1,720,967 research outputs found
CPM: A Cross-Layer Framework to EfficientlySupport Distributed Resources Management
No full textResource management, and especially power management, is a key aspect for the success of modern battery supplied multimedia devices. This class of devices are usually based on SoCs with a wide range of heterogeneous subsystems, competing for shared resources while offering several power control mechanisms. Many of these mechanisms require suitable software support to be exploited effectively. Unfortunately, real commercial systems focusing on mobile multimedia exposes a software layer composed by a collection of fairly independent local optimization policies, each focusing on a specific device or subsystem. This paper presents CPM, a cross-layer model and framework to support system wide resource management. The main goals of this framework are to efficiently support the aggregation of applications' QoS requirements and to provide a dynamic, system-wide, and multi-objective optimization to coordinate devices' local policies. A real solution, which is well integrated within the existing Linux kernels, has been developed and evaluated to asses its negligible overhead
Power management using constraints in multi-dimensional parameter space
No full textTecnica per la riduzione del consumo di potenza in sistemi embedded, operando a livello di sistema operativoAn embodiment of a method and system are provided for
managing both system resources and power consumption of a
computer system, involving different layers of the system: an
application layer, a middle layer where the operating system is running and where a power manager is provided, and a
hardware layer used for communicating with the hardware
devices. Hardware devices have different operating modes
which provide distinct trade-offs between performances and
power consumption. Performance requirements defined at
the level of the application layer, as well as the device power
status of the system, set constraints on the system resources.
The middle layer power manager may be in charge of retriev
ing performance requirements in form of constraints set on
System parameters, aggregating these constraints oppor
tunely and communicating corresponding information to the
device drivers which may then select a best operating mode
Predictive Models for Multimedia Applications Power Consumption Based on Use-Case and OS Level Analysis
No full textPower management at any abstraction level is a key
issue for many mobile multimedia and embedded applications.
In this paper a design workflow to generate system-level power
models will be presented, tailored to support quantitative runtime
power optimization policies to be implemented within
an operating system. The approach we followed to derive
power models is strongly use-case oriented. Starting from a
comprehensive general and accurate model of a representative
architecture for embedded applications (including a multi core
MPSoC, accelerators, interfaces and peripherals), a methodology
to derive compact models is presented, based upon the distinctive
characteristics of the selected use cases. The methodology to
generate such model, whose exploitation is foreseen within a
power manager working at the OS level, is the focus of the paper.
The value and accuracy of the approach is quantitatively and
statistically justified through extensive experiments carried out
on a development board designed for multimedia applications
A Hierarchical Distributed Control for Power and Performances Optimization of Embedded Systems
No full textPower and resource management are key goals for the success of modern battery-supplied multimedia devices. This kind of devices are usually based on SoCs with a wide range of subsystems, that compete in the usage of shared resources, and offer several power saving capabilities, but need an adequate software support to exploit such capabilities.
In this paper we present Constrained Power Management (CPM), a cross-layer formal model and framework for power and resource management, targeted to MPSoC-based devices. CPM allows coordination and communication, among applications and device drivers, to reduce energy consumption without compromising QoS. A dynamic and multi-objective optimization strategy is supported, which has been designed to have a negligible overhead on the development process and at run-time
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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