1,721,124 research outputs found
theta-curve polynomials and finite-type invariants
No full textThe normalized Yamada polynomial, (R) over tilde (A), is a polynomial invariant in variable A for theta-curves. In this work, we show that the coefficients of (R) over tilde (x)(e) which is obtained by replacing A with e(x) = Sigma x(n)/n! are finite-type invariants for theta-curves although the coefficients of original (R) over tilde (A) are not finite-type. A similar result can be obtained in the case of Yokota polynomial for theta-curves
An elementary set for theta(n)-curve projections
No full textA finite set of nontrivial theta(n)-curves is shown to be minimal among those which produce all projections of nontrivial theta(n)-curves
Strongly almost trivial theta-curves
No full textA theta-curve is called almost trivial if it does not contain any non-trivial knot. A theta-curve is called strongly almost trivial if it has a planar projection which does not contain a projection of any non-trivial knot. In this paper, we introduce a method to present strongly almost trivial theta-curves. We also give an almost trivial theta-curve which may not be strongly almost trivial
Suicidal intent as a risk factor for mortality in high-level falls: A comparative study of suicidal and accidental falls
Full text linkObjective Suicide is a major issue in South Korea, and falling is a common method of suicide. Further, accidental falls are a common cause of death. However, whether suicidal falls differ from accidental falls is inconclusive. This study aimed to compare suicidal and accidental falls to identify risk factors for mortality. Methods From March 2010 to December 2016, patients admitted to our hospital because of falls were reviewed retrospectively. Characteristics and outcomes were compared between suicide and accident groups. Injury distribution was compared using the Injury Severity Score and Abbreviated Injury Scales. Multivariate analysis was performed to identify risk factors, including suicide intent, for mortality. Results Of 242 patients, 42 were included in the suicide group and 200 were included in the accident group. The suicide group showed higher fall heights and injuries of greater severity. The accident group was younger and included a higher number of men. The suicide group showed a higher mortality (23.8% vs. 6.5%, P=0.001) and a higher proportion of injuries in the lower extremities or abdomen. In the multivariate analysis, Glasgow Coma Scale score (0.575 [0.433–0.764], P<0.001), body mass index (1.638 [1.194–2.247], P=0.002), suicide intent (9.789 [1.026–93.404], P=0.047) and Injury Severity Score (1.091 [1.000–1.190], P=0.049) were identified as risk factors for mortality. Conclusion Suicidal falls were associated with poorer outcomes and a greater tendency to land feet first relative to accidental falls. Suicide intent was a risk factor for mortality
Continuation of the hydrothermal fluid chemistry time series at TAG, and the effects of ODP drilling
No full textNew data are presented for major dissolved species in vent fluids from the TAG hydrothermal mound on the Mid-Atlantic Ridge, sampled in 1993, 1994, and 1995. The latter two cruises bracket the drilling of the mound by the Ocean Drilling Program in September-November 1994. Changes in venting patterns have been observed over this time period, both before and after drilling. However the major ion chemistry of venting fluids appears to be stable, indicating that the drilling did not penetrate the primary plumbing system of the mound.N
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
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
Temperature effect on the growth of carbon nanotubes using thermal chemical vapor deposition
No full textVertically aligned carbon nanotubes (CNTs) are grown on iron-deposited silicon oxide substrates by thermal chemical vapor deposition (CVD) of acetylene gas at the temperature range 750-950 degreesC. As the growth temperature increases from 750 degreesC to 950 degreesC, the growth rate increases by four times and the average diameter also increases from 30 mn to 130 nm while the density decreases by a factor of about two. The relative amount of crystalline graphitic sheets increases progressively with the growth temperature and a higher degree of crystalline perfection can be achieved at 950 degreesC. This result demonstrates that the growth rate, diameter, density, and crystallinity of CNT can be controlled with the growth temperature. (C) 2001 Elsevier Science B.V. All rights reserved
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