We present Deep Start, a new algorithm for automated performance diagnosis that uses stack sampling to augment our search-based automated performance diagnosis strategy. Our hybrid approach locates performance problems more quickly and finds problems hidden from a more straightforward search strategy. Deep Start uses stack samples collected as a by-product of normal search instrumentation to fi...

We prove a new bound on the mixing time of a Markov chain by considering the conductance of its connected subsets.

BACKGROUND Poor quality of care and access to effective and affordable interventions have been attributed to constraints and bottlenecks within and outside the health system. However, there is limited understanding of health system barriers to utilization and delivery of appropriate, high-impact, and cost-effective interventions at the point of service delivery in districts and sub-districts in...

With the increasing number of documents that are available in digital form, also the number of digital historical documents is increasing (Berkvens, 2001). It cannot be assumed that standard IR systems perform well on historical documents: historical texts differ from modern texts in three ways (Hüning, 1996; Van Der Horst and Marschall, 1989): (a) vocabularies have changed, (b) spelling has ch...

Bottlenecks are key features of any freeway system and represent the emerging location for recurrent and non-recurrent traffic congestion. In Oregon, a freeway data archive known as PORTAL records volume, occupancy, and speed measurements from over 600 freeway locations every 20 seconds. This archive has enabled development of online freeway performance and reliability analysis tools. This pape...

The performance of a manufacturing or logistic system is determined by its constraints. Therefore, in order to improve the performance, it is necessary to improve the constraints, also known as the bottlenecks. Finding the bottlenecks, however, is not easy. This paper compares the two most common bottleneck detection methods, based on the utilization and the waiting time, with the shifting bott...

BACKGROUND Preterm birth is now the leading cause of under-five child deaths worldwide with one million direct deaths plus approximately another million where preterm is a risk factor for neonatal deaths due to other causes. There is strong evidence that kangaroo mother care (KMC) reduces mortality among babies with birth weight <2000 g (mostly preterm). KMC involves continuous skin-to-skin con...

High-performance data centers have been aggressively moving toward parallel technologies like clustered computing and multi-core processors. While this increased use of parallelism overcomes the vast majority of computational bottlenecks, it shifts the performance bottlenecks to the storage I/O system. To ensure that compute clusters deliver the maximum performance, storage systems must be opti...

We present the Q-Cut algorithm, a graph theoretic approach for automatic detection of sub-goals in a dynamic environment, which is used for acceleration of the Q-Learning algorithm. The learning agent creates an on-line map of the process history, and uses an efficient MaxFlow/Min-Cut algorithm for identifying bottlenecks. The policies for reaching bottlenecks are separately learned and added t...