Practical Minimum Cut Algorithms

The minimum cut problem for an undirected edge-weighted graph asks us to divide its set of nodes into two blocks while minimizing the weight sum of the cut edges. Here, we introduce a linear-time algorithm to compute near-minimum cuts. Our algorithm is based on cluster contraction using label propagation and Padberg and Rinaldi's contraction heuristics [SIAM Review, 1991]. We give both sequential and shared-memory parallel implementations of our algorithm. Extensive experiments on both real-world and generated instances show that our algorithm finds the optimal cut on nearly all instances significantly faster than other state-of-the-art algorithms while our error rate is lower than that of other heuristic algorithms. In addition, our parallel algorithm shows good scalability

ILP-based Local Search for Graph Partitioning

Computing high-quality graph partitions is a challenging problem with numerous applications. In this paper, we present a novel meta-heuristic for the balanced graph partitioning problem. Our approach is based on integer linear programs that solve the partitioning problem to optimality. However, since those programs typically do not scale to large inputs, we adapt them to heuristically improve a given partition. We do so by defining a much smaller model that allows us to use symmetry breaking and other techniques that make the approach scalable. For example, in Walshaw\u27s well-known benchmark tables we are able to improve roughly half of all entries when the number of blocks is high

A Standard Protocol for the Calibration of Capillary Electrophoresis (CE) Equipment

Calibration of complex analytical systems is always a difficult task. Nevertheless, a suitable approach has to be designed before the systems can be introduced into routine analysis. In literature, many methods have been described for the purpose of calibrating such systems, but only a few of them deal with capillary elctrophoresis. Here, we want to demonstrate a general approach to how the calibration of this type of analytical instrument becomes feasible

Finding All Global Minimum Cuts in Practice

We present a practically efficient algorithm that finds all global minimum cuts in huge undirected graphs. Our algorithm uses a multitude of kernelization rules to reduce the graph to a small equivalent instance and then finds all minimum cuts using an optimized version of the algorithm of Nagamochi, Nakao and Ibaraki. In shared memory we are able to find all minimum cuts of graphs with up to billions of edges and millions of minimum cuts in a few minutes. We also give a new linear time algorithm to find the most balanced minimum cuts given as input the representation of all minimum cuts

GPU Accelerated Viscous-fluid Deformable Registration for Radiotherapy

In cancer treatment organ and tissue deformation betweenradiotherapy sessions represent a significant challenge to op-timal planning and delivery of radiation doses. Recent de-velopments in image guided radiotherapy has caused a soundrequest for more advanced approaches for image registrationto handle these deformations. Viscous-fluid registration isone such deformable registration method. A drawback withthis method has been that it has required computation timesthat were too long to make the approach clinically appli-cable. With recent advances in programmability of graph-ics hardware, complex user defined calculations can now beperformed on consumer graphics cards (GPUs). This pa-per demonstrates that the GPU can be used to drasticallyreduce the time needed to register two medical 3D imagesusing the viscous-fluid registration method. This facilitatesan increased incorporation of image registration in radio-therapy treatment of cancer patients, potentially leading tomore efficient treatment with less severe side effects

La modificación de los artículos 62 y 63 de la Ley de Arbitraje para implementar la falta de motivación del laudo arbitral

El presente trabajo de investigación versa sobre la incorporación de la falta de motivación como recurso para la anulación del laudo arbitral, con el objeto de poder garantizar el derecho de las partes que acuden a esta vía jurisdiccional buscando justicia de manera más pronta. El proceso arbitral, conforme a nuestro ordenamiento es un proceso supuestamente rápido y conforme al D.L. Nº 1071- Ley del Arbitraje, para su inicio se requiere la preexistencia de una cláusula arbitral o el pacto de las partes renunciando al fuero ordinario, asimismo, que la única forma de cuestionar el Laudo emitido durante el proceso es mediante el Recurso de Anulación del Laudo Arbitral, por el cual no se puede revisar el fondo de la controversia o los criterios utilizados por el Árbitro Único o Colegio que integre el Tribunal Arbitral. Esta prohibición de revisión permite que en el proceso arbitral se pueda faltar al principio-garantía de motivación de resoluciones, pues, permitiría la emisión de decisiones arbitrarias, la cuales al momento de ser impugnadas adquirían la calidad de firmes por la prohibición de pronunciarse sobre el fondo, produciendo así un estado constante vulneración del derecho de las partes. La presente investigación busca darle solución a esta situación de impunidad a través de la regulación de la falta de motivación como una nueva causal para el recurso de anulación del Laudo Arbitral.Tesi