Adaptive structured parallelism for computational grids

Algorithmic skeletons abstract commonly-used patterns of parallel computation, communication, and interaction. They provide top-down design composition and control inheritance throughout the whole structure. Parallel programs are expressed by interweaving parameterised skeletons analogously to the way sequential structured programs are constructed. This design paradigm, known as structured parallelism, provides a high-level parallel programming method which allows the abstract description of programs and fosters portability. That is to say, structured parallelism requires the description of the algorithm rather than its implementation, providing a clear and consistent meaning across platforms while their associated structure depends on the particular implementation. By decoupling the structure from the meaning of a parallel program, it benefits entirely from any performance improvements in the systems infrastructure

Towards Ad-Hoc GPU Acceleration Of Parallel Eigensystem Computations

This paper explores the early implementation of high- performance routines for the solution of multiple large Hermitian eigenvector and eigenvalue systems on a Graphics Processing Unit (GPU). We report a perfor- mance increase of up to two orders of magnitude over the original EISPACK routines with a NVIDIA Tesla C2050 GPU, potentially allowing an order of magnitude in- crease in the complexity or resolution of a neutron scat- tering modeling application

Energy Efficient Scheduling Methods for Computational Grids and Clouds, Journal of Telecommunications and Information Technology, 2017, nr 1

This paper presents an overview of techniques developed to improve energy efficiency of grid and cloud computing. Power consumption models and energy usage proles are presented together with energy efficiency measuring methods. Modeling of computing dynamics is discussed from the viewpoint of system identication theory, indicating basic experiment design problems and challenges. Novel approaches to cluster and network-wide energy usage optimization are surveyed, including multi-level power and software control systems, energy-aware task scheduling, resource allocation algorithms and frameworks for backbone networks management. Software-development techniques and tools are also presented as a new promising way to reduce power consumption at the computing node level. Finally, energy-aware control mechanisms are presented. In addition, this paper introduces the example of batch scheduler based on ETC matrix approach

Distributed aggregation of heterogeneous Web-based Fine Art Information: enabling multi-source accessibility and curation

The sources of information on the Web relating to Fine Art and in particular to Fine Artists are numerous, heterogeneous and distributed. Data relating to the biographies of an artist, images of their artworks, location of the artworks and exhibition reviews invariably reside in distinct and seemingly unrelated, or at least unlinked, sources. While communication and exchange exists, there is a great deal of independence between major repositories, such as museum, often owing to their ownership or heritage. This increases the individuality in the repository’s own processes and dissemination. It is currently necessary to browse through numerous different websites to obtain information about any one artist, and at this time there is little aggregation of Fine Art Information. This is in contrast to the domain of books and music, where the aggregation and re-grouping of information (usually by author or artist/band name) has become the norm. A Museum API (Application Programming Interface), however, is a tool that can facilitate a similar information service for the domain of Fine Art, by allowing the retrieval and aggregation of Web-based Fine Art Information, whilst at the same time increasing public access to the content of a museum’s collection. In this paper, we present the case for a pragmatic solution to the problems of heterogeneity and distribution of Fine Art Data and this is the first step towards the comprehensive re-presentation of Fine Art Information in a more ‘artist-centric’ way, via accessible Web applications. This paper examines the domain of Fine Art Information on the Web, putting forward the case for more Web services such as generic Museum APIs, highlighting this via a prototype Web application known as the ArtBridge. The generic Museum API is the standardisation mechanism to enable interfacing with specific Museum APIs

The ParaPhrase project : parallel patterns for adaptive heterogeneous multicore systems

Funding: This work has been supported by the European Union Framework 7 grant IST-2011-288570 “ParaPhrase: Parallel Patterns for Adaptive Heterogeneous Multicore Systems”This paper describes the ParaPhrase project, a new 3-year targeted research project funded under EU Framework 7 Objective 3.4 (Computer Systems) , starting in October 2011. ParaPhrase aims to follow a new approach to introducing parallelism using advanced refactoring techniques coupled with high-level parallel design patterns. The refactoring approach will use these design patterns to restructure programs defined as networks of software components into other forms that are more suited to parallel execution. The programmer will be aided by high-level cost information that will be integrated into the refactoring tools. The implementation of these patterns will then use a well-understood algorithmic skeleton approach to achieve good parallelism. A key ParaPhrase design goal is that parallel components are intended to match heterogeneous architectures, defined in terms of CPU/GPU combinations, for example. In order to achieve this, the ParaPhrase approach will map components at link time to the available hardware, and will then re-map them during program execution, taking account of multiple applications, changes in hardware resource availability, the desire to reduce communication costs etc. In this way, we aim to develop a new approach to programming that will be able to produce software that can adapt to dynamic changes in the system environment. Moreover, by using a strong component basis for parallelism, we can achieve potentially significant gains in terms of reducing sharing at a high level of abstraction, and so in reducing or even eliminating the costs that are usually associated with cache management, locking, and synchronisation.Postprin

Miradas y voces de la investigación educativa I

Fil: Ferreyra, Horacio Ademar. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Calneggia, María Isabel. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Di Francesco, Adriana Carlota. Universidad Católica de Córdoba. Facultad de Educación; Argentin

A grid-based stochastic simulation of unitary and membrane Ca2+ currents in spherical cells

We present a stochastic simulation of L-type Ca2+ current assuming thousands of calcium channels on the membrane of a spherical cell. We propose a three-state Markov model to simulate the individual contribution of each channel. Rather than using a statistical approximation, we actually consider each individual channel transitions between states and evaluate the unitary channel current. We compare this aggregated unitary contributions with simulated whole cell currents, both in response to a depolarising voltage pulse. On the computational side, we have employed a parameter sweep, component based approach. Being embarrassingly parallel by design, we have parallelised it in a naive manner. We argue its possible extension using algorithmic skeletons. The results presented account for hours of processing time on a dedicated grid

Parallel stochastic simulation of macrosopic calcium currents

This work introduces MACACO, a macroscopic calcium currents simulator. It provides a parameter-sweep framework which computes macroscopic Ca2+ currents from the individual aggregation of unitary currents, using a stochastic model for L-type Ca2+ channels. MACACO uses a simplified 3-state Markov model to simulate the response of each Ca2+ channel to different voltage inputs to the cell. In order to provide an accurate systematic view for the stochastic nature of the calcium channels, MACACO is composed of an experiment generator, a central simulation engine and a post-processing script component. Due to the computational complexity of the problem and the dimensions of the parameter space, the MACACO simulation engine employs a grid-enabled task farm. Having been designed as a computational biology tool, MACACO heavily borrows from the way cell physiologists conduct and report their experimental work

On the Abstraction of Message-Passing Communications Using Algorithmic Skeletons

This is an initial case on exploring the application of algorithmic skeletons to abstract low-level interprocess communication in MPI. The main purpose is intended to illustrate the competitive performance demonstrated by the skeletal approach when compared to utilization of the pure MPI, whilst providing an abstraction with reusability advantages. This initial work involves the implementation of the Wagar’s hyperquicksort algorithm in conjunction with the MPI-based eSkel skeleton library. The reported results compare three MPI-based implementations of hyperquicksort. Firstly a canonic MPI one; secondly, two implementations using the MPI-based skeletal library eSkel. Lastly, the S3L_sort routine, part of its optimized numerical libraries from Sun, is employed as baseline. This overall comparison demonstrates that the use of algorithmic skeletons caused a slight performance degradation, while providing some promising guidance on the use of abstraction for low-level communication operations using the eSkel model