchronous events to applications. Per-process signals and timers are grossly inadequate for complex multithreaded applications that require per-thread signals and timers that operate at finer granularity. To respond to this ...