3,213 research outputs found

    Performance evaluation and enhancement of Dendro

    Get PDF
    DENDRO is a collection of tools for solving Finite Element problems in parallel. This package is written in C++ using the standard template library (STL) and uses the Message Passing (MPI). Dendro uses an octree data-structure to solve image-registration problems using finite element techniques. For analyzing the behavior of the package in terms of speed-up and scalability, it is important to know which part of the package is consuming most of the execution-time. The single node performance and the overall performance of the package is dependent on the code-organization and class-hierarchy. We used the PETSC profiler to collect the performance statistics and instrument the code to know which part of the code takes most of the time. Along with the function-specific execution timings, PETSC profiler also provides the information regarding how many floating point operations is being performed in total and on average (FLOP/second). PETSC also provides information related to memory usage and number of MPI messages and reductions being performed to execute that particular function. We have analyzed these performance-statistics to provide some guidelines to how we can make Dendro more efficient by optimizing certain functions. We obtained around 12X speedup over the performance of (default) Dendro by using compiler-provided optimizations and achieved more than 65% speedup over compiler optimized performance (20X over the naive Dendro performance) by manually tuning some-block of code along with the compiler-optimizations

    A Cognitive Mind-map Framework to Foster Trust

    Get PDF
    The explorative mind-map is a dynamic framework, that emerges automatically from the input, it gets. It is unlike a verificative modeling system where existing (human) thoughts are placed and connected together. In this regard, explorative mind-maps change their size continuously, being adaptive with connectionist cells inside; mind-maps process data input incrementally and offer lots of possibilities to interact with the user through an appropriate communication interface. With respect to a cognitive motivated situation like a conversation between partners, mind-maps become interesting as they are able to process stimulating signals whenever they occur. If these signals are close to an own understanding of the world, then the conversational partner becomes automatically more trustful than if the signals do not or less match the own knowledge scheme. In this (position) paper, we therefore motivate explorative mind-maps as a cognitive engine and propose these as a decision support engine to foster trust.Comment: 5 pages, 4 Figures, Extended Version, presented at the 5th International Conference on Natural Computation, 200

    Higher congruence companion forms

    Get PDF
    For a rational prime p3p \geq 3 we consider pp-ordinary, Hilbert modular newforms ff of weight k2k\geq 2 with associated pp-adic Galois representations ρf\rho_f and modpn\mod{p^n} reductions ρf,n\rho_{f,n}. Under suitable hypotheses on the size of the image, we use deformation theory and modularity lifting to show that if the restrictions of ρf,n\rho_{f,n} to decomposition groups above pp split then ff has a companion form gg modulo pnp^n (in the sense that ρf,nρg,nχk1\rho_{f,n}\sim \rho_{g,n}\otimes\chi^{k-1}).Comment: 13 page
    corecore