Cristobal Camarero

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Dragonfly networks are composed of interconnected groups of routers. Adaptive routing allows packets to be forwarded minimally or non-minimally adapting to the traffic conditions in the network. While minimal routing sends traffic directly between groups, non-minimal routing employs an intermediate group to balance network load. A random selection of this(More)
Current High-Performance Computing (HPC) and data center networks rely on large-radix routers. Hamming graphs (Cartesian products of complete graphs) and dragonflies (two-level direct networks with nodes organized in groups) are some direct topologies proposed for such networks. The original definition of the dragonfly topology is very loose, with several(More)
A construction of 2-quasi-perfect Lee codes is given over the space Z n p for p prime, p ≡ ±5 (mod 12) and n = 2[ p 4 ]. It is known that there are infinitely many such primes. Golomb and Welch conjectured that perfect codes for the Lee-metric do not exist for dimension n ≥ 3 and radius r ≥ 2. This conjecture was proved to be true for large radii as well as(More)
Dragonfly networks have been recently proposed for the interconnection network of forthcoming exascale supercomputers. Relying on large-radix routers, they build a topology with low diameter and high throughput, divided into multiple groups of routers. While minimal routing is appropriate for uniform traffic patterns, adversarial traffic patterns can(More)
Dragonfly networks have a two-level hierarchical arrangement of the network routers, and allow for a competitive cost-performance solution in large systems. Non-minimal adaptive routing is employed to fully exploit the path diversity and increase the performance under adversarial traffic patterns. Throughput unfairness prevents a balanced use of the(More)
Adaptive deadlock-free routing mechanisms are required to handle variable traffic patterns in dragonfly networks. However, distance-based deadlock avoidance mechanisms typically employed in Dragonflies increase the router cost and complexity as a function of the maximum allowed path length. This paper presents on-the-fly adaptive routing (OFAR), a(More)
In order to propose a new metric over QAM constellations, diagonal Gaussian graphs defined over quotients of the Gaussian integers are introduced in this paper. Distance properties of the constellations are detailed by means of the vertex-to-vertex distribution of this family of graphs. Moreover, perfect codes for this metric are considered. Finally,(More)
The use of high-performance computing systems to help to make the right investment decisions in financial markets is an open research field where multiple efforts have being carried out during the past few years. Specifically, the Heath–Jarrow–Morton (HJM) model has a number of features that make it well suited for implementation on massively parallel(More)
The SMILE project accelerates scientific and industrial applications by means of a cluster of low-cost FPGA boards. With this approach the intensive calculation tasks are accelerated using the FPGA logic, while the communication patterns of the applications remains unchanged by using a Message Passing Library over Linux. This paper explains the cluster(More)