1,720,968 research outputs found
Methods and models for analyzing and controlling the safety in operations of autonomous marine systems
Get PDFAutonomous marine systems (AMS), such as autonomous underwater vehicles (AUVs), and unmanned surface vehicles (USVs) have evolved over the past decades. Maritime autonomous surface ships (MASS) are gradually being developed and commissioned. AMS are applied in different types of industries and research. Examples include the application of USVs or AUVs for ocean monitoring, and the development of MASS for future cargo and personnel transportation.
In these operations, AMS can help reduce the risk of personnel exposure to harsh environments, reduce the operational costs, and improve the efficiency and performance of the human operators. However, compared to conventional marine systems, new types of failure might be introduced to AMS operations due to unforeseen interdependencies in the system design, dynamic operating environments, maintenance challenges, insufficient situation awareness and decision-making from human operators, etc. Also, AMS functions are constantly being improved, and the operations of AMS are becoming more complex and advanced. The safety issues of these systems have become even more critical. Techniques for analyzing and controlling the safety of AMS operations are therefore required.
The overall aim of this PhD project is to develop methods and models for analyzing and controlling safety in operations of AMS. It is refined into the following three research objectives that are addressed in five research articles:
• Identify and analyze hazards and hazardous events in the operation of autonomous marine systems and evaluate the applicability of relevant methods as a basis for online risk modeling of autonomous marine systems.
• Analyze the dynamic changes in the operating environment and system status, and model their impacts on the safe operation.
• Propose a general method for developing online risk models for autonomous marine systems and operations, supporting risk-based control.
The work presented here reviews the existing methods and models and identifies the main research challenges and gaps with respect to the above research objectives. The research presented in the thesis addressed some of these issues. The main contributions of this thesis are summarized as follows:
• Investigation of the potential hazards/ hazardous events during the operation with multiple AMS and how these hazards/ hazardous events may affect the safe and reliable operations of AMS. The results highlight the importance of considering unsafe interactions in hazard identification or risk assessment in AMS operations.
• Comprehensive hazard identification works with a number of potential hazards/ hazardous events that may affect the safe operation of an under-ice AUV operation through various methods. The results contribute research and practical implications for improved engineering design and operational procedures to enhance the safety and robustness of future AMS operations in the Arctic.
• Identification of a list of evaluation criteria for online risk models for AMS and comprehensive evaluation of the applicability of several existing methods for online risk modeling of AMS. The evaluation results contribute to an appropriate first step towards a general framework for online risk modeling for AMS.
• Proposal for a dynamic risk analysis method to determine the dynamic changes in the operating environment and assess the environmental impact on the safe operation of AMS.
• Proposal for a novel dynamic maintenance planning method for AMS that addresses challenges in maintenance planning, including the high consequence of system shutdown, limited and irregular maintenance opportunities, and various dependencies among components.
• Proposal for a general framework for the online risk modeling of AMS to enhance the intelligence of the AMS, its situation awareness, and decision-making. The proposed framework addresses several challenges in developing online risk modeling, e.g., evidence uncertainty.
• Proposal for a two-level strategy to develop a supervisory risk control (SRC) system for AMS operations based on the developed online risk model. The SRC system can improve the intelligence of AMS by enabling its risk-based control.
In conclusion, the research and findings presented in the thesis provide researchers and practitioners in the field with a comprehensive overview of safety issues in AMS operations, and novel methods and models for analyzing and handling these. The proposed methods and models are expected to improve the safety of future AMS operations
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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