1,722,280 research outputs found
A Cost Analysis of Systems Subject to Random Field Environments and Reliability
No full textWe present a generalized cost model subject to random field environments with considerations of cost to remove failures during testing and warranty periods, and penalty cost due to the system failures. We also determine the optimal release time policies that minimize the expected system cost. Many scientific contributions have been developed in software reliability modeling, while none has studied the manufacturing or industrial system reliability growth yet, considering also the differences between testing and operating environments. The application of the proposed model, in comparison to the nonhomogenous Poisson process Goel-Okumoto model, to an industrial application is discussed to illustrate how the proposed model can be used in practice
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
Systemability Function to Optimisation Reliability in Random Environment
No full textIn this article, we present a new mathematical function, called systemability, by introducing the uncertainty of the operating environments as a random variable for predicting the reliability of systems in the field. Industrial manufacturers must deal with problems of how to predict reliability performance of systems during operating conditions in various applications from the customers' perspectives. The authors recently introduced a new model, called systemability, which appears very interesting and suitable for industry applications, because it separates the effects related to the machine components from the environmental factors. After a brief literature review, we discuss the use of systemability function to predict the reliability of the system in the field. In this article, the adequacy of systemability model that fit the observed real-world data of the two applications, in the automatic packaging machines for beer production and the motorcycle system, has also been assessed. At the end, the results are shown and also discussed
The impact of operational risk on performance in supply chains and the moderating role of integration
No full textPurpose: This study aims to empirically investigate the impact of operational risk (i.e. supply, manufacturing and demand risks) on supply chain performance and the moderating role of integration (i.e. supplier, internal and customer integrations) in mitigating the impact of these risks, respectively. Design/methodology/approach: A research framework of hypotheses is tested by structural equation modeling with data collected from the fourth round of the high-performance manufacturing project. Findings: It is revealed that manufacturing and demand risks negatively impact operational performance, and more importantly, internal and customer integrations help to reduce the impact of these two risks. Additionally, the effects of both supply risk and supplier integration are only significant for large firms. Practical implications: Supply chain managers need to appropriately develop the levels of integration to mitigate the adverse impact of operational risk. Originality/value: Operational performance is always threatened by different types of risk that adversely affect the supply, production and demand sides of manufacturing firms. Despite this fact, large-scale data-based empirical research on the impact of operational risk on the performance of supply chains has been scarce. This study aims to fill this literature gap
Dynamic Programming for an Investment/Consumption problem in illiquid markets with regime-switching
No full textVariations 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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