1,720,955 research outputs found
Virtual GDI Engine as a Tool for Model-Based Calibration
No full textRecent and forthcoming fuel consumption reduction
requirements and exhaust emissions regulations are forcing
the development of innovative and particularly complex
intake-engine-exhaust layouts. In the case of Spark Ignition
(SI) engines, the necessity to further reduce fuel consumption
has led to the adoption of direct injection systems,
displacement downsizing, and challenging intake-exhaust
configurations, such as multi-stage turbocharging or turboassist
solutions. Further, the most recent turbo-GDI engines
may be equipped with other fuel-reduction oriented
technologies, such as Variable Valve Timing (VVT) systems,
devices for actively control tumble/swirl in-cylinder flow
components, and Exhaust Gas Recirculation (EGR) systems.
Such degree of flexibility has a main drawback: the
exponentially increasing effort required for optimal engine
control calibration. Even if extremely efficient and
statistically-based experiments have recently been introduced
as standard protocols during test-cell calibration activity, the
time and the instrumentation required for a fully-validated
test-cell calibration dataset has been steeply increasing during
the last few years.
The methodology proposed in this paper is based on
computing technologies, and deeper understanding of
physical phenomena, which have been accessible only in very
recent times. If the availability of dimensional models fast
enough to be used in an iterative loop (aimed at the
optimization of pre-designed cost or goal functions) allows
the introduction of virtual-engine based calibration
techniques, the challenge is to identify the best way to take
advantage of them.
One necessary step is the reduction of fully 1-D engine
models to simpler (and faster to resolve) but still-dimensional
engine thermo-fluid-dynamics representations. One of the
outcomes of this work is the demonstration that fullyautomatic
geometry simplifications (to reduce the
computational effort) may still not guarantee model
consistency, the main reasons being the assignment of
inadequate boundary parameters (such as imposed wall
temperatures) resulting after merging various elements, in an
effort to reduce model complexity.
The second and most important phase is the definition of the
calibration scheme. As it always happens with model-based
design, the goals of the overall activity should be closely
related to the accuracy of the simulation tool. The present
project demonstrates the possibility of using simulation tools
in a new environment, which is somehow in-between desktop
design-oriented simulation (1-D and 3-D models) and realtime
model-based control (0-D). The model reliability, and
therefore the geometry reduction consistency, has been
carefully checked to limit significant accuracy loss, especially
for the variables being used for virtual calibration. Also, in
the paper the limits of the model are introduced and taken
into account, and the definition of cost functions and
constraints (related to emissions limitation, fuel consumption
reduction, and components protection criteria) is discussed.
Finally, the paper shows the application of the overall virtualengine
based calibration methodology to a Gasoline Direct
Injection (GDI) turbocharged engine, equipped with tumbleflaps
and Variable Valve Timing (VVT) systems. Simulation
(and corresponding look-up-tables calibration) results are
compared to experimentally measured ones (with similar sets
of calibration parameters), demonstrating the potential of adopting the proposed methodology as an intermediate step
between engine development and calibration-related test cell
(and on-board) activities
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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