1,721,040 research outputs found
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
A system perspective on warranty problems within a supply chain
Get PDFThesis (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, February 2005 [first author]; and, (S.M.)--Massachusetts Institute of Technology, System Design and Management Program, February 2006 [second author].Includes bibliographical references (p. 111-113).Warranty is important financially to American manufacturers, especially automotive companies. Carmakers and suppliers must work aggressively to improve their warranty management approach as warranty cost often equals or exceeds their investment in engineering. This thesis focuses on studying warranty management in a supply chain from a systems perspective. Warranty data in the automotive industry, focused upon a "Tier one" supplier, is analyzed to obtain general warranty trends and typical failure types. Following the data analysis and hypothesis formation, a sequential series of surveys and interviews within the supplier are conducted in attempt to determine the root causes of warranty failures. A major finding of the study is the lack of a cross-company and long-term approach for dealing with warranty. Other root causes (though not as deeply imbedded as that noted first) include the lack of design discipline, design knowledge, and resources in the product development process. In addition, unclear accountability, poor communication, and lack of a supplier management process delay the warranty resolution process. Furthermore, the culture and mindset in an organization is a critical element in effective warranty management. A reactive warranty firefighting mindset is inadequate to attack the significant warranty issues. Based upon solving the root causes found in the research, the thesis provides five specific recommendations. These recommendations appear likely to be useful to a wide variety of automotive companies as well as manufacturers in other industries.by Wei Shen and Wangquan (Winston) Cheng.S.M
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
Standards as interdependent artifacts : the case of the Internet
Get PDFThesis (Ph. D.)--Massachusetts Institute of Technology, Engineering Systems Division, 2008.Includes bibliographical references.This thesis has explored a new idea: viewing standards as interdependent artifacts and studying them with network analysis tools. Using the set of Internet standards as an example, the research of this thesis includes the citation network, the author affiliation network, and the co-author network of the Internet standards over the period of 1989 to 2004. The major network analysis tools used include cohesive subgroup decomposition (the algorithm by Newman and Girvan is used), regular equivalence class decomposition (the REGE algorithm and the method developed in this thesis is used), nodal prestige and acquaintance (both calculated from Kleinberg's technique), and some social network analysis tools. Qualitative analyses of the historical and technical context of the standards as well as statistical analyses of various kinds are also used in this research. A major finding of this thesis is that for the understanding of the Internet, it is beneficial to consider its standards as interdependent artifacts. Because the basic mission of the Internet (i.e. to be an interoperable system that enables various services and applications) is enabled, not by one or a few, but by a great number of standards developed upon each other, to study the standards only as stand-alone specifications cannot really produce meaningful understandings about a workable system. Therefore, the general approaches and methodologies introduced in this thesis which we label a systems approach is a necessary addition to the existing approaches. A key finding of this thesis is that the citation network of the Internet standards can be decomposed into functionally coherent subgroups by using the Newman-Girvan algorithm.(cont.) This result shows that the (normative) citations among the standards can meaningfully be used to help us better manage and monitor the standards system. The results in this thesis indicate that organizing the developing efforts of the Internet standards into (now) 121 Working Groups was done in a manner reasonably consistent with achieving a modular (and thus more evolvable) standards system. A second decomposition of the standards network was achieved by employing the REGE algorithm together with a new method developed in this thesis (see the Appendix) for identifying regular equivalence classes. Five meaningful subgroups of the Internet standards were identified, and each of them occupies a specific position and plays a specific role in the network. The five positions are reflected in the names we have assigned to them: the Foundations, the Established, the Transients, the Newcomers, and the Stand-alones. The life cycle among these positions was uncovered and is one of the insights that the systems approach on this standard system gives relative to the evolution of the overall standards system. Another insight concerning evolution of the standard system is the development of a predictive model for promotion of standards to a new status (i.e. Proposed, Draft and Internet Standards as the three ascending statuses). This model also has practical potential to managers of standards setting organizations and to firms (and individuals) interested in efficiently participating in standards setting processes. The model prediction is based on assessing the implicit social influence of the standards (based upon the social network metric, betweenness centrality, of the standards' authors) and the apparent importance of the standard to the network (based upon calculating the standard's prestige from the citation network).(cont.) A deeper understanding of the factors that go into this model was also developed through the analysis of the factors that can predict increased prestige over time for a standard. The overall systems approach and the tools developed and demonstrated in this thesis for the study of the Internet standards can be applied to other standards systems. Application (and extension) to the World Wide Web, electric power system, mobile communication, and others would we believe lead to important improvements in our practical and scholarly understanding of these systems.by Mo-Han Hsieh.Ph.D
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
Objective comparison of design of experiments strategies in design and observations in practice
Get PDFThesis (S.M.)--Massachusetts Institute of Technology, System Design & Management Program, 2004.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Includes bibliographical references (p. 146-149).Design of Experiments (DoE) strategies in robust engineering determine which prototypes and how many of each are created and tested. A better strategy is one that delivers a closer-to-optimal performance at a lower experimental cost. Prototype testers who may use statistical DoE, design-build-test, or one-at-a-time methods in a wide variety of industries were sought out and interviewed to examine the strategies used in practice and how they fit into a proposed five-layer process support model. From these interviews, we see that DoE are competently and widely practiced. Some improvements to the state of the practice may include: contracts to specify and reward quality engineering among suppliers to complex product systems and wider use in light of new computing power of system level mathematical models for experimentation on complex systems. This thesis also examines the relative value of strategies in a particular response surface using a software-based comparator. The data is modified to simulate data environments with other levels of repeatability and interactions, and the way that these variables effect the performance of strategies is examined. The concept of an optimal design of experiments strategy is developed by abstracting the characteristics of a generic strategy and letting it develop in a genetic algorithm in that comparator. The framework for the evaluation of DoE strategies is one significant output to come out of this work that may be of use in future research. Further, the particular abstraction chosen for DoE strategies is offered to other researchers as an exemplar of a particular perspective, to help engender dialogue about methods for optimizing prototype testing policy.by Ion Chalmers Freeman.S.M
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
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