1,720,970 research outputs found
SYSTEM-COMPLEXITY MEASURE IN THE ASPECT OF OPERATIONAL DIFFICULTY
No full textThe complexity of a system arises not only due to the number of components and the characteristics of each component, but also to the types of interconnections between the components. A new method to measure this structural complexity is suggested in the aspect of system operational difficulty using an information theoretic approach. This method, the functional entropy measure, can denote the structural complexity induced from the interconnections between components. An equation to calculate the diagnostic entropy without introducing any approximation is derived. The role of monitoring instruments is also studied, and the results show that the monitoring of a system not only can reduce, but also increase the entropy of the system. And to know the true condition of a monitored system with far greater confidence than if it remains unmonitored, the monitoring instrument must be much more reliable than the monitored component
STRATEGY AND TOOL DEVELOPMENT FOR NUCLEAR-POWER-PLANT DESIGN SYNTHESIS WITH MEASUREMENT OF RELIABILITY AND SIMPLICITY
No full textIn this work, the conceptual design supporting tools for nuclear power plants have been developed. These tools are made for system synthesis, complexity measure and reliability analysis. This design synthesis program combined with the reliability analysis program accomplishes the system synthesis. This design strategy can reduce mistakes, effort and time. This design tool, based on Prolog language, is applied to the auxiliary feedwater system. A logic based fault tree analysis program (LOFT) is also developed using Prolog language. As LOFT performs symbolic computation during the fault tree analysis, linking with knowledge-base systems is very easy and the partial usage of the program is possible. The importance measure of components obtained from the system reliability analysis and the complexity measure of the system give very important information to the system designer
The analysis of brain activity in wakefulness and deep sleep states from a dog EEG
No full textWe obtained an EEG from a dog in a deep sleep and a wakefulness state. The change of the spectral distribution, the standard deviation and the Poincare section constructed from the delay map were found between the two states. The many couplings between neurons in the wakefulness state cause various frequency modes. Some of the coupling are weakened in the deep sleep state, so the fundamental mode and its first harmonics are excited. The sequential decrease of the a-value from the wakefulness to the deep sleep state shows that entropy increases in the deep sleep state. The lower EEG activity in the deep sleep state can be observed from the value of SD which is smaller than the value in the wakefulness state. In the deep sleep state the delay map for a shape is similar to a quadratic shape, and the shape remains unchanged during the deep sleep state. However, in the wakefulness state, although the quadratic shape remains unchanged, it is rotated or translated in a random fashion
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
High-efficiency surface-emitting channel drop filters in two-dimensional photonic crystal slabs
No full textWe analyze theoretically the output efficiencies of surface-emitting channel drop filters using channel drop tunneling processes in two-dimensional photonic crystal slabs. By using the channel drop tunneling processes, the output efficiencies of the filters can be easily improved to the values much higher than 50%, the maximum output efficiency of surface-emitting channel drop filters using one single-mode cavity, and the output efficiency of 100% is possible theoretically. In order to demonstrate the theoretical results, we present a surface emitting channel drop filter using the channel drop tunneling processes in a two-dimensional photonic crystal slab. The output efficiency of the presented filter is about 94% in good agreement with the theoretical analysis. (C) 2005 American Institute of Physics
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
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