1,720,952 research outputs found
Learning based algorithms for temperature control and fouling prediction in heat-exchangers
Get PDFMy thesis broadly explores different data-driven algorithmic frameworks for solving two class of problems pertaining to heat-exchangers: temperature control and fouling resistance modeling and prediction.
Designing robust and accurate temperature controllers for heat exchangers is very challenging primarily because of complexities associated with the synthesis of dynamics of industrial heat exchangers. It is practically infeasible to synthesize an accurate dynamical model of heat-exchanger's flow and heat transfer physics because of unmodeled system dynamics and random noise. The use of non-model based control approaches such as PI control is limited by the challenges faced in the accurate tuning of its parameters. Further, an optimally tuned PI controller will not be universally applicable across the entire operating range of heat-exchanger's outlet temperatures due to changing controller set-points caused by large-scale stochastic fluctuations in the heat exchanger's flow and temperature inputs. We propose a couple of data-driven temperature control solutions for heat-exchangers based on -step advance deep neural networks and a hybrid control approach based on steady state neural network with a proportional controller. We compared the performance of these two control approaches with PI control and open loop (no control) scenarios on a simulated water-air heat exchanger system. The heat-exchanger control objective was to accurately track the user-defined set-point temperature signal at the air-outlet duct of the heating coil system. We assess the response characteristics of the developed control approaches for two set-point temperature signals- a constant temperature and a high frequency (periodic) square pulse. We obtained over 70% reduction in absolute set-point temperature tracking error compared to a PI controller, over a 50-minute duration for both the developed control approaches. Further, we explained the working of the neural network + proportional control module in great detail along with the rationale behind our design choices for ensuring the controller's stability and robustness.
The complexities involved in fouling prediction in heat-exchangers have deterred traditional model based approaches and other empirical methods. Many existing data-driven prediction approaches are typically application-driven or heat-exchanger specific. Hence, these algorithms are limited either by the scale of data they can handle or by the geometrical and flow configurations of the heat-exchanger for which they were conceived. Here, we develop a generalized and scalable statistical model for accurate prediction of fouling resistance using commonly measured parameters of industrial heat-exchangers. This prediction model is based on deep learning which is a family of computational data-driven methods that allows a scalable algorithmic architecture to learn non-linear functional relationships between a set of target and predictor variables from large number of training samples. The efficacy of this modeling approach is demonstrated for predicting fouling in a simulation of a flue-gas and water cross flow heat exchanger designed for waste-heat recovery. The results demonstrate that the average coefficient of determination, which quantifies the accuracy of predictions is over 99% in predicting flue-gas side, water side and overall fouling resistances. This prediction framework is also evaluated under varying levels of input noise and it was demonstrated that averaging predictions over an ensemble of multiple neural networks achieves better accuracy and robustness to noise. We find that the proposed deep-learning fouling prediction framework learns to follow heat-exchanger flow and heat transfer physics, which we confirm using locally interpretable model agnostic explanations around randomly selected operating points.Submission published under a 24 month embargo labeled 'Closed Access', the embargo will last until 2021-12-01The student, Sreenath Sundar, accepted the attached license on 2019-12-12 at 21:00.The student, Sreenath Sundar, submitted this Thesis for approval on 2019-12-12 at 21:38.This Thesis was approved for publication on 2019-12-13 at 17:12.DSpace SAF Submission Ingestion Package generated from Vireo submission #14822 on 2020-02-28 at 17:38:26Made available in DSpace on 2020-03-02T22:39:00Z (GMT). No. of bitstreams: 3
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Previous issue date: 2019-12-13Embargo set by: Seth Robbins for item 114048
Lift date: 2022-03-02T22:39:04Z
Reason: Author requested closed access (OA after 2yrs) in Vireo ETD systemLimited Restriction Lifted for Item 114048 on 2022-03-03T10:15:16Z
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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