In the past a number of I/O-efficient algorithms were designed to solve a problem on a static data set. However, many data sets like social networks or web graphs change their shape frequently. We provide experimental results of the first external-memory dynamic breadth-first search (BFS) implementation based on earlier theoretical work [13] that crucially relies on a randomized clustering. We ...

The search for Blank Field Sources (BFS), i.e. X-ray sources without optical counterparts, paves the way to the identification of unusual objects in the X-ray sky. Here we present four BFS detected in the Brera Multiscale Wavelet catalog of ROSAT HRI observations. This sample has been selected on the basis of source brightness, distance from possible counterparts at other wavelengths, point-lik...

On a GPU cluster, the ratio of high computing power to communication bandwidth makes scaling breadthfirst search (BFS) on a scale-free graph extremely challenging. By separating high and low out-degree vertices, we present an implementation with scalable computation and a model for scalable communication for BFS and direction-optimized BFS. Our communication model uses global reduction for high...

Let G = (V,E) be a graph with n vertices and m edges, with a designated set of σ sources S ⊆ V . The fault tolerant subgraph for any graph problem maintains a sparse subgraph H = (V,E) of G with E ⊆ E, such that for any set F of k failures, the solution for the graph problem on G\F is maintained in its subgraph H \F . We address the problem of maintaining a fault tolerant subgraph for computing...

A fault-tolerant structure for a network is required to continue functioning following the failure of some of the network’s edges or vertices. This paper addresses the problem of designing a fault-tolerant (α, β) approximate BFS tree (or FT-ABFS tree for short), namely, a subgraph H of the given network G such that subsequent to the failure of a single edge, the surviving part of H still contai...

Estimating a safe and tight upper bound on the Worst-Case Execution Time (WCET) of a parallel program is a major challenge for the design of real-time systems. This paper, proposes for the first time, a framework to estimate the WCET of dynamically scheduled parallel applications. Assuming that the WCET can be safely estimated for a sequential task on a multicore system, we model a parallel app...

EXTRACTION, SIMULATION AND IDDQ TEST GENERATION FOR EFFICIENT BRIDGING FAULT DETECTION IN DIGITAL VLSI CIRCUITS Tzuhao Chen Ibrahim N. Hajj Department of Electrical and Computer Engineering and Coordinated Science Laboratory University of Illinois, Urbana, IL 61801, USA [email protected] Abstract | In this paper we give an overview of recent work in extraction, simulation, and IDDQ test generatio...

In this class, we discuss some geometrical interpretations of linear programs and a high-level description of the simplex algorithm. We also introduce methods for implementing the two phases of the simplex algorithm. These notes also include the tutorial presented on January 19. 1 Review In our previous class, we took some important steps toward defining an efficient algorithm for solving linea...

We present an algorithm that exploits the complimentary benefits of best-first search (BFS) and depth-first search (DFS) by performing limited DFS lookaheads from the frontier of BFS. We show that this continuum requires significantly less memory than BFS. In addition, a time speedup is also achieved when choosing the lookahead depth correctly. We demonstrate this idea for breadth-first search ...

This paper introduces the concept of Vertex Unique Labelled Subgraph Mining (VULSM), a specialised form of subgraph mining. A VULS is a subgraph defined by a set of edge labels that has a unique vertex labelling associated with it. A minimal VULS is then a VULS which is not a supergraph of any other VULS. The application considered in this paper, for evaluation purposes, is error prediction wit...