1,721,009 research outputs found
Human brain cortical electric current source localization from the surface laplacian of a visual and motor event-related potential
No full textThe surface Laplacian of the human-brain event-related potential were applied to an experiment designed to compare the known cognitive sites for mental tasks with the peak positions of the surface Laplacians of the subject's cortical electric potentials at each instant during a task. The computer was programmed to present randomly a letter 'L' or 'R' On a computer screen. When the monitor commands the subject to press the keyboard with subject's left (right) index finger depending on 'L' ('R'), the subject presses the left (right) shift-key on the keyboard. Multichannel event-related potentials were used to estimate the distributions of the surface Laplacians of cortically generated electric potentials on the scalp. The locus of the surface Laplacian peak corresponds to the sites and the stages of cortical source localization of the neural activity in both the visual and the motor area. The locus of the surface Laplacian peak seems to track the sequence of known cortical localization of cognitive process
Eddy current testing probe with dual half-cylindrical coils
No full textWe have developed a new eddy current probe composed of a dual half-cylindrical (2HC) coil as an exciting coil and a sensing coil that is placed in the small gap of the 2HC coil. The 2HC coil induces a linear eddy current on the narrow region within the target medium. The magnitude of eddy current has a maximum peak with the narrow width, underneath the center of the exciting 2HC coil. Because of the linear eddy current, the probe can be used to detect not only the existence of a crack but also its direction in conducting materials. Using specimen with a machined crack, and varying the exciting frequency from 0.5 to 100 kHz, we investigated the relationships between the direction of crack and the output voltage of the sensing coil. (C) 2000 American Institute of Physics. [S0034-6748(00)01402-7]
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
Adhesively Bonded Lap-Joints for the Composite-Steel Shell Structure of High-Speed Vehicles
No full textGoing 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
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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