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Computing high-quality independent sets quickly is an important problem in combinatorial optimization. Several recent algorithms have shown that kernelization techniques can be used to find exact maximum independent sets in medium-sized sparse graphs, ...

A node separator of a graph is a subset S of the nodes such that removing S and its incident edges divides the graph into two disconnected components of about equal size. In this work, we introduce novel algorithms to find small node separators in large ...

Concurrent hash tables are one of the most important concurrent data structures with numerous applications. Since hash table accesses can dominate the execution time of the overall application, we need implementations that achieve good speedup. ...

Given a set of basic areas, the territory design problem asks to create a predefined number of territories, each containing at least one basic area, such that an objective function is optimized. Desired properties of territories often include a ...

We present an algorithm for inversion of symmetric positive definite matrices that combines the practical requirement of an optimal number of arithmetic operations and the theoretical goal of a polylogarithmic critical path length. The algorithm reduces ...

We show how full-text search based on inverted indices can be accelerated by clustering the documents without losing results SeCluD --- Search with Clustered Documents. We develop a fast multilevel clustering algorithm that uses query cost of ...

Future power grids will offer enhanced controllability due to the increased availability of power flow control units (FACTS). As the installation of control units in the grid is an expensive investment, we are interested in using few controllers to ...

Individual multi-modal trip planning is a major task in transportation science. With increasing availability of new means of transportation personal constraints (e.g. elevator phobia or fear of flying) and preferences (e.g. train over bus) gain higher ...

Computing maximum independent sets in graphs is an important problem in computer science. In this paper, we develop an evolutionary algorithm to tackle the problem. The core innovations of the algorithm are very natural combine operations based on graph ...

We propose the design and an implementation of a bulk-parallel external memory priority queue to take advantage of both shared-memory parallelism and high external memory transfer speeds to parallel disks. To achieve higher performance by decoupling ...

We present a simple, concurrent data structure that approximates the behavior of a priority queue and that gives very good performance guarantees. We also discuss models for the semantics of relaxed priority queues and introduce a technique for "...

Previous parallel sorting algorithms do not scale to the largest available machines, since they either have prohibitive communication volume or prohibitive critical path length. We describe algorithms that are a viable compromise and overcome this gap ...

For decades researchers have studied the duality of hashing and sorting for the implementation of the relational operators, especially for efficient aggregation. Depending on the underlying hardware and software architecture, the specifically ...

Modern computers have deepening memory hierarchieswith multiple levels of (partially shared) cachesand non-uniform memory access (NUMA). This makes itincreasingly difficult and important to schedule computationsin such a way that expensive memory ...

Processing large complex networks like social networks or web graphs has recently attracted considerable interest. To do this in parallel, we need to partition them into pieces of about equal size. Unfortunately, previous parallel graph practitioners ...

The graph partitioning problem is widely used and studied in many practical and theoretical applications. Today, multilevel strategies represent one of the most effective and efficient generic frameworks for solving this problem on large-scale graphs. ...

In this paper, we develop semi-external and external memory algorithms for graph partitioning and clustering problems. Graph partitioning and clustering are key tools for processing and analyzing large complex networks. We address both problems in the (...

In the past, parallel processing was a specialized approach to high-performance computing. Today, we have to rethink the computational cores of algorithmic and data structures applications. In this article we discuss how this process of rethinking can ...

The most commonly used method to tackle the graph partitioning problem in practice is the multilevel approach. During a coarsening phase, a multilevel graph partitioning algorithm reduces the graph size by iteratively contracting nodes and edges until ...

Recent work has shown that perfect hashing and retrieval of data values associated with a key can be done in such a way that there is no need to store the keys and that only a few bits of additional space per element are needed. We present FiRe — a new, ...