1,720,990 research outputs found
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
Nonlinear analysis of the EEG of schizophrenics with optimal embedding dimension
No full textWe estimated the correlation dimensions of EEGs in patients with schizophrenia to investigate the dynamical properties underlying the EEG. We employed a new method, proposed by Kennel et al. (Kennel MB; Brown R, Abarbanel HDI. Determining embedding dimension for phase-space reconstruction using a geometrical construction. Phys Rev A 1992,45:3403-11), to calculate the correlation dimension D2. That method determined the proper minimum embedding dimension by looking at the behaviour of nearest neighbours under a change in the embedding dimension d from d to d + 1. We demonstrated that for limited noisy data, our algorithm was strikingly faster and more accurate than previous ones. We estimated the D2 of EEGs from 16 channels in patients with schizophrenia according to DSM-IV whereas previous studies, which estimated chaoticity of EEG in schizophrenia, recorded EEG only in a limited number of channels. Schizophrenic patients had a lower correlation dimension in the left inferior frontal and anterior temporal regions compared with controls. Our finding of decreased left frontal and temporal chaotic activity in schizophrenics is in Line with the findings of a hypofrontality and hypotemporality reported in previous clinical studies such as EEG, blood flow, brain MRI and positron emission tomography studies in schizophrenia. This result suggests that chaos analysis may be a useful tool in analysing EEG data to explore the brain mechanism of schizophrenia. (C) 1999 IPEM. Published by Elsevier Science Ltd. All rights reserved.This research was supported by the G7-project from
the Ministry of Science and Technology and the Biotech
2000 project
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
Numerical analysis of the three-dimensional blood flow in the Korean artificial heart
No full textFlow in the blood sac of the Korean artificial heart is numerically simulated by finite element method. Fluid-structure interaction algorithm is employed to compute the three-dimensional blood flow interacting with the sac material. For verification of the numerical method of fluid-structure interaction, two-dimensional flow in a collapsible channel with initial tension is simulated and the results are compared with numerical solutions from the literature. Incompressible viscous flow and linear elastic solid are assumed for the blood and the sac material in the device, respectively. The motion of the actuator is simplified by a time-varying pressure boundary condition imposed on the outer surface of the sac. Numerical solutions on the unsteady three-dimensional blood flow in the sac are provided for the cactus-type model in this study. During systole, the inlet is closed and the blood sac is squeezed by the action of the prescribed pressure on the surface. During diastole, the sac is filled with the blood coming from the inlet while the outlet is closed. A strong flow to the outlet and a stagnated flow near the inlet are observed during systole. Shear stress distribution is also delineated to assess the possibility of thrombus formation. We also simulate numerically the hemodynamics of "the reversed model" where the inlet and outlet are reversed for surgical convenience. It is observed that a recirculating flow was generated near the inner corner of the sac in the reversed model. To assess the material strength of the sac, the shear stress distribution in the solid material is also presented
Optical studies of ZnO thin films grown on O- and H-plasma treated Al2O3 substrates by plasma-assisted molecular beam epitaxy
No full textComparative analysis of the structural and optical properties of ZnO thin films, grown on oxygen (O)- and hydrogen (H)-plasma treated sapphire substrates (denoted by samples O and H, respectively), by plasma-assisted molecular beam epitaxy is reported. We found that sample O has better crystal structure quality as Compared to sample H by means of high-resolution X-ray diffraction, atomic force microscopy, and Hall measurements. We observed higher intensity ratio of excitonic emission to deep-level emission, longer radiative recombination lifetime, and lower Stimulated emission threshold for sample O compared to sample H. From the results, we conclude that the O-plasma treatment on sapphire substrates may result in a decrease in the number of oxygen vacancies and better lattice matching conditions, thereby leading to an enhancement of the crystal quality and the optical properties of ZnO thin films grown on O-plasma treated sapphire substrates. (C) 2008 Elsevier Ltd. All rights reserved.
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
The association of personality trait on treatment outcomes in patients with chronic prostatitis/chronic pelvic pain syndrome: an exploratory study.
No full textOBJECTIVE:
This study investigated the association of personality traits with the baseline clinical characteristics and treatment outcomes of patients with chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS).
METHODS:
Subjects were evaluated at baseline and at week 12 following routine treatment for CP/CPPS using the Korean version of the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI) to measure the severity of CP/CPPS; the Korean version of the Patient Health Questionnaire-9 (PHQ-9) to assess depression; the Korean version of the Patient Health Questionnaire-15 (PHQ-15) to evaluate somatization; and the Korean version of the EuroQol Questionnaire-5 Dimensions (EQ-5D), specifically the EQ-5D utility index and the EQ-5D visual analog scale (EQ-5D VAS), to assess quality of life (QoL). Personality traits including extraversion, agreeableness, conscientiousness, neuroticism, and openness were determined at baseline using the 44-item Big Five Inventory (BFI). The influence of personality traits on the clinical characteristics and treatment outcomes of patients with CP/CPPS was assessed using relevant statistical analyses.
RESULTS:
Neuroticism was associated with a significantly poorer treatment response and higher levels of depression and somatization. Extraversion, agreeableness, and conscientiousness had some influence on clinical characteristics but openness did not affect overall symptoms or the treatment response in patients with CP/CPPS.
CONCLUSIONS:
We found that neuroticism may be the most important personality trait associated with treatment response and the severity of depression and somatization in patients with CP/CPPS. However, our exploratory findings should be confirmed by additional studies with adequate power and improved designs
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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