1,720,959 research outputs found
Simulation of a runoff model running with multi-criteria in a cluster system
No full textThis paper shows simulations aspects of a Scenario-based run-time task mapping application. The application falls into the category of hydrologic prediction based on meteorological forecast. These applications demand computational resources, which depend on the scenario. In our case the study is focused partly on the rainfall-runoff model, the uncertainties that have to be computed with time constraints and with a minimum requirement of quality (i.e. precision).
The main aim of this paper is to detect the simulation aspects and the trade-offs (such as power vs. time) which give a runtime manager running a safety-critical system. It shows two scenarios, the first a multi-core machine where several instances of the model have to compete for resources. And the second one presents the range of High Performance Computing resources needed to compute such model that can vary significantly depending on the scenario
Framework for scheduling and resource management in time-constrained HPC application
No full textThe silicon technology continues reducing scale following the Moore's law. Device variability increases due to a lost in controllability during silicon chip fabrication. The current methodologies based on error detection and thread re-execution (roll back) cannot be enough, when the number of errors increase and arrive to a threshold. This dynamic scenario can be very negative if we are executing programs in HPC systems where a correct, accurate and time constraints solution is expected. The objective of the paper is to show preliminary results of Barbeque OpenSource Project (BOSP) and its potential use in HPC systems
Flood Prediction Model Simulation With Heterogeneous Trade-Offs In High Performance Computing Framework
No full textIn this paper, we propose a safety-critical system with a run-time resource management that is used to operate an application for flood monitoring and prediction. This application can run with different Quality of Service (QoS) levels depending on the current hydrometeorological situation. The system operation can follow two main scenarios - standard or emergency operation. The standard operation is active when no disaster occurs, but the system still executes short-term prediction simulations and monitors the state of the river discharge and precipitation intensity. Emergency operation is active when some emergency situation is detected or predicted by the simulations. The resource allocation can either be used for decreasing power consumption and minimizing needed resources in standard operation, or for increasing the precision and decreasing response times in emergency operation. This paper shows that it is possible to describe different optimal points at design time and use them to adapt to the current quality of service requirements during run-time
Harnessing Performance Variability: A HPC-Oriented Application Scenario
No full textThe technology scaling towards the 10nm of the silicon manufacturing, is going to introduce variability challenges, mainly due to the growing susceptibility to thermal hot-spots and time-dependent variations (aging) in the silicon chip. The consequences are two-fold: a) unpredictable performance, b) unreliable computing resources. The goal of the HARPA project is to enable next-generation embedded and high-performance heterogeneous many-core processors to effectively address this issues, through a cross-layer approach, involving several component of the system stack. Each component acts at different levels and time granularity. This paper focus on one of the components of the HARPA stack, the HARPA-OS, showing early results of a first integration step of the HARPA approach in a real High-Performance Computing (HPC) application scenario
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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